Structural characteristics of silica sonogels prepared with additions of isopropyl alcohol

Wet silica gels with similar to 1.4 x 10(-3) mol SiO2/cm(3) and similar to 92 vol% liquid phase were obtained from sonohydrolysis of tetraethoxysilane (TEOS) with different additions of isopropyl alcohol ( IPA). The IPA/TEOS molar ratio R was changed from 0 to 4. Aerogels were obtained by supercritical CO2 extraction. The samples were analyzed by small-angle X-ray scattering (SAXS) and nitrogen adsorption. The wet gels exhibit mass fractal structure with fractal dimension increasing from D similar to 2.10 to D similar to 2.22, characteristic length xi decreasing from similar to 9.5 to similar to 6.9 nm, as R increases from 0 to 4, and an estimated characteristic length for the primary silica particles lower than similar to 0.3 nm. The supercritical process apparently eliminates a fraction of the porosity, increasing the mass fractal dimension and shortening the fractality domain in the mesopore region. The fundamental role of isopropyl alcohol on the structure of the resulting aerogels is to decrease the porosity and the pore mean size as R changes from pure TEOS to R = 4. A secondary structure appearing in the micropore region of the aerogels can be described as a mass/surface fractal structure, with correlated mass fractal dimension D-m similar to 2.7 and surface fractal dimension D-s similar to 2.3, as inferred from SAXS and nitrogen adsorption data.

Physical and postural aspects of teachers during work activity

Studies indicate that teachers constitute a professional segment, in which the work characteristics and the demands originating from the act of teaching, favor the emergence of sickness, concerning physical or emotional aspects. The present work aimed to describe physical and postural aspects during the working activity of teachers. A total of 120 elementary school teachers (1st to 8th grade) took part in the survey. For data collection, a questionnaire was applied: it included personal and occupational information, perception of discomfort and being off work; physical strength activities; posture at work and physical conditioning activities. The average age of teachers of the present sample corresponds to 35,8 years. In relation to activities which generate more physical strength, the answer none of the activities was predominant with 30 answers; followed by writing on the board, standing up during the period of classes, explanation of the subjects, class elaboration, correction of homework and others. The area of the body with higher amount of occurrences and prevalent discomfort referred to the lower limbs and spinal cord. These data inform the necessity of investing in prevention programs for the teachers, in order to develop strategies into the organizational context and interventions at the work environment.

Physiological Responses and Characteristics of Table Tennis Matches Determined in Official Tournaments

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Habitat heterogeneity and use of physical acoustic space in anuran communities in southeastern Brazil.

We intended to verify if structural and physiognomical characteristics of water bodies influence on the degree of overlap among calling sites of 23 anurans species, if anuran species use different calling sites in different water bodies, and if there is some relationship between the degree of advertisement call (based on seven call features) and calling site differentiation. Then, we determined calling sites (based in four variables) and recorded the advertisement call for anuran species that occurred in 10 water bodies of northwestern São Paulo State. We also determined the environmental heterogeneity (based in four environmental descriptors) for each water body. Males of most species used similar calling sites in each water body, probably because of the high uniformity of the environment, as a consequence of agricultural impacts on edge vegetation of the studied ponds. Most species (18 out of 19 species) called from different sites in the ponds where they occurred, which can be associated with differences in horizontal and vertical distribution of vegetation in the studied ponds. From the 19 species analyzed, only males of Pseudopaludicola aff. saltica called in sites with the same characteristics in different ponds. Advertisement call of Hylidae species was more similar to each other than were Leiuperidae and Leptodactylidae among themselves. The aquatic/terrestrial anurans (Bufonidae, Leiuperidae, Leptodactylidae and Microhylidae) occupied similar calling sites but presented quite distinct advertisement calls, while Hylidae species presented an inverse pattern: a high similarity on advertisement call features but used different calling sites, which indicates a niche complementarity between physical (calling site use) and acoustic (advertisement call) space use.

Physical-chemical characterization of processing tomato fruit

Fruit of 28 tomato cultivars for industrial processing were characterized to identify cultivars with potential for in natura consumption. The experiment was carried out in Jaboticabal-SP, Brazil (21o15'22'' South, 48o18'58'' West, altitude 595 m), on a Haplorthox soil during June-December. The cultivars used in this study were: H 7155, Hypeel 108, Andino, U 573, H 9036, Ipa 6, H 9494, AG 33, Yuba, RPT 1294, AG 72, Peelmech, Curicó, Hypeel 45, RPT 1478, H 9492, H 9498, H 2710, Hitech 45, Halley, Botu 13, H 9553, U 646, NK 1570, AG 45, RPT 1095, RPT 1570 and PSX 37511. The experimental design was randomized blocks, replicated four times. Ten fruits per plot were analyzed, evaluating the following characteristics: shape (oblong or round); length and diameter (mm); external and internal coloration; presence of fissures; number of loci; pulp thickness (mm); soluble solids content (Brix) and total acidity. Only cultivars Hypeel 108, AG 72, NK 1570, RPT 1570 had oblong fruit. Cultivars which had pulp thicker than 5.5 mm, a characteristic which is directly related to fruit yield for industrial purposes were: Ipa 6, Andino, U 646, H 9553, RPT 1294 and Hypeel 108. Cultivars Ipa 6 and Andino also presented elevated values for length, diameter and pulp thickness, indicating them as quality material for industry or, alternatively, for in natura market. Among the cultivars which presented better values for acidity (higher or equal to 0.3 g citric acid 100 g-1) were RPT 1095, AG 45, H 9553 and Hypeel 45.

Habitat heterogeneity and use of physical and acoustic space in anuran communities in Southeastern Brazil

Habitat heterogeneity and use of physical and acoustic space in anuran communities in Southeastern Brazil. We intended to verify if structural and physiognomical characteristics of water bodies influence on the degree of overlap among calling sites of 23 anurans species, if anuran species use different calling sites in different water bodies, and if there is some relationship between the degree of advertisement call (based on seven call features) and calling site differentiation. Then, we determined calling sites (based in four variables) and recorded the advertisement call for anuran species that occurred in 10 water bodies of northwestern São Paulo State. We also determined the environmental heterogeneity (based in four environmental descriptors) for each water body. Males of most species used similar calling sites in each water body, probably because of the high uniformity of the environment, as a consequence of agricultural impacts on edge vegetation of the studied ponds. Most species (18 out of 19 species) called from different sites in the ponds where they occurred, which can be associated with differences in horizontal and vertical distribution of vegetation in the studied ponds. From the 19 species analyzed, only males of Pseudopaludicola aff. saltica called in sites with the same characteristics in different ponds. Advertisement call of Hylidae species was more similar to each other than were Leiuperidae and Leptodactylidae among themselves. The aquatic/terrestrial anurans (Bufonidae, Leiuperidae, Leptodactylidae and Microhylidae) occupied similar calling sites but presented quite distinct advertisement calls, while Hylidae species presented an inverse pattern: a high similarity on advertisement call features but used different calling sites, which indicates a niche complementarity between physical (calling site use) and acoustic (advertisement call) space use. © 2008 Departamento de Ciências Biológicas.

Absence motivated by illness: A non-concurrent prospective study of physical education teachers in the municipal education system of the city of Campinas, São Paulo, Brazil

The object of this investigation was to identify and analize aspects of the health status related to absenteism in physical education teachers in the municipal education system of the city of Campinas, Brazil, as related to the medical leave program. The non-concurrent prospective study was accomplished by means of a comparison with teachers who work only in the classroom, refering to a three year period. In the variables of greatest interest, the Pearson non-parametric chi-square (X2) statistical test was adopted. Calculations of relative risk and level of confidence were made using the Epi-info computer program. Significant differences were observed in the following diagnostic groups favoring the not exposed group: i) Supplementary Classification of factors that exercise influence over the health status and access to health services and ii) Digestive system illness; while the physical education teachers showed a significant difference in: i) diseases of the musculoskeletal and connective tissue system and ii) Injuries and poisoing. Possible explications for some of the adverse effects as well as the protective ones that were observed include physical activity as a way of life along with being a physical education teacher and on the other side, peculiar behavior of epidemiological descriptive characteristics, like sex and age, within the socio-economic context of the country. © Copyright Moreira Jr. Editora.

Indicators of soil degradation in urban forests: Physical and chemical parameters

The fragmentation of forest habitats in urban areas has aroused increasing interest in recent years according to the growing environmental problems. The fragmentation of theses ecosystems is caused, in general, by the pressure of housing, agriculture and industry, causing losses in biodiversity and problems of soil degradation in the border areas of theses remnants. The establishment of indicators of soil degradation becomes essential for the implementation of conservation and reclamation. This study analyzes physical and chemical characteristics of soil under different forms of vegetation in the forest surrounding the Quilombo Forest, located in Campinas/SP - Brazil, and examines the possibility of using these indices as indicators of environmental degradation in urban remnants. The parameters analyzed were: specific weight natural (γn), specific weight of solids (γs) Ca, P, K, Mg, pH, organic matter, H + Al, Sum of Base (SB) Percent Base Saturation (V%), Cation Exchange Capacity (CEC). The study shows that in general the different forms of land used in the study area significantly changed (or according to) the physical aspects of soil The porosity and voids of the soil stood out as the best indicators of soil physical degradation in the layer 0-20 cm deep. In relation to chemical indices, the soil under the cultivation of cane sugar had a significantly higher pH, K, Ca, Mg and sum of bases. The areas of forest showed higher levels of phosphorus, organic matter and CEC, indicating the importance of maintaining vegetation and replacement for the cycling of organic matter.

Physical inactivity and related barriers: A study in a community dwelling of older brazilians

This study sought to investigate the prevalence of physical inactivity and related barriers in older Brazilian adults. A cross-sectional, population-based study was conducted, and a stratified random sampling procedure was used. A total of 359 older adults were interviewed. The long version of the International Physical Activity Questionnaire (IPAQ) and the Questionnaire of Barriers to Physical Activity Practice were used to assess physical activity level and barriers, respectively. No statistically significant difference was observed on the prevalence of physical inactivity in either gender or age groups. Regarding barriers, the proportion of 9 out of 22 barriers was statistically significant between men and women. Self-reported physical inactivity/activity in older Brazilian adults continues to be a concern. Uncommonly, older males reported a higher prevalence of physical inactivity compared to their counterparts. Additionally, physical inactivity prevalence continued to increase with the aging process. Yet, personal barriers such as lack of time and poor health were strongly associated with physical inactivity. The results of this study may help health professionals and public policy makers to better address the issues related to a healthy lifestyle among older adults and promote physical activity among Brazilian older adults and in other countries with similar characteristics. © 2012 Sebastião Gobbi et al.

Effect of drying technique on some physical properties of cross-linked high amylose/pectin mixtures

Polymers mixtures as well as cross-linking reactions are approaches that have been used successfully to modulate the polymers characteristics in order to improve the control over drug release rate. High amylose and pectin are polysaccharides frequently used to prepare drug delivery systems. Since the drying technique can strongly influence the properties of such systems, the aim of this work was to characterize high amylose/pectin mixtures cross-linked with sodium trimetaphosphate and dried by different techniques-oven and lyophilization. The results showed that samples dried by lyophilization presented reduced particle size, higher porosity and higher swelling ability than the samples dried in oven. Besides, lower thermal stability and different diffraction patterns showed by the former particles should reflect the structural changes as a function of drying technique. © 2013 Informa Healthcare USA, Inc.

Centesimal composition and physical-chemistry analysis of the edible mushroom Lentinus strigosus occurring in the Brazilian Amazon

Avaliou-se a composição centesimal e análise físico-química do Lentinus strigosus, um cogumelo comestível de ocorrência na Amazônia brasileira, produzidos em substratos alternativos à base de resíduos madeireiros e agroindustriais. Com este objetivo, determinou-se C, N, pH, sólidos solúveis, atividade de água, proteína, lipídios, fibra total, cinzas, carboidratos e energia. Os substratos foram formulados a partir de serragem de Simarouba amara Aubl. (marupá), Ochroma piramidale Cav. ex. Lam. (pau-de-balsa) e Anacardium giganteum (cajuí); e do estipe de Bactris gasipaes Kunth (pupunheira) e de Saccharum officinarum (cana-de-açúcar). Os resultados demonstraram que: a composição nutricional do L. strigosus variou com o substrato de cultivo; os valores de proteína encontrados nos cogumelos cultivados nos diferentes substratos (18 - 21,5%) variaram de acordo com o substrato, sendo considerados elevados; os sólidos solúveis presentes nos cogumelos podem ter relação com vitaminas hidrossolúveis do complexo B; o L. strigosus pode ser considerado um importante alimento devido suas características nutricionais: alto teor de proteína, carboidratos metabolizáveis e fibras; baixos teores de lipídios e de calorias.

Some Physical and Mechanical Properties of Medium-Density Fiberboard Made from Giant Bamboo

The objective of this study was to evaluate the density, density profile, water swelling and absorption, modulus of elasticity and rupture from static bending, and tensile strength of experimental medium-density fiberboards manufactured using Dendrocalamus giganteus (Munro bamboo). The fiber production was carried out through the chemo-thermo-mechanical pulping process with four different conditions. The panels were made with 10% urea formaldehyde resin based on dry weight of the fibers, 2.5% of a catalyzer (ammonium sulfate) and 2% paraffin. The results indicate that treatments with the highest alkali (NaOH) percentage, time and splinter heating temperature improved the physical properties of the panels. The root-fiber interface was evaluated through scanning electron microscopy in fracture zones, which revealed fibers with thick, inflexible walls. The panels' mechanical properties were affected due to the fiber wall characteristics and interaction with resin. Giant bamboo fiber has potential for MDF production, but other studies should be carried out.

Analysis of the electrical characteristics and surge protection of EHV transmission lines supported by tall towers

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The Relationship between Biofilm and Physical-Chemical Properties of Implant Abutment Materials for Successful Dental Implants

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

Prediction of the combustion process in fluidized bed based on physical-chemical properties of biomass particles and their hydrodynamic behaviors

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)