College of Science

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A Comparative Analysis Of Network Performances Of Ethernet, Token Ring And Fddi Protocols In Distributed Systems
(KNUST, 2018-06) Ayatey, Perfect Aku
Internet connectivity is growing with most enterprises shifting to the use of web-based services to satisfy the demands of clients in their organisations. The choice of suitable LAN protocols in network design is of great concern to individuals and organisations. Failure to make the right choice can lead to poor network performances that lower the speed to access information. How can organizations' LAN performances be improved? How fast is data or information transmitted to and from business organization? This research work was carried out to investigate a comparative analysis of network performances of Ethernet, Token Ring and FDDI protocols in terms of throughput and delay in a distributed system. In the study, three LAN protocols; Ethernet, FDDI and Token Ring were modelled and devices within the network were configured using Cisco Packet Tracer Version 7.1 to evaluate their network performances. Varied packet sizes were sent from one station to another workstation on each of the scenarios created. The simulation exercise was conducted after which the time it takes for a machine to receive a packet and sending machine to receive an acknowledgement is recorded and evaluated. The difference between the times a packet was sent from machine to another and the time to take acknowledgement of receipt of the packet was computed as delay. Several scenarios were evaluated through simulations using Cisco Packet Tracer Version 7.1 to show network performances of the three networks. The simulation was done 10 times each for the different scenarios using FTP and SMTP application of a constant packet sizes with varied time and vice versa. The time was recorded as well as averages computed. The general conclusion is that based on the perfomance metrics; delay and throughput used in the study, FDDI recorded the least values of throughput and delay in most of the scenarios according to the tables and figures. FDDI therefore have better network performance than Token Ring and Ethernet.
A Comparative Study Of Different Laboratory Storage Conditions And Dna Extraction Methods For Enhanced Forensic Analysis Of Soil-Human Blood Mixed Sample
(KNUST, 2018-06) Alexander Badu-Boateng
Crime scene investigation is an important step in the entire criminal investigation process because this is where evidence is gathered. Blood from the perpetrator or victim of a crime can be left at crime scenes or transferred to other materials such as clothing, knives and guns. Most often, this body fluid is contaminated with soil at outdoor crime scenes but this might be the only or the most important evidence in solving a crime. This study aimed at identifying the most appropriate method of storing crime scene soil-human blood mixed sample prior to analysis. The best DNA extraction method for this soil-blood mixed sample was also studied. Three commercial DNA extraction kits (PrepFiler Forensic DNA Extraction kit, Promega DNA IQ Kit, Blood Miniprep kit) that have been claimed by the manufacturers to be effective in extracting DNA from soil contaminated samples were used for the DNA extractions. Hemastix and Hexagon OBTI kits were used for the serological analysis in this study. Human blood was mixed with soil and stored at three different storage conditions (i.e., Room temperature/25℃, 4℃ and 20℃). Hemastix and Hexagon OBTI serological tests for blood and human blood, respectively were positive for soil-blood mixed samples at all storage conditions throughout the 12 week study period. Samples stored at room temperature saw significant reduction in DNA concentration as storage time increased (P=0.001 and 0.0055 for Prepfiler and DNA IQ extractions, respectively). Samples stored at 4℃ saw a drastic decrease in DNA concentration just after two weeks of storage. By the eighth week of storage at 4℃, there was no detectable DNA (P=0.000 for all extraction methods). Samples stored at -20℃ recorded no specific pattern in decrease or increase in DNA concentration for the entire 12 week storage (P=0.324 and 0.161 for PrepFiler and DNA IQ extractions respectively). The PrepFiler kit yielded more DNA than the DNA IQ and Blood Miniprep kits at all storage conditions with no significant difference between PrepFiler and DNA IQ (P=0.603). The PrepFiler kit and DNA IQ kit were successful at removing possible PCR inhibitors from the soil during DNA extraction with no significant difference (p=0.887). The Blood Miniprep kit performed poor in terms of removing possible PCR inhibitors. There were full STR Profiles generated for room temperature stored samples and -20℃ stored samples extracted with PrepFiler and DNA IQ kits throughout the study. There were no allele recorded for room temperature stored samples and -20℃ stored samples extracted with Blood Miniprep kit. There were full, partial and null Profiles generated for 4℃ stored samples extracted with PrepFiler and DNA IQ kits depending on the sample storage duration. There were no alleles recorded for 4℃ stored samples extracted with Blood Miniprep kit. In conclusion, the -20℃ and PrepFiler Forensic DNA extraction kit were identified as the best storage condition and extraction method, respectively.
A Framework for setting up effective procurement units in the MMDA, Ghana.
(KNUST, 2018-05) Sitsofe Kwame Yevu
Procurement in the public sector has garnered sufficient attention in public sector due to its magnitude on a country’s economic expenditure and this has led to attempts by stakeholders to drive efforts at making it effective. In Ghana, public procurement has been improved with the formulation of procurement laws and regulations which were recently reformed. The reform produced the Public Procurement Amendment which stipulated the formation of procurement units within the public entity to cater for the organizations procurement operations. The formation of procurement units is a good management strategy but the absence of guideline for setting up procurement units for it to be effective may cause the procurement unit to fail in its operations. The research study sought to answer the question of what factors are needed in setting up procurement units. This leads to the development of aim of the study thus developing a guideline for setting up effective procurement units in the MMDA in Ghana. To attain this aim three objectives were formulated and a mixed methodology approach was adopted in two stages. A review of germane literature was initially conducted to identify the factors required for procurement units to be effective. The first stage involved interviewing experts in public procurement which were purposively selected concerning information gathered from literature and were consequently used to guide the questionnaire for the survey at the second stage. The questionnaire were distributed to MMDAs in Ghana which were subsequently analysed using the confirmatory factor analysis, exploratory factor analysis, mean index score and one sample t-test. The first objective sought to identify the factors for setting up effective procurement units. The confirmatory factor analysis and the mean index score was used to identify the dynamics of the procurement structure with high levels of specialization, configuration and hybrid (de)centralization and this indicated that the procurement unit size should be large to accommodate its operations. Exploratory factor analysis using principal component analysis was used to identify the key requirements needed for setting up effective procurement units thus resource and operations management requirement, top management requirement, organizational structure alignment requirement and procurement law and regulations requirement. The second objective sought to identify the factors that influence the performance of the procurement units. The one sample t-test was used to produce eleven factors that influence the procurement units in public organizations. Subsequently the success factors needed for the procurement units to be successful and effective in the public entity were also identified using one sample t-test. To attain the third objective, a framework was developed using the findings from the study to provide a clearer view of these factors and their influence on the procurement units. Further studies is suggested in the areas of assessing the impact of these requirements on the performance of these procurement units.
A Proposed Framework / System For Online Assessment Of Students On Industrial Attachment Program In Technical And Vocational Institutions In Ghana: A Case Study Of Cape Coast Technical Institute.
(KNUST, 2018-08) Eyram Donne Kuenyehia
Assessment is a vital part of every institution, be it formal or non-formal. Students, teachers and education authorities rely on assessment to take important decisions concerning the grades and possible future of their students. Technical and Vocational Institutions as part of their curriculum engage in Supervised Industrial Attachment (SIA) programme for students. This Supervised Industrial Attachment (SIA) programme helps to equip students with the necessary knowledge and skills to buttress what they learnt at school. It also gives them the opportunity to practice on the field of work and to prepare them for the work environment. Students on Industrial Attachment are assessed on their performance in the various Industries where they are attached to. This research analyses the processes involved in the assessment of students on Supervised Industrial Attachment (SIA), and proposes ways to improve these assessment processes to make it more effective, efficient, well-structured and secured by means of an easily accessible electronic system that runs on all android systems. A survey was carried out with questionnaires in order to elicit from users their views, experience, and short comings of the current manual system of assessing students on industrial attachment the challenges faced with that system and the need for a new improved online computerized system which is a more efficient system and what the requirements of this proposed system should be. Some limitations of the current system of assessment from the survey showed that student’s assessment report can easily get lost or damaged, student can manipulate their assessment reports, and these reports sometimes get to their institution late. There is also the case of inadequate record or lack of records on industrial attachment of previous years in the institutions. The outcome of the survey focused on students, teachers, operational managers of some Industries in Ghana, some privately-owned construction companies and tailoring shops all in Cape Coast. The outcome of the survey revealed that most of these teachers, students and operational managers would rather prefer an online electronic computerized system to the currently used paper based manual system, which is secure, fast, convenient and easily accessible. From the survey conducted, most of these teachers, students and operational managers have the basic knowledge in Information Technology needed to use such an online system, they all have access to internet and computers in their various institutions needed to connect to the proposed system’s platform and fill out attachment assessment details and overall attachment assessment marks for the students. These marks can be accessible by both the student’s institution and the industries’ operational managers. Based on these findings a prototype of the electronic / online industrial attachment assessment system was proposed, designed and developed. There are few recommendations such as; Industrial attachment supervisors should be given inservice training on how to train students and assess them on industrial attachment, student’s marks from industrial attachment should be part of the term’s academic report, the online application be explored further to encompass all institutions that run industrial attachment program. Educational institutions and ICT industries also have the opportunity to improve the system and incorporate other modules that might be needed in educational and employment industry. Furthermore, mobile friendly versions of this online assessment system can be developed as future work.
A Proposed Framework For Interoperability Of Electronic Health Record Systems In Ghana
(KNUST, 2018-06) Anthony Kobina Emil Jnr
Electronic Health Record Systems (EHR’s) plays a major role in today’s health care delivery. Problems associated with patients’ records scattered across many different health facilities have become enormous. It has therefore become very necessary that these Electronic Health Records systemsare interoperable. This would enable health care providers to have comprehensive records about their patients in order to provide them with better care. This work proposes a framework that would enable interoperability of Electronic Health Records from different health facilities across Ghana. The framework underlines certain key requirements such as reliable internet connectivity, biometric finger print scanner and mapping of various tables of the individual databases from different EHRs to the adapter of the framework for interoperability to take place. A simulation and virtualization test about the framework was conducted based on connectivity,search for patients who has visited many facilities and those who don’t have their records in any of the facilities to examine how it would perform if used in the real world. The simulation results from the virtualized framework revealed that it does not require many resources such as high internet speed, one programming language platform for the EHRs, computer servers with high memory and CPU to allow interoperability of patients’ records. Therefore, the framework would highly help health care providers to care for their patients well, due to the vast amount of information they would have on their patients. As part of the recommendations, each EHR in the health facility needs a backup internet, electricityand standby sever for the framework in order to function effectively. Finally, further works could also be done on this study to generate trends reports
Absenteeism Among Rural Teachers: The Contribution of “Poor Remuneration”, “Qualification of Teachers” and “Furthering Studies on Distance Learning”
(2013-07-09) Basiru, Nsoah Kwesi
According to Julius Nyerere― Education will not give one the chance to escape poverty but it will fight poverty from ones community. Education is therefore an earn in itself as well as means to other earns. However, people in the Pru district are gradually losing these enormous benefits of education,this largely is due to absenteeism of teachers from class. The negative effect absenteeism poses to education calls for a study into it. Constas and Vichas (1980) however determined some common variables such as poor remuneration, teachers furthering education and Qualification of teachers as the main contributors of absenteeism.This research is to further check the contribution of these variables, formulate a model for absenteeism and use it to model and predict absenteeism.Poor remuneration is the number contribution to absenteeism and it will be very appropriate to redirect a larger chunk of budget on remuneration of teacher instead of recruiting substitute teachers among others. There is a 99.9% chance that a teacher whose remuneration is good will always be in school irrespective of their Qualification or them furthering education.A database should also be set on attendance of teachers then monitoring and evaluation should be enforced.
Abuse of psychotropic substances -a survey of some first and second cycle institutions in the Bosomtwi and Atwima-Kwanwoma Districts in Ashanti Region of Ghana
(2010-06-02) Assabil, James Kwesi
A random survey using semi-structured questionnaires was conducted in 13 selected first and second cycle schools in the Bosomtwi and Atwima Kwanwoma Districts of Ashanti Region to ascertain the effects of increased abuse of psychotropic substances on the academic performances of 600 students interviewed at random. The psychotropic drugs identified to be abused by the students include: amphetamines; coffee; cigarette; cocaine; marijuana; alcohol and heroine. Majority (94%) of pupils abuse both coffee and alcohol and 31% of pupils abuse marijuana, amphetamine, cocaine and heroine. Although majority (about 56%) of them claim the use of these drugs had improved their academic performances, about 11% of them rather developed truant behavioral problems with abysmal academic performances in the long run. The majority (about 61%) of them also got introduced to the drugs by their families and friends. Ninety six percent of the pupils were exposed to the problem of psychotropic substances abuse at an average age of about 11.5 years. This problem is worst in pupils with single parents or divorcees and also when adolescents are in serious financial problems. Parent remittances were the main source of money for the purchase of drugs. Majority (51%) of the student drug abusers were males although females constitute 45% of the population in these schools. However, the likelihood ratio of abuse amongst male and female students were either asymptotically insignificant (P<0.07) or linearly insignificant (P<0.4). The study generally revealed little improvement in academic performances in schools with increased drug use and the District Education Oversight Committees (DEOCs) as well as Parent Teacher Associations in the two Districts need to seriously get involved in school management programs to assist the implementation of child care monitoring programmes at home and schools in order to find a lasting solution to the rampant drug abuse problem.
Accummulation And Bioaccessibility Of Heavy Metals In Some Root Tubers And Soil In Selected Communities In The Ashanti Region Of Ghana
(KNUST, 2018-04) Adjei Samuel
The presence of metal contaminants in agricultural soils or lands and subsequent uptake of heavy metals by food crops pose serious risk to human health. The study assessed the levels of toxic metals -arsenic, chromium, copper, iron, manganese, nickel, and zinc- in soils and some edible root tuber crops in the Ashanti region to evaluate the potential human health risks associated with exposure to these metals. Concentrations of heavy metals in the 154 samples were initially screened using field portable x-ray fluorescence spectrometer prior to confirmation on an inductively coupled plasma-mass spectrometer. The mean metal concentrations analyzed in the various samples were in the order; As ˂ Cu ˂ Ni ˂Cr ˂ Zn ˂ Mn ˂ Fe for cassava and cocoyam, As ˂ Cu ˂ Zn ˂ Ni ˂ Cr ˂ Mn ˂ Fe, As ˂ Zn ˂ Cu ˂ Ni ˂ Cr ˂ Mn ˂ Fe As ˂ Cu ˂ Ni ˂ Cr ˂ Mn ˂ Fe and Cu ˂ As ˂ Ni ˂ Cr ˂ Z n ˂ Mn ˂ Fe for yam, sweet potato, cassava peels and soil respectively. Soil pH and electrical conductivity ranged between 5.30 to 9.17 and 37.8 µS/cm to 4020 µS/cm respectively. The contamination indices indicated low to moderate contamination. The bioaccumulation factor of these heavy metals in foodstuffs from soil indicated that cassava peels had higher capacity to absorb zinc and iron gave the lowest capacity of absorption. Arsenic recorded the highest value in terms of target hazard quotient (THQ) followed by nickel and chromium, the least value. Comparing the THQ values for adults and children, results for children were higher than that of adults which indicates that children are more likely to express the effect than adults.
Accumulation of Copper from Application of Copper-Based Fungicides and its Relationship with Soil Chemical Properties and Microbial Biomass in Bibiani-Anhwiaso-Bekwai District of Ghana
(SEPTEMBER, 2016) Kakutey, Kingsford
Black pod disease is a major cause of yield loss in cocoa production worldwide and the disease is mostly controlled by copper-based fungicides. However, prolong usage of these fungicides might have negative impact on soil fauna and other soil chemical properties. Ghana Cocoa Board continues to assist farmers to spray their cocoa farms with copper-based fungicides. This study was conducted in selected cocoa farms and uncultivated forests close to these farms which have never been sprayed with fungicides as reference. The study was to investigate the extent of accumulation of copper from the application of copper-based fungicides and its relationship with soil chemical properties and microbial biomass in three communities namely Akaasu, Kyeikrom and Tuntum in Bibiani-Anhwiaso-Bekwai District. Soil samples were collected at two distinct depths, 0-15 cm and 15-30 cm. The fresh soil samples were divided into two. One was immediately sieved through 4 mm mesh and stored at 4 0C for the soil microbial test. The other half was air dried, sieved through a 2 mm mesh and stored in plastic bags for the chemical analysis. Results showed that Tuntum cocoa plantation recorded the highest concentration of total copper (286.54 mgkg-1) while Akaasu cocoa plantation recorded the least total copper concentration of (215.63 mgkg-1). Extractable and total copper vary significantly (P < 0.05) in both top and sub soils of the cocoa plantations from their respective reference values. However, soil pH, nitrogen and organic matter from soils of the cocoa plantations did not vary significantly (P > 0.05) from their reference soils. Results from correlation analysis revealed that extractable and total copper in both the top and sub soils correlated negatively with the levels of organic matter. The relationship between extractable and total copper with microbial biomass were also negatively correlated but not significant (P > 0.05) from the regression analysis in all the study locations. The findings have also shown that the concentrations of copper in the soils of cocoa plantations have not reached their critical levels.
Accumulation of Toxic and Essential Elements in Clams and Sediments from the Volta Estuary
(2013-12-10) Baffoe, Stephen Yaw
The clams (Galatea paradoxa) and sediments were collected from the Volta Estuary in Ghana for six months’ period at Ada and Aveglo. They were analysed for six different elements (Cd, Cr, Cu, Hg, Ni, and Se) using Flame Atomic Absorption Spectrometer (AAS) and Automatic mercury analyzer Model HG 5000. A total of one hundred and eighty (180) clams were analysed over the period. The mean elements concentrations in the tissues of the G. paradoxa from Ada sampling site ranged from: Cd: 0.09 -0.17 mg/kg; Cr: 3.42 – 20.51 mg/kg; Cu: 0.55 – 3.10 mg/kg; Hg: 0.05 – 0.12 mg/kg; Ni: 5.49 – 27.96 mg/kg and Se: 0.34 – 0.49 mg/kg. That of o sediments were: Cd: 0.09 mg/kg; Cr: 15.03 mg/kg; Cu: 89.94 mg/kg; Hg: 0.06 mg/kg; Ni: 47.16 mg/kg and Se: 0.41 mg/kg. For Aveglo the mean metal concentrations in clam tissues were: Cd: 0.07 - 0.14 mg/kg; Cr: 2.01 –24.10 mg/kg; Cu: 0.79 – 3.65 mg/kg; Hg: 0.04 – 0.09 mg/kg; Ni: 10.25 – 28.14 mg/kg and Se: 0.13 – 0.29 mg/kg and the sediment samples recorded the mean metal concentrations as: Cd: 0.07 mg/kg; Cr: 16.28 mg/kg; Cu: 75.66 mg/kg; Hg: 0.04 mg/kg; Ni: 51.25 mg/kg and Se: 0.38 mg/kg. The analysis of the elements concentrations in the tissues of the different clams in relation to body size for the Ada sampling site shows significant difference (p < 0.05) for Cd and Cu in the various clam sizes. The mean concentrations of Cr, Hg, Ni and Se exhibited significant differences (p>0.05) in concentration between some clam sizes at Ada sampling site. The test for difference in mean concentrations of Cd and Cr showed significant differences (p < 0.05) between the various clam size classes at the Aveglo sampling site. Nevertheless, there was no significant differences (p > 0.05) showed between the mean concentrations of Cu, Hg, Ni and Se for some clam sizes. The evaluation of the risk associated with consumption of clams from the Volta estuary using WHO/FAO Standards for Bivalves, the Tolerable daily Intake (TDI), the rate of shellfish consumption (RSC), Risk Quotients (RQs) and the levels of concerns (LOCs) suggest that the normal consumption rates should be safe with regards to Cd, Cu, Hg, Ni and Se in the clam tissues except for Cr in medium to large clam sizes whose concentrations exceeded the WHO/FAO Standards for Bivalves legal limits The mean elements concentration of Cu in sediments for both Ada and Aveglo exceeded the NOAA Effects Range – Low (ERL) value of 20.9 mg/kg and CSQG Threshold Effects Level (TEL) value of 52.3 mg/kg whilst Ni at both sampling sites exceeded the NOAA Effects Range – Low (ERL) of 20.9 mg/kg. Sediment metal concentrations for Cd, Cr, Hg and Se were below the various effect ranges at all sites. The geoaccumulation index indicates practically unpolluted sediments as far as elements Cd, Cr, Hg, Ni and Se are concerned except for Cu.
Acid Mine Drainage: Effect of acid mine drainage on water and soil resources within the Bogoso/Prestea Mine Resource. (Bogoso Concessional Area)
(FEBURARY, 2009) Afriyie – Debrah, Charles
Heavy metals contamination (As, Fe, Cu, Zn, Mn and Cd) and other physico-chemical changes (pH, temperature, EC, DO, alkalinity, S042-, free CN) in underground and surface water, and carbonate carbon and sulphate sulfur in soil samples due to the effect of acid mine drainage (AMD) were assessed around Golden Star Resource Mine (Bogoso concession). Underground and surface water samples were collected from seven different sites and soil samples from three different sites within Golden Star Resources Mine (Bogoso concession) between November, 2006 and April, 2007. Atomic Absorption Spectrometry (AAS) was used to determine the heavy metal concentrations whilst the physico-chemical parameters were determined using standard methods. Average total levels of arsenic, iron, copper, zinc, manganese and cadmium were 0.0313, 3.7675, 0.0518, 0.0382, 0.8102 and 0.008 (mg/l) and average dissolved levels were 0.0104, 0.6737, 0.0356, 0.0256, 0.6998 and < 0.005 (mg/l) in surface water respectively. In underground water, average total levels of arsenic, iron, copper, zinc, manganese and cadmium were 0.0058, 5.8220, 0.1676, 0.0339, 0.2521 and 0.0065 (mg/l) whilst average dissolved levels were 0.0050, 4.3496, 0.1219, 0.0215, 0.2239 and 0.006 (mg/l) respectively. Iron and manganese levels in surface and underground waters exceeded Ghana Environmental Protection Agency standards for mining effluent. Differences in pH, temperature, E.C, alkalinity, S042-, iron, Cu, Zn and Mn levels in the seven water samples were statistically significant (p ≤ 0.05). Surface water samples recorded values of EC and S042- ions higher than in underground water samples which exceeded acceptable limits. Carbon and sulfur in soil samples varied from 0.1922 to 1.8247 % and 0.0237 to 1.5830 % respectively. The results of the study showed high impact of AMD on water quality in Bogoso mining area. This effect could be attributed to the release of metals as a result of oxidation of metal-bearing sulphides in the mine dumps and pits at the selected sampling sites. The study showed that addition of lime as a treatment option has not been effective. Hence new conventional methods should be considered in the treatment of acidic water (AMD) in the mining area.
Acrylamide Exposure And Risks In Most Frequently Consumed Foods In A Total Diet Study
(KNUST, 2018-05) Michelle Oppong Siaw
The neurotoxic and carcinogenic nature of acrylamide, coupled with the recent emphasis of the ―probable carcinogenic‖ status of acrylamide is a cause for concern requiring further studies. The objective of this study was to determine the carcinogenic and neurotoxic risks associated with the consumption of frequently consumed foods in a Total Diet Study (TDS). From a selection of 80 frequently consumed foods, the a Total Diet Study (TDS). From a selection of 80 frequently consumed foods, the acrylamide concentrations in the foods were purified by the QuEChERS method of extraction and purification, and the concentrations of acrylamide were determined using the HPLC. Acrylamide was detected in 82% of all the foods analyzed, and the levels ranged from 1.33×10-3 ± 1.89 to 14.39×10-3 ± 6.33 mg/g. The probabilistic approach was used to model the chronic exposures using the Monte Carlo simulation of the Palisade @Risk software. The mean, 50th and 95th percentile values for acrylamide exposures were in the range of 1.56×10-3 to 1.88×10-2, 3.21×10-4 to 5.85×10-3 and 6.16×10-3 to 8.32×10-2 mg/kg bw/day respectively. The mean and 95th percentile values for the margins of exposure (MOE) for the risk of tumorigenesis and neurotoxicity were below the thresholds, hence posing significant public health concern. Generally, the lifetime cancer risks of male consumers were higher compared to that of the female consumers. The median and 95th percentile consumers presented unacceptable risk, since their lifetime cancer risks were greater than the de minimus (10-6). The elements that imparted the most on the overall lifetime cancer risk of the consumers were the exposure duration and the concentration of acrylamide in the foods. To lower these lifetime cancer risks, mitigation studies can thus, be mounted in order to help lower the concentrations of acrylamide in the foods.
Acrylamide Exposure and Risks in Most Frequently Consumed Foods in a Total Diet Study
(2018-10-31) Siaw, Michelle Oppong
The neurotoxic and carcinogenic nature of acrylamide, coupled with the recent emphasis of the “probable carcinogenic” status of acrylamide is a cause for concern requiring further studies. The objective of this study was to determine the carcinogenic and neurotoxic risks associated with the consumption of frequently consumed foods in a Total Diet Study (TDS). From a selection of 80 frequently consumed foods, the acrylamide concentrations in the foods were purified by the QuEChERS method of extraction and purification, and the concentrations of acrylamide were determined using the HPLC. Acrylamide was detected in 82% of all the foods analyzed, and the levels ranged from 1.33×10-3 ± 1.89 to 14.39×10-3 ± 6.33 mg/g. The probabilistic approach was used to model the chronic exposures using the Monte Carlo simulation of the Palisade @Risk software. The mean, 50th and 95th percentile values for acrylamide exposures were in the range of 1.56×10-3 to 1.88×10-2, 3.21×10-4 to 5.85×10-3 and 6.16×10-3 to 8.32×10-2 mg/kg bw/day respectively. The mean and 95th percentile values for the margins of exposure (MOE) for the risk of tumorigenesis and neurotoxicity were below the thresholds, hence posing significant public health concern. Generally, the lifetime cancer risks of male consumers were higher compared to that of the female consumers. The median and 95th percentile consumers presented unacceptable risk, since their lifetime cancer risks were greater than the de minimus (10-6). The elements that imparted the most on the overall lifetime cancer risk of the consumers were the exposure duration and the concentration of acrylamide in the foods. To lower these lifetime cancer risks, mitigation studies can thus, be mounted in order to help lower the concentrations of acrylamide in the foods.
Acrylamide resulting from heat-time treatment in pigeon pea, a neglected and underutilized legume
(2014-10-15) Dankwah, Rita
The influence that heat-time treatment has on the concentration of acrylamide in roasted pigeon pea was analysed. The study focussed on optimising the roasting conditions using Response Surface Methodology (RMS) to minimise concentration of acrylamide in roasted Pigeon pea. The treatment conditions used were temperatures in the range of 80 – 120 oC and time of 10 - 60 min, additive of 0.1-1.0 g and soaking solvent prepared with citric acid or phosphoric acid. Analysis of the data showed that the concentration of acrylamide content significantly increased as the temperature and time of processing increased (p<0.005). Citric acid and phosphoric acid used as additives in soaking the Pigeon pea had no significant effect on acrylamide formation. The optimization of process parameters to give low level of acrylamide resulted in roasting temperature of 80ºC for 10 min and 0.1g mass of additive with citric acid as the soaking solvent having a desirability of 0.972. The roasted Pigeon pea produced using the optimized conditions resulted in a concentration of acrylamide (1.76g/kg).
Actuarial Applications of Hierarchical Modeling to Health Insurance Claims
(October 22, 2015) Atta-Mensah, Michael
This study demonstrates actuarial applications that can be performed on the Health insurance claims in the country. To achieve this, data from the CPC scheme in Accra of the NHIA in the year 2013 was employed for the study. this consisted of facility type, number of claims submitted(in-patient and out-patient) and amount submitted (in-patient,out-patient,drugs and services charges). A hierarchical model allowing for frequency, claim type and severity amount to be jointly modeled was used. Based on this hierarchical model, we proceeded to estimate premium values under various conditions, however due to lack of information from the insurer most of these estimates could not be stated categorically. Applications of the study was also made to the Value-at-Risk theory. This fact not withstanding, a case has been made for the consideration of the hierarchical modeling approach to be considered as the means of analyzing health insurance claims since this model takes into consideration not only the loss (severity) amount submitted but also considers most especially factors integral to the planning and budgeting of the insurer, and these are, the frequency and type of claim. The hierarchical modeling approach thus provided further insight which previously was overlooked.
Actuarial modeling of health insurance claim reserves using the chainladder
(NOVEMBER, 2019) Opoku, Genevieve;
The preparation for outstanding claims is one of the main factors of technical provisions of Insurance company’s liabilities. Minimising the digression of the true amount of reserves from its estimation is one of the major actuarial challenges. Though the NHIA request the use of Chain Ladder method amidst the various actuarial models for reserve, most health insurance companies default in settling their claims on time leading to the pullout of some healthcare service providers in providing services to customers under the defaulters’ schemes. This thesis summarizes the salient techniques typically used for the estimation of outstanding claims reserves in non-life insurance specifically health insurance, including those to estimate the claims development. This research goes for estimation of health claim reserves in Ghana utilizing Inflation-adjusted chain ladder, Mack chain ladder and Bootstrap chain ladder technique. Claim data on Nationwide Medical Insurance Co. Ltd for my examination ranges from January 2008 to December 2017. Results indicate the Inflation-adjusted Chain Ladder had a superior reserve estimate than that of Mack Chain ladder and Bootstrap Chain Ladder methods.
The acute toxicity of karate, dursban and actellic to Heterobranchus Bidorsalis (Geoffrey St. Hilaire) Tiliapia Zillii (Gervais), Oreochromis Niloticus (Linn) and Sarotherodon Galilaeus (Artedi)
(1995) Godzi, Trinity Ama
The acute toxicity of Karate, Dursban and Actellic to Heterobranchus bidorsalis, Tilapia zillii, Oreochromis niloticus and Sarotherodon galilaeus was investigated by the static method for 96 hours. The 96-hour LC50 values obtained for Karate, Dursban and Actellic to Heterobrancbus bidorsalis and Tilapia zillii showed that Karate is the most toxic to the two species of fish. This is followed by Dursban while Actellic is the least toxic. For Oreochromis niloticus, the 96 hour LC50 values obtained indicated that Dursban is more toxic than Karate. The 96 hour LC50 values obtained with Karate to the various fish species showed Heterobranchus bidorsalis to be the least resistant of the four species. Sarotherodon galilaeus came next, followed by Tilapia zillii with Oreochromis niloticus being the most resistant. Actellic was shown to be more toxic to Tilapia zillii than it is to Heterobranchus bidorsalis. For Dursban, Oreochromis niloticus was the least resistant followed by Heterobranchus bidorsalis while Tilapia zillii was the most resistant. The 96-hour LC50 values obtained for the acute toxicity tests for Karate using Heterobranchus bidorsalis, Tilapia zilhii, Oreochromis niloticus and Sarotherodon galilaeus were 0.006±0.001mg/l, 0.020±0.017mg/l, 0.040±0.032mg/l and 0.016±0.008mg/l respectively. For Actellic, the LC50s obtained using Heterobranchus bidorsalis and Tilapia zillii were 1.250±0.833mg/i and 0.700±0.250mg/l respectively. The values obtained for Dursban using Heterobranchus bidorsalis, Tilapia zillii, and Oreochromis niloticus were 0.270±0.l7Omg/l, 0.280±0.088mg/l and 0.040±0.019mg/l respectively. The percentage mortality of the species of fish used was directly proportional to increasing concentration and time. The plot of median mortality times against concentration on a semi- log paper produced curves which were asymptotic to the LC50s of Karate with Tilapia zillii, Dursban with Oreochromis niloticus and Actellic with Heterobranchus bidorsalis. This is an indication that Karate, Dursban and Actellic are not acutely toxic to Tilapia zillii, Oreochromis niloticus and Heterobranchus bidorsalis respectively at infinite dilution.
Adaptation and effects of social media in teaching and learning at the second cycle institution level in Ghana
(AUGUST, 2016 ) Dore-Natteh, Doris
The proliferation of social media platforms freely accessible online using cell mobile devices, PCs and the immense interest of this generation of students in such platforms to the detriment of their studies has cause for concern. As it is almost impossible to block students from engaging on these platforms, it therefore becomes imperative to find a way to make them use the social media for useful purposes. The primary reason for this study is to determine the feasibility of adapting the use of social media in teaching and learning; and to assess the effectiveness and efficiency of these media for instructional engagement by instructors and learners at the second cycle institution level in Ghana. In the course of the study, Facebook© and WhatsApp© were used to supplement traditional classroom instruction and the impacts on students' motivation, learning experience and performance were assessed. Qualitative Case Study research method was used for this study. Interviews conducted were transcribed and composed into three phases of sorting out subjective information as suggested by Strauss and Corbin (1998). The results of the study demonstrate positive results in the use of the social media (Facebook and WhatsApp) to augment classroom teaching and learning with respect to students’ motivation, learning experience and performance suggesting effectiveness and efficiency of the instructional blend. Implication of the results is that the findings can be utilized as a reference for educators and curriculum designers to find meaningful use of social media for teaching and learning in second cycle institutions in Ghana. The study however reveals some challenges such as affordance, access to mobiles devices and irregular power supply that need to be addressed in order not exacerbate the problem of digital divide.
Adding value to agricultural waste: production and quality assessment of coconut coir as soilless media for plant production
(2005) Adomako, Charles
Coconut husks from two major sources (coastal and inland areas) were used in the study. Coir dust (CD) produced were grouped into five treatments and labeled CD- 1 to CD- 5. The study was to investigate the physical and chemical characteristics of the five media and the growth response of Salvia splendeus seeds. Five media mixes based on mixture of coir dust and sawdust with coir dust in increment of volume from 0 to 100% coir dust and KNUST soil mix as control substrate. The 50% coir and 50% sawdust blend had the best percentage germination (90%) with KNUST mix the lowest of 65%. There was no difference in percentage germination of 100% coir and 100% sawdust media. However, it was realized that various media had significant effect on growth rate after 4thi week of germination. The various sources of husks also had significant effect (p< 0.05) on Electrical conductivity, potassium, Nitrogen, Manganese, Moisture, Bulk Density, pH, Calcium, Iron, Sodium and Chloride contents but there were no significant difference (p> 0.05) in Phosphorus and Magnesium contents. Although significant differences were observed among sources of coconut coir with respect to physical and chemical properties, most mineral elements were within ranges reported for coir and sphagnum peats (Handreck, 1993) and considered acceptable substrates to be used in most horticultural applications. Due to the variability of minerals that exist among coir produced from various sources, coir products must be evaluated and amended before use. It should be noted that coconut coir dusts does not support and sustain plant growth for a lifetime unless otherwise supplied with continuous fertilizer regimes or are prepared in combination with other media.
Adsorptive removal of arsenic and manganese from groundwater
(2005-11-14) Addae-Mensah, Afiba
Groundwater remains the most important source of water supply for rural communities in Ghana. Currently, over 95% of the domestic water needs of rural communities are obtained from this source. In some localities, the quality of groundwater is affected by the occurrence of Arsenic (As) and Manganese (Mn) in concentrations above tough and 0.1mg/l respectively which are the World Health Organization (WHO) acceptable limits for drinking water. This is a limiting factor in the choice of this resource. Water supply companies are currently seeking to improve the process of As and Mn removal from groundwater. In this study, Adsorption capacity of locally available filter media namely, laterite and Iron Oxide Coated Sand (ICS) were investigated for removal of As and Mn from synthetic water. Batch studies were conducted under aerobic and anaerobic conditions. Changes in concentrations of As and Mn were determined using the Atomic Adsorption Spectrometer (AAS) and Graphite furnace AAS. Adsorption isotherms were prepared using different concentrations of Mn. Isotherms were not prepared for As due to constraints of time. The effect of pH on adsorptive trends was also investigated into. The filter media was then used for treatment of real groundwater seeded with different concentrations of Mn and As from Ayeduase Township. Results of the study show that adsorption under conditions of anaerobic and aerobic is comparable prior to the attainment of equilibrium by the anaerobic case. However the aerobic adsorption process continues slowly and consistently probably because the adsorbed Mn2+ gets oxidized to form manganese oxides and manganese oxyhydroxide complexes. These complexes form a new external coating round the media and facilitate further adsorption of Mn2+ ions, The anaerobic adsorption data of both ICS and laterite fined well with the Freundlich’s Isotherm. The results revealed that, iron oxide coated sand has higher adsorption capacity than laterite. This may be due to higher iron and manganese oxide content in the coating of the coated sand as compared to the amount in the laterite. The iron oxide coated sand also had higher adsorption intensity as compared to the laterite. Better adsorption trends were realized at higher pH for both media.

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