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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.
381

Parameter Evaluation and Sensitivity Analysis for an Automotive Damper Model

Thornton, Ben Johnston 18 December 2012 (has links)
No description available.
382

Bulk segregant analysis for anther culture response and leptine content in backcross families of diploid potato

Boluarte, Tatiana 06 January 2000 (has links)
Diploid potato populations between a primitive cultivated species, <I>Solanum phureja</I>, and a weedy species, <I>S. chacoense</I>, were used to examine the segregation of microsatellite markers and three traits in backcrosses. Two of the traits, anther culture competence and 2<I>n</I> pollen production, originated from <I>S. phureja</I> whereas the third, leptine production (a specific glycoalkaloid known to convey resistance to the Colorado potato beetle) originated from <I>S. chacoense</I>. Using CP2, a self-incompatible F₁ hybrid originating from a cross between <I>S. chacoense</I> clone 80-1 and <I>S. phureja</I> clone 1-3, three populations were developed: 1-3 x CP2 (PBCp), CP2 x 1-3 (PBCc), and CP2 x 80-1 (CBC). For the microsatellite study, four simple sequence repeat (SSR) primer pairs that amplified fragments within potato sequences found in the GenBank were used to look at segregation ratios in our backcross populations and to eliminate possible spurious genotypes bearing non-parental alleles in these populations. Seventeen spurious genotypes were discarded from PBCp; none was found in PBCc or CBC. Two SSR loci showed skewed segregation in PBCp (favoring transmissnion of the allele originally found in 80-1), PBCc showed normal segregation at all loci, and CBC showed distorted segregation at one locus (revealing a deficiency of homozygotes). In the study of anther culture, three components of ACR were investigated in a preliminary study: 1) embryos produced per anther (EPA), 2) embryo regeneration rate and 3) percentage of monoploids (2<I>n</I>=1<I>x</I>=12) among regenerants. CP2 was intermediate, 80-1 was low, and 1-3 was high for ACR. Only EPA was selected for further characterization in our populations. PBCp (78 genotypes) and CBC (57 genotypes), were characterized for anther culture response ACR/EPA in a series of studies. Nine high and ten low selections were identified in CBC, and ten high and ten low selections were identified in PBCp. EPA selections were used for bulk segregant analysis (BSA) using 214 RAPD primers. Two bands, one amplified by OPQ-10 and another by OPZ-4 were linked in coupling and in repulsion, respectively, to ACR in PBCp. One band amplified by OPW-14 primer was linked in coupling to ACR in CBC. One-way ANOVAs for data from remaining genotypes of the populations verified linkage of the markers to ACR/EPA. For 2n pollen production, a total of 77 PBCp genotypes was characterized; 80-1 produces low % 2<I>n</I> pollen, and 1-3 produces high % 2<I>n</I> pollen. Pollen samples were stained with propidium iodide and examined by flow cytometry. The frequency of 2n pollen varied continuously from 1.7 % to 40.6 % among the 41 genotypes that flowered sufficiently to allow three separate pollen collections. Variation due to the environment was observed where the frequency of 2n pollen appeared greater over a range of genotypes on single collection days. BSA could not be used due to limited population size and a low number of selections at the extremes of the distribution of phenotypes. The continuous variation for 2<I>n</I> pollen production suggests multigenic control of the trait. In the study of leptine content in reciprocal backcross populations, 87 genotypes within PBCp, and 42 genotypes within PBCc were characterized using gas chromatography of leaf samples. CP2 was intermediate, 1-3 had zero, and 80-1 was high for leptine content in the foliage. Leptines were present in low levels in 43 of 87 genotypes in PBCp, indicating simple genetic control. In PBCc, only 7 of 42 genotypes expressed leptines, generally at a higher level than in PBCp, indicating cytoplasmic inheritance. Ten high and ten nil selections within PBCp, and seven high and eight nil selections within PBCc were used for BSA using 214 RAPD primers. Three primers OPQ-2, OPT-16 and OPT-20 amplified bands segregating with high bulks in both populations. These markers were linked in coupling to leptine content in PBCp. Linkage was verified by ANOVAs for leptine content in the entire population. / Ph. D.
383

Three Problems Involving Compressible Flow with Large Bulk Viscosity and Non-Convex Equations of State

Bahmani, Fatemeh 27 August 2013 (has links)
We have examined three problems involving steady flows of Navier-Stokes fluids. In each problem non-classical effects are considered. In the first two problems, we consider fluids which have bulk viscosities which are much larger than their shear viscosities. In the last problem, we examine steady supersonic flows of a Bethe-Zel'dovich-Thompson (BZT) fluid over a thin airfoil or turbine blade. BZT fluids are fluids in which the fundamental derivative of gasdynamics changes sign during an isentropic expansion or compression. In the first problem we consider the effects of large bulk viscosity on the structure of the inviscid approximation using the method of matched asymptotic expansions. When the ratio of bulk to shear viscosity is of the order of the square root of the Reynolds number we find that the bulk viscosity effects are important in the first corrections to the conventional boundary layer and outer inviscid flow. At first order the outer flow is found to be frictional, rotational, and non-isentropic for large bulk viscosity fluids. The pressure is found to have first order variations across the boundary layer and the temperature equation is seen to have two additional source terms at first order when the bulk viscosity is large. In the second problem, we consider the reflection of an oblique shock from a laminar flat plate boundary layer. The flow is taken to be two-dimensional, steady, and the gas model is taken to be a perfect gas with constant Prandtl number. The plate is taken to be adiabatic. The full Navier-Stokes equations are solved using a weighted essentially non-oscillatory (WENO) numerical scheme. We show that shock-induced separation can be suppressed once the bulk viscosity is large enough. In the third problem, we solve a quartic Burgers equation to describe the steady, two-dimensional, inviscid supersonic flow field generated by thin airfoils. The Burgers equation is solved using the WENO technique. Phenomena of interest include the partial and complete disintegration of compression shocks, the formation of expansion shocks, and the collision of expansion and compression shocks. / Ph. D.
384

Bulk-boundary correspondence in non-Hermitian point-gap topological phases / 非エルミート点ギャップトポロジカル相におけるバルク境界対応

Nakamura, Daichi 25 March 2024 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第25102号 / 理博第5009号 / 新制||理||1715(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 佐藤 昌利, 教授 柳瀬 陽一, 准教授 吉田 恒也 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
385

[en] ANALYSIS OF OUTSOURCED FLEET MANAGEMENT: CASE STUDY IN A LUBRICATING OIL COMPANY IN BRAZIL / [pt] ANÁLISE DA GESTÃO DE FROTA TERCEIRIZADA: ESTUDO DE CASO EM UMA EMPRESA DE ÓLEOS LUBRIFICANTES NO BRASIL

MARCELO ANTUNES CAIXAO ZUCARINO 25 November 2024 (has links)
[pt] A presente dissertação aborda a análise do contingente atual e futuro da frota terceirizada utilizada pela empresa para a distribuição de óleo lubrificante a granel no Brasil. O objetivo central é propor uma melhor utilização dos recursos logísticos, visando ganhos operacionais e financeiros. Inicialmente, é destacada a importância dos óleos lubrificantes para veículos e equipamentos motorizados e a relevância do mercado de lubrificantes no contexto econômico brasileiro. Uma análise prévia fornecida pela companhia revelou que aproximadamente 55 por cento do valor pago em contrato, valor referente a disponibilidade da frota, às transportadoras não vem sendo revertido em ganhos para a empresa. Evidenciando um gap na eficiência da operação. O objetivo dessa dissertação, portanto, é identificar as demandas e projetar cenários futuros para três propostas principais: reduzir a quantidade de veículos disponíveis, expandir a operação aumentando os volumes vendidos ou aplicar as duas propostas simultaneamente, reduzindo o contingente e aumentando os volumes vendidos. A proposta de expansão do volume vendido no contingente atual indicou um ganho superior à redução da frota, tendo sido considerados diversos custos e receitas, sendo, portanto, a opção recomendada. Este trabalho também contribui para a literatura acadêmica e para a prática empresarial ao fornecer uma visão abrangente sobre a gestão de frota terceirizada no contexto brasileiro de distribuição de óleos lubrificantes. Utilizando metodologias quantitativas, foram fornecidas recomendações práticas para otimizar operações logísticas, melhorando a competitividade e sustentabilidade da empresa. Ao final desse estudo foram observados possíveis estudos futuros, com o objetivo de aprofundar mais sobre o tema. / [en] This dissertation addresses the analysis of the current and future contingent of the outsourced fleet used by the company for the distribution of bulk lubricating oil in Brazil. The main objective is to propose a better use of logistics resources, aiming at operational and financial gains. Initially, the importance of lubricating oils for vehicles and motorized equipment and the relevance of the lubricants market in the Brazilian economic context are highlighted. A previous analysis provided by the company revealed that approximately 55 percent of the amount paid in the contract, the amount referring to the availability of the fleet, to the transporters has not been reverted into gains for the company, highlighting a gap in the efficiency of the program. The objective of this dissertation, therefore, is to identify the demands and project future scenarios for three main proposals: reduce the number of vehicles available, expand the program by increasing the volumes sold or apply both proposals simultaneously, reducing the contingent and increasing the volumes sold. The proposal to expand the volume sold in the current contingent indicated a gain greater than the reduction of the fleet, having considered several costs and revenues, and is, therefore, the recommended option. This work also contributes to the academic literature and business practice by providing a comprehensive overview of outsourced fleet management in the Brazilian context of lubricating oil distribution. Using quantitative methodologies, practical recommendations were provided to optimize logistics operations, improving the company s competitiveness and sustainability. At the end of this study, possible future studies were observed, with the aim of further deepening the topic.
386

DNA Damage in Healthy Individuals and Respiratory Patients after Treating Whole Blood In vitro with the Bulk and Nano Forms of NSAIDs

Najafzadeh, Mojgan, Normington, Charmaine, Jacob, B.K., Isreb, Mohammad, Gopalan, Rajendran C., Anderson, Diana 2016 August 1923 (has links)
Yes / Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit COX enzyme activity which affects the inflammatory response. Inflammation is associated with increasing cancer incidence. Pre-clinical and clinical studies have shown that NSAID treatment could cause an anti-tumor effect in cancers. In the present study, blood was taken from healthy individuals (n = 17) and patients with respiratory diseases or lung cancer (n = 36). White blood cells (WBC) were treated with either a micro-suspension, i.e., bulk (B) or nano-suspension (N) of aspirin (ASP) or ibuprofen (IBU) up to 500 μg/ml in the comet assay and up to 125 μg/ml in the micronucleus assay. In this study results were compared against untreated lymphocytes and their corresponding treated groups. The results showed, that NSAIDs in their nano form significantly reduced the DNA damage in WBCs from lung cancer patients in bulk and nano compared to untreated lymphocytes. Also, there was a decrease in the level of DNA damage in the comet assay after treating WBCs from healthy individuals, asthma and COPD groups with aspirin N (ASP N) but not with IBU N. In addition, the number of micronuclei decreased after treatment with NSAIDs in their nano form (ASP N and IBU N) in the healthy as well as in the lung cancer group. However, this was not the case for micronucleus frequency in asthma and COPD patients. These data show that lymphocytes from different groups respond differently to treatment with ASP and IBU as measured by comet assay and micronucleus assay, and that the size of the suspended particles of the drugs affects responses. / The present study was part funded by United Kingdom India Education Research Initiative (UKERI) SA 07-067.
387

ROS-induced Oxidative Damage in Lymphocytes Ex Vivo/in Vitro From Healthy Individuals and MGUS Patients: Protection by Myricetin Bulk and Nanoforms

Akhtar, Shabana, Najafzadeh, Mojgan, Isreb, Mohammad, Newton, L., Gopalan, Rajendran C., Anderson, Diana 27 February 2020 (has links)
Yes / We investigated the protective role of myricetin bulk and nanoforms, against reactive oxygen species (ROS)-induced oxidative stress caused by hydrogen peroxide and tertiary-butyl hydro peroxide in lymphocytes in vitro from healthy individuals and those from pre-cancerous patients suffering with monoclonal gammopathy of undetermined significance (MGUS). The change in intracellular reactive oxygen species was measured once cells were treated with myricetin bulk forms and nanoforms with and without either hydrogen peroxide or tertiary-butyl hydro peroxide co-supplementation. The direct and indirect antioxidant activity of myricetin was spectrofluometrically measured using the fluorescent dye 2',7'-dichlorofluorescin diacetate and using the Comet assay, respectively. Hydrogen peroxide (50 µM) and tertiary-butyl hydro peroxide (300 µM) induced a higher level of reactive oxygen species-related DNA damage and strand breaks. Addition of myricetin nanoform (20 µM) and bulk (10 µM) form could, however, significantly prevent hydrogen peroxide- and tertiary-butyl hydro peroxide-induced oxidative imbalances and the nanoform was more effective. Glutathione levels were also quantified using a non-fluorescent dye. Results suggest that myricetin treatment had no significant effect on the cellular antioxidant enzyme, glutathione. The current study also investigates the effect of myricetin on the induction of double-strand breaks by staining the gamma-H2AX foci immunocytochemically. It was observed that myricetin does not induce double-strand breaks at basal levels rather demonstrated a protective effect.
388

Ex vivo/in vitro protective effect of myricetin bulk and nano-forms on PhIP-induced DNA damage in lymphocytes from healthy individuals and pre-cancerous MGUS patients

Akhtar, Shabana, Najafzadeh, Mojgan, Isreb, Mohammad, Newton, L., Gopalan, Rajendran C., Anderson, Diana 15 June 2020 (has links)
Yes / 2-Amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) is a central dietary mutagen, produced when proteinaceous food is heated at very high temperatures potentially causing DNA strand breaks. This study investigates the protective potential of a well-researched flavonoid, myricetin in its bulk and nano-forms against oxidative stress induced ex vivo/in vitro by PhIP in lymphocytes from pre-cancerous monoclonal gammopathy of undetermined significance (MGUS) patients and those from healthy individuals. The results from the Comet assay revealed that in the presence of myricetin bulk (10 µM) and myricetin nano (20 µM), the DNA damage caused by a high dose of PhIP (100 µM) was significantly (P < 0.001) reduced in both groups. However, nano has shown better protection in lymphocytes from pre-cancerous patients. Consistent results were obtained from the micronucleus assay where micronuclei frequency in binucleated cells significantly decreased upon supplementing PhIP with myricetin bulk (P < 0.01) and myricetin nano (P < 0.001), compared to the PhIP treatment alone. To briefly determine the cellular pathways involved in the protective role of myricetin against PhIP, we studied gene expression of P53 and ATR kinase (ATM- and Rad3-related), using the real-time PCR technique.
389

An in vitro investigation into the protective and genotoxic effects of myricetin bulk and nano forms in lymphocytes of MGUS patients and healthy individuals

Akhtar, Shabana, Najafzadeh, Mojgan, Isreb, Mohammad, Newton, L., Gopalan, Rajendran C., Anderson, Diana 15 June 2020 (has links)
Yes / The present study investigated the genoprotective and genotoxic effects of myricetin bulk (10 μM) and nano forms (20 μM) in the lymphocytes from pre-cancerous, monoclonal gammopathy of unknown significance (MGUS) patients and healthy individuals using the Comet and micronucleus assays. The study also evaluated the effect of myricetin on P53 expression levels, using the Western blot technique. Results showed that throughout the in-vitro treatment, lymphocytes from the patients group had higher levels of baseline DNA damage compared to the healthy group. Myricetin in both forms induced significant DNA damage, only at higher concentrations (>40 μM). The micronucleus assay showed a significant reduction (P < 0.01) in the frequency of micronuclei in mono-nucleated cells in the patient group treated with the nano form of myricetin at the non-toxic dose of 20 μM. There was a significant increase in both gene and protein P53 levels in lymphocytes isolated from healthy individuals and pre-cancerous patients. These results suggested a protective effect of myricetin and indicated its nutritional supplement potential for protection against cancer development among patients suffering from MGUS. / This study was kindly funded by Mr Nasir Qayyum, Bradford, UK.
390

Forest Productivity as a Function of Root Growth Opportunity

Siegel-Issem, Cristina Marie 15 September 2003 (has links)
Compaction caused by certain intensive forest management practices can reduce tree growth, but the causes of growth reduction are usually complex interactions between soil properties and tree species. We used a 7 by 7 factorial greenhouse experiment to create a matrix of bulk density ((Ï b)) and volumetric water content (θv) to determine soil compaction effects on seedling growth of: (i) ponderosa pine (Pinus ponderosa Dougl. ex Laws) grown on Dome and Cohasset soils from California; (ii) shortleaf pine (Pinus echinata) on a Clarksville soil from Missouri; and (iii) loblolly pine (Pinus taeda) on an Argent soil from South Carolina. We also characterized soil physical properties and determined compaction effects on soil strength, air/water balance and least limiting water range (LLWR) for each of the soils. Optimum water content for compaction varied from 19%(Argent) to 34%(Cohasset). Compactive effort curves varied for the four soils;maximum Ï b were 1.33, 1.52, 1.58 and 1.65 Mg m-3 for the Cohasset, Dome, Clarksville, and Argent soils, respectively. Compression indices ranged from 0.33 to 0.38. In general, soil strength increased linearly with a θv decrease at the higher Ï b levels, but the effect varied with each soil type. Cohasset, with the lowest BD, had the highest soil strength (3.5 MPa), while strengths exceeding 2.0 MPa were not found for the Argent soil. Compaction affected the soil water retention curves and associated air/water balance parameters for all soils, particularly the Cohasset and Dome soils. Aeration porosity became limiting at Ï b of 1.3, 1.42, 1.44 and 1.55 Mg m-3 for the Cohasset, Dome, Clarksville and Argent soils respectively. The LLWR was lowest for the Dome and Argent soils (0.3 cm 3 cm-3 ) and in some cases increased with compaction. Models of root growth opportunity were developed using multiple regression. The general model of root length density (RLD) = b0 + b1 θv + b2 Ï b + b3 θv2 described rooting response for the Clarksville-shortleaf and Argent-loblolly soil-species combinations (p = 0.005). However, the root response of ponderosa pine on Cohasset was linear and pine roots in the Dome soil responded to an interaction between θv and Ï b. No model adequately described oak seedling growth as a function of BD and VW. High soil strength at low water contents and low aeration porosity at high water contents limited root growth. Shoot mass of seedlings growing within the least limiting water range (LLWR) was greater than those growing outside the range for all soil-species combinations except the Argent-loblolly pine (p = 0.05). The loblolly pines had greater shoot mass at volumetric water contents above the upper LLWR limits (aeration limiting). The LLWR is a promising method for integrating compaction's influence on soil properties and thus root growth potential since single factors did not appear to adequately explain each soil's compressibility. Furthermore, response surface models of RLD as a function of VW and BD in conjunction with the LLWR and seasonal site water data have potential for determining compaction- induced soil limitations for tree growth, but need to be calibrated for both soil and species. / Master of Science

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