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31.
With the ever-increasing amount of generated waste governments around the world are looking for, and implementing, ways to minimize waste output and maximize waste recovery. The main difficulties are sorting waste items, identifying the different types of plastics, and the time taken to sort them manually. Bioplastics such as polylactic acid and Novatein thermoplastic protein can be incorporated into the recycling stream to minimize waste. Laser-induced breakdown spectroscopy spectra analyzed by k-nearest neighbor and soft independent modeling by class analogy were investigated as methods that can rapidly identify recyclables. Raw, peak normalized, and total intensity normalized spectra were used to identify which would improve classification. Laser-induced breakdown spectroscopy spectra were generated by single laser shots to different locations on nine samples, glass (brown, green, and clear), tin, aluminum, polylactic acid, Novatein, polyethylene terephthalate, and high-density polyethylene. To prove that the system has the potential to be used on a waste sorting stream an autofocus unit was developed to move the laser-induced breakdown spectroscopy beam into focus on the different sample geometries. Two classification methods were investigated, soft independent modeling by class analogy and the k-nearest neighbors algorithm. k-Nearest neighbors on raw spectra produced the best results. Discrimination between bioplastics and plastics were 100%. Glass samples could not be reliably distinguished from each other. Surface contamination produced three misclassifications from 450 spectra. Similar results were obtained when the spectral range was reduced from 182.26–908.07?nm to 313.20–495.12?nm. 相似文献
32.
研究考虑消费者低碳偏好的闭环供应链回收、碳减排与专利授权决策问题。分别构建制造商回收再制造、零售商回收再制造支付固定专利费、零售商回收再制造支付单位专利费的闭环供应链模型,分析低碳消费者比例、普通消费者对再制品的接受程度及碳权交易价格,对企业回收、碳减排及定价决策的影响,并比较了三种模式下企业及供应链的利润。研究表明:随着市场中低碳消费者比例及普通消费者对再制品接受程度的提高,总会使得回收率及碳减排率增加;碳权交易价格的提高,也会促使制造商提高碳减排率;对制造商来说,其利润在零售商回收再制造且支付固定专利费用下实现最优。从自身利润最优的角度出发,作为领导者的制造商将总是选择零售商回收再制造且支付固定专利费用模式。 相似文献
33.
Wanlop Harnnarongchai Naret Intawong Narongrit Sombatsompop 《Journal of Macromolecular Science: Physics》2013,52(6):1074-1086
An experimental rig coupled with a high speed data-logging and recording system and a personal computer was specially designed and constructed for the real-time measurement of mechanical strength (in terms of drawdown force) as a function of volumetric flow rate and roller speed for virgin low-density polyethylene (LDPE) and reprocessed LDPE during a filament stretching process. The effect of the number of extrusion passes for the reprocessed LDPE was our main interest. The experimental rig was connected to the end of a single-screw extruder, which was used to melt and extrude the polymers. The LDPE filaments were then solidified and collected for studying the mechanical properties. The mechanical strength of the virgin LDPE and reprocessed LDPE were investigated in both molten and solidified states. The mechanical strengths of the virgin and reprocessed LDPEs under these two states are discussed and compared in terms of change in magnitude under a wide range of processing conditions (volumetric flow rate, die temperature, and roller speed). The results suggested that in the molten state the drawdown force for LDPE melts was dependent on volumetric flow rate, die temperature, roller speed, and the number of reprocessing passes. The drawdown force being affected by the number of reprocessing passes could be explained by molecular degradation and gelation effects when using high volumetric flow rates. In the solidified state, the tensile properties of the solidified LDPE increased with roller speed. The effect of the number of extrusion passes for the solidified LDPE was similar to that for the molten LDPE. In the case of volumetric flow rates, the mechanical properties of the solidified LDPE decreased with increasing volumetric flow rate, whereas those of the molten LDPE exhibited the opposite effect. Thus, the mechanical strength of the molten LDPE could not always be used to assess the mechanical properties of the solidified LDPE. 相似文献
34.
随着我国报废汽车数量的增多,由其造成的交通隐患、环境污染和资源浪费已成为重要社会问题,而如何设计合理可行的回收模式成为解决问题的关键。以制造商主导为前提,提出了基于企业社会责任的报废汽车回收模型,构建了制造商回收、销售商回收和第三方回收模式下的回收流程和数学模型,通过实例对考虑和不考虑企业社会责任两种情况下的回收模型进行了分析,探讨了不同政府奖励下报废汽车回收模式的策略选择。通过研究发现:(1)不论是否考虑企业社会责任,随着政府奖励的增加,制造商最终都会选择由自己进行回收;(2)当考虑企业社会责任时,政府奖励和决策者经济责任偏好都会导致决策的改变,随着政府奖励和赋予经济责任权重的同步增加,制造商的决策由第三方企业回收模式或销售商回收模式变成了制造商回收模式,表明政府奖励和企业社会责任对报废汽车回收模式选择具有显著影响。 相似文献
35.
36.
Influence of multiple processing on selected properties of poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) 下载免费PDF全文
Krzysztof Moraczewski 《先进技术聚合物》2016,27(6):733-739
The effect of multiple (up to 10 times) injection molding of processed poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) (P(3,4HB)) on its phase transition temperatures, degree of crystallinity, degradation temperature, mass flow rate, mechanical properties, dynamic mechanical properties, and Charpy's impact strength is presented. The studies have shown that the multiple injection lowers the degree of crystallinity and the thermal stability of P(3,4HB). The mass flow rate values increased with increasing the injection number. It was found that the multiple injections had no substantial effect on the tensile strength up to 10 injection cycles and the tensile strength at break, tensile strain at tensile strength, and tensile strain at break up to 6 injection cycles. The maximum value of storage modulus at 30 °C and impact strength were recorded for sample after 4 cycles of injection, while the values of storage modulus at 120 °C increased with increase of the injection cycles. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
37.
T. Kleps M. Piaskiewicz W. Parasiewicz 《Journal of Thermal Analysis and Calorimetry》2000,60(1):271-277
Thermogravimetry was employed to study the changes occurring in rubber vulcanizates during devulcanization carried out by
microwave treatment, a new promising method of recycling rubber waste. The thermogravimetric parameters T
i , T
5 and T
p and the compositions of devulcanizates in comparison with vulcanizates were determined. The results obtained allowed estimation
of the degree of destruction of the polymer chains in response to microwave treatment and permitted establishment of the most
advantageous conditions of devulcanization in order to obtain the best properties of rubber devulcanizates for reuse in rubber
processing.
The results demonstrated that thermogravimetry is a very useful method for investigation and control of the microwave devulcanization
process.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
38.
A microtiter plate assay for quantitation of reduced (GSH) and oxidized (GSSG) glutathione in the rat liver tissue and bile
is described. The assay is based on the established enzymatic recycling method and a new thiol-masking reagent, 1-methyl-4-vinyl-pyridinium
trifluoromethane sulfonate (M4VP). Samples were first processed by homogenization with (liver) or addition of (bile) sulfosalicylic
acid. The total glutathione and GSSG were then determined before and after rapid (≤2 min) and efficient (100%) masking of
the GSH content of the samples with M4VP followed by the enzymatic recycling assay. The percentages of error and coefficient
of variation of the assay were within the accepted guidelines, indicating the accuracy and precision of the assay in the range
of 6.25–100 pmol GSH per microplate well and 2.17–140 pmol GSSG per well, with lower limit of quantitation of 6.25 and 2.17 pmol
per well for GSH and GSSG, respectively. Furthermore, the recoveries of added GSH or GSSG from the liver and bile samples
were accurate and precise. The assay was applied to measurement of GSH, GSSG, and GSH:GSSG ratio in the liver and serially
collected bile samples in sham-operated and ischemic rat livers, demonstrating a depletion of glutathione and a decrease in
the GSH:GSSG ratio as a result of ischemia. The developed assay is rapid, sensitive, accurate, and precise and is suitable
for studies of the redox status of liver under physiologic and pathophysiologic conditions. 相似文献
39.
SBA-15负载Pd催化剂的制备及其在Heck反应中的应用研究 总被引:2,自引:0,他引:2
利用水热反应制备了表面离子液体功能化的SBA-15介孔材料,在丙酮溶液中与氯化钯反应,然后使用水合肼在乙醇中还原.测试了这种催化剂在Mizoroki-Heck反应中的催化活性.与直接负载在SBA-15上的钯催化剂相比,这种表面修饰的介孔SBA-15负载催化剂表现出更高的催化活性、可回收性和反应稳定性.氮气吸脱附实验和小角XRD衍射实验表明,在合成中,材料的介孔性能并没有被破坏.透视电镜也表征了该材料的表面形貌.最后,Mizoroki-Heck反应表明该催化剂具有很高的催化活性,且循环五次后,其催化活性降低并不明显. 相似文献
40.
Fangyi Cheng Qing Zhao Xiaopeng Han Jun Chen 《Angewandte Chemie (International ed. in English)》2015,54(14):4338-4343
The ever‐increasing consumption of a huge quantity of lithium batteries, for example, Li–MnO2 cells, raises critical concern about their recycling. We demonstrate herein that decayed Li–MnO2 cells can be further utilized as rechargeable lithium–air cells with admitted oxygen. We further investigated the effects of lithiated manganese dioxide on the electrocatalytic properties of oxygen‐reduction and oxygen‐evolution reactions (ORR/OER). The catalytic activity was found to be correlated with the composition of LixMnO2 electrodes (0<x<1) generated in situ in aprotic Li–MnO2 cells owing to tuning of the Mn valence and electronic structure. In particular, modestly lithiated Li0.50MnO2 exhibited superior performance with enhanced round‐trip efficiency (ca. 76 %), high cycling ability (190 cycles), and high discharge capacity (10 823 mA h gcarbon?1). The results indicate that the use of depleted Li–MnO2 batteries can be prolonged by their application as rechargeable lithium–air batteries. 相似文献