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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.
101

On branching laws of Speh representations / Speh表現の分岐則について

Ito, Nozomi 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23674号 / 理博第4764号 / 新制||理||1683(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)准教授 市野 篤史, 教授 池田 保, 教授 雪江 明彦 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
102

Effect of water temperature on cohesive soil erosion

Parks, Olivia Waverly 28 January 2013 (has links)
In light of increased stream temperatures due to urbanization and climate change, the<br />effect of water temperature on cohesive soil erosion should be explored. The objectives of this study are to: determine the effect of water temperature on the erosion rates of clay; determine how erosion rates vary with clay mineralogy; and, explore the relationship between zeta potential and erosion rate. Samples of kaolinite- and montmorillonite-sand mixtures, and vermiculite-dominated soil were placed in the wall of a recirculating flume channel using a vertical sample orientation. Erosion rate was measured under a range of shear stresses (0.1-20 Pa) for a period of five minutes per shear stress at water temperatures of 12, 20, and 27�"C. The zeta potential was determined for each clay type at the three testing temperatures and compared to mean erosion rates. The kaolinite erosion rate doubled when the temperature increased from 12 to 20�"C, and erosion of vermiculite samples tripled when the temperature increased from 20 to 27�"C. The montmorillonite samples generally eroded through mechanical failure rather than fluvial erosion, and the limited fluvial erosion of the montmorillonite-sand mixture was not correlated with water temperature. The data suggest correlation between zeta potential and erosion rate; however, due to the small sample size (n=3), statistically significant correlation was not indicated. Research should continue to explore the influence of water temperature on cohesive soil erosion to better understand the influence of clay mineralogy. Due to the high degree of variability in cohesive soil erosion, multiple replications should be used in future work. The vertical sample orientation enabled discrimination between fluvial erosion and mass wasting and is recommended for future studies. / Master of Science
103

Characterization of magnetorheological fluids

Chamma, Karima Hoceine 01 January 1999 (has links)
No description available.
104

Torção Analítica e extensões para o Teorema de Cheeger Müller. / Analytic Torsion and extensions for the Cheeger Müller theorem

Hartmann Júnior, Luiz Roberto 10 December 2009 (has links)
Estudamos a Torção Analítica para variedades com bordo e ainda com singuaridades do tipo cônico, mais especificamente, para um cone métrico limitado, com o propósito de investigar a extensão natural do Teorema de Cheeger Müller para tais espaços. Começamos determinando a Torção Analítica do disco e de variedades com o bordo totalmente geodésico, por meio de ferramentas geométricas desenvolvidas por J. Brüning e X. Ma. Posteriormente, usando ferramentas analíticas desenvolvidas por M. Spreafico, determinamos a Torção Analítica do cone sobre uma esfera de dimensão ímpar e provamos um teorema do tipo Cheeger Müller para este espaço. Mais ainda, provamos que o resualto de J. Brüning e X. Ma estende para o cone sobre uma esfera de dimensão ímpar / We study for Analytic Torsion of manifolds with boundary and also with conical singularities , more specifically, for a finite metric cone, with the purpose of investing the natural extension of the Cheeger Müller theorem for such spaces. we start by computing the Analytic Torsion of an any dimensional disc and of a manifold with totally boundary, by using geometric tools development by J. Brüning and X. Ma. Then, by using analytic tools development by M. Spreafico, we determine the Analytic Torsion of a cone over an odd dimensional sphere and we prove a theorem of Cheeger Müller type space. Moreover, we prove that the result of J. Brüning and X. Ma extends to the cone over an odd dimensional sphere
105

Torção Analítica e extensões para o Teorema de Cheeger Müller. / Analytic Torsion and extensions for the Cheeger Müller theorem

Luiz Roberto Hartmann Júnior 10 December 2009 (has links)
Estudamos a Torção Analítica para variedades com bordo e ainda com singuaridades do tipo cônico, mais especificamente, para um cone métrico limitado, com o propósito de investigar a extensão natural do Teorema de Cheeger Müller para tais espaços. Começamos determinando a Torção Analítica do disco e de variedades com o bordo totalmente geodésico, por meio de ferramentas geométricas desenvolvidas por J. Brüning e X. Ma. Posteriormente, usando ferramentas analíticas desenvolvidas por M. Spreafico, determinamos a Torção Analítica do cone sobre uma esfera de dimensão ímpar e provamos um teorema do tipo Cheeger Müller para este espaço. Mais ainda, provamos que o resualto de J. Brüning e X. Ma estende para o cone sobre uma esfera de dimensão ímpar / We study for Analytic Torsion of manifolds with boundary and also with conical singularities , more specifically, for a finite metric cone, with the purpose of investing the natural extension of the Cheeger Müller theorem for such spaces. we start by computing the Analytic Torsion of an any dimensional disc and of a manifold with totally boundary, by using geometric tools development by J. Brüning and X. Ma. Then, by using analytic tools development by M. Spreafico, we determine the Analytic Torsion of a cone over an odd dimensional sphere and we prove a theorem of Cheeger Müller type space. Moreover, we prove that the result of J. Brüning and X. Ma extends to the cone over an odd dimensional sphere
106

Obten??o e caracteriza??o de nanopart?culas de quitosana

Tavares, Idylla Silva 08 November 2011 (has links)
Made available in DSpace on 2014-12-17T15:41:55Z (GMT). No. of bitstreams: 1 IdyllaST_DISSERT.pdf: 1649846 bytes, checksum: b16782ef605bdc7a1d3225b281a6f2b3 (MD5) Previous issue date: 2011-11-08 / Chitosan nanoparticles have been used in several systems for the controlled release of drugs. The aim of this study was to obtain and characterize chitosan nanoparticles prepared by the method of coacervation / precipitation using sodium sulfate at different concentrations as the crosslinking agent. The characterization was done using zeta potential and small angle Xray scattering, SAXS. The dispersions of chitosan were obtained at pH 1 and pH = 3. The results of zeta potential at pH = 1 ranged from +64.8 to +29.27 mV and for pH = 3 they varied from +72.4 to +23.48 mV, indicating that the chain of chitosan is positively charged in acidic pH and the behavior of nanoparticles in terms of surface charge was independent of pH. However, the results indicated a dependence of particle size in relation to pH. This difference in behavior was explained by the influence of enthalpic and entropic components / Nanopart?culas de quitosana t?m sido utilizadas em v?rios sistemas destinados a libera??o controlada de f?rmacos. O objetivo desse trabalho foi a obten??o e caracteriza??o de nanopart?culas de quitosana atrav?s do m?todo de coacerva??o/precipita??o utilizando o sulfato de s?dio em diferentes concentra??es como agente reticulante. A caracteriza??o foi feita utilizando potencial zeta e espalhamento de pequenos ?ngulos, SAXS. As dispers?es de quitosana foram obtidas a pH=1 e pH=3. Os resultados do potencial zeta variaram no pH = 1 de +64,8 a +29,27 mV e no pH = 3 de +72,4 a +23,48 mV, indicando que a cadeia de quitosana fica carregada positivamente em pH ?cido e que comportamento das nanopart?culas em termos de carga superficial foi independente do pH. Entretanto, os resultados indicaram depend?ncia do tamanho de part?cula em rela??o ao pH. Essa diferen?a em termos de comportamento foi explicada pela influ?ncia dos componentes ent?lpicos e entr?picos
107

Lercho ir Selbergo dzeta funkcijų reikšmių pasiskirstymai / Value distribution of Lerch and Selberg zeta-functions

Grigutis, Andrius 27 December 2012 (has links)
Disertaciją sudaro mokslinių tyrimų medžiaga, kurie atlikti 2008 -2012 metais Vilniaus universitete Matematikos ir informatikos fakultete. Disertacijoje įrodomos naujos teoremos apie Lercho ir Selbergo dzeta funkcijų reikšmių pasiskirstymą, atliekami kompiuteriniai skaičiavimai matematine programa MATHEMATICA. Disertaciją sudaro įvadas, 3 skyriai, išvados ir literatūros sąrašas. Disertacijos rezultatai atspausdinti trijuose moksliniuose straipsniuose, Lietuvos ir užsienio žurnaluose, pristatyti Lietuvoje ir užsienyje vykusiose mokslinėse konferencijose bei katedros seminarų metu. Pirmajame skyriuje įrodinėjamos ribinės teoremos Lercho dzeta funkcijai. Praėjusio šimtmečio ketvirtame dešimtmetyje Selbergas įrodė, kad tinkamai normuotas Rymano dzeta funkcijos logaritmas ant kritinės tiesės turi standartinį normalųjį pasiskirstymą. Selbergo įrodymas rėmėsi Oilerio sandauga, kuria turi Rymano dzeta funkcija, bet bendru atveju jos neturi Lercho dzeta funkcija. Antrajame skyriuje įrodoma teorema apie Lercho transcendentinės funkcijos nulių įvertį vertikaliose kompleksinės plokštumos juostose bei atliekami kompiuteriniai nulių skaičiavimai srityje Re(s)>1 programa MATHEMATICA. Trečiajame skyriuje nagrinėjamos dviejų Selbergo dzeta funkcijų monotoniškumo savybės, kurios yra tiesiogiai susijusios su šių funkcijų nulių išsidėstymu kritinėje juostoje. Monotoniškumo savybės lyginamos su Rymano dzeta funkcijos monotoniškumo savybėmis ir nulių išsidėstymu, kuris yra viena didžiausių... [toliau žr. visą tekstą] / The doctoral dissertation contains the material of scientific investigations done in 2008-2012 in the Faculty of Mathematics and Informatics at Vilnius University. The dissertation includes new theorems for the value distribution of Lerch and Selberg zeta-functions and computer calculations performed using the computational software program MATHEMATICA. The dissertation consists of the introduction, 3 chapters, the conclusions and the references. The results of the thesis are published in three scientific articles in Lithuanian and foreign journals, reported in scientific conferences in Lithuania and abroad and at the seminars of the department. In the first chapter, the limit theorems for several cases of the Lerch zeta-functions are proved. In the 1940s, Selberg proved that suitably normalized logarithm of modulus of the Riemann zeta-function on the critical line has a standard normal distribution. Selberg's proof was based on the Euler product; however, in general, Lerch zeta-functions have no Euler product. In the second chapter, the theorem concerning the zero distribution of the Lerch transendent function is proved, and computer calculations of zeros in the region Re(s)>1 are performed using MATHEMATICA. In the third chapter, the monotonicity properties of Selberg zeta-functions are investigated. Monotonicity of these two functions is directly related to the location of zeros in the critical strip. The results are compared to the monotonicity... [to full text]
108

Value distribution of Lerch and Selberg zeta-functions / Lercho ir Selbergo dzeta funkcijų reikšmių pasiskirstymai

Grigutis, Andrius 27 December 2012 (has links)
The doctoral dissertation contains the material of scientific investigations done in 2008-2012 in the Faculty of Mathematics and Informatics at Vilnius University. The dissertation includes new theorems for the value distribution of Lerch and Selberg zeta-functions and computer calculations performed using the computational software program MATHEMATICA. The dissertation consists of the introduction, 3 chapters, the conclusions and the references. The results of the thesis are published in three scientific articles in Lithuanian and foreign journals, reported in scientific conferences in Lithuania and abroad and at the seminars of the department. In the first chapter, the limit theorems for several cases of the Lerch zeta-functions are proved. In the 1940s, Selberg proved that suitably normalized logarithm of modulus of the Riemann zeta-function on the critical line has a standard normal distribution. Selberg's proof was based on the Euler product; however, in general, Lerch zeta-functions have no Euler product. In the second chapter, the theorem concerning the zero distribution of the Lerch transendent function is proved, and computer calculations of zeros in the region Re(s)>1 are performed using MATHEMATICA. In the third chapter, the monotonicity properties of Selberg zeta-functions are investigated. Monotonicity of these two functions is directly related to the location of zeros in the critical strip. The results are compared to the monotonicity... [to full text] / Disertaciją sudaro mokslinių tyrimų medžiaga, kurie atlikti 2008 -2012 metais Vilniaus universitete Matematikos ir informatikos fakultete. Disertacijoje įrodomos naujos teoremos apie Lercho ir Selbergo dzeta funkcijų reikšmių pasiskirstymą, atliekami kompiuteriniai skaičiavimai matematine programa MATHEMATICA. Disertaciją sudaro įvadas, 3 skyriai, išvados ir literatūros sąrašas. Disertacijos rezultatai atspausdinti trijuose moksliniuose straipsniuose, Lietuvos ir užsienio žurnaluose, pristatyti Lietuvoje ir užsienyje vykusiose mokslinėse konferencijose bei katedros seminarų metu. Pirmajame skyriuje įrodinėjamos ribinės teoremos Lercho dzeta funkcijai. Praėjusio šimtmečio ketvirtame dešimtmetyje Selbergas įrodė, kad tinkamai normuotas Rymano dzeta funkcijos logaritmas ant kritinės tiesės turi standartinį normalųjį pasiskirstymą. Selbergo įrodymas rėmėsi Oilerio sandauga, kuria turi Rymano dzeta funkcija, bet bendru atveju jos neturi Lercho dzeta funkcija. Antrajame skyriuje įrodoma teorema apie Lercho transcendentinės funkcijos nulių įvertį vertikaliose kompleksinės plokštumos juostose bei atliekami kompiuteriniai nulių skaičiavimai srityje Re(s)>1 programa MATHEMATICA. Trečiajame skyriuje nagrinėjamos dviejų Selbergo dzeta funkcijų monotoniškumo savybės, kurios yra tiesiogiai susijusios su šių funkcijų nulių išsidėstymu kritinėje juostoje. Monotoniškumo savybės lyginamos su Rymano dzeta funkcijos monotoniškumo savybėmis ir nulių išsidėstymu, kuris yra viena didžiausių... [toliau žr. visą tekstą]
109

Moment problem for the periodic zeta-function / Momentų problema periodinei dzeta funkcijai

Černigova, Sondra 11 November 2014 (has links)
In the thesis, problems related to the moments of the periodic zeta-function are considered. The aim of the thesis is to obtain asymptotic formulae for some analytic objects related to the periodic zeta-function. The problems are the following: 1. To prove the Atkinson-type formula with a new error term in the critical strip for the periodic zeta-function with rational parameter. 2. To prove a mean square formula for the error term in the Atkinson-type formula on the critical line for the periodic zeta-function. 3. To prove a mean square formula for the error term in the Atkinson-type formula in the critical strip for the periodic zeta-function. 4. To obtain an asymptotic formula for the fourth power moment of the periodic zeta-function. / Disertacijos tyrimo objektas yra periodinė dzeta funkcija. Mokslinė problema - šios funkcijos momentų problema. Darbo tikslas - įrodyti asimptotines formules periodinės funkcijos momentams bei kai kuriems objektams, susijusiems su šios funkcijos momentais. Darbo uždaviniai yra šie: 1. Įrodyti Atkinsono tipo formulę su korektišku liekamuoju nariu kritinėje juostoje periodinei dzeta funkcijai su racionaliuoju parametru. 2. Įrodyti Atkinsono tipo formulės periodinei dzeta funkcijai kritinėje tiesėje vidurkio formulę liekamojo nario modulio kvadratui. 3. Įrodyti Atkinsono tipo formulės periodinei dzeta funkcijai kritinėje juostoje vidurkio formulę liekamojo nario modulio kvadratui. 4. Gauti asimptotinę formulę periodinės dzeta funkcijos ketvirtajam momentui.
110

Momentų problema periodinei dzeta funkcijai / Moment problem for the periodic zeta-function

Černigova, Sondra 11 November 2014 (has links)
Disertacijos tyrimo objektas yra periodinė dzeta funkcija. Mokslinė problema - šios funkcijos momentų problema. Darbo tikslas - įrodyti asimptotines formules periodinės funkcijos momentams bei kai kuriems objektams, susijusiems su šios funkcijos momentais. Darbo uždaviniai yra šie: 1. Įrodyti Atkinsono tipo formulę su korektišku liekamuoju nariu kritinėje juostoje periodinei dzeta funkcijai su racionaliuoju parametru. 2. Įrodyti Atkinsono tipo formulės periodinei dzeta funkcijai kritinėje tiesėje vidurkio formulę liekamojo nario modulio kvadratui. 3. Įrodyti Atkinsono tipo formulės periodinei dzeta funkcijai kritinėje juostoje vidurkio formulę liekamojo nario modulio kvadratui. 4. Gauti asimptotinę formulę periodinės dzeta funkcijos ketvirtajam momentui. / In the thesis, problems related to the moments of the periodic zeta-function are considered. The aim of the thesis is to obtain asymptotic formulae for some analytic objects related to the periodic zeta-function. The problems are the following: 1. To prove the Atkinson-type formula with a new error term in the critical strip for the periodic zeta-function with rational parameter. 2. To prove a mean square formula for the error term in the Atkinson-type formula on the critical line for the periodic zeta-function. 3. To prove a mean square formula for the error term in the Atkinson-type formula in the critical strip for the periodic zeta-function. 4. To obtain an asymptotic formula for the fourth power moment of the periodic zeta-function.

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