We describe a novel and cost-effective method to enhance the photo-conversion efficiency of blended PbI2/TiO2 perovskite photovoltaic cells by pre-annealing the constituent film components during the fabrication. This approach is also unique because it does not presume a strictly controlled fabrication environment. The average conversion efficiencies of the cells of the final devices were observed to rise from 6.6% to 10.8% for annealing temperatures of 60 ◦C to 100 ◦C, respectively. Anne...
ABSTRACT Men‘s involvement in maternity care has been recognized as one of the key strategies in improving maternal health and accelerating reduction of maternal mortality. Men impact women‘s reproductive health through their role as partners, fathers and close family providers in terms of financial power and decision control they have. Factors that determine men‘s involvement in maternity care have been documented in other parts of the globe, but very little research has been conducted...
Abstract Twenty Concrete Blocks from (20) different Local Governments in Katsina state was measured using Gamma Ray Spectroscopy with NaI (TL) detector. Three naturally Occurring Radionuclides and their activity concentrations were determined, are 40K 226Ra, and 232Th. Their activity Concentrations ranges from 40K 46.11 ± 826.59 to 46.11± 8.55 Bq/kg, (226Ra) ranged from10.19 ± 2.43Bq/kg to 75.09 ± 4.98 Bq/kg and (232Th) ranged from 2.77 ± 9.59Bq/kg to 123.49 ± 9.35Bq/kg respectivel...
Abstract The High Energy Stereoscopic System (H.E.S.S.) is an array of imaging atmospheric Cherenkov telescopes located in the Khomas highlands of Namibia. Their primary purpose is to detect Cherenkov light (CL) produced by particles in extensive air showers which are produced by incident high energy particles (gamma rays or cosmic rays) on the Earth’s atmosphere. The array consists of four 107 m2 optical telescopes and a larger 614 m2 collective surface area telescope in the centre of th...
Abstract In this study, natural dye-sensitized solar cells (NDSSCs) were fabricated using crude and purified natural dye extracts aimed at investigating the effect of purified natural dyes on the dye-sensitized solar cell (DSSC) performance. Ethanol and methanol solvents were used to extract natural dyes from Senna singueana flowers, Senna singueana leaves, Ximenia caffra fruits, and Bougainvillea glabra bracts. Liquid-liquid extraction (LLE) method was used to purify the ethanol and methano...
ABSTRACT Radiation exposure during diagnostic X-ray examinations has been widely reported as one of the sources of cancer induction. Information on X-ray machine and exposure parameters are crucial to risk assessment, which in turn are important for optimization of radiation protection measures. The documentation of radiation risk in Nigeria is sparse and hence the effectiveness of radiation protection measures at diagnostic centres has not been well established. This work was aimed at measur...
Abstract A modification of Biot's pornelastic differential equi~tionsis made to include nrarrix-fluid interaction mech~ismsw hich assume n solid-fluid relaxation hnction coiipli~igc c~eflicient. Vulucs of physical propcrtics of scdi~iicntsn .rc incorporuted'into cqilationswhicl~d cfinc phnsc yelocity nnd attei~uatibnf or pcirous media which are dependent on the co~~posidteen sities of various medin (silt, and lnediu~na nd coqfse sand). The results enable us to coinpare tlie .atenuation and ve...
ABSTRACT Ionizing radiations resulting from either natural or artificial radioactivity are useful but associated with them are health risks which increase with exposure. The natural radioactivity levels in soils of some locations in Jos and Abeokuta are significantly higher than the world average. Enhanced internal and external radiation exposures to man may result from physical presence in, and ingestion of food items grown in these areas. Scientific data are sparse on the radionuclide conte...
Abstract Thls artlcle introduces Monte Carlomethds which are duerent from conrentio~nl ~mieticanl lethods andshow bow some of the methods can be applled in Physlcs,ro simrclate or solve physical proble~its. thtwr~hco rrilvrrer ~vrgrrrr>rr' (wrltten In FORTRAN In thls ca.r@, by ruing a few cxnml~lrrt oltchinff ,n doi.11 arid c/ns.~l[:olI 'lr~!!:ricrsh r~t~.rrr~s ~g r~lrfihess. A functional approach to probab//ity and statisticscl is describeJJor the p,1rynre o/tbn work r*.st~nd of comp/eto tre...
ABSTRACT Clays have some properties which make them good adsorbents. The adsorption of heavy metal ions by clay usually affects its thermal properties and these properties have direct influence on seed germination and crop growth. In this study, the variation of thermophysical properties of clay with adsorption of some heavy metal ions at different concentrations was investigated. An Atomic Absorption Spectrophotometer (AAS) was used to determine the concentrations in the samples. A known mas...
Abstract Reliable estimates of petroleum reserves are invaluable in reservoir management decisions and economic evaluation. Classical decline curve analysis techniques have been routinely used and are generally accepted in the industry to reliably estimate developed reserves up to a predetermined economic limit qec in oil wells. However Decline curve analysis techniques are based on the assumption that past production trends and their controlling factors will continue in the future and theref...
ABSTRACT A transition length is normally observed when fluid flows through a conduit before laminar flow is accomplished. This work examined a situation whereby porous materials were filled into the conduit and fluid was made to flow through. An attempt was made to determine this transition length for flow of water through riverbed sand of varying porosities filled into a horizontal cylindrical pipe of diameter 0.345 x m with piezomefric water head, set at 0.06m. The transition length was obs...
Abstract Presently, there are deep concerns over the environmental consequences and the consumption of non-renewable energy sources, with the accelerated greenhouse effect which triggered enormous interest in the use of renewable energy sources e.g. solar, hydropower, wind and geothermal. However, the intermittent nature of harvesting renewable energy sources has recently gained considerable attention in the alternative, reliable, cost effective and environmentally friendly energy storage de...
Abstract The High-Energy Stereoscopic System (H.E.S.S.) is an array of five imaging atmospheric Cherenkov telescopes located in the Khomas Highland in Namibia, dedicated to very-high-energy (VHE, 100 GeV – 100 TeV) gamma-ray astronomy. It consists of four identical 12 m diameter telescopes (H.E.S.S.-I) which started operating in 2003 and a large 28 m diameter telescope (H.E.S.S.-II) which was brought online in 2012 [1]. The H.E.S.S.-I camera upgrade project was aimed to increase the stabil...
ABSTRACT The hydrogeological system of the Ga East and Adentan Districts of the Greater Accra Region of Ghana was studied using numerical modelling on the Groundwater Modelling System platform (version 10.0). Historical hydrogeological data and groundwater monitoring data on twenty wells drilled in 2012 were relied on in conceptualising the hydrogeological system of the study area. A single aquifer system made up of quartzite-schist formation was identified. The borehole logs reveal four lith...