• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 5
  • Tagged with
  • 20
  • 7
  • 6
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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.
1

Plasma-catalyst interactions in treatment of gas phase contaminants and in electrical discharge in water

Kirkpatrick, Michael Joseph. Locke, Bruce R. January 2004 (has links)
Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Bruce R. Locke, Florida State University, College of Engineering, Dept. of Chemical Engineering. Title and description from dissertation home page (viewed Jan. 13, 2005). Includes bibliographical references.
2

Fingerprinting Pennisetum purpureum Schumach. varieties and cultivars using ALFP analyses / M. Struwig

Struwig, Madeleen January 2007 (has links)
Pennisetum Rich, is one of the most important genera in the family Poaceae because it includes forage and crop species such as Pennisetum purpureum Schumach. and Pennisetum glaucum (L.) R. Br. Both P. purpureum and P. glaucum have a number of cultivars and varieties arising due to natural crossing which are very difficult to distinguish morphologically. P. purpureum and P. glaucum also hybridize naturally because they are protogynous and cross pollinated. The resulting hybrids are highly sterile and resemble P. purpureum. Lepidopteran stem borers cause great yield loss in maize produced by resource-poor farmers in Africa and are managed by habitat management or push-pull strategies, in which P. purpureum cultivars and hybrids are used as a trap crop. The aims of this project were to genotype different P. purpureum cultivars and hybrids using Amplified Fragment Length Polymorphism (AFLP) as well as Random Amplified Polymorphic DNA (RAPD) in order to identify cultivars and hybrids and possible misidentifications, assess the congruency of results between AFLPs and RAPDs and to attempt to relate these results to the oviposition preference of Chilo partellus for different P. purpureum cultivars. The individuals to be fingerprinted were collected from several countries in sub-Saharan Africa, a few from the USA and one from China. The AFLP analysis of these individuals were done with primer combinations EcoRI/MseI and Mlul/Msel on polyacrylamide gels and an ABI 3130 xl Genetic Analyzer respectively. The automated sequencer visualized more bands than the polyacrylamide gels. The RAPD technology was not developed any further after 17 primers were tested and no polymorphic bands detected. Overall results indicated that cultivars did not cluster according to geographical origin, and cultivars known by popular names did not always cluster together, indicating diversity within the cultivar or misidentifications. An example of a misidentification is the cultivar Green Gold being no other than cultivar Harare, or cultivar Swaziland 3 being cultivar Sanitas. Proper management by nursery managers cannot be stressed enough, as this will prevent plants getting mixed up, causing confusion. There was no relationship between the relatedness of cultivars and moth oviposition preference. The AFLP technology could be a powerful tool for the DNA fingerprinting and molecular characterization of this grass species, but poor germ plasm management negates its application. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2008.
3

Fingerprinting Pennisetum purpureum Schumach. varieties and cultivars using ALFP analyses / M. Struwig

Struwig, Madeleen January 2007 (has links)
Pennisetum Rich, is one of the most important genera in the family Poaceae because it includes forage and crop species such as Pennisetum purpureum Schumach. and Pennisetum glaucum (L.) R. Br. Both P. purpureum and P. glaucum have a number of cultivars and varieties arising due to natural crossing which are very difficult to distinguish morphologically. P. purpureum and P. glaucum also hybridize naturally because they are protogynous and cross pollinated. The resulting hybrids are highly sterile and resemble P. purpureum. Lepidopteran stem borers cause great yield loss in maize produced by resource-poor farmers in Africa and are managed by habitat management or push-pull strategies, in which P. purpureum cultivars and hybrids are used as a trap crop. The aims of this project were to genotype different P. purpureum cultivars and hybrids using Amplified Fragment Length Polymorphism (AFLP) as well as Random Amplified Polymorphic DNA (RAPD) in order to identify cultivars and hybrids and possible misidentifications, assess the congruency of results between AFLPs and RAPDs and to attempt to relate these results to the oviposition preference of Chilo partellus for different P. purpureum cultivars. The individuals to be fingerprinted were collected from several countries in sub-Saharan Africa, a few from the USA and one from China. The AFLP analysis of these individuals were done with primer combinations EcoRI/MseI and Mlul/Msel on polyacrylamide gels and an ABI 3130 xl Genetic Analyzer respectively. The automated sequencer visualized more bands than the polyacrylamide gels. The RAPD technology was not developed any further after 17 primers were tested and no polymorphic bands detected. Overall results indicated that cultivars did not cluster according to geographical origin, and cultivars known by popular names did not always cluster together, indicating diversity within the cultivar or misidentifications. An example of a misidentification is the cultivar Green Gold being no other than cultivar Harare, or cultivar Swaziland 3 being cultivar Sanitas. Proper management by nursery managers cannot be stressed enough, as this will prevent plants getting mixed up, causing confusion. There was no relationship between the relatedness of cultivars and moth oviposition preference. The AFLP technology could be a powerful tool for the DNA fingerprinting and molecular characterization of this grass species, but poor germ plasm management negates its application. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2008.
4

Fingerprinting Pennisetum purpureum Schumach. varieties and cultivars using ALFP analyses / M. Struwig

Struwig, Madeleen January 2007 (has links)
Pennisetum Rich, is one of the most important genera in the family Poaceae because it includes forage and crop species such as Pennisetum purpureum Schumach. and Pennisetum glaucum (L.) R. Br. Both P. purpureum and P. glaucum have a number of cultivars and varieties arising due to natural crossing which are very difficult to distinguish morphologically. P. purpureum and P. glaucum also hybridize naturally because they are protogynous and cross pollinated. The resulting hybrids are highly sterile and resemble P. purpureum. Lepidopteran stem borers cause great yield loss in maize produced by resource-poor farmers in Africa and are managed by habitat management or push-pull strategies, in which P. purpureum cultivars and hybrids are used as a trap crop. The aims of this project were to genotype different P. purpureum cultivars and hybrids using Amplified Fragment Length Polymorphism (AFLP) as well as Random Amplified Polymorphic DNA (RAPD) in order to identify cultivars and hybrids and possible misidentifications, assess the congruency of results between AFLPs and RAPDs and to attempt to relate these results to the oviposition preference of Chilo partellus for different P. purpureum cultivars. The individuals to be fingerprinted were collected from several countries in sub-Saharan Africa, a few from the USA and one from China. The AFLP analysis of these individuals were done with primer combinations EcoRI/MseI and Mlul/Msel on polyacrylamide gels and an ABI 3130 xl Genetic Analyzer respectively. The automated sequencer visualized more bands than the polyacrylamide gels. The RAPD technology was not developed any further after 17 primers were tested and no polymorphic bands detected. Overall results indicated that cultivars did not cluster according to geographical origin, and cultivars known by popular names did not always cluster together, indicating diversity within the cultivar or misidentifications. An example of a misidentification is the cultivar Green Gold being no other than cultivar Harare, or cultivar Swaziland 3 being cultivar Sanitas. Proper management by nursery managers cannot be stressed enough, as this will prevent plants getting mixed up, causing confusion. There was no relationship between the relatedness of cultivars and moth oviposition preference. The AFLP technology could be a powerful tool for the DNA fingerprinting and molecular characterization of this grass species, but poor germ plasm management negates its application. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2008.
5

Determinacao de microconstituintes em compostos de uranio por espectrometria de emissao atomica com fonte de plasma induzido (ICP-AES)

FURUSAWA, HELIO A. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:37:28Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:31Z (GMT). No. of bitstreams: 1 02046.pdf: 4605414 bytes, checksum: 083bd884df538642741b4cf2176f8795 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
6

Determinacao de microconstituintes em compostos de uranio por espectrometria de emissao atomica com fonte de plasma induzido (ICP-AES)

FURUSAWA, HELIO A. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:37:28Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:31Z (GMT). No. of bitstreams: 1 02046.pdf: 4605414 bytes, checksum: 083bd884df538642741b4cf2176f8795 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
7

On-Chip Quantum Photonics: Low Mode Volumes, Nonlinearities and Nano-Scale Superconducting Detectors

Saman Jahani (5929817) 03 January 2019 (has links)
<div>Miniaturization of optical components with low power consumption fabricated using a CMOS foundry process can pave the way for dense photonic integrated circuits and on-chip quantum information processing. Optical waveguides, modulators/switches, and single-photon detectors are the key components in any photonic circuits, and miniaturizing them is challenging. This requires strong control of evanescent waves to reduce the cross-talk and bending loss as well as low mode volumes to increase light-matter interaction.</div><div><br></div><div><div>In this thesis, we propose a paradigm shift in light connement strategy using transparent all-dielectric metamaterials. Our approach relies on controlling the optical</div><div>momentum of evanescent waves, an important electromagnetic property overlooked in photonic devices. For practical applications, we experimentally demonstrate</div><div>photonic skin-depth engineering on a silicon chip to conne light and to reduce the cross-talk and bending loss in a dense photonic integrated circuit.</div></div><div><br></div><div><div>We demonstrate that due to the strong light connement in the proposed waveguides, it is possible to miniaturize and integrate superconducting nanowire singlephoton detectors (SNSPDs) into a silicon chip. The timing jitter and dark-count</div><div>rate in these miniaturized SNSPDs can be considerably reduced. Here, we propose a theoretical model to understand the fundamental limits of these nanoscale SNSPDs and the trade-off between timing jitter, dark-count, and quantum effciency in these detectors. We propose experimental tests to verify the validity of our model.</div></div><div><br></div><div><div>Switching/modulating cavity Purcell factor on-chip is challenging, so we have proposed a nonlinear approach to switch Purcell factors in epsilon near zero (ENZ) materials. We demonstrate fourfold change in the Purcell factor with a switching time of 50 fs. The work in this thesis can lead to a unique platform for on-chip quantum nanophotonics.</div></div>
8

Analyzing the molecular mechanism of Bucky ball localization during germ cell specification in zebrafish

Riemer, Stephan 05 December 2014 (has links)
No description available.
9

Estudo da permea??o em membranas quitosana

Sobreira, Raimundo Nonato Meneses 23 August 2008 (has links)
Made available in DSpace on 2014-12-17T14:06:50Z (GMT). No. of bitstreams: 1 RaimundoNMS.pdf: 436165 bytes, checksum: 1ef32081d941d323bf771b6bcb23e258 (MD5) Previous issue date: 2008-08-23 / This study proposes to do a study on the mathematical modeling of permeation of films based on chitosan. To conduct the study were obtained membranes with various compositions: a virtually pure membrane-based chitosan; one of chitosan associated with poly (ethylene oxide (PEO). The membranes of pure chitosan were treated with plasma in atmospheres of oxygen, argon and methane. The various types of films were characterized as to its permeation regarding sufamerazina sodium. In the process of mathematical modeling were compared the standard method of obtaining the coefficient of permeation recital straight down the slope of the plot obtained by extinction / time with a the integration process of numerical permeability rate will be calculated from the spectroscopy UV / O presente trabalho prop?e fazer um estudo sobre a modelagem matem?tica da permea??o de pel?culas ? base de quitosana. Para realizar o estudo foram obtidas membranas com duas composi??es: Uma membrana pura praticamente ? base de quitosana e uma de quitosana associada com poli(?xido de etileno(PEO) .No trabalho foram usados tamb?m resultados obitidos em ensaios de permea??o com membranas de quitosana pura tratadas com plasma em atmosferas de oxig?nio; arg?nio e metano Os diversos tipos de pel?culas foram caracterizados quanto ? sua permea??o em rela??o ? sufamerazina de s?dio. No processo de modelagem matem?tica foram comparado o m?todo padr?o de obten??o do coeficiente de permea??o considerando a inclina??o da reta regressiva obtida pela plotagem absorb?ncia/tempo com um processo de integra??o num?rica A taxa de permeabilidade ser? calculada a partir da espectroscopia do UV usando como substancia alvo a sulfamerazina de s?dio
10

Altera??es no metabolismo de zinco relacionadas ao envelhecimento

Medeiros, Anna Cec?lia Queiroz de 20 June 2008 (has links)
Made available in DSpace on 2014-12-17T14:13:36Z (GMT). No. of bitstreams: 1 AnnaCQM.pdf: 331321 bytes, checksum: d4329ae02e1718e26e150e9d4894a746 (MD5) Previous issue date: 2008-06-20 / Although many studies point to alterations in the organic concentrations of zinc in elderly patients, the mechanisms by which aging might cause changes in the metabolism of this nutrient remain unclear. Thus, we assessed the changes in plasma zinc, Zinc Binding Capacity to Plasma Protein (ZnBCPP) and Saturation Index (SI), comparing elderly individuals and young adults. The zinc analyses were performed by atomic absorption spectrophotometry. A statistically significant difference (p < 0.001) was found between the two groups, in relation to plasma zinc and SI, but the ZnBCPP did not differ between the younger and older subjects. In agreement with this result, it was shown in the young group that 76% (R2 = 0.760) of the ZnBCPP variations are explained by the variations in plasma zinc and SI. In the elderly group this measure decreased to 30.5% (R2 = 0.305). We conclude, therefore, that aging may be a factor associated to changes in control mechanisms and in zinc homeostasis, and could even alter ZnBCPP response patterns and other zinc-related indicators of nutritional status. / Embora muitos estudos apontem altera??es nas concentra??es org?nicas de zinco em pacientes idosos, os mecanismos pelos quais o envelhecimento poderia implicar em mudan?as no metabolismo deste nutriente ainda permanecem obscuros. Assim, procuramos avaliar as mudan?as relativas ao zinco plasm?tico, Capacidade de Liga??o do Zinco ? Prote?na Plasm?tica (CLPPZn) e ?ndice de Satura??o (IS). As an?lises de zinco foram realizadas por espectrofotometria de absor??o at?mica, comparando idosos e adultos jovens. Foi encontrada diferen?a estaticamente significante (p<0,001), entre os dois grupos, em rela??o ao zinco plasm?tico e IS, sendo que a CLPPZn n?o diferiu entre os idosos e adultos jovens. Corroborando este resultado, foi demonstrado que, no grupo jovem as varia??es na CLPPZn s?o explicadas em 76% (R2= 0,760) pelas varia??es no zinco plasm?tico e IS. J? no grupo de idosos esta medida diminui para 30,5% (R2= 0,305). Conclu?mos ent?o que o envelhecimento pode ser um fator associado ?s mudan?as nos mecanismos de controle e homeostase do zinco, alterando inclusive padr?es de resposta relativos a CLPPZn e demais indicadores do estado nutricional relativo ao zinco.

Page generated in 0.0763 seconds