1000 resultados para Avaliação climática


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Os modelos climáticos globais são considerados a melhor ferramenta para gerar cenários prováveis de alterações climáticas futuras, apesar das incertezas. As projeções são diferentes para cada região e variam ao longo das estações do ano. O objetivo deste trabalho foi avaliar a similaridade entre projeções dos modelos climáticos globais do IPCC-AR4 para temperatura média na região Sudeste do Brasil, no período de 2071 a 2100, cenário A2. Para tanto, foram realizadas análise de componentes principais e análise de agrupamento hierárquico para agrupar os modelos de comportamentos semelhantes. Adotando-se quatro grupos de modelos, os valores médios de temperatura variaram de 23,7°C a 25,4°C.

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This Masters Degree dissertation seeks to make a comparative study of internal air temperature data, simulated through the thermal computer application DesignBuilder 1.2, and data registered in loco through HOBO® Temp Data Logger, in a Social Housing Prototype (HIS), located at the Central Campus of the Federal University of Rio Grande do Norte UFRN. The prototype was designed and built seeking strategies of thermal comfort recommended for the local climate where the study was carried out, and built with panels of cellular concrete by Construtora DoisA, a collaborator of research project REPESC Rede de Pesquisa em Eficiência Energética de Sistemas Construtivos (Research Network on Energy Efficiency of Construction Systems), an integral part of Habitare program. The methodology employed carefully examined the problem, reviewed the bibliography, analyzing the major aspects related to computer simulations for thermal performance of buildings, such as climate characterization of the region under study and users thermal comfort demands. The DesignBuilder 1.2 computer application was used as a simulation tool, and theoretical alterations were carried out in the prototype, then they were compared with the parameters of thermal comfort adopted, based on the area s current technical literature. Analyses of the comparative studies were performed through graphical outputs for a better understanding of air temperature amplitudes and thermal comfort conditions. The data used for the characterization of external air temperature were obtained from the Test Reference Year (TRY), defined for the study area (Natal-RN). Thus the author also performed comparative studies for TRY data registered in the years 2006, 2007 and 2008, at weather station Davis Precision Station, located at the Instituto Nacional de Pesquisas Espaciais INPE-CRN (National Institute of Space Research), in a neighboring area of UFRN s Central Campus. The conclusions observed from the comparative studies performed among computer simulations, and the local records obtained from the studied prototype, point out that the simulations performed in naturally ventilated buildings is quite a complex task, due to the applications limitations, mainly owed to the complexity of air flow phenomena, the influence of comfort conditions in the surrounding areas and climate records. Lastly, regarding the use of the application DesignBuilder 1.2 in the present study, one may conclude that it is a good tool for computer simulations. However, it needs some adjustments to improve reliability in its use. There is a need for continued research, considering the dedication of users to the prototype, as well as the thermal charges of the equipment, in order to check sensitivity

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As estimativas atuais de biomassa florestal contêm erros não dimensionados pela escassez de dados dos sistemas radiculares. Esta lacuna se deve às custosas estratégias de amostragem de raízes, que demanda grande quantidade de labor manual enquanto a estimativa da biomassa aérea pode ser feita com apenas a medida de diâmetro do tronco (DAP) conforme apontado por Chave et al, Houghton recomenda um valor geral de 20% da parte aérea para quantificar biomassa radicular, apesar de Silver haver demonstrado que o clima, o solo e a qualidade da serapilheira devam ser levados em conta. Dentre os principais determinantes da biomassa radicular destacam-se, no Estado do Rio de Janeiro, as contrastantes condições de clima e solo, além da composição e estrutura dos diferentes fragmentos florestais que ocorrem na paisagem. De acordo com Davis & Naghettini, ocorre expressiva variação climática representada por precipitações anuais desde 750 mm no Vale do Rio Paraíba do Sul a 4000 mm na Serra da Mantiqueira. Há grande variedade de solos no estado. A título de ilustração, em dois municípios costeiros, um deles incluído no presente estudo, Lumbreras et al encontraram a dominância, nas partes elevadas, de Latossolos, Argissolos, Nitossolos, Luvissolos, Planossolos, Cambissolos e Neossolos. Já nas baixadas, relacionadas aos sedimentos recentes, ocorrem as classes: Espodossolos, Planossolos, Gleissolos, Neossolos e Organossolos. Associados a outros atributos da feição paisagística, compuseram 45 unidades de mapeamentos. Nesse ambiente distribuem-se diversos fragmentos florestais, alguns remanescentes, em geral interferidos ou de difícil acesso e vegetação secundária em sua maioria. Os fragmentos florestais fluminenses resultam, primordialmente, da conversão das florestas nativas em cafezais e pastagens nos séculos 19 e 20, do uso crônico do fogo nas pastagens (ou por vandalismo), e da extração seletiva de árvores, cujo impacto pode ser detectado na ciclagem de nutrientes, conforme demonstrado por Villela et al., que deve influenciar significativamente a biomassa radicular. Ante o exposto o presente estudo visou estimar a biomassa radicular fina de diferentes fragmentos florestais da Planície Costeira Fluminense, comparando-as entre si.

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Apresenta-se, neste trabalho, um estudo realizado sobre a qualidade de enlace e alcance de conectividade entre os nós de uma rede de sensores sem fio, a partir de dois indicadores: o de intensidade de sinal recebido e o de qualidade de enlace. O ambiente agrícola considerado foi um vinhedo cultivado sob cobertura plástica, cujas variáveis ambientais de importância foram monitoradas, por influenciarem no desenvolvimento fisiológico das videiras, afetando o rendimento e a qualidade das uvas produzidas. A incorporação de tecnologias que permitam um melhor gerenciamento dessa variabilidade microclimática é importante para a viticultura brasileira, bem como a realização de levantamentos experimentais para aperfeiçoar o uso das redes de sensores sem fio em ambientes agrícolas. Dos resultados obtidos, quantificou-se a interferência que os vegetais exercem sobre a comunicação, principalmente perto do dossel das videiras, sendo discutidos no trabalho.

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Attention deficit hyperactivity disorder (ADHD) is characterized by a persistent pattern of inattention and/or hyperactivity/impulsivity. The aim of this research was to contribute more precisely to the diagnosis of ADHD, to propose a battery of neuropsychological assessment and to analyze the contribution of each test. We studied 10 matched pairs of children with ADHD and normal controls (7 to 11 years). Inclusion criteria were: presence of ADHD typical behavior, positive diagnosis of ADHD based on DSM-IV, normal IQ, normal neurological examination and parental consent. We used extensive neuropsychological battery. The results showed differential sensitivity for detection of attentional problems in children with ADHD, although most tests did not reach statistical significance. The item, errors, of WCST revealed statistically significant difference between the two groups: ADHD performance was inferior to controls . In conclusion the neuropsychological assessment battery used in this research contributed to the diagnosis of ADHD.

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The purpose of this study is to introduce a method to evaluate visual functions in infants in the first three months of life. An adaptation of the Guide for the Assessment of Visual Ability in Infants (Gagliardo, 1997) was used. The instrument was a ring with string. It was implemented a pilot study with 33 infants, selected according to the following criteria: neonates well enough to go home within two days of birth; 1 to 3 months of chronological age; monthly evaluation with no absence; subjects living in Campinas/SP metropolitan area. In the first month we observed: visual fixation (93,9%); eye contact (90,9%); horizontal tracking (72,7%); inspects surroundings (97,0%). In the third month, we observed: inspects own hands (42,4%) and increased movements of arms (36,4%). This method allowed the evaluation of visual functions in infants, according to the chronological age. Alterations in this function will facilitate immediate referral to medical services for diagnoses.

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This text offers some contributions to the debate on the changes proposed to the National Curricular Directives to reform secondary education in Brazil. In the first part, the political and economic scene is evaluated as the context which generated the last stage of reforms in the educational field in the 90s. It questions the option for a model of structural reform (in the Brazilian case more restricted to the Program for Reform of Professional Education - PROEP) and of the curriculum, whose themes find their justification in the contemporary economic, social cultural and political context. It discusses the use of a model that bases itself on experiences developed in other countries and takes the international orientation of the multilateral organizations as its theoretical methodological reference, leaving out the peculiarities and injunctions of the Brazilian political administrative system. Such a policy measure can increase the tension and distance normally existing between government programs and the possibility of their real implementation in the school network. In the second part, it discusses the Resolution of the National Education Council, the Congress on Basic Education, no.3, of 16.698 that instituted the National Curricular Directives for secondary education, as well as the Legal Bases - Part I - of the National Curricular Parameters for secondary education. The analysis of official discourse takes Bardin's (1977, p. 209) proposals as its methodological reference for the models of structural analysis, seeking to make the implicit values and the connotations of the legal texts explicit

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Vitamin C stability and concentration was evaluated in isotonic beverages and B group vitamins (B1, B2, B3, B5 and B6) in power beverages. The amount of vitamins was found to be above of that declared on the labels, even after the shelf life had been exceeded. A small decrease in the amount of B group vitamins was observed during the shelf life of the products. In the case of vitamin C this decrease was slightly higher. The present research shows the need of increased quality control and inspection.

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Volatile compounds from green and roasted yerba mate were analyzed by gas chromatography/mass spectrometry and the flavor profile from yerba mate beverages was determined by descriptive quantitative analyses. The main compounds tentatively identified in green mate were linalool, alpha-terpineol and trans-linalool oxide and in roasted mate were (E,Z)-2,4-heptadienal isomers and 5-methylfurfural. Green mate infusion was qualified as having bitter taste and aroma as well as green grass aroma while roasted mate was defined as having a smooth, slightly burnt aroma. The relationship between the tentatively identified compounds and flavor must be determined by olfatometric analysis.

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A discussion about groundwater contamination is presented in this work. Contamination by agricultural activity, more specifically by pesticides is emphasized. Indirect and direct estimates could be used to predict pesticide behavior in soil, and consequently, to evaluate the potential of groundwater contamination. These results could be applied to advise about the possibility of groundwater contamination by pesticides, and to provide subsidies for making decisions more quickly and efficiently.

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Antimony is a common catalyst in the synthesis of polyethylene terephthalate used for food-grade bottles manufacturing. However, antimony residues in final products are transferred to juices, soft drinks or water. The literature reports mentions of toxicity associated to antimony. In this work, a green, fast and direct method to quantify antimony, sulfur, iron and copper, in PET bottles by X-ray fluorescence spectrometry is presented. 2.4 to 11 mg Sb kg-1 were found in 20 samples analyzed. The coupling of the multielemental technique to chemometric treatment provided also the possibility to classify PET samples between bottle-grade PET/recycled PET blends by Fe content.

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This paper discusses the historical and methodological fundaments of the dynamics and quantification of acid volatile sulfides (AVS) and simultaneously extracted metals (SEM) in aquatic sediments. It also discusses the SEM/AVS relationship, which involves several controversial aspects such as sulfide stability, sulfide-organic matter interaction, and the inability to predict the toxicity of organic compounds in the environment. This relationship is an important tool for the inference of metal bioavailability. The use of ecotoxicological tests with target organisms regulated by international standards is also a relevant aspect.

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The aggregation behavior of the non-ionic surfactant Renex-100 in aqueous solutions and mesophases was evaluated by SAXS in a wide range of concentrations, between 20 and 30 °C. Complementary, water interactions were defined by DSC curves around 0°C. SAXS showed that the system undergoes the following phase transitions, from diluted to concentrated aqueous solutions: 1) isotropic solution of Renex aggregates; 2) hexagonal mesophase; 3) lamellar mesophase; and 4) isotropic solution. DSC analysis indicated the presence of interfacial water above 70wt%, which agreed with the segregation of free water to form the structural mesophases observed by SAXS bellow this concentration.

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Remotely sensed imagery has been widely used for land use/cover classification thanks to the periodic data acquisition and the widespread use of digital image processing systems offering a wide range of classification algorithms. The aim of this work was to evaluate some of the most commonly used supervised and unsupervised classification algorithms under different landscape patterns found in Rondônia, including (1) areas of mid-size farms, (2) fish-bone settlements and (3) a gradient of forest and Cerrado (Brazilian savannah). Comparison with a reference map based on the kappa statistics resulted in good to superior indicators (best results - K-means: k=0.68; k=0.77; k=0.64 and MaxVer: k=0.71; k=0.89; k=0.70 respectively for three areas mentioned). Results show that choosing a specific algorithm requires to take into account both its capacity to discriminate among various spectral signatures under different landscape patterns as well as a cost/benefit analysis considering the different steps performed by the operator performing a land cover/use map. it is suggested that a more systematic assessment of several options of implementation of a specific project is needed prior to beginning a land use/cover mapping job.

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This study had as objective the evaluation of mechanical damages occurred in banana Nanicão during the improvement process, packing and distribution, identifying the probable critical points. The mechanical damages caused by transport, first cleaning; cleanness and sorting; preservation in the packing, transport, and mature were evaluated. The studied packing had been: torito wooden packing (18 kg), wood type ½ box, (13 kg) and cardboard (18 kg). The stage of preservation and transport of the fruits to the distribution center duplicated the light defects and quintupled the serious defects, causing rottenness after the acclimatization. The cardboard packing did not support the piling up and presented deformations, that resulted in the kneading the fruits of the inferior packing, causing a significant increase of the serious defects. The fruits conditioned in the involved packing of plastic bubble had presented an inferior number of serious damages when compared with the others packing, without the plastic.