• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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.
1

Estado da arte dos estudos sobre percep??o ambiental no Brasil no per?odo entre 2008 e 2015 / State of the art of environmental perception studies in Brazil between 2008 and 2015

Alves, Soraya Cristina Vital 14 July 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-10-30T11:57:30Z No. of bitstreams: 1 2016 - Soraya Cristina Vital Alves.pdf: 3158007 bytes, checksum: 28282ef34bc84f5887cf1e4433c9c1fa (MD5) / Made available in DSpace on 2017-10-30T11:57:30Z (GMT). No. of bitstreams: 1 2016 - Soraya Cristina Vital Alves.pdf: 3158007 bytes, checksum: 28282ef34bc84f5887cf1e4433c9c1fa (MD5) Previous issue date: 2016-07-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / In this paper we characterized the academic production on Environmental Perception (EP) developed by brazilian Stricto Sensu Postgraduate Programs (PGP) in the great knowledge areas, with special attention in the production from Biological Sciences and Psychology, from 2008 to 2015. The research sought to continue the research of Vasco (2009), which made a similar survey between 1988 and 2007. We also aim to broaden the study above by pointing out the philosophical currents that direct the analyzed productions. We also intend to investigate how Biological Sciences has been dialoguing with Psychology in the study of EA. This paper has quantitative-qualitative methodological approach, and the State of the Art type of research was used. In the first stage, we identified brazilian Stricto Sensu PGPs that research Environmental Perception, as well as dissertations and theses which AP is its main theme. In the second step, we mapped the academic production about AP in several available repositories, creating a Database containing informations about the studies. In the third step, we analyzed critically the main characteristics inserted in the Database. From the built database, we note AP is studied in the large Areas of Environmental, Human, Biological, Social, Exact and Agrarian Sciences. In the investigation period, we identified 188 PPG productions in PA. The largest number of brazilian production is in the Northeast region, soon followed by the Southeast. Most of the researches adopted the qualitative methodology, with a structuralist philosophical current. The thematic focus of most surveys was AP on urban environment and AP on water resources, involving residents of the study site. In general, all the surveys have been relevant to a better understanding of the environmental problems raised by them. However, the confusion about philosophical currents and the lack of a better knowledge in the main works on AP are questions to be pointed out. The approach between Biological Sciences and Psychology in the researches in AP is still very discreet, so it?s necessary an effort from these areas to deep the study of environmental issues / Neste trabalho foi caracterizada a produ??o acad?mica sobre Percep??o Ambiental (PA) desenvolvida pelos Programas de P?s-Gradua??o (PPG) Stricto Sensu brasileiros, nas Grandes ?reas do conhecimento, com especial aten??o ? produ??o das ?reas de Ci?ncias Biol?gicas e Psicologia, no per?odo de 2008 a 2015. A pesquisa buscou dar continuidade ao trabalho de Vasco (2009), que fez levantamento semelhante entre os anos de 1988 a 2007. Objetivamos, ainda, ampliar o trabalho citado ao apontarmos as correntes filos?ficas que direcionam as produ??es analisadas e ao investigarmos como as Ci?ncias Biol?gicas v?m dialogando com a Psicologia no estudo da PA. O presente trabalho possui enfoque metodol?gico quanti-qualitativo, de car?ter bibliogr?fico do tipo Estado da Arte. Na primeira etapa, identificamos os PPG Stricto Sensu brasileiros que pesquisam sobre Percep??o Ambiental, bem como as disserta??es e teses que apresentavam a PA como tema principal do seu trabalho. Na segunda etapa, mapeamos a produ??o acad?mica acerca do tema PA em diversos reposit?rios dispon?veis, criando um Banco de Dados cotendo determinadas informa??es sobre os trabalhos. Na terceira etapa, analisamos criticamente as principais caracter?sticas inseridas no Banco de Dados em quest?o. A partir do Banco de Dados constru?do, notamos que a PA ? estudada nas Grandes ?reas de Ci?ncias Ambientais, Humanas, Biol?gicas, Sociais Aplicadas, Exatas e Agr?rias. No per?odo investigado, identificamos 188 produ??es pelos PPG em PA. O maior n?mero de produ??es brasileiras divulgadas ? a regi?o Nordeste, logo seguida pela Sudeste. A maioria das pesquisas adotou a metodologia qualitativa, com corrente filos?fica estruturalista. O foco tem?tico da maioria das pesquisas foi PA sobre ambiente urbano e PA sobre recursos h?dricos, envolvendo moradores do local do estudo. De maneira geral, todos os trabalhos encontrados mostraram-se relevantes para a melhor compreens?o dos problemas ambientais levantados pelos mesmos. Por?m, a confus?o sobre as correntes filos?ficas existentes e a car?ncia de um conhecimento mais embasado na maioria dos trabalhos sobre PA s?o quest?es a serem apontadas. A aproxima??o entre Ci?ncias Biol?gicas e Psicologia nas pesquisas em PA ainda se mostra muito discreta, sendo necess?rio o esfor?o das duas ?reas para que o di?logo entre ambas seja aprofundado no estudo das quest?es ambientais
2

Uniformidade e estabilidade da cor da madeira termorretificada de Tectona grandis L. f. / Uniformity and stability of color of the heat-treated Tectona grandis L. f. wood

LOPES, Juliana de Oliveira 26 April 2012 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-04-12T20:41:07Z No. of bitstreams: 1 2012 - Juliana de Oliveira Lopes.pdf: 1518311 bytes, checksum: 21fc297e17199bf911f4cf85812c2694 (MD5) / Made available in DSpace on 2017-04-12T20:41:07Z (GMT). No. of bitstreams: 1 2012 - Juliana de Oliveira Lopes.pdf: 1518311 bytes, checksum: 21fc297e17199bf911f4cf85812c2694 (MD5) Previous issue date: 2012-04-26 / CAPES / The teak wood (Tectona grandis L. f.) from young plantations (12 years old) has some undesirable characteristics in terms of color uniformity as well as presenting a high proportion of sapwood, which is distinguished from heartwood by the lower durability and light color. In addition, teak wood has color change when exposed to ultraviolet (UV) radiation, which depreciates the product over time. Heat treatments can be applied to change, standardize and stabilise the color of the wood, thus adding more value to the final product. In this context, the objectives of this study were: (1) to determine the effect of spacing between trees on the physical properties (density and moisture content) and the original color of wood, (2) to determine the color change of wood after heat treatments, (3) to evaluate the color uniformity of the wood (pieces containing heartwood and sapwood) after heat treatments and (4) to evaluate the color stability of heat-treated wood after UV radiation in accelerated aging conditions. Nine trees from three different levels of spacing (4 x 2 m, 5 x 2 m and 6 x 2 m) were used, with three trees per spacing. Samples of 150 x 75 x 20 mm were produced and divided into three groups: I: samples with a predominance of heartwood (? 75% heartwood in relation to sapwood), II: samples with 100% of sapwood and III: samples with approximately 50% heartwood and 50% sapwood. The groups I and II were used to determine the physical properties, wood color changes before and after heat treatments and color stability after exposure to UV radiation, whereas those of group III were used to determine the color uniformity after heat treatments. Heat treatments were performed in a laboratorial electric oven from Linn Elektro Therm under two temperatures: 180 and 200?C. Color measurements were performed using the portable spectrophotometer CM 2600d in the CIE-L*a*b* space. The accelerated aging test was performed in a QUV/Spray from Q-Lab chamber. The total cycle of exposure to UV radiation was 168 hours, and color measurements were taken to every 42 hours. The spacing affected the physical properties and the original color of wood. The heat treatment affected more the density of heartwood than sapwood. Heartwood and sapwood presented an average decrease of the 52% in equilibrium moisture content after heat treatments. Heartwood and sapwood had the same lightness pattern at the different spacings. After the heat treatment, wood had a loss of lightness, becoming darker, and this was more pronounced in the treatment at 200?C. Heartwood and sapwood presented different behavior for the coordinates a* and b* depending of spacing, before and after heat treatments. There was a greater formation of red hue and loss on yellow hue of heartwood and sapwood treated at 200?C. Heat treatments caused a higher color change on sapwood than heartwood, which provided greater uniformity to the pieces of wood with heartwood and sapwood. The color of sapwood heat-treated at 180oC woods had higher stability at UV radiation, thus demonstrating the potential of heat treatment to obtain products of higher added value. / A madeira de teca (Tectona grandis L. f.) proveniente de plantios jovens (12 anos de idade) apresenta algumas caracter?sticas indesej?veis em termos de uniformidade de cor al?m de apresentar alta propor??o de alburno, o qual distingue-se do cerne pela menor durabilidade e cor clara. Al?m disso, a madeira de teca apresenta altera??o de cor quando exposta ? radia??o ultravioleta (UV), o que acaba depreciando o material ao longo do tempo. Tratamentos termorretificadores podem ser aplicados para alterar, uniformizar e estabilizar a cor da madeira, agregando assim maior valor ao produto final. Neste contexto, os objetivos deste estudo foram: (1) determinar o efeito do espa?amento entre ?rvores nas propriedades f?sicas (densidade e teor de umidade) e na cor original da madeira, (2) determinar a altera??o da cor da madeira ap?s a termorretifica??o, (3) avaliar a uniformidade da cor da madeira (pe?as contendo cerne e alburno) ap?s os tratamentos termorretificadores e (4) avaliar a estabilidade da cor da madeira termorretificada ? radia??o UV em condi??es de envelhecimento acelerado. Foram utilizadas nove ?rvores de teca provenientes de tr?s espa?amentos (4 x 2 m, 5 x 2 m e 6 x 2 m), sendo 3 ?rvores para cada espa?amento. Amostras de 150 x 75 x 20 mm foram produzidas e divididas em tr?s grupos: I: amostras com predomin?ncia de madeira do cerne (? 75% de cerne em rela??o ao alburno), II: amostras com 100% de alburno e III: amostras com aproximadamente 50% de cerne e 50% de alburno. Os grupos I e II foram utilizados para determinar as propriedades f?sicas, a varia??o da cor da madeira antes e ap?s a termorretifica??o e a estabilidade da cor ap?s ? radia??o UV, enquanto que o grupo III foi utilizado para determinar a uniformidade da cor ap?s a termorretifica??o. A termorretifica??o foi realizada em um forno mufla el?trico laboratorial Linn Elektro Therm sob duas temperaturas: 180 e 200?C. As medi??es de cor foram realizadas atrav?s do espectrofot?metro port?til CM 2600d no espa?o CIE-L*a*b*. O ensaio de envelhecimento acelerado foi realizado em uma c?mara QUV/Spray da Q-Lab. O ciclo total de exposi??o ? radia??o UV foi de 168 horas, sendo realizadas medi??es de cor ? cada 42 horas. O espa?amento afetou as propriedades f?sicas e a cor original da madeira. A termorretifica??o afetou mais a densidade do cerne que do alburno. As madeiras de cerne e alburno apresentaram uma redu??o m?dia de 52% no teor de umidade de equil?brio ap?s a termorretifica??o. O cerne e o alburno apresentaram o mesmo padr?o de luminosidade nos diferentes espa?amentos. Ap?s a termorretifica??o, a madeira teve perda de luminosidade, tornado-se mais escura, sendo isso mais acentuado para o tratamento ? 200?C. As madeiras de cerne e alburno apresentaram comportamentos diferentes para as coordenadas a* e b* dependendo do espa?amento, antes e ap?s a termorretifica??o. Ocorreu uma maior forma??o de pigmento vermelho e perda de pigmento amarelo nas madeiras de cerne e alburno tratadas ? 200?C. A termorretifica??o proporcionou uma maior altera??o ? cor do alburno, o que resultou em uma maior uniformidade ?s pe?as de madeira contendo cerne e alburno. A cor da madeira de alburno termorretificada ? 180?C apresentou maior estabilidade ? radia??o UV, mostrando assim o potencial da termorretifica??o para obten??o de produtos de maior valor agregado.

Page generated in 0.052 seconds