Дисертації з теми "Purification"
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1
Du, Plessis Jan-Paul. "The Purification Works." Diss., University of Pretoria, 2018. http://hdl.handle.net/2263/63619.
Анотація:
This dissertation aims to propose an appropriate architectural intervention within a site that requires both ecological restitution and the commemoration of industrial heritage. The Johannesburg Gasworks site serves as a clear example of how the Industrial Revolution and subsequent industrial technologies have both damaged the natural environment and left blighted legacies within ever developing urban conditions.The project aims to uphold the general significance of Industrial heritage as proposed by charters such as the Nizhny Tagil charter prepared by The International Council for the Commemoration of Industrial Heritage as well as the unique heritage significance of the Gasworks site. An appropriate theoretical framework and precedents are explored that reconcile the two seemingly opposing requirements of post-industrial sites - that of commemoration and ecological restitution. In post-industrial sites scarred by water, soil and air pollution, as well as dangerous or inaccessible places, maintaining an appreciation of heritage whilst employing the various rehabilitative actions required need to be balanced to ensure both. The project undertaken forms part of four schemes proposed for the site that aim to maintain the iconic identity of the Johannesburg Gasworks by proposing ecologically sensitive industries. These industries and interventions within the site aim to bring about urban resilience, site specific environmental rehabilitation as well as integration with the surrounding urban context. The proposed project for the site draws its program from global ecological issues as well as site specific heritage factors. The aim of scripting a new layer of intervention onto the Gas Works site is to make a legible reading between the site’s history and its ecologically resilient future legacy.Mini Dissertation MArch(Prof)--University of Pretoria, 2018.
Architecture
MArch(Prof)
Unrestricted
2
Hiltbrunner, Jean-Michel. "Purification de l'hexafluorure d'uranium." Thesis, Université Clermont Auvergne (2017-2020), 2017. http://www.theses.fr/2017CLFAC009.
Анотація:
L’hexafluorure d’uranium, de formule chimique UF 6 , est un composé clé du cycle du combustible car il est utilisé pour l’étape d’enrichissement isotopique. Toutefois, des impuretés présentes et mélangées à l’UF 6 sont à éliminer afin de garantir un uranium de pureté nucléaire. Dans ce manuscrit, les réactions chimiques entre les polluants et les filtres chimiques retenus pour la purification sont étudiées. Par ailleurs, l’étude de la réactivité en milieu liquide est réalisée afin de se rapprocher des conditions industrielles. Une voie de recyclage des filtres chimiques est également investiguée afin de réutiliser les adsorbants sur plusieurs cycles de purification. L’ensemble des performances (taux de sorption des polluants, décontamination lors du recyclage) sont évaluées avant la mise au point du pilote à l’échelle industrielleUranium hexafluoride, which chemical formula is UF 6 , is a key compound of nuclear fuel cycle due to its use during isotopic enrichment process. Nethertheless, pollutants melted with UF 6 have to be removed in order to ensure a nuclear purity fuel. In this manuscript, the reactions occurring between pollutants and chemical filters selected for this application are studied. Then, the reactivity in liquid UF 6 is also examined with the aim of being close to the industrial process. The regeneration of adsorbents is investigated so that chemical filter can be used for several purification cycles. The performances (sorption rate of pollutants, purifying during recycling step) are evaluated before simulations at industrial scale
3
Allaire, André. "Copper matte vacuum purification." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=70215.
Анотація:
An investigation of copper matte vacuum purification was undertaken. A mathematical model using monatomic, diatomic sulphide and diatomic oxide vapours of the impurities was developed to explain the vacuum refining process. The model was used to predict the overall refining rates for variables such as temperature, matte grade, oxygen activity and chamber pressure of the melt.A series of experiments was undertaken to characterize the dust produced during vacuum refining of copper matte. An attempt to selectively condense the vapours produced during the vacuum refining experiments was carried out.
The "Lift-Spray" vacuum refining process was used to refine 15 to 40 kg batches of molten copper matte containing 35 to 78% copper. The removal rates of lead, bismuth, arsenic, antimony, selenium, nickel and silver were measured under different levels of matte grade, chamber pressure, lifting gas flow rate and dissolved oxygen content in the melt. The ranges of the variables under study were from 10 to 600 pascals chamber pressure, 0 to 40 normal milliliter per second of lifting gas flow rate and 10$ sp{-16}$ to 10$ sp{-7}$ atmosphere of oxygen activity.
In conclusion, LSV refining of copper matte was shown to be a promising process. Furthermore, scale-up to industrial size is now possible. The scale-up dimensions compare well to the dimensions of the RH degassing unit presently used in the steel industry. (Abstract shortened by UMI.)
4
Kent, Laura. "Photocatalysts for water purification." Thesis, University of Surrey, 2018. http://epubs.surrey.ac.uk/850035/.
Анотація:
Advanced water purification methods are required to answer the growing demand for clean water throughout the world. Current methods of removing the pollutants rely on moving the pollutants from one place to another rather than breaking them down. The use of advanced oxidative processes (AOPs) presents a highly effective opportunity to achieve the full mineralisation of pollutants without the added cost of regeneration methods. Photocatalysts, such as titanium dioxide and zinc oxide, can be used as AOPs when activated by electromagnetic radiation in the form of ultraviolet and visible light. To facilitate the activation with visible light, titanium dioxide doped with rare earth elements was produced via a sol gel method. Both single doped and co-doped systems were investigated with efficiency determined by the percentage of degraded methylene blue over 48 hours under ultraviolet filtered visible light. The incorporation of rare earth ions restricted the growth of the more active anatase phase and the method produced highly agglomerated, sintered nano particles which exhibited as micron sized particles. The highest methylene blue removal rate achieved in 48 hours for a single doped system was 70% for the 1 mol% yttrium doped titanium dioxide. This was improved further on inclusion of 1 mol% praseodymium which showed an 86% removal of methylene blue over the same time period. The coating of known up-converting phosphors with the successfully developed doped titanium dioxide was investigated. Yttrium silicate doped with praseodymium and lithium, was found to be the most successful known phosphor when used with the commercially available P25 titanium dioxide. When coated with the doped titanium dioxide shell at a 2:1 ratio of phosphor to titanium dioxide, a methylene blue degradation of 94% was reached. Initial tests on the coating of titanium dioxide with the known up-converting phosphor showed that methylene blue was absorbed rather than broken down so was not developed further. An investigation into the incorporation of zinc oxide, both pure and doped with the same successful titanium dioxide system was carried out. Zinc oxide shells were coated onto doped titanium dioxide, the known up-converting phosphor and the doped titanium dioxide coated known phosphor. The crystalline form of zinc oxide was inhibited by the incorporation of rare earth ions, as with the titanium dioxide system, and from the thickness of the zinc oxide shell. The highest degradation achieved was a 91% removal rate for the ZnO-PrY:TiO2-PrY:Y2SiO5-Pr,Li core shell shell structure indicating there was no further improvement on incorporation of zinc oxide, either doped or un-doped.
5
Rutt, George Clifford. "Purification of recombinant proteins." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/42614.
6
Benzouaa, Rachid. "Purification de l'hexafluorure d'uranium." Thesis, Clermont-Ferrand 2, 2014. http://www.theses.fr/2014CLF22433.
Анотація:
L’hexafluorure d’uranium (UF6), est le seul composé utilisé à l’état gazeux dans les procédés d’enrichissement pour la production du combustible nucléaire. Pour le bon déroulement de l’étape d’enrichissement, la qualité de UF6 est primordiale. Cette étude s’est intéressée principalement aux impuretés volatiles sous forme de fluorures et oxyfluorures et leur réactivité avec des matériaux en présence ou non de l’UF6. La nature des produits adsorbés et de réactions a été identifiée. Les mécanismes physico-chimiques mis en jeux lors de la sorption ont été investigués. Les performances (capacité de sorption, sélectivité et régénération) de ces matériaux absorbants et adsorbants ont été évaluées en vue de leur utilisation comme filtre UF6 dans les usines de conversionUranium hexafluoride (UF6), is the only compound used in the gaseous state in the process of enrichment to produce nuclear fuel. For the success of the enrichment step, the UF6 quality is paramount. This study is mainly concerned with volatile impurities in form of fluorides and oxyfluorides and their reactivity with the materials in presence or not of UF6. The nature of the adsorbed compounds and reactions products was identified. The physico-chemical mechanisms of sorption were investigated. The performances (sorption capacity, selectivity and regeneration) of the absorbent and adsorbent materials have been evaluated to be used as UF6 filters in conversion plants
7
Albornoz, Rodrigo Nicolas. "Purification : Research & Exhibition." Thesis, Konstfack, Institutionen för Konst (K), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:konstfack:diva-6738.
Анотація:
In recent years I have been working on topics related to Post-colonialism in South America, as well as the conditions of immigrants in Europe. The main interest of my work involves questions about my roots and personal stories of migration. This situation has been the engine of my art for the last ten years. Through my installations, I have tried to express or represent some certain facts, that have marked the post-colonial situation in Latin America and Europe over the last years. The slavery and exploitation of illegal labor are common working conditions for many people in South America, especially for those located in the jungles and slums. The Indigenous culture -its languages, values and traditions- have begun to disappear and been displaced by Western culture. Here in Europe, on the other hand, I feel 'alien' to the territory of my ancestors, due to the fact that my family comes from European immigrants in Argentina. Illegal labor has been also a part of my life, having experienced the condition of 'otherness' in Europe. Therefore, this project reflects upon my personal experience in relation to the unfair conditions of labor in autochthonous communities, researching the concept of 'otherness' taken from Post-colonial theories. It is for this purpose, that my methodologies include self-reflection, parallelism and metaphor. One of my purposes is toreveal those 'fake stories' used by the European acculturation in South America. I called these fake stories 'strategies', as they were used by the Colony for the reconstruction of a new National Identity in those countries. Therefore, convincing the Indigenous culture to adopt Western culture. The parts of my essay are a metaphor of different stages of narcotic's production, best called 'mobile labs' of the Amazon jungle.I have taken this concept to tell my story and to build up the laboratory as final representation. The first stage of this process is to weigh and measure the ingredients, followed by a mixture of substances and chemicals. Once mixed, it proceeds to three stages of filtering and purification. Then it is subjected to a press for semi-solid consistency and introduced into the oven to reach the compact state. The blocks will finally be packed with plastic film and adhesive tape, protecting them from adverse environmental conditions during transport and storage. Each chapter of this essay is also connected to the 'machines' constructed for my solo exhibition, following the same steps of Purification. Through this essay, I wanted to broaden my concept relating three main aspects: the colonial strategies of domination in South America, my personal work experience in Europe, and finally the unfair working conditions in marginal societies. Each of the 'machines' constructed for my installation is functional, ready to be activated according to the different parts of the cooking process and as a representation of a 'production line' in the system of labor. I also have chosen to wrap my body, as well as carefully chosen representative objects of the popular culture of South America, to finally pack them in cling film. As a result of this process of Purification, I have produced the 'final products' ready to be consumed here in the Western European countries.
8
Aufy, A. A. S. M. "PROTEIN PURIFICATION FROM GASTROPODS." Doctoral thesis, Università degli Studi di Milano, 2011. http://hdl.handle.net/2434/152912.
Анотація:
Gastropods are a class of invertebrates within the mollusks, commonly known as snails and slugs. Recently, scientific interest is directed on snails as pollution indicators, as destroyers of crops, but also as parasites carriers. Furthermore, some species of snails are considered as an important human food source in countries like France and Australia.
In scientific research, snails are used as model animals especially in molecular biology and immunology. Some snails secrete purple matter with anti-cancer property; the snails use it to protect their eggs and scientists hope to create with it a weapon against breast cancer. In the light of this, the aim of the present work was to purify and characterize exoglycosidases, i.e. sugars-hydrolyzing enzymes, extracted from different species of snails and to study the glycosylation pattern of their tissues by using lectins as glycoprotein-specific antibodies.
Purification work started with the screening of 7 different exoglycosidases (α-fucosidase, β-xylosidase, α-mannosidase, β-mannosidase, α-glucosidase, β-glucosidase, β- galactosidase and β-N-acetylglucosaminidase) in 8 different species of snails (Arion lusitanicus, Biomphalaria glabrata, Achatina fulica, Limax maximus, Cepaea hortensis, Lymnea stagnalis, Arianta arbustorum, Planorbarius corneus and egg from Achatina fulica).
In order to create a purification scheme, many trials have been performed on the chosen enzyme, i.e. β-galactosidase from Arion lusitanicus. Ten snails were carefully washed after complete removal of the abdomen content to eliminate other sources of the enzyme. Snails were then homogenized and protein was precipitated by 1.2 M ammonium sulfate under cooling centrifugation. Then the precipitate was fractionated by the column hydrophobic interaction chromatography. Fractions exhibiting high enzyme activity were pooled, concentrated, desalted by ultrafiltration and then applied to affi gel blue. As the use of affi gel blue resulted in no binding between the enzyme and the gel beads, the unbound fractions were directly applied to anion exchange chromatography. As this procedure behaved as the same way of affi gel blue, the unbound fractions were pooled, concentrated to less than 2 ml and applied to size exclusion chromatography. Size exclusion chromatography exhibited high resolution purification, because a narrow peak was obtained, after testing the eluate for the enzyme activity. The fractions within this narrow peak were then applied to cation exchange chromatography, resulting in two new very sharp peaks. Fractions of the second peak from cation exchange chromatography were exposed to SDS-PAGE that indicated high quality purification, because just two proteins’ bands appeared. Finally, β-galactosidase specific affinity was the last purification step, where four different buffers were used (50mM sodium citrate pH 4.6, 1M NaCl in50 mM sodium citrate pH 4.6, 50 mM Tris/HCl pH 7.5 and 1M NaCl in 50 mM Tris/HCl pH 7.5) and the enzyme was eluted only with 50 mM Tris/HCl pH 7.5 buffer.
Electrophoresis of this eluate resulted in a single protein band in one fraction, identified by LC-MS as galactocerebrosidase with molecular weight about 74 kDa.
β-galactosidase characterization tests indicated that the optimal enzyme activity was at pH range 3.5 to 5.0 regardless to the used salt, i.e. the enzyme needs no special cations to be active, and indicated that the maximum activity of the enzyme is reached after 4 h incubation at 37 °C.
β-galactosidase purification from species other than Arion lusitanicus resulted in different purified proteins but not the β-galactosidase.
Moreover, as fucose and sialic acid are frequent and common modifications in snail glycans and they occur in a variety of different linkages and may therefore contribute to a number of recognition and adhesion processes, the glycosylation patterns of snails’ tissue were studied by different lectins, i.e. glycoproteins specific antibodies. We analysed eggs and adult land snails and water snails (Achatina fulica, Arion lusitanicus, Arianta arbustorum, Biomphalaria glabrata, Cepaea hortensis, Limax maximus, Lymnea stagnalis, Planorbarius corneus) for their N- and O-glycosylation pattern with a focus on their sialylation and fucosylation abilities. Their sialylation potential was investigated by Sambucus nigra agglutinin and Maackia amurensis agglutinin while their fucosylation potential was investigated by Aleuria aurantia lectin, Lens culinaris agglutin, Lotus tetragonolobus agglutinin and Ulex europaeus agglutinin before and after tissues’ digestion with glycopeptidase F and β-elimination, respectively.
In conclusion, 1) β-galactosidase purification from Arion lusitanicus needs several purification steps and must be conducted with specific β-galactosidase affinity chromatography, otherwise several unwanted proteins will appear as co-purified proteins.
2) The same purification scheme of Arion lusitanicus, when adopted in other snails, did not result in purifying β-galactosidase.
3) From the lectin study, it was confirmed that fucose and sialic acid are frequent and common modifications in snail glycans.
9
Blom, Hans. "Purification Processes for Complex Biomacromolecules." Doctoral thesis, Uppsala universitet, Fysikalisk-organisk kemi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-172892.
Анотація:
This thesis details various techniques and considerations for the purification of complex biomacromolecules. Initially an α-mannosidase from babaco fruit was purified using anion exchange-, lectin affinity- and size exclusion chromatography. The enzyme was approximately 260-280 kDa in size with an apparent an unusual octagonal stoichiometry and displayed properties similar to other known plant α-mannosidases. Mucins were fractionated by ion exchange and size exclusion chromatography to assess the properties that govern the mucin surface coating interactions in biomaterial research. Commercially available mucins, of bovine and porcine origin, as wells as crude human mucin were tested. All showed to consist of a population of molecules which differ in size, charge and composition. The third part of the thesis concerns different aspects of plasmid DNA purification processes. A two-step method for analysis of plasmid DNA consisting of size exclusion followed by thiophilic adsorption chromatography was evaluated. It allowed determination of the supercoiled plasmid DNA concentration in all process steps without requirement for extensive sample preparation. This method was shown to be fully comparable in terms of accuracy to capillary gel electrophoresis, considered as the industry standard. Purification of plasmid DNA generally involves bacterial cell alkaline lysis, which creates a solution with flocculate material which needs to be removed prior to further processing. The addition of ammonium hydrogen carbonate to the suspension was evaluated to clarify the solution. The released carbon dioxide and ammonium lifts the flocculate to the surface and allows draining of a clear solution. The method is fully scalable, does not affect the plasmid DNA quality and requires no special equipment. Thiophilic adsorption chromatography was evaluated for simplification of an existing commercial large scale purification process and was shown to increase both product purity and yields of several tested plasmids. Also, implementation of this step significantly reduced overall production process time.
10
Leah, Labib. "Helicase Purification for DNA Sequencing." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31341.
Анотація:
BACKGROUND: A method to increase accuracy and ease-of-use, while decreasing time and cost in deoxyribonucleic acid (DNA) sequence identification, is sought after. Helicase, which unwinds DNA, and avidin, which strongly attracts biotin for potential attraction of biotinylated DNA segments, were investigated for use in a novel DNA sequencing method.
AIM: This study aimed to (1) purify bacteriophage T7 gene product 4 helicase and helicase-avidin fusion protein in a bacterial host and (2) characterize their functionality.
METHODS: Helicase and helicase-avidin were cloned for purification from bacteria. Helicase-avidin was solubilised via urea denaturation/renaturation. DNA and biotin binding were assessed using Electrophoretic Mobility Shift Assays and biotinylated resins, respectively.
RESULTS: (1) Helicase and helicase-avidin proteins were successfully purified. (2) Helicase protein was able to bind DNA and avidin protein strongly bound biotin.
CONCLUSION: Helicase and helicase-avidin can be purified in a functional form from a bacterial host, thus supporting further investigation for DNA sequencing purposes.
11
Irving, Stephen L. "Synthesis and purification of peptides." Thesis, University of Edinburgh, 1994. http://hdl.handle.net/1842/28282.
Анотація:
Improved routes to tetrabenz[a,c,g,i]fluorene derivatives have been developed, allowing the synthesis of Nα-17-tetrabenzo[a,c,g,i]fluorenyl-methoxycarbonyl (tbfmoc) urethane derivatives of alanine, leucine, isoleucine, methionine and valine. The chloroformate and pentafluorophenyl carbonate of 17-tetrabenzo[a,c,g,]fluorenylmethanol have been prepared and used to introduce the base-labile Tbrmoc group onto the Nα-termini of resin-bound peptides. The high affinity of the Tbrmoc group for porous graphitised carbon (PGC) has been exploited for the purification of a range of synthetic peptides (23-85 residues). A comparison of various basic solvent systems used to elute the purified peptide from PGC is presented. The hydrophobicity of the Tbfmoc group has been used to simplify the purification of a ubiquitin analogue, UbY59F (76 residues), by the enhanced retention of the Tbfmoc peptide on RP-HPLC. A new synthesis of 2-hydroxydibenzocycloheptadien-5-one has been advised. This compound has been used to develop acid-labile linkers for the synthesis of peptide C-terminal alkyl amides and aza-glycine peptides, compatible with the Fmoc/tBu solid phase method. Alternative modes of attachment of the linker to polystyrene resin are compared for the synthesis of bombesin, a peptide amide.
12
Lacoursière, Stéphanie. "Water purification by membrane distillation." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26112.
Анотація:
The objective of this work was to evaluate the technical feasibility of potable water production from both sea water and sodium chloride solutions via the membrane distillation process. Membrane distillation is a thermally driven process in which a hydrophobic microporous membrane separates a hot or warm saline solution from a cold desalinated one. Water, in the form of vapour, migrates from the hot solution to the cold one.Two different hollow fibre membrane distillation modules were used to conduct experiments. Tests were performed to determine the sensitivity of permeate flux and quality to stream temperatures and flowrates, and feed concentration. The hot side temperature was found to have a greater effect on the water flux than the cold side temperature. Water flux values ranged from 0.5 to 1.6 Kg/m$ sp2$hr with salt removals of over 99.99%. A semi-empirical model, based on well established heat and mass transfer correlations, was developed and its predictions were validated with the experimental results.
13
Davies, R. H. "Semiconductor photocatalysis for water purification." Thesis, Swansea University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636399.
Анотація:
Although many aspects of the semiconductor photocatalysed mineralisation of water contaminants have been studied by researchers over the past decade, there are still certain areas which need further clarification, if the technique is to be used as an alternative to the presently available methods of water purification. It was the objective of the work in this thesis to provide further understanding of some of these remaining areas. One of the greatest inducements for the introduction of the technique of semiconductor photocatalysed pollutant mineralisation, in preference to the currently available technology, would be an efficiency advantage. The work in Chapter 3, studies the effect of many reaction variables (e.g. T, pH, [TiO2]) in order to provide rate enhancements and therefore further efficiency of the technique. In Chapter 4 the model pollutant, 4-chlorophenol, is used to illustrate the role of activation energies in semiconductor photocatalysed mineralisation reactions, an area which has been largely ignored by researchers in this field to date. In order to speed up the process of reactor designs for commercial semiconductor photocatalysis reactors, there was a need for a predictive kinetic model, to provide information on individual pollutant mineralisation rates, under certain reaction conditions. Chapter 5 outlines a kinetic model which is able to accurately model the mineralisation of various pollutants and can also be used as a predictive tool for non-standard conditions. Chapter 6 enhances this work, to provide a model capable of modelling further pollutant systems, previously unable to be modelled. The technique of semiconductor photocatalysed pollutant mineralisation, will only become a plausible alternative to the currently available technology, if it can be scaled up from the batch reactor level. The work in Chapter 7 aims to provide scale up of the batch system used in Chapter 3 from 2.5 ml to 101.
14
Gerrard, Mark Leslie. "Purification of nitrogen containing feedstreams." Thesis, Nottingham Trent University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341280.
15
Scott, G. "Purification studies of UDP-Glucuronyltransferase." Thesis, University of Strathclyde, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371377.
16
Choi, Siwon (Siwon Chloe). "Microfluidic engineering of water purification." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111415.
Анотація:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemical Engineering, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references.
The demand for clean water has been increasing for several reasons, such as rapid industrialization of developing countries, environmental pollution and climate change, and development of biofuels and the resulting irrigation growth. To meet the needs for this growing demand for clean water, desalination has become an appealing solution as saline water (brackish water, seawater and brine) are the most abundant water source for most of the world. However, desalination is energy and capital intensive compared to other water treatment processes, and oftentimes it is not economically feasible. Current desalination technologies require further engineering and development to become more sustainable in the long term. My Ph.D thesis is focused on engineering of electromembrane desalination, which is a set of electrically driven desalination technologies that utilize ion transport through ion exchange membranes. We employed microfluidic platforms and numerical modeling tools for the study, for they help reveal novel insights regarding the micro-scale details that are difficult to be discovered from the conventional large-scale systems. In this thesis, we consider three topics: i) engineering of structures that enhance mass transport in electrodialyis (ED), ii) techno-economic analysis of ion concentration polarization (ICP) desalination for high salinity brine treatment, and iii) development of electrocoagulation (EC) - ion concentration polarization (ICP) desalination hybrid that removes dissolved ions and non-ionic contaminants from water in a single device. First, we employed an electrodialysis (ED) system as a model to investigate the mass transport effects of embedded microstructures, also known as spacers, in electromembrane desalination systems. The spacer engineering is especially critical for low salinity (i.e., brackish water) desalination, where the mass transport in the solution is a dominant contributor to the electrical energy consumption in the system. Parametric studies of the spacer design revealed that small cylindrical structures effectively re-distribute the local flow velocity and enhance mass transport in the system. Furthermore, we found that relative diffusivities of cation and anion in the solution should be considered in designing the spacer and that the optimal design should maximize the mass transport while keeping the effect on the hydrodynamic resistance small. Next, we built an empirical model to estimate an electrical energy consumption of ICP desalination and utilized it to obtain the water cost and optimal operating parameters for high salinity applications. We performed cost analyses on two specific cases (i.e., partial desalination of high salinity brine to the seawater level, and brine concentration for salt production) and compared the performance with mainstream desalination technologies for each application. Lastly, we combined two electrical water treatment technologies and created an EC-ICP hybrid for total water treatment, which removes dissolved ions and non-ionic contaminants from the feed solution. We demonstrated a continuous EC-ICP operation that successfully removed salt and suspended solids. Our system is flexible in terms of the system size, and the type and concentration of contaminants it can handle, and thus it can find applications as a portable water treatment system.
by Siwon Choi.
Ph. D.
17
Wahl, Franck Olivier. "Synthesis and purification of oligodeoxyribonucleotides." Thesis, University of Edinburgh, 1993. http://hdl.handle.net/1842/14625.
Анотація:
A new highly hydrophobic 5'-hydroxyl protecting group (Tbf-DMTr) has been designed for the purification of synthetic oligonucleotides. Tbf-DMTr-oligonucleotides are strongly retained on RP-HPLC allowing a facile separation from truncated sequences. Subsequently the group can be removed in acidic conditions. The fluorescent properties of TBf-DMTr enable easy detection. The synthesis and purification of long oligonucleotides (> 100-mer) has been undertaken. Additionally a new fluorescent label for oligonucleotides has been developed which enables detection of DNA probes to concentration down to 10-10 mol/l.
18
Yapi, Litha. "Ammonium fluoride : transition metal purification." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/62805.
Анотація:
Pelchem NF3 plant produces an ammonium acid fluoride waste stream. The material of construction for the piping and stirrer fabrication in the plant is Monel. As a predominantly nickel-copper alloy, with minute quantities of carbon, manganese, silicon, sulfur and iron, these may leach into process fluids involved. The two biggest constituents of Monel contaminate the ammonium acid fluoride waste stream. Despite being the lesser of the two in terms of the composition of the Monel, copper is higher in concentration than nickel in the waste stream: the solubility of copper (II) cation in ammonium fluoride is higher than that of nickel (II) cation. Additionally, the ammonium acid fluoride is stored in steel barrels because of the relatively high process temperature that preclude the use of polymeric drums. This results in the leaching of iron from the steel drum to the solution. Pelchem expressed an interest in a suitable method of purification of ammonium fluoride, with specific interest of removing nickel (II) cation, copper (II) cation as well as iron (II) cation. The constraints to consider when selecting the appropriate methods are operating costs as well as the capital costs, but the most important factor to consider is the effectiveness of the method in removing the contaminant. In this regard, cationic exchange resins are very suitable, and they are very practical for industrial applications. In its simplest form, ammonium fluoride solutions are prepared by bubbling ammonia gas through solutions of hydrofluoric acid. Quite a few interesting uses of ammonium fluoride are available, these include as a chemical modifier in lead analysis, synthesis of beta zeolites, etc. The most prominent use is as a technical grade etchant in the electronics industry. The main aim of this research was to investigate ion exchange as a method of removing contaminants from Pelchem ammonium acid fluoride. Static equilibrium/selectivity experiments reveal that Purolite S930 Plus and Lewatit TP207 show a great affinity for the copper cation. For the limiting step of the reaction, the analysis includes apparent kinetics modelling contrasted with mass transfer modelling. In the case of reaction kinetics, Arrhenius and Van’t hoff equations were used to determine reaction parameters: the activation energies are 14 368 J∙mol-1 and 24 116 J∙mol-1, for Purolite and Lewatit respectively. The pre-exponential constants are 2 213 and 269 682 L2∙min-1∙mol-2 for Purolite and Lewatit in that order. The heats of reaction are -26 555 and -4 696 J∙mol-1 for Purolite and Lewatit respectively. Whilst the equilibrium pre-exponential constants are 75 057and 150 for Purolite and Lewatit respectively. Diffusivities for the two resins were found to be in reasonable agreement with those recorded in literature. They follow a temperature dependency trajectory. Weisz-Prater analysis of the observed reaction rate and the diffusion rate, in the two resins, reveals that intraparticle diffusion is the limiting step in the reaction.Dissertation (MEng)--University of Pretoria, 2017.
Chemical Engineering
MEng
Unrestricted
19
Lyu, Shicheng. "Membraneless Water Purification via diffusiophoresis." Digital WPI, 2020. https://digitalcommons.wpi.edu/etd-theses/1360.
Анотація:
Clean water is hard to obtain in certain areas, such as remote locations and during emergency response. Our study developed a membraneless water purification system using diffusiophoresis and tested the influence of various factors (gas pressure, liquid flow rate, etc.) on the turbidity of filtered water. The main component in the separation system is a tube-in-tube-in-tube separator. The inner tube and the middle tube are made of a semipermeable material (Teflon AF-2400), which allows gas (CO2) to permeate through it, but retains liquid (water). In this strategy, the CO2 permeates through the inner tube (the end is sealed) then dissolves into the dirty water/particle suspension passing through the middle tube. It then diffuses radially to the outer tube, where a vacuum collects the CO2, forming a concentration gradient of ions through the water, which induces the migration of charged particles to concentrate at the inner wall of the middle tube. The vacuum phase in the outer tube can increase the concentration gradient of ions in the water and recycle the CO2. Finally, purified water can be collected from the center of the middle tube by a needle in the effluent. The purification system is able to take initial turbid water (243 NTU) to below the WHO drinking water standard (
20
Jones, Samuel Casey. "Static mixers for water treatment : a computational fluid dynamics model." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/20718.
21
Li, June Yonghong. "A study of ozonation kinetics of phenolic compounds in single and solute systems." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/20821.
22
Yang, Jingming. "Characteristics of a novel anaerobic fluidized bed reactor for waste water treatment." Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/25318.
23
Kulati, Thanduxolo Cullinan. "Evaluation of physiochemical qualities and heavy metal levels of the final effluents of some wastewater treatment facilities in the Eastern Cape Province of South Africa." Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/1547.
Анотація:
Water is the most abundant substance in nature and vital for life activities. The major water sources for use are surface water bodies such as rivers and lakes, and underground aquifers and pore spaces down the water table (Ring, 2003). Water derived from these sources is not necessarily pure since it contains dissolved inorganic and organic substances, living organisms (viruses, bacteria, etc). For these reasons, water intended for domestic uses should be free from toxic substances and microorganisms that are of health significance (WHO, 2005). The availability and quality of water always have played an important role in determining the quality of life. Water quality is closely linked to water use and to the state of economic development (Chennakrishnan et al., 2008). Ground and surface waters can be contaminated by several sources. In urban areas, the careless disposal of industrial effluents and other wastes may contribute greatly to the poor quality of water (Mathuthu et al., 1997). In most developing countries, most areas are located on the watersheds which are the end points of effluents discharged from various industries (Oberholster and Ashton, 2008). South Africa, as a developing country, is experiencing rapid demographic changes due to urbanization, industrialization and population growth. The country has also been identified as being water-scarce, which can lead to a challenge of meeting the increasing water demand due to industrialization and urbanization. Such population growth increase may result in an increase in wastewater output, especially around urban areas.
24
Mangombo, Zelo. "The electrogeneration of hydroxyl radicals for water disinfection." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5745_1190373027.
Анотація:
This study has shown that OHË radicals can be generated in an Fe/O2 cell from the electrode products via Fenton&rsquo
s reaction and used for water disinfection. The cell system in which the experiments were carried out was open and undivided and contained two electrodes with iron (Fe) as the anode and oxygen (O2) gas diffusion electrode. Typically, 100 ml of Na2SO4.10H2O (0.5M) solution was used as a background electrolyte. OHË radicals were produced in-situ in an acidic solution aqueous by oxidation of iron (II), formed by dissolving of the anode, with hydrogen peroxide (H2O2). The H2O2 was electrogenerated by reduction of oxygen using porous reticulated vitreous carbon (RVC) as a catalyst.
25
Weinberg, Marla Kaye. "The effectiveness of an electrochemical treatment process and its applications in textile wastewater treatment." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/8697.
26
Skeens, Brian Michael. "Pilot scale evaluation and comparison of static mixers for coagulation in water treatment." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/19522.
27
Shah, Anup G. "Fate and effect of the antioxidant ethoxyquin on a mixed methanogenic culture." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/19904.
28
Palazolo, Paul Joseph. "Use of genetic algorithms in bounded search for design of biological nitrification/denitrification waste treatment systems." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/32777.
29
Wong, Kit Iong. "Chemical removal of dichloromethane (DCM) from contaminated water using advanced oxidation processes (AOPs) :Hydrogen Peroxide Ozone UV." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3868740.
30
Chang, Li-Ching. "Cloning, purification and crystallization of selenophosphate synthetase cloning, purification and crystallization of ERp44 from Mus musculus /." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980297311.
31
Forrer, Nicola. "Antibody purification with ion-exchange chromatography." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17784.
32
Mandal, Ipshita. "Microcapillary membranes for purification of biomolecules." Thesis, University of Cambridge, 2016. https://www.repository.cam.ac.uk/handle/1810/255867.
Анотація:
Opportunities exist for alternative chromatography separation media which possess high binding capacity and throughput, avoid column packing, are economically feasible for single-use disposability and work with standard chromatography systems. Two types of microcapillary membranes, hollow fibre membranes (HFM) and microporous walled microcapillary film (MMCF) membranes have been previously studied for a diverse range of filtration applications. The MMCF membranes unique geometry has not yet been studied for separation of biomolecules. The aim of this thesis is to develop microcapillary membranes for proof-of-concept biomolecule separations through various chromatography module constructions, surface chemistries and matrix composition modifications. The microcapillary membranes used in this work have been produced through a non-solvent induced phase separation process using ethylene vinyl alcohol copolymer. The matrices are constructed into two types of modules, straight columns and helical columns, and the flow behaviour and dynamic binding capacity of each is studied. The matrix surface is modified using sulfonic acid groups for cation-exchange chromatography and quaternary amines for anion-exchange chromatography. The straight MMCF module operates on standard AKTATM chromatography systems at pressures of up to 1.5 MPa and linear velocities of up to 54,000 cm h-1. A sharp column breakthrough is observed with a dynamic binding capacity at 10% breakthrough of 13.8 mg lysozyme/ml adsorbent volume. Frontal analysis bio-separation studies of lysozyme and BSA show a purification of 98.8% of lysozyme in the eluted sample. The anion functionalised straight MMCF module has a dynamic binding capacity of 10% breakthrough of 1.26 mg ovalbumin/ ml adsorbent volume, isolating BSA from lysozyme to the limit of detection of the gel assay used. The concept of activated carbon (AC) in membranes for removal of impurities is applied to the HFM matrix geometry by modifying the NIPS process to form AC-HFM mixed-matrix membranes. AC-HFMs with AC compositions of 0.7%, 3.2%, 6.3%, 11.8% and 21.1% by mass are extruded. Generally, as the AC composition of the HFM increases, the average pore size across the capillary membrane decreases, and the overall amount of adsorption of test molecules methylene blue and humic acid increases. This thesis contributes to the study of microcapillary membranes as a chromatography medium which is high capacity, high throughput, and pressure tolerant whilst avoiding column packing. This thesis sets the research area for advanced bioprocessing studies by optimising the porosity and permeability of the microcapillary membranes, studying affinity chromatography, and advanced large biomolecule studies using mixed-matrix microcapillary membrane studies.
33
Sanghera, Jasbinder Singh. "Purification and regulation of CTP:phosphocholine cytidylyltransferase." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/29280.
Анотація:
CTP:phosphocholine cytidylyltransferase was purified to homogeneity using a procedure involving aggregation of enzyme with exogenous lipid and selective dissociation with detergents and chromatography on conventional and FPLC columns. SDS-PAGE of purified enzyme showed a single protein of molecular weight ~42 Kd. Native-PAGE showed the protein to migrate at a molecular weight of ~90 Kd, indicating that the native enzyme may be a dimer. IEF-PAGE revealed the enzyme to have a pI of ~5.8. 2-D-PAGE showed the enzyme to have at least two isoforms.
Attempts to generate polyclonal antibody to the purified enzyme in rabbits were unsucessful. Even after two booster injections, the antibody titre was still weak indicating that the enzyme may not be a good antigen. However, Dr Harris Jamil was able to generate antibodies in the chicken. This antibody detected cytidylyltransferase by the Western-blotting technique and inhibited enzyme activity in a concentration-dependent manner, but was unable to immunoprecipitate the cytidylyltransferase in solution. Using this antibody, the cytidylyltransferase was found to occur in a
variety of isoforms.
Kinetic studies using the purified enzyme showed the K[sub m] for
CTP and phosphocholine to be 0.31 mM and 0.15 mM respectively. Activation of cytidylyltransferase by commercial and microsomal lipids showed the enzyme to be activated by anionic phospholipids. The presence of oleate did not greatly enhance the activation of the enzyme by these lipids.
The purified cytidylyltransferase was shown to be a substrate for cAMP-dependent protein kinase. Phosphorylation of the enzyme led to inactivation and increased recovery of the enzyme in the cytosol, while dephosphorylation by alkaline phosphatase led to activation and increased recovery of the enzyme in the microsomes. A serine residue(s) was phosphorylated on cytidylyltransferase. Twice as much phosphate was incorporated if cytidylyltransferase were dephosphorylated prior to phosphorylation. Incubation of hepatocytes with ³²Pi and then detection of cytidylyltransferase with antibody after 2-D-PAGE and Western-blotting, showed the cytidylyltransferase may be phosphorylated in vivo.
Incubation of hepatocytes with Ca²⁺, Ca²⁺-mobilizing agents and phospholipase A₂ resulted in translocation of
cytidylyltransferase from the cytosol to the microsomes. Incubation of hepatocytes with Ca²⁺ resulted in an increase in PC and LPC formation. Incubation of hepatocytes with phospholipase A₂ resulted
in an increase in PC formation.
Regulation of cytidylyltransferase activity by reversible phosphorylation and by Ca²⁺ may be important during short term regulation of enzyme activity by hormones.Medicine, Faculty of
Biochemistry and Molecular Biology, Department of
Graduate
34
Cinar, Dursun. "Purification and antimicrobial properties of oleuropein." Thesis, University of West London, 2009. https://repository.uwl.ac.uk/id/eprint/381/.
Анотація:
Olive leaves contain substantial amounts of phenolic substances, including the polyphenol oleuropein. This compound has been reported to possess antimicrobial properties. The purpose of this study was to develop an improved method for the extraction and purification of oleuropein from olive leaves and characterise its activity as well as the mode of action against a range of bacteria. Phenolic compounds from olive leaves were extracted in methanol and oleuropein was separated from the mixture by countercurrent chromatography (CCC). Separation was confirmed by high performance liquid chromatography. CCC processing resulted in a purity of oleuropein of 60% and this was later improved to 90% (compared to 83% in a commercially available oleuropein product). Flash chromatography was successfully introduced as an additional purification step and this eliminated some of the surfactants in the extract. Fifteen strains of bacteria and one yeast, including species commonly associated with hospital infections, were tested for their sensitivity to oleuropein in agar supplemented with oleuropein and by disc diffusion on agar media. Most of the bacteria used in this study were inhibited by oleuropein but the amount of oleuropein required for inhibition varied from 0.25 to 3.0%. The two most sensitive strains were Enterobacter faecalis and one strain of group A Streptococci in agar supplemented with oleuropein. Staphylococcus spp. were inhibited by oleuropein concentrations of 0.5 to 1.5%. Gram-negative species, such as Escherichia coli and Pseudomonas aeruginosa, the Gram-positive Micrococcus Iuteus and Bacillus subtilis as well as the fungus Candida albicans were not inhibited in the same assay. In the disc diffusion test, 10% oleuropein inhibited Gram-negatives (4-15 mm) whereas 5 and 10% oleuropein resulted in inhibition zones from 12 to 30 mm in Gram-positives and C. albicans. Four strains of S. aureus were subjected to further studies. In bacterial-time kill assays, exposure to 2% oleuropein resulted in reductions of up to 6 log cfu mL-1 in 4 hours and 6 hours for two methicillin resistant and two methicillin susceptible strains, respectively. A methicillin susceptible and a methicillin resistant S. aureus were investigated using transmission electron microscopy following exposure to 2% oleuropein. Cells of both types showed leakage of cell contents and ultimately lysis within two and four hours of exposure. Further work on leakage of cell constituents based on absorbance measurements was inconclusive due to interference by coloured compounds formed by the oxidation of oleuropein. Leakage of amino acids from cells treated with oleuropein was investigated using ninhydrin and Bradford assays. It was observed that 12 to 38% of amino acids leaked from S. aureus treated with oleuropein. The results were confirmed by sodium dodecyl acrylamide electrophoresis where several bands were absent from treated cell extracts. In addition, fluorescent microscopy of lectin labelled S. aureus cells was attempted to investigate damage of glycoproteins attached on the extracellular cell wall. Lectin binding was unsuccessful and was replaced by fluorescein isocyanate, which selectively binds to lysine groups; the latter indicated reduced fluorescence in treated cells. In conclusion this work demonstrated the application of a novel purification method based on countercurrent chromatography to obtain oleuropein with improved purity. The antimicrobial studies showed that oleuropein has the potential to eliminate bacteria. The mode of action studies showed that denaturation of proteins by oleuropein occurred, resulting in irreversible cell degradation. Oleuropein might be contemplated as a cleaning agent in envirnoments where strong acids and bases are harmful for equipment.
35
Abedinzadegan, Abdi Majid. "Purification of partially degraded diethanolamine solutions." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25006.pdf.
36
Huang, Da Wei. "Purification and characterization of HP1 oligomers." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0006/MQ44185.pdf.
37
Roche, Iain. "Nanoporous polymeric adsorbents for blood purification." Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/8143.
Анотація:
This thesis is concerned with applying engineering principles to the use of polymeric nanoporous adsorbents for use in blood purification to obtain original knowledge. Styrene divinylbenzene copolymer nanoporous adsorbents offer a potential means to remove middle molecular (MM) sized molecules when in direct contact with blood. (Continues...).
38
Wang, S. "Acetic acid purification using ionic liquids." Thesis, Queen's University Belfast, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546433.
39
Forde, G. M. "Plasmid DNA purification by affinity methods." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599116.
Анотація:
Two affinity mechanisms were investigated for their suitability to pDNA purification: (1) GSH/GST-ZnF/pTS: a dual affinity fusion protein, comprised of Glutathione-S-Transferase (GST) and a zinc finger transcription factor (ZnF), was utilised to purify target pDNA. The fusion protein was firstly adsorbed to an immobilised glutathione (GSH) ligand via the GST segment followed by specific adsorption of a pUC19 based plasmid (pTS) to the exposed zinc finger; and (2) lac I peptide/pLS3: a lac repressor (lacI) peptide that displays affinity for lac operator (lacO) sequences was used to purify target pDNA. A pUC19 based plasmid containing lacO sequences (pLS3) was adsorbed to the immobilised lacI peptide. The lac I peptide/pLS3 mechanism showed characteristics that make it more applicable to the commercial purification of pDNA. These included: a simpler adsorption mechanism (i.e. no intermediate affinity molecule such as GST-ZnF was required), high ligand utilization, the peptide ligand can be directly immobilised to an adsorbent matrix, and high purity pDNA can be eluted directly into a formulation buffer suitable for pDNA storage (i.e. 10 mM Tris Base, 1 mM EDTA, pH 8) so that no further processing is required. The major disadvantages of the system are low elution yields (34 %) and the cost of producing the affinity ligand. These draw backs may be reduced by designing a peptide ligand that does not bind pDNA as strongly and is less expensive to produce (i.e. shorter or synthetic). Through process innovation (utilisation of an affinity binding mechanism in scalable unit operations), the potential for affinity chromatography as a process for pDNA purification was realised.
40
Blackwelder, Sara K. "Syncretism in contemporary pagan purification practices." Honors in the Major Thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1370.
Анотація:
This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.Bachelors
Sciences
Anthropology
41
Kerry, Maria Elizabeth. "Purification and characterisation of callose synthase." Thesis, Royal Holloway, University of London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394540.
42
Santoyo-Gutierrez, Socrates. "Absorption heat pump assisted effluent purification." Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245055.
43
Foaden, Shaun Patrick. "Continuous affinity partitioning for protein purification." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335093.
44
Ramat, Fabien M. "Protein purification using expanded bed chromatography." Digital WPI, 2004. https://digitalcommons.wpi.edu/etd-theses/92.
Анотація:
Expanded bed chromatography using ion-exchange media is a powerful first step in purification processes. Expanded bed chromatography can be used to extract components from complex and viscous solution. This can be achieved because of the void created between adsorbent particles where as in packed bed chromatography, the adsorbent is too compact and dense for a complex feed stock to flow through. Expanded bed chromatography was used to purify bovine serum albumin (BSA) from chicken egg white (CEW). The high viscosity of CEW presents a unique challenge for efficient large-scale protein purification. This project aimed to optimize and evaluate a separation method that is believed to be particularly suitable for high viscosity solutions: expanded-bed ion exchange chromatography. The BSA was admixed into the CEW and the solution was pumped through the column for purification. The media used in the column was Streamline DEAE which is an anion-exchanger. The yield obtained was 85% and the purity was 57%. A mathematical model to understand and predict the behavior of expanded bed chromatography was developed to provide an estimation of the breakthrough curves obtained for BSA. A small sized porous dense adsorbent was also synthesized to enhance the purification process. This zirconia-based adsorbent allows use of higher flow velocities that is a key factor when working with viscous fluids such as chicken egg white.
45
Hahne, Hampus. "Modification of nanocellulose for blood purification." Thesis, Uppsala universitet, Nanoteknologi och funktionella material, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-296218.
Анотація:
This reports treats chemicalmodification of nanocellulose with aimto employ it in dialysis. Themodification steps consists of oxidizingand sulfonation reactions. Infra-redspectroscopy, BET surface area analysisand zeta potential was used tocharacterize the modified nanocellulose.The results shows that the modifiednanocellulose achieve the desiredproperties.
46
Fernandes, Telma Godinho Barroso Maciel. "Functional monolithic platforms for antibody purification." Doctoral thesis, Faculdade de Ciências e Tecnologia, 2014. http://hdl.handle.net/10362/11550.
Анотація:
Dissertação para obtenção do Grau de Doutor em Química SustentávelFundação para a Ciência e Tecnologia - contracts PEst-C/EQB/LA0006/2011, MIT-Pt/BS-CTRM/0051/2008, PTDC/EBB-BIO/102163/2008, PTDC/EBBBIO/ 098961/2008, PTDC/EBB-BIO/118317/2010 and doctoral grant SFRH/ BD/62475/2009, and Fundação Calouste Gulbenkian
47
Stevenson, Steven A. "Chromatography and purification of endohedral metallofullerenes." Diss., Virginia Tech, 1995. http://hdl.handle.net/10919/29176.
Анотація:
At the conception of this research, a separation methodology for obtaining purified metallofullerene [ Am@C2n; m = # of metal atoms, A, and C2n = # of carbons in the surrounding cage] samples was not yet developed. Isolation of these metal-encapsulated fullerenes was strongly desired for characterization of their physical and chemical properties. Predicted applications for these novel species include their use as possible superconductors, catalysts, and non-linear optical devices. However, initial purification efforts have been hindered by several difficulties. These factors include a low abundance (<1 %) in the raw extract, uncertain stability in aerobic environments, coelution of Am@C2n with empty-cage fullerenes, and the need for selective chromatographic detection.
In this research, these difficulties have been overcome with the development of a continuous-flow, online HPLC-EPR apparatus. Advantages include a selective, non-invasive detector with chromatographic separations being performed in a controlled anaerobic environment. This on-line approach permits the selective detection of only those metallofullerenes with an odd-number of encapsulated atoms. The ability to continually monitor separations of these paramagnetic species ultimately permits the optimization of chromatographic parameters. The methodology developed from this on-line HPLC-EPR approach has ultimately resulted in purified empty-cage...Ph. D.
48
Yang, Zi. "INORGANIC MEMBRANES FOR WATER PURIFICATION APPLICATIONS." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1588556057684163.
49
Talha, Fouzia Tagmouti. "Séparation et purification de quelques ciguatoxines." Bordeaux 1, 1987. http://www.theses.fr/1987BOR10576.
Анотація:
Purification par diverses techniques chromatographiques d'extraits ciguatoxiques bruts obtenus a partir de poissons contamines appartenant a la famille des carangides et des scombrides. Etude de la structure et des activites biologiques des ciguatoxines ainsi separees (action sur des organes isoles de grenouille)
50
Amourache, Leïla. "Purification et immobilisation de la chymosine." Compiègne, 1986. http://www.theses.fr/1986COMPI217.
Анотація:
La chromatographie d'affinité utilisant un ligand biospécifique (pepstatine couplée à l'agarose) pour la purification de la chymosine permet l'obtention d'un rendement en activité de 60 % et un facteur de purification de 6, à partir d'un extrait brut. Cependant, le ligand acide aminé histidine couplé au Sepharose 4B et à la silice, a donné de meilleurs résultats, on obtient respectivement après purification de la chymosine, à partir d'un extrait brut : des rendements en activité de 330 %, 55 % ; et des facteurs de purification de 26 et 9. Le L-histidyl-silice présente des résultats peu satisfaisants par rapport au support L-histidyl- Sepharose 4B. Une optimisation des conditions d'utilisation du gel histidyl-silice serait souhaitable afin d'utiliser ce dernier en HPLC. La purification d'enzyme d'origine microbienne sur gel de L- histidyl-Sepharose permettrait de connaitre l'efficacité de ce gel pour ce type d'enzyme. Notre étude d'immobilisation de la chymosine sur un support nylon nous amène à considérer, que le choix du nylon offre l'avantage d'une mise en œuvre aisément applicable en industrie alimentaire, toutefois l'activité résiduelle reste encore faible notamment lors de l'emploi du glutaraldéhyde. L'activité résiduelle est considérablement améliorée par la BSA et le NaC1 ajoutés au milieu en fin de réaction et aussi lors de l'utilisation de l'agent covalent carbodiimide. Une application industrielle de la chymosine immobilisée nécessiterait un travail complémentaire : 1 - Neutraliser les groupements du support amine et carboxyl restant disponibles après immobilisation par la liaison covalente. Ceux-ci sont la cause d'une adsorption du substrat non désiré. 2- Approfondir la réalité des liaisons qui s'établissent entre l'enzyme et le support. 3 - Obtenir une enzyme très stableAffinity chromatography using pepstatine agarose for crude chymosine purification a 60 % yield with a 6 fold increase in specific activity. On the other hand, L-histidine coupled Sepharose 4B and silica gave better results with 33 % and 55 % yields and 26 and 9 fold purifications, respectively. The silica support, as seen the above results, gives less satisfying results when compound with hystidyl-sepharose. It would be necessary to optimise the end conditions before applying this technique for chymosine purification by HPLAC. Also, studies using chymosine of microbial origin would enable as to evaluate the efficiency of the gel for this sat of enzyme. After studies on the immobilization of chymosine we consider that the choice of nylon as an immobilization support would be advantageous for the food industry, the usidial activity, however remain low especially when glutaraldehyde is used. The use of BSA and NaC1 in the medium during storage increases the residual activity considerably. The use of carbodiimide equally gives better results. The industrial application of immobilized chymosine would require the following complementary studies : the neutralizations of free amine and carboxyl groups on the nylon surface after the immobilization ; to pursue an in-dyth study into the sort of bond existing between enzyme and the nylon support ; to procure a highly stable enzyme