ghanaopendata/ghanaian-research-english huggingface dataset:
Telecobalt machine beam intensity modulation with aluminium compensating filter using missing tissue approach

The present study aimed to generate intensity-modulated beams with Aluminium compensating filters for a conventional telecobalt machine based on the outputs of a treatment planning system (TPS) performing forward planning and cannot simulate directly the compensating filter. Materials and Methods: In order to achieve the beam intensity modulation during treatment planning with the TPS, we used a bolus placed on the surface of a tissue-equivalent phantom. The treatment plans replicated on the telecobalt machine with the bolus were represented with compensating filters placed at a certain distance from the phantom surface. An equation was proposed for the conversion of the bolus thickness to the compensating filters thickness such that any point within the phantom would receive the planned dose. Correction factors were introduced into the proposed equation to account for the influences of field size, treatment depth, and applied bolus thickness. The proposed equation was obtained based on the analyses of empirical data measured in a full scatter water phantom with and without the compensating filter. Results: According to the results, the dosimetric verification of the proposed approach outputs in a solid water phantom with calibrated Gafchromic EBT2 films were comparable to that of the TPS with deviation of ±4.73% (mean: 2.98±1.05%). Conclusion: As the findings of the present study indicated, the discrepancy between the measured doses and TPS-estimated doses was within the tolerance of ±5%, which is recommended for dose delivery in external beam radiotherapy. Therefore, the proposed approach is recommended for clinical application

Source: UCC
Television exposure and overweight/ obesity among women in Ghana

Background: Although the public health importance of the association between television (TV) viewing and obesity and/or related outcomes have been demonstrated in both cross-sectional and prospective studies elsewhere, similar studies are lacking within the African region. With the view to fill this gap in the literature, the current study explored the association between TV exposure and overweight/obesity among Ghanaian women. Methods: Based on a sample of 4158 women, descriptive statistics and binary logistic regression were applied to data on TV ownership, TV viewing frequency, and body mass index (BMI) measures from the 2014 Ghana Demographic and Health Survey (GDHS) to explore the association between TV exposure and overweight/obesity among Ghanaian women. Results: Despite controlling for other factors (age educational level, marital status, wealth quintile, occupation, type of locality, and parity), the results show that women with TV in their households, and with high TV exposure were significantly (P < 0.05) more likely (OR = 1.39, 95% CI = 1.002, 1.923) to be overweight/obese compared to those with no TV in their households, and no TV exposure. Conclusion: The study demonstrates that increased TV exposure is significantly associated with overweight/ obesity among women in Ghana even after adjusting for other factors. Interventions aimed at tackling obesity in Ghana should focus on encouraging the uptake of more physically demanding pastime activities in place of TV “sit time

Source: UCC
Temperature dependence of the thermal conductivity of single-wall carbon nanotubes

The thermal conductivity of several single-wall carbon nanotubes has been calculated over a temperature range of 100–500 K using molecular dynamics simulations with the Tersoff–Brenner potential for C–C interactions. In all cases, starting from similar values at 100 K, the thermal conductivities show a peaking behaviour before falling off at higher temperatures. The peak position shifts to higher temperatures for nanotubes with larger diameters and no significant dependence on the tube chirality is observed. It is shown that this phenomenon is due to the onset of Umklapp scattering, which shifts to higher temperatures for nanotubes with larger diameters

Source: UCC
Tense in academic discourse: a study of two disciplines

The study examined the types of tense used in the results and discussion sections of academic writings in M.Phil. theses in English and Health Science in the University of Cape Coast, Ghana. The mixed method approach was used for the study. The sample was drawn, using purposive and simple random sampling techniques. The total sample for the study was 20 M.Phil. theses. The quantitative approach of data analysis was used to analyse research question one and results presented in frequencies and percentages. Research questions two and three were analysed qualitatively. The descriptive, content, case and inductive analyses were generally adopted in organising the data for analysis. The study revealed that the simple present and simple past tense occurred most frequently in the results and discussion section of the M.Phil. theses in English Language and Health Sciences. The analysis revealed that the use of tense in the results and discussion section of the English and Health Science theses writing has some functions which include: advance labelling, recapitulation, commentary and evaluation, signalling, and references to previous research. The study revealed that there are number of factors that play a crucial role in tense choice and variation; the temporal references factors, the basic meanings of tenses, and uses of tense affect tense choice in academic writing. Variation in the choice of tense in thesis writing is also influenced by the author’s point of view, disciplinary culture, and purpose of writing. It was recommended that in a follow-up activity, the candidates could take partial or complete authentic texts from their own disciplines and identify the categories of the future, occurrences in each rhetorical section, and communicative purposes.

Source: UCC
Tenure Arrangements Accompanying Commercial Agriculture And Livelihood Choices Of The Aged Smallholder Pineapple Farmers In The Ekumfi District, Ghana

The study explored how the aged smallholder farmers negotiate their livelihood choices without institutionalised social safety nets and waves of tenure forms accompanying commercial agricultural investment. The study used qualitative methods to gather data through semi-structured interviews and observations with smallholder pineapple farmers aged 60 years and above, leaders of land-holding groups, managers of pineapple producer groups and the district agricultural office over three weeks. Maximum variation and expert sampling techniques were used to select aged smallholder pineapple farmers and other agricultural players respectively, while snowball sampling was used to identify study participants from sample groups. In all, a total of 27 individual interviews were conducted. The study adopted the continuity theory and institutional theory as its theoretical underpinnings whilst thematic analysis approaches were employed in analysing the data. It was revealed that the aged smallholder farmers gain access to land for commercial agricultural purposes through direct access and lease agreements. The aged smallholder pineapple farmers engaged in non-farm and other crop diversification activities aside from pineapple cultivation. Commercial agriculture and its attendant tenure arrangements have adversely impacted the yield and trading volumes of other food crops and other off-farm activities such as firewood harvesting, charcoal making, and herbal medicine, but had improved rural wages and rental income from land and other assets. The study recommends that a comprehensive policy, like the recent cocoa farmers’ pension scheme, should be streamlined to include all informal rural agricultural workers.

Source: UCC
Terahertz generation and amplification in graphene nanoribbons in multi-frequency electric fields

We study theoretically a multi-frequency response of electrons in confined graphene subject to dc-ac driven fields. We explore the possibility for using graphene nanoribbons (GNRs) to generate and amplify terahertz (THz) radiations in electric field domainless regime. We discover two main important schemes of generation; when the frequencies are commensurate, THz generation is due to wave mixing and when they are non-commensurate, a single strong field suppresses space charge instability and any weak signals can get amplified. The use of graphene as a best substitute for semiconductor nanoelectronic devices is suggested

Source: UCC
Ternary solubility phase diagrams of mandelic acid and n-methylephedrine in chiral solvents with different carbon chain lengths

Ternary solubility phase diagrams of mandelic acid and N-methylephedrine species in chiral solvents, (S)-methyl lactate, (S)-propyl lactate, and (S)-butyl lactate, have been determined. Solubility measurements were performed for enantiomeric compositions ranging from 50:50 mixtures to the pure enantiomers and temperatures ranging from 0 to 35 C for mandelic acid and from 0 to 25 C for N-methylephedrine, respectively. The ternary solubility phase diagrams of mandelic acid and N-methylephedrine showed symmetric behavior. It became obvious that increasing chain length of chiral solvents, i.e. from (S)-methyl lactate to (S)-butyl lactate, resulted in decreasing solubility.1HNMR and Raman spectroscopy have been applied to characterize the solute-solvent interaction in the liquid phase for mandelic acid system. Molecular modeling calculations were performed for mandelic acid to get a deeper understanding of the solute-solvent interactions. The effect of the solvent on the shape of the solubility isotherms is discussed by determining the relative solubility ratios (Rmol-values) ust for N-methylephedrine

Source: UCC
Tertiary Students’ Engagement with Professional Learning Networks and Emerging Technologies in Learning: The Case of a Coastal University in West Africa

The main aim of this study was to investigate students’ views on their engagement with professional learning networks and emerging technologies for students’ use and how these impact their studies. A sample of 150 students from the University of Cape Coast, Ghana was used for study. Respondents were selected from second year to final year students pursuing undergraduate degree programmes from three different departments of the university. The research instrument used was a carefully constructed questionnaire. Undergraduate students generally exhibited positive attitude towards the use of professional learning networks and emerging technologies across the five attitudinal subscales they were measured on. As a result, from the findings, it is recommended that the use of professional learning networks and emerging technologies should be taken advantage of at all levels in a university curriculum.

Source: UCC
Test Construction and Administration Practices Among Lecturers and Staff of Examinations Unit of the University of Cape Coast

The study assessed the extent to which lecturers applied principles of test construction and administration in the University of Cape Coast. The descriptive survey design was used for the study. The census sampling procedure was used to include 131 lecturers in four faculties/schools and 40 Examinations Unit staff in the University of Cape Coast for the study. Seven research questions guided the study. A 67-item and 14-item questionnaires for lecturers and Examinations Units were used for data collection. The Cronbach’s coefficient alpha for the lecturers and Examinations Unit questionnaires were 0.73 and 0.70 respectively. The results showed that, to a great extent, lecturers were aware of the test construction principles. Lecturers indicated that they defined the purpose of every test prior to construction, determined the test items format and prepared marking scheme as soon as test items were written. Again, it was found out that lecturers were aware of the test administration principles. Students were made aware of the rules and regulations governing the test during test administration. The study also showed that lecturers had difficulty in controlling large classes during quizzes and examinations. It is recommended that lecturers are given timely in-service training on test item construction and administration. Furthermore, university management should allocate funds for workshops, seminars and others for lecturers on test item construction and administration.

Source: UCC
A test of Wagner’s hypothesis for the Ghanaian economy

The economy of Ghana profiles a trajectory of increasing government expenditure at the backdrop of an inconsistent growth in real GDP. Thus, this study explores the causal relationship between real economic growth and real government expenditure in Ghana between the period 1960 to 2017. The Johansen (1991, 1995) cointegration method, the Autoregressive Distributed Lag bounds test approach and the Toda-Yamamoto non-Granger causality test are employed in this study. The findings are that the variables are cointegrated, and there is no Granger causality from real economic growth to real government expenditure. In effect, the causality shows that the Wagner’s hypothesis does not hold in the case of the Ghanaian economy and that the Keynesian theoretical standpoint that public expenditure is an exogenous factor is not deflated in this case.

Source: UCC
Testing and validating a conceptual framework for e-collaboration in an undergraduate course

Electronic collaboration can provide the environments for educators and learners to connect electronically via the Internet to study together, communicate discuss, and to exchange information and resources from anywhere, anytime and in any place. However, despite the progress registered in the use of e-collaboration system as educational tools through the incorporation of constructivism learning theories and its related didactics in higher educational institution, the approach has not yet been successfully transferred to the classroom. More importantly, there are still misconceptions among researchers regarding students achieving authentic learning from online interaction and collaboration. In an attempt to close this gap, a framework was developed to assist in the design, development and implementation of e-collaboration in a higher education institution. The framework addresses the development process of e-collaboration content, approaches for e-collaboration, pedagogical didactics, learning theories, and roles of users in e-collaboration. In an attempt to validate the framework, an e-collaboration system named ‘Teach, Learn, and Research E-collaboration System’ (TELERECS), was developed and experimentally implemented in a classroom context. An experimental research design based on control and experimental groups, pre/post-test and usability survey were used to validate the framework. The results revealed that there is significant difference between the post-test mean scores of the experimental and control groups. In addition, there is moderate, positive monotonic correlation between easy to use and post-test-scores; and between useful for team work and post-test-score for the experimental group. These imply that the frame work offers a promising basis for meaningful learning. Future work includes a further exploration and validation of the framework and comparing results

Source: UCC
Testing long run relationship between exports and imports: evidence from Ghana

This study examines the long-run relationship between exports and imports for the Ghanaian economy for the period of 1948 to 2010. Empirically, we find that Ghana’s exports and imports are cointegrated using Granger and Engle (1987) two-step procedure. However, the slope coefficients from the cointegration equations were not statistically equal to 1 and the equilibrium relationship further indicates that the economy of Ghana imports more than 1 dollar to get 1-dollar exports revenue. Conclusively, the sustainability of Ghana’s foreign deficit is doubtful

Source: UCC
Testing practices of junior high school teachers in the Cape Coast Metropolis

The study aimed at finding out whether teachers in Junior High Schools in the Cape Coast Metropolis follow the basic laid down principles in their testing practices, with respect to test construction, administration and scoring of classroom or teacher made tests. The study adopted the quantitative method and descriptive survey design was used for the analysis. A total of 50 public Junior High Schools comprising 300 teachers were used for the study. Simple random and purposive sampling procedures were used to select the subject teachers at the Junior High Schools. The main instrument used for the study was questionnaire comprising 55 items with overall reliability coefficient of .873. The data was analysed using means and standard deviations, frequency, and percentages, and One-Way Analysis of Variance (ANOVA). The level of significance for all tests were at 0.05. The result from the study showed that, most teachers at the Junior High Schools did not follow the basic principles of test construction, and scoring of essay type test to an appropriate level, 7 out of 20 construction principles were often practice and 5 out of 13 scoring principles were followed. In test administration, most of the principles were followed, 7 out of 12 principles were often practiced. A statistically significant differences were found among teachers and their subject areas of specification (Mathematics, English, Social Studies, Science and Religious and Moral Education). It was recommended that regular in-service training in testing practices be organized for teachers in Junior High Schools by the Educational Directorate in Cape Coast Metro.

Source: UCC
Testing practices of senior secondary school teachers in the Ashanti region of Ghana

The study aimed at finding out whether Senior Secondary School teachers in the Ashanti Region of Ghana followed the basic principles in their testing practices. It also sought to find out whether pre-service training in testing contributes to competence in actual testing practice. Cluster and simple random sampling techniques were adopted to select 265 teachers of Mathematics, Integrated Science and English Language in 26 Senior Secondary Schools for the study. Eight research questions guided the study. A 52-item questionnaire and a 17-item observation guide were used for data collection. The reliability coefficient of the questionnaire was 0.70. The study showed that to a great extent, teachers followed the basic principles in test construction, administration and scoring. Teachers applied seven out of 10 principles in test construction, 12 out of 18 principles in test administration and six out of nine principles in test scoring. Also, teachers reported they used both norm-referenced and criterion-referenced approaches in their test-score interpretation. Again, the findings indicated that pre-service instruction in educational measurement had a positive impact on actual testing practice, although the impact was quite subtle. It was recommended that since competence in assessment is key to teacher effectiveness, every teacher must be given formal training in educational measurement and evaluation during pre-service training. Again, the teacher training universities in Ghana should accentuate the practical classroom aspects of the testing principles in their educational measurement courses to help teachers practicalise the theoretical knowledge they acquire.

Source: UCC
Testing the effects of earnings of cocoa and non-traditional exports on real exchange rate in Ghana

Exchange rate basically influences a currency value of an economy. As such it plays a critical role in international trade as well as economic growth and development for every economy. The study sought to investigate the impact of earnings of cocoa and non-traditional exports on real exchange rate in Ghana. Using a disaggregated data for exports, annual time series data were interpolated into quarterly series over the sample period 1990Q1 to 2011Q4. Johansen co-integration test and error correction model were employed for examining both the long run and short run relationships. The outcome of the study showed that real exchange rate is appreciated for export earnings thus earnings of cocoa and non-traditional export, foreign aid as well as export earnings of mineral while trade openness, government expenditure and money supply depreciate the real exchange rate. The study recommended that the government should make production of cocoa more attractive by way of providing incentives such as scholarship to the wards of cocoa farmers in addition to subsidies (mass spraying) among others. It is equally expedient to channel a little more resources to the nontraditional export sector especially the production of cashew in order to attract more foreign exchange. Summing up, it is a high time the country diversified and added value to our exports commodities, most especially the cash crops.

Source: UCC
Testing the Validity of the Capital Asset Pricing Model and Existence of Market Volatility: An Analysis of the Ghana Stock Exchange

Volatility and the risk-return trade-off of equities or stock market play essential role in investment, decision making and financial stability among others. This study proposes to test the validity of the capital asset pricing model and existence of market volatility in the Ghana Stock Exchange (GSE). An investigation of eight companies listed on the GSE and market returns of GSE was done through a secondary data collected on daily basis from 4th January 2010 to 31st December 2018. The CAPM is tested on portfolios by adopting the Fama and Mcbeth (1973) two-stage regression methodology using GARCH (1,1) model in estimating the time series regressions present in the study. The study however found that in as much as the use of portfolios addresses the flaws associated with individual securities in testing the validity of CAPM, it is invalid in the GSE, as market and firm-specific risk have significant effect on the average portfolio returns of investors. The findings also revealed the GSE is mean reverting and takes a longer period (35 days) for the market to be stable overtime. The study recommends that the Central Bank of Ghana must ensure risks, which are almost inevitable, are properly priced by considering the impact they have on the economies. Also, with GSE being volatile, investors must consider day trading to avoid too many losses.

Source: UCC
Testing the weak form Market Efficiency of selected African Stock Markets

The ability of African stock markets to operate effectively depends on their level of informational efficiency. This study tests the weak form efficiency of six African stock markets which comprised three smaller and three larger stock markets. Using monthly and weekly stock market returns series from 1995 to 2013, the study tested the degree of weak form market efficiency by employing unit root tests, run test and the more robust Wright’s variance ratio test. By employing a general autoregressive conditional heteroscedasticity (GARCH) approach with time varying parameters on the monthly stock market returns series, a test of evolving efficiency which captures gradual changes in efficiency was carried out. The results shows that the three larger markets used in the study, Egypt, South Africa and Zimbabwe, were found to be weak form efficient. Among the smaller markets used in this study, Mauritius was found to be weak form efficient while Ghana and Nigeria were not weak form efficient. In order to improve efficiency of African stock markets, securities and exchange commissions of stock markets in Africa are encouraged to set up information dissemination institutions to enhance the dissemination of information relating to stock market.

Source: UCC