The protective performance of a molten salt frozen wall in the process of fluoride volatility of uranium

The fluoride volatility method (FVM) is a technique tailored to separate uranium from fuel salt of molten salt reactors. A key challenge in R&D of the FVM is corrosion due to the presence of molten salt and corrosive gases at high temperature. In this work, a frozen-wall technique was proposed to produce a physical barrier between construction materials and corrosive reactants. The protective performance of the frozen wall against molten salt was assessed using FLiNaK molten salt with introduced fluorine gas, which was regarded as a simulation of the FVM process. SS304, SS316L, Inconel 600 and graphite were chosen as the test samples. The extent of corrosion was characterized by an analysis of weight loss and scanning electron microscope studies. All four test samples suffered severe corrosion in the molten salt phase with the corrosion resistance as: Inconel 600>SS316L>graphite>SS304. The presence of the frozen wall could protect materials against corrosion by molten salt and corrosive gases, and compared with materials exposed to molten salt, the corrosion rates of materials protected by the frozen wall were decreased by at least one order of magnitude.

Effect of Phase Change Materials on the Thermal Protective Performance of the Multi-layered Fabrics Examined by TPP Tester under Flash Fire

Cotton fabrics treated with phase change materials( PCMs)were used in multi-layered fabrics of the fire fighter protective clothing to study its effect on thermal protection. The thermal protective performance( TPP) of the multi-layered fabrics was measured by a TPP tester under flash fire. Results showed that the utilization of the PCM fabrics improved the thermal protective performance of the multi-layered fabrics. The fabric with a PCM add on of 41. 9% increased the thermal protection by 50. 6% and reduced the time to reach a second degree burn by 8. 4 s compared with the reference fabrics( without PCMs). The employment of the PCM fabrics also reduced the blackened areas on the inner layers. The PCM fabrics with higher PCM melting temperature could bring higher thermal protective performance.

Effect of Air Gap under Fabric on Thermal Protective Performance Using an Improved Apparatus

The bench top test is one of the most important and effective methods to evaluate the total thermal protective performance(TPP) of firefighters' protective clothing,which is greatly influenced by the air gaps entrapped.In this paper,to investigate the effect of air gap width on TPP,a new improved apparatus with two height changeable buttons to hold the thermal sensor was developed to get a series of air gap sizes from 0 mm to 40 mm.The TPP of two types of flame-resistant outer fabrics was measured with TPP test apparatus respectively.Analysis of temperature rise with each air gap width was made to determine the effects of different air gaps on protective performance.It was indicated that air gap size had great effect on TPP of fabrics in the bench top test.An air gap width above 8 mm was suggested for the thermal protective clothing design.

Modeling Thermal Protective Performance of Multilayer Fabrics for Firefighters

This paper is to report a prediction model for thermal protective performance of multilayer fabrics based on Matlab neural network toolbox. Then a back propagation (BP) neural network model is developed to predict thermal protective performance of multilayer fabrics for firefighters. The network consists of twelve input nodes, six hidden nodes, and one output node. The inputs are weight, thickness, density of warp and weft, limited oxygen index (LOI), and heat conductivity of each-layer fabric. Thermal protective performance (TPP) rating of multilayer fabrics is the output. In this paper, the data from the experiments are used as learning information for the neural network to develop a reliable prediction model. Finnally the model performance is verified, and the proposed model can be applied to predict the thermal protective performance of multilayer fabrics for firefighters.

Productive performance and blood metabolites as affected by protected protein in sheep

This investigation included two experiments. Experiment 1 was executed to study the effect of feeding different rations of protected protein of canola meal on digestibility and nutritive values within sheep. Twenty male, healthy sheep were divided into five treatments according to the methods of protein protection (control, heat, sodium hydroxide, formaldehyde, and acetic acid treatments). Experiment 2 was carried out on developing lambs to investigate the effect of protected protein on growth performance and some blood metabolites. Animals in this ex-periment were also divided into the same treatments as Experiment 1. Animals in the first and second experiment were fed concentrate ration (80%) and wheat straw (20%) to cover the feed requirements. Nutritive values expressed as total digestible nutrients (TDN %) and digestible crude protein (DCP%) of the experimental rations was calculated. In the second experimental all animals were weighed biweekly and the amounts of rations were adjusted throughout the experimental period (120 days) according to their body weight change. Results indicated that in the first experimental protected protein by heat (HE) and sodium hydroxide (NH) had positive (P<0.05) effects on most of digestibility coefficients of different nutrients. Protein protection methods also improved (P<0.05) the nutritive values (TDN and DCP) in the HE treatment and NH treatment. In the second experiment body weight increased by 14% and 7% and also daily gain by 27% and14 % in HE and NH, respectively, while FM and AC decreased body weight by 8% and 4.4%. Higher values (P<0.01) in both thyroid hormones were observed in HE and NH than those other treatments. Also, higher values (P<0.01) of total protein, albumin, and glucose were observed in HE and NH than other treatments. The control (CTL) group recorded higher concentrations of urea-N and creatinine at different periods of the experiment in comparison with other treatments. Generally, from the present investigation it can be concluded that protected protein of canola meal by heat or sodium hydroxide treatments were more efficient for productive performance and some blood metabolites of sheep.

Research on Evaluating Index of Lightning Protection Safety Performance of High Voltage Overhead Transmission Line

In order to improve the lightning protection performance of transmission lines, lightning protection management has been divided into every tower that lightning protection performance has been evaluated respectively. According to factors such as landform, span, tower type, grounding resistance, isolator type, and so on, relative ratio of tripping operation of every tower in the line has been calculated to evaluate its lightning protection safety performance, it is beneficial to operation maintenance and lightning reconstruction of transmission lines.

Composite armor philosophy(CAP):Holistic design methodology of multi-layered composite protection systems for armored vehicles

A philosophy for the design of novel,lightweight,multi-layered armor,referred to as Composite Armor Philosophy(CAP),which can adapt to the passive protection of light-,medium-,and heavy-armored vehicles,is presented in this study.CAP can serve as a guiding principle to assist designers in comprehending the distinct roles fulfilled by each component.The CAP proposal comprises four functional layers,organized in a suggested hierarchy of materials.Particularly notable is the inclusion of a ceramic-composite principle,representing an advanced and innovative solution in the field of armor design.This paper showcases real-world defense industry applications,offering case studies that demonstrate the effectiveness of this advanced approach.CAP represents a significant milestone in the history of passive protection,marking an evolutionary leap in the field.This philosophical approach provides designers with a powerful toolset with which to enhance the protection capabilities of military vehicles,making them more resilient and better equipped to meet the challenges of modern warfare.

Experimental Study on Engineering Behavior of Solidified Soil for Scour Repair and Protection

A new scour countermeasure using solidified slurry for offshore foundation has been proposed recently.Fluidized solidified slurry is pumped to seabed area around foundation for scour protection or pumped into the developed scour holes for scour repair as the fluidized material solidifies gradually.In the pumping operation and solidification,the engineering behaviors of solidified slurry require to be considered synthetically for the reliable application in scour repair and protection of ocean engineering such as the pumpability related flow value,flow diffusion behavior related rheological property,anti-scour performance related retention rate in solidification and bearing capacity related strength property after solidification.In this study,a series of laboratory tests are conducted to investigate the effects of mix proportion(initial water content and binder content)on the flow value,rheological properties,density,retention rate of solidified slurry and unconfined compressive strength(UCS).The results reveal that the flow value increases with the water content and decreases with the binder amount.All the solidified slurry exhibits Bingham plastic behavior when the shear rate is larger than 5 s^(-1).The Bingham model has been employed to fit the rheology test results,and empirical formulas for obtaining the density,yield stress and viscosity are established,providing scientific support for the numerical assessment of flow and diffusion of solidified slurry.Retention rate of solidified slurry decreases with the water flow velocity and flow value,which means the pumpability of solidified slurry is contrary to anti-scour performance.The unconfined compressive strength after solidification reduces as the water content increases and binder content decreases.A design and application procedure of solidified soil for scour repair and protection is also proposed for engineering reference.

A procedural study of building up a performance evaluation indicator system of intellectual property protection

The intellectual property protection, whether judicial or administrative, is evaluated through a performance evaluation indicator system. To building up such a system, we must follow certain working procedures which usually consist of four steps： to determine the performance objectives, to design the structure of indicator system, to specify the indicators and to set up the weight of indicators. Each step plays a different role in performance evaluation indicator system and has its own impact on the realization of performance evaluation objectives respectively. So the scientifically building up a performance evaluation indicator system is the key to determine whether the intellectual property is protected well or not.

Numerical Simulations of the Performance of Steel Guardrails Under Vehicle Impact

Road side barriers are constructed to protect passengers and contain vehicles when a vehicle crashes into a barrier. In general, full-scale crash testing needs to be carried out if a geometrically and structurally equivalent barrier has not previously been proven to meet the requirements of containing the vehicle and dissipating sufficient impact energy for passenger protection. As full-scale crash testing is very expensive, the number of data that can be measured in a test is usually limited, and it may not always be possible to obtain good quality measurements in such a test, a reliable and efficient numerical simulation of crash testing is therefore very useful. This paper presents finite element simulations of a 3-rail steel road traffic barrier under vehicle impact. The performance levels defined in Australian Standards AS5100 Clause 10.5 for these barriers are checked. The numerical simulations show that the barrier is able to meet low performance levels. However, the maximum deceleration is higher than the acceptable limit for passenger protection. If present, a kerb launches the vehicles into the barrier, allowing for the possibility of overriding the barrier under certain circumstances, but it redirects the vehicle and reduces the incident angle, which reduces impact force on the barrier. Further investigation into all common kerb profiles on roads should be carried out, as only one kerb profile is investigated in this study.

浅析IEC/EN 61643-11 Low Voltage Surge Protective Devices(低压浪涌保护器)标准及认证测试过程中常见问题

本文解读了IEC 61643-11:2011及EN 61643-11:2012,Low Voltage Surge Protective Devices低压浪涌保护器测试标准,分析了TYPE 1 SPD,TYPE 2 SPD,TYPE 3 SPD产品在认证测试过程中的常见问题。

The Effect of Evidence-based Management on Occupational Protection of Nurses Who Perform Chemotherapy

Objective:The study was to explore the effect of evidence-based management in occupational protection for nurses who perform chemotherapy.Methods:40 chemotherapy nurses were selected,20 of them were included in the experimental group for evidence-based management,and the other 20 were included in the control group for routine management.Results:Compared with the control group,there were significantly fewer adverse nursing events in the experimental group,and P<0.05.Conclusion:The effect of evidence-based management in occupational protection of nurses who perform chemotherapy is significant.

页岩储层防水锁聚合物水基钻井液体系研究

开发一种适用于页岩储层的水基钻井液体系,以优化钻井过程中的页岩稳定性和防水锁效果。通过页岩滚动回收率、线性膨胀率测试以评价不同处理剂的效果。结果表明:0.5%WEDM+1.5%SFTH复配体系可显著提高页岩的回收率,同时最大线性膨胀率由37.6%降至16.80%。封堵剂CMS在控制滤失量方面表现出色,包被剂KPAM在提高钻井液稳定性和降低滤失量方面具有显著效果。防水锁水基钻井液配方为:4%基浆+1.0%WEDM+1.5%SFTH+1.5%CMS+0.3%KPAM+2.0%op-10。该体系在高温高压条件下展现出了优异的流变特性和滤失控制能力,特别是在抗温性和抗污染性方面表现卓越。该体系在150℃高温下保持了良好的稳定性,且对NaCl和CaCl_(2)的抗污染能力强。在储层保护方面,该体系能有效减少钻井液对储层的伤害,实现高达85.69%的渗透率恢复率,同时形成的泥饼质量良好。研究成果对于页岩气开采具有重要意义。

环境规制影响企业税收规避吗?--基于新《环保法》实施的准自然实验

作为重要的命令控制型环境规制工具,新《环保法》实施对企业经营产生了广泛的影响。以2010-2020年我国A股上市公司为样本,利用新《环保法》这一外生冲击事件,采用双重差分模型检验环境规制对企业税收规避的影响。结果表明,环境规制趋严促使企业提高税收规避程度。机制检验表明,环境规制导致企业融资约束程度和经营风险增加。进一步分析发现,环境规制与税收规避的正相关关系主要存在于融资难度较高和经营压力较大的企业,新《环保法》实施情境下的企业避税行为提升了财务业绩和企业价值。研究结论提供了微观企业如何应对宏观环境规制的经验证据,为政府部门结合税收政策优化环境政策提供了参考。

环境保护费改税对企业ESG表现的持续作用研究

选取2015-2021年沪深两市A股重污染行业上市公司为处理组,非重污染行业上市公司为对照组,采用双重差分法研究环境保护费改税对企业ESG表现的影响。研究发现,环境保护费改税显著且持续提升企业ESG表现。异质性分析结果表明环境保护费改税政策效应显著存在于资产规模较大企业分组,不受省际税额标准差异影响。进一步分析发现,环境保护费改税通过加大技术创新进而提升企业ESG表现。

新型两性离子粘土稳定剂的制备及其性能研究

以丙烯酰胺(AM)、二甲基二烯丙基氯化铵(DMDAAC)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和N-乙烯基吡咯烷酮(NVP)为反应单体,以过硫酸胺、亚硫酸氢钠为引发剂,制备了一种新型的两性离子粘土稳定剂,并采用红外光谱对其结构进行了表征。结果表明,在40℃下,当引发剂加量为0.55%,AM∶AMPS∶DMDAAC∶NVP物质的量比为160∶20∶13∶2,反应时间为3 h时,所制备的四元共聚物AM/AMPS/DMDAAC/NVP防膨率可达90.74%,具有良好的耐温耐盐性及耐酸碱性能,可以有效防止粘土水化膨胀、分散运移,有利于降低采油成本,在油气田领域具有良好的应用潜力。

水分对消防灭火防护服织物系统辐射热防护性能的影响

现阶段消防灭火服热防护性能评估中,对水分影响的考虑不足。为研究水分在不同织物层中对其热防护性能的影响差异,在低热辐射暴露下,分别在外层、舒适层、外层与舒适层设置不同含水量水平,分别针对直接热暴露、包含热暴露与蓄热释放全程两种情形进行试验测评。研究发现,无论是直接热暴露还是综合考虑蓄热释放的作用,增加外层织物水分含量有利于提升多层织物整体热防护能力,且随着水分含量的增大而上升;舒适层织物润湿则会削弱多层织物整体热防护能力,提高舒适层的吸湿排汗能力,保持其干燥是保持灭火防护服热防护性能的手段之一。外层与舒适层同时润湿时,二者之间呈现交互影响,未来可进一步深入研究。

高温环境下烧蚀热防护结构隔热性能测试方法

目的建立高精度的烧蚀热防护结构隔热性能测试方法。方法分析烧蚀热防护结构地面热试验特点,设计烧蚀热防护结构隔热性能试验方案,提出考虑地面热损失的高精度热载荷模拟方法。采用自研模块化石英灯加热器作为加热装置,设计可重复使用夹具封装试验件和热流计,建立烧蚀热防护结构隔热性能测试装置。结果成功完成了典型烧蚀热防护结构隔热性能考核试验,获得了结构在瞬态和稳态热流条件下的背温数据,试验装置运行稳定可靠,可有效消除热边界效应,保证热流长时测控。试验结果验证了试验边界条件模拟的可重复性、热场均匀性以及良好的控制精度。结论有效解决了烧蚀热防护结构受热后产生明火、浓烟而导致的高温环境模拟难题,为烧蚀热防护结构材料筛选及结构定尺寸设计提供了高精度测试方法。

军用防护服发展现状与趋势

军用防护服在军事作战和应急救援中发挥着重要作用,因而对其特殊环境下的防护性能提出了更高的要求。从防护服的色彩、面料、结构3个方面介绍军用防护服的主要功能,其中,面料是军用防护服的核心组成部分,直接关系到防护能力和作战效能,高性能纤维材料在军用防护服中已得到广泛应用。结合研究现状,提出未来军用防护服的发展趋势,将聚焦于高性能纤维材料、智能可穿戴材料和环保材料的综合应用,进而为军用防护服设计的系统研究提供一定的参考。