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1.
In this article, foundry sand as waste material has been valorized in ceramic brick manufacturing at industrial scale. The employment of a waste coming from one industry as an input for another is one of the key concepts of industrial ecology. To study the environmental behavior of the ceramic bodies in different life cycle stages, three leaching tests have been developed. We used an EN 12457 equilibrium leaching test with distilled water and a Wastewater Technology Centre acid neutralization capacity (WTC‐ANC) leaching test with different acidic leachates to carry out the environmental evaluation under different granular scenarios to ascertain the possibilities of the reuse or disposal of this granular material at the end of its useful life (end‐of‐life stage). Finally, we used a NEN 7345 diffusion leaching test for construction materials, with the aim of studying the environmental assessment at the use stage. Regulated pollutants in both stages have been evaluated. Furthermore, other soluble salts have been analyzed because they are closely related to the efflorescence phenomenon in bricks. Results indicate that core and green sand from the foundry industry can be used to replace clay content in construction materials, and that these foundry‐sand‐based ceramics improve some soluble salt results. Despite this fact, at the end‐of‐life stage in an inert waste landfill, lead, arsenic and chromium can be an environmental problem, both for commercial bricks and for foundry‐sand‐based bricks. This work can contribute to the determination of viability of sustainable processes of brick manufacturing that use foundry wastes as raw materials. 相似文献
2.
The present study aimed at ergonomic evaluation of the prevalence of work-related musculoskeletal disorders among construction labourers working in unorganized sectors in West Bengal, India. A modified Nordic questionnaire was applied to one hundred forty male and ninety female construction labourers to acquire information about musculoskeletal symptoms like pain in different body parts. Work-rest schedules of the labourers in different work activities were studied. Working postures were analyzed by means of the Rapid Entire Body Assessment (REBA) tool. Body part discomfort (BPD) scale was used to assess the intensity of feeling of discomforts in the different body parts. It was revealed that the labourers performed repetitive, stressful work for a long period of time in a single work-rest cycle and the load lifted and carried by them were more than the NIOSH recommended weight limit. The analyses of working postures revealed that most of their working postures were unsafe and ranked under REBA action level 3 and 4. The results obtained by applying the Nordic questionnaire and BPD scale revealed that the prevalence of pain in various regions of the body, especially low-back pain, was alarmingly high in both male and female labourers. Training for safe lifting of materials, proper work-rest schedule, modifications of some working procedures and the use of ergonomically designed equipment may certainly reduce the work-related musculoskeletal disorders and improve the health status of construction labourers working in unorganized sectors. 相似文献
3.
In India, fired clay bricks are produced in small-scale factories. There are 60, 000 active brick kilns, providing employment to nearly 12 million people in different suboccupations. This industry is largely non-mechanized and operates from November to June. Almost all the workers are exposed to direct sunlight for 8-10 h a day. Cellular DNA-protein crosslinks (DPCs) are the biologically active nucleoprotein complexes formed between DNA and proteins. Ultraviolet light and gamma-rays, and other suspected carcinogens in humans, induce DPC formation in blood cells. DPCs have therefore been identified as a biomarker for monitoring exposure to these hazardous agents. Here we report steady-state levels of DPCs in human peripheral lymphocytes from 46 brick-kiln workers exposed occupationally for 8-10 h a day to solar radiation in brickfields and 25 unexposed controls. A significant increase (p <0.05) in DPC content and DPC coefficients in peripheral lymphocytes was observed in the brick-kiln workers compared with the controls. The data suggest that the DPC content of lymphocytes could be a possible biomarker of exposure to solar radiation. However, further work is necessary to confirm this. 相似文献
4.
Internationalization and technological developments have changed the work organization in developed and developing industrial economies. Information and communication technologies, such as computers and smartphones, are increasingly used, allowing more temporal and spatial flexibility of work. This may lead to an increase in supplemental work, i.e. constant availability or working in addition to contractually agreed work hours. This in turn extends work hours and leads to work hours in evenings and weekends, causing interferences of work hours with biological and social rhythms for sleep, recovery and social interaction. However, empirical findings on the effects of supplemental work and work hours on occupational health are rather scarce. Therefore, the aim of this study was to investigate the association between (1) work-related contacts outside of regular work hours and (2) working in the free time with self-reported work-related health impairments in the fourth and fifth European Working Conditions Surveys (EWCS 2005, EWCS 2010). Out of these cross-sectional, large-scale surveys, data on n?=?22?836 and n?=?34?399 employed workers were used for weighted logistic regression analyses. About half of the sample reported at least occasional supplemental work. The results showed an increased risk of reporting at least one health problem for employees who had been contacted by their employer (EWCS 2005), or worked in their free time to meet work demands (EWCS 2010) in the last 12 months, compared to those reporting no supplemental work or work-related contacts during free time. These results were controlled for demographic variables, physical and mental work load, worker autonomy, and several work hours characteristics (e.g. hours per week, unusual and variable hours). The risk of reporting health problems was increased by being contacted both sometimes (Odds Ratio [OR] 1.26, 95% Confidence Interval [CI] 1.14–1.39) and often (OR 1.13, 95% CI 1.02–1.25), whereas the frequency of working in the free time showed a clear dose-response effect (sometimes: OR 1.14, 95% CI 1.04–1.24; often: OR 1.60, 95% CI 1.47–1.75), both compared to the category “never”. The findings, thus, indicate that even a small amount of supplemental work beyond contractually agreed work hours may increase the risk of work-related health impairments. Working in the free time was associated with a substantial risk increase and might be a better indicator for actual work load than being contacted by the employer outside of contractually agreed work hours. Thus, in order to minimize negative health effects, availability requirements for employees outside their regular work hours should be minimized. While these effects definitely need further study, especially regarding a quantification of actual supplemental work and its temporal location, addressing the company culture and using incentives and policies might be options to reduce the amount of supplemental work and maintain the risks of health impairments in the working population at a lower level. 相似文献
5.
There is considerable evidence showing that night work is associated with increased morbidity, but only a few studies have focused on its relation to mortality. This study investigates the relationship between the type of working-time arrangement (weekly night work/daytime work) and total and cause-specific mortality among men and women. The data consist of a representative working conditions survey of Finnish employees conducted in 1984 (2286 men/2216 women), which has been combined with register-based follow-up data from Statistics Finland covering the years 1985-2008. In the 1984 survey, the employees were asked if they worked during the night (23:00-06:00 h) and if so, how often. In this study, the authors compare employees who worked at night (121 men/89 women) to daytime employees who did not do night work (1325 men/1560 women). The relative risk of death was examined by Cox proportional hazards analyses adjusted for background (age, level of education, family situation, and county), health (longstanding illness, pain symptoms, smoking status, and psychological symptoms), and work-related factors (weekly working hours, physical and psychological demands, demands of learning at work, and perceived job insecurity). Female employees working at night had a 2.25-fold higher risk of mortality than female dayworkers (95% confidence interval [CI] 1.20-4.20) after adjustment for background and health- and work-related factors. In addition to total mortality, night work was also associated with tumor mortality. Female night workers had a 2.82-fold higher risk of tumor mortality than female dayworkers (95% CI 1.20-6.65) in the adjusted model. Among men, no such significant association was observed. The present study indicated that female night workers had a higher risk of both total and tumor mortality compared to female daytime employees. Additional research on the potential factors and mechanisms behind the association between night work and mortality is required. 相似文献
6.
This article investigates social and cultural aspects of "teenage life" among south Asian girls in Britain, particularly their experiences of relationships with boys and the extent to which they become involved in sexual activities. In-depth interviews were carried out with teenage girls and young women from Indian, Pakistani and Bangladeshi backgrounds and a comparative group of white British girls, in four schools and one college in the South and West Health Authority Region. Asian teenage girls conformed to different behavioural norms than their white peers. They were influenced by cultural traditions, religious obligations, family loyalties and community expectations. Few Asian girls became involved in relationships or sexual activities. However, once removed from the parental home, the influence of parents and their Asian community, their social and sexual behaviour changes; they experience an independence which often involves relationships and sexual activities. In contrast, white teenage girls experienced a different set of pressures which came from peers and boyfriends and accepted involvement with boys and sexual activity. 相似文献
7.
【背景】定陶王墓地M2汉墓出土了一批处于防护层的重要汉砖,目前部分汉砖表面出现了真菌病害问题。【目的】根据现场文物保护状况,选取了5块汉砖表面的微生物病害样本,检测并分析了汉砖表面的真菌病害,将分离得到的7株真菌进行抑菌试验。【方法】使用扫描电镜观察、高通量测序、纯培养和抑菌试验等方法对样本中的真菌进行分析。【结果】发现未经抑菌处理的汉砖表面真菌病害问题严重,经75%乙醇和0.5%硝酸咪康唑处理过的汉砖表面真菌病害问题减弱。汉砖上的主要真菌不同,汉砖9表面含量最多的真菌为 Boeremia,汉砖13表面含量最多的为虫草科( Cordycipitaceae)。然而硝酸咪康唑和硼酸硼砂并无抑菌效果,抑菌产品K100(2-甲基-4-异噻唑啉-3-酮)具有较好的抑菌效果。【结论】本研究对分析和防治汉砖表面的真菌病害及对汉砖进行科技保护具有重要意义。 相似文献
8.
A computer code called Virtual Igor is presented. The code generates an analytical representation of the Saint Petersburg brick phantom family (Igor, Olga, Irina), which is frequently used for the calibration of whole-body counters, in arbitrary user-defined layouts for the use in the Monte-Carlo radiation transport code MCNP. The computer code reads a file in the ldraw format, which can easily be produced by simple freeware software with graphical user interfaces and which contains the types and coordinates of the bricks. Ldraw files with the canonical layouts of the brick phantom are provided with Virtual Igor. The code determines the positions of (2.75 cm)3 segments of the bricks, where 2.75 cm is the smallest length in the layout and, therefore, represents the spacing of the segment lattice. Each segment contains the exact geometry of the respective part of the brick, using cuboid and cylindrical surfaces. The user can define which rod source drill holes of which bricks contain the rod-type radionuclide sources. The method facilitates the comparison of different layouts of the Saint Petersburg brick phantom with each other and with anthropomorphic computational phantoms. 相似文献
9.
Out of 100 teenage girls attending a sexually transmitted disease clinic for the first time, 77 were found to be using a reliable method of contraception and had similar characteristics to teenage girls attending a family planning clinic. The 23 girls not using any reliable contraception exhibited a different pattern of sexual behaviour and were at high risk of unplanned pregnancy. Subsequently, another group of 23 girls not using contraception when seen at the sexually transmitted disease clinic were actively encouraged to attend a family planning clinic. Their risk of unplanned pregnancy was much reduced, although their pattern of sexual activity was unchanged. Ready availability of contraceptive advice for unprotected teenagers in sexually transmitted disease clinics would reduce their high risk of unplanned pregnancy. 相似文献
11.
Absorbed doses were determined by thermoluminescence (TL) measurements for bricks from a height of 6 m from the south-western wall of the former mill in Metlino that faced the Techa river. Measurements of the internal beta-radiation and alpha-radiation in the brick samples and of radionuclide activities in soil samples from the Techa river valley were performed. The absorbed dose in bricks due to the natural radiation was derived and subtracted from the total dose in order to obtain the absorbed dose in the bricks caused by anthropogenic sources. The results were combined with results from two previous studies. The absorbed dose in the bricks due to the radiation field after relocation of the Metlino population in 1956 was derived from dose rates in air measured in front of the sampling locations in 1996/1997. Based on these dose rates the dose to bricks was calculated by means of conversion factors from the literature. The absorbed dose accumulated in the bricks in the period 1949–1956 was nearly 80% of the total dose that had been determined by TL measurements. Previously derived conversion factors were applied to obtain an estimate of the gamma dose in air at the former shore of the Techa river. An uncertainty and sensitivity analysis was performed with the program package Crystal Ball. Care was taken to treat statistical and systematic uncertainties separately and to take parameter correlations into account. The resulting distribution for the gamma dose accumulated in the period 1949–1956 at the Techa river shore has a median value of 32 Gy with a 95% confidence interval of 21–45 Gy. This study confirms the corresponding value of 26.6 Gy that is used in the Techa River Dosimetry System (TRDS) 2000. 相似文献
12.
The International Journal of Life Cycle Assessment - Fired bricks are an essential construction material in Thailand where the majority of fired brick kilns use rice husk as feedstock. Given the... 相似文献
13.
Boundaries between work and private life are diminishing, but little is known on how this influences worker health. Therefore, we examined the association between work-related contacts outside of regular working hours by e-mail or phone and self-reported health in a representative sample of European employees ( n?=?23 760). The risk of reporting ≥1 health problem(s) was increased in workers contacted sometimes (odds ratio [OR]: 1.16, 95% confidence interval [CI]: 1.06–1.27) or often (OR: 1.23, 95% CI: 1.12–1.34) as compared with never, controlling for several demographic and workplace characteristics. Further research is needed to quantify work and nonwork patterns and their health effects. 相似文献
14.
为了解决停车场、甬路、渠坝与草坪争地的矛盾,增加城市绿地面积,在已研究粉煤灰草坪基质最佳混合比例的基础上,进一步探讨草坪砖作为草坪栽培环境(砖孔内填人粉煤灰混合基质,简称砖孔环境)的肥力效应与生物效应。为了对比分析,特此设置了土孔环境(在土壤中挖取与草坪砖形状和容积相同的孔并填入粉煤灰混合基质)与土灰环境(在粉煤灰混合基质中按照草坪砖孔模式划出同样大小的圈)种植黑麦草作为对照。研究结果表明:坪草N、K、Na、Cu、Zn等含量以砖孔环境最高,土灰环境和土孔环境较低,差异显著,说明砖孔环境能为植物生长提供较多的养分元素;砖孔环境中的坪草含有的Fe、Cu、Zn浓度远高于坪草最佳需求量,今后不再需要补充铁肥、铜肥和锌肥。试验还表明砖孔环境的蒸散率最小,基质含水量最大,基质势最高,持续供水能力强,抗旱效果十分明显。砖孔环境与土孔环境中的草坪草屑累积量差异不显著,但均比土灰环境中的高,且差异显著。夏季高温期砖孔环境中的草坪质量显著高于土孔环境和土灰环境中的草坪质量。 相似文献
15.
Recently discovered historical documents indicate that large releases of noble gases (mainly 41Ar and radioactive isotopes of Kr and Xe) from the Mayak Production Association (MPA) over the period from 1948 to 1956 may
have caused considerable external exposures of both, inhabitants of Ozyorsk and former inhabitants of villages at the upper
Techa River. To quantify this exposure, seven brick samples from three buildings in Ozyorsk, located 8–10 km north-northwest
from the radioactive gas release points, were taken. The absorbed dose in brick was measured in a depth interval of 3–13 mm
below the exposed surface of the bricks by means of the thermoluminescence (TL) and the optically stimulated luminescence
(OSL) method. Generally, luminescence properties using TL were more favorable for precise dose determination than using OSL,
but within their uncertainties the results from both methods agree well with each other. The absorbed dose due to natural
radiation was assessed and subtracted under the assumption of the bricks to be completely dry. The weighted average of the
anthropogenic dose for all samples measured by TL and OSL is 10 ± 9 and 1 ± 9 mGy, respectively. An upper limit for a possible
anthropogenic dose in brick that would not be detected due to the measurement uncertainties is estimated at 24 mGy. This corresponds
to an effective dose of about 21 mSv. A similar range of values is obtained in recently published dispersion calculations
that were based on reconstructed MPA releases. It is concluded that the release of radioactive noble gases from the radiochemical
and reactor plants at Mayak PA did not lead to a significant external exposure of the population of Ozyorsk. In addition,
the study demonstrates the detection limit for anthropogenic doses in ca. 60-year-old bricks to be about 24 mGy, if luminescence
methods are used. 相似文献
16.
Ultraporous fired bricks (porosities from 56 to 72%) were developed from materials locally available in Nigeria. The grog particle size was used to modulate the porosity of the bricks. The porous bricks produced were then employed as supports for the immobilization of a yeast strain isolated from a local alcoholic beverage, palm wine. The influence of a brick's porosity and particle size on the cell-loading capacity and cell growth inside the fired brick support were studied. The study revealed that a brick's porosity varied linearly with the mean particle size of the grog, increasing from a porosity of 56% at a particle size of 0.805 mm to 72% at a particle size of 0.075 mm. Cell saturation of the surface area available within the support matrix was completed within four hours of contact between the cell and the adsorbing surface especially for the most porous samples. Cell growth was therefore not observed in such cases; however, the less porous samples supported some cell growth upon incubation. Cell holdup was also observed to increase exponentially when either the porosity was increased or the particle size was decreased. The influence of particle size, however, became insignificant at very high porosities. 相似文献
17.
BackgroundOnline social networks present wide-reaching and flexible platforms through which to deliver health interventions to targeted populations. This study used a social marketing approach to explore teenage girls’ perceptions of physical activity and the potential use of online social networks to receive a physical activity intervention. MethodsSix focus groups were conducted with 19 Australian teenage girls (ages 13 to 18 years) with varying levels of physical activity and socioeconomic status. A semi-structured format was used, with groups discussion transcribed verbatim. Content analysis identified emergent themes, with triangulation and memos used to ensure accuracy. ResultsPhysical activity was most appealing when it emphasised sport, exercise and fitness, along with opportunities for socialisation with friends and self-improvement. Participants were receptive to delivery of a physical activity intervention via online social networks, with Facebook the most widely reported site. Participants commonly accessed online social networks via mobile devices and particularly smartphones. Undesirable features included promotion of physical activity in terms of walking; use of cartoon imagery; use of humour; and promotion of the intervention via schools, each of which were considered “uncool”. Participants noted that their parents were likely to be supportive of them using an online social networking physical activity intervention, particularly if not promoted as a weight loss intervention. ConclusionThis study identified key features likely to increase the feasibility and retention of an online social networking physical activity intervention for teenage girls. Guidelines for the design of interventions for teenage girls are provided for future applications. 相似文献
18.
There have been some reports concerning high complaint rates of fatigue or fatigue-related symptoms including lower back pain in flight attendants (FA). Thus, the relations of working conditions with work stress and fatigue symptoms were studied chiefly by focusing on working hours. From analysis of the time-table and fatigue symptoms of workers on international flights, it was suspected that there were some work-related factors jointly causing serious FA fatigue symptoms; night time and early morning work, long flight hours and a large time difference, thus disturbing their biological rhythms. On domestic flights, showing up early in the morning and debriefing late in the night were often observed together with a highly irregular FA time schedule. By statistical analyses, some factors including long working hours, frequent landing and late debriefing hours were considered to contribute significantly to the high fatigue complaint rates. Thus, it should be emphasized that many countermeasures are necessary to improve FA working conditions including working hours, rest on the airplane (ONO et al., 1990) and sleep during layover, in order to reduce their work stress and fatigue symptoms. 相似文献
19.
There is considerable evidence showing that night work is associated with increased morbidity, but only a few studies have focused on its relation to mortality. This study investigates the relationship between the type of working-time arrangement (weekly night work/daytime work) and total and cause-specific mortality among men and women. The data consist of a representative working conditions survey of Finnish employees conducted in 1984 (2286 men/2216 women), which has been combined with register-based follow-up data from Statistics Finland covering the years 1985–2008. In the 1984 survey, the employees were asked if they worked during the night (23:00–06:00?h) and if so, how often. In this study, the authors compare employees who worked at night (121 men/89 women) to daytime employees who did not do night work (1325 men/1560 women). The relative risk of death was examined by Cox proportional hazards analyses adjusted for background (age, level of education, family situation, and county), health (longstanding illness, pain symptoms, smoking status, and psychological symptoms), and work-related factors (weekly working hours, physical and psychological demands, demands of learning at work, and perceived job insecurity). Female employees working at night had a 2.25-fold higher risk of mortality than female dayworkers (95% confidence interval [CI] 1.20–4.20) after adjustment for background and health- and work-related factors. In addition to total mortality, night work was also associated with tumor mortality. Female night workers had a 2.82-fold higher risk of tumor mortality than female dayworkers (95% CI 1.20–6.65) in the adjusted model. Among men, no such significant association was observed. The present study indicated that female night workers had a higher risk of both total and tumor mortality compared to female daytime employees. Additional research on the potential factors and mechanisms behind the association between night work and mortality is required. (Author correspondence: jouko.natti@uta.fi) 相似文献
20.
Two field experiments were carried out totest whether effects of intraspecific competition ina Littorina littorea population can be detectedin a short-term investigation. Different size classesof L. littorea showed no significant differencein preferences when offered four kinds of eitherpossible food or substrata (Fucus vesiculosus,Ulva lactuca, Carcinus maenas, brick).Large and medium winkles preferred Fucusvesiculosus, followed by Ulva lactuca. Deadshore crabs (Carcinus maenas) were the leastpreferred objects for all size classes. On the firstday of the experiment bricks were more attractive tosmall littorines than to larger ones. Considering allfour days, the same ranking occurred for all sizeclasses: Fucus vesiculosus > Ulvalactuca > brick > Carcinus maenas. The reactionofjuveniles to increased densities was examined using anin situ caging experiment on a mussel bed. Meshsize of the cages allowed adult densities to beincreased while juveniles could escape by passingthrough the meshes. However, there was no significantemigration of small winkles even from cages with 10 to20 times natural density of large individuals. Ofgreater importance was the original number of winklesat the site. The available resources on the musselbeds appear to be sufficient to maintain a highpopulation density. Intraspecific competition does notseem to play a major role in this L. littorea-population. 相似文献
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