A Study on the Assessment of Management Frameworks for Waste Electronic Home Appliances

Serious adverse impacts on the environment and human health from the recycling and disposal of electronic waste have occurred in the past and continue to occur in China today, due to the lack of a national management strategy. With aiming to support the management strategy development, a study was carried out to plan and quantitatively evaluate the optional management frameworks for the selected five main types of large electronic home appliances in Beijing, the capital city and a typically big municipality in China. This paper outlined the main findings yielded from the series of assessment studies which started from the generation amount prediction and material flow analysis of the used electronic appliances, planning and optimization of the collection & transportation frameworks and ended at the economic evaluation of the optional recycling processes for the waste appliances. Although the revenue could be expected from the result of isolated evaluation of the recycling processes, the entire system will be economically unavailable if the used appliances are still collected from the owners at current prices. The traditional understanding of householders on the values of their used appliances should be changed in Beijing and China as a whole. Establishment of a formal collection system that could take back the used appliances at lower prices (less than 40% of the current level) is the key for the construction of a formal management framework with sustainability

An analysis of the costs of energy saving and CO 2 mitigation in rural households in China

Households may imperfectly implement energy saving measures. This study identifies two factors resulting in imperfect use of energy-saving technology by households. Households often continue to use old technologies alongside new ones, and the energy-saving technologies have shorter actual lifetimes than their designed lifetimes. These two factors are considered when computing marginal energy conservation cost and marginal CO₂ abatement cost using data collected from a survey of rural households in three provinces in China. The results show that there are cost reduction for most space heating technologies, and their marginal abatement cost under full implementation ranges from −60 to 15 USD/t-CO₂, while the marginal abatement cost of cooking technologies ranges from 12 to 85 USD/t-CO₂. The marginal abatement costs of the majority of technologies increased after accounting for the two implementation factors. The marginal abatement cost in the imperfect implementation scenario is higher, with a range of −1 to 15 USD/t-CO₂ for space heating, and 18 to 165 USD/t-CO₂ for cooking. Assuming implementation factors are constant until 2035, annually achievable CO₂ abatement by 2035 is estimated to be 57, 11, and 10 Mt-CO₂/y in Hebei, Guizhou, and Guangxi Provinces.The authors gratefully acknowledge the financial support of the China Ministry of Science and Technology in the national 973 program: Equity and justice in climate change and regional development (funding code: A.02.12.00301). This research was partly funded by the General Research Fund of the Hong Kong Research Grants Council (14619315

Intracellular Trafficking Network of Protein Nanocapsules: Endocytosis, Exocytosis and Autophagy

The inner membrane vesicle system is a complex transport system that includes endocytosis, exocytosis and autophagy. However, the details of the intracellular trafficking pathway of nanoparticles in cells have been poorly investigated. Here, we investigate in detail the intracellular trafficking pathway of protein nanocapsules using more than 30 Rab proteins as markers of multiple trafficking vesicles in endocytosis, exocytosis and autophagy. We observed that FITC-labeled protein nanoparticles were internalized by the cells mainly through Arf6-dependent endocytosis and Rab34-mediated micropinocytosis. In addition to this classic pathway: early endosome (EEs)/late endosome (LEs) to lysosome, we identified two novel transport pathways: micropinocytosis (Rab34 positive)-LEs (Rab7 positive)-lysosome pathway and EEs-liposome (Rab18 positive)-lysosome pathway. Moreover, the cells use slow endocytosis recycling pathway (Rab11 and Rab35 positive vesicles) and GLUT4 exocytosis vesicles (Rab8 and Rab10 positive) transport the protein nanocapsules out of the cells. In addition, protein nanoparticles are observed in autophagosomes, which receive protein nanocapsules through multiple endocytosis vesicles. Using autophagy inhibitor to block these transport pathways could prevent the degradation of nanoparticles through lysosomes. Using Rab proteins as vesicle markers to investigation the detail intracellular trafficking of the protein nanocapsules, will provide new targets to interfere the cellular behaver of the nanoparticles, and improve the therapeutic effect of nanomedicine

Microgrinding of nanostructured materials: Experimentation and theoretical modeling

This study is aimed at experimentally investigating the effect of microgrinding on the integrity of thermally sprayed nanostructured WC/12Co and Al2 O3/13TiO2 coatings and theoretically developing a mechanical model to simulate the machining process of ceramics. A comprehensive microgrinding experiment is designed to study the effects of the grinding process parameters, such as abrasive grit size, wheel bond type, wheel depth of cut, and workpiece feedrate, on surface finish, subsurface damage, and residual stresses of these coatings. The correlation between the grinding conditions and the integrity of ground samples helps provide an experimental basis for developing a viable microgrinding technique for nanostructured materials and coated samples. A simple X-ray diffraction technique, glancing incident X-ray diffraction (GIXD), is introduced to measure the depth profiles of residual stresses in the coatings. The results of the experiment show that the effects of the microgrinding process are limited to the surface layer of ground coatings; the wheel depth of cut is the most influential parameter in the cup-type grinding; ductile flow is the dominant material removal mechanism in grinding n-WC/12Co coatings under all conditions and in grinding n-A1 2O3/13TiO2 at a low material removal rate, the residual stresses induced by the microgrinding process are compressive, strongly depend on the grinding direction, and show a strong gradient in the thickness direction for both coatings. ^ Based on continuum damage mechanics, a theoretical model is developed for predicting the behavior of ceramics under complex loadings. Unlike the linear elastic fracture mechanics, this damage model includes the effects of cracks, microcracks and inelastic deformation. The model is employed to simulate the damage development in ceramic samples during the machining process using a fourth order isotropic damage tensor. The simulated machining process is similar to the interaction between the abrasive grit and a ceramic sample in surface grinding. The final state of damage and residual stresses in the machined ceramic samples is calculated with this model. The simulation results agree well with the experimental results.

Nitric oxide as a new fumigant for postharvest pest control: Presentation

Nitric oxide (NO) is a new fumigant for postharvest pest control. It is effective against all pests tested to date, including external and internal pests of fresh and stored product insects, and mites. Efficacious treatment time ranges from 2 h to 72 h, and NO concentrations range from 0.1% to 5%, depending on species and life stages of the pests. Nitric oxide fumigation must be conducted under ultralow oxygen conditions because NO reacts with O2 spontaneously to produce nitrogen dioxide (NO2), which is toxic to perishable fresh products. Fresh product fumigation must, therefore, also be terminated by flushing with N2 to dilute NO at the end of fumigation to avoid damage to delicate products by NO2. Nitric oxide fumigation was safe in small-scale tests to postharvest quality of all fresh commodities when terminated with N2 flush. In addition, NO fumigation resulted in better postharvest quality of strawberries and apples as compared with controls, indicating its beneficial effects on postharvest quality of fresh products. Twenty fresh fruit and vegetables and 10 stored products were fumigated with NO to determine residue levels of nitrate and nitrite. When terminated properly with N2 flush, NO fumigation does not increase nitrate or nitrite levels in fumigated products. NO fumigation was demonstrated to be effective against all pests, safe to fresh products, and has no toxic residues and, therefore, has the potential to be a practical alternative to methyl bromide fumigation for postharvest pest control on both fresh and stored products.Nitric oxide (NO) is a new fumigant for postharvest pest control. It is effective against all pests tested to date, including external and internal pests of fresh and stored product insects, and mites. Efficacious treatment time ranges from 2 h to 72 h, and NO concentrations range from 0.1% to 5%, depending on species and life stages of the pests. Nitric oxide fumigation must be conducted under ultralow oxygen conditions because NO reacts with O2 spontaneously to produce nitrogen dioxide (NO2), which is toxic to perishable fresh products. Fresh product fumigation must, therefore, also be terminated by flushing with N2 to dilute NO at the end of fumigation to avoid damage to delicate products by NO2. Nitric oxide fumigation was safe in small-scale tests to postharvest quality of all fresh commodities when terminated with N2 flush. In addition, NO fumigation resulted in better postharvest quality of strawberries and apples as compared with controls, indicating its beneficial effects on postharvest quality of fresh products. Twenty fresh fruit and vegetables and 10 stored products were fumigated with NO to determine residue levels of nitrate and nitrite. When terminated properly with N2 flush, NO fumigation does not increase nitrate or nitrite levels in fumigated products. NO fumigation was demonstrated to be effective against all pests, safe to fresh products, and has no toxic residues and, therefore, has the potential to be a practical alternative to methyl bromide fumigation for postharvest pest control on both fresh and stored products