A field assessment of floor slipperiness in a fish market in Taiwan

A field assessment of floor slipperiness in 10 fish stands in a fish market in Taiwan was conducted using both friction measurements and subjective ratings. The friction measurements were conducted using the Portable Skid Resistance Tester (PSRT). The subjective ratings of floor slipperiness of both the workers and the customers were collected. The friction measurement results showed that the sink areas had both the lowest friction values and subjective ratings. The overall friction measurement results and the subjective ratings were in fair agreement (r = 0.46 and ρ = 0.49). The customers perceived the walkways as somewhere between “very slippery” to “somewhat slippery” and the picking-up areas as “very slippery.” These were different from the perceptions of the workers where they perceived both areas as “somewhat slippery.”     

Temperature Dependence of Nickel Stabilization in Inorganic Oxide Matrices

Abstract

Scanning electron microscopy, X‐ray diffractometry, X‐ray absorption spectroscopy, and other means are used to investigate the effect of thermal treatment temperature, 105–1100 °C, on the immobilization of nickel (Ni) by the inorganic oxides of latosol. Ni is more firmly immobilized by the latosol with increasing temperature. Spectral analyses indicate that a shoulder toward the edge‐jump appears in the spectra of X‐ray absorption near‐edge structure for the samples heated at 900 and 1100 °C. Moreover, the intensity of the main peak at the edge increases with higher temperature; this information indicates the distortion of the divalent nickel [Ni(II)] environment in the samples heated at 900 and 1100 °C. Nevertheless, the distortion is absent from the samples heated at 105 and 500 °C. The fact of the distortion of the Ni(II) environment suggests the occurrence of a chemical reaction between the Ni compound and the inorganic matrices of the latosol soil during the heating process at 900 and 1100 °C. In addition, the extended X‐ray absorption fine structure results correspond well to the X‐ray absorption near‐edge structure results; the former are supportive of the occurrence of a distorted Ni(II) environment in the samples heated at 900 and 1100 °C. The wet‐chemistry results show that the samples heated at 900–1100 °C leach less Ni than the 105–500 °C samples do. The change of the Ni environment is related to the observation that less Ni is leached from the samples heated at 900–1100 °C. Furthermore, the pore closing phenomenon is observed only in the 1100 °C sample; this phenomenon corresponds with the fact that the 1100 °C sample leaches less Ni than the 900 °C sample does.     

Temperature dependence of nickel stabilization in inorganic oxide matrices

Scanning electron microscopy, X-ray diffractometry, X-ray absorption spectroscopy, and other means are used to investigate the effect of thermal treatment temperature, 105-1100 degrees C, on the immobilization of nickel (Ni) by the inorganic oxides of latosol. Ni is more firmly immobilized by the latosol with increasing temperature. Spectral analyses indicate that a shoulder toward the edge-jump appears in the spectra of X-ray absorption near-edge structure for the samples heated at 900 and 1100 degrees C. Moreover, the intensity of the main peak at the edge increases with higher temperature; this information indicates the distortion of the divalent nickel [Ni(II)] environment in the samples heated at 900 and 1100 degrees C. Nevertheless, the distortion is absent from the samples heated at 105 and 500 degrees C. The fact of the distortion of the Ni(II) environment suggests the occurrence of a chemical reaction between the Ni compound and the inorganic matrices of the latosol soil during the heating process at 900 and 1100 degrees C. In addition, the extended X-ray absorption fine structure results correspond well to the X-ray absorption near-edge structure results; the former are supportive of the occurrence of a distorted Ni(II) environment in the samples heated at 900 and 1100 degrees C. The wet-chemistry results show that the samples heated at 900-1100 degrees C leach less Ni than the 105-500 degrees C samples do. The change of the Ni environment is related to the observation that less Ni is leached from the samples heated at 900-1100 degrees C. Furthermore, the pore closing phenomenon is observed only in the 1100 degrees C sample; this phenomenon corresponds with the fact that the 1100 degrees C sample leaches less Ni than the 900 degrees C sample does.     

Molecular study of thermal immobilization of chromium(VI) with clay

Clay that contains kaolinite has been used extensively as a raw material for manufacturing of bricks and china at 900-1100 degrees C. This study used clay to stabilize the contaminant chromium(VI) [Cr(VI)] through a heating process at 500-1100 degrees C. X-ray absorption spectroscopic results indicated that the 500-900 degrees C heating process transformed hazardous Cr(VI) to nontoxic Cr(III); Cr2O3 was the species detected as most abundant. The 1100 degrees C heating process caused the formation of Cr2SiO5, which was not detected in the samples heated at 500-900 degrees C. Fourier transformed extended X-ray absorption fine structure spectra were fitted by use of WinXAS software. Phase shifts and backscatter(ing) amplitudes for specific atom pairs, based on the crystallographic data for CrO3 and Cr2O3, were theoretically calculated with the FEFF software. The processed XAS data show that the first shell coordination numbers were similar to each other as the temperature was increased from 500 to 900 degrees C and 1100 degrees C, implying that their Cr(III) crystallite size was relatively similar. The interatomic distance between the target center element and the first shell for the 500-1100 degrees C samples was 1.98 A. The Debye-Waller factor for the 1100 degrees C sample was increased compared with the 500 and 900 degrees C samples and probably indicates the formation of Cr2SiO5.     

Comparison of mercury bioaccumulation between wild and mariculture food chains from a subtropical bay of Southern China

Bioaccumulation and trophic transfer of mercury (Hg) both in the natural marine ecosystem and the mariculture ecosystem were studied at Daya Bay, a subtropical bay in Southern China. Averaged Hg concentrations in sediment, phytoplankton, macrophyte, shrimp, crab, shellfish, planktivorous fish, carnivorous fish, farmed pompano, farmed snapper, compound feed and trash fish were 0.074, 0.054, 0.044, 0.098, 0.116, 0.171, 0.088, 0.121, 0.210, 0.125, 0.038 and 0.106 μg g⁻¹ dw, respectively. These Hg levels were at the low–middle ends of the global range. Positive correlation between Hg concentrations in farmed fish and fish weights/sizes was observed, whereas no clear correlation between Hg concentrations and lipid contents was found. Hg concentrations followed macrophyte < phytoplankton < sediment < planktivorous fish < shrimp < crab < carnivorous fish < shellfish, and commercial feed < trash fish < farmed fish. Hg was biomagnified along the marine food chain in the ecosystem of Daya Bay. Hg levels in the farmed fish were higher than those in the wild fish primarily because of the higher Hg level in fish feed and the smaller size of marine wild fish.

     

1985 Directory of Governmental Air Pollution Control Agencies

Abstract

Clay that contains kaolinite has been used extensively as a raw material for manufacturing of bricks and china at 900–1100 °C. This study used clay to stabilize the contaminant chromium(VI) [Cr(VI)] through a heating process at 500–1100 °C. X-ray absorption spectroscopic results indicated that the 500–900 °C heating process transformed hazardous Cr(VI) to nontoxic Cr(III); Cr₂O₃ was the species detected as most abundant. The 1100 °C heating process caused the formation of Cr₂SiO₅, which was not detected in the samples heated at 500–900 °C. Fourier transformed extended X-ray absorption fine structure spectra were fitted by use of WinXAS software. Phase shifts and backscatter(ing) amplitudes for specific atom pairs, based on the crystallographic data for CrO₃ and Cr₂O₃, were theoretically calculated with the FEFF software. The processed XAS data show that the first shell coordination numbers were similar to each other as the temperature was increased from 500 to 900 °C and 1100 °C, implying that their Cr(III) crystallite size was relatively similar. The interatomic distance between the target center element and the first shell for the 500– 1100 °C samples was 1.98Å. The Debye-Waller factor for the 1100 °C sample was increased compared with the 500 and 900 °C samples and probably indicates the formation of Cr₂SiO₅.