Open Access Original Research Article

Hybrid Lateral Multi-junction Solar Cell Using Nonpolar InxGa(1-x)N Material

Manoj Thosar, R. K. Khanna, Ashwini Joshi Thosar

Current Journal of Applied Science and Technology, Page 1-7
DOI: 10.9734/BJAST/2016/24678

The efficiency of nonpolar InxGa(1-x)N material based hybrid lateral multi-junction solar cells was simulated using finite element approach. In this work we have used p-i-n and p-n structures for designing the sub-cells of hybrid lateral multi-junction solar cells. We have optimized both the sub-cell structures separately at different values of indium composition (x) for maximum efficiency. We have proposed fourteen sub-cells for our hybrid lateral multi-junction solar cell device through which it absorbs solar spectrum from 0.3 to 1.7 µm wavelength range. Results of simulation are presented here, which predict 37.08% average efficiency for lateral multi-junction solar cell based on p-i-n sub-cells while 40.21% average efficiency for lateral multi-junction solar cell based on p-n sub-cells. But the proper hybrid combination of p-i-n and p-n sub-cells provided 41.5% average efficiency.

Open Access Original Research Article

Interaction of Ciprofloxacin and Extract of Hibiscus sabdariffa Linn (Roselle) Calyses in Antimicrobial Assays by ‘Agar-well Cross-reaction Technique’

Nmema Eucharia Ezenwanyi

Current Journal of Applied Science and Technology, Page 1-8
DOI: 10.9734/BJAST/2016/24793

Aims: To evaluate the antibacterial activities of aqueous extract of Hibiscus sabdariffa Linn calyces and ciprofloxacin, separately and in combination, and introduce a simple method in the study of drug interactions.

Study Design: Experimental design.

Place and Duration of Study: Department of Biological Sciences, Ondo State University of Science and Technology, Okitipupa, between March 2013 and June 2015.

Methodology: Antimicrobial assays using five bacterial isolates including S. aureus, Pseudomonas aeruginosa, and S. aureus NCTC 6571, by agar-well diffusion method were performed. Interaction assay of extract and ciprofloxacin by an ‘Agar-well Cross-reaction Technique’ was performed. Inferences for synergistic, additive, indifferent or antagonistic interaction were drawn from the percentage differences in the inhibition zone diameters (IZDs) produced.

Results: All test bacteria were susceptible to the extract, IZDs ranging from 10 mm to 32 mm. Four test bacteria were susceptible to ciprofloxacin, IZDs ranging from 15 mm to 35 mm. Out of the twenty five interactions against S. aureus O1, there were 6 (24%) synergistic, 6 (24%) additive, 3 (12%)  indifferent, 5 (20%) antagonistic reactions, and 5 (20%) showed no activity. Out of the twenty five interactions against P. aeruginosa PA2, there were 2 (8.0%) synergistic, 2 (8.0%) additive, 1 (4%) indifferent, 9 (36%) antagonistic reactions, and 11 (44%) showed no activity. Summing up the fifty interactions for the two test isolates, 36 (72%) interactions were favorable or indifferent while 14 (28%) interactions were antagonistic. Results of Chi square test showed this to be statistically significant (P = .05).

Conclusion: H. sabdariffa calyces extract posseses antibacterial properties similar to ciprofloxacin, and inhibited ciprofloxacin-resistant isolates. Concomitant use of ciprofloxacin and H. sabdariffa extract may not produce antagonistic reactions. The ‘Agar-well Cross-reaction Technique’ proved to be sensitive and effective, eliminating many of the difficulties experienced with other methods of studying drug interactions.

Open Access Original Research Article

Parametrical Fluctuations of Epicycle in Wheel Gearboxes

Victor Yaglinskiy, Sergiy Gutyrya, Andriy Chanchin

Current Journal of Applied Science and Technology, Page 1-7
DOI: 10.9734/BJAST/2016/24685

Purpose: To develop mathematical model of the parametrical fluctuations, conditions of its emergence and development caused by cyclically variable in time rigidity of gearings.

Methodology: Modeling of structural parametrical fluctuations of an epicycle is executed on the basis of the differential equation of Mathieu-Hill with variable periodic coefficients and diagnosing of instability of oscillatory system is carried out according to Ains-Strett’s chart.

Results: It is established that width of area of instability of parametrical fluctuations of an epicycle for a 2k-h gear depends on coefficient μ pulsations of mesh rigidity and the relation of frequency of own fluctuations k0 of an epicycle to the angular frequency ω of parametrical excitement. Calculations for the given algorithm on the example of wheel gearbox Raba designs 118.77 and 318.78, which are widely applied as a part of transmissions of car and electrical wheel transport, confirmed possibility of an elimination of parametrical fluctuations of an epicycle by means of an arrangement of axes of planets, uneven on a circle.

Conclusion: The positive effect of influence of an arrangement of axes of planets, uneven on a circle, on depth of a pulsation of rigidity of multiline gearing and narrowing of area of instability of parametrical fluctuations of an epicycle is confirmed.

Open Access Original Research Article

Influence of Gender on National Poverty Eradication Programme (NAPEP) Capacity Acquisition Scheme (CAS) Graduates on their Ability to Acquire Tailoring Skills for Entrepreneurship

T. T. Adebisi, D. O. Arubayi

Current Journal of Applied Science and Technology, Page 1-7
DOI: 10.9734/BJAST/2016/24193

The purpose of this study was to investigate Gender Influence on graduates of National Poverty Eradication Programme (NAPEP) capacity Acquisition Scheme (CAS) on their ability to acquire Tailoring Skills in Ogun and Osun States in Nigeria. The study adopted an expost facto research design. The target population consisted of 2,396 graduates who were trained between 2003-2007 when the programme was functional. A multistage sampling technique was adopted to select a sample size of 484 respondents. A structured questionnaire consisting of eleven (11) item statements were utilized. The data gathered, were analysed using means and standard deviation for the research question while the t-test was used to determine the level of significance for the hypothesis tested. Findings revealed that gender had no influence on graduates’ abilities to acquire tailoring skills. Furthermore, gender had no influence male students’ abilities to acquire tailoring skills as six (6) out of the eleven (11) items had mean below 2.50. For females, gender influenced their abilities to acquire Tailoring skills as six (6) out of eleven (11) items had scores above 2.50. Finding also showed gender influence on NAPEP Capacity Acquisition Scheme among urban graduates on their abilities to acquire tailoring skills for entrepreneurship than the rural graduates. Based on the finding, it was recommended that skills training which is a way out of the harsh economic and poverty eradiation is gender inclusive, therefore cultural and societal prescription of specific roles for males/females should be discouraged.

Open Access Original Research Article

Variations in Under-five Child Mortality among Regional States of Ethiopia: A Multi-level Modelling Approach

Ashenafi Senbeta Bedane, Tilahun Ferede Asena, Aklilu Toma Shamenna, Amanuel Disassa Abshoko

Current Journal of Applied Science and Technology, Page 1-16
DOI: 10.9734/BJAST/2016/24448

Background: Improvements in child survival have been one of the major targets of development programs during the past three decades. The main aim of this study is to investigate under-five child mortality variations among regional states of Ethiopia. In this study, single level and multilevel binary logistic regression models is adopted for the analysis.

Methods: This study is conducted based on Demographic and Health Survey (DHS) 2011 data, collected for 10,156 children under-five years of age in Ethiopia. 

Results: Based on the model adequacy tests the random intercept binary logistic regression model is found to be best fitting to the data. The variance of the random component model related to the intercept term is statistically significant, implying the presence of under-five child mortality variations among regional states of the country and it is accounted by the random intercept term.

Conclusion: The major significant factors affected under-five child mortality are: mother’s education level, birth index, child size at birth, mother’s age at birth, type of birth and breastfeeding status. It also revealed that there is a contribution of those major factors to under-five child mortality variations among regional states. However, those factors significantly affecting under-five child mortality is explicitly did not show significant effects on variations of under-five child mortality across regional states. The implication of the study is that all regional states should makes remedial measures on public health policy, design strategies to improve facilities and aptitudes of stakeholder living in their region toward those major factors affecting under-five child mortality and contributing to its variations among regional states to reduce under-five child mortality in the country.

Open Access Original Research Article

Photoelectric Characterization of a Dye-sensitized Solar Cell Based on Natural Pigment Extracted from Roselle (Hibiscus sabdariffa) Flower and TiO2 Nanoparticles

Eli Danladi, M. Y. Onimisi, S. G. Abdu, Ezeoke Jonathan, S. O. Yakubu

Current Journal of Applied Science and Technology, Page 1-6
DOI: 10.9734/BJAST/2016/24437

Dye-sensitized solar cell (DSSC) was fabricated using natural dye extracted from Roselle flower. The sensitization performance related to interaction between the dye and titanium dioxide (TiO2) surface was evaluated under 100 mWcm-2 light intensity. The DSSC based on the Hibiscus sabdariffa organic dye gave a short-circuit current density (Jsc) of 0.0259 mAcm-2, open-circuit voltage (Voc) of 0.432 V and fill factor (FF) of 0.594, yielding an overall solar conversion efficiency (η) of 0.0067%. The result obtained shows some improvement over similar studies carried out by Adenike et al. [1] with lower efficiency of 0.002%. The improved performance might be attributed to the differences in concentrations of phytoconstituents in different parts of the plant and also the type of solvent used to extract the sensitizer.

Open Access Original Research Article

Oxygen and Hydrogen Reaction “In situ” with Magnesium and Tantalum in a Mechanical Milling System When a Solvent is Used

José Luis Iturbe-García, Beatriz Eugenia López-Muñoz

Current Journal of Applied Science and Technology, Page 1-9
DOI: 10.9734/BJAST/2016/23371

The purpose of this paper is study the preparation “in situ” of magnesium–tantalum phases when reacted with oxygen and hydrogen during a mechanical milling process. Different phases were formed as function of the milling time. High energy ball milling was utilized to prepare hydrogenated compounds by controling the milling between 5 and 20 hours with a ball powder weight ratio of 10 and using methanol as the control agent. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the compounds. The XRD results at 20 h of milling revealed that only hydrogenated species (Ta2H and TaH0.5) and Mg(OH)2  were present.

Open Access Original Research Article

Assessing the Possible Impacts of Climate Change on the Tourism Potentials of Ebomi Lake, Ondo State, Nigeria

A. J. Oloruntade, O. S. Sajo, O. B. Imoukhuede

Current Journal of Applied Science and Technology, Page 1-11
DOI: 10.9734/BJAST/2016/24285

Climate change as one of the greatest threats to environmental sustainability, can impact on any sector of the economy including tourism. Thus, this study examined the possible impacts of climate change on the tourism potential of Ebomi Lake, Ondo State, Nigeria. Available literature showed that biodiversity and water resources which are the greatest assets of tourism in Nigeria are being negatively impacted by climate change. With respect to the study area, field observation showed that human activities such as farming, timber logging and bush burning which are all drivers of climate change are predominantly high. In addition, information from oral interviews conducted also showed that the lake may have shrunk while the environment appeared less forested compared to the situation some 50 years ago. Thus, it was concluded that Ebomi Lake might be suffering from the negative impacts of climate change such as changing micro-climate, biodiversity loss, degradation of landscape and drying-up of lake amongst others. Therefore, our recommendations included (1) acquisition of additional portion of lands around the lake by the government to ward-off intruders and prevent illegal human activities, (2) implementation of policies and laws that prohibit human activities which are inimical to ecosystem conservation, while (3) perpetrators of illegal activities should be apprehended and punished to serve as deterrent and thus protect the environment against biodiversity loss.

Open Access Original Research Article

Microstructure and in vitro Bioactivity of Metal Substituted Hydroxyapatite

G. El-Damrawi, H. Kamal, H. Doweidar, A. E. Dawood

Current Journal of Applied Science and Technology, Page 1-12
DOI: 10.9734/BJAST/2016/24940

Pure Hydroxyapatite (HAp) nanoparticles doped with Mn2+ and Fe3+ ions were synthesized using wet chemical method (WCM). Samples were characterized by different spectroscopic techniques such as XRD, FTIR, and ESR. The measurements revealed that a typical HAp powder pattern was obtained.  Comparing with pure stoichiometric HAp, both Mn+2 substituted HAp (Mn-HAp) and Fe+3 substituted HAp (Fe-HAp) did not demonstrate significant structure deviation. Since ion exchange mechanism was applied for the preparation process, the morphology and particle size were not significantly affected. The FTIR absorption spectra of the doped samples are presented as absorption bands characterizing Mn+2, and Fe+3 which occupy different crystalline sites. The obtained data agrees well with that obtained from XRD. The crystal field parameters and degree of crystallinity for sites of these ions in the HAp matrix can be estimated. The addition of iron and manganese ions into hydroxyapatite results in improvement of the biological performance of the implant. Iron and manganese substituted hydroxyapatite has shown superior biological performance compared to its stoichiometric counterparts in vitro. The addition of such ions also enhances the magnetic properties of hydroxyapatite for the use in hyperthermia medical applications.

Open Access Original Research Article

Molecular Characterization and Antibiotic Resistance Profile of Bacteria Associated with Brycinus longipinnis from Eggua Station on Yewa River

O. O. Oyelakin, A. Akinyemi, A. R. Oloyede, A. K. Agboola, I. O. Oloye, P. A. Akinduti

Current Journal of Applied Science and Technology, Page 1-7
DOI: 10.9734/BJAST/2016/18287

Fish is one of the most highly perishable food products, during handling and storage, causing rapid quality deterioration of fresh fish and limits the shelf life of the product. Bacteria isolates were collected from the gills, skins and guts of Brycinus longipinnis from Eggua, station on Yewa River. The bacteria isolates were assessed using 16S rRNA gene sequencing method to identify them and to construct the phylogenetic relationship. Sixteen bacteria isolates were selected, their  morphological characteristics were determined, the DNA of the isolates were extracted using CTAB method, PCR amplification of 16S ribosomal RNA gene of isolates was carried out using universal primer for bacteria, purification of the PCR product was done using ethanol precipitation, later it was sequenced using an automated DNA sequencer. The sequence data were compared with other gene sequences in GenBank database (NCBI) using a BLAST search to find closely related sequences. Eight different bacteria strains were identified from skins, gills and guts of Brycinus longipinnis. The strains are Pseudomonas spp (15%), Comamonas spp (10%), Escherichia coli (10%), Proteus spp (10%), Entrobacter spp (10%), Pseudoalteromonas spp (5%), Alcaligenes  faecalis (5%), and Serratia marcescens (5%) frequency of bacteria. Most of the strains from Brycinus longipinnis were sensitive to Ofloxacin and Ciprofloxacin antibiotics; and resistant to Cefuroxime and Cefixime. It can therefore be concluded that Brycinus longipinnis harbors different species of bacteria.