Number of Tape Twists Effects on Solar Water Heater Performance

In solar applications, research into appropriate methods to improve the performance of the solar water heater is important. The current work studies improved the performance of the solar water heater by analyzing the effect of the number of added tape twists. A four-pipe solar water heater was built, and four twisted tapes were used, each with a different number of twists (flat, one, three, and five twists), and each tape was inserted into a pipe. The addition of twisted tapes has found that improved the performance of the solar water heater, and this improvement increased with the number of twists. A one, three, and five-twisted tapes achieved a temperature increase of (5.33, 14.09, and 20.27%) respectively, relative to a flat tape, and the instantaneous efficiency of the five twists tape was the highest, where the highest instantaneous efficiency of the four types rates (9.6, 13.4, 13.8, and 15 %) respectively

Number of Tape Twists Effects on Solar Water Heater Performance

In solar applications, research into appropriate methods to improve the performance of the solar water heater is important. The current work studies improved the performance of the solar water heater by analyzing the effect of the number of added tape twists. A four-pipe solar water heater was built, and four twisted tapes were used, each with a different number of twists (flat, one, three, and five twists), and each tape was inserted into a pipe. The addition of twisted tapes has found that improved the performance of the solar water heater, and this improvement increased with the number of twists. A one, three, and five-twisted tapes achieved a temperature increase of (5.33, 14.09, and 20.27%) respectively, relative to a flat tape, and the instantaneous efficiency of the five twists tape was the highest, where the highest instantaneous efficiency of the four types rates (9.6, 13.4, 13.8, and 15 %) respectively

Investigation into design and optimisation of solar adsorption cooling/air conditioning under the Iraq climate

Solar adsorption cooling system can be defined as a system produces a cooling effect by using Sun’s thermal energy. In present study, a solar adsorption cooling system was modelled and simulated using TRNSYS and MATLAB programmes. Parametric investigations have been done on the system by varying several of the crucial design parameters, and their effects on the performance of the system were introduced. The system was analysed on the energy, exergy and economy basis, and it was further optimised by employing a multi-objective genetic algorithm technique with two objective functions. The first objective was maximising the exergy efficiency, and the second objective was minimising the total cost rate over life. The Pareto front optimal solutions that achieved from the multi-objective optimisation were presented. Moreover, Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) method was applied to find the final optimal solution. The optimal design was simulated and analysed for individual components of the system. Finally, a comparison has been made with an existing solar cooling system; the comparison showed that the proposed solar adsorption system driven by evacuated tube collector, integrated with hot and cold storage tanks, has a smaller size and better performance, which in turn means less costs. The payback period method is also used in the present study. The techno-economical results showed that due to the high cost of the system and the low cost of electricity in Iraq, financial payback is not feasible, and thus would require further efforts in driving down the costs and government incentives

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

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

Traumatic Brain Injury: Oxidative Stress and Novel Anti-Oxidants Such as Mitoquinone and Edaravone

Traumatic brain injury (TBI) is a major health concern worldwide and is classified based on severity into mild, moderate, and severe. The mechanical injury in TBI leads to a metabolic and ionic imbalance, which eventually leads to excessive production of reactive oxygen species (ROS) and a state of oxidative stress. To date, no drug has been approved by the food and drug administration (FDA) for the treatment of TBI. Nevertheless, it is thought that targeting the pathology mechanisms would alleviate the consequences of TBI. For that purpose, antioxidants have been considered as treatment options in TBI and were shown to have a neuroprotective effect. In this review, we will discuss oxidative stress in TBI, the history of antioxidant utilization in the treatment of TBI, and we will focus on two novel antioxidants, mitoquinone (MitoQ) and edaravone. MitoQ can cross the blood brain barrier and cellular membranes to accumulate in the mitochondria and is thought to activate the Nrf2/ARE pathway leading to an increase in the expression of antioxidant enzymes. Edaravone is a free radical scavenger that leads to the mitigation of damage resulting from oxidative stress with a possible association to the activation of the Nrf2/ARE pathway as well

Traumatic brain injury: Oxidative stress and novel anti-oxidants such as mitoquinone and edaravone

Traumatic brain injury (TBI) is a major health concern worldwide and is classified based on severity into mild, moderate, and severe. The mechanical injury in TBI leads to a metabolic and ionic imbalance, which eventually leads to excessive production of reactive oxygen species (ROS) and a state of oxidative stress. To date, no drug has been approved by the food and drug administration (FDA) for the treatment of TBI. Nevertheless, it is thought that targeting the pathology mechanisms would alleviate the consequences of TBI. For that purpose, antioxidants have been considered as treatment options in TBI and were shown to have a neuroprotective effect. In this review, we will discuss oxidative stress in TBI, the history of antioxidant utilization in the treatment of TBI, and we will focus on two novel antioxidants, mitoquinone (MitoQ) and edaravone. MitoQ can cross the blood brain barrier and cellular membranes to accumulate in the mitochondria and is thought to activate the Nrf2/ARE pathway leading to an increase in the expression of antioxidant enzymes. Edaravone is a free radical scavenger that leads to the mitigation of damage resulting from oxidative stress with a possible association to the activation of the Nrf2/ARE pathway as well.Funding: This research was funded by UAEU Program for Advanced Research, grant number 31S398-UPAR to Yusra Al Dhaheri.Scopu