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Évaluation d’une stratégie d’immunothérapie peptidique antivirale dans le carcinome du nasopharynx associé au virus d’Epstein Barr : de l’expérimentation in vitro à la proposition de nouveaux essais thérapeutiques / Evaluation of an antiviral peptide immunotherapy strategy in nasopharyngeal carcinoma associated with Epstein Barr virus : From in vitro experimentation up to proposal of new therapeutic trialsMrizak, Dhafer 13 December 2013 (has links)
Le carcinome du nasopharynx (CNP) est associé à la latence II d’EBV et serait une cible préférentielle de peptides vaccinaux, dérivés des antigènes de latence II d’EBV, au sein d’une approche d’immunothérapie ciblant une réponse de type Th1. Cependant, les cellules de CNP sécrétaient des exosomes immunosuppresseurs qui induisent la mort des cellules T CD4+ Th1. En outre, cet environnement immunosuppressif est aggravé par un recrutement important de lymphocytes T régulateurs (Treg) qui sont associés à un mauvais pronostic dans le CNP. Ainsi, les objectifs de ma thèse ont consisté à (i) étudier l’impact des exosomes tumoraux de CNP (Exo-CNP) sur le phénotype et la fonctionnalité des Treg (ii) explorer les moyens de favoriser l’expansion et l’efficacité des effecteurs anti-tumoraux, notamment des lymphocytes T CD4+ Th1 anti-EBV, en proposant une stratégie d’immunothérapie peptidique. Dans la première partie, nous avons montré in vivo que la chimiokine CCL-20 était responsable du recrutement des Treg au sein de la tumeur. Par ailleurs, nous avons montré que les exosomes de CNP expriment la CCL-20 et sont capables de favoriser in vitro l’attraction des Treg via cette chimiokine. En parallèle, nous avons montré que les Exo-CNP (i) augmentent significativement l’expansion des Treg, (ii) augmentent significativement le niveau d’expression du CD25 et du FoxP3 sur les Treg, (iv) conduisent à la conversion des cellules T CD4+CD25neg en Treg CD4+CD25high. L’ensemble de ces résultats a été corrélé à une augmentation significative de l’activité suppressive des Treg en présence des exosomes de CNP. Dans la deuxième partie, nous avons validé ex vivo l’immunogénicité des peptides sur des cellules immunitaires humaines. Les résultats obtenus montrent également que des lignées T CD4+ humaines spécifiques d’EBV induisent une lyse des cellules de CNP EBV+. Et, de façon inattendue, la présence des Exo-CNP ne semble pas altérer les capacités de lyse des lignées. Enfin, nous avons pu valider l’efficacité des peptides dans un modèle in vivo. En effet, nous avons évalué l’effet anti-tumoral de la vaccination par les peptides dérivés d’EBV en mesurant l’évolution des masses tumorales. Nous avons pu montrer que la reconstitution immunitaire des souris SCID-CNP couplée à la vaccination peptidique permet la stabilisation de la croissance tumorale au cours du temps. En conclusion, la mise en évidence d’une coopération entre les Exo-CNP et les Treg est très importante et pourrait représenter ainsi un nouveau mécanisme d’échappement du CNP au système immunitaire. Par ailleurs, nos résultats consolident l’efficacité des peptides EBV qui pourraient être utilisés, à terme, dans une stratégie de vaccination peptidique ou de thérapie cellulaire en complément des traitements de référence chez les patients atteints d’un CNP. / Nasopharyngeal carcinoma (NPC) is associated to the EBV latency II and should be a preferential target for our previously selected peptides derived from EBV latency II antigens. However, previous studies performed showed that NPC cells release exosomes which are able to induce apoptosis in mature Th1 lymphocytes. Furthermore, the NPC immunosuppressive environment is compounded by significant recruitment of natural regulatory T cells (Treg) associated with a poor prognosis in NPC. Thereby, this immunosuppressive environment could potentially be an obstacle to the use of this promiscious peptide coktail as a future vaccine in EBV associated nasopharyngeal carcinoma. In this context, the main objectives of my thesis consisted of (i) investigating the impact of NPc-derived-exosomes and Treg and (ii) exploring ways to promote expansion and efficiency of anti-tumoral effectors, notably anti-EBV Th1 CD4+ lymphocytes. First, we showed for the first time that NPC exosomes contain CCL-20 chemokine and are able to facilitate the recruitment of Treg cells in a CCL-20 dependent manner. This finding was confirmed by in vivo experiments in immunodeficient (SCID) and humanized mouse model xenografted with human NPC. NPC exosomes significantly increase the expansion, significantly increase the expression level of CD25 and FoxP3 on Treg and lead to the conversion of CD4+CD25neg T cells into CD4+CD25high Treg. These converted cells showed an effective immunosuppressive activity on autologous PBMCs. Moreover, NPC exosomes induce Treg suppressive activity and recruitment. In the second part, we validated peptides immunogenicity ex vivo. Then, we showed efficient EBV specific T CD4+ cytotoxicity in NPC cells. Furthermore, tumor exosomes do not affect the lysis capacity of our generated EBV specific T CD4+ cell lines. Finally, the efficiency of the EBV peptides coktail was evaluated in vivo by injecting EBV peptides into SCID mice xenografted with human NPC cells and reconstituted with human PBMCs. Here we showed that immune reconstitution coupled to peptide vaccination could stabilize tumor growth. In conclusion, our findings give new insights about NPC-derived exosomesimmunoregulatory properties and we showed that interactions of NPC-exosomes with Treg cells support immune evasion of human NPC. Our results also confirm that EBV peptides coktail could eventually be used in a vaccination strategy in combination with standard treatments in NPC patients to minimize relapse and control residual disease.
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Titulación de anticuerpos al virus Chikungunya mediante la técnica de neutralización por reducción de placasUbillus Borja, Elizabeth Noelia January 2016 (has links)
El presente trabajo de tesis tuvo como objetivo titular anticuerpos neutralizantes contra una cepa endémica del virus Chikungunya que circula en la costa norte peruana. Para desarrollar esta investigación, se empleó la prueba de neutralización por reducción en placas (PRNT), la cual se realizó en el Instituto Nacional de Salud (INS)– Laboratorio de Aislamiento y Cultivo Celular perteneciente al área de Metaxénicas Virales.
La justificación de la investigación se basa en la necesidad de comprobar que los anticuerpos detectados por la prueba de ELISA son neutralizantes y logran inhibir la dispersión del CHIKV en el cuerpo humano. Además, la prueba es necesaria para evaluar drogas antivirales y futuras vacunas que lleguen al Perú.
El diseño metodológico utilizado fue analítico y experimental. La cepa y las muestras fueron proporcionadas por el INS y provinieron del departamento de Tumbes. Las muestras positivas fueron previamente diagnosticadas con ELISA utilizando IgM e IgG y las muestras negativas fueron de individuos sanos sin contacto previo con arbovirus. La prueba de PRNT se realizó en 24 horas usando la línea celular VERO CCL-81 en monocapa. La valoración de la prueba se realizó al 50% de neutralización.
Se obtuvo como resultado títulos de anticuerpos en el rango de 1/8 y 1/16. Ésta variación responde a una relación inversa con el inicio de los días de síntomas. Por lo tanto, se concluye que la población de la costa norte del Perú sí está desarrollando anticuerpos neutralizantes para contrarrestar el virus Chikungunya endémico en la región.The present thesis aims to titrate neutralizing antibodies against an endemic strain of the Chikungunya virus that circulates in the northern coast of Peru. In order to develop this research, the plaque reduction neutralization test (PRNT) has been used, which has been carried out at the National Institutes of Health (INS) - Isolation and Cell Culture Laboratory belonging to the Viral Metaxenics area.
The justification of the investigation is based on the need to verify that the antibodies detected by the ELISA test are neutralizing and manage to inhibit the dispersion of CHIKV in the human body. In addition, the test is necessary to evaluate antiviral drugs and future vaccines that arrive in Peru.
The methodological design used was analytical and experimental. The strain and samples were provided by the INS. The strain is endemic to the department of Tumbes. The positive samples were previously diagnosed with ELISA using IgM and IgG and the negative samples were from individuals that had not had contact with any arbovirus. The PRNT test was performed in 24 hours using the VERO CCL-81 cell line in monolayer. The titration of the test was performed at 50% neutralization.
Antibody titres were obtained in the range of 1/8 and 1/16. This variation responds to an inverse relationship with the onset of symptom days. Therefore, it is concluded that the population of the northern coast of Peru is developing neutralizing antibodies to counteract the endemic Chikungunya virus in the region.
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Cold Chain Logistics in China : a case study of a Chinese Food ManufacturerWang, Meizi, Luo, Xiyu January 2012 (has links)
Abstract Background/motivation for the study: Since the late 1970s, China has seen an unprecedented growth in its economy and with that growth follows the improvement in the quality of life for a majority of its citizens. Naturally, people will focus more on the quality of their daily nutritional products as a result. One of the technologies for preserving food products is called Cold Chain Logistics, which is deal with processing, transporting and storing food products. Despite its rapid development in China, the Cold Chain Logistics system still has many problems to be dealt with by its new users thus exploring how it can better adapt to a more demanding consumers is very interesting. We will use Henan Province QI County Yongda Food Industry CO.LTD as an example for illustrating how a food industry company can effectively manage its Cold Chain Logistics system. Purpose: The purpose of this thesis is to first learn about in Cold Chain Logistics in the food industry through different literatures and second, to understand the main differences in Cold Chain Logistics in the food industry when China is compared with USA and Japan and third, to help Cold Chain Logistics in China be improved through technology and management. Methods: In order to answer the purposes of this thesis, firstly, we read and write an extensive literature review related to this thesis. Secondly, we use Yongda Company as a case study. Interviews with the one manager and two employees are major source of data collection. Findings: We present and compare the differences between Chinese, American and Japaneses’ implementation of systems through various angles. China's Cold Chain Logistics is still in the development stage. The whole Cold Chain Logistics has not matured. Furthermore, a case study is conducted on how Yongda Company can have many significant advantages over its competitors in Cold Chain Logistics and how their techniques and management styles can benefit other companies if applied correctly throughout China. Contributions: This thesis will show that how to management Cold Chain Logistics in the real company. Key words: Cold Chain Logistics, CCL, Yongda Company, food industry.
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Transporte de solutos em barreiras de material argiloso compactado (CCL) e geocomposto bentonítico (GCL): fluxos diretos, acoplados e comportamento membrana / Solute transport through compacted clay liner (CCL) and geosynthetic clay liner (GCL): direct and coupled flux and membrane behaviorMarcos Andrés Musso Laespiga 20 August 2008 (has links)
Neste trabalho foi analisado o comportamento de um solo argiloso compactado (CCL) da Fm. Corumbataí e de um geocomposto bentonítico (GCL) composto por bentonita \'NA\', frente a gradientes hidráulicos e químicos. As propriedades físicas e mineralógicas dos solos foram avaliadas, bem como determinados em ensaios de adsorção em lote os parâmetros das isotermas de Freundlich e Langmuir. Foi desenvolvido um equipamento para avaliar o comportamento membrana e poder calcular o coeficiente de eficiência químico-osmótico (\'ômega\') em ensaio de difusão-membrana. Os ensaios de advecção foram executados com o equipamento já existente no departamento de Geotecnia. Em todos os ensaios foram utilizadas soluções monoiônicas de \'KCL\' e \'CU\'CL IND.2\' 2\'H IND.2\'O\'. O valor do factor de retardamento Rd determinado no ensaio em lote (batch test) foi maior que o Rd medido no ensaio de advecção, enquanto que, no ensaio de difusão-membrana, obteve-se o menor valor de Rd. Tanto o GCL quanto o CCL apresentaram comportamento membrana e geração de pressão osmótica para as soluções utilizadas. No entanto, com a solução de \'K POT.+\' as diferenças de pressão se mantiveram durante o ensaio, enquanto que no caso da solução de \'CU POT.+2\' a pressão induzida no corpo de prova do CCL e do GCL tem um pico e logo diminue até zero. O GCL teve um aumento na condutividade hidráulica, no ensaio de advecção, quando permeado com solução de \'CU POT.+2\'. Este comportamento é atribuído ao colapso da dupla camada difusa das partículas de argila. O CCL não apresentou este comportamento. Os resultados deste trabalho sugerem que o CCL da Fm. Corumbataí tem melhor desempenho como barreira que o GCL, nas condições de laboratório e para as soluções usadas. / In this research the behavior of a compacted clayey liner (CCL) of Corumbataí Fm. and a geosynthetic clay liner (GCL) containing \'NA\'-bentonite, was evaluated in presence of hydraulic and chemical gradients. Physical and mineralogical properties of the soils were determined and batch tests were executed to obtain the adsorption parameters of the Freundlich and Langmuir models. A laboratory apparatus was developed for assessment of the membrane behavior allowing determining the chemico-osmotic efficiency coefficient (\'ômega\') in diffusion-membrane test. The advection test was carried out with existent equipment in geotechnical department. Both tests were performed with single salt \'KCL\' and \'CU\'CL IND.2\' 2\'H IND.2\'O\' solutions. The measured value of the retardation factor (Rd) for the batch test is bigger than the Rd measured in advection test while in the diffusion-membrane test, the Rd obtained is the smallest. Both GCL and the CCL exhibit membrane behavior and they generate osmotic pressure with both solutions. However with \'KCL\' solution the difference of pressure are maintained during the test, while in the case of \'CU POT.+2\' solution the induced pressure across the specimen of CCL and GCL have a peak to after decrease to zero. The GCL had an increase in the hydraulic conductivity for a \'CU POT.+2\' solution in the advection test. This behavior is attributed to the collapse of the diffuse double layers of clay particles. The CCL did not exhibit this behavior. The results of this study suggest that the CCL of Corumbataí Fm. has a better performance as clay barrier tha the GCL, considering the solutions used and in the laboratory conditions.
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Transporte de solutos em barreiras de material argiloso compactado (CCL) e geocomposto bentonítico (GCL): fluxos diretos, acoplados e comportamento membrana / Solute transport through compacted clay liner (CCL) and geosynthetic clay liner (GCL): direct and coupled flux and membrane behaviorLaespiga, Marcos Andrés Musso 20 August 2008 (has links)
Neste trabalho foi analisado o comportamento de um solo argiloso compactado (CCL) da Fm. Corumbataí e de um geocomposto bentonítico (GCL) composto por bentonita \'NA\', frente a gradientes hidráulicos e químicos. As propriedades físicas e mineralógicas dos solos foram avaliadas, bem como determinados em ensaios de adsorção em lote os parâmetros das isotermas de Freundlich e Langmuir. Foi desenvolvido um equipamento para avaliar o comportamento membrana e poder calcular o coeficiente de eficiência químico-osmótico (\'ômega\') em ensaio de difusão-membrana. Os ensaios de advecção foram executados com o equipamento já existente no departamento de Geotecnia. Em todos os ensaios foram utilizadas soluções monoiônicas de \'KCL\' e \'CU\'CL IND.2\' 2\'H IND.2\'O\'. O valor do factor de retardamento Rd determinado no ensaio em lote (batch test) foi maior que o Rd medido no ensaio de advecção, enquanto que, no ensaio de difusão-membrana, obteve-se o menor valor de Rd. Tanto o GCL quanto o CCL apresentaram comportamento membrana e geração de pressão osmótica para as soluções utilizadas. No entanto, com a solução de \'K POT.+\' as diferenças de pressão se mantiveram durante o ensaio, enquanto que no caso da solução de \'CU POT.+2\' a pressão induzida no corpo de prova do CCL e do GCL tem um pico e logo diminue até zero. O GCL teve um aumento na condutividade hidráulica, no ensaio de advecção, quando permeado com solução de \'CU POT.+2\'. Este comportamento é atribuído ao colapso da dupla camada difusa das partículas de argila. O CCL não apresentou este comportamento. Os resultados deste trabalho sugerem que o CCL da Fm. Corumbataí tem melhor desempenho como barreira que o GCL, nas condições de laboratório e para as soluções usadas. / In this research the behavior of a compacted clayey liner (CCL) of Corumbataí Fm. and a geosynthetic clay liner (GCL) containing \'NA\'-bentonite, was evaluated in presence of hydraulic and chemical gradients. Physical and mineralogical properties of the soils were determined and batch tests were executed to obtain the adsorption parameters of the Freundlich and Langmuir models. A laboratory apparatus was developed for assessment of the membrane behavior allowing determining the chemico-osmotic efficiency coefficient (\'ômega\') in diffusion-membrane test. The advection test was carried out with existent equipment in geotechnical department. Both tests were performed with single salt \'KCL\' and \'CU\'CL IND.2\' 2\'H IND.2\'O\' solutions. The measured value of the retardation factor (Rd) for the batch test is bigger than the Rd measured in advection test while in the diffusion-membrane test, the Rd obtained is the smallest. Both GCL and the CCL exhibit membrane behavior and they generate osmotic pressure with both solutions. However with \'KCL\' solution the difference of pressure are maintained during the test, while in the case of \'CU POT.+2\' solution the induced pressure across the specimen of CCL and GCL have a peak to after decrease to zero. The GCL had an increase in the hydraulic conductivity for a \'CU POT.+2\' solution in the advection test. This behavior is attributed to the collapse of the diffuse double layers of clay particles. The CCL did not exhibit this behavior. The results of this study suggest that the CCL of Corumbataí Fm. has a better performance as clay barrier tha the GCL, considering the solutions used and in the laboratory conditions.
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Studies on the elimination of volatile organic compounds in industry waste gas streamsLi, Shang-Chuan 17 August 2010 (has links)
This study aimed to develop a biofilter packed only with fern chips for the removal of air-borne low concentration VOCs (volatile organic compounds) emitted from various industries such as semiconductor manufacturing and electronic ones. The fern chip biofilters could avoid the shortcomings of traditional media, such as compaction, drying, and breakdown, which lead to the performance failure of the biofilters.
The study contains two topics. The first is a performance test on the elimination of mixed VOCs used in semiconductor manufacturing industries in an air stream. The second is the one on the elimination of a single VOC (methyl ethyl ketone) in a waste gas drawn from a CCL (copper clad laminate) plant.
Two pilot-scale biofilters consisted of two columns (0.40 mW¡Ñ0.40 mL¡Ñ0.70 mH acrylic column) arranged in series were used for the performance tests. Each of the two columns was packed with fern chips to a packing volume of around 56 L (0.40 mW¡Ñ0.40 mL¡Ñ0.35 mH). A sprinkler was set over the packed fern chips for providing them with water and nutrition solutions. Liquid leached from both layers of chips were collected in the bottom container of the column.
In the first topic, tests were performed for biofiltration removal of VOCs in simulated semiconductor manufacturing emitted gases which consisted of IPA (isopropyl alcohol), acetone, HMDS (hexamethylene disilazane), PGME (propylene glycol monomethyl ether), and PGMEA (propylene glycol monomethyl ether acetate). From the results, it could be proposed that for achieving over 94% of the VOC removal, appropriate operation conditions are media moisture content = 52-68%, media pH = 7-8, influent VOC concentration = 150-450 mg/Am3, empty bed residence time (EBRT) = 0.75 min, and volumetric organic loading L to the whole media = 11.4-34.1 g/m3.h.
In the second topic, performances of biofiltration for the removal of methyl ethyl ketone (MEK) in a gas stream from a copper clad laminate (CCL) manufacturing process were tested. Experimental results indicate that with L of <115 g /m3.h., EBRT = 0.5-1.28 min , media pH = 5.3-6.8, influent MEK concentration = 215-1,670 mg/Am3, MEK removal efficiencies of over 91% were obtained. Instant milk powder was essential to the good and stable performance of the biofilter for MEK removal.
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Investigação de fatores pró-inflamatórios no plexo coroide de cães com leishmaniose visceral /Silva, José Eduardo dos Santos. January 2017 (has links)
Orientador: Gisele Fabrino Machado / Banca:Valéria Marcal Felix de Lima / Banca: Suely Regina Mogami Bomfim / Banca: Paulo Ricardo Dell'Armelinda Rocha / Banca: Monica Regina Vendrame Amarante / Resumo: A leishmaniose visceral (LV) é uma doença que causa manifestações clínicas variadas em cães, incluindo alterações neurológicas, entretanto, existem poucos relatos que caracterizam as lesões observadas e que contribuem para elucidar a patogenia da forma neurológica da LV. O plexo coroide (PC) forma uma importante interface entre o liquor e o sistema periférico vascular, e é uma estrutura com potencial para permitir a passagem de células inflamatórias no sistema nervoso central além de servir como fonte de mediadores inflamatórios. O objetivo deste estudo foi avaliar as lesões encefálicas incluindo o PC em cães com LV e avaliar a possível participação do PC como estrutura produtora de mediadores pró-inflamatórios como citocinas (IL-1β, IL-6, INF-γ, TNF-α) e quimiocinas (CCL-3, CCL-4, CCL-5, CXCL-10), e disfunção da barreira hematoencefálica (BHE) através da presença de albumina, anticorpo anti- Leishmania no liquor e também pelo quociente de albumina o que poderia facilitar a passagem de células imunes e contribuir para as alterações inflamatórias encefálicas. Foi observado infiltrado inflamatório variando de leve a acentuado principalmente em PC e meninges. Aumento na expressão gênica de CCL-5 e tendência no aumento da CXCL-10 em PC de cães infectados. Presença de formas amastigotas e DNA de Leishmania no PC, além de anticorpos anti-Leishmania e albumina no liquor de cães com LV. Esses resultados indicam que há disfunção da BHE em cães com LV e que a CCL-5 poderia ser produzid... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract:Visceral leishmaniasis (VL) is a disease that causes several clinical manifestations in dogs, including neurological alterations, however, there are few reports that characterize the lesions observed and that contribute to elucidate the pathogenesis of the neurological form of VL. The choroid plexus (CP) forms an important interface between the cerebrospinal fluid and the vascular peripheral system, and is a structure with the potential to allow the passage of inflammatory cells into CNS and serve as a source of inflammatory mediators. The objective of this study was to evaluate brain lesions including CP in dogs with VL and to evaluate the possible participation of CP as a producer of pro-inflammatory mediators such as cytokines (IL-1β, IL-6, INF-γ, TNF-α) and chemokines (CCL-3, CCL-4, CCL-5, CXCL-10), and blood brain barrier (BBB) dysfunction through the presence of albumin, antibody anti-Leishmania in the cerebrospinal fluid and also by the albumin quotient facilitate the passage of immune cells and contribute to inflammatory brain disorders. Inflammatory infiltrates were observed ranging from mild to severe, mainly in CP and meninges. Increased gene expression of CCL-5 and tendency to increase CXCL-10 in CP from infected dogs. Presence of amastigotes and Leishmania DNA in CP, as well as anti-Leishmania antibodies and albumin in the cerebrospinal fluid of dogs with VL. These results indicate that there is dysfunction of BBB in dogs with VL and that CCL-5 could be produced by CP, on the other hand, this tissue did not prove to actively contribute to the production of other cytokines evaluated in this study / Doutor
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Brandmal-Erkennung zur Detektion beschädigter Glaskappenisolatoren an HochspannungsfreileitungenJunghanns, Nico 23 September 2020 (has links)
Für den zuverlässigen Betrieb von Hochspannungsfreileistungen ist es notwendig, die an ihnen eingesetzten Isolatoren regelmäßig zu überprüfen. Somit können gravierendere Beschädigungen vorgebeugt werden. Für diese Überprüfung sind verschiedene Verfahren geeignet. Die Brandmalerkennung ist dabei noch ein relativ neues Verfahren. Mit ihrer Hilfe ist es jedoch möglich auch kleinste Beschädigungen zu erkennen.
Im Rahmen dieser Bachelorarbeit wird ein neues Verfahren zur Erkennung von Brandmalen vorgestellt. Dieses verwendet einen Template-Matching-Algorithmus zum Finden der Isolatoren. Dessen Erkennungsrate liegt bei 90,18 %. Alle damit gefundenen Isolatoren untersucht man nach Brandmalen. Diese werden segmentiert und durch ein Connected-Component-Labeling lokalisiert. Insgesamt konnten 71,05% der Brandmale erkannt werden. So wurde der Zustand von 88,19% der Isolatoren korrekt bestimmt.
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Resonance Enhanced Multiphoton Ionization Studies of Dichlorotoluenses, Dichloroanilines, and Dichlorophenolsde Laat, Richard 09 January 2013 (has links)
A new instrument using a time-of-flight (TOF) mass filter (MF) for resonance enhanced multiphoton ionization (REMPI) studies of gas phase molecules was developed. This instrument was designed to make use of the selectivity of the REMPI process and the sensitivity of a TOF-MF with a microchannel plate detector. A pulsed valve inlet system was tested to determine its effectiveness in “cooling” molecules but it was not used for the bulk of the studies performed.
The instrument was tested using molecular and atomic bromine, atomic carbon, and atomic iodine. The atomic bromine, carbon, and iodine, were generated by the photodissociation of molecular bromine, hydrocarbons, and methyl iodide respectively. Nitrogen gas in air was used to test the pulsed valve system.
The instrument was then used to conduct REMPI studies of five dichlorotoluene (DCT) isomers (2,4-DCT; 2,5-DCT; 3,4-DCT; 2,6-DCT; and 2,3-DCT). REMPI studies of six dichloroaniline (DCA) isomers, including 2,5-DCA; 3,4-DCA; 3,5-DCA; 2,6-DCA; 2,4-DCA; and 2,3-DCA were conducted. Six isomers of dichlorophenol (DCP) were studied (2,5-DCP; 3,4-DCP; 3,5-DCP; 2,3-DCP; 2,4-DCP; and 2,6-DCP). It was determined that the 2,3-DCP; 2,4-DCP; and 2,6-DCP isomers photodissociated to form CCl, which itself could be observed through a REMPI process.
The results from the REMPI studies of the dichloroaromatics and data from previous ultraviolet, infrared, and RAMAN studies of these molecules was used in order to assign the observed peaks.
The observed 0,0 π→π* transition energies of the dichloroaromatics studied were used along with ultraviolet 0,0 π→π* transition energies from previous works in order to discuss substituent effects. A qualitative method of predicting the relative location of 0,0 π→π* transition energies of dichloroaromatics was developed.
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The relationships among the extent of participant involvement in cross-cultural learning activities, individual differences of participants, and adaptation of expatriate managers to the host country in a Korean multinational corporationYoon, Dong-Yeol 20 October 2011 (has links)
No description available.
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