Production of green surfactants: Market prospects

Science has greatly contributed to the advancement of technology and to the innovation of production processes and their applications. Cleaning products have become indispensable in today’s world, as personal and environmental hygiene is important to all societies worldwide. Such products are used in the home, in most work environments and in the industrial sectors. Most of the detergents on the market are synthesised from petrochemical products. However, the interest in reducing the use of products harmful to human health and the environment has led to the search for detergents formulated with natural, biodegradable surfactant components of biological (plant or microbiological) origin or chemically synthesised from natural raw materials usually referred to as green surfactants. This review addresses the different types, properties, and uses of surfactants, with a focus on green surfactants, and describes the current scenario as well as the projections for the future market economy related to the production of the different types of green surfactants marketed in the world.How to cite: Farias CBB, Almeida FCG, Silva IA, et al. Production of green surfactants: Market prospects. Electron J Biotechnol 2021;51. https://doi.org/10.1016/j.ejbt.2021.02.002     

基于SOM网络聚类的数据清洗技术

在数据装入数据仓库之前,应该对数据进行数据清洗.而数据清洗的核心工作就是清洗近似重复记录.聚类是将相似度高的数据对象聚集到一个类中,于是我们提出将该技术用于近似重复记录的发现上.本文主要介绍如何将SOM网络聚类强大的学习功能及良好的自组织性、自适应性和鲁棒性应用到数据清洗中。     

Acrylic emulsion paint films: The effect of solution pH,conductivity, and ionic strength on film swelling and surfactant removal

To date, a limited number of aqueous conditions have been tested experimentally as potential cleaning reagents on modern acrylic paint films. Those assessed have tended to extract measurable quantities of paint film components and distort the paint films physically. In this paper the results of a series of experiments designed to examine pH, conductivity, and specific ion effects of potential aqueous cleaning solutions on a series of commercial acrylic paints are reported. A three-dimensional microscopic technique was used to characterize the physical (volume and surface roughness) changes and liquid chromatography-tandem mass spectrometry was used to characterize the chemical (extracted surfactant) changes following paint film exposure to the aqueous solution. The tested paint films in this study clearly exhibit an isotonic point below which swelling and extraction is significant, and above which the swelling and extraction is diminished. Manipulation of conductivity and the ionic species in solution can reduce both the physical film changes and surfactant extraction from acrylic paint films; while pH appears to be of limited use in controlling aqueous cleaning effects. Moreover, there seems to be a specific ion effect for both swelling and de-swelling in acrylic paint films that can be rationalized through the Hofmeister Series.     

两型PS版高效再生剂的研制

通过复配技术,研制出分别以醇类和羰基化合物为主要成分的Ⅰ型、Ⅱ型ＰＳ版高效清洗剂,可用于手工和机械清洗再生ＰＳ版,经试用验证,产品可产生一张打样３－１６次,印刷版２－３次。     

水陆两用垃圾清理船机械结构设计研究

设计水陆两用垃圾清理船主要为打捞水面垃圾和收集陆地垃圾提供操作灵活的设备.机械装置是水陆两用垃圾清理船的重要组成部分.文中重点介绍了船体、中心转塔支柱、大小支撑臂和机械手等主要机械部件的设计过程.根据设计结果经过制作并装配调试,证明设计的机械装置完全能满足功能需要.     

SQL存储过程实现相似重复记录检测

＂相似重复记录检测＂是数据清洗要解决的主要问题之一,对于提高数据质量及决策可靠性起到关键作用。编写SQL存储过程脚本实现了一种相似重复记录检测算法———PCM算法,测试了算法性能,针对PCM算法时间复杂度较高的缺陷,提出了利用SQL语句优化技术改进算法执行效率。     

深度清洁装置清洁睑缘治疗睑板腺功能障碍相关干眼症的初步研究（英文）

目的:评价深度清洁装置清洁睑缘治疗睑板腺功能障碍相关干眼症的安全性和有效性.创新点:评估了一个干眼症治疗新方法的疗效.方法:将睑板腺功能障碍相关干眼症患者的两只眼随机分入治疗组和对照组.对照组进行人工泪液和眼睑热敷治疗,治疗组在上述治疗基础上加用深度清洁装置进行一次睑缘清洁.在基线和治疗一周后测量非侵入性泪膜破裂时间和泪河高度,用问卷调查表对每个人干眼症状进行评分.结论:深度清洁装置睑缘清洁是一种安全有效的方法,适用于睑板腺功能障碍相关干眼症患者.     

The combined use of cross-section analysis and other stratigraphic recording systems in the cleaning of two panel paintings from the fifteenth- and sixteenth-century

Abstract

Cross sections are frequently used in the stratigraphic study of pictorial structures. Thanks to cross sections, it is possible to study and record original and non-original strata that may provide important information regarding the artist's technique and later restoration processes. This information helps conservators design different strategies in processes such as cleaning. However, it is often in cleaning where the advantages and limitations of cross sections become obvious. When dealing with a complex structure, cross sections may not be enough to record in a comprehensive and accurate manner all the strata removed during cleaning. In some cases, the conservator may obtain during cleaning a great amount of stratigraphic information that is not visible in the cross sections. Therefore, it may be necessary to resort to other recording systems, such as the stratigraphic unit recording sheet and the stratigraphic diagram, which are frequently used in archaeological stratigraphy. This article demonstrates how cross-section analysis was combined with stratigraphic study during the cleaning of two panel paintings to gain an improved understanding of their complicated layer structure.     

Combination of a Liquid-Dispensing and Micro-Aspiration Device for the Cleaning of Sensitive Painted Surfaces

Many painted surfaces, not necessarily only those with a contemporary binding media, display high sensitivity to water. The resulting damage, including swelling, leaching out of some components, even partial solubility, may lead to a shrunken, impoverished, de-plasticized, more porous paint film. Different approaches to the cleaning of such surfaces have been developed throughout the years, as awareness of this sensitivity grew worldwide. Some deal with the proper physico-chemical conditions of the aqueous solutions, and others with the proper ways of delivering these solutions to the surface. The strategy proposed in this technical note is concerned with the latter, the application stage, and is based on the combined and simultaneous use of a device capable of delivering a constant, precise amount of the aqueous cleaning solution and a surgical micro-aspirator to immediately remove the soiled solution from the surface and speed up its drying. Also, using a different apparatus, non-polar solvents can be delivered, for cleaning surfaces contaminated by non-polar, more lipophilic soiling materials.