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Traditional plastics are usually obtained from nonrenewable petroleum feedstocks. In this study, crosslinked polymers were synthesized from cottonseed oil. Unsaturated fatty acids, the major components of cottonseed oils, were initially epoxidized. A network polymer was then formed by crosslinking the epoxidized oil with maleic anhydrate. Mechanical properties of these polymers were altered by varying the amount of maleic anhydrate. These polymers have a tensile modulus of the order 1 MPa and are stable in the acidic and alkaline environment. Our results provide a new synthetic strategy to obtain a network polymer from cottonseed oil. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47655.  相似文献   
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对介质阻挡(DBD)低温等离子体法辅助制备催化剂的方法进行了研究。用DBD等离子体法制备了Mo/Co/K/ZSM-5催化剂。利用X射线衍射、热重分析、扫描电子显微镜等对催化剂进行表征。结果表明,等离子体法和传统焙烧处理制备的催化剂性能相近,并且利用DBD低温等离子体处理的催化剂在预处理速度,催化剂微观颗粒尺寸,分散度等方面均优于传统焙烧的处理方式。预处理后的催化剂表面活性更有利于直接通过合成气制备液体烃类燃料。  相似文献   
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Telecommunications Regulatory Commission of Sri Lanka is the governing body which is responsible for the frequency allocation and monitoring the unauthorized Electromagnetic frequency (EMF) signal transmitting violations. However, in Sri Lanka, currently there is not any proper mechanism to monitor the radiation hazard level and its impact to the people living in the vicinity of mobile communication towers. There are approximately 7000 mobile transmitting towers in Sri Lanka to date and the used frequency range lies between 900MHz to 3GHz for mobile communication. Over the last few decades, many of the health hazard conditions were reported due to the radiation of those harmful EMFs. To cater this problem, a portable real time EMF signal strength measuring system with a radiation hazard level indicator was developed to monitor the EMF level and its impact. The proposed system operates with three intermediate frequency bands (i.e.900MHz, 1800 MHz and 2400MHz) and it’s capable of measuring the power density and the radiation hazard level at that particular point which is being measured. Moreover, the corresponding radiation hazard level is indicated with reference to the standard power density levels published by the International Commission on Non-Ionizing Ra-diation Protection (ICNIRP*). The system works with the overall accuracy of 88% in terms of identifying the power densities and its corresponding radiation hazard levels.  相似文献   
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