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In this study, a new rubber surface pattern for a footwear sole was developed to prevent slip-related falls. This pattern shows a high static coefficient of friction (SCOF) and a high dynamic coefficient of friction (DCOF) when sliding against a liquid contaminated surface. A hybrid rubber block, in which a rubber block with a rough surface (Ra = 30.4 μm) was sandwiched between two rubber blocks with smooth surfaces (Ra = 0.98 μm), was prepared. The ratio of the rough surface area to the whole rubber block surface area r was 0%, 30%, 50%, 80%, and 100%. The coefficient of friction of the rubber blocks was measured when sliding against a stainless steel plate with Ra of 0.09 μm contaminated with a 90% aqueous solution of glycerol. While the SCOF increased with an increase of the rough surface area ratio r, the DCOF during steady-state sliding decreased with an increase of the rough surface area ratio r. The rough surface area ratio of 50% achieved a SCOF value around 0.5 or more and a DCOF value greater than 0.5. Furthermore, the difference in the value of the SCOF and DCOF was the smallest for the rubber block with r of 50%. The results indicated that the rubber block with r of 50% would be applicable to a footwear sole surface pattern to prevent slip and fall accidents on contaminated surfaces.  相似文献   
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34.
To evaluate the effect of increasing nitrogen (N) deposition and tropospheric ozone (O3) concentrations on N-saturated forest ecosystems, we investigated the response of Japanese red pine (Pinus densiflora), an N-saturation sensitive tree species, to increasing N load under elevated O3 concentrations. One-year-old seedlings of red pine were treated with three levels of N supply (0, 50 and 100 mg N L-1 fresh soil volume) under two levels of atmospheric O3 concentration (< 5 and 60 ppb) for two growing seasons. Nitrogen treatment did not stimulate dry matter production of the seedlings. Growth inhibition was observed in the highest N treatment under low O3 and in the two higher N treatments under elevated O3. Irrespective of the O3 concentration, increasing N supply negatively affected root growth and mycorrhizal development in fine roots, resulting in a reduction in P and Mg uptake from the soil. Net photosynthetic rate was significantly reduced by both the highest N treatment under low O3 and the two higher N treatments under elevated O3, together with decreased N-availability to Rubisco. Nitrogen assimilated from NO3 - to amino acid in the needles was not affected by the treatments. However, needle protein concentration was reduced by the highest N-treatment under low O3 and by the two higher N-treatments under elevated O3. These results suggest that elevated O3 potentially disturbs the N-availability in the form of protein including Rubisco, and may advance the negative effects of excessive N-deposition on N-sensitive plant species in N-saturated forests.  相似文献   
35.
Using a novel high-sensitivity capillary electrophoretic method, vertical distributions of iodate, iodide, total inorganic iodine, dissolved organic iodine and total iodine in the North Pacific Ocean (0-5500 m) were determined without any sample pre-treatment other than UV irradiation before total iodine analysis. An extensive set of data demonstrated that the iodine behaviour in the ocean water collected during a cruise in the North Pacific Ocean in February-March 2003 was not conservative but correlated with variations in concentrations of dissolved oxygen and nutrient elements such as silicon, nitrogen and phosphorus. This suggests that the vertical distribution of iodine is associated with biological activities. The dissolved organic iodine was found in the euphotic zone in accord with observations elsewhere in the oceans. The vertical profile of dissolved organic iodine also appears to be related to biogeochemical activity. The concentrations of all measured iodine species vary noticeably above 1000 m but only minor latitudinal changes occur below 1000 m and slight vertical alterations can be observed below 2400 m. These findings are thought to reflect the stratification of nutrients and iodine species with different biological activities in the water column.  相似文献   
36.
The purpose of this study was to develop a one-step metal extraction process that would effectively remove hazardous elements from wood powder or chips of western hemlock [Tsuga heterophylla (Raf.) Sarg.] treated with chromated copper arsenate (CCA) preservative. In addition, we tested this method for wood treated with other copper-based preservatives such as ammoniacal copper quaternary (ACQ) and copper, boron, and azole (CuAz). A bioxalate solution consisting of 0.125 M oxalic acid adjusted to pH 3.2 with sodium hydroxide was tested for its ability to extract chromium, copper, and arsenic from wood treated with CCA and copper from ACQ, CuAz, or a mixture of CCA-, ACQ-, and CuAz-treated wood in single step. The extraction proceeded efficiently with 6 h of treatment, and was insensitive to the differences in chemical characteristics, including solubility of individual elements. After 6 h of treatment, approximately 90% of chromium, copper, and arsenic were effectively removed from wood treated with CCA or a mixture of CCA, ACQ, and CuAz and 90% of copper from ACQ- and CuAz-treated wood. These results demonstrate that the solvent extraction technique using pH-adjusted bioxalate solution with sodium hydroxide is a promising method for pollution minimization by various types of wastes contaminated with heavy metals and arsenic.  相似文献   
37.
Industrialization and urbanization result in significant changes in lifestyle. These lifestyle changes seem to lead to unsustainable consumption patterns and increase the generation of various kinds of environmental loads, especially the amount of municipal solid waste (MSW). Taiwan is a small island with scarce natural resources. The economic development in Taiwan has resulted in the generation of large amounts of MSW. As a result, the Taiwan Environmental Pollution Administration (TEPA) has produced regulations for waste minimization and has imposed several important policy measures that have successfully reduced the MSW discard rate in recent years and have established a public recycling network as a part of the MSW collection. Nowadays, the objective of the MSW policies in Taiwan is to develop a “zero-waste society.” This article aims to review the MSW management progress in Taiwan and to project future MSW discards up to 2011 based on the national plan and assumed scenarios for socioeconomic variables. According to the analysis results, a more sustainable consumption pattern can be proposed and the corresponding MSW management system can be planned so as to develop a low-waste-discard society.  相似文献   
38.
To recycle municipal solid waste incinerator (MSWI) bottom ash, synthesis of hydrothermal minerals from bottom ash was performed to stabilize heavy metals. MSWI bottom ash was mixed with SiO(2), Al(OH)(3), and Mg(OH)(2) so its chemical composition was similar to that of hydrothermal clay minerals. These solid specimens were mixed with water at a liquid/solid ratio of 5. The reaction temperature was 200 degrees C, and reactions were performed for 24-240h. Generation of kaolinite/smectite mixed-layer clay mineral was found in the samples after the reaction of the mixture of bottom ash, SiO(2), and Mg(OH)(2). Calcium silicate hydrate minerals such as tobermorite and xonotlite were also generated. X-ray powder diffraction suggested the presence of amorphous materials. Leaching tests at various pHs revealed that the concentration of heavy metals in the leachates from MSWI bottom ash hydrothermally treated with SiO(2) and Mg(OH)(2) was lower than that in leachates from non-treated bottom ash, especially under acid conditions. Hydrothermal treatment with modification of chemical composition may have potential for the recycling of MSWI bottom ash.  相似文献   
39.
To analyze the effect of polychlorinated biphenyl (PCB) 118 on fish bone metabolism, we examined osteoclastic and osteoblastic activities, as well as plasma calcium levels, in the scales of PCB (118)-injected goldfish. In addition, effect of PCB (118) on osteoclasts and osteoblasts was investigated in vitro. Immature goldfish, in which the endogenous effects of sex steroids are negligible, were used. PCB (118) was solubilized in dimethyl sulfoxide at a concentration of 10 ppm. At 1 and 2 days after PCB (118) injection (100 ng/g body weight), both osteoclastic and osteoblastic activities, and plasma calcium levels were measured. In an in vitro study, then, both osteoclastic and osteoblastic activities as well as each marker mRNA expression were examined. At 2 days, scale osteoclastic activity in PCB (118)-injected goldfish increased significantly, while osteoblastic activity did not change significantly. Corresponding to osteoclastic activity, plasma calcium levels increased significantly at 2 days after PCB (118) administration. Osteoclastic activation also occurred in the marker enzyme activities and mRNA expressions in vitro. Thus, we conclude that PCB (118) disrupts bone metabolism in goldfish both in vivo and in vitro experiments.  相似文献   
40.

Purpose  

The purpose of this study was to evaluate the influences of volatile organic compounds (VOCs) emissions on hazardousness and photochemical reactivity and to propose efficient VOCs abatement strategies.  相似文献   
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