Permeability of Medical Gloves to Mono- and Dimethacrylate Monomers in Dental Restorative Materials

Dental personnel manually handle methacrylate-based restorative materials, which can cause skin irritation and allergies. The protection given by different types of medical gloves is not well known. Breakthrough time (BTT, min) was used as a measure of protection according to a European standard, using 2 test mixtures consisting of respectively 3 and 5 monomers. Fourteen gloves representing natural rubber latex, synthetic rubber, and synthetic polymeric material were tested. The BTT ranged from some minutes to more than 2 hrs for the 4 monomers with a molecular mass less than 300. The longest protection was recorded for Nitra Touch (nitrile rubber), Tactylon (synthetic rubber), and Metin (PVC).     

Gloves against mineral oils and mechanical hazards: composites of carboxylated acrylonitrile–butadiene rubber latex

Resistance to permeation of noxious chemical substances should be accompanied by resistance to mechanical factors because the glove material may be torn, cut or punctured in the workplace. This study reports on glove materials, protecting against mineral oils and mechanical hazards, made of carboxylated acrylonitrile–butadiene rubber (XNBR) latex. The obtained materials were characterized by a very high resistance of the produced materials to oil permeation (breakthrough time?>?480?min). The mechanical properties, and especially tear resistance, of the studied materials were improved after the addition of modified bentonite (nanofiller) to the XNBR latex mixture. The nanocomposite meets the requirements in terms of parameters characterizing tear, abrasion, cut and puncture resistance. Therefore, the developed material may be used for the production of multifunctional protective gloves.     

Method of Testing the Penetration of Acid Solutions Through Safety Gloves

Because they cause burns that are difficult to heal, acids are dangerous, and steps should be taken to ensure that the human skin does not come into contact with them. For this purpose safety gloves are generally used by workers who have to handle acids. Such gloves need to be tested to ensure that they are acid resistant. Standard EN 374 (European Committee for Standardization [CEN], 1993c) specifies a method of testing the permeation of liquid chemicals, on a molecular level, through glove material, but it may be difficult to ensure the fitness of the joints of a two-compartment cell, when gloves are lined with jersey. To deal with this a simple pH-meter method to test the permeation of acid and alkali solutions through safety gloves has been developed. The permeation of H₂S0₄, HCI, HN0₃, and CH₃COOH through gloves made from neoprene, nitrile, and PVC was tested. This method seems to be simple and economical.     

Permeability of Organic Solvents Through Two-Layer Safety Gloves Determined by a Gravimetric Method

Organic solvents are harmful to humans, and many of them are recognized as carcinogens. Therefore, it is necessary to protect hands from contact with them. Most methods for testing solvent resistance of gloves use gas chromatography. However, these methods are expensive and so complex that they present application problems for most glove producers and users. A simple gravimetric method to test solvent resistance o f gloves was developed. It was tested by measuring the permeability of organic solvents such as white spirit, acetone, isopropyl alcohol, benzene, p-xylene, and trichloroethylene through gloves made of natural rubber, polyvinyl chloride, neoprene, perbunan, polyvinyl alcohol, and two-layer gloves made of natural rubber and neoprene. This method proved to be a simple, economical, and reliable way to examine glove permeability.     

The Effect of Protective Gloves on Manual Dexterity in the Cold Environments

This article presents a study on the effect of different protective gloves (which are commercially available and commonly used in the cold) on manual dexterity in cold environments. The experiments compared statistically four different types of gloves and two different types of gloving (outer or double) at +19 °C and -10 °C. Performance was determined both objectively and subjectively using two manual dexterity tasks: bolt-nut and pick-up tasks. The response measured was the time of performing each task. Statistical analysis showed that all independent factors such as glove type, participant, object size, and temperature had significant effects on the hand cooling reaction. A significant difference in the performance between the gloves was found in the bolt-nut task. It was also found that outer-inner combination gloving may be an approach to use for precision tasks.     

Evaluation of the flexibility of protective gloves.

Two mechanical methods have been developed for the characterization of the flexibility of protective gloves, a key factor affecting their degree of usefulness for workers. The principle of the first method is similar to the ASTM D 4032 standard relative to fabric stiffness and simulates the deformations encountered by gloves that are not tight fitted to the hand. The second method characterizes the flexibility of gloves that are worn tight fitted. Its validity was theoretically verified for elastomer materials. Both methods should prove themselves as valuable tools for protective glove manufacturers, allowing for the characterization of their existing products in terms of flexibility and the development of new ones better fitting workers' needs.     

Examining the effectiveness of anti-vibration gloves with a neural network

Whether anti-vibration gloves are effective in protecting against vibrations depends not only on the materials they are made of, but also on the parameters of the source of vibration. Depending on those parameters, the effectiveness of the same means of protection may be radically different. This article presents a methodology of using a neural network to test anti-vibration gloves. A network can map gloves in various conditions, i.e., for vibrations of various amplitudes and spectra, and for various forces exerted by the worker on a tool. Real, measured vibration signals produced by different tools were used in training a neural network. The results presented in this article prove that real properties of gloves are accurately represented by their models developed as a result of training a neural network.     

Hands on explosives: Safety testing of protective measures

Several attempts have been made to test the suitability of protective measures for the handling of explosives. We investigated the suitability of safety gloves and a combined safety helmet and face shield. In the presented studies, three different experimental setups were used to simulate the effects of an explosion of a primary explosive in a glass flask on the glove or helmet protected body. Depending on the experimental setup, the fragment effects were evaluated and compared. Furthermore, the fragment distribution of an explosion inside a glass flask was investigated. The explosion of 1 g of lead azide in a 10 mL flask yielded approximately 14,000 glass fragments. However, most of the shards were accelerated down- and side-wards and only few upwards. Holding a flask on its neck (instead of its bottom) is therefore a simple but effective way of diminishing the risk of injury, when handling explosives. The safety helmet/face shield performed very well, by shielding the face from all fragments. Furthermore, it could be proven that DIN and EN standard testing procedures for gloves are unsuitable to simulate the effects of a respective explosion.In this article, the progress in the development of realistic testing procedures for the testing of gloves for the protection against fragmentation effects of glassware in situations involving explosions is reported and the results and methods of previous tests are summarized.     

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.     

离子色谱分析法用于化学防护服材料渗透性能检测的研究

渗透性能是化学防护服最重要的防护性能指标之一。本文采用PTC200型渗透测试池、蠕动泵、超滤装置和离子色谱分析仪,构建了测试化学防护服渗透性能的装置,并利用该装置对一系列化学防护服面料对浓硫酸和NaOH溶液的渗透性能进行了检测。结果表明,利用该装置可以方便准确地实现服装面料渗透性能测试,是一种具有重要应用价值的检测方法。该方法的开发为规范我们国家化学防护服装及相关产品防护性能检测方式,提高检测结果的准确度和一致性,具有重要的意义。     

The Correlation Between Symptoms,Frequent Use of Dental Polymers,and Evaluation of Health Risk

Dental personnel are at risk as they manually handle polymer products containing monomers and additives that cause irritation and induce allergy. Gloves and face masks can be easily penetrated by monomers. A total of 587 dental personnel and a referent group (585) in the 2 most northern regions of Sweden were included in a questionnaire study (response rate 76%). Questions were asked regarding symptoms of atopy, asthma, conjunctivitis, atopic dermatitis, hand dermatitis, and hay fever/rhinitis. The dental personnel were asked to give the name of polymer products used in their practice and the frequency of use. They were also asked to risk evaluate 5 different types of polymer materials on a scale from 1 to 5. Analysis was done to find if the occurrence of a symptom was associated with a high risk evaluation of a polymer material, or with frequent use of a certain polymer product. Significantly more dentists reported symptoms of atopic dermatitis and conjunctivitis compared to referents and chair assistants. Results show that dental personnel with symptoms risk evaluated most materials significantly higher than dental personnel without symptoms. Further, the occurrence of some symptoms was associated with frequent use of 8 polymer products.     

多功能内层手套的研制

本文针对隔绝式防毒手套存在透气性、舒适性较差以及保温功能不佳等问题,研制了一种新型多功能内层手套,提高了防毒手套的舒适性和安全性。     

用盐桥支撑双分子层脂膜模拟研究锌离子跨细胞膜输运

采用盐桥支撑技术制备镶嵌胆固醇的双分子层卵磷脂(脑磷脂)膜,用以模拟细胞膜.用正辛烷做溶剂,对不同卵磷脂(脑磷脂)与胆固醇配比进行制膜,膜的稳定性均超过100h.实验发现,纯脂质体不能输运重金属离子,胆固醇能输运重金属离子.胆固醇与重金属离子之间存在吸附作用,无化学反应.采用电化学工作站对双分子层脂膜的稳定性、离子通透性、双层膜中胆固醇对离子通透性的影响等进行了研究,并利用实验制备的双分子层脂膜模拟研究锌离子跨细胞膜的输运过程,建立了锌离子跨细胞膜的吸附-扩散模型,该模型计算值与实验值基本吻合.     

含聚乙烯氧基长侧链共聚物阻磷酸钙垢性能研究

以过硫酸铵为引发剂,含不同乙烯氧基重复单元数n的烯丙基聚乙烯氧基硫酸铵(ASn,n=5,10,15,20)和马来酸酐(MA)为单体在水溶液中聚合,合成对循环冷却水系统中磷酸钙垢有显著阻垢效果的共聚物MSn(n=5,10,15,20),并利用红外光谱(FT-IR)和核磁共振氢谱(1H-NMR)对聚合物MS10结构进行了表征。采用静态阻垢方法探讨了共聚物MSn中n值以及聚合物用量、溶液中Fe2+、Ca2+、杀生剂和溶液pH值、溶液温度对共聚物阻磷酸钙垢性能的影响。结果表明MSn用量存在临界值效应,MS10阻磷酸钙垢性能最好,在投加量为6 mg/L时MS10阻磷酸钙垢率达92%,且在高Fe2+浓度、高Ca2+浓度、高pH值以及高温条件下具有优异的阻磷酸钙垢性能,与异噻唑啉酮杀生剂和含氯含溴杀生剂有很好的配伍性。实验表明MS10是一种性能优异的循环水用阻磷酸钙阻垢剂。     

Two discrete choice experiments on laboratory safety decisions and practices

IntroductionThe path toward enhancing laboratory safety requires a thorough understanding of the factors that influence the safety-related decision making of laboratory personnel. Method: We developed and administered a web-based survey to assess safety-related decision making of laboratory personnel of a government research organization. The survey included two brief discrete choice experiments (DCEs) that allowed for quantitative analysis of specific factors that potentially influence safety-related decisions and practices associated with two different hypothetical laboratory safety scenarios. One scenario related to reporting a laboratory spill, and the other scenario involved changing protective gloves between laboratory rooms. The survey also included several brief self-report measures of attitude, perception, and behavior related to safety practices. Results: Risk perception was the most influential factor in safety-related decision making in both scenarios. Potential negative consequences and effort associated with reporting an incident and the likelihood an incident was detected by others also affected reporting likelihood. Wearing gloves was also affected somewhat by perceived exposure risk, but not by other social or work-related factors included in the scenarios. Conclusions: The study demonstrated the promise of DCEs in quantifying the relative impact of several factors on safety-related choices of laboratory workers in two hypothetical but realistic scenarios. Participants were faced with hypothetical choice scenarios with realistic features instead of traditional scaling techniques that ask about attitudes and perceptions. The methods are suitable for addressing many occupational safety concerns in which workers face tradeoffs in their safety-related decisions and behavior. Practical Application: Safety-related decisions regarding laboratory practices such as incident reporting and use of PPE were influenced primarily by workers’ perceptions of risk of exposure and severity of risks to health and safety. This finding suggests the importance of providing laboratory workers with adequate and effective education and training on the hazards and risks associated with their work. DCEs are a promising research method for better understanding the relative influences of various personal, social, and organizational factors that shape laboratory safety decisions and practices. The information gained from DCEs may lead to more targeted training materials and interventions.     

一维脉冲波透过压电介质摩擦接触界面的传播

以压电材料为核心的结构和元件在装置中,总是和其他材料组合在一起,常用来传导表面波或承受动荷载,界面是其中的重要组成部分。当扰动很强时,会引起接触界面的局部滑移和分离,对结构安全产生威胁。笔者对一维脉冲波透过横观各向同性压电介质摩擦接触界面的传播进行了研究。利用Fourier分析的方法,将混合边值问题化为非线性代数方程组,通过迭代修正,确定了界面上分离、滑移和粘着3种区域的分布范围,同时计算了界面剪力和相对滑移速度的分布。笔者进一步丰富了压电弹性波动理论,利用波所携带的力学或电学信息,可望无损探测界面的接触状态及接触力等参量,对结构的安全评估与寿命预测具有重要的理论价值与实际意义。     

泥浆含砂量对泥水盾构泥浆成膜性能影响的试验研究

为在高渗透砂卵石地层泥水盾构施工中确保开挖面稳定、保证施工安全,泥浆顺利成膜至关重要.依托京张高铁清华园隧道工程,采用自行设计的泥浆渗透试验装置,配制6种不同含砂量的泥浆,在与实际地层渗透系数相似的试验地层中进行渗透试验.对泥浆在渗透过程中的成膜类型、成膜质量、渗透深度、滤失量、闭气性能等相关指标进行分析,得到适用于高...     

湿润剂表面张力对硫化矿尘吸湿效果的影响

采用毛细管反向渗透实验装置,以湿润剂表面张力为衡量指标,通过分析3种硫化矿尘在十二烷基苯磺酸钠（SDBS）、十二烷基磺酸钠(SDS)、十二烷基硫酸钠(K12)3种阴离子表面活性剂中的吸湿效果,比较得出3种表面活性剂湿润性能大小。利用ZISMA图得出表面活性剂在3种硫化矿表面铺展的临界表面张力值,并探究其值对湿润行为和湿润效果的影响。研究表明:3种阴离子活性剂的湿润性能SDBS＞SDS＞K12,湿润剂在3种硫化矿表面铺展的临界表面张力分别为27.3,26.6,26.0 mN/m,且吸湿增重和吸湿速度的峰值是受铺展润湿作用的影响。     

A transportation network assessment tool for hazardous material cargo routing: Weighing exposure health risks,proximity to vulnerable areas,delay costs and trucking expenses

The inherent risks associated with accidental releases of hazardous materials during transport have drawn attention and concerns in the recent decades. The aim of this study is to propose a tool for evaluation and comparison of the transportation networks which can be used to assess the routing options between origins and destinations of the cargos for their suitability for transporting hazardous material cargos by tanker trucks and to identify routes which provide lower accidental release risks, lower public exposure risks, and offer economical benefits. Each route segment of transportation networks were evaluated using specific criteria which included health risk and cost of delay in case of an accidental release of materials, trucking cost and proximity to vulnerable areas. Since, the health impact of hazardous materials differ depending on the characteristics of the material being transported as well as release quantities and atmospheric conditions; this paper aimed in providing a tool that can be used to estimate the impact radius (for health risks) after accidental release of hazardous materials by taking into account different atmospheric conditions based on the meteorological data and solar elevation angle. The Gaussian air dispersion model paired with ArcGIS using Python programming were employed to estimate the health risk impact zones by considering the meteorological data, and accordingly to analyze road segments for cost impacts (delay and trucking costs), and the proximity to vulnerable areas. The route assessment tool was demonstrated with a case study. The results of this study can efficiently aid decision makers for transportation of hazardous materials.     

A non-destructive single plate method for measurement of thermal resistance of polymer sheets and fabrics

Measurement of thermal resistance of polymer sheets and fibrous layers is important in various applications including those within the engineering, ergonomics, clothing design and personal protective equipment fields. Standard methods for measurement of thermal resistance of plain materials are generally time consuming, expensive and often require the sample to be cut. Moreover, the temperature difference between the surfaces of both plates surrounding the sample must be known, as well as the sample thickness. This article describes a new measuring device named the Thermoscope. The Thermoscope is not limited by the aforementioned requirements and is able to evaluate the thermal resistance of polymer sheets and textiles by touching the sample on one surface alone. Simultaneously, the other surface is kept in thermal contact with the supporting base. The accuracy of this device was compared with the Alambeta thermal insulation tester. Effects of various base materials on measurement precision were also studied.