The effect of moisture content within multilayer protective clothing on protection from radiation and steam

The moisture from skin sweat and atmospheric water affects the thermal protective performance provided by multilayer protective clothing. Four levels of moisture content were selected to evaluate the impact of moisture on thermal protection under dry (thermal radiation) and wet (thermal radiation and low-pressure steam) heat exposure. Also, the role of moisture and its relationship with exposure time were analyzed based on skin heat flux and Henriques integral value. The addition of moisture to a fabric system was found to result in differences in second-degree and third-degree skin burn times. When moisture is added to a fabric system, it both acts as a thermal conductor to present a negative effect and provides a positive effect owing to thermal storage of water and evaporative heat loss. The positive or negative effects of moisture are mainly dependent on the thermal exposure time, the moisture content and the presence of hot steam.     

The photocatalytic degradation of carbamazepine and prediction by artificial neural networks

The three layer artificial neural network model was applied to predict the degradation efficiency for carbamazepine in photocatalytic oxidation under UV radiation. Titania–zirconia was employed as a catalyst for the photooxidation. The catalyst was prepared using titanium isopropoxide and zirconium oxychloride by sol–gel method and characterized by transmission electron microscopy and BET analysis. Different process parameters such as, initial concentration of carbamazepine, pH of the solution, catalyst concentration and time of UV irradiation were employed as the input to the artificial neural network model and the output of the network was degradation efficiency of carbamazepine. The multilayer feed-forward networks with the Levenberg–Marquardt (trainlm) backpropagation training algorithm was used for the network training. The smallest mean square error was obtained for three-layer network with ‘logsig’ transfer function and five neurons in the hidden layer gave optimal results. A comparison between the predicted values and selective experimental data of degradation efficiency showed a high correlation coefficient (R²) of 0.997.     

Methods of Assessing Efficiency of UV-Protecting Products

A few aspects of skin protection against ultraviolet (UV) light and methods of assessing efficacy of UV-protecting cream or gels have been discussed. UV-protection in cream and gels is not only a strategy of the cosmetic industry but a necessity because of human occupational activity and daily habits.     

碳氢燃料泄漏火灾火焰热辐射强度估算

介绍了一种关于碳氢燃料泄漏火灾火焰热辐射强度的估算方法,并运用具体实例进行了验证。同时,还提出了一定强度的火焰热辐射造成对人伤害所需时间的计算方法。     

Method for Evaluating Germicidal Ultraviolet Inactivation of Biocontaminated Surfaces

Safety issues related to work-site conditions often deal with potential worker exposure to infectious airborne microorganisms due to their dissemination in indoor air and contamination of surfaces. Germicidal ultraviolet (GUV) radiation is used in health-care settings and other occupational environments for microbial inactivation. In this study, a new methodology for determining the efficiency of GUV microbial inactivation of surfaces was developed and evaluated. The method utilizes identical chambers in which test microorganisms are irradiated on agar surfaces at different humidity and irradiation intensity levels. The effects of GUV intensity and exposure time on microbial inactivation were examined for Micrococcus luteus and Serratia marcescens. It was found that at low humidity levels (20–25%) both organisms can be inactivated with at least 95% efficiency if the GUV intensity exceeds 50 μW/cm² for at least 3-5 min (corresponding to a dose of ~ 10 mJ/cm²). The radiation dose needed for effective inactivation of S. marcescens, as measured by a UV meter near the microbial sample, was found not to be affected by the humidity level, whereas that of M. luteus increased at higher humidities. The findings of this study can be used to determine sufficient GUV inactivation doses for occupational environments with various microbial contaminations.     

Physiological Method of Evaluating Protective Clothing for Work in a Cold Environment

The purpose of this study was to determine the usefulness of physiological studies in the evaluation of protective clothing for work in a cold environment. The study included the examination of the dynamics of changes in chosen physiological parameters (core and skin temperatures, heart rate, pulmonary minute ventilation) as well as physical ones (the temperature and relative humidity under the clothes) during work in protective clothing with unknown thermal insulation. The experiment was conducted in extreme environmental conditions (–10 and –15°C) at a work load defined by the clothing manufacturer as moderate. Results show that thermal equilibrium was achieved and maintained throughout the investigated work time (60 min) and that the protective clothing ensures safety on the time scale of a regular 8-hour work day. It was also shown that the dynamics of thermal stress physiological parameters can be used to determine the maximum duration of exposure for cold protective clothing with unknown thermal insulation.     

FeSO4/H2O2/UV体系处理化纤厂棉浆粕黑液的研究

Fenton法是处理难降解有毒有机污染物的一种有效的方法.以棉浆粕黑液为研究对象,讨论了H2O2和FeSO4投加量、pH值、搅拌时间等因素对废水CODCr去除率的影响,将紫外光照引入Fenton试剂能提高废水中有毒有机污染物的降解速度,提高氧化能力 .实验确定了最佳工艺条件:pH=7,FeSO4投加量4 g/L,H2O2投加量为1.13%(V/V),搅拌时间15 min,此时CODCr去除率达到66.96%.     

航空活塞发动机点火强度均衡性测试及防火研究

针对磁电机故障和点火电嘴故障会使发动机失去动力引起飞行事故,高压导线破损放电可能导致动力系统起火并引发飞机火灾等安全隐患,利用紫外探测技术和虚拟仪器技术设计了航空活塞发动机点火强度均衡性测试系统,利用该测试系统完成航空活塞发动机点火系统的安全隐患检测。以四缸活塞发动机正常点火、高压导线破损、点火电嘴积碳等三种点火系统作为测试对象,测试发动机在不同转速下各气缸点火电火花紫外辐射强度,用以表征点火能量强度。实测得到,在不同转速下点火电嘴积碳故障都会导致点火强度降低;高压导线破损漏电会同时导致点火能量损失与点火强度不均衡,并且与转速呈正相关。测试结果可为航空活塞发动机点火系统故障排除及发现可能存在的高压导线破损放电电气火灾隐患点提供技术依据。     

Pre-Employment Screening Among Health Care Workers—Ethical Issues

Occupational health practitioners deal with the questions of confidentiality, relation between the right to work and the right to health, between individual freedom and the risks other can run. An audit of pre-employment health assessment of health care workers, in the United Kingdom and in France, discussed the efficiency of pre-employment screening. Screening tests and medical examinations should not be used as a pretext to avoid implementing effective preventive measures. The pre-employment examination has mostly to be used for education of the future employees and for collection of baseline data. Appropriate procedures such as developing preventive policies, health promotion, and control of hazards in the work environment are efficient for the promotion of equal employment rights for women, older workers, or people with disabilities.     

An Analysis of Work Environments and Operations in Hot and Humid Areas

Crews on tankers traveling and hauling cargo on the lower reaches of the Mississippi River during the hot and humid (H&H) summer season face various occupational safety and ergonomics problems. Evaluation of medical data reveals that a large number of the crewmembers experience job related injuries, diseases, disorders, and exhaustion as a result of adverse environmental conditions (National Institute for Occupational Safety and Health [NIOSH], 1993). The accidents and injuries that occurred were characterized and then analysis was used to recommend constructive remedies and solutions. The results were also used to design and develop better work environments on the tankers and in the general industry. In H&H conditions, the body’s chemical reactions constantly change in order to maintain the best possible reaction to changing environments. This chemical reaction increases blood flow to the skin through sweating. Body metabolism stabilizes body temperature through muscular work and convection, evaporation and radiation remove heat.     

Using state administrative data to study nonfatal worker injuries: challenges and opportunities

PROBLEM: Administrative data from states have the potential to capture broader representation of worker injury, facilitating examination of trends, correlates, and patterns. While many states use their workers' compensation (WC) data to document frequency and type of injury, few conduct in-depth examinations of patterns of injury and other etiologies. Administrative data are generally an untapped resource. METHOD: Comparisons are made among four state databases used in a study linking worker injuries and patient outcomes in hospitals and nursing homes. RESULTS: Worker injury data varies in terms of inclusion criteria, variables, and coding schemes used. Linkages to organizational level characteristics can be difficult. CONCLUSIONS: Despite limitations, data can be used to study injury patterns and etiologies. Users must be knowledgeable and recognize how database characteristics may influence results.     

An Exploratory Study of Meanings of Risk Control for Long Term and Acute Effect Occupational Health and Safety Risks in Small Business Construction Firms

A qualitative study of employers' and employees' meanings of occupational health and safety (OHS) risk control was conducted among a sample of small businesses engaged in the Australian construction industry. Two OHS risks relevant to the construction industry were selected for study. One risk (falls from height) represented an immediate consequence, whereas the other (occupational skin disease) represented a long-term health effect. Meanings of the sources and control for these risks were explored during in-depth interviews. Participants perceived the immediate effect, falls from height OHS risk, as being more important in their workplaces than the delayed effect, skin disease OHS risk. The risk of falls from height was perceived to be controllable but requiring a great deal of effort to prevent, whereas there was a fatalistic resignation to the risk of occupational skin disease. Meanings of risk control for both occupational skin disease and falls from height focused on individual rather than technological risk controls. Organizational barriers to the adoption of technological OHS risk controls in the construction industry were identified.     

Skin reactions to latex in dental professionals – first Croatian data

Purpose. To determine the prevalence of undesirable skin reactions to latex in dental professionals and students of the School of Dental Medicine in Zagreb, Croatia. Methods. Our research included 444 participants, of which 200 agreed to undergo a skin prick test (SPT). All participants answered a questionnaire in which we asked about incidence of skin lesions, duration of occupational exposure to latex, localization of skin lesions and symptoms. Statistical analysis of the questionnaire and test results was then carried out. Results. Of the total 444 participants surveyed, 249 (56.1%) reported lesions on their skin (professionals 64.8%, students 6.1–58.5%). From the questionnaire, 239 (96.0%) respondents reported lesions on the hands and fingers, mostly in the form of erythema (37.0%) and occasional dryness of skin (29.0%). Positive SPT results were found in 14 (7.0%) out of the 200 respondents who underwent the test. Conclusions. While a large number of subjects (56.1%) reported skin lesions when using latex products at their workplace, the SPT test was positive only in 7.0%. The results show that the prevalence of self-reported skin lesions was significantly related to the length of occupational exposure, with a substantial effect size (p?<?0.001; V?=?0.334).     

Analysis of the selected optical parameters of filters protecting against hazardous infrared radiation

The paper analyses the selected optical parameters of protective optic filters used for protection of the eyes against hazardous radiation within the visible (VIS) and near infrared (NIR) spectrum range. The indexes characterizing transmission and reflection of optic radiation incident on the filter are compared. As it follows from the completed analysis, the newly developed interference filters provide more effective blocking of infrared radiation in comparison with the currently used protective filters.     

辐射防护标准的历史回顾和ICRP1990年新建议书

国际放射防护委员会(ICRP)是非官方国际学术权威团体。目前世界各国制订自己的辐射防护标准都参考ICRP的建议。ICRP自1928年组建以来,关于辐射防护标准的总建议发布了四次。即第1、2号出版物(1958年,1959年),第6、9号出版物(1962年,1965年),第26号出版物(1977年),第60号出版物(1990年)。本文概述了ICRP历次制订辐射防护标准的原则和依据。ICRP的辐射防护指导思想变化代表了不同历史时期放射生物学、辐射剂量学及与辐射防护有关的其他学科的国际水平。ICRP研究辐射防护标准的历史经验可供其他行业劳动保护参考。     

Computational fluid dynamics (CFD) study of heat radiation from large liquefied petroleum gas (LPG) pool fires

Liquefied petroleum gas (LPG) is flammable and has risks of pool fires during its transportation, storage, and applications. The heat radiation by LPG pool fires poses hazards to individuals nearby and can lead to potential failures of ambient facilities. Due to the high costs and invasive nature of experiments for investigating large-scale pool fires, computational fluid dynamics (CFD) is employed in this study as the cost-effective and noninvasive method to simulate the process and analyze the characteristics of large hydrocarbon pool fires. Specifically, an experimentally validated 3-D CFD model has been built to simulate surface emissive power (SEP) and incident radiation of large-scale LPG pool fires with three different diameters and wind speeds. Steady-state simulations with P1 radiation and probability density function (PDF) combustion models were employed to obtain reliable data after the optimizations based on the comparisons with experimental data and empirical models. The comparison with benchmark experimental data demonstrates that the CFD model employed in this study can accurately predict the incident radiation of large LPG pool fires. A new SEP correlation is also proposed, which is specifically for LPG pool fires with a diameter between 10 m and 20 m. Additionally, the safe separation distances between LPG facilities and surrounded objects have been estimated based on the CFD simulation results. The high-resolution CFD model for large LPG pool fires in this work provides noninvasive and direct quantitative evidence to enhance the fundamental understanding on the safety of large LPG pool fires and can assist regulatory agencies in refining the safety limits in the cost-effective and time-saving manners.     

Decomposition of 1,4-dioxane by vacuum ultraviolet irradiation: Study of economic feasibility and by-product formation

We report the first use of vacuum ultraviolet (VUV) treatment to decompose 1,4-dioxane, a persistent organic contaminant that is difficult to remove by conventional drinking water treatment processes. The efficiency of VUV treatment was compared to that of VUV- and UV-based advanced oxidation processes (AOPs) (VUV/TiO₂, VUV/H₂O₂, UV/TiO₂, and UV/H₂O₂), and by-product formation was investigated. VUV treatment decomposed 1,4-dioxane more rapidly than did UV and UV/TiO₂ treatments. The decomposition rate was enhanced when VUV irradiation was combined with TiO₂ or H₂O₂. VUV/H₂O₂ decomposed 1,4-dioxane more rapidly than UV/H₂O₂ at a low H₂O₂ dose (1 mg/L), but the rate difference became small at a high H₂O₂ dose (5 mg/L). Electrical energy per order analysis revealed that VUV treatment, and the VUV- and UV-based AOPs, were economically feasible for 1,4-dioxane decomposition. Using raw water samples, we investigated by-product formation during VUV treatment and the effect of VUV irradiation on chlorinated disinfection by-product formation potential. Although the samples contained high concentrations of bromide, no bromate was produced by VUV treatment. VUV treatment slightly decreased trihalomethane formation potential (THMFP), whereas haloacetic acid formation potential (HAAFP) was unchanged, and total aldehyde concentration increased. The trend in HAAFP agreed with that had been reported for the VUV irradiation with much higher dose (Buchanan et al., 2006), whereas the trend in THMFP was different from that with much higher dose. THMFP, HAAFP, and aldehyde concentration were reduced by subsequent treatment with granular activated carbon (GAC) or biological activated carbon (BAC). Nitrite was produced by VUV treatment but disappeared after subsequent BAC treatment. These results suggest that VUV treatment should be combined with GAC or BAC treatment to suppress by-product formation.     

Incorporating the 2007 recommendations of the International Commission on Radiation Protection into the J-value analysis of nuclear safety systems

The newly released findings by the International Commission on Radiation Protection (ICRP) led to a review of the lifetime risk coefficients for fatal cancer used in J-value analysis of nuclear safety systems. The change in life expectancy a safety system brings about by averting a radiation exposure needs to be estimated in order to calculate the safety system's J-value, and this is done following the ICRP's practice of using risk coefficients that are uniform across both genders and all ages in the defined population group (either workers or the general population). The ICRP predicted uniformly lower radiation risks in 2007 than in 1990 on a like-for-like basis, but it was found that the ICRP's new risk coefficients needed to be multiplied by a compensating factor specific to each population when used in calculating the radiation-induced change in life expectancy. Incorporating the new compensating factor leads to a decrease in the J-value calculated of about 5% for workers and 15% for the general population compared with earlier, reported results. These adjustments are not large compared with the uncertainties associated with radiation harm and the economics of installing a safety system, but will strengthen slightly the case for spending on a nuclear safety measure.     

电离辐射防护涂料的研究

针对电离辐射的危害及防护,重点介绍了具有吸收、屏蔽射线功能的防辐射涂料的构成及要求。报导了一种对χ—射线(γ—射线)具有良好的屏蔽、吸收功能的涂料的研制过程和测试结果。该涂料由一种单相、均匀、化学性质稳定、分散性能优良、有较优的屏蔽能力的无机固熔体填料,配以经改性的耐高温骨架材料而构成。该涂料施工方便、涂膜光亮、无公害,可望在广泛的领域内有大的应用前景。