防尘口罩结构/材料及其加工技术探讨

介绍了防尘口罩的结构及选用时应注意的一些问题,分析了作为防尘口罩核心组件的滤料的过滤机制。论述了一些非织造布材料和非织造布加工方式对于防尘口罩滤料生产的优点和不足之处。对于广泛应用于口罩滤料的聚丙烯材料及滤料的主要加工方式——熔喷法非织造布生产技术,进行了重点介绍。同时也简要介绍了为完善口罩的综合性能而采用的非织造布复合技术。最后研究分析了提高口罩过滤效率的一种非常重要的方法——非织造布驻极加工方法,并对目前防尘口罩应用中存在的问题进行了简要的分析。     

如何正确选择口罩的类型

在上一期中,我们给您介绍了一个好的防护口罩所应具备的基本条件,但是面对各式各样的口罩,您也许还不知道,到底哪种最适合您的工作环境需要。本期我们就给您介绍一下口罩的分类,以及如何正确选择适当类型的口罩。口罩的分类方法有多种,通常我们按其结构与工作原理,...     

呼吸器官防护用品系列——防尘口罩的选购

第1、2期我们分别向读者介绍了供气式呼吸器和过滤式呼吸器的相关知识,本期我们为大家介绍工业用防尘口罩的功能、分类、应用和选择方法,同时探讨一些常见的关于防尘口罩的误区,防尘口罩有哪些优势等。     

如何正确选用口罩的滤料

上一期,我们介绍了如何正确选择口罩的类型。有了面具的主体,就必须要有适当的滤材与之配合使用,才能构成一个完整的防护口罩。本期中,我们会给您介绍有关口罩滤料的知识,帮您选择适当的滤料。所谓防护口罩的滤料,主要分两类,即防尘类及防毒类。它们的作用都是将有...     

为什么必须坚持佩戴口罩──个体防护用品知识讲座(四)

前两期，我们向您介绍了如何选择口罩的本体以及滤材，那么是不是正确地做到了这两点就能使您免受污染物的影响，真正有效地发挥口罩的功效呢？其实不然。下面，我们给您介绍影响口罩功效的几个因素，并让您了解在污染环境中要坚持配戴口罩的重要性。一般来说，能真正地使...     

简易防尘口罩鉴定会

湖南省卫生局、劳动局于1979年12月,在长沙召开防尘口罩鉴定会。省劳动卫生研究所防尘口罩课题组介绍了以维棉棉毛布、腈纶绒布、针刺绒布、尼纶毡、无纺布等新型防尘滤料分别制作的湘劳79-Ⅱ型、湘劳79-Ⅲ型简易防尘口罩。使用单位作了试用情况汇报。认为这种口罩可逐步代替落后的纱布口罩和湘劳-Ⅱ型氯纶棉布口罩(不耐热水洗,阻尘率低)。会议通过了“湘劳79-Ⅱ型维棉防尘口罩鉴定书”和“湘劳79-Ⅲ型腈轮防尘口罩样品鉴定书”。建议湖南、广东等生产单位小批量生产79-Ⅱ型口罩,推广使用;少量试产79-Ⅲ型口罩,扩大使用。简易防尘口罩鉴定会…     

活性碳纤维防护口罩

本文简述了活性碳纤维（简称ACF）防护口罩的结构、性能及适用范围，重点介绍了该产品的滤芯——新陈代谢型高效功能村料ACF，并对ACF与颗粒状活性炭进行对比，阐明了ACF的独特性能。同时，通过对ACF防护口罩与传统普通纱布口罩的性能对比，展望了ACF防护口罩的应用前景。     

过滤式防尘口罩的性能简介

过滤式防尘口罩有简易式与复式两种,目前简易防尘口罩在国内外已广泛应用,这里从防尘效率,舒适性方面与复式防尘口罩相比,介绍其性能及特点。 1.阻尘效率过滤式防尘口罩(简称口罩)的阻尘效率取决于两个因素:滤料本身的效率和口罩与戴口罩者面部的配合情况。滤料的效率(E) E∝D/d_f式中 D-填充料的稠密度; d_f-纤维直径。通过一种纤维织物的阻力或压降(△P)与织物的填充稠密度有关,亦与纤维直径(d_f)有关: △P∝D/d_(f~2)     

柴油机车司机用送风口罩的研制

本文介绍一种适于柴油机车司机用的送风口罩.该口罩固定在柴油机车上,由口罩、软管、电机、风机、滤毒罐、固定支架等组成.其系统阻力为746Pa,送风量为60L/min.能过滤柴油机排气中的黑烟、氮氧化物、醛类等有害物质.     

隐形口罩

笔者在参加中国职业安全健康协会个体防护专业委员会2013年年会时．听到一家企业介绍一种名为“隐形口罩“的新型防护设备．觉得非常有趣。据该生产企业代表介绍．隐形口罩是作用于鼻孔内的自吸式防颗粒物呼吸器装置。     

Anthropometry for Design for the Elderly

This paper presents anthropometric data on elderly people in Australia. Data were collected in the metropolitan city of Sydney, NSW, Australia. In all 171 elderly people (males and females, aged 65 years and above) took part in the study. Mean values, standard deviations, medians, range, and coefficients of variation for the various body dimensions were estimated. Correlation coefficients were also calculated to determine the relationship between different body dimensions for the elderly population. The mean stature of elderly Australian males and females were compared with populations from other countries. The paper discusses design implications for elderly people and provides several examples of application of the anthropometric data.     

Methodology for selecting hole sizes for consequence studies

Predicting release rates is the first step, and a crucial step, in consequence analysis. When the release is from an isolated volume of vessel and/or piping, the release rate decreases with time. There is often debate about what equivalent hole sizes should be used for a consequence study, and usually a range of hole sizes (3–4 values) is examined.This paper shows the effect of hole size on the ultimate impact of hydrocarbon releases for several scenarios and the methodology to select them. The impact depends on the intensity and exposure time. The intensity for a fire is the thermal radiation level, and that for an unignited release is the gas concentration. As the release rate decreases with time, so does the intensity. Probit functions describe the probability of a given impact based on the time-varying intensity. For a number of example scenarios, the predictions show that the worst-case hole size is an intermediate hole size, i.e., the impact goes through a maximum with increasing hole size. For smaller holes, the event is small enough that its impact is low even though the duration is long. For larger holes, the initial event is large but decreases so rapidly that the impact is low. For the intermediate hole, the event is large enough, and the duration long enough, to cause the greatest impact.This consequence study was made evaluating hole sizes with diameters between 5 and 400 mm in a fixed volume upstream process vessel. Worst case scenario consequence predictions for fire damages, effects on people and toxic releases were determined to be somewhat different for different hole sizes. However, hole sizes in the 30 mm–90 mm range seems to have the highest impact in dry gas service.     

大气扩散计算流体力学模型综合评估方法研究

模型评估方法研究是模型研发工作的重要组成部分。基于科学性验证与统计性确认提出了大气扩散CFD模型的综合确认评估方法,通过示例的方式展示了方法的使用效果。综合确认评估方法可以提高模型筛选的速度,降低统计性评估对确认性试验数据的需求量,从总体上提高模型确认的效率。评估理论的研究有助于提高基于模型的大气扩散研究的准确性,也有利于高精度模型和试验的设计、开发与遴选。     

Test Method for Retractable Type Fall Arresters Designed for Horizontal Use

Retractable type fall arresters are designed to protect against falls from a height of people who need freedom of vertical movement. The practice of fall protection shows that the devices are also used to protect people who work on flat roofs. This application creates quite different operating conditions for the devices. In some situations those conditions can be dangerous for users. The article presents a theoretical analysis of phenomena occurring during a fall arrest with retractable type fall arresters arranged horizontally. The analysis was verified with laboratory tests. The article presents a proposal for the construction of a test stand and a test method for estimating retractable type fall arresters intended for horizontal use.     

FA型高炉煤气管道火焰捕器研制

研制满足高炉煤气管道阻火的火焰捕器.内径88 mm、199 mm和305 mm组合爆炸管道模拟实验结果表明,FA型火焰捕器的阻火性能良好,满足高炉煤气管道阻火的技术要求,各项技术性能指标达到了设计要求.     

Limiting oxygen concentration for coal dusts for explosion hazard analysis and safety

Investigation of explosion characteristics of coal dust was undertaken as a part of regular research program at CSIR-CBRI, Roorkee, India, for designing explosion safety measures for coal dust handling installations. This paper presents results of detailed experimental work on determination of Limiting Oxygen Concentration (LOC) and influence of reduced oxygen levels on explosion severity data for two types of coals with varying volatile matter as 27.18% (coal A) and 19.69% (coal B) from Jharia coalfield of India determined at ambient conditions with 20-L Spherical Vessel established at CSIR-CBRI. The effects of coal particle size and moisture content were evaluated. Data presented will be used for hazard analysis, designing explosion preventive measures, and explosion severity reduction by involving the use of inert gases for installations handling pulverized coal with similar nature. The importance of ignition source energy in determining LOC data is highlighted. The data collected lead to an extension of the current data for coal dusts as found in the literature. Limiting oxygen concentrations were found as 7% for coal A and 8% for coal B for the size representative to that used in pulverized coal boilers and moisture content ～4%.     

Announcing the CDC guideline for prescribing opioids for chronic pain

This guideline provides recommendations for primary care providers who are prescribing opioids for chronic pain outside of active cancer treatment, palliative care, and end-of-life care. The guideline addresses: (a) when to initiate or continue opioids for chronic pain; (b) opioid selection, dosage, duration, follow-up, and discontinuation; and (c) assessing risk and addressing harms of opioid use. This guideline is intended to improve communication between providers and patients about the risks and benefits of opioid therapy for chronic pain, improve the safety and effectiveness of pain treatment, and reduce the risks associated with long-term opioid therapy, including abuse, dependence, overdose, and death (Dowell D, Haegerich TM, Chou R. CDC Guideline for Prescribing Opioids for Chronic Pain — United States, 2016. MMWR Recomm Rep 2016;65:1–49. DOI: http://dx.doi.org/10.15585/mmwr.rr6501e1.)     

Personal need for structure as a boundary condition for humor in leadership

Recent research has established a positive relationship between humor in leadership and organizational behavior variables. However, neither the mechanisms nor the boundary conditions of the positive effects of humor in leadership are completely understood. In this study, we contribute to these questions by investigating the relationship between humor in leadership and follower commitment and burnout in more detail. We propose that these relationships unfold via a relational process and specified this relational process in terms of leader–member exchange. Moreover, we assume that these relationships depend on followers' personal need for structure. We tested the hypothesized moderated‐mediation model in a two‐wave survey study with 142 employees. Our results support the proposed model. We found the predicted indirect effect of humor on commitment and disengagement to be stronger for followers low in need for structure. However, we did not find the proposed effects for emotional exhaustion. We discuss implications for leadership theory, humor theory, and for leadership training and practice. Copyright © 2016 John Wiley & Sons, Ltd.     

A methodology for assessing underground coal mines for high safety-related risk

In 2008 the authors developed a methodology for assessing underground coal mines for high risk for major-hazard events. It focused on major hazard-related violations of safety standards associated with high-risk conditions. Later using the same stratified pilot sample of 31 mines, injury measures and MSHA citation data were combined into a Safe Performance Index (SPI). Using 2009 data, the database was expanded to 107 mines, which is a 30% sampling of all underground coal mines. The SPI was used to assess the relative safety-related risk of mines, including by mine-size category. The methodology can be used to assist companies, the Mine Safety and Health Administration, or state agencies in targeting mines with high risk for serious injuries and elevated citations for remediation of their violation and/or injury experience.     

A framework for definition of logical scenarios for safety assurance of automated driving

Abstract

Objective: In order to introduce automated vehicles on public roads, it is necessary to ensure that these vehicles are safe to operate in traffic. One challenge is to prove that all physically possible variations of situations can be handled safely within the operational design domain of the vehicle. A promising approach to handling the set of possible situations is to identify a manageable number of logical scenarios, which provide an abstraction for object properties and behavior within the situations. These can then be transferred into concrete scenarios defining all parameters necessary to reproduce the situation in different test environments.

Methods: This article proposes a framework for defining safety-relevant scenarios based on the potential collision between the subject vehicle and a challenging object, which forces the subject vehicle to depart from its planned course of action to avoid a collision. This allows defining only safety-relevant scenarios, which can directly be related to accident classification. The first criterion for defining a scenario is the area of the subject vehicle with which the object would collide. As a second criterion, 8 different positions around the subject vehicle are considered. To account for other relevant objects in the scenario, factors that influence the challenge for the subject vehicle can be added to the scenario. These are grouped as action constraints, dynamic occlusions, and causal chains.

Results: By applying the proposed systematics, a catalog of base scenarios for a vehicle traveling on controlled-access highways has been generated, which can directly be linked to parameters in accident classification. The catalog serves as a basis for scenario classification within the PEGASUS project.

Conclusions: Defining a limited number of safety-relevant scenarios helps to realize a systematic safety assurance process for automated vehicles. Scenarios are defined based on the point of the potential collision of a challenging object with the subject vehicle and its initial position. This approach allows defining scenarios for different environments and different driving states of the subject vehicle using the same mechanisms. A next step is the generation of logical scenarios for other driving states of the subject vehicle and for other traffic environments.