The influence of moisture on the permeability of crushed shale samples

Shale cuttings and cores recovered from the subsurface and stored for hours to decades tend to dry out and lose moisture and hydrocarbons,leading to an increase in the effective matrix permeability.Moisture loss in shale samples is a fundamental sample preservation problem which can be solved by applying a standard moisture equilibration procedure to restore lost moisture.Our aim was to investigate the relationship between permeability and variable moisture as-received,as-received moisture-equilibrated and saturated moisture-equilibrated samples.Samples were crushed to a series of particle sizes(0.6-2.0)mm and moisture equilibrated at 97% relative humidity.Results show that moisture equilibration in the samples was achieved after 72 h.The permeability of the saturated moisture-equilibrated and as-received moisture-equilibrated samples decreased exponentially with increase in moisture content.The high correlation coefficient between permeability and particle size(r = 0.96 and 0.97)for moisture-equilibrated samples compared to 0.76 for as-received samples indicates that moisture equilibration improves permeability measurements in crushed shale samples.Furthermore,permeability measurements are repeatable for moisture-equilibrated samples compared to samples that were not equilibrated(as-received).We conclude that moisture content affects permeability and moisture equilibration normalizes and improves the repeatability of permeability measurements in crushed shale.

How moisture loss affects coal porosity and permeability during gas recovery in wet reservoirs?

Moisture in coal seams changes gas adsorption capacity, induces coal deformation, and affects coal porosity. However, fewer studies have investigated the dynamic process of moisture loss. In this study, a fully coupled multi-physical model for coal deformation, gas flow and moisture loss was implemented. It validated the coal-gas-moisture interactions of the decay of gas adsorption capacity and the coal shrinkage.Subsequently, the proposed model was applied to a simulation of coal seam gas recovery from wet reservoir and solved using the finite method in COMSOL Multiphysics 3.5. Analyses of the component factors and the sensitive parameters of moisture loss on coal porosity and permeability were comprehensively studied at last. The results reveal that moisture loss enhances coal porosity and permeability. The decay of gas adsorption capacity decreases coal permeability while the coal shrinkage promotes it. The decrease of the adsorption decay coefficient and the increase of the initial density of saturated water vapor and water evaporation constant can enhance the permeability of wet coal seams.

Assessment of Moisture Permeability and Closure Systems of High Density Polyethylene Plastic Bottles Used as Primary Packaging Containers for Moisture Sensitive Medicines

Introduction: Moisture permeability and a loose closure system might allow a significant gain of moisture into container and this could lead to significant loss of potency of drug sensitive to moisture and as well promoting the growth of microorganisms. Typical examples of the drugs sensitive to moisture include Tenofovir Disoproxil Fumarate (TDF). Product claimed to be a “Tight container” does not make it a tight container until proved practically. A plastic container is tight if “not more than one of the 10 tested containers exceeds 100 mg per day per L in moisture permeability. Objectives: The goal of this study was to determine rate of moisture permeability of selected High Density Polyethylene plastic bottles for packaging of moisture sensitive medicines in particular Lamivudine/Tenofovir Disoproxil fumarate tablets. Methodology: The determination of rate of moisture permeability was achieved by assessing closure systems of plastics as per USP 37 method, while the difference in absorption pattern was achieved by assessing the spectrum obtained through transmittance by Fourier Transform-Infrared (FT-IR). The plastic bottles were randomly selected from supplier A, B and C. Results: The plastic bottles from supplier A and B had an average moisture permeability of 12.57 and 51.55 mg/day/L with none of the containers exceeding moisture permeability of 100 mg/day/L whereas containers from supplier C had an average of 149.95 mg/day/L with seven of the containers exceeding of 100 mg/day/L. Conclusion: Containers from supplier A and B met the USP specifications hence could be used as primary packaging for moisture sensitive medicines whereas the containers from supplier C did not meet the USP specifications for them to be regarded as “Tight Containers” and hence, unsuitable for packaging of moisture sensitive medicines.

A Darcy-Law Based Model for Heat and Moisture Transfer in a Hill Cave

A hill can be regarded as an environmental carrier of heat.Water,rocks and the internal moisture naturally pre-sent in such environment constitute a natural heat accumulator.In the present study,the heat and moisture trans-fer characteristics in a representative hill cave have been simulated via a method relying on the Darcy’s law.The simulations have been conducted for both steady and unsteady conditions to discern the influence of permeability and geometric parameters on the thermal and moisture transfer processes.The reliability of the simulation has been verified through comparison of the numerical results with the annual observation data.As revealed by the numericalfindings,the internal temperature of the hill accumulator is proportional to the permeability,outside surface temperature,overground height,underground constant temperature layer depth,and underground tem-perature of the hill,and it is inversely proportional to the horizontal size of the hill.Moreover,in the considered case,the order of magnitude of the permeability of the hill is contained in the range 10-15–10-13,and displays a certain sensitivity to the rainwater seepage.

A STUDY OF TRANSMISSION OF MOISTURE THROUGH FABRICS

Based on the Dynamic Dress Model which can simulate the body core temperature and skintemperature,as well as body sweating,this paper holds a further inquiry into the new method formeasuring heat resistance of fabrics and moisture transmission in terms of“clo”unit andpermeability index“im”.It is found out that the values of Tex of warp and weft have the greatestinfluence on permeability index im and when the thread count increases to a certain limit,thepermeability index“im”is in direct proportion to thread count.

Study on the Factors to Influence Dynamic Heat - moisture Comfort of Summer Clothing Fabrics

In this paper, the factors to influence the dynamic heat - moisture comfort of summer clothing fabrics have been studied. It is pointed out that, when the wind speed outside is high, or the air permeability is very good, the sweat of human body will evaporate mainly through turbulent diffusion. Because of the rapid sweat evaporation, human body will feel cold, and then, the difference in temperature and humidity of the micro - climatic section will be very slight. On the contrary, when the wind speed outside is slow or the air permeability is unsatisfactory, the sweat of human body will evaporate mainly through molecular diffusion, and in this case, the humidity of the micro - climatic section will be depended on the hygroscopicity of the fabric, that’ s to say, the better the hygroscopicity, the lower the humidity. It is difficult for pure wool fabric to loss heat because of its giving out much heat during the course of moisture - absorption in the initial stages of sweating. For pure polyester fabric,

Analysis of the Porosity Changing after Moisture Absorption in Functional Knitted Fabrics

The paper analyses the effect of stitch geometrical modality changing after moisture absorption on the porosity of knitted fabrics,and educes the formulas between porosity and stitch parameters.Regarding as the cell stitch,the increasing of yarn diameter brings the porosity decreasing and the fabric shrinking in the wale direction.While the diameter keeps invariability,the yarn elongating brings the fabric humping up as well as the increasing porosity.The air-permeability experiments have been conducted to validate the theoretical analysis,and there is reasonable agreement between the theories and experiments.

溴-锑阻燃剂对聚氨酯薄膜性能的影响

为提升聚氨酯(PU)薄膜材料的阻燃性能,通过采用复配三氧化二锑(Sb2O_(3))和十溴二苯乙烷(DBDPE)组成的协效阻燃体系,制备出不同含量溴-锑复配的PU阻燃透湿薄膜,采用热重分析(TG)、垂直燃烧测试(UL94)分析PU阻燃透湿薄膜的阻燃性,通过接触角、透湿率(WVT)研究其疏水性和透湿性,并通过扫描电子显微镜(SEM)观察其微观结构,研究不同含量溴-锑复配阻燃剂对PU阻燃透湿薄膜的透湿性、疏水性,阻燃性及热稳定性的影响。结果表明,溴-锑复配阻燃剂能有效提升PU阻燃透湿薄膜的阻燃性能;当复配阻燃剂含量为28%时,PU阻燃透湿薄膜接触角由112.99°增大到123.69°,提升了9.5%,疏水性增强;PU复合材料的初始热分解温度(Tonset)从235℃提升至271℃,残炭率(600℃)达到22.48%,提高了4.21个百分点,UL94垂直燃烧等级为V-0级;SEM形貌分析中,溴-锑复配阻燃剂含量的增加,其排列从疏松至紧密,阻燃空白区域减少,有利于提升PU阻燃透湿薄膜的阻燃性能。

高密度聚乙烯超细纤维篷布的闪蒸-水刺法制备及其防水透湿性

为获得适用于户外高价值目标遮盖的高强轻薄超细纤维材料,利用闪蒸-水刺工艺制备了高密度聚乙烯(HDPE)超细纤维材料,并对其形貌结构、防护特性和力学性能进行测试。结果表明:所制备样品表现出致密的超细纤维非织造结构,即1~6μm的纤维相互纠缠成孔隙率为82.7%~85.9%、模态孔径为6~8μm的柔性多孔材料;纵向拉伸断裂强力和顶破强力随水针能量的增大分别提高到217.8 N和301.3 N,且柔软得分高于80;耐静水压随着样品单位面积质量增大到110 g/m^(2)而提高到6695.7 Pa,且透气率和水蒸气透过率分别为48.3 mm/s和2321.2 g/(m^(2)·24 h)。所制备样品兼具有高强、柔软和防水透气性,可作为篷布用于户外运动、物资存储和军用物资等安全防护。

乳胶枕物理性能影响因素的研究

乳胶枕头因具有舒适性的特点与有益于身体健康的作用而备受消费者青睐。乳胶枕头的物理性能是衡量其质量品质的重要指标之一。设计实验探讨影响乳胶枕头物理性能的关键因素。结果显示:苯乙烯和4苯基环己烯在多个样品中被检出,但含量相对较低;乳胶枕样品在N亚硝基胺测试中均未检出;pH值均在6.7~7.3之间,呈中性或弱酸性范围,8个乳胶枕样本中的铬含量未检出,3#、4#、7#、10#、12#、14#样本检测到了铬的存在,未超过安全阈值;铅的含量均较低,最高为35.6 mg/kg(14#),均在安全范围之内。为乳胶枕头的生产与质量控制提供了有价值的参考信息。

双真空过滤机在尾矿脱水方面的应用

选矿厂现用尾矿库库容严重不足,为了减少尾矿入库量,延长尾矿库使用年限,借鉴双真空盘式过滤机在精矿脱水方面的良好应用效果,开展了双真空盘式过滤机在尾矿脱水方面的研究及应用。双真空盘式过滤机与带式真空过滤机和压滤机实验对比,在装机数量、过滤系数、滤饼水分、占地面积、设备价格等多方面指标占优,脱水工艺相对简单,操作方便,日常维护点少,是最优脱水设备。

芳纶针织面料透气透湿及隔热性能研究

通过棉、蚕丝混纺纱,竹炭纤维、丙纶混纺纱和芳纶纱的科学搭配,由龙星制版系统进行双面针织物结构数字化设计,利用艺术设计方法有效地在结构和空间中进行科学合理的分配和排列,制备了纬编间隔织物和罗纹空气层织物,探讨了芳纶协同高舒适性双面针织物的透气透湿、隔热等性能。结果表明:通过有效的数字化方法所设计的空气层组织中,芳纶与竹炭、丙纶混纺纱搭配织造的空气层织物透气性更好,纬编间隔组织中,芳纶与竹炭、丙纶混纺纱间隔织物比芳纶与蚕丝、棉混纺纱间隔织物的透气性好。蚕丝的透湿性比竹炭纤维更好,更适用于制作服装纤维材料。

低渗致密气藏防水锁剂配方性能评价

基于吐哈油田低渗致密气藏,研发一种新型气藏防水锁剂GY-HE85,对其界面张力、表面张力和润湿性等基本性能进行研究,并分析了岩心渗透率恢复效果。实验结果表明,氟碳表面活性剂与碳氢表面活性剂复配后,碳氢表面活性剂除降低界面张力的作用之外,由于异电性亲水基之间强烈的静电吸引作用,表面活性剂分子在更低含量即可达到饱和吸附,还可降低表面活性剂的使用量。防水锁剂GY-HE85含量为0.1%~0.5%(w)的溶液时,表面张力为20.23~47.52 mN/m,随着溶液含量减小,拟黏附功逐渐降低,降幅呈“先快后慢”趋势,防水锁剂GY-HE85溶液优选含量为0.3%(w)。防水锁剂GY-HE85溶液具有较好的抗吸附性能,岩心渗透率恢复率在86.44%~91.20%,较好地预防了致密气藏储层“水锁”现象的发生。

热塑性聚氨酯-聚酯复合面料开发及其服用性能研究

为提升聚酯面料防水性能,扩展聚酯面料应用范围,将热塑性聚氨酯(TPU)薄膜与聚酯面料进行复合,通过正交实验分析复合温度、TPU膜厚度和复合压力对复合产品剥离强力、透气率、柔软度、抗静电性、透光性、紫外防护性能、防水性、透湿性的影响,通过研究得到结论为:TPU与聚酯复合面料的紫外防护性、防水性和静电荷衰减速度有所提升,透气率、柔软度、透湿率有所下降,透光性变化不大;TPU膜厚度和复合压力对复合产品综合服用性能影响同等重要,而温度影响略小;复合工艺为温度130℃、TPU膜厚度0.5mm、压力15MPa时复合面料综合服用性能最佳。

空气除湿用抗菌透湿复合膜的制备

为提高膜式全热交换器的除湿性能并使膜具备抗菌性能,以LiCl为亲水添加剂,AgNO_(3)为抗菌剂,添加到聚乙烯醇(PVA)水溶液中制成铸膜液,以聚丙烯(PP)膜为支撑层,制备了一种抗菌透湿复合膜。搭建了薄膜透湿性测量平台,测试了复合膜的水蒸气透过量,对复合膜的抗菌性进行了检测。结果表明,复合膜的水蒸气透过量随LiCl含量的增加而增加,LiCl含量为5%的复合膜是不含LiCl复合膜的1.79倍,是商用纸膜的2.67倍。加入AgNO_(3)后薄膜的透湿性没有明显变化,抗菌实验结果显示,复合膜对表皮葡萄球菌、大肠杆菌有抗菌作用,对表皮葡萄球菌的抗菌作用更强。

防水透湿户外运动产品及未来发展趋势

文章聚焦防水透湿户外运动产品,以其中的典型品类冲锋衣为例,基于对新/旧版《户外运动服装冲锋衣》标准的对比解读,对防水透湿薄膜的透湿机理及常用薄膜种类进行了介绍和梳理,同时结合产品案例分析了防水透湿户外运动产品的特点,对户外运动冲锋衣产品的未来趋势进行了展望。

体育服饰用超细纤维合成革针刺非织造基布的力学性能表征

为有效解决开纤处理后海岛超细纤维针刺非织造基布致密性低且针刺痕迹等一系列问题,以促使其在体育服饰用超细纤维合成革中广泛应用,本文基于针刺法将高收缩聚酯纤维掺入海岛超细纤维合成革非织造基布,以制备生成了超细纤维合成革针刺非织造基布,并对其力学性能进行了测试表征。结果发现,随着高收缩聚酯纤维掺入量增加,超细纤维合成革针刺非织造基布断裂强度与撕裂强度皆逐渐增大;透湿性与吸湿性先降低后升高;热收缩率逐步增高;耐磨性逐渐提升,且基布均匀度较好;弯曲长度与弯曲刚度皆逐渐增大,柔软度随之降低;以针刺非织造基布为原料制成的体育服饰用超细纤维合成革表面平整且光滑,底面平整且粗糙度适中,致密性较好,且断裂强度、撕裂强度、透湿性与吸水性均表现优异。

纳米微晶纤维素复合膜的制备及性能分析

以具有可持续性和环保特点的棉纤维为原料制备纳米微晶纤维素(NCC),再通过硫酸水解法简单高效地制得NCC悬浮液,将该悬浮液与壳聚糖混合,制备出NCC复合膜.利用万能试验机测试NCC复合膜的力学拉伸性能,同时用拟杯子法测试NCC复合膜的透湿性、用覆盖油脂的过氧化值测试NCC复合膜的阻氧性、用分光光度计测试NCC复合膜的透光性、用金黄色葡萄球菌和大肠杆菌测试NCC复合膜的抗菌性,最后用细胞培养试验评估复合膜对人体细胞的毒性.结果表明,NCC用量在45%质量分数时,制备的NCC复合膜拉伸强度最大、力学性能最高、断裂界面更粗糙;NCC复合膜水蒸气透过率保持在2.8×10^(-11) g·(m·s·Pa)^(-1)以上;NCC复合膜氧气阻隔性的过氧化值在2.0以上;经过与NCC复合膜32 min的接触,金黄色葡萄球菌和大肠杆菌接近完全被杀灭;24 h人体细胞存活率在70%以上.综上,所制备的NCC复合膜性能优良,值得开发.

防水型密胺泡沫制备工艺及发泡反应器研究

本文介绍一种防水型密胺泡沫的制备工艺及发泡反应器。针对现有密胺泡沫工业发泡技术的不足,通过对材料配方的优化以及特定发泡反应器的应用,制备出综合性能优良的防水型密胺基泡沫材料。结果显示,其开孔率<20%、吸潮率≤0.7%,在潮湿环境应用前景好,为密胺基泡沫材料拓展了应用空间。

断层影响下煤层开采突水风险流固耦合数值模拟研究

断层引起的底板采动突水是煤矿防治水中的重要问题,研究因采动引起断层活化,以及对底板渗透性变化全程进行演化是解决此类问题的关键。在前人成果的基础上总结了采动过程中围岩渗透性变化规律及渗透系数-体积应变耦合方程,将其嵌入FLAC3D流固耦合模型中。并以济宁二矿103下03工作面八里铺断层为背景,模拟不同煤柱尺寸情况下底板断层突水演化规律。结果表明:八里铺断层对于103下03工作面安全开采具有重要影响。防水煤柱尺寸为90 m时,奥灰水会沿导水通道进入采空区,引发突水事故;当其为100 m时,采动过程是安全的,且有效隔水层厚度约5 m。最终确定济宁二矿103下03工作面八里铺断层防水煤柱留设宽度取100 m。