Investigating Calotropis Procera natural dye extracts and PDOT:PSS hole transport material for dye-sensitized solar cells

Received: February 24th, 2021 ; Accepted: May 2nd, 2021 ; Published: May 4th, 2021 ; Correspondence: [email protected] this work, natural dye extracts from Calotropis Procera are used as the main dyesensitizer in solar cells. The Calotropis plant is a non-food item capable of surviving the harsh climate of the United Arab Emirates. Its incorporation into dye-sensitized solar cells is tested by constructing various cells, whose performance was also compared to that of more common chlorophyll-based dye extracts (i.e. spinach) as well as compared against a baseline cell sensitized with a synthetic ruthenium dye. The performance of the Calotropis-based cells was in general better than those with other natural sensitizers, but of course scored lower efficiency results when compared to cells built with synthetic dyes (0.075% compared to 5.11%). The advantage in using a natural sensitizer include facile extraction and preparation, low cost and abundance, since the Calotropis source has no competing applications in terms of food, livestock feed, etc. The figureof-merit of cell output vs. cost for such cells makes them a good contender for further research and development effort to overcome the obvious drawbacks of stability and service longevity. Adding a hole-transport material to the cells in the form of PEDOT:PSS was also attempted to assess the enhancement it could provide to the cells. This did not yield the desired results and more experiments have to be done to better understand the interaction of each added layer to the original cell design

Insight into potassium's role in childhood mortality due to severe acute malnutrition

Hypokalaemia is associated with an increase in mortality in children with severe acute malnutrition (SAM) and diarrhoea. This is a descriptive cross-sectional retrospective study conducted in the Nutritional Ward at Mohamed Alamin Hamid Pediatrics Hospital in Omdurman, Sudan. It aimed to assess the frequency of hypokalaemia among children with SAM to understand the influence of hypokalaemia and potassium supplementations contributed on the children survival rates (January-December 2015). It included 215 patients with SAM and acute diarrhoea. The potassium levels of all the patients were assessed upon hospital admission and this correlated with the mortality according to the degree of hypokalaemia and treatment initiated. Hypokalaemia was evident in 70.2% of the patients. Mortality was 3.1% in normokalaemic and 13.9% in hypokalaemic patients. The patients' survival was significantly associated with their serum potassium levels and the treatment received. The survival rates have been assessed via the Multinomial Logistic Model, which reveals that normokalaemic children had a chance of 157.349 (95% confidence interval 18.479-1,339.811) times higher than that compared to the baseline children with advanced hypokalaemia with serum levels <2 mEq/l (; p; -value < 0.001). Children with mild hypokalaemia within the serum levels of 3.0-3.4 mEq/ml showed an increased survival chance of 549.970 (95% CI 19.293-3,238.716) times compared to the baseline children (p-value = 0.000). In patients with SAM, who presented with acute diarrhoea, there was an increase in mortality in patients with hypokalaemia compared with patients who presented with normal potassium levels. Corresponding mortality rates increased significantly with the severity of hypokalaemia. In severe hypokalaemia, there is a significant difference in mortality between patients treated with oral rehydration solutions for malnutrition in relation to patients treated with oral potassium supplements or with intravenous potassium