51 resultados para Soil physical and chemical characters


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Background: Studies have shown associations between health indices and access to “green” environments but the underlying mechanisms of this association are not clear.

Objectives: To examine associations of perceived neighbourhood “greenness” with perceived physical and mental health and to investigate whether walking and social factors account for the relationships.

Methods: A mailed survey collected the following data from adults (n  =  1895) in Adelaide, Australia: physical and mental health scores (12-item short-form health survey); perceived neighbourhood greenness; walking for recreation and for transport; social coherence; local social interaction and sociodemographic variables.

Results: After adjusting for sociodemographic variables, those who perceived their neighbourhood as highly green had 1.37 and 1.60 times higher odds of better physical and mental health, respectively, compared with those who perceived the lowest greenness. Perceived greenness was also correlated with recreational walking and social factors. When walking for recreation and social factors were added to the regression models, recreational walking was a significant predictor of physical health; however, the association between greenness and physical health became non-significant. Recreational walking and social coherence were associated with mental health and the relationship between greenness and mental health remained significant.

Conclusions: Perceived neighbourhood greenness was more strongly associated with mental health than it was with physical health. Recreational walking seemed to explain the link between greenness and physical health, whereas the relationship between greenness and mental health was only partly accounted for by recreational walking and social coherence. The restorative effects of natural environments may be involved in the residual association of this latter relationship.

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Objective
The role local neighbourhood environments play in influencing purpose-specific walking behaviors has not been well-explored in prospective studies. This study aimed to cross-sectionally and prospectively examine whether local physical and social environments were associated with mothers' walking for leisure and for transport.

Methods
In 2004, 357 mothers from Melbourne, Australia, provided information on their local physical and social neighbourhood environments, and in 2004 and 2006 reported weekly time spent walking for leisure and for transport. Environmental predictors of high levels of walking and increases in walking were examined using log binomial regression.

Results
Public transport accessibility and trusting many people in the neighbourhood were predictive of increases in walking for leisure, while connectivity, pedestrian crossings, a local traffic speed were predictive of increases in transport-related walking. Satisfaction with local facilities was associated with increasing both types of walking, and the social environment was important for maintaining high levels of both leisure- and transport-related walking.

Conclusion
The findings provide evidence of a longitudinal relationship between physical and social environments and walking behaviors amongst mothers. Enhancing satisfaction with local facilities and giving consideration to ‘walkability’, safety and public transport accessibility during environment planning processes may help mothers to increase walking.

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This work investigated the potential of improving flexural properties of natural fiber (jute) reinforced biocomposites by atmospheric pressure helium plasma treatment. Composites were made by the use of combined hand lay-up and vacuum bagging technique followed by newly developed Australia patented QuickstepTM curing. The physical properties of helium plasma modified fibers were investigated by means of wettability time, coefficient of friction (COF), atomic force microscopy (AFM) and chemical nature of the surface with ATR-FTIR and XPS. There was found a logical correlation between physical and chemical characteristics of the surface of fiber with the fracture mechanical behavior of their resulting biocomposites. In addition, the use of helium atmospheric plasma treatment prior to QuickstepTM process has proved to be a potential way to positively alter the fracture-mechanical behavior of biocomposites. This study will lead to new commercial applications of natural fiber jute for the composite industry that go beyond wrapping and packaging.

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Research has addressed the consequences of being a victim of physical and relational aggression but less so the consequences of being an aggressor during adolescence. Consequently, relatively little is known about the extent to which aggression in early adolescence increases the risk of later aggression and other psychosocial problems. This study involves a representative sample of seventh- and ninth-grade students from Washington State ( N = 1,942). Students were surveyed on recruitment and then again 1 and 2 years later to learn about ongoing behavior problems, substance use, depression, and self-harm behaviors. Surveys also included measures of several hypothesized promotive factors: attachment to family, school commitment, and academic achievement. Findings suggest that being physically and/or relationally aggressive in grades 7 to 9 increases the risk of aggression and possibly other problem behaviors after accounting for age, gender, race, and a prior measure of each outcome. Independent promotive effects were observed in most analyses, although family attachment appeared a less robust predictor overall. Implications for prevention include acting on the behavior itself and enhancing promotive influences to lessen the risk of agression and other related problems.

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Depression is a significant public health issue among Australian adolescents. A number of family, school and community level factors have been identified as important determinants of adolescent's health and well-being, including depression. This study examines associations between measures of the social and physical environment and adolescent mental health, specifically depressive symptomotology using data from the Healthy Neighbourhoods study, a large observational study carried out in 231 Australian schools stratified by socioeconomic quartiles and urban/non-urban geography, which focuses on adolescent health and well-being. Participants were 8256 year 6 and 8
students (48% male), aged 11-16 years (M = 11.6, SD = 0.8 years) from schools across Victoria,Queensland and Western Australia who completed a comprehensive on-line survey. Data collected included the Short Mood and Feeling Questionnaire (SMFQL a tool for assessing depressive symptomotology in adolescents. Results showed that the mean total depression score (possible range 0-26 with total scores;:: 8 used as the cutoff for depression symptomotology) was 6.4 (SD = 5.9), with scores for females (M = 6.8, SD = 6.3) higher than those for males (M = 5.9, SD = 5.5), and scores for year 8 students (M = 6.7,SD = 6.1) higher than those for year 6 students (M = 6.2, SD = 5.8) (p < .001). Greater access to sporting and play equipment, local parks, and more functional neighbourhoods for walking and jogging reduced the odds for depressive symptomotology (p < .05L while increased levels of abandoned homes, and higher levels of fighting within the neighbourhood, and fewer scout/guide clubs, local teams to play sport, and adults in the neighbourhood to talk with, as well as reduced neighbourhood safety increased the odds for depressive symptomotology (p < .05). These findings support the important role of physical and social environments in influencing adolescent health and well-being. Modifications to particular aspects of these environments at the community level may assist in providing adolescents some protection from depression.

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[No Abstract]

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Wool powders with various particle sizes have been produced using different milling techniques. Scanning electron microscopy (SEM) showed gradual breakdown of the fibre as it was progressively converted into powder form. Chlorination enhanced the effectiveness of subsequent air-jet milling. X-ray photoelectron spectroscopy (XPS) revealed an increase in the surface concentrations of oxygen and nitrogen, and a decrease in carbon and sulphur on conversion of the fibres into powders, as the cortex became exposed on the powder surface. An increased surface concentration of cysteic acid was observed for the chlorinated powder. Rapid uptake of dye by wool powders was observed in situations where there was virtually no uptake by the original fibre. Hydrophobic dyes were more readily sorbed than were hydrophilic dyes. The chlorination treatment led to a decrease in the sorption of acid dyes. Confocal microscopy, used in conjunction with a fluorescent stain, showed that chemicals were able to penetrate wool particles, even at room temperature. The rate and extent of uptake of dye by the finer powders were comparable to that obtained with activated charcoal, even though the surface area of the charcoal was 100 times greater.

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Wool powders with different particle sizes were examined in terms of their crystal structures, thermal properties, surface chemical compositions and moisture regains. It was found that the crystallinity of wool powders was increased, and the moisture regains were decreased as the particle sizes of wool powders were reduced. For comparison, the properties of activated charcoal were also investigated. The higher dye uptake of activated charcoal at pH 10. compared to that of wool powder, could be due to its greater surface area and porous structure.

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Objective: To describe the pattern of alcohol consumption and associated physical and lifestyle characteristics in a population-based sample of Australian men.
Method: A community-based age-stratifi ed random sample of 1420 men (median age 56 years, range 20 – 93) participating in the Geelong Osteoporosis Study, an epidemiological study set in south-eastern Australia. Daily alcohol intake was ascertained from a detailed food frequency questionnaire and categorized according to the Australian National Health and Medical Research Council 2009 guidelines (non-drinkers, greater than zero but ≤ 2 drinks per day, > 2 drinks per day), with a standard drink equivalent to 10 g of ethanol. Anthropometry was measured and lifestyle factors self-reported. Body composition was determined using dual energy absorptiometry. Socio-economic status was categorized according to the Australian Bureau of Statistics data. Results were age standardized to the Australian male population figures.
Results: The median daily ethanol consumption was 12 g (IQR 2 – 29) per day with a range of 0 – 117 g/day. The age-standardized proportion of non-drinkers was 8.7%, 51.5% consumed up to two drinks per day ( ≤ 20 g ethanol/day), and 39.9% exceeded 2 standard drinks per day ( > 20 g ethanol/day). Alcohol consumption was positively associated with cigarette smoking, weight, higher SES and inversely with age and physical activity.
Conclusions: Approximately, 40% of Australian men consume alcohol at levels in excess of current recommendations, which in combination with other risk factors may adversely impact upon health.

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This paper highlights the importance of surface coverage in modeling the removal of particles in deep bed filtration. A model that considers the saturation of sites on which particle deposition occurs is used. Experimental results obtained with monodispersed suspensions of 0.46 and 0.816 μm latex particles at different influent concentrations and ionic strengths were used to calculate the fraction of filter grain surface (β1) on which actual particle deposition occurs. This will be useful in evaluating the filter performance in terms of the utilization of available surface area of the filter medium. Further, the level of dendrite formation of particles on filter grains during filtration is expressed in terms of β1 and the specific surface coverage, θT (the fraction of a filter grain surface that is covered by particles at time T, assuming that the filter grain is covered by a monolayer of particles). This can be used to compare the contribution of deposited particles in the removal efficiency of deep bed filtration for suspensions with different physical and chemical characteristics.

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Stevioside is a natural sweetener extracted from leaves of Stevia rebaudiana Bertoni, which is commercially produced by conventional (chemical/physical) processes. This article gives an overview of the stevioside structure, various analysis technique, new technologies required and the advances achieved in recent years. An enzymatic process is established, by which the maximum efficacy and benefit of the process can be achieved. The efficiency of the enzymatic process is quite comparable to that of other physical and chemical methods. Finally, we believe that in the future, the enzyme-based extraction will ensure more cost-effective availability of stevioside, thus assisting in the development of more food-based applications.