Mechanism of improvement in the strength and volume change behavior of lime stabilized soil

An attempt has been made to bring out the influence on strength and volume change behavior of fabric changes and new cementitious compound formation in a soil upon addition of various lime contents and with curing periods. The effects of changes in fabric of treatment with various lime contents (0, 2,4 and 6%) and with curing periods (0, 7, 14 and 28 days) have been evaluated by one-dimensional consolidation tests, in terms of void ratio changes and compressibility. The strength of soil treated with different lime contents with curing periods up to 28 days, and with the optimum lime content of 6% up to one year has been determined by unconfined compression tests. Comparison of effects of lime on the strength and volume change behavior of the soil brings out that the formation of flocculated fabric and cation exchange significantly reduces the compressibility of soil but marginally increases the strength. Cementation of soil particles and filling with cementitious compounds of the voids of flocculated fabric in the soil marginally reduces the compressibility but significantly increases the strength. Thus, the mechanism of volume change behavior of soil treated with lower lime content at short curing periods is distinctly different from that of the soil treated with optimum lime content at longer curing periods. This is consistent with the increase in the permeability caused by the addition from 2 to 4% lime and the decrease following the addition of 6% lime. Changes consistent with mechanical behavior have been determined by scanning electron microscope, X-ray diffraction and thermal analyses, energy dispersive X-ray spectrometer and pH value in microstructure, mineralogy, chemical composition and alkalinity, respectively. (C) 2015 Published by Elsevier B.V.

Volume change behavior of lime treated gypseous soil - influence of mineralogy and microstructure

Series of oedometer tests and micro-analytical studies (XRD, SEM and EDAX) have been carried out to investigate the influence of varying gypsum content on swell, compressibility and permeability of lime treated montmorillonitic soil after curing for different period. Immediate swell is observed on inundation of compacted samples with water and continuously increased with gypsum content. However, changes in swell are found to be marginal with curing. This is attributed to the formation and growth of ettringite crystals by ionic reactions of aluminum calcium-sulfate in the presence of water which is confirmed through detailed micro-analysis. The higher swell in uncured specimens and gradual reduction in swell with increase in curing periods are due to relative dominance of formation and growth of ettringite and cementitious compounds, respectively. Also, the ionic reaction products are found to bear a significant influence on the compressibility and permeability behavior. (C) 2015 Elsevier B.V. All rights reserved.

A field model interpretation of crack initiation and growth behavior in ferroelectric ceramics: change of poling direction and boundary condition

Strain energy density expressions are obtained from a field model that can qualitatively exhibit how the electrical and mechanical disturbances would affect the crack growth behavior in ferroelectric ceramics. Simplification is achieved by considering only three material constants to account for elastic, piezoelectric and dielectric effects. Cross interaction of electric field (or displacement) with mechanical stress (or strain) is identified with the piezoelectric effect; it occurs only when the pole is aligned normal to the crack. Switching of the pole axis by 90degrees and 180degrees is examined for possible connection with domain switching. Opposing crack growth behavior can be obtained when the specification of mechanical stress sigma(infinity) and electric field E-infinity or (sigma(infinity), E-infinity) is replaced by strain e and electric displacement D-infinity or (epsilon(infinity), D-infinity). Mixed conditions (sigma(infinity),D-infinity) and (epsilon(infinity),E-infinity) are also considered. In general, crack growth is found to be larger when compared to that without the application of electric disturbances. This includes both the electric field and displacement. For the eight possible boundary conditions, crack growth retardation is identified only with (E-y(infinity),sigma(y)(infinity)) for negative E-y(infinity) and (D-y(infinity), epsilon(y)(infinity)) for positive D-y(infinity) while the mechanical conditions sigma(y)(infinity) or epsilon(y)infinity are not changed. Suitable combinations of the elastic, piezoelectric and dielectric material constants could also be made to suppress crack growth. (C) 2002 Published by Elsevier Science Ltd.

Effects of seasonal change on activity rhythms and swimming behavior of age-0 bluefish (Pomatomus saltatrix) and a description of gliding behavior

Daily and seasonal activity rhythms, swimming speed, and modes of swimming were studied in a school of spring-spawned age-0 bluefish (Pomatomus saltatrix) for nine months in a 121-kL research aquarium. Temperature was lowered from 20° to 15°C, then returned to 20°C to match the seasonal cycle. The fish grew from a mean 198 mm to 320 mm (n= 67). Bluefish swam faster and in a more organized school during day (overall mean 47 cm/s) than at night (31 cm/s). Swimming speed declined in fall as temperature declined and accelerated in spring in response to change in photoperiod. Besides powered swimming, bluefish used a gliding-upswimming mode, which has not been previously described for this species. To glide, a bluefish rolled onto its side, ceased body and tail beating, and coasted diagonally downward. Bluefish glided in all months of the study, usually in the dark, and most intensely in winter. Energy savings while the fish is gliding and upswimming may be as much as 20% of the energy used in powered swimming. Additional savings accrue from increased lift due to the hydrofoil created by the horizontal body orientation and slightly concave shape. Energy-saving swimming would be advantageous during migration and overwintering.

Thermally-induced change in the relaxation behavior of skin tissue.

Skin biothermomechanics is highly interdisciplinary, involving bioheat transfer, burn damage, biomechanics, and physiology. Characterization of the thermomechanical behavior of skin tissue is of great importance and can contribute to a variety of medical applications. However, few quantitative studies have been conducted on the thermally-dependent mechanical properties of skin tissue. The aim of the present study is to experimentally examine the thermally-induced change in the relaxation behavior of skin tissue in both hyperthermal and hypothermic ranges. The results show that temperature has great influence on the stress-relaxation behavior of skin tissue under both hyperthermal and hypothermic temperatures; the quantitative relationship that has been found between temperature and the viscoelastic parameter (the elastic fraction or fractional energy dissipation) was temperature dependent, with greatest dissipation at high temperature levels.

Can information alone change behavior? Response to arsenic contamination of groundwater in Bangladesh

We study how effectively information induces Bangladeshi households to avoid a health risk. The response to information is large and rapid; knowing that the household's well water has an unsafe concentration of arsenic raises the probability that the household changes to another well within one year by 0.37. Households who change wells increase the time spent obtaining water fifteen-fold. We identify a causal effect of information, since incidence of arsenic is uncorrelated with household characteristics. Our door-to-door information campaign provides well-specific arsenic levels without which behavior does not change. Media communicate general information about arsenic less expensively and no less effectively. © 2006 Elsevier B.V. All rights reserved.

Did children’s perceptions of an after-school social learning program predict change in their behavior?

This research explored the influence of children’s perceptions of a pro-social behavior after-school program on actual change in the children’s behavioral outcomes over the program’s duration. Children’s perceptions of three program processes were collected as well as self-reported pro-social and anti-social behavior before and after the program. Statistical models showed that: Positive perceptions of the program facilitators’ dispositions significantly predicted reductions in anti-social behavior; and positive perceptions with the program activities significantly predicted gains in pro-social behavior. The children’s perceptions of their peers’ behavior in the sessions were not found to a significant predictor of behavioral change. The two significant perceptual indicators predicted a small percentage of the change in the behavioral outcomes. However, as after-school social learning programs have a research history of problematic implementation children’s perceptions should be considered in future program design, evaluation and monitoring.

Policy interventions implemented through sporting organisations for promoting healthy behaviour change (review)

Background
Sporting organisations provide an important setting for health promotion strategies that involve policies, communication of healthy messages and creation of health promoting environments. The introduction of policy interventions within sporting organisations is one strategy to target high risk behaviours such as smoking, alcohol consumption, excess sun exposure, unhealthy eating and discrimination.

Objectives
To review all controlled evaluation studies of policy interventions organised through sporting settings to increase healthy behaviour (related to smoking, alcohol, healthy eating, sun protection, discrimination, safety and access).

Search strategy
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsyclNFO, CINAHL, SPORTDiscus, Sociological Abstracts, Dissertation Abstracts, freely available online health promotion and sports-related databases hosted by leading agencies, and the internet using sport and policy-related key words. We identified further studies in the bibliographies of articles and by contacting authors of key articles in the area.

Selection criteria
We aimed to identify research that had used study designs that incorporated an evaluated intervention and comparison. Uncontrolled studies, meeting other inclusion criteria, were to be reported in an annex to the review.
Types of studies: Studies in which sporting organisations were allocated to a policy intervention or control/comparison group. No minimum follow-up required.
Types of participants: People of all ages.
Types of interventions: Any policy intervention implemented through sporting organisations to instigate and/or sustain healthy behaviour change, intention to change behaviour, or changes in attitudes, knowledge or awareness of healthy behaviour. Policies must address any of the following: smoking, alcohol, healthy eating, sun protection, access for disadvantaged groups, physical safety (not including injuries), and social and emotional health (e.g.. anti-vilification, anti-discrimination).
Types of outcome measures: Behaviour change, intention to change behaviour, change in attitudes, knowledge or awareness of healthy behaviour, and policy presence.

Data collection and analysis
We assessed whether identified citations were controlled evaluation studies and investigated the use of policy implemented in sporting settings. Abstracts were independently inspected by two reviewers and full papers were obtained where necessary. As no controlled evaluation studies were located, no data collection or analysis was undertaken. No uncontrolled studies meeting other inclusion criteria were identified and therefore no annex is presented.

Main results
No rigorous studies were located to test the effectiveness of policy interventions organised through sporting organisations to increase healthy behaviours, attitudes, knowledge or inclusion of health oriented policies within the organisarions.

Authors' conclusions
We were unable to find any controlled studies to guide the use of policy interventions used in sporting settings. The search process revealed a number of case studies with anecdotal reporting of outcomes. We strongly recommend that rigorous evaluation techniques are employed more commonly in this field to illuminate the impact of health promoting policy on outcomes, and the contexts and processes which are likely ro be effective in reducing harmful behaviours.

Dissonance-based interventions for health behaviour change : a systematic review

Purpose Increasing evidence suggests that various health behaviours are amenable to change following the induction of cognitive dissonance. This systematic review sought to evaluate the effectiveness and methodological quality of dissonance-based health behaviour interventions and to explore identified sources of heterogeneity in intervention effects.

Methods Bibliographic databases were searched for relevant articles from inception to March 2012. Only studies targeting non-clinical health behaviour in non-clinical populations were included in the review. One author extracted data and assessed quality of evidence and a second author verified all content.

Results Reports of 20 studies were included. A variety of health behaviours and outcome measures were addressed across studies. Most studies produced one or more significant effects on measures of behaviour, attitude or intention. Across studies, methodological risk for bias was frequently high, particularly for selection bias. Gender and self-esteem were identified as potential moderator variables.

Conclusions The evidence for the effectiveness of dissonance-based interventions was generally positive. The hypocrisy paradigm was found to be the most commonly applied research paradigm and was most effective at inciting change across a range of health behaviours. There was no observable link between type of target behaviour and positive outcomes. Researchers are encouraged to minimize potential for bias in future studies and explore moderators of the dissonance effect.

Correlates of change in adults’ television viewing time : a four-year follow-up study

Purpose: Adults tend to increase their television (TV) viewing time as they age, but little is known about attributes associated with change in TV viewing over time. This study examined individual, social, and environmental correlates of change in TV viewing time for 4 yr.

Methods: Adult participants (n = 897) from a longitudinal epidemiological study in Adelaide, Australia, reported TV viewing time at baseline (2003–2004) and at follow- up (2007–2008). Generalized linear modeling was used to examine correlates of change in TV viewing time.

Results: The mean TV viewing time increased from 112 to 116 min·d-1 from baseline to follow-up. Adjusted for TV viewing time at baseline, having a tertiary education was associated with a 13% lower TV time at follow-up (P = 0.007). Each additional hour of occupational and transport physical activity at baseline was associated with a 2% and 7% lower TV viewing at follow-up (P = 0.031 and P = 0.023, respectively). For men, an additional hour of domestic physical activity was associated with a 7% higher TV viewing time at follow-up (P = 0.006). A significant neighborhood walkability × working status interaction (P = 0.035) indicated that, for those who were not working, living in a highly walkable neighborhood was associated with a 23% lower TV viewing time at follow-up (P = 0.003).

Conclusions: Adults with lower educational attainment, adults with lower occupational and transport physical activity, men with higher domestic physical activity, and nonworking adults living in lowly walkable neighborhoods were at higher risk of increase in TV viewing time. Interventions should target multiple variables at the individual, social, and environmental levels to address age-related increases in TV viewing time.