10 research outputs found

    Experimental and Theoretical Study on Reverse Osmosis Based Water Desalination

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    Freshwater availability has dropped due to population growth, inefficient use, climate change, and industrial pollution. Although the reverse osmosis, RO, system is one of the most effective desalination technologies worldwide, spiral wound membranes still need deeper theoretical and experimental investigations for removing salts under low energy consumption. In this study, the performance of a commercial pilot RO plant that utilizes a spiral wound seawater membrane module is experimentally investigated under a wide range of operating parameters. In addition, a Mathematical model is developed based on the solution-diffusion model theory and then solved using an in-house MATLAB algorithm to analyze its performance. The theoretical and experimental results were then compared. The present results revealed that the mathematical model’s predictions were highly consistent with the actual experimental results, achieving an average accuracy of about 98%. The average deviation was 4.0578% when predicting water productivity and just 0.2755% when estimating the salt rejection coefficient. The findings of this study could assist designers in predicting the membrane’s performance and selecting the most advantageous operational parameters for supplying water to the RO system

    Experimental and Theoretical Study on Reverse Osmosis Based Water Desalination

    Get PDF
    Freshwater availability has dropped due to population growth, inefficient use, climate change, and industrial pollution. Although the reverse osmosis, RO, system is one of the most effective desalination technologies worldwide, spiral wound membranes still need deeper theoretical and experimental investigations for removing salts under low energy consumption. In this study, the performance of a commercial pilot RO plant that utilizes a spiral wound seawater membrane module is experimentally investigated under a wide range of operating parameters. In addition, a Mathematical model is developed based on the solution-diffusion model theory and then solved using an in-house MATLAB algorithm to analyze its performance. The theoretical and experimental results were then compared. The present results revealed that the mathematical model’s predictions were highly consistent with the actual experimental results, achieving an average accuracy of about 98%. The average deviation was 4.0578% when predicting water productivity and just 0.2755% when estimating the salt rejection coefficient. The findings of this study could assist designers in predicting the membrane’s performance and selecting the most advantageous operational parameters for supplying water to the RO system

    Updated upper limit of normal for serum alanine aminotransferase value in Vietnamese population

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    Background: Alanine aminotransferase (ALT) is a marker of hepatic damage and its range can be affected by viral hepatitis, alcoholic hepatitis and non-alcoholic fatty liver diseases. We aimed to study the factors associated with higher ALT level and update the upper limit of normal (ULN) in the Vietnamese population.Methods: This cross-sectional study enrolled 8383 adults, aged 18 years and older who visited the Medical Center at Ho Chi Minh City for a health check-up. Following the exclusion criteria, 6677 subjects were included in the analysis.Results: Age ≤40 years, male gender, body mass index >23 kg/m2, diastolic blood pressure >85 mm Hg, cholesterol >5.2 mmol/L, triglyceride >1.7 mmol/L, positivity, anti-hepatitis C virus positivity and fatty liver (p40 U/L). Without considering age and gender, healthy group is defined after exclusion of participants with one of the mentioned contributing factors. The median ALT level in the healthy group was 18 in men and 13 in women. The ULN at the 95th percentile of the healthy group was 40 U/L in men and 28 U/L in women.Conclusion: The ULN for ALT in healthy women was lower than in healthy men. Updated ULN for ALT level can promote the identification of unhealthy subjects. More studies that involve ethnicity and lifestyle factors are needed to confirm the new ULN in the Vietnamese population

    Updated upper limit of normal for serum alanine aminotransferase value in Vietnamese population

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    BACKGROUND: Alanine aminotransferase (ALT) is a marker of hepatic damage and its range can be affected by viral hepatitis, alcoholic hepatitis and non-alcoholic fatty liver diseases. We aimed to study the factors associated with higher ALT level and update the upper limit of normal (ULN) in the Vietnamese population. METHODS: This cross-sectional study enrolled 8383 adults, aged 18 years and older who visited the Medical Center at Ho Chi Minh City for a health check-up. Following the exclusion criteria, 6677 subjects were included in the analysis. RESULTS: Age ≤40 years, male gender, body mass index >23 kg/m(2), diastolic blood pressure >85 mm Hg, cholesterol >5.2 mmol/L, triglyceride >1.7 mmol/L, positivity, anti-hepatitis C virus positivity and fatty liver (p40 U/L). Without considering age and gender, healthy group is defined after exclusion of participants with one of the mentioned contributing factors. The median ALT level in the healthy group was 18 in men and 13 in women. The ULN at the 95th percentile of the healthy group was 40 U/L in men and 28 U/L in women. CONCLUSION: The ULN for ALT in healthy women was lower than in healthy men. Updated ULN for ALT level can promote the identification of unhealthy subjects. More studies that involve ethnicity and lifestyle factors are needed to confirm the new ULN in the Vietnamese population

    Religious Fasting of Muslim Patients After Metabolic and Bariatric Surgery: a Modified Delphi Consensus

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    Background Fasting during Ramadan is one of the five pillars of the Muslim faith. Despite the positive effects of fasting on health, there are no guidelines or clear recommendations regarding fasting after metabolic/bariatric surgery (MBS). The current study reports the result of a modified Delphi consensus among expert metabolic/bariatric surgeons with experience in managing patients who fast after MBS

    Pancreatic surgery outcomes: multicentre prospective snapshot study in 67 countries

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    Background: Pancreatic surgery remains associated with high morbidity rates. Although postoperative mortality appears to have improved with specialization, the outcomes reported in the literature reflect the activity of highly specialized centres. The aim of this study was to evaluate the outcomes following pancreatic surgery worldwide.Methods: This was an international, prospective, multicentre, cross-sectional snapshot study of consecutive patients undergoing pancreatic operations worldwide in a 3-month interval in 2021. The primary outcome was postoperative mortality within 90 days of surgery. Multivariable logistic regression was used to explore relationships with Human Development Index (HDI) and other parameters.Results: A total of 4223 patients from 67 countries were analysed. A complication of any severity was detected in 68.7 percent of patients (2901 of 4223). Major complication rates (Clavien-Dindo grade at least IIIa) were 24, 18, and 27 percent, and mortality rates were 10, 5, and 5 per cent in low-to-middle-, high-, and very high-HDI countries respectively. The 90-day postoperative mortality rate was 5.4 per cent (229 of 4223) overall, but was significantly higher in the low-to-middle-HDI group (adjusted OR 2.88, 95 per cent c.i. 1.80 to 4.48). The overall failure-to-rescue rate was 21 percent; however, it was 41 per cent in low-to-middle-compared with 19 per cent in very high-HDI countries.Conclusion: Excess mortality in low-to-middle-HDI countries could be attributable to failure to rescue of patients from severe complications. The authors call for a collaborative response from international and regional associations of pancreatic surgeons to address management related to death from postoperative complications to tackle the global disparities in the outcomes of pancreatic surgery (NCT04652271; ISRCTN95140761)
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