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Wyszukujesz frazę "particle-particle" wg kryterium: Temat


Tytuł:
Lagrangian Model for a Single Saltating Grain in the Near-Wall Region of an Open-Channel Flow
Autorzy:
Czernuszenko, W.
Powiązania:
https://bibliotekanauki.pl/articles/241181.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
Lagrangian model
open-channel flow
particle-particle interaction
Opis:
A mathematical model for the continuous saltation of a particle near the granular bed in an open-channel flow is developed in detail. The model is based on the Lagrangian equations governing particle motion, and it takes into account the following forces: drag, lift, gravitation, virtual mass and the force responsible for particle-particle interactions. A model of particle-particle collisions is developed and used to determine the mean impulsive force acting upon a particle flowing and rebounding from the channel bed. The model can simulate the continuous saltation trajectories of a single particle in the near-bed region of turbulent flows, in which particle motion is controlled by collisions. The model has been calibrated and verified with available published data in a rather wide range of grain sizes from 0.53 mm to 15 mm. All parameters, such as lift, drag, restitution, friction coefficients and roughness height, have been set on the basis of a reanalysis of these published data.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2013, 60, 1-4; 31-50
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of flotation and aggregation characteristics of muscovite particles through the extended DLVO theory
Autorzy:
Tunç, Berivan
Guven, Onur
Ozdemir, Orhan
Çelik, Mehmet Sabri
Powiązania:
https://bibliotekanauki.pl/articles/2146923.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
muscovite
theoretical analysis
particle-particle
particle-bubble
XDLVO
vdW
EDL for ces
Opis:
In this study, the flotation and aggregation characteristics of muscovite mineral particles were determined as a function of dodecyl amine hydrochloride (DAH) concentration and correlated with the theoretically calculated “particle-particle” and “particle-bubble” interactions using extended DLVO theory. In this series of tests, the flotation and aggregation characteristics of the muscovite mineral were determined with micro-flotation and turbidity measurements, respectively. In addition to these analyses, surface tension measurements were carried out as a function of pH. Also, the zeta potential and contact angle measurements were also performed as a function of DAH concentration prior to the flotation and aggregation tests. The experimental studies showed that while almost minimum and maximum points of flotation and turbidity values were obtained up to a critical concentration of DAH as 6.10-6 mol/dm3, a significant increment was obtained following that concentration. Accordingly, while repulsive forces dominated the interactions up to that concentration, the attractive forces became more effective at further concentrations such as 2.10-5, 4.10-5, 8.10-5, and 1.10-4 mol/dm3 DAH concentrations for both “particle-particle” and ”particle-bubble” interactions. This in turn suggested that the determination of energy barrier heights between ”particle-particle” and ”particle bubble” may provide important insights into both flotation and aggregation characteristics of particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 5; art. no. 151789
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie modelu DEM do symulacji oddziaływań międzycząsteczkowych
Application of DEM approach for predicting particles interactions
Autorzy:
Widuch, Agata
Powiązania:
https://bibliotekanauki.pl/articles/101705.pdf
Data publikacji:
2016
Wydawca:
Politechnika Śląska. Wydział Inżynierii Środowiska i Energetyki. Instytut Techniki Cieplnej
Tematy:
CFD
DEM
cząsteczka
współczynnik tarcia
particle-particle interaction
coefficient of friction
Opis:
Modele komputerowe coraz częściej znajdują zastosowanie w bardzo wielu gałęziach przemysłu, szczególnie do modelowania złożonych zjawisk cieplno-przepływowych. Jednym z przykładów może być energetyka zawodowa, gdzie modele komputerowe wykorzystywane są do optymalizacji procesu konwersji energii chemicznej paliwa w ciepło użyteczne wykorzystując kotły pyłowe oraz fluidalne. Obecnie szczególnym zainteresowaniem cieszy się ta druga grupa dzięki ich dużej sprawności, małej wrażliwości na jakość spalanego paliwa, oraz możliwości łatwej redukcji NOx, a także wychwytu SOx. W celu zamodelowania silnych odziaływań międzycząsteczkowych zachodzących w warstwie fluidyzującego materiału konieczne jest stosowanie odpowiednich modeli wielofazowych. Do modelowania przepływu wielofazowego może być stosowana metoda Eulera, hybrydowy model Euler-Lagrange oraz modele bazujące na metodzie elementów dyskretnych (ang. Discrete Element Method – DEM). Podejście DEM, w porównaniu ze wspomnianymi dwoma technikami obliczeniowymi pozwala na fizyczne uwzględnienie oddziaływań międzycząsteczkowych [1], umożliwia modelowanie pękania czy aglomeracji ziaren. Technika DEM jest alternatywą dla metod opartych na koncepcji ciągłości ośrodka, dająca możliwość odwzorowania bezpośrednich interakcji między cząstkami. W porównaniu z metodą Eulera, podejście DEM nie jest zbyt popularne w przypadku jego stosowania do modelowania procesu fluidyzacji. W prezentowanej pracy sprawdzono możliwość wykorzystania modelu DEM do modelowania oddziaływań międzycząsteczkowych na poziomie ziarnowym.
The applications of numerical techniques for modeling of various industrial processes are getting very popular. One of the examples can be found in energy sector where advanced numerical models are often applied for optimization of the fuel chemical energy conversion processes into the useful form of energy. This process generally occurs within pulverized or fluidized coal boilers. Over the years, the popularity of the second boiler group constantly increased, mainly due to the reason that they are less sensitive to fuel quality and ensure high conversion of fuel into heat. Nevertheless, it is not a trivial task to simulate all interaction between particles, which occur during fluidization process. The fluidization process in nature is very complex and requires a specific approach. Multiphase flow can be simulated using Euler-Euler, hybrid Euler-Lagrange approaches or using the Discrete Element Method (DEM). The DEM approach contrary to both earlier mentioned techniques takes into account impact of material properties on the particles collision process. The DEM approach compared to the Euler-Euler technique has not been well tested yet for modelling fluidization process. In the present work the strength and weakness of the DEM model has been tested using simple test looking on collision of individual or groups of particles.
Źródło:
Archiwum Instytutu Techniki Cieplnej; 2016, 2; 155-169
2451-277X
Pojawia się w:
Archiwum Instytutu Techniki Cieplnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation of particle separation in a centrifugal air separator
Autorzy:
Kaczyński, J.
Kraft, M.
Powiązania:
https://bibliotekanauki.pl/articles/175534.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CFD simulation
discrete particle model
particle separation
Opis:
This paper presents the modeling approaches and results of numerical investigations into particle separation in a production-scale industrial centrifugal air separator. The gaseous phase was modeled using an Eulerian formulation, while the particle phase was modeled using a Lagrangian particle tracking approach. Two-way coupling between continuous and disperse phase was included and turbulence modeled using the realizable k-ε model. The resulting comprehensive system model provides correct predictions of the power consumption and of pressure losses in the device over the full operation range, and proved ability of accurately predicting the size-dependent particle separation efficiencies down to nominal particle sizes of 2 µm.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2017, 135; 57-71
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Accelerator and detector physics at the Bern medical cyclotron and its beam transport line
Autorzy:
Auger, M.
Braccini, S.
Ereditato, A.
Häberli, M.
Kirillova, E.
Nesteruk, K. P.
Scampoli, P.
Powiązania:
https://bibliotekanauki.pl/articles/147455.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
beam monitoring
medical cyclotrons
particle accelerators
particle detectors
Opis:
The cyclotron laboratory for radioisotope production and multi-disciplinary research at the Bern University Hospital (Inselspital) is based on an 18-MeV proton accelerator, equipped with a specifi cally conceived 6-m long external beam line, ending in a separate bunker. This facility allows performing daily positron emission tomography (PET) radioisotope production and research activities running in parallel. Some of the latest developments on accelerator and detector physics are reported. They encompass novel detectors for beam monitoring and studies of low current beams.
Źródło:
Nukleonika; 2016, 61, 1; 11-14
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the sand particle shape on particle size distribution measured by laser diffraction method
Autorzy:
Polakowski, C.
Sochan, A.
Bieganowski, A.
Ryzak, M.
Foldenyi, R.
Toth, J.
Powiązania:
https://bibliotekanauki.pl/articles/25877.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
sand
particle shape
particle size distribution
laser diffraction
Opis:
The aim of this paper was to show how the shape of sand particles affects the results of particle size distribution obtained by the laser diffraction method. On the basis of the results obtained one can conclude: the shape of the investigated particles influences particle size distribution obtained by the laser diffraction method. This phenomenon occurs in the sand fraction, as shown in our investigation. The importance of this effect depends on the type of the measured material and on the aim of the investigations. For most researchers in soil science and sedimentology who investigate sand fractions, this impact can be negligible. Further investigations with other soil and sediment fractions are needed.
Źródło:
International Agrophysics; 2014, 28, 2
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design criterion for hydrodynamic vortex separator
Autorzy:
Gronowska-Szneler, M.A.
Sawicki, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/175226.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
centrifugal force
particle trajectory
sedimentation
suspended particle
vortex separator
Opis:
The process of designing technical objects involves determination of geometrical parameters that characterize a given device. When device operation is described by differential equations, an inverse problem brings difficulties, as geometrical values being sought condition the solution to the problem. Vortex separators, used for removal of suspension from storm wastewater are usually designed by the ‘criterion method’. Firstly, a critical particle is distinguished such that bigger particles are removed from wastewater stream, whereas smaller particles stay in the stream. Next, by comparing values of major forces acting on the critical particle at the most unfavourable point within the separator (usually at outflow cross-section), a force balance is made. The resulting algebraic relation becomes the design criterion.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2017, 135; 3-9
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model of Particle-Particle Interaction for Saltating Grains in Water
Autorzy:
Czernuszenko, W.
Powiązania:
https://bibliotekanauki.pl/articles/241341.pdf
Data publikacji:
2009
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
Lagrangian model
saltation
particle motion
dense flow
particle collision
Opis:
A model of particle-particle interaction for bed sediment-laden flows, based on impulse equations, is presented. The model is applicable to dense flows in which particle motion is dominated by collisions. The model takes into account the possibility of sliding during the collision process. However, particle rotation is not considered in this model. The governing equations do not incorporate dimension of angular momentum. To verify this model, calculation of post-collision velocities was performed for several different collision simulations. The term of particle-particle interaction is implemented into a general Lagrangian model of trajectory of a sediment grain in a fluid flow. This general Lagrangian model is written according to Newton's second law; the rate of change of momentum of a particle is balanced against the surface and body forces.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2009, 56, 3-4; 101-120
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Auxiliary and Rao-Blackwellised particle filters comparison
Autorzy:
Kozierski, P.
Lis, M.
Powiązania:
https://bibliotekanauki.pl/articles/376777.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
particle filters
PF
SIR algorithm
Bootstrap Filter
Auxiliary Particle Filter
Rao-Blackwellised Particle Filter
Opis:
Particle filters are very popular - number of algorithms based on Sequential Monte Carlo methods is growing. Paper describes and compares the performance of two of them - Auxiliary and Rao-Blackwellised Particle Filters. Comparison includes also Bootstrap Filter and some variety of SIR algorithm.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2013, 76; 79-88
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on characteristics of three-dimensional granular meso-reconstruction of coal gangue roadbed
Autorzy:
Fan, Xiang-Xi
Hui, Bing
Ma, Shi-Jie
Fu, Jian-Cun
Zhang, Wen-Jun
Meng, Ling-Xiao
Sun, Zhi
Powiązania:
https://bibliotekanauki.pl/articles/2086979.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
coal gangue roadbed
particle flow
mesoscopic reconstruction
particle breakage
Opis:
The dynamic evolution process of the coal gangue particles’ core retention phenomenon in the process of crushing under stress, the evolution law of grading and the corresponding microscopic mechanical characteristics after continuous particle crushing are analyzed. The meso-level which reveals deformation phenomena of granular materials under the action of external loads is highly complex. At the qualitative level, the static compaction process of coal gangue samples can be roughly divided into three stages: initial compaction stage, compaction and crushing stage, and crushing (compaction) stage. It is proved that the interaction of lateral confined unidirectional compression of granular materials is mainly compression.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 3; 361--374
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetic modelling of flotation column and Jameson cell in coal
Autorzy:
Karaca, Sevgi
Ucar, Ali
Sahbaz, Oktay
Powiązania:
https://bibliotekanauki.pl/articles/2146872.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coarse particle
flotation column
Jameson cell
kinetics
particle size
Opis:
Physical enrichment technologies can be used worldwide in various coal washing plants to enrich up to 500 μm particle size. Conversely, coals smaller than this are discarded as waste, causing storage and environmental issues. In this regard, studies on coal below 500 μm in Turkey have recently acquired attraction. The Jameson flotation cell and flotation column, which have many uses worldwide but are not used throughout the plant in Turkey, were used to investigate the separation possibilities of coals below 500 μm. In the study, the flotation column and Jameson cell performances for three different particle sizes (-500+300, -300+212 and -212+106 μm) were compared. For the first time, both machines operated in a negative bias condition. In addition, the flotation kinetics of the machines were modelled with some critical operating parameters. Models illustrating the main and multiple effects of the parameters were developed using the data derived from the experimental results, and the models were statistically significant at the 95% confidence level. In the experiments performed with both flotation machines, the flotation rate increases with the decrease in particle size in general. According to the results, the velocity increase in the Jameson cell was 0.0050-0.0075 min-1 compared to the flotation column in the experiments performed in the size range of -500+300 μm, and the flotation rate constant increased approximately twice. In the size range of -212+106 μm, the difference became larger, and the flotation rate of the Jameson cell increased up to six times with a difference of 0.0450-0.0500 min-1.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 5; art. no. 152848
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation on the particle size and shape of iron ore pellet feed using ball mill and HPGR grinding methods
Autorzy:
Abazarpoor, A.
Halali, M.
Powiązania:
https://bibliotekanauki.pl/articles/109944.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
HPGR
ball mill
particle size
particle shape
image analysis
SEM
Opis:
An effect of a grinding method, that is ball mill and high pressure grinding rolls (HPGR), on the particle size, specific surface area and particle shape of an iron ore concentrate was studied. The particle size distribution was meticulously examined by sieve, laser and image analyses. To measure the specific surface area of particles, Brunauer-Emmett-Teller (BET) and Blaine methods were used. It was found that for samples having equal Blaine specific surface areas numbers, the amount of fine particles produced in HPGR was higher than that produced in a ball mill. A higher surface area was observed from HPGR treatment in comparison to ball mill grinding, provided by a higher porosity, cracks, roughness and new surfaces. A shape factor of particles was determined using the circularity, roughness, and aspect ratio. It was also observed that HPGR produced particles that were more elongated, less circular and rougher than those processed by the ball mill.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 908-919
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Żeby było_ i co_. Notka o znaczeniu
Żeby było_ and co_. Brief note on their meaning
Autorzy:
Kisiel, Anna
Powiązania:
https://bibliotekanauki.pl/articles/568050.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Mikołaja Kopernika w Toruniu. Wydawnictwo UMK
Tematy:
particle
contextuality
valence
Opis:
The article is devoted to semantic and grammatical description of two of the four strenghtening particles: żeby było_ and co_. These are very interesting language units, not attested in dictionaries, the only ones in the group of particles containing valency positions. Despite the semantic similarity between them and the two other items of the group - tym bardziej and co dopiero - they tend to occur in different sentence structures, i.e. containing joint conjuctions, restrictive or analogy particles. They do not occur in the context of non-assertive sentences. This paper considers the type of structure formed by the examined language units, the possibilities of filling their valency positions and, in result, their meaning.
Źródło:
Linguistica Copernicana; 2012, 2(8); 205-213
2080-1068
2391-7768
Pojawia się w:
Linguistica Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of ultrasonic treatment on the particle size, shape and ash content of fine coal
Autorzy:
Mao, Yuqiang
Xie, Guangyuan
Liang, Long
Xia, Wencheng
Peng, Yaoli
Powiązania:
https://bibliotekanauki.pl/articles/109544.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ultrasonic time
fine coal
particle size
particle shape
ash content
Opis:
The effects of ultrasonic treatment of different time on the particle size, morphology, ash content, and elementary composition of fine coal particles (74-45 μm) were investigated in this paper. The size reduction of coal particles induced by ultrasonic treatment was analyzed through the Focused Beam Reflectance Measurement (FBRM) and the variation of mechanical pulverization mechanism was discussed. The Scanning Electron Microscope (SEM) measurements showed that the sharp corners on coal particles was ground to round ones after ultrasonic treatment. This may be not conducive to coal flotation. It was also found that the ash content of 74-45 μm coal particles was increased gradually with the increase of ultrasonic time, while the ash content of -45 μm fraction was decreased. This was supported by the EDS measurements, indicating that the carbon content on the surfaces of 74-45 μm coal was reduced while the aluminium and silicon contents were increased after ultrasonic treatment.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 3; 679-688
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of exposure to nano-sized particles among transport and vehicle service workers
Autorzy:
Bujak-Pietrek, Stella
Mikołajczyk, Urszula
Powiązania:
https://bibliotekanauki.pl/articles/2087543.pdf
Data publikacji:
2021-11-19
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
ultrafine particles
particle number concentration
particle surface area concentration
nanoparticles exposure
diesel engine exhaust
particle number size distribution
Opis:
BackgroundExposure to fine and ultrafine particles from transport processes is a main consequence of emissions from engines, especially those with self-ignition. The particles released in these processes are a source of occupational and environmental particles exposure. The aim of this study was to assess the fine and nano-sized particles emission degree during work connected with transport and vehicle servicing.Material and MethodsThe tests were carried out at 3 workplaces of vehicles service and maintenance (a car repair workshop, a truck service hall, and a bus depot) during 1 work day in each of them. Measurements were performed using the following devices: DISCmini meters, GRIMM 1.109 optical counter and the DustTrak monitor. The number, surface area and mass concentration, and the number size distribution were analyzed.ResultsThe mean number concentration (DISCmini) increased during the analyzed processes, ranging from 4×104 p/cm3 to 8×104 p/cm3, and the highest concentration was found in the car repair workshop. The particles mean diameters during the processes ranged 31–47 nm, depending on the process. An increase in the surface area concentration value was observed in correlation with the particles number, and its highest concentration (198 m2/cm3) was found during work in the car repair workshop. The number size distribution analysis (GRIMM 1.109) showed the maximum value of the number concentration for particles sized 60 nm. The mean mass concentrations increased during the tested processes by approx. 40–70%, as compared to the background.ConclusionsAccording to the measurement results, all the workplaces under study constituted a source of an increase in all analyzed parameters characterizing emissions of nano-sized particles. Such working environment conditions can be harmful to the exposed workers; therefore, at such workplaces solutions for minimizing workers’ exposure, such as fume hoods or respiratory protection, should be used. Med Pr. 2021;72(5):489–500
Źródło:
Medycyna Pracy; 2021, 72, 5; 489-500
0465-5893
2353-1339
Pojawia się w:
Medycyna Pracy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza nieliniowego obserwatora i filtru cząsteczkowego jako estymatorów pozycji statku
Enhancement of posiotioning estimation of vessel
Autorzy:
Jaroś, K.
Witkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/267170.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
Nieliniowy model statku
Particle Filter
Nieliniowy obserwator
Nonlinear observer
Particle Filtering
Opis:
W artykule została przedstawiona analiza porównawcza dokonana pomiędzy dwoma estymatorami pozycji. Analiza ta została przedstawiona na podstawie różnicy pomiędzy wartością estymowaną a rzeczywistą. Badania estymatorów zostały przeprowadzone na podstawie równania kinematyki i dynamiki statku dynamicznie pozycjonowanego. Wartościami wykorzystywanymi w symulacji są pomiary z symulowanego odbiornika GPS i siły wytworzone przez napędy statku w czasie wykonywania manewrów. W artykule zawarto nieliniowy model statku z zakłóceniami w globalnym układzie współrzędnych, oraz dwa estymatory nieliniowy obserwator (NO) i filtr cząsteczkowy (PF) (ang. Particle filter). Badania zostały przeprowadzone w środowisku MATLAB/Simulink z użyciem modeli symulacyjnych. W badaniach wykazano że PF jest lepszym estymatorem niż NO podczas manewru zmiany pozycji statku natomiast sytuacja jest odwrotna podczas utrzymywania stałej pozycji statku.
An estimation of measured variables is very important in dynamic positioning systems of the vessels. There is required to a filtering of the signal environmental noise and the measurements noises to get high-precision estimate of the vessel’s position. The dynamic positioning systems uses a different algorithms for estimating and filtering measured signals. More suitable algorithms of estimating and filtering, allows to obtain an accurate control of the vessel’s position at sea, in seaports and near oil rigs. It improve safety level and decrease fuel consumption. That is the reason why many evaluations and investigations of estimation parameter. The goal of research, described in the paper is which of estimator is most suitable estimation of the vessel’s position. In this paper used three estimator to compare which of this estimation give the better solution in different tasks in dynamic positioning system. To comparison filters in this paper used simulation where the vessel has been used to different tasks. Ship model simulates the signal from the GPS receiver with disturbances and provides information about the force generated by the propellers. These values was used to estimation position of vessel. Studies have shown that PF is a better estimator than NO by tracking the position of a time-varying but the opposite is true for estimating the position of the invariant over time.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2015, 47; 71-74
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Systematic error of acoustic particle image velocimetry and its correction
Autorzy:
Mickiewicz, W.
Powiązania:
https://bibliotekanauki.pl/articles/221013.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
particle image velocimetry
acoustic measurement
acoustic particle velocity
sound field analysis
Opis:
Particle Image Velocimetry is getting more and more often the method of choice not only for visualization of turbulent mass flows in fluid mechanics, but also in linear and non-linear acoustics for non-intrusive visualization of acoustic particle velocity. Particle Image Velocimetry with low sampling rate (about 15Hz) can be applied to visualize the acoustic field using the acquisition synchronized to the excitation signal. Such phase-locked PIV technique is described and used in experiments presented in the paper. The main goal of research was to propose a model of PIV systematic error due to non-zero time interval between acquisitions of two images of the examined sound field seeded with tracer particles, what affects the measurement of complex acoustic signals. Usefulness of the presented model is confirmed experimentally. The correction procedure, based on the proposed model, applied to measurement data increases the accuracy of acoustic particle velocity field visualization and creates new possibilities in observation of sound fields excited with multi-tonal or band-limited noise signals.
Źródło:
Metrology and Measurement Systems; 2014, 21, 3; 447-460
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of space charge effects in the sector cyclotron
Autorzy:
Onischenko, L.
Samsonov, E.
Aleksandrov, V.
Shevtsov, V.
Shirkov, G.
Tuzikov, A.
Powiązania:
https://bibliotekanauki.pl/articles/148737.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
sector cyclotron
particle dynamics
Opis:
To study the effects of space charge in cyclotrons and synchrocyclotrons the code PHASCOL is developed. A method of large (macro)particles is realized in this code. The complete equations of motion of the charged particle in electromagnetic field of accelerator are integrated taking into account the three-dimensional self-electric field of beam. Two methods were used for the calculation of the beam field: the particle-to-particle method and the particle-in-cell one. The results of calculations which illustrate space-charge effects on the parameters of beam in the process of acceleration are given. Both methods have shown a similar influence of space charge on the beam.
Źródło:
Nukleonika; 2003, 48,suppl.2; 45-48
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Overview of Particle Agglomeration Techniques to Waste Utilization
Autorzy:
Borowski, Gabriel
Powiązania:
https://bibliotekanauki.pl/articles/1955573.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
particle agglomeration
utilization
waste
Opis:
Particulate materials and waste from industrial processes are troublesome in storage, transport and utilization, mainly due to their large volume and dusting. Therefore, originally the main reason for developing the agglomeration processes was to eliminate the afore-mentioned disadvantages. However, the modifications introduced to the merging processes of materials enabled obtaining a new type of products widely used in various applications. For the agglomeration of the inorganic materials, often containing hazardous substances, the disposal and transformation technologies are available for the safe products that can be used, for example, in civil engineering and construction. In turn, the agglomeration of the materials containing organic substances or fine coal, producing alternative fuels for energy recovery. Obviously, the combustion of these fuels results in a subsequent generation of waste in the form of bottom and fly ash, but they can be successfully further agglomerated to produce more valuable products. The numerous examples of the use of various agglomeration techniques to complete utilization of fine grains was shown. An additional effect of the agglomeration processes was also the fulfilment of the economy criteria, which matches with the principles of sustainable development of the environment. Supporting by worldwide literature, the selected agglomeration techniques were discussed, such as: solidification, granulation, extrusion, briquetting, as well as post-agglomeration high-temperature processing.
Źródło:
Journal of Ecological Engineering; 2021, 22, 9; 263-271
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
2D simulations of liquid percolation through model porous media: preliminary MD and DPD results
Autorzy:
Rychcik, M.
Bośko, J.
Rybicki, J.
Alda, W.
Dzwinel, W.
Mancini, G.
Fioretti, L.
Powiązania:
https://bibliotekanauki.pl/articles/1964080.pdf
Data publikacji:
2001
Wydawca:
Politechnika Gdańska
Tematy:
2D flow simulations
particle methods
molecular dynamics
dissipative particle dynamics method
Opis:
In the paper we make a short overview of computer models based on particle approach, which can be suitable for the simulation of fluid flow through porous media. We concentrate on Molecular Dynamics (MD) and Dissipative Particle Dynamics (DPD) methods. We describe main features of our simulation programs, and present and discuss preliminary results of MD and DPD simulations of 2D fluid flow through a simple model rigid porous media. The paper aims at the evaluation of the applicability of MD and DPD methods for simulations of liquid flows in media of complicated geometry.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 1; 85-97
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sum rule of the correlation function
Autorzy:
Mrówczyński, S.
Maj, R.
Powiązania:
https://bibliotekanauki.pl/articles/147374.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
particle correlations
nuclear collisions
Opis:
We discuss a sum rule satisfied by the correlation function of two particles with small relative momenta. We first derive the sum rule, which results from the completeness condition of the quantum states of the two particles, and then we discuss it for the case of strongly interacting pair of neutron and proton and for the Coulomb system of two charged particles.
Źródło:
Nukleonika; 2004, 49,suppl.2; 27-31
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Partykuły spajające jako podklasa jednostek metatekstowych
Conjuncting particles as a subclass of metatextual units
Autorzy:
Kisiel, Anna
Powiązania:
https://bibliotekanauki.pl/articles/29431721.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Mikołaja Kopernika w Toruniu. Wydawnictwo UMK
Tematy:
partykuła
partykuła spajająca
spójnik
szyk
metatekst
particle
conjuncting particle
conjunction
word order
metatext
Opis:
Autorka komentuje istniejące w polskim językoznawstwie opisy klasy partykuł spajających. Za podstawowe trzy kryteria wyróżniania tej klasy uznaje ich dozdaniowość, zależność od przedtekstu oraz zmienność pozycyjną. Zauważa, że partykuły spajające preferują pozycję w pobliżu (przed, po, a nawet wewnątrz) części tematycznej i często towarzyszy im silny przycisk prozodyczny na wyrażeniu tematycznym. Preferują one również dłuższe, zdaniowe konteksty. Zaproponowana w tym tekście interpretacja partykuł spajających sprowadza się do uznania ich za komentarze dotematyczne, wiążące to, co jest mówione o nowym obiekcie z tym, co zostało wcześniej powiedziane o czymś innym. Ponieważ tego typu wiązanie tematyczne jest interpretacyjnie bardziej wymagające niż wiązanie rematyczne (odbywające się wszak w ramach jednego nadrzędnego tematu), partykuły spajające wymagają, aby odpowiedni przedtekst był bezpośrednio przylegający do struktury T-R, którą one komentują.
In this paper, the author tries to collect and comment on the statements that have been made in Polish linguistics on conjuncting particles. Among three main features of conjuncting particles that are discussed are: their adsentential nature, contextual dependency,and positional mobility. Conjuncting particles prefer placement near (before, after, and even within) a thematic part, are often accompanied by prosodic stress on a thematic expression, and prefer longer, sentential contexts. This paper proposes their interpretation as adthematic operators that link what is being said about a new topic to what has been said before on another topic. Because topic linking is more challenging for a conversational partner than conjucting rhemes (where a supreme theme ensures a bond between them), conjuncting particles require the relevant preceding context to be adjacent to the theme-rheme structure introduced by them.
Źródło:
Linguistica Copernicana; 2023, 19; 169-183
2080-1068
2391-7768
Pojawia się w:
Linguistica Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Grammatikalisierung, Pragmatikalisierung und die Entstehung von Diskursmarkern im Deutschen
Autorzy:
Rojek, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/700373.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Germanistów Polskich
Tematy:
grammaticalisation, pragmatisation, discourse markers, particle
Opis:
Since about 20 years linguists attempt to apply the grammaticalisation concept to the description of pragmatic phenomena. In this context some linguists speak about ‘pragmatisation’ – a kind of language change, which concerns the linguistic codification of certain pragmatic contents. The term ‘pragmatisation’ suggests a new process, which runs in opposite direction to the development of grammatical elements. Irrespective of how we define the relation between both processes, this means always a reinterpretation (mostly extention) of the grammaticalisation concept. The present article focus on the question whether such attempts indeed result in a new insight into development of pragmatic units, or lead to terminological confusion by different terming already well described linguistic mechanisms.
Źródło:
Zeitschrift des Verbandes Polnischer Germanisten; 2013, 2, 2
2353-656X
2353-4893
Pojawia się w:
Zeitschrift des Verbandes Polnischer Germanisten
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Derivation of the kinetic equation for dispersed particles in turbulent flows
Wprowadzenie równania kinetycznego dla cząstek w turbulentnym przepływie dwufazowym
Autorzy:
Pozorski, J.
Powiązania:
https://bibliotekanauki.pl/articles/280061.pdf
Data publikacji:
1998
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
turbulence
particle dispersion
kinetic equation
Opis:
An alternative way to obtain the kinetic equation for dispersed particles in turbulent flows is presented. The method uses some tools developed within the theory of the stochastic differential equations. They are presented first in an outline, including the cumulant expansion of linear stochastic equations as well as the approach to non-linear equations. Then, the general method is applied to the equation of motion of small particles in turbulent flows. The governing kinetic equation for particles is derived; it involves the correlations of the fluctuating fluid velocity along the particle trajectories.
W pracy przedstawiono alternatywny sposób wyprowadzenia równania kinetycznego dla cząstek w turbulentnym przepływie dwufazowym. Wykorzystano metody rozwinięte w ramach teorii stochastycznych równań różniczkowych. Przedstawiono je w zarysie, łącznie z rozwinięciem liniowych i nieliniowych równań stochastycznych w szereg półniezmienników (kumulantów). Następnie, to ogólne podejście zastosowano do równania ruchu małych cząstek w przepływie turbulentnym i wyprowadzono odpowiadające mu równanie kinetyczne. Zawiera ono korelacje fluktuacji prędkości płynu wzdłuż trajektorii cząstek.
Źródło:
Journal of Theoretical and Applied Mechanics; 1998, 1; 31-46
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Understanding of wet and alternative particle removal processes in microelectronics: theoretical capabilities and limitations
Autorzy:
Tardif, F.
Danel, A.
Raccurt, O.
Powiązania:
https://bibliotekanauki.pl/articles/308976.pdf
Data publikacji:
2005
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
cleaning
SC1
particle removal
Opis:
A 2 orders of magnitude range of van der Waals interactions is considered here to take the majority of the variety of shapes and materials of actual particles into account. Comparing these interactions with the repulsive forces generated by electrostatic charges, drag, surface tension, shock waves, high accelerations and aerosol particles, the intrinsic capabilities and limitations of the different cleaning processes can be predicted. Three kinds of particle-removal processes have been identified { universal processes capable of removing all particle sizes and types, even from patterned wafers, processes that present the same theoretical ability but are actually limited by the accessibility of the particles, and finally cleanings that are not able to remove all particle sizes.
Źródło:
Journal of Telecommunications and Information Technology; 2005, 1; 11-19
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Linguistic concepts across languages: The category of epistemic adverbs in English and Polish
Autorzy:
Rozumko, Agata
Powiązania:
https://bibliotekanauki.pl/articles/1152270.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
adverb
particle
epistemic
English
Polish
Opis:
The category of epistemic adverbs has recently received increased attention in both Anglophone and Polish linguistics, but English–Polish contrastive research in this area has so far been rather fragmentary. English and Polish grammars differ considerably in the ways they classify epistemic adverbs. The differences largely result from the different understanding of adverbs as a category, which in English grammar tends to be presented as broad and heterogeneous while in Polish grammar – rather narrow and uniform. Polish equivalents of English epistemic adverbs are classified as particles – a distinct word class with its own characteristic properties. This paper presents an overview of approaches to epistemic adverbs taken in Anglophone and Polish linguistics with the aim of identifying their convergent points and suggesting a framework for a contrastive analysis. In the case of Anglophone research, the focus is largely on discourse studies because epistemic adverbs are usually seen as a discourse category. In Polish linguistics, however, they are analysed within different theoretical frameworks, which is why the discussion will not be limited to one specific methodological school. Reference is also made to more general issues, such as the treatment of adverbs as a category.
Źródło:
Yearbook of the Poznań Linguistic Meeting; 2016, 2, 1
2449-7525
Pojawia się w:
Yearbook of the Poznań Linguistic Meeting
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza wydajności silnika Unity3D w aspekcie symulacji cząsteczkowych
Efficiency analysis of Unity3D engine in terms of particle simulation
Autorzy:
Walczyna, M.
Plechawska-Wójcik, M.
Powiązania:
https://bibliotekanauki.pl/articles/98158.pdf
Data publikacji:
2017
Wydawca:
Politechnika Lubelska. Instytut Informatyki
Tematy:
cząsteczka
system cząsteczek
Unity 3D
wydajność
symulacja
particle
particle system
efficiency
simulation
Opis:
Dokument ten przedstawia badania w sektorze wydajności cząsteczek utworzonych przez wbudowany w Unity3D system cząsteczek oraz tworzonych poprzez skrypt napisanym w języku C#. Autor skupił się na zbadaniu wpływu poszczególnych zadań na szybkość renderowania klatki, różnicy jakie występują podczas generowania cząsteczek przez system cząsteczek, a tych generowanych przez skrypt oraz jak duży wpływ ma złożoność siatki cząsteczki generowanej na zachwianie wydajności aplikacji. W tym celu, z użyciem Unity3D, Microsoft Visual Studio oraz Blendera, została utworzona aplikacja na komputery z systemem Windows która pozwala na dostosowanie parametrów symulacji (liczby generowanych cząsteczek, kształtu cząsteczki – kula, sześcian).
This document reviews research in efficiency analysys of particles created by Unity 3D built-in particle system compared to those created via sctript written in C# language. Author focused his research on examining the impact of the various tasks on the speed of rendering frames, a difference which occur during the generation of particle by particle system and those generated by a script, and how influential is the complexity of the mesh particles generated on the application performance. For this purpose, using Unity3D, Microsoft Visual Studio and Blender, an applications for computers that are ruunniong on Windows system was created, application allows to adjust the simulation parameters (the number of generated particles, particle shape - sphere, cube).
Źródło:
Journal of Computer Sciences Institute; 2017, 3; 59-63
2544-0764
Pojawia się w:
Journal of Computer Sciences Institute
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the influence of particle and poplar fibres share on selected properties of particle-fibre boards
Autorzy:
Zaraziński, Karol
Boruszewski, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2200109.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
fiber boards
particle boards
particle-fibre boards
plantation
płyty pilśniowe
płyty wiórowe
plantacja
Opis:
Analysis of the influence of particle and poplar fibres share on selected properties of particle-fibre boards. As a part of the study, one-layer particle-fibre boards with 12 mm thick and of average density 650 kg/m3 were manufactured from plantation poplar ‘Hybrid 275’ wood.. For the control variant a typical industrial raw material (pine wood) was used. The following properties were determined for the boards: modulus of rapture (MOR), density profile, modulus of elasticity at static bending (MOE), internal bond (IB), thickness swelling (TS) after 2h and 24h soaking in water. On the basis of conducted study, it was found that the addition of poplar fibers to particle-fibre boards in most cases has a positive effect on the values of determined properties – an increase in strength was noted, except for internal bond (IB). In the case of thickness swelling of the boards after 24 h soaking in water, it was noted that with the increase in the share of poplar fibers in the boards, the value of the tested property decreased (which was not clear in the case of thickness swelling of boards after 2 h soaking in water).
Analiza wpływu udziału wiórów i włókien topolowych na wybrane właściwości płyt wiórowo- włóknistych. W ramach pracy wytworzono jednowarstwowe płyty wiórowo – włókniste z topoli plantacyjnej ‘Hybrida 275’, o grubości 12 mm i średniej gęstości 650 kg/m3. Do wariantu kontrolnego użyto typowego surowca przemysłowego (drewna sosnowego). Dla powstałych płyt wyznaczono: wytrzymałość na zginanie statyczne (MOR), profil gęstości, moduł sprężystości przy zginaniu statycznym (MOE), wytrzymałość na rozciąganie w kierunku prostopadłym do płaszczyzn płyt (IB), spęcznienie na grubość po 2h oraz 24h moczeniu w wodzie. Na podstawie przeprowadzonych badań stwierdzono, że dodatek włókien topolowych do płyt wiórowo – włóknistych w większości przypadków wpływa pozytywnie na wartości określanych właściwości - odnotowano wzrost wytrzymałości z wyjątkiem rozciągania w kierunku prostopadłym do płaszczyzn (IB). W przypadku pęcznienia płyt na grubość po 24 h moczenia w wodzie odnotowano, że wraz ze wzrostem udziału włókien topolowych w płytach, wartość badanej cechy maleje (co nie było jednoznaczne w przypadku pęcznienia pyt na grubość po 2 h moczenia w wodzie).
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2020, 112; 22--31
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Próba zastosowania metody elementów dyskretnych w mechanice ciała stałego
An attempt to use Discrete Element Method in solid mechanics
Autorzy:
Nowicki, T.
Powiązania:
https://bibliotekanauki.pl/articles/390929.pdf
Data publikacji:
2016
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
metoda elementów dyskretnych (odosobnionych)
ESys-Particle
skala mezo
discrete element method
mesoscale
Esys-Particle
Opis:
Praca poświęcona jest metodzie elementów dyskretnych. W chwili obecnej jest to metoda numeryczna służąca do modelowanie materiałów, głównie skał. W pracy zawarto opis najprostszej wersji metody. Przedstawiono również przeprowadzoną symulację komputerową z zastosowaniem pakietu obliczeniowego ESys-Particle. Artykuł należy traktować jako wprowadzenie do prac nad zastosowaniami tej metody w inżynierii budowlanej.
The paper is devoted to Discrete Element Method. Currently the method is mainly used for mechanics of rock. The paper contains the description of the simplest version of the method. Computer simulation using Esys-Particle computer code is presented. The paper is an introduction to the study on the method applications to building engineering.
Źródło:
Budownictwo i Architektura; 2016, 15, 4; 153-162
1899-0665
Pojawia się w:
Budownictwo i Architektura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SPH computation of incompressible viscous flows
Obliczenia nieściśliwych przepływów lepkich metodą cząstek rozmytych (SPH)
Autorzy:
Pozorski, J.
Wawreńczuk, A.
Powiązania:
https://bibliotekanauki.pl/articles/281151.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
viscous flow
particle method
incompressibility
Opis:
The paper is concerned with the numerical flow computation using the method of Smoothed Particle Hydrodynamics (SPH). Fundamental concepts of the method are briefly recalled. Physical aspects of the incompressibility and its mathematical formulation are described. A new proposal for the incompressibility constraint is put forward in the SPH context. Numerical implementation of the method is described and main parts of the algorithm are presented, including the issue of boundary conditions. Some validation cases and examples of results for viscous flows are presented.
Praca dotyczy numerycznych obliczeń przepływów z wykorzystaniem metody cząstek rozmytych (ang. SPH - Smoothed Particle Hydrodynamics). Przypomniano pokrótce podstawy metody, a także fizyczne i matematyczne aspekty nieściśliwości. Przedstawiono nową propzycję spełnienia warunku nieściśliwości w podejściu SPH. Opisano numeryczną implementację metody i podstawowe elementy algorytmu, w tym sposób stawiania warunków brzegowych. przedstawiono wyniki testów metody oraz przykłady obliczeń przepływów lepkich.
Źródło:
Journal of Theoretical and Applied Mechanics; 2002, 40, 4; 917-937
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods for close-track efficiency study
Autorzy:
Mikhailov, K.
Stavinskiy, A.
Vlassov, A.
Mestayer, M.
Powiązania:
https://bibliotekanauki.pl/articles/147426.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
particle correlations
close track efficiency
Opis:
We describe two new methods for the study of close track efficiency. One is based on the study of a correlation function for particles with different masses as a function of their relative momenta in the laboratory reference system. The other method is based on the analysis of artificial events, constructed by merging raw data from separate events. Both methods and the standard Monte Carlo method were applied to data from the CLAS detector at Jefferson Laboratory. All three methods provide the same result for close track efficiency with an accuracy sufficient for practical application.
Źródło:
Nukleonika; 2004, 49,suppl.2; 85-88
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
O dwóch metatekstowych jednostkach: „zaś" i „natomiast"
On two Metatextual Units: "zaś" and "natomiast"
Autorzy:
Kisiel, Anna
Powiązania:
https://bibliotekanauki.pl/articles/568086.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Mikołaja Kopernika w Toruniu. Wydawnictwo UMK
Tematy:
metatext
pronoun
particle
conjunction
TRS
Opis:
The article presents two units of unclear grammatical classification, both derived from the pronoun phrases: zaś and natomiast. In the first part of the article the units are contrasted with units considered in lexicography as being semantically close: za to, z kolei, ale and a. The first one is equally dubious when it comes to its classification, the second belongs to the class of particles, the last two - to the class of conjunctions. Based on the analysis of the TR structure of sentences with the aforementioned units and their word order, together with observations on their ability to co-occur with other metatextual units, it can be pointed out that zaś and natomiast cannot be seen neither as particles, nor as conjunctions (as identified in modern Polish linguistics). The second part of the article provides a more detailed observation on TR structure of sentences with zaś and natomiast in order to recognise their specificity.
Źródło:
Linguistica Copernicana; 2015, 12; 53-69
2080-1068
2391-7768
Pojawia się w:
Linguistica Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie cyfrowej anemometrii obrazowej do analizy segregacji cząstek monodyspersyjnych pod kątem zastosowań w gospodarce odpadami
Assessment of monodispersing material segregation with the used of digital particle image velocimetry (DPIV) technique in waste management contest
Autorzy:
Ligus, G.
Ignasiak, K.
Powiązania:
https://bibliotekanauki.pl/articles/391897.pdf
Data publikacji:
2010
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Ceramiki i Materiałów Budowlanych
Tematy:
gospodarka odpadami
cząstka monodyspersyjna
segregacja cząstek
metoda badań
cyfrowa anemometria obrazowa
waste management
monodispersive particle
particle segregation
examination technique
digital particle image velocimetry
Opis:
Przedstawiono wizualne badania procesu segregacji cząstek monodyspersyjnych w separatorze powietrznym. Opisano koncepcję stanowiska pomiarowego z aplikacją toru optycznego do pomiarów za pomocą szybkiej kamery wideo. Do opisu zjawisk zastosowano algorytmy cyfrowej anemometrii obrazowej (DPIV). Zaprezentowano ocenę zmiany stopnia segregacji w zależności od parametrów przepływowych w urządzeniu.
Authors propose visualization research of monodispersing material separation in pneumatic separator. Conception of experimental stand with application of optical track based on fast video camera was described. Digital Particle Image Velocimetry (DPIV) for assessment of physical phenomena during pneumatic segregation was used. In the paper also correlation between two-dimensional concentration factor and flow parameters in device was described.
Źródło:
Prace Instytutu Ceramiki i Materiałów Budowlanych; 2010, R. 3, nr 6, 6; 104-113
1899-3230
Pojawia się w:
Prace Instytutu Ceramiki i Materiałów Budowlanych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
STR zdań z partykułami dodającymi
TRS of sentences containing additive particles
Autorzy:
Kisiel, Anna
Powiązania:
https://bibliotekanauki.pl/articles/568146.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Mikołaja Kopernika w Toruniu. Wydawnictwo UMK
Tematy:
particle
prepositional expression
contextuality
additive index
Opis:
The author discusses Ewa Walusiak's proposal to distinguish three homogenous and synonymous language units belonging to three groups: prepositions, particles and conjunctions. It is argued that the criteria used by Walusiak do not allow for clear differentiation of the three groups. Therefore the author suggests an opposite hypothesis to be true: all of the language units in question belong to one and only one group of particles. The final part of the article is devoted to a preliminary semantic distinction between na dodatek, w dodatku, na dobitkę, na dobitek, na dokładkę and na domiar złego.
Źródło:
Linguistica Copernicana; 2012, 1(7); 139-151
2080-1068
2391-7768
Pojawia się w:
Linguistica Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Obtaining the specific heat of hadronic matter from CERN/RHIC experiments
Autorzy:
Mekjian, A.
Powiązania:
https://bibliotekanauki.pl/articles/148451.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
specific heat
particle-yields mass-spectrum
Opis:
The specific heat of hot hadronic matter is related to particle production yields from experiments done at CERN/RHIC. The mass fluctuation of excited hadrons plays an important role. Connections of the specific heat, mean hadronic mass excited and its fluctuation with properties of baryon and electric charge chemical potentials (value, slope and curvature) are also developed. A possible divergence of the specific heat as 1/(T0 – T)2 is discussed. Some connections with net charge fluctuations are noted.
Źródło:
Nukleonika; 2006, 51,suppl.3; 73-78
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Predictive modeling in a VoIP system
Autorzy:
Simionovici, A. M.
Tantar, A. A.
Bouvry, P.
Didelot, L.
Powiązania:
https://bibliotekanauki.pl/articles/308590.pdf
Data publikacji:
2013
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
particle algorithms
prediction
user-profiles
VoIP
Opis:
An important problem one needs to deal with in a Voice over IP system is server overload. One way for preventing such problems is to rely on prediction techniques for the incoming traffic, namely as to proactively scale the available resources. Anticipating the computational load induced on processors by incoming requests can be used to optimize load distribution and resource allocation. In this study, the authors look at how the user profiles, peak hours or call patterns are shaped for a real system and, in a second step, at constructing a model that is capable of predicting trends.
Źródło:
Journal of Telecommunications and Information Technology; 2013, 4; 32-40
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Swarm intelligence integrated approach for experimental investigation in milling of multiwall carbon nanotube/polymer nanocomposites
Autorzy:
Kharwar, Prakhar Kumar
Verma, Rajesh Kumar
Mandal, Nirmal Kumar
Mondal, Arpan Kumar
Powiązania:
https://bibliotekanauki.pl/articles/139582.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nanocomposites
epoxy
particle
swarm
Pareto front
Opis:
In manufacturing industries, the selection of machine parameters is a very complicated task in a time-bound manner. The process parameters play a primary role in confirming the quality, low cost of manufacturing, high productivity, and provide the source for sustainable machining. This paper explores the milling behavior of MWCNT/epoxy nanocomposites to attain the parametric conditions having lower surface roughness (Ra) and higher materials removal rate (MRR). Milling is considered as an indispensable process employed to acquire highly accurate and precise slots. Particle swarm optimization (PSO) is very trendy among the nature-stimulated metaheuristic method used for the optimization of varying constraints. This article uses the non-dominated PSO algorithm to optimize the milling parameters, namely, MWCNT weight% (Wt.), spindle speed (N), feed rate (F), and depth of cut (D). The first setting confirmatory test demonstrates the value of Ra and MRR that are found as 1.62 µm and 5.69 mm3/min, respectively and for the second set, the obtained values of Ra and MRR are 3.74 µm and 22.83 mm3/min respectively. The Pareto set allows the manufacturer to determine the optimal setting depending on their application need. The outcomes of the proposed algorithm offer new criteria to control the milling parameters for high efficiency.
Źródło:
Archive of Mechanical Engineering; 2020, LXVII, 3; 353-376
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics of Silver Nanoparticles in Different pH Values
Autorzy:
Mražíková, A.
Velgosová, O.
Kavuličová, J.
Matvija, M.
Čižmárová, E.
Willner, J.
Powiązania:
https://bibliotekanauki.pl/articles/355669.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Ag nanoparticles
particle size
stability
pH
Opis:
Stability of silver nanoparticles strongly influences the potential of their application. The literature shows wide possibilities of nanoparticles preparation, which has significantly impact on their properties. Therefore, the improvement of AgNPs preparation plays a key role in the case of their practical use. The pH values of the environment are one of the important factors, which directly influences stability of AgNPs. We present a comparing study of the silver nanoparticles prepared by „bottom-up“ methods over by chemical synthesis and biosynthesis using AgNO3 (0.29 mM) solution. For the biosynthesis of the silver nanoparticles, the green freshwater algae Parachlorella kessleri and Citrus limon extracts were used as reducing and stabilizing agents. Chemically synthesized AgNPs were performed using sodium citrate (0.5%) as a capping agent and 0.01% gelatine as a reducing agent. The formation and long term stability of those silver nanoparticles synthesized either biologically and chemically were clearly observed by solution colour changes and confirmed by UV-vis spectroscopy. The pH values of formed nanoparticle solutions were 3 and 5.8 for biosynthesized AgNPs using extract of Citrus limon and Parachlorella kessleri, respectively and 7.2 for chemically prepared AgNPs solution using citrate. The SEM as a surface imaging method was used for the characterization of nanoparticle shapes, size distribution and also for resolving different particle sizes. These micrographs confirmed the presence of dispersed and aggregated AgNPs with various shapes and sizes.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 993-998
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of the Schrödinger particle non-elastic scattering with emission of photon in the quantum register
Autorzy:
Ostrowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/200499.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
quantum simulations
nonelastic scattering
Schrödinger particle
Opis:
This paper investigates whether a quantum computer can efficiently simulate the non-elastic scattering of the Schrödinger particle on a stationary excitable shield. The return of the shield to the ground state is caused by photon emission. An algorithm is presented for simulating the time evolution of such a process, implemented on standard two-input gates. The algorithm is used for the computation of elastic and non-elastic scattering probabilities. The results obtained by our algorithm are compared with those obtained using the standard Cayley’s method.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 5; 1217-1225
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation and evaluation of jigging separation features
Badania i ocena argumentu rozdziału w osadzarce
Autorzy:
Surowiak, A.
Powiązania:
https://bibliotekanauki.pl/articles/220123.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wielkość ziaren
współczynnik kształtu
gęstość ziaren
cecha rozdziału w osadzarce
jig separation feature
particle size
particle density
shape coefficient
particle settling velocity
separation precision
Opis:
The process of enrichment in a jig has usually been described and analysed using particle density as a separation feature. However, a degree of particle loosening in the jig bed is affected by, inter alia, the terminal particle free settling velocity which in turn is affected by the size, density and shape of a particle. Therefore, the terminal particle settling velocity clearly characterises the feed transferred to a jig for the enrichment process. Taking the comprehensive particle geometric (particle size and shape) and physical properties (particle density) into account comes down to the calculation of the terminal particle settling velocity. The terminal particle settling velocity is therefore a complex separation feature which comprises three basic particle features (particle density, size and shape). This paper compares the effects of enrichment of coal fines in a jig, for two cases: when the commonly applied particle density is separation feature and for the particle settling velocity. Particle settling velocities were calculated in the selected three particle size fractions: –3.15+2.00, –10.00+8.00 and –20.00+16.00 mm based on the industrial testing of a jig for coal fines and detailed laboratory tests consisting in determining particle density, projective diameter and volume and dynamic particle shape coefficient. The calculated and drawn partition curves for two variants, i.e. when particle density and particle settling velocity were taken into account as the separation argument in selected particle size fractions, allowed to calculate and compare separation precision indicator. With the use of a statistical test, the assumption on the independence of random variables of the distribution of components included in the distribution of the particle settling velocity as a separation feature during enrichment in a jig was verified.
Zazwyczaj proces wzbogacania w osadzarce opisywano i analizowano przy użyciu gęstości ziaren jako cechy rozdziału. Jednakże na stopień rozluzowania ziaren w łożu osadzarki ma wpływ między innymi graniczna prędkość opadania swobodnego ziarna, na którą ma wpływ wielkość, gęstość i kształt ziarna. Zatem graniczna prędkość opadania ziaren w sposób jednoznaczny charakteryzuje nadawę kierowaną do procesu wzbogacania w osadzarce. Uwzględnienie kompleksowych właściwości geometrycznych ziaren (wielkość i kształt ziaren) oraz fizycznych (gęstość ziaren) sprowadza się do wyliczenia granicznej prędkości opadania ziaren. Zatem graniczna prędkość opadania ziaren jest to złożona cecha rozdziału zawierająca w sobie trzy podstawowe cechy ziarna (gęstość, wielkość i kształt ziarna). W tej pracy porównano efekty wzbogacania miałów węglowych w osadzarce dla dwóch przypadków: kiedy cechą rozdziału jest powszechnie stosowana gęstość ziaren oraz dla prędkości opadania ziaren. Na podstawie opróbowania przemysłowego osadzarki miałowej i szczegółowych badań laboratoryjnych, polegających na określeniu gęstości ziaren, średnicy projekcyjnej i objętościowego oraz dynamicznego współczynnika kształtu ziaren wyliczono prędkości opadania ziaren w wybranych trzech klasach ziarnowych: 2.0-3.15, 8.0-10.0 i 16.0-20.0 mm. Wyliczone i wykreślone krzywe rozdziału dla dwóch wariantów tzn. kiedy brano pod uwagę gęstość ziaren i prędkość opadania ziaren jako argument rozdziału w wybranych klasach ziarnowych, pozwoliły na wyliczenie i porównanie wskaźników dokładności rozdziału. Przy pomocy testu statystycznego dokonano weryfikacji założenia o niezależności zmiennych losowych rozkładu składowych wchodzących w skład rozkładu prędkości opadania ziaren jako cechy rozdziału przy wzbogacaniu w osadzarce.
Źródło:
Archives of Mining Sciences; 2018, 63, 4; 839-851
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie dyfrakcyjnej analizy laserowej do kontroli uziarnienia produktów przeróbki rud metali
Application of Diffraction Laser Analysis to Monitor Granulation of Copper Ores Processing Products
Autorzy:
Krawczykowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/318458.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
analiza uziarnienia
dyfrakcja laserowa
analiza sitowa
zgazowanie węgla
particle size control
laser diffraction
particle size analyzers
Opis:
Artykuł dotyczy problemu wyboru właściwej metody pomiaru uziarnienia paliw węglowych przeznaczonych do naziemnego zgazowania w różnych typach reaktorów. Dokonano przeglądu technik pomiarowych wraz z określeniem uwarunkowań do ich stosowania. Uziarnienie węgli przeznaczonych do zgazowania badano w klasach ziarnowych dostosowanych do odpowiednich technologii zgazowania. Wyniki analiz granulometrycznych poddano aproksymacji i ocenie statystycznej. Wykazano możliwości aplikacyjne dla dwóch standardowych metod: analizy sitowej – dla grubo uziarnionych węgli zgazowywanych w reaktorze ze złożem stałym, przesuwnym lub fluidalnym oraz dyfrakcji laserowej – dla drobno uziarnionych węgli zgazowywanych w technologiach z reaktorem strumieniowym.
The laser diffraction was characterized in the paper as standard method of fine < 2 mm particles size measurement. Author made the review of newest solutions of industrial analyzers working in online mode in ores processing plants and available laboratory devices supporting technological process monitoring which should be used by quality control units. The possibilities of applying analyzers in technological system of copper ores processing as well the benefits occurring from change of previous measuring technique based on mechanical methods of particle size analysis by precise laser diffraction method were indicated.
Źródło:
Inżynieria Mineralna; 2017, R. 18, nr 1, 1; 233-240
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bo – bowiem – albowiem. Między spójnikiem a partykułą
Bo – bowiem – albowiem. Between a conjunction and a particle
Autorzy:
Kisiel, Anna
Powiązania:
https://bibliotekanauki.pl/articles/468388.pdf
Data publikacji:
2015
Wydawca:
Wydawnictwo Uniwersytetu Śląskiego
Tematy:
spójnik
partykuła
konektor
particle
conjunction
connector
Opis:
The article presents three etymologically related units: bo, bowiem i albowiem. Basing on analysis of the contexts of their use (requirement of a weaker / stronger pause, ability to cooperate with an elliptic sentence, possibility of changing position within a sentence), with particular regard to binding between a rheme of the sentence with which these units coocurate and a preceeding rheme, the possibility of including bowiem and albowiem into the classes of particles and conjunctions is discussed.
Źródło:
Forum Lingwistyczne; 2015, 2; 73-84
2449-9587
2450-2758
Pojawia się w:
Forum Lingwistyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization multiplexed bit data recording to submicron-particles-arrayed optical storage
Autorzy:
Okuzono, Daiki
Egami, Chikara
Powiązania:
https://bibliotekanauki.pl/articles/2060688.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
submicron particle
confocal microscope
optical storage
Opis:
In this study, a submicron-particles-arrayed optical storage disk was fabricated by the spin coating method. Moreover, we have formed a multi-valued pit by irradiating linearly polarized laser beams at multiple angles (0° and 90°). The optical setup has the semiconductor laser (λ = 637 nm) for reconstructing and the SHG-YVO4 laser (λ = 532 nm) for recording. The optical setup measured the submicron-particles-arrayed optical storage as a confocal image by 2D scanning with a motorized stage.
Źródło:
Optica Applicata; 2022, 52, 1; 67--76
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wave-quasi-particle dualism in the transmission-reflection problem for elastic waves
Dualizm falowo-quasi-korpuskularny w zagadnieniu przesyłania i odbicia fal sprężystych
Autorzy:
Maugin, G. A.
Rousseau, M.
Powiązania:
https://bibliotekanauki.pl/articles/280334.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
elastic waves
quasi-particle
transmission-reflection
Opis:
Following along the line of recent works in which the notion of quasi-particles associated with surface acoustic waves of different types was introduced via canonical conservation laws, here the emphasis is placed on the possible exploitation of this dualism in the classical problem of the transmission and reflection of waves by a discontinuity between two media (in perfect contact or with possible delamination) and the more general case of a mono-layer or multi-layer sandwiched slab.
Idąc w ślad za ostatnimi publikacjami, w których użyto pojęcia tzw. quasi-cząstek wprowadzonego poprzez zastosowanie kanonicznych praw zachowania w odniesieniu do powierzchniowych fal akustycznych różnego rodzaju, w prezentowanej pracy położono nacisk na możliwe wykorzystanie dualizmu falowo-quasi-korpuskularnego w klasycznym zagadnieniu przesyłania i odbicia fal na nieciągłości pomiędzy dwoma ośrodkami (doskonale połączonych lub zdelaminowanych) i w ogólniejszym przypadku jednolub wielowarstwowej płycie typu sandwich.
Źródło:
Journal of Theoretical and Applied Mechanics; 2012, 50, 3; 797-805
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of laser sheet technique for analysis of 3D particle velocity fields
Autorzy:
Mirek, P.
Powiązania:
https://bibliotekanauki.pl/articles/280557.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
PIV
specklegram
velocity fields
particle trajectory
Opis:
The author has applied the laser sheet technique to acquire velocity fields and mass flows at the outlet of nozzle system, used for introducing limestone particles into a power boiler for a desulfurization process. This brings an effect in the form of multiexposure pictures, called specklegrams, which record single particle trajectories or their agglomerates in selected areas of the flow. On the basis of this the parameters of velocity field can be estimated. The author proposes a new approach to quantitative analysis of the specklegrams. It enables one to combine correlation processing with scanline particle tracking.
Zastosowanie techniki noża świetlnego w analizie trójwymiarowych pól prędkości ziaren. Autor zastosował technikę noża świetlnego do rejestracji pól prędkości i przepływów masowych przy wylocie dyszy służącej do wprowadzania sorbentu wapniowego do kotła energetycznego w procesie odsiarczania spalin. Efektem są wieloekspozycyjne obrazy zwane speklogramami, rejestrujące pojedyńcze tory cząstek lub ich aglomeratów w wybranych strefach przepływu. Na tej podstawie oszacować można parametry pola prędkości. Analiza jakościowa speklogramów może zostać przeprowadzona za pomocą zaproponowanego przez autra algorytmu, będącego połączeniem tradycyjnychmetod korelacyjnych oraz techniki obrotowej linii skanującej.
Źródło:
Journal of Theoretical and Applied Mechanics; 2001, 39, 1; 33-49
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasonic Properties of Magnetic Nanoparticles with an Additional Biocompatible Dextrane Layer
Autorzy:
Dąbek, L.
Hornowski, T.
Józefczak, A.
Skumiel, A.
Powiązania:
https://bibliotekanauki.pl/articles/176605.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetic nanoparticles
ultrasound
particle size distribution
Opis:
The temperature dependence of the particle size distribution (PSD) of the magnetic fluid with an additional biocompatible dextran layer was studied using a ultrasonic method. The measurements of the ultrasound velocity and attenuation were carried out as a function of the volume concentration of magnetite particles at temperatures ranging from 15°C to 40°C. In order to extract the PSD from ultrasonic measurements, the theoretical model of Vinogradov-Isakovich was used. The extraction of PSD from the ultrasonic data requires also the measurements the density and viscosity of the ferrofluid samples. The calculated PSD of the magnetic fluid with an additional biocompatible layer shows a greater thermal stability than that of a magnetic fluid with a single surfactant layer.
Źródło:
Archives of Acoustics; 2013, 38, 1; 93-98
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Consolidation and Characterisation of Hard Metal Powders Milled under Dichloromethane
Autorzy:
Chicinaș, Horea
Jucan, Ovidiu-Darius
Gădălean, Rares Vasile
Conțiu, Glad
Cotai, Ana
Popa, Catalin
Powiązania:
https://bibliotekanauki.pl/articles/2106588.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hard metal
sintering
milling
particle
dichloromethane
Opis:
This work presents the development of a safer processing route for hard metals. Traditional processing of fine particles under organic solvents presents significant explosion risks. The milling under dichloromethane (DCM) reduces the risks associated with fire hazards. After milling and drying, the samples have been sintered in an industrial sintering furnace under a vacuum at 1380°C. The materials’ characterisation has been done by X-ray diffraction, scanning electron microscopy, particle size analysis, optical microscopy, and by magnetic measurements. The present work results reveal the powders’ appropriate properties after milling and drying and the desired biphasic (Co-WC) phases obtained after sintering, thus proving the feasibility of such a route, therefore the diminishing of specific fire hazards.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 2; 541--545
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First-order and second-order breakage rate of coarse particles in ball mill grinding
Autorzy:
Barani, K.
Balochi, H.
Powiązania:
https://bibliotekanauki.pl/articles/109734.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ball mill
grinding kinetic
particle breakage
Opis:
It has been observed by many authors that the breakage rates of coarse particles in a ball mill slow down with increasing grinding time and deviate from the first order. In this paper it is intended to find out whether the breakage rates of coarse particles obey second-order kinetics or not. For this purpose, quartz, limestone, iron ore and a mixture of quartz/limestone (weight ratio of 1:1) were selected as a ball mill feed. The first-order breakage rate was determined for the four particle sizes of quartz, limestone, iron ore and the mixture of quartz/limestone. Results indicating good first-order kinetics were obtained with the fine-sized particles (-1.2+1 mm, -0.6+0.42 mm). However, the coarse-sized particles (-5+4 mm, -3.15+2.5 mm) showed deviations from the first order. These coarse particles were in the abnormal breakage region. The second-order breakage rate was determined for the coarse particles (-5+4 mm, -3.15+2.5 mm). It can be seen that, for both sizes and all the materials, the second-order plot had better fit than the first-order plot. Also, it can be concluded that the second-order kinetics could model the breakage of coarse particles better than the first-order kinetics, and the validity of the second-order breakage rate was increased with increasing particle size. However, it is suggested to examine the validity of the second-order breakage rate kinetics for other materials and particle sizes.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 268-278
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of intergrown particle liberation on difficult-to-separate coking coal flotation
Autorzy:
Gui, X.
Liu, J.
Cao, Y.
Xing, Y.
Deng, Y.
Li, S.
Powiązania:
https://bibliotekanauki.pl/articles/109875.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
liberation
particle size
coking coal
hydrophobicity
Opis:
Flotation tests with intergrown particle liberation were conducted to explore a separation method of difficult-to-separate coking coal from the Tangshan Kailuan mine in China. The particle size distribution, density and coal petrography were investigated. The difficult-to-separate coking coal sample resulted in intergrown particles, such as non-liberated coal and rocks. Thus, intergrown coal particle liberation and re-separation tests were conducted. The results showed that grinding time had a great effect on the flotation performance. Grinding prompted coal to dissociate and improve the surface hydrophobic properties of minerals. However, heterogeneous fine silt covered the surface of coal particles when coal was ground too long. The inorganic mineral particles were over-ground and reduced the contact angle of coal. The results of coal rock dissociation and laboratory re-separation tests showed that clean coal combustible recovery increased through intergrown particle liberation and re-separation.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 279-294
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of operating pressure and stand-off distance on coal comminution by waterjet
Autorzy:
Li, Y.
Galecki, G.
Şen, G. A.
Şen, S.
Powiązania:
https://bibliotekanauki.pl/articles/110840.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal
waterjet
comminution
particle size distribution
Opis:
Comminution of coal to ultrafine sizes by high-pressure waterjet coupled with cavitation cell provides a novel method for preparation of coal-water fuels for next generation, near-zero emission electric power generation. To establish the fundamental performance of the waterjet mill, the effects of the operating pressure and stand-off distance were comprehensively investigated using a high ash bituminous coal. The comminution products were evaluated in terms of the particle size, particle size distribution, and surface area change. The experimental results indicated that the waterjet-mediated comminution of coal was strongly affected by all these operating parameters. Higher operating pressure led to finer products, while the efficiency of the waterjet mill in terms of particle size strongly depended on the stand-off distance. This research provides a deeper insight into the high-pressure waterjet for coal comminution and a basis for process parameter optimization.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 394-401
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum mechanics of identical particles
Autorzy:
Kuś, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2140652.pdf
Data publikacji:
2022-11-08
Wydawca:
Copernicus Center Press
Tematy:
quantum identical particle
indiscernibility
Leibniz Principle
Opis:
Leibniz’s principium identitatis indiscernibilium excludes the existence of two different objects possessing all properties identical. Although perfectly acceptable for macroscopic systems, it becomes questionable in quantum mechanics, where the concept of identical particles is quite natural and has measurable consequences. On the other hand, Leibniz’s principle seems to be indispensable when we want to individuate an item and ascribe to it particular property (e.g. value of the projection of spin on a chosen axis). We may thus abandon the principle on the quantum level, claiming it falsity here, or (better) try to find other ways of individuation of objects, possibly by adopting appropriately the very concept of it. All these problems, and many other connected with identity and indiscernibility of quantum objects, are thoroughly discussed in the book of Tomasz Bigaj, unique in the world literature due to its comprehensiveness.
Źródło:
Zagadnienia Filozoficzne w Nauce; 2022, 72; 169-178
0867-8286
2451-0602
Pojawia się w:
Zagadnienia Filozoficzne w Nauce
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Funkcje partykuły „no” w dziecięcych wypowiedziach mówionych
The Functions of the Polish Particle no*29 in Children’s Spoken Utterances
Autorzy:
Matuszewska, Izabela
Powiązania:
https://bibliotekanauki.pl/articles/1045454.pdf
Data publikacji:
2014-01-01
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
functions of the particle “no”
particle “no”
child’s speech
children’s speech
frequency of particles
frequency of the particle “no” in children’s utterances
Opis:
It was important for the study to determine the frequency of the analysed part of speech. As a result of investigation of the linguistic material it has been demonstrated that nowadays the particles constitute 12.8% of the wordforms used by children. The particle no represented 2.2% of the total of used words. The obtained results have been compared with the data collected during similar research, which was completed thirty years ago (7.5% – all particles, 1.6% – the particle no). On the basis of a comprehensive analysis and the comparison of research results, it can be concluded that in the contemporary spoken Polish of children there occurred a visible increase in the use of particles. This, in turn, may be a symptom of the impoverishment of the Polish language.
Źródło:
Poznańskie Studia Polonistyczne. Seria Językoznawcza; 2014, 21, 1; 151-167
1233-8672
2450-4939
Pojawia się w:
Poznańskie Studia Polonistyczne. Seria Językoznawcza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Particle-in-Cell electrostatic numerical algorithm
Algorytm numeryczny Particle-in-Cell dla problemu elektrostatycznego
Autorzy:
Konior, W.
Powiązania:
https://bibliotekanauki.pl/articles/212864.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
plasma
neutral particles
Particle-In-Cell
Monte-Carlo method
plazma
heliosfera
Particle-in-Cell
Monte-Carlo
Opis:
Existing global models of interaction between the solar wind (SW) and the local interstellar medium (LISM) describe the heliosphere that arises as a result of this interaction. There is a strong motivation to develop a kinetic model using the Particle-in-Cell (PIC) method to describe phenomena which appear in the heliosphere. This is however a long term scientific goal. This paper describes an electrostatic Particle-in-Cell numerical model developed in the Institute of Aviation in Warsaw, winch includes mechanical and charge exchange collisions between particles in the probabilistic manner using Direct Simulation Monte Carlo method. This is the first step into developing simulations of the heliosphere incorporating kinetic effects in collisionless plasmas. In this paper we focus only on presenting the work, which have been done on the numerical PIC algorithm.
Istniejące globalne modele oddziaływania wiatru słonecznego (SW) z lokalną materią międzygwiazdową (LISM) opisują heliosferę, która powstaje w wyniku interakcji tych dwóch ośrodków. Istnieje silna motywacja do opracowania modelu kinetycznego wykorzystującego metodę Particle-in-Cell (PIC) w celu opisu zjawisk, które zachodzą w heliosferze. Jednakże jest to długoterrninowy cel naukowy. W artykule przedstawiono elektrostatyczny model numeryczny PIC. opracowany w Instytucie Lotnictwa w Warszawie, który obejmuj e kolizje mechaniczne i rezonansową wymianę ładunków pomiędzy cząstkami w sposób probabilistyczny metodą Direct Simulation Monte Carlo. Jest to pierwszy krok w opracowywaniu symulacji heliosfery zawierającej efekty kinetyczne w plazmach bezzderzeniowych. W tym artykule koncentrujemy się tylko na prezentowaniu prac, które zostały wykonane z wykorzystaniem algorytmu numerycznego PIC.
Źródło:
Prace Instytutu Lotnictwa; 2017, 3 (248); 24-45
0509-6669
2300-5408
Pojawia się w:
Prace Instytutu Lotnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie parametrów cząstek stałych z samochodów osobowych w rzeczywistych warunkach ruchu
Modeling of particulate matter parameters for passenger cars under real traffic conditions
Autorzy:
Pielecha, J.
Merkisz, J.
Powiązania:
https://bibliotekanauki.pl/articles/133631.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
masa cząstek stałych
liczba cząstek stałych
rzeczywiste warunki ruchu
particle mass
particle number
real traffic conditions
Opis:
W artykule wyznaczono modele masy, liczby i średnicy cząstek stałych emitowanych z pojazdów wyposażonych w silniki o zapłonie samoczynnym. Przedstawiono nowe możliwości wykorzystania wartości charakteryzujących warunki ruchu pojazdu do identyfikacji parametrów cząstek stałych. Do opisu warunków pracy pojazdu wykorzystano dwuwymiarowe histogramy, które ujmują wartości prędkości i przyspieszenia pojazdu oraz czasu jego pracy w rzeczywistych warunkach ruchu. Wynikiem tych działań jest propozycja modeli matematycznych opisujących podstawowe właściwości cząstek stałych (ich masę, liczbę i średnicę) w różnych warunkach pracy samochodów osobowych. Tworzone modele parametrów cząstek stałych wykorzystujące parametry wejściowe uzyskane w warunkach dynamicznych potraktowano priorytetowo. Badania takie, niewykonywane dotychczas, wykonano dla pojazdów lekkich, a następnie dowiedziono poprawności uzyskanych modeli parametrów cząstek stałych przez weryfikację, do której wykorzystano inne pojazdy niż użyte do tworzenia odpowiednich modeli.
In the paper models of mass, number and diameters of particulate matter generated by vehicles fitted with diesel engines have been determined. The author presents new possibilities of application of the values characterizing the vehicle traffic conditions for the identification of the particulate matter parameters. For the description of the vehicle operating conditions two-dimensional histograms have been used that include the values of vehicle speed and acceleration and its time of operation under actual traffic conditions. The result of these actions is the proposal of mathematical models describing the basic properties of particulate matter (its mass, number and diameters) under different operating conditions of passenger vehicles. The created models of particulate matter parameters using the input parameters obtained in the dynamic conditions have been treated with priority. Such research, a pioneer one to date, has been carried out for light duty vehicles and then the correctness of the obtained models has been confirmed of the particulate matter parameters by a validation on vehicles other than those used for the creation of the models.
Źródło:
Combustion Engines; 2013, 52, 3; 232-242
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stable Bose-Einstein correlations
Autorzy:
Csörgo, T.
Hegyi, S.
Zajc, W.
Powiązania:
https://bibliotekanauki.pl/articles/147334.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
particle correlations
Bose-Einstein correlations
HBT
Lévy distributions
multiparticle production in high energy particle and nuclear physics
Opis:
The shape of Bose-Einstein (or HBT) correlation functions is determined for the case when particles are emitted from a stable source, obtained after convolutions of large number of elementary random processes. The two-particle correlation function is shown to have a stretched exponential shape, characterized by the Lévy index of stability 0 < alfa less-than or equal to 2 and the scale parameter R. The normal, Gaussian shape corresponds to a particular case, when alfa = 2 is selected. The asymmetry parameter of the stable source, beta is shown to be proportional to the angle, measured by the normalized three-particle cumulant correlations.
Źródło:
Nukleonika; 2004, 49,suppl.2; 7-10
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
DPF retrofit program in Israel – effects of diesel particle filters on performance of in-use buses
Autorzy:
Tartakovsky, L.
Fleischmann, R.
Powiązania:
https://bibliotekanauki.pl/articles/132839.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
particle emissions
diesel particle filter
heavy-duty vehicle
DPF retrofit
emisja cząstek
filtr cząstek stałych
pojazdy ciężarowe
Opis:
A long service life of heavy-duty diesel vehicles results in a large number of older-technology trucks and buses of various types running on roads nowadays. Cleaning up exhaust gases of these older vehicles gives an opportunity to improve air quality at affordable costs. Retrofitting older buses with diesel particulate filters (DPF) is a cost-effective measure to quickly and efficiently reduce particulate matter (PM) emissions and contribute to mitigation of air pollution in urban conglomerates. In this paper, the milestones on a way to wide-scale retrofitting of heavy-duty vehicles with DPF are discussed on the example of Israel DPF retrofit program. Crucial importance of a balanced governmental approach combining regulation and economic incentives, together with collaboration of government, academia and vehicle operators, is underlined. Main results of the one-year pilot project focused on urban and intercity buses are discussed. Impact of DPF retrofitting on particulate emissions and engine performance and maintenance aspects of in-use diesel buses is analyzed. Very high particle filtration efficiency (in average, about 97%) together with relatively low fuel economy penalty (0.6–1.8%, depending on the bus type) are proved. Vital importance of careful monitoring and correct maintenance of DPF-equipped vehicles is underlined.
Źródło:
Combustion Engines; 2017, 56, 3; 176-178
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A hybrid PSO approach for solving non-convex optimization problems
Autorzy:
Ganesan, T.
Vasant, P.
Elamvazuthy, I.
Powiązania:
https://bibliotekanauki.pl/articles/229756.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Kuhn-Tucker conditions (KT)
non-convex optimization
particle swarm optimization (PSO)
semi-classical particle swarm optimization (SPSO)
Opis:
The aim of this paper is to propose an improved particle swarm optimization (PSO) procedure for non-convex optimization problems. This approach embeds classical methods which are the Kuhn-Tucker (KT) conditions and the Hessian matrix into the fitness function. This generates a semi-classical PSO algorithm (SPSO). The classical component improves the PSO method in terms of its capacity to search for optimal solutions in non-convex scenarios. In this work, the development and the testing of the refined the SPSO algorithm was carried out. The SPSO algorithm was tested against two engineering design problems which were; ‘optimization of the design of a pressure vessel’ (P1) and the ‘optimization of the design of a tension/compression spring’ (P2). The computational performance of the SPSO algorithm was then compared against the modified particle swarm optimization (PSO) algorithm of previous work on the same engineering problems. Comparative studies and analysis were then carried out based on the optimized results. It was observed that the SPSO provides a better minimum with a higher quality constraint satisfaction as compared to the PSO approach in the previous work.
Źródło:
Archives of Control Sciences; 2012, 22, 1; 87-105
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
LES of turbulent channel flow and heavy particle dispersion
Zastosowanie metody dużych wirów do przepływu turbulentnego w kanale i dyspersji cząstek
Autorzy:
Pozorski, J.
Wacławczyk, T.
Łuniewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/279209.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
turbulent flow
large eddy simulation
particle dispersion
Opis:
The Eulerian-Lagrangian approach has been applied to two-phase turbulent flows with dispersed heavy particles. First, numerical computations of the continuous phase (fluid) have been performed using the Direct Numerical Simulations (DNS) and Large-Eddy Simulations (LES) for the case of a fully-developed channel flow. Parallelisation efficiency of flow and particle solvers has been estimated. Residual turbulent kinetic energy has been found from filtered DNS (also called a priori LES); a model for this quantity has been assessed. Then, heavy particles have been tracked in the LES velocity field. Statistics of particle motion (mean velocity, intensity of velocity fluctuations) and the profile of cross-stream number density as well as preliminary results for particle wall deposition have been obtained.
W pracy zastosowano podejście Eulera-Lagrange'a do wyznaczenia ruchu fazy dyspersyjnej (cząstki, krople) w turbulentnym przepływie dwufazowym. Obliczenia ruchu fazy ciągłej (płynu) przeprowadzono za pomocą rozwiązania pełnych równań przepływu (DNS) oraz przy użyciu metody dużych wirów (LES) dla przypadku rozwiniętego przepływu w kanale płaskim. Oszacowano efektywność zrównoleglenia obliczeń numerycznych. Określono poziom energii kinetycznej skal podsiatkowych; porównano ją z wynikami uzyskanymi z modelu dynamicznego. Wyznaczono trajektorie cząstek fazy dyspersyjnej w polu prędkości LES. Określono statystyki ich ruchu: prędkość średnią, intensywność fluktuacji prędkości, profil koncentracji cząstek w poprzek kanału; uzyskano wstępne wyniki dla separacji cząstek na ściankach.
Źródło:
Journal of Theoretical and Applied Mechanics; 2007, 45, 3; 643-657
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on the rheological properties of CL-20/HTPB casting explosives
Autorzy:
Li, H.-X..
Wang, J-Y.
An, C.-W.
Powiązania:
https://bibliotekanauki.pl/articles/358310.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
casting explosive
particle gradation
rheological properties
plasticizer
Opis:
The rheological properties of ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12hexaazaisowurtzitane (CL-20)/hydroxy-terminated polybutadiene (HTPB) casting explosives with different formulations were tested and analyzed. The effects of both the weight percentage (wt.%) of CL-20 and its particle size, as well as the type and content of plasticizers, on the rheological properties of CL-20/HTPB casting explosives were investigated in detail. The results show that the viscosity and pseudoplasticity of CL-20/HTPB casting explosives increase with increasing wt.% of CL-20 and decreasing particle size. The gradation of CL-20 particle size also affects the rheological properties of the casting explosives. When the mixing ratio of 30 μm to 2 μm particles is 3:1, the viscosity reaches its lowest value and the non-Newtonian index reaches the maximum value of 0.5698. The viscosity, non-Newtonian index and impact sensitivity of the samples studied are clearly decreased by the addition of dioctyl adipate (DOA), dioctyl sebacate (DOS) or dibutyl phthalate (DBP). However, the three plasticizers do not appear to affect the thermal decomposition of CL-20/HTPB casting explosives. With respect to the rheological properties, mechanical properties and sensitivity, DOA is the optimum plasticizer to use in CL-20/HTPB casting explosives.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 2; 237-255
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Syntax Phonology Interface of Mood Particles in Mandarin Chinese
Autorzy:
Daoshan, Ma
Powiązania:
https://bibliotekanauki.pl/articles/1030966.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Mood particle
externalization
sentence affix
syntactic position
Opis:
The present thesis focuses on the syntactic study of the position of mood particles in Mandarin Chinese. The most popular mood particles in Mandarin Chinese are six: “ne”, “a”, “ma”, “ba”, “le” and “de”, used at the end of the sentences, traditionally believed to denote interrogative, declarative, imperative, and exclamative moods. This thesis argues that the mood particles don’t carry any lexical meanings themselves, and as sentence affixes, they are adjoined to the head complementizer at the end of the sentence in head final language of Chinese at the sensorimotor interface after the spellout in PF level. Therefore, mood particles are not computed in the internal grammar but in the externalization process of the computation.
Źródło:
World Scientific News; 2020, 145; 313-325
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations upon roughness of particleboard surfaces after manual sanding
Badania chropowatości powierzchni płyt wiórowych szlifowanych manualnie
Autorzy:
Proszyk, S.
Fiszbach, K.
Pinkowski, G.
Powiązania:
https://bibliotekanauki.pl/articles/8767.pdf
Data publikacji:
2014
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
investigation
roughness
particle board
surface
manual sanding
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2014, 87
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of bubble-particle interactions in a column flotation process
Autorzy:
Cheng, G.
Shi, C.
Yan, X.
Zhang, Z.
Xu, H.
Lu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/109635.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle
bubble
column flotation
collision
attachment
detachment
Opis:
Bubble-particle interactions play an important role in flotation. This study examines the behaviour of bubble clusters in a turbulent flotation cell. Particularly, the bubble-particle interaction characteristics in flotation are investigated. The bubble size in a flotation column was measured using an Olympus i-SPEED 3 high-speed camera. Relationships between the circulating volume, bubble size and bubble terminal velocity were discussed. Probabilities of collision, attachment, detachment and acquisition between bubbles and particles in different circulating volumes were calculated based on the flotation kinetic theory. Using the extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theory, the relationship between the potential energy and distance in bubble-particle interaction was analysed. The results demonstrated that as the circulating volume increased, the bubble size and velocity decreased. When the circulating volume increased from 0.253 to 0.495 m3/h, the bubble diameter decreased from 511 to 462 μm, and the corresponding bubble velocity decreased from 43.1 to 37.5 mm/s. When the circulating volume remained constant as the particle size increased, probabilities of collision, attachment, detachment and acquisition increased. When the particle size remained constant as the circulating volume increased, these probabilities also increased. At a constant circulating volume as the particle size increased, the absolute value of the total potential energy between the particle and bubble increased. When the distance between the bubble and particle was 30 nm, the energy barrier appeared.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 17-33
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Micro-Particle Image Velocimetry for imaging flows in passive microfluidic mixers
Autorzy:
Witkowski, D.
Kubicki, W.
Dziuban, J. A.
Jašíková, D.
Karczemska, A.
Powiązania:
https://bibliotekanauki.pl/articles/221227.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
micro-Particle Image Velocimetry
microfluidics
microfluidic devices
Opis:
The micro-Particle Image Velocimetry (micro-PIV) was used to measure flow velocities in micro-channels in two passive micromixers: a microfluidic Venturi mixer and a microfluidic spiral mixer, both preceded by standard “Y” micromixers. The micro-devices were made of borosilicate glass, with micro-engineering techniques dedicated to micro-PIV measurements. The obtained velocity profiles show differences in the flow structure in both cases. The micro-PIV enables understanding the micro-flow phenomena and can help to increase reproducibility of micromixers in mass production.
Źródło:
Metrology and Measurement Systems; 2018, 25, 3; 441-450
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation, characterization and rheological behavior of chitosan nanocapsule emulsion encapsulated tuberose fragrance
Autorzy:
Xiao, Z.
Wang, E.
Zhu, G.
Zhou, R.
Niu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/778241.pdf
Data publikacji:
2016
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
chitosan nanocapsules
encapsulation
rheological
viscoelasticity
particle size
Opis:
In this paper, ionic gelation method was adopted to produce nanocapsules (CNs) encapsulated tuberose fragrance with chitosan (CS) and sodium tripolyphosphate (TPP) as wall materials. The effects of CS/TPP mass ratio, pH value of CS solution, molecular mass of CS and tuberose fragrance (TF) concentration on particle size and particle size distribution (PDI) of chitosan nanocapsules encapsulated tuberose fragrance (CNTs) were investigated systematically. CNTs were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analyzer (TGA) and differential scanning calorimetry (DSC). The results showed that CNTs were successfully prepared. The optimum preparation conditions were as follows: CS/TPP mass ratio 5:1, pH of CS solution 4.0, and molecular mass of CS 150 kda. CNTs emulsions were also systematically investigated by steady-state shear and oscillatory shear measurements respectively. The rheological behaviors of CNTs were obtained.
Źródło:
Polish Journal of Chemical Technology; 2016, 18, 2; 1-8
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wrong transition and measurement models in power system state estimation
Autorzy:
Kozierski, P.
Lis, M.
Horla, D.
Powiązania:
https://bibliotekanauki.pl/articles/141129.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
particle filter
estimation quality
Population Monte Carlo
Opis:
The influence of wrong information about transition and measurement models on estimation quality has been presented in the paper. Two methods of a particle filter, with and without the Population Monte Carlo modification, and also the extended and unscented Kalman filters methods have been compared. A small 5-bus power system has been used in simulations, which have been performed based on one data set, and this data set has been chosen from among 100 different – to draw the most general conclusions. Based on the obtained results it has been found that for the particle filter methods the implementation of the slightly higher standard deviation than the true value, usually increases the estimation quality. For the Kalman filters methods it has been concluded that optimal values of variances are equal to the true values.
Źródło:
Archives of Electrical Engineering; 2016, 65, 3; 559-574
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An extension to the Rayleigh–Gans formula: model of partially absorbing particles
Autorzy:
Komar, L
Kocifaj, M
Kohut, I
Powiązania:
https://bibliotekanauki.pl/articles/173693.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
scattering
absorption
spherical particle
Rayleigh-Gans approximation
Opis:
The Rayleigh–Gans (R–G) approximation is widely employed in various optical models to simulate the optical response of transparent media. However, the R–G concept can only succeed if the refractive index of scatterers approaches that of surrounding medium. In addition, the sizes of scattering domains are assumed to be small enough. Because of these reasons, the validity of R–G solution is fairly limited. In this paper, a semi-analytical extension to the R–G theory is introduced, resulting in an approximate formula for efficiency factor for scattering Qsca. It is proven numerically that this formula works much better than that for traditional R–G model. The computations have been made on absorbing particles with sizes comparable to or smaller than the wavelength of an incident radiation. The conventional R–G theory is either inapplicable or at least inappropriate for such particles.
Źródło:
Optica Applicata; 2013, 43, 2; 313-323
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The dynamics of the human arm with an observer for the capture of body motion parameters
Autorzy:
Babiarz, A.
Bieda, R.
Jaskot, K.
Klamka, J.
Powiązania:
https://bibliotekanauki.pl/articles/201899.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
human arm
observability
Kalman filter
particle filter
Opis:
The paper presents an analysis of a mathematical model of the human arm dynamics in terms of observability. The purpose of the performed experiments is the selection of an observer for the possibility of arm tracking. The arm model is based on the two-link manipulator moving horizontally and vertically. For the study a model was linearized and the model part responsible for the work of human muscles was omitted. The experimental part involved simulated measurements of the motion parameters that imitate real-IMU (Inertial Measurement Unit) measurements. Finally, the simulation results using the observer in the form of a Kalman filter and the particle filter have been presented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 4; 955-971
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of yttrium citrate by the reaction of yttrium hydroxide with sodium citrate
Autorzy:
Janusz, Władysław
Skwarek, Ewa
Sternik, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/1450116.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
yttrium citrate synthesis
CHN
TGA
particle size
Opis:
A method of obtaining yttrium citrate by transformation of freshly precipitated yttrium hydroxide in the solutions of sodium citrate under hydrothermal conditions has been proposed. To determine the synthesis time, transformation kinetics consisted in by taking the solid samples for the C and H contents analysis after 6, 12, 24, 48 and 72 hours of synthesis. Simultaneously these samples were subjected to the thermogravimetric analysis. As follows from the thermogravimetric analysis adsorption of citrate dihydrate on yttrium hydroxide is observed in the initial period up to 24 hours. Later the yttrium citrate dihydrate is formed. The thermogravimetric analysis of the final product i.e. amorphous yttrium citrate showed that the decomposition/oxidation of the sample occurs in six stages the particle size analysis method of static light scattering showed that 45% of the particles had a diameter of 0.1-0.9 µm and 55% of particles with sizes from 0.9 to 5 µm.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 6; 51--59
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ARIES 2018 : infrastructure, innovation, outreach
Autorzy:
Romaniuk, Ryszard S.
Powiązania:
https://bibliotekanauki.pl/articles/226770.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
particle accelerators
accelerator science and technology
novel accelerators
high field magnets
superconducting magnets
RF particle guns
particle detectors
high energy physics
applications of particle accelerators
laser and plasma accelerators
community and social implications of ARIES
EC Integrating Introduction
Opis:
This article has two outreach aims. It concisely summarizes the main research and technical efforts in the EC H2020 ARIES Integrating Activity – Accelerator Research and Innovation for European Science and Society [1] during the period 2017/2018. ARIES is a continuation of CARE, TIARA and EuCARD projects [2-3]. The article also tries to show these results as an encouragement for local physics and engineering, research and technical communities to participate actively in such important European projects. According to the author’s opinion this participation may be much bigger [4-27]. All the needed components to participate – human, material and infrastructural are there [4,7]. So why the results are not satisfying as they should be? The major research subjects of ARIES are: new methods of particles acceleration including laser, plasma and particle beam interactions, new materials and accelerator components, building new generations of accelerators, energy efficiency and management of large accelerator systems, innovative superconducting magnets, high field and ultra-high gradient magnets, cost lowering, system miniaturization, promotion of innovation originating from accelerator research, industrial applications, and societal implications. Two institutions from Poland participate in ARIES – these are Warsaw University of Technology and Institute of Nuclear Chemistry and Technology in Warsaw. There are not present some of the key institutes active in accelerator technology in Poland. Let this article be a small contribution why Poland, a country of such big research potential, contributes so modestly to the European accelerator infrastructural projects? The article bases on public and internal documents of ARIES project, including the EU Grant Agreement and P1 report. The views presented in the paper are only by the author and not necessarily by the ARIES.
Źródło:
International Journal of Electronics and Telecommunications; 2019, 65, 1; 119-124
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sequential extraction of uranium isotopes in sediments from an estuary historically affected by anthropogenic inputs of natural radionuclides
Sekwencyjna ekstrakcja izotopów uranu z osadów estuariowych, skażonych naturalnymi izotopami promieniotwórczymi pochodzenia antropogenicznego
Autorzy:
Aguadol, J.
Bolivar, J.
Garcia-Tenorio, R.
Powiązania:
https://bibliotekanauki.pl/articles/340210.pdf
Data publikacji:
2004
Wydawca:
Główny Instytut Górnictwa
Tematy:
izotopy uranu
spektrometria alfa
specjacja
osady
TENORM
U-isotopes
α-particle spectrometry
alpha-particle spectrometry
speciation
sediments
Źródło:
Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa; 2004, 1; 64-64
1643-7608
Pojawia się w:
Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mach’s Principle and Particle-antiparticle pairs: A Heuristic Stable Wormhole Mechanism for Swift Dynamics in Spacetime, Non-locality and Time Travel
Autorzy:
Kabe, Koustubh
Powiązania:
https://bibliotekanauki.pl/articles/1190209.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Mach’s principle
non-classical spacetimes
particle-antiparticle pairs
wormholes
spacetime quantum tunneling
quantum particle dynamics
non-locality
Opis:
The following paper is purely hypothetical in nature in that it is based on pure hypothesis and mathematical physics. The effect of Mach’s principle on the quantum regime has been studied especially with reference to the quantum mechanical vacuum and the Hawking radiation. A new concept of history dependent “energy reservoir” has been introduced as a consequence of Mach’s principle and associated with every free quantum particle-antiparticle pairs, based on Feynman’s idea of sum over histories of a particle and application of Mach’s principle to the quantum regime. A new H-field-anti-H-field has been associated with this reservoir that is shown to have a repulsive gravitational effect. It is in principal possible that these fields constructs a wormhole in spacetime taken as a (non-)classical one. This is in accord with the fact that wormholes cannot be constructed by classical means for all observable matter with positive energy. The large distance traversed by a particle in curved space in a very short time scale has been treated as a barrier penetration problem. The tunnel effect is produced by the associated H-field via the wormhole mechanism. An expression has been derived for the transmission coefficient for the potential (distance) barrier. The time scale of travel from one event situated to another event situated , where is very large, being very small, to any stationary or inertial observer in his proper frame the particle will appear to travel with velocities ( being the velocity of light in vacuo space). From this it implicitly follows that the particle will have traveled from a time co-ordinate corresponding to to another time co-ordinate corresponding to the co-ordinate i.e. the particle will appear to have violated causality of spacetime and traveled in time.
Źródło:
World Scientific News; 2016, 44; 168-180
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of UF molar ration selected particleboard properties
Wpływ stosunku molowego żywicy UF na wybrane właściwości płyt wiórowych
Autorzy:
Frackowiak, I.
Warcok, F.
Fuczek, D.
Andrzejak, C.
Powiązania:
https://bibliotekanauki.pl/articles/52601.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
particle board property
particle board
formaldehyde content
formaldehyde emission
urea-formaldehyde resin zob.UF resin
resin
UF resin
Opis:
This paper presents the preliminary research results of a project whose main objective is to quantify the impact of formulations and technological parameters on formaldehyde content in and emission from particleboards produced using urea-formaldehyde resin with a low molar ratio of F/U. The formaldehyde content reduction is possible by using a resin with a molar ratio of F/U of 1.065 hardened with 3% solution of urea and ammonium nitrate or a resin with a molar ratio of F/U of 0.96 to which 3% urea was added. For these variants, reductions by 22% and 21% respectively of formaldehyde content in particleboards were obtained, while at the same time, strength properties that meet the requirements of the EN-312: 2011 standard for P2 particleboards were maintained.
Przedstawiono wyniki badań pierwszego etapu projektu, którego głównym założeniem jest próba kwantyfikacji wpływu receptur i parametrów technologicznych na zawartość i emisję formaldehydu z płyt wiórowych wytwarzanych z zastosowaniem żywicy mocznikowo- formaldehydowej o niskim stosunku molowym F/U. Spośród przeprowadzonych badań wybrano dwa optymalne warianty. Pierwszy dotyczy żywicy o stosunku molowym F/U 1,065 utwardzanej roztworem saletrzano-mocznikowym w ilości 3%, drugi żywicy o stosunku molowym F/U 0,96 utwardzanej azotanem amonu dodanego w ilości 2% w stosunku do suchej masy kleju, do której dodano 3% mocznika. W obydwu wariantach uzyskano obniżenie zawartości formaldehydu w płycie odpowiednio o 22% oraz 21% przy jednoczesnym zachowaniu właściwości wytrzymałościowych spełniających wymagania normy EN-312: 2011 dla płyt wiórowych klasy P2.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2011, 54, 186
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation of the influence of explosive welding process setup on the Ti/Cu interlayer morphology
Autorzy:
Mojżeszko, Mateusz
Setty, Mohan
Powiązania:
https://bibliotekanauki.pl/articles/29520271.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
explosive welding
meshless model
smoothed particle hydrodynamics
Opis:
Explosive welding is a complex process involving various phenomena influenced by a series of parameters in a noticeably short span of time which affect the morphology and eventually the quality of the weld. Therefore, this paper aims to investigate the influence of these parameters on material behavior with a series of numerical simulations based on a meshless approach. The developed model is based on the SPH (Smoothed Particle Hydrodynamics) method and is used to investigate Ti/Cu system behavior as a case study. Examples of the resulting temperatures and pressures as a function of process setup are presented within the paper. The results obtained demonstrate how weld morphology is related to the process conditions.
Źródło:
Computer Methods in Materials Science; 2020, 20, 3; 113-120
2720-4081
2720-3948
Pojawia się w:
Computer Methods in Materials Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of air pollution with dust in the Ouenza iron mine – NE Algeria
Autorzy:
Abederahmane, N.
Khochemane, L.
Gadri, L.
Rais, K.
Bennis, O.
Powiązania:
https://bibliotekanauki.pl/articles/88990.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Tematy:
particle deposition
emissions
modeling
concentration model
dispersion
Opis:
Dust generation and its dispersion has been the major concern in ambient air quality in mines. This paper focuses on generation and dispersion of particles during mining operations. Atmospheric pollution in mines areas of Ouenza has become a serious problem. The goal of this study is therefore to review the air pollutants of the approach by discussing studies applying mass conservation model methods. To support these theoretical calculations, field measurements will be performed to determine the air quality in the region concerned and to develop a program to prevent excessive air pollution that threatens human health and the environment. For the treatment of the results, we used regression analysis, assuming that the relationship between the pollutant concentration Ci and weight of various Pi sampling stations in the mine of Ouenza is a straight line following a linear tendency. Validation of the results from this study for urban air pollution would be highly beneficial.
Źródło:
Mining Science; 2018, 25; 19-31
2300-9586
2353-5423
Pojawia się w:
Mining Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of capacitance of a cryogenic by-pass line for SIS100 particle accelerator at FAIR
Autorzy:
Tomków, Ł.
Trojanowski, S.
Ciszek, M.
Chorowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/140368.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
line capacitance
superconducting bus-bars
particle accelerators
Opis:
Safety and operation efficiency of the particle accelerators strongly depend on the quality of the supplied electric current and is affected by the electric properties of all elements of the circuit. In this paper the capacitance of the superconducting bus-bars applied in the cryogenic by-pass line for the SIS100 particle accelerator at FAIR is analysed. The unit capacitance of the bus-bars is calculated numerically and found experimentally. A 2D numerical model of a cross-section of the cable is applied. The capacitance is found with three methods. The stored energy, electric displacement field and charge gathered on the surfaces of the device are calculated and analysed. The obtained values are consistent. Experimental measurements are performed using the resonance method. The measuring system is undamped using a negative conductance converter. Small discrepancies are observed between numerical and experimental results. The obtained values are within the requirements of the accelerator design.
Źródło:
Archives of Electrical Engineering; 2018, 67, 4; 803-814
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on stability of emulsions containing carotenoids
Autorzy:
Igielska-Kalwat, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/1038379.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
carotenoids
particle size
semisolid formulations
stability studies
Opis:
Emulsions are commonly used to improve aesthetics but they may also be applied to deliver active ingredients. Recently, a group of pigments known as carotenoids has been added to emulsions as an active compound mainly due to their antioxidant properties. The stability of these formulations is a critical parameter for both, pharmaceutical and cosmetics industry. Therefore, in this study two analytical methods, multiple light scattering and laser diffraction, were tested to determine the stability of various emulsions containing carotenoids (β-carotene, lycopene, astaxanthin). Even small changes in stability of emulsions were determined very early. The results of both methods proved that the type of carotenoid used did not influence the emulsions' stability. The stability of emulsions depends mainly on the preparation methods and on the type of emulsifier applied.
Źródło:
Acta Biochimica Polonica; 2018, 65, 3; 455-463
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Face Tracking and Recognition with the Use of Particle-Filtered Local Features
Autorzy:
Stasiak, Ł. A.
Pacut, A.
Powiązania:
https://bibliotekanauki.pl/articles/308537.pdf
Data publikacji:
2010
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
biometrics
face recognition
particle filtering
video analysis
Opis:
A consistent particle filtering-based framework for the purpose of parallel face tracking and recognition from video sequences is proposed. A novel approach to defining randomized, particle filtering-driven local face features for the purpose of recognition is proposed. The potential of cumulating classification decisions based on the proposed feature set definition is evaluated. By applying cumulation mechanisms to the classification results determined from single frames and with the use of particle-filtered features, good recognition rates are obtained at the minimal computational cost. The proposed framework can operate in real-time on a typical modern PC. Additionally, the application of cumulation mechanisms makes the framework resistant to brief visual distortions, such as occlusions, head rotations or face expressions. A high performance is also obtained on low resolution images (video frames). Since the framework is based on the particle filtering principle, it is easily tunable to various application requirements (security level, hardware constraints).
Źródło:
Journal of Telecommunications and Information Technology; 2010, 4; 26-36
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vortex particle method and parallel computing
Metoda cząstek wirowych w obliczeniach równoległych
Autorzy:
Kosior, A.
Kudela, H.
Powiązania:
https://bibliotekanauki.pl/articles/282033.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
vortex particle method
vortex ring
parallel computations
Opis:
In this paper, it was presented numerical results related to three dimensional simulation of motion of a vortex ring. For the simulation it was chosen the Vortex In Cell method. The method was shortly described in the paper. The numerical results were obtained on the single processor (x86) architecture. The disadvantage of the single processor computation is a very long time of computation. To menage this problem, we switched to the parallel architecture. In our first approach to the multicore architecture we tested the possibility and algorithms for the solution of the algebraic system of equations that resulted form discretization of the Poisson equation. We presented the results obtained with CUDA architecture. In order to better understand how does the parallel algorithms work on CUDA architecture, it was shortly presented a scheme of the device and how programs are executed on it. We showed also our results which are related to the parallelization of some simple iterative methods like the Jacobi method and Red-Black Gauss-Seidel method for solution of the algebraic system. The results were ncouraging. For the Red Black Gauss-Seidel using GTX480 card, the calculations were 90-times shorter than on a single processor. As we know the solution to the Poisson equation is equivalent to the solution to the algebraic systems.
W pracy przedstawiono wyniki numeryczne ruchu trójwymiarowego pierścienia wirowego. W obliczeniach zastosowano metodę cząstek wirowych, która została pokrótce opisana. Obliczenia przeprowadzono na pojedynczym procesorze (x86). Wadą takiej realizacji jest długi czas obliczeń. Dla przyspieszenia obliczeń zaproponowano algorytm obliczeń równoległych w środowisku wieloprocesorowym karty graficznej z technologią CUDA. Architekturę karty krótko opisano. Znajomość architektury ma istotne znaczenie dla efektywności kodu. Napisany program przetestowano, rozwiązując układ równań algebraicznych otrzymany po dyskretyzacji równania Poissona. Przedstawiono wyniki obliczeń dla zrównoleglonych, prostych metod iteracyjnych rozwiązywania układów równań takich jak metoda Jacobiego czy „Red-Black Gauss-Seidel”. Dla metody „Red-Black Gauss-Seidel” oraz karty GTX480 otrzymano 90-krotne przyspieszenie czasu obliczeń względem pojedynczego procesora.
Źródło:
Journal of Theoretical and Applied Mechanics; 2012, 50, 1; 285-300
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation and Analysis of Particle Filter Based SLAM System
Autorzy:
Kaniewski, P.
Słowak, P.
Powiązania:
https://bibliotekanauki.pl/articles/320637.pdf
Data publikacji:
2018
Wydawca:
Polskie Forum Nawigacyjne
Tematy:
SLAM
particle filter
simulation
INS
monocular camera
Opis:
The paper describes a problem and an algorithm for simultaneous localization and mapping (SLAM) for an unmanned aerial vehicle (UAV). The algorithm developed by the authors estimates the flight trajectory and builds a map of the terrain below the UAV. As a tool for estimating the UAV position and other parameters of flight, a particle filter was applied. The proposed algorithm was tested and analyzed by simulations and the paper presents a simulator developed by the authors and used for SLAM testing purposes. Chosen simulation results, including maps and UAV trajectories constructed by the SLAM algorithm are included in the paper.
W artykule przedstawiono problematykę i algorytm równoczesnego pozycjonowania i tworzenia mapy terenu (SLAM) przeznaczony dla bezzałogowych statków powietrznych (UAV). Opracowany przez autorów algorytm estymuje trajektorię lotu i tworzy mapę terenu znajdującego się pod UAV. Jako narzędzie estymacji położenia statku powietrznego zastosowano filtr cząsteczkowy. Zaproponowany algorytm poddano badaniom symulacyjnym. W artykule opisano opracowany przez autorów symulator przeznaczony do badania algorytmu SLAM oraz zamieszczono wybrane wyniki badań, zawierające utworzone mapy terenu i estymowane trajektorie UAV.
Źródło:
Annual of Navigation; 2018, 25; 137-153
1640-8632
Pojawia się w:
Annual of Navigation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Właściwości kompozytowych powłok zawierających twarde cząstki
Properties of composite coatings containing hard particles
Autorzy:
Derek, I.
Powiązania:
https://bibliotekanauki.pl/articles/404455.pdf
Data publikacji:
2016
Wydawca:
Wydawnictwo AWART
Tematy:
coating
wear
particle
cząstka
powłoka
charakterystyki tribologiczne
Opis:
W artykule przedstawiono rezultaty badań tribologicznych, których celem było określenie wpływu obecności twardych cząstek w powłokach kompozytowych na wybrane charaktrystyki tribologiczne. Stwierdzono, że zarówno sama obecność twardych cząstek w powłokach jak również ich wymiary w istotny sposób wpływają na charakterystyki tribologiczne współpracujących powierzchni z powłokami.
The article concerns electroplated coating reinforced with hard particles. As a result of the trials wear shown the type and particle size increase resistance against wear.
Źródło:
Obróbka Metalu; 2016, 3; 36-38
2081-7002
Pojawia się w:
Obróbka Metalu
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the Mechanical and Thermal Properties, and Impact Sensitivity of Pressed HMX-based PBX
Autorzy:
Li, Yuxiang
Wu, Peng
Hua, Cheng
Wang, Jun
Huang, Bing
Chen, Jin
Qiao, Zhiqiang
Yang, Guangcheng
Powiązania:
https://bibliotekanauki.pl/articles/358006.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
nanoexplosives
impact sensitivity
particle size
hot spot
Opis:
Submicron- and nano-explosives have attracted growing attention, while the mechanism of how particle size influences the impact sensitivity is not completely understood. In the present work, HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) based PBXs (plastic bonded explosives) of three particle size distributions (1-2 and 10-20 μm, and 100-300 nm) and two pressed densities (91%TMD and 79%TMD) were characterized and tested with a range of techniques to determine their mechanical and thermal properties and impact sensitivities. The results demonstrated that with decreased particle size, the mechanical strength as well as the thermal conductivity were dramatically improved, and the impact sensitivity was significant decreased. The structure of impacted samples suggested that the ignition mechanism is dependant on the particle size. Samples with higher density were more sensitive to impact, as the impact force acting on these samples was higher. The correlation between particle size and impact sensitivity is discussed in detail.
Źródło:
Central European Journal of Energetic Materials; 2019, 16, 2; 295-315
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cosmic future of nuclear and particle physics
Autorzy:
Wrochna, G.
Powiązania:
https://bibliotekanauki.pl/articles/147930.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
astronomy
nuclear physics
particle physics
astroparticle physics
Opis:
Abstract Astronomy and nuclear or particle physics are often considered as two opposite extremes, but in fact their common part is not empty and still enlarging. In this brief review we trace their common roots and we look for their common future. We predict that soon they will de facto merge in terms of phenomena being studied, theories used to describe them as well as experimental techniques. We gave several examples, devoting special attention to the "Pi of the Sky" project searching for optical flashes of astrophysical origin.
Źródło:
Nukleonika; 2005, 50,suppl.3; 25-31
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies on the Tailoring of Particle Size and Micromeritic Properties of Reduced Shock Sensitivity RDX (RSS-RDX)
Autorzy:
Ramavat, V.
Sarangapani, R.
Reddy, S. T.
Patil, R. S.
Gore, G. M.
Sikder, A. K.
Powiązania:
https://bibliotekanauki.pl/articles/951500.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
crystallization
RSS-RDX
micromeritics
particle size distribution
Opis:
The microstructure of explosive particles, as well as formulations, has a significant influence on the shock sensitivity of various energetic formulations. Particle shape and specific size distributions are always important considerations in explosives processing in order to realize better process parameters. The present study aimed to explore crystallization variables required to achieve a specific particle size of Reduced Shock Sensitivity RDX (RSS-RDX). Crystallization process factors such as cooling rate, agitator speed and configuration, etc. have been systematically studied to understand their effect on the particle size. The study also established the crystallization process parameters required to tightly control a specific particle size distribution ranging from 50 to 500 μm by cooling crystallization. Fine particles ranging from 15 to 30 μm were prepared by an ultrasonication technique. Ultrasonic process parameters, including temperature, time and ultrasonic frequency, were studied and the process conditions were optimized. Micromeritic characterization of RSS-RDX revealed the nature of flowability, which in-turn is useful in identifying the ease of processability. Overall, our interest stemmed from an investigation which showed that careful optimization of crystallization variables can lead to a specific particle size distribution.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 4; 581-592
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation femtoscopy
Autorzy:
Lednický, R.
Powiązania:
https://bibliotekanauki.pl/articles/147326.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
particle
emission
correlations
spin
flow
delay
interaction
Opis:
Recent results on particle momentum and spin correlations are discussed, particularly, in view of the role played by the effect of final state interaction. It is demonstrated that this effect allows for (i) correlation femtoscopy with unlike particles; (ii) study of the relative space-time asymmetries in the production of different particle species (e.g., relative time delays or spatial shifts due to collective flows); (iii) study of the particle strong interaction hardly accessible by other means (e.g., in logical and logical and system).
Źródło:
Nukleonika; 2004, 49,suppl.2; 3-6
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Motion of a particle with stick-slip boundary conditions towards a flat interface: hard wall or free surface
Autorzy:
Ekiel-Jeżewska, M.
Wajnryb, E.
Powiązania:
https://bibliotekanauki.pl/articles/109616.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle
boundary conditions
hard wall
free surface
Opis:
Motion of a particle with stick-slip boundary conditions towards a hard wall or free surface is investigated in the range of Reynolds numbers much smaller than unity, based on the multipole expansion of the Stokes equations. The slip parameter can be interpreted as a measure of a solid particle roughness or as the effect of a surfactant on the motion of a small spherical non-deformable bubble. The particle friction coefficient is evaluated as a function of the distance from its center to the wall, based on the inverse power series expansion, and the results are used to derive explicit lubrication expressions for the friction coefficient, in a wide range of the slip parameters. It is pointed out that for a very small thickness of the fluid film, the lubrication expressions are more accurate than the series expansion. The drainage time is calculated and analyzed, and estimated in terms of explicit lubrication expressions.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 1; 203-209
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of fenugreek-gum and particle size on performance of talc flotation
Autorzy:
Gu, G.
Mo, C.
Zhao, K.
Chen, Z.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/109940.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
talc
particle size
fenugreek-gum
depression
flocculation
Opis:
Talc usually exists as a gangue mineral in copper-nickel sulfide, molybdenite etc. In order to separate precious metals, naturally hydrophobic talc should be depressed effectively in flotation process. The effect of fenugreek-gum (FG) on the flotation performance of talc with different particle sizes was studied. The depression mechanism was investigated extensively through tests of flotation, adsorption and zeta potential, as well as infrared spectroscopy and laser particle size analysis. Flotation results indicated that the FG had a strong depression ability for talc with the particle size of -0.074 + 0.037 mm, -0.037 mm and -0.010 mm when proper dosage of FG was added. The coarse talc was completely depressed by 2.5 mg/ dm3 FG. When the particle size decreased, more FG was required to obtain the maximum depressing effect, which was verified by adsorption tests. FG reduced the electronegativity on the talc surface by chemical adsorption, and flocculation of talc powders caused a high efficient depressing effect.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 1026-1033
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models of particle size distribution in simulation analysis of high-pressure grinding roll operations
Autorzy:
Saramak, D.
Powiązania:
https://bibliotekanauki.pl/articles/110253.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
HPGR
comminution
particle size distribution
ore processing
Opis:
The high-pressure grinding roll (HPGR) technology is currently one of the most efficient methods of hard ore comminution from the scope of the energy consumption. Throughput and energetic models of performance are quite well developed, but technological models predicting the comminution effects still needs an in-depth research. In the paper author presents the method of modeling of HPGR products’ particle size distribution by using suitable mathematical models. A basis of the HPGR perfor-mance assessment and HPGR-based crushing circuits design is a product’s particle size distribution. In order to precisely determine the particle size distribution of a HPGR product, parameters of product’s particle size distributions should be conditional on the main technical parameters of the roller press like operating pressure and the speed of rolls. The most accurate approximation of a distribution of size parti-cle appears to be Weibull’s truncated distribution and it is possible to obtain significant relationships between the approximation formula and the value of operating pressure, or feed characteristics. It makes possible a determination of mass recoveries of the product’s respective size fractions and the productivity planning. Instead of pressure, the other HPGR operating parameters can be applied, but the pressure value appears to produce the most relevant relationship. A determination of HPGR product’s particle size dis-tribution is a basis of the press operation simulation analysis.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 1; 121-131
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of particle size on the oxidation and flotation behavior of galena particles
Autorzy:
Lu, Yalin
Tong, Xiong
Xie, Xian
Yang, Bo
Hua, Zhongbao
Powiązania:
https://bibliotekanauki.pl/articles/110497.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
galena
particle size
surface oxidation
flotation behavior
Opis:
The aim of this study was to determine the effect of particle size on the oxidation and flotation behavior of galena particles. Coarse (-0.074+0.038 mm), intermediate (-0.038+0.025 mm) and fine (-0.025 mm) galena particles were used in this study. Dissolution tests demonstrated that the amount of oxidation products increased with the decrease of particle sizes. The surface oxidization of galena was the greatest at pH 7.3, followed by pH 12 and 9, which were consist with the result of XPS. The micro-flotation results indicated that the effect of pH on the flotation recovery of galena enhanced with the reduction of particle sizes. The decreasing of particle sizes increases both the sorption rate of collector and the dissolution of galena, while the generation of hydrophilic product caused by dissolution is dominant, rendering the mineral hydrophilic. This study shows the differences in the surface oxidation and flotation behavior of different size fractions of galena particles. To promote the flotation recovery of the fine size fraction of galena particles, alleviating their oxidation is the key.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 208-216
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of frothers and particle size on the flotation kinetics of the Jameson Cell
Autorzy:
Şahbaz, Oktay
Demir, Muhammet Kubilay
Powiązania:
https://bibliotekanauki.pl/articles/1845223.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation kinetics
Jameson cell
frothers
particle size
Opis:
Determination of the flotation kinetic is crucial for optimization, simulation, and plant design for flotation processes. Even though there are many studies carried out to clarify the kinetic properties of the conventional flotation cells, there is not enough detailed study about the Jameson cell which is used more than 300 plants but no application in Turkey yet. One of the most important parameters affects the kinetic of flotation is a frother. The effects of common frothers on the kinetic of Jameson cell can be crucial due to the possible further application of the cell in European and Turkish flotation industries. The present study was performed out to reveal the kinetic properties of the Jameson cell by using both pure quartz and coal particles. Besides, the effects of three different types of frothers on the kinetic of the Jameson cell were investigated for various particles sizes. According to the results, aliphatic alcohol type frother (MIBC) provided higher recovery for fine particles, while polypropylene glycol type frother (AF65) gave a better ability to float medium and coarse size particles. Additionally, the results show that the Jameson cell was four times faster than the mechanical cell for medium size while the ratio was three times for coarse particles. Lastly AF65 can be used for flotation of coarse particles in the Jameson cell while MIBC can be preferred for fines.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 829-838
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of selected properties of rhenium sulphide dispersion
Autorzy:
Pawlak, D. W.
Parus, J. L.
Skwarek, E.
Janusz, W.
Powiązania:
https://bibliotekanauki.pl/articles/951830.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
rhenium sulphide
particle size distribution
zeta potential
Opis:
Due to potential application of rhenium sulphide in medicine and industry, this study is focused on the properties of synthetic and commercial rhenium sulphide. The main reaction of rhenium sulphide preparation involves potassium perrhenate and sodium thiosulphate in the acidic environment giving a mixture of rhenium sulphide and sulphur. The next step is removing sulphur by its dissolution in ether. Stabilization by Povidone K-25 is needed to obtain rhenium sulphide dispersed with the grain size of 0.5–4 m. The extrapolated value of pHiep for synthesised rhenium sulphide is 2.3 whereas for commercial samples this value is lower than 2. For synthetic sample a dependence of zeta potential on the carrier electrolyte concentration is found. It is larger than that for the commercial sample, probably due to surface oxidation during synthesis or purification.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 1; 387-397
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of Yu and Meyer bivariate stochastic volatility model by iterated filtering
Autorzy:
Szczepocki, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2204278.pdf
Data publikacji:
2023-05-31
Wydawca:
Główny Urząd Statystyczny
Tematy:
multivariate stochastic volatility
iterated filtering
particle filters
Opis:
In financial applications, understanding the asset correlation structure is crucial to tasks such as asset pricing, portfolio optimisation, risk management, and asset allocation. Thus, modelling the volatilities and correlations of multivariate stock market returns is of great importance. This paper proposes the iterated filtering algorithm for estimating the bivariate stochastic volatility model of Yu and Meyer. The iterated filtering method is a frequentist-based approach that utilises particle filters and can be applied to estimating the parameters of non-linear or non-Gaussian state-space models. The paper presents an empirical example that demonstrates the way in which the proposed estimation method might be used to estimate the correlation between the returns of two assets: Standard and Poor's 500 index and the price of gold in US dollars. This is accompanied by a simulation study that proves the validity of the approach.
Źródło:
Przegląd Statystyczny; 2022, 69, 4; 1-19
0033-2372
Pojawia się w:
Przegląd Statystyczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of coal mineral matter liberation efficiency index
Ocena stopnia uwolnienia frakcji mineralnej węgla
Autorzy:
Surowiak, A.
Powiązania:
https://bibliotekanauki.pl/articles/319165.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
liberation efficiency
hard coal
particle size distribution
particle density distribution
stopień uwolnienia
węgiel kamienny
skład ziarnowy
skład densymetryczny
Opis:
The main tool allowing to forecast effects of gravitational beneficiation of hard coals is density analysis. The obtained results of such analysis should show real minerals liberation level in connection with their physical properties. In purpose of calculating mineral phase liberation from hard coal the size and density analysis was performed for raw hard coal which was feed directed to mineral processing. For each obtained size-density fraction its yield and ash contents were determined. The Hall’s separation curve was used in the paper to evaluate liberation efficiency of mineral phase from hard coal. The advantage of this curve is the fact that it is possible to describe it mathematically by means of hyperbolic equation. It was stated that if particle size is lower the liberation level of mineral substance grows.
Podstawowym narzędziem pozwalającym prognozować efekty wzbogacania grawitacyjnego węgli kamiennych jest analiza densymetryczna. W związku z tym otrzymane wyniki takiej analizy powinny odzwierciedlać rzeczywisty stopień uwolnienia minerałów w powiązaniu z ich właściwości fizycznymi. W celu wyliczenia uwolnienia fazy mineralnej z węgla kamiennego wykonano analizę granulometryczną i densymetryczną surowego węgla kamiennego – nadawy kierowanej do przeróbki mechanicznej. W otrzymanych klaso-frakcjach wyliczono wychody oraz oznaczono zawartość popiołu. W artykule wykorzystano krzywą separacji Halla do oceny stopnia uwolnienia frakcji mineralnej z węgla kamiennego. Zaletą krzywej separacji Halla jest to, że można ją opisać w sposób matematyczny przy pomocy równania hiperboli. Stwierdzono, że ze wraz z zmniejszaniem się wielkości ziaren wzrasta stopień uwolnienia substancji mineralnej.
Źródło:
Inżynieria Mineralna; 2013, R. 14, nr 2, 2; 153-158
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust optical flow estimation applied to particle image velocimetry images for high resolution velocity measurements
Autorzy:
Stryczniewicz, W.
Powiązania:
https://bibliotekanauki.pl/articles/246407.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
Particle Image Velocimetry
optical flow estimation
particle image density
image occlusion
estymacja przepływu optycznego
gęstość obrazu cząstki
okluzja obrazu
Opis:
The article discusses application of Robust Optical Flow Estimation for increasing of Particle Image Velocimetry measurement resolution. Nowadays, one of the promising approaches for increasing the performance of the PIV systems is application of the Optical Flow Estimation for image analysis. Nevertheless, some of the OF implementations do not perform well in case of motion discontinues typically occurring in the PIV images. The purpose of this study is to validate the performance of the Robust Optical Flow Estimation. The tests were performed on simulated images of vortex flow and the results were compared with displacement fields calculated with the typical correlation PIV algorithm. The velocity for high and medium particle concentration was similar for Optical Flow and PIV-like analysis. Furthermore, the performance of the robust optical flow framework was tested with images corrupted with blurs and occlusions. The tests proved good performance of proposed analysis in case of non-Gaussian sources of measurement errors. The robust estimation framework performed well in the case of common image artefacts and proved to be a promising method for precise PIV flow measurements. The presented approach can be useful in development hybrid OF-PIV post processing software aimed for high-resolution measurements and provide a help in designing of experimental investigation of microscale fluid flow phenomena.
Źródło:
Journal of KONES; 2018, 25, 1; 371-377
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selected methods of measuring drilling mud settling
Autorzy:
Zwierzyński, A.J.
Wróblewski, T.
Wiśniiowski, R.
Stryczek, S.
Powiązania:
https://bibliotekanauki.pl/articles/298589.pdf
Data publikacji:
2014
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
particle settling
barite sag
drilling muds
drilling fluids
Opis:
Methods of measuring settling rate of drilling muds have been selected and the basic theoretical data on this process are addressed in the paper. A brief discussion is also given on the negative influence of settling in drilling mud on the stability of wellbore and formation of potential drilling complications. The results of an analyses of the settling processes taking place in oil-based muds made according to 8 recipes are presented. The direct weighing method has been used in the measurements.
Źródło:
AGH Drilling, Oil, Gas; 2014, 31, 4; 471-483
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charge balance functions and the transverse flow
Autorzy:
Bożek, P.
Powiązania:
https://bibliotekanauki.pl/articles/148366.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
ultrarelativistic heavy-ion collisions
particle correlations
collective flow
Opis:
Correlations between opposite charge particles emitted in ultrarelativistic heavy-ion collisions can be used as a measure of the transverse flow present at the time of the decoupling of the charged pair. The width of the charge balance function in azimuthal angle depends on the transverse velocity and the temperature of the emitting source. Asymmetry in the balance function between in plane and out of plane emission can serve as a probe of the azimuthal asymmetry of the velocity field in the source.
Źródło:
Nukleonika; 2006, 51,suppl.3; 51-54
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An experimental analysis of the flow structure in various configurations of a circular-planar SOFC fuel channel
Analiza eksperymentalna struktury przepływu gazu w zróżnicowanychprzepływu gazu w zróżnicowanych geometriach kanału paliwowego ogniwa paliwowego typu SOFC
Autorzy:
Nowak, R.
Szmyd, J. S.
Powiązania:
https://bibliotekanauki.pl/articles/281000.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
particle image velocimetry
error analysis
flow distribution
SOFC
Opis:
In the presented paper, the authors focus on the analysis of flow structure in various configurations of a circular-planar SOFC fuel channel. The research was carried out on the premise that a proper channel design would help minimize the thermal stress in the cell, which is affected by the heat generated and consumed by the reforming, water gas-shift and hydrogen consumption reactions. For the measurement process, PIV method was used to calculate the velocity fields, and an extensive error analysis was done to evaluate the accuracy of the calculated velocities.
W zaprezentowanym artykule, tematem realizowanych badań jest analiza eksperymentalna struktury przepływu gazu w trzech modelach kanałów transportowych ogniwa paliwowego typu SOFC (Solid Oxide Fuel Cell). Celem badań było zaproponowanie geometrii kanału, która pozwoliłaby utrzymać jednorodny rozkład pola prędkości na powierzchniach elektrod w rzeczywistych warunkach pracy ogniwa. Dobór odpowiedniej geometrii kanałów transportowych jest istotny z punktu widzenia wydajności oraz bezpieczeństwa pracy ogniwa, ponieważ bezpośrednio wpływa na wydajność reakcji elektrochemicznych zachodzących w ogniwie oraz na rozkład temperatury w jego wnętrzu, uwarunkowany silnie egzotermicznymi reakcjami elektrodowymi oraz w przypadku wykorzystania paliwa węglowodorowego dodatkową, endotermiczną reakcją reformingu i egzotermiczną reakcją tlenku węgla z parą wodną. Na potrzeby eksperymentu zaprojektowano oraz wykonano z pleksi trzy przykładowe geometrie kanałów przepływowych. Badania eksperymentalne przeprowadzono w temperaturze pokojowej. Gazem wykorzystanym w badaniach było powietrze. Bazując na teorii podobieństwa ustalono wartości liczby Reynoldsa na poziomie odpowiadającym wielkościomliteraturowym, dzięki czemu otrzymane wyniki można traktować jako wiarygodne i oddające charakter przepływu paliwa w rzeczywistym ogniwie paliwowym. Profile prędkości wyznaczono wykorzystując bezinwazyjną metodę Particle Image Velocimetry. Ponadto, na podstawie analizy błędów określono zestaw parametrów obliczeniowych, dla których wyznaczone pole wektorowe charakteryzowało się największą dokładnością.
Źródło:
Journal of Theoretical and Applied Mechanics; 2011, 49, 2; 541-564
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat recovery system in a future diesel particle filter
Autorzy:
Mitianiec, W.
Powiązania:
https://bibliotekanauki.pl/articles/245386.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport
compression ignition engine
diesel particle filter
regeneration
Opis:
The main problem in conventional diesel engines and HCCI diesel is reduction of solid particles emitted to atmosphere. applying of particle filters requires special methods for their regeneration after some period of the engine work in a result of closing of substrate pores by soot. These methods require additional energy for combustion of soot (additional fuel or electric energy). The new method takes into account a self-regeneration of diesel particle filter by use of special heat recovery system. The paper shows an example of DPF self-regeneration. the exhaust temperature behind the turbine and catalytic converter is very low and particularly for HCCI engine the emission of particles is low in comparison to conventional diesel engines. for that case an additional energy is required for increase of gas temperature before DPF. the preliminary studies show a possibility of using the special design of DPF with heat recovery system. the paper shows the simulation results of such system and possibility of increasing the heat recovery ratio by change of geometry of DPF. the gas heat exchange formulas between dpf and the heat exchange module are partly included in the paper. the preliminary results of calculations shows the possibility of increase of exhaust gases in front of DPF about 20%, which enables a continuous regeneration of DPF. the work is carried out as part of the european project ipsy.
Źródło:
Journal of KONES; 2009, 16, 4; 333-342
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Di-stimuli Responsive poly(N-Isopropylacrylamide-co-Diethylaminoethylmethacrylate) Copolymer: Synthesis, Characterization and Investigation of Aqueous Dispersion Properties
Autorzy:
Ashaduzzaman, Md.
Islam Shahidul, Md.
Powiązania:
https://bibliotekanauki.pl/articles/411593.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
di-stimuli responsive
copolymer
NIPAAm
DEAEMA
nano-particle
Opis:
We report on the synthesis, characterization and aqueous dispersion properties of well-defined double hydrophilic copolymer with pH- and thermo-responsive segments via atom transfer radical polymerization (ATRP). Poly(N-isopropylacrylamide-co-Diethylaminoethylmeth-acrylate), P(NIPAAm-co-DEAEMA), was prepared by ATRP using methyl-4-bromomethyl benzoate initiator. The product was characterized by proton-nuclear magnetic resonance (1H NMR) and attenuated total reflectance infrared (ATR-IR) spectroscopy. The multi-responsive switching between unimer and two types of micellar aggregates were characterized by temperature-dependent dynamic light scattering (DLS). Self-assembles into two types spherical aggregates in 1 mg/mL (0.0315 mM) aqueous solution, depending on solution pH and temperatures were widely investigated. The result shows two types of aggregate with large (280 nm) aggregate and variable sizes of small (17 nm, 25 nm, 45 nm) aggregates depending on temperature ranges from 26 to 40 °C at pH 4.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 20, 2; 136-144
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Celestial navigation fix based on particle swarm optimization
Autorzy:
Tsou, M.-C.
Powiązania:
https://bibliotekanauki.pl/articles/258524.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
particle swarm optimization (PSO)
Celestial navigation
Intercept method
Opis:
A technique for solving celestial fix problems is proposed in this study. This method is based on Particle Swarm Optimization from the field of swarm intelligence, utilizing its superior optimization and searching abilities to obtain the most probable astronomical vessel position. In addition to being applicable to two-body fix, multi-body fix, and high-altitude observation problems, it is also less reliant on the initial dead reckoning position. Moreover, by introducing spatial data processing and display functions in a Geographical Information System, calculation results and chart work used in Circle of Position graphical positioning can both be integrated. As a result, in addition to avoiding tedious and complicated computational and graphical procedures, this work has more flexibility and is more robust when compared to other analytical approaches.
Źródło:
Polish Maritime Research; 2015, 3; 20-27
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of Synchronous Data Streams Processing in the RPC Muon Trigger System of the CMS Experiment
Autorzy:
Poźniak, K. T.
Powiązania:
https://bibliotekanauki.pl/articles/226758.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
synchronization
particle measurements
data acquisition
triggering
measurement system
Opis:
This paper presents signal synchronization aspects in a large, distributed, multichannel RPC Muon Trigger system in the CMS experiment. The paper is an introduction to normalized structure analysis methods of such systems. The method introduces a general model of the system, presented in a form of a network of distributed, synchronous, pipeline processes. The model is based on a definition of a synchronous data stream and its formal, fundamental properties. Theoretical considerations are supported by a practical application of synchronous streams and processes management. The following processes were modeled and implemented in hardware: window synchronization, derandomization, data concentration and generation of test pulses. There are presented chosen results of the model application in the CMS experiment.
Źródło:
International Journal of Electronics and Telecommunications; 2010, 56, 4; 489-502
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł

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