The digenetic trematode, Bolbophorus damnificus, poses a substantial threat to catfish aquaculture, causing significant economic losses. Infestations lead to suppressed feed consumption, secondary bacterial infections and poor production performance. Survey data reveals widespread infestation in the in the southeastern United States. Current control strategies involve the application of a concentrated copper sulfate solution to reduce snail populations which serve as the first intermediate host of the trematode life cycle. This study aimed to improve treatment efficacy by developing a granular copper sulfate application system. A modified Gandy fertilizer applicator, equipped with a programmable control system, demonstrated accurate distribution of copper sulfate crystals along pond margins at various speeds. Granular copper sulfate was effective in killing snails along the pond margins at treatment rates between 1-3 ppm. The innovative system offers a practical, single-pass solution to combat trematode infestations in catfish ponds and minimizes logistical challenges associated with multiple applications.

Dissertation submitted to the Faculty of Science, University of the Witwatersrand, for completion of the Degree of' Master of Science / The atmospheric response of the Colorado State University Regional Atmospheric Modelling System (RAMS) to sea-surface temperature anomaliesis investigated. A period of four days was chosen from 21 to 24 January 1981, where focus was placed on the development and dissipation of a tropical-temperate trough across Southern Africa. Previous experimenting this mesoscalenumerical model have detemined the kinematic, moisture, and thermodynamic nature of these synoptic features. The research in this dissertation focuses specifically on the sensitivity of the numerical model's simulated responses to positive sea-surface temperature anomalies. Three separate experiments were devised, in which positive anomalous temperatures were added to the ocean surface north of Madagascar (in the tropical Indian Ocean), at the region of the Agulhas Current retroflection, and along the tropical African west coast (in the Northern Benguela and Angola currents). The circulation aspects of each sensitivity test were investigated through the comparison of simulated variables such as vapour and cloud mixing ratios, temperature, streamlines and vertical velocity, with the same variables created by a control simulation. The results indicate that for the first sensitivity test, (the Madagascar anomaly), cyclogenesis was initiated over the area of modified sea temperatures which resulted in a marginal decrease in continental precipitation. The second sensitivity test (over the Agulhas retroflection) produced a much smaller simulated response to the addition of anomalously warm sea temperatures than the tropical Indian Ocean anomaly. Instability and precipitation values increased over the anomalously warm retroflection region, and were slowly transferred along the westerly wave perturbation and the South African east coast. The third sensitivity experiment showed a predominantly localised simulated increase in precipitation over Gabon and the Congo, with the slow southward progression of other simulated circulation differences taking place. The small perturbations in each of the simulated meteorological responses are consistent with the expected climate response to anomalously warm sea-surface temperatures in those areas. / AC 2018

La mise en place d’une politique de maintenance prévisionnelle est un défi majeur dans l’industrie qui tente de réduire le plus possible les frais relatifs à la maintenance. En effet, les systèmes sont de plus en plus complexes et demandent un suivi de plus en plus poussé afin de rester opérationnels et sécurisés. Une maintenance prévisionnelle nécessite d’une part d’évaluer l’état de dégradation des composants du système, et d’autre part de pronostiquer l’apparition future d’une panne. Plus précisément, il s’agit d’estimer le temps restant avant l’arrivée d’une défaillance, aussi appelé Remaining Useful Life ou RUL en anglais. L’estimation d’une RUL constitue un réel enjeu car la pertinence et l’efficacité des actions de maintenance dépendent de la justesse et de la précision des résultats obtenus. Il existe de nombreuses méthodes permettant de réaliser un pronostic de durée de vie résiduelle, chacune avec ses spécificités, ses avantages et ses inconvénients. Les travaux présentés dans ce manuscrit s’intéressent à une méthodologie générale pour estimer la RUL d’un composant. L’objectif est de proposer une méthode applicable à un grand nombre de cas et de situations différentes sans nécessiter de modification majeure. De plus, nous cherchons aussi à traiter plusieurs types d’incertitudes afin d’améliorer la justesse des résultats de pronostic. Au final, la méthodologie développée constitue une aide à la décision pour la planification des opérations de maintenance. La RUL estimée permet de décider de l’instant optimal des interventions nécessaires, et le traitement des incertitudes apporte un niveau de confiance supplémentaire dans les valeurs obtenues. / Predictive maintenance strategies can help reduce the ever-growing maintenance costs, but their implementation represents a major challenge. Indeed, it requires to evaluate the health state of the component of the system and to prognosticate the occurrence of a future failure. This second step consists in estimating the remaining useful life (RUL) of the components, in Other words, the time they will continue functioning properly. This RUL estimation holds a high stake because the precision and accuracy of the results will influence the relevance and effectiveness of the maintenance operations. Many methods have been developed to prognosticate the remaining useful life of a component. Each one has its own particularities, advantages and drawbacks. The present work proposes a general methodology for component RUL estimation. The objective i to develop a method that can be applied to many different cases and situations and does not require big modifications. Moreover, several types of uncertainties are being dealt With in order to improve the accuracy of the prognostic. The proposed methodology can help in the maintenance decision making process. Indeed, it is possible to select the optimal moment for a required intervention thanks to the estimated RUL. Furthermore, dealing With the uncertainties provides additional confidence into the prognostic results.

Submitted by ANA KARLA PEREIRA RODRIGUES (anakarla_@hotmail.com) on 2017-08-22T13:57:08Z No. of bitstreams: 1 arquivototal.pdf: 1762696 bytes, checksum: 53bf47b7590ebc1271d2f0d81822f00c (MD5) / Made available in DSpace on 2017-08-22T13:57:08Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1762696 bytes, checksum: 53bf47b7590ebc1271d2f0d81822f00c (MD5) Previous issue date: 2017-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work aims to determine the maximum number of pairwise disjoint lines that a non-singular surface of degree d in P3 can contain. In the case of degrees d = 1 and d = 2 we found that these values are zero and in nite, respectively. Furthermore, in the case of degree d = 3 we did show that the maximum number of pairwise disjoint lines is 6, these con gurations were studied in 1863 by the Swiss Ludwig Schl a i (1814-1895) in [15]. For the case d = 4, in 1975 the Russian Viacheslav Nikulin in [10] showed that non-singular quartic surfaces contain at most 16 pairwise disjoint lines. In our work, we have been able to show that Schur's famous quartic achieves this bound and that Fermat's quartic has at most 12 pairwise disjoint lines. We also determined lower bounds for the maximum number of pairwise disjoint lines in the case of non-singular surfaces of degree d 5. For example, the Rams's family in [11] allows us to nd one of these lower bounds. / Este trabalho objetiva determinar a quantidade máxima de retas duas a duas disjuntas que uma superfície não singular de grau d em P3 pode conter. No caso dos graus d = 1 e d = 2 verificamos que estes valores s~ao zero e in nito, respectivamente. Al em disso, no caso de grau d = 3 mostramos que o n umero m aximo de retas duas a duas disjuntas e 6, ditas con gura c~oes foram estudadas em 1863 pelo sui co Ludwig Schl a i (1814-1895) em [15]. Para o caso d = 4, em 1975 o russo Viacheslav Nikulin em [10] mostrou que as superf cies qu articas n~ao singulares cont^em no m aximo 16 retas duas a duas disjuntas. No nosso trabalho, conseguimos mostrar que a famosa qu artica de Schur atinge essa cota e que qu artica de Fermat possui no m aximo 12 retas duas a duas disjuntas. Determinamos ainda cotas inferiores para o n umero m aximo de retas duas a duas disjuntas no caso de superf cies n~ao singulares de grau d 5. Por exemplo, a fam lia de Rams em [11] nos permite achar uma dessas cotas inferiores.

Sources of lipids based on polyunsaturated fatty acids have been used for qualitative improvement of cryopreserved semen. Supplementation of diets with unsaturated oils for ruminants is recommended with the addition of a protector to facilitate their absorption. The objective of this study was to evaluate the influence of different levels of polyunsaturated fatty acids in the diet on the fatty acid view and quality of the semen cryopreservation of rams. Twenty-four Santa Inês raced rams were randomly distributed into four groups fed with isoproteic diets: G0 - without polyunsaturated fatty acids complexed with calcium salts (Ca-PUFA) and G3, G6 and G9 with Ca-PUFA levels in 3, 6, 9%, respectively. The semen was collected and frozen in French straws in the following periods: 0 (P0), 30 (P30), 60 (P60) and 90 (P90) days beginning the administration of diets. The fresh semen samples were analyzed for motility subjective, and the fatty acid profile, while samples of frozen-thawed semen were analyzed for sperm kinetics in a computerized system, evaluation of sperm membranes integrity, sperm capacitation and acrossome reaction. The results were subjected to a multivariate analysis including comparison tests of average between treatments on fatty acid profile in the P90, with the correlation of coefficient for axis 1 and 2 NMS and correlation of coefficient of the parameters of sperm for axis 1 and 2 NMS with a Monte Carlo test, at the significance level of 5%. It was identified in experiment 1 were identified lower proportions of stearic acid, oleic, -linolenic, arachidonic sperms in groups of rams treated with 9% Ca-PUFAs (G9) when compared to the control group (G0) after 90 days of administration diet. It was observed in experiment 2 a lower average kinetic parameters ALH and VCL of semen from rams fed with 9% diet. It was concluded that supplementing the diet with 9% Ca-PUFA after 90 days, produces no changes in the kinetic parameters such as curvilinear velocity and amplitude of lateral head of semen cryopreservation produced by rams, even containing lower proportions of oleic, - linolenic and arachidonic. / Fontes de lipidios a base de acidos graxos poli-insaturados tem sido usadas para melhoria dos aspectos quantitativos e qualitativos do semen criopreservado. A suplementacao de oleos insaturados em dietas para ruminantes requer a adicao de um protetor que facilite a sua absorcao. O objetivo do estudo foi avaliar a influencia de diferentes niveis de acidos graxos poli-insaturados na dieta ao perfil de acidos graxos e na qualidade dos espermatozoides criopreservados de carneiros. Vinte e quatro carneiros da raca Santa Ines foram distribuidos aleatoriamente em quatro grupos alimentados durante 90 dias com dietas isoproteicas: G0 - sem acidos graxos poli-insaturados complexados com sais de calcio (PUFA-Ca) e G3, G6 e G9 com PUFA-Ca em teores de 3, 6, 9%, respectivamente. O semen foi coletado e congelado em palhetas nos periodos: 0 (P0), 30 (P30), 60 (P60) e 90 (P90) dias do inicio da administracao das dietas. As amostras de semen in natura foram analisadas quanto a motilidade subjetiva, e ao perfil de acidos graxos, enquanto que aquelas descongeladas foram analisadas quanto a cinetica espermatica em sistema computadorizado, integridade das membranas espermaticas e capacitacao e reacao acrossomal. Os dados obtidos foram submetidos a analise multivariada com o teste de comparacao de medias entre os tratamentos, quanto ao perfil de acidos graxos dentro do P90, com o coeficiente de correlacao para os eixos 1 e 2 NMS e com coeficiente de correlacao dos parametros dos espermatozoides para os eixos 1 e 2 NMS com teste de Monte Carlo, ao nivel de significancia minimo de 5%. No experimento 1 foram identificadas menores proporcoes dos acidos estearico, oleico, ×-linolenico, araquidonico nos espermatozoides dos carneiros do grupo tratado com 9% de PUFAs-Ca (G9), quando comparado ao grupo controle (G0) aos 90 dias da administracao da dieta. No experimento 2 foram observadas menores medias nos parametros cineticos ALH e VCL dos espermatozoides dos carneiros alimentados pela dieta 9%. Conclui-se que a suplementacao da dieta de carneiros com 9% de acidos graxos poli-insaturados complexados com sais de calcio por um periodo de 90 dias produz uma mudanca no perfil de acidos graxos dos espermatozoides ovinos associada significativamente a diminuicao das proporcoes dos acidos estearico, oleico, ×-linolenico, araquidonico, do somatorio de acidos graxos poli-insaturados e da razao entre os somatorio dos acidos graxos poli-insaturados e saturados, alem de reduzir a qualidade do semen criopreservado associada ao deslocamento lateral da cabeca e a velocidade curvilinear.

La sûreté de fonctionnement (SdF) des produits, processus et services est une préoccupation permanente de tous les acteurs industriels. C'est le cas notamment dans le secteur automobile à l'exemple des équipementiers confrontés à des clients de plus en plus exigeants en matière de sûreté de fonctionnement. Jusqu'alors uniquement intéressé par les résultats, le client requiert aujourd'hui, dès les négociations couplées à l'appel d'offre (AO), une information précise sur la démarche même que le fournisseur prévoit de mettre en place pour satisfaire aux exigences SdF. Conscients de ces nouveaux besoins, nous nous sommes intéressés à la problématique d'identification de la "dimension SdF" du produit au stade de l'AO et à l'évaluation de l'impact économique de son intégration sur le développement futur du produit. Les conséquences de la prise en compte de la SdF sont doubles puisqu'elles concernent à la fois le produit qui voit sa robustesse optimisée mais aussi la démarche d'analyse permettant de dimensionner les solutions appropriées. Dans l'objectif de répondre à la problématique, nous avons proposé une organisation du processus de réponse à appel d'offre en différentes étapes instrumentées allant de l'identification des éléments relatifs à la SdF dans les documents clients fournis pour l'AO à la définition et à l'évaluation de l'impact SdF. / Products Dependability, process and services is a major and permanent topic for industrial actors and especially in automotive industry, where products suppliers are faced to customers more and more aware about dependability. Until now, Customers was only interested about results, they request today, in bid process timeframe, informations about processes put in place in order to reach dependability objectives. Taking these new requirements into accounts, we have focused our work on dependability identification during bid process and the evaluation its cost impact on development. Taking dependability into account allow to increase product robustness but also to make better design choice in term of dependability. Thus, in order to reach this objective, we propose a step by step process for bid phases from dependability topics identification to cost impact.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-14T10:58:52Z No. of bitstreams: 1 EWERTON CLEUDSON DE SOUSA MELO - TESE (PPGMet) 2016.pdf: 4714414 bytes, checksum: 399def91bcd71b3e8a00a6b001dcfd4b (MD5) / Made available in DSpace on 2018-08-14T10:58:52Z (GMT). No. of bitstreams: 1 EWERTON CLEUDSON DE SOUSA MELO - TESE (PPGMet) 2016.pdf: 4714414 bytes, checksum: 399def91bcd71b3e8a00a6b001dcfd4b (MD5) Previous issue date: 2011-06-30 / CNPq / Neste trabalho a versão 6.0 do modelo numérico RAMS (Regional Atmospheric Modeling System) é usada com o objetivo principal de simular a influência da expansão agrícola nas trocas de água e energia em áreas de Caatinga, e quantificar os efeitos das mudanças na cobertura e uso da terra na geração de circulações termicamente induzidas e na atividade convectiva. Os cenários de uso da terra investigados neste estudo foram construídos para representar condições ambientais nativas (sem influências antrópicas), e com alterações decorrentes da construção da represa de Sobradinho, e da expansão de atividades agrícolas e irrigação em região de clima semiárido. O ambiente atmosférico de grande escala é caracterizado pela estrutura dinâmica e termodinâmica típica da área central de um vórtice ciclônico de altos níveis (VCAN). A escolha do período de estudo teve como objetivo garantir condições ambientais com ampla diversidade agrícola em áreas de Caatinga (culturas de sequeiro e agricultura irrigada), e pouca nebulosidade. A evolução temporal da precipitação convectiva acumulada nas simulações da expansão agrícola mostra diferenças marcantes nos efeitos da agricultura de sequeiro e vegetação irrigada. O aumento na taxa da evapotranspiração nas áreas irrigadas eleva consideravelmente o teor de umidade nos baixos níveis da troposfera, reduz a temperatura do ar e diminui a precipitação convectiva. A descontinuidade na umidade e tipo de cobertura vegetal modifica a intensidade e distribuição dos fluxos turbulentos que são importantes na formação dos gradientes de pressão que geram circulações de brisa (brisa lacustre e de vegetação), de forma que o domínio nos transportes verticais de calor e água passa a ser da mesoescala. Verificou-se que as principais forçantes locais na determinação da distribuição espacial dos fluxos turbulentos e da chuva convectiva foram a topografia e a descontinuidade no teor de umidade do solo. Com relação a estabilidade atmosférica percebeu-se a existência de uma relação quase linear entre a Energia Potencial Convectiva Disponível (CAPE) e a temperatura potencial equivalente. / In this work the version 6.0 of the numerical model RAMS (Regional Atmospheric Modeling System) is used with the main objective of simulating the influence of agricultural expansion on the water and energy exchange in Caatinga vegetation areas, and to quantify the effects that changes on soil use and coverage have on the generation of thermally induced circulations and convective activity. The scenarios of soil use investigated are designed to represent native environmental conditions (without anthropogenic influences) and with alterations due to the implementation of the Sobradinho reservoir, and the expansion of agricultural activities and irrigation in a semiarid climate area. The large scale atmospheric ambient is characterized by the dynamic and thermodynamic structure typical of the central area of an upper level cyclonic vortex. The period of study was chosen aiming at environmental conditions with largely diversified agricultural use in Caatinga vegetation areas (agriculture with and without irrigation), and almost cloudless skies. The temporal evolution of the accumulated convective precipitation in the numerical simulations of the agricultural expansion shows large differences in the effects of agriculture with and without irrigation. The irrigated areas higher evapotranspiration rate causes a substantial increase in the moisture content in the lower troposphere, and lower the air temperature and convective precipitation.

Thesis (M.Ed.(Socio-Ed.))--University of South Africa, 2002.

No description available.