Green Composites as Panacea? Socio-Economic Aspects of Green Materials

Much academic research and industrial development explores new ways to create greener and environmentally friendlier chemicals and materials for a variety of applications. A significant part of this work focuses on the development, processing and manufacturing, recycling and disposal of green plastics, adhesives, polymer composites, blends and many other industrial products from renewable resources. Natural fibres offer the potential to deliver greater added value, sustainability, renewability and lower costs especially in the automotive industry. Further research involves the fibre crop production. The ever-increasing volume of scientific literature refers with enthusiasm to the potential of natural fibres in technological, economic and ecological terms. This enthusiasm tends to also expand to the areas of human life and socio-economic development for the fibre crop growers and their communities. However, there is very little debate or evidence to support statements about the assumed advantages for the affected population in rural areas. We argue that despite the predicted new boom in the demand of natural fibres, it is unlikely that this will represent a real improvement in the quality of life of crop fibre growers and their communities. This paper examines the experience of Mexico as a case study and argues that only through consistent political will and co-operation between governments, industry, scientists, consumer groups and local communities, as well as a suitable economic strategy such as local subsidies, a truly sustainable economic development, social equity and improved environmental quality will be achieved for tens of thousands of natural fibre growers.     

九寨沟风景区游客入游距离特征研究

九寨沟风景区属于长江支流水系的上游，是长江支流源头区以景观资源（尤其是水景观）及生态旅游资源为特色的典型地区，目前旅游业成为当地及同类地区的旅游重要产业。旅游市场是当地旅游发展基础之一。在实地游客抽样调查及旅游区游客登记统计共涉及约2万人统计资料及数据库处理的基础上较系统地研究了九寨沟入游游客的入游距离特征。对九寨沟不同目标市场游客的入游距离特征进行了统计描述，揭示了游客入游距离与年龄、收入、职业、文化、心理收入、旅游态度相关，而与旅游动机相关性不明显，景观偏好可以反映游客的旅游心理特征，并在一定程度上影响入游距离。同时揭示了入游距离感知的距离衰减特征，印证了心理学感知理论中的韦伯理论在距离感知中的体现。还解释了游客的主观假设替代旅游地的旅游距离与入游距离呈线性相关关系。     

湿地退耕还湿与替代生计选择的农民响应研究——以三江自然保护区为例

通过对三江自然保护区核心区内6个村屯和实验区内5个村屯的310家农户家庭就退耕还湿和替代生计选择的问卷调查分析发现,在退耕还湿问题上,不同区域位置、年龄结构和耕地拥有量决定了他们对退耕还湿支持意愿的不同,表现在实验区内的农民和农民中的年轻人支持率要高,耕地在6~12hm²之间的农民支持率最低;农民反对退耕还湿的原因和农民接受退耕还湿的补偿选择都凝结着农民对现有耕地及补偿制度的思考。在替代生计选择上,当地居民没有明确的目标,多倾向于有保障的种植业调整。研究表明:农民对退耕还湿的支持主要取决于能否保证自身的经济利益,并且与农民的收入来源和谋生能力有关;替代生计发展的不健全和不稳定,使得农民仍把土地作为重要的生活保障。缺乏明确的退耕还湿补偿制度和替代生计引导是退耕还湿实施的制度障碍和政策缺失;基于当地农民考虑,提出了核心区生态移民、缓冲区传统农业改造和实验区多元化产业发展总体替代生计模式。     

Reaction kinetic model for a recent co-produced water treatment technology

With the increasing demand for fossil based energy and implementation of progressively strict environmental pollution control standards, treatment of a large amount of co-produced waters (CPWs) from fossil based energy production has become increasingly important. Removal of bicarbonate with H2SO4 has been recently studied as a simple and cost-e ective method to decrease the alkalinity of CPWs. The present work investigates the kinetics of the reaction between H2SO4 and NaHCO3, which could provide the base for scaling-up the CPW treatment technology. Based on the measured quantity change of the CO2 gas generated from the reaction between H2SO4 and NaHCO3 with time under specified initial reaction conditions, the reaction orders with respect to H2SO4 and NaHCO3 were determined. Experiments were also conducted within the temperature of 15–30°C to find various global rate coe cients of the reaction to calculate the activation energy and the pre-exponential factor of the empirical Arrhenius form of the bicarbonate removal reaction, which are 197.7 kJ/mol and 3.13 1034 (mol??3:7 L3:7 sec??1), respectively.     

Characterization of disinfection byproduct formation potential in 13 source waters in China

The formation potential of four trihalomethanes (THMFP) and seven haloacetic acids (HAA7FP) in 13 source waters taken from four major water basin areas in China was evaluated using the simulated distribution system (SDS) chlorination method. The specific ultraviolet absorbance (SUVA254: the ratio of UV254 to dissolved organic carbon (DOC)), which ranged between 0.9 and 5.0 L/(mg m), showed that the organic compounds in di erent source waters exhibited di erent reactivities with chlorine. The HAA7FP of source waters ranged from 20 to 448 g/L and the THMFP ranged from 29 to 259 g/L. The HAA7FP concentrations were higher than the THMFP concentrations in all but one of the samples. Therefore, the risks of haloacetic acids (HAAs) should be of concern in some source waters. TCM (chloroform) and BDCM (bromodichloromethane) were the major THM constituents, while TCAA (trichloroacetic acid) and DCAA (dichloroacetic acid) were the major HAA species. Br-THM (brominated THM species) were much higher than Br- HAA (brominated HAA species), and the formation of Br-DBP (Br-THM and Br-HAA) should be of concern when the bromide concentration is over 100 g/L.     

汽车发动机超声清洗废水处理实验研究

汽车发动机超声清洗废水中含有有机油、表面活性剂等物质,呈黑色,COD较高,较难处理。本实验采用化学絮凝法对其进行处理,取得了良好的效果。实验结果表明,在pH 7.2~8.2范围内,向样品中投入PAC400 mg/L,PAM50 mg/L,氯化钙200 mg/L时,处理效果明显,COD去除率达到96.7%。     

Spreading the News on Carbon Capture and Storage: A State-Level Comparison of US Media

Carbon capture and storage (CCS) has received abundant federal support in the USA as an energy technology to mitigate climate change, yet its position within the energy system remains uncertain. Because media play a significant role in shaping public conversations about science and technology, we analyzed media portrayal of CCS in newspapers from four strategically selected states. We grounded the analysis in Luhmann's theory of social functions, operationalized through the socio-political evaluation of energy deployment (SPEED) framework. Coverage emphasized economic, political/legal, and technical functions and focused on benefits, rather than risks of adoption. Although news coverage connected CCS with climate change, the connection was constrained by political/legal functions. Media responses to this constraint indicate how communication across multiple social functions may influence deployment of energy technologies.     

A low pressure direct gas injection system for a four stroke LPG: Diesel dual fuel engine

Internal combustion engines running on gaseous fuels produce low torque because the inducted gaseous fuel displaces air and reduces the volumetric efficiency. This can be overcome by injecting the gaseous fuel directly into the cylinder after the intake of air is completed. This work is a step in developing and demonstrating a cost effective system, as such systems are not readily available for small applications. A low-pressure gas injector was mounted on the cylinder barrel of a fully instrumented dual fuel engine. Its location is such that the injector will be exposed to the cylinder gases about 65.5 degrees before bottom dead center, where the cylinder pressure and temperature will be relatively low. An electronic controller was also developed to time the injection process to occur after the intake valve closes and also to control the duration of injection (quantity). Experiments were conducted with LPG (Liquefied petroleum gas) as the primary fuel that was injected with this new system and diesel as the pilot fuel at the rated speed of 1500 rpm with different amounts of LPG at 80% and 100% load. Comparisons of performance, combustion and emissions with the conventional manifold injection of LPG were done. The system allowed greater amounts of LPG to be used without knock as compared to manifold injection. On the whole the developed system has potential for application in small dual fuel and spark ignited gas engines and can be taken up for further optimization.     

Carbon taxation,OPEC and the end of oil

I develop a differential game between an oil cartel and an importer investing in research and development (R&D) to reduce the cost of a green substitute to oil. In equilibrium, the cartel is forced to deter the substitute, which thus imposes a price ceiling falling over time. Credible carbon taxes are below the Pigovian level, implying the importer cannot internalise the full pollution externality, much less capture resource rents. Without carbon pricing, the importer curtails long-run pollution using a costly R&D programme. Normatively, climate policy will be more expensive if relying on green R&D programmes only.     

Updraft gasification of juniper wood biomass using CO2–O2 and Air (N2–O2)

Biomass gasification is being considered as one of the most promising technologies for converting low-quality solid biomass fuel into gaseous fuel. Redberry juniper (Juniperus pinchotii), one of the woody species that dominate uncultivated lands in the southern great plains, USA, may have a great potential for bioenergy utilization. In this study, the results of gasification of juniper are presented. Juniper wood chips were gasified in an adiabatic fixed bed updraft gasifier using air and the mixture gas of carbon dioxide and oxygen (CO₂:O₂) as gasification medium. The effect of gasification parameters such as moisture contents, gasification mediums, and gasification temperature on produced gas properties and the tar yield were investigated. It was observed that oxy fuel gasification (the reaction of woody fuels with carbon dioxide) of juniper resulted in the increase of production of carbon monoxide, especially at higher peak gasification temperatures. As a result, the CO₂ gasification resulted in producing higher heating value gas (6264 kJ/nm³ with dilution of CO₂ and 19,750 kJ/nm³ inert free) compared to air gasification. For air gasification, it was observed that the updraft gasification produced large amount of the tar in the product gas (more than 100 g/nm³) for the fuels with moisture content between 6% and 11%. Generally, the tar yield increased with the increase of equivalence ratio (er) and moisture content. However, when the fuel moisture content reached 23.5%, the tar yield reduced significantly due low gasification temperature which reduced the less tar cracking.