Management of agricultural biomass wastes: Preliminary study on characterization and valorisation in clay matrix bricks

In this work the feasibility of using woody agricultural biomass wastes as grapes and cherries seeds, sawdust, as pore forming agent, and sugar cane ash, as silica precursor, in bricks, were reported.Sawdust and grapes and cherries seeds, thanks to their organic substances content, during their combustion, bring an energetic support in the bricks firing phase and act as pore forming agent. Usually the addition of this kind of waste is limited to 10 wt.% in order to reach an equilibrium between positive (weight and shrinkage decrease and porosity increase) and negative (increase of water absorption and mechanical resistance decrease) effects. The results show that grapes and cherries seeds, added in a percentage of 5 wt.% to a brick formulation, have better influence with respect to the sawdust, maintaining the mechanical properties of the fired brick (950 °C), showing modulus of rupture around 21–23 MPa with a weight reduction of 3–10% (respect to the standard one). Regarding the sugar cane ash, the addition of 5 wt.% improves the mechanical properties (modulus of rupture around 27 MPa) and no weight decrease is observed. These results confirmed the role played by this kind of agricultural waste, which thanks to its high silica content (61 wt.%) is capable to demonstrate a filler and plasticity reducing effect on the brick bodies. Tests carried out highlighted that the addition of these by-products (5 wt.%) do not change negatively the main technological properties measured (water absorption, linear shrinkage, flexural resistance, etc.) and permit to hypothesize their use to obtain bricks with both insulating and higher mechanical properties using a pore agent forming or silica carrier alternative raw materials, respectively.     

Toxicity of building materials: a key issue in sustainable construction

To avoid the use of toxic building materials is one of the principles of sustainable construction. However and contrary to general beliefs, current residential buildings frequently contain many toxic building materials, some of which even comply with legal regulations. Part of the problem is because architects and civil engineers have no form of knowing the toxicity of building materials. The other part is economically related. Some regulations about toxicity limits are influenced by economic reasons. For instance, although scientific evidence about the toxicity of lead plumbing has existed for quite some time, legal regulations avoid imposing very tight thresholds because of the cost of lead pipe substitution (in Europe that could cost almost 200,000 million euros). It is then no surprise to see that the related Directive (98/83/CE) established a 15-year delay period before the 10 μg/l lead content threshold is enforced. This paper discusses some cases of toxic building materials by reviewing previously published work, it also covers the emission of volatile organic compounds from paints and varnishes, the toxicity of impregnating agents, materials that release toxic fumes during a fire, asbestos-based materials, radioactive materials and lead plumbing.     

Workplace Hazards and Prevention Options From a Nonrandom Sample of Retail Trade Businesses

Employer commitment is a key factor in an effective safety program, yet limited research has focused on the safety priorities of retail store managers. To address this, the U.S. National Institute for Occupational Safety and Health recruited 4 experienced ergonomists, who met and interviewed 9 retailers in different parts of the eastern USA. The reports from the 9 interviews were used to document the hazards facing retailers and the interventions they attempted. Those interviewed were managers/owners of establishments that ranged from a small bakery with 11 employees to a supermarket with 85 or more employees. The main hazards across all establishments included overexertion, contact-with-objects, and falls-to-the-same-level. We also compared the retailers’ perceptions of safety hazards with injuries from actual hazards as supplied by the U.S. Bureau of Labor Statistics. This report provides insight into the retailers ‘ perceptions of safety hazards as well as their commitment to the prevention of workplace injuries.     

Resistance of Medical Gloves to Permeation by Methyl Methacrylate (MMA), Ethylene Glycol Dimethacrylate (EGDMA), and 1,4-Butanediol Dimethacrylate (1,4-BDMA)

Gloves afford hand protection by minimizing skin contact. The effectiveness of medical gloves to protect against permeation of the monomers, methyl methacrylate (MMA), ethylene glycol dimethacrylate (EGDMA), and 1,4-butanediol dimethacrylate (1,4-BDMA), was assessed focusing on permeation rates and degradation of glove materials caused by monomer contact. Fifteen different brands of gloves were tested using a European Standard procedure. Surface images of glove materials before and after exposure to the monomer mixture were obtained using a scanning electron microscope. The standard is not applicable as the only method for estimating the safety of gloves, but it is useful as guideline together with the cumulative permeation of acrylic monomers. Monomer contact on the outside resulted in substantial swelling of most glove materials, and structure changes of the inside surface.     

Deposition and Resuspension of Selected Aerosols Particles on Electrically Charged Filter Materials for Respiratory Protective Devices

The primary aim of the study was to analyse the non-steady state of filtration for selected electrostatic filter materials designed for use in respiratory protective devices. The obtained results showed that the filtration process in electrostatic filters was dependent in the main on the following factors: type of the filter material, electrostatic field strength of the material, and the charge of the aerosol.

To a lesser degree the filtration process depended on the sign of the charge and the relative humidity of the air. A significant correlation was found between the increase in the penetration and the decrease in breathing resistance while the filter was being loaded.

The effect of resuspension (tearing off and re-deposition of dust agglomerates inside the filter) on the filtration process very significant. It was also observed that under certain conditions electrostatic filter materials lost their protection properties.     

常用过滤材料对微细颗粒过滤性能的研究

通过实验手段对几种过滤材料的阻力、过滤效率进行了研究。结果表明,目前常用的过滤材料对超细颗粒物的除尘效果并不理想,尚有很大的提升空间。     

Fatty Acids as Phase Change Materials (PCMs) for Thermal Energy Storage: A Review

Abstract

Thermal energy storage (TES) technologies in general and phase change materials (PCMs) in particular, have been topic in research for the last 20 years. Traditionally, available heat has been stored in the form of sensible heat (typically by raising temperature of water, rocks, etc). Latent heat storage on the other hand, is a novel and developing technology, which has found considerable interest due to its operational advantages of smaller temperature swing, smaller size, and lower weight per unit of storage capacity. The interest on thermal energy storage by using fatty acids as PCM has risen in recent times since they have desired thermodynamic and kinetic criteria for low temperature latent heat storage. An added advantage is that fatty acids are derived from the vegetable and animals oil that provides an assurance of continuous supply. This article will review the development of fatty acids as PCMs for solar thermal energy storage application.     

中国循环经济建设中的废旧物资再生模式研究

在循环经济建设中,发展废旧物资再生产业是实现区域"大循环"、连接消费与生产领域之间的关键环节,是目前许多国家发展循环经济的重点领域.本文以产品生命周期评价、工业代谢、再利用和再循环原则等理论方法为指导,通过分析各种废旧物资的产生、利用特征,系统构建出中国废旧物资的循环再生模式,为提高中国废旧物资回收利用率、提升资源利用价值和减小环境污染危害提供科学发展方向.     

Industrial ecology: engineered representation of sustainability

Industrial ecology is a relatively new field of research and academic study and is well established in North America and in several Asian countries. However, it has not yet received the attention it deserves in some other important parts of the industrialized world, including Germany. This paper may contribute to a better appreciation of industrial ecology as a tool in the process of sustainable development of economies, social systems, and of aquatic and terrestrial biotopes under the pressure of rapidly changing conditions triggered by global warming and urban growth. For this reason, methods are needed to quantify the successful application of industrial ecology measures. The “Integrated Sustainability Triangle” is introduced as a promising new possibility of quantification and monitoring. It enables justification of the contributions industrial ecology can make to sustainable development. The aggregation of individual economic contributions is assumed to create an overall impetus to the entire industrial sector including the sector of environmental engineering. Thus, the potential of industrial ecology is discussed from the macro-economic and the engineering perspective using the concept of sustainable development as a guiding principle. But the authors come to the conclusion that finding solutions to the pressing problems of our time requires more than collaboration of economy and engineering. It requires joint efforts of the whole spectrum of scientific disciplines in close collaboration with industrial and political stakeholders.     

烘干时间与滤纸上悬浮物量对悬浮物测定的影响

对水质悬浮物的测定方法进行了探讨。通过控制取样体积，使地表水和低粘度废水在滤纸上的悬浮物量≤50．0mg，而高粘度废水在滤纸上的悬浮物量≤20．0mg，则样品在烘干1h与烘干2h后恒重分析结果相同。