Adding suitable quantity of polypropylene fiber is very effective for controlling plastic crack of cement mortar. During the experience stage, adding quantity of polypropylene fiber is 1.5 kg/m3, and crack rate of mortar is only 7.7%. Theoretical analysis is made for plastic crack mechanism of cement mortar, the results indicate that adding polypropylene fiber improves critical stress of crack expansion in mortar and notably reduces crack of cement mortar.
In China, the environmental impact from the construction of the distribution system is seldom discussed. In this study, the environmental impact from construction of district pipes is considered. The purpose is to identify environmental significant parts in the construction of district pipes and to use the results in the actual projects including once more parts of the district distribution system have been investigated with LCA methodology.(Methods) Construction of district pipe networks according to the technical specification was studied. The total consumption of energy and materials was calculated based on budget norm for projects. The functional unit used in the study is construction of 100 metres of pipe system. The studied pipes are: pipe of the dimension DN100, DN200 (Seamless steel tubes) and DN500 (spirally welded steel tubes) .Urban environment surroundings were studied. A short description of the inventory, some inventory results and a life cycle impact assessment are presented. Based on the concept of the End-point damage weighting method, the total environment load is given.
In China, the environmental impact from the construction of the distribution system is seldom discussed. In this study, the environmental impacts in production of district pipes are considered. The functional unit used in the study is production of one pipe unit. The studied pipes are: pipe of the dimension DN100, DN200 (Seamless steel tubes) and DN500 (spirally welded steel tubes) with specified length (12m). Based on the concept of the Distance-to-Target weighting method, the total environment load is given. The results can be used to identify environmental significant parts in the actual projects including once more parts of the district distribution system have been investigated with LCA methodology.
The uniform hierarchical and microspheric copper oxide (CuO) nanostructures, which have been successfully prepared via a simple one-pot method. The detailed morphology and structure of the synthesized hierarchical and microspheric nanostructures were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) and UVvisible spectroscopy. The morphology of CuO particles depends on the ammonium dihydrogen phosphate (ADP) used in the synthesis, the formation mechanisms were proposed based on the experimental results. The catalytic activity of as-synthesized CuO was demonstrated by catalytic oxidation of methylene blue in the presence of hydrogen peroxide (H2O2) and CuO with hierarchical nanostructures was found to be the best catalyst.
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