50 research outputs found

    Avaliação das propriedades físico-mecânicas de polpas produzidas por novas sequências de branqueamento.

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    The efficiency of oxygen delignification is very low for pulps of low number kappa and with high concentrations of hexenuronic acids, therefore the oxygen does not react with these acids, so being minimum the elimination of these during the oxygen delignification (pre-O2) in simple or double stage. In this study, the physical-mechanical properties of pulp of kappa number 17 and 14, produced with modified cooks and with the application of AD(EO)D techniques for pulp of kappa 17 and DHT(EPO)DP for pulp of kappa 14 for the bleaching up to 90% ISO, had been investigated. The main objective of this study was to evaluate the physical-mechanical properties in pulps submitted to the bleaching sequences without oxygen in the beginning of the sequence. As references, cooks had been carried until numbers kappa 17 and 14, oxygen delignification and conventional bleaching for sequences A/D(EO)D for pulp of kappa 17 and DHT(EPO)DP for pulp of kappa 14. The alternative bleaching, without pre-O2, resulted in bleached pulps with bigger integrity that of the reference, what it was confirmed by the values significantly higher of bulk, tear index, opacity and air resistance of the pulp weakly refined (for tissue papers). However, the high integrity of the fibers from pulps bleached with alternative processes lowered their conformabilities and collapsibility, with consequent reduction of tensile index of the pulp weakly refined. Therefore, with more intensive beating (for printing and writing papers), the tensile index was recovered. The high integrity of the bleaching pulps without pre-O2 makes beating difficulty. To reach the draining degree of 35°SR with the pulps proceeding from alternative processes of bleaching, it was necessary to apply 30% more energy than the reference.A eficiência da deslignificação com oxigênio (pré-O2) é muito baixa para polpas de baixo número kappa e que contêm altas concentrações de ácidos hexenurônicos, pois o oxigênio não reage com esses ácidos, sendo mínima a eliminação destes durante a deslignificação com oxigênio em simples ou duplo estágio. Neste estudo, investigaram-se as propriedades físico-mecânicas de polpas produzidas por cozimentos cineticamente modificados até número kappa 17 e 14 e branqueadas pelas técnicas AD(EO)D, para polpa de kappa 17 e DHT(EPO)DP, para polpa de kappa 14. O objetivo principal do estudo foi o de avaliar as propriedades físico-mecânicas das polpas submetidas a sequências de branqueamento sem o oxigênio, no início da sequência. Como referências, foram produzidas polpas de número kappa 17 e 14 as quais foram posteriormente deslignificadas com oxigênio e branqueadas com sequências convencionais: A/D(EO)D, para polpa de número kappa 17 e DHT(EPO)DP, para polpa de kappa 14. O branqueamento alternativo, sem a pré-O2, resultou em polpas branqueadas de maior integridade que as da referência, o que foi comprovado pelos valores significativamente mais altos de VEA (bulk), índice de rasgo, opacidade e resistência à passagem de ar (RPA) da polpa fracamente refinada (polpa para produzir papel tissue). Por outro lado, a alta integridade das fibras oriundas das polpas branqueadas por processos alternativos diminuiu suas conformabilidades e colapsabilidades, com consequente diminuição do índice de tração da polpa fracamente refinada. Porém, mediante um refino mais intenso (polpa para produzir papel de imprimir e escrever - P&W) o índice de tração foi recuperado. A alta integridade das polpas branqueadas sem a pré-O2 dificulta o seu refino. Para alcançar o grau de drenagem de 35oSR com as polpas provenientes dos processos alternativos de branqueamento, foi necessário aplicar cerca de 30% a mais de energia em relação à referência

    Physical-Mechanical Properties Evaluation Of Pulps Produced With Novel Bleaching Sequences

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    A efici\ueancia da deslignifica\ue7\ue3o com oxig\ueanio (pr\ue9-O2) \ue9 muito baixa para polpas de baixo n\ufamero kappa e que cont\ueam altas concentra\ue7\uf5es de \ue1cidos hexenur\uf4nicos, pois o oxig\ueanio n\ue3o reage com esses \ue1cidos, sendo m\uednima a elimina\ue7\ue3o destes durante a deslignifica\ue7\ue3o com oxig\ueanio em simples ou duplo est\ue1gio. Neste estudo, investigaram-se as propriedades f\uedsico-mec\ue2nicas de polpas produzidas por cozimentos cineticamente modificados at\ue9 n\ufamero kappa 17 e 14 e branqueadas pelas t\ue9cnicas AD(EO)D, para polpa de kappa 17 e DHT(EPO)DP, para polpa de kappa 14. O objetivo principal do estudo foi o de avaliar as propriedades f\uedsico-mec\ue2nicas das polpas submetidas a sequ\ueancias de branqueamento sem o oxig\ueanio, no in\uedcio da sequ\ueancia. Como refer\ueancias, foram produzidas polpas de n\ufamero kappa 17 e 14 as quais foram posteriormente deslignificadas com oxig\ueanio e branqueadas com sequ\ueancias convencionais: A/D(EO)D, para polpa de n\ufamero kappa 17 e DHT(EPO)DP, para polpa de kappa 14. O branqueamento alternativo, sem a pr\ue9-O2, resultou em polpas branqueadas de maior integridade que as da refer\ueancia, o que foi comprovado pelos valores significativamente mais altos de VEA (bulk), \uedndice de rasgo, opacidade e resist\ueancia \ue0 passagem de ar (RPA) da polpa fracamente refinada (polpa para produzir papel tissue). Por outro lado, a alta integridade das fibras oriundas das polpas branqueadas por processos alternativos diminuiu suas conformabilidades e colapsabilidades, com consequente diminui\ue7\ue3o do \uedndice de tra\ue7\ue3o da polpa fracamente refinada. Por\ue9m, mediante um refino mais intenso (polpa para produzir papel de imprimir e escrever \u2013 P&W) o \uedndice de tra\ue7\ue3o foi recuperado. A alta integridade das polpas branqueadas sem a pr\ue9-O2 dificulta o seu refino. Para alcan\ue7ar o grau de drenagem de 35oSR com as polpas provenientes dos processos alternativos de branqueamento, foi necess\ue1rio aplicar cerca de 30% a mais de energia em rela\ue7\ue3o \ue0 refer\ueancia.The efficiency of oxygen delignification is very low for pulps of low number kappa and with high concentrations of hexenuronic acids, therefore the oxygen does not react with these acids, so being minimum the elimination of these during the oxygen delignification (pre-O2) in simple or double stage. In this study, the physical-mechanical properties of pulp of kappa number 17 and 14, produced with modified cooks and with the application of AD(EO)D techniques for pulp of kappa 17 and DHT(EPO)DP for pulp of kappa 14 for the bleaching up to 90% ISO, had been investigated. The main objective of this study was to evaluate the physical-mechanical properties in pulps submitted to the bleaching sequences without oxygen in the beginning of the sequence. As references, cooks had been carried until numbers kappa 17 and 14, oxygen delignification and conventional bleaching for sequences A/D(EO)D for pulp of kappa 17 and DHT(EPO)DP for pulp of kappa 14. The alternative bleaching, without pre-O2, resulted in bleached pulps with bigger integrity that of the reference, what it was confirmed by the values significantly higher of bulk, tear index, opacity and air resistance of the pulp weakly refined (for tissue papers). However, the high integrity of the fibers from pulps bleached with alternative processes lowered their conformabilities and collapsibility, with consequent reduction of tensile index of the pulp weakly refined. Therefore, with more intensive beating (for printing and writing papers), the tensile index was recovered. The high integrity of the bleaching pulps without pre-O2 makes beating difficulty. To reach the draining degree of 35\ub0SR with the pulps proceeding from alternative processes of bleaching, it was necessary to apply 30% more energy than the reference

    An interactive key (Lucid) for the identifying of the genera of seed plants from the Ducke Reserve, Manaus, AM, Brazil

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    The identification of Amazonian plants is still difficult for many reasons, one being the lack of collections over large areas of the region. As a consequence of the poor knowledge on the Amazonian flora, many taxonomic publications (revisions and floristic treatments) become out of date within a few years. In this context, the on-line publication of taxonomic treatises has been suggested, since it allows constant data updates; and this type of publication should therefore be more valued by the scientific community. An excellent field guide for the Ducke Reserve (Manaus, central Amazonian Brazil) was published, based exclusively on vegetative characters. However, the presence of reproductive structures in the collected material does not facilitate identification with this type of field guide. Furthermore, as in any printed key, the text cannot be updated, except through a new edition. As an example of a way to facilitate the identification of Amazonian plants, an interactive, multiple-entry key to the seed plant genera that occur in the Ducke Reserve was created using the program Lucid 3.5. The key includes vegetative and reproductive characters and many illustrations, and is available on-line. We discuss here the peculiarities and advantages of this type of electronic publication

    Vascular flora of the Legado das Águas, Reserva Votorantim, municipalities of Tapiraí, Miracatú and Juquiá, São Paulo, Brazil

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    We present  a list of vascular plants found in Legado das Águas, Reserva Votorantim, a private reserve having an area of approximately 35,000 ha that spans the municipalities of Tapiraí, Miracatú, and Juquiá, in the state of São Paulo, Brazil. The reserve is part of a complex of state-protected areas including Alto Ribeira Touristic State Park, Intervales State Park , Carlos Botelho State Park, Jurupará State Park, and Serra do Mar State Park. Together, these form an important and large area of continuous and well-preserved forest. Our study, which involved two main floristic surveys in March/April 2013 and April 2014, recorded 768 species, representing 131 families and 432 genera. The majority of species were angiosperms (619) representing 106 families and 370 genera. There were also two species of gymnosperms belonging to two genera in separate families; 147 species of ferns and lycophytes belonging to 23 families and 60 genera. In demonstrating the presence of almost 800 species of plants, of which 16 are threatened, our study highlights the importance of floristic surveys and the critical role of private protected areas in managing and preserving native flora

    Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

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    Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

    Taxonomic studies in Matayba Aubl. sect. Matayba (Sapindaceae)

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    Orientadores: Vinicius Castro Souza, Maria Silvia FerrucciDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Sapindaceae apresenta cerca de 140 gêneros e aproximadamente 1600 espécies. No Brasil está representada por 24 gêneros e cerca de 400 espécies. Matayba Aubl. conta com 56 espécies arbustivas ou arbóreas, distribuídas desde o México até o norte da Argentina e no Brasil são referidas 26 espécies presentes em diversas formações vegetacionais incluindo os cerrados, campos, florestas de restinga, a floresta amazônica e a floresta atlântica. Matayba sect. Matayba é a maior seção do gênero em número de espécies e está presente apenas na América do Sul. No Brasil a seção está distribuída predominantemente fora da Amazônia, com exceção de M. guianensis de ampla distribuição e M. artropurpurea que ocorre na Amazônia brasileira e colombiana, cujo posicionamento taxonômico está aqui sendo questionado. O objetivo deste trabalho é delimitar morfologicamente as espécies de Matayba sect. Matayba através de descrições, chave de identificação e ilustrações, além de apresentar comentários taxonômicos e distribuição geográfica das espécies. O trabalho foi realizado através de levantamento bibliográfico, consultas aos herbários (39 brasileiros e um na Argentina ¿ CTES) e expedições de coleta. Os principais caracteres para a separação das espécies desta seção são o número e forma dos folíolos, a proeminência e tipos de venação e a posição das domácias. Nas flores destacam-se como caracteres diagnósticos o tamanho do apêndice petalífero basal em relação as pétalas e o tipo de indumento de partes florais como sépalas, pétalas e filetes. Foram encontradas 16 espécies de Matayba sect. Matayba, sendo duas delas novas para a Ciência, além de uma nova sinonímia para M. elaeagnoides e três espécies que foram tratadas aqui, apesar de por apresentarem um posicionamento incerto. Em Minas Gerais, encontra-se o maior número de espécies desta seção (7 spp.) distribuídas principalmente nos cerrados e campos rupestres, sendo duas delas endêmicas (M. mollis e M. punctata). Entre as espécies com maior distribuição geográfica merecem destaque M. elaeagnoides que ocorre de Minas Gerais até o Rio Grande do Sul, e M. guianensis que ocorre em toda a América do sul, com exceção da ArgentinaAbstract: Sapindaceae presents about 140 genera and approximately 1600 species in Brazil is represented by 24 genera and about 400 species. Matayba Aubl. counts with 56 species being bushes or trees, distributed from Mexico to the north of Argentina and in Brazil 26 species are referred for several plant formations including the savannahs, campos rupestres, sandbank forests and the Atlantic forest. Matayba sect. Matayba is the largest section of the genus in number of species (18) and it is presented just in South America. In Brazil the section is distributed predominantly out of the Amazonia, except M. guianensis with wide distribution and M. artropurpurea that occurs in the Amazonian Brazilian and Colombian, but that appears with an uncertain positioning in this work. The objective of this work is to delimit morfologically the species of Matayba sect. Matayba through descriptions, a identification key and illustrations, besides presents taxonomic comments and geographical distribution about the species. The work was accomplished through bibliographical survey, consults to the herbaria (39 in Brazil and one in Argentina - CTES) and collection from expeditions. The main characters used to separate the species of this section are the number and form of the leflets, the prominence and venation types and the position of the domatia. In the flowers they stand out this diagnoses characters are the size of the appendix in realation with the petals and the presence of hairs in of floral parts like the sepals, petals and threads. The results obtained in this work counts with 16 species, being two of them new for the Science, besides a new synonymy for M. elaeagnoides and three species that were treated as uncertain positioning. Minas Gerais has the largest number of species of this section (7 spp.) distributed mainly in the savannahs and campos rupestres, being two of them endemic (M. mollis and M. punctata). Among the species with largerest geographical distribution make stand out M. elaeagnoides that occurs from Minas Gerais to Rio Grande do Sul, and M. guianensis in the whole South America with the exception in ArgentinaMestradoBiologia VegetalMestre em Biologia Vegeta

    Sistematic studies of the neotropical species of Allophylus L. (Sapindaceae)

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    Orientador: Maria do Carmo Estanislau do AmaralTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: A família Sapindaceae apresenta cerca de 141 gêneros e aproximadamente 1900 espécies sendo representada no Brasil por 24 gêneros e cerca de 400 espécies. O presente trabalho foi realizado através de consultas bibliográficas, atividades de campo, consulta aos acervos dos principais herbários, além dos resultados obtidos através das análises moleculares filogenéticas e da metodologia de barcoding e refere-se a um estudo sistemático e filogenético das espécies neotropicais de Allophylus L. (Sapindaceae) que conta com espécies arbustivas ou arbóreas, distribuídas em todas as regiões tropicais do mundo alcançando algumas áreas temperadas. Desta forma, o trabalho conta com descrições das espécies, ilustrações, chave de identificação, mapas de distribuição geográfica, comentários, fotografias das espécies quando obtidas, análise filogenética utilizando-se os marcadores ITS e trnL-F e finalmente o teste da metodologia de barcoding aplicada às espécies neotropicais do gênero e outros integrantes da família. As análises filogenéticas apresentam evidencias de monofiletismo do gênero e sua relação com Thouinia, como gênero irmão, e integrantes da tribo Paullinieae. Em seguida, as essas análises foram importantes para a tomada de decisão em relação ao número de espécies e finalmente para o teste da metodologia de barcoding que se mostrou funcional entre as espécies do gênero. O gênero Allophylus é representado na região neotropical por 43 espécies sendo a região amazônica apresentando a maior diversidade no número de espécies (25 spp.). Além disso, são apresentados 33 novos sinônimos e 10 novas lectotipificações para o gênero.Abstract: Sapindaceae presents 141 genera and approximately 1900 species being represented in Brazil by 24 genera and around 400 species. This work has been carried out through bibliographic research, field activities, consult of the main herbarium collections, as well as the results obtained through phylogenetic molecular analysis and the testing of barcoding methodology and refers to a systematic and phylogenetic study of neotropical Allophylus L. (Sapindaceae) that counts with shrubby or arboreous species distributed in all tropical regions of world reaching some temperate areas. Thus the work counts with the description of the species, illustrations, an identification key, maps of geographical distribution, taxonomic comments, photographs of the species when it was possible to obtain, a phylogenetic analysis using the ITS and trnL-F markers and finally to test the barcoding methodology applied to the neotropical species of the genus. The phylogenetic analysis confirmed the monophyly of the genus and its sister-group relation with Thouinia and part of the Paullinieae tribe related with both genera. Then, the analysis were important to make a decision on the number of species and finally to the test of the barcoding methodology among the species of the genus. Allophylus is represented in the neotropical region by 43 species being the Amazon region presenting the greatest diversity in species number (25 spp.). Furthermore, 33 new synonyms and 10 new lectotypifications are presented to the genusDoutoradoBiologia VegetalDoutor em Biologia Vegeta
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