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Wyszukujesz frazę "granular" wg kryterium: Temat


Tytuł:
Modelling selected parameters of granular elements in the mixing process
Autorzy:
Matuszek, D.
Powiązania:
https://bibliotekanauki.pl/articles/24182.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
modelling
granular mixture
funnel flow
granular structure
product quality
granular material
Opis:
This paper presents the effects of mixing non-homogeneous bicomponent granular structures by the flow method with the use of an inverted cone insert as a supporting element. The analysis of homogeneity of mixtures after 10 consecutive flows was carried out based on computer image analysis. Based on these tests, the use of a nonlinear regression for the mo-delling of two selected parameters of the process was proposed. Spatial dependence was described by the relation between the va-riance of the tracer distribution (dependent variable) and density ratio of the mixed components, and the diameter of the cone insert used (independent variables). The mathematical description was made with the use of a ‘nonlinear regression’ module. The results obtained in these tests proved that the use of supporting insert improves the degree of mixability of granular materials. The two-dimensional model in the form of a quadratic function may be a for-mula for describing the influence of selected parameters on the homogeneity of a granulate mixture before the beginning of the mixing process.
Źródło:
International Agrophysics; 2015, 29, 1
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Topograficzna analiza dwuwymiarowych obrazów materiału ziarnistego
Topographic analysis of two-dimensional images of granular materials
Autorzy:
Heyduk, A.
Powiązania:
https://bibliotekanauki.pl/articles/187011.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technik Innowacyjnych EMAG
Tematy:
materiał ziarnisty
obraz materiału ziarnistego
granular material
image of granular material
Opis:
W artykule przedstawiono wykorzystanie metod geometrii różniczkowej do celów segmentacji obrazu materiału ziarnistego. Podstawową techniką jest analiza wartości własnych macierzy hesjanu jasności obrazu w danym punkcie - umożliwiająca precyzyjną topograficzną klasyfikację tego punktu. Taka klasyfikacja w istotny sposób ułatwia wyodrębnienie sąsiadujących ze sobą ziaren. Klasyfikacja ta dokonywana jest przy wykorzystaniu dwusześciennej aproksymacji otoczenia tego piksela opartej na ortogonalnych wielomianach bazowych.
The methods of a differential geometry to be used for segmentation purposes of an image of a granular material have been presented in the paper. A basic technique is an analysis of the characteristic values of an image brightness of a Hessian matrix at a given point - allowing a precise topographic classification of that point to be done. That classification facilitates really a separation of vicinal grains. The classification is made by use of a bicubic approximation of a neighbourhood of the pixel based on orthogonal basic polynomials.
Źródło:
Mechanizacja i Automatyzacja Górnictwa; 2009, R. 47, nr 2, 2; 5-10
0208-7448
Pojawia się w:
Mechanizacja i Automatyzacja Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mieszanie i segregacja podczas procesu ujednorodniania pasz
Mixing and segregation during the unification process of fodder
Autorzy:
Królczyk, J.
Tukiendorf, M.
Powiązania:
https://bibliotekanauki.pl/articles/287500.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
materiał ziarnisty
niejednorodna mieszanina ziarnista
wieloskładnikowa mieszanina ziarnista
pasza
segregacja
granular matter
non-homogenous granular matter
multicomponent granular matter
fodder
segregation
Opis:
W pracy zaprezentowano wyniki badań mieszania układu ziarnistego składającego się z dwunastu komponentów zbóż. Badania prowadzono w warunkach przemysłowych w pionowym mieszalniku z mieszadłem ślimakowym o działaniu okresowym. Specyfiką procesu przebiegającego w mieszalniku jest dodatkowa recyrkulacja komponentów mieszaniny, odbywająca się w sposób ciągły podczas 30 minutowego czasu mieszania. Na podstawie udziałów procentowych określonych w próbach pobranych w czasie trwania procesu obserwowano charakter zjawiska.
In the article research results of mixing granular matter consisting of twelve crops components has been presented. The research has been conducted in industrial conditions in vertical mixer with worm agitator of periodical work. What is specific about the process taking place in the mixer is that an additional ingredients' recirculation, occurred which continued throughout in 30-minute mixing time. On the basis of percentages share determined in samples taken during the process, the nature of the process has been observed.
Źródło:
Inżynieria Rolnicza; 2007, R. 11, nr 6 (94), 6 (94); 105-111
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza zmian jakości wieloskładnikowych mieszanin ziarnistych na linii mieszania w przemysłowej wytwórni pasz
Analysis of quality changes of multi-component granular mixture during mixing process in industrial feed manufacturing plant
Autorzy:
Królczyk, J.
Powiązania:
https://bibliotekanauki.pl/articles/292223.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
mieszanina ziarnista
wieloskładnikowa mieszanina ziarnista
mieszalnik ślimakowy
granular mixture
multicomponent granular mixture
spiral mixer
Opis:
W artykule dokonano analizy zmian jakości trzynastoskładnikowej, niejednorodnej mieszaniny ziarnistej podczas mieszania w przemysłowym mieszalniku pasz. Jakość mieszaniny w czasie została określona za pomocą parametru jednozmiennowej analizy regresji liniowej - resztowej sumy kwadratów. Dodatkowo dokonano analizy porównawczej dla wybranych parametrów statystycznych otrzymanych wartości RSK dla mieszaniny trzynastoskładnikowej i mieszanin: dziewięcio-, dziesięcio- i dwunastoskładnikowych otrzymanych w wyniku prowadzonych wcześniej badań eksperymentalnych. Badania prowadzono na linii mieszania w przemysłowej wytwórni pasz w układzie: mieszalnik, kosz zasypowy i przenośnik kubełkowy.
Analysis of quality changes of thirteen-component, heterogeneous granular mixture during mixing in the industrial feed mixer. The quality of mixture was determined by means of a parameter of univariant analysis of linear regression - residual sum of squares. Additionally, comparative analysis was carried out for particular statistical parameters of resid. sum of squares obtained values for thirteen -component mixture and nine-, ten-, and twelve -component mixtures obtained as a result of experimental studies previously carried out. The research was performed during mixing in the industrial feed production plant operating in the following system: mixer, charging hopper and bucket conveyor.
Źródło:
Inżynieria Rolnicza; 2011, R. 15, nr 5, 5; 125-133
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Clustering instabilities, arching and anomalous interaction probabilities as examples for cooperative phenomena in dry granular media
Autorzy:
Luding, S.
Powiązania:
https://bibliotekanauki.pl/articles/1953965.pdf
Data publikacji:
1998
Wydawca:
Politechnika Gdańska
Tematy:
clustering instabilities
arching
anomalous interaction probabilities
cooperative phenomena
dry granular media
freely cooling granular material
Opis:
In a freely cooling granular material fluctuations in density and temperature cause position dependent energy loss. Due to strong local dissipation, pressure and energy drop rapidly and material moves from "hot" to "cold" regions, leading to even stronger dissipation and thus causing the density instability. The assumption of "molecular chaos" is valid only in the homogeneous cooling regime. As soon as the density instability occurs, the impact parameter is no longer uniformly distributed. The pair-correlation and the structure functions show that the molecular chaos assumption-together with reasonable excluded volume modeling-is important for short distances and irrelevant on large length scales. In this study, the probability distribution of the collision frequency is examined for pipe flow and for freely cooling granular materials as well. Uncorrelated events lead to a Poisson distribution for the collision frequencies. In contrast, the fingerprint of the cooperative phenomena discussed is a power-law decay of the probability for many collisions per unit time.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1998, 2, 3; 417-442
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis and settlement evaluation of an end-bearing granular pile with non-linear deformation modulus
Autorzy:
Sharma, J. K.
Gupta, P.
Powiązania:
https://bibliotekanauki.pl/articles/178917.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
end-bearing granular pile
relative stiffness
bearing stratum
granular pile
deformation modulus
settlement influence factor
Opis:
Ground improvement with granular piles increases the load-carrying capacity, reduces the settlement of foundations built on the reinforced ground and is also a good alternative to concrete pile. Granular piles or stone columns are composed of granular material, such as crushed stone or coarse dense sand. An analytical approach based on the continuum approach is presented for the non-linear behaviour of the granular pile. The formulation for pile element displacement is done considering the non-homogeneity of the granular pile as it reflects the true behaviour and also accounts for the changes in the state of the granular pile due to installation, stiffening and improvement effects. The present study shows that the settlement influence factor for an endbearing granular pile decreases with increase in the relative stiffness of the bearing stratum. The settlement influence factor decreases with increase in linear and non-linear non-homogeneity parameters for all values of relative length. For a shorter pile, the rate of decrease of the settlement influence factor is greater in comparison to that for a longer pile. Shear stress at the soil-granular pile interface reduces in the upper compressible portion of the granular pile and increases in the lower stiffer portion of the granular pile due to the non-homogeneity of an endbearing granular pile.
Źródło:
Studia Geotechnica et Mechanica; 2018, 40, 3; 188-201
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Use of the Inverse Problem Methodology in Analysis of Fluid Flow Through Granular Beds With Non-Uniform Grain Sizes
Autorzy:
Sobieski, Wojciech
Trykozko, Anna
Powiązania:
https://bibliotekanauki.pl/articles/2081496.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
granular media
reverse problem
Darcy
Forchheimer
Opis:
The pressure drop during water flow through two gravel beds with 2-8 and 8-16 [mm] grain size was measured across a wide range of filtration velocities, and the optimal method for calculating the coefficients for Darcy’s law and Forchheimer’s law was selected. The laws and the experimental data were used to develop a computational program based on the Finite Element Method (FEM). The results were compared, and errors were analyzed to determine which law better describes flow data. Various methods of measuring porosity and average grain diameter, representative of the sample, were analyzed. The data were used to determine the limits of applicability of both laws. The study was motivated by the observation that computational formulas in the literature produce results that differ by several orders of magnitude, which significantly compromises their applicability. The present study is a continuation of our previous research into artificial granular materials with similarly sized particles. In our previous work, the results produced by analytical and numerical models were highly consistent with the experimental data. The aim of this study was to determine whether the inverse problem methodology can deliver equally reliable results in natural materials composed of large particles. The experimental data were presented in detail to facilitate the replication, reproduction and verification of all analyses and calculations.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2021, 24(1); 83-104
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of liquefaction potential for loose minefill slopes
Autorzy:
Kudella, P.
Powiązania:
https://bibliotekanauki.pl/articles/1954561.pdf
Data publikacji:
2022-02-07
Wydawca:
Politechnika Gdańska
Tematy:
liquefaction
granular materials
hypoplasticity
instability
failure
Opis:
Uncompacted embankments of certain fine sands exhibit a spontaneous liquefaction potential, which cannot be evaluated basing on undrained shear strength alone. A novel procedure for stability analysis has been developed, basing on Hill's stability criterion and a hypoplastic constitutive law. With given relative densities, assumed initial stress states and variations of perturbation directions, stability or instability of slope sections can be assessed. Catastrophic landslides observed in the past could thus be explained.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2000, 4, 3; 439-451
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of the relations between porosity and tortuosity in granular beds
Autorzy:
Sobieski, W.
Lipiński, S.
Powiązania:
https://bibliotekanauki.pl/articles/950448.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
porous media
granular beds
porosity
tortuosity
Opis:
In the paper, functions describing different porosity-tortuosity relations were collected, and then the tortuosity values were calculated for a one granular bed consisting of spherical particles with normal distribution of diameters. Information about the bed porosity and particle sizes was obtained from measurements conducted for an artificial granular bed, consisting of glass marbles. The results of calculations were compared with the results of two other methods of tortuosity determination, performed for the same case (details are not described in this paper): the first of them uses the Path Tracking Method, the second one - information about the velocity components in a creeping flow (the Lattice-Boltzmann Method was applied to obtain the velocity field in the flow). The main aim of our article was to test whether the functions linking tortuosity with porosity, which are available in the literature, give similar results as the methods described above. To achieve this aim, the relative errors between results of calculations for the collected formulas and values from the both previous mentioned methods were calculated.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2017, 20(1); 75-85
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational domain discretization for CFD analysis of flow in a granular packed bed
Autorzy:
Sosnowski, Marcin
Gnatowska, Renata
Sobczyk, Jacek
Wodziak, Waldemar
Powiązania:
https://bibliotekanauki.pl/articles/281600.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
granular materials
computational domain
discretization
CFD
Opis:
The paper reports results of an analysis concerning the infuence of a computational domain discretization method on the numerical stability of a model as well as the calculation error. The topology of a packed bed of a granular material consisting of granules contacting tangentially in one point makes the modeling of heat and mass transfer due to the fluid flow in such a domain a chalenging task. Therefore, the contribution of this paper constitutes a summary of discretization methods with discussion and guidelines allowing one to effectively select the most favourable method dedicated to discretization of the domain. The validation using Particle Image Velocimetry and evaluation of the impact of inflow velocity on the experimental and numerical research results are also presented in the paper.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 4; 833-842
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Basic set of experiments for determination of mechanical properties of sand
Autorzy:
Sawicki, A.
Mierczyński, J.
Świdziński, W.
Powiązania:
https://bibliotekanauki.pl/articles/202447.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
granular soils
mechanical properties
experimental determination
Opis:
A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 1; 129-137
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relations of granular worlds
Autorzy:
Pedrycz, W.
Vukovich, G.
Powiązania:
https://bibliotekanauki.pl/articles/908015.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
elektrotechnika
granular computing
clustering
models of collaborative computing
fuzzy models
collaboration and competition
FCM
granular modeling
Opis:
In this study, we are concerned with a two-objective development of information granules completed on a basis of numeric data. The first goal of this design concerns revealing and representing a structure in a data set. As such it is very much oriented towards coping with the underlying relational aspects of the experimental data. The second goal deals with a formation of a mapping between information granules constructed in two spaces (thus it concentrates on the directional aspect of information granulation). The quality of the mapping is directly affected by the information granules over which it operates, so in essence we are interested in the granules that not only reflect the data but also contribute to the performance of such a mapping. The optimization of information granules is realized through a collaboration occurring at the level of the data and the mapping between the data sets. The operational facet of the problem is cast in the realm of fuzzy clustering. As the standard techniques of fuzzy clustering (including a well-known approach of FCM) are aimed exclusively at the first objective identified above, we augment them in order to accomplish sound mapping properties between the granules. This leads to a generalized version of the FCM (and any other clustering technique for this matter). We propose a generalized version of the objective function that includes an additional collaboration component to make the formed information granules in rapport with the mapping requirements (that comes with a directional component captured by the information granules). The additive form of the objective function with a modifiable component of collaborative activities makes it possible to express a suitable level of collaboration and to avoid a phenomenon of potential competition in the case of incompatible structures and the associated mapping. The logic-based type of the mapping (that invokes the use of fuzzy relational equations) comes ...
Źródło:
International Journal of Applied Mathematics and Computer Science; 2002, 12, 3; 347-357
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena jakości wieloskładnikowej, niejednorodnej mieszaniny ziarnistej
An estimation of the quality of multicomponent, non-homogenous granular blend
Autorzy:
Królczyk, J.
Tukiendorf, M.
Powiązania:
https://bibliotekanauki.pl/articles/289027.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
materiał ziarnisty
niejednorodna mieszanina ziarnista
wieloskładnikowa mieszanina ziarnista
pasza
suma kwadratów reszt
granular matter
non-homogenous granular blend
multicomponent granular blend
fodder
error sum of squares
Opis:
Dotychczas stosowane miary oceny jakości mieszanin ziarnistych nie znalazły zastosowania w prezentowanych badaniach. Do oceny jakości badanych mieszanin zastosowano sumę kwadratów reszt. Badania prowadzono w mieszalni pasz zajmującej się produkcją i dystrybucją pasz dla gołębi. Mieszanie prowadzono w pionowym mieszalniku z mieszadłem ślimakowym z recyrkulacją składników. Zaprezentowano wyniki oceny jakości mieszanin 14 oraz 9 składnikowej. Analiza zmian wartości sumy kwadratów reszt w zależności od czasu mieszania pozwoliła na obserwację przebiegu procesu.
Granular blends' quality measures use have not found application in presented research in so far. For quality assessment of the presented mixtures the Error Sum of Squares (SSE) has been applied. The research has been conducted in fodder mixing plant that are utilized to production and to distribute fodders for pigeons. Mixing takes place in a vertical mixer with worm agitator with ingredients' recirculation. A quality assessment results have been presented for 14- and 9-components mixture. An analysis of changes of the SSE depending upon mixing time makes a possible observation of the run of a process.
Źródło:
Inżynieria Rolnicza; 2007, R. 11, nr 2 (90), 2 (90); 119-127
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Economical and safe method of granular material storage in silos in offshore port terminals
Autorzy:
Sondej, M.
Ratnayake, C.
Wójcik, M.
Powiązania:
https://bibliotekanauki.pl/articles/260491.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
silo
corrugated sheet
granular material
port terminal
Opis:
The article discusses issues related with storage of granular materials in silos made of corrugated sheets and reinforced with vertical ribs. Advantages and disadvantages of these structures are named, and typical technological solutions used by largest silo producers are presented. Moreover, basic assumptions of Eurocode 3 are discussed in the context of determining the buckling load capacity of a ribbed jacket. Alternative methods are indicated to determine the silo stability using analytical and FEM based methods. General conclusions are formulated with respect to designing of silos made of corrugated sheets.
Źródło:
Polish Maritime Research; 2018, 3; 62-68
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł

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