Layer‐by‐layer deposition of antimicrobial polymers on cellulosic fibers: a new strategy to develop bioactive textiles

In recent years, there has been an increase of infectious diseases caused by different microorganisms and the development of antibiotic resistance. In this way, the search for new and efficient antibacterial materials is imperative. The main polysaccharides currently used in the biomedical and pharmaceutical domains are chitin and its derivative chitosan (CH) and alginates (ALG). In this study, a simple technique of Layer by Layer (LbL) of applying polycation CH and polyanion ALG was used to prepare CH/ALG multilayers on cotton samples via the electrostatic assembly with success. The CH/ALG cotton samples (functionalized) were investigated for their antibacterial properties towards Staphylococcus aureus and Klebsiella pneumonia using the international standard method JIS L 1902:2002. The antibacterial activity of the functionalized samples was tested in terms of bacteriostatic and bactericidal activity, and results showed that the samples exhibited a bacteriostatic effect on the two bacteria tested, as expected. In addition, samples with five layers (CH/ALG/CH/ALG/CH) were more effective in inhibiting bacterial growth. This new coating for cellulosic fibers is a new strategy and may open new avenues for the development of antimicrobial polymers with potential application in health‐care field. Copyright © 2013 John Wiley & Sons, Ltd.     

False Detection of Cyanide Ion in Photographic Processing Waste Solutions Using Standardized Reference Methods

Abstract

Although cyanide compounds are not incorporated in photographic processing solutions, false detection of cyanide ion is often encountered during the determination of total cyanide by various standardized methods such as ISO, ANSI and JIS. Various organic compounds and nitrogen compounds in the processing solutions were examined because of this false detection. The results suggest that hydrogen cyanide is formed by a reaction between these compounds during the distillation process for the separation of total cyanide, even though ISO, ANSI and JIS were used. The results support the following three mechanisms of cyanide formation involved in the process: (1) Hydroxylammonium salts reacts with another ingredient, formaldehyde, to form formaldoxime, which then decomposes to HCN. (2) Hydroxylammonium is oxidized by air to form nitrite ion, which subsequently reacts with organic compounds such as aminocarboxylic acids and aromatic amines (the colour-developing agent) to form HCN. (3) Potassium permanganate oxidizes aromatic amines to form HCN.     

锂离子单电池强制内部短路试验

本文阐述了JISC8714：2007标准中单电池强制内部短路试验条件和方法,说明了各个试验步骤的要求和意图,总结了内部短路试验的注意事项,介绍了试验设备,并对强制内部短路试验的有效性进行了探讨。     

Scheme and studies of reference materials for volumetric analysis in Japan

This paper describes the history and scheme of reference materials and standard solutions for titrimetry in Japan. Titrimetry is one of the most fundamental and precise methods for determination of a constituent, based on the effective purity of reference materials in stoichiometric analysis. It has wide-ranging applications based on titrimetric reactions such as neutralization, redox, chelatometric, and precipitation titration processes, which are used in various analytical fields all over the world. Japanese Industrial Standards (JIS) have played an important role in establishing a stable supply of reference materials for titrimetry since the 1950s. There are several reports of preparations and their determination, including coulometric studies, in order to establish highly reliable reference materials. This paper briefly reviews the schemes and studies of standardization through the provision of reference materials and standard solutions based on JIS, and several applications in other standards. Presented at Berm-11, October 2007, Tsukuba, Japan.     

腐蚀性气体试验方法在提高电子产品性能中的应用

介绍了通过腐蚀试验来评价电气、电子产品、装置在使用及储备条件下的耐腐蚀性能，最新的多种低浓度混合气体试验方法的研究现状，ISO、IEC及日本标准JIS中的标准腐蚀性气体试验方法。讨论了模拟一般环境下SO2及H2S混合气体的试验条件，对铜试样做含臭氧的高加速混合腐蚀性气体的试验方法。探讨了交流阻抗法应用于腐蚀性气体试验及其影响因素。     

The potential use of nanosilver-decorated titanium dioxide nanofibers for toxin decomposition with antimicrobial and self-cleaning properties

While chemical and biological attacks pose risk to human health, clean air is of scientific, environmental and physiological concerns. In the present contribution, the potential use of nanosilver-decorated titanium dioxide (TiO₂) nanofibers for toxin decomposition with antimicrobial activity and self-cleaning properties was investigated. Titanium dioxide nanofibers were prepared through sol-gel reaction followed by an electrospinning process. Following the Japan Industrial Standard (JIS) protocol, decompositions of nitrogen oxide (NOx) and volatile organic compound (VOC) by the TiO₂ nanofibers suggested that these materials were capable of air treatment. To further enhance their anti-microbial activity, silver nanoparticles were decorated onto the TiO₂ nanofibers’ surfaces via photoreduction of silver ion in the presence of the nanofibers suspension. Furthermore, tests of photocatalytic activity of the samples were performed by photodegrading methylene blue in water. The nanofibrous membranes prepared from these nanofibers showed superhydrophilicity under UV. Finally, the possibility of using these hybrid nanofibers in environmental and hygienic nanofiltration was proposed, where the self-cleaning characteristics was expected to be valuable in maintenance processes.     

电气电子产品的腐蚀性气体试验方法

介绍了通过腐蚀试验来评价电气、电子产品、装置在使用及储备条件下的耐腐蚀性能,多种低浓度混合气体试验方法的最新的研究现状,ISO、IEC及日本工业标准JIS中的标准腐蚀性气体试验方法。讨论了模拟一般环境下SO2及H2S混合气体的试验条件,对铜试样做含臭氧的高加速混合腐蚀性气体的试验方法。探讨了交流阻抗法应用于腐蚀性气体试验及其影响因素。     

Analytical chemistry of the persistent organic pollutants identified in the Stockholm Convention: A review

Persistent organic pollutants (POPs) are major environmental concern due to their persistence, long-range transportability, bio-accumulation and potentially adverse effects on living organisms. Analytical chemistry plays an essential role in the measurement of POPs and provides important information on their distribution and environmental transformations. Much effort has been devoted during the last two decades to the development of faster, safer, more reliable and more sensitive analytical techniques for these pollutants. Since the Stockholm Convention (SC) on POPs was adopted 12 years ago, analytical methods have been extensively developed. This review article introduces recent analytical techniques and applications for the determination of POPs in environmental and biota samples, and summarizes the extraction, separation and instrumental analyses of the halogenated POPs. Also, this review covers important aspects for the analyses of SC POPs (e.g. lipid determination and quality assurance/quality control (QA/QC)), and finally discusses future trends for improving the POPs analyses and for potential new POPs.     

电气、电子产品的腐蚀性气体试验方法

介绍了通过腐蚀试验来评价电气、电子产品、装置在使用及储备条件下的耐腐蚀性能,最新的多种低浓度混合气体试验方法的研究现状,ISO、IEC及日本标准JIS中的标准腐蚀性气体试验方法。讨论了模拟一般环境下SO2及H2S混合气体的试验条件,对铜试样做含臭氧的高加速混合腐蚀性气体的试验方法。探讨了交流阻抗法应用于腐蚀性气体试验及其影响因素。     

近十二年来印制板标准进展

概述2001年至2012年间IEC、IPC、JPCA和我国印制板及有关方面标准进展情况。