Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2001. / Härtill 4 uppsatser.

Thesis (M. S.)--Economics, Georgia Institute of Technology, 2006. / Haizheng Li, Committee Chair ; Patrick McCarthy, Committee Member ; Vivek Ghosal, Committee Member. Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:31:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-09Bitstream added on 2014-06-13T19:02:01Z : No. of bitstreams: 1 malinovski_ra_dr_botfca.pdf: 1199387 bytes, checksum: e679445a3eaeb5feb0d0f50429c6c75b (MD5) / A gestão das atividades e operações ligadas à colheita de madeira carece de ferramentas computacionais que auxiliem os técnicos florestais na tarefa de redução dos custos. Em muitos casos, máquinas de elevado investimento são utilizadas na colheita de madeira sem um planejamento adequado da operação, conseqüentemente, o custo por hora dessas máquinas, que é elevado, poderia ser reduzido, caso fossem utilizados recursos tecnológicos como o Sistema de Informações Geográficas (SIG) integrado com o Sistema de Posicionamento Global, os quais, são a base da colheita de precisão. Nesta pesquisa desenvolveu-se, através de técnicas matemáticas e de funcionalidades disponíveis no Sistema de Informações Geográficas GRASS, uma ferramenta tecnológica capaz de calcular e otimizar a distância média de extração (DME) de madeira com forwarder, em diferentes tamanhos e formatos de talhões. A ferramenta desenvolvida, chamada de modelo otimizado, compartimentaliza o talhão em função da menor distância de extração. A principal variável considerada foi o alinhamento de plantio. Para testar o modelo foram considerados talhões do gênero Eucalyptus sp de uma fazenda localizada no Estado de São Paulo. Foram selecionados aleatóriamente oito talhões com formato poligonal retangular e oito talhões com formato poligonal irregular. Visitaram-se os talhões para coletar as principais variáveis (sentido de alinhamento de plantio e condições para o depósito da madeira na beira da estrada). Foram criadas, de forma teórica, dez classes de ângulos do sentido de alinhamento de plantio, sendo que um deles foi o alinhamento em nível. Com o modelo otimizado, calculou-se a DME da madeira com forwarder para todas as classes de ângulos, comparando-se com o sentido de alinhamento adotado pela empresa. Realizou-se uma simulação do custo de deslocamento do forwarder utilizando... / The management of activities and operations on the wood harvesting, does not have good computational tools to help the forest technicians with the task of cost reduction. In many cases, machines with high investment are used in wood harvesting without any adequate operation planning, consequently, the cost per hour of these machines, which is high, could be reduced, using technological resources such as the Geographic Information Systems (GIS) integrated with the Global Positioning System (GPS), which are the base of the precision harvest. In this research, a technological tool capable of calculating and optimizing the medium distance of skidding of the forwarder, in different sizes and formats of the stands, was developed through mathematical techniques and available functionalities in the Geographic Information System GRASS. The developed tools, called optimized model, divides the stand in small parts in relation to shorter distance of skidding. The main variable considered was the alignment of plantation. To test the model eucalypt stands located in the state of São Paulo were considered. Sixteen stands were randomly selected: eight with rectangular polygon form and eight with irregular polygon form. The stands were visited to collect the main variables. Ten angle classes of plantation alignment direction were theoretically created, one of them alignments was the direction of plantation following contour lines. The medium distance of skidding for all angle classes was calculated with the optimized model and was compared to the plantation alignment direction adopted by the company. The cost of forwarder dislocation was simulated using as a base the medium distance of skidding and the size of the small areas of the stand. The results showed that the optimized model developed is efficient and flexible. The stands with irregular form had a shorter medium distance of skidding... (Complete abstract click electronic access below)

Resumo: A gestão das atividades e operações ligadas à colheita de madeira carece de ferramentas computacionais que auxiliem os técnicos florestais na tarefa de redução dos custos. Em muitos casos, máquinas de elevado investimento são utilizadas na colheita de madeira sem um planejamento adequado da operação, conseqüentemente, o custo por hora dessas máquinas, que é elevado, poderia ser reduzido, caso fossem utilizados recursos tecnológicos como o Sistema de Informações Geográficas (SIG) integrado com o Sistema de Posicionamento Global, os quais, são a base da colheita de precisão. Nesta pesquisa desenvolveu-se, através de técnicas matemáticas e de funcionalidades disponíveis no Sistema de Informações Geográficas GRASS, uma ferramenta tecnológica capaz de calcular e otimizar a distância média de extração (DME) de madeira com forwarder, em diferentes tamanhos e formatos de talhões. A ferramenta desenvolvida, chamada de modelo otimizado, compartimentaliza o talhão em função da menor distância de extração. A principal variável considerada foi o alinhamento de plantio. Para testar o modelo foram considerados talhões do gênero Eucalyptus sp de uma fazenda localizada no Estado de São Paulo. Foram selecionados aleatóriamente oito talhões com formato poligonal retangular e oito talhões com formato poligonal irregular. Visitaram-se os talhões para coletar as principais variáveis (sentido de alinhamento de plantio e condições para o depósito da madeira na beira da estrada). Foram criadas, de forma teórica, dez classes de ângulos do sentido de alinhamento de plantio, sendo que um deles foi o alinhamento em nível. Com o modelo otimizado, calculou-se a DME da madeira com forwarder para todas as classes de ângulos, comparando-se com o sentido de alinhamento adotado pela empresa. Realizou-se uma simulação do custo de deslocamento do forwarder utilizando... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The management of activities and operations on the wood harvesting, does not have good computational tools to help the forest technicians with the task of cost reduction. In many cases, machines with high investment are used in wood harvesting without any adequate operation planning, consequently, the cost per hour of these machines, which is high, could be reduced, using technological resources such as the Geographic Information Systems (GIS) integrated with the Global Positioning System (GPS), which are the base of the precision harvest. In this research, a technological tool capable of calculating and optimizing the medium distance of skidding of the forwarder, in different sizes and formats of the stands, was developed through mathematical techniques and available functionalities in the Geographic Information System GRASS. The developed tools, called optimized model, divides the stand in small parts in relation to shorter distance of skidding. The main variable considered was the alignment of plantation. To test the model eucalypt stands located in the state of São Paulo were considered. Sixteen stands were randomly selected: eight with rectangular polygon form and eight with irregular polygon form. The stands were visited to collect the main variables. Ten angle classes of plantation alignment direction were theoretically created, one of them alignments was the direction of plantation following contour lines. The medium distance of skidding for all angle classes was calculated with the optimized model and was compared to the plantation alignment direction adopted by the company. The cost of forwarder dislocation was simulated using as a base the medium distance of skidding and the size of the small areas of the stand. The results showed that the optimized model developed is efficient and flexible. The stands with irregular form had a shorter medium distance of skidding... (Complete abstract click electronic access below) / Orientador: Paulo Torres Fenner / Coorientador: Helmer Schack-Kirchner / Coorientador: Jorge Roberto Malinovski / Banca: Lincoln Gehring Cardoso / Banca: Ricardo Marques Barreiros / Banca: Fernando Seixas / Banca: Julio Eduardo Arce / Doutor

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No description available.

This study investigated the use of activated carbon and ion exchange for the removal of color and dissolved solids from pulp and paper wastewater generated by the Union Camp Corporation mill in Franklin, Virginia. The objective of the treatment was to provide a high quality effluent suitable for direct recycling. This advanced treatment followed pretreatment by lime, alum, or ferric chloride. Required effluent quality was defined as being 5 Pt-Co units color and 75 mg/L chloride. Granular and powdered carbons, manufactured by the Westvaco Corporation, were utilized in the study. The ion exchange resin investigated was Amberlite IRA-68, manufactured by Rohm and Haas. Carbon treatment consisted of batch and column operation; ion exchange column treatment was used. The results of the study indicated that the required effluent quality was achieved by activated carbon and ion exchange treatment of wastewater that had been chemically pretreated. The most successful treatment schemes for the biotreated effluent were pretreatment with 500 mg/L alum or 2500 mg/L lime, followed by carbon column treatment for color polishing and ion exchange for chloride removal. The lime pretreated sample produced an effluent containing less than 5 Pt-Co units color as necessary for reuse, while the alum pretreated sample would require dilution with make-up water or additional treatment (i.e. ion exchange) to obtain recycle quality. The use of ion exchange for chloride removal is not practical due to the preferential exchange for sulfates. Until such time as sulfate can be eliminated from the wastewater source, other methods of dissolved solids removal should be investigated. / M. Eng.

The first objective of this study was to evaluate Eucalyptus urophylla S.T. Blake provenances in terms of their growth, basic wood density and pulp yield properties. The second objective was to determine the genetic and phenotypic associations that may exist between growth, basic wood density and pulp yield. Data of 9022 open-pollinated progenies representing 306 families, collected from 17 provenances, were used to evaluate growth. To evaluate basic wood density and pulp yield, as well as the genetic and phenotypic associations between the three traits, data of 300 open-pollinated progenies representing 30 selected families from 11 provenances were used. Narrow-sense heritabilities for all three traits were estimated from data collected in a single E. urophylla provenance/progeny trial planted in northern KwaZulu-Natal. The results showed that significant provenance effects for growth, basic wood density and pulp yield were observed. Heritability was found to be strong for basic wood density (h2 = 0.51) and moderate to weak for volume growth and pulp yield (h2 = 0.17 and h2 = 0.11, respectively). This suggests that big genetic gains can be achieved for basic wood density. Although the heritability estimates for volume growth and pulp yield were weaker, this still allows for tree breeders to make significant genetic gains through accurate selection from this E. urophylla breeding population. Genetic and phenotypic associations between the three traits were estimated from data collected in the same trial. The genetic correlation between volume growth and pulp yield was positive and moderately strong (rA = 0.66). The genetic correlation estimate between volume growth and basic wood density was found to be negative but weak (rA = -0.08). The genetic association between pulp yield and basic wood density was found to be positive but weak (rA = 0.17). Correlation estimates between volume growth and basic wood density, as well as between pulp yield and basic wood density produced standard errors greater than the correlation itself (s.e. = ± 0.32 and ± 0.22, respectively). These high standard errors, coupled with weak genetic correlations, suggest that these correlation estimates are non-significant, but are probably a result of utilizing a small sample size. However, these correlations have a value in making breeding choices, if treated with caution. Key words: Eucalyptus urophylla, provenance, growth, basic wood density, pulp yield, heritability, genetic correlation / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Following sound economic theory, paper mills vertically integrate into pulp production, partly because internalizing the production of their inputs allows them to avoid transaction costs. Higher market concentration, a proxy of higher asset specificity and transaction costs, should encourage vertical integration in the pulp and paper industry. However, this relationship has not been robust in previous studies or in our replication with updated FPL-UW data. Upon a deeper analysis of the data, this study should clarify the mechanism by which transaction cost can induce vertical integration in this particular industry, which does not have well-defined intermediate goods markets. In order to specify the pulp markets where paper mills are likely to trade, we construct a mill-specific concentration measure as a substitute to traditional regional concentration measures. We also narrow our sample to mills producing free sheet paper, the most profitable paper grade in this industry. With such model refinement, this research exhibits a significantly positive correlation between transaction cost and vertical integration.