• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 492
  • 254
  • 60
  • 35
  • 33
  • 12
  • 10
  • 10
  • 10
  • 10
  • 10
  • 10
  • 9
  • 8
  • 8
  • Tagged with
  • 1119
  • 232
  • 142
  • 106
  • 101
  • 85
  • 82
  • 79
  • 73
  • 72
  • 66
  • 65
  • 65
  • 61
  • 60
  • 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.
251

Effects of nitrogen and water on growth, photosynthesis, and leaf properties of deciduous tree species with consequences for gypsy moth herbivory

Myers, Teri S. January 2000 (has links)
Thesis (Ph. D.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains ix, 118 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
252

Research in photosynthesis.

Anderson, Joan Mary. January 1959 (has links)
Thesis--University of California, Berkeley, 1959. / "Biology and Medicine" -t.p. "TID-4500 (15th Ed.)" -t.p. Includes bibliographical references (p. 109-113, 156-158).
253

Subsurface light conditions and light attenuation mechanisms in Missouri reservoirs /

Watanabe, Shohei, January 2004 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 80-85). Also available on the Internet.
254

The effects of water and shade treatments on photosynthesis and root-rhizosphere respiration in young ponderosa pine /

Johnson, Theresa J. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references. Also available on the World Wide Web.
255

Evaluating pulse-amplitude modulated fluorometry for landscape scale assessment of photosynthetic characteristics /

Belshe, Elizabeth F. January 2005 (has links) (PDF)
Thesis (M.S.)--University of North Carolina at Wilmington, 2005. / Includes bibliographical references (leaves: [87]-88)
256

Control of plant development by light, CO2 and oligosaccharins in vitro with emphasis to strawberry (Fragaria x ananassa) 'Red Joy' /

Miranda, John Hubert. January 2001 (has links) (PDF)
Thesis (Ph.D.) - University of Queensland, 2002. / Includes bibliography.
257

Impact of elevated temperature and (CO₂) on spring phenology and photosynthetic recovery of boreal Norway spruce /

Slaney, Michelle. January 2006 (has links)
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2006. / Thesis documentation sheet and errata sheet inserted. Appendix reprints five manuscripts co-authored with others. Includes bibliographical references. Also partially issued electronically via World Wide Web in PDF format; online version lacks appendix.
258

Inorganic carbon uptake by acidophilic algae /

Balkos, Konstantine Dino. January 2005 (has links)
Thesis (M.Sc.)--York University, 2005. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 88-95). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11743
259

Modeling the TyrZ-His 190 Pair of Photosystem II for the Study of Proton Coupled Electron Transfer

January 2011 (has links)
abstract: The work described in the thesis involves the synthesis of a molecular triad which is designed to undergo proton coupled electron transfer (PCET) upon irradiation with light. Photoinduced PCET is an important process that many organisms use and the elucidation of its mechanism will allow further understanding of this process and its potential applications. The target compound designed for PCET studies consists of a porphyrin chromophore (also a primary electron donor), covalently linked to a phenol-imidazole (secondary electron donor), and a C60 (primary electron acceptor). The phenol-imidazole moiety of this system is modeled after the TyrZ His-190 residues in the reaction center of Photosystem II (PS II). These residues participate in an intermolecular H-bond between the phenol side chain of TyrZ and the imidazole side chain of His-190. The phenol side chain of TyrZ is the electron transfer mediator between the oxygen evolving complex (OEC) and P680 (primary electron donor) in PSII. During electron transfer from TyrZ to P680*+, the phenolic proton of TyrZ becomes highly acidic (pKa~-2) and the hydrogen is preferentially transferred to the relatively basic imidazole of His-190 through a pre-existing hydrogen bond. This PCET process avoids a charged intermediate, on TyrZ, and results in a neutral phenolic radical (TyrZ*). The current research consists of building a molecular triad, which can mimic the photoinduced PCET process of PSII. The following, documents the synthetic progress in the synthesis of a molecular triad designed to investigate the mechanism of PCET as well as gain further insight on how this process can be applied in artificial photosynthetic devices. / Dissertation/Thesis / M.S. Chemistry 2011
260

Fisiologia de plantas de meloeiro cultivadas sob diferentes níveis de irrigação / Phisiology of plants the melon cultivaded under different levels of irrigation

Silveira, Enio Marques de Castro January 2013 (has links)
SILVEIRA, Enio Marques de Castro. Fisiologia de plantas de meloeiro cultivadas sob diferentes níveis de irrigação. 2013. 56 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2013. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-17T19:48:10Z No. of bitstreams: 1 2013_dis_emcsilveira.pdf: 622829 bytes, checksum: b4531a2152319722c83fb11370726eec (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-07-05T17:25:40Z (GMT) No. of bitstreams: 1 2013_dis_emcsilveira.pdf: 622829 bytes, checksum: b4531a2152319722c83fb11370726eec (MD5) / Made available in DSpace on 2016-07-05T17:25:40Z (GMT). No. of bitstreams: 1 2013_dis_emcsilveira.pdf: 622829 bytes, checksum: b4531a2152319722c83fb11370726eec (MD5) Previous issue date: 2013 / The melon is the most exports of fresh fruit produced in Brazil, especially being produced in the states of Rio Grande do Norte and Ceará. All this curcubitaceae commercial orchard in the two regions is performed under irrigated conditions. Thus, measures of efficient use of water become essential for this crop. The improvement in efficiency of water use will depend primarily on a management plan that deliver only the amount of water necessary for their full development. The study aimed to evaluate plant growth, water status, gas exchange and yield of yellow melon grown under different irrigation levels. Therefore, two experiments were conducted in the experimental field of Curu, Paraipaba, CE, using hybrid Gold Mine, with spacing of 2.0 m x 0.4 m, under drip irrigation. The first experiment consisted of weekly evaluation of plant growth in response to applying three different irrigation water levels: 100% 80% and 120% (T1, T2 and T3 respectively) of calculated levels. In the second experiment, in addition to the treatments mentioned above, was inserted another factor: the irrigation schedule of 24 to 48 hours, with four replicates. In this it, was evaluated gas exchange, water potential, the carbohydrate in different parts of the plant, yield and fruit quality. In all treatments the plants showed the lowest water potential daily between 12:00 to 2:00pm. Although stomatal conductance decreases during the day curse, it remained in amounts sufficient for photosynthetic rate nearly constant, with a slight reduction after noon and marked decrease only after 4:00pm. In turn, with the exception of transpiration, which was higher in plants irrigated every 48 hours, the irrigation water levels and the irrigation schedule did not affect gas exchange of plants. Likewise, the production, the size and quality of melon fruits were practically not influenced by treatments. Thus, under the experimental conditions used, the increase or decrease of 20% of irrigation water level calculated and recommended to the melon in the region, did not affect plant development, nor the production. Only the amount of total soluble solids was positively influenced by the addition of 20% of the water levels calculated, when applied daily. / O melão representa a maior parte das exportações de frutas frescas produzidas no Brasil, sendo cultivado em larga escala nos estados do Rio Grande do Norte e Ceará. Todo o cultivo comercial desta curcubitácea nestas duas regiões é realizado sob condições de irrigação. Assim, medidas de uso eficiente da água tornam-se essenciais para esta cultura. A melhoria na eficiência do uso da água irá depender principalmente de um manejo que entregue à planta somente a quantidade de água necessária para o seu pleno desenvolvimento. Neste sentido, o presente trabalho teve por objetivo avaliar o crescimento das plantas, o estado hídrico, as trocas gasosas e a produção do meloeiro amarelo cultivado sob diferentes lâminas de irrigação. Para tanto, conduziram-se dois experimentos no Campo Experimental do Curu, no município de Paraipaba, CE, utilizando híbrido Gold Mine, com espaçamento de 2,0 m x 0,4 m e irrigado por gotejamento. O primeiro experimento consistiu na avaliação semanal do crescimento das plantas em resposta à aplicação de três diferentes lâminas diárias de irrigação: 100% 80% e 120% (T1, T2 e T3 respectivamente) da lâmina calculada. No segundo experimento, além dos tratamentos citados anteriormente, foi inserido outro fator: turno de rega de 24 e 48 horas, com quatro repetições por tratamento. Neste, se avaliou as trocas gasosas, o potencial hídrico, os teores de carboidratos nas diversas partes das plantas e a produção e qualidade dos frutos. Em todos os tratamentos, as plantas apresentaram o menor potencial hídrico diário no período de 12h00min às 14h00min. Apesar de a condutância estomática decrescer ao longo do dia, a mesma se mantinha em valores suficientes para permitir uma taxa fotossintética praticamente constante, com leve redução após o meio dia e decréscimo acentuado somente após as 16h00min. Por sua vez, com exceção da transpiração, que foi mais alta nas plantas irrigadas a cada 48 horas, o turno de rega e as lâminas hídricas aplicadas não influenciaram as trocas gasosas das plantas. Da mesma forma, a produção, o tamanho e a qualidade dos frutos de meloeiro praticamente não foram influenciados pelos tratamentos aplicados. Assim, nas condições experimentais utilizadas, o acréscimo ou diminuição de 20% da lâmina de água calculada recomendada para o melão na região, não influenciou o desenvolvimento das plantas, nem tampouco a produção. Apenas a quantidade de sólidos solúveis totais (ºBrix) foi influenciada positivamente pelo o acréscimo de 20% da lâmina calculada, quando aplicada diariamente.

Page generated in 0.0152 seconds