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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.
1

Níveis de retinol sérico após consumo de arroz enriquecido com vitamina A - UltraRice

Helena de Castro Chagas, Maria January 2003 (has links)
Made available in DSpace on 2014-06-12T23:04:16Z (GMT). No. of bitstreams: 2 arquivo8930_1.pdf: 299711 bytes, checksum: d9a7d8cb5456a5f22e43060a44c60c44 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2003 / Apesar do tempo transcorrido desde o descobrimento e síntese da vitamina A a carência desta vitamina continua sendo um dos maiores problemas de saúde e nutrição, afetando quase um bilhão de pessoas no mundo, com conseqüências devastadoras dada a ubiqüidade do seu papel no metabolismo intermediário. A carência de vitamina A afeta desde a integridade do sistema imune até as taxas de morbidade e mortalidade infantil. A carência de vitamina A, é considerada a maior causa de cegueira (nutricional) do mundo. O programa para controlar esta carência específica inclui a suplementação periódica com doses maciças de vitamina A, a diversificação dietética e o enriquecimento de alimentos básicos, este último sendo considerado a de maior eficácia e eficiência e a de maior facilidade de operacionalização. O desenvolvimento de uma pré-mistura que incorpora vitamina A a grãos de arroz reconstituídos, misturando com arroz comum, apareceu como uma estratégia de eleição, visto que as áreas onde o problema é prevalente são as mesmas em que o consumo de arroz é suficiente para considerá-lo um alimento vetor perfeitamente adequado. Esta alternativa leva a declinar todos os requisitos necessários para implementação do programa, entre estes, descartar a possibilidade de efeitos indesejáveis e definir quantidades excessivas principalmente entre o grupo de mulheres em idade fértil. Este trabalho mostra que o consumo de 10.000 até 20.000 UI, não provocou elevação dos níveis de retinol circulante acima dos valores normais (homeostáticos), o que faz do arroz uma das melhores opções para garantir o bom estado nutricional de vitamina A em populações
2

Text orienting cues: Enhancing dynamic visual acuity for targets of unknown origin

Shevlin, Joseph P. 27 April 1999 (has links)
Dynamic Visual Acuity (DVA) refers to an observer's ability to resolve a critical detail in a visual target under conditions of relative motion between an observer and a target. DVA research has conventionally used visual targets originating from a single fixation point and moving in a predictable linear path. These procedures (dictated by apparatus constraints), ensured observers knew when and from where targets would appear. Shevlin, Prestrude, and Shevlin (1997) examined DVA using computer-generated targets presented from fixed (left to right) and random (six possible) origins. As hypothesized, random targets were more difficult to resolve than fixed targets. Fixed target data supported the conventional DVA findings - faster targets and targets displayed more briefly were harder to resolve. Random target data contradicted the DVA literature suggesting increased target velocity actually improved DVA (Shevlin et al., 1997). In the current study all targets moved in similar fashion, eliminating type of movement as a confound from the 1997 study. Twenty-eight West Point cadets observed computer DVA targets under each of two viewing conditions. Prior to viewing each target, observers in the "known origin" condition saw text cues revealing the origin of the next target; whereas, observers in the "unknown origin" condition received text notification that a target would appear. As hypothesized, known origin target data supported conventional DVA relationships - faster targets and targets exposed more briefly were more difficult to resolve. As predicted, unknown origin data partially contradicted conventional DVA relationships. At the briefest duration (170 ms), faster targets were easier to resolve than slower targets. Observers in the known origin condition displayed a DVA advantage from the text cues. The patterns of individual differences in the data suggest not all observers benefited from the DVA advantage offered by the text cues. Analysis of target data indicated a slight DVA decrement for left-oriented Landolt C targets. Implications of the computerized DVA testing platform are discussed for future DVA research. / Ph. D.
3

The effects of random linear target direction in a computerized Dynamic Visual Acuity task

Shevlin, Joseph P. 03 March 2009 (has links)
Research on Dynamic Visual Acuity (DVA) to date has conventionally used visual targets originating from a single fixation point and moving in a single, predictable linear direction. These procedures (presumably dictated by apparatus constraints) ensured the observer knew when and from where the target would appear. A computerized test for DVA was developed and used to test DVA under viewing conditions not testable with conventional apparatuses. Two target direction conditions were compared over 3 durations (170, 370, 570 ms) and 5 velocities (0, 22, 45, 70, and 100 deg/s): fixed target direction (target originated from single fixation point, and moved horizontally from the observer’s left to the observer’s right, as has been the convention in DVA research over the past 57 years ) and random target direction (the target emanated randomly from one of six screen locations and move linearly across the screen to a point 180 deg opposite its origin). As hypothesized, the random direction condition, which may more closely represent DVA as applied in the real world, proved to be significantly more difficult relative to the fixed direction condition. Contrary to expectations of the current research as well as the general consensus in the DVA literature, data were also presented indicating that the generally accepted relationship between increased target velocity and increased DVA thresholds, may be in part the consequence of conventional apparatuses and procedures. The effect training was also investigated on under both fixed and random target direction conditions. No significant effect of training was demonstrated over four sessions, which may be a result inadequate sensitivity of the test. Strengths and weaknesses of a computer testing platform to test DVA are discussed. / Master of Science
4

Utilizing Distributed Vibration Absorbers to Reduce Noise Transmission Through the Windshield of a Cessna 150

Nash, Grant 20 August 2004 (has links)
High levels of noise have historically been present in the interior of aircrafts. This causes passenger, pilot, and other aircraft employee fatigue as well as speech interference and discomfort issues. In general aviation aircraft, little has been done to reduce the noise in the interior of fuselages. Noise transmitting into the cabin of a single engine aircraft is complex. Researchers have identified areas of noise transmission in general aviation aircraft to include the windshield, exhaust, side windows, and little through the engine firewall. Sources originally noted that structure-borne and airborne noise transmission paths were equal contributors to interior energy penetration of single-engine aircraft. However, additional studies found that airborne noise transmission paths dominate interior energy transmission for single-engine aircraft. Energy transmits mostly through the front of the aircraft via the windshield. Little goes through the engine firewall, which contradicts the original assumption that engine vibration contributed to large noise transmission into the cabin of the aircraft via the firewall. Airborne noise and some exhaust noise transmit through the firewall, but not near as much as noise that transmits through the windshield. Reducing interior aircraft noise levels is a complicated joint effort, combining propeller radiation control; fuselage wall reduction methods; exhaust emission regulation, management of air turbulence; some propeller, wake-induced vibration control; and a little engine vibration restraint. For minimum propeller acoustic propagation, it is important to control propeller radiation by using techniques such as increasing the number of blades, altering blade airfoil (especially using a felix or grooved design); applying small angle of attack; utilizing swept blades; decreasing blade diameter; lowering tip speed; and reducing the load on a propeller (i.e. by controlling the blade thickness, tip volume, and blade shape). Controlling the vibration in the fuselage skin can also help to reduce interior noise. Some early attempts were made using ribs/stiffeners, tuned dampers, and a limp mass double wall. More recently, dynamic vibration absorbers have been utilized, quite successfully, to reduce fuselage skin vibration and thus, interior noise levels. Attempting to control the exhaust emission and induced vibration from air turbulence has contributed to lower airplane cabin noise levels as well. For large aircrafts, the strategic location of luggage compartments and bathrooms help in keeping the interior quiet. Most importantly for small single-engine aircraft, the windshield has been found to contribute heavily to aircraft interior noise levels. Currently, the use of active control methods (especially the active structural acoustic control methods) and the utilization of dynamic vibration absorbers (a form of passive noise control) are the most popular techniques to reduce interior aircraft noise levels. In small general aviation aircraft, the blade passage frequency (bpf) and the first few harmonics have been found to be the largest contributor to noise transmitting into the fuselage. This project analyzes a two degree-of-freedom (DOF) dynamic vibration absorber in hopes of reducing windshield vibration of a Cessna 150 fuselage at the fundamental blade passage frequency of approximately 87 Hz and thus, reducing noise transmitting into the interior of the aircraft. This research project is unique in several ways. First, numerous passive noise control techniques have been utilized to control vibration and acoustics on an aircraft, but none have used the two degree of freedom Distributed Vibration Absorbers (DVA) employed in this project, as a noise reduction method on the windshield of an aircraft. Secondly, little research has been done on analyzing noise transmission into small, single engine general aviation aircraft, which is conducted in the work here. Third, little work has been done on analyzing and reducing noise propagation through the windshield of a small engine aircraft, which is also analyzed in this project. Finally, the modal analysis conducted on the windshield of the small engine plane is one of the few modal decompositions that has been conducted on a small general aircraft windshield. / Master of Science
5

Manejo sanitário de aviário de pequeno porte de frangos de corte e sua relação com a presença de Salmonella spp / Sanitary management of small broiler house and the presence of Salmonella spp

Lima, Larissa de Assis 11 July 2018 (has links)
Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-09-27T12:09:55Z No. of bitstreams: 2 Dissertação - Larissa de Assis Lima - 2018.pdf: 3058046 bytes, checksum: a5b939547ee386a987c881d0c897ef1c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-09-27T12:09:55Z (GMT). No. of bitstreams: 2 Dissertação - Larissa de Assis Lima - 2018.pdf: 3058046 bytes, checksum: a5b939547ee386a987c881d0c897ef1c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-07-11 / Item withdrawn by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-10-01T11:33:22Z Item was in collections: Mestrado em Biociência Animal (RJ) (ID: 126) No. of bitstreams: 2 Dissertação - Larissa de Assis Lima - 2018.pdf: 3058046 bytes, checksum: a5b939547ee386a987c881d0c897ef1c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Item reinstated by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-10-01T11:35:58Z Item was in collections: Mestrado em Biociência Animal (RJ) (ID: 126) No. of bitstreams: 2 Dissertação - Larissa de Assis Lima - 2018.pdf: 3058046 bytes, checksum: a5b939547ee386a987c881d0c897ef1c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Foodborne Diseases (FVB) are public health problem with Salmonella spp., one of the main pathogens in poultry industry. The objective was to evaluate the sanitary management of a small aviary in Jataí-GO and its relation with the presence of Salmonella spp. The establishment was characterized as family run poultry businesses with small scale production and female management. In two plots were collected for microbiological analysis environmental samples at the entrance (D0); at 28° (D28) and at 60° (D60) days; carcasses, evisceration gutter and defeathering machine. The pH and chlorine of the water were also analyzed; ambient temperatures and carcasses were measured and a good production practices monitoring form was carried out. Data analysis was descriptive considering current legislation. There was absence of Salmonella spp. in all samples (bottoms of the chicks' transport boxes; residues of egg shells from the boxes; starter grower and fattening feed; and disposable overshoes of chicks reception sheds, feeders and drinking fountains, screens, area outside the shed and compost house) and adequate values of pH, chlorine and temperature. These results showed that implementation and rigor in the monitoring of the standards present in Good Manufacturing Practices (GMP) and Standard Operating Procedures in the process of creation and processing of chicken meat, besides controlling the propagation of this pathogen in the plants and in the carcasses, ensured a final quality product to the consumer. / As Doenças Veiculadas por Alimentos (DVA) são uma problemática de saúde pública, sendo a Salmonella spp. um dos principais patógenos na avicultura. Objetivou-se avaliar o manejo sanitário de um aviário de pequeno porte em Jataí-GO e sua relação com a presença de Salmonella spp. O estabelecimento era caracterizado como agricultura familiar com produção em pequena escala e gestão feminina. Em dois lotes foram coletas amostras para análises microbiológicas do ambiente na entrada (D0), no 28º (D28) e no 60º (D60) dia; das carcaças, da bancada de evisceração e da depenadeira. Também foram aferidos o pH e o cloro da água; aferido as temperaturas do ambiente e das carcaças e realizado formulário de acompanhamento das boas práticas de produção. A análise dos dados foi descritiva considerando a legislação vigente. Verificou-se ausência de Salmonella spp. em todas as amostras (fundos das caixas de transporte dos pintinhos; resíduos das cascas de ovos das caixas; rações das fases inicial e engorda; própés da cama do galpão de recepção dos pintinhos, comedouros e bebedouros, paredes e telas, área externa ao galpão e composteira; e carcaças) e valores adequados de pH, cloro e temperatura. Desta forma, a implementação e o rigor no monitoramento dos padrões presentes nos programas de Boas Práticas de Fabricação (BPF) e Procedimentos Padrão de Higiene Operacional (PPHO) no processo de criação e processamento da carne de frango, além de controlar a propagação desse patógeno nos plantéis e nas carcaças, asseguraram um produto final de qualidade ao consumidor
6

Gestão de risco de crédito de contraparte: DVA e os desafios de implementação

Marussig, Fabio 18 May 2015 (has links)
Submitted by FABIO MARUSSIG (fabio.marussig@gmail.com) on 2016-08-28T15:55:18Z No. of bitstreams: 3 Gestão de Risco de Crédito de Contraparte_Fabio Marussig_Rev_II.pdf: 347700 bytes, checksum: 79c44c5dbbe19eed747d9a5ddf1f4a65 (MD5) Ficha_Assinatura.pdf: 145045 bytes, checksum: e6e5b09ebe1ecda5a5becb9beb76ce3d (MD5) EPGE Ficha catalográfica.pdf: 23666 bytes, checksum: c6c687585c17e7cf4f6e3ed966ef6011 (MD5) / Approved for entry into archive by Maria Almeida (maria.socorro@fgv.br) on 2016-08-30T17:32:00Z (GMT) No. of bitstreams: 3 Gestão de Risco de Crédito de Contraparte_Fabio Marussig_Rev_II.pdf: 347700 bytes, checksum: 79c44c5dbbe19eed747d9a5ddf1f4a65 (MD5) Ficha_Assinatura.pdf: 145045 bytes, checksum: e6e5b09ebe1ecda5a5becb9beb76ce3d (MD5) EPGE Ficha catalográfica.pdf: 23666 bytes, checksum: c6c687585c17e7cf4f6e3ed966ef6011 (MD5) / Approved for entry into archive by Maria Almeida (maria.socorro@fgv.br) on 2016-08-30T17:32:35Z (GMT) No. of bitstreams: 3 Gestão de Risco de Crédito de Contraparte_Fabio Marussig_Rev_II.pdf: 347700 bytes, checksum: 79c44c5dbbe19eed747d9a5ddf1f4a65 (MD5) Ficha_Assinatura.pdf: 145045 bytes, checksum: e6e5b09ebe1ecda5a5becb9beb76ce3d (MD5) EPGE Ficha catalográfica.pdf: 23666 bytes, checksum: c6c687585c17e7cf4f6e3ed966ef6011 (MD5) / Made available in DSpace on 2016-08-30T17:33:28Z (GMT). No. of bitstreams: 3 Gestão de Risco de Crédito de Contraparte_Fabio Marussig_Rev_II.pdf: 347700 bytes, checksum: 79c44c5dbbe19eed747d9a5ddf1f4a65 (MD5) Ficha_Assinatura.pdf: 145045 bytes, checksum: e6e5b09ebe1ecda5a5becb9beb76ce3d (MD5) EPGE Ficha catalográfica.pdf: 23666 bytes, checksum: c6c687585c17e7cf4f6e3ed966ef6011 (MD5) Previous issue date: 2015-05-18 / Este trabalho tem como objetivo expor os desafios a serem enfrentados pelas instituições participantes do mercado de derivativos no que diz respeito à gestão de risco de crédito de contraparte, levando em consideração o aumento no volume de operações de derivativos nos últimos anos, bem como a sofisticação destas e o enquadramento às novas regulamentações como Basiléia III e IFRS 13.
7

Vícestupňové čerpadlo s protiběžnými koly / Multistage pump with counter - rotating runners

Müller, Patrik January 2017 (has links)
The main objective of this thesis is to design blades for the axial pump with two counter-rotating rotors for design point. Then compare results with the standard concept with one runner and guide blades.
8

Heuristiky a zkreslení: Model intuitivního usuzování / Heuristics and biases: A model of intuitive judgement

Bahník, Štěpán January 2011 (has links)
The present work describes the model of heuristic judgment of Kahneman & Frederick (2002) and two experiments based upon it. According to the model people answer a question with an answer to an easier question when making a heuristic judgment. This process is called the attribute substitution because a target attribute of a question is substituted by an associated and easier accessible heuristic attribute. The first experiment investigated whether two heuristic attributes can be used simultaneously during making of a judgment. A part of participants gave 1 or 4 reasons for one of the statements in Linda problem (Tversky & Kahneman, 1983). Numbers of reasons were selected so as to produce a feeling of fluency of disfluency. Although the conjunction fallacy occurred, the writing of the reasons didn't have any influence on the assessment of the probability of the related statement. The second experiment investigated whether the priming of the relation between processing fluency and risk can influence the effect of pronounceability of a food additive name on the assessment of its harmfulness. In accord with previous study (Song & Schwarz, 2009) it was shown that food additives with less pronounceable names were considered as more harmful. The priming didn't have any effect. The present studies...
9

Default contagion modelling and counterparty credit risk

Li, Wang January 2017 (has links)
This thesis introduces models for pricing credit default swaps (CDS) and evaluating the counterparty risk when buying a CDS in the over-the-counter (OTC) market from a counterpart subjected to default risk. Rather than assuming that the default of the referencing firm of the CDS is independent of the trading parties in the CDS, this thesis proposes models that capture the default correlation amongst the three parties involved in the trade, namely the referencing firm, the buyer and the seller. We investigate how the counterparty risk that CDS buyers face can be affected by default correlation and how their balance sheet could be influenced by the changes in counterparty risk. The correlation of corporate default events has been frequently observed in credit markets due to the close business relationships of certain firms in the economy. One of the many mathematical approaches to model that correlation is default contagion. We propose an innovative model of default contagion which provides more flexibility by allowing the affected firm to recover from a default contagion event. We give a detailed derivation of the partial differential equations (PDE) for valuing both the CDS and the credit value adjustment (CVA). Numerical techniques are exploited to solve these PDEs. We compare our model against other models from the literature when measuring the CVA of an OTC CDS when the default risk of the referencing firm and the CDS seller is correlated. Further, the model is extended to incorporate economy-wide events that will damage all firms' credit at the same time-this is another kind of default correlation. Advanced numerical techniques are proposed to solve the resulting partial-integro differential equations (PIDE). We focus on investigating the different role of default contagion and economy-wide events have in terms of shaping the default correlation and counterparty risk. We complete the study by extending the model to include bilateral counterparty risk, which considers the default of the buyer and the correlation among the three parties. Again, our extension leads to a higher-dimensional problem that we must tackle with hybrid numerical schemes. The CVA and debit value adjustment (DVA) are analysed in detail and we are able to value the profit and loss to the investor's balance sheet due to CVA and DVA profit and loss under different market circumstances including default contagion.
10

Reliability and Normative Data for the Dynamic Visual Acuity Test for Vestibular Screening

Riska, Kristal M., Hall, Courtney D. 01 June 2016 (has links)
Hypothesis: The purpose of this study was to determine reliability of computerized dynamic visual acuity (DVA) testing and to determine reference values for younger and older adults. Background: A primary function of the vestibular system is to maintain gaze stability during head motion. The DVA test quantifies gaze stabilization with the head moving versus stationary. Commercially available computerized systems allow clinicians to incorporate DVA into their assessment; however, information regarding reliability and normative values of these systems is sparse. Methods: Forty-six healthy adults, grouped by age, with normal vestibular function were recruited. Each participant completed computerized DVA testing including static visual acuity, minimum perception time, and DVA using the NeuroCom inVision System. Testing was performed by two examiners in the same session and then repeated at a follow-up session 3 to 14 days later. Intraclass correlation coefficients (ICCs) were used to determine inter-rater and test–retest reliability. Results: ICCs for inter-rater reliability ranged from 0.323 to 0.937 and from 0.434 to 0.909 for horizontal and vertical head movements, respectively. ICCs for test–retest reliability ranged from 0.154 to 0.856 and from 0.377 to 0.9062 for horizontal and vertical head movements, respectively. Overall, raw scores (left/right DVA and up/down DVA) were more reliable than DVA loss scores. Conclusion: Reliability of a commercially available DVA system has poor-to-fair reliability for DVA loss scores. The use of a convergence paradigm and not incorporating the forced choice paradigm may contribute to poor reliability.

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