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Wyszukujesz frazę "velocity" wg kryterium: Temat


Tytuł:
Matematicheskaja model dinamiki dvizhenija ehlektrotekhnicheskogo robotizirovannogo kompleksa fitomonitoringa v teplice
Mathematical model of dynamics of movement of robotic systems electrical phytomonitoring in the greenhouse
Autorzy:
Lysenko, V.
Bolbot, I.
Chernov, I.
Powiązania:
https://bibliotekanauki.pl/articles/77830.pdf
Data publikacji:
2015
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
greenhouse
dynamics model
robot
angular velocity
linear velocity
Źródło:
Motrol. Motoryzacja i Energetyka Rolnictwa; 2015, 17, 4
1730-8658
Pojawia się w:
Motrol. Motoryzacja i Energetyka Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Explosive Properties of Melt Cast Erythritol Tetranitrate (ETN)
Autorzy:
Künzel, M.
Matyáš, R.
Vodochodský, O.
Pachman, J.
Powiązania:
https://bibliotekanauki.pl/articles/358875.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
sensitivity
detonation velocity
melt cast
erythritol tetranitrate
Gurney velocity
Opis:
Erythritol tetranitrate (ETN) is a low melting, solid, nitrate ester with significant explosive properties. The increased availability of its precursor (erythritol), which is now used as a sweetener, has attracted attention to the possible misuse of ETN as an improvised explosive. However, ETN also has some potential to be used as a component of military explosives or propellants. This article focuses on the properties of melt-cast ETN. The sensitivity of the compound towards impact and friction was tested. The explosive performance was evaluated, based on cylinder expansion tests and detonation velocity measurements. The impact energy and friction force required for 50% probability of initiation was 3.79 J and 47.7 N, respectively. A Gurney velocity value of G = 2771 m·s−1 and a detonation velocity of 8027 m·s−1 at a charge density of 1.700 g·cm−3, were found for the melt-cast material. The sensitivity characteristics of melt-cast ETN does not differ significantly from either literature values or the authors’ data measured using the crystalline material. The explosive performance properties were found to be close to those of PETN.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 2; 418-429
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase and group velocities of surface waves in left-handed material waveguide structures
Autorzy:
Taya, S. A.
Elwasife, K. Y.
Qadoura, I. M.
Powiązania:
https://bibliotekanauki.pl/articles/173396.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
slab waveguide
phase velocity
group velocity
left-handed materials
Opis:
We assume a three-layer waveguide structure consisting of a dielectric core layer embedded between two left-handed material claddings. The phase and group velocities of surface waves supported by the waveguide structure are investigated. Many interesting features were observed such as normal dispersion behavior in which the effective index increases with the increase in the propagating wave frequency. The phase velocity shows a strong dependence on the wave frequency and decreases with increasing the frequency. It can be enhanced with the increase in the guiding layer thickness. The group velocity peaks at some value of the normalized frequency and then decays.
Źródło:
Optica Applicata; 2017, 47, 2; 307-318
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of tripping velocity profiles on wellbore pressures and dynamic loading of drillstring
Autorzy:
Wang, Z.
Miska, S.
Yu, M.
Takach, N.
Powiązania:
https://bibliotekanauki.pl/articles/298649.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
trapping velocity
optimization
Opis:
Tripping events are expensive and time-consuming. Thus, minimizing tripping time through choosing optimized tripping velocity becomes urgent. Surge or swab pressures in the wellbore and dynamic loading of drillstring will be generated during tripping. Also, dynamic velocity, which is the velocity at the bottom of drillstring, is different from the input velocity at surface. The effect of tripping velocity profile, i.e., tripping velocity changes with time, on the hook load, downhole pressure changes and drillstring dynamic velocity should be fully studied to achieve the optimization. In this study, the effects of tripping velocity profile on loading of drillstring, dynamic velocity and downhole pressure is investigated using numerical simulation. Bergeron's graphical method and Lubinski's approach are utilized to perform the simulations. Components of drillstring, wellbore depth, drillstring length and mud properties are also included in the simulations. Through the current work, a driller's typical way of changing tripping velocity may not be the best one. Selection of tripping velocity profiles should be adapted to depth: higher velocity, triangular/parabolic profiles in shallow wells and lower velocity, trapezoidal profiles in deep wells. Also, based on simulations, the oscillation magnitude of dynamic velocity can be as high as twice that of velocity at surface.
Źródło:
AGH Drilling, Oil, Gas; 2013, 30, 1; 269-286
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure and velocity distribution in slide journal bearing lubricated micropolar oil
Autorzy:
Krasowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/247206.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
micropolar lubrication
journal bearing
hydrodynamic pressure
velocity
velocity of microrotation
Opis:
Present paper shows the results of numerical solution Reynolds equation for laminar, steady oil flow in slide bearing gap. Lubrication oil is fluid with micropolar structure. Materials engineering and tribology development helps to introduce oils with the compound structure (together with micropolar structure) as a lubricating factors. Properties of oil lubrication as of liquid with micropolar structure in comparison with Newtonian liquid, characterized are in respect of dynamic viscosity additionally dynamic couple viscosity and three dynamic rotation viscosity. Under regard of build structural element of liquid characterized is additionally microinertia coefficient. In modelling properties and structures of micropolar liquid one introduced dimensionless parameter with in terminal chance conversion micropolar liquid to Newtonian liquid. The results shown on diagrams of hydrodynamic pressure, velocity and velocity of microrotation distribution in dimensionless form in dependence on coupling number N2 and characteristic dimensionless length of micropolar fluid A1. Differences were showed on graphs in the schedule of the circumferential velocity oils after the height of the gap in the flow of the micropolar and Newtonian liquid. In presented flow, the influence of lubricating fluid inertia force and the external elementary body force field were omitted. Presented calculations are limited to isothermal models of bearing with infinite length.
Źródło:
Journal of KONES; 2011, 18, 4; 213-220
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Autonomous hydroacoustic sound velocity profiler
Autorzy:
Jedel, A.
Marszal, J.
Ostrowski, Z.
Kilian, L.
Powiązania:
https://bibliotekanauki.pl/articles/332093.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
hydroacoustics
sound velocity profiler
Opis:
The paper presents the autonomous hydroacoustic sound velocity profiler collaborating with ordinary PC by small box included interface & battery charger. The measurement and calibration methods and block diagram of the meter are presented as well as principles of operation, data collection, selection and transmission. There are described three versions of this meter - dropped from "normal" ships, installed in the light hull of submarines and casings in the hulls of variable depth sonar antennas.
Źródło:
Hydroacoustics; 2003, 6; 261-266
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure and velocity distribution in slide journal plane bearing lubricated with micropolar oil
Autorzy:
Krasowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/246956.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
micropolar lubrication
journal plane bearing
hydrodynamic pressure
velocity
velocity of microrotation
Opis:
Present paper shows the results of numerical solution Reynolds equation for laminar, steady oil flow in slide plane bearing gap. Lubrication oil is fluid with micropolar structure. Materials engineering and tribology development helps to introduce oils with the compound structure (together with micropolar structure) as a lubricating factors. Properties of oil lubrication as of liquid with micropolar structure in comparison with Newtonian liquid, characterized are in respect of dynamic viscosity additionally dynamic couple viscosity and three dynamic rotation viscosity. Under regard of build structural element of liquid characterized is additionally microinertia coefficient. In modelling properties and structures of micropolar liquid one introduced dimensionless parameter with in terminal chance conversion micropolar liquid to Newtonian liquid. The results shown on diagrams of hydrodynamic pressure, velocity and velocity of microrotation distribution in dimensionless form in dependence on coupling number N2 and characteristic dimensionless length of micropolar fluid Lambda 1. Differences were showed on graphs in the schedule of the longitudinal velocity oils after the height of the gap in the flow of the micropolar and Newtonian liquid. In presented flow, the influence of lubricating fluid inertia force and the external elementary body force field were omitted. Presented calculations are limited to isothermal models of bearing with infinite breadth.
Źródło:
Journal of KONES; 2010, 17, 2; 249-256
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Changes in Bar Velocity and Muscular Activity During the Bench Press in Relation to the Load Lifted
Autorzy:
Gołaś, Artur
Maszczyk, Adam
Wilk, Michał
Statsny, Petr
Petr, Miroslav
Wróbel, Grzegorz
Król, Henryk
Powiązania:
https://bibliotekanauki.pl/articles/1054723.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
EMG
bar velocity
sticking region
Opis:
The purpose of the study was to determine velocity changes in relation to the load lifted along with their muscular activity. Twenty athletes representing different sport disciplines, familiar with the flat bench press took part in the research project. The ANOVA analysis revealed a significantly higher effect on range of mean velocity (F = 128.34; η2 = 1.22 with p = 0.001) and maximal velocity (F = 7 3.31; η 2 = 0 .81 w ith p = 0 .001) t o m easured l oads ( 70÷100% 1-RM) i n a scending p hase. Tukey’s p ost-hoc t ests revealed a statistically significant difference between 70% and 100% 1-RM loads, in mean velocity with p = 0.001 and maximal velocity with p = 0.001. Similarly the results revealed a statistically significant difference between 80% and 100% 1-RM loads in mean velocity (p = 0,012) and maximal velocity (p = 0,021) during the ascending phase. Relationship between velocity and the muscles activity indicates that the anterior deltoid and latissimus dorsi muscles show synergy and a significant relationship for loads 90 and 100% 1-RM. The triceps brachii muscle shows a higher relationship with velocity of the barbell for loads 70% and 80%, then the relationship of the pectoralis major muscle with velocity only for 90% 1-RM.
Źródło:
Central European Journal of Sport Sciences and Medicine; 2015, 11, 3; 95-101
2300-9705
2353-2807
Pojawia się w:
Central European Journal of Sport Sciences and Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of meat types by ultrasonic methods
Autorzy:
Nowak, K. W.
Powiązania:
https://bibliotekanauki.pl/articles/298316.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
ultrasonics
sound velocity
meat
identification
Opis:
The ability of identification of meat types using ultrasonic measurement was evaluated in this work. Four types of muscles were analyzed (turkey breast and thigh, and pork loin and ham). Ultrasonic measurements were performed at storage (5 ±1oC) and room (20±1oC) temperatures using the through-transmission technique and differential method of determination of sound velocity and the attenuation coefficient. The mean values of sound velocity for the breast, thigh, loin and ham were respectively: 1550.7, 1536.6, 1558.7, 1559.7 m/s at the storage temperature, and 1582.7, 1578.5, 1596.9, 1592.7 m/s at the room temperature. The mean values of the attenuation coefficient in the same order were: 21.3, 23.2, 30.6, 28.1 m-1 and 22.2, 18.9, 22.0, 22.4 m-1. Statistically significant differences in the sound velocity were observed between pork and turkey muscles, therefore, the meat of those species can be identified based on ultrasound measurements of sound velocity. The attenuation coefficient cannot be applied in the identification of meat types due to absence of significant differences in the mean values.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2015, 18(2); 79-84
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of velocity sensing in harvesters for magnetorheological dampers
Autorzy:
Sapiński, B.
Matras, A.
Powiązania:
https://bibliotekanauki.pl/articles/386498.pdf
Data publikacji:
2018
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
harvester
electromotive force
velocity
sensor
Opis:
This paper investigates the performance of electromagnetic vibration harvesters that can be incorporated in energy harvesting magnetorheological (MR) dampers. The study outlines the structure and operating principles of harvesters and compares results of numerical calculations with measurement data obtained under idle run. Results demonstrate the potential applications of harvesters as velocity sensors. The relationship between electromotive force (emf) and velocity across the devices is established. The discussion section suggests that power generation by harvesters can provide the velocity information by utilising the sensing function applicable to a variety of control algorithms.
Źródło:
Acta Mechanica et Automatica; 2018, 12, 3; 186-189
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of explosive charge temperature on the velocity of detonation of ANFO explosives
Autorzy:
Dobrilović, M.
Bohanek, V.
Žganec, S.
Powiązania:
https://bibliotekanauki.pl/articles/358379.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
ANFO
temperature
velocity of detonation
Opis:
ANFO is the most common explosive for civil use in the fields of mining and civil engineering. The effect of the explosive and the quantity of energy released by the detonation depends on the velocity of detonation. The influence on explosive performance of a large number of physical aspects of ANFO explosives and the conditions of initiation during blasting operations are mostly known, but the influence of the charge temperature on the velocity of detonation is not known. In order to quantify that influence, research on laboratory samples of smaller diameter and field samples of larger diameter, detonated in steel pipes, has been carried out. By processing and analysing the measured results the influence of charge temperature on the velocity of detonation of ANFO explosive has been determined.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 2; 191-197
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the Initiation Energy on theVelocity of Detonation of ANFO Explosive
Autorzy:
Bohanek, V.
Dobrilović, M.
Škrlec, V.
Powiązania:
https://bibliotekanauki.pl/articles/358833.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
ANFO
initiation energy
velocity detonation
Opis:
ANFO explosives have been widely used for blasting operations in mining and civil engineering. From a scientific point of view, ANFO is interesting due to its non-ideal detonation. There are numerous factors that affect the velocity of detonation of ANFO explosives. This paper presents measured velocities of detonation of ANFO explosives initiated by various initiation methods and initiation energies. ANFO explosives were tested in steel pipes, and detonators and boosters of different masses and initiation energies were used for initiation. The initiation energy of a detonator was determined using the underwater initiation capability test. The influence of the equivalent shock energy and the equivalent bubble energy on the velocity of detonation of ANFO was also determined. These measured results contribute to a better understanding of the non-ideal detonation of ANFO explosives.
Źródło:
Central European Journal of Energetic Materials; 2013, 10, 4; 555-568
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Surface-Plasmon-Polariton-Like Acoustic Surface Waves at the Interface Between Two Semi-Infinite Media
Autorzy:
Kiełczyński, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/31340115.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
shear horizontal acoustic waves
surface plasmon polaritons
phase velocity
group velocity
Poynting vector
Opis:
This paper presents theory of new shear horizontal (SH) acoustic surface waves that propagate along the interface of two semi-infinite elastic half-spaces, one of which is a conventional elastic medium and a second one an elastic metamaterial with a negative and frequency dependent shear elastic compliance. This new surface waves have only one transverse component of mechanical displacement, which has a maximum at the interface and decays exponentially with distance from the interface. Similar features are also shown by the acoustic shear horizontal Maerfeld-Tournois surface waves propagating at the interface of two semi-infinite elastic media due to the piezoelectric effect that should occur in at least one semi-space. The proposed new shear horizontal acoustic surface waves exhibit also strong formal similarities with the electromagnetic surface waves of the surface plasmon polariton (SPP) type, propagating along a metal-dielectric planar interface. In fact, the new shear horizontal elastic surface waves possess a large number of properties that are inherent for the SPP electromagnetic surface waves, such as strong subwavelength concentration of the wave field in the proximity of the guiding interface, low phase and group velocity etc. As a result, the new shear horizontal acoustic surface waves can find applications in sensors with extremely high sensitivity, employed in measurements of various physical parameters, such as viscosity of liquids, as well as in biosensors, chemosensors, or a near field acoustic microscopy (subwavelength imaging) and miniaturized devices of microwave acoustics.
Źródło:
Archives of Acoustics; 2022, 47, 3; 363-371
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of Equivalence of Small and Large Orifice Computational Models
Autorzy:
Kubrak, M.
Powiązania:
https://bibliotekanauki.pl/articles/241432.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
orifice
velocity
flow
computational models
Opis:
The aim of this paper was to analyze theoretical aspects of calculating steady water flow through unsubmerged circular orifices. Theoretical analysis shows that the values of discharge obtained by using formulas intended for small orifices are greater than those calculated using formulas for large orifices. These differences attain a maximum value when the water level reaches the upper edge of the orifice, and decrease when water head increases. It has been proven that the volumetric flow rate for circular unsubmerged orifices can be calculated by formulas for small orifices when the water level above the center of gravity is at least four times as high as the diameter of the orifice.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2015, 62, 3-4; 67-76
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of flow structure and performance of the centrifugal compressor impeller
Autorzy:
Grzelczak, M.
Tralewski, A.
Pałucki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/175160.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
centrifugal compressors
cross-section of the rotor
velocity fluctuation
tangential/meridional velocity
comppressor impellers
Opis:
The presently applied desulfurization technologies require a supply of air through centrifugal compressors realizing the pressure increment on the level of 150–200 kPa. Taking the necessary mass flow rate of the processed air into account it is necessary to increase the efficiency of the compression process realized in these machines. The paper will include the results of the works related to the analysis of the gas flow in the compression stage operating with two impellers. The first one has been described with a mathematical function preserving the condition of ruled surface and the geometry of the other impeller has been modeled according to the shape of the meridional velocity profile in the inlet section thus forming leading edge. The common feature of both impellers is the same mathematical function that describes the meridional section and the profile of the blade. The outer diameter of each of the impellers is 200 mm and the blade angle in the outlet section 45◦. The compression stage reaches the pressure ratio of 1.4 at the nominal mass flow of 0.73 kg/s maintaining the impeller rotational speed on the level of 24 400 rpm. For the evaluation of the operating parameters and the nature of the gas flow in the compression stage operating with two impellers computational fluid dynamics simulations were carried out and experimental research has been performed using laser Doppler anemometry for impeller of ruled surface.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 132; 87-101
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł

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