Browsing by Author "Ahmed, R."

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    Annealing effects on interdiffusion in layered FA-rich perovskite solar cells
    (AIP Advances, 2021) Oyewole, D.O.; Koech, R.K.; Ichwani, R.; Ahmed, R.; Tamayo, J.H.; Adeniji, S.A.; Cromwell, J.; Ulloa, E.C.; Oyewole, O.K.; Agyei-Tuffour, B.; Titova, L.V.; Burnham, N. A.; Soboyejo, W. O.
    Annealing is one of the processing methods that are used for the fabrication of defect-free, photoactive perovskite films with compact grains in highly efficient and stable perovskite solar cells (PSCs). Thus, the annealing temperature is a key parameter for the control of the interdiffusion (of constituent elements) in photoactive films. In this paper, we present the results of a systematic study of the effects of annealing on the interdiffusion of constituent elements in efficient formamidinium-based PSCs. We also explore the effects of annealing-induced interdiffusion on layer microstructures, local strains, and the optoelectronic properties of perovskite films. We observe a dramatic upward diffusion of tin (Sn) and titanium (Ti) from fluorine-doped tin oxide and titanium dioxide (TiO2) to the perovskite films. We also observe a downward diffusion of lead (Pb) and iodine (I) from the perovskite films to the mesoporous layer of the electron transporting layer (ETL), after annealing at temperatures between 100 and 150 ○C. The diffused I substitutes for Ti in the ETL, which improves the optoelectronic properties of the films, for annealing temperatures between 100 and 130 ○C. The annealing-induced interdiffusion that occurs at higher temperatures (between 140 and 150 ○C) results in higher levels of interdiffusion, along with increased local strains that lead to the nucleation of pores and cracks. Finally, the implications of the results are discussed for the design of PSCs with improved photoconversion efficiencies and stability.
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    Assessing the Implementation of the Test, Treat and Track Strategy for Malaria Diagnosis and Management in the Atebubu-Amantin District
    (University of Ghana, 2018-10) Ahmed, R.
    Background: The World Health Organization places emphasis on the test and confirm any suspected malaria case either by microscopy or by rapid diagnostic test before treatment with ACT. Almost half of all suspected malaria cases in endemic countries in Africa are still being treated presumptively. This study assessed prescribers’ compliance to the Test, Treat and Track (T3) strategy for diagnosing and managing uncomplicated malaria. Methods: Out Patients Department records covering the period 2012 to 2016 at the Atebubu Government Hospital were reviewed in 2017 to determine the proportion of fever cases that were tested for malaria before Artemisinin-based Combination Therapy (ACT) was prescribed and whether cases that tested negative were prescribed antimalarial medicine (ACT). A data capturing form was developed and used to capture data on hospital attendants (all cases) of suspected malaria cases that were referred to the laboratory for testing before treatment was given. The tool also captured the number of cases that tested negative and yet were prescribed antimalarial medicine. Results: Out of the 385 fever cases that were reviewed, 72.8% was tested, out of which 42.9% was confirmed malaria (positive). All the confirmed cases (42.9%) were treated with ACT, whilst 10.1% of cases that tested negative were also treated with ACT. Also, 40.4% were not asked to return for review. Conclusions: Compliance with the test of fever cases by prescribers was poor as 29.3% of them were not tested for malaria and yet were diagnosed as malaria and treated with ACTs. A proportion (10.1%) of the fever cases that tested negative were presumptively treated with ACT as malaria. Also compliance to the treatment guidelines of ACT for malaria and requesting for patients who were treated to return for review was poor, so the tracking component of the T3 strategy still remains a challenge. The Ministry of Health and the Ghana Health Service should ensure regular supervision and sensitization of prescribers on the relevance of the T3 strategy.
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    Factors Contributing to Food and Water Borne Illnesses among Households in the Ashaiman Municipality in Ghana
    (University of Ghana, 2018-07) Ahmed, R.
    Background: Food and water borne illnesses are of great concern to all humanity and for this reason there is a need for every individual to take part in curbing this condition since it is preventable to a large extent. This could be achievable when the contributing factors are well known. This study therefore sought to assess the factors that contribute to food and water borne illnesses among households in the Ashaiman Municipality. Method: A descriptive cross sectional study was carried out to identify the factors that contribute to reported food and water borne illnesses among households in the Ashaiman Municipality. A total of 230 household heads/ representatives were interviewed using a structured questionnaire. The compiled data were analysed using Stata version 15 which included the use of frequency distribution tables and the chi- square test was used to show association between variables. A significance level of 5% was used for the study. Results: When logistic regression analyses was done for each independent variable, significant effects were observed between employment status, storage of left- over/ fresh foods on shelf, storage of domestic water in barrels, storage of drinking water in sachet bags/ bottle and reported food and water borne illnesses. Multiple logistic regression analyses on assessing the relationship that existed between, housing environmental factors, socio- economic factors and reported food and water borne illnesses revealed that employment status and storage of left- over/ fresh food on shelf were significant and independent predictors of reported food and water borne illnesses. Conclusion- The findings revealed that, socioeconomic factors such as employment status and housing environmental factors such as storage of fresh/ left-over food on shelf were associated positively with reported food and water borne illnesses among the sampled residents of the Ashaiman Municipality.
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