The effect of strong ambient winds on the efficiency of solar updraft power towers: a numerical case study for Orkney.

Solar updraft tower (SUT) is a simple power plant in which ventilation of heated air inside a channel drives a turbine. This system is recognised as suitable for areas with abundant solar radiation. As a result, there is no extensive research on the performance of SUTs under mild solar radiation. Studies show that strong ambient crosswinds can affect the performance of a SUT. In this paper, the efficiency of SUTs in areas which benefit from strong winds, despite low solar radiation, is investigated through numerical modelling. Comparison is made between the efficiency of a commercial-scale SUT in Manzanares (Spain) with intensive solar radiation, and one of the same size potentially located in the windy and mild climate of Orkney Islands in Scotland. The results show that ambient crosswinds can increase internal air speed and efficiency of a SUT by more than 15% and 50%, respectively. Consequently, such a SUT in Orkney can offer more than 70% of the efficiency of the one in Manzanares. The results show that, for a given power capacity, a wind turbine enclosed in a SUT can be considered as an alternative to a number of conventional wind turbines installed at height in the open air

Global Leadership Initiative on Malnutrition and Mini Nutritional Assessment in Evaluation of Nutritional Status of COVID-19 Patients

Background: Considering that nutritional status is one of the influential factors in the process of recovery of patients with COVID-19, this study was conducted to determine the nutritional status of COVID-19 patients and its relationship with clinical outcomes.Methods: This cross-sectional study included 155 patients diagnosed with COVID-19 disease (18-80 years) using PCR test and chest CT scan. The nutritional status of participants was assessed employing Mini Nutritional Assessment (MNA) questionnaire, Global Leadership Initiative on Malnutrition (GLIM) criteria, and Nutrition Risk in Critically(NUTRIC) score.Results: Among 81 men (52.3%) and 74 women (47.7%) based on MNA, 30 participants (19.4%) and based on GLIM criteria, 42 participants (27.1%) suffered from malnutrition. Also, systolic and diastolic blood pressure (GLIM: p=0.038, p=0.008, respectively; MNA: p=0.04, p=0.01, respectively) and blood oxygen saturation (MNA: p=0.01; GLIM: p=0.012)were significantly associated with nutritional status of participants. MNA and GLIM findings showed a relative agreement of 0.35 (p<0.0001).Conclusion: Nutritional status was demonstrated to be a critical factor that can affect the clinical condition and recovery process of COVID-19 patients. GLIM was shown to be practical and reliable criteria to measure the nutritional status for diagnosis and prognosis of patients with COVID-19