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The aim of this study was to design and build a software for noise propagation prediction (indoor and from indoor to outdoor spaces) being commonly used in industry. In this regard, firstly a mathematical complex model was created based on existing relationships on noise propagation in indoor spaces and transmission through the walls and propagation in outdoor spaces. To model noise propagation from indoor to outdoor, the function of this model is based on meshing the wall which is effective on outdoor receiver point. By analyzing the required inputs and outputs and designing and documenting the process algorithm, the mathematical model was created and the software was built. In the process of meshing the wall, the software divides the effective wall into 20 parts in length and width and calculations related to sound pressure level on inner wall surface, transmission loss through the wall and leakage from the pores are performed on these meshes. The built software was designed in five forms. Form one for defining hall dimensions and areas of used materials, form two and tree for defining sound sources inside the hall and form five for defining and managing materials were designed. Form four was used for completing required information and monitoring calculation results and software outputs. The software was run with the input data of a gas power plant and outputs were analyzed. The average relative difference between outputs of software (sound pressure levels in given points) and field measurements was below 5%. [ABSTRACT FROM AUTHOR]

Carbon Monoxide (CO) poisoning is one of the most common causes of death in Iran. The present study investigated the indoor and outdoor CO concentrations at hospitals under the supervision of Mazandaran University of Medical Sciences in Sari, Iran. Indoor and outdoor measured CO were conducted over a period of one month during the 2012 winter season in 4 hospital kitchens using a direct measurement device specialized for CO. The average concentrations of CO gas through gas measuring stations were considered at three stations both in and out of the kitchens. The highest and the lowest average concentrations of outdoor CO in Fatemeh Zahra Hospital (about 2 ppm) and Zare Hospital (about 0.33 ppm) were measured respectively. Besides, the highest and the lowest average concentrations of indoor CO were detected in Imam Hospital (as 9.66 ppm) and BuAli Hospital (as7.66 ppm). The highest ratios of I/O (approximately 10 ppm) have been conducted between 8:00 and 9:00a.m. The lowest median concentrations of CO (approximately 8 ppm) between 11:00 and 12:00 a.m. have been measured. Concentrations of CO in all hospitals in this study were significant. This fact shows poorly ventilation of kitchen due to lack of ventilation design engineering. [ABSTRACT FROM AUTHOR]