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- ItemAnalysis of electrical power usage in houses using smart electrical distribution switch(KNUST, 2019-10) Fofie,KofiThere is high demand for electrical energy because electrical energy is very important in both industrial and domestic activities and that has call for the introduction of different energy meters by various electricity companies. In Ghana families living in large and compound houses wish to have separate energy meters from other occupants. This is because individual’s cannot monitor and control the energy consumption of each individual and that brings misunderstanding in energy bill sharing which also brings about a household having about ten energy meters causing overcrowding of energy meters on the wall of a building which makes the wall loses its beauty and there is likelihood of fire outbreak in the house because the wires are not well arranged. Moreover, energy companies need huge sum of money and labour to produce more energy meters and this can cause financial loss to the energy companies. This has therefore call for the introduction of smart distribution switch which will enhance the monitoring and adequate sharing of energy purchased by the household base on the amount paid by each of the users of the meter. The amount paid will be entered into the system that will be stored on EPROM of a microcontroller that will reduce each consumer’s energy base on the rate of consumption. The smart distribution switch may have different switches allocated to each user which monitor the consumption rate of each user. It will then isolate the user connected to a line out when he /she completely consumes his share.
- ItemAssessment of Land use Induced Land Surface Temperature Changes in the Greater Accra Region, Ghana(KNUST, 2019-08) Agbozo,MathiasThis study explored the application of geospatial technology in understanding change pattern of Land use/Land cover (LULC) and associated Land Surface Temperature (LST) variability in the Greater Accra region between 1986 and 2018. Landsat satellite imagery between the months of December and February (dry season) were used for LULC analysis and LST Estimation. MODIS LST data for 1986, 2002 and 2018 were also utilized for the validation of satellite derived LST. The aim of this research was to investigate how LULC changes affects LST. The results of analysis show that LULC in Greater Accra region has changed significantly over the 32-year period. Four major LULC types identified were; vegetation, built-up, bare land and waterbody. Bare land cover type indicated decrease from 1986 to 2018 of 60.22%. Water bodies experienced varying trend of 7.84% decrease representing 9.11 Km2. Vegetation cover indicated 16.20% increase in 2002 and 28.02% decrease in 2018. This amounted to a total of 11.82% decrease in vegetation cover. On the contrary, built-up increased by 654.03% (724.3 Km2) between 1986 and 2018. LST was observed to have increased by 3.05 over the 32-year period of this study across the Greater Accra region. with the highest LST of 36.95 and the lowest of 20.19 , both recorded in 2002. The trend however indicated a significant increase between 1986 and 2002 but a decrease in LST from 2002 to 2018. The increasing trend in LST over time was found to be consistent with the observed urban expansion of the study area. High temperatures are also more apparent along the coastal belt of the region stretching northwards as development spread in the same direction. Total change in LST for the entire period of the study show increases of 3.53 , 3.04 , 2.78 and 2.65 for bare land, vegetation, built-up and waterbody land use/land cover types respectively. LULC association with LST shows that bare land experienced the highest negative change of 60.22% and this corresponded to the highest increase in LST of 3.53 over the same period. Correlation analysis and Coefficient of variation indicated largely that, MODIS LST data validated derived LST from Landsat satellite imagery. Trend of both LST values follow identical pattern with few instances where derived LST is greater than MODIS LST. Both NDBAI and NDBI exhibited a positive correlation with LST. NDVI demonstrated a negative linear correlation while NDWI indicated the strongest negative linear correlation with LST. Land use/Land cover change can be linked to rising Land Surface Temperature Changes in the Greater Accra region of Ghana. The research stresses the need to ensure effective land use planning by relevant regulatory bodies to control urban development and address anthropogenic causes of surface temperature changes.
- ItemStakeholder Management Practices: Case Study of Marine rehabilitation Project at Ghana Ports and Harbour authority (Takoradi Shipyard)(KNUST, 2019-10) Charles Alampahii ABSTRACT Stakeholder management is a vital activity, using simple procedures and investing a modest effort can make a big difference to the eventual success of the project simply by understanding the stakeholders and what they want. Communications with stakeholders who have high levels of interest and influence will be managed differently from those with stakeholder of low interest and influence. This study seeks to examine the stakeholder management practices implemented in marine rehabilitation projects activity in Ghana Ports and Harbours Authority – Takoradi shipyard, challenges of stakeholder management, causes of the identified challenges as well as to provide recommendations on strategies for effective stakeholder management. The research design for this study is of quantitative type, this study used descriptive statistics to achieve its objectives. The key findings of this study are: the critical challenges of stakeholder management practices at Ghana Ports and Harbours Authority, Takoradi shipyard in their order of ranking of occurrence include unclear stakeholders, negative community reactions to the project, Inadequate resources assigned to the project, changes in scope of work and lack of support from stakeholders. The study found several causes of the identified challenges which includes poor planning, lack of human personnel and lack of effective communication. The study also found several proposed strategies for effective stakeholder management including effective planning, effective communication and effective stakeholder engagement.
- ItemImproved propagation models for LTE path loss prediction in Ghana(KNUST, 2019-11) Stephen Jeswinde NuagahLong Term Evolution (LTE) Networks offer significant advancement compared with third- generation (3G) Networks in the areas of capacity, latency, network complexity and quality of service. To maximize these benefits of LTE cellular networks, careful and proper planning is needed. This requires the use of accurate propagation models to quantify the path loss required for base station (BS) deployment. However deployed LTE networks in Ghana mostly do not offer the desired 100Mbps throughput leading to customer dissatisfaction. This stems from the fact that Network operators rely on transmission planning tools designed for generalized environments, having no detailed knowledge of the Ghanaian environment. These transmission planning tools come with already embedded propagation models for path loss prediction suited to other environments. A challenge therefore to Ghanaian Network operators at the planning stage will be choosing a propagation model that best suits the Ghanaian environment for accurate path loss prediction. Therefore an accurate and precise propagation model reflecting the Ghanaian environment is needed. In view of this, this study considers extensive LTE path loss measurements at 800MHz and 2600MHz taken in selected urban(Adum, Sunyani, Techiman) and suburban(Agogo, Afrancho, New Dorma, Berekum) environments in Ghana. The measured path loss is compared with the corresponding results obtained from six(6) commonly used propagation models: Stanford University Interim model (SUI), Electronic Communication Committee model (ECC-33), Hata model, COST 231 model, Free space path loss model , and the Ericson model. The commonly used industry standard propagation models that best fit measurement data in these Ghanaian environments were then selected. The measured results show that the Ericson model predicts best in urban areas at 800MHz, the SUI model predicts best rather in suburban areas at 800MHz and the ECC 33 model best predicts path loss in urban and suburban areas at 2.6GHz.These models were modified and developed to predict more accurately the path loss in these environments.
- ItemAssessment of Risk Priority Number of 2.5 Mw Polycrystalline Silicon Photovoltaic Power Plant at Navrongo, Ghana in Sub-Sahara Africa(KNUST, 2019-04) Alhassan SullaimanUnderstanding failures of photovoltaic (PV) modules is one key factor in enhancing the reliability and service lifetime of PV modules; and hence reducing the cost of PV systems and financial implications on investment. This study seeks to identify the field failures associated with installed PV modules in the Ghanaian climatic condition, which minimize the performance of modules, and pose reliability issues to the solar plants as well as financial implications to manufacturers and investors in the PV sector. Physical examination of the modules using visual inspection checklist and their corresponding electrical performance parameters (I-V characteristics) measurement using multimeter and I-V tracer were performed on two models of the five (5) year old 2.5 MW PV power plant at Navrongo. A MatLab program was used to evaluate the failures and degradation modes of 144 Polycrystalline silicon (Poly-Si) framed modules under the hot dry climate of Navrongo. The program is a statistical reliability tool that uses Risk Priority Number (RPN) to determine the dominant failures by means of ranking and prioritizing the failure modes. The visual inspection revealed front glass slightly soiled, junction box lid fell off, cell interconnect discoloration and backsheet crack between cells as the peculiar failure issues either affecting the performance of the modules and/ or posing safety concern to personnel and properties on site. Mean degradation rates of 1.11%/year and 1.23%/year were respectively computed for Model A (Jinko solar) and Model B (Suntech technologies) types of modules for the power plant studied. These degradation rates values are beyond the standard warranty limit of 1.0%/year reported in literature. In addition, short circuit current (Isc) and fill factor (FF) were determined as the dominant I-V parameters affecting the power degradation rates of the Model A and Model B modules respectively. The study also determined the total Global RPN value of 606 for the Model A type of modules for this plant, whereas that for Model B is 583. These RPN values fall within the reported values ranging from 500 to 755 in literature. With this information, investors can have an insight on the worth of a PV Plant and viability of their investment before making a decision. From this study, it can be concluded that, the five years old PV plant in operation is not performing very well and needs urgent attention to avoid loss based on the degradation rates of the fielded modules.