Minerals and constitutes in drinking water are vital for the nutrition of human bodies. Certain limits of water quality parameters must be met to ensure the safety of bottled drinking water for the human consumption. ...Minerals and constitutes in drinking water are vital for the nutrition of human bodies. Certain limits of water quality parameters must be met to ensure the safety of bottled drinking water for the human consumption. Thirty two local and twelve imported brands of bottled water in Saudi Arabia have been collected to verify their compliance with international and local standards which are EPA (2016), WHO (2013) and SASO (2009). A proposed scoring system is used to evaluate the water quality. Fayha and Hilwa brands have been selected as the best local brands whereas Volvic brand as the optimal imported brand in the western region of Saudi Arabia. The local water brands are more reliable to the standards than the imported brands. Licensed water brands in Saudi Arabia are found to have a good water quality which satisfied the quality requirements.展开更多
This paper describes the method of two important mathematical techniques used in chemical engineering applications. Solving a mass transfer problem, weather in finite or semi-infinite domain, may seem difficult withou...This paper describes the method of two important mathematical techniques used in chemical engineering applications. Solving a mass transfer problem, weather in finite or semi-infinite domain, may seem difficult without the practice of Finite Fourier Transform (FFT) and Similarity Transformation. Finite systems refer to any closed system that has a specific boundary that can be determined. For example, polymer sheets, membranes, storage tanks, oil reservoirs and a human stomach are determined to be finite systems where FFT is applicable to derive expressions for concentration profiles of the materials in the system. However, Similarity Transformation method is used to identify the concentration profile in semi-infinite systems that have no limits. It has been approved that we may also use the similarity procedure for finite systems since our results are almost the same. Methodologies of both techniques have been discussed thoroughly in order to apply them to a water-polymer diffusion system for the determination of the concentration of water in a polymer sheet of PET. Discussion and comparison between FFT and similarity is included to illustrate the power of each mathematical procedure in predicting and modeling mass concentrations.展开更多
文摘Minerals and constitutes in drinking water are vital for the nutrition of human bodies. Certain limits of water quality parameters must be met to ensure the safety of bottled drinking water for the human consumption. Thirty two local and twelve imported brands of bottled water in Saudi Arabia have been collected to verify their compliance with international and local standards which are EPA (2016), WHO (2013) and SASO (2009). A proposed scoring system is used to evaluate the water quality. Fayha and Hilwa brands have been selected as the best local brands whereas Volvic brand as the optimal imported brand in the western region of Saudi Arabia. The local water brands are more reliable to the standards than the imported brands. Licensed water brands in Saudi Arabia are found to have a good water quality which satisfied the quality requirements.
文摘This paper describes the method of two important mathematical techniques used in chemical engineering applications. Solving a mass transfer problem, weather in finite or semi-infinite domain, may seem difficult without the practice of Finite Fourier Transform (FFT) and Similarity Transformation. Finite systems refer to any closed system that has a specific boundary that can be determined. For example, polymer sheets, membranes, storage tanks, oil reservoirs and a human stomach are determined to be finite systems where FFT is applicable to derive expressions for concentration profiles of the materials in the system. However, Similarity Transformation method is used to identify the concentration profile in semi-infinite systems that have no limits. It has been approved that we may also use the similarity procedure for finite systems since our results are almost the same. Methodologies of both techniques have been discussed thoroughly in order to apply them to a water-polymer diffusion system for the determination of the concentration of water in a polymer sheet of PET. Discussion and comparison between FFT and similarity is included to illustrate the power of each mathematical procedure in predicting and modeling mass concentrations.
