劳动特效护肤霜的研制及效果观察

为防治职业性皮肤病,保护工人身体健康,采用水解明胶研制和生产出劳动特效护肤霜。对这种护肤霜的使用,作者用统一的方法,在冬季对５１９ 例皲裂患者进行效果观察。发现对各种程度的皲裂均有显著疗效。有效率达９８．２０％ ,治愈率达８９．２１％ ,皲裂程度愈轻效果愈明显。在使用过程中,未见任何刺激性和副作用,部分患者用这种护肤霜擦脸后,皮肤变得细嫩光滑。经过安全和毒性试验表明：无毒性、无致敏性、无刺激性。三种致突变试验均属阴性。长期使用是安全的。观察表明：对皮肤皲裂有显著的治疗功效,同时还能有效地保护皮肤     

Rheological and sensory properties of hydrophilic skin protection gels based on polyacrylates

Introduction. With the current increases in occupational skin diseases, literature data attesting the decreasing efficiency of barrier creams with respect to the manufacturer’s declarations and legal regulations granting skin protection gels for employees, research is required to analyse and evaluate the recipes used for hydrophilic skin protection gels based on polyacrylates. Methods. This study investigated the rheological properties, pH and sensory perception of hydrophilic barrier gels based on polyacrylates. Results. The acrylic acid derivatives used were good thickeners, and helped to form transparent gels of adequate durability. They could be used to create hydrophilic films on the surface of the skin to protect it against hydrophobic substances. A correlation was shown between the results of the rheological properties and the barrier properties of the gels. This confirms the possibility of monitoring the quality of the gels at the stage of recipe development. Conclusions. Polyacrylates are viable for use in industry to produce hydrophilic barrier creams suitable for skin protection.     

新型劳动保护用美容美发品的研制

对自制的斯珀绿系列劳保用品类的美容美发产品的效果作了进一步研究,比较了斯珀绿系列用品与市售一般劳保用品的使用效果,说明在劳保用品的使用上,更具有其优越性。     

Analytical characterization of movements of the spinal column and risk assessment due to repeated movements of the upper limbs of building painters

Manual activities of construction workers may induce musculoskeletal disorders. This study on a group of painters aimed to analytically characterize movements of the spinal column by both lumbar motion monitor and television cameras and to determine, using the Occupational Repetitive Actions (OCRA) Index method, the risk exerted by repeated movements of the upper limbs. The main results are: painting with a roller generally exposes workers to a lesser risk for upper limbs than painting with a brush; a roller-stick fixed at the wrong length can lead to stretching of the back at lumbar and cervical levels; to remain within the range of ‘acceptable risk’ (OCRA Index evaluation), a worker should not paint a vertical wall for over 3 h if using a roller and 2.5 h if painting with a brush; and, on average, a painter who paints for 5 h in a day lifts the bucket about 120,140 times.     

Analysis of Conditions and Organization of Work of Notebook Computer Users

Abstract

Aim. The aim of this study was to evaluate working conditions with a notebook computer (notebook) as a potential cause of musculoskeletal disorders. Material and methods. The study had 2 stages. The first one was a questionnaire survey among 300 notebook users. The next stage was an expert analysis of 53 randomly selected workstations. The questionnaire survey included questions about the participants, their working conditions, work organization and also duration of work with a notebook. Results and conclusions. The results of the research showed that most examined operators used a notebook as a basic working tool. The most important irregularities included an unadjustable working surface, unadjustable height of the seat pan and backrest, unadjustable height and distance between the armrests and no additional ergonomic devices (external keyboard, docking station, notebook stand or footstool).     

Influence of thermal shock of piezoelectric pressure sensors on the measurement of explosion pressures

Piezoelectric pressure sensors are susceptible to changing temperatures, because resulting mechanical deformations of the sensor membrane and housing may exert a positive or negative force on the piezo crystal, thus changing the reading of this sensor. The consideration and compensation of this influence quantity is a frequent topic of many investigations in the field of combustion chambers, of spark-ignition engines and internal combustion engines. However, this is not the case in the field of the type of protection “flameproof enclosures”. Here a peculiarity is the fast temperature rise during a single explosion and the concurrent influence of the temperature gradient, which is often described as thermal shock. The whole event has a typical duration time of the order of seconds and less. Thermal shocks have so far received little attention, as was also a lesson learnt from the evaluation of an interlaboratory comparison between Ex testing laboratories. The laboratories handle thermal shock in a variety of ways, starting from complete ignorance up to various sophisticated coatings. This was a main source of different results within the field of participants. This work evaluates the behavior of different piezoelectric pressure sensor types with respect to thermal shock. Different temperature protection measures are investigated regarding their functionality, practicability and stability. Possible influences on the sensitivity of the sensors due to the used protective measures regarding thermal shock are shown. The transient temperature load of the sensor membrane is estimated by physical calculations as well as numerical analysis based on surface temperature measurements transformed in a surface heat flux density. This work provides guidelines for typical end-users in the field of flameproof enclosures how to handle thermal shock correctly.     

Experimental investigation of the influence of inert solids on ignition sensitivity of organic powders

This work presents the results of the experimental characterization of the ignition sensitivity of solid inertant/combustible powders mixtures. Three inert solids (alumina, Kieselguhr, aerosil) and eleven organic powders have been considered and the following parameters have been determined: (1) the minimum ignition energy, (2) the minimum ignition temperature in cloud and (3) the minimum ignition temperature in 5 mm layer. The effects of the addition of inert solids are described and a simple model is proposed to represent the experimental results.Generally, increasing inert solid content in a powder leads to a higher minimum ignition energy as well as a higher minimum ignition temperatures in cloud and in layer. In some cases, the flammability is influenced above a threshold concentration value, which can be quite high (up to 85 wt.%). Indeed, the proposed model shows a zone below the minimum ignition concentration (MIC), which does not enable an efficient or safe inerting: either the admixed inert solid does not provide a sufficient effect, or it can even facilitate the ignition of the dust by notably improving its dispersability.The influence of key parameters such as the thermal conductivity or optical properties on the efficiency of the inerting by admixed solid need to be further assessed in a future work in view to better understand the mechanisms involved and to extend the scope to other types of oxidizable materials.     

生产安全监督管理人员的胜任特征模型

安全管理工作是关系到企业平稳发展、员工生命安危至关重要的职位,安全监管人员的招聘、培训、考核和晋升是目前企业不够重视却十分重要的问题,因此建构安全监管人员的胜任特征模型有着重要的现实意义。本文对在安全管理处于领先地位的生产型企业的安全管理状况进行了深度访谈,在此基础上开发了安全监管人员胜任特征调查问卷,对浙江、山东、江苏省的10家企业进行了大样本调查,并进行了探索性和验证性因素分析,构建了安全管理人员的胜任特征模型,包括敬业自信、踏实认真、创新运作、团队合作、积极主动这五方面,并且进行了方差分析,证明该模型能够区分和预测安全管理绩效,具有岗位针对性和可应用性。     

Prediction of the self-ignition temperature in lagging fires by means of isothermal calorimetry

Under certain circumstances, contamination of a porous insulation material by a combustible liquid may result in a lagging/insulation fire. In the current study, a method based on isothermal calorimetry and modelling to estimate the risk of a lagging fire, or a maximum insulation thickness for a certain system temperature, is presented. The studied system was a combination of mineral wool and rapeseed oil. Full-scale tests were performed to determine suitable ignition criteria and to validate the results from the isothermal calorimetry tests and modelling. We contaminated the lagging using two methods – a direct method and a solvent method. These methods were evaluated in the full-scale tests. The solvent method resulted in more repeatable results than the direct method, where the contaminant was poured on the insulation. Using the calorimetric measurements, we estimated the parameters for the kinetic equation. This result was used to estimate the self-ignition temperature of contaminated lagging installed on a pipe. We found that a temperature increase of 40 °C was a reasonable ignition criterion when modelling.     

Dynamics of calling: A longitudinal study of musicians

The dominant view of calling among management scholars is that it is a stable construct that does not change. This view has resulted in a research void about calling's early development and subsequent evolution. Insight into the dynamic process through which callings develop is fundamental to understanding its role in people's careers and lives. In this study, I focus on the antecedents of calling, a consuming, meaningful passion people can experience toward a domain. I propose a dynamic model in which calling can change over time and can be shaped by antecedent factors, specifically, through people's ability, behavioral involvement, and social comfort in the area toward which they feel a calling. I tested these ideas in a seven‐year, four‐wave prospective longitudinal survey study of 450 amateur musicians. Multilevel analyses indicate individuals who were more behaviorally involved and felt higher social comfort in the calling domain (e.g., music) experienced higher levels of calling early on but experienced a decline in calling over time. Individuals' ability in the calling domain was not related to initial calling or change in calling. I discuss the implications for theory and research on calling, meaning of work, and the dynamics of careers. Copyright © 2012 John Wiley & Sons, Ltd.     

分散式污水处理设施集约化管理创新探索

随着近年来大量农村污水处理设施的新建,项目污水处理设施面广、点多、单体规模小、污染物浓度变化大、经营困难等问题凸显,如何突破困境找到一条相对适合分散式污水处理设施的运营管理十分必要。本文提出了集约化管理创新探索,在生产标准化管理、人力资源管理、安全管理、设备设施管理及物资管理等方面全方位的总结了运营管理经验,为分散式污水处理设施管理提供了参考和借鉴。     

A Comparison of Two Methods of Determining Thermal Properties of Footwear

The present European Standard for footwear testing (Standard No. EN 344:1992; European Committee for Standardization [CEN], 1992) classifies footwear thermally by a temperature drop inside the footwear during 30 min at defined conditions. Today, other methods for footwear thermal testing are also available. The aim of this study was to compare EN 344:1992 with a thermal foot method. Six boots were tested according to both methods. Additional tests with modified standard tests were also carried out. The methods ranked the footwear in a similar way. However, the test according to standard EN 344:1992 is a pass-or-fail test, whereas data that is gained from the thermal foot method gives more information and allows further use in research and product development. A change of the present standard method is suggested.     

液氯瞬时泄放扩散过程实时仿真

分析液氯钢瓶或容器爆炸后的氯气扩散各阶段的数学模型，设计了计算机实时仿真软件，最后给出大气扩散模型计算的云团在风力驱使下漂浮途中造成污染区域的等浓度曲线。文章的结论和实施方案对其它液化气体、尤其是重气的扩散过程模拟及实时仿真有参考价值。     

我国安全培训机构分布现状分析

为了解现有安全培训机构分布状况,对当前全国3813家机构有关信息进行了统计分析。分析结果表明：安全培训机构建设已经进入了规范提高阶段,当前安全培训机构合理利用了各类资源,但四级安全培训机构定位尚不明确。建议充分发挥四级机构作用,建立安全培训机构地域分布合理的判定标准。     

Study into influence of different types of igniters on the explosion parameters of dispersed nitrocellulose powder

Nitrocellulose is a flammable compound produced by cellulose nitration. The nitrocellulose production and handling are associated with a risk of fire and explosion. Nitrocellulose is used as either collodion cotton (<12.5% N) or as an explosive (>12.5% N). Nitrocellulose is a fibrous or powdered substance and may detonate or burn upon certain conditions. The article compares the combustion parameters of dry nitrocellulose in the KV-150M2-UIBE explosion chamber at the concentrations of 250, 500 and 750 g m⁻³. To ignite a nitrocellulose sample, six different types of igniters were used. A commercially available 5 kJ pyrotechnic igniter was used as the standard. Also used were a nitrocellulose igniter, a pyrotechnic igniter with magnesium powder and KNO₃/KClO₃, and an exploding wire (Kanthal and tungsten wire). The examined igniters were found to affect the explosion parameters of dispersed nitrocellulose. The deviation of the explosion constant K_st reached 50% of the standard value. The highest pressure of 12.73 bar g was reached at a concentration of 750 g m⁻³ and an igniter exploding wire with Kanthal wire. The highest K_st value of 287.9 bar.m.s⁻¹ was achieved at a concentration of 750 g m⁻³, when using the pyrotechnic igniter with KClO₃ and magnesium powder.     

膨润土在危废填埋场防渗系统粘土层改性中的应用

通过阐述在工程实践中采用膨润土改性天然粘土的相关情况,分析膨润土在填埋场防渗系统粘土层改性中的应用,表明该方案技术可行、经济合理,可作为类似工程的参考。     

Application of CFD on the sensitivity analyses of some parameters of the modified Hartmann tube

The aim of this work is to determine the influence of operating parameters such as the dispersion pressure, the ignition delay and height on the dust flammability. A Computational Fluid Dynamics (CFD) simulation, based on an Euler–Lagrange approach, was developed with Ansys Fluent™ and validated experimentally. Such analysis will facilitate the choice of the most conservative conditions for a flammability test. This paper is focused on a case study performed on wheat starch with the modified Hartmann tube. The dispersion process of the powder was studied with granulometric analyses performed in situ and high speed videos. Tests were performed with injections at gas pressure ranging from 3 to 6 bars and the evolution of the particle size distribution (PSD) was recorded at different ignition heights (5, 10 and 15 cm over the dispersion nozzle). The observations highlighted the presence of agglomeration/deagglomeration processes and dust segregation. Besides, a CFD simulation analysis was aimed at evaluating the impact of a set of parameters on the PSD and the local turbulence, which are closely linked to some flammability parameters. For this computational analysis, the CFD simulation was coupled with a collision treatment based on a Discrete Element Method (DEM) in order to consider the cohesive behavior of the combustible dust. Thus the results suggest performing the injection of the gases at approximately 5 bars for the flammability tests of wheat starch in order to obtain the finest PSD at a given ignition height. It is also shown that the finest PSD are obtained at 5 cm over the dispersion nozzle. However, the local instabilities and turbulence levels are so high during the first stages of the dispersion that the flame growth can be disturbed for short ignition delays. Moreover, the stabilization of the bulk of the dust cloud requires longer periods of time when the ignition sources are located at 15 cm. As a result, the recommended height to perform a flammability test is 10 cm in this case. Finally, this study proposes some tools that might improve the procedure of dust flammability testing.     

Evaluation of Different Scales for Measurement of Perceived Physical Strain During Performance of Manual Tasks

The main objective of this study was to evaluate different scales of perceived strain during the performance of various physical tasks. A total of 52 male and female participants took part in 4 experiments to achieve the study objective. The results suggest that a bipolar comfort-discomfort scale is a more appropriate instrument than a discomfort scale for assessing cumulative physical stresses at work, especially at the beginning of the shift. For assessing discomfort at the end of the work shift, a unipolar scale may also be used. On the basis of the obtained results, red, green, and yellow zones are suggested to establish priorities for work redesign efforts in ergonomic control programs.     

A new approach to quantitative assessment of reliability of passive systems

The objective of this paper is to show how probabilistic reliability can be assessed for complex systems in the absence of statistical data on their operating experience, based on performance evaluation of the dominant underlying physical processes. The approach is to distinguish between functional and performance probabilities when dealing with the quantification of the overall probability of a system to perform a given function in a given period of time (reliability). In the case of systems where sufficient statistical operating experience data are available, one can focus the quantitative evaluation entirely on the assessment of the functional probability for a given active item (e.g. a pump) by assuming that the specification, layout, construction and installation is such that the item is providing the assigned performance, e.g. in the form of generating the required flow rate. This is how traditional probabilistic safety assessments (PSAs) focus the reliability analysis for the various safety features on the calculation of values for the availability per demand. In contrast, for various systems relevant in advanced technical applications, such as passive safety features in innovative reactor designs, it is essential to evaluate both functional and performance probabilities explicitly and combine the two probabilities later on. This is of course due to the strong reliance of passive safety systems on inherent physical principles. In practice, this means that, for example, in case of a passive cooling system based on natural circulation of a given medium, one has to evaluate and to assess the probability to have a medium condition and a flow rate such that a cladding temperature, represented by a probability distribution, can be hold at a required level. A practical example of this method is given for the case of the reliability assessment of a residual passive heat removal system. General conclusions are drawn regarding reliability estimation of complex, interconnected systems in the absence of statistical performance data, such as for infrastructures.     

Determination of the performance limits of flame arresters at increased oxygen concentrations

This investigation shows how an increased oxygen concentration influences the performance limits of crimped ribbon deflagration flame arresters at elevated pressures. An evaluation of the maximum experimental safe gap (MESG) as reliable criterion for describing the performance limits under non-atmospheric conditions is given. Measurements of MESGs and flame arrester performance tests were performed. Various fuel/oxygen/air mixtures containing ethylene and propane were used as testing gases. Former studies on the pressure dependence and the influence of oxygen on the MESG were initially confirmed. Furthermore, performance tests using a commercial deflagration flame arrester revealed that such a flame arrester may prevent flame transmission also at non-atmospheric conditions within a limited range. For various oxygen concentrations the performance limits were reached at the same MESG. Hence, it can be assumed that a flame arrester possesses a device- and fuel-specific maximum experimental safe gap for a specific gas mixture in different concentrations and at different pressures. This performance-related maximum safe gap can be used as a parameter for estimating and describing the performance limits of a flame arrester. It offers an attempt to simplify the testing and qualification of deflagration flame arresters for non-atmospheric conditions.