• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 196
  • 123
  • 20
  • 19
  • 12
  • 9
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 3
  • 3
  • Tagged with
  • 488
  • 488
  • 125
  • 120
  • 112
  • 91
  • 77
  • 60
  • 56
  • 56
  • 55
  • 48
  • 46
  • 41
  • 41
  • 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.
181

The isotopic signature of nitrous oxide emitted from agricultural soils measured by FTIR spectroscopy

Parkes, Stephen. January 2008 (has links)
Thesis (Ph.D.)--University of Wollongong, 2008. / Typescript. Includes bibliographical references.
182

Cover crop and soil amendment effects on carbon sequestration in a silage corn-soybean cropping system

Fronning, Bradley Eric. January 2008 (has links)
Thesis (Ph. D.)--Michigan State University. Crop & Soil Sciences, 2008. / Title from PDF t.p. (viewed on Aug. 17, 2009) Includes bibliographical references. Also issued in print.
183

A model to evaluate CO₂ emission reduction strategies in the US

Arar, Joseph I., January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 149-154).
184

Land use forecasting in regional air quality modeling

Song, Ji Hee, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.
185

An apparatus to investigate photon induced gaseous reactions using Fourier transform infrared spectroscopy /

Manning, Gregory A. January 2000 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 132-137). Also available on the Internet.
186

Continuous measurement of soil surface carbon dioxide, nitrous oxide and methane fluxes to estimate global warming potentials in Great Plains maize-based agroecosystems

Shen, Hui. January 2008 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Jan. 15, 2009). PDF text: 147 p. : col. ill. ; 9 Mb. UMI publication number: AAT 3316416. Includes bibliographical references. Also available in microfilm and microfiche formats.
187

Consumo alimentar residual e produção de metano entérico de bovinos em confinamento e pastagem

Oliveira, Luíza Freitas de [UNESP] 11 July 2014 (has links) (PDF)
Made available in DSpace on 2015-03-03T11:52:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-11Bitstream added on 2015-03-03T12:07:05Z : No. of bitstreams: 1 000811404.pdf: 1077724 bytes, checksum: 848c14b08bb91fb93e0d059f6e9108c1 (MD5) / O estudo foi realizado com o objetivo de determinar o consumo alimentar residual (CAR) e a produção de metano entérico em bovinos Nelore confinados e em pastagem. Os animais foram avaliados em teste de desempenho pós-desmama confinados e em pastagem posteriormente. No confinamento foram coletados dados de consumo de alimentos e peso corporal de 163 animais jovens da raça Nelore, para a classificação quanto ao CAR. Destes, 49 animais (25 baixo e 24 alto CAR) foram submetidos à coleta de metano (CH4) entérico e 73 (49 baixo e alto CAR que participaram da coleta de CH4 e 24 médio CAR) foram avaliados novamente em pastagem. Quando confinados, os animais foram alimentados com dieta à base de silagem de milho e no pasto (Brachiaria brizhanta cv Marandu) foi fornecido suplemento múltiplo. No pasto, a excreção fecal foi estimada através do uso de indicador externo óxido de cromo, o consumo de suplemento, pelo indicador dióxido de titânio e o consumo de matéria seca foi obtido utilizando a FDNi como indicador interno. A mensuração do CH4, em ambos os experimentos, foi realizada através da técnica do SF6 durante 7 dias no confinamento e 6 dias no pasto. Os dados foram analisados utilizando procedimento GLM do SAS e as correlações entre o CAR calculado no confinamento e no pasto bem como as correlações entre as suas variáveis foram obtidas através do procedimento PROC CORR do SAS. Não foram encontradas diferenças (P<0,10) entre as classes de CAR no PC inicial, final e metabólico e no GMD em ambos os sistemas. No confinamento foram encontradas diferenças na excreção fecal (P=0,0008), no consumo de MS (P<0,0001), de FDN (P=0,0050), EB (P=0,0003) e na produção de CH4 (g/dia; P=0,0842) entre as classes de CAR. Na avaliação de CH4 feita em pastagem, não houve diferenças significativas entre as classes em nenhuma das medidas. No confinamento aproximadamente 31,5% dos animais mantiveram a classe de CAR, ao passo que ... / The study was conducted in order to determine the residual feed intake (RFI) and enteric methane production in Nelore cattle feedlot or pasture. The animals were evaluated on performance of feedlot post-weaning test and pasture later. In confinement data of food consumption and body weight of 163 young Nellore, for the classification of the CAR were collected. Of these, 49 animals (25 low and 24 high RFI) underwent collection of methane (CH4), enteric and 73 (49 low and high RFI that participated in the collection of CH4 and 24 average CAR) were evaluated again in pasture. When confined, the animals were fed a diet based on corn silage and pasture (Brachiaria brizhanta cv Marandu) was supplied multiple supplements. In the pasture, fecal excretion was estimated through the use of external markers of chromium oxide, supplement intake, the indicator titanium dioxide and dry matter intake was obtained using iNDF as internal indicator. The measurement of CH4, in both experiments, was performed using the technique of SF6 in confinement for 7 days and 6 days in the pasture. Data were analyzed using GLM procedure of SAS and the correlations between the CAR calculated in the feedlot and on pasture as well as the correlations between their variables were obtained from PROC CORR procedure of SAS. No differences (P <0.10) were found between classes of CAR in the initial, final and metabolic PC and GMD in both systems. In confinement differences were found in the fecal excretion (P = 0.0008) in DM intake (P <0.0001), NDF (P = 0.0050), EB (P = 0.0003) and in the production of CH4 (g / day, p = 0.0842) among the classes of CAR. In evaluating CH4 made on pasture, there were no significant differences between the classes in any of the measures. At approximately 31.5% of feedlot animals remained class of CAR, whereas 68.5% class switched on pasture. However, only 5% of the animals changed CAR CAR low to high, ie, efficient became inefficient and 17% were ...
188

Estudo de gases de efeito estufa na Amazônia

D'AMELIO, MONICA T.S. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:51:33Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:30Z (GMT). No. of bitstreams: 0 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP / FAPESP:04/04148-3
189

Factors affecting environmental sustainability of the downstream oil industry in Western Cape, South Africa

Tondhlana, Lawrence January 2018 (has links)
Thesis (MTech (Business Administration))--Cape Peninsula University of Technology, 2018. / The oil industry has been a major contributor to economic development in many countries; providing jobs, revenue, infrastructure and businesses to third parties. However, this development has also come with adversity on the physical environment. The oil industry accounts for the highest Green House Gas (GHG) emissions in the world, making it the number one polluter. In addition, South Africa has been regarded as the biggest polluter in Africa, with fossil-based fuel cited as the major cause of environmental degradation. South Africa’s physical environment is also cited as having degraded more than most countries in Africa. This proposition requires players in the oil industry to urgently address this situation. As the future of economic development is likely to be spearheaded by the oil industry, concerns have been raised at the slow rate of addressing oil companies’ operations which causes the environment to be less sustainable. This study uses a qualitative content analysis to explore the oil companies’ actions towards addressing environmental adversity caused by their unsustainable operations. In order to be environmental sustainable, oil companies must; incorporate environmental sustainability into missions and visions, financial investment into sustainable initiatives, involve top management in environmental programs, engage stakeholder, comply and align organisational processes and operations with environmental legislations and introducing renewable energy.
190

Vliv způsobu ochrany rostlin na řepku olejku a emise skleníkových plynů z jejího pěstování / Influence of plant protection system on oil rape and greenhouse gases emissions from oil rape growing

SAMEC, Jakub January 2017 (has links)
The theses serves as a comparison of different ways in the intensity of Brassica napus protection through the vegetational period. There were various protection types evaluated and their harmfulness was specified. Theses confronts the production of greenhouse gases emissions. The result is the surface unit emissive burden assesment and its conversion into the Brassica napus yield unit. These conclusions are based on the practical experiment which was realised in the farm located in Krty-Hradec village.

Page generated in 0.0352 seconds