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Attergren, Max y Martin Lindwall. "Air Liquid Interface System". Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299329.
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The ALI-System is used to determine the toxicity of airborne nanoparticles to the human lungs. The following report seeks to describe the process of preparing an ALI-system built in a laboratory, for use outdoor. The project also involves preparing the existing ALI-system for manufacturing. The report mainly discusses the ALI-systems components, how these are constructed, demands and function. The ALI-system is very complex and needs many assisting systems to work. Some of these systems and problems with current solutions are discussed within this report. The main focus of the report is electrical systems, CAD and drafts. But also discussed are some thermal analyses. The project generated a complete set of drafts of the exposure unit, a concept for all the electrical components and an evaluation of the heating system. The project departed from its main thesis since the available time to work on the thesis was cut short since all of the parts were not available from start, but also since there was a shortage of available workshop workers after June. Despite this the project could be regarded as successful since the client was happy with the end result.Ett ALI-System används för att undersöka om luftburna nanopartiklar kan vara skadliga för människliga lungor. Nedan följer en rapport där ett ALI-System byggt i labb anpassas och förbereds för tillverkning. Tanken är att det skall konstrueras ett mobilt ALI-System som möjliggör mätningar i fält. Rapporten behandlar i huvudsak vilka komponenter som ingår, utformning av dessa samt krav och funktion. Systemet som skall konstrueras är komplext och kräver många delsystem för att klara av mätningar i fält. Delar av dessa system och lösningar på problem behandlas i rapporten. Huvudområden som behandlas är elektriska system, CAD och ritningar samt termiska analyser för att möta de krav som ställs. Projektet genererade ett komplett ritningsunderlag av exponeringsenhet, konceptframtagning för elektriska system samt dimensionering och analys av uppvärmningskällor. Projektets initiala mål att konstruera ett mobilt system, frångicks då upphandlingar av komponenter försenades samt att uppdragsgivaren behövde ritningsunderlag omgående på grund av tillgängligheten av verkstadspersonal under projektets gång. Trots detta anses projektet lyckat då uppdragsgivaren tillhandhölls det som önskades och arbetet som gjordes kan ligga till grund för vidareutveckling av ett mobilt system.
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Floyd, Tamara M. (Tamara Michelle) 1974. "A novel microchemical system for rapid liquid-liquid chemistry". Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8273.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, February 2002.Includes bibliographical references (leaves 110-119).
Microchemical systems are sub-milliliter systems for chemical processes. They are constructed using microfabrication techniques originally developed for the fabrication of microelectronic circuits. The reduction in size, as compared to conventional systems, offers several advantages in improvement of heat and mass transfer and control of flow fields. In addition, microchemical systems are smaller, therefore inherently safer and capable of shorter thermal response times. The focus of this work has been a microchemical system with a multi-inlet contactor for liquid-liquid processes. The systems are fabricated using, primarily, silicon and glass in which feature sizes range from approximately 10 to 500 [mu]m. The multi-inlet contactor consists of 10 alternating inlets for two components. Fluids continuously enter the contactor, are focused by a converging channel, mix and react in a 50 m channel. The contactor is the central element in the microchemical system that also includes a parallel plate heat exchanger, infrared transmission detection capabilities and thin film metal temperature sensors. Quantitative data are obtained using on-chip optical detection methods, integrated thin film sensors, and off-chip pressure sensors. For microchemical systems, the length scales are short. Consequently, Reynolds numbers are small and the flow is laminar. When two or more streams are contacted in a homogeneous system, the flow is stable. The short length scales of the resulting lamellar stream enable rapid diffusion mixing for applications, such as kinetics studies or reaction-rate-limited operation of fast reactions.
(cont.) The mixing characteristics in the multi-inlet contactor are investigated through experiments and simulations. Without optimization, sub-second mixing times are achieved. By using experiments and simulations to gain a better understanding of diffusion mixing in the system, 99% mixing is achieved in less than 25 ms. Characterization of the microchemical system also includes determining the overall heat transfer coefficient for the parallel plate heat exchanger and demonstrating on-chip infrared transmission detection from 4000-1000 cm-1. Thus, these devices combine all the features necessary for kinetic studies, specifically control of residence time, control and monitoring of temperature, and concentration measurement by infrared spectroscopy. As a demonstration of microchemical systems as tools for kinetics studies, the microchemical mixer was used with in situ Fourier Transform infrared spectroscopy to monitor the alkaline hydrolysis of methyl formate. This reaction follows second order kinetics and is fast with a half life of 70 ms for the conditions used in this study. The rate constant that was extracted was in good agreement with the literature value. Moreover, in contrast to a previous study, no sample post processing was needed and the half-life of the reaction was reduced by an order of magnitude. Microchemical systems can also be useful tools in achieving and understanding heterogeneous fluid contacting. When an aqueous phase and organic phase are contacted in a 1:1 volumetric ratio, flow segregation can occur ...
by Tamara M. Floyd.
Ph.D.
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Zeiner, Tim. "Diffusion across the interface of an liquid-liquid system". Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-198780.
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Zeiner, Tim. "Diffusion across the interface of an liquid-liquid system". Diffusion fundamentals 24 (2015) 57, S. 1-2, 2015. https://ul.qucosa.de/id/qucosa%3A14576.
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Gelbart, W. "Bulk liquid-metal irradiation system". Helmholtz-Zentrum Dresden - Rossendorf, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-165893.
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Introduction
Low melting point metals are often encapsulated in a hermetic container, irradiated and the container transferred to hot-cell for material removal and processing. An important process of this kind is the production of 82Sr from rubidium (melting point: 39.5 °C.)
This new concept departures completely form the encapsulated targets approach and allows an almost continues production by the irradiation of the bulk metal. As well, eliminated is the target transfer. By placing the target material dissolution chamber right in the target station, only the dissolution product is pumped to the hotcell for further processing.
Material and Methods
Some of the disadvantages of the encapsulated target are:
1. Complicated transfer system that is ex-pensive to install, slow and prone to failures.
2. Complex and expensive encapsulation procedure.
3. Loss of production time during the lengthy target changing.
4. Capsule geometry is constrained by the encapsulating process and transfer demands compromising heat transfer and beam power.
To avoid the difficulties of liquid metal handling, metal salts are often used instead (rubidium chloride is one example). This creates other problems and limits the beam currents and production yields.
In the system described, the liquid metal is transferred (by gravity) from a bulk container to an irradiation chamber. The chamber, made out of nickel-plated silver, holds the correct quantity of rubidium for one irradiation run. Because of the geometry of the chamber and the efficient cooling, up to 40KW of beam power can be delivered to the target. The chamber is equipped with thermocouples and a liquid-metal level detector and is entirely of welded/brazed construction. The alloy foil that forms the beam window is electron-beam welded to the chamber front ring.
At the end of irradiation the irradiated liquid metal is gravity fed into a reaction chamber situ-ated below the irradiation chamber, and a new load of fresh rubidium released into the irradia-tion chamber. The liquid-metal transfer and the irradiation components are shown on FIG. 1, and the sectional view on FIG. 2.
Appropriate chemicals (n-butanol in the case of rubidium) are delivered to the reaction chamber and the irradiated metal dissolved. The liquid dissolution product is transferred back to the hotcell. Since all steps of the reaction involve liquids, only small diameter tubes connect the target station with the hotcell. The transfer is fast and simple.
The bulk liquid-metal storage container can be constructed to hold enough material for 10 or more runs. When empty, it is replaced with a pre-loaded one. The container is connected to the target system with one coupling and the exchange takes a short time. A robotic bottle exchange can be implemented if desired.
The station is equipped with its own vacuum system, beam diagnostic (consisting of a four-sector mask) and a collimation. The target chamber and each of the beam intercepting components are electrically insulated to allow beam current monitoring.
Constructed entirely out of metal and ceramic the target core assembly does not suffer from radiation damage. The use of aluminum, silver and alumina reduce component activation.
Results and Conclusion
A large part of the station design is based on the well proven construction of high current solid target system and is using the same, or similar components.
Test was performed to optimize the liquid-metal transfer and the chamber filling with the correct volume, while leaving some room for expansion.
A process for niobium coating of sliver is investi-gated. Niobium is known to provide good corro-sion resistance against liquid metals.
Thermal modelling of the target and flow analysis of the cooling geometry is under way.
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Braibant, Bertrand. "Synthèse et étude de systèmes fluorés pour l'extraction liquide-liquide de métaux stratégiques". Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT175/document.
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Aujourd’hui, une large part des métaux utilisés par l’industrie provient généralement des mines. Certains, dits stratégiques, pourraient présenter un risque d’approvisionnement voire d’épuisement des ressources naturelles. Ces métaux sont généralement utilisés dans des processus dispersifs, et se retrouvent répartis de façon inégale, avec d’autres métaux, dans des matrices toujours plus complexes, ce qui rend leur récupération couteuse en termes de procédés et d’énergie. Que ce soit pour des raisons stratégiques, économiques ou sociétales, il apparait que le recyclage des métaux est amené à devenir une activité importante dans le futur. L’approche hydrométallurgique, et en particulier l’extraction-séparation liquide-liquide, est une technique adaptée et éprouvée à ce jour pour répondre au recyclage des métaux. Ce travail de thèse s’intéresse au développement et l’étude de systèmes moléculaires fluorés pour l’extraction et la séparation de métaux par une approche liquide-liquide. La modularité de la partie fluorée de ce type de système moléculaire permet l’étude des diverses interactions (complexations, supramoléculaires) importantes d’un point du vue fondamental dans l’extraction liquide-liquide de métaux. De plus, leurs propriétés physico-chimiques (miscibilité,…) permettent d’envisager le design de procédés innovants dans le domaine de la séparation liquide-liquide, comme la mise en œuvre de systèmes tri-phasiques. Pour cela, deux séries de malonamides fluorés avec des espaceurs de taille variable, entre la tête complexante et le groupement perfluoré, ont été synthétisés. La modulation par l’espaceur de l’effet inductif des chaines perfluorées sur les propriétés physico-chimiques des extractants et sur la complexation d’un métal a été étudiée. De même, l’influence de certains paramètres d’extraction comme la charge en extractant, en acide et l’influence du diluant ont été caractérisés. La comparaison avec les ligands homologues hydrogénés a été effectuée, et les limites des différents systèmes établies. Une série de phosphates de trialkyles a également été étudiée et appliquée à un système tri-phasique d’extraction liquide-liquide. Des résultats préliminaires valident de manière encourageante l’approche choisieA large part of the metals used by the industry is still coming from mines. Some metals, called strategic metals, may encounter a supply risk or even a total depletion of natural resources. They are usually used in dispersive way which make their recovery complicated, costly and energy intensive since they are in unequal amount, with other metal, in ever more complex matrices. Whether for strategic, economic or societal reason, the metal recycling is about to become an important industry in a near future. Hydrometallurgical processes, and liquid-liquid extraction in particular, are a robust technic giving answer to some of the recycling challenge. Our aim was to develop and study some fluorinated system for the extraction and the separation of metal through liquid-liquid approach. The tenability of the fluorinated part of these system allow the study of multiple interaction (complexation or supramolecular ordering) important in a fundamental point of view in liquid-liquid extraction. Physical and chemical properties such as their miscibility allow the development of new processes in the solvent extraction field such as triphasic liquid extraction system. To this end, two series of fluorinated malonamides with various spacer length between the complexing head and the fluorinated moiety were synthetized. The modulation, through the spacer, of the inductive effect of the fluorinated chain on the physical and chemical properties of the extractant and the complexation of the metal was studied. The influence of various extraction parameters such as the concentration in extractant, the acid and the diluent were characterized. The comparison of these malonamides with their hydrogenated homologues was done and the limits of these systems established. A family of trialkylphosphate was developed and apply to a triphasic extraction system. Preliminary results confirm the approach
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Zhang, Liqin. "A new liquid-liquid partitioning system for bioseparations at low temperatures". Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1184618209.
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Shih, Victor Chi-Yuan Tai Yu-Chong. "Temperature-controlled microchip liquid chromatography system /". Diss., Pasadena, Calif. : Caltech, 2006. http://resolver.caltech.edu/CaltechETD:etd-04182006-162552.
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Du, Lingguo. "Rôle des films liquides sur des problèmes de mouillage dynamiques pour des systèmes liquide-liquide". Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14566/document.
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La récupération assistée du pétrole implique la progression dans unmilieu poreux d'une phase aqueuse qui pousse une phase organique. Al'échelle du pore, les forces visqueuses et la gravité sontnégligeables, et la capillarité joue un rôle prépondérant : ledéplacement des fluides est gouverné par leur affinité avec lessurfaces et par les hétérogénéités de canaux. Les films liquidesexistent dans les pores d'une roche. Trois systèmes microfluidiquessont mis en place pour étudier le rôle des films microscopiques (demouillage) ou des films macroscopiques (de coins). Le premier consisteen un capillaire de section circulaire dans lequel on suit lemouvement d'un ménisque dans des conditions de mouillage variées. Enparticulier, en mouillage pseudo-partiel, un hystérésis d'angle decontact est observé, mais les films de mouillage présents dans cesystème conduisent à un accrochage de ligne de contact beaucoup plusfaible qu'en absence de film. Les deuxième et troisième systèmesmettent en évidence l’influence des films de coins dans un canalrectangulaire sur l'avancée du ménisque. Le couplage de l'écoulemententre la phase du coin et la phase du milieu entraîne le drainage del’huile piégée. Les propriétés de ce nouveau mécanisme sontcaractérisées par des expériences et s’accordent avec le modèleconstruitEnhanced oil recovery involves the displacement of an organic fluid byan aqueous one in the pores of the rocks. At the pores scale. Thedisplacement of fluids is governed by wetting condition of the system.The viscous and gravity forces are negligible and the capillarityplays a dominant role heterogeneities of channel sizes. Threemicrofluidic systems are designed to study experimentally the role ofmicroscopic liquid films (wetting) or macroscopic ones (corners) inthe pores level. The first one consists of the displacement of ameniscus in a circular capillary with various wetting conditions. Inparticular, for pseudo-partial wetting systems, a contact anglehysteresis is observed but with a weak pinning as compared to partialwetting systems where there are non wetting films. The second andthird ones show the influences of liquid films in the corners of asquare channel. The coupling between the corner flows and the mainflow involves the drainage of the trapped oil cluster. The propertiesof this new mechanism are consistent with the theoretical model, andalso characterized by experiments
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Tan, Junyi y 譚軍毅. "Investigation of novel liquid desiccant cooling system". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42664251.
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Tan, Junyi. "Investigation of novel liquid desiccant cooling system". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42664251.
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Kholany, Mariam Achraf Mohamed Bahie El Din El. "Enantioselective separation of chiral compounds using aqueous biphasic systems and solid-liquid biphasic system". Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22708.
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Mestrado em Biotecnologia - Industrial e AmbientalTipicamente, apenas um dos enantiómeros é responsável pelo efeito pretendido de um fármaco, sendo que o outro pode levar a respostas menos potentes ou até mesmo indesejadas. As entidades reguladoras praticam políticas restritas em relação à comercialização de fármacos como misturas racémicas. Assim, a indústria farmacêutica tem enfrentado desafios relacionados com o desenvolvimento de métodos para produção de fármacos oticamente puros. No entanto, e considerando a dificuldade acrescida na produção de enantiómeros puros por síntese direta, a síntese de misturas racémicas seguida da sua purificação surge como uma alternativa mais barata, simples e flexível. Os sistemas aquosos bifásicos (SABs) e os sistemas de duas fases sólida-líquida (SDFSL) são técnicas alternativas mais biocompatíveis que têm sido utilizados como técnicas de separação enantiosseletiva de fármacos e/ou aminoácidos com enantiosseletividades bastante promissoras. Para além disso, apresentam benefícios de custo, rapidez, simplicidade e versatilidade de operação e possibilidade de aumento de escala. Este trabalho foca-se no desenvolvimento de SABs e SDFSL constituídos por seletores quirais que possam atuar simultaneamente como solvente. Numa primeira abordagem o objetivo foi desenvolver novos SABs quirais, mais biocompatíveis, simples e eficientes. Para tal, SABs constituídos por açúcares, aminoácidos e líquidos iónicos quirais foram aplicados na resolução enantiomérica de ácido mandélico racémico. O sistema mais promissor, composto por [C1Qui][C1SO4] + K3PO4, obteve um excesso enantiomérico de -33.4%. Numa segunda abordagem, foi possível criar uma alternativa mais simples e mais eficiente recorrendo a SDFSL. Com estes sistemas, foi obtido o valor mais elevado de excesso enantiomérico deste trabalho, de 49.0%, através da precipitação enantiosseletiva do R-ácido mandélico por interação com [N4444][D-Phe].
Conventionally, only one of the enantiomers is responsible for the intended effect of a drug, whilst the other may lead to a less potent or even undesired response. Regulation entities are very strict regarding the commercialization of racemic drugs. Thus, pharmaceutical industry has been facing challenges related to the creation of methods to produce optically active drugs. However, considering the increased difficulty in the production of pure enantiomers by direct synthesis, the synthesis of racemic mixtures followed by their purification appears as a cheaper, simpler and more flexible alternative. Aqueous biphasic systems (ABS) and solid-liquid biphasic system (SLBS) are more biocompatible alternatives that have been used to separate racemic drugs and amino acids with promising enantioselectivities. Furthermore, these are cost-effective, quick, simple and operationally flexible. This work intended to develop ABS and SLBS using chiral selectors that can simultaneously act as solvents. In a first attempt, chiral ABS of better biocompatibility, simplicity and efficiency were developed. For that purpose, ABS constituted by sugars, amino acids and chiral ionic liquids (CILs) were applied for chiral resolution of racemic mandelic acid (MA). The most promising ABS was a system composed of [C1Qui][C1SO4] + K3PO4 which yielded the maximum enantiomeric excess of -33.4%. In a second approach, it was possible to create a simpler and more efficient technique resorting to SLBS. The enantiomeric excess value of 49.0% was achieved, by the enantioselective precipitation of the R-MA caused by interactions with [N4444][D-Phe].
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Goyette, Bernard. "Development and evaluation of a liquid-ice system". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68178.
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The deterioration of freshly harvested horticultural crops prior to storage can be minimized by rapid pre-cooling. This deterioration occurs for two reasons: (i) the respiration rate is typically high due to high ambient temperatures at harvest, and (ii) physiological activity of the produce is at peak levels. Thus, precooling is essential.Many precooling techniques are used in the horticulture industry today. Their main purpose is to rapidly extract heat from the produce by using a suitable fluid for the heat extraction/rejection process.
The efficiency of a cooling method depends on many factors: the cooling fluid used, the morphological characteristics of the product, the type and shape of packing, the system design, etc.. It is therefore relatively difficult to compare the efficiencies of cooling systems or to evaluate the effect of each parameter on system efficiency. A new method for assessing cooling system efficiency was therefore developed. The technique was based on the capacity of the system to maintain the product temperature at the surface as low as possible without affecting the morphological characteristics of the product. It was shown that this method of assessing efficiency was effective under field conditions.
A low cost liquid-ice system was designed and tested for broccoli precooling. It is based on ice particle injection into a water stream, the mixture then being pumped into the box of produce to be precooled. The effects of different ice particle sizes and ice-water ratios on the medium temperature of broccoli, the mass of ice remaining in the boxes of produce and the icing efficiency were analyzed. The results led to the establishment of optimum conditions for the parameters of the proposed system.
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Rees, G. J. "Interfacial adsorption in a gas-liquid chromatographic system". Thesis, Swansea University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638636.
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Chromatographic retention due to adsorption at the liquid/gas and liquid/solid interfaces is possible in gas-liquid chromatographic (GLC) systems, especially with polar solutes from a non-polar stationary phase. The variation of retention volumes with sample size at 60oC on several series of columns, using different support materials, was studied for di iso-propyl ether (DIPE), a polar solute, on squalane, a non-polar stationary phase. Isolation of the total adsorption contributions to retention was then performed using a semi-empirical curve fitting procedure devised by Mathiasson and Jonsson. The adsorption retentions at infinite dilution on a fully wetted porous silica support (Porasil F) was extrapolated to zero loading where the gas/liquid interfacial area (Ax) approaches the value of the support surface area (As). As was measured using the BET nitrogen adsorption method, and the sum of the support/liquid and vapour/liquid adsorption coefficients was obtained. The solid/liquid interfacial adsorption coefficient, Ks, was estimated from adsorption liquid chromatographic parameters, and was found to be small in comparison with the gas/liquid interfacial adsorption coefficient, Kx. The variation with liquid loading of the adsorption contribution to retention on two silanised supports (Chromosorb P-AW DMCS and HMDS treated Porasil F) was studied. The gas liquid interfacial area at high loading was found to be small in comparison with that of untreated Porasil F, and comparable with values obtained by other workers. At squalane loadings where a wetting transition is postulated on the silanised support, the magnitude of Ax approaches that of the unsilanised support, and helps confirm the model for the wetting transition proposed by Conder and coworkers.
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Al, Anqah Laila. "Trace element contaminants in the Kuwait water production system". Thesis, Brunel University, 1996. http://bura.brunel.ac.uk/handle/2438/5012.
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Fresh water in Kuwait is produced by non- conventional methods. About 95% of this water comes from desalinated seawater using multi-stage flash distillation technique and the remainder comes from underground brackish water. The blended water containes organic, inorganic and trace metal impurities within the recommended international standard limits. The purpose of this work is to identify the source of selected trace metals present in the drinking water in Kuwait. Chromium, copper, iron, lead, manganese, nickel, vanadium and zinc have been analysed using atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectroscopy (ICPMS). Efforts were made to improve the preconcentration of the selected metals and their separation from the high concentration of salts in seawater which affect the accuracy and cause major interference in the analysis. Solid-liquid extraction (chelex-100 resin) and liquid-liquid extraction (methyl iso-butyl ketone and freon) with and without back-extraction into nitric acid were investigated. Liquid-liquid extraction without back-extraction proved to give optimum recovery of the selected metals. Results confirmed that both AAS and ICP-MS are suitable for the analysis of trace metals in Kuwait's waters. Although AAS technique proved to be more accurate in analysing the selected metals than ICP-MS, the latter was adopted since its accuracy is acceptable (1.1-4.4%) and it is easier and faster than the former technique. The study revealed that the source of copper, iron, nickel and zinc is the construction materials of the distillation plants, while the source of lead and vanadium is the brackish water. Manganese and chromium concentrations are very low in all sources. No direct relationship between the metal concentration in the seawater and the distillate could be deduced.
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Singha, Pradip. "Fundamental Properties of the Liquid Marble Shell". Thesis, Griffith University, 2022. http://hdl.handle.net/10072/418760.
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Liquid marble is a non-wetting droplet coated with micro- or nanometre-sized particles and exhibits excellent versatility as a standalone microfluidic system. Liquid marble, as an emerging platform for digital microfluidics has shown its potential in biomedical applications, cosmetics, and chemical industries. Unique features such as low evaporation rate, low friction, and a porous shell enable liquid marble to be a potential tool for gas sensing, cell culture, and drug delivery. With the growing interest in liquid marble-based applications, it is important to study the fundamentals of the liquid marble shell. Existing works on liquid marble shell discuss only the structure of the shell but detailed research on the liquid marble shell is still lacking. My research work during my PhD candidature focuses on understanding the behaviour and structure of a liquid marble shell at various conditions and how it affects the liquid marble properties.
The integrity of a liquid marble depends on the properties of the shell which comprises of encapsulating particles and pores. The size of the particles, properties of the particles, and the number of layers in the shell determines a liquid marble’s macroscopic properties. For instance, multiple particle layers on the shell give a rough shape and fluffy appearance of a liquid marble which brings uncertainties to the effective surface tension values. A monolayered liquid marble has a smoother surface which minimises the error in the effective surface tension measurement. On the other hand, pores in the shell reduce the effective surface tension which affects the evaporation rate of the liquid marble. The behaviour and the structure of a liquid marble shell depend on the preparation method, morphology of the encapsulating particles, and the properties of the core liquid. The details will be discussed in this thesis.
We varied the core liquid surface tension to study the liquid marble shell characteristics. We found that the thickness and the mass of a liquid marble shell vary with core liquid surface tension. Surfactant-mediated surface tension reduction of the core liquid allows the encapsulating particles to penetrate more into the core liquid and decrease the shell thickness. The shell thickness decreases significantly with the surface tension whereas the mass remains almost constant. Interestingly, the trend reverses with a further decrease of the surface tension. In this regime, both the thickness and the mass of the shell increase due to interfacial jamming. We understand the contribution of the particle distribution at the shell to its behaviour and the stability of a liquid marble. We also understand that the preparation method is crucial in determining the liquid marble properties.
Next, we investigated the effect of the liquid marble preparation method on its effective surface tension. This work attempts to solve the long-standing problem of inconsistent effective surface tension values of liquid marbles. The effective surface tension values reported in the literature are inconsistent due to particle agglomeration, volume of a liquid marble or the preparation method. Moreover, the prevailing liquid marble preparation method is to roll a droplet on a powder bed. We hypothesize that the lack of rolling duration or revolution speed control contribute to inconsistent effective surface tension values and a systematic preparation approach improves the consistency of the effective surface tension values. We (i) determine the effective surface tension using the natural oscillation of a sessile liquid marble and (ii) investigate the effects of liquid marble preparation methods on the effective surface tension for the first time in this thesis. We find that the systematic preparation method improves the consistency of the measured effective surface tension values. Interestingly, higher revolution speed during preparation causes interfacial jamming at the liquid marble shell which decreases the consistency.
We studied the liquid marble shell and its effective surface tension but the detailed understanding of the liquid marble shell is still impeded due to its opaque and fuzzy appearance. We used X-ray computerized microtomography (CMT) to generate an image with a visible interface between the core liquid and the shell to overcome this problem. The visible interface facilitates accurate measurement of the shell thickness and consequently the effective surface tension of the liquid marble. We investigate the effect of liquid marble preparation methods and liquid marble volumes on shell thickness and effective surface tension. We found that increasing the revolution speed during liquid marble preparation increases shell thickness. A liquid marble shell has a uniform packing when the revolution speed is 200-300 rpm. We also found that the effective surface tension of liquid marbles decreases with increasing volume. This could be due to a stronger effect of gravitational force for a large liquid marble. We believe that this thesis could provide a new insight into the characterization of liquid marble and open up a new direction of fundamental research of liquid marble and its shell.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Vuorenkoski, Anni Kaisa. "Development of a liquid-phase LPG MPI conversion system". Thesis, Cranfield University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408470.
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Tomashevskyi, Roman, Yevhen Vikarii y Zinaida Dotsenko. "System for Recording Evoked Potentials in Liquid Biological Matrix". Thesis, IPM NASU, 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/34109.
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The article deals with the development and investigation of a system for recording, amplifying and processing weak evoked potentials in liquid biological matrix. The main attention is paid to the study of the parameters of this system.
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Lu, Yanfeng. "A Study on Liquid Bridge Based Microstereolithography (LBMSL) System". University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1468252608.
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Holcomb, Sarah E. "A Complete Interfacial System Solution for Liquid Metal Electronics". University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1562674870496862.
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Booth, Alexander John. "A novel, biomimetically inspired, flash evaporation liquid atomization system". Thesis, University of Leeds, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.713482.
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The increasing demands placed on conventional methods of liquid atomization, in terms of spray quality, now mean that there is a need for a new, disruptive, liquid atomization technology which can rapidly improve spray performance to meet the growing sophistication required of modern liquid spray systems. This thesis details an investigation into the mode of action of a liquid atomization system (pMISTe) which shows promise to be able to provide this disruptive new spray technology. Influenced by the defence mechanism of the bombardier beetle, this atomization method produces a large amount of volumetric shear in a body of liquid, by inducing a flash evaporation of a proportion of the total liquid mass in an enclosed chamber. The flash evaporation is created firstly by heating the liquid far above its saturation temperature at an ambient external pressure - in a chamber cavity sealed by an electronically controlled ejection valve. This valve is released very rapidly, causing the liquid in the chamber to suddenly `see' the ambient external pressure. It is this sudden exposure of a superheated liquid to the low external ambient pressure that drives the flash evaporation and the atomisation. The atomization system was investigated using a staged experimental method, including a mixture of Taguchi Design of Experiment (DoE) and full factorial techniques. From these investigations the main characteristics of the mode of action of the system were identified. These were that, in general, increases in chamber liquid temperature caused decreasing average droplet size, and that increases in refill flow rate caused increasing droplet size; due to the primary flash evaporation mechanism. In addition more complex secondary behaviours, attributed to the fluid dynamic properties of the system, were discovered. The performance of the system is also discussed with reference to its suitability for a range of spray applications
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Zhou, Zhipeng (Joe Zoe). "Performance analysis of hybrid liquid desiccant solar cooling system". Thesis, Queensland University of Technology, 2009. https://eprints.qut.edu.au/40088/1/Zhipeng_Zhou_Thesis.pdf.
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This thesis investigates the coefficient of performance (COP) of a hybrid liquid desiccant solar cooling system. This hybrid cooling system includes three sections: 1) conventional air-conditioning section; 2) liquid desiccant dehumidification section and 3) air mixture section. The air handling unit (AHU) with mixture variable air volume design is included in the hybrid cooling system to control humidity. In the combined system, the air is first dehumidified in the dehumidifier and then mixed with ambient air by AHU before entering the evaporator. Experiments using lithium chloride as the liquid desiccant have been carried out for the performance evaluation of the dehumidifier and regenerator. Based on the air mixture (AHU) design, the electrical coefficient of performance (ECOP), thermal coefficient of performance (TCOP) and whole system coefficient of performance (COPsys) models used in the hybrid liquid desiccant solar cooing system were developed to evaluate this system performance. These mathematical models can be used to describe the coefficient of performance trend under different ambient conditions, while also providing a convenient comparison with conventional air conditioning systems. These models provide good explanations about the relationship between the performance predictions of models and ambient air parameters. The simulation results have revealed the coefficient of performance in hybrid liquid desiccant solar cooling systems substantially depends on ambient air and dehumidifier parameters. Also, the liquid desiccant experiments prove that the latent component of the total cooling load requirements can be easily fulfilled by using the liquid desiccant dehumidifier. While cooling requirements can be met, the liquid desiccant system is however still subject to the hysteresis problems.
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North, Thomas B. "Liquid Nitrogen Propulsion Systems for Automotive Applications: Calculation of Mechanical Efficiency of a Dual, Double-acting Piston Propulsion System". Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc6070/.
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A dual, double-acting propulsion system is analyzed to determine how efficiently it can convert the potential energy available from liquid nitrogen into useful work. The two double-acting pistons (high- and low-pressure) were analyzed by using a Matlab-Simulink computer simulation to determine their respective mechanical efficiencies. The flow circuit for the entire system was analyzed by using flow circuit analysis software to determine pressure losses throughout the system at the required mass flow rates. The results of the piston simulation indicate that the two pistons analyzed are very efficient at transferring energy into useful work. The flow circuit analysis shows that the system can adequately maintain the mass flow rate requirements of the pistons but also identifies components that have a significant impact on the performance of the system. The results of the analysis indicate that the nitrogen propulsion system meets the intended goals of its designers.
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Towlson, David Stephen. "Mesophase behaviour in a system of self-assembling discotic amphiphiles". Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238552.
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Rudin, Malin. "Evaluation of Optical Flow for Estimation of Liquid Glass Flow Velocity". Thesis, Linköpings universitet, Datorseende, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-179072.
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In the glass wool industry, the molten glass flow is monitored for regulation purposes. Given the progress in the computer vision field, the current monitoring solution might be replaced by a camera based solution. The aim of this thesis is to investigate the possibility of using optical flow techniques for estimation of the molten glass flow displacement. Three glass melt flow datasets were recorded, as well as two additional melt flow datasets, using a NIR camera. The block matching techniques Full Search (FS) and Adaptive Rood Pattern Search (ARPS), as well as the local feature methods ORB and A-KAZE were considered. These four techniques were compared to RAFT, the state-of-the-art approach for optical flow estimation, using available pre-trained models, as well as an approach of using the tracking method ECO for the optical flow estimation. The methods have been evaluated using the metrics MAE, MSE, and SSIM to compare the warped flow to the target image. In addition, ground truth for 50 frames from each dataset was manually annotated as to use the optical flow metric End-Point Error. To investigate the computational complexity the average computational time per frame was calculated. The investigation found that RAFT does not perform well on the given data, due to the large displacements of the flows. For simulated displacements of up to about 100 pixels at full resolution, the performance is satisfactory, with results comparable to the traditional methods. Using ECO for optical flow estimation encounters similar problems as RAFT, where the large displacement proved challenging for the tracker. Simulating smaller motions of up to 60 pixels resulted in good performance, though computation time of the used implementation is much too high for a real-time implementation. The four traditional block matching and local feature approaches examined in this thesis outperform the state-of-the-art approaches. FS, ARPS, A-KAZE, and ORB all have similar performance on the glass flow datasets, whereas the block matching approaches fail on the alternative melt flow data as the template extraction approach is inadequate. The two local feature approaches, though working reasonably well on all datasets given full resolution, struggle to identify features on down-sampled data. This might be mitigated by fine-tuning the settings of the methods. Generally, ORB mostly outperforms A-KAZE with respect to the evaluation metrics, and is considerably faster.
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Bryan, Charles Edward. "An electron beam addressed liquid crystal light valve projector". Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235841.
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The contents of this dissertation relate to a liquid crystal light valve which is addressed by an electron beam. The light valve has been configured with a computer aided designed optical projection system, to produce an electron beam addressed liquid crystal light valve projector. The projector is capable of turning an electrical signal into a corresponding projected picture. A minimum resolution of 33um was demonstrated in a smectic-A liquid crystal light valve and one of 40um in a dyed phase change guest-host liquid crystal light valve. The diameter of the active area of the light valve was 45mm. Crucial to the realization of the projector was the patented invention and design of an electrically highly anisotropic disc of 47mm diameter which was approximately 2mm thick. The disc, which was conducting through its thickness and insulating across its plane, formed the top interface of the liquid crystal light valve and permitted the electron beam to deposit a charge pattern which could be conveyed to the thin liquid crystal layer without loss of resolution. The disc was made using a specially constructed piece of apparatus wherein the holes in a glass capillary array were filled with a low melting point alloy. Discs were made using three different low melting point alloys and their various merits were considered. Consideration was also given to developing the deflection coils used in this projector. Computer aided design resulted in a deflection coil system capable of a resolution of over 8 x 108 pixels in a 50mm x 50mm frame at a half angular aperture of 1mrad. In order to evaluate the resolution of the light valve, a micro-computer controlled dot pattern generator was built. This was used to drive the deflection coils in such a way as to control both the dwell time and position of the electron beam spot. Lines of different spacings were written on the light valve. Electron and optical micrographs are presented to demonstrate the quality of the anisotropic disc. Photographs and optical micrographs are included to show the pictures which were obtained from the projector and also the lines written on the light valve.
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Blaylock, Charles Robert. "Statistical evidence for competing equilibria models in the system Tri-N-Butyl phosphate-nitric acid-water-diluent". Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/12030.
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Sibanda, V. S. "The determination of excess thermodynamic functions of binary liquid mixtures". Thesis, Keele University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376300.
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Elliott, Alice Margaret Sophie. "The physical structure of a system of mesogenic side chain polymers". Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388435.
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Samuelsson, Jörgen. "Development of Methods for Phase System Characterization in Liquid Chromatography". Doctoral thesis, Uppsala universitet, Ytbioteknik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8597.
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The aim of this thesis is first and foremost to improve the fundamental knowledge of nonlinear and preparative separation theory by focusing on some of the remaining “white spots” on the theoretical chromatographic map. Secondly, the acquired knowledge is used to develop, validate and execute new methods for phase characterization in liquid chromatography. The methodology used in this thesis is a combination of experiments, fundamental nonlinear theory and systematic computer simulations. A fundamental knowledge of the molecular interactions between the compounds to be separated and the separation media requires the determination of adsorption isotherms over a broad concentration range to give a complete picture of all interactions in the separation system - weak as well as strong. In addition, such adsorption data is essential for optimization in preparative chromatography. For the first time, it has been experimentally shown that the injected molecules are not present in the detected peak when a small excess of molecules are injected into a chromatographic system equilibrated with a constant stream of identical molecules. Several experimental procedures for this method were developed such as (i) the optimal injection strategy and (ii) different labeling methods for visualizing the injected molecules. Remarkable phenomena in the single-component case, such as invisible peak deformation and deformed (invisible) frontal chromatograms, are reported, investigated, and explained. This phenomenon has asides from its future practical implementation, also a large didactic value. The accuracy of the ECP method is experimentally improved, and used to characterize the separation of protolytic compounds at different pH on modern commercially available silica and hybrid silica column packing materials. That investigation enables us to answer why basic compounds give a much more compact preparative peak profile at pH 11 than they yields at lower pH.
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Barker, Simon William. "Diffusion induced liquid film migration in the aluminum-copper system /". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0001/NQ42721.pdf.
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Mason, Karen B. "An electro-optic logic system employing liquid crystal display devices". Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329084.
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Hui, Sam S. B. Massachusetts Institute of Technology. "Design and implementation of liquid cooling system for ArchiMITes vehicle". Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/69512.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 27).
MIT Vehicle Design Summit is building ArchiMITes, a lightweight hybrid vehicle with a modular auxiliary power unit. For testing purposes, the vehicle platform will first be built as an all-electric vehicle. It will be powered by five lithium ion batteries that generate a total of 700 W of heat. Without a cooling system, the batteries will quickly rise above 50 'C and become damaged. This project seeks to design and put together a liquid cooling system to remove the heat from the batteries. Calculations indicate that the battery cell temperature will be 17.39 'C above the ambient temperature. This temperature difference incorporates a factor of safety of 2. Further studies on battery placement, working fluid fill methods, and fan and pump control are recommended.
by Sam Hui.
S.B.
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Miquel, Valentin. "Propellant Feeding System of a Liquid Rocket With Multiple Engines". Thesis, KTH, Rymdteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-276460.
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Multiengine first stages are the new trend in recent rockets. Reusability and an oxygen/methane based engine complete this picture. ArianeGroup wants to develop its own rocket following these principles. This thesis presents the study of the feeding system for a seven Prometheus engine rocket. Several ways of connecting propellant tanks to engines were proposed and analyzed. Two configurations were selected and studied with more detail. One consists of a main feeding line which is then split in seven secondary lines. The other one adds one rank of pipes to reduce the number of feeding valves. Their performances were assessed according to classic space industry drivers. Furthermore, the impact of the two solutions on the efficiency of the tank was evaluated. CAD drawings and simulation models were made and could be a base for future work if one of the systems is chosen. The study shows that a falcon 9 like feeding system is performant in terms of mass and pressure losses but another cost-effective configuration is possible and gives good results.Första stegen med flera motorer är den nya trenden i de senaste raketerna. Återanvändbart och en syre och metan-baserad motor kompletterar denna bild. ArianeGroup vill utveckla sin egen raket enligt dessa principer. Denna avhandling presenterar studien av drivmedelsrör för en sju Prometheus-motorraket. Flera sätt att ansluta drivmedelstankar till motorer föreslogs och analyserades. Två konfigurationer valdes ut och studerades mer detaljerat. En består av en huvudlinje som sedan delas upp i sju sekundära linjer som på SpaceX Falcon 9. Den andra lösningen lägger till en rang av rör för att minska antalet ventiler. Deras prestanda utvärderades först enligt klassiska kriterier för rymdindustrin. Dessutom utvärderades de två lösningarnas påverkan på tankens effektivitet. CAD-ritningar och simuleringsmodeller gjordes och kan vara en bas för framtida arbeten om ett av systemen väljs. Studien visar att ett Falcon 9-liknande konfiguration har bättre prestanda när det gäller massa och tryckförluster men en annan kostnadseffektiv konfiguration är möjlig och ger goda resultat.
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Huang, Chou Cheng y 周正晃. "Liquid Liquid Equilibrium of Ternary System". Thesis, 1993. http://ndltd.ncl.edu.tw/handle/43433199334269233648.
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Wang, Bo-Jyun y 王柏鈞. "Liquid-Liquid Equilibrium of Caprolactam+MImSO4+Hydroxyl Group System". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/70493805366732116439.
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Tien, Chi-Chung y 田其錩. "The Drag Force Analysis and Phenomenon Study of Liquid Droplets in Liquid-Liquid system". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/03846813906158498677.
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碩士國立臺灣大學
機械工程學研究所
89
The experiments discuss the drag and phenomenon vibration of liquid droplets which fall or rise in liquid-liquid system. The temperature is controlled between 20-23℃,and the pressure is 1atm. To avoid the mass transition, we use water, heptane, dodecane and hexadecane to be as for the droplet and the continued fluid. The range of Reynolds numbers are between 0.2 to 2200. The present data shows that the drag coefficients, for all fall or rise systems,whould be decreased gradually, reached a minimum, and then rise rapidly. The reasons can be solved by the effectivies of surface flow, internal flow, and deformation . After the critical Reynolds numbers, the development of oscillations lead to lower velocities. Otherwise,the velocities are just dependent upon their physical properties. In general, the higher density difference and the lower interfacial tension lead to the easier oscillation, and the fall or rise path of droplets are zigzag.
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Giannelos, Nikolaos Fotios. "An expert system for the synthesis of solid-liquid-liquid separations". 1997. https://scholarworks.umass.edu/dissertations/AAI9721453.
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The synthesis of separation systems involving solid-liquid-liquid mixtures is an important problem that has not received appreciable attention in the literature of process synthesis in the past. The main objective of this research is the development of a complete design methodology for solid-liquid-liquid separations in the context of total flowsheet synthesis, along with its computer implementation, including the initial synthesis of flowsheet structures, the generation of process alternatives, and a preliminary cost analysis. The implementation part of this work is stressed as a means of testing heuristics and formalizing the design activity. The proposed synthesis approach is heuristic in nature. Separation methods are selected and the interconnections among equipment types are deduced based on expert knowledge in the form of rules. Short-cut calculations are employed for equipment design and cost estimations. The final product of this research has been implemented in a prototype expert system, facilitating the screening of alternative separation schemes and the invention of preliminary flowsheets.
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Shih, Victor-Chi-Yuan. "Temperature-Controlled Microchip Liquid Chromatography System". Thesis, 2006. https://thesis.library.caltech.edu/1408/1/thesis.pdf.
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High-performance liquid chromatography (HPLC) is one of the most important analytical tools heavily used in the fields of chemistry, biotechnology, pharmaceutics, and the food industry. The power of liquid chromatography comes from its ability to achieve molecular separation with extremely high efficiency and its great flexibility of incorporating versatile sensors for detecting a broad range of analytes. In the past decades, great efforts have been put into liquid chromatography instrumentation and methods, aiming to further improve separation efficiency, sensitivity, repeatability, throughput, and costs. The contribution of this thesis is to illustrate with real examples the great potential of MEMS microchip liquid chromatography systems with on-chip temperature control for replacing and improving the conventional desktop HPLC systems.
This thesis is composed of seven chapters. Chapter 1 gives an introduction to MEMS technology and its application in making lab-on-a-chip systems. Chapter 2 describes the theoretical background and the evolution of HPLC technology. Chapter 3 demonstrates how to use state-of-the-art MEMS technology to make high-pressure microfluidic channels, which will be used for constructing microchip HPLC systems later. Chapter 4 describes a temperature-controlled microchip HPLC system that uses a temporal temperature gradient to achieve analyte elution. Separation of amino acids and low density lipoproteins was successfully demonstrated using the proposed system. Chapter 5 describes a novel embedded HPLC system, which demonstrated a record high pressure capacity (> 1000 psi) among microchip HPLC systems. High quality separation results of trace-level daunorubicin and doxorubicin were obtained using the proposed system and laser-induced fluorescence detection. A novel C4D sensor together with the RISE sensitivity enhancement method was proposed and investigated for the first time for microchip HPLC analyte detection. Chapter 6 describes the first work to pack 30 nm gold nanoparticles into the HPLC separation column as the stationary phase with the assistance of in-situ molecular self-assembly between nanoparticles and thiolated molecules. Preliminary results demonstrated the possibility of building fully filled nanoparticle HPLC columns for extremely high separation efficiency application. Chapter 7 then gives the conclusions of this thesis.
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吳慶謨. "Investigation of system characteristics of liquid-liquid-solid three-phase fluidized bed". Thesis, 1986. http://ndltd.ncl.edu.tw/handle/87493887138319165043.
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Cheng, Hui-Chun y 鄭慧君. "Synthesis of n-Heptyl o-Hydroxybenzoate by Phase-Transfer Catalyst and Ionic Liquid in Liquid-Liquid System". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/58354550142988760969.
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碩士國立中興大學
化學工程學系所
103
The study aimed at synthesizing n-heptyl o-hydroxybenzoate by using o-hydroxybenzoic acid sodium salt and 1-bromoheptane under the catalysis of phase transfer catalyst in liquid-liquid system. The operating parameters included agitation rate, ultrasonic effect, reaction temperature, type and amount of catalyst, type of solvent, type and amount of ionic liquid. The reaction mechanism and kinetics of reaction were obtained from experimental results. The esterification reaction between 1-bromoheptane and o-hydroxybenzoic acid sodium salt occurs in organic phase, and Aliquat 336 can be used to reach the highest yield among all catalysts employed in this study. Using low-polar or non-polar solvents such as toluene and heptane the yield would be lowered and indicated the influence of the level of solvent polarity on the rate. Due to the concern of green reaction, toluene was selected as the solvent, without using high polar and toxic organic solvent, methly isobutyl ketone (MIBK). In this liquid-liquid phase transfer system, the aqueous-phase reactant can be transported from aqueous-phase to organic-phase by the hydrophobic characters of catalytic Aliquat336, which thus can catalyze esterification of sodium benzoate and benzyl bromide. The experimental results showed that the more the mounts of catalyst, the faster the synthesizing reaction rate would be. Effects of different organic solvents and ionic liquids for Aliquat336 were carried out, and above 74% yield of benzyl benzoate is easily achieved within 3 hours. At 3 hours, the product yield was 0% without adding both ionic liquid and catalyst.The yield was 74.37% by adding catalyst but without ionic liquid; adding both catalyst and ionic liquid would promote yield to 77.88%. Both ultrasound and stirring assisting liquid -liquid phase-transfer catalysis could be effectively applied in synthesizing ether-ester. Pesudo-first-order kinetic equation was applied to correlate experimental results. Using toluene as solvent, the kinetic results were correlated by using -ln(1-Y)=kappt equation successfully , where kapp was the apparent reaction rate constant, with ultrasound, the apparent activation energy was 18.31 kcal/mol.
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Chuang, Fu-Chun y 莊富鈞. "Synthesis of n-Heptyl 4-Hydroxybenzoate by Phase-Transfer Catalyst and Ionic Liquid in Liquid-Liquid System". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/34039778106917644588.
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碩士國立中興大學
化學工程學系所
102
The study aimed at synthesizing n-heptyl 4-hydroxybenzoate by using 4-hydroxybenzoic acid sodium salt and 1-bromoheptane under the catalysis of phase transfer catalyst in liquid-liquid system. In addition to reactants, the operating parameters in the reaction system include agitation rate, ultrasonic effect, reaction temperature, type and amount of catalyst, type of solvent, type and amount of ionic liquid. The reaction mechanism and kinetics of reaction were obtained from experimental results. The esterification reaction Between 1-bromoheptane and 4-hydroxybenzoic acid sodium salt occurs in organic phase, and using Aliquat 336 can reach the highest yield among all catalysts employed in this study. Because Aliquat 336 is oil-soluble, n-heptane could be selected without using high polar and toxic organic solvent, methly isobutyl ketone (MIBK). In general, there is an induction period in the beginning of reaction due to the catalyst solubility. Ionic liquid can be added to overcome this problem and reduce the reaction time. The experimental result shows that activation energy Ea= 6.19 kcal/mol by Arrhenius equation. Adding more organic phase reactant can further improve the reaction rate. The result shows that after reacting 3 hours, the yield is 54% by using Aliquat 336, and the reaction temperature is only 60℃, the non-toxic organic solvents can be used. Instead of using strong acid and alkali as catalyst and toxic organic solvents. The system that needs high reaction temperature also can be improved. By doing so, we can reduce the production cost and danger as well.
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HUNG, CHIH-HSIUNG y 洪智雄. "Multi Pulley Modular Liquid Level Control System". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/24v9aw.
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碩士國立高雄應用科技大學
電子工程系碩士班
104
Level control for the industrial production of the most common and basic control system, common level control pressure liquid level transmitter, ultrasonic level transmitter, connecting rod float level switch, float switches and other mercury Wait. Regardless of the type, in space, the basic requirements of the position Jie erection, erection often caused inconvenience, or after the completion of the erection derivatives other issues, such as: poor erection space, maintenance correction inconvenience, adverse environmental failure is high. The system is designed to pulley module as the core, the use of float and bob balance principle, and to detect the liquid level within Tongcao, and then to the pulley module to guide the design, can improve the poor above the space, the inconvenience and correction adverse environmental and other factors. After converting pulley module design, applicable to all non-sealed type Tongcao, one multi-purpose, to achieve complete customization.
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Hsin-Chang, Cheng y 鄭信彰. "Control of A Liquid Flow Calibration System". Thesis, 1998. http://ndltd.ncl.edu.tw/handle/31410790966283955790.
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碩士中原大學
化學工程研究所
86
The fluid transients caused by the enormous change of flow rate maybe harmful to the piping system. The flow and pressure process in a liquid flow calibration system have highly interaction. The selection of the controlled point of pressure could have large effect on the control performance. The main purpose of this research is to concern the related topics smoothing the operation of the calibration system. Mathematical models of the fluid transients were derived by the principle of the mass and momentum balance. The characteristic method is applied for numerical analysis. The simulation studies on the fluid transients of the calibration system were executed by this method. A steady state equation governing the flow and pressure relation was also derived for the control purpose. Simulation results show that the elapsed time of the valve closing have the great effect on the fluid transients. The increase of the pressure during the transients is larger for the shorter closing time. It shows that the controlled point of pressure nearest to the closing valve have the best control performance. A decoupler was applied to reduce the interaction between the flow and pressure control loop.
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WENG, MIN-REN y 翁明仁. "Dynamic simulation of a liquid calibration system". Thesis, 1992. http://ndltd.ncl.edu.tw/handle/28820667044254590561.
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ZHANG, REN-YAO y 張仁耀. "Expert system for vapor-liquid equilibrium predictions". Thesis, 1990. http://ndltd.ncl.edu.tw/handle/08521806938793114079.
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Chen, Bo-Han y 陳柏翰. "Study of Nozzle System for Liquid Inoculation". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/p8u8r5.
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碩士國立虎尾科技大學
機械設計工程研究所
102
The purpose of this study was the choice of three different commercially available nozzles and establish its measurement system to simulate the test results when performing the experimental measurements of biological applications when inoculated with mycelium of liquid at different heights subjected to different pressures and time, to observe the testing of its spray the angle, width, area and the flow rate changes, and uniformity of the spray with the average particle size. Test conditions were set nozzle inlet pressure of 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, the spray time was 0.2 s, 0.4 s, 0.6 s, 0.8 s, nozzle height change lines to 1 cm, 2 cm, 3 cm to observe the test. In addition, this study high-speed cameras to capture and record the variations of spray nozzles, each photo shoot time interval is approximately 0.04 s, in order to observe the spray nozzle from the surface of the spray outlet to the situation. Flow part is a graduated cylinder to measure the nozzle within a specific period of time (0.2 s, 0.4 s, 0.6 s, 0.8 s) changes in flows. Comprehensive above findings can be used to compare the suitability of the nozzle, the nozzle selected more suitable for agricultural biotechnology industry in a reference liquid bio mycelium inoculation nozzle system with automated machine when the machine design. Keywords: a nozzle, spray, liquid inoculation biological mycelium.
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Lin, Cheng-Liang y 林承亮. "Kinetics and Interfacial Characteristics for Phase-Transfer Catalyzed Benzylation in Liquid-Liquid System". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/62139303882175289711.
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碩士國立中興大學
化學工程學系
90
The objectives of the present study are to apply phase-transfer catalytic technique in synthesizing benzyl benzoate by conducting nucleophilic substitutions in the organic solution in solid-liquid and liquid-liquid system. The operating conditions for investigation include agitation speeds , reaction temperatures, catalyst amounts, types of solvents, molar ratio of reactants, type of phase-transfer catalysts, volume ratio of aqueous to solvent , and so on. The reaction mechanism and apparent reaction rate constants were obtained from the experimental results. It will decrease interficial tension of two phases,while Aliquat 336 added to organic phase and sodium benzoate added to aquenous phase. Aliquat 336 is widely used as the fibers soften in textile industry. In liquid-liquid phase transfer system, the aqueous-phase reactant can be transported from aqueous-phase to organic-phase by the hydrophobic characters of catalytic Alliquat 336. The Aliquat 336 can catalyze sodium benzoate and benzyl bromide into esterification. The the formation of intermediate (PhCOOQ) and its the effects of the change on operating conditions were all investigate. The experimental results show that the more the amounts of catalyst, the faster the synthesizing reaction rate will be. Effects of different organic solvents for Aliquat 336 are carried out, and above 95% yield of benzyl benzoate is easily achieved within 3 hours as using chlorobenzene as the solvent. The kinetics of pseudo-first-order reaction can be applied to describe the overall reaction rate successfully. In the other quaternary ammonium system, the product selectivity and kinetics of sodium benzoate with benzyl bromide to produce benzyl benzoate via liquid-liquid phase-transfer catalysis were explored. When the agitation speed exceeds 200 rpm，the mass transfer resistance at the liquid-liquid interface can be ignored. Different phase-transfer catalysts were employed to compare their catalytic efficiency , and the reactivity order was found： Aliquat 336 > TBPB > TBAI > TBAHS > TBAB > PEG series.
49
Dadgostar, Nafiseh. "Investigations on Colloidal Synthesis of Copper Nanoparticles in a Two-phase Liquid-liquid System". Thesis, 2008. http://hdl.handle.net/10012/4005.
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Synthesis of copper nanoparticles by a colloidal recipe in a two-phase liquid-liquid mixture (toluene/water) was investigated. The synthesis recipe used in this work was originally applied for the fabrication of alkylamine-capped gold nanoparticles. This method involves transferring metal cations from the aqueous layer to the organic one by the phase transfer reagent, tetraoctylammonium bromide, followed by reduction with sodium borohydride in the presence of oleylamine, which was used as the stabilising ligand.
Several modifications were made to the original recipe to produce copper nanoparticles with high degrees of purity and stability. These particles are potentially applicable in various industries and are considered as an alternative for expensive metal nanoparticles, such as gold, silver, and platinum. Due to the high tendency of copper for oxidation, all of the synthesis experiments were carried out in a glove box under the flow of an inert gas (N2 or Ar). The concentration of Cl− was initially increased to form anionic complexes of copper that could later react with the cationic phase transfer reagent. This modification was followed to enhance the efficiency of the transferring step; however, the presence of anion, Cl−, at the surface of the synthesized particles was reported to change their properties; thus, increasing chloride concentration was eventually ignored.
The decanting of two phases prior to the reduction step was also investigated to examine whether the site of the reduction reaction could be limited to cores of reverse micelles.
The aggregated nanoparticles, which were fabricated by reducing the decanted organic phase, were heated after the synthesis at 150°C for 30 minutes to obtain a light green solution of nanoparticles. However, further characterization was not possible due to the hydrocarbon impurities. Dodecane, which was employed as the solvent for post-synthesis heating procedure, is believed to result in these impurities. Further investigation is required to explain the mechanism by which post-synthesis heating facilitates nanoparticle stabilization.
Duplication of the original recipe for copper in an inert atmosphere resulted in a mixture of assembled layers of separated copper nanocrystals with an average size of ~ 5 nm and aggregated clusters of cubic copper (I) oxide nanoparticles. The possible mechanism for this division is believed to be the presence of the phase transfer reagent capped to the surface of a portion of synthesized particles leading to their metastability.
50
chang, Hsiu-Ying y 張綉英. "A Study on Liquid-Liquid Equilibria of Acrylic Monomer + Sec-Alcohol + Water Mixture System". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/69961559858678768265.
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碩士明新科技大學
化學工程研究所
95
Liquid-liquid equilibrium (LLE) data for the systems water + 2-propanol + methyl methacrylate, butyl methacrylate or isobutyl methacrylate, water + 2-butanol + methyl methacrylate, butyl methacrylate or isobutyl methacrylate, and water + 2-pentanol + butyl methacrylate and isobutyl methacrylate were determined at atmospheric pressure over temperatures of 288.15 K and 318.15 K. The reliability of the experimental tie-line data was determined through the Othmer-Tobias and Bachman plots. The new LLE data were also compared with the values correlated by the NRTL and UNIQUAC models. Good quantitative agreement was obtained with these models. Overall average deviation values are below 0.0080.