• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1096
  • 75
  • 64
  • 28
  • 12
  • 12
  • 12
  • 10
  • 9
  • 8
  • 7
  • 6
  • 4
  • 2
  • 2
  • Tagged with
  • 1303
  • 648
  • 199
  • 172
  • 143
  • 119
  • 117
  • 111
  • 101
  • 94
  • 71
  • 67
  • 66
  • 63
  • 61
  • 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

CLIENT MOTIVE FOR COUNSELOR SELECTION, AND SATISFACTION WITH COUNSELING IN AN UNASSIGNED COUNSELOR SETTING

Deardorff, Chester Duane, 1933- January 1972 (has links)
No description available.
182

Some late prehistoric villages southeast of Tucson, Arizona

Zahniser, Jack L., 1937- January 1965 (has links)
No description available.
183

Bioarchaeological analysis of commingled skeletal remains from Bee Cave Rockshelter (41VV546), Val Verde County, Texas

Simmons, Terrie L. January 1900 (has links)
Thesis (M.A.)--Texas State University-San Marcos, 2007. / Vita. Appendix: leaves 87-151. Includes bibliographical references (leaves 152-160).
184

Prehistoric settlement and physical environment in the Mesa Verde area

Herold, Joyce. January 1961 (has links)
Thesis (M.A.)--University of Colorado. / Bibliography: p. 132-153.
185

Bioarchaeological analysis of commingled skeletal remains from Bee Cave Rockshelter (41VV546), Val Verde County, Texas /

Simmons, Terrie L. January 1900 (has links)
Thesis (M.A.)--Texas State University-San Marcos, 2007. / Vita. Appendix: leaves 87-151. Includes bibliographical references (leaves 152-160).
186

Mineral Constraints on the Source Lithologies at Fogo, Cape Verde. / Geokemiska ledtrådar till de aktiva mantelkomponenterna på Fogo, Kap Verde.

Rydeblad, Elin January 2018 (has links)
Variations in major, minor, and trace elements compositions and ratios, as well as isotope ratios are all useful tools in studying the composition of the Earth’s mantle, and heterogeneities present therein. Since the mantle itself doesn’t easily lend itself to study, ocean island basalt (OIBs) are commonly used as a proxy due to compositional differences combined with the range of origination depth, a combination that allows them to represent the heterogeneity of the mantle, sampling everything from the core mantle boundary to the old or recent additions of recycled oceanic crust. Fogo, being one of the most active volcanoes in the world, continuously samples the interior of our planet, and as such is a prime location for studies of mantle geochemistry. This study aims to determine the origin of the mantle lithologies present at Fogo. The study is a continuation and extension of the studies conducted by Barker et al. (2014) and Magnusson (2016). This study utilises major, minor, and trace element geochemistry in clinopyroxene and olivine phenocrysts, as well as Ni-isotopes from whole rock samples. Using the relative values of Ni, Mn, and trace elements and their ratios in olivine and clinopyroxene phenocrysts we aim to further unravel the mechanics of the creation of ocean islands and provide additional constraints regarding the mechanics of the formation of heterogeneities in the Earth’s mantle. This study will focus on Ni* and Mn* in olivine phenocrysts, trace element composition and ratios of olivine phenocrysts and clinopyroxene phenocrysts, and Ni-isotope data.  This study found evidence for both pyroxenite, carbonatite, and carbonated eclogite source lithologies at Fogo. A correlation between La/Sm and δ60Ni was also found, indicating a control on the δ60Ni by source pyroxenite. This study suggests a carbonated eclogite origin for the lithologies present at Fogo, which would have hosted the majority of the olivine phenocrysts. The phenocrysts then resided within a separated carbonatite melt fraction that either contaminated or metasomatized a pyroxenite melt where the clinopyroxene phenocrysts nucleated. The melt then evolved to an alkali basalt melt through melt-rock reactions, principally via the dissolution of orthopyroxenes and concomitant precipitation of clinopyroxene and olivine (Zhang, Chen, Jackson & Hofmann 2017).
187

Avaliação de biocompostos e composição mineral de extratos provenientes de duas macroalgas lóticas do estado de São Paulo /

Tófoli, Rodolfo José. January 2017 (has links)
Orientador: Ivanise Guilherme Branco / Banca: Eliana Janet Sanjinez Argandoña / Banca: Cássia Roberta Malacrida Mayer / Resumo: No Brasil, há uma grande biodiversidade de espécies de algas lóticas, Dentre as mais conhecida, encontradas em rios e riachos da região sudeste do estado de São Paulo destaca-se a Oedogonium sp. e a Nitella microcarpa var. wrightii., dois gêneros de algas verdes. Entretanto, estudos de caracterização química de extratos destas algas ainda são inexistentes. Por esse motivo destaca-se a importância deste trabalho, o qual encontra-se subdivido em dois estudos. O primeiro teve por objetivo avaliar e quantificar compostos fenólicos e capacidade antioxidade de extratos de diferentes solventes da alga Oedogonium sp. Utilizou-se um delineamento experimental de mistura para determinar a influência dos solventes e verificou-se qual desses apresentou melhor rendimento na extração desses compostos da alga em pó. O segundo estudo teve por objetivo realizar a caracterização de duas macroalgas verdes: Nitella microcarpa var. wrightii, e Oedogonium sp., através da obtenção de um extrato, com o melhor sistema de solventes obtidos no primeiro estudo. Desta forma, foi possível quantificar quanto a presença de minerais, flavonoides, umidade, carotenoides, compostos fenólicos e capacidade antioxidante. No primeiro estudo, os resultados sugeriram que a mistura acetona-etanol apresentou melhor rendimento de extração tanto para compostos fenólicos como à capacidade antioxidante. No segundo estudo, a alga Oedogonium sp. destacou-se por apresentar uma grande quantidade de carotenoides totais. Já a e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In Brazil, there is a great biodiversity of lotic algae species. Among the most well known species found in rivers and streams in the southeast region of the state of São Paulo is Oedogonium sp. and Nitella microcarpa var. Wrightii., Two genus of green algae. However, studies of chemical characterization of extracts of these algae are still non existent. For this reason the importance of this work is highlighted, which is subdivided in two studies. The first one had the objective to evaluate and quantify phenolic compounds and antioxidant capacity of extracts of different solvents of the algae Oedogonium sp. An experimental design of the mixture was used to determine the influence of the solvents and it was verified which of them presented better yield in the extraction of these compounds from the powdered seaweed. The second study aimed to characterize two green macroalgae: Nitella microcarpa var. Wrightii, and Oedogonium sp., by obtaining an extract, with the best solvent system obtained in the first study. In this way, it was possible to quantify the presence of minerals, flavonoids, moisture, carotenoids, phenolic compounds and antioxidant capacity. In the first study, the results suggested that the acetone-ethanol-water mixture had a better extraction yield for both phenolic compounds and antioxidant capacity. In the second study, the alga Oedogonium sp. was characterized by a large amount of total carotenoids. The other alga, of the species Nitella microcarpa var... (Complete abstract click electronic access below) / Mestre
188

Adubação nitrogenada e doses do herbicida glyphosate como regulador de crescimento em grama esmeralda /

Gazola, Raíssa Pereira Dinalli January 2017 (has links)
Orientador: Salatiér Buzetti / Resumo: A adubação nitrogenada proporciona, além da nutrição, a manutenção da coloração verde intensa em gramados ornamentais, imprescindível do ponto de vista estético. Mas, o nitrogênio (N) aumenta o crescimento da parte aérea e, assim, maior será frequência de cortes, principal fator do custo de manutenção em gramados. Neste contexto, objetivou-se avaliar a adubação nitrogenada (via solo com ou sem via foliar), e o uso de doses do herbicida glyphosate em grama esmeralda (Zoysia japonica Steud.), visando reduzir o crescimento do gramado, bem como manter sua qualidade visual (verde intenso) e nutricional. O experimento foi conduzido na Fazenda de Ensino, Pesquisa e Extensão da UNESP, Campus de Ilha Solteira/SP, de agosto de 2014 a fevereiro de 2017, em um ARGISSOLO VERMELHO Eutrófico areno-argiloso. Utilizou-se o delineamento em blocos casualizados com 20 tratamentos dispostos em fatorial 5 x 4, com quatro repetições, em 10 m2 por parcela. Os tratamentos foram: testemunha (sem N); 15 g m-2 de N aplicado via solo e sem N via foliar; 30 g m-2 de N aplicado via solo e sem N via foliar; 15 g m-2 de N aplicado via solo e com N via foliar (1% de ureia) e 30 g m-2 de N aplicado via solo e com N via foliar (1% de ureia), combinados com quatro doses de glyphosate (0, 200, 400 e 600 g ha-1 do ingrediente ativo - i.a.). As doses de N via solo foram parceladas em cinco aplicações durante o ano e, portanto, corresponderam a 3 e 6 g m-2 de N a cada aplicação, respectivamente, para as doses de 15 ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Nitrogen fertilization provides, in addition to nutrition, the maintenance of intense green color in ornamental turfgrasses, necessary underesthetic view point. However, nitrogen (N) increases the shoots growth and, thus, the frequency of cuts, the main factor in the cost of turfgrasses maintenance. In this context, this study aimed to evaluate nitrogen fertilization (via soil and/or foliar) and the use of rates of glyphosate in zoysiagrass (Zoysia japonica Steud.) to reduce growth and maintain the visual quality (intense green) and good nutritional quality. The research was conducted at the Experimental Station of UNESP, Ilha Solteira/SP, from August/2014 to February/2017, on an Ultisol. It was used a randomized block design with 20 treatments arranged in a factorial scheme 5 x 4 with four replications and 10 m2 per plot. The treatments was: control (without N), 15 g m-2 of N in the soil without application of foliar N; 30 g m-2 of N in the soil without application of foliar N; 15 g m-2 in the soil with foliar application of N (1% urea) and 30 g m-2 of N in the soil with foliar application of N (1% urea) combined with four rates of glyphosate (0, 200, 400 and 600 g ha-1 active ingredient (a.i.)). N rates in the soil were split in five times during the year and, therefore, corresponded to 3 and 6 g m-2 of N at each application, respectively, for the rates of 15 and 30 g m-2 of N. Were evaluated: the chemical attributes of the soil, height and dry matter of leaves, leaf area, ... (Complete abstract click electronic access below) / Doutor
189

Desenvolvimento de método analítico para a determinação do herbicida paraquat em urina humana /

Santiago, João Victor Biagi. January 2018 (has links)
Orientador: Leonardo Pezza / Banca: Jose Anchieta Gomes Neto / Banca: Aristeu Gomes Tininis / Resumo: A proposta apresentada por este trabalho foi estudar e desenvolver um método analítico para a determinação do herbicida paraquat em urina humana, de modo que este seja rápido, sensível, econômico e com uma menor geração de resíduos em relação aos métodos disponíveis, atualmente empregados para esta finalidade, atendendo assim os princípios e requisitos da Química Verde (Green Chemistry) e da Química Analítica Verde (Green Analytical Chemistry). Outro aspecto também abordado, é o emprego da técnica de análise por imagem digital utilizando software analítico através da geração de imagens digitais por meio das fotografias obtidas dos spot-tests, tornando a metodologia portátil e consequentemente mais acessível. O método desenvolvido consiste na reação de redução do dicátion paraquat (PQ2+) para a formação de um cátion radicalar (PQ*+) de coloração azul, utilizando uma solução de glicose (Glc) em meio alcalino (NaOH) como reagente redutor. As concentrações dos reagentes foram otimizadas para obter a maior resposta analítica possível, com o auxílio de ferramentas quimiométricas. O produto colorido possui máxima absorbância em torno de 600 nm, e, devido a coloração azul intenso desenvolvida na sua redução, tornou-se possível sua detecção e quantificação por análise das imagens digitais dos spot-tests da reação no canal de cor vermelho (canal Red do sistema RGB), utilizando-se o software livre "ImageJ - Image Processing and Analysis in Java". Através da análise da intensidade efetiv... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work was proposed study and develop an analytical method for determination and quantification of paraquat herbicide in human urine samples, so that this is rapid, sensible, economic, and lesser waste generating that the related methods in literature, currently employed for this purpose, following with Green Chemistry (G.C.) and Green Analytical Chemistry (GAC) principles. Another approached aspect is employ of Digital Image Analysis (DIA) technique using analytical software through the generating digital images photographed of the spot-tests, making the methodology portable and consequently most accessible. The method developed is based in reduction reaction between paraquat dicátion (PQ2+) for this formation of the radicalar cation (PQ*+) of blue coloring, using a glucose (Glc) solution in alkaline mean (NaOH) as reducing reagent, the reagent concentrations was being optimized for the highest analytical response possible, with the help of the chemometric tools. The colored product has max absorbance at 600 nm, and, because intense blue coloring developed in the reduction, was possible to the detection and quantification from analysis of the digital images of the spot-tests of reaction in red color channel (Red channel of the model RGB), employing the free software ImageJ - Image Processing and Analysis in Java. Through of the analysis of effective intensity (Ar) of the coloring, measured in the red color channel, was plotted an analytical curve that present linearity in... (Complete abstract click electronic access below) / Mestre
190

Plant Community Composition along the Historic Verde River Irrigation System: Does Hydrochory Play a Role?

January 2010 (has links)
abstract: As an industrial society, humans have increasingly separated agricultural processes from natural ecosystems. Many areas of the Southwestern US, however, maintain traditional practices that link agricultural systems to the natural environment. One such practice, diverting river water into fields via earthen irrigation canals, allows ditch water to recharge groundwater and riparian vegetation to prosper along canal banks. As there is growing interest in managing landscapes for multiple ecosystem services, this study was undertaken to determine if irrigation canals function as an extension of the riparian corridor. I was specifically interested in determining if the processes within semi-arid streams that drive riparian plant community structure are manifested in earthen irrigation ditches. I examined herbaceous and woody vegetation along the middle Verde River, AZ, USA and three adjacent irrigation ditches across six months. I also collected sieved hydrochores--seeds dispersing through water--within ditches and the river twelve times. Results indicate that ditch vegetation was similar to streamside river vegetation in abundance (cover and basal area) due to surface water availability but more diverse than river streamside vegetation due to high heterogeneity. Compositionally, herbaceous vegetation along the ditch was most similar to the river banks, while low disturbance fostered woody vegetation along the ditches similar to high floodplain and river terrace vegetation. Hydrochore richness and abundance within the river was dependent on seasonality and stream discharge, but these relationships were dampened in the ditches. Species-specific strategies of hydrochory, however, did emerge in both systems. Strategies include pulse species, which disperse via hydrochory in strict accordance with their restricted dispersal windows, constant species, which are year round hydrochores, and combination species, which show characteristics of both. There was high overlap in the composition of hydrochores in the two systems, with obligate wetland species abundant in both. Upland species were more seasonally constant and abundant in the ditch water than the river. The consistency of river processes and similarity of vegetation suggest that earthen irrigation ditches do function as an extension of the riparian corridor. Thus, these man-made irrigation ditches should be considered by stakeholders for their multiple ecosystem services. / Dissertation/Thesis / M.S. Biology 2010

Page generated in 0.3654 seconds