ghanaopendata/ghanaian-research-english huggingface dataset:
Comparative Cost Analysis of Precast and In Situ Concrete Floor Slabs in Ghana

There is a huge housing deficit in Ghana. As a result, majority of people in both rural and urban communities put up their own houses. The principal factor clients consider before initiating projects is cost. Precast and in situ reinforced concrete are widely used in the construction industry for the construction of suspended floor slabs. An informal survey conducted by the researcher showed that the use of cast in situ reinforced concrete slab surpasses the use of precast concrete slabs. In Ghana, it costs one a lifetime to put up a decent accommodation. Others have found the need to put up commercial and other buildings for renting using sub-standard materials or compromising on standards, all in the name of cutting down cost. In doing this some have compromised on quality to the detriment of society. There is the need to explore other alternatives and avenues that meet quality standards at a reduced cost. The purpose of this study was to analyse and compare the initial cost of precast and in situ reinforced concrete slabs. The study made use of descriptive research design and quantitative approach. Estimates of precast/prestressed beams and hollow blocks as well as Bills of Quantities were prepared from the structural drawings of slabs and beams of the suspended floors for the study. Results from the study confirmed that the initial cost of constructing a precast floor slab is cheaper than the cast in situ, and the cost savings made depends on the function of the building as its design parameters are not the same. The recommendation made were: the use of precast floors must be encouraged, prestressed beam and block precast slab could be adopted as oversight concrete slab in water logged area to avoid hardcore filling which aids rising damp and awareness of the cost reduction in the use of precast floors must be created. Further research works that arose from the study were: a study into the feasibility of using iv other precast elements like beams and column in Ghana, a survey must be conducted to see society‟s readiness to use the precast floor system and a study to find out if pretensioned cables could be used to reduce the amount of reinforcement in slabs and a study to find the whole life cycle cost of precast and in situ floor slabs.

Source: KNUST
Comparative Diagnosis of Escherichia Coli-Induced Urinary Tract Infection Using Dipstick, Microbiological Culturing and PCR Methods in School-Going Adolescents

Urinary tract infection (UTI) poses serious future clinical repercussions, such as hypertension, anaemia, kidney failure and death. Therefore, there is the need for the early detection and diagnosis of UTI. Currently, the use of the standard microbiological culture diagnostic method is hindered by the microbial tendency of being viable but non-culturable. On the other hand, direct Polymerase Chain Reaction (PCR) has proven to be more sensitive in detecting pathogens in various biological samples, although interference by specimen components and the possibility of contamination are some challenges. This work was thus aimed at the design of a simple and reliable PCR protocol for detecting uropathogens and comparing it with dipstick and culture, using Escherichia coli as the indicator uropathogen. This study, a cross-sectional one, involved the collection of urine samples from 272 adolescent students, aged between 13 and 18 years. The PCR protocol targeted a more specific pap C gene for fimbriae formation and the bacteriocin usp gene sequences for amplification. A general prevalence of 30.9% UTI was found. Using a sub-population made up of 195 subjects, for the comparative diagnosis of the three methods, the prevalence were 42.1%, 39.8% and 72.7% for dipstick, microbiological culturing and PCR respectively. PCR had a higher sensitivity of 71% and Receiver Operator Characteristic curve area of 0.7231± 0.0262, p< 0.0001, compared to the microbiological culture method. In addition, the ROC curve area for PCR was significantly higher than dipstick (0.7205± 0.0262, p< 0.0001) indicating PCR’s superiority as a diagnostic tool. On the other hand, there was no statistical difference between the microbiological culturing method and dipstick as diagnostic tools (0.5026± 0.02927, p= 0.9302). The leukocyte esterase parameter in the dipstick method was found to be more useful to the physician in making diagnosis with a positive predictive value of 52% and a negative predictive value of 76%. The usp gene was also found to be more significantly distributed in urine isolates than pap C with P value of 0.0020. This suggests that most of the strains of Escherichia coli implicated in UTI in the sample population employ more of bacteriocin production to compete with other microbes in the urinary tract than the production of adhesion structures. The PCR is therefore, a good complementary tool for diagnosis of UTI.

Source: KNUST
Comparative effect of crude pectinase and commercial enzymes in Shea fat extraction

Pectinases are one of the most used enzymes in food industry. Enzymes are widely used to improve upon process parameters such as product yield and rate of product formation. Such biotechnological applications are not currently exploited by most industries in Ghana. The objective of the study was to determine the efficacy of locally produced pectinases from S. cerevisiae and other commercial enzymes in the extraction processes of shea butter. The crude pectinase was produced using corn cobs as a substrate and the microorganism Saccharomyces cerevisiae ATCC 52712 in a solid state fermentation process for four days. The crude pectinase had optimal protein concentration of 7 mg/ml with enzyme specific activity of 0.130 U/mg. The commercial enzymes were Viscozyme L (beta endo- 1, 3 (4)-glucanase activity with declared activity of 100 FBG/g as well as side activities of xylanase, cellulase and hemicellulases) and Pectinex 5XL (polygalacturonase activity with declared activity of 4500 PECTU/ml as well as arabinase side activity). The following operational parameters: water to seed (w/s) ratio, pH, hydrolysis time, enzyme dosage and temperature were optimized for better oil recover. The optimum w/s ratio in the present study was 4:1 for the enzymes and 2:1 for the control. The study revealed that the crude pectinase works under a wide range of pH. Crude Pectinase exhibited maximum activity at pH range of 3 to 6. Commercial Pectinex and Viscozyme showed maximum activity at pH range of 4 to 6. The maximum oil yield for crude pectinases and commercial Pectinex was obtained at 90 minutes and that of Viscozyme treated seed was observed at 60 minutes incubation time. When all parameters were optimized, the control gave an optimum oil recovery of 40 % while the application of the crude pectinase gave an optimum oil recovery of 44 % with an enzyme dosage of 1.2 %. The commercial Pectinex and commercial Viscozyme gave optimum oil recovery of 58.6 % and 72.0 % respectively at enzyme dosage of 0.8 %. Analyses of the proximate composition of the residues revealed that with the exception of protein, no significant variations were observed for the fiber and ash content. The physicochemical characteristics of the extracted oils such as Density, Moisture, Sample melting point (SMP), Unsaponifiable matter (UM) with the exception of the fatty acids (FFA) and peroxide value (PV), were not significantly affected (P ˃ 0.05) by the type of enzyme used. These results indicate the possible use of crude pectinase to improve shea fat extraction processes in Ghana if the enzymes are made available.

Source: KNUST
Comparative estimation of the impact of transaction cost of traditional and design-build procurement systems in public construction works

The study set out to compare the magnitude of transaction costs for the design-bid-build and design-build procurement methods in construction works in district assemblies in Central Region of Ghana. The study adopted a quantitative approach and to that effect, a descriptive design was adopted to study 42 purposively sampled employees from six district assemblies including Cape Coast Metropolitan Assembly, Mfantseman Municipal Assembly, Ekumfi District Assembly, Ajumako District Assembly, KEEA Municipal Assembly and Abura Dunkwa District Assembly. Questionnaires were used to collect data from the sampled respondents and the statistical tools used to analyse the data collected included descriptive tools such as means, medians, frequencies, and percentages. Paired sample t-test was used to compare the differences in transaction costs for pre-contract phase and post-contract phases. The independent sample t-test was also used to compare the differences in transaction costs between the traditional and design-build procurement systems. The study found that the respondents were of the opinion that the Public Procurement Acts 663 was not efficient and convenient for procurement in the district assemblies. This assertion was mainly due to politicisation of the processes involved in the procurement, poor staffing, poor implementation and ambiguity in the clauses of the Act. The study also revealed that the estimated TC for the traditional procurement system was higher than that of the design-build system over a six-month period. In most cases, the pre-construction TCs incurred by all the other district assemblies were higher than the post-construction costs. The study recommended streamlining vendors for competitive bidding of contracts, computerising transactions, and building stronger relationships with service providers and vendors.

Source: KNUST
Comparative Evaluation and Analysis of Different Tropospheric Delay Models in Ghana

Tropospheric delay prediction models have become increasingly important in Global Navigation Satellite System (GNSS) as they play a critical role in GNSS positioning applications. Due to the different atmospheric conditions over the earth regions, tropospheric effect on GNSS signals also differs, influencing the performance of these prediction models. Thus, the choice of a particular prediction model can significantly degrade the positioning accuracy especially when the model does not suit the user’s environs. Therefore, a performance assessment of existing prediction models in various regions for a suitable one is very imperative. This paper evaluates and analyses seven commonly used tropospheric delay models in Ghana in terms of performances in Zenith Tropospheric Delay (ZTD) estimation and baseline positional accuracies using data from six selected Continuously Operating Reference Stations (CORS). The 1˚x1˚ gridded Vienna Mapping Functions 3 (VMF3) ZTD product and coordinates solutions from the CSRS-PPP positioning service were respectively used as references. The results show that the Black model performed better in estimating the ZTD, followed by Askne and Nordius model. The Saastamoinen, Marini and Murray, Niell, Goads and Goodman and Hopfield models respectively performed poorly. However, the result of the baseline solutions did not show much variation in the coordinate difference provided by the use of the prediction models, nonetheless, the Black and Askne and Nordius models continue to dominate the other models. Of all the models evaluated, either Black or Askne and Nordius model is recommended for use to mitigate the ZTD in the study area, however, the choice of the Black model will be more desirable.

Source: KNUST
Comparative Evaluation of Malting Properties and Processing Conditions on Enzymatic Activity of Ten Rice Varieties

Diastatic power or activity gives a measure of the saccharifying power of enzymes in prepared malt. There are about 80,000 varieties of rice that exist and new varieties are being developed through continuous plant breeding research. Among these new varieties are some whose malts possess beneficial qualities such as good diastatic activity for the sugar, confectionery, pharmaceutical and brewing industries. Hence, the need to explore these varieties as a cheap source of glucose.Themalting parameters of the ten rice varieties namely; Wita 7, Digang, Bourke’189, ITA 320, Jasmine’85, China, ITA 324, Viwornor, China and Sikamo were studied. Different conditions (pH, temperature, substrate conc. and time) were also examined to assess their effects on enzyme activity in ten varieties of malted rice. The effect of pH (2-9), temperature (10-60oC), substrate concentration (0.5-3.0w/v) and time (5-15mins) on the enzyme activity was studied using correlation whiles the optimum conditions for all Rice Malt Extract was determined using principal component analysis and response surface plots. The out-of-steep -moisture content ranged between 30.07% (Digang) and 35.26% (Bourke’189). With the exception of Sikamo (steeping loss of 2.41%), the other varieties showed steeping losses of greater than 3% after grain steeping. Germination energy of >80 % was obtained for each variety and this signified their viability.The findings show that the different varieties had good malting properties. Among all the conditions varied, temperature had the most significant effect on enzyme activity. An increase in temperature increased enzyme activity of the varieties and vice versa. The optimum conditions determined for diastatic activity of the rice malts werepH of 5.5, substrate concentration of 3.0%w/v, temperature of 60ºC and time of 15minutes.Viwornor,China and Wita 7 varietieswere found to produce the highestdiastatic power among the ten rice varieties.

Source: KNUST
Comparative evaluation of the physicochemical and disintegrant properties of starch from five improved varieties of cassava in paracetamol tablet formulations

Starch has been employed in pharmaceutical industries extensively as diluents, binding agents and disintegrants in tablet formulations and various studies have been conducted to develop novel starches from local sources for use as excipients. The objective of this study was to determine the physicochemical and tablet disintegrant properties of starches obtained from five improved cassava varieties to assess their potential as disintegrants substitute for the pharmaceutical manufacturing industry. The cassava varieties used were Sika Bankye, Ampong, AW/ 10 / 008, 12/ 0245 and 12/0197 and were assigned with codes V10, V20, V30, V40 and V50, respectively. The cassava starches were obtained by wet separation techniques and the organoleptic properties of the starches were determined to be fine texture, odourless, bland taste and white in colour. The physicochemical properties of the starches namely: pH, moisture content, angle of repose, solubility, bulk and tapped densities, Hausner‟s ratio and Carr‟s index were determined to assess their suitability for pharmaceutical use. The percentage yield of the starches ranged from 7.97 – 26.82 % with V50 and V20 having the lowest and highest starch yield, respectively. The particle density, bulk density and tapped density of the starches followed the same pattern of V20 > V30 > V50 > V40 > V10. All the starches had particle size distributed from 162.2μm – 177.5μm. All the starches showed good swelling and water retention capacities with an order of swelling power of V30 > V20 > V40 > V10 > V50. The toxic metal analysis showed an insignificant amount of arsenic, lead, cadmium and mercury, suggesting the safety of the cassava starches for use as pharmaceutical excipient. FTIR study confirmed there was no interaction of the starches with the pure paracetamol powder. The uniformity of weight, tensile strength, hardness and friability of the paracetamol tablets containing different concentrations of the cassava starches as disintegrant were not significantly different (p > 0.05) from compacts vi containing the commercial disintegrant, maize starch. The cassava starches caused faster tablet disintegration and the release of paracetamol from the cassava starches showed comparative effectiveness as disintegrants to compacts containing maize starch at the same concentration. The Crushing strength-friability (CSFR) and Crushing strength-friability/ disintegration time (CSFR/DT) values of tablets containing cassava starches were high (formed strong tablets) and were comparable to compacts containing maize starch at the same concentration. All tablets containing different concentrations of starch passed the dissolution and assay tests for immediate release dosage forms. The results obtained establish the suitability for pharmaceutical use of the cassava starches as disintegrants with comparable properties to the commercially available maize starch.

Source: KNUST
Comparative Performance Evaluation of the Traditional Design-Bid-Build (DBB) and Design-Build (DB) Procurement Methods in Ghana

The data gathered was analysed using analysis of variance with the aid of Statistical Package for Social Sciences (SPSS 13). The success factors were also identified by subjecting each of the factors to significant test at 99% confidence interval. The study revealed that most DB projects are completed within their respective budgets whilst a greater number of DBB projects incur cost overruns due to variations and price fluctuations. The time performance comparison also placed DB projects better than their DBB counterparts as most of the DB projects were completed within programme. The study further revealed that, there is no significant difference between the qualities of completed projects executed under the two procurement methods. Out of 35 factors listed, 11 were identified as significant to the performance of DBB projects 4 which are: awarding bids to the right bidder, availability of resources, clients' ability to adequately fund the project, overall managerial action in planning, organizing, leading and controlling, project team leaders' commitment to time, cost and quality, inflation, interest rates, payment procedures, arbitration as a method of conflict resolution, progress meeting and control mechanism of sub-contractors work. Six (6) factors were also identified as significantly important to the success of DB projects. These are: awarding bids to the right bidder, availability of resources, clients' ability to adequately fund the project, overall managerial action in planning and organizing, contract documentation and project team leaders' knowledge and skill (competence). (Keywords: building projects, traditional design-bid-build (DBB), design and build (DB), success factors and project performance)

Source: KNUST
Comparative studies of the use of alum and moringa oleifera in surface water treatment

Fifteen samples of raw water from reservoirs and dug-outs in the Tamale and Tolon-Kumbungu Districts of the Northern Region were used for laboratory based jar tests using Moringa oleifera and alum as coagulants. The results indicate that when Moringa oleifera was used as a coagulant, the reductions in colour and turbidity were comparable to those obtained when alum was used. The percentage reductions with Moringa oleifera were 61.5-98.6% for colour and 68.8-98.9% for turbidity whilst those for alum were 76.9-99.7% for colour and 78.1-99.3% for turbidity. It was also observed that the pH range for the optimum performance of Moringa olefera as a coagulant was between 4 and 7.5. This range is broader than what has been quoted in the literature for alum, i.e, 5.5-7.5. The pH and conductivity of the water were not significantly affected by Moringa olefera but alum drastically reduced pH and increased conductivity. Also, the sludge produced from alum was two times that from Moringa olefera. The study also showed a reduction of 90-99% in faecal coliform when the surface waters were treated with Moringa olefera. Filtration of settled water (after Moringa olefera treatment) through a pilot slow sand filter further reduced the remaining turbidity, colour, iron, manganese and faecal coliform by the following respective percentages: 37-80%, 33-75%, 25-80%, 25-81% and 40-86%. This study has therefore revealed that Moringa olefera is technically feasible for the treatment of surface water. It was however not possible to perform an economic analysis of the two coagulants because cost involved in the production of Moringa olefera seeds is not available.

Source: KNUST
Comparative studies on growth and yield of pleurotus ostreatus on different types of substrates

So many agricultural wastes such as coconut coir and bean straw can be turned into useful products to increase their biomass use in Ghana. Proper composting and effective management of these wastes can render them useful in mushroom production. The project was carried out to compare the response of Pleurotus ostreatus on three types of substrates at three different composting periods. The substrate types used included sole bean straw, bean straw mixed with coconut coir at 2:3 ratio and sole coconut coir substrate. These were composted at different time periods and different parameters such as rate of mycelia formation; number of bags full y colonized; time of first flush; length, width and perimeter of fruits; yield of mushroom; dry matter content of the mushroom; biological efficiency and cost benefit analysis of using the different substrate types were determined. The sole coconut coir substrates gave the highest C:N ratios ranging from 97. 75 for the sole coir composted for 21 days to 106. 85 for the same substrate composted for a day. The sole bean straw and the mixed substrates produced similar C:N ratios of between 33.70 – 53.48. The substrates with the least C:N ratio gave the highest yield of mushrooms more especially in the sole coir and in the mixed substrates. Composting period did not affect the rate of mycelia formation, however, it affected the yield of the mushrooms. Substrates composted for longer periods in the sole coir gave the highest yield while the substrate composted for just a day in the mixed substrates produced the highest yield with the highest profit margin. The mixed substrates gave the greatest biological efficiencies ranging between 11.0 to 22.90 % as well as the highest returns. The results indicated that the effectiveness of substrates to produce higher returns depends on the initial C:N ratio of the substrates. As a result, substrates with high C:N ratio need longer periods of composting, while substrates with initial C:N ratio equal or below 55 do not need any composting

Source: KNUST