OPTICAL AND STRUCTURAL PROPERTIES OF PbCdS TERNARY THIN FILMS DEPOSITED BY CHEMICAL BATH DEPOSITION

Thin films of PdCdS ternary compound have been successfully deposited using chemical baths containing cadmium acetate, lead acetate thiourea and ammonia. The films were characterised using a variety of techniques. X-ray diffraction analysis revealed that a number of prominent high intensity diffraction peaks originating from reflections of the tetragonal lead sulphide structure. Several smaller low intensity peaks related to reflections of the hexagonal structure of cadmium sulphide, were also observed. Scanning electron microscopy showed a compact layer with a surface composed of platelike shaped nanocrystals of different dimensions with well defined boundaries. Energy dispersive X-ray spectroscopy confirmed the presence of lead cadmium and sulphide. The band gap determined from optical absorption spectroscopy was found to be 1.9 eV

Optical Behavior of PANI/Sno2 Nanocomposites

This article reports the synthesis of Polyaniline (PANI) in Emeraldine form by in situ chemical oxidation method by using Ammonium persulphate as an oxidizing agent and a simultaneous synthesis of polyaniline (PANI)/SnO2 nanocomposites. The UV-Vis absorption spectra were studied to explore the optical behavior after incorporating SnO2 nanoparticles into PANI matrix. The absorption bands for the PANI/SnO2 sample were observed at ~370nm, ~550 nm and ~910 nm wavelengths. This, however shows significant shifts in the absorption spectral to higher wavelength when comparing the absorption spectrum of both PANI and PANI/SnO2. These bands may well correspond to ?-?* transition, polaron-?* transition and polaron-? transition, respectively. This could be attributed to the successful interaction of the SnO2 with the polymer chain. Hence, such shifts in absorption peak positions are related to the presence of the SnO2 in the matrix of PANI. The Attenuated Total Reflectance (ATR) spectrum of PANI/SnO2 provided the characteristic absorption peaks at 3227.54cm-1,1569.03cm-1, 1496.71cm-1, 1444.86cm-1, 1289.13cm-1, 1145.65cm-1,821.57cm-1, 506.68cm-1, and 412.08cm-1 due to the provision of information about the changes in the chemical structure of polymer. ATR spectra also give indication that the incorporation of SnO2 in the matrix of PANI seems to be effective for the improvement of the physicochemical properties of conducting polymers

Contraceptive use and associated factors among sexually active female adolescents in Atwima Kwanwoma District, Ashanti region-Ghana

Introduction: unintended pregnancies and adolescent childbearing are on the increase in Sub-Saharan Africa. In Ghana, 14% of adolescents aged 15-19 are already mothers or pregnant with their first child. Most of these pregnancies are associated with poor outcomes such as miscarriages, stillbirths, unsafe abortions and other complications that might result in infant or mortality. In addition, sexually-active adolescents (16-19 years) are at higher risk of contracting STIs. Evidence suggest that contraceptive use help reduce fertility rate and adolescent reproductive health. This study therefore sought to understand the magnitude and associated factors that influence female adolescents' use of contraceptive in the Atwima Kwanwoma District, Ghana. Methods: a descriptive and analytic cross-sectional study design was used for this study. Using a structured questionnaire, data were collected from randomly sampled 200 sexually active female adolescents; aged 16-19 for a three month period; June to September 2017. The questionnaire elicited data on the socio-demographic characteristics of respondents, their knowledge and perception, use of contraceptives and factors influencing their contraceptive use. Data were analyzed using STATA version 12.1 software. Results: ninety-five percent of the respondents exhibited some knowledge about contraceptives, but this high knowledge did not translate into its use as the prevalence rate was 18%. Condom was the most widely used contraceptive (33%) and perceived side effects of contraceptives was found to be the main reason for not using the contraceptives (53.66%). Marital status and the participants who were staying with both parents were found to be associated with contraceptive use with their p-values of 0.023 and 0.002 respectively. Conclusion: considering the fact that contraceptive knowledge does not necessarily translate into use, further studies (qualitative), are needed to understand why high knowledge levels are not associated with high usage patterns

Synthesis and Characterization of CdSe Nanocrystalline Thin Film by Chemical Bath Deposition Technique

A well adherent nanocrystalline thin film of cadmium selenide (CdSe) has been successfully deposited from chemical bath containing cadmium acetate, tartaric acid, ammonia and sodium selenosulphate, at a bath temperature of 85 0C and a pH of 9.5. The films were characterized using a variety of techniques. Powder X-ray diffraction revealed a cubic phase of CdSe nanocrystalline thin film with preferred orientation along the (111) plane. The SEM micrographs showed the film surface was composed of spherically shaped grains over the entire glass substrate. The elemental composition of the thin film was confirmed by energy dispersive X-ray spectroscopy. The optical band gap energy was found to be 1.86 eV

Application of Laboratory-Synthesized Ammonium Zeolite LTX as Soil Amendment Additive

The production of ammonium-exchanged zeolite X (NH4-LTX) and its soil amendment activity is presented. The ammonium-exchanged zeolite X was characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, particle size analysis and Fourier transformed infrared (FTIR) spectroscopy. The addition of NH4-LTX increased the pH, total nitrogen, potassium, sodium content and water retention capacity of the soil. Consequently, the fresh weight, dry weights, plant heights, stem thickness, stem length, number of leaves, leaves areas was remarkably greater for both maize and okro planted in soils containing NH4-LTX compared to plants in soil without NH4-LTX

Remittances and Income Inequality in Africa: Financial Development Thresholds for Economic Policy

The study employs macrodata on 42 African countries to examine whether remittances and financial development (including the sub-components of access, depth and efficiency) contribute to the equalisation of incomes across the continent. Robust evidence from the dynamic GMM estimator shows that: (i) remittances heighten income inequality in Africa, (ii) Africa’s financial system is not potent enough for repacking remittances towards the equalisation of incomes, and (iii) vis-à-vis financial access and depth, inefficiencies characterising Africa’s financial institution is the main reason remittances contribute to the widening of the income disparity gap. Nonetheless, the optimism which we provide by way of threshold analysis shows that channelling efforts into the development of Africa’s financial sector could yield shared income distribution dividends. In particular, efforts should be made to achieve a minimum of 23.05 per cent of financial access, and 3.02 per cent for that of efficiency of financial institutions if Africa’s financial sector is to repackage external finance towards the equalisation of incomes. A few policy recommendations are provided in the end

Adsorptive Removal of Iron and Manganese from Groundwater Samples in Ghana by Zeolite Y Synthesized from Bauxite and Kaolin

Ground water samples from residential homes in three Regions of Ghana: Central, Greater Accra and Ashanti, were analyzed for iron and manganese contamination. The samples were exposed to characterized zeolite Y by X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, Fourier transformed-infrared spectroscopy and thermos gravimetric-differential thermal analysis. Zeolite Y is able to remove 98% of iron and 97% of manganese within an hour. The adsorption of both iron and manganese follows the Freundlich model, whilst the kinetic studies show that pseudo-first order and intra particle and film diffusion models provided the best fit, suggesting the transport of the ions onto the zeolite Y surface and the subsequent diffusion into the zeolite Y framework. The adsorption at 0.2 mg L−1 Fe (0.2) is calculated to be 0.023 mg g−1 for the Freundlich adsorption model, whilst that of manganese at 0.05 mg L−1 Mn (0.05) is evaluated to be 0.015 mg g−1. The zeolite retains its adsorption properties when retrieved from the first exposure water sample, washed copiously with distilled water and added to fresh water samples. The results suggest that zeolite Y can be used as a potential adsorbent for the removal of iron and manganese from groundwater.Third World Academy of Sciences (TWAS) (Grant # 16-471 RG/PHYS/AF/AC_G), Grand Challenges Canada (Grant # RS-0148 -01) and National Environment Research Council (NERC) (Grant # NE/R009376/1). The authors are grateful to Royal Society, UK and Grand Challenges Canada for their financial support

Towards inclusive growth in Africa: Remittances, and financial development interactive effects and thresholds

The study employs macro data for 42 African countries to examine the interactive and threshold effects of financial development in the remittances-inclusive growth relationship. First, evidence based on the system GMM estimator shows that remittances are not statistically significant in promoting inclusive growth in Africa. Notably, across the economic growth and income inequality dimensions of inclusive growth, we find that although remittances are ineffective in boosting the former, they deepen the latter. Second, we find that Africa’s underdeveloped financial sector dampens the marginal positive effect of remittances on inclusive growth. Third, our threshold analysis indicates that for financial development to interact with complementary policies to foster inclusive growth in Africa, a minimum threshold of 14.5% is required. We conclude by informing policy on the level of investments needed for financial development to promote fairer income growth and distribution in Africa

Electricity generation Using a hybridized zeolite adsorption heatpump and heat engine

© 2020 The Authors. Published by the Canadian Center of Science and Education. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.5539/apr.v12n4p75The use of adsorption in Thermal Energy Storage has gained considerable research interest of late. Some applications have focused on the use of TES for transformation of low temperature heat in applications such as cooling and heating. Zeolite and water have been studied as suitable materials. Their characteristics as environmentally friendly materials and high affinity makes them conspicuous. The unique properties of zeolites to hold adsorbed water/heat with very minimal loss is also significant. With the aid of a dynamo, a Stirling engine as heat engine and the adsorption energy storage system serving as heat pump was used to generate electricity. The relationship between electricity generation and temperature was investigated. The obtained average temperature and pressure of the zeolite - water adsorption heat pump was also compared with the basic adsorption cycle

Treatment of Malaria Infection and Drug Resistance

Malaria is a public health challenge that requires prompt treatment for those infected to make a full recovery. Treatment of malaria infection is to be started as soon as a diagnosis is confirmed. Antimalarial medications are administered to prevent and also to treat malaria. The type of medication used and the duration of therapy is dependent on the type of malaria-causing plasmodium species, the severity of the symptoms, geographical area where malaria infection occurred and the medication used to prevent malaria and whether there is pregnancy. Treatment of malaria from public health perspective is to reduce transmission of the infection to others, by reducing the infectious reservoir and to prevent the emergence and spread of resistance to antimalarial medicines. Medications used in the treatment of malaria infection come from the following five groups of chemical compounds: quinolines and aryl amino alcohols, antifolate, artemisinin derivatives, hydroxynaphthoquinones and antibacterial agents. The treatment of malaria is not initiated until the diagnosis has been established through laboratory testing. Artemisinin-based Combination Therapy (ACTs) has been used for the treatment of uncomplicated malaria. ACTs are also to enhance treatment and protect against the development of drug resistance. IV artesunate is used in the treatment of severe malaria, regardless of infecting species