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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.
11

<b>UNVEILING THE EFFECTS OF DIETARY MODULATIONS ON AVIAN COCCIDIOSIS: INSIGHTS INTO GUT HEALTH AND GROWTH DYNAMICS</b>

Jing Yuan (18625108) 28 May 2024 (has links)
<p dir="ltr">For this dissertation, two experiments were conducted to evaluate the effects of a multienzyme mix and partially defatted black soldier fly larvae meal on chicken coccidiosis, focusing on growth performance, intestinal health, and microbiota dynamics. Experiment 1 examined the growth performance, nutrient utilization, microbiota modulations, and other gut health-related indicators of broiler chickens under coccidia challenge, with dietary supplementation of multienzyme, including phytase, xylanase, β-glucanase, amylase, hemicellulase, and pectinase. Ross 308 broilers were assigned to 4 treatments in a 2×2 factorial arrangement comprising of 0 or 50 g·kg-1 multienzyme and oral challenge with PBS or mixed Eimeria spp. oocysts (250,000 E. acervulina, 50,000 E. maxima, and 50,000 E. tenella). Multienzyme reduced (P < 0.05) Eimeria-induced loss in feed efficiency and nutrient utilization, partially explained by reduced decrease of b0,+ amino acid transporter in jejunum. Multienzyme suppressed (P < 0.05) the overexpression of interleukin-8 in the duodenum and jejunum and ameliorated (P = 0.05) the decreased expression of antioxidant heme oxygenase 1 in ileum induced by Eimeria infections. Multienzyme facilitated (P < 0.01) the bloom of short-chain fatty acid-producing and fiber-degrading microbes. The study concluded that multienzyme supplementation partially alleviated the adverse effects of Eimeria infections through various mechanisms, including enhanced nutrient utilization, reduced local inflammations, and restoration of microbial homeostasis. Experiment 2 investigated the growth dynamics, nutrient assimilation, and gut health responses of broiler chickens under coccidia challenge, with dietary supplementation of partially defatted black soldier fly larvae meal (pBSFLM) with increasing concentrations of 0, 60, 120 g/kg. During the infection phase (from d 13 to 19), interactions between Eimeria and pBSFLM revealed significant associations with gain to feed ratio (G:F) (P < 0.05) and cecal interferon-γ (IFN-γ, P < 0.05), while showing tendencies for crypt depth (P = 0.088) and cecal acetate concentration (P = 0.06). The incremental inclusion of pBSFLM demonstrated a negative effect on the G:F and the generation of IFN-γ and acetate in the ceca during coccidia challenge. Conversely in the non-challenged birds, the impact of dietary pBSFLM varied from neutral (e.g. G:F) to potentially advantageous (e.g. acetate). Challenged broilers exhibited decreased (P < 0.01) BW, feed intake (FI), G:F, as well as the apparent ileal digestibility (AID) and total tract nutrient utilization (ATTU) of DM, gross energy (GE), and nitrogen (N). Eimeria challenge led to reduced (P < 0.01) serum carotenoid concentrations, increased (P < 0.01) ileal crypt depth (CD), and an increase in the generation of branched-chain fatty acids, specifically isobutyrate (P = 0.059) and isovalerate (P < 0.05) in the ceca. Dietary pBSFLM addition caused a linear reduction (P < 0.05) in BW, FI, G:F, and N utilization. Furthermore, a tendency (P < 0.06) was observed where pBSFLM linearly decreased the villi height: CD ratio and reduced goblet cell density in the villi. Results from this experiment reveal that higher levels of pBSFLM supplementation, especially at 12%, had detrimental effects on growth, ileal morphology, cecal acetate production, and downregulated the expression of key cytokines in response to coccidia infection. In summary, these studies shed light on the multifaceted effects of dietary interventions on Eimeria infections in broiler chickens, with a specific emphasis on growth, nutrient utilization, and indicators of gut health.</p>
12

Mobile Network Traffic Modeling A Thesis Submitted To The Graduate School Of Natural And Applied Sciences Of Middle East Technical University By Yadigar Cakmak In Partial Fulfillment Of The Requirements For The Degree Of Master Of Science In El

Cakmak, Yadigar 01 January 2005 (has links) (PDF)
The aim of this thesis is to investigate the traffic patterns in the mobile data networks. In this work, a simple Cellular Digital Packet Data (CDPD) network was modeled in order to be used in simulations. For the purpose of using in the CDPD model, a synthetic bursty traffic model was produced and using different traffic patterns some performance investigations were made in CDPD network. During the whole work, OPNET simulation tool was used. The CDPD network modeled by OPNET simulation tool was compared with a CDPD model described in the literature and the differences were shown. The new model has some new features: 1) Burst transmission of MAC blocks. 2) Exponential backoff. 3) New packet structures. 4) Frame segmentation and encapsulation into MAC layer frames. Using OPNET, a traffic having higher level of burstiness was produced and applied to the CDPD network model. Under the bursty traffic, some CDPD performance parameters were collected and according to the collected results some suggestions were given.
13

Quantification of Solar Photovoltaic Encapsulant Browning Level Using Image Processing Tool

January 2016 (has links)
abstract: In recent years, solar photovoltaic (PV) industry has seen lots of improvements in technology and of growth in market with crystalline silicon PV modules being the most widely used technology. Plant inspections are gaining much importance to identify and quantitatively determine the impacts of various visual defects on performance. There are about 86 different types of defects found in the PV modules installed in various climates and most of them can be visually observed. However, a quantitative determination of impact or risk of each of identified defect on performance is challenging. Thus, it is utmost important to quantify the risk for each of the visual defects without any human subjectivity. The best way to quantify the risk of each defect is to perform current-voltage measurements of the defective modules installed in the plant but it requires disruption of plant operation, expensive measuring equipment and intensive human resources. One of the most riskiest and dominant visual defects is encapsulant browning which affects the PV module performance in the form of current degradation. The present study deals with developing an automated image processing tool which can address the issues of human subjectivity on browning level impacting performance. The image processing tool developed in this work can be directly used to quantify the impact of browning on performance without intrusively disconnecting the modules from the plant. In this work, the quantified browning level impact on performance has also been experimentally validated through a correlation study using short-circuit current and reflectance/transmittance measurements of browned PV modules retrieved from aged plants/systems installed in diverse climatic conditions. The primary goal of the image processing tool developed in this work is to determine the performance impact of encapsulant browning without interrupting the plant operation for I-V measurements. The use of image processing tool provides a single numerical value, called browning index (BI), which can accurately quantify browning levels on modules and also correlate with the performance and reflectance/transmittance parameters of the modules. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2016
14

Způsoby definování požadavků pro výkonnostní testování softwaru / Ways of defining the requirements for performance testing software

Vodrážka, Michal January 2015 (has links)
This thesis is focused on ways of defining the requirements for performance testing software, both in practice (based on survey) as well as in theory. The aim of this thesis is to analyze ways of defining performance requirements, which are actually used on IT projects. In order to achieve this goal it is necessary to define concepts of performance testing, implement and evaluate the survey of the using ways of defining performance requirements in practice and then analyze ways of defining performance requirements in terms of their applicability to different types of IT projects. The contribution of this thesis is the comprehensive introduction performance testing software issues and mainly insight into ways of defining performance requirements used in practice and problems associated with them, through the survey, which was implemented and evaluated by myself. The conclusions resulting from this survey summarize which ways of defining performance requirements are applied to specific types of IT projects, which of these ways worked and which problems in certain cases that occur in practice. The thesis is divided into theoretical and practical part. The theoretical part explains the basic concepts associated with performance testing software. In this part, there is also described the methodology of defining performance requirements according to Tom Gilb. The practical part is focused on the realization and evaluation of survey of the using ways of defining performance requirements in practice and on the analysis ways of defining performance requirements with respect to certain types of projects.
15

Metody měření výkonnostních a kvalitativních parametrů datových sítí / Methods for measurement of data network performance and quality parameters

Sukup, Luboš January 2012 (has links)
Master thesis involves the development of quality measurement issues and performance parameters in data networks. It describes the main technologies as they affect the quality and performance parameters and the effect of these parameters for voice, video and data services. Next are listed some methods for measuring parameters of the data network.In the practical part is selected one method of measuring network parameters and properties of this method are demonstrated by illustrative examples.
16

Metody měření výkonnostních a kvalitativních parametrů datových sítí / Methods for measurement of data network performance and quality parameters

Sukup, Luboš January 2013 (has links)
Master thesis involves the development of quality measurement issues and performance parameters in data networks. It describes the main technologies as they affect the quality and performance parameters and the effect of these parameters for voice, video and data services. Next are listed some methods for measuring parameters of the data network.In the practical part is selected one method of measuring network parameters and properties of this method are demonstrated by illustrative examples.
17

Analyse et amélioration de la qualité de services WEB multimédia et leurs mises en oeuvre sur ordinateur et sur FPGA

Al-Canaan, Amer January 2014 (has links)
Résumé : Les services Web, issus de l’avancée technologique dans le domaine des réseaux informatiques et des dispositifs de télécommunications portables et fixes, occupent une place primordiale dans la vie quotidienne des gens. La demande croissante sur des services Web multimédia (SWM), en particulier, augmente la charge sur les réseaux d’Internet, les fournisseurs de services et les serveurs Web. Cette charge est essentiellement due au fait que les SWM de haute qualité nécessitent des débits de transfert et des tailles de paquets importants. La qualité de service (par définition, telle que vue par l’utilisateur) est influencée par plusieurs facteurs de performance, comme le temps de traitement, le délai de propagation, le temps de réponse, la résolution d’images et l’efficacité de compression. Le travail décrit dans cette thèse est motivé par la demande continuellement croissante de nouveaux SWM et le besoin de maintenir et d’améliorer la qualité de ces services. Nous nous intéressons tout d’abord à la qualité de services (QdS) des SWM lorsqu’ils sont mis en œuvre sur des ordinateurs, tels que les ordinateurs de bureau ou les portables. Nous commençons par étudier les aspects de compatibilité afin d’obtenir des SWM fonctionnant de manière satisfaisante sur différentes plate-formes. Nous étudions ensuite la QdS des SWM lorsqu’ils sont mis en œuvre selon deux approches différentes, soit le protocole SOAP et le style RESTful. Nous étudions plus particulièrement le taux de compression qui est un des facteurs influençant la QdS. Après avoir considéré sous différents angles les SWM avec mise en œuvre sur des ordinateurs, nous nous intéressons à la QdS des SWM lorsqu’ils sont mis en œuvre sur FPGA. Nous effectuons alors une étude et une mise en œuvre qui permet d’identifier les avantages à mettre en œuvre des SWM sur FPGA. Les contributions se définissent en cinq volets comme suit : 1. Nous introduisons des méthodes de création, c’est-à-dire conception et mise en œuvre, de SWM sur des plate-formes logicielles hétérogènes dans différents environnements tels que Windows, OS X et Solaris. Un objectif que nous visons est de proposer une approche permettant d’ajouter de nouveaux SWM tout en garantissant la compatibilité entre les plate-formes, dans le sens où nous identifions les options nous permettant d’offrir un ensemble riche et varié de SWM pouvant fonctionner sur les différentes plate-formes. 2. Nous identifions une liste de paramètres pertinents influençant la QdS des SWM mis en œuvre selon le protocole SOAP et selon le style REST. 3. Nous développons un environnement d’analyse pour quantifier les impacts de chaque paramètre identifié sur la QdS de SWM. Pour cela, nous considérons les SWM mis en œuvre selon le protocole SOAP et aussi selon style REST. Les QdS obtenues avec SOAP et REST sont comparées objectivement. Pour faciliter la comparaison, la même gamme d’images (dans l’analyse de SWM SOAP) a été réutilisée et les mêmes plate-formes logicielles. 4. Nous développons une procédure d’analyse qui permet de déterminer une corrélation entre la dimension d’une image et le taux de compression adéquat. Les résultats obtenus confirment cette contribution propre à cette thèse qui confirme que le taux de compression peut être optimisé lorsque les dimensions de l’image ont la propriété suivante : le rapport entre la longueur et la largeur est égal au nombre d’or connu dans la nature. Trois libraires ont été utilisées à savoir JPEG, JPEG2000 et DjVu. 5. Dans un volet complémentaire aux quatre volets précédents, qui concernent les SWM sur ordinateurs, nous étudions ainsi la conception et la mise en œuvre de SWM sur FPGA. Nous justifions l’option de FPGA en identifiant ses avantages par rapport à deux autres options : ordinateurs et ASICs. Afin de confirmer plusieurs avantages identifiés, un SWM de QdS élevée et de haute performance est créé sur FPGA, en utilisant des outils de conception gratuits, du code ouvert (open-source) et une méthode fondée uniquement sur HDL. Notre approche facilitera l’ajout d’autres modules de gestions et d’orchestration de SWM. 6. La mise à jour et l’adaptation du code open-source et de la documentation du module Ethernet IP Core pour la communication entre le FPGA et le port Ethernet sur la carte Nexys3. Ceci a pour effet de faciliter la mise en œuvre de SWM sur la carte Nexys3. // Abstract : Web services, which are the outcome of the technological advancements in IT networks and hand-held mobile devices for telecommunications, occupy an important role in our daily life. The increasing demand on multimedia Web services (MWS), in particular, augments the load on the Internet, on service providers and Web servers. This load is mainly due to the fact that the high-quality multimedia Web services necessitate high data transfer rates and considerable payload sizes. The quality of service (QoS, by definition as it is perceived by the user) is influenced by several factors, such as processing time, propagation delay, response time, image resolution and compression efficacy. The research work in this thesis is motivated by the persistent demand on new MWS, and the need to maintain and improve the QoS. Firstly, we focus on the QoS of MWS when they are implemented on desktop and laptop computers. We start with studying the compatibility aspects in order to obtain MWS functioning satisfactorily on different platforms. Secondly, we study the QoS for MWS implemented according to the SOAP protocol and the RESTful style. In particular, we study the compression rate, which is one of the pertinent factors influencing the QoS. Thirdly, after the study of MWS when implemented on computers, we proceed with the study of QoS of MWS when implemented on hardware, in particular on FPGAs. We achieved thus comprehensive study and implementations that show and compare the advantages of MWS on FPGAs. The contributions of this thesis can be resumed as follows: 1. We introduce methods of design and implementation of MWS on heterogeneous platforms, such as Windows, OS X and Solaris. One of our objectives is to propose an approach that facilitates the integration of new MWS while assuring the compatibility amongst involved platforms. This means that we identify the options that enable offering a set of rich and various MWS that can run on different platforms. 2. We determine a list of relevant parameters that influence the QoS of MWS. 3. We build an analysis environment that quantifies the impact of each parameter on the QoS of MWS implemented on both SOAP protocol and RESTful style. Both QoS for SOAP and REST are objectively compared. The analysis has been held on a large scale of different images, which produces a realistic point of view describing the behaviour of real MWS. 4. We develop an analysis procedure to determine the correlation between the aspect ratio of an image and its compression ratio. Our results confirm that the compression ratio can be improved and optimised when the aspect ratio of iiiiv an image is close to the golden ratio, which exists in nature. Three libraries of compression schemes have been used, namely: JPEG, JPEG2000 and DjVu. 5. Complementary to the four contributions mentioned above, which concern the MWS on computers, we study also the design and implementation of MWS on FPGA. This is justified by the numerous advantages that are offered by FPGAs, compared to the other technologies such as computers and ASICs. In order to highlight the advantages of implementing MWS on FPGA, we developed on FPGA a MWS of high performance and high level of QoS. To achieve our goal, we utilised freely available design utilities, open-source code and a method based only on HDL. This approach is adequate for future extensions and add-on modules for MWS orchestration.
18

Estudo dos parâmetros de emissão laser de vidros fosfatos dopados com nanocristais de ZnTe e co-dopados com íons de Yb3+

Freitas, Alysson Miranda de 30 March 2015 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-09T11:42:53Z No. of bitstreams: 1 alyssonmirandadefreitas.pdf: 61947422 bytes, checksum: fabd334a3f9ff790ff3a3b4c6d2016d5 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-06-26T19:59:08Z (GMT) No. of bitstreams: 1 alyssonmirandadefreitas.pdf: 61947422 bytes, checksum: fabd334a3f9ff790ff3a3b4c6d2016d5 (MD5) / Made available in DSpace on 2017-06-26T19:59:08Z (GMT). No. of bitstreams: 1 alyssonmirandadefreitas.pdf: 61947422 bytes, checksum: fabd334a3f9ff790ff3a3b4c6d2016d5 (MD5) Previous issue date: 2015-03-30 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho, propomos uma nova matriz vítrea, denominada de PZABP, de composição nominal 60P205 . 15ZnO . 5A/203 . 10Ba0 . 10Pb0, em mol %, nanoestruturada com nanocristais de ZnTe e dopada com íons de Yb3+ e avaliamos a viabilidade de utilização deste material para aplicações em dispositivos fotônicos, tais como, lasers de alta potência, fibras ópticas lasers, lasers de pulsos ultra-curtos e lasers sintonizáveis na região do infravermelho. As amostras foram produzidas através do método de fusão-resfriamento, sendo confeccionado dois conjuntos. Um deles, PZABP + xYb, foi dopado apenas com íons de Yb3+ em concentrações que variam de 0% a 10%, em wt%, com acréscimos de 1%. Outro conjunto, PZABP + 1ZnTe + xYb, foi dopado com 1% de nanocristais semicondutores de ZnTe e íons de Yb3+ em concentrações que variam de 0% a 5%, em wt%. As propriedades ópticas das amostras e as interações entre os íons de Yb3+ vizinhos e entre os nanocristais de ZnTe e os íons Yb3+ foram estudadas através das técnicas de Absorção Óptica, Fotoluminescência e Fotoluminescência Resolvida no Tempo. A Espectroscopia de Lente Térmica e a técnica de Capacidade Térmica Volumétrica, também conhecida como pc, foram utilizadas para caracterizar as propriedades térmicas das amostras. Alguns dos principais parâmetros que analisam o desempenho e o limiar de ação laser do material foram estimados a partir da determinação das seções de choque de absorção e emissão dos íons de Yb3+ quando inseridos nessa matriz. De forma geral, a matriz vítrea PZABP demonstrou-se um excelente material hospedeiro para os íons de Yb3+ por apresentar uma ampla janela óptica, ser tolerante a altas concentrações de dopantes e não formar aglomerados de íons de Yb3+, garantindo assim uma boa qualidade óptica para aplicações em fotônica. Parâmetros importantes como o tempo de vida e a eficiência quântica do material apresentaram valores comparáveis aos encontrados na literatura. Foi verificado que a presença dos nanocristais de ZnTe intensificou a emissão dos íons de Yb3+, indicando que houve transferência de energia entre os nanocristais e os íons. Com relação a análise térmica, foram encontrados valores desejáveis para aplicações que envolvem ambientes superaquecidos. A alta difusividade e condutividade térmica das amostras as permitem dissipar calor rapidamente e a baixa variação do caminho óptico com a temperatura (ds/dT) indica que o feixe não sofre desvios muito acentuados no interior da cavidade óptica. Os parâmetros de emissão laser encontrados estão comparáveis aos de outras matrizes vítreas já estudadas, embora a presença dos nanocristais de ZnTe pareça prejudicar esses parâmetros. Portanto, de acordo com os resultados encontrados e com base nas possíveis melhoras que podem ser realizadas, concluímos que a matriz vítrea PZABP nanoestruturada com nanocristais semicondutores de ZnTe e dopada com íons de Yb3+ é um material viável para aplicações em dispositivos fotônicos de alta potência. / In this work, we have proposed a new glass matrix, called PZABP, with nominal composition 60P205 . 15ZnO . 5A/203 . 10Ba0 . 10Pb0, in mol %, nanostructured with ZnTe semiconductor nanocrystals and doped with Yb3+ ions, then, we analized its availability to photonics devices application like high power lasers, optical fiber lasers, ultra-short pulses lasers and tunable lasers in the infrared region. The samples were produced by fusion method, being made two sets. One, PZABP + xYb, was doped with Yb3+ ions at various concentrations from 0% to 10%, in wt%.The other one, PZABP + 1ZnTe + xYb, was doped with semiconductors nanocrystals of ZnTe and Yb3+ ions at concentrations from 0% to 5%, in wt%. The optical properties of the samples and the interactions between neighbors Yb3+ ions and between semiconductors nanocrystals of ZnTe and Yb3+ ions were studied by Optical Absorption, Photoluminescence and Time Resolved Photoluminescence techniques. Thermal Lens Spectroscopy and Heat Volumetric Capacity, also know as pc, were used to characterize the thermal properties of the samples. The main parameters that avail the performance laser and the threshold action laser were estimated by the determination of absorption and emission cross section of the Yb3+ ions when they are inserted in this matrix. The PZABP glass matrix showed to be an excellent host material to Yb3+ ions because it present a large optical window, it is tolerant to high dopants concentration and not showed Yb3+ clusters. Important parameters like lifetime and quantum efficience showed values comparable to others found in the literature. It was verified that the presence of ZnTe nanocrystals had enhanced the emission of the Yb3+ ions, indicating that have occurred energy transfer between ZnTe nanocrystals and Yb3+ ions. Thermal properties have presented interesting values to applications that involved superheated environment. The high thermal diffusivity and high thermal conductivity allow the sample to dissipate the heat quickly. The low variation of the optical path with the temperature (ds/dT) indicate that the laser beam not strongly deviates into the optical cavity. The laser performance parameters obtained are comparable to the other glass matrix found in the literature, although the presence of the ZnTe nanocrystals seems to prejudice these parameters. According with the results found and the improvement that could be done, we have conclude that the glass matrix PZABP nanostructured with semiconductores nanocrystals of ZnTe and doped with Yb3+ ions is a viable material to application in high power photonics devices materials.

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