Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "porous" wg kryterium: Temat

  Lista filtrów

Dostawca treści

Wyrównaj
Wyświetlanie 1-15 z 513
Tytuł:
Fabrication and Characterization of Porous Silicon
Autorzy:
Duaa, Jabbar Hussein
Alzubaidy, Muneer H. Jaduaa
Abd, Ahmed N.
Powiązania:
https://bibliotekanauki.pl/articles/1157178.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Anodization
Nanocrystalline porous silicon
XRD
porous silicon
Opis:
In this work, nanocrystalline porous silicon layers were fabricated by photoelectrochemical etching of n type silicon (n-Si) wafer. Different etching time (15, 20, 25 and 30) min and 10 mA/cm2 current density were tested to study their effect on the formation nanosized pore array. Porous silicon is investigation by X-Ray diffractions (XRD) and atomic force microscopy properties (AFM). Crystallites size was estimated by X-Ray diffraction. Atomic Force microscopy confirmed the nonmetric size Chemical Anodization the electrochemical etching was noticed of PS. The atomic force microscopy investigation showed the rough silicon surface which increased with etching time porous structure nucleates which leads to an increase in the depth and width (diameter) of surface pits.
Źródło:
World Scientific News; 2018, 94, 2; 321-328
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of piezoelectricity on bulk waves in monoclinic poro-elastic materials
Autorzy:
Gupta, V.
Vashishth, A. K.
Powiązania:
https://bibliotekanauki.pl/articles/281774.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
piezoelectricity
porous
monoclinic
Opis:
Piezoelectric materials are materials which produce electric field when stress is applied and get strained when electric field is applied. Piezoelectric materials are acting as very important functional components in sonar projectors, fluid monitors, pulse generators and surface acoustic wave devices. Wave propagation in porous piezoelectric material having crystal symmetry 2 is studied analytically. The Christoffel equation is derived. The phase velocities of propagation of all these waves are described in terms of complex wave velocities. The effects of phase direction, porosity, wave frequency and piezoelectric interaction on the phase velocities are studied numerically for a particular model.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 2; 571-577
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porous silicon: fabrication, characterization and photoelectronic applications
Autorzy:
Shuihab, Aliyah A.
Khalf, Surour A.
Powiązania:
https://bibliotekanauki.pl/articles/1177955.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Anodization
FTIR & AFM
Nanocrystalline porous silicon
XRD
porosity
porous silicon
Opis:
In this paper, the nanocrystalline porous silicon (PS) films are prepared by electrochemical etching of p-type silicon wafer with current density (15 mA/cm2) and etching times on the formation nanosized pore array with a dimension of around different etching time. The films were characterized by the measurement of XRD, FTIR spectroscopy and atomic force microscopy properties (AFM). We have estimated crystallites size from X-Ray diffraction about nano scale for porous silicon and Atomic Force microscopy confirms the nanometric size Chemical fictionalization during the electrochemical etching show on the surface chemical composition of PS. The etching possesses inhomogeneous microstructures that contain a -Si clusters (Si3–Si–H) dispersed in amorphous silica matrix. From the FTIR analyses showed that the Si dangling bonds of the as-prepared PS layer have large amount of Hydrogen to form weak Si–H bonds. The atomic force microscopy investigation shows the rough silicon surface, with increasing etching process (current density and etching time) porous structure nucleates which leads to an increase in the depth and width (diameter) of surface pits. Consequently, the surface roughness also increase.
Źródło:
World Scientific News; 2018, 97; 264-273
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation on the nanofluids heat transfer inside a porous inclined cavity with wavy boundary
Autorzy:
Karimi, B.
Pirmohammadi, M.
Salehi-Shabestari, A.
Powiązania:
https://bibliotekanauki.pl/articles/38610227.pdf
Data publikacji:
2020
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
free-convective heat transfer
porous medium
nanofluid
inclined porous cavity
Opis:
In the present work, a numerical study on the free-convective heat transfer in a porous media cavity with a wavy boundary was carried out. The validation was done by comparing the results with the experimental data. The cavity inclination angle, material of nanofluid, nanoparticles volume fraction, the Rayleigh number, and porosity of the medium are the parameters which are investigated in this study. Results suggested that, due to the thermophysical properties of Cu particles in water, the heat transfer rate was increased for Cu-Water nanofluid in comparison to Al2O3-Water nanofluid, while the heat transfer rate decreased by increasing the volume fraction of nanoparticles. Numerical results showed that the Rayleigh number has significant effect on the heat transfer rate so that increase in the Rayleigh number from 100 to 10 000 increased the averaged Nusselt number between 2 to 3 times. The effect of porosity on heat transfer proved that the convective heat transfer rate increased with increasing the porosity of the porous medium. The effect of inclination angle of cavity on the heat transfer rate suggested that the optimum angle of cavity causing the highest heat transfer rate from wavy wall is 45°.
Źródło:
Archives of Mechanics; 2020, 72, 6; 511-524
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of a high-speed air bearing spindle
Autorzy:
Ha, Y.-H.
Lee, D.-W.
Hwang, Y.-K.
Lee, C.-M.
Powiązania:
https://bibliotekanauki.pl/articles/1429126.pdf
Data publikacji:
2008
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
aerostatic bearing
metal foam
porous thrust bearing
porous radial bearing
Opis:
This paper investigates an air spindle with both radial and thrust air bearings of newly developing one-directional porous materials. At present, orifice type and porous type are adopted for thrust air bearings. Orifice type thrust air bearing is fabricated by machining several micro-holes on a bearing pad bearing, permeability significantly affected by particle size and machining conditions is an important factor of performance, but it is hard to c porosities is suggested. It has many micro-porosities through axial direction, so stable and plenty of air can be supplied to the thrust bearing pad. A radial air bearing also can be substituted by a radial direction porous bearing as the same reason. In case of driving parts, built-in motor type is widely applied. But it needs additional cooling parts to drop heat from a motor. So application of an air turbine drive with light-weight shaft is suggested and additionally it will reduce fabricating cost.
Źródło:
Journal of Machine Engineering; 2008, 8, 4; 25-31
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flow of conductive fluids through poroelastic media with piezoelectric properties
Przepływ cieczy przewodzącej przez ośrodek porowaty o własnościach piezoelektrycznych
Autorzy:
Telega, J.J.
Wojnar, R.
Powiązania:
https://bibliotekanauki.pl/articles/281335.pdf
Data publikacji:
1998
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
homogenization
porous medium
elektrokinetics
Opis:
The aim of this contribution is to elaborate a general framework for modelling flows of electrolytes through porous piezoelectric media. Organic materials like animal and human bones provide an example of materials to which our results apply, though in wet bones the piezoelectric effect is smaller than the electrokinetic one. Those materials may be treated as piezoelectric porous materials through which a condictive fluid flows. The present work is confined to a regular distribution of poroes. On the interfaces between the piezoelectric skeleton and conductive fluid natural jump conditions are imposed. By using the method of two-scale asymptotic expansions, the macroscopic phenomenological equations describing electrokinetics of such a two-phase structure are derived and the formulae for the effective mechanical and nonmechanical coefficients are given.
W pracy podajemy ogólny opis przepływu elektrolitu przez porowaty ośrodek piezoelektryczny. Otrzymane wyniki mogą być wykorzystane do materiałów organicznych; kości zwierząt i ludzi stanowią przykład takich materiałów, choć w kościach żywych efekt piezoelektryczny jest mniejszy od elektrokinetycznego. W niniejszej pracy ograniczamy się do regularnego (okresowego) rozkładu porów. Na powierzchniach między fazami zakładamy naturalne warunki styku. Korzystamy z metody dwuskalowych rozwinięć asymptotycznych i wyprowadzamy makroskopowe równanie fenomenologiczne dla elektrokinetyki takiego układu dwufazowego. Podajemy też wzory matematyczne na współczynniki skuteczne (zhomogenizowane), zarówno mechaniczne jak i niemechaniczne.
Źródło:
Journal of Theoretical and Applied Mechanics; 1998, 3; 775-794
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utilization of Waste Nitrocellulose Propellants by Obtaining Porous Materials
Autorzy:
Shishkov, P.
Ganev, R.
Tzvetkoff, T.
Glavchev, I.
Powiązania:
https://bibliotekanauki.pl/articles/358461.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
waste propellant
porous propellant
Opis:
Technology for utilization of waste single and double based propellants by obtaining porous propellants was worked out. The technology contains the preparation of solutions of waste propellants with concentration up to 20%, mixing with additives, forming a liquid layer with determined thickness, evaporation of some amount of the solvent, leaching liquid components with water and draying the porous propellants. The time for evaporation of some amount of the solvent was determined from the results of the rates of evaporation. The investigated additives were 1-butanol, ethylene glycol and polyethylene glycol 400. The porous propellants with specific density from 0.5 to 0.7 g/cm3 and regular distribution of voids of dimensions from 0.1 to 500 žm were obtained.
Źródło:
Central European Journal of Energetic Materials; 2011, 8, 2; 93-98
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computer aided evaluation of poroaccessibility of porous coatings outer layer on intra-osseous implants
Autorzy:
Uklejewski, R.
Winiecki, M.
Radomski, W.
Powiązania:
https://bibliotekanauki.pl/articles/285924.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
porous coatings
implants
biomaterials
Opis:
The poroaccessibility of intra-osseous implant coating is the ability of the porous coating outer layer to accommodate the ingrowing bone tissue filling its pore space and effective new bone formation mineralizing in the pores to form biomechanically functional bone - implant fixation. The poroaccessibility determines the functional features of intra-osseous implant porous coating which are called its structural-osteoinductive properties [6, 8]. The structural-osteoinductive properties can be characterized by the set of three-dimensional parameters of poroaccessibility describing the functional properties of microgeometry of implant porous coatings: the effective volumetric porosity φ Vef , the index of the porous coating space capacity VPM, the representative surface porosity φ Srep, the representative pores size pSrep, the representative angle of the poroaccessibility Ωrep and the bone-implant interface adhesive surface enlargement index ψ [3,7,1]. The original method of stereometric evaluation of the microstructural properties of intra-osseous implants porous coatings by means of the parameters of poroaccessibility [4] is based the 3D roughness profilometry and was preliminary verified during experimental tests performed on the representative examples of porous coated femoral stems and acetabular cups of various hip endoprostheses [2,5,9]. In this paper we present the possibilities of computer aiding for evaluation of the poroaccessibility of porous coating outer layer of intra-osseous implants illustrated by the measurement data from the experimental tests performed on porous coated components of various hip endoprostheses. The computer aided evaluation of the microstructure of implant porous coatings can be realized b y t he authoring application software PoroAccess_1. 0 elaborated for our purposes in our research team in Java programming language. The screen of the application software is presented in FIG. 1. The PoroAccess_1.0 software lets to perform the dynamic analysis of the surface porosity φS in function of the pores depth pd which is showed as the map of porosity situated on the right side of the screen (see FIG. 1). The application software imports results from the series of contact profilometry measurements as the 2D matrices in ASC II format and calculates the values of the poroaccessibility parameters of porous coating outer layer according to the mathematical formulas given in [3,11]. The applications software also has the module enabling 3D visualization of measured region of porous coating outer layer as the isometric plot. The presented methodology provides the characterization of the effective part of porous coating – its outer layer, which is full of pores open for penetrating bone tissue with the diameter of many macro pores surpassing 100 μm. Such size of pores, according to clinical research [1], is beneficial for bone tissue to grow into the coating, so the pore space of the porous coating outer layer participates in creating biomechanically functional bone-porous implant fixation. The set of poroaccessibility parameters characterizes some major aspects of porous coating outer layer features. The parameters describe spatial (φVef, φSrep), volumetric (VPM), hybrid (pdef, ΩMMrep) and some functional (physicochemical) properties of implant porous coatings outer layer, e.g. enhancement of the adhesive properties (ψ), which can be indirectly interpreted in the aspect of its structural-osteoinductive properties [10]. The presented methodology of characterization of implant porous coatings with use of the poroaccessibility parameters is going to be applied as a specific tool in research on designing porous coatings with functionally graded pore distribution and designed poroaccessibility. Nowadays, the best potential to manufacture implant porous coatings with designed poroaccessibility have Direct Metal Manufacturing (DMM) technologies like Selective Laser Sintering / Melting (SLS/M) or Electron Beam Melting (EBM), so the next stage of this research is the investigation on the possibilities to manufacture the porous coating with designed poroaccessibility in one of DMM technologies. The biostructural evaluation of the manufactured in DMM technologies porous coatings together with its biological evaluation in NHOst cultures is expected to provide more information about the representative features of the microstructure of the porous coatings and allow to evaluate the most advantageous poroaccessibility of their pore spaces for potential bone tissue ingrowth to be verified in further in vivo test on animal models.
Źródło:
Engineering of Biomaterials; 2011, 14, no. 109-111 spec. iss.; 42-43
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and characterization of porous composites based on polyurethanes and bioceramics
Autorzy:
Złocista-Szewczyk, N.
Król, K.
Pielichowska, K.
Powiązania:
https://bibliotekanauki.pl/articles/284700.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
porous composites
polyurethanes
bioceramics
Źródło:
Engineering of Biomaterials; 2016, 19, 138; 85
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of temperature and pore size on cell growth and proliferation on hydroxyapatite scaffolds
Autorzy:
Soukup, D.
Bacakova, M.
Pabst, W.
Gregorova, E.
Bacakova, L.
Powiązania:
https://bibliotekanauki.pl/articles/284010.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
biomaterials
porous biomaterials
scaffolds
Opis:
Porous biomaterials, especially synthetic porous ceramics, are of significant importance in bone tissue engineering, and there has been rapid growth in the medical use of these biomaterials over the last 50 years. The reason is that they are relatively easy to prepare and are available in unlimited supply, unlike the allografts and autografts that are used in clinical practice. Various hydroxyapatite (HAp) scaffolds can be prepared, using various pore-forming techniques and firing temperatures. The firing temperature significantly affects microstructural parameters such as total porosity, pore size, the interconnected pore network, and also the chemical and phase composition. Last but not least, it also affects the mechanical properties of the samples. Knowledge about these factors is therefore essential for designing a sample with the desired controlled microstructure and properties. In this work, uniaxial pressing has been used for preparing HAp disks from nanocrystalline HAp powder, using saccharose as a pore-forming agent. The highest porosity achieved (after partial sintering at 800°C) was in the range of 64.7-70.6%. The firing temperature significantly affects porosity, pore size, grain size and mechanical strength, whereas the dwell time has only a minor effect on these parameters. After firing, XRD confirmed more than 98.4% HAp in all cases. Mercury porosimetry confirmed the presence of nanosized interstitial voids for partially sintered materials and pore throat sizes of approximately 100μm (much smaller than the pore cavities), which is adequate for bone cell penetration and further ingrowth. After firing at 1200°C, the matrix is more or less fully sintered, and nanosized pores are absent or closed. The biological part of the paper summarizes the results from cell-seeding and cultivation experiments to determine the cell adhesion, proliferation, viability, mitochondrial activity and osteogenic cell differentiation on the scaffolds, and thus the biocompatibility and bioactivity of the scaffolds. The highest values for all these parameters, particularly the number of cells, were on HAp fired at 1200°C. The samples fired at 1200°C were prepared with various pore sizes (in the range of 100 - 800μm). We found that pore size has a non-significant effect on cell colonization, whereas the firing temperature has a major influence. All tested HAp samples showed a remarkable ability to adsorb proteins on their surfaces, namely albumin and fibronectin, and to promote cell adhesion. Some cytotoxic activity was observed on the samples fired at 800 and 1000°C. Possible reasons for this cytotoxicity have been discussed. However, it can be concluded that the HAp samples created in this study and fired at 1200°C hold great promise for bone tissue engineering.
Źródło:
Engineering of Biomaterials; 2012, 15, no. 116-117 spec. iss.; 127
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption efficiency of selected natural and synthetic sorbents
Autorzy:
Pavolova, H.
Bakalar, T.
Puskarova, P.
Powiązania:
https://bibliotekanauki.pl/articles/184318.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
porous surface
radius
curvature
Opis:
Sorbents are substances binding other substances on their surface. Effective sorbents have a porous surface. The adsorption activity of the surface is closely related to the local radius of curvature of surface irregularities. Suitable sorbents are natural and synthetic solids of amorphous or microcrystalline structure (Kyncl et al. 2008). Globally, the following adsorbents are the most used: activated carbon, zeolites, silica gel, activated alumina (Bakalár et al. 2005). A characteristic of effective adsorbents is large surface area of hundreds of square meters multiply by gram to the power of minus one [m 2 ∙g −1 ]. Other important features of adsorbents include specific volume, porosity, average pore diameter, pore distribution, etc. Some natural materials or industrial waste with high adsorption capacity, which naturally reduces the overall cost of their disposal, can be used for adsorption of heavy metal cations. Some of low-cost sorbents are: lignin, chitin, seaweed/ algae, zeolites, clays, fly-ash, peat, sand grains coated with iron oxide, modified cotton and wool (Pavolová et al 2006). In experiments of Cu and Zn removal from wastewater the following adsorbents were used (Bakalár et al. 2005): - Lewatit S100, which is strongly acidic, gel-like cationic ion exchange resin with particles of equal size based on styrene-divinylbenzene copolymers. Monodisperse beads are chemically and osmotically highly stable. - Chitosan, which is prepared from chitin, naturally occurring in the shells of crustaceans, by deacetylation using strongly alkaline solution. Chitin is a homopolymer composed of β-(1-4)- -N-acetyl-D-glucosamine. The ability of crustaceans shells to bind metal ions is assigned to the presence of exoskeleton in the molecule of chitin and chitosan. - Synthetic zeolite, which is included in the group of aluminosilicates, was prepared by zeolitization of fly-ash from energy industry. - Bentonite, which is included in the group of hydrated aluminosilicates, the main ingredient is mineral montmorillonite. - Slovakit, which is an inorganic composite sorbent made from pure natural ingredients. Its composition is a subject of patent protection. The aspect of time, i.e. the time the specific sorbent reaches the maximum adsorption capacity for the heavy metal removed, is also important in removal of Cu 2+, Zn 2+ and Pb 2+ cations. The experimental measurements of cations adsorption using the above mentioned sorbents are made at the initial concentration of 10 mg∙L −1 of heavy metal. The time to reach the equilibrium for all sorbent during separation of Cu 2+ cations from model solutions of wastewater was about 60 seconds except for chitosan for which it was almost 2 minutes. This is relatively very good result. The equilibrium of Zn 2+ cations adsorption at the experimental measurements for all the selected sorbents was reached in about 80 seconds except for chitosan for which this time was 2 minutes 5 seconds. This time was on average around 20 minutes longer compared to the adsorption of Cu 2+ ions. The adsorption of Pb 2+ cations was carried out at the experimental measurements in about 83 seconds for all the selected sorbents, except for synthetic zeolite for which the time was 1 min 15 seconds. The adsorption of Pb 2+ cations compared to the cations of Cu 2+ was 23 seconds faster and compared to the cations of Zn 2+ was 3 seconds longer. The most appropriate for the removal of Cu 2+, Zn 2+, and Pb 2+ is Lewatit S100 among the used sorbents; the equilibrium was reached in approximately 35 seconds, 45 seconds, and 83 seconds for Zn 2+, Cu 2+, and Pb 2+, respectively. According to the experimental measurements the longest adsorption time was for chitosan – about 2 minutes for Cu 2+ and Zn 2+, and about 1.5 minutes for Pb 2+.
Źródło:
Geology, Geophysics and Environment; 2016, 42, 1; 114-115
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of mass-transfer process in porous media with complex shape : [abstract]
Autorzy:
Ualyiev, Z.
Kaltayev, A.
Bekbauov, B.
Powiązania:
https://bibliotekanauki.pl/articles/300046.pdf
Data publikacji:
2007
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
ośrodek porowaty
porous medium
Opis:
Some rare minerals and metals are extracted by underground leaching. Thus sorption extraction of minerals on mass-transfer devices with use ion-exchange resin is the most widespread method of productive solutions processing. Now wide application finds sorbing device which represents the cylindrical column, filled by a layer of ion-exchange resin in the form of spherical porous granules. Through a column from below upwards with the filtration velocity the solution containing sorbing a mineral is pumped over. Velocity of solution admission is calculated off on kinetic parameters. A cone barrier located before a submitting pipe is intended for achievement of uniform distribution of a solution across a column [fig.]. On an output from a column through certain time tests of a solution which are analyzed on the maintenance in them of mineral are selected. Sorption proceeds until concentration of mineral on an outlet from a column will not be equal some admissible value. After that the saturated layer of a sorbent being below by a mineral is unloaded. Sorbing device from above is supplemented with a fresh sorbent and process repeats. There are some questions, a degree of an involvement of a sorbent in mass-transfer process (especially, in a transverse direction of a column) and change of column resistance depending on the size and forms of cone barrier, influence of dispersive and kinetic characteristics on thickness of the saturated layer.
Źródło:
Wiertnictwo, Nafta, Gaz; 2007, 24, 1; 57-58
1507-0042
Pojawia się w:
Wiertnictwo, Nafta, Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interaction of elastic waves with a fluid-saturated porous solid boundary
Oddziaływanie fal sprężystych z brzegiem nasyconego płynem ośrodka porowatego
Autorzy:
Cieszko, M.
Kubik, J.
Powiązania:
https://bibliotekanauki.pl/articles/281300.pdf
Data publikacji:
1998
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
saturated porous solids
wave reflection
Opis:
The problem of energy reflection and transmission of an oblique incident plane harmonic wave at the surface of an elastic porous solid halfspace immersed in fluid is considered. The case of pure elastic behaviour of the system with incompressible material of skelton is analysed. Considerations are based on the two parametric theory of fluid-saturated porous solid in which the isotropic pore structure is described by the volume porosity and the parameter characterising tortuosity of pores. The influence of mechanical properties of both the physical constituents and angle of wave incidence on the energy reflection and transmission coefficients is analysed. Two general cases of the wave interaction are investigated: waves incident from the bulk fluid on the surface of porous halfspace, and waves (fast, slow and shear) incident from a fluid-saturated porous solid. Calculations have been made for the system composed of porous fused glass bead solid filled with water in one case and with ethyl alcohol in the other case and diagrams of the results have been shown.
W pracy rozważono zagadnienie odbicia i przenikania fal harmonicznych ukośnie padających na powierzchnię porowatej półprzestrzeni zanurzonej w płynie. Przeanalizowano czysto sprężyste zachowanie się układu o nieściśliwym materiale szkieletu. Do rozważań wykorzystano dwuparametrową teorię deformowalnego ośrodka porowatego nasyconego płynem, w której struktura porów szkieletu charakteryzowana jest przez porowatość objętościową i krętość porów. Przeanalizowano wpływ mechanicznych własności składników fizycznych oraz kąt padania fali na energetyczne współczynniki odbicia i przenikania fal. Rozważono dwa przypadki: gdy fala pada na powierzchnię porowatej półprzestrzeni od strony samego płynu oraz przypadek, gdy fale (szybka, wolna i poprzeczna) padają od strony nasyconego płynem porowatego ośrodka. Obliczenia przeprowadzono dla ośrodka porowatego ze spiekanych kulek szklanych wypełnionych wodą w jednym przypadku oraz alkoholem etylowym w drugim przypadku.
Źródło:
Journal of Theoretical and Applied Mechanics; 1998, 3; 561-580
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The phenomenon of colmatage as a generalization of filtration
Zjawisko kolmatacji jako uogólnienie filtracji i jego wpływ na zmianę porowatości i ciśnienia
Autorzy:
Trzaska, A.
Sobowska, K.
Powiązania:
https://bibliotekanauki.pl/articles/281330.pdf
Data publikacji:
1998
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
suspension
porous media
filtration
colmatage
Opis:
In this paper various models of the process of colmotage are presented. Three kinds of kinetics are discussed, describing the course of this phenomenon, and the relevant systems of partial differential equations. Examples of the solutions of these equations, are given and the function of porosity of a medium during the colmatage process, is determined from these equations. Besides, by introducing the adequate equation of motion, the way of determining the pressure distribution in a medium when the flow proceeds at the assumed discharge and at the constant difference of pressure, Eq, is presented. In the latter case the discharge of flow as a descreasing function of time Eq is additionally determined. Calculations are made for each kinetics. The diagram enclosed illustrates the distribution of pressure versus time t when the flow proceeds at a constant pressure difference. It should be noticed that the distribution obtained from the theory of colmatage at the moment t = 0 agrees with that obtained when Darcy's law is applied.
W pracy zaprezentowano różne modele przebiegu zjawiska kolmatacji. Omówiono mianowicie trzy kinetyki opisujące przebieg zjawiska oraz odpowiadające im układy równań różniczkowych cząstkowych. Przedstawiono przykłady rozwiązań tych układów i wyznaczono w ich wyniku funkcję porowatości ośrodka w trakcie trwania procesu kolmatacji. Ponadto wprowadzając odpowiednie równanie ruchu przedstawiono sposób określenia rozkładu ciśnienia w ośrodku w przypadku gdy przepływ następuje przy zadanym wydatku oraz przy stałej różnicy ciśnień. W tym drugim przypadku wyznaczono dodatkowo wydatek przepływu jako funkcję malejącą czasu. Obliczenia podano dla wszystkich trzech kinetyk. Zamieszczony wykres ilustruje rozkłady ciśnienia dla różnych chwil t, przy przepływie realizowanym przy stałej różnicy ciśnień. Należy zwrócić uwagę, że w chwili t = 0 uzyskany z teorii kolmatacji rozkład pokrywa się z rozkładem uzyskanym z przwz Darcy'ego.
Źródło:
Journal of Theoretical and Applied Mechanics; 1998, 3; 807-817
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Colmatage accompanying the flow of gasified liquid through porous media
Kolmatacja towarzysząca przepływowi zgazowanej cieczy przez ośrodki porowe
Autorzy:
Trzaska, A.
Sobowska, K.
Powiązania:
https://bibliotekanauki.pl/articles/281339.pdf
Data publikacji:
1998
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
colmatage
filtration
porous media
suspension
Opis:
The paper deals with a flow of liquid containing dissolved gas though a porous medium. Due to a pressure drop below the saturation pressure along the flow course, bubbles of gas can be emitted in the liquid. They are deposited in the pores of medium, desreasing its porosity and permeability. Thus, the phenomenon of colmatage occurs. This process is described by Henry's equations , the equations of balance transport , motion which initial boundary conditions taken into consideration. Basing on these equations there are obtained: function of the position and time of medium porosity e (x, t), function of the pressure distribution h (x,t), and time-dependent discharge of flow q (t). Diagrams of these functions are shown.
Tematem prac jest przepływ cieczy zawierającej rozpuszczony gaz przez ośrodek porowaty. W wyniku spadku ciśnienia poniżej ciśnienia nasycenia na drodze przepływu może dochodzić do wytrącania się gazu w postaci pęcherzyków. Osadzają się one w przestrzeni porowej ośrodka doprowadzając do zmniejszenia jego porowatości i przepuszczalności. Zachodzi więc zjawisko kolmatacji. Proces ten opisano równaniami Henry'ego, bilansu transportu i ruchu, z uwzględnieniem warunków początkowo-brzegowych. W oparciu o te równania uzyskano funkcję położenia i czasu porowatości ośrodka e (x,t), rozkładu ciśnienia h(x,t), oraz wydatek przepływu w funkcji czasu q (t). Wykresy tych funkcji ilustrują rysunki.
Źródło:
Journal of Theoretical and Applied Mechanics; 1998, 3; 795-806
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 513

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies