ghanaopendata/ghanaian-research-english huggingface dataset:
Correlation between Dynamic Cone Penetrometer (n-Value) and Allowable Bearing Pressure of Shallow Foundation Using Model Footing

An allowable bearing pressure is one of the most important basic parameters to be determined before the design and construction of foundations for civil engineering structures. The conventional methods of estimating this parameter is becoming relatively expensive and time consuming for small scale projects such as residential buildings. The DCP is a versatile equipment that may be applied to obtain the bearing capacity. However, currently, there are no reliable correlations between the DCP test results and the bearing capacity. This project was undertaken to develop a reliable correlation between the Dynamic Cone Penetrometer (DCP) n-value (blows/100mm) and the allowable bearing pressure qati (kN/m2) for shallow foundations using a model footing. In this work, compacted soil sample of different dry densities in a mould was loaded with a model footing until the sample yielded. On the same sample, DCP testing was performed at two locations to determine the average D- value (mm/blow). Triaxial samples were also taken for triaxial test. Results from the triaxial test were used to calculate ultimate bearing capacity using Terzaghi bearing equation. The measured DCP D-value (mm/blow) was processed into n-value (blows/100mm) which is the standard form of recording the DCP test results in the field. The results were analysed and a correlation qau=48n + 57, with a coefficient of correlation, R2=0.98 was obtained for the model footing. This correlation was similar to the correlation between the n-value and the allowable bearing pressure computed using the Terzaghi approach, except that the Model underestimated the allowable bearing pressure by a constant value of 165 kN/m2 for all values of n.

Source: KNUST
Correlation between the dynamic cone penetration index and the subgrade resilient modulus obtained from the Falling Weight Deflectometer

Modern pavement design characterizes the subgrade soil in terms of the resilient modulus. This parameter is determined in a non-destructive in-situ method using the falling weight deflectometer (FWD) and in the laboratory from the repeated load triaxial test. These methods however are both expensive and time consuming and are not readily available in most highway departments in developing countries. On the other hand, the simple and inexpensive dynamic cone penetrometer has been extensively used for pavement in-situ subgrade characterization. The objective of this thesis is to find a correlation between the results of the Dynamic Cone Penetrometer index, DCPI and the output of the Falling Weight Deflectometer (FWD) test for purposes of estimating the subgrade resilient modulus. The study road is a major urban arterial road in Accra with varying terrain, comprising of a hill flanked by two valleys. The study road was sectioned into three according to the terrain, i.e. section 1 and 3 are in the valley whiles section 2 is on the hill. Fifty-two FWD deflections and Dynamic Cone Penetrometer field tests were conducted at these sections. Laboratory tests, performed on soils recovered from five trial pits sunk within this varying terrain, revealed two types of soils, namely, A-2-7 soil on the hill and A-6 soil in the valley. The results of the output of the FWD sensors were analyzed and correlated with the DCP penetration index, DCPI, for the subgrade soils and the unbound material lying on the subgrade. Statistical regression model for predicting the subgrade resilient modulus was developed based on the the results of the Dynamic Cone Penetrometer index, DCPI and the output of the Falling Weight Deflectometer (FWD) test for the subgrade soils. This was extended to the unbound material overlying the subgrade soil. The statistical regression model for predicting the resilient modulus based on the field tests of FWD and DCP penetration index results were developed on section by section basis for the subgrade soils and also for the unbound material. Combined sections with similar soil characteristics were also considered for both the subgrade and the unbound material. The model correlates the subgrade resilient modulus to the DCP penetration index, DCPI. Poor agreement were obtained between the resilient modulus of the of subgrade soils (A-6 and A-2-7) on the study road and the DCP penetration index, DCPI.

Source: KNUST
Correlation of local cost factors for process industries in Ghana

There has always been an urgent need for a cost-estimating model that reflects the situation in Ghana. Thus, this thesis has actually achieved the main aim of developing a cost model that is capable of estimating the total cost of process plants in Ghana. This has been made possible through the use of linear programming with special reference to the simplex algorithm. Two models have been developed for solid and fluid processing plants respectively. Application of these models ensures that the total plant cost is always minimized with a probable error of ±8.25% for solid processing plant and ±10.18% for fluid processing plants.

Source: KNUST
Correlation of serum level of inflammatory markers with CD4 count in HAART naïve HIV patient and patient on HAART

The objective of the study was to evaluate the correlation of the inflammatory markers with absolute CD4 count in on HAART and HAART naïve HIV patients. one hundred and fifty participants, comprising of 50 on-treatment and 50 treatment naïve HIV patients, and 50 sero-negative subjects were recruited for the study. Serum CRP, IL-6 and TNF- α were measured using ELISA, CD4 count analysis was done using the BD FACS count and hematology parameters were measured using an XS-500i automatic blood cell analyzer (Sysmex Corporation Co. Ltd, Japan). IL-6 and TNF- α concentrations in HIV-seropositive group were significantly higher than those in seronegative group, and mutually correlated. No significant differences in serum IL-6, CRP and TNF-α level between on HAART, and HAART naïve, groups were observed. Median levels of proinflammatory cytokines (IL-6, CRP and TNF-Alpha) significantly increased with decreasing CD4 count. Subjects with CD4 count less than 200 cells/mm3 were associated with significantly higher median levels of IL-6, CRP and TNF-Alpha compared to those with CD4 count of 500 cells/mm3 and more. The data observed indicated an association between CD8 and CD3 and between the ratio of CD4/CD8 and the ratio of CD4/CD3. A significant and negative correlation of CD8 was observed with the ratio of CD4/CD8 and CD4/CD3 and TNF-alpha with Hb; HCT and RBC but not WBC in all the studied participants. A negative correlation between TNF-alpha and Hb, HCT, RBC and WBC count and also between TNF-alpha and the ratio of CD4/CD8 among HAART naïve HIV participants were observed. Meanwhile Hb, HCT, RBC and WBC were not significantly associated with both IL-6 and CRP. Regardless of the source and initial stimulus, continued immune activation and inflammation results in the over-production of IL-6, CRP and TNF-α and thus create an oxidised environment replication of new virion of HIV. The attack of these viruses will decrease CD4 T cell which will speed up the progression of HIV pathogenesis.

Source: KNUST
Correlation properties of doppler fading in cellular networks in Ghana

Fading is the most observed and frustrating problem in transmitting and receiving radio signals. Studying the correlation properties of fading helps us to design proper communication systems that are robust to it. In this project, received power signal is obtained by drive-test technique. The data collection is done in an operating frequency of 900MHz and 1800MHz and the environments used for the data collection are urban and suburban. The analysis is done using curve fitting tool and distribution fitting tool in Matlab software 7.5.0 (R2007b).The following fading distributions are used, Rayleigh, Rician, Nakagami-m, Lognormal and Weibull. Weibull fading distribution is found to give the best description of fading experienced in Ghana. On the other hand, Rician distribution, Nakagami-m distribution and lognormal distribution have less agreement with the measured data while Rayleigh fading distribution has much less agreement with measured data. The obtained mean scale parameter and the mean shape parameter in the Weibull distribution for the environment considered are 133.76 and 15.93, respectively. Furthermore, the path loss exponents in the near and far fields are also calculated; and the standard deviation of shadowing falls in the range of 4.368dB to 6.180dB. Last but not least, a clear dependence between the root-mean square (rms) delay spread values of the received power signals and the transmitter-receiver separation distance is observed. Ultimately, the analysis on the large-scale fading tends to describe the terrain profile of the environment and it is dependent on the distance.

Source: KNUST
Cost Analysis in Kiln Drying of Some Timber Species in a Conventional Kiln Dryer (A Case Study)

Kiln drying is seen as the first step towards value addition and downstream wood processing for export. The study was carried out in sawmill in Kumasi to analyse the cost of Kiln drying of some timber species in a conventional kiln for six months (November 1996 - April 1997). A conventional kiln dryer of 300m3 capacity was used. The methods employed were desk study, questionnaire and field work. The desk study was carried out to compile relevant literature. Data was obtained through questionnaires and field measurements. The cost-benefit analysis was carried out to identify’ the cost and revenue associated with kiln drying and was presented in the form of a cash flow. The results revealed that the payback period of the kiln was 13.03 months, the percentage rate of return of 33.37% and an average profit per month of ¢52,405,965.00 was recorded during the period. Generally, it was found that the cost of kiln drying the lumber was relatively low as compared to the profit and hence it has been recommended that the banks should grant loans to saw millers to invest in kiln drying.

Source: KNUST
Cost and schedule control on engineering, procurement & construction (EPC) projects in Ghana (A case study of Kpone thermal power project)

Many EPC projects in Ghana and across the globe have experienced delays resulting in unreasonable cost and schedule overruns. While there exist several factors connected to this phenomenon, the control of project costs and schedule continues to be important factors. The need to reduce the risk of projects‟ poor performance is very crucial in the emerging countries as most of the socio-economic programmes have an element of a construction project. This research aimed at identifying the factors inhibiting the practitioner‟s ability to effectively control their project and the corresponding mitigation measures for cost and schedule control on EPC projects in Ghana using Kpone Thermal Power Project (KTPP) as case study. The methodology adopted for this research was quantitative research using the questionnaire survey. From the study, the top five factors inhibiting cost control are comparable to the one‟s affecting schedule control also. By means of the Spearman's rank correlation coefficient, the test run showed a moderate positive correlation of the factors identified for both cost and schedule control. The top four factors inhibiting cost control are Risk and uncertainty associated with projects, inaccurate evaluation of projects time/duration, Inflation of prices and Fluctuation of currency/exchange rate. Similarly, there ones inhibiting schedule control are financing and payment for completed works, inaccurate evaluation of projects time/duration, Complexity of works and Risk and uncertainty associated with projects. These inhibiting factors can be mitigated by implementing these measures identified in the study. The six top mitigating measures are: To ensure adequate project finance is available before start of the project, Employ Value Management techniques, Proper project planning and scheduling, Plan realistically and built up from first principle, Refuse to accept unrealistic project time scale by client and Perform a preconstruction planning of project tasks and resources needs. The least three desired mitigation measure from the study in the descending order are Proper emphasis on past experience, Clear information and communication channels and frequent coordination between the parties. It is recommended that future research is extended to investigating more than one EPC project in order make a cross comparative analysis and conclusion

Source: KNUST
A cost benefit analysis of pay as you dump waste management programme by the Kumasi metropolitan assembly

This study generally sought to examine the cost benefit analysis of the pay as you dump waste management program practiced by the Kumasi Metropolitan Assembly (KMA). The research method used was descriptive. The population of households within the Asokwa Metropolitan area is estimated at 140,161. Out of this number, 200 households were sampled in addition to 4 waste collectors. Both primary and secondary sources of data were harnessed for the study. The main sampling technique used was cluster and purposive sampling. In ascertaining the effects of pay as you dump on household waste generation, the results indicated that, pay as you dump policy forced households to reduce volume of waste generated. The study also found that, lack of waste segregation on the part of households was a major challenge for waste collectors in addition to the fact that huge proportions of plastic waste form part of the total waste generated and collected. Poor Street naming in the community was also identified as a challenge. In view of the above, it is recommended that, District Assemblies ensure transparency in the way revenue generated from pay as you dump system is used. There is also the need for strict enforcement of by-laws on sanitation to compel households to change their attitude. Even though, the National Sanitation Day exercise is a good initiative, it would lose its value if people are not educated on the need to clean their immediate environs.

Source: KNUST
Cost efficiency and economies of scale in broiler production in Ghana. A case study of the Ashanti Region.

The steep decline in broiler production in Ghana is largely attributed to high cost of production. However, empirical evidence from other African countries suggests that low cost efficiency levels among the broiler farms/farmers could be a contributory factor to this soaring production cost. This study, therefore, measured the economies of scale and cost efficiency levels of the broiler farms in the Ashanti region of Ghana. Through multi-stage sampling technique, 114 broiler farms/farmers were selected as respondents for this study. Stochastic cost frontier model was then used in estimating the cost efficiency levels. The empirical result of this study showed that the cost efficiency levels of the broiler farms in the study area ranged from 1.03 to 1.43 with the mean of 1.14. This implies that an average broiler farm in the study area spent about 14% above the frontier cost (minimum cost). Farm size, Farmers’ level of education and technical advice from veterinary services were identified as factors that significantly improved cost efficiency in the study area. On the other hand, economies of scale was computed to be 1.513. Since the value of the economies of scale is greater than one, it implies that there is presence of positive scale economies among the farms. This is an indication that most of the broiler farms in the study area could reduce their production cost by further increasing their scale of production. It is, therefore, recommended that the Government should support the broiler farmers with funds to increase their scale of production in order to benefit from the cost advantage associated with scale. The farm owners should recruit farm managers who have at least acquired formal education up to the Senior High School (S.H.S) standard or at best use them on part-time basis. In addition, more veterinarians should be trained by the government and assigned to the various poultry/broiler farming communities to enable the broiler farmers receive technical advice from a professional source instead of relying hugely on their fellow farmers.

Source: KNUST
Cost estimation model for cost analysis of concrete works at the initial stages of construction projects in Ghana

The use of construction cost estimation model has gained worldwide recognition as a fast and a reliable means of predicting project cost. Cost models are developed for cost estimation at different stages of the construction process and for different work sections. This study focused on the development of regression cost model for estimating the cost of concrete works at the preliminary stage of construction where designs are not complete. It also sought to identify the factors which affect the accuracy of initial cost estimates, identify the dominant methods used for project cost estimation at the initial stages of construction projects in Ghana; and find out the extent of utilization of cost models for project cost estimation in Ghana. To achieve this, questionnaires were developed and administed to 30 cost estimation consultants operating within the Accra Metropolis. These respondents were purposively selected. Historical cost data for some construction projects were also gathered. The data collected were analyzed using Statistical Package for Social Scientist (SPSS) version 16 software package. Descriptive statistics such as mean, frequencies, percentages and Relative Importance Index (RII) were used to analyzed the data. The results revealed that even though a number of cost estimating techniques are in use however, the most dominant ones are the Superficial Area method, Unit cost method and Elemental cost method. Moreover, the significant factors which affects the accuracy of initial cost estimates are adequacy and accuracy of information required to prepare the estimate, level of experience of the estimator, complexity of the design, the time available to prepare the data and the method used for the estimation. The study also found that most cost estimators lacked adequate knowledge about the use of cost models and this consequently affected the extent of its utilization in the Ghanaian construction industry. Based on the historical data collected a cost model was developed. It is recommended that, the use of cost models should be encouraged as they offer a fast and reliable means of estimating pro

Source: KNUST
Cost Management Practices on Large Building Projects: A Case Study of the Association of African Universities Secretariat Building Project in Accra

Cost management system has been considered as an important tool in controlling cost of a project and keeping it within the pre-determined budget. In the case of large building projects, cost management is critical due to the high uncertainties surrounding such projects. The cost management practices of construction firms for large building projects and the challenges associated with them was examine. A case study of the Association of African Universities Secretariat Building Project in Accra was used. Face to face structured interview was held with the key professionals namely the Project manager, Construction manager, Site supervisor, Quantity surveyor, Architect, Civil engineer and the Risk manager who are involved in managing the cost of the project. The data collected was analyzed using content analysis. From the study, it was found that cost management on large building projects starts as earlier as the design/planning stage of the project. The techniques and tool used by firms to manage project cost include: estimating, cost planning and control, budgeting, cash flow forecasting, cost reporting and cost code system. These techniques are used together to support the overall project cost management. The challenges associated with managing cost on large building projects include: frequent variations/changes made to the scope, specification etc. of the project during the construction stage; Poor communication and coordination among project parties; lack of coordination between project processes and the need to manage large cost data create difficulties for the cost management on large building projects. It was recommended that frequent changes/variations in project scope and specifications during the construction stage should be avoided. Moreover, Information and Communication Technology should be utilized for information sharing to enhance communication and coordination. The used of computerized systems for data storage and handling is also encouraged.

Source: KNUST
Cost minimisation for cassava production in the Transition and Forest Agro-Ecological zones, Ghana

Despite the important role cassava plays in the economy as food security and income generation crop, its development has been faced by a number of challenges. Prominent among these challenges is the high cost of production emanating from cost of stem cuttings (planting material), harvesting and transportation. This study was therefore undertaken to find out how farmers can minimise cost of production through an optimal expenditure approach on activities of production. Knowing the major activities of production and how much should be spent on each activity to minimise total cost of production is a key step in reducing cost of production. Data was collected from the Eastern and Brong Ahafo regions which are the two major cassava producing regions in Ghana representing the Forest and Transition zones respectively. Multi-stage sampling was used in selecting two Municipals from each region. Suhum/Kraboa/Coaltar and West Akim Municipals were selected for the Eastern Region and Techiman and Wenchi Municipals for the Brong Ahafo Region. Classical optimisation theory was used to investigate whether farmers in the Transition and Forest agro-ecological zones operate at minimal cost. Boarded Hessian determinants through the use of Laplace expansion was applied to estimate the optimal levels of expenditure and total cost of production as well as cost at major activity levels. From the study, it was realised that cassava farmers in the study area were cost minimisers. They were however not operating at the optimal expenditure levels which curtail their ability to further reduce cost. For them to operate at the optimal level, they need to cut down on activity expenditure for land preparation, planting, farm maintenance and harvest and post-harvest and increase expenditure on fixed inputs.

Source: KNUST