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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.
161

Erosão hídrica em solo cultivado com aplicação de dejeto líquido de suínos / Water erosion in cultivetad soil with pig slurry application

Fontanive, Maicon 30 September 2016 (has links)
Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-03-07T14:38:13Z No. of bitstreams: 1 PGCS16MA152.pdf: 1026343 bytes, checksum: 9aece6d47b63a39320a6d4385220f021 (MD5) / Made available in DSpace on 2018-03-07T14:38:13Z (GMT). No. of bitstreams: 1 PGCS16MA152.pdf: 1026343 bytes, checksum: 9aece6d47b63a39320a6d4385220f021 (MD5) Previous issue date: 2016-09-30 / Many of the existing swine production systems in southern Brazil, provide high production of pig slurry. This situation leads to management problems, storage, distribution and environmental pollution caused by the improperly disposal of this waste product. The objective of this work was to determine the effect of application of dose increase of pig slurry on physical and chemical attributes of a Cambisol, in the production of plant biomass and water erosion, under three crops and compare the results with those obtained in soil condition uncultivated and without waste, in Rio do Sul - SC. The treatments were the control (no tillage and zero dose) and the doses 0 (zero), 50, 100 and 200 m³ ha-¹ of pig slurry applied on the soil surface. The application was performed in three stages after the implementation of millet, oat and sunn hemp in plots of 15 x 2.0 m, bounded by galvanized sheet, with an average gradient of 23.3%. The samples of erosive rainfall were collected to quantify the soil loss, water and nutrients. Before and after the experiment, soil samples were collected to evaluate the physical and chemical properties. At the end of each cultivation, dry matter production of shoot was determined. The increase of pig slurry doses increased production of biomass in the cultivated area, due to the improved porosity and, in part, of calcium, phosphorus and potassium, especially in the soil surface. Therefore, the water erosion reduces, after three cycles of cultivation. Soil losses were more influenced than the loss of water. The Ca, Mg, P and K contents in runoff water are the largest in treatments with higher doses of pig slurry. In the 200-m3 h-1 of pig slurry dose, the total nutrients losses in runoff are greatest / A erosão hídrica é a principal causa de degradação do solo agrícola e do ambiente no entorno dos sistemas de produção, fortemente influenciada pelo manejo do solo que, por sua, vez, é influenciando pelas adubações, dentro outros fatores. A maior parte dos sistemas de produção de suínos no sul do Brasil propicia produção de dejeto em alta quantidade. O dejeto gera problemas de manejo, armazenamento, distribuição e poluição ambiental causada pela erosão hídrica devido ao descarte do produto de forma de adubação, de maneira inadequada. Com o experimento objetivou-se estudar o efeito de dejeto líquido de suínos (DLS) em atributos de um Cambissolo Háplico, na produção de massa vegetal da parte aérea das plantas (MS) e na erosão hídrica em solo cultivado, e comparar os resultados com os obtidos em condição de solo sem cultivo e sem dejeto, em Rio do Sul - SC. Os tratamentos foram constituídos em testemunha (sem cultivo e sem dejeto) e pelas doses 0 (zero), 50, 100 e 200 m³ ha- ¹ de DLS aplicado na superfície do solo em três momentos após a implantação das culturas de milheto, aveia preta e crotalária, em parcelas de 15 x 2,0 m delimitadas por chapas galvanizadas, com declividade média de 23,3%. Ao longo da pesquisa foram determinadas as perdas de água e solo por erosão e coletadas amostras de enxurrada resultantes de chuvas erosivas para, nelas, determinar as perdas de alguns nutrientes. Antes da instalação do experimento e após o final da pesquisa, amostras de solo foram coletadas para avaliar as propriedades físicas e químicas e, ao final de cada cultivo, determinou-se ainda a produção de MS das plantas cultivadas no experimento. Identificou-se que o DLS aumentou a MS com o aumento da dose de dejeto, devido à melhoria da porosidade e, em parte, dos teores de cálcio, fósforo e potássio, em especial na superfície do solo. Com isso diminuiu a erosão hídrica ao final de três ciclos de cultivo. Em relação à erosão, as perdas de solo (PS) foram mais influenciadas do que as perdas de água (PA); os teores de Ca, Mg, P e K na água de escoamento superficial foram maiores nos tratamentos com as maiores doses de DLS do que naqueles das menores doses. As perdas totais de nutrientes na enxurrada, no entanto, foram maiores apenas na dose 200 m3 ha-1 de dejeto do que nas demais
162

Cobertura e rugosidade da superfície na proposição de indicadores de qualidade de um Cambissolo Húmico relacionados ao controle da erosão hídrica / Cover and surface roughness on proposing of quality indicators of a Humic Dystrupept related to the control of water erosion

Ramos, Júlio César 24 June 2015 (has links)
Made available in DSpace on 2016-12-08T15:50:05Z (GMT). No. of bitstreams: 1 PGCS15DA026.pdf: 2460426 bytes, checksum: 732fa428282a36b63e71ddb4a8f21830 (MD5) Previous issue date: 2015-06-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Soil management systems differ in the surface conditions and physical attributes and, consequently, on water erosion control. Soil quality indicators with a view to reducing water erosion can be generated by relationships of soil and water losses and runoff velocity with surface conditions and physical soil properties, which directly and indirectly influence the erosion. With de support of path coefficient analysis, this study aimed to identify and quantify indicates of soil quality in order to reduction of water erosion. The experiment was developed in the field, between May 2011 and April 2013, on a Humic Dystrupept with a mean slope of 0.134 m m-1, in southern Brazil under simulated rainfall condition with controlled intensity of 65 mm h-1 for 90 minutes of duration each one. The treatments were: a) cultivated soil: no tilled and covered by ryegrass (Lolium multiflorum) residue, with minimal roughness (HCR); no tilled and covered by vetch (Vicia sativa) residue, with minimal roughness (HCV); chiseled soil after ryegrass crop removing the above-ground residues and maintaining only the root system, with high roughness (HRR); chiseled soil after vetch crop removing the above-ground residues and maintaining only the root system, with high roughness (HRV); b) Uncultivated soil: bare and chiseled soil, with high roughness (BHR). Eight simulated rainfall were applied to each treatment, respectively on the days 17/12/2011, 10/01/2012, 07/02/2012, 10/03/2012, 11/05/2012, 18/08/2012, 02 / 11/2012 and 18/12/2012. In each rainfall applied, quantified the soil cover by residues, surface roughness, hydrological processes and some soil physical properties, relating the results later. The soil loss are less when the soil is covered by ryegrass residue than vetch. In soil covered by vetch residue, soil losses are equal to the chiseling containing only ryegrass roots.The soil scarification which remains only roots of ryegrass and vetch crops, reduces the total organic carbon content, the geometric mean diameter of the aggregates and increases soil density compared to the cultivated soil and covered with residues of these crops. The path coefficient analysis shows that the cover and the soil surface roughness, rate of water infiltration, total organic carbon and geometrical average diameter of aggregates are closely related to soil and water losses and runoff velocity on a Humic Dystrupept, and can be used as soil quality indicators to your resistance to water erosion. On a rough soil, the total organic carbon content, the geometric mean diameter of the aggregates, the root mass of roots and soil macroporosity have greater influence as indicators for soil resistance effect to water erosion. However, in the presence of soil cover by crop residues, such properties have lower weight as soil quality indicators to erosion / Os sistemas de manejo do solo diferem quanto às condições de superfície e atributos físicos e, consequentemente, no controle da erosão hídrica. Índices de qualidade do solo com vistas à redução da erosão hídrica podem ser gerados por meio de relações das perdas de solo e água e velocidade da enxurrada com as condições de superfície e atributos físicos do solo, os quais, direta e indiretamente influenciam a erosão. Com o auxílio da análise de trilha, este estudo objetivou identificar e quantificar indicadores de qualidade do solo com vistas à redução da erosão hídrica. O experimento foi desenvolvido em campo, entre maio de 2011 e abril de 2013, em um Cambissolo Húmico com declividade média de 0,134 m m-1, no sul do Brasil, sob condição de chuva simulada com intensidade planejada de 65 mm h-1 e 90 minutos de duração. Os tratamentos estudados foram: a) solo cultivado: sem preparo e coberto por resíduo cultural de azevém (Lolium multiflorum), com rugosidade mínima (SRA); sem preparo e coberto por resíduo cultural de ervilhaca (Vicia sativa), com rugosidade mínima (SRE); escarificado após o cultivo de azevém sem o resíduo cultural da parte aérea e mantendo-se apenas as raízes da cultura, com rugosidade alta (SEA); escarificado após o cultivo de ervilhaca sem o resíduo cultural da parte aérea e mantendo-se apenas as raízes da cultura, com rugosidade alta (SEE); b) solo sem cultivo: sem cobertura, escarificado, com rugosidade alta (SDE). Foram aplicadas oito chuvas simuladas em cada tratamento, respectivamente nos dias 17/12/2011, 10/01/2012, 07/02/2012, 10/03/2012, 11/05/2012, 18/08/2012, 02/11/2012 e 18/12/2012. Em cada chuva aplicada, quantificou-se a cobertura do solo por resíduos, a rugosidade superficial, processos hidrológicos e alguns atributos físicos do solo, relacionando os resultados posteriormente. As perdas de solo são menores quando o solo é coberto por massa de resíduo de azevém do que ervilhaca. No solo coberto por massa de resíduo de ervilhaca, as perdas de solo não diferem às do solo escarificado contendo apenas raízes de azevém. A escarificação do solo onde mantém-se somente as raízes das culturas de azevém e ervilhaca, diminui o teor de carbono orgânico total, o diâmetro médio geométrico dos agregados e aumenta a densidade do solo em comparação ao solo cultivado e coberto com os resíduos destas culturas. A análise de trilha mostra que a cobertura e rugosidade superficial do solo, taxa de infiltração de água, carbono orgânico total e diâmetro médio geométrico dos agregados têm estreita relação com as perdas de solo e água e velocidade de escoamento superficial em um Cambissolo Húmico, e podem ser utilizadas como indicadoras de qualidade do solo do ponto de vista de sua resistência à erosão hídrica. Em um solo rugoso, o carbono orgânico total, o diâmetro médio geométrico dos agregados, a massa de raízes e a macroporosidade do solo tem maior peso como indicadoras para efeito de resistência do solo à erosão hídrica. Entretanto, na presença de cobertura do solo por resíduos culturais, as referidas propriedades tem menor peso como indicadoras de qualidade do solo para erosão
163

Modelagem das perdas na agrologística de grãos no Brasil: uma aplicação de programação matemática. / Modeling of the losses in grains\' agro-logistics in Brazil: an application of mathematical programming

Thiago Guilherme Pera 13 April 2017 (has links)
A redução das perdas é de grande importância para estabilizar a oferta de alimentos ao longo da cadeia de suprimentos e fortalecer a segurança alimentar. O objetivo geral desta pesquisa foi realizar um diagnóstico detalhado sobre as perdas que ocorrem nas diversas atividades logísticas de soja e milho no Brasil, envolvendo a quantificação das perdas físicas, econômicas e ambientais acumuladas na cadeia de suprimentos de tais grãos e a identificação de estratégias e políticas públicas para mitiga-las, através da modelagem de programação matemática. Além disso, foi possível estruturar uma função de perdas na agrologística de grãos a partir de quatro variáveis: tipo de armazenagem, qualidade das vias rodoviárias, modalidade de transporte e canal de comercialização. As perdas totais na cadeia de suprimentos de soja e milho no ano de 2015 no Brasil atingiram o patamar de 2,381 milhões de toneladas, ou seja, algo em torno de 1,303% da produção, incorrendo em perdas econômicas decorrentes do custo de oportunidade com vendas perdidas e de gastos logísticos desnecessários na ordem de R$ 2,04 bilhões (US$ 610,78 milhões). Os cenários avaliados demonstram que a ampliação no uso da armazenagem dentro da fazenda, melhoria nas condições das rodovias brasileiras e das estradas que conectam as fazendas aos armazéns apresentam grande potencial para mitigação das perdas. Apesar da perda relativa de uma atividade logística assumir valor decimal, a perda acumulada ao longo da cadeia de suprimentos assume um valor global bastante considerável. Esse retrato enfatiza a necessidade de conscientização sobre as perdas visando fomentar políticas públicas e gestões eficientes para mitiga-las, dado as externalidades econômicas, ambientais e sociais geradas. / Reducing losses is of great importance in stabilizing the supply of food throughout the supply chain and strengthening food security. The general objective of this research was to perform a detailed diagnosis of the losses that occur in the many logistic activities of soybeans and maize in Brazil, involving the quantification of accumulated physical, economic and environmental losses in the supply chain of such grains and the identification of strategies and public policies to mitigate such losses through mathematical programming modeling. Besides, it was possible to structure a loss function of grains\' agrologistics in terms of four variables: type of storage, quality of roads, modality of transportation and marketing channel. Total losses in the soy and maize supply chain in 2015 in Brazil reached up to 2.381 million tons, or about 1.303% of production, incurring economic reductions due to the cost of loss (reduced sales and unnecessary logistical expenses for the handling of losses) in the order of R$ 2.04 billion (US$ 610.78 million). The evaluated scenarios show that the increase in the use of on-farm storage, the improvement in the conditions of the Brazilian highways and roads that connect the farms to the external warehouses present great potential to mitigate the losses. In spite the relative loss of a logistic activity takes on decimal value, the cumulative loss along the supply chain assumes a fairly considerable overall value. This reality emphasizes the need to raise awareness about losses in order to foster public policies and efficient management to mitigate them, given the created economic, environmental and social externalities.
164

Assessed losses: the trade and income from trade requirements as set out in section 20 of the Income Tax Act of 1962 / Trade and income from trade requirements as set out in section 20 of the Income Tax Act of 1962

Pillay, Neermala Neelavathy January 2012 (has links)
Section 20 of the Income Tax Act, No 58 of 1962 allows a taxpayer that incurs an assessed loss to carry forward the balance of assessed loss incurred, to be set off against taxable income earned in or added to losses incurred in future years. The issues regarding the carry forward of assessed losses in terms of section 20 is complex and in terms of the said section, a company is only entitled to set off its assessed loss from the previous year against its taxable income in the current year, if the taxpayer has carried on a trade during the current year and has derived income from that trade. Under the provisions of section 20(2A), a taxpayer other than a company can utilise an assessed loss even if no trading has been conducted. Assessed losses of natural persons, may however be ring-fenced. The aim of this treatise was twofold. Firstly it was to gain clarity on the „trade‟ and „income from trade‟ issues and secondly to compare South African legislation with that of Australia, with a view to recommending a change in our rules regarding the treatment of assessed losses in the context of companies. The critical lessons to be learned from the cases presented, is that liquidators, creditors and others must ensure that the company continues trading in order to x keep the assessed losses valid. Realisation of assets (including stock), and the collection of outstanding debts during liquidation does not constitute the carrying on of a trade in terms of s 20(1). The continuity of trade is an important element in regard to the carry forward of assessed losses to be utilised in the current and future years. Therefore it is important that a company carries on some activity that falls within the definition of trade. In the landmark case of SA Bazaars, it was held that a company did not have to trade continuously throughout the year to qualify for the set-off of the assessed loss or carry forward of the assessed loss, that is, to trade for say part of the year. The court however left open the issue of whether it was necessary to derive income from that trade. In order to clarify the issues regarding assessed losses, SARS issued Interpretation Note 33 granting taxpayers a concession in certain cases where a company has traded, but not derived income from that trade. But in ITC 1830, the court ruled that a company must trade and must derive income from that trade in order to carry forward its assessed loss, which effectively means that SARS cannot apply Interpretation Note 33. SARS does not have the authority to make concession which is contrary to the wording of the Act. xi In Australia, operating losses can be carried forward indefinitely to be set-off against future income, provided a company meets the more than 50% continuity of ownership test. Where the continuity test fails, losses can be deducted if the same business is carried on in the income year (the same business test). From the research conducted and in order to solve the issues surrounding the carry forward of assessed losses it was suggested that one of the following be adopted :- The method used in Australia for the carry forward of assessed losses., or A decision of the Supreme Court of Appeal is needed for a departure from the literal meaning of the words pertaining to the requirements regarding the carry forward of assessed losses. Furthermore, to clarify the definition of „income‟, as used in the context of s20, is it gross income less exempt income or taxable income?. If section 20 relates to taxable income, then an assessed loss will never be increased, which it is submitted, is not what the legislature intended. Section 20 ought to be revisited to eliminate any uncertainty about the income requirement and in the context in which the word „income‟ is used in that section.
165

Debt defeasance : an income tax loophole or a pointless pursuit

Bryant, Cathrine 15 August 2012 (has links)
LL.M. / The concept of a debt defeasance transaction has recently come under scrutiny in the South African financial market. In the financial arena lower lending rates and efficient tax planning are of paramount consideration to corporate entities seeking to raise finance and to properly structure their affairs. Debt defeasance transactions recognise the time value of money. Companies with long-term borrowings obtain financial advantages if those borrowings can be retired early as the present value of the liability is less than the face value thereof. The objective of this paper is to present a comparative study of the manner in which debt defeasance transactions have been dealt with in the Australian jurisdiction and how the South African courts would view the income tax consequences of such transactions. The choice of the Australian jurisdiction finds its motivation in the similarity of the income tax regime of that country with the system applied in South Africa. Although the Australian income tax legislation allows for a wider range of income to be recognised as assessable income (hence the frequent references to "income according to ordinary concepts" in the judicial pronouncements in that country) the concept of an accrual of income is recognised and applied in the Australian legislation in a similar manner to that of the South African income tax legislation. In addition, there have been a number of recent decisions in the Australian courts on debt defeasance transactions that were implemented during the 1980's. Given that the South African courts are mindful of developments in 2 Australia and will seek guidance from that jurisdiction, the contemporary nature of the Australian decisions referred to below is insightful and useful in a comparative study. The conclusions reached in this dissertation are that the income tax benefits sought by the parties to the transaction and which are pivotal to the success of the transaction, will not be available in the South African context, just as they are not available in Australia. In certain circumstances the debt defeasance profit, as it is termed in this paper, will be fully taxable in the hands of the taxpayer to whom it accrues, particularly in regard to instantaneous defeasances and where the taxpayer is a financial institution. It is this outcome of the application of the general principles of the South African income tax legislation that leads to the failure of the transaction as a fund raising tool in the structured finance environment. Thought has been given to whether or not the South African legislation should be amended to cater specifically for the debt defeasance transaction. There are no issues that are created by these transactions, such as mismatches in the timing of accruals and deductions as is the case in the trading of financial instruments, that are not already catered for in the current income tax legislation. The main enquiry in determining the consequences of a debt defeasance transaction is in the application of the gross income definition in section 1 of The Income Tax Act 58 of 1962. The application of the gross income definition is trite law and the judicial pronouncements thereon are 3 adequate guidance and it is submitted that no amendment to the Income Tax Act is required to cater for debt defeasance transactions. The structure of this paper will be to give an overview of the mechanics of debt defeasance transactions and the defeasance transactions and the consequences thereof. A survey of the Australian examples of debt defeasances is undertaken and the judgements given by the Australian courts in response to such transactions are canvassed. An analysis will finally be undertaken on the income tax consequences of debt defeasances as they have been imported into South Africa
166

Horkovodní roštový kotel / Hot Water Grate Boiler

Svoboda, Marek January 2019 (has links)
This thesis deals with design of hot water grate boiler, where the output is water with parameters 130 °C and pressure 16 bar. In the content of the whole thesis is gradually introduced a stoichiometric calculations, which is based on the specified fuel – wood chips. This is followed by the design of the individual heating surfaces according to the thermal calculations given in the thesis. Finally, the calculation is extended by hydraulic and aerodynamic losses. Dimensional design, as a basic scheme, is shown at thesis. More detailed drawing documentation is attached to this thesis.
167

Zlepšení energetických parametrů asynchronních strojů malého výkonu / Improvement Power Parameter of Small Induction Motors

Halfar, Tomáš January 2013 (has links)
The master’s thesis Improvement power parameter of small induction motors deals with issues of lowering the losses of small induction motors. The first part introduces with design and principles of operation of induction motors. Also introduces to theoretical problematic of losses, their lowering and measuring. In the practical part there are results of the measuring the losses in the induction motor ATAS Elektromotory Náchod a.s. T22VT512 (71-0512). There are proposed methods of increasing the efficiency of induction motor due to measuring and their verification in the Maxwell software. The last part is dedicated to measuring the losses of prototype motor from ATAS and comparison of results with previous motor.
168

Hydraulika potrubních sítí ve vzduchotechnice / Hydraulic of pipeline network in ventilation systems

Bernard, Jiří January 2014 (has links)
This diploma thesis describes hydraulic properties of specific types of fittings designed to HVAC systems with primary focus on pressure losses of these fittings. We are focusing on comparison of specific fittings with usual systems of spiro pipes in the project part of this thesis.
169

Ekonomický náhled volby rychlozávěrného ventilu pro vodní dílo Vranov / Economic view of the fast closing valve selection for HPP Vranov

Gipka, Ondřej January 2012 (has links)
The thesis deals with the evaluation of the investment in the fast closing valve replacement in The dam Vranov using Computational fluid dynamics (CFD). The final effects of the fast closing valve replacement will be examined on three different types of valves with regard to the turbine output in operation zone and without the influence of water intake runner and turbine draft tube. The aim of the thesis is to theoretically evaluate alternatives of the fast closing valve replacement and define its basic characteristics and classifications.
170

Vlastnosti asynchronního motoru napájeného z frekvenčního měniče / Induction motor powered from inverter

Fiala, Petr January 2016 (has links)
This master’s thesis studies additional losses generated in the induction motor powered from inverter. The first chapter was used for literature search and it mentions valuable publications. The second chapter discusses the different types of losses in the induction motor. The third chapter describes other negative effects on motor caused by inverter, the fourth one defines possible measuring methods, which would lead to the quantification of additional losses. The fifth chapter introduces the electromotor tested as well as the measuring instruments used. The last chapter presents pivotal results of the measurement in the testing room.

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