Enhanced stability in CO2 of Ta doped BaCe0.9Y 0.1O3-δ electrolyte for intermediate temperature SOFCs

The influence of Ta concentration on the stability of BaCe 0.9-xTaxY0.1O3-δ (where x=0.01, 0.03 and 0.05) powders and sintered samples in CO2, their microstructure and electrical properties were investigated. The ceramic powders were synthesized by the method of solid state reaction, uniaxially pressed and sintered at 1550 °C to form dense electrolyte pellets. A significant stability in CO2 indicated by the X-ray analysis performed was observed for the samples with x≥0.03. The electrical conductivities determined by impedance measurements in the temperature range of 550-750 °C and in various atmospheres (dry argon, wet argon and wet hydrogen) increased with temperature but decreased with Ta concentration. The highest conductivities were observed in the wet hydrogen atmosphere, followed by those in wet argon, while the lowest were obtained in the dry argon atmosphere for each dopant concentration. The composition with Ta content of 3 mol% showed satisfactory characteristics: good resistance to CO2 in extreme testing conditions, while a somewhat reduced electrical conductivity is still comparable with that of BaCe0.9Y0.1O3-δ. © 2012 Elsevier Ltd and Techna Group S.r.l.

Water balance and locomotor performance in three species of neotropical toads that differ in geographical distribution

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

Probing the kinetics of single molecule protein folding

We propose an approach to integrate the theory, simulations, and experiments in protein-folding kinetics. This is realized by measuring the mean and high-order moments of the first-passage time and its associated distribution. The full kinetics is revealed in the current theoretical framework through these measurements. In the experiments, information about the statistical properties of first-passage times can be obtained from the kinetic folding trajectories of single molecule experiments ( for example, fluorescence). Theoretical/simulation and experimental approaches can be directly related. We study in particular the temperature-varying kinetics to probe the underlying structure of the folding energy landscape. At high temperatures, exponential kinetics is observed; there are multiple parallel kinetic paths leading to the native state. At intermediate temperatures, nonexponential kinetics appears, revealing the nature of the distribution of local traps on the landscape and, as a result, discrete kinetic paths emerge. At very low temperatures, exponential kinetics is again observed; the dynamics on the underlying landscape is dominated by a single barrier. The ratio between first-passage-time moments is proposed to be a good variable to quantitatively probe these kinetic changes. The temperature-dependent kinetics is consistent with the strange kinetics found in folding dynamics experiments. The potential applications of the current results to single-molecule protein folding are discussed.

Nucleation and crystallization of titania nanoparticles in silica titania planar waveguides: A study by low frequency Raman scattering

SiO2 (1-x) - TiO2 (x) waveguides, with the mole fraction x in the range 0.07 - 0.20 and thickness of about 0.4 μm, were deposited on silica substrates by a dip-coating technique. The thermal treatments at 700-900°C, used to fully densify the xerogels, produce nucleation of TiO2 nanocrystals even for the lowest TiO2 content. The nucleation of TiO2 nanocrystals and their growth by thermal annealing up to 1300°C were studied by waveguide Raman spectroscopy, for the SiO2 (0.8) - TiO2 (0.2) composition. By increasing the annealing temperature, the Raman spectrum evolves from that typical of the silica-titania glass to that of anatase, but brookite phase is dominant at intermediate temperatures. In the low. frequency region (5-50 cm-1) of the Raman spectra, acoustic vibrations of the nanocrystals are observed. From the measured line shapes, we can deduce the size distribution of the particles. The results are compared with those obtained from the line widths in the X-ray diffraction patterns. Nanocrystals with a mean size in the range 4-20 nm are obtained, by thermal annealing in a corresponding range of 800-1300°C.

Metodologias de avaliação de sêmen e procedimentos de fertilização artificial de surubim-do-paraíba, Steindachneridion parahybae

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

O espaço-tempo não comutativo em Teoria Quântica de Campos, Matéria Condensada Mole e Física Biológica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Acclimation to short-term low temperatures in two Eucalyptus globulus clones with contrasting drought resistance

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Improving the affinity of tomato grafted on Solanum torvum using an intermediate rootstock

Most of the interspecific rootstocks (Lycopersicum esculentum × L. hirsutum) used in grafted Spanish tomato crops are resistant to Meloidogyne nematodes, but the 'Mi' resistance gene does not work well at high soil temperatures. Ralstonia solanacearum is a bacterial disease usual in tropical areas, but recently identified with low incidence in several European countries. This disease could be controlled by grafting tomato on Solanum torvum, which is also resistant to Meloidogyne. However, S. torvum and tomato have low grafting affinity, which could be improved using an intermediate rootstock. Some cultivars of eggplant have a relatively good affinity with tomato and complete affinity with S. torvum. In this study we compared two tomato cultivars (one resistant to Verticillium dalihae, Fusarium oxysporum v. lycopersici race 2 and Meloidogyne spp., and one non-resistant) grafted onto 'Beaufort' (Lycopersicum esculentum × L. hirsutum), 'Torvum Vigor' (Solanum torvum) and also with an intermediate grafting of eggplant ('Cristal') between tomato and S. torvum, with nongrafted plants as controls. This arrangement was carried out in two cropping cycles (winter-spring and summer-autumn). In both cycles, plants grafted onto S. torvum, both single or double grafted, yielded less than those grafted onto 'Beaufort' or nongrafted plants. In the spring cycle, no differences were found between single and double-grafted plants using S. torvum rootstocks, but in the autumn cycle double grafted plants had higher yields than the single grafted plants. The severity of nematode infections, in terms of reducing yields, and/or hypothetical infections of Ralstonia, will determine the utility of this technique in tomato production.

Influence of the bipartite scrotum on the testicular and scrotal temperatures in goats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of different temperatures on the life history of Evania appendigaster L. (Hymenoptera: Evaniidae), a solitary oothecal parasitoid of Periplaneta americana L. (Dictyoptera: Blattidae)

The influence of temperatures on the life parameters of the solitary oothecal parasitoid Evania appendigaster, was investigated in the laboratory. Parasitized oothecae of Periplaneta americana were left to develop under seven constant temperatures: 15, 17, 20, 25, 30, 35, and 40 degrees C. At the end, we found that: (i) E. appendigaster was able to complete development within the temperature range of 17-34 degrees C; (ii) mean adult longevity decreased as temperature increased, with the temperature of 40 degrees C being fatal in a matter of hours; (iii) males lived longer than females between 15 and 30 degrees C; (iv) adult emergence rate was the highest at 25 degrees C, and (v) no wasps emerged at 15 or 40 degrees C. Non-emerged oothecae contained either unhatched eggs or dead larvae. We determined the theoretical lower developmental threshold and thermal constant for the complete development as 12.9 degrees C and 584.8 day-degrees for males, and 13.1 degrees C and 588.2 day-degrees for females, respectively. A good balance between faster development, maximum adult longevity and good egg viability was obtained between 25-30 degrees C, and that would be the best temperature range for rearing E. appendigaster. (C) 2009 Elsevier B.V. All rights reserved.

Multivariate analysis of fresh-cut carambola slices stored under different temperatures

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

Physical-chemical analysis of the cerebrospinal fluid of healthy dogs submitted to different storage periods and temperatures

Disfunções envolvendo o sistema nervoso são de grande importância na Medicina Veterinária, pois tratam-se de enfermidades de elevada incidência e com poucos subsídios auxiliares no seu diagnóstico, prognóstico e na avaliação de terapias empregadas. Ainda hoje, o diagnóstico baseia-se, em grande parte, no histórico e no exame clínico neurológico. Dessa forma, a análise dos constituintes do fluido cefalorraquidiano torna-se uma das poucas alternativas de acesso clínico ao sistema nervoso central (SNC). Mesmo com a grande utilidade do exame físico-químico e citoscópico do liquor na neurologia veterinária, poucos são os estudos sobre a estabilidade dos seus constituintes sob estocagem. Dessa forma, o presente trabalho teve como finalidade verificar a influência da temperatura e do tempo de conservação nas características físico-químicas do liquor de cães hígidos. Para tanto, foram coletadas amostras de LCR, através da punção da cisterna cerebelo-medular de cães clinicamente sadios, as quais foram submetidas à análise da densidade específica, do pH, da glicorraquia, das proteínas totais e das atividades das enzimas creatina quinase (CK) e aspartato aminotransferase (AST), após conservá-las em diferentes temperaturas (25°C, 4°C e -4°C) e por diferentes períodos de tempo (logo após a colheita, 24 horas, 48 horas, uma semana e um mês). Dentre os resultados obtidos, foi possível verificar, principalmente, que houve estabilidade dos parâmetros estudados por até um mês de estocagem nas amostras mantidas sob a temperaturas de congelamento de -4°C.

Fertility life table of Trichogramma pretiosum and Trichogramma acacioi (Hymenoptera : Trichogrammatidae) on Sitotroga cerealella (Lepidoptera : Gelechiidae) eggs at different constant temperatures

Fertility life tables were developed for both Trichogramma pretiosum and Trichogramma acacioi reared on Sitotroga cerealella eggs as an alternative host at five different temperatures. The egg parasitoids were first collected from Nipteria panacea eggs, a lepidopterous pest of avocado. Egg parasitoid females were individualized in small glass vials along with 40 eggs of the host during 24 h for parasitization. For evaluation of the parasitism capacity, a similar procedure was adopted, but cardboards with eggs were replaced every day. The net reproductive rate (Ro), intrinsic rate of increase (rm), finite rate of increase (lambda), and mean generation time (T) were estimated. Temperature affected all parameters for both Trichogramma species. The highest fecundity for both species was observed at 25degreesC. Extreme temperatures such as 15degreesC or 35degreesC negatively affect the development rate of both species.

Environmental temperature and cloacal and surface temperatures of broiler chicks in first week post-hatch

Adequate environmental temperature during the brooding period is very important to future broiler performance. Thus, the objective of this study was to investigate the extent to which environmental temperature affects the body weight and cloacal and surface (back, head, wing, and shank) temperatures. The study also investigated the sensible heat loss by radiation of broiler chicks reared at three environmental temperatures (35, 25, and 20 degrees C) up to 7 days of life. The results showed that chicks raised at low environmental temperature (20 degrees C) had lower body weight at 7 days of age. Birds kept at 20 degrees C also had significantly lower cloacal and surface temperatures than did other birds. The most marked difference was seen in the shanks. These findings revealed that body weight declined in chicks reared at 20 degrees C, and radiant heat loss (W) was nine times higher than for the birds kept at 35 degrees C at 7 days of age.

Influence of early quantitative food restriction on long bone growth at different environmental temperatures in broiler chickens

1. This investigation was carried out to study the influence of early quantitative food restriction (40% of ad libitum intake from 7 to 14 d of age) and environmental rearing temperature (thermoneutral, cold and hot) on long bone (tibia, femur and humerus) development in broiler chickens.2. Tibia, femur and humerus were obtained at the ages of 14, 21, 28, 35 and 42 d; and the variables studied were: length and width (mm, expressed as absolute values), bone breaking strength (kgf) and bone weight/bone length index (BW/BL, mg/mm).3. All bone variables increased with bird age. Food restriction reduced bone length and width but did not affect bone weight. High environmental rearing temperature reduced bone length and width at 42 d of age. Bone strength was not affected by environmental temperature but the calculated BW/BL index was reduced by heat exposure.4. The findings suggest that food restriction and high environmental rearing temperature reduce long bone growth; bone breaking strength was affected by bird age but not by food restriction nor rearing ambient temperature.