نتایج جستجو برای: formaldehyde threshold limit values
تعداد نتایج: 792106 فیلتر نتایج به سال:
Background and Objective: Formaldehyde is a hazardous compound that used as a chemical preservative and disinfectant in medical laboratories and hospitals. The aim of this study was to risk assessment of occupational exposure to formaldehyde in different educational hospitals of Baqiyatallah University of Medical Sciences in Tehran. Materials and Methods: This descriptive cross-sectional st...
A previous study of synthesizing low mole ratio urea–formaldehyde (UF) and urea–melamine–formaldehyde (UMF) resins, which included an acidic reaction step at the beginning of the typical resin synthesis procedure to obtain higher uron-type methylene–ether group contents, was repeated with the acidic reaction step extended to a higher viscosity. Compared to previous resins, the synthesized resin...
A spectrophotometric method for the determination of formaldehyde in foodstuffs was described by using phloroglucinol as the chromogenic agent. The reaction between formaldehyde and phloroglucinol could occur rapidly at room temperature under mild conditions. The spectrophotometric measurements were conducted at 474nm of an unstable intermediate orange product of the reaction, which greatly inc...
The objective of this study was to measure formaldehyde present in the atmosphere of a machine shop using a water-based emulsion metalworking fluid containing the formaldehyde-generating antimicrobial agent methylenebismorpholine. Measured formaldehyde values were compared to estimated atmospheric values calculated from vapor-liquid equilibrium (evaporative) and aerosol (mist) generation. Good ...
in this study, the particleboard was made with rice husk and urea formaldehyde resin of 7, 8, 9 and 10 percent (based on dry weight of rice husk). to improve mechanism of bondability a definite amount of isocyanate resin is introduced to replace the same amount of urea formaldehyde resin. the effect of urea formaldehyde resin and diisocyanate content on bondability was evaluated by studying the...
Research has demonstrated that swine feed can be a fomite for viral transmission and additives reduce contamination. Therefore, the objective of this study was to evaluate two in contaminated with PEDV or PRRSV. Feed included: no treatment, 0.33% commercial formaldehyde-based product, 0.50% medium chain fatty acids (MCFA) blend. samples were inoculated PRRSV alone together at an inoculation con...
formaldehyde in small quantities is commonly analyzed by spectrophotometric methods. one of the most-commonly used spectrophotometric techniques for this purpose is based on the reaction with chromotropic acid. because of its simplicity, sensitivity, selectivity and its low cost, it is still widely used. investigations for replacing the concentrated sulfuric acid with other acids or using more ...
It is essential to understand the consumption pattern of food and how it changes over time to formulate sound economic policies as well as marketing and pricing strategies. In this study, we estimate the Quadratic Almost Ideal Demand System with six rounds of the Family Income Expenditure Survey exploiting the conditional linearity of the demand system. We find that the Filipino diet has become...
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