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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

Use of non-woven geotextiles for the sealing of earthen manure storage facilities.

Raimondo, Robert. January 1991 (has links)
No description available.
2

Conception d'un dôme géodésique pour des réservoirs à lisier

Dupéré, Richard January 1994 (has links)
A roof over a manure reservoir eliminates the entry of precipitations, reduces odour and volatile gas emissions, lowers the storage and handling costs and alleviates environmental impacts. / Structural analysis and testing were carried out to establish the feasibility of geodesic domes as manure reservoir roofting. A stress analysis, conducted by computer was used to determine maximum compression loads on roof members. Compression tests were carried out in the laboratory to test two laminated designs and to evaluate the performance of a member joint. / Structural analysis showed that the Lamella type dome, with a diameter/height ratio of 4, offers the best geometry considering design criteria for manure roofs. Compression tests confirmed that laminated members, made of 38 x 89 mm and 38 x 140 mm pieces, can resist the design stress developed in a 22 meter diameter dome. / Loading tests revealed that non laminated wood members failed at 80% of the design load. However, the joints (formed by two 3,1 mm thick steel plates bolted to the members) were still able to resist an increase in loading. / Data obtained from the tests were used for a preliminary design of a geodesic roof taking into account specific conditions such as humidity and manure gas. However further study is required to adapt this concept to real conditions over a manure reservoir. / The cost of a 22 meter diameter dome, for covering manure reservoirs, is estimated at 79$/m$ sp2$ which is more expensive than the cost of the currently used, least expensive manure pit roof (wood truss design).
3

La perméabilité des réservoirs à lisier en béton /

Denis, Jacques January 1989 (has links)
Two underground concrete manure reservoirs of 70 m$ sp3$ were tested for their infiltration rate to water as well as to 1% and 3% total solid dairy manure. Positive and negative infiltration were measured for the water test while only negative infiltration was measured with the manure. / Positive infiltration is met when the water table into the soil is above the liquid level into the reservoir. In that case, the water is moving from the outside to the inside of the reservoir. An opposite situation is met when the infiltration is negative. / From the results, the infiltration rate varied from 0.00 to 6.684 $ times$ 10$ sp{-7}$ m/s. The minimum value was recorded at the reservoir 55 with 1% of total solid manure and the maximum value was recorded with same reservoir with positive pressure to water.
4

Experimental and Numerical Investigation of Liquid Storage Tanks Under Seismic Excitation

Bahreini Toussi, Iman January 2016 (has links)
Liquid storage tanks are a crucial type of structures. They are used to store various types of liquids and liquefied gases in different situations. In seismic regions, functionality of these structures after severe earthquakes is an important factor in their design. In earthquake-prone regions, the sloshing phenomena has an important role in the design procedure. Current design codes and guidelines (e.g. ACI 350.3 and ASCE 7) are based on analytical studies that in some cases can be inaccurate in prediction of forces and pressures. Since a long time ago scientists have studied the sloshing phenomena in liquid storage tanks with different methods including analytical, numerical and experimental studies. In the current study, rectangular ground-supported tanks are studied and the effect of seismic loading on them is investigated both experimentally and numerically. For the experimental tests, the tanks were placed on a shaking table and using high-speed HD cameras, tests were filmed and later analyzed frame by frame to capture the critical moments. To investigate the bi-lateral effect of base excitation on the tanks, they were oriented on the table with four different angles. In the numerical study, a computational fluid dynamics tool - OpenFOAM - was used to simulate the tank motion and finally the results were compared with the experiment in order to develop a reliable model.
5

Conception d'un dôme géodésique pour des réservoirs à lisier

Dupéré, Richard January 1994 (has links)
No description available.
6

La perméabilité des réservoirs à lisier en béton /

Denis, Jacques January 1989 (has links)
No description available.
7

Influência do resveratrol na qualidade e na fertilidade do espermatozoide suíno refrigerado entre 15-17°C por 72 horas para inseminação artificial intrauterina / Influence of resveratrol on quality and fertility of cooled boar spermatozoa at 15-17ºC for 72 hours to intrauterine insemination

Rigo, Victor Henrique Bittar 16 December 2016 (has links)
A preservação do sêmen suíno refrigerado para fins de inseminação artificial é a forma mais utilizada no mundo. Para tal, os espermatozoides são diluídos em meios que forneçam substratos para nutrir e proteger estas células. Porém, a faixa de temperatura de armazenamento do sêmen suíno refrigerado não é capaz de cessar completamente os mecanismos metabólicos dos espermatozoides, que em ambiente aeróbico da dose inseminante, produzem e liberam continuamente produtos do metabolismo do oxigênio. A ação das espécies reativas de oxigênio sobre o espermatozoide é uma das razões do declínio na população de células espermaticas estrutural e funcionalmente aptas à fertilizarem os gametas femininos. Portanto, a adição de um composto antioxidante ao meio diluidor poderia melhorar ou manter constante o número de espermatozoides viáveis ao longo do período de conservação da dose inseminante. Neste contexto, este trabalho objetivou verificar se a adição do antioxidante resveratrol geraria modificações positivas em parâmetros celulares relacionados à qualidade do sêmen suíno refrigerado à 15-17°C avaliados por sistema computadorizado da motilidade espermática e citometria de fluxo (experimento in vitro), e se este antioxidante melhoraria os índices de fertilidade na inseminação artificial intrauterina (IAIU) através da recuperação, contagem e identificação dos embriões (experimento in vivo). As concentrações testadas no experimento in vitro não superaram os resultados do tratamento controle (p<0,05), sendo a concentração de 1,0 mM prejudicial ao espermatozoide suíno (p<0,05). A utilização da concentração de 0,01 mM de resveratrol para inseminação das fêmeas suínas no experimento in vivo não apresentou efeito positivo nos índices de taxa de prenhez e fertilidade ajustada total (p>0,05), além de ter resultado em uma baixa taxa de embriões viáveis (p<0,05), quando comparados ao tratamento controle. Deste modo, pode concluir que não é indicado a adição do antioxidante resveratrol ao meio diluidor para inseminação artificial, uma vez que compromete a qualidade das células espermáticas do reprodutor suíno e impacta negativamente na fertilidade das fêmeas. / The preservation of chilled boar semen for artificial insemination is the most performed worldwide. For this, the sperm are extended in medium that provides substrates to nourish and protect these cells. However, the storage temperature range of chilled semen is not able to completely stop the metabolic mechanisms of sperm, which keeps producting and releasing oxygen reactive products in aerobic environment of insemination doses. The action of reactive oxygen species on the sperm is one of the reasons for decreasing sperm population with structural and functional capacity to fertilize the female gamete. Therefore, the addition of antioxidant compound to the extender medium could improve or maintain the number of viable spermatozoa throughout the conservation time of insemination doses. In this context, this work aimed to determine whether addition of antioxidant resveratrol would generate positive changes in cell parameters related to the quality of boar semen cooled to 15-17 °C assessed by computered analysis of sperm motility and flow citometry (in vitro experiment) and whether this antioxidant would improve fertility rates using intrauterine insemination (IUI) by the recovery, counting and embryos identification (in vivo experiment). The concentrations tested in vitro experiment have not exceed control treatment results (p <0.05), with the concentration of 1.0 mM being detrimental to the boar spermatozoa (p <0.05). The concentration of 0.01 mM of resveratrol used for gilts insemination in experiment in vivo has not shown positive effect on pregnancy rate and the total adjusted fertility (p> 0.05) and have resulted in a low rate viable embryos (p <0.05) compared to control. Thus, we conclued that the addition of resveratrol antioxidant in boar extender medium is not suitable for artificial insemination, once it compromises the quality of boar sperm cells and impairs on female fertility.
8

Influência do resveratrol na qualidade e na fertilidade do espermatozoide suíno refrigerado entre 15-17°C por 72 horas para inseminação artificial intrauterina / Influence of resveratrol on quality and fertility of cooled boar spermatozoa at 15-17ºC for 72 hours to intrauterine insemination

Victor Henrique Bittar Rigo 16 December 2016 (has links)
A preservação do sêmen suíno refrigerado para fins de inseminação artificial é a forma mais utilizada no mundo. Para tal, os espermatozoides são diluídos em meios que forneçam substratos para nutrir e proteger estas células. Porém, a faixa de temperatura de armazenamento do sêmen suíno refrigerado não é capaz de cessar completamente os mecanismos metabólicos dos espermatozoides, que em ambiente aeróbico da dose inseminante, produzem e liberam continuamente produtos do metabolismo do oxigênio. A ação das espécies reativas de oxigênio sobre o espermatozoide é uma das razões do declínio na população de células espermaticas estrutural e funcionalmente aptas à fertilizarem os gametas femininos. Portanto, a adição de um composto antioxidante ao meio diluidor poderia melhorar ou manter constante o número de espermatozoides viáveis ao longo do período de conservação da dose inseminante. Neste contexto, este trabalho objetivou verificar se a adição do antioxidante resveratrol geraria modificações positivas em parâmetros celulares relacionados à qualidade do sêmen suíno refrigerado à 15-17°C avaliados por sistema computadorizado da motilidade espermática e citometria de fluxo (experimento in vitro), e se este antioxidante melhoraria os índices de fertilidade na inseminação artificial intrauterina (IAIU) através da recuperação, contagem e identificação dos embriões (experimento in vivo). As concentrações testadas no experimento in vitro não superaram os resultados do tratamento controle (p<0,05), sendo a concentração de 1,0 mM prejudicial ao espermatozoide suíno (p<0,05). A utilização da concentração de 0,01 mM de resveratrol para inseminação das fêmeas suínas no experimento in vivo não apresentou efeito positivo nos índices de taxa de prenhez e fertilidade ajustada total (p>0,05), além de ter resultado em uma baixa taxa de embriões viáveis (p<0,05), quando comparados ao tratamento controle. Deste modo, pode concluir que não é indicado a adição do antioxidante resveratrol ao meio diluidor para inseminação artificial, uma vez que compromete a qualidade das células espermáticas do reprodutor suíno e impacta negativamente na fertilidade das fêmeas. / The preservation of chilled boar semen for artificial insemination is the most performed worldwide. For this, the sperm are extended in medium that provides substrates to nourish and protect these cells. However, the storage temperature range of chilled semen is not able to completely stop the metabolic mechanisms of sperm, which keeps producting and releasing oxygen reactive products in aerobic environment of insemination doses. The action of reactive oxygen species on the sperm is one of the reasons for decreasing sperm population with structural and functional capacity to fertilize the female gamete. Therefore, the addition of antioxidant compound to the extender medium could improve or maintain the number of viable spermatozoa throughout the conservation time of insemination doses. In this context, this work aimed to determine whether addition of antioxidant resveratrol would generate positive changes in cell parameters related to the quality of boar semen cooled to 15-17 °C assessed by computered analysis of sperm motility and flow citometry (in vitro experiment) and whether this antioxidant would improve fertility rates using intrauterine insemination (IUI) by the recovery, counting and embryos identification (in vivo experiment). The concentrations tested in vitro experiment have not exceed control treatment results (p <0.05), with the concentration of 1.0 mM being detrimental to the boar spermatozoa (p <0.05). The concentration of 0.01 mM of resveratrol used for gilts insemination in experiment in vivo has not shown positive effect on pregnancy rate and the total adjusted fertility (p> 0.05) and have resulted in a low rate viable embryos (p <0.05) compared to control. Thus, we conclued that the addition of resveratrol antioxidant in boar extender medium is not suitable for artificial insemination, once it compromises the quality of boar sperm cells and impairs on female fertility.
9

Investigation of Liquid Containers and Their Supporting Structures Under Seismic Loading

Bahreini Toussi, Iman 16 May 2023 (has links)
Liquid Storage Tanks (LSTs) are essential infrastructure systems that are used in various municipal and industrial settings. They play a critical role in storing and transporting liquids such as drinking water, oil, and gas that are used in daily life. Failure of these structures due to their poor seismic performance can have devastating consequences including the release of the stored liquid and damage to the surrounding area with potentially irreversible environmental impacts. In addition, the damage caused to the tank structure can be extensive, resulting in significant financial losses. Furthermore, the disruption of services provided by the tank such as water supply, oil and gas storage can be considerable. It is therefore crucial to study the seismic behaviour of these structures and ensure their safety and reliability to minimize the potential damages. The aim of this study is to investigate the behavior of LSTs in terms of the contained liquid, the tank’s structure, and its supports when subjected to seismic excitations. To obtain accurate results, different numerical techniques are applied in different phases of the study, including the Finite Volume Method (FVM), Finite Elements Method (FEM), Volume of Fluids (VoF) method, and Smoothed Particles Hydrodynamic (SPH) method. These techniques allow for a detailed analysis of the behavior of the tank and its supports during seismic excitation, providing a comprehensive understanding of the performance of LSTs during earthquakes. In order to examine the reliability and accuracy of the numerical model, the first part of the study includes the validation of the developed numerical model through comparison of the model and experimental results. The validated numerical model is then used to obtain the hydrodynamic pressures at different locations on the roof of tanks subjected to base excitations. The effect of liquid impact and hydrodynamic pressures on the roof of LSTs can be significant, however, limited studies have been completed on this issue. In the second part of the study, Artificial Intelligence (AI) techniques such as Genetic Programming are used to formulate these pressure values so that the maximum pressure can be obtained using the tank characteristics such as size and fill depth by the relationship obtained based on the AI approach. In the third part of the study, the supporting structures of LSTs subjected to base excitations are analyzed, and their shear forces are extracted and compared with the National Building Code of Canada (NBC 2020) in order to evaluate the reliability of the code and discuss possible improvements. The results of this study can be used to evaluate and make improvements in standards and guidelines for the seismic design of LSTs, which can help ensure the safety and reliability of these crucial infrastructures during seismic events.

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