29 research outputs found
ELF Electric and Magnetic Fields Exposure Assessment of Live-Line Workers for 132 kV Transmission Line of SEC
This paper presents an exposure assessment study for live-line workers exposed to transmission line power frequency electric and magnetic fields. A double circuit transmission line is selected. Practical exposure scenarios which represent actual working conditions for live-line workers have been identified. The charge simulation method has been adopted to compute the external electric field around the selected 132 kV transmission line. A method based on Ampere law has been chosen to compute the external magnetic field around the transmission line. Both methods are numerically solved using the EPRFs EMF Workstation software. A comparison between the values of external electric and magnetic fields, with the allowable exposure limits set by the international standards has been conducted. The paper concluded that the levels of workers exposures to extremely low frequency electric and magnetic fields are below the recommended international standards limits for the scenarios considered in this wor
ELF Electric and Magnetic Fields Exposure Assessment of Live-Line Workers for 132 kV Transmission Line of SEC
This paper presents an exposure assessment study for live-line workers exposed to transmission line power frequency electric and magnetic fields. A double circuit transmission line is selected. Practical exposure scenarios which represent actual working conditions for live-line workers have been identified. The charge simulation method has been adopted to compute the external electric field around the selected 132 kV transmission line. A method based on Ampere law has been chosen to compute the external magnetic field around the transmission line. Both methods are numerically solved using the EPRFs EMF Workstation software. A comparison between the values of external electric and magnetic fields, with the allowable exposure limits set by the international standards has been conducted. The paper concluded that the levels of workers exposures to extremely low frequency electric and magnetic fields are below the recommended international standards limits for the scenarios considered in this wor
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
A simple and rapid spectrophotometric method for the determination of nitrite by its decolorizing effect on peroxovanadate complex
A rapid, simple, and most economical spectrophotometric method was proposed for the determination of nitrite in various water samples, soil samples, and roots of leguminous plants. The method is based on decolorizing effect of nitrite on complex formed between hydrogen peroxide and vanadate in acidic medium. The decolorization of that complex by nitrite was exploited to monitor the reaction spectrophotometrically at 470nm.The method was optimized for effect of concentrations of ammonium metavanadate, hydrogen peroxide, various acids, concentrations of sulphuric acid, order of reagents addition and color stability. The color of the complex was found to be stable for about 2 days, and the stability constant of the complex was also calculated by modified Job's method. The linearity range of the calibration graph was over 6.67–66.7μgml−1 of nitrite with molar absorptivity, 0.276×103mol−1lcm−1 and Sandell's sensitivity, 0.1667μgcm−2. The method was applied successfully for the determination of nitrite in soil samples, various wastewater samples and roots of leguminous plants
Simple spectrophotometric method for the determination of sulfur dioxide by its decolorizing effect on the peroxovanadate complex
A simple, rapid, and economical spectrophotometric method is developed for the determination of sulfur dioxide in sugar and air samples. The developed method is based on a red-brown peroxovanadate complex (λmax = 470 nm) produced in 2 M sulfuric acid when ammonium metavanadate is treated with hydrogen peroxide. Under fixed concentrations of hydrogen peroxide and ammonium metavanadate, when sodium metabisulfite (Na2S2O5 = 2SO2) is added, it preferentially reacts with hydrogen peroxide producing sulfuric acid, and the unreacted hydrogen peroxide then reacts with ammonium metavanadate; therefore, the concentration of sulfur dioxide is directly proportional to a decrease in the concentration of the peroxovanadate complex. The stoichiometric ratio between hydrogen peroxide and ammonium metavanadate as well as the stability constant of the complex are determined by the modified Job’s method and the respective values are found to be 1: 1 and 2.5 × 104 mol−1 L, respectively. The system obeys Lambert-Beer’s law in the concentration range 3.57–64.26 ppm of sulfur dioxide. The molar absorptivity, correlation coefficient, and Sandell’s sensitivity values are found to be 0.649 × 103 L mol−1 cm−1, 0.9908, and 0.1972 μg cm−2, respectively. The method is applied to the determination of sulfur dioxide present in commercial sugars and air samples. The results obtained are reproducible with a standard deviation of 0.02–0.05. For method validation, sulfur dioxide is also determined separately following the AOAC method for an air sample and the ICUMSA method for commercial sugars. The results obtained by the developed and official methods are in good agreement
A simple spectrophotometric determination of Phosphate in sugarcane juices, water and detergent Samples
A simple spectrophotometric method is developed for the determination of phosphate in sugar cane juice, water and detergent samples. The method is based on the formation of phosphomolybdate with added molybdate followed by its reduction with sodium sulphide in aqueous sulfuric acid medium. The system obeys Lambert-Beer’s law at 715 nm in the concentration range 0.3-12.24 ppm. Molar absorptivity, correlation coefficient and Sandell’s sensitivity values were found to be 6.1x103 mol-1 cm-1, 0.999 and 0.0156 µg cm-2 respectively. The results obtained were reproducible with acceptable standard deviation 3.7% and relative error 3.4%. For a comparison of the method phosphate present in various samples were also determined separately following an official method. The results of the developed method compare well with those of the official method
A New Spectrophotometric Method for Hydrogen Sulphide Through Electrolytically Generated Mn(III) With O-Tolidine
A simple, sensitive and economical spectrophotometric method for the determination of hydrogen sulphide is developed. The method is based on a redox reaction in that Mn(III) generated electrolytically is taken in excess, which is oxidizing a known but a less quantity of hydrogen sulphide and the unreacted oxidant will oxidize further o-tolidine to produce an orange yellow quinonediimine absorbing cation (λ max. 455 nm). Therefore, in principle, the decrease in color intensity of the absorbing system is proportional to the concentration of hydrogen sulphide. The stoichiometry between Mn(III) and o-tolidine and stability constant of the complex were determined by Job's continuous method, the corresponding values were found to be 2:1 and 1.42X105 Lmol-1. The system was obeying Lambert-Beer's law in the range 0.2-1.4 μg mL-1 of hydrogen sulphide. Molar absorptivity, correlation coefficient and Sandell's sensitivity values were also calculated and found to be 4.2062X103 L mol-1 cm-1, 0.999 and 0.0012 μg cm-2 respectively. The method was employed for the determination of hydrogen sulphide in water samples. The results obtained were reproducible with acceptable standard deviation 0.01-0.068 and relative standard deviation, less than 3.21%. For a comparison, hydrogen sulphide present in water samples were also determined separately following the methylene blue official method. The results of the proposed method compare well with the official method