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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

Estudo teórico e experimental de esforços devidos a cabos de termometria fixados em estruturas de coberturas de silos cilíndricos para armazenamento de grãos / Theoretical and experimental study of efforts due to temperature cables fixed to roof structures of cylindrical storage silos for granular products

Gisele Cristina Antunes Martins 09 March 2012 (has links)
Um dos acidentes comuns em estruturas de armazenamento é o colapso da estrutura de cobertura do silo. Na prática, observa-se que as ruínas estruturais nesse sistema são na maior parte devidas ao desconhecimento das ações nestas estruturas. Devido à escassa informação disponível sobre os esforços de cabos de termometria fixados em estruturas de cobertura de silos cilíndricos verticais, a ênfase desta pesquisa é a análise teórica e experimental da avaliação destes esforços com o objetivo de fornecer subsídios para os projetistas e informações para uma futura normalização no dimensionamento de estruturas de cobertura para silos metálicos cilíndricos. Inicialmente realizou-se uma ampla revisão bibliográfica sobre as ações, esforços e sistemas estruturais e construtivos de cobertura para silos cilíndricos. Com base na análise teórica e experimental realizada dos esforços em cabos de termometria conclui-se que as equações propostas pela norma Argentina IRAM 8 015: 1977 são as mais adequadas para avaliação desses esforços / One of the common accidents in storage structures is the silos roof failure. In practice, it is observed that the structural problems in this system are mostly due to the lack of knowledge about the actions in these structures. Due to limited available information on temperature cables loads fixed to roof structure of vertical silos, this work has the aim in the theoretical and experimental analysis of these efforts in two different silos: the pilot-silo in LaMEM - SET - EESC-USP and silo Kepler Weber Industry, in order to provide support for designers and informations for the development of a future Brazililan Standard for the design of roof structures of cylindrical steel silos. Initially was carried out an extensive literature review on the loads, efforts and structural systems for silos roofs. The conclusions obtained from the experimental and theoretical analyzes are that the equations proposed by Argentina Standard IRAM 8015: 1977 is the most suitable for the evaluation of these loads
12

Viabilidade da utilização de aditivos na ensilagem de capim-braquiarão (Brachiaria brizantha (Hochst ex A. Rich.) Stapf cv. Marandu), manejado sob intensidades de pastejo / Viability on the addictives utilization in braquiarão grass [Brachiaria brizantha (Hochst ex A. Rich.) cv. Marandu] silage process, managed under grazing intensities

Felipe Barros Macedo 15 May 2006 (has links)
Silagem é um alimento volumoso obtido de forragens produzidas na estação das águas, conservando-as através de fermentações, para ser oferecida no período de escassez, garantindo a eficiência de utilização da forragem produzida. Este processo de conservação de forragem tem como objetivo preservar a forragem de alto valor nutritivo com o mínimo de perdas. Neste contexto, o presente trabalho teve como objetivos: Avaliar a viabilidade de produzir silagem de capim-braquiarão (Brachiaria brizantha (Hochst ex A. Rich.) cv. Marandu) de pastos sob intensidades de pastejo, utilizando ou não aditivos. Determinar as perdas por gases e efluentes e, verificar as possíveis diferenças na composição química e bromatológica dessas silagens relativo às estratégias de ensilagem que o produtor poderia realizar, no início ou no final dos ciclos das águas. O experimento foi implantado e conduzido no Departamento de Zootecnia da Faculdade de Zootecnia e Engenharia de Alimentos da Universidade de São Paulo - FZEA/USP. O delineamento experimental foi o inteiramente ao acaso e o experimento em fatorial 4 x 3, com quatro repetições. Os fatores foram, a saber: 1º Fator – Ofertas de forragem (5% - 5 kg de massa seca/100 kg de peso animal.dia, 10%, 15% e 20%). A pastagem estava sendo manejada em lotação rotacionada, com ciclo de pastejo de 35 dias (7 dias de ocupação e 28 dias de descanso); 2º Fator – Aditivo (a) Testemunha - sem polpa cítrica peletizada e inoculante; (b) Polpa cítrica peletizada a 7,5% (75 kg/t de forragem); (c) Inoculante Sil-All C4 - recomendação comercial: 250g do produto em 50 litros de água potável; pulveriza-se 1 litro/tonelada. O experimento apresentou um total de 48 mini-silos - parcelas (12 tratamentos x 4 repetições) para cada ciclo de pastejo, que se utilizou a colheita da forragem (1º 23/02/04 e 2º 27/03/04). No trabalho avaliaram-se as perdas por Gases e Gases+Efluente durante o processo fermentativo e, as características químicas e bromatológicas da silagem. O processo de conservação de capim-braquiarão numa propriedade que se utiliza do manejo de seus animais em lotação rotacionada pode ser instalado mediante o corte mecânico das plantas forrageiras em piquetes estrategicamente escolhidos. Em menores intensidades de pastejo o capim-braquiarão apresenta melhores características para ensilar, pois é relevante que a planta forrageira utilizada no pastejo tenha potencial de alta produção de massa de forragem e alto teor de matéria seca, o que diminui os custos de produção por unidade de área e garante a qualidade do produto final. Na colheita de forrageiras tropicais com alto teor de umidade e baixo teor de carboidratos fermentescíveis é viável e necessário a utilização de aditivo, quer seja para aumentar os teores de matéria seca e de carboidratos fermentecíveis e manter o poder tampão em níveis baixos (polpa cítrica) ou de microorganismos (Sil-All C4) para favorecer o processo fermentativo e assim obter uma silagem de bom valor nutritivo. / Silage is a grassing food conserved by a fermentative process specialy used during scarcity period (dry season). It aims to conserve a high nutritional value with a minimum of losses. In order to assure its produced forage utilization efficiency, it needs to considerate its harvest by animals and machines in a system that uses rotational stocking method. In this context, this work has had as objectives: to evaluate the viability to produce braquiarão grass silage [Brachiaria brizantha (Hochst ex A. Rich.) cv. Marandu] from pasture under grazing intensities, using addictives or not. To determinate the gases and effluent losses and, to verificate the possible differences in chemical-bromatologic composition in the silage related to the strategies to process the silage that the producer is able to use, at the beginning or at the end of summer season (rain period). The experiment was conducted in the Animal Science Department at the Faculty of Animal Science and Food Engeneering of University of São Paulo – FZEA/USP. The experimental design was totally alleatory in a 4X3 factorial mode, with four replications. The factors were: 1st Factor – Forage allowance (FA) (5% - 5Kg of dry mass/ 100kg living animal weight.day, 10%, 15% and 20%). The pasture was being managed in rotational stocking method, with a 35 day grazing cycle (7 day animal occupation time and 28 day pasture rest time); 2nd Factor – addictive A) Control – without peletized citric pulp and inoculant. B) 7,5 % peletized citric pulp (75 Kg/ton of forage). C) Sil-All C4 inoculant – Trading recommendation: 250 g of the product in 50 liters of potable water; pulverizing 1 liter/ton. The experiment were composed by 48 small plastic silos – parcels ( 12 treatments X 4 replications) for each grazing cycle, that was used the forage harvest (1st 23/02/04 and 2nd 27/03/04). The gases and gases+effluent losses were evaluated during the fermentative process and, the silage chemical-bromatologic characteristics. The braquiarão grass conservation process, in a property that uses animals handled in a rotational stocking method, can be installed through forage mechanical cuts in strategically chosen pickets. In lower grazing intensities the braquiarão grass shows better characteristics to ensile, once it´s important to the forage used in grazing process to have a potential to high mass production just like its dry matter rate, that can decrease the expense per unit of area and it guarantees the final product quality. In tropical forage harvest with high humidity and low fermentable carbohydrate rate, the addictives utilization is a feasible and necessary method to increase the dry matter and fermentable carbohydrate rate and keep the buffering in low rate (citric pulp) or in microorganisms (Sil-All C4) to collaborate the fermentative process in order to obtain better nutritional value silage.
13

Direccion del proyecto de ampliacion de la capacidad de almacenamiento de cemento con la implementación del Silo 07 - Yura S.A.

Angulo Choque, Jimmy Oscar, Gonza Sumari, Marco Antonio, Carpio Pauca, Víctor Raúl 08 March 2016 (has links)
Yura S.A forma parte del Grupo Gloria y cuenta con su división de cementos, produciendo y comercializando cemento, teniendo como producto estrella el cemento puzolánico portland IP. Yura S.A. es la segunda empresa productora del país, con una capacidad de producción de 2 millones de toneladas de clinker y de 3,18 millones de toneladas de cemento al año. Su planta se encuentra ubicada en la ciudad de Arequipa, distrito de Yura Km 26 de la vía Arequipa-Juliaca.
14

Feasibility of storing canola in silo bags (harvest bags)

Vellaichamy, Chelladurai 05 April 2016 (has links)
Silo bags are a recently-developed temporary grain storage system that is becoming more widely used in Western Canada without any scientific information about the effect of changing conditions over time on seed quality. The main goal of this study was to examine the conditions that would allow safe storage of canola in these bags in the Canadian Prairie provinces. Canola at three different moisture contents (m.c.) 8.9, 10.5 and 14.4% (wet basis), which represent dry, straight and damp classifications, were stored in silo bags for 40 weeks and seed germination, free fatty acid value (FAV), and moisture content of canola were analysed every 2 weeks along with carbon dioxide concentrations of intergranular air and temperature of canola. For dry grade canola, the germination was maintained above 90%, and FAV stayed within 1.5 times the initial value. However, the germination of damp canola dropped to below 80%, and FAV doubled its initial value within 8 weeks of storage. Another study was conducted for two storage years (2011-12 and 2013-14) to determine the changes in grain quality over time while storing 12% moisture content canola seeds in silo bags. The germination of canola seeds at most parts of the silo bags stayed above a safe level up to the end of the winter season. At the top layer of the silo bags, germination of canola seeds decreased to below 30% and FAV increased more than 2-fold of initial values during summer storage. A polynomial regression model was developed using field data to predict CO2 concentration inside a silo bag with canola. The coefficient of determination of this regression model was 0.76 and had a root mean square error (RMSE) value of 0.196. The standardized coefficients indicated that initial moisture content was 3.9 times more important than storage temperature for CO2 prediction. Permeability to CO2 and O2 of the silo bag material was determined using a specially designed testing unit and the permeability of silo bag material to CO2 was 21.61 ±1.50×10-6 m3 m d-1m-2atm-1, and for O2 was 1.95 ± 0.36×10-6, m3 m d-1m-2atm-1 at room temperature. / May 2016
15

Spannungsberechnung in Silos mit der Charakteristikenmethode

Wilms, Harald, January 1984 (has links)
Thesis--Brunswick. / In Periodical Room.
16

Determinants of the supply-side fragmentation of maize storage in the North Western Free State production area / Mathys Johannes Nicolaas van der Merwe.

Van der Merwe, Mathys Johannes Nicolaas January 2012 (has links)
For decades commercial silos in South Africa was the only option in which maize could be delivered and sold. After deregulation in the late 1990s commercial silo owners came to face the challenge of alternative storage solutions and loss of market share. The reasons are determined for a shift from commercial storage to on-farm storage. The extent to which on-farm storage will change the current maize storage industry is discussed. The study commences by describing the birth and rapid growth of maize production in South Africa. Soon after maize became a major role-player in the export industry, it was characterised by regulation. The rationale why the market was regulated and how it influenced grain storage is explained. The deregulation process and the objectives of the new Marketing of Agricultural Products Act, No. 47 of 1996, are paraphrased. In the deregulated market, current and future, maize prices are determined by supply and demand. Incentives for storage emerged and cheaper substitutes with various other advantages began to propose alternative storage solutions to farmers. These concurrences of circumstances then lead to fragmentation of grain storage in South Africa. As a relatively young free market, the maize value chain is described to illustrate the position of each role-player in relation to the silo owner. The new price determination factors, price movement rationale and the use of market instruments are subsequently explained. Naturally, a critical assessment of the main different storage solutions available for farmers, are investigated next. Fragmentation is defined and discussed in terms of market equilibrium. A comparison is drawn between the South African and the Australian as well as the US maize storage industry. The empirical research was conducted on two sample groups of farmers in the Free State. The first group is farmers that already make use of an on-farm storage facility. The second group is farmers that annually produce more than 5000 tons of maize and currently do not make use of an on-farm storage facility. Seven important reasons for an on-farm storage facility are determined in the literature study as well as a qualitative study that preceded the quantitative study. Respondents are asked to rank the reasons in order of, in their opinion, importance. A generalized profile of a respondent in each sample group was compiled. Hereafter the outcome of the reasons ranked by both sample groups is discussed. It appeared that Flexible Marketing Option was the most important reason for farmers that already make use of on-farm storage. Farmers did not indicate that Handling and Storage costs are the most important reason why they would invest in an on-farm storage facility. Correlations are drawn between groups and the significance of differences is determined. It is concluded that on-farm storage is sustainable and there will be an increase of the phenomenon over the next three years. Recommendations are given for commercial silo owners to regain market share. Costs analyses and effective cost management along with the promotion that marketing options are just as flexible within commercial silos, as it is outside, are some of the recommendations made. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.
17

Determinants of the supply-side fragmentation of maize storage in the North Western Free State production area / Mathys Johannes Nicolaas van der Merwe.

Van der Merwe, Mathys Johannes Nicolaas January 2012 (has links)
For decades commercial silos in South Africa was the only option in which maize could be delivered and sold. After deregulation in the late 1990s commercial silo owners came to face the challenge of alternative storage solutions and loss of market share. The reasons are determined for a shift from commercial storage to on-farm storage. The extent to which on-farm storage will change the current maize storage industry is discussed. The study commences by describing the birth and rapid growth of maize production in South Africa. Soon after maize became a major role-player in the export industry, it was characterised by regulation. The rationale why the market was regulated and how it influenced grain storage is explained. The deregulation process and the objectives of the new Marketing of Agricultural Products Act, No. 47 of 1996, are paraphrased. In the deregulated market, current and future, maize prices are determined by supply and demand. Incentives for storage emerged and cheaper substitutes with various other advantages began to propose alternative storage solutions to farmers. These concurrences of circumstances then lead to fragmentation of grain storage in South Africa. As a relatively young free market, the maize value chain is described to illustrate the position of each role-player in relation to the silo owner. The new price determination factors, price movement rationale and the use of market instruments are subsequently explained. Naturally, a critical assessment of the main different storage solutions available for farmers, are investigated next. Fragmentation is defined and discussed in terms of market equilibrium. A comparison is drawn between the South African and the Australian as well as the US maize storage industry. The empirical research was conducted on two sample groups of farmers in the Free State. The first group is farmers that already make use of an on-farm storage facility. The second group is farmers that annually produce more than 5000 tons of maize and currently do not make use of an on-farm storage facility. Seven important reasons for an on-farm storage facility are determined in the literature study as well as a qualitative study that preceded the quantitative study. Respondents are asked to rank the reasons in order of, in their opinion, importance. A generalized profile of a respondent in each sample group was compiled. Hereafter the outcome of the reasons ranked by both sample groups is discussed. It appeared that Flexible Marketing Option was the most important reason for farmers that already make use of on-farm storage. Farmers did not indicate that Handling and Storage costs are the most important reason why they would invest in an on-farm storage facility. Correlations are drawn between groups and the significance of differences is determined. It is concluded that on-farm storage is sustainable and there will be an increase of the phenomenon over the next three years. Recommendations are given for commercial silo owners to regain market share. Costs analyses and effective cost management along with the promotion that marketing options are just as flexible within commercial silos, as it is outside, are some of the recommendations made. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.
18

Velocity distributions in conical hoppers

Cleaver, James Arnold Stafford January 1991 (has links)
No description available.
19

Development and Implementation of an Advanced Storage Model

Aronsson, Oscar January 2017 (has links)
The European process industry is in need of modernization if it shall retain its competitiveness on the growing global market and at the same time reduce the environmental impact that the industrial activities have. The concept behind industrial automation has been very successful in increasing the efficiency for the material handling process, but some industries still have a lack in the field of automation. One of these industries is the mining industry. ABB is currently working within the EU-funded project DISIRE in order to increase the amount of traceability and therefore also the potential of automation in the mining industry by introducing a flow simulation over the mine infrastructure. But one of the largest inherited problems that this industry has over other process industries is that the flow partly consists of a batch structure where the continuous flows of the product only takes place between bunkers and buffer zones. ABB has developed a Matlab simulation where these bunkers are modelled by a simple queue algorithm which does not take the blending or time delays of the ore into account. The main task of this master thesis was to investigate which different modelling approaches that could increase the accuracy of the simulation. The Cellular Automata (CA) were found to be most suitable modelling approach due to its simplicity and a Matlab toolbox were developed and implemented based on the theories behind CA. The results were partly evaluated with the results of an ongoing experiment at Luleå university and by comparison to theories of granular media movement. The CPU-time for the silo flow with 10.000 particles in a flat silo using a MacBook Pro 2.26GHz was about 8 seconds.
20

SILO 72 : Ombyggnad av Lantmännens silo i Östra Hamnen, Västerås

Ingemarsson, Cristoffer, Bovellán, John January 2012 (has links)
This project includes a small study of Västerås city's housing needs, and a proposal on theuse of the property 1:207, Lantmännens silo in the Eastern Harbour, Västerås.The project intends to produce a basic study of the useful systems for this rebuilding projectwith regards to sustainable development and energy saving light buildings.The end result, which consists of a detailed visualization of the proposal, intends to becomean iconic natural focus for the Eastern port of Västerås and an example of the use andadaptation of existing structures.The property must also link the eastern parts of Västerås with the center through anextension of Mälarleden.The work has been performed through literature studies, site visits, contacts with the City ofVästerås and by calculations.The proposal consists of architectural proposals drawings and visualizations.Furthermore, a suggestion is given of how the property can be used and fitted into theoverall plan for urban density development currently underway in the city of Västerås.Computer programs used have been Microsoft Office Excel, AutoCAD and ArchiCAD.

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