Dissertations / Theses on the topic 'Interfacial area'
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Spooner, Stephen. "Quantifying the transient interfacial area during slag-metal reactions." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/93620/.
Full textEl, Ouni Asma. "Measuring Air-Water Interfacial Area in Unsaturated Porous Media Using the Interfacial Partitioning Tracer Test Method." Thesis, The University of Arizona, 2013. http://hdl.handle.net/10150/297008.
Full textWang, Xia. "Simulations of Two-phase Flows Using Interfacial Area Transport Equation." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1282066341.
Full textRajapakse, Achula, and s9508428@student rmit edu au. "Drop size distribution and interfacial area in reactive liquid-liquid dispersion." RMIT University. Civil Environmental and Chemical Engineering, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080717.163619.
Full textPeng, Sheng. "Characterizing air-water interfacial area in variably saturated sandy porous media." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280732.
Full textHollis, Peter Graham. "The overall oxygen transfer coefficient and interfacial area in hydrocarbon-based bioprocesses." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96868.
Full textENGLISH ABSTRACT: Bioconversion of hydrocarbons to value-added intermediates and products has significant industrial potential using both prokaryotic and eukaryotic organisms. In particular, alkanes can be converted to an expansive range of commercially important products using aerobic bioprocesses under mild process conditions. Coupled with the relative abundance of alkanes derived from gas to liquid (GTL) technologies, such as those employed by SASOL, South Africa, the commercial potential for bioconverison of alkanes is large. However, unlike carbohydrate substrates, alkane feedstocks are devoid of oxygen in their molecular structure. This means that the entire oxygen demand needs to be met by oxygen transfer. Furthermore, a decline in oxygen transfer in aqueous-hydrocarbon dispersions with increasing alkane concentration has been observed to result from depression of the overall volumetric oxygen transfer coefficient (KLa). Therefore, understanding KLa and the fundamental parameters underpinning its behaviour is critical to ensuring the bioprocess is kinetically, rather than transport, limited in terms of both operation and scale-up. Previous studies have examined KLa in aerated-alkane-aqueous systems. In light of the importance of oxygen transfer in bioprocesses, this study expands on the KLa understanding in 3-phase studies by including a fourth solid phase, thus more closely representing a hydrocarbonbased bioprocess. The project aimed to determine the impact of agitation, alkane concentration and solid loading on the Sauter mean bubble diameter (DSM), gas hold-up and specific interfacial area (a) and correlate these parameters to KLa. This ultimately determined which parameter was dominant over a range of process conditions. Furthermore, concurrent measurement of the KLa and interfacial area meant the behaviour of the liquid side oxygen transfer coefficient (KL) could be defined, providing further insight into how changes in the process conditions impact on KLa. Experiments were conducted in a 5 litre stirred tank bioreactor containing n-C14-20 straight chain alkane, sparged with air at 0.8 vvm. In line with process conditions typical of a hydrocarbonbased bioprocess, KLa and a were measured for agitation rates from 450 to 1000 RPM, alkane concentrations from 2 to 20% v/v and yeast solids from 1 to 10 g/l. KLa was measured using the gassing out procedure using a dissolved oxygen (DO) probe which measured the response of the system to a step change in the sparge gas oxygen pressure. The probe response lag ( P), equal to the time taken for the probe to reach 63.2% of the saturation DO concentration, was determined for every set of process conditions. The inverse of P, KP was taken into account when calculating KLa from the DO probe response. The area was calculated from DSM and gas hold-up. DSM was quantified using high speed photography and image analysis was performed in Matlab® using bespoke routines. Elimination of optical distortion and the development of an adequate light source was key to acquiring clear images. Both KLa and interfacial area were found to be affected by changes in agitation, alkane concentration and yeast loading. An increase in agitation increased the KLa over the entire range of alkane concentration and yeast loading. Similarly, an increase in agitation resulted in an increase in interfacial area, underpinned by a decrease in the DSM. It is therefore likely that the interfacial area plays a dominant role in defining KLa when considering an increase in agitation. Increases in alkane concentration resulted in a peak in KLa between 2.5 and 5% alkane concentration while further increases in alkane concentration depressed KLa. This peak was not observed in interfacial area, where an increase in alkane concentration resulted only in a decrease in interfacial area, thus indicating a positive influence of KL on KLa at low alkane concentrations. Further increases in alkane concentration beyond those creating the peak KLa resulted in KLa depression, suggesting that the increasing viscosity imparted by the alkane decreases both KL and interfacial area. Increased yeast loading had opposing effects at low and high agitation rates. At low agitation rates, increased loadings were observed to increase KLa, while increased loadings at high agitation rates caused a decrease in KLa. This behaviour was also evident in interfacial area, suggesting that in this regime KLa was defined by interfacial area behaviour. Increased yeast loading was observed to depress the KLa for all alkane concentrations when examined at a constant midpoint agitation rate. This trend was not evident in interfacial area, which increased with increasing yeast loading at the same agitation rate. The positive influence of yeast on interfacial area was likely caused by adhesion of the yeast particles to the bubble surface, lowering the DSM by preventing coalescence. The disagreement between the KLa and interfacial area results suggested that yeast loading impacted negatively on KL, which had an over-riding negative impact on KLa. The use of reliable methods for the determination of both interfacial area and KLa were demonstrated for application in model hydrocarbon-based bioprocesses. The combined results offer a unique insight into how changes in the process conditions impact independently on KL and interfacial area, which when combined ultimately defined the KLa behaviour. Quantification of the relative magnitude of the impact each parameter had on KLa contributed toward a fundamental understanding of oxygen transfer in model hydrocarbon-based bioprocesses.
AFRIKAANSE OPSOMMING: Biologiese omsetting van koolwaterstowwe na produkte met finansiële waarde het beduidende industriële potensiaal met behulp van beide prokariotiese en eukariotiese organismes. In die besonder, kan alkane omgeskakel word na ’n uitgebreide reeks van kommersieel belangrike produkte met behulp van aerobiese bioprosesse onder ligte proses voorwaardes. Tesame met die relatiewe oorvloed van alkane afgelei van GTL tegnologie, soos dié van Sasol, Suid-Afrika, die kommersiële potensiaal vir bioconverison van alkane is groot. Maar, in teenstelling koolhidrate substrate, alkaan voerstowwe is beroof van suurstof in hul molekulêre struktuur. Dit beteken dat die hele suurstof vereiste moet nagekom word deur suurstof oordrag. Verder het ’n afname in suurstof oordrag in waterige-koolwaterstof dispersies met toenemende alkaan konsentrasie waargeneem te lei van depressie van die algehele volumetriese suurstofoordragkoëffisiënt (KLa). Daarom verstaan KLa en die fundamentele parameters onderliggend sy gedrag is van kritieke belang om te verseker dat die bioprocess is kineties, eerder as vervoer, beperk in terme van beide werking en skaal-up van bioprosesse. Vorige studies het KLa in deurlug-alkaan-waterige stelsels ondersoek. In die lig van die belangrikheid van suurstof oordrag in bioprosesse hierdie studie brei uit op die KLa begrip in driefase studies deur die insluiting van ’n vierde soliede fase, dus meer nou wat ’n koolwaterstofgebaseerde bioprocess. Die doel van die projek is om die impak van vermengingstempo, alkaan konsentrasie en soliede inhout op die Sauter gemiddelde borrel deursnee (DSM), gas-vasvanging en spesifieke gas-vloistof oppervlakarea (a) te kwantifiseer en korreleer met KLa gedrag. Dit sou defineer die dominante parameter oor ’n verskeidenheid van proses voorwaardes. Verder, gelyktydige meting van die KLa en oppervlakarea kan die gedrag van die vloeistof-kant suurstofoordragkoëffisiënt (KL) gedefinieer. Dit sal verskaf verdere insig in hoe die veranderinge in die proses voorwaardes impak op KLa. Eksperimente was uitgevoer in ’n 5 liter belugte geroerde tenk bioreaktor bevat n - C14-20 reguitketting alkane, met lug met lug deurgeborrel by 0.8 VVM. In lyn met die proses voorwaardes tipies van ’n koolwaterstof-gebaseerde bioprocess, KLa en a was gemeet vir vermengignstempos van 450-1000 RPM, alkaan konsentrasies van 2-20 % v/v en gis vastestowwe van 1 tot 10 g / l. KLa is gemeet deur die vergassinguit prosedure met behulp van ’n suurstofmeter wat die reaksie van die stelsel na ’n stap verandering in die voer gas suurstof druk gemeet het. Die suurstofmeter reaksie vertraging ( P), gelyk aan die tyd wat dit neem vir die suurstofmeter 63.2 % van die versadiging DO konsentrasie te bereik, is bepaal vir elke procesopset. Die inverse van P, KP is in ag geneem by die berekening van KLa uit die suurstofmeter reaksie. Die gas-vloistof oppervlak is bereken vanaf DSM en gas hold-up. DSM is gekwantifiseer met behulp van hoë spoed fotografie en beeld analise is uitgevoer in Matlab ® roetines. Uitskakeling van optiese vervorming en die ontwikkeling van ’n voldoende ligbron was die sleutel tot die verkryging van helder beelde. Beide KLa en grens oppervlakarea gevind geraak word deur veranderinge in vermengignstempo, alkaan konsentrasie en gis laai. ’N toename in geroer het die KLa verbeter oor die hele reeks van alkaan konsentrasie en gis laai. Net so, ’n toename in geroer het gelei tot ’n toename in grens oppervlak, ondersteun deur ’n afname in die DSM. Dit is dus waarskynlik dat die grens oppervlak speel ’n dominante rol in die definisie van KLa by die oorweging van ’n toename in roering. Stygings in alkaan konsentrasie gelei tot ’n hoogtepunt in KLa tussen 2.5 en 5 % alkaan konsentrasie terwyl verdere verhogings in alkaan konsentrasie druk die KLa af. Die piek was nie in oppervlakarea duidelik, waar ’n toename in alkaan konsentrasie gelei net tot ’n afname in oppervlakarea, dus dui op ’n positiewe invloed van KL op KLa teen lae alkaan konsentrasies waargeneem. Verdere stygings in alkaan konsentrasie verder as die skep van die piek KLa gelei tot KLa depressie, wat daarop dui dat die toenemende viskositeit meegedeel deur die alkaan verminder beide KL en grens oppervlak. Verhoogde gis laai het opponerende effekte teen ’n lae en hoë vermengingstempo. By lae vermengingstempo, ’n verhoging in gis laai waargeneem KLa te verhoog, terwyl ’n verhoging in gis laai op ’n hoë vermengingstempo veroorsaak ’n afname in KLa . Hierdie gedrag was ook duidelik in grens oppervlak, wat daarop dui dat daar in hierdie regime KLa gedefinieer deur grens oppervlak gedrag. Verhoogde gis laai waargeneem die KLa te onderdruk vir alle alkaan konsentrasies wanneer ondersoek teen ’n konstante middelpunt vermengingstempo. Hierdie tendens was nie duidelik in tussenvlak gebied, wat verhoog met toenemende gis laai op dieselfde geroer koers. Die positiewe invloed van gis op grens oppervlak is waarskynlik veroorsaak deur adhesie van die gis deeltjies aan die borrel oppervlak, die verlaging van die DSM deur die voorkoming van die saamsmelting van gasborrels. Die meningsverskil tussen die KLa en grens oppervlakarea resultate voorgestel dat gis laai negatiewe uitwerking op KL, met ’n dominante negatiewe impak op KLa. Die gebruik van ’n betroubare metodes vir die bepaling van beide oppervlakarea en KLa gedemonstreer vir toepassing in model koolwaterstof-gebaseerde bioprosesse. Die gekombineerde resultate bied ’n unieke insig in hoe die veranderinge in die proses voorwaardes impak onafhanklik op KL en oppervlakarea, wat wanneer gekombineer gedefinieer die KLa gedrag. Kwantifisering van die relatiewe grootte van die impak elke parameter het op KLa bygedra tot ’n fundamentele begrip van suurstof oordrag in model koolwaterstof-gebaseerde bioprosesse.
Morel, Christophe. "Modélisation multidimensionnelle des écoulements diphasiques gaz - liquide : application à la simulation des écoulements à bulles ascendants en conduite verticale." Châtenay-Malabry, Ecole centrale de Paris, 1997. http://www.theses.fr/1997ECAP0543.
Full textLyu, Ying, Mark L. Brusseau, Ouni Asma El, Juliana B. Araujo, and Xiaosi Su. "The Gas-Absorption/Chemical-Reaction Method for Measuring Air-Water Interfacial Area in Natural Porous Media." AMER GEOPHYSICAL UNION, 2017. http://hdl.handle.net/10150/626480.
Full textBarigou, Mostafa. "Bubble size, gas holdup and interfacial area distributions in mechanically agitated gas-liquid reactors." Thesis, University of Bath, 1987. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376338.
Full textPrasser, Horst-Michael, Tobias Sühnel, Christophe Vallée, and Thomas Höhne. "Experimental investigation and CFD simulation of slug flow in horizontal channels." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-28061.
Full textPrasser, Horst-Michael, Tobias Sühnel, Christophe Vallée, and Thomas Höhne. "Experimental investigation and CFD simulation of slug flow in horizontal channels." Forschungszentrum Dresden-Rossendorf, 2007. https://hzdr.qucosa.de/id/qucosa%3A21634.
Full textKang, Narae. "The effect of carbon nanotube/organic semiconductor interfacial area on the performance of organic transistors." Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5335.
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Masters
Physics
Sciences
Physics
Cloete, Jannean Christelle. "Oxygen transfer in a model hydrocarbon bioprocess in a bubble column reactor." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96981.
Full textENGLISH ABSTRACT: The expansion of the global fuels industry has caused an increase in the quantity of hydrocarbons produced as a by-product of refinery gas-to-liquid processes. Conversion of hydrocarbons to higher value products is possible using bioprocesses, which are sustainable and environmentally benign. Due to the deficiency of oxygen in the alkane molecule, the supply of sufficient oxygen through aeration is a major obstacle for the optimization of hydrocarbon bioprocesses. While the oxygen solubility is increased in the presence of hydrocarbons, under certain process conditions, the enhanced solubility is outweighed by an increase in viscosity, causing a depression in overall volumetric oxygen transfer coefficient (KLa). The rate at which oxygen is transferred is defined in terms of a concentration driving force (oxygen solubility) and the overall volumetric oxygen transfer coefficient (KLa). The KLa term comprises an oxygen transfer coefficient (KL) and the gas-liquid interfacial area (a), which are dependent on the uid properties and system hydrodynamics. This behaviour is not well understood for hydrocarbon bioprocesses and in a bubble column reactor (BCR). To provide an understanding of oxygen transfer behaviour, a model hydrocarbon bioprocess was developed using a BCR with a porous sparger. To evaluate the interfacial area, the Sauter mean bubble diameter (D32) was measured using an image analysis algorithm and gas holdup (ϵG) was measured by the change in liquid height in the column. Together the D32 and ϵG were used in the calculation of interfacial area in the column. The KLa was evaluated with incorporation of the probe response lag, allowing more accurate representation of the KLa behaviour. The probe response lag was measured at all experimental conditions to ensure accuracy and reliability of data. The model hydrocarbon bioprocess employed C14-20 alkane-aqueous dispersions (2.5 - 20 vol% hydrocarbon) with suspended solids (0.5 - 6 g/l) at discrete super ficial gas velocity (uG) (1 - 3 cm/s). For systems with inert solids (corn our, dp = 13.36 m), the interfacial area and KLa were measured and the behaviour of KLa was described by separation of the in uences of interfacial area and oxygen transfer coefficient (KL). To further the understanding of oxygen transfer behaviour, non-viable yeast cells (dp = 5.059 m) were used as the dispersed solid phase and interfacial area behaviour was determined. This interfacial area behaviour was compared with the behaviour of systems with inert solids to understand the differences with change in solids type. In systems using inert solids, a linear relationship was found between G and uG. An empirical correlation fo rthe prediction of this behaviour showed an accuracy of 83.34% across the experimental range. The interfacial area showed a similar relationship with uG and the empirical correlation provided an accuracy of 78.8% for prediction across the experimental range. In inert solids dispersions, the KLa increased with uG as the result of an increase in interfacial area as well as increases in KL. An increase in solids loading indicated an initial increase in KLa, due to the in uence of liquid-film penetration on KL, followed by a decrease in KL at solids loading greater than 2.5 g/l, due to diffusion blocking effects. In systems with yeast dispersions, the presence of surfactant molecules in the media inhibited coalescence up to a yeast loading of about 3.5 g/l, and resulted in a decrease in D32. Above this yeast loading, the fine yeast particles increased the apparent viscosity of the dispersion sufficiently to overcome the in uence of surfactant and increase the D32. The behaviour of G in yeast dispersions was similar to that found with inert solids and demonstrated a linear increase with uG. However, in yeast dispersions, the interaction between alkane concentration and yeast loading caused a slight increase in dispersion viscosity and therefore G. An empirical correlation to predict G behaviour with increased uG was developed with an accuracy of 72.55% for the experimental range considered. Comparison of yeast and inert solids dispersions indicated a 37.5% lower G in yeast dispersions compared to inert solids as a result of the apparent viscosity introduced by finer solid particles. This G and D32 data resulted in a linear increase in interfacial area with uG with no significant in uence of alkane concentration and yeast loading. This interfacial area was on average 6.7% lower than interfacial area found in inert solid dispersions as a likely consequence of the apparent viscosity with finer particles. This study provides a fundamental understanding of the parameters which underpin oxygen transfer in a model hydrocarbon bioprocess BCR under discrete hydrodynamic conditions. This fundamental understanding provides a basis for further investigation of hydrocarbon bioprocesses and the prediction of KLa behaviour in these systems.
AFRIKAANSE OPSOMMING: Die uitbreiding van die internasionale brandstofbedryf het 'n toename veroorsaak in die hoeveelheid koolwaterstowwe geproduseer as 'n deur-produk van raffinadery gas-tot-vloeistof prosesse. Omskakeling van koolwaterstowwe na hoër waarde produkte is moontlik met behulp van bioprosesse, wat volhoubaar en omgewingsvriendelik is. As gevolg van die tekort aan suurstof in die alkaan molekule, is die verskaffing van voldoende suurstof deur deurlugting 'n groot uitdaging vir die optimalisering van koolwaterstof bioprosesse. Terwyl die suurstof oplosbaarheid verhoog in die teenwoordigheid van koolwaterstowwe, onder sekere proses voorwaardes is die verhoogde oplosbaarheid oortref deur 'n toename in viskositeit, wat 'n depressive veroorsaak in die algehele volumetriese suurstofoordragkoëffisiënt (KLa). Die suurstof oordrag tempo word gedefinieer in terme van 'n konsentrasie dryfkrag (suurstof oplosbaarheid) en KLa. Die KLa term behels 'n suurstofoordragkoëffisiënt (KL) en die gas-vloeistof oppervlakarea (a), wat afhanklik is van die vloeistof eienskappe en stelsel hidrodinamika. Hierdie gedrag is nie goed verstaan vir koolwaterstof bioprosesse nie, asook in kolom reaktors (BCR). Om 'n begrip van suurstof oordrag gedrag te voorsien, is 'n model koolwaterstof bioproses ontwikkel met 'n BCR met 'n poreuse besproeier. Om die oppervlakarea te evalueer, is die gemiddelde Sauter deursnit (D32) gemeet deur 'n foto-analise algoritme en gas vasvanging ( G) is gemeet deur die verandering in vloeibare hoogte in die kolom. Saam is die D32 en G gebruik in die berekening van die oppervlakarea in die kolom. Die KLa is geëvalueer met insluiting van die meter se reaksie sloering, om n meer akkurate voorstelling van die KLa gedrag te bereken. Die meter reaksie sloering was gemeet op alle eksperimentele toestande om die akkuraatheid en betroubaarheid van data te verseker. Die model koolwaterstof bioproses gebruik n-C14-20 alkaan-water dispersies (2.5 - 20 vol% koolwaterstof) solide partikels (0.5 - 6 g/l) op diskrete oppervlakkige gas snelhede (1 - 3 cm/s). Vir stelsels met inerte solides (koring meel, dp = 13.36 m), is die oppervlakarea en KLa gemeet en die gedrag van KLa beskryf deur skeiding van die invloede van oppervlakarea en KL. Om die begrip van suurstof oordrag se gedrag te bevorder, is nie-lewensvatbare gisselle (dp = 5.059 m) gebruik as die verspreide solide fase en oppervlakarea is bepaal. Hierdie oppervlakarea gedrag is vergelyk met die van stelsels met inerte solides om die verskille met verandering in solide tipes te verstaan. In stelsels met inerte solides, is 'n line^ere verwantskap gevind tussen G en uG. 'n Empiriese korrelasie vir die voorspelling van hierdie gedrag is opgestel met 'n akkuraatheid van 83.34% in die eksperimentele reeks. Die oppervlakarea het 'n soortgelyke verhouding met uG en die empiriese korrelasie verskaf 'n akkuraatheid van 78,8% vir die voorspelling van oppervlakarea oor die eksperimentele reeks. In inerte solide dispersies, het die KLa toegeneem met uG as die gevolg van 'n toename in grens oppervlak asook stygings in KL. 'n Toename in solides belading het n aanvanklike styging in KLa aangedui, as gevolg van die invloed van die vloeistof-film penetrasie op KL, gevolg deur 'n afname in KL op vastestowwe ladings groter as 2.5 g/l, te danke aan diffusie blokkeer effekte. In stelsels met gis dispersies, het die teenwoordigheid van benattings molekules in die media samesmelting geïnhibeer tot 'n gis lading van ongeveer 3.5 g/l, en het gelei tot 'n afname in D32. Bo hierdie gis lading, het die fyn gis partikels die skynbare viskositeit van die verspreiding verhoog genoegsaam om die invloed van benattings molekules te oorkom en die D32 te verhoog. Die gedrag van G in gis dispersies was soortgelyk aan die van inerte solides en dui op 'n lineêre toename met uG. Maar in gis dispersies, het die interaksie tussen alkaan konsentrasie en gis lading 'n effense toename veroorsaak in die verstrooiing viskositeit en dus in G. 'n Empiriese korrelasie is ontwikkel om G gedrag te voorspel en het 'n akkuraatheid van 72,55% vir die eksperimentele verskeidenheid beskou. Vergelyking van gis en inerte patrikel dispersies wys 'n 37.5% laer G in gis dispersies in vergelyking met inerte vaste stowwe as 'n gevolg van die skynbare viskositeit bekendgestel deur fyner vastestowwe partikels. Hierdie G en D32 data het gelei tot 'n linere toename in grens oppervlak met uG met geen beduidende invloed van alkaan konsentrasie en gis lading nie. Die oppervlakarea was gemiddeld 6.7% laer as oppervlakarea gevind in inerte partikel dispersies as 'n waarskynlike gevolg van die skynbare viskositeit met fyner partikels. Hierdie studie bied 'n fundamentele begrip van die veranderlikes wat die suurstof oordrag definieer in 'n model koolwaterstof bioproses BCR onder diskrete hidrodinamiese voorwaardes. Hierdie fundamentele begrip bied n basis vir verdere ondersoek van koolwaterstof bioprosesse en en die voorspelling van KLa gedrag in hierdie stelsels.
Ji, Xinsheng. "Parameter estimation of liquid film mass transfer coefficient and effective interfacial area for random and structured packings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ30485.pdf.
Full textSampaio, Neto Oscar Zalla. "Area interfacial em colunas de recheio : influencia da viscosidade do liquido e da velocidade superficial do gas." [s.n.], 1994. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254800.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Foram realizados experimentos em uma coluna de vidro com 78 mm de diâmetro interno empacotada com anéis de Raschig de 7 mm, em um leito de 1,15 m objetivando-se estudar a influência da viscosidade da fase líquida e das condições hidrodinâmicas da fase gasosa na formação da área interfacial efetiva de transferência de massa. Este fundamental parâmetro nos projetos de torres recheadas, foi determinado em experimentos de absorção acompanhada de reação de pseudo-primeira ordem. A reação se deu entre o dióxido de carbono e a dietanolamina em solução aquosa de etilenoglicol no primeiro conjunto de experimentos e entre o dióxido de carbono e o hidróxido de sódio em solução de água e açúcar. A concentração de dióxido de carbono na fase gasosa foi de 2,5%. A escolha desses sistemas possibilitou variar a viscosidade do líquido em uma faixa de 1x10-3 até 2x10-2 Kg/m.s e a velocidade superficial da fase gasosa de 8x10-3 até 2x10-1m/s. A viscosidade do líquido apresentou uma influência em geral negativa sobre a formação da área interfacial efetiva'. Sob condições de baixa velocidade superficial da fase gasosa, a viscosidade do líquido influenciou positivamente em uma faixa de 1xl0-3até 3x10-3Kgjm.s, em função possivelmente da melhoria da molhabilidade do recheio. Na faixa estudada a velocidade superficial do gás tem um efeito positivo, no entanto, sua influência diminui com o aumento da viscosidade do líquido. Todos os dados puderam ser satisfatoriamente correlacionados por uma equação onde a área interfacial efetiva é apresentada como uma função dos números de Reynolds das fases . líquida e gasosa, sendo que para este último o expoente traz o numero de Kaptisa
Abstract: Experiments were carried out in a 78 mm glass column packed with 7 mm glass Raschig rings to a depth of 1,15 m. The subject of this work was to study the influence of the liquid phase viscosity and hydrodynamic conditions on mass transfer effective interfacial area. Effective interfacial area was determined by chemical absorption experiments with .pseudo-first order reaction. Two gas-liquid systems have been used: (1) carbon dioxide - diethanolamine in aqueous ethyleneglycol solutions and (2) carbon dioxide - sodium hydroxide in aqueous sugar solutions. The gas phase dioxide carbon concentration was 2,5%. These systems covered a viscosity range from 1x10-3 to 2x10-2 Kg/m. s and superficial gas velocity from 8x10-3 to 2x10-1 m/s. The liquid viscosity presented negative influence upon effective interfacial area formation. Under low superficial gas velocity conditions the liquid viscosity could influence positively with range of 1xl0-3 to 3x10-3 Kg/m.s, caused possibly by the improvement packed wetabillity. The superficial gas velocity in the studied range had a positive effect, but its influence decreases as liquid viscosity increases. All the data could be satisfactorily represented by an equation which relates the effective interfacial area as a function of vapor and liquid phase Reynolds numbers. The expoente for the vapor phase Reynolds number is the Kaptisa number
Mestrado
Mestre em Engenharia de Alimentos
Li, Liqing. "Water saturation and air/water interfacial area measurements by partitioning gas tracers in the vadose zone and landfills." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 176 p, 2008. http://proquest.umi.com/pqdweb?did=1464133931&sid=30&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Full textAPRAHAMIAN, EDWARD JR. "ROLE OF THE INTERFACE IN THE KINETICS AND MECHANISM OF SOLVENT EXTRACTION SYSTEMS (DITHIZONE, OXINE, INTERFACIAL AREA, DISPERSION)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/187968.
Full textDu, Preez Louis Jacobus. "Reactive absorption kinetics of CO2 in alcoholic solutions of MEA: fundamental knowledge for determining effective interfacial mass transfer area." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86656.
Full textENGLISH ABSTRACT: The reactive absorption rate of CO2 into non-aqueous solvents containing the primary amine, mono-ethanolamine (MEA) is recognised as a suitable method for measuring the effective interfacial mass transfer area of separation column internals such as random and structured packing. Currently, this method is used under conditions where the concentration of MEA in the liquid film is unaffected by the reaction and the liquid phase reaction is, therefore, assumed to obey pseudo first order kinetics with respect to CO2. Under pseudo first order conditions, the effect of surface depletion and renewal rates are not accounted for. Previous research indicated that the effective area available for mass transfer is also dependent upon the rate of surface renewal achieved within the liquid film. In order to study the effect of surface depletion and renewal rates on the effective area, a method utilising a fast reaction with appreciable depletion of the liquid phase reagent is required. The homogeneous liquid phase reaction kinetics of CO2 with MEA n-Propanol as alcoholic solvent was investigated in this study. A novel, in-situ Fourier Transform Infra-Red (FTIR) method of analysis was developed to collect real time concentration data from reaction initiation to equilibrium. The reaction was studied in a semi-batch reactor set-up at ambient conditions (T = 25°C, 30°C and 35°C, P = 1 atm (abs)). The concentration ranges investigated were [MEA]:[CO2] = 5:1 and 10:1. The concentration range investigated represents conditions of significant MEA conversion. The reaction kinetic study confirmed the findings of previous research that the reaction of CO2 with MEA is best described by the zwitterion reactive intermediate reaction mechanism. Power rate law and pseudo steady state hypothesis kinetic models (proposed in literature) were found to be insufficient at describing the reaction kinetics accurately. Two fundamentally derived rate expressions (based on the zwitterion reaction mechanism) provided a good quality model fit of the experimental data for the conditions investigated. The rate constants of the full fundamental model were independent of concentration and showed an Arrhenius temperature dependence. The shortened fundamental model rate constants showed a possible concentration dependence, which raises doubt about its applicability. The specific absorption rates (mol/m2.s) of CO2 into solutions of MEA/n-Propanol (0.2 M and 0.08 M, T = 25°C and 30°C, P = ±103 kPa) were investigated on a wetted wall experimental setup. The experimental conditions were designed for a fast reaction in the liquid film to occur with a degree of depletion of MEA in the liquid film. Both interfacial depletion and renewal of MEA may be considered to occur. The gas phase resistance to mass transfer was determined to be negligible. An increase in liquid turbulence caused an increase in the specific absorption rate of CO2 which indicated that an increase in liquid turbulence causes an increase in effective mass transfer area. Image analysis of the wetted wall gas-liquid interface confirmed the increase in wave motion on the surface with an increase in liquid turbulence. The increase in wave motion causes an increase in both interfacial and effective area. A numerical solution strategy based on a concentration diffusion equation incorporating the fundamentally derived rate expressions of this study is proposed for calculating the effective area under conditions where surface depletion and renewal rates are significant. It is recommended that the reaction kinetics of CO2 with MEA in solvents of varying liquid properties is determined and the numerical technique proposed in this study used to calculate effective area from absorption rates into these liquids. From the absorption data an effective area correlation as a function of liquid properties may be derived in future.
AFRIKAANSE OPSOMMING: Die reaktiewe absorpsie van CO2 in nie-waterige oplossings van die primêre amien, monoetanolamien (MEA) word erken as ‘n geskikte metode om die effektiewe massaoordragsarea van gepakte skeidingskolomme te bepaal. Tans word die metode gebruik onder vinnige pseudo eerste orde reaksietoestande met betrekking tot CO2. Die pseudo eersteorde aanname beteken dat die konsentrasie van MEA in die vloeistoffilm onbeduidend beïnvloed word deur die reaksie en effektief konstant bly. Onder pseudo eerste orde toestande word oppervlakverarming- en oppervlakvernuwingseffekte nie in ag geneem nie, juis as gevolg van die konstante konsentrasie van MEA in die vloeistoffilm. Daar is voorheen bevind dat oppervlakverarming en oppervlakvernuwing ‘n beduidende invloed het op die beskikbare effektiewe massaoordragsarea. Hierdie invloed kan slegs bestudeer word met ‘n vinnige reaksie in die vloeistoffilm wat gepaard gaan met beduidende oppervlakverarming van die vloeistoffase reagens. Die homogene vloeistoffase reaksiekinetika van CO2 met MEA in die alkohol oplosmiddel, n- Propanol, is in hierdie studie ondersoek. ‘n Nuwe, in-situ Fourier Transform Infra-Rooi (FTIR) metode van analiese is ontwikkel in hierdie ondersoek. Die reaksie is ondersoek in ‘n semienkelladings reaktor met MEA wat gevoer is tot die reaktor om met die opgeloste CO2 te reageer. Die FTIR metode meet spesiekonsentrasie as ‘n funksie van tyd sodat die konsentrasieprofiele van CO2, MEA en een van die soutprodukte van die reaksie gebruik kan word om verskillende reaksiesnelheidsvergelykings te modelleer. Die reaksie is ondersoek onder matige toestande (T = 25°C, 30°C and 35°C, P = 1 atm (abs)). Die konsentrasiebereik van die ondersoek was [MEA]:[CO2] = 5:1 en 10:1. Hierdie bereik is spesifiek gebruik sodat daar beduidende omsetting van MEA kon plaasvind. Die reaksiekinetieka studie het, ter ondersteuning van bestaande teorie, bevind dat die reaksie van CO2 met MEA in nie-waterige oplosmiddels soos alkohole, beskyf word deur ‘n zwitterioon reaksiemeganisme. Die bestaande reaksiesnelheids modelle (eksponensiële wet en pseudo gestadigde toestand hipotese) kon nie die eksperimentele data met genoegsame akuraatheid beskryf nie. Twee nuwe reaksiesnelheidsvergelykings, afgelei vanaf eerste beginsels en gebaseer op die zwitterioon meganisme, word voorgestel. Hierdie volle fundamentele model het goeie passings op die eksperimentele data getoon oor die volledige temperatuur en konsentrasiebereik van hierdie studie. Die reaksiekonstantes van die fundamentele model was onafhanklik van konsentrasie en tipe oplosmiddel en het ‘n Arrhenius temperatuurafhanklikheid. Die verkorte fundamentele model se reaksiekonstantes het ‘n moontlike konsentrasieafhanlikheid gewys. Dit plaas onsekerheid op die fundamentele basis van hierdie model en kan dus slegs as ‘n eerste benadering beskou word. Die spesifieke absorpsietempos (mol/m2.s) van CO2 in MEA/n-Propanol oplossings (0.2 M en 0.08 M MEA, T = 25°C and 30°C, P = ±103 kPa) is ondersoek met ‘n benatte wand (‘wetted wall’) eksperimentele opstelling. Die eksperimentele toestande is gekies sodat daar ‘n vinnige reaksie in die vloeistoffilm plaasgevind het, met beide beduidende en nie-beduidende MEA omsetting. Die doel met hierdie eksperimentele ontwerp was om die invloed van intervlakverarming en intervlakvernuwing op die spesifieke absorpsietempo te ondersoek. Gas fase weerstand was nie-beduidend onder die eksperimentele toestande nie. Beide intervlakverarming en intervlakvernuwing gebeur gelyktydig en is waargeneem vanuit die eksperimentele data. ‘n Beeldverwerkingstudie van die gas-vloeistof intervlak van die benatte wand het bevind dat daar ‘n toename in golfaksie op die vloeistof oppervlak is vir ‘n toename in vloeistof turbulensie. Hierdie golfaksie dra by tot oppervlakvernuwing en ‘n toename in effektiewe massaoordragsarea. ‘n Numeriese metode word voorgestel om die effektiewe area van beide die benatte wand en gepakte kolomme te bepaal vanaf reaktiewe absorpsietempos. Die metode gebruik die fundamentele reaksiesnelheidsvergelykings, bepaal in hierdie studie, in a konsentrasie diffusievergelyking sodat oppervlakverarming en vernuwing in ag geneem kan word. Daar word voorgestel dat die reaksiekinetika van CO2 met MEA in oplossings met verskillende fisiese eienskappe (digtheid, oppervlakspanning en viskositeit) bepaal word sodat die numeriese metode gebruik kan word om ‘n effektiewe area korrelasie as ‘n funksie van hierdie eienskappe te bepaal.
Gregor, Sabine, Matthias Beyer, and Horst-Michael Prasser. "Thermohydraulische Modellierung der Kondensation von Dampf in einer unterkühlten Flüssigkeitsströmung." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-28393.
Full textGregor, Sabine, Matthias Beyer, and Horst-Michael Prasser. "Thermohydraulische Modellierung der Kondensation von Dampf in einer unterkühlten Flüssigkeitsströmung." Forschungszentrum Rossendorf, 2006. https://hzdr.qucosa.de/id/qucosa%3A21666.
Full textNascimento, Érica Regina Filletti. "Desenvolvimento de modelos neurais para o processamento de sinais acústicos visando a medição de propriedades topológicas em escoamentos multifásicos." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/18/18147/tde-05042007-133001/.
Full textA new methodology for measuring the volumetric fraction and interfacial area in two-phase flows is proposed in this work, based on neural network for processing the responses obtained from an acoustic interrogation signal. The geometrical distribution of the phases within the flow is mapped by the local acoustic propagation velocity which is considered in the governing differential equation. This equation is solved numerically by the finite difference method with boundary conditions reproducing the pulse/echo strategy. A significant number of propagation velocities distributions were considered in the solution of the differential equation in order to construct a database from which the neural model parameters could be adjusted. Specifically, the neural model is constructed to map the features extracted from the signals delivered by four acoustic sensors, placed on the external boundary of the sensing domain, into the corresponding volumetric fraction and interfacial area. These features correspond to the amplitudes and the times of arrival on the three first peaks of the acoustic wave. Numerical results showed that the neural model can be trained in a reasonable computational time and it is capable of estimating the values of the volumetric fraction and the interfacial area of examples of the set of test.
Coffey, Paul David. "Interfacial measurements of colloidal and bio-colloidal systems in real-time." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/interfacial-measurements-of-colloidal-and-biocolloidal-systems-in-realtime(8be29df9-3730-467a-b45d-d46acadd2207).html.
Full textDoup, Benjamin. "Methodology Development of a Gas-Liquid Dynamic Flow Regime Transition Model." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1409031809.
Full textFlores, Henry Alexander Rodriguez. "Absorção de dióxido de carbono em soluções aquosas de aminas em uma coluna de parede molhada com promotor de película." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-02052011-122123/.
Full textThe CO2 absorption process in alkanolamine aqueous solutions was studied in a wetted wall column employing a film promotor of thin stainless steel woven wire, 28 mesh, which was operated in countercurrent. The tested alkanolamines were monoethanolamine (MEA), 2-amino-2-methyl-1-propanol (AMP) and piperazine (PZ). The absorption experiments were performed in individual aqueous solutions of MEA and AMP and the mixtures MEA:AMP and AMP:PZ, with the aim of evaluating the CO2 absorption rate in different liquid flow rates, namely: 3.10-7, 6.10-7 e 10.10-7 m3/s. This absorption system was characterized through determining of the main parameters of mass transfer: effective interfacial area, individual mass transfer coefficient of the gas phase and the average overall mass transfer volumetric coefficient. The effective interfacial area was determined by the absorption of CO2 diluted in air into an aqueous solution of NaOH for the different liquid flow rates, and the results obtained are 106, 126 and 144 m2/m3, respectively. The mass transfer volumetric coefficient of the gas phase was determined by chemical method of the absorption of SO2 diluted in air into an aqueous solution of NaOH. The experimental results show that the individual mass transfer coefficient and interfacial area are a function of liquid flow rate. On the other hand, the results of the performance of CO2 absorption into amine aqueous solutions were expressed in function of the average overall mass transfer volumetric coefficient and liquid phase diffusive kinetic parameters, which were measured experimentally for different liquid flow rates. The absorption rate in MEA are higher in comparison with AMP and NaOH. In the case of the blended, the absorption rate in AMP is enhanced by piperazine, even in low concentration.
Sun, Haomin. "Study on Upward Air-Water Two-Phase Turbulent Flow Characteristics in a Vertical Large Square Duct." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188585.
Full textLéonard, Clément. "Etude d'une colonne à bulles pour le traitement d'effluents par oxydation en voie humide." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4382.
Full textWet Air Oxidation (WAO) is a process dedicated to degrade the organic matter contained in wastewater with the help of an oxidation reaction. WAO works at high pressure (10 – 30 MPa) and high temperature (373 – 613 K) using oxygen from air as oxidiser. WAO processes are carried out in bubble column reactors in order to maximise both the liquid residence time and the mass transfer of oxygen from the gas to the liquid, one of the key element of the process. The lack of available data and correlations, needed for the prediction of the parameters governing mass transfer in bubble columns working in WAO conditions, is then penalising. Measurements of gas holdup, bubble diameters and interfacial area in clear water and in presence of a pollutant (phenol), in reactive and non-reactive conditions, show major effects of superficial gas velocity, phenol concentration and saturation of the gas by water vapor. The primary bubble, formed at the gas distributor, and the column diameter, are important design parameters for the process optimisation. Measurement of the mass transfer coefficient by a new chemical technique using phenol oxidation shows that it depends primarily on the bubble diameter and on the gas and liquid velocities. This experimental work is completed by the development of correlations of the key parameters in WAO conditions, providing relevant elements for the design of WAO units working in continuous mode
Narter, Matthew. "Characterizing Non-Wetting Fluid in Natural Porous Media Using Synchrotron X-Ray Microtomography." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/268376.
Full textSühnel, Tobias, Horst-Michael Prasser, and Christophe Vallée. "Experimentelle Untersuchung von geschichteten Luft/Wasser Strömungen in einem horizontalen Kanal." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-28073.
Full textSühnel, Tobias, Horst-Michael Prasser, and Christophe Vallée. "Experimentelle Untersuchung von geschichteten Luft/Wasser Strömungen in einem horizontalen Kanal." Forschungszentrum Dresden-Rossendorf, 2007. https://hzdr.qucosa.de/id/qucosa%3A21635.
Full textPellacani, Filippo [Verfasser], Rafael [Akademischer Betreuer] Macián-Juan, and Vicent Sergio [Akademischer Betreuer] Chiva. "Development and Validation of Bubble Breakup and Coalescence Constitutive Models for the One-Group Interfacial Area Transport Equation / Filippo Pellacani. Gutachter: Sergio Chiva Vicent ; Rafael Macián-Juan. Betreuer: Rafael Macián-Juan." München : Universitätsbibliothek der TU München, 2012. http://d-nb.info/104199480X/34.
Full textBrahem, Rim. "Étude de l'effet d'échelle sur les plateaux à clapets de colonnes d'absorption." Phd thesis, Toulouse, INPT, 2013. http://oatao.univ-toulouse.fr/10849/1/brahem.pdf.
Full textBannari, Rachid. "Mathematical modeling of cellulase production in an airlift bioreactor." Thèse, Université de Sherbrooke, 2009. http://savoirs.usherbrooke.ca/handle/11143/1930.
Full textSouzy, Nicolas. "Experimental study and improvement of mass transfer in vertical bubble columns." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10201/document.
Full textBubble column are involved in many industrial fields ranging from chemical industry to mineral processing. It recently became an industrial stake for the production of micro-algae intended for medicinal use, food or energy: the oxygen and carbon dioxide concentrations can be controlled via the efficient mass transfer induced by the significant gas-liquid interfaciale area into the bubble column. Firstly, experimental closed-loop study has been carried out to simulate the passage of gas in a succession of columns in series. The associated theoretical model confirms the critical importance of the bubble diameter for mass transfer.Therefore, an innovative Micro-Bubble Generator (MBG) has been designed and tested. The prototype is able to produce micro-bubbles of average diameter Dbubble = 0.252 mm. The invention has been officially declared. The last chapter aims at improving data treatment methods for Planar Laser-Induced Fluorescence (PLIF), which enables to obtain experimentally mass transfer coefficient kl through concentration measurements. The first presented correction takes into account variations of the fluorescence extinction due to pH during the calibration step, and has been evaluated on CO2 concentration measurement in the wake of a free rising bubble. The second proposed correction should be applied when the length in the measurement region over which pH variations are observed increases: variations of the extinction coefficient will affect the local incident light intensity and therefore the measurements. The need for this correction has been illustrated on a test case in the wake of a cloud of free rising bubbles
Alali, Abdullah [Verfasser], Rafael [Akademischer Betreuer] Macián-Juan, and Vicent Sergio [Akademischer Betreuer] Chiva. "Development and validation of new solver based on the interfacial area transport equation for the numerical simulation of sub-cooled boiling with OpenFOAM CFD code for nuclear safety applications / Abdullah Alali. Gutachter: Sergio Chiva Vicent ; Rafael Macián-Juan. Betreuer: Rafael Macián-Juan." München : Universitätsbibliothek der TU München, 2014. http://d-nb.info/1048677257/34.
Full textMcDonald, Kieran, Kenneth C. Carroll, and Mark L. Brusseau. "Comparison of fluid-fluid interfacial areas measured with X-ray microtomography and interfacial partitioning tracer tests for the same samples." AMER GEOPHYSICAL UNION, 2016. http://hdl.handle.net/10150/622505.
Full textChiciuc, Igor. "Étude des paramètres affectant le transfert d'oxygène dans les vins." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14163/document.
Full textMicro-oxygenation of the wines, by the dispersion of oxygen bubbles, is a practice increasingly used in oenology. This technique is not always suitably controlled for lack of scientific knowledge on the parameters governing the transfer of oxygen. Research was focused on the study of transfer coefficients in function of wine components (CO2, ethanol, sucrose, consuming oxygen) and of operating conditions (type of diffuser, temperature, relationship between height and diameter of the container of liquid). The results show that during micro-oxygenation, the dissolved carbon dioxide and the sucrose have a negative incidence on the transfer whereas the presence of ethanol improves the transfer. As operating conditions are concerned, the increase in gas output and the increase in micro-oxygenation tank height/diameter ratio positively influence oxygen transfer. For wines, the specific surface of the bubbles and the mass transfer coefficient could be dissociated. The surfactant nature of wine components seems to be the most important factor in mass transfer. The knowledge so acquired was applied to micro-oxygenation during two stages of wine making: alcoholic fermentation with the oxygen yield control and the simulation of ageing technique in barrels coupled with the wood chips addition. A new approach relates to the study of a membrane contactor application allowing the oxygen transfer by diffusion
Kuidjo, Kuidjo Emmanuel Vianney. "Towards a predictive model to reproduce flow regime transitions in gas-liquid flows with Neptune CFD : from a dispersed to a separated regime." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0456.
Full textIn nuclear reactors, several regimes of gas-liquid flows may occur with some transitions between them. The main challenges associated with simulating these transitions in 3D CFD codes are associated with deformable interfaces of different sizes, accounting for coalescence and breakup interactions between gas structures and developing flow regime independent closure relations. This work aims at modelling and simulating the hydrodynamics of adiabatic gas-liquid flows thanks to a three-field two-fluid model in Neptune CFD. In a first step, a model with one continuous liquid field and two dispersed gas fields for small and large bubbles is used to simulate cap and churn flows with a void fraction up to 0.5 and a focus is put on the interfacial area prediction. In a second step, the second dispersed field is replaced by a hybrid continuous/dispersed field representing both large bubbles and continuous gas regions. The model is validated on several flow regimes in large diameter pipes and in confined rectangular channels
Araújo, Juliana Botelho. "Measuring Air-Water Interfacial Areas: Contributions of Capillary and Film Domains in Natural Porous Media." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/333353.
Full textLandry, Christopher James Karpyn Zuleima Tharays. "Experimental pore-scale analysis of fluid interfacial areas in oil-wet and water-wet bead packs." [University Park, Pa.] : Pennsylvania State University, 2009. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-4613/index.html.
Full textAkbar, Muhammad Khalid. "Transport Phenomena in Complex Two and Three-Phase Flow Systems." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4897.
Full textYoshino, Hirokazu. "Non-linear model fitting for the measurement of thin films and surface topography." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/25482.
Full textNiessner, Jennifer [Verfasser], and Rainer [Akademischer Betreuer] Helmig. "The role of interfacial areas in two-phase flow in porous media : bridging scales and coupling models / Jennifer Niessner. Betreuer: Rainer Helmig." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2011. http://d-nb.info/1013073932/34.
Full textZhong, Hua, Ouni Asma El, Dan Lin, Bingguo Wang, and Mark L. Brusseau. "The two-phase flow IPTT method for measurement of nonwetting-wetting liquid interfacial areas at higher nonwetting saturations in natural porous media." AMER GEOPHYSICAL UNION, 2016. http://hdl.handle.net/10150/622507.
Full textNix, Ernest E. "Modeling and simulation of a Fiber Distributed Data Inferface Local Area Network (FDDILAN) using OPNET for interfacing through the Common Data Link (CDL)." Thesis, Monterey, California. Naval Postgraduate School, 1994. http://hdl.handle.net/10945/28371.
Full textThe Optimized Network Engineering Tool (OPNET) is a commercially available communications network simulation package. This thesis involves the modification of OPNET's Fiber Distributed Data Interface Local Area Network (FDDI LAN) model in order to enhance its usefulness as an aid in the development of recommendations for the characteristics and metrics to be eventually included in the Defense Service Project Office's (DSPO) Common Data Link (CDL) project. This work includes a step-by-step guide for FDDI simulation in OPNET, and a discussion of the changes made to the original model to enhance its performance and data display characteristics. Simple tests are provided to verify the completed model's performance and usefulness as a working tool for further development
Yildirim, Ismail. "Surface Free Energy Characterization of Powders." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/27525.
Full textPh. D.
Tsai, Ching-Yi, and 蔡靜誼. "Determination of the effective interfacial area in blade-packing rotating packed bed with baffles." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/95430794789795896925.
Full text中原大學
化學工程研究所
101
In this works, we used chemical absorption of CO2 to measure the effective gas-liquid interfacial area (a) and used the stripping of dissolved oxygen to measure the volumetric liquid-side mass transfer coefficient (kLa) in blade packing rotating packed bed equipped with baffles. By substituting the overall volumetric gas-side mass transfer coefficient (KGa) from our previous work (Sung, 2011) and the experimental data from this study into the two-film theory, the volumetric gas-side mass transfer coefficient (kGa)、gas-side mass transfer coefficient (kG) and liquid-side mass transfer coefficient (kL) were obtained. The influence of operation conditions, such as gas flow rate, liquid flow rate, rotational speed, existence of baffles and packing types on mass transfer coefficients and effective gas-liquid interfacial area were investigated to figure out the reason for KGa enhancement in blade packing rotating packed bed equipped with baffles. From the results, the removal efficiency of carbon dioxide was proportional to the liquid flow rate and the rotational speed. Conversely, it decreased with the increasing of gas flow rate. In addition, it was possible to increase the removal efficiency by adding the baffles. According to the experimental results, the mass transfer characteristics of the blade-packing RPB with baffles are: (1) kLa and a were proportional to liquid flow rate and rotational speed, (2) kGa was proportional to gas flow rate, liquid flow rate and rotational speed, (3) kG was affected by gas flow rate obviously, but unrelated to rotational speed, (4) kL was proportional to liquid flow rate and rotational speed. Furthermore, it is found that adding stationary baffles will enhance both of the kG and a. Finally, based on the experimental results, correlations for kLa, kGa, kG, kL and a were developed. These correlations are valid under different operation conditions in blade packing rotating packed bed equipped with baffles.
(11015943), Zhuoran Dang. "An Interfacial Area Transport Modeling for Two-phase Flow in Small and Large Circular Pipes." Thesis, 2021.
Find full text鍾年勉. "The studies of compressibility, sound velocity and interfacial area density measurements in a two-phase bubbly flow." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/96653716398309600430.
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