Estudo da influência da temperatura na degradação termoquímica da biomassa de avelós (euphorbia tirucalli Linn)

The bio-oil obtained from the pyrolysis of biomass has appeared as inter-esting alternative to replace fossil fuels. The aim of this work is to evaluate the influence of temperature on the yield of products originating from the pyrolysis process of the powder obtained from the dried twigs of avelós (Euphorbia tirucalli), using a rotating cylinder reactor in laboratory scale. The biomass was treated and characterized by: CHNS, moisture, volatiles, fixed carbon and ashes, as well as evaluation of lignin, cellulose and hemicellulose, besides other instrumental techniques such as: FTIR, TG/DTG, DRX, FRX and MEV. The activation energy was evaluated in non-isothemichal mode with heating rates of 5 and 10 oC/min. The obtained results showed biomass as feedstock with potential for biofuel production, because presents a high organic matter content (78,3%) and fixed-carbon (7,11%). The activation energy required for the degradation of biomass ranged between 232,92 392,84 kJ/mol, in the temperature range studied and heating rate of 5 and 10°C/min. In the pyrolysis process, the influence of the reaction temperature was studied (350-520 ° C), keeping constant the other variables, such as, the flow rate of carrier gas, the centrifugal speed for the bio-oil condensationa, the biomass flow and the rotation of the reactor. The maximum yield of bio-oil was obtained in the temperature of 450°C. In this temperature, the results achieved where: content of bio-oil 8,12%; char 32,7%; non-condensed gas 35,4%; losts 23,8%; gross calorific value 3,43MJ/kg; pH 4,93 and viscosity 1,5cP. The chromatographic analysis of the bio-oil produced under these conditions shows mainly the presence of phenol (17,71%), methylciclopentenone (10,56%) and dimethylciclopentenone (7,76%)

Impactos do estresse salino e da cobertura morta nas características químicas do solo e no desenvolvimento do amaranto

Availability of good quality water has been reduced vertiginously, over the last decade, in the world. In some regions, the water resources have high concentration of the dissolved salts, these characteristics of the water make it s use impossible. Water quality can be a limitation for irrigated agriculture, principally in regions of arid or semiarid climate where the water resources are generally saline and are exposed at high evaporation ratio. For that reason, precipitation of the salts occurs near the soil surface and those salts themselves cumulate in the vegetal tissue, reducing the soil fertility and crop production. The adoption of tolerant crop to the water salinity and soil salinity, adaptable to the climatic conditions is other emergent necessity. This work had the goal of studying the effects of four salinity levels of the irrigation water salinity and use of mulch, dried leaves of Forest mangrove (Acacia mangiumWilld), in cultivated soil with amaranth (Amaranthus cruentus, BRS Alegria variety), in greenhouse. It was utilized the transplant of plants to PVC columns, containing 30 kg of silty loam soil, 10 days after emerging, with space of 50 x 50 cm between lines. Treatments were composed by combination of four levels of salinity (0.147; 1.500; 3.000 e 4.500 dS m-1), obtained by addition NaCl (commercial) to irrigation water and soil with and without protection, by mulch. A factorial system 4 x 2 was used with four repetitions, totalizing 32 parcels. The concentrations of nutrients in soil solution have been evaluated, in the dry matter of the vegetal tissue (roots, stem, leaves and raceme residue), at the end of the vegetative cycle. The use of soil protection reduced time for the beginning inflorescence of plants, at the same time, the increase of the salinity delayed this phase of amaranth development. The use of the mulch effectively increased the height, stem diameter, area of the larger leaf, humidity and dry matter content and amaranth grain production. The vegetal species showed salinity tolerance to experimented levels. The adopted treatments did not affect the pH values, exchangeable cation contents, electrical conductivity of soil solution (EC1:5) and saturated extract (ECSE), and Ca+2, Mg+, Fe+2 and Mn+2 contents, in the soil solution. The increase of the salinity concentration in the irrigation water inhibited the mineralization process of the organic matter (OM) and, consequently, the efficiency in the it´s utilization by plants, at the same time, produced increase in the values of the exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR) and potassium adsorption ratio (PAR), in the soil solution. Therefore, the use of the mulch did not affect the first three parameters. The protein and nutrient contents: K+, Ca+2, P, Mg+2 e Cu+2, in amaranth grains, were improved by tillage condition. The raceme residues showed chemical/nutritional composition that makes advantageous its application in animal ration. In this context, it follows that amaranth tolerate the saline stress, of the irrigation water, until 4.500 dS m-1, temperature and relative humidity of the air predominant in the experimental environment

Influência do teor e granulometria da calcita e da temperatura de sinterização no desenvolvimento de massas cerâmicas para revestimento poroso(BIII)

This work aims at studying the influence of the concentration of calcite, its grain size and sintering temperature to obtain porous coating formulations that meet the design specifications. The experiments involved the physical-chemical and mineralogical caracterization of the raw materials, and mechanical tests on specimens dried and sintered, performing a planning mixture and factorial experiment, using the response surface methodology. The ceramic bodies studied were prepared by dry process, characterized, placed in conformity by uniaxial pressing and sintered at temperatures of 940 º C, 1000ºC, 1060ºC, 1120°C and 1180°C using a fast-firing cycle. The crystalline phases formed during sintering at temperatures under study, revealed the presence of anorthite and wolastonite, and quartz-phase remaining. These phases were mainly responsible for the physical and mechanical properties of the sintered especimens. The results shown that as increases the participation of carbonate in the composition of ceramic bodies there is an increase of water absorption and a slight reduction in linear shrinkage for all sintering temperatures. As for the mechanical strength it was observed that it tended to decrease for sintering at temperatures between 940 ° C and 1060 ° C and to increase for sintering at temperatures above 1060 ° C occurring with greater intensity for compositions with higher content of calcite. The resistence decreased with increasing participation of quartz in all sintering temperatures. The decrease in grain size of calcite caused a slight increase in water absorption for formulation with the same concentration of carbonate, remaining virtually unchanged the results of linear shrinkage and mechanical strength. In conclusion, porous ceramic coating (BIII) can be obtained using high concentrations of calcite and keeping the properties required in technical standards and that the particle size of calcite can be used as tuning parameter for the properties of ceramic products.

Influência da geometria e da temperatura na cinética de secagem de tomate (Lycopersicum esculentum)

O tomate é um fruto muito perecível por causa do seu conteúdo de umidade. A secagem é uma das práticas industriais mais utilizadas em alimentos para manter a qualidade do produto final. A pesquisa foi desenvolvida para estudo dos parâmetros de secagem de tomate (Lycopersicon esculentum Mill), cv Carmen, com relação ao tipo de corte (meio e um quarto) e à temperatura de processo (60 e 70 ºC), bem como à escolha do tempo de secagem para a obtenção de um produto com umidade de 45% (base úmida). As cinéticas de secagem foram determinadas experimentalmente por convecção forçada e ajustadas ao modelo de Page. Os resultados obtidos mostraram que a geometria de corte influenciou na taxa de secagem e no tempo de desidratação. Os tomates cortados em quatro partes e desidratados a 70 ºC alcançaram umidade de 45% em menor tempo (10 horas), quando comparados aos tomates com o corte em metades. O modelo de Page forneceu bom ajuste nas cinéticas de secagem

Elaboração e aplicação de uma estratégia de ensino sobre os conceitos de calor e de temperatura

This piece of work has investigated the alternative conceptions shown by students of secondary school, concerned to the concepts of warmth and temperature, aiming the elaboration and application of a learning strategy as of the diagnose risen from the conceptions present in students. The learning strategy was built up by a sequence of activities that involve History of Science and experiments, put in a course that had as a base the proposal of the Group of Redevelopment of Physics Teaching (GREF). We have used as the conductor wire of our research the development of thermo dynamics since the development of the first thermo machines, passing by the Industrial Revolution and the evolution of concepts of warmth and temperature. The learning strategy was applied to a group of second grade of secondary school in a public school in Mossoró (RN). By doing these activities we tried to become the concepts, which are part of thermo dynamics, more meaningful to the students. We have estimated that the application of the strategy has represented some profits to the students of the group, concerning to learning of laws and concepts of thermo dynamics (specifically the concepts of warmth and temperature), as well as what it is referred to the overcoming of its initial conceptions

Comportamento elétrico a alta temperatura de termistor cerâmico alfa-Fe2O3 com coeficiente de temperatura negativo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito da temperatura de estocagem de leveduras de panificação sobre a atividade da glicerol-3-fosfato desidrogenase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência da salinidade e temperatura da água nas respotas comportamental e fisiológica de camarões marinhos Litopenaeus vannamei(BOONE 1931)

The shrimp Litopenaeus vannamei has been grown in highly variable environments, especially in relation to salinity and water temperature. The adjustment to such conditions mainly involves changes in behavior, physiology, particularly in the immune response. This may consequently reduce the welfare of these animals. Despite the widespread farming of the species, little is known about their behavioral and physiological responses under stressful conditions. Thus, the objective of this study was to assess the influence of different salinities and temperatures in the behavior of the marine shrimp L. vannamei, and its relation to the total hemocytes count. In the laboratory, juvenile shrimp were kept in glass aquaria with a closed water recirculation system, continuous aeration and filtration, and under a 12:12 h light/dark cycle. Behavioral observations occurred 1, 4, 7 and 10 h after the start of each phase (light or dark). To assess the influence of salinity, shrimp were first acclimated and then observed at 2, 30 or 50 ppm salinity water, while temperatures tested were 18, 28 and 33 ° C. At the end of each experiment (30 days), shrimp hemolymph was collected for subsequent total hemocytes count (THC), a parameter used to assess stress. In general, feeding behavior was modified under lower salinity and temperature, with reduced values in feeding, exploration and digestive tract filling. Inactivity and burrowing were prevalent under extreme conditions water salinity and temperature, respectively: 2 and 50 ppm and 18 and 33 ° C; crawling was also less frequent under these conditions. In regards to light/dark cycle, shrimp were more active during the dark phase (crawling and swimming), while burrowing was higher during the light phase, regardless of salinity or temperature of the water. Inactivity behavior did not vary according to the light/dark cycle. Moreover, the total hemocytes count (THC) was reduced under 2 and 50 ppm salinity and 18 ° C temperature. Farming of L. vannamei under extremely low or high salinities and low temperatures is harmful. This suggests the species must be cultivated in salinities closer to those of the sea as well as at high temperatures, which seems to be ideal for a management focused on animal welfare, therefore, producing healthier shrimp

Sincronização dos ritmos de atividade motora e temperatura central à disponibilidade de glicose em ratos

Food is essential for the survival of all animals. Its temporal availability is an important enviromental cue for the behavioral and physiological organization throughout the 24 hours of day in different species. Rats and mice, for example, show increased locomotion in the hours before food availability when it is presented in a recurrent manner, a behavior named foodanticipatory activity. Several lines of evidence indicate that this anticipation is mediated by a circadian oscillator. In this work, based on the hypothesis that pre- or post-ingestive humoral signals are involved in the entrainment process, we tested whether the daily intake of glucose is sufficient to induce anticipatory activity in rats. The rhythms of motor activity and central temperature were recorded in animals undergoing 10 days of temporal glucose (solution at 50%) or chow restriction in light-dark (LD) and constant darkness (DD). Animals under temporal glucose restriction increase motor activity and and central temperature in the hours preceding glucose availability and such aticipation is extremely similar to that observed in animals under temporal chow restriction. Glucose ingestion is, therefore, a sufficient temporal cue to induce anticipation in rats. It is possible that the increase in plasma glucose after food ingestion constitutes one of the signals involved in the behavioral entrainment process to food availability

Influência da temperatura no desempenho mecânico de compósitos PEI/fibras de vidro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comportamento plástico do aço inoxidável austenítico em baixa temperatura

Ensaios de tração uniaxiais foram empregados para deformar aços inoxidáveis austeníticos do tipo 304, em diferentes temperaturas abaixo da ambiente (de 77 K a 300 K). A relação entre a estabilidade da austenita e o encruamento, em função da temperatura de teste, é discutida quanto à transformação martensítica induzida por deformação e ao deslizamento de discordâncias na austenita. em curvas tensão-deformação que assumem a equação de Ludwik sigma = sigmao + képsilonn, na qual sigma é a tensão verdadeira e e a elongação plástica verdadeira, um modo conveniente para analisar o encruamento é por meio do diagrama log dsigma / dépsilon versus log épsilon. O aspecto significativo é a variação da taxa de encruamento dsigma / dépsilon com a elongação plástica verdadeira nas diferentes temperaturas. As mudanças no comportamento do encruamento motivando até três estágios de deformação são associadas a diferentes processos microestruturais. A transformação martensítica pode ser considerada como um processo de deformação que compete com o processo usual de deslizamento. A investigação desses estágios, na região plástica, produz uma referência qualitativa de como diferentes fatores, tais como o grau de deformação, temperatura e composição química da austenita, afetam a transformação austenita-martensita.

Partículas inteligentes de poli (nisopropilacrilamida), quitosana e poli (ácido acrílico): efeito da temperatura e do pH sobre suas propriedades em suspensões aquosas

The present study describes the stability and rheological behavior of suspensions of poly (N-isopropylacrylamide) (PNIPAM), poly (N-isopropylacrylamide)-chitosan (PNIPAMCS), and poly (N-isopropylacrylamide)-chitosan-poly (acrylic acid) (PNIPAM-CS-PAA) crosslinked particles sensitive to pH and temperature. These dual-sensitive materials were simply obtained by one-pot method, via free-radical precipitation copolymerization with potassium persulfate, using N,N -methylenebisacrylamide (MBA) as a crosslinking agent. Incorporation of the precursor materials into the chemical networks was confirmed by elementary analysis and infrared spectroscopy. The influence of external stimuli such as pH and temperature, or both, on particle behavior was investigated through rheological measurements, visual stability tests and analytical centrifugation. The PNIPAM-CS particles showed higher stability in acid and neutral media, whereas PNIPAM-CS-PAA particles were more stable in neutral and alkaline media, both below and above the LCST of poly (Nisopropylacrylamide) (stability data). This is due to different interparticle interactions, as well as those between the particles and the medium (also evidenced by rheological data), which were also influenced by the pH and temperature of the medium. Based on the results obtained, we found that the introduction of pH-sensitive polymers to crosslinked poly (Nisopropylacrylamide) particles not only produced dual-sensitive materials, but allowed particle stability to be adjusted, making phase separation faster or slower, depending on the desired application. Thus, it is possible to adapt the material to different media

Estudos epidemiológicos e controle químico de Phakopsora euvitis

Em janeiro de 2003 foram constatados sintomas típicos de ferrugem em folhas maduras de videira (Vitis vinifera), nas áreas experimentais da Universidade Estadual Paulista, Campus de Ilha Solteira, em Selvíria - MS e Ilha Solteira - SP. Este é o primeiro relato desta doença da videira no Centro-Oeste do Brasil. Considerando a intensidade da doença, a importância da cultura da videira na região e a falta de informações sobre a ferrugem, os objetivos deste trabalho foram: reconfirmar a patogenicidade de Phakopsora euvitis; estudar a influência da luz e da temperatura na germinação de urediniósporos; estudar o efeito do tipo de superfície na germinação de urediniósporos; determinar a longevidade in vivo de urediniósporos e avaliar a eficiência agronômica de fungicidas para o controle da ferrugem. Sintomas da ferrugem foram verificados somente em folhas maduras de videira. A temperatura de 25 ºC, no escuro, e a superfície inferior da folha de videira foram as melhores condições para a germinação de urediniósporos de P. euvitis. A germinação dos urediniósporos foi reduzida em 94%, em folhas de videira que foram retiradas das plantas e mantidas durante sete dias na superfície do solo. em dois experimentos realizados em campo constatou-se que os fungicidas tebuconazole, propiconazole e azoxystrobin proporcionaram as menores intensidades da doença. Tebuconazole apresentou-se como o fungicida mais eficiente no controle da ferrugem. No geral, maior intensidade da ferrugem foi observada em videira conduzida no sistema de espaldeira.

Incubabilidade e Qualidade de Pintos de Ovos Matrizes de Frangos de Corte Submetidos a Estresse de Temperatura

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Geoprocessamento de dados meteo-oceonográficos (cor do oceano e temperatura da superfície do mar) aplicado ao monitoramento ambiental na costa setentrional do Rio Grande do Norte

Orbital remote sensing has been used as a beneficial tool in improving the knowledge on oceanographic and hydrodynamic aspects in northern portion of the continental shelf of Rio Grande do Norte, offshore Potiguar Basin. Aspects such as geography, temporal and spatial resolution combined with a consistent methodology and provide a substantial economic advantage compared to traditional methods of in situ data collecting. Images of the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard NASA's AQUA satellite were obtained to support systematic data collections related to the campaign of environmental monitoring and characterization of Potiguar Basin, held in May 2004. Images of Total Suspension Matter (TSM) and values of radiance standard were generated for the calculation of concentrations of total suspension matter (TSM), chlorophyll-a and sea surface temperature (SST). These data sets were used for statistical comparisons between measures in situ and satellite estimates looking validate algorithms or develop a comprehensive regional approach empirically. AQUA-MODIS images allowed the simultaneous comparison of two-dimensional water quality (total suspension matter), phytoplankton biomass (chlorophyll-a) variability and physical (temperature). For images of total suspension matter, the generated models showed a good correlation with the field data, allowing quantitative and qualitative analysis. The images of chlorophyll-a showed a consistent correlation with the in situ values of concentration. The algorithms adjusted for these images obtained a correlation coefficient fairly well with the data field in order that the sensor can be having an effect throughout the water column and not just the surface. This has led to a fit between the data of chlorophyll-the integration of the average sampling interval of the entire water column up to the level of the first optical depth, with the data generated from the images. This method resulted in higher values of chlorophyll concentration to greater depths, due to the fact that we are integrating more values of chlorophyll in the water column. Thus we can represent the biomass available in the water column. Images SST and SST measures in situ showed a mean difference DT (SST insitu - SST sat) around -0.14 ° C, considered low, making the results very good. The integration of total suspension matter, chlorophyll-a, the temperature of the sea surface (SST) and auxiliary data enabled the recognition of some of the main ways to fund the continental shelf. The main features highlighted were submerged canyons of rivers Apodi and Açu, some of the lines and beachrocks reefs, structural highs and the continental shelf break which occurs at depths around -60 m. The results confirmed the high potential for use of the AQUA-MODIS images to environmental monitoring of sea areas due to ease of detection of the field two-dimensional material in suspension on the sea surface, temperature and the concentration of chlorophyll-a