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Effective and efficient visual description based on local binary patterns and gradient distribution for object recognitionZhu, Chao 03 April 2012 (has links) (PDF)
Cette thèse est consacrée au problème de la reconnaissance visuelle des objets basé sur l'ordinateur, qui est devenue un sujet de recherche très populaire et important ces dernières années grâce à ses nombreuses applications comme l'indexation et la recherche d'image et de vidéo , le contrôle d'accès de sécurité, la surveillance vidéo, etc. Malgré beaucoup d'efforts et de progrès qui ont été fait pendant les dernières années, il reste un problème ouvert et est encore considéré comme l'un des problèmes les plus difficiles dans la communauté de vision par ordinateur, principalement en raison des similarités entre les classes et des variations intra-classe comme occlusion, clutter de fond, les changements de point de vue, pose, l'échelle et l'éclairage. Les approches populaires d'aujourd'hui pour la reconnaissance des objets sont basé sur les descripteurs et les classiffieurs, ce qui généralement extrait des descripteurs visuelles dans les images et les vidéos d'abord, et puis effectue la classification en utilisant des algorithmes d'apprentissage automatique sur la base des caractéristiques extraites. Ainsi, il est important de concevoir une bonne description visuelle, qui devrait être à la fois discriminatoire et efficace à calcul, tout en possédant certaines propriétés de robustesse contre les variations mentionnées précédemment. Dans ce contexte, l'objectif de cette thèse est de proposer des contributions novatrices pour la tâche de la reconnaissance visuelle des objets, en particulier de présenter plusieurs nouveaux descripteurs visuelles qui représentent effectivement et efficacement le contenu visuel d'image et de vidéo pour la reconnaissance des objets. Les descripteurs proposés ont l'intention de capturer l'information visuelle sous aspects différents. Tout d'abord, nous proposons six caractéristiques LBP couleurs de multi-échelle pour traiter les défauts principaux du LBP original, c'est-à-dire, le déffcit d'information de couleur et la sensibilité aux variations des conditions d'éclairage non-monotoniques. En étendant le LBP original à la forme de multi-échelle dans les différents espaces de couleur, les caractéristiques proposées non seulement ont plus de puissance discriminante par l'obtention de plus d'information locale, mais possèdent également certaines propriétés d'invariance aux différentes variations des conditions d'éclairage. En plus, leurs performances sont encore améliorées en appliquant une stratégie de l'image division grossière à fine pour calculer les caractéristiques proposées dans les blocs d'image afin de coder l'information spatiale des structures de texture. Les caractéristiques proposées capturent la distribution mondiale de l'information de texture dans les images. Deuxièmement, nous proposons une nouvelle méthode pour réduire la dimensionnalité du LBP appelée la combinaison orthogonale de LBP (OC-LBP). Elle est adoptée pour construire un nouveau descripteur local basé sur la distribution en suivant une manière similaire à SIFT. Notre objectif est de construire un descripteur local plus efficace en remplaçant l'information de gradient coûteux par des patterns de texture locales dans le régime du SIFT. Comme l'extension de notre première contribution, nous étendons également le descripteur OC-LBP aux différents espaces de couleur et proposons six descripteurs OC-LBP couleurs pour améliorer la puissance discriminante et la propriété d'invariance photométrique du descripteur basé sur l'intensité. Les descripteurs proposés capturent la distribution locale de l'information de texture dans les images. Troisièmement, nous introduisons DAISY, un nouveau descripteur local rapide basé sur la distribution de gradient, dans le domaine de la reconnaissance visuelle des objets. [...]
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Estratégias analíticas para determinação de espécies inorgânicas em medicamentos utilizados no tratamento de anemia ferroprivaBarbosa, Uenderson Araújo 28 September 2015 (has links)
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Tese Uenderson Araujo Barbosa -final.pdf: 2006362 bytes, checksum: 7f8502d02bb06b7f75032fb7a79d79bc (MD5) / CAPES e CNPq / Neste trabalho foram propostas estratégias analíticas visando à avaliação
toxicológica de metais e metaloides em medicamentos utilizados no tratamento
da anemia ferropriva, empregando técnicas cromatográficas e não
cromatográficas. Na primeira parte desta tese determinou-se chumbo nos
medicamentos aplicando espectrometria de absorção atômica com atomização
eletrotérmica (ETAAS). O preparo da amostra foi realizado fazendo uso de
digestão ácida em bloco digestor com sistema de refluxo “dedo frio” usando 3
mL de HNO3 (69% v/v) e 1 mL de H2O2 (30% v/v). Foram otimizadas as
temperaturas de pirólise e atomização usando uma mistura de paládio e
magnésio como modificador químico convencional, obtendo-se 1100ºC e
2000ºC para pirólise e atomização, respectivamente. Com uma massa
característica de 21,3 pg e 0,25 e 0,82 µg L-1, para os limites de detecção (LD)
e de quantificação (LQ), respectivamente. A precisão, expressa pelo desvio
padrão relativo de 5.92% para uma amostra com concentração de chumbo
igual a 2,98 µg g-1. A exatidão foi estimada por comparação entre os resultados
obtidos por ETAAS e espectrometria de massas com plasma indutivamente
acoplado (ICP-MS). As concentrações de chumbo nas amostras variaram entre
0,096 e 7,068 µg g-1. Na segunda parte deste trabalho, foi efetuada a
determinação de mercúrio através de amostragem em suspensão e
espectrometria de absorção atômica com alta resolução e fonte contínua com
geração de vapor frio (HR-CS CVAAS). As condições ótimas de preparo das
suspensões (1,5 mol L-1 de HCl, 1,25% (m/v) de tioureia e 15 minutos de
sonicação) foram otimizadas por planejamento fatorial completo. Os limites de
detecção e quantificação foram 0,63 ng g-1 e 2,11 ng g-1, respectivamente. O
desvio padrão relativo para avaliação da precisão foi calculado usando duas
amostras com concentrações 4,82 e 9,61 ng g-1 com resultados 10,89 e 6,84%,
respectivamente. Foi estimada a possível perda de mercúrio durante o
procedimento proposto e a exatidão, mediante testes de adição e recuperação,
variando entre 85,0 e 106,0%. As concentrações de mercúrio ficaram entre
3,17 e 34,86 ng g-1. A terceira parte deste trabalho descreve a determinação
de macro e microelementos e o estudo in vitro da bioacessibilidade de ferro em
medicamentos usados no tratamento da anemia ferropriva. Foi escolhida a
espectrometria de emissão ótica com plasma indutivamente acoplado (ICP
OES) como técnica analítica de medida. Foi efetuada digestão ácida para
tratamento das amostras e o método foi validado, demonstrando boa
sensibilidade, com limites de quantificação (mg L-1) 0,52 para Ca, 0,14 para K,
0,03 para Mg, 0,07 para Mn, 0,40 para Na, 0,36 para P e 0,24 para Zn. A
precisão do método foi reconhecida mediante experimentos repetitivos intradia
e interdia com resultados abaixo de 20%. Durante estudo da exatidão, testes
de adição e recuperação foram executados em diferentes concentrações com
resultados entre 81,85 e 114,97%. A robustez do plasma foi calculada
mediante uma razão entre as linhas iônica e atômica de magnésio, Mg(II)/Mg(I)
e os resultados, mediante análise componentes principais (PCA) e análise por
agrupamentos hierárquicos (HCA). O estudo de bioacessibilidade in vitro de Fe
demonstrou que alguns medicamentos são melhores bioacessíveis, sendo
portanto, mais recomendados para o tratamento da anemia, comprovando
dados da literatura farmacológica. Na quarta parte deste trabalho descreve-se
o estudo da determinação e especiação simultânea de arsênio e cromo por
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cromatografia líquida de alta eficiência acoplada à ICP-MS (HPLC-ICP-MS). A
determinação total de arsênio e cromo foi realizada usando uma digestão ácida
em forno de micro-ondas, uma mistura de 4 mL HNO3 (69% v/v) e 1 mL de
H2O2 (30% v/v) e análise por ICP-MS. Para o estudo de especiação foi
elaborado um estudo com três possíveis procedimentos para extração das
espécies, sendo selecionado um procedimento com água a 80ºC por 30
minutos em energia de micro-ondas. Usando uma fase móvel contendo 1,0
mM de hidróxido de tetrabutilamônio (TBAH), 0,7 mM de ácido
etilenodiaminotetracético (EDTA) e 5% de metanol (v/v) em pH 7,2 foi possível
separar as espécies presentes com tempo de retenção de 5 minutos com
separação de As(III), As(V), Cr(III) e Cr(VI), com limites de detecção de 0,002,
0,003, 0,140 e 0,042 µg g-1, respectivamente. A exatidão do método foi
avaliada conforme testes de adição e recuperação, entre 80,64 e 109,36%. O
método foi aplicado em amostras do Brasil e Espanha, com concentrações
entre 0,1-1,3 e 0,18-62,27 µg g-1 para As e Cr, respectivamente. / In this thesis work analytical strategies have been proposed for toxicological
assessment of metals and metalloids in medicines used to treat iron deficiency
anemia, using chromatographic and non-chromatographic techniques. In the
first part of this thesis, lead was determined in drugs using electrothermal
atomic absorption spectrometry (ETAAS). Sample preparation was performed
using acid digestion in digester block with reflux system "cold finger" using 3
mL of HNO3 (69% v / v) and 1 mL of H2O2 (30% v / v). Pyrolysis and
atomization temperatures were optimized using a mixture of palladium and
magnesium as conventional chemical modifier, yielding 1100°C and 2000°C for
pyrolysis and atomization, respectively. With a characteristic mass of 21.3 pg
and 0.25 and 0.82 µg g-1, for limit of detection (LOD) and limit of quantification
(LOQ), respectively. The accuracy, expressed as relative standard deviation
was 5.92% for a sample with lead concentration of 2.98 µg g-1. The accuracy
was evaluated by comparing the results obtained by ETAAS and inductively
coupled plasma mass spectrometry (ICP-MS). Lead concentrations found in
samples ranged between 0.096 and 7.068 µg g-1. In the second part of this
work, the determination of mercury using slurry sampling and high resolution
continuous source cold vapor atomic absorption spectroscopy (HR-CS CVAAS)
was performed. The optimum conditions for preparation of slurries (1.5 mol L-1
HCl, 1.25% (w / v) thiourea and 15 minutes sonication) were optimized using a
two level full factorial design. The limits of detection and quantification were
0.63 ng g-1 and 2.11 ng g-1, respectively. The relative standard deviation for
accuracy evaluation was calculated using two samples with concentrations 4.82
and 9.61 ng g-1 from which was obtained as results 10.89 and 6.84%,
respectively. The possible loss of mercury was evaluated for the proposed
procedure and the accuracy was studied by addition/recovery test, with
recoveries ranging from 85.0 to 106.0%. Mercury concentrations ranged
between 3.17 and 34.86 ng g-1. The third part of this work describes the
determination of macro and micro elements and the in vitro study of iron
bioaccessibility in medicines used to treat iron deficiency anemia. It was used
inductively coupled plasma optical emission spectrometry (ICP OES) measured
as an analytical technique. Acid digestion treatment was conducted to the
samples and the method was fully validated by demonstrating good sensitivity
with quantification limits (mg L-1) 0.52 for Ca, 0.14 for K, 0.03 for Mg, 0.07 for
Mn, 0.40 for Na, 0.36 for P and 0.24 for Zn. The precision of the method was
evaluated by intraday and interday repetitive experiments with results below
20%. During accuracy evaluation, addition/recovery tests were performed at
different concentrations with results between 81.85 and 114.97%. The
robustness of plasma was evaluated by a ratio between magnesium atomic and
ionic lines, Mg(II)/Mg(I). The results were evaluated by multivariate analysis
tools, principal component analysis (PCA) and hierarchical cluster analysis
(HCA). The study of in vitro bioaccessibility of Fe showed that some drugs are
better bioaccessible, being therefore more recommended for anemia treatment,
confirming data of pharmacological literature. The fourth part of this work
describes the simultaneous determination of arsenic and chromium speciation
using high-performance liquid chromatography coupled to ICP-MS (HPLC-ICP-
MS). The total arsenic and chromium determination was carried out using an
acid digestion in microwave oven, using a mixture of 4 mL HNO3 (69% v / v)
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and 1 mL of H2O2 (30% v / v) and analyzed by ICP-MS. For speciation, a study
was performed with three possible procedures for extraction of species, being
employed a procedure with water at 80 °C for 30 minutes in microwave energy.
Using a mobile phase containing 1.0 mM tetrabutylammonium hydroxide
(TBAH), 0.7 mM ethylenediaminetetraacetic acid (EDTA) and 5% methanol (v /
v) under pH 7.2 was possible the separation of the species present with
retention time of 5 minutes with separation of As(III) As(V), Cr(III) and Cr(VI),
with a LOD of 0.002, 0.003, 0.140 and 0.042 µg g-1, respectively. The accuracy
was assessed using addition/recovery tests, ranging between 80.64 and
109.36%. The method was applied in samples from Brazil and Spain.
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Development and metrological characterization of a high-performance Cs cell atomic clock based on coherent population trapping / Développement et caractérisation métrologique d'une horloge atomique à cellule de Cs à piégeage cohérent de population de haute performanceAbdel Hafiz, Moustafa 01 June 2017 (has links)
Ce travail de thèse, effectué dans le cadre du projet européen MClocks (http://www.inrim.it/mclocks), reporte le développement et la caractérisation métrologique d’une horloge atomique à cellule de césium de haute performance basée sur le phénomène de piégeage cohérent de population (CPT). Cette horloge exploite un schéma de pompage CPT optimisé nommé push-pull optical pumping (PPOP), permettant la détection de résonances CPT à fort contraste sur la transition d’horloge 0-0. Une caractérisation détaillée des différents éléments de l’horloge est reportée. L’horloge fut exploitée en mode continu (CW) et en mode impulsionnel de type Ramsey. Dans les deux modes de fonctionnement, l’horloge démontre une stabilité relative de fréquence de l’ordre de 2 10−13 τ−1/2 jusque 100 s d’intégration, principalement limitée par des effets de puissance laser. Cette horloge atomique, parmi les meilleures horloges à cellule développées à travers le monde, pourrait trouver des applications pour les systèmes de télécommunications, d’instrumentation, de défense ou navigation par satellite.Cette thèse reporte aussi une technique originale de stabilisation de fréquence laser par spectroscopie sub-Dopplerbi-fréquence en cellule. La plateforme constituée par l’horloge a été utilisée pour mener des tests de physique plus amont incluant la caractérisation par spectroscopie CPT d’une cellule de césium avec un revêtement anti-relaxant OTS (octadecyltrichlorosilane) ou la caractérisation de microcellules à vapeur de césium avec gaz tampon développées à FEMTO-ST pour des horloges atomiques miniatures. / This thesis work, performed in the frame of the MClocks European project (http://www.inrim.it/mclocks), reports the development and metrological characterization of a high-performance Cs vapor cell atomic clock based on coherent population trapping (CPT). The clock uses an optimized CPT pumping scheme, named push-pull optical pumping (PPOP), allowing the detection of high-contrast CPT resonances on the 0-0 magnetic-field insensitive clock transition. A detailed characterization of key components of the clock is reported. The clock was operated in the continuous-wave (CW) regime and in a Ramsey-like pulsed regime. In both regimes, the clock demonstrates a short-term fractional frequency stability at the level of 2 10−13 τ−1/2 up to 100 s averaging time, mainly limited by laser power effects. This CPT clock, ranking among the best microwave vapor cell atomic frequency standards, could find applications in telecommunication, instrumentation, defense or satellite-based navigation systems.This thesis reports also a novel laser frequency stabilization technique using dual-frequency sub-Doppler spectroscopy in a vapor cell. The clock ”platform” has also been used to perform using CPT spectroscopy the characterization of a Cs vapor cell coated with octadecyltrichlorosilane (OTS) or original buffer-gas filled Cs vapor micro-fabricated cells developed in FEMTO-ST for CPT-based miniature atomic clocks.
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Porovnání radiologických a chemických zbraní v rámci jejich použití při teroristických útocích proti civilnímu obyvatelstvu / Comparison of radiological and chemical weapons in the context of their use in terrorist attacks against civiliansGUBRICKÝ, Václav January 2010 (has links)
The thesis is focused on radiological and chemical weapons in the context of their use in terrorist attacks against the civilian population in relation to rescue and clean up operations of the Integrated Rescue System (IRS) of the Czech Republic. The objective of the thesis is to specify the terms of radiological and chemical weapons, to assess potential negative consequences of their use with the emphasis on the threat to life and health of the population, to evaluate the economic impact on society and to compare the IRS activities during the immediate intervention carried out after a terrorist attack. The topic is dealt with based on the research and the analysis of rules of law in force regulating activities of the IRS components in these major incidents and also of documents of the IAEA (International Atomic Energy Agency) and other works focused on the misuse of radioactive and chemical agents in terrorist attacks. Severity and complexity of the issue is illustrated by information given on the radiological accident in Goiana in Brazil, sarin attacks of the Japanese sect Óm šinrikjó and consequences of the model example of the use of radionuclide 137Cs. In the thesis the current methodology on which the IRS components operate in such emergencies is analyzed, and some aspects that are subject of the set of type activities, worked out by the Civil Emergency Planning Committee and DG Fire Rescue Service of the CR, which may become weak points during a real action of the IRS, are pointed out. One of major issues analyzed in this study is comparison of radiological and chemical attacks with the focus on the initial phase of the intervention of the IRS components. Presentation of differences in individual activities of the IRS components in such interventions can contribute significantly to understanding and subsequently managing the activities carried out by the IRS components in these major incidents.
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Estabilização de lasers de diodo para utilização em espectroscopia atômica. / Stabilization of diode lasers for use in atomic spectroscopy.Aparecida Marika Tuboy 13 July 1990 (has links)
Um dos primeiros requisitos para utilização de lasers de diodo em espectroscopia é sua estabilização térmica. Neste trabalho desenvolvemos um sistema de controle de temperatura para laser de diodo que permite estabilização melhor que 0.01°C. O controle é feito através de um sistema sensor e um elemento Peltier como atuador. Lasers somente estabilizados em temperatura (estabilização primária) foram utilizados para realização de espectroscopia de vapores atômicos de Rb e Cs. / One of the first requisites for utilization of diode lasers in spectroscopy is its thermal stabilization. In this work, we develop a diode laser temperature controlling system, which yields stabilization better than 0.01°C. The controlling is obtained by means of a sensor system and a Peltier element as actuator. Lasers stabilized in temperature only (primary stabilizations) were utilized in the spectroscopy of atomic vapors of Rb and Cs.
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Planejamento de experimento empregado na otimização de métodos analíticos para a determinação de macronutrientes, micronutrientes e elementos traço em fertilizantes minerais por espectometria atômicaSouza, Sidnei de Oliveira 24 July 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work were applied experimental designs to the optimization of analytical methods using atomic spectrometry. Firstly, simultaneous experimental designs were applied to the optimization of two analytical methods, being the first analytical method for the simultaneous determination of macronutrients (Ca, Mg, Na and P), micronutrients (Cu, Fe, Mn and Zn) and trace elements (Al, As, Cd, Pb and V) and other for the simultaneous determination of Th and U in mineral fertilizers, both employing inductively coupled plasma optical emission spectrometry (ICP OES). The results of the analysis of mineral fertilizers showed that the elements regulated by Ministry of Agriculture, Livestock and Food Supply (Ministério da Agricultura, Pecuária e Abastecimento MAPA) were in agreement with the same, and that the high resolution ICP OES allowed to selectivity possible interfering Ca, Fe and Th in the determination of U, indicating that can be performed simultaneous determination of Th and U by technique. In the second part, univariate designs were applied to the optimization of two analytical methods using direct solid sampling (SS) and detection by high resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS), one for the determination of Cu and other for Hg in phosphate fertilizers. The results showed that simple superphosphate and triple superphosphate 2 fertilizers samples obtained concentrations of Hg above the maximum limit established by MAPA, as well showed the highest concentrations of Cu, however this is not regulated. The analytical methods proposed in this work were simple, efficient, fast, accurate and reliable for the determination of macronutrients, micronutrients and trace elements in mineral fertilizers by atomic spectrometry. / Neste trabalho foram aplicados planejamentos de experimentos para a otimização de métodos analíticos utilizando a espectrometria atômica. Primeiramente, foram aplicados planejamentos simultâneos para a otimização de dois métodos analíticos, sendo o primeiro método analítico para a determinação simultânea de macronutrientes (Ca, Mg, Na e P), micronutrientes (Cu, Fe, Mn e Zn) e elementos traço (Al, As, Cd, Pb e V), e outro para a determinação simultânea de Th e U em fertilizantes minerais, ambos empregando espectrometria de emissão óptica com plasma acoplado indutivamente (ICP OES). Os resultados das análises de fertilizantes minerais demonstraram que os elementos regulamentados pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA) estavam de acordo com a mesma, e que a alta resolução do ICP OES permitiu a seletividade dos possíveis interferentes Ca, Fe e Th na determinação do U, indicando que pode ser realizada a determinação simultânea de Th e U pela técnica óptica. Na segunda parte, foram aplicados planejamentos univariados para a otimização de dois métodos analíticos utilizando análise direta de sólidos (SS) e detecção por espectrometria de absorção atômica de alta resolução com fonte contínua e atomização em forno de grafite (HR-CS GF AAS), um para a determinação de Cu e o outro para Hg em fertilizantes fosfatados. Os resultados mostraram que as amostras de fertilizantes superfosfato simples e superfosfato triplo 2 obtiveram concentrações de Hg acima dos limites máximo estabelecidos pelo MAPA, bem como apresentaram as maiores concentrações de Cu, porém este não é regulamentado. Os métodos analíticos propostos neste trabalho foram simples, eficientes, rápidos, exatos e confiáveis para a determinação de macronutrientes, micronutrientes e elementos traço em fertilizantes minerais por espectrometria atômica.
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Inactivation of Microorganisms by PhotocatalysisSontakke Sharad, M January 2012 (has links) (PDF)
Photocatalysis is an advanced oxidation process, which has shown to possess an enhanced capability to remove a wide range of contaminants. It involves the use of a semiconductor photocatalyst and a photon source. Photocatalysis has several advantages such as mild reaction conditions like ambient temperature and pressure, good control over the reaction and faster reaction kinetics. Semiconductor photocatalysts such as TiO2, ZnO, Fe2O3, CdS, ZnS, etc. absorbs light of energy greater than or equal to its band gap and the electron in the valence band gets excited to conduction band leaving behind the hole in valence band. These charge carrier pair results in the formation of various reactive oxygen species such as hydroxyl and superoxide radicals which results in the degradation of chemical contaminants and inactivation of microorganisms.
TiO2 is the most widely used catalyst in photocatalytic studies because of its high photocatalytic activity, non-toxicity and wide availability. Anatase phase TiO2 has been reported to possess higher photocatalytic activity than the rutile phase. Although there are several methods to synthesize TiO2, solution combustion synthesis is a single step process to produce pure anatase phase TiO2. The catalyst produced by this method has been shown to be superior to the commercially available Degussa P-25 catalyst for the degradation of various chemical contaminants. The present investigation focuses on the use of combustion synthesized catalyst for the inactivation of microorganisms. The photocatalytic activity was compared with commercial Degussa P-25 catalyst.
The various aspects of photocatalytic inactivation reactions studied in this dissertation are: i) photocatalytic inactivation of microorganisms in presence of UV light, ii) effect of various parameters on the inactivation, iii) photocatalytic inactivation in presence of visible light, iv) use of immobilized catalyst for the photocatalytic inactivation, v) understanding of mechanism and kinetics of inactivation.
Combustion synthesized TiO2 (CS-TiO2), combustion synthesized 1% Ag substituted TiO2 (Ag/TiO2 (Sub)) and 1% Ag impregnated CS-TiO2 (Ag/TiO2 (Imp)) were used as photocatalysts. The catalysts were characterized by powder XRD, TEM, BET surface area, UV-Vis spectroscopy, TGA and photoluminescence spectroscopy. The photocatalytic inactivation experiments were carried out using E. coli (K-12 MG 1655), a bacterial strain and P. pastoris (X-33), a yeast strain, as model microorganisms.
The results demonstrate higher photocatalytic activity of all the combustion synthesized catalysts than commercial Degussa P-25 catalyst. The optimum catalyst concentration was 0.25 g/L and the maximum inactivation was observed in the presence of Ag/TiO2 (Imp) catalyst. Rapid and complete inactivation of the microorganisms was observed at lower initial cell concentrations. A reduced photocatalytic inactivation was observed in presence of various anions (HCO3¯ , SO4 2¯ , Cl¯ and NO3¯ ) and cations (Na, K, Caand Mg). Even a small addition of H2O2 was observed to improve the photocatalytic inactivation. At higher dosage of H2O2, a 2 min exposure was sufficient to result in a complete inactivation. Changing the initial pH of the solution was observed to have no significant effect on the photocatalytic inactivation.
All the combustion synthesized catalysts showed higher activity as compared to those obtained with commercial Degussa P-25 TiO2 in presence of visible light. The higher photocatalytic activity of combustion synthesized TiO2 can be attributed to the lesser crystallite size, higher surface area, large amount of hydroxyl groups and decreased band-gap energy of the catalyst.
The present study demonstrates the potential use of catalyst immobilized thin films for the photocatalytic inactivation of E. coli in the presence of UV light. The CS-TiO2 catalyst was immobilized on glass substrate by LbL deposition technique. The performance of immobilized CS-TiO2 was compared to commercial Degussa Aeroxide TiO2 P-25 (Aeroxide) catalyst. The effect of various operating parameters like catalyst loading, surface area and number of bilayers on inactivation has been investigated. It was observed that increasing the number of bilayers and the concentration did not influence the inactivation but increased surface area led to an increase in inactivation. It was observed that the catalyst immobilized on glass slides can be used for repeated experimental cycles with the same efficiency. It was observed that the inactivation process can be studied in continuous mode by using catalyst immobilized on glass beads.
The work also focused attention towards understanding the microorganism inactivation mechanism and kinetic aspects. Various microscopy techniques such as optical microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to study the inactivation mechanism. From the images obtained, it was suggested that the inactivation is caused due to rupture of cell wall. The mechanism was also examined by carrying out degradation experiments on cell component such as protein and media component such as dextrose. UV alone was
observed to degrade protein and the presence of catalyst showed no additional effect. On the other hand, dextrose does not respond to photocatalytic degradation even at a lower concentration. The photocatalytic degradation of Orange G dye was reduced by addition of dextrose sugar or protein which shows a possibility of competitive degradation.
The kinetics of inactivation was studied by various models available in literature such as the power-law model, Chick-Watson model, modified Hom model, GInaFIT tool and a Langmuir-Hinshelwood type model. It was observed that power-law based kinetic model showed good agreement with the experimental data. A mechanistic Langmuir-Hinshelwood type model was also observed to model the inactivation reactions with certain assumptions.
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Compressive Sensing: Single Pixel SWIR Imaging of Natural ScenesBrorsson, Andreas January 2018 (has links)
Photos captured in the shortwave infrared (SWIR) spectrum are interesting in military applications because they are independent of what time of day the pic- ture is captured because the sun, moon, stars and night glow illuminate the earth with short-wave infrared radiation constantly. A major problem with today’s SWIR cameras is that they are very expensive to produce and hence not broadly available either within the military or to civilians. Using a relatively new tech- nology called compressive sensing (CS), enables a new type of camera with only a single pixel sensor in the sensor (a SPC). This new type of camera only needs a fraction of measurements relative to the number of pixels to be reconstructed and reduces the cost of a short-wave infrared camera with a factor of 20. The camera uses a micromirror array (DMD) to select which mirrors (pixels) to be measured in the scene, thus creating an underdetermined linear equation system that can be solved using the techniques described in CS to reconstruct the im- age. Given the new technology, it is in the Swedish Defence Research Agency (FOI) interest to evaluate the potential of a single pixel camera. With a SPC ar- chitecture developed by FOI, the goal of this thesis was to develop methods for sampling, reconstructing images and evaluating their quality. This thesis shows that structured random matrices and fast transforms have to be used to enable high resolution images and speed up the process of reconstructing images signifi- cantly. The evaluation of the images could be done with standard measurements associated with camera evaluation and showed that the camera can reproduce high resolution images with relative high image quality in daylight.
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Návrh přední časti trupu letounu TL-4000 a zástavby motoru / Design of fore part of fuselage and engine mounting of TL-4000 aircraftLöffelmann, František January 2014 (has links)
The thesis solves mounting of Continental IO-55ON to four-seat all composite aeroplane. Weight analysis of weights carried by engine mounting was done and loads of mounting and nose gear attached directly to mounting was computed according to CS-23 regulation. Mounting was designed based on affordable information about similar aeroplanes and it was sized due to Nastran/Patran system strength analysis. Further reinforcing of fire wall, engine covers and forms for their manufacture was suggested.
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The perceptual thinking processes of victims of repetitive armed robberies in the workplace : a Rorschach studyE'Silva, Julie D M 02 December 2005 (has links)
The current study describes the impact of trauma on the perceptual thinking processes of participants who have sustained repeated criminal victimisation in South Africa. Fifteen adult males, (mean age 40.73 years) participated voluntarily in this descriptive study. The Rorschach Inkblot Method (RIM) is the psychometric instrument used to describe the participants and Exner’s Comprehensive System (CS) is the method of interpretation employed. The Perceptual Thinking Index (PTI) is the cluster of variables selected to describe each participant’s level of reality testing and perceptual functioning. Together with this, the D and Adjusted D Score variables are discussed to describe the participants’ overall and current coping capacities. From the research findings yielded in this study, it appears that the majority of these participants (73%) can be described as experiencing problems in terms of their perceptual thinking processes. They are also unable to appropriately engage in accurate reality testing. The results of the research study may serve as an incentive for further studies of this nature as according to the RIM, participants with this level of impaired reality testing generally present with psychotic features. However, these research results were found in participants who present with an absence of a psychotic or any schizophrenic type disorder diagnoses. Other researchers who used the RIM to assess trauma victims have found results similar to this. Furthermore, participants who present with this level of impaired reality testing, generally experience severe problems in coping with basic psychological aspects of daily functioning. This however, does not appear to be the case with this sample group, which was one of the motivating factors for conducting this research. A concluding suggestion is made for possible research into investigating how, and at what expense, other psychological features of functioning are employed, in order to manage in a seemingly well-adaptive manner. / Dissertation (MA (Clinical Psychology))--University of Pretoria, 2006. / Psychology / unrestricted
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