Search results for: African film
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2497

Search results for: African film

667 Structural and Optical Properties of RF-Sputtered ZnS and Zn(S,O) Thin Films

Authors: Ould Mohamed Cheikh, Mounir Chaik, Hind El Aakib, Mohamed Aggour, Abdelkader Outzourhit

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Zinc sulfide [ZnS] and oxygenated zinc sulfide Zn(O,S) thin films were deposited on glass substrates, by reactive cathodic radio-frequency (RF) sputtering. The substrates power and percentage of oxygen were varied in the range of 100W to 250W and from 5% to 20% respectively. The structural, morphological and optical properties of these thin films were investigated. The optical properties (mainly the refractive index, absorption coefficient and optical band gap) were examined by optical transmission measurements in the ultraviolet-visible-near Infrared wavelength range. XRD analysis indicated that all sputtered ZnS films were a single phase with a preferential orientation along the (111) plane of zinc blend (ZB). The crystallite size was in the range of 19.5 nm to 48.5 nm, the crystallite size varied with RF power reaching a maximum at 200 W. The Zn(O,S) films, on the other hand, were amorphous. UV-Visible, measurements showed that the ZnS film had more than 80% transmittance in the visible wavelength region while that of Zn(O,S is 85%. Moreover, it was observed that the band gap energy of the ZnS films increases slightly from 3.4 to 3.52 eV as the RF power was increased. The optical band gap of Zn(O,S), on the other hand, decreased from 4.2 to 3.89 eV as the oxygen partial pressure is increased in the sputtering atmosphere at a fixed RF-power. Scanning electron microscopy observations revealed smooth surfaces for both type of films. The X-ray reflectometry measurements on the ZnS films showed that the density of the films (3.9 g/cm3) is close that of bulk ZnS.

Keywords: thin films Zn(O, S) properties, Zn(O, S) by Rf-sputtering, ZnS for solar cells, thin films for renewable energy

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666 Enhancing Fracture Toughness of CF/PAEK Laminates for High-Velocity Impact Applications: An Experimental Investigation

Authors: Johannes Keil, Eric Mischorr, Veit Würfel, Jan Condé-Wolter, Alexander Liebsch, Maik Gude

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In the aviation sector wastewater pipes are subjected to many different mechanical and medial loads. Worst-case scenarios include high-velocity impacts resulting from the introduction of foreign objects into the system. The industry is seeking to reduce the weight of these pipes, which are currently manufactured from titanium. A promising alternative is the use of fiber-reinforced polymers (FRP), specifically carbon fiber (CF) reinforced polyaryletherketone (PAEK) laminates. This study employs an experimental methodology to investigate the impact resistance of CF/PAEK laminates, with a particular focus on three configurations: crimp, non-crimp, and interleaved matrix rich films in cross-ply laminates. High-velocity impacts were performed using a gas gun resulting in three-dimensional damage patterns. Afterwards the damage behavior was qualitatively and quantitatively analyzed using ultrasonic scans and computed tomography (CT). Samples with an interleaved matrix-rich film led to a reduction of the damage area by around 40% compared to the non-interleaved, non-crimp samples, while the crimp architecture resulted in a reduction of more than 60%. Therefore, these findings contribute to understanding the influence of laminate architecture on impact resistance, paving the way for more efficient materials in aviation applications.

Keywords: fracture toughness, high-velocity-impact, textile architecture, thermoplastic composites

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665 Setting the Baseline for a Sentinel System for the Identification of Occupational Risk Factors in Africa

Authors: Menouni Aziza, Chbihi Kaoutar, Duca Radu Corneliu, Gilissen Liesbeth, Bounou Salim, Godderis Lode, El Jaafari Samir

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In Africa, environmental and occupational health risks are mostly underreported. The aim of this research is to develop and implement a sentinel surveillance system comprising training and guidance of occupational physicians (OC) who will report new work-related diseases in African countries. A group of 30 OC are recruited and trained in each of the partner countries (Morocco, Benin and Ethiopia). Each committed OC is asked to recruit 50 workers during a consultation in a time-frame of 6 months (1500 workers per country). Workers are asked to fill out an online questionnaire about their health status and work conditions, including exposure to 20 chemicals. Urine and blood samples are then collected for human biomonitoring of common exposures. Some preliminary results showed that 92% of the employees surveyed are exposed to physical constraints, 44% to chemical agents, and 24% to biological agents. The most common physical constraints are manual handling of loads, noise pollution and thermal pollution. The most frequent chemical risks are exposure to pesticides and fuels. This project will allow a better understanding of effective sentinel systems as a promising method to gather high quality data, which can support policy-making in terms of preventing emerging work-related diseases.

Keywords: sentinel system, occupational diseases, human biomonitoring, Africa

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664 Divergences in Interpreters’ Oral Interpretation among Pentecostal Churches: Sermonic Reflections

Authors: Rufus Olufemi Adebayo, Sylvia Phiwani Zulu

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Interpreting in the setting of diverse language and multicultural congregants, is often understood as integrating the content of the message. Preaching, similar to any communication, takes seriously people’s multiple contexts. The one who provides the best insight into understanding “the other”, traditionally speaking could be an interpreter in a multilingual context. Nonetheless, there are reflections in the loss of spiritual communication, translation and interpretive dialogue. No matter how eloquent the preacher is, an interpreter can make or mere the sermon (speech). The sermon that the preacher preaches is not always the one the congregation hears from the interpreter. In other occurrences, however, interpreting can lead not only to distort messages but also to dissatisfied audiences and preacher being overshadowed by the pranks of the interpreter. Using qualitative methodology, this paper explores the challenges and the conventional assumptions about preachers’ interpreter as influenced by spirituality, culture, and language in empirical and theoretical perspectives. An emphasis on the bias translation and the basis of reality that suppresses or devalues the spiritual communication is examined. The result indicates that interpretation of the declaration of guilt, history of congregation, spirituality, attitudes, morals, customs, specific practices of a preacher, education, and the environment form an entangled and misinterpretation. The article concludes by re-examining these qualities and rearticulating them into a preliminary theory for practice, as distinguished from theory, which could possibly enhance the development of more sustainable multilingual interpretation in the South African Pentecostal churches.

Keywords: congregants, divergences, interpreting/translation, language & communication, sermon/preaching

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663 Animation: A Footpath for Enhanced Awareness Creation on Malaria Prevention in Rural Communities

Authors: Stephen Osei Akyiaw, Divine Kwabena Atta Kyere-Owusu

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Malaria has been a worldwide menace of a health condition to human beings for several decades with majority of people on the African continent with most causalities where Ghana is no exception. Therefore, this study employed the use of animation to enhance awareness creation on the spread and prevention of Malaria in Effutu Communities in the Central Region of Ghana. Working with the interpretivist paradigm, this study adopted Art-Based Research, where the AIDA Model and Cognitive Theory of Multimedia Learning (CTML) served as the theories underpinning the study. Purposive and convenience sampling techniques were employed in selecting sample for the study. The data collection instruments included document review and interviews. Besides, the study developed an animation using the local language of the people as the voice over to foster proper understanding by the rural community folks. Also, indigenous characters were used for the animation for the purpose of familiarization with the local folks. The animation was publicized at Health Town Halls within the communities. The outcomes of the study demonstrated that the use of animation was effective in enhancing the awareness creation for preventing and controlling malaria disease in rural communities in Effutu Communities in the Central Region of Ghana. Health officers and community folks expressed interest and desire to practice the preventive measures outlined in the animation to help reduce the spread of Malaria in their communities. The study, therefore, recommended that animation could be used to curtail the spread and enhanced the prevention of Malaria.

Keywords: malaria, animation, prevention, communities

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662 Student Teachers' Experiences and Perceptions of a Curriculum Designed to Promote Social Justice

Authors: Emma Groenewald

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In 1994, numerous policies of a democratic dispensation envisage social justice and the transformation of the South Africa society. The drive for transformation and social justice resulted in an increasing number of university students from diverse backgrounds, which in turn, lead to the establishment of Sol Plaatje University (SPU) in 2014. A re-curriculated B. Ed. programme at SPU aims to equip students with knowledge and skills to realise the aim of social justice and to enhance the transformation of the South African society. The aim of this study is to explore the experiences and perceptions of students at a diverse university campus on a curriculum that aims to promote social justice. Four education modules, with the assumption that it reflects social justice content, were selected. Four students, representative of different ethnic and language groupings found at the SPU, were chosen as participants. Data were generated by the participants through four reflective exercises on each of the modules, spread over a period of four years. The module aims, linked with the narratives of the participants' perceptions and experiences of each module, provided an overview of the enacted curriculum. A qualitative research design with an interpretivist approach informed by Vygotsky's theory of learning was used. The participants' experiences of the four modules were analysed, and their views were interpreted. The students' narratives shed light on the strengths and weaknesses of how the B.Ed. Curriculum works towards social justice and revealed student's perceptions of otherness. From the narratives it became apparent that module did promote a social justice orientation in prospective teachers trained at a university.

Keywords: student diversity, social justice, transformation, teacher education

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661 Electrochemically Reduced Graphene Oxide Modified Boron-Doped Diamond Paste Electrode on Paper-Based Analytical Device for Simultaneous Determination of Norepinephrine and Serotonin

Authors: Siriwan Nantaphol, Robert B. Channon, Takeshi Kondo, Weena Siangproh, Orawon Chailapakul, Charles S. Henry

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In this work, we demonstrate a novel electrochemically reduced graphene oxide (ERGO) modified boron-doped diamond paste (BDDP) electrode on paper-based analytical devices (PADs) for simultaneous determination of norepinephrine (NE) and serotonin (5-HT). The BDD paste electrode was easily constructed by filling BDD paste in small channels, which made in transparency film sheets using a CO₂ laser etching 
system. The counter and reference electrodes were fabricated on paper by in-house screen-printing and then combined with BDD paste microelectrode. The electrochemical characterization of the device was investigated by cyclic voltammetry (CV). Differential pulse voltammetry (DPV) was employed for the simultaneous determination of NE and 5-HT. The ERGO-modified BDDP electrode displayed excellent electrocatalytic activities toward the oxidation of NE and 5-HT and strong function for resolving the overlapping voltammetric responses of NE and 5-HT into two well-defined voltammetric peaks. This device was capable of simultaneously detecting NE and 5-HT in wide concentration ranges and with a low limit of detections. In addition, it has the advantages in terms of ease of use, low cost, and disposability.

Keywords: boron-doped diamond paste electrode, electrochemically reduced graphene oxide, norepinephrine, paper-based analytical device, serotonin

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660 Policies Promoting the Development of Green Buildings in Sub-Saharan Africa: A South African Case-Study

Authors: Peter Adekunle, Clinton Aigbavboa, Matthew Ikuabe, Opeoluwa Akinradewo

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Contemporary building methods typically pay little attention to the built environment's greater economic, environmental, or social impacts or energy efficiency. Green construction aims to sever ties with these conventions. In order to provide better living and working conditions and lessen environmental consequences, green building today combines numerous building design, construction, and operation and maintenance approaches. As one of Sub-Saharan Africa's most industrialized nations, South Africa has a good number of green building projects. Therefore, this study examines the elements impacting the adoption of green buildings and regulations created to encourage the growth of green buildings using South Africa as a case study. The study has a survey-style design. A total of one hundred fifty (150) questionnaires were distributed to professionals in the construction industry in South Africa, of which one hundred and twenty-four (128) were returned and judged appropriate for investigation. The gathered data was examined using percentage, mean item scores, standard deviation, and Kruskal-Wallis. The findings show that cost and market circumstances are the two main elements impacting the adoption of green construction, while leadership advice is the most important policy. The study concluded that in order to encourage the construction of green buildings, additional Sub-Saharan nations should adopt these suggested policies.

Keywords: green building, Sub-Saharan Africa, building design, environmental conditions

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659 Approximation of PE-MOCVD to ALD for TiN Concerning Resistivity and Chemical Composition

Authors: D. Geringswald, B. Hintze

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The miniaturization of circuits is advancing. During chip manufacturing, structures are filled for example by metal organic chemical vapor deposition (MOCVD). Since this process reaches its limits in case of very high aspect ratios, the use of alternatives such as the atomic layer deposition (ALD) is possible, requiring the extension of existing coating systems. However, it is an unsolved question to what extent MOCVD can achieve results similar as an ALD process. In this context, this work addresses the characterization of a metal organic vapor deposition of titanium nitride. Based on the current state of the art, the film properties coating thickness, sheet resistance, resistivity, stress and chemical composition are considered. The used setting parameters are temperature, plasma gas ratio, plasma power, plasma treatment time, deposition time, deposition pressure, number of cycles and TDMAT flow. The derived process instructions for unstructured wafers and inside a structure with high aspect ratio include lowering the process temperature and increasing the number of cycles, the deposition and the plasma treatment time as well as the plasma gas ratio of hydrogen to nitrogen (H2:N2). In contrast to the current process configuration, the deposited titanium nitride (TiN) layer is more uniform inside the entire test structure. Consequently, this paper provides approaches to employ the MOCVD for structures with increasing aspect ratios.

Keywords: ALD, high aspect ratio, PE-MOCVD, TiN

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658 Inhibition of Streptococcus Mutans Biofilm Development of Dental Caries In Vitro and In Vivo by Trachyspermum ammi Seeds: An Approach of Alternative Medicine

Authors: Mohd Adil, Rosina Khan, Danishuddin, Asad U. Khan

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The aim of this study was to evaluate the influence of the crude and active solvent fraction of Trachyspermum ammi on S. mutans cariogenicity, effect on expression of genes involved in biofilm formation and caries development in rats. GC–MS was carried out to identify the major components present in the crude and the active fraction of T. ammi. The crude extract and the solvent fraction exhibiting least MIC were selected for further experiments. Scanning electron microscopy was carried out to observe the effect of the extracts on S. mutans biofilm. Comparative gene expression analysis was carried out for nine selected genes. 2-Isopropyl-5-methyl-phenol was found as major compound in crude and the active fraction. Binding site of this compound within the proteins involved in biofilm formation was mapped with the help of docking studies. Real-time RT-PCR analyses revealed significant suppression of the genes involved in biofilm formation. All the test groups showed reduction in caries (smooth surface as well as sulcal surface caries) in rats. Moreover, it also provides new insight to understand the mechanism influencing biofilm formation in S. mutans. Furthermore, the data suggest the putative cariostatic properties of T. Ammi and hence can be used as an alternative medicine to prevent caries infection.

Keywords: bio-film, Streptococcus mutans, dental caries, bio-informatic

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657 A Study of Electric Generation Characteristics for Thin-Film Piezoelectric PbZrTiO₃ Ceramic Plate during the Static and Cyclic Loading Conditions

Authors: Tsukasa Ogawa, Mitsuhiro Okayasu

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To examine the generation properties of electric power for piezoelectric (PbZrTiO3) ceramic plates, the electric-power generation characteristics were examined experimentally and numerically during cyclic bending under various loading fixtures with different contact condition, i.e., point and area contact. In the low applied loading condition between 10 and 50 N, increasing the load-contact area on the piezoelectric ceramic led to a nonlinear decrease in the generated voltage. Decreasing contact area, including the point contact, basically enhanced the generated voltage, although the voltage saturated during loading when the contact area is less than ϕ5 mm, which was attributed to the high strain status, resulting in the material failure, i.e., high stress concentration. In this case, severe plastic deformation and the domain switching were dominated failure modes in the ceramic. From this approach, it is clear that the applied load became more larger (50 ~100 N), larger contact area (ϕ10 ~ ϕ20 mm) became advantageous for power generation. Based upon this cyclic loading was carried out to investigate the fatigue characteristics of the piezoelectric ceramic late. For all contact conditions, electric voltage dropped in the beginning of the cyclic loading, although the higher electric generation was stable in the further cyclic loading for the contact area of ϕ10 ~ ϕ20 mm. In constant, further decrement of electric generation occurred for the point contact condition, and the low electric voltage was generated for the larger contact condition.

Keywords: electric power generation, piezoelectric ceramic, lead zirconate titanate ceramic, loading conditions

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656 Effect of Intrinsic Point Defects on the Structural and Optical Properties of SnO₂ Thin Films Grown by Ultrasonic Spray Pyrolysis Method

Authors: Fatiha Besahraoui, M'hamed Guezzoul, Kheira Chebbah, M'hamed Bouslama

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SnO₂ thin film is characterized by Atomic Force Microscopy (AFM) and Photoluminescence Spectroscopies. AFM images show a dense surface of columnar grains with a roughness of 78.69 nm. The PL measurements at 7 K reveal the presence of PL peaks centered in IR and visible regions. They are attributed to radiative transitions via oxygen vacancies, Sn interstitials, and dangling bonds. A bands diagram model is presented with the approximate positions of intrinsic point defect levels in SnO₂ thin films. The integrated PL measurements demonstrate the good thermal stability of our sample, which makes it very useful in optoelectronic devices functioning at room temperature. The unusual behavior of the evolution of PL peaks and their full width at half maximum as a function of temperature indicates the thermal sensitivity of the point defects present in the band gap. The shallower energy levels due to dangling bonds and/or oxygen vacancies are more sensitive to the temperature. However, volume defects like Sn interstitials are thermally stable and constitute deep and stable energy levels for excited electrons. Small redshifting of PL peaks is observed with increasing temperature. This behavior is attributed to the reduction of oxygen vacancies.

Keywords: transparent conducting oxide, photoluminescence, intrinsic point defects, semiconductors, oxygen vacancies

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655 University Students’ Perceptions of the Influence of Cannabis Use on Mental Health

Authors: Konesh Navsaria, Itumeleng Ramodumo

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The study explored university students’ perceptions of cannabis use on academic life at a higher education institution (HEI) in Nelson Mandela Bay, South Africa. Cannabis is described as the most commonly-used drug by youth, especially those who are in tertiary institutions. The use of cannabis has both negative and positive effects; this is evident in different areas of human functioning. Cannabis usage has been debated upon in courts regarding its legalization and decriminalization, and on the 18th of September 2018, the South African High Court decriminalized cannabis for personal use. Cannabis use has increased in academic settings, and this has raised concerns about how it affects the mental health of students. A qualitative approach was used for the study with an explorative, descriptive design. Purposive sampling was used to select 15 participants for the study. Data were collected using focused-group interviews, following ethical clearance from the HEI. The collected data were analyzed and interpreted using thematic analysis, and cognitive behavioural theory was used as the theoretical framework. The research findings indicated both positive and negative influences of cannabis use on mental health. Most participants who expressed positive effects have used cannabis before, whereas most participants with negative perspectives of cannabis use on mental health are non-cannabis users. The findings revealed that participants perceived that the quantity of cannabis smoked determined whether there was a positive or negative effect on mental health; that is, large doses of cannabis were perceived as having negative effects. The research findings also revealed that the legalization of cannabis is very likely to increase its use and also highlighted precautionary measures users take to avoid the substance’s negative effects on mental health.

Keywords: cannabis use, mental health, university students, legalization

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654 Preparation and Characterization of Phosphate-Nickel-Titanium Composite Coating Obtained by Sol Gel Process for Corrosion Protection

Authors: Khalidou Ba, Abdelkrim Chahine, Mohamed Ebn Touhami

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A strong industrial interest is focused on the development of coatings for anticorrosion protection. In this context, phosphate composite materials are expanding strongly due to their chemical characteristics and their interesting physicochemical properties. Sol-gel coatings offer high homogeneity and purity that may lead to obtain coating presenting good adhesion to metal surface. The goal behind this work is to develop efficient coatings for corrosion protection of steel to extend its life. In this context, a sol gel process allowing to obtain thin film coatings on carbon steel with high resistance to corrosion has been developed. The optimization of several experimental parameters such as the hydrolysis time, the temperature, the coating technique, the molar ratio between precursors, the number of layers and the drying mode has been realized in order to obtain a coating showing the best anti-corrosion properties. The effect of these parameters on the microstructure and anticorrosion performance of the films sol gel coating has been investigated using different characterization methods (FTIR, XRD, Raman, XPS, SEM, Profilometer, Salt Spray Test, etc.). An optimized coating presenting good adhesion and very stable anticorrosion properties in salt spray test, which consists of a corrosive attack accelerated by an artificial salt spray consisting of a solution of 5% NaCl, pH neutral, under precise conditions of temperature (35 °C) and pressure has been obtained.

Keywords: sol gel, coating, corrosion, XPS

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653 Study on Properties of Carbon-based Layer for Proton Exchange Membrane Fuel Cell Application

Authors: Pei-Jung Wu, Ching-Ying Huang, Chih-Chia Lin, Chun-Han Li, Chien-Yuan Wang

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The fuel cell market has considerable development potential, but the cost is still less competitive. Replacing the traditional graphite plate with a stainless steel plate as a bipolar plate can greatly reduce the weight and volume of the stack, and has more cost advantages. However, the passivation layer on the surface of stainless steel makes the contact resistance reach the ohmic level and reduces the performance of the fuel cell. Therefore, it is necessary to reduce the interfacial contact resistance through the surface treatment. In this research, the thickness, uniformity, interfacial contact resistance (ICR), and adhesion of the carbon-based layer was analyzed. On the other hand, the effect of coating properties on the performance of the fuel cell was verified through I-V tests. The results show that after coating the contact resistance is greatly reduced by three stages to the microohm level, and as the film thickness is reduced, the contact resistance is reduced from 229~118 mΩ-cm² to 135~73 mΩ-cm² at a general assembly pressure of 1 to 2 MPa., and the current density at 0.6 V increased from 485.7 mA/cm² to 575.7 mA/cm². This study verifies the importance of the uniformity and ICR of the coating on proton exchange membrane fuel cell (PEMFC), and the surface coating technology is the key to affecting the characteristics of the coating.

Keywords: contact resistance, proton exchange membrane fuel cell, PEMFC, SS bipolar plate, spray coating process

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652 Factors Influencing the Uptake of Family Planning Services among Young People (18-24 Years) at Community Level in Rural Budaka District, Uganda

Authors: Mathew Nyashanu, George K. Kiggundu, Mandu S. Ekpenyong

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There is an increased number of young people engaging in early sexual relationships worldwide. Furthermore, statistics for early pregnancy among young people have also increased, especially in low and middle-income countries. This has health implications for both the parents and the baby. High uptake in family planning contraception among young people can reduce early pregnancy and subsequent negative health outcomes on the young parents and the baby. This study was set to explore the factors influencing the uptake of family planning contraceptive services among young people (18-24 years) at a community level in rural Budaka district, Uganda. The study utilised an explorative qualitative approach. The study found out that religion, partner resistance; perceived loss of libido, perceived barren, long waiting time and distance from the health facility, lack of privacy/confidentiality, excessive menstrual bleeding, cancer, and fear of having disabled babies, limited the utilisation of family planning contraceptive services while contraception as HIV prevention and child spacing encouraged young people to use family planning contraceptive services. There is a need for a culturally orientated community-based contraceptive health promotion approach to increase the uptake of family planning contraception services among young people.

Keywords: Young people, Family Planning, Contraceptives, Black sub-Sahara African

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651 The Role of Identity Politics in the 2023 General Election in Nigeria: An Overview

Authors: Adekunle Saheed Ajisebiyawo

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This paper examines the influence of identity politics on the development of electoral democracy in Nigeria. The paper was anchored on a theory of African democracy adopted the qualitative methodology and deployed data from secondary sources to evaluate the 2023 presidential election, and found that ethnicity, religion, and regional sentiments played a major role in the election. The practical implications of this paper are that while Nigeria’s democracy is tending towards consolidation, if the unexpected does not happen, e.g., military takeover, religious and ethnic identities can mar the country’s development as competent candidates that have good policies will be voted out based on religious and ethnic sentiments. Thus, there is a need to de-emphasize religion and ethnicity in the Nigerian polity. Candidates and parties that campaign based on racial or religious narratives should be barred from contesting elective positions. The paper concluded that identity politics is inimical to Nigeria’s democratization process as well as efforts aimed at uniting and integrating the country; it, therefore, recommended that to establish a sound electoral democracy and a strong united country, the menace of ethnic, religious, and regional cleavages should be addressed. To achieve this, efforts should be intensified towards providing a set of principles for nation-building which should be included in the constitution. In addition, the paper urges the media to support the formation of an inclusive government, cutting across tribes and religions in the country to reduce the negative impact of ethnicity and religion in the country.

Keywords: cleavages, democracy, ethnicity, election, identity politics, religion

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650 Anatomical Studies on the Spleen and Mesenteric Lymph Node of the Grasscutter

Authors: R. M. Korzerzer, J. O. Hambolu, S. O. Salami, S. B. Oladele

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The grasscutter (Thryonomys swinderianus) has become an important source of protein and income to rural dwellers in most West African countries including Nigeria. Twelve apparently healthy grasscutters consisting of six males and six females between the ages of three and seven months were obtained from rural dwellers in Benue state and used for this study. The animals were transported by means of constructed cages to the Department of Veterinary Anatomy, Ahmadu Bello University, Zaria and sacrificed using chloroform inhalation gaseous anaesthesia by suffocation. The spleen and mesenteric lymph nodes were extirpated and the tissues prepared using standard methods, haematoxilin and eosin stain was used for routine histology, while Rhodamine B-aniline-methylene blue stain was used for staining reticular and elastic fibres. The spleen was dark red in colour and roughly triangular in outline, and was observed to increase consistently with age, maximum values were recorded at seven months of age in both males and females. Mean ± SEM values for splenic weights were 0.67 ± 0.09 g, 1.65 ± 0.35 g and 2.31 ± 0.06 g at three, five and seven months of age, respectively. The percentage ratio of splenic weight to body weight was 0.1%. Histologically, the germinal centres revealed three zones; the germinal centre, cortical layer and the marginal zone. The mesenteric lymph nodes were constantly bean shaped and appeared as opaque white masses which resemble fat but were distinguished from fat by their pearly glossy nature. The mean ± SEM values for mesenteric lymph node weights were 0.056 ± 0.005 g, 0.143 ± 0.034 g and 0.1600 ± 0.023 g at three, five and seven months of age, respectively.

Keywords: anatomical, spleen, mesenteric lymph node, grasscutter

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649 Students' Ability to Solve Complex Accounting Problems Using a Framework-Based Approach

Authors: Karen Odendaal

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Accounting transactions are becoming more complex, and more extensive accounting guidance is provided on a continuous basis. It is widely perceived that conceptual teaching of accounting contributes to lifelong learning. Such a conceptual teaching approach also contributes to effective accounting problem-solving. This framework-based approach is rooted in educational psychologies such as constructivism and Ausubel’s subsumption theory. This study aimed at investigating the ability of students to solve complex accounting problems by using only concepts underlying the Conceptual Framework. An assignment was administered to pre-graduate students at a South African university and this study made use of an interpretative research design which implemented multiple research instruments to investigate the ability of students to solve complex accounting problems using only concepts underlying the Conceptual Framework. Student perceptions were analysed and were aided by a related reflective questionnaire. The importance of the study indicates the necessity of Accounting educators to enhance a conceptual understanding among students as a mechanism for problem-solving of accounting issues. The results indicate that the ability of students to solve accounting problems effectively using only the Conceptual Framework depends on the complexity of the scenario and the students’ familiarity with the problem. The study promotes a balanced and more conceptual (rather than only technical) preference to the problem-solving of complex accounting problems. The study indubitably promotes considerable emphasis on the importance of the Conceptual Framework in accounting education and the promotion of life-long learning in the subject field.

Keywords: accounting education, conceptual teaching, constructivism, framework-based, problem-solving

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648 Metabolome-based Profiling of African Baobab Fruit (Adansonia Digitata L.) Using a Multiplex Approach of MS and NMR Techniques in Relation to Its Biological Activity

Authors: Marwa T. Badawy, Alaa F. Bakr, Nesrine Hegazi, Mohamed A. Farag, Ahmed Abdellatif

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Diabetes Mellitus (DM) is a chronic disease affecting a large population worldwide. Africa is rich in native medicinal plants with myriad health benefits, though less explored towards the development of specific drug therapy as in diabetes. This study aims to determine the in vivo antidiabetic potential of the well-reported and traditionally used fruits of Baobab (Adansonia digitata L.) using STZ induced diabetic model. The in-vitro cytotoxic and antioxidant properties were examined using MTT assay on L-929 fibroblast cells and DPPH antioxidant assays, respectively. The extract showed minimal cytotoxicity with an IC50 value of 105.7 µg/mL. Histopathological and immunohistochemical investigations showed the hepatoprotective and the renoprotective effects of A. digitata fruits’ extract, implying its protective effects against diabetes complications. These findings were further supported by biochemical assays, which showed that i.p., injection of a low dose (150 mg/kg) of A. digitata twice a week lowered the fasting blood glucose levels, lipid profile, hepatic and renal markers. For a comprehensive overview of extract metabolites composition, ultrahigh performance (UHPLC) analysis coupled to high-resolution tandem mass spectrometry (HRMS/MS) in synchronization with molecular networks led to the annotation of 77 metabolites, among which 50% are reported for the first time in A. digitata fruits.

Keywords: adansonia digital, diabetes mellitus, metabolomics, streptozotocin, Sprague, dawley rats

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647 Maternal-Fetal Bonding for African American Mothers

Authors: Tracey Estriplet-Adams

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This paper focuses on the influence of maternal-fetal bonding by examining attachment theory, psycho-social-cultural influences/adaptations, and maternal well-being. A systematic review methodology was used to synthesize research results to summarize current evidence that can contribute to evidence-based practices. It explores the relationship between attachment styles, prenatal attachment, and perceptions of maternal-infant bonding/attachment six weeks postpartum. It also examines the protective factors of maternal-fetal attachment development. The research explores Bowlby's attachment theory and its relevance to maternal-fetal bonding with a Black Feminist Theory lens. Additionally, it discusses the impact of perceived stress, social support, and ecological models on maternal-fetal attachment. The relationship between maternal well-being, maternal-fetal attachment, and early postpartum bonding is reviewed. Moreover, the paper specifically addresses black mothers and maternal-fetal bonding, exploring the intersectionality of race, ethnicity, class, geographic location, cultural identities, and immigration status. It considers the role of familial and partner support, as well as the relationship between maternal attachment style and maternal-fetal bonding, within the framework of attachment theory and black feminist theory. Therefore, it is imperative to center Black women's voices in research, policy, and healthcare practices. Black women are experts in their own experiences and advocate for their autonomy in decision-making regarding maternal-fetal health. By amplifying their voices, we can ensure that interventions are grounded in their lived experiences.

Keywords: maternal-fetal bonding, infant well-being, maternal-infant attachment, black mothers

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646 Efficiency and Reliability Analysis of SiC-Based and Si-Based DC-DC Buck Converters in Thin-Film PV Systems

Authors: Elaid Bouchetob, Bouchra Nadji

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This research paper compares the efficiency and reliability (R(t)) of SiC-based and Si-based DC-DC buck converters in thin layer PV systems with an AI-based MPPT controller. Using Simplorer/Simulink simulations, the study assesses their performance under varying conditions. Results show that the SiC-based converter outperforms the Si-based one in efficiency and cost-effectiveness, especially in high temperature and low irradiance conditions. It also exhibits superior reliability, particularly at high temperature and voltage. Reliability calculation (R(t)) is analyzed to assess system performance over time. The SiC-based converter demonstrates better reliability, considering factors like component failure rates and system lifetime. The research focuses on the buck converter's role in charging a Lithium battery within the PV system. By combining the SiC-based converter and AI-based MPPT controller, higher charging efficiency, improved reliability, and cost-effectiveness are achieved. The SiC-based converter proves superior under challenging conditions, emphasizing its potential for optimizing PV system charging. These findings contribute insights into the efficiency, reliability, and reliability calculation of SiC-based and Si-based converters in PV systems. SiC technology's advantages, coupled with advanced control strategies, promote efficient and sustainable energy storage using Lithium batteries. The research supports PV system design and optimization for reliable renewable energy utilization.

Keywords: efficiency, reliability, artificial intelligence, sic device, thin layer, buck converter

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645 A Legal Opinion on Mitigation and Adaptation on Air Pollution Strategies for Local Governments in South Africa

Authors: Marjone Van Der Bank, C. M. Van Der Bank

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This paper presents an overview of the foundation and evolution of environmental related problems in local governments with specific reference on air pollution in South Africa. Local government has a direct mandate in terms of the Constitution of the Republic of South Africa, 1996 (hereafter, the Constitution). This mandate to protect, fulfil, respect and promote the Bill of Rights by local governments in respect of the powers and functions creates confusion around the role of where a local government fits in, in addressing the problem of climate change in South Africa. A reflection of the evolving legislations, developments, and processes regarding climate change that shaped local government dispensation in South Africa is addressed by the notion of developmental local governments. This paper seeks to examine the advances for mitigation and adaptation regulation of air pollution and application in South Africa. This study involves a qualitative approach that will involve South African national legislation as well as an interpretation of international strategies. A literature review study was conducted to undertake the various aspects of law in order to support the argument undertaken of mitigation and adaptation strategies. The paper presents a detailed discussion of the current legislation and the position as it currently stands, as well as the relevant protections as outlined in the National Environmental Management Act and the National Environmental Management: Air Quality Act. It then proceeds to outline the responsibilities of local governments in South Africa to mitigate and adapt to air pollution strategies.

Keywords: adaptation, climate change, disaster, local governments and mitigation

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644 The Role of Development in Settling Migration Crisis: The Preventive Approach of the European Union in Relations with Sub-Saharan African States

Authors: Artsiom Zinchanka

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The world faces now one of the largest migration crisis and the European Union meets challenges in accepting the flow of migrants that could not be handled finally at this step. This crisis is complicated with many factors, such as military conflict in the Middle East; absence of the appropriate conditions in the refugees’ camps; but also with the complicity of the migration flow consisting of the Sub-Saharan migrants. This type of migrants leave their homelands for many reasons including poverty, not appropriate level of social and economic conditions, absence of infrastructure and access to the education and medical care. In practice, when the restrictive approach directed to limit the flow of illicit migration and to send illicit migrants back to their homelands is not always working, the approach directed to the root causes of the migration crisis can be more effective in settling the crisis. The Cotonou Agreement and the following treaties concluded between the European Union, and Sub-Saharan states show that the European Union considers the development of human rights and appropriate social and economic conditions in the Sub-Saharan states as one of the most important factors addressing the migration crisis. The preventive approach as the efforts of the European Union to develop appropriate social and economic conditions in Sub-Saharan states is considered in this article, as well as its evolution and current condition. This article also considers pros and cons of this approach and the obstacles that this approach faces. The research methods include review of literature and documents, analytical and descriptive methods.

Keywords: migration crisis, preventive approach, Sub-Saharan States, the European Union

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643 Theoretical Study of Structural, Magnetic, and Magneto-Optical Properties of Ultrathin Films of Fe/Cu (001)

Authors: Mebarek Boukelkoul, Abdelhalim Haroun

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By means of the first principle calculation, we have investigated the structural, magnetic and magneto-optical properties of the ultra-thin films of Fen/Cu(001) with (n=1, 2, 3). We adopted a relativistic approach using DFT theorem with local spin density approximation (LSDA). The electronic structure is performed within the framework of the Spin-Polarized Relativistic (SPR) Linear Muffin-Tin Orbitals (LMTO) with the Atomic Sphere Approximation (ASA) method. During the variational principle, the crystal wave function is expressed as a linear combination of the Bloch sums of the so-called relativistic muffin-tin orbitals centered on the atomic sites. The crystalline structure is calculated after an atomic relaxation process using the optimization of the total energy with respect to the atomic interplane distance. A body-centered tetragonal (BCT) pseudomorphic crystalline structure with a tetragonality ratio c/a larger than unity is found. The magnetic behaviour is characterized by an enhanced magnetic moment and a ferromagnetic interplane coupling. The polar magneto-optical Kerr effect spectra are given over a photon energy range extended to 15eV and the microscopic origin of the most interesting features are interpreted by interband transitions. Unlike thin layers, the anisotropy in the ultra-thin films is characterized by a perpendicular magnetization which is perpendicular to the film plane.

Keywords: ultrathin films, magnetism, magneto-optics, pseudomorphic structure

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642 Negotiated Peace in Africa: A Case Study on the Pretoria Peace Deal between Federal Democratic Republic of Ethiopia and Tigray Peoples Liberation Front

Authors: Daniel Gidey, Kunwar Siddarth Dadhwal, Tagel Wondimu

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There are numerous ways for ending conflict; hitherto, most conflicts are resolved either through negotiated or victor's peace, this article is about the former. Negotiations entail concessions, consensus-building, and mutual trust in order to transform a belligerent situation into a settlement. In such a context, regional and sub-regional organizations play a critical role in mediating conflicting parties so as to prevent, manage, and resolve conflicts between and among conflicting parties. This article is about the AU-led negotiated peace deal on the bloody conflict between the Tigray Peoples Liberation Front (TPLF) and the Federal Democratic Republic of Ethiopia (FDRE) by undertaking the Pretoria Peace Accord as a case study. In terms of research method, the article is based on a critical evaluation of the literature and content analysis on the very research topic. Findings of the study revealed that the AU, through Olusegun Obasanjo and other dignitaries, played a critical role in nurturing compromise and mutual trust between the TPLF and the Ethiopian federal government so as to take along the Pretoria peace deal. Through critical literature review and content analysis of the Peace deal, the article has concluded that negotiated peace is likely, at least, to achieve negative peace.

Keywords: regional organizations, peace promotion, African Union, negotiating conflicts, Northern Ethiopia, conflict resolution

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641 A Retrospective Study of the Effects of Xenophobia on South Africa-Nigeria Relations

Authors: O. Fayomi, F. Chidozie, C. Ayo

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The underlying causes of xenophobia are complex and varied. Xenophobia has to do with being contemptuous of that which is foreign, especially of strangers or of people from different countries or cultures. Unemployment and mounting poverty among South Africans at the bottom of the economic ladder have provoked fears of the competition that better educated and experienced migrants can represent. South Africa’s long track-record of violence as a means of protest and the targeting of foreigners in particular, and, the documented tensions over migration policy and the scale of repatriation serve a very good explanation for its xenophobia. It was clear that while most of the attacks were directed against foreign, primarily African, migrants, this was not the rule. Attacks were also noted against Chinese-speakers, Pakistani migrants as well as against South Africans from minority language groups (in the conflict areas). Settlements that have recently experienced the expression of ‘xenophobic’ violence have also been the site of violent and other forms of protest around other issues, most notably service delivery. The failure of government in service delivery was vexed on this form of xenophobia. Due to the increase in migration, this conflict is certainly not temporary in nature. Xenophobia manifests in different regions and communities with devastating effects on the affected nationals. Nigerians living in South Africa have been objects of severe attacks and assault as a result of this xenophobic attitude. It is against this background that this study seeks to investigate the xenophobic attacks against Nigerians in South Africa. The methodology is basically qualitative with the use of secondary sources such as books, journals, newspapers and internet sources.

Keywords: xenophobia, unemployment, poverty, Nigeria, South Africa

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640 Studies of the Corrosion Kinetics of Metal Alloys in Stagnant Simulated Seawater Environment

Authors: G. Kabir, A. M. Mohammed, M. A. Bawa

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The paper presents corrosion behaviors of Naval Brass, aluminum alloy and carbon steel in simulated seawater under stagnant conditions. The behaviors were characterized on the variation of chloride ions concentration in the range of 3.0wt% and 3.5wt% and exposure time. The weight loss coupon-method immersion technique was employed. The weight loss for the various alloys was measured. Based on the obtained results, the corrosion rate was determined. It was found that the corrosion rates of the various alloys are related to the chloride ions concentrations, exposure time and kinetics of passive film formation of the various alloys. Carbon steel, suffers corrosion many folds more than Naval Brass. This indicated that the alloy exhibited relatively strong resistance to corrosion in the exposure environment of the seawater. Whereas, the aluminum alloy exhibited an excellent and beneficial resistance to corrosion more than the Naval Brass studied. Despite the prohibitive cost, Naval Brass and aluminum alloy, indicated to have beneficial corrosion behavior that can offer wide range of application in seashore operations. The corrosion kinetics parameters indicated that the corrosion reaction is limited by diffusion mass transfer of the corrosion reaction elements and not by reaction controlled.

Keywords: alloys, chloride ions concentration, corrosion kinetics, corrosion rate, diffusion mass transfer, exposure time, seawater, weight loss

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639 Assessment of Tidal Current Energy Potential at LAMU and Mombasa in Kenya

Authors: Lucy Patricia Onundo, Wilfred Njoroge Mwema

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The tidal power potential available for electricity generation from Mombasa and Lamu sites in Kenya will be examined. Several African countries in the Western Indian Ocean endure insufficiencies in the power sector, including both generation and distribution. One important step towards increasing energy security and availability is to intensify the use of renewable energy sources. The access to cost-efficient hydropower is low in Mombasa and Lamu hence Ocean energy will play an important role. Global-Level resource assessments and oceanographic literature and data have been compiled in an analysis between technology-specific requirements for ocean energy technologies (salinity, tide, tidal current, wave, Ocean thermal energy conversion, wind and solar) and the physical resources in Lamu and Mombasa. The potential for tide and tidal current power is more restricted but may be of interest at some locations. The theoretical maximum power produced over a tidal cycle is determined by the product of the forcing tide and the undisturbed volumetric flow-rate. The extraction of the maximum power reduces the flow-rate, but a significant portion of the maximum power can be extracted with little change to the tidal dynamics. Two-dimensional finite-element, numerical simulations designed and developed agree with the theory. Temporal variations in resource intensity, as well as the differences between small-scale and large-scale applications, are considered.

Keywords: energy assessment, marine tidal power, renewable energy, tidal dynamics

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638 Blade Runner and Slavery in the 21st Century

Authors: Bülent Diken

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This paper looks to set Ridley Scott’s original film Blade Runner (1982) and Denis Villeneuve’s Blade Runner 2049 (2017) in order to provide an analysis of both films with respect to the new configurations of slavery in the 21st century. Both Blade Runner films present a de-politicized society that oscillates between two extremes: the spectral (the eye, optics, digital communications) and the biopolitical (the body, haptics). On the one hand, recognizing the subject only as a sign, the society of the spectacle registers, identifies, produces and reproduces the subject as a code. At the same time, though, the subject is constantly reduced to a naked body, to bare life, for biometric technologies to scan it as a biological body or body parts. Being simultaneously a pure code (word without body) and an instrument slave (body without word), the replicants are thus the paradigmatic subjects of this society. The paper focuses first on the similarity: both films depict a relationship between masters and slaves, that is, a despotic relationship. The master uses the (body of the) slave as an instrument, as an extension of his own body. Blade Runner 2019 frames the despotic relation in this classical way through its triangulation with the economy (the Tyrell Corporation) and the slave-replicants’ dissent (rejecting their reduction to mere instruments). In a counter-classical approach, in Blade Runner 2049, the focus shifts to another triangulation: despotism, economy (the Wallace Corporation) and consent (of replicants who no longer perceive themselves as slaves).

Keywords: Blade Runner, the spectacle, bio-politics, slavery, imstrumentalisation

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