Suchergebnisse

Benzene in the body can cause central nervous system disorder, hematology disorder and the target is bone marrow. Benzene is used widely at the painting workshop as dissolvent since it is easily dissolved in paint. Workers who work at the workshop using spray paint have a high risk to benzene. The aim of the study was to analyze factors such as work experience, duration of spraying, ventilation, respirator and the most dominant factor affecting the Phenol level in the urine of the workers. The study was conducted at Painting workshop In Makassar and taking urine samples workers in the Occupational and Health Safety (OHS) laboratory. The study is done using a cross sectional design. The selection of samples was done by proportional random sampling with the Chi square analyses. The study benzene concentration in phenol level urine result that: (1) the employment duration ? 1 year (new) have poisoning 0%, normal 6,7% and the employment > 1 year (old) have poisoning 30%, normal 63,3%, (2) duration of spraying > 8 jam (long time) have poisoning 30%, normal 26,7% and spraying < 8 jam (short time) have poisoning 0%, normal 43,3%, (3) mild poisoning 26,6%, moderate poisoning 3,33%. The study indicates that benzene concentration have an effect Phenol levels in the urine are duration of employment and duration of spraying. It is recommended that control in working environment be done and use personal protective equipment for the workers. Related institution is hoped to control, guide and enforce rulers and legislation on matters pertaining to manpower especially occupational health and safety.

Dietary medicinal herbs (DMHs) are superior reservoirs for natural antioxidants and safe for long‐term consumption. Chinese government recently announced an official list of traditional Chinese DMHs to support civil health promotion. However, antioxidative capacity (AOC) and total phenol contents (TPC) of these listed herbs were not comprehensively and systematically evaluated. In this study, AOC of 94 listed DMHs in water extract were investigated by three techniques including radical scavenging and ferric reducing antioxidative power. The results showed that emblic leafflower, rose, and clove possessed the highest AOC, while TPC was significantly correlated with AOC. While traditional Chinese medicines are categorized by the nature of Yin‐Yang, this study demonstrated that Yin DMHs are statistically correlated with high AOC. Practical application: In this study, AOC and TPC of 94 traditional Chinese DMHs were documented systematically. Emblic leafflower, rose and clove were shown to possess the highest AOC. TPC in traditional Chinese DMHs was significantly correlated with the AOC, while DMHs with Yin characteristic might be used as an indicator to identify potential antioxidative herbs.

[Abstract] Photocatalyzed degradation of phenol in aqueous solution over surface impregnated TiO₂ (M = Cu, Cr, V) under UV-Vis (366 nm) and UV (254 nm) irradiation is described. Nanosized photocatalyts were prepared from TiO₂-P25 by wet impregnation, and characterized by X-ray diffraction, X-ray fluorescence, transmission electron microscopy, UV-Vis diffuse reflectance spectroscopy, Raman spectroscopy, and adsorption studies. No oxide phases of the metal dopants were found, although their presence in the TiO₂-P25 lattice induces tensile strain in Cu-impregnated TiO₂-P25, whereas compressive strain in Cr- and V-impregnated TiO₂-P25. Experimental evidences support chemical and mechanical stability of the photocatalysts. Type IV N₂ adsorption–desorption isotherms, with a small H3 loop near the maximum relative pressure were observed. Metal surface impregnated photocatalysts are mesoporous with a similar surface roughness, and a narrow pore distribution around ca. 25 Å. They were chemically stable, showing no metal lixiviation. Their photocatalytic activity was followed by UV-Vis spectroscopy and HPLC–UV. A first order kinetic model appropriately fitted the experimental data. The fastest phenol degradation was obtained with M (0.1%)/TiO₂-P25, the reactivity order being Cu > V » Cr > TiO₂-P25 under 366 nm irradiation, while TiO₂-P25 > Cu > V > Cr, when using 254 nm radiation. TOC removal under 366 nm irradiation for 300 min showed almost quantitative mineralization for all tested materials, while 254 nm irradiation for 60 min led to maximal TOC removal (ca. 30%). Photoproducts and intermediate photoproducts were identified by HPLC–MS, and appropriate reaction pathways are proposed. The energy efficiency of the process was analysed, showing UV lamps are superior to UVA lamps, and that the efficiency of the surface impregnated catalyst varies in the order Cu > V > Cr. ; This research was partially supported by the Group of Chemical Reactivity & Photoreactivity at University and funded by the Spanish Ministerio de Economía y Competitividad through project CTQ2015-71238-R (MINECO/FEDER), and the regional government Xunta de Galicia (Project Grupo Potencial Crecemento (GPC) ED431B 2017/59), respectively ; Xunta de Galicia; ED431B 2017/59

Dietary medicinal herbs (DMHs) are superior reservoirs for natural antioxidants and safe for long‐term consumption. Chinese government recently announced an official list of traditional Chinese DMHs to support civil health promotion. However, antioxidative capacity (AOC) and total phenol contents (TPC) of these listed herbs were not comprehensively and systematically evaluated. In this study, AOC of 94 listed DMHs in water extract were investigated by three techniques including radical scavenging and ferric reducing antioxidative power. The results showed that emblic leafflower, rose, and clove possessed the highest AOC, while TPC was significantly correlated with AOC. While traditional Chinese medicines are categorized by the nature of Yin‐Yang, this study demonstrated that Yin DMHs are statistically correlated with high AOC.

Organosolv wheat straw lignin extracted using the CIMV processTM is a linear, low molecular weight, and natural phenolic oligomer. In this study, organosolv wheat straw lignin was tested as a substitute for 50% to 70% of the phenol in a phenol-formaldehyde-resol resin. The lignin was used without any chemical modification in a one-step synthesis reaction. Parameters such as reaction time and formaldehyde-to-phenol sources (phenol + lignin) mass ratios were optimized to achieve the requirements for industrial wood adhesives in terms of pH, viscosity, and dry matter. For the first time, the formaldehyde ratio was studied in order to reduce resin residual free formaldehyde below 1%. Lignin-phenol-formaldehyde resins were successfully synthesized up to a phenol substitution rate of 70% and showed physico-chemical properties close to standard phenol-formaldehyde resins. The thermo-mechanical properties analyzed in dynamic load thermo mechanical analysis were similar to those of the reference resins. Plywood panels manufactured using these lignin-based resins reached the specifications for industrial panels according to the French standard for exterior plywood panels. Moreover, the formaldehyde content of these plywoods was low enough to satisfy even the most rigorous legislation.

International audience ; Organosolv wheat straw lignin extracted using the CIMV processTM is a linear, low molecular weight, and natural phenolic oligomer. In this study, organosolv wheat straw lignin was tested as a substitute for 50% to 70% of the phenol in a phenol-formaldehyde-resol resin. The lignin was used without any chemical modification in a one-step synthesis reaction. Parameters such as reaction time and formaldehyde-to-phenol sources (phenol + lignin) mass ratios were optimized to achieve the requirements for industrial wood adhesives in terms of pH, viscosity, and dry matter. For the first time, the formaldehyde ratio was studied in order to reduce resin residual free formaldehyde below 1%. Lignin-phenol-formaldehyde resins were successfully synthesized up to a phenol substitution rate of 70% and showed physico-chemical properties close to standard phenol-formaldehyde resins. The thermo-mechanical properties analyzed in dynamic load thermo mechanical analysis were similar to those of the reference resins. Plywood panels manufactured using these lignin-based resins reached the specifications for industrial panels according to the French standard for exterior plywood panels. Moreover, the formaldehyde content of these plywoods was low enough to satisfy even the most rigorous legislation.

AbstractBoron nitride (BN) and reduced graphene oxide (rGO) of different loadings were composited with commercial P25 TiO2 (Ti) through the hydrothermal method. The as-prepared nanocomposites were characterized using various techniques: X-ray photoelectron spectroscopy, X-ray diffraction, thermal gravimetric analysis, Fourier transform infrared and Raman spectroscopies, and transmission and scanning electron microscopies. It was observed that 10% and 0.1% of BN and rGO, respectively, loaded on TiO2 (10BNr0.1GOTi) resulted in the best nanocomposite in terms of phenol degradation under simulated sunlight. A 93.4% degradation of phenol was obtained within 30 min in the presence of H2O2. Finally, to ensure the safe use of BNrGOTi nanoparticles in the aquatic environment, acute zebrafish toxicity (acutoxicity) assays were studied. The 96-h acute toxicity assays using the zebrafish embryo model revealed that the LC50 for the BNrGOTi nanoparticle was 677.8 mg L−1 and the no observed effect concentration (NOEC) was 150 mg L−1. Therefore, based on the LC50 value and according to the Fish and Wildlife Service Acute Toxicity Rating Scale, BNrGOTi is categorized as a "practically not toxic" photocatalyst for water treatment.