Dissertations / Theses on the topic 'Porous Liquid'
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Stevar, M. S. P. "Dissolution dynamics of liquid/liquid binary mixtures in porous media." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/349974/.
Full textShin, Youn-Ok. "Vapor and liquid equilibria in porous media." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0022/MQ50659.pdf.
Full textShin, Youn-Ok 1971. "Vapor and liquid equilibria in porous media." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21323.
Full textMonser, Lotfi Ibrahim. "Modified porous graphitic carbon for liquid chromatography." Thesis, University of Hull, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318379.
Full textRusso, Ann. "Immiscible Liquid Dissolution in Heterogeneous Porous Media." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/194522.
Full textGuo, Tianle. "Effects of buoyancy forces on miscible liquid-liquid displacements in porous media." Thesis, University of Ottawa (Canada), 1994. http://hdl.handle.net/10393/6825.
Full textZhdanov, Sergey. "Kinetics of spreading over porous substrate." Thesis, Loughborough University, 2002. https://dspace.lboro.ac.uk/2134/33884.
Full textPourmand, Payam. "NMR detection of liquid dynamics in porous matrices." Thesis, KTH, Skolan för kemivetenskap (CHE), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145864.
Full textDias, H. "Gas and liquid chromatography on porous graphitic carbon." Thesis, University of Edinburgh, 1990. http://hdl.handle.net/1842/13643.
Full textWan, Quian-Hong. "Surface modification of porous graphite for liquid chromatography." Thesis, University of Edinburgh, 1992. http://hdl.handle.net/1842/13187.
Full textTran, Kien Nguyen. "Modelling of vapour-liquid phase equilibrium and adsorptions on non-porous and porous carbon /." St. Lucia, Qld., 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17383.pdf.
Full textDamronglerd, Piyasak Zhang Yuwen. "Infiltration and solid-liquid phase change in porous media." Diss., Columbia, Mo. : University of Missouri--Columbia, 2009. http://hdl.handle.net/10355/6143.
Full textAl-Saffar, H. B. S. "Fluid flow through porous media : liquid distribution and mass transfer." Thesis, Swansea University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635715.
Full textGLADDING, SARAH M. "POROUS INORGANIC SUPPORTED LIQUID MEMBRANES FOR USE IN ION CHANNELING." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1109343185.
Full textPalakurthi, Nikhil Kumar. "Direct Numerical Simulation of Liquid Transport Through Fibrous Porous Media." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1406881191.
Full textColeman, Nicholas Richard Boldero. "Direct liquid crystal templating of mesoporous silica and platinum." Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302011.
Full textTörnkvist, Anna. "Aspects of porous graphitic carbon as packing material in capillary liquid chromatography /." Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3306.
Full textPastore, Andrea. "Syngas production from heavy liquid fuel reforming in inert porous media." Thesis, University of Cambridge, 2010. https://www.repository.cam.ac.uk/handle/1810/237704.
Full textWhelan, Michael P. "Dissolution of non-aqueous phase liquid pools in saturated porous media." Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/20140.
Full textNikolopoulos, Panagiotis. "Mass transfer in non-aqueous phase liquid contaminated heterogeneous porous media." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611535.
Full textKaur, Bulvinder. "Porous graphitic carbon : a new material for high performance liquid chromatography." Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/12218.
Full textKuzmich, A. G., D. A. Andrusenko, P. A. Teselko, M. V. Isaiev, and R. M. Burbelo. "Examination of Thermally Induced Deformations of Composite System “Porous Silicon – Liquid”." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35171.
Full textOladyshkin, Sergey. "Découplage de la thermodynamique et hydrodynamique et solutions asymptotiques des problèmes d'écoulement compositionnel gaz-liquide en milieux poreux." Thesis, Vandoeuvre-les-Nancy, INPL, 2006. http://www.theses.fr/2006INPL059N/document.
Full textThe present work deals with the problem of the compositional gas-liquid flow for the well representation in reservoir simulations. The objective is to develop analytical relationships which would be able to link the wellbore pressure, saturation and component concentrations to their mean values within each zone of the well influence. It is shown that N-2 equations describing the transport of phase concentrations can be transformed into the space- and time-independent ordinary differential equations (differentiation with respect to pressure) when examined along flow streamlines. These transformed equations represent additional thermodynamic relations reducing the thermodynamic degree of freedom. Due to this the thermodynamic variance of the limit compositional model is shown to be equal to 1 for any number of chemical components. This transformation ensure a total splitting of the limit compositional model into the new thermodynamic model and a hydrodynamic model, which may be resoved inedpendently of one another. The split thermodynamic model is totally independent on the hydrodynamic one, and describes the equilibrium behaviour of an open gas-liquid system. This model contains the classic equilibrium equations and EOS, as well as N-2 new differential equations called the "delta-law" which determine the composition variation in an open system, in which the mass of each component is not conserved. The split hydrodynamic model consists of two equations for pressure and saturation. The split hydrodynamic model was used to develop asymptotic solutions of gas-condensate flow problems. The problem was shown to be singularly perturbed with formation of a boundary layer in the vicinity of the well. In this layer the basic contrast property of gas and liquid mobilities is perturbed. A special technique is developed which enables to construct asymptotic expansions in the form of two various series, one of them is valid far from the well (the exterior expansion), while the second one in valid in the vicinity of the well (the boundary-layer or interior expansion). By applying the suggested asymptotic method, we have developed the asymptotic solutions for the problem of multi-component gas-condensate flow to a well in a bounded domain at a variable flow rate. In several cases the solution may be obtained in the analytical form, while in general case of flow the method leads to a semi-analytical solution presented as an initial problem for a differential equation. This solution, even being presented in non-analytical form, is much simpler than the original compositional model, as the equation for saturation does not depend on the local pressure, but on the boundary pressure only. In the last chapter we extended this approach to the case when the capillary pressure is not neglected. We assumed however that the capillary forces are lower than the pressure difference between the wellbore and reservoir boundary, due to which we applied the perturbation method over the small inverse capillary number. The improved asymptotic solutions are obtained which take into account the capillary effect. Numerical simulations shown that these effects are maximal in the vicinity of the well. For the practice, the obtained asymptotic solutions may be used in the following way to resolve the problem of gas-condensate well representation. The case of a long-term exploitation of the reservoir}. First of all, the traditional simulation of the reservoir behaviour can be performed with ECLIPSE by adding the Peaceman method of well representation, which is an analytical relation for the wellbore pressure via the production rate. This relation includes a condensate saturation which can be evaluated as a mean reservoir saturation. Such a simulation provides a good result for the wellbore pressure (or the production rate), and a good result for the boundary saturation, but poor data for the wellbore saturation. This value can be calculated next by using the asymptotic solutions suggested in the presented project. The case of a short-term well production (a well test). It is sufficient to simulate the reservoir behaviour in the domain of the well influence, by assuming that the boundary state remains invariable (and known a priori). In this case the asymptotic solutions suggested in the presnet work can be directly used to simulate the problem (without using ECLIPSE)
Nguyen, Khac Long. "Multiscale analysis of transport in porous media." Thesis, Aix-Marseille, 2019. http://theses.univ-amu.fr.lama.univ-amu.fr/190522_NGUYEN_156sqbpnr595zlxet195ycj854nvqyn_TH.pdf.
Full textThe correlation of the structural parameters with the transfer properties of a fluid through a porous media is a significant subject in physics, chemistry, geology, and engineering. The architectural parameters such as porosity and pore size distribution do not describe the complexity of most porous organizations consisting of labyrinths of interconnected pores with random shapes and cross-sections. This complexity is described by a parameter called tortuosity. The apparent total and particle tortuosities are determined by electrical measurements or the analysis of the peak shape of chromatographic probes. In the latter case, the particle tortuosity of silica is calculated from effective intraparticle diffusion coefficient determined by modelling the chromatographic peak broadening of polystyrenes obtained either in dynamic or in static conditions under non-adsorbing conditions by using the solvent tetrahydrofuran (THF). In dynamic conditions, the constant term in the van Deemter equation is a combined contribution of eddy diffusion and polydispersity of the polystyrenes and depends on the size of the molecule. The broad pore size distribution of totally porous silica contributes also to the spreading of the peak. The transport of polystyrenes through silica columns has also been studied in adsorbing conditions by changing the solvent. With the mixture of n-Heptane and THF, one obtains many peaks for a polystyrene sample due to the polydispersity of the polystyrene. In fact, the adsorption increases with the molecular weight of the polystyrenes. The surface diffusion of polystyrene decreases with an increase in the retention factor
Swan, Geoffrey Ian. "Structural studies of formic acid and water in porous silica by neutron diffraction." Thesis, University of Kent, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328234.
Full textHemming, Ellen. "Exploring the application of porous and ionic liquids for sustainable chemistry." Thesis, The University of Sydney, 2019. https://hdl.handle.net/2123/22103.
Full textGuo, Tianle. "Experimental and theoretical studies of the effects of buoyancy forces on liquid/liquid displacement processes in porous media." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq26121.pdf.
Full textTörnkvist, Anna. "Aspects of Porous Graphitic Carbon as Packing Material in Capillary Liquid Chromatography." Doctoral thesis, Uppsala University, Analytical Chemistry, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3306.
Full textIn this thesis, porous graphitic carbon (PGC) has been used as packing material in packed capillary liquid chromatography. The unique chromatographic properties of PGC has been studied in some detail and applied to different analytical challenges using both electrospray ionization-mass spectrometry (ESI-MS) and ultra violet (UV) absorbance detection.
The crucial importance of disengaging the conductive PGC chromatographic separation media from the high voltage mass spectrometric interface has been shown. In the absence of a grounded point between the column and ESI emitter, a current through the column was present, and changed retention behaviors for 3-O-methyl-DOPA and tyrosine were observed. An alteration of the chromatographic properties was also seen when PGC was chemically oxidized with permanganate, possibly due to an oxidation of the few surface groups present on the PGC material.
The dynamic adsorption of the chiral selector lasalocid onto the PGC support resulted in a useful and stable chiral stationary phase. Extraordinary enantioselectivity was observed for 1-(1-naphthyl)ethylamine, and enantioseparation was also achieved for other amines, amino acids, acids and alcohols.
Finally, a new strategy for separation of small biologically active compounds in plasma and brain tissue has been developed. With PGC as stationary phase it was possible to utilize a mobile phase of high content of organic modifier, without the addition of ion-pairing agents, and still selectively separate the analytes.
Richardson, David Jeremy. "Enhanced mass transport in liquid-saturated porous media due to surface shear." Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/27112.
Full textJohns, M. L. "MRI studies and modelling of two phase-liquid systems in porous media." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.605617.
Full textArdelean, Ioan, German Farrher, Carlos Mattea, and Rainer Kimmich. "From "fast" to "slow" liquid-vapor exchange in partially filled porous media." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-194922.
Full textSaito, Haruko. "Formation Process and Liquid Transport of Sol-gel Derived Monolithic Porous Silica." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/57273.
Full textHippauf, Felix. "Tailoring Pore Size and Polarity for Liquid Phase Adsorption by Porous Carbons." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-223482.
Full textPizzoccaro, Marie-Alix. "Confinement et greffage de liquides ioniques dans des membranes céramiques mésoporeuses pour le transport sélectif du CO2." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTS007/document.
Full textIn competition with amines, ionic liquids (ILs) are known to interact strongly and reversibly with acid gases, making supported IL-membrane (SILMs) versatile materials for use in CO2 membrane separation applications. It is possible to finely tune SILMs properties for CO2 adsorption/separation by tailoring the characteristics of both the support (e.g., porosity, surface area, composition, etc.) and the ionic liquid (cations and anions). Up to now, nanoporous polymer supports have been favored for preparing SILMs, in spite of their relative instability during continuous separation processes in the presence of acidic gases. Recently, porous ceramic supports have been considered due to their excellent thermal and mechanical resistance. Most of the SILMs are prepared by impregnation/infiltration of IL in the pores of ceramic support which leads to the formation of composite membrane materials with either a physisorbed or mechanically trapped IL in the support. Despite their promising performance, such SILMs exhibit inherent limitations such as facile IL disarrangement, heterogeneous distribution, and limited stability upon ageing.In this Ph.D work, carried out in collaboration between the Institut Européen des Membranes (IEM) and the Institut Charles Gerhardt de Montpellier (ICGM), a new generation of SILMs has been developed in which ILs are confined within the pores of a mesoporous ceramic support by chemical grafting. The membranes are prepared in three steps:i) Synthesis and characterization of new ILs bearing a coupling function which allow the grafting on the surface of ceramic oxide supports and determination of the CO2 absorption capacity of the new ILs developed;ii) Elaboration and/or optimization of relevant synthesis protocols for grafting ILs on/in γ-alumina powders and physico-chemical characterizations of the hybrid materials;iii) Transfer of the optimized grafting protocols on commercial porous ceramic support with γ-alumina top-layer to produce Grafted Ionic Liquid Membranes (GILMs) and evaluate their performance for CO2 separation.An original research strategy, based on new ionic liquids and innovative membrane concepts have been addressed in this work, illustrating the contribution of a multi-step approach towards the development of membranes for CO2 separation
Gamero, Rafael. "Mass transfer during isothermal drying of a porous solid containing multicomponent liquid mixtures." Licentiate thesis, KTH, Chemical Engineering and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1748.
Full textMass transfer in a porous solid, partially saturated with asingle solvent and multicomponent liquid mixtures, has beenexperimentally and theoretically studied. A porous materialcontaining single liquids and mixtures of organic solvents wasisothermally dried. Experiments were performed using a jacketedwind tunnel, through which a humidity andtemperature-controlled air stream flowed. The wetted porousmaterial was placed in a cylindrical vessel, whose top isexposed to the air stream until the material became dried to acertain extent. Drying experiments with the single solventswater, methanol, ethanol and 2-propanol, were performed atdifferent temperatures and transient liquid content profileswere determined. In isothermal drying experiments with liquidmixtures,the transient concentration profiles of thecomponents along the cylindrical sample as well as the totalliquid content were determined. The liquid mixtures examinedwere water-methanolethanol and isopropanol-methanol-ethanol.Two different temperatures and initial compositions were usedin the experiments. Mathematical models that describe nonsteadystate isothermal drying of a solid containing single liquidsand multicomponent liquid mixtures were developed. In the solidwetted with a single liquid, capillary movement of the liquidwas the main mechanism responsible for mass transfer. In thesolid containing liquid mixtures, interactive diffusion inliquid phase was superimposed to the capillary movement of theliquid mixture. In addition, interactive diffusion of thevapours in empty pores was considered. The parameters todescribe the retention properties of the solid and thecapillary movement of the liquid were determined by comparingtheoretical and experimental liquid content profiles obtainedduring drying of the solid wetted with single liquids. Tosimulate the transport of the liquid mixtures these parameterswhere weighed according to liquid composition. A fairly goodagreement between theoretical and experimental liquidcomposition profiles was obtained if axial dispersion isincluded in the model when the moisture consists of amixture.
Keywords:Internal mass transfer, capillary flow,multicomponent, diffusion, solvent mixtures
Harding, S. G. "NMR studies of structure-transport relationships in porous media : liquid diffusion in polymers." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603691.
Full textCoslovich, Daniele, Dieter Schwanzer, and Gerhard Kahl. "Diffusion-localization and liquid-glass transitions of a colloidal fluid in porous confinement." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-190390.
Full textPham, Quang Nhat. "Fabrication of Copper Inverse Opals for Microscale Liquid Transport in Polycrystalline Porous Media." Thesis, University of California, Irvine, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10828027.
Full textThe continually increasing power density of high-performance electronics is bottlenecked by the challenges faced with thermal management requirements for reliable operation. While the traditional convective air-cooling approach is limited in its effectiveness at dissipating high heat fluxes, the use of latent heat in liquid-vapor phase change is an attractive strategy for managing the most aggressive thermal loading demands. Passive two-phase cooling operates by capillary pumping fluid through void spaces within porous metals to transport energy over long distances. The performance of such liquid delivery through porous structures is governed by the pore distribution, porosity, and morphology. Analogous to energy transport in polycrystalline solids, hydraulic transport in polycrystalline porous media is also limited by structural defects and grain boundaries. This work reports on the capillary performances of both single- and polycrystalline microporous copper with varying pore diameters from 300 to 1000 nm. The hydraulic transport through the arrays of interconnected spherical pores is modeled and quantified with experimental wicking measurements, and the influence of grain boundaries on the hydraulic transport in polycrystalline microporous media contributes to the hydraulic resistance presented by the structural defects. By combining multiple pore diameters and systematically layering them, this study creates heterogeneous porous media to emulate the transport within biological systems. The gradient layering of pores enhances the liquid delivery by circumventing grain boundary defects in three dimensions. The fundamental understanding of hydraulic transport physics through porous crystals and boundaries will pave the way for the spatial design of heterogeneous porous materials for future capillary-driven technologies.
Coslovich, Daniele, Dieter Schwanzer, and Gerhard Kahl. "Diffusion-localization and liquid-glass transitions of a colloidal fluid in porous confinement." Diffusion fundamentals 11 (2009) 58, S. 1-2, 2009. https://ul.qucosa.de/id/qucosa%3A14023.
Full textCarroll, Kenneth Cooper. "Characterization, Dissolution, and Enhanced Solubilization of Multicomponent Nonaqueous Phase Liquid in Porous Media." Diss., The University of Arizona, 2007. http://hdl.handle.net/10150/195399.
Full textBai, Guiyun 1964. "Biosurfactant-enhanced nonaqueous phase liquid (NAPL) removal and bacterial transport in porous media." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282451.
Full textYien, Linen Ling-Ying. "An investigation into the electro-convective motions of liquid hydrocarbons in porous media." Thesis, University of Bristol, 1992. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333873.
Full textTytarenko, A. I., D. A. Andrusenko, M. V. Isaiev, and R. M. Burbelo. "Investigation of Heat Transfer in Nanocomposite Structures “PS-liquid” Using Photoacoustic Method." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35111.
Full textAfonso, Josiana Prado. "Towards cryogenic liquid –vapor energy storage units for space applications." Doctoral thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10158.
Full textWith the development of mechanical coolers and very sensitive cryogenic sensors, it could be interesting to use Energy Storage Units (ESU) and turn off the cryocooler to operate in a free micro vibration environment. An ESU would also avoid cryogenic systems oversized to attenuate temperature fluctuations due to thermal load variations which is useful particularly for space applications. In both cases, the temperature drift must remain limited to keep good detector performances. In this thesis, ESUs based on the high latent heat associated to liquid-vapor phase change to store energy have been studied. To limit temperature drifts while keeping small size cell at low temperature, a potential solution consists in splitting the ESU in two volumes: a low temperature cell coupled to a cryocooler cold finger through a thermal heat switch and an expansion volume at room temperature to reduce the temperature increase occurring during liquid evaporation. To obtain a vanishing temperature drift, a new improvement has been tested using two-phase nitrogen: a controlled valve was inserted between the two volumes in order to control the cold cell pressure. In addition, a porous material was used inside the cell to turn the ESU gravity independent and suitable for space applications. In this case, experiments reveal not fully understood results concerning both energy storage and liquid-wall temperature difference. To capture the thermal influence of the porous media, a dedicated cell with poorly conductive lateral wall was built and operated with two-phase helium. After its characterization outside the saturation conditions (conduction, convection), experiments were performed, with and without porous media, heating at the top or the bottom of the cell with various heat fluxes and for different saturation temperatures. In parallel, a model describing the thermal response for a cell containing liquid and vapor with a porous medium heated at the top (“against gravity”) was developed. The experimental data were then used as a benchmark for this model based on a balance of three forces: capillarity force, gravity force and pressure drop induced by the liquid flow.
Fundação da Ciência e da Tecnologia - PhD scholarship(SFRH/BD/60357/2009); project “Cryogenic Temperature Stabilizers” (PTDC/EME-MFE/101448/2008)
Ross, P. "The use of porous graphitic carbon in liquid chromatography performance and polar retention effect." Thesis, University of Edinburgh, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529492.
Full textHaeri, Nejad Masoud. "Drying of Porous Particles containing Liquid Mixtures in a Continuous Vibrated Fluid Bed Dryer." Thesis, KTH, Skolan för kemivetenskap (CHE), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-156215.
Full textInverkan av driftparameter på torkning av sfäriska porösa partiklar som innehåller lösningsmedelblandningar som avdunstar i kväve i en kontinuerligt viberande fluidbädd-tork studerades. En simuleringsmodell baserad på den analytiska lösningen till värme- och materieöverföringsekvationerna användes och ändringar föreslogs. Fyra olika tärnar vätskeblandningar valdes: aceton-kloroform-metanol(ACM), etanol-2- propanolvatten,(EIpW), vatten-etanol-etylacetat (WEEa) och etanol-metyletylketon- toluen(EMekT). För den fasta fasen användes fysikaliska egenskaper liknande Pyrex. Sammansättnings- och temperatur-profiler visade att det inte finns något motstånd mot värmeöverföring i den fasta fasen och att värmeöverföringen sker mycket snabbare än materieöverförningen. Selektivitetsdiagram ritades. Resultaten indikerar att selektivititen är en viktig parmeter för att förutsäga beteendet vid torkning. Retentionsförhållandet användes som ett prestandamått. Dess variation med avseende på förändringar av driftsparmetrar, bland annat gasen hastighet och temperatur samt den fasta fasens temperatur och partikelstorlek, studerades. En modifiering av modellen undersöktes genom att införa en vätskehalts-beroende faktor för diffusionsmotståndet. Detta minskade värdena på retentionsförhållandena. Vibrationens inverkan på värme- och materieöverföring infördes genom att använda Sbrodov samband, och den resulterande effekten på retentionsförhållandet observerades.
Noman, Rashed. "High velocity gas flow in porous media : effects of pore structure and liquid saturation." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47205.
Full textLapkin, Alexei A. "Porous membrane phase contactor for gas-liquid homogeneous catalytic reactions : direct hydration of propene." Thesis, University of Bath, 2000. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760743.
Full textCourtney, Daniel George. "Ionic liquid ion source emitter arrays fabricated on bulk porous substrates for spacecraft propulsion." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/67173.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 305-321).
Ionic Liquid Ion Sources (ILIS) are a subset of electrospray capable of producing bipolar beams of pure ions from ionic liquids. Ionic liquids are room temperature molten salts, characterized by negligible vapor pressures, relative high conductivities and surface tensions lower than water. Compared with the colloid form of electrospray, renowned for its applications to spectroscopy, ILIS yield highly monoenergetic beams composed entirely of ions. In this respect they are similar to Liquid Metal Ions Sources, but offer the ability to emit both positive and negative ions from a benign propellant that remains in the liquid state over a wide range of temperatures. When applied to spacecraft propulsion these sources are very power efficient and yield high specific impulses. Furthermore. the low flow rates and negligible vapor pressures of ionic liquids allow for passive feeding systems which can remain exposed to the vacuum of space. This configuration would remove the need for pressurized propellant tanks or valves, both of which are difficult to miniaturize for small satellites. However; the thrust produced from each emitter is very low, less than 0.1 [mu]N. As a result, compact arrays of active ILIS have been sought since their discovery. If arrays of modest packing density (~ 5 emitters/mm²) could be achieved, ILIS as thrusters would offer a scalable form of propulsion capable of providing useful thrust levels to small satellites with performance comparable to established, but difficult to miniaturize, plasma based ion engines. This research has sought a technique for creating arrays of ILIS from bulk porous substrates as part of an overall process for microfabricating complete thrusters. The thesis includes a survey of potential fabrication methods considering both suitability for forming arrays of ILIS and the ability to integrate each technique within a thruster packaging process. Electrochemical etching is highly selective and can proceed at rates which are limited by mass transport conditions. In this thesis we show how this etching regime can be exploited to smoothly remove material from the surface of a bulk porous metal substrate without damaging the internal pore structure. Dry film photoresists have been identified as a suitable alternative to spin on techniques for porous materials and have been applied within an electrochemical etching process. A two step process for forming arrays of ILIS has been motivated using numerical simulations of the etching process to predict emitter profiles and investigate the impacts of non-uniform etching conditions. These concepts have been applied experimentally using a custom built, automated, etching station capable of repeatedly producing arrays of 480 emitters spaced 500 pm apart on a 1 x 1 cm porous nickel substrate pre-mounted, and aligned, within a silicon thruster package. The emitters are typically 165 [mu]m tall with rounded tips suitable for operation as ILIS. Pulsed voltage conditions were found to significantly enhance wafer level uniformity enabling fabrication of functional emitters within a few hundred [mu]m of the substrate boundary. The structures have been smoothed and rounded, making them suitable for use as ILIS, during a secondary etch process using electrolytes doped with nickel chloride to suppress transient effects. These doped solutions enabled a few [mu]m of material to be removed selectively from the porous surface while maintaining smooth features. These arrays have been mounted and aligned with electrostatic grids to demonstrate their emission capabilities. Propellant has been fed to the emitters by capillarity within the porous bulk and then extracted at potentials as low as 850 V. Beam currents exceeding several 100 [mu]A at both positive and negative polarities have been measured using both EMIIm and EMI-BF₄ ionic liquid propellant. Two complete devices were tested yielding large beam currents and very high transmission fractions (- 88-100 %) from both attempts. We estimate that these devices can supply 10's of [mu]N of thrust at modest operating potentials, ~ 1.5 kV. with a specific impulse of roughly 2000-3000 s. When completely packaged, the thrusters measure 1.2 x 1.2 x 0.2 cm, weigh less than 1 g and require less than 0.65 W of operating power. These characteristics would be ideal for a small satellites where volume, mass and power are all at a premium, while the thrust levels would be sufficient to enable a variety of orbit variation and attitude control maneuvers. For example, applied to a CubeSat, this type of thruster system, including PPU, would occupy roughly 10 % of the spacecraft volume and mass while enabling de-orbiting from an 800 km altitude in roughly 100 days, compared with many years when left to decay naturally.
by Daniel George Courtney.
Ph.D.
Kordás, K. (Krisztián). "Laser-assisted chemical liquid-phase deposition of metals for micro- and optoelectronics." Doctoral thesis, University of Oulu, 2002. http://urn.fi/urn:isbn:9514266862.
Full text