• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1262
  • 255
  • 186
  • 128
  • 69
  • 56
  • 29
  • 25
  • 21
  • 21
  • 21
  • 21
  • 21
  • 21
  • 14
  • Tagged with
  • 2381
  • 453
  • 399
  • 350
  • 332
  • 331
  • 275
  • 268
  • 217
  • 202
  • 192
  • 181
  • 130
  • 125
  • 117
  • 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.
171

Land disposal of newsprint mill effluents.

Salloum, John Duane. January 1973 (has links)
No description available.
172

Physical and mechanical properties of paper mulches in assessing degradation

Krishnamurthy, Harish. January 1996 (has links)
No description available.
173

A survey of industrial water pollution in the pulp and paper industry of the United States.

Campbell, Stephen Wayne 01 January 1972 (has links) (PDF)
No description available.
174

Party for One: A Monologue of The Importance of Oneself Through Book Arts

Wan, Jacob Zhefu 01 January 2020 (has links)
This thesis explores the importance of oneself through sexuality, context, and introspection in the art of book arts. I work with memories, imagination, and consciousness in the form of book arts to express the importance of the self from my personal experience. Through the use of colors, materials, spatial compositions, and other visual components to manifest the content of my art, I want to illuminate the awareness of otherness including gender issues and an individual's vulnerability. Playing with the texts of Chinese and English, I intend to create narratives with languages, images, and other mixed media. In addition to crafting traditional bound books with handmade paper and assembling sculptural book-like objects, I also expand the idea of a book into space. With my books, I share my experience of being a loner, yet solitude helps me to be my better self. Through sharing my personal stories, I hope to invite my audience to empathize themselves with their sympathy and invoke a sense of the importance of the self.
175

Design and Development of a Paper Spray Air Sampling Device for Use in Clinical, Defense, and Environmental Applications

Murillo, Wilbert Alberto 12 1900 (has links)
Environmental monitoring is becoming increasingly important, primarily in urban areas due to the concentrated levels of human activities. The air sampling device presented is a novel method to sample air which harnesses the power of paper spray ionization paired with the intrinsic advantages of mass spectrometry such as high sensitivity, high selectivity, high throughput, and the ability to monitor multiple compounds at once.
176

Institutional consumer preferences for Forest Stewardship Council certified paper

Gados, Alicja Irena Unknown Date
No description available.
177

Institutional consumer preferences for Forest Stewardship Council certified paper

Gados, Alicja Irena 11 1900 (has links)
The Forest Stewardship Council (FSC) certifies forests that have been grown in an environmentally and socially responsible manner. It attempts to increase market share for certified paper via a Business Development Plan (BDP). This thesis provides analysis of the FSCs marketing using a survey and case study approach. The survey of institutional paper buyers reveals trends that suggest that the market for FSC and other certified papers is gaining popularity with institutional buyers, even though final consumers remain price sensitive. Components of institutional behavior that might cause an organization to adopt FSC are analyzed. This analysis reveals that adoption is more likely if it is important to an institution’s stakeholders and if reputation can be increased, even given increased costs. However, much of the growth in market share of FSC remains unexplained by the BDP. Hence the market for FSC and certified paper may be expanding independent of FSC and BDP. / Agricultural and Resource Eonomics
178

A study of the factors affecting the size distribution of micro-capsules for carbonless copy paper.

Chetty, Ezekiel. January 2002 (has links)
The process of micro-encapsulation by emulsifying a solution in a stirred tank has been accepted as the most suitable method for the production of microcapsules for carbonless copy paper and is currently used by Mondi Paper in Merebank. The focus of this project was to obtain a more uniform size distribution of the microcapsules so that oversize capsules would not smudge when they are coated on paper. There was also concern that the formation of very small ink/oil droplets was consuming wall material unnecessarily and was not contributing to the formation of an image on paper. The reduction of these tiny droplets would result in a saving of the cost of the wall material. Mondi currently produces microcapsules with an average diameter between 4 and 5 microns. The amount of capsules produced above 10 microns, the oversize, is less than 1 per cent (v/v) and the amount of capsules produced below 2 microns, the undersize, is between 25 and 30 per cent. Mondi wishes to reduce the amount of undersize capsules, thereby producing a narrower size distribution. This could result in large savings, as discussed above. It could also lead to the production of a six-sheet set of carbonless papers instead of the four-sheet set, which is currently produced. The production of microcapsules by emulsification was investigated in a 2.5-1iter laboratory tank, using an impeller measuring 45 mm in diameter. A range of agitation speeds was investigated and it was seen that at the lowest speed that formed emulsions, 6600 rpm, 15.03 per cent of undersize capsules was produced and an average capsule diameter of 7.57 microns, after 40 minutes of agitation. At the highest impeller speed, 8000 rpm, the average capsule diameter was reduced to 1.93 microns and 67.02 per cent of undersize capsules were classified as "undersize". No oversize capsules were observed. These capsule specifications were not favourable. Further experimentation showed that at 7500 rpm, an average capsule diameter of 5.12 microns and an undersize of 24.20 per cent were observed. The proportion of oversize capsules was 1.63 per cent. Since these results were similar to the results obtained from the plant, 7500 rpm was used accepted as the "standard" speed for the experiments. A reduction in the impeIler speed from 7500 rpm to 7200 rpm after the first 20 minutes of emulsification was one· way on reducing the proportion of undersize particles further. The proportion of undersize particles was reduced from 20.20 per cent to 19.71 per cent at standard conditions. The average capsule diameter and the oversize were not affected significantly. The effect of the emulsification temperature on the particle size distribution was investigated with temperatures ranging from 22 to 40°C, in increments of 2 QC. A temperature of 30 °c was used as a standard temperature as this temperature was being used at the plant. A decrease in the proportion of undersize capsules to 17.12 per cent was seen at temperatures below 30°C and an average of 23.87 per cent was noticed above 30 QC. Although the proportion of undersize capsules decreased, the average capsule diameter increased beyond the specified range to an average of 7.77 microns at temperatures below 30°C. At temperatures above 30 °c the average size was reduced to 5.59 microns. Hence the selection 000 °c as the optimum temperature was confirmed. Experimentation with the emulsification time showed that there were times when a unimodal size distribution was produced. However, these were at times just after the polymerisation had begun, and the reaction was not complete at this stage. A bimodal distribution was always noticed after 40 minutes of emulsification, i.e. after the completion of the reaction. The effects of the baffle widths on the microcapsules were also investigated. Baffle sizes of 5, 10 and 15 mm were used. It was shown that with an increase in baffle width, there was a decrease in the amount of undersize capsules produced. However, the average capsule diameter became too large. A baffle width of 5 mm was shown to produce desirable capsule sizes, although the undersize did not improve, or worsen. Too much of air was trapped in the emulsion when no baffles were used in the tank. Alternatives to the current surfactant, called "Lupasol" were tested so that Mondi could produce the capsules independently instead of relying on the original raw material supplier. This investigation was done based on limited informa.tion on Lupasol. Results from these experiments were inconclusive since more data on Lupasol was required. Samples of the microcapsule emulsion were sent to different companies, in South Africa and abroad, to determine whether the particle size analyser used at Mondi was giving correct results. The results obtained from the companies in South Africa differed by a small amount from that measured at Mondi. However, results obtained from companies abroad varied considerably and it is recommended that Mondi change their particle analyser settings. The power absorbed by the emulsion, in the laboratory-scale equipment was also found. This was determined by monitoring torque. The power was found to be 141.97 Wand the power number was calculated as 0.357. It was noted that the power per unit volume in the laboratory equipment was significantly higher than the plant data (47 kW/m3 vs. 12 kW/m3). The design of the impeller was not changed but the effect of baffle spacing was investigated. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2002.
179

Higroexpansibilidade de papel reprográfico produzido com fibras de eucalipto em máquina industrial. / Hygroexpansivity of reprographic paper manufactured from eucalyptus fibers in an industrial paper machine.

Mendes, Afonso Henrique Teixeira 10 March 2006 (has links)
Como qualquer material fabricado a partir de fibras de madeira, o papel também apresenta variações dimensionais decorrentes de modificações no seu teor de umidade. O presente trabalho aborda o comportamento desta propriedade do papel, denominada higroexpansibilidade, medida em papel reprográfico fabricado a partir de fibras de eucalipto, durante o processo de produção em uma máquina industrial. O estudo foi realizado com amostras de papel de 75 g/m2, coletadas em diversos pontos de uma máquina comercial, operando à velocidade de 1256 m/min. No estudo, encontram-se dados de higroexpansibilidade medidos ao longo da máquina de papel, desde a seção de formação até o acabamento, e na direção transversal da folha na enroladeira. A análise dos resultados permite a verificação de influências das operações e tratamentos envolvidos na fabricação do papel (formação, prensagem, secagem e acabamento) sobre a sua higroexpansibilidade. Os resultados das medições desta propriedade são discutidos em termos de efeitos provenientes das condições operacionais estabelecidas para a fabricação do papel, permitindo reconhecer influências da orientação de fibras, do processo de secagem e da restrição ao encolhimento, da aplicação de amido superficial e da aplicação de tensões na direção longitudinal e transversal do papel. Para comparação e suporte à discussão de resultados, foram também medidas propriedades estruturais, de resistência e propriedades elásticas do papel. Na conclusão do trabalho, são apresentadas sugestões para controle e minimização da higroexpansibilidade do papel destinado ao uso final, com enfoque em ações a serem tomadas, no que se refere ao ajuste do processo de fabricação. Finalmente, apresentam-se comentários sobre futuros trabalhos que poderão ser desenvolvidos, a fim melhor entender fenômenos adicionais relacionados à higroexpansibilidade e buscar alternativas para seu controle, por se tratar de uma propriedade cada vez mais importante para os processos de impressão e operações de conversão, cujos efeitos podem limitar o desempenho e a utilização final do papel. / Like any material made from wood fibers, the paper also exhibits dimensional changes as a result of change in moisture content. This work deals with the behavior of this paper property, called hygroexpansivity, which was measured in reprographic paper manufactured from eucalyptus fibers, during the production process in an industrial paper machine. The study was developed using 75 g/m2 paper samples collect in different positions of a commercial paper machine running at the speed of 1256 m/min. In the study, data of hygroexpansivity measured along the paper machine can be found from the forming section up to the finishing section and from the cross machine direction at the reel. The analysis of the results reveals the effects of the operations and treatments involved in the papermaking (formation, pressing, drying and finishing) on the hygroexpansivity. The measurements results of this property are discussed with focus on the effects of the operating conditions established for the papermaking operation, what leads to the recognition of the effects of the fiber orientation, drying process, shrinkage restraint, starch sizing and tensions applied to the paper in machine direction and cross machine direction. For comparison purposes and result discussion support, some structural, strength and elastic paper properties were also measured. In the conclusion of the study, some suggestions for control and minimization of hygroexpansivity of the end use paper are presented, focusing on actions to be taken, which are related to the adjustment of papermaking process. Finally, comments referred to future work for better understanding of additional hygroexpansivity mechanisms are also mentioned, in order to suggest future investigation of control alternatives for this property, since it’s importance has been more and more highlighted in printing and conversion operations because, at times, it can limit the performance and usefulness of paper.
180

Avalia??o dos fatores da perda de competitividade das empresas brasileiras de pap?is de impress?o revestidos: o couch?. / Evaluation of the factors responsible for the loss of competitiveness in the Brazilian s printing coated paper industry: Coated Wood Free.

VILELA, Antonio Carlos 09 June 2009 (has links)
Made available in DSpace on 2016-04-28T20:19:23Z (GMT). No. of bitstreams: 1 2009 - Antonio Carlos Vilela.pdf: 1562012 bytes, checksum: 6336ba47d980fb5d06f60391e0fc9e7f (MD5) Previous issue date: 2009-06-09 / This study has had as objective, the identification of the main factors responsible for the loss of competitiveness in the Brazilian?s printing and coated industry. Coated wood free. For this identification was applied a strategy of data evaluation through structured interviews with four professionals with experience in the Paper Sector. It was used information issued in articles, magazines, dissertations, newspapers and on top of that primary and secondary data from the Pulp and Paper Sector were used, specifically the coated wood free for printing segment. The study had as assumption that there was loss of competitiveness in the Brazilian market, and the main factor responsible for this loss could be attributed to a systemic factor, the exchange rate. There was an increase of importation and reduction of exportation in the period of the study. The main factors identified in the interviews in sequence of importance and according to the interviewers were; exchange rate, the illegal usage of duty free operation during the importation and the lack of update the industrial equipments in the Brazilian Mills The currency, as a main factor of competitiveness loss for the Coated paper sector and it was confirmed through the evaluation of secondary figures of importation grow and exportation reduction in the period of 2003 till 2008. Other factor, the illegal usage of duty free operation during the importation, was based only in the perception of the interviewers; there were no dada available due to the subjectivity of this topic. The third factor, the lack of update the industrial equipments in the Brazilian Mills appointed during the interviews. It could be confirmed in the analyze of the world?s fastest paper machines and more competitive in the world in comparison with Brazilian?s paper machines which speed are very far from the more competitive machines in the world. The Brazil is not even mentioned in this article of machines caparison. When the factors that determine the competitiveness of printing coated papers are analyzed in group, the conclusion is that Brazil is not competitive in this segment due to several business factors. The currency that is a systemic factor and appears in the periods of currency valuation works in the process of exposure of the low competitiveness already existent. / Este trabalho teve como objetivo identificar os principais fatores que levaram a ind?stria brasileira de papel de imprimir revestido, o Couch?, ? perda de competitividade. Para identifica??o desses fatores foi aplicada a estrat?gia de an?lise de dados atrav?s da realiza??o de entrevista estruturada com quatro profissionais experientes ligados ao setor de pap?is, informa??es publicadas em artigos, revistas, teses e disserta??es, alem dos dados prim?rios e secund?rios do setor de celulose e papel, especificamente os do segmento do papel de imprimir revestidos ? o Couch?. Dentro deste objetivo foi adotada a suposi??o de que houve perda de competitividade no mercado brasileiro, e que um dos principais fatores da perda desta competitividade poderia ser atribu?do a um fator sist?mico, o cambio, havendo aumento das importa??es e redu??o das exporta??es no per?odo estudado. Os principais fatores identificados nas entrevistas, por ordem de import?ncia e segundo os entrevistados, foram: o cambio, a pr?tica desleal de isen??o tribut?ria e a falta de atualiza??o do parque industrial brasileiro. O cambio, como principal fator de perda de competitividade do setor de pap?is revestidos, pode ser corroborado atrav?s da an?lise dos dados secund?rios de importa??o crescente e exporta??o declinante no per?odo analisado de 2003 a 2008. O outro fator de pr?tica desleal da isen??o tribut?ria ficou apenas na percep??o dos entrevistados, n?o havendo dados dispon?veis para sua avalia??o pelo pr?prio grau de subjetividade deste tema. O terceiro fator de perda de competitividade apontado nas entrevistas foi a falta de atualiza??o do parque industrial brasileiro. Isto pode ser confirmado pela an?lise dos dados das m?quinas de papel mais velozes e competitivas do mundo em compara??o com as do Brasil, cujas velocidades est?o muito aqu?m das mais competitivas do mundo. O Brasil n?o ? sequer citado no artigo comparativo. Quando os fatores determinantes da competitividade dos pap?is de imprimir revestidos s?o analisados em conjunto, observa-se que o Brasil n?o ? competitivo neste segmento devido a diversos fatores empresarias. Quando a quest?o cambial, que ? um fator sist?mico, aparece em per?odos de valoriza??o cambial, este somente exp?e e agrava mais ainda esta baixa competitividade existente.

Page generated in 0.0423 seconds