188 research outputs found
Relation between Mental Health Status and Psychosocial Stressors among Pregnant and Puerperium Women in Japan: From the Perspective of Working Status
Mental health problems during pregnancy and postpartum periods are one of the alarming health issues among women in Japan. This study analyzed data on the Japanese version of the Kessler 6 (K6), specific psychosocial stressors, and working status of pregnant and puerperium women (n=1126) from respondents in the Comprehensive Survey of People’s Living Conditions (CSPLC) conducted in 2007 by Ministry of Health, Labour and Welfare in Japan. Multiple logistic analyses showed the significant associations between mental health and psychosocial stressors: “family relationship,” “pregnancy and birth,” and “incomes/ family budgets/ debts”, regardless of “employed” or “unemployed”. After stratified by working status, whereas “one’s job” stressor had an association with mental health only for employed females, stressors for “one’s disease/long -term care” and “housework” had associations only for unemployed ones. For employed women, the primary factor for mental health was “family relationship” stressor. Although mental health status measured by K6 was not different between employed or unemployed female population, primary stressors related mental health was revealed to differ with working status. Especially, “family relationship” stressor was the highest risk factor of mental health in employed women. More importantly, the results provided evidence on the differences in associations between mental health and specific psychosocial stressors by working status. Psychosocial risk assessments and interventions on working status among pregnant and puerperium women should be imperative to pay attention for social politics.DOI: http://dx.doi.org/10.11591/ijphs.v1i2.80
Modeling of Mechanical Properties of Concrete Mixed with Expansive Additive
This study modeled the compressive strength and elastic modulus of hardened cement that had been treated with an expansive additive to reduce shrinkage, in order to determine the mechanical properties of the material. In hardened cement paste with an expansive additive, hydrates are generated as a result of the hydration between the cement and expansive additive. These hydrates then fill up the pores in the hardened cement. Consequently, a dense, compact structure is formed through the contact between the particles of the expansive additive and the cement, which leads to the manifestation of the strength and elastic modulus. Hence, in this study, the compressive strength and elastic modulus were modeled based on the concept of the mutual contact area of the particles, taking into consideration the extent of the cohesion between particles and the structure formation by the particles. The compressive strength of the material was modeled by considering the relationship between the porosity and the distributional probability of the weakest points, i.e., points that could lead to fracture, in the continuum. The approach used for modeling the elastic modulus considered the pore structure between the particles, which are responsible for transmitting the tensile force, along with the state of compaction of the hydration products, as described by the coefficient of the effective radius. The results of an experimental verification of the model showed that the values predicted by the model correlated closely with the experimental values
Manufacturing of sintered lightweight aggregate using high-carbon fly ash and its effect on the mechanical properties and microstructure of concrete
Fly ash is the largest source of industrial solid waste in China. Fly ash with its high content of unburned carbon has to be discarded in landfills and cause environmental problem. To reduce the environmental impacts, lightweight aggregate (LWA) was manufactured utilizing high-carbon fly ash (HCFA) (loss on ignition, LOI = ∼16.3%). Trial tests were conducted on high-carbon fly ash lightweight aggregate (HCFA-LWA) in a laboratory electric furnace and in a manufacturer's batch furnace. A new temperature profile was proposed for the HCFA-LWA sintering process in which carbon served as a partial fuel substitute during the burning period, which can decrease the sintering period in the sintering stage of the LWA and save energy
Relation Between Mental Health Status and Psychosocial Stressors Among Pregnant and Puerperium Women in Japan - From the Perspective of Working Status-
Background Mental health problems during pregnancy and postpartum periods are one of the alarming health issues among women in Japan. Many studies have reported that psychosocial risk factors could be correlated with maternal mental health status. Although increased numbers of women who are employed during the pregnancy and postpartum periods have been observed, it is unclear about the link between mental health and psychosocial stressors in terms of working status during pregnancy and postpartum periods. Therefore, this study examined difference in mental health status and the association between mental health and psychosocial stressors by working status amongpregnant and puerperium women, using nationally representative data in Japan. Methods This study analyzed data on the Japanese version of the Kessler 6 (K6), specific psychosocial stressors, and working status of pregnant and puerperium women (n=1126) from respondents in the Comprehensive Survey of Peoples Living Conditions (CSPLC) conducted in 2007 by Ministry of Health, Labour and Welfare in Japan.. The univariate logistic regression analysis and a forward multiple regression analysis were used to examine K6 and related factors including specific psychosocial stressors for working status (employedand unemployed).Results Those who scored five or higher in K6 accounted for 33.2% of 1126 respondents, and mental health had no significant association with working status among pregnant and puerperium women. Multiple logistic analyses showed the significant associations between mental health and psychosocial stressors: family relationship, pregnancy and birth, andincomes/ family budgets/ debts,regardless of employed or unemployed. After stratified by working status, whereas ones job stressor had an association with mental health only for employed females, stressors forones disease/long -term care and housework had associations only for unemployed ones. For employed women, the primary factor for mental health wasfamily relationship stressor. Conclusion Although mental health status measured by K6 was not different between employed or unemployed female population, primary stressors related mental health was revealed to differ with working status. Especially, family relationship stressor was the highest risk factor of mental health in employed women. More importantly, the results provided evidence on the differences in associations between mental health and specific psychosocial stressors by working status. Psychosocial risk assessments and interventions on working status among pregnant and puerperium women should be imperative to pay attention for social politics
Exercise or sports in midlife and healthy life expectancy: an ecological study in all prefectures in Japan
BackgroundWith the increase of overall life expectancy in Japan, effective and beneficial lifestyle approaches and practices are crucial for individuals to have a long, productive and healthy life. Although previous studies suggest that exercise or sports, especially when performed with others, from midlife level have a positive impact on enhancing healthy life expectancy, there is paucity of information regarding these contexts and possible associations. The present study intends to clarify the relationship between engagement in exercise or sports among middle-aged persons and healthy life expectancy through an ecological study in all prefectures in Japan.MethodsWe tabulated (1) the ratios of middle-aged individuals engaged in exercise or sports and (2) the different methods by which they are engaged in exercise or sports for each prefecture by using data from the 2005–2010 Longitudinal Survey of Middle-aged and Elderly Persons by the Ministry of Health, Labour and Welfare of Japan. Weighted multiple linear regression analyses were performed by sex, using healthy life expectancy in 2010 of each prefecture calculated by Hashimoto (2013) as a criterion variable; indices of (1) and (2) of each year as explanatory variables; and age, living conditions, employment, and chronic diseases as adjusted variables.ResultsFor middle-aged males, the ratio of those engaged in exercise or sports in each year from 2005 to 2010 was positively correlated with healthy life expectancy; this relationship was found in the ratio of middle-aged engaging in exercise or sports “with families or friends”. For females, such a relationship could only be found in the ratio of middle-aged females engaged in exercise or sports in 2008, and those engaging in exercise or sports “with families or friends” in 2006, 2008 and 2010.ConclusionPrefectures with a higher ratio of middle-aged individuals engaging in exercise or sports, especially when done with families or friends, have longer healthy life expectancies. This was particularly evident for males. Thus, exercise or sports with families or friends in midlife seems to be more effective in promoting healthy life expectancy for males than females in Japan
Analysis of Change of Physical Properties of Organic Repair Products due to Fire Exposition
Organic repair products for concrete can be exposed to accidental incidents, like fire. The increase of temperature produces a modification in some of their properties. In general, these types of repair products have organic fibers to increase their tixotropic properties, but they are more sensible to the high temperature than the Portland cement or aggregates. In order to analyze the behavior of organic repair mortars with temperature three types of repair mortars are studied. These repair products have the organic components composed by acetate fiber of polyvinyl like Vinyl Acetate Acrylate (VAA), Copolymer of Vinyl Acetate Vinyl Versatate (VeoVA) and Acrylic polymers fibres. The repair products are tested increasing the temperature from 1.7ºC /min until 200ºC, 400ºC or 600ºC respectively during 20 minutes. After that, the samples are cooled in four different cooling conditions two of them slow and two others fast, and with and without oxygen. These conditions are used in order to simulate the different conditions that can occur during the cooling after fire. After the testing the visual aspect, the color and brightness and the open porosity is analyzed in each condition of test. In this work the relationship between the temperature of exposition, the cooling conditions and the change in some physical properties are studied
Carbonation Behavior of Powdered Cement-Based Materials Under Different Relative Humidities and CO2 Concentrations
The aim of the current study is to investigate the carbonation behavior of cement hydrates at different environments. Hardened cement pastes are prepared using OPC and BFS and crushed into ~90μm powder. The powder samples are carbonated at 5/20% CO2 and at 60/85%RH. TGA, XRD and phenolphthalein tests are conducted before and after carbonation. The results show that CH remain uncarbonated even after CO2 uptake apparently ended and that the amount of the residual CH affects the results of phenolphthalein test. External humidity strongly affects the carbonation behavior of both CH and other hydrates. The degree of CH carbonation is greater at higher humidity, while the degree of other hydrates carbonation is greater at lower humidity. This conflicting effect can occur at surface of bulk concretes and changes in its properties (coarsening of pore structure and cracking) can be caused without apparent carbonation detected by phenol phthalein test. The effect of relative humidity on CSH carbonation should be taken into consideration when estimating long-term performance of carbonated concretes
Evaluation on the Mechanical Performance of Low-Quality Recycled Aggregate Through Interface Enhancement Between Cement Matrix and Coarse Aggregate by Surface Modification Technology
In this study, a quantitative review was performed on the mechanical performance, permeation resistance of concrete, and durability of surface-modified coarse aggregates (SMCA) produced using low-quality recycled coarse aggregates, the surface of which was modified using a fine inorganic powder. The shear bond strength was first measured experimentally and the interface between the SMCA and the cement matrix was observed with field-emission scanning electron microscopy. The results showed that a reinforcement of the interfacial transition zone (ITZ), a weak part of the concrete, by coating the surface of the original coarse aggregate with surface-modification material, can help suppress the occurrence of microcracks and improve the mechanical performance of the aggregate. Also, the use of low-quality recycled coarse aggregates, the surfaces of which were modified using inorganic materials, resulted in improved strength, permeability, and durability of concrete. These results are thought to be due to the enhanced adhesion between the recycled coarse aggregates and the cement matrix, which resulted from the improved ITZ in the interface between a coarse aggregate and the cement matrix
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