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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

異なる採取法による土壌水中の溶存無機イオン濃度の違い

竹井, 理絵, TAKEI, Rie, 辻村, 真貴, TSUJIMURA, Maki, 高木, 丈子, TAKAGI, Takeko 12 1900 (has links) (PDF)
農林水産研究情報センターで作成したPDFファイルを使用している。
112

Vznik mikrosuspenze perikinetickou a ortokinetickou koagulací / Formation of microsuspension by perikinetic and orthokinetic koagulation

Fojtíková, Radka January 2008 (has links)
This diploma thesis is focused on study of physico-chemical influences on model surface-water treatment which contain humic compounds. From those factors were monitored especially the dose of destabilizing reagent, pH value, temperature, velocity gradient of mixing and time of its duration. As destabilizing reagents were used Al2(SO4)3 .18H2O a Fe2(SO4)3 . 9H2O.
113

Možnosti enkapsulace přírodních antioxidantů / Encapsulation of natural antioxidants

Štindlová, Jitka January 2012 (has links)
In theoretical part of this diploma thesis the basic properties of antioxidants, especially anthocyanins and phenolic compounds are described, as well as the basic features and principles of free radicals formation. The theoretical part also describes some possible ways of encapsulation of antioxidants into polysaccharide and lipid particles. In the experimental part basic characteristics of extracts from selected lyophilized fruits and vegetables (carrots, apples and mixed berries) are described. As group parameters of plant extracts the total antioxidant activity, content of flavonoids and phenolics, carotenoids, anthocyanins and ascorbic acid were determined. In experimental part also various encapsulation techniques were tested, encapsulation effectiveness of each technique was evaluated and the stability and size of the created particles were determined. As the best encapsulation method in terms of encapsulation efficiency in most of samples/parameters ethanol injection was found. On the other hand the particles prepared by ethanol injection are relatively unstable in terms of zeta potential, which is followed by their tendency to aggregate. As the most stable particles prepared by thin layer evaporation (TLE) and reverse phase thin layer evaporation (RP-TLE) were evaluated. Particles prepared by TLE, RP-TLE and chitosan-alginate particles exhibited a negative charge, while particles prepared by ethanol injection stayed uncharged and chitosan particles have a positive charge.
114

Untersuchungen zur kapazitationsassoziierten Signaltransduktion in humanen Spermatozoen und Evaluation des MACS-Verfahrens zur Ejakulataufbereitung

Kriegel, Christian 17 May 2013 (has links) (PDF)
Als Kapazitation bezeichnet man den im weiblichen Reproduktionstrakt stattfindenden Reifungsschritt, der Spermien das volle Fertilisierungspotential verleiht. Die molekularbiologischen Grundlagen dieses für eine erfolgreiche natürliche oder auch artifizielle Befruchtung essenziellen Prozesses sind bis heute nur unvollständig verstanden. Im Rahmen der vorliegenden Dissertation wurden die mit der Kapazitation einhergehenden funktionellen und strukturellen spermalen Veränderungen untersucht. Die kapazitative Stimulation führte zu einer gesteigerten Motilität bis hin zur Hyperaktivierung, zu einer vermehrt induzierten Akrosomenreaktion und zu einer deutlich reduzierten Apoptoseaktivität. Anhand von Inhibitionsexperimenten wurde die Rolle der potentiellen Signaltransduktoren Caspase-1, Calpain und Calmodulin analysiert. Dabei wies die Calmodulinantagonisierung auf eine ausgeprägte Calciumabhängigkeit aller untersuchten kapazitationsassoziierten Prozesse hin. Die Hemmung von Caspase-1 und Calpain führte zu einer Beeinträchtigung der Motilität und der Akrosomenreaktion ohne das Ausmaß der Apoptoseinduktion zu beeinflussen. Die vorstehend genannten Erkenntnisse wurden zur Evaluation verschiedener Ejakulataufbereitungsprotokolle genutzt. Dabei konnte gezeigt werden, dass die Kombination des modernen Verfahrens der immunomagnetische Zellseparation mit der etablierten Methode der Dichtegradientenzentrifugation dem einfachen Standard in Bezug auf die Anreicherung hochmotiler Spermien mit minimaler Apoptoseaktivität aus frischen wie auch aus kryokonservierten Ejakulaten deutlich überlegen war. Bedeutsam im Hinblick auf eine mögliche pratische Anwendung der immunomagnetischen Zellseparation erscheint der Befund, dass die durch das kombinierte Anreicherungsverfahren erhaltene Spermatozoensubpopulation im Hamsteroozytenpenetrationstest ein signifikant höheres Fertilisierungspotential zeigte.
115

Drinking water treatment sludge production and dewaterabilityф

Verrelli, D. I. January 2008 (has links)
The provision of clean drinking water typically involves treatment processes to remove contaminants. The conventional process involves coagulation with hydrolysing metal salts, typically of aluminium (‘alum’) or trivalent iron (‘ferric’). Along with the product water this also produces a waste by-product, or sludge. The fact of increasing sludge production — due to higher levels of treatment and greater volume of water supply — conflicts with modern demands for environmental best practice, leading to higher financial costs. A further issue is the significant quantity of water that is held up in the sludge, and wasted. / One means of dealing with these problems is to dewater the sludge further. This reduces the volume of waste to be disposed of. The consistency is also improved (e.g. for the purpose of landfilling). And a significant amount of water can be recovered. The efficiency, and efficacy, of this process depends on the dewaterability of the sludge.In fact, good dewaterability is vital to the operation of conventional drinking water treatment plants (WTP’s). The usual process of separating the particulates, formed from a blend of contaminants and coagulated precipitate, relies on ‘clarification’ and ‘thickening’, which are essentially settling operations of solid–liquid separation.WTP operators — and researchers — do attempt to measure sludge dewaterability, but usually rely on empirical characterisation techniques that do not tell the full story and can even mislead. Understanding of the physical and chemical nature of the sludge is also surprisingly rudimentary, considering the long history of these processes. / The present work begins by reviewing the current state of knowledge on raw water and sludge composition, with special focus on solid aluminium and iron phases and on fractal aggregate structure. Next the theory of dewatering is examined, with the adopted phenomenological theory contrasted with empirical techniques and other theories.The foundation for subsequent analyses is laid by experimental work which establishes the solid phase density of WTP sludges. Additionally, alum sludges are found to contain pseudoböhmite, while 2-line ferrihydrite and goethite are identified in ferric sludges. / A key hypothesis is that dewaterability is partly determined by the treatment conditions. To investigate this, numerous WTP sludges were studied that had been generated under diverse conditions: some plant samples were obtained, and the remainder were generated in the laboratory (results were consistent). Dewaterability was characterised for each sludge in concentration ranges relevant to settling, centrifugation and filtration using models developed by LANDMAN and WHITE inter alia; it is expressed in terms of both equilibrium and kinetic parameters, py(φ) and R(φ) respectively.This work confirmed that dewaterability is significantly influenced by treatment conditions.The strongest correlations were observed when varying coagulation pH and coagulant dose. At high doses precipitated coagulant controls the sludge behaviour, and dewaterability is poor. Dewaterability deteriorates as pH is increased for high-dose alum sludges; other sludges are less sensitive to pH. These findings can be linked to the faster coagulation dynamics prevailing at high coagulant and alkali dose.Alum and ferric sludges in general had comparable dewaterabilities, and the characteristics of a magnesium sludge were similar too.Small effects on dewaterability were observed in response to variations in raw water organic content and shearing. Polymer flocculation and conditioning appeared mainly to affect dewaterability at low sludge concentrations. Ageing did not produce clear changes in dewaterability.Dense, compact particles are known to dewater better than ‘fluffy’ aggregates or flocs usually encountered in drinking water treatment. This explains the superior dewaterability of a sludge containing powdered activated carbon (PAC). Even greater improvements were observed following a cycle of sludge freezing and thawing for a wide range of WTP sludges. / Further aspects considered in the present work include deviations from simplifying assumptions that are usually made. Specifically: investigation of long-time dewatering behaviour, wall effects, non-isotropic stresses, and reversibility of dewatering (or ‘elasticity’).Several other results and conclusions, of both theoretical and experimental nature, are presented on topics of subsidiary or peripheral interest that are nonetheless important for establishing a reliable basis for research in this area. / This work has proposed links between industrial drinking water coagulation conditions, sludge dewaterability from settling to filtration, and the microstructure of the aggregates making up that sludge. This information can be used when considering the operation or design of a WTP in order to optimise sludge dewaterability, within the constraints of producing drinking water of acceptable quality.
116

Molekulárně genetické a biochemické studie vybraných dědičných metabolických onemocnění, vývoj a aplikace nových metod. / Molecular genetic and biochemical studies of selected inherited metabolic disorders, development and applications of new methods

Mušálková, Dita January 2016 (has links)
Inherited metabolic disorders (IMD) form a diverse group of several hundred different diseases with a relatively high cumulative incidence (stated up to 1:600). They are associated with accumulation of the substrates and lack of the products in specific metabolic pathways, which is caused by deficiency of the enzyme or its activator, or dysfunction of the transport protein. However, the underlying cause is at the DNA level. The grounds for different phenotype manifestation in patients with the same genotype are often not known. During my work at the Institute of Inherited Metabolic Disorders, I designed several new methods for the research of IMD and applied them in the patients and their families. I created procedures for the isolation of lysosomal membranes that are used for the research of lysosomal storage disorders and general properties of lysosomes. Next, I introduced several novel assays for determination of the X-inactivation ratio, which led to a significant increase of informative women. Nowadays, we use these methods in heterozygous women with X-linked diseases in order to study the influence of X-inactivation on the manifestation of the diseases. The cases of a girl with mucopolysaccharidosis type II, a girl with OTC deficiency and a family with the mutation in HPRT1 gene are described...
117

Využití různých technik enkapsulace k řízenému uvolňování aktivních látek v potravinářských a kosmetických přípravcích / Use of some encapsulation techniques to controlled release of active substances in food and cosmetics products.

Skoumalová, Petra January 2015 (has links)
The presented doctoral thesis is focused on preparation, characterization and application of organic micro- and nanoparticles as transport systems for active components and some their complex natural sources. Active component were packed into liposomes and polysaccharide particles. As active components were used caffeine, some drugs – clotrimazole and ibuprofen, further antioxidants and vitamins. Antimicrobial herbs and spices extract, antimicrobial peptides lysozyme, nisin and other antimicrobial ingredients were encapsulated too. Encapsulation of selected hydrolytic enzymes was tested, too. Particles were also used for encapsulation of probiotic strains Bifidobacterium breve and Lactobacillus acidophilus and prebiotic components. These prebiotics were co-encapsulated into capsules with probiotic cells. Natural extracts were encapsulated e.g. extracts of guarana, ginseng, goji, green barley, propolis, black, green and white tea, coffee, fruit and vegetable extracts. The efficiency of encapsulation was determined by HPLC/PDA and by spectrophotometry. Long-term stability of particles and amount of released component in model/real foods, in model cosmetic conditions and in a model physiological environment were monitored too. Size of prepared liposomes and polysaccharide particles was determined by dynamic light scattering and by light microscopy and electron microscopy, respectively. Stability of the particles was measured using a zeta potential. Also, analytical centrifugation was used to measurement of sedimentation velocity and stability of the prepared particles. The antimicrobial activity were tested using two Gram-positive (Bacillus subtilis, Micrococcus luteus), two Gram-negative (Escherichia coli, Serratia marcescens) bacteria and one fungal strains (Candida glabrata). For determining the antimicrobial properties of active component and prepared particles two the most widely used methods were used - agar diffusion method and broth dilution method. The viability of probiotic strains were performed using flow cytometry and fluorescence microscopy. Encapsulation of active component was successful in all types of particles. Liposome showed a very good long-term stability mainly in water conditions with neutral pH and polysaccharide particles were stable in acidic conditions. Prepared particles showed a very good stability in model stomach environment, while in model intestines environments particles were disintegrated and active component were released. Prepared particles with encapsulated caffeine as well as other tested antioxidants and vitamins could be used to modern types of energy drinks, food supplements and also for some cosmetics applications. Encapsulated antimicrobial components could be used for food application as well as for cosmetics and pharmaceutical application like antimicrobial wound formulation. Encapsulated enzymes can be used for controlled release of proteases in wound healing, as delivery systems in digestive tract and as a part of pharmaceutical preparative and food supplements for enzyme therapy. The study revealed that encapsulation of probiotics and also co-encapsulation of probiotics with prebiotics exhibited longer stability of particles and survival bacterial cells. So, prepared particles are suitable for use to food product with beneficial effects on the human body.
118

Molekulárně genetické a biochemické studie vybraných dědičných metabolických onemocnění, vývoj a aplikace nových metod. / Molecular genetic and biochemical studies of selected inherited metabolic disorders, development and applications of new methods

Mušálková, Dita January 2016 (has links)
Inherited metabolic disorders (IMD) form a diverse group of several hundred different diseases with a relatively high cumulative incidence (stated up to 1:600). They are associated with accumulation of the substrates and lack of the products in specific metabolic pathways, which is caused by deficiency of the enzyme or its activator, or dysfunction of the transport protein. However, the underlying cause is at the DNA level. The grounds for different phenotype manifestation in patients with the same genotype are often not known. During my work at the Institute of Inherited Metabolic Disorders, I designed several new methods for the research of IMD and applied them in the patients and their families. I created procedures for the isolation of lysosomal membranes that are used for the research of lysosomal storage disorders and general properties of lysosomes. Next, I introduced several novel assays for determination of the X-inactivation ratio, which led to a significant increase of informative women. Nowadays, we use these methods in heterozygous women with X-linked diseases in order to study the influence of X-inactivation on the manifestation of the diseases. The cases of a girl with mucopolysaccharidosis type II, a girl with OTC deficiency and a family with the mutation in HPRT1 gene are described...
119

Untersuchungen zur kapazitationsassoziierten Signaltransduktion in humanen Spermatozoen und Evaluation des MACS-Verfahrens zur Ejakulataufbereitung

Kriegel, Christian 16 April 2013 (has links)
Als Kapazitation bezeichnet man den im weiblichen Reproduktionstrakt stattfindenden Reifungsschritt, der Spermien das volle Fertilisierungspotential verleiht. Die molekularbiologischen Grundlagen dieses für eine erfolgreiche natürliche oder auch artifizielle Befruchtung essenziellen Prozesses sind bis heute nur unvollständig verstanden. Im Rahmen der vorliegenden Dissertation wurden die mit der Kapazitation einhergehenden funktionellen und strukturellen spermalen Veränderungen untersucht. Die kapazitative Stimulation führte zu einer gesteigerten Motilität bis hin zur Hyperaktivierung, zu einer vermehrt induzierten Akrosomenreaktion und zu einer deutlich reduzierten Apoptoseaktivität. Anhand von Inhibitionsexperimenten wurde die Rolle der potentiellen Signaltransduktoren Caspase-1, Calpain und Calmodulin analysiert. Dabei wies die Calmodulinantagonisierung auf eine ausgeprägte Calciumabhängigkeit aller untersuchten kapazitationsassoziierten Prozesse hin. Die Hemmung von Caspase-1 und Calpain führte zu einer Beeinträchtigung der Motilität und der Akrosomenreaktion ohne das Ausmaß der Apoptoseinduktion zu beeinflussen. Die vorstehend genannten Erkenntnisse wurden zur Evaluation verschiedener Ejakulataufbereitungsprotokolle genutzt. Dabei konnte gezeigt werden, dass die Kombination des modernen Verfahrens der immunomagnetische Zellseparation mit der etablierten Methode der Dichtegradientenzentrifugation dem einfachen Standard in Bezug auf die Anreicherung hochmotiler Spermien mit minimaler Apoptoseaktivität aus frischen wie auch aus kryokonservierten Ejakulaten deutlich überlegen war. Bedeutsam im Hinblick auf eine mögliche pratische Anwendung der immunomagnetischen Zellseparation erscheint der Befund, dass die durch das kombinierte Anreicherungsverfahren erhaltene Spermatozoensubpopulation im Hamsteroozytenpenetrationstest ein signifikant höheres Fertilisierungspotential zeigte.
120

Advanced Chemical-Mechanical Dewatering of Fine Particles

Asmatulu, Ramazan 05 April 2001 (has links)
In the present work, novel dewatering aids and a novel centrifuge configuration were developed and applied for the purpose of dewatering fine particles. Three different types dewatering reagents were tested in different filtration and centrifugation units. These chemicals included low-HLB surfactants, naturally occurring lipids, and modified lipids. Most of these reagents are insoluble in water; therefore, they were used in solutions of appropriate solvents, such as light hydrocarbon oils and short-chain alcohols. The role of these reagents was to increase the hydrophobicity of the coal and selected mineral particles (chalcopyrite, sphalerite, galena, talc, clay, phosphate, PCC and silica) for the dewatering. In the presence of these reagents, the water contact angles on the coal samples were increased up to 90o. According to the Laplace equation, an increase in contact angle with the surfactant addition should decrease the capillary pressure in a filter cake, which should in turn increase the rate of dewatering and help reduce the cake moisture. The use of the novel dewatering aids causes a decrease in the surface tension of water and an increase in the porosity of the cake, both of which also contribute to improved dewatering. A series of batch-scale dewatering tests were conducted on a variety of the coal and mineral samples using the novel dewatering aids. The results obtained with a Buchner funnel and air pressure filters showed that cake moistures could be reduced substantially, the extent of which depends on the particle size, cake thickness, drying time, reagent dosage, conditioning time, reagent type, sample aging, water chemistry, etc. It was determined that use of the novel dewatering aids could reduce the cake formation time by a significant degree due to the increased kinetics of dewatering. At the same time, the use of the dewatering aids reduced the cake moistures by allowing the water trapped in smaller capillaries of the filter cake. It was found that final cake moistures could be reduced by 50% of what can be normally achieved without using the reagents. However, the moisture reduction becomes difficult with increasing cake thickness. This problem can be minimized by applying a mechanical vibration to the cake, spraying a short-chain alcohol on the cake and by adding a small amount of an appropriate coagulant, such as alum and CaCl2 to the coal and mineral slurries. The novel dewatering aids were also tested using several different continuous filters, including a drum filter, disc filter and horizontal belt filter (HBF). The results obtained with these continuous filtration devices were consistent with those obtained from the batch filters. Depending on the coal and mineral samples and the type of the reagent, 40 to 60% reductions in moisture were readily achieved. When using vacuum disc filters, the cake thickness increased substantially in the presence of the novel dewatering aids, which could be attributed to the increased kinetics of dewatering. A dual vacuum system was developed in the present work in order to be able to control the cake thickness, which was necessary to achieve lower cake moistures. It was based on using a lower vacuum pressure during the cake formation time, while a full vacuum pressure was used during the drying cycle time. Thus, use of the dual vacuum system allowed the disc filter to be used in conjunction with the novel dewatering aids. Its performance was similar to that of HBF, which is designed to control cake thickness and cake formation time independently. The effectiveness of using the novel dewatering aids were also tested in a full-continuous pilot plant, in which coal samples were cleaned by a flotation column before the flotation product was subjected to the disc filter. The tests were conducted with and without using novel dewatering aids. These results were consistent with those obtained from the laboratory and batch-scale tests. The novel centrifuge developed in the present work was a unit, which combined a gravity force and air pressure. The new centrifuge was based on increasing the pressure drop across the filter cake formed on the surface of the medium (centrifuge wall). This provision made it possible to take advantage of Darcy s law and improve the removal of capillary water, which should help lower the cake moisture. A series of tests were conducted on several fine coal and mineral particles and obtained more than 50% moisture reduction even at very fine particle size (2 mm x 0). Based on the test results obtained in the present work, two proof-of-concept (POC) plants have been designed. The first was for the recovery of cyclone overflows that are currently being discarded in Virginia, and the other was for the recovery of fines from a pond in southern West Virginia. The former was designed based on the results of the plant tests conducted in the present work. Cost vs. benefit analyses were conducted on the two POC plants. The results showed very favorable internal rates of return when using the novel dewatering aids. Surface chemistry studies were conducted on the coal samples based on the results obtained in the present investigation. These consisted mainly of the surface characterization of the coal samples (surface mineral composition, surface area, zeta potential, x-ray photoelectron microscopy (XPS)), acid-base interactions of the solids and liquids, dewatering kinetic tests, contact angle measurements of the coal samples and surface force measurements using AFM. In addition, carbon coating on a silica plate using palsed laser deposition (PLD) and Langmuir-Blodgett (LB) film deposition tests were conducted on the sample to better understand the surfactant adsorption and dewatering processes. The test results showed that the moisture reductions on the fine particles agree well with the surface chemistry results. / Ph. D.

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