Search results for: Isaac Diaka
69 Didactical and Semiotic Affordance of GeoGebra in a Productive Mathematical Discourse
Authors: Isaac Benning
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Using technology to expand the learning space is critical for a productive mathematical discourse. This is a case study of two teachers who developed and enacted GeoGebra-based mathematics lessons following their engagement in a two-year professional development. The didactical and semiotic affordance of GeoGebra in widening the learning space for a productive mathematical discourse was explored. The approach of thematic analysis was used for lesson artefact, lesson observation, and interview data. The results indicated that constructing tools in GeoGebra provided a didactical milieu where students used them to explore mathematical concepts with little or no support from their teacher. The prompt feedback from the GeoGebra motivated students to practice mathematical concepts repeatedly in which they privately rethink their solutions before comparing their answers with that of their colleagues. The constructing tools enhanced self-discovery, team spirit, and dialogue among students. With regards to the semiotic construct, the tools widened the physical and psychological atmosphere of the classroom by providing animations that served as virtual concrete to enhance the recording, manipulation, testing of a mathematical idea, construction, and interpretation of geometric objects. These findings advance the discussion of widening the classroom for a productive mathematical discourse within the context of the mathematics curriculum of Ghana and similar Sub-Saharan African countries.Keywords: GeoGebra, theory of didactical situation, semiotic mediation, mathematics laboratory, mathematical discussion
Procedia PDF Downloads 13268 Effect of Nanoparticles Concentration, pH and Agitation on Bioethanol Production by Saccharomyces cerevisiae BY4743: An Optimization Study
Authors: Adeyemi Isaac Sanusi, Gueguim E. B. Kana
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Nanoparticles have received attention of the scientific community due to their biotechnological potentials. They exhibit advantageous size, shape and concentration-dependent catalytic, stabilizing, immunoassays and immobilization properties. This study investigates the impact of metallic oxide nanoparticles (NPs) on ethanol production by Saccharomyces cerevisiae BY4743. Nine different nanoparticles were synthesized using precipitation method and microwave treatment. The nanoparticles synthesized were characterized by Fourier Transform Infra-Red spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Fermentation processes were carried out at varied NPs concentrations (0 – 0.08 wt%). Highest ethanol concentrations were achieved after 24 h using Cobalt NPs (5.07 g/l), Copper NPs (4.86 g/l) and Manganese NPs (4.74 g/l) at 0.01 wt% NPs concentrations, which represent 13%, 8.7% and 5.4% increase respectively over the control (4.47 g/l). The lowest ethanol concentration (0.17 g/l) was obtained when 0.08 wt% of Silver NPs was used. And lower ethanol concentrations were observed at higher NPs concentration. Ethanol concentration decrease after 24 h for all the processes. In all set up with NPs, the pH was observed to be stable and the stability was directly proportional to nanoparticles concentrations. These findings suggest that the presence of some of the NPs in the bioprocesses has catalytic and pH stabilizing potential. Ethanol production by Saccharomyces cerevisiae BY4743 was enhanced in the presence of Cobalt NPs, Copper NPs and Manganese NPs. Optimization study using response surface methodology (RSM) will further elucidate the impact of these nanoparticles on bioethanol production.Keywords: agitation, bioethanol, nanoparticles concentration, optimization, pH value
Procedia PDF Downloads 18867 Epidemiological Survey of Feline Leukemia Virus in Domestic Cats on Tsushima Island, Japan: Tsushima Leopard Cats Are at Risk
Authors: Isaac Makundi, Kazuo Nishigaki
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The Tsushima leopard cat (TLC) Prionailurus bengalensis euptilurus, designated a National Natural Monument of Japan, inhabits Tsushima Island, Nagasaki Prefecture, Japan. TLC is considered a subspecies of P. bengalensis, and lives only on Tsushima Island. TLCs are threatened by various infectious diseases. Feline leukemia virus (FeLV) causes a serious infectious disease with a poor prognosis in cats. Therefore, the transmission of FeLV from Tsushima domestic cats (TDCs) to TLCs may threaten the TLC population. We investigated the FeLV infection status of both TDCs and TLCs on Tsushima Island by screening blood samples for FeLV p27 antigen and using PCR to amplify the full-length FeLV env gene. The prevalence of FeLV was 6.4% in TDCs and 0% in TLCs. We also demonstrated that the virus can replicate in the cells of TLCs, suggesting its potential cross-species transmission. The viruses in TDCs were classified as genotype I/clade 3, which is prevalent on a nearby island, based on previous studies of FeLV genotypes and FeLV epidemiology. The FeLV viruses identified on Tsushima Island can be further divided into two lineages within genotype I/clade 3, which are geographically separated in Kamijima and Shimojima, indicating that FeLV may have been transmitted to Tsushima Island at least twice. Monitoring FeLV infection in the TDC and TLC populations is highly recommended as part of the TLC surveillance and management strategy.Keywords: epidemiology, Feline leukemia virus, Tsushima Island, wildlife management
Procedia PDF Downloads 20666 Communication Styles of Business Students: A Comparison of Four National Cultures
Authors: Tiina Brandt, Isaac Wanasika
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Culturally diverse global companies need to understand cultural differences between leaders and employees from different backgrounds. Communication is culturally contingent and has a significant impact on effective execution of leadership goals. The awareness of cultural variations related to communication and interactions will help leaders modify their own behavior, and consequently improve the execution of goals and avoid unnecessary faux pas. Our focus is on young adults that have experienced cultural integration, culturally diverse surroundings in schools and universities, and cultural travels. Our central research problem is to understand the impact of different national cultures on communication. We focus on four countries with distinct national cultures and spatial distribution. The countries are Finland, Indonesia, Russia and USA. Our sample is based on business students (n = 225) from various backgrounds in the four countries. Their responses of communication and leadership styles were analyzed using ANOVA and post-hoc test. Results indicate that culture impacts on communication behavior. Even young culturally-exposed adults with cultural awareness and experience demonstrate cultural differences in their behavior. Apparently, culture is a deeply seated trait that cannot be completely neutralized by environmental variables. Our study offers valuable input for leadership training programs and for expatriates when recognizing specific differences on leaders’ behavior due to culture.Keywords: communication, culture, interaction, leadership
Procedia PDF Downloads 11365 Identification of Functional T Cell Receptors Reactive to Tumor Antigens from the T Cell Repertoire of Healthy Donors
Authors: Isaac Quiros-Fernandez, Angel Cid-Arregui
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Tumor-reactive T cell receptors (TCRs) are being subject of intense investigation since they offer great potential in adoptive cell therapies against cancer. However, the identification of tumor-specific TCRs has proven challenging, for instance, due to the limited expansion capacity of tumor-infiltrating T cells (TILs) and the extremely low frequencies of tumor-reactive T cells in the repertoire of patients and healthy donors. We have developed an approach for rapid identification and characterization of neoepitope-reactive TCRs from the T cell repertoire of healthy donors. CD8 T cells isolated from multiple donors are subjected to a first sorting step after staining with HLA multimers carrying the peptide of interest. The isolated cells are expanded for two weeks, after which a second sorting is performed using the same peptide-HLA multimers. The cells isolated in this way are then processed for single-cell sequencing of their TCR alpha and beta chains. Newly identified TCRs are cloned in appropriate expression vectors for functional analysis on Jurkat, NK92, and primary CD8 T cells and tumor cells expressing the appropriate antigen. We have identified TCRs specifically binding HLA-A2 presenting epitopes of tumor antigens, which are capable of inducing TCR-mediated cell activation and cytotoxicity in target cancer cell lines. This method allows the identification of tumor-reactive TCRs in about two to three weeks, starting from peripheral blood samples of readily available healthy donors.Keywords: cancer, TCR, tumor antigens, immunotherapy
Procedia PDF Downloads 6964 Mineral Chemistry of Barium and Titanium-Bearing Biotite in Alkaline Trachyte from Upper Benue Valley (Northern Cameroon)
Authors: Fadimatou Ngounouno Yamgouota, Isaac Bertrand Gbambié Mbowoub, Ismaila Ngounounob
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Barium and titanium bearing biotite from alkaline trachyte of Upper Benue valley, Northern Cameroon is studied. The iron enrichment index of mica (average I.E.=0.40) is intermediate between annite and phlogopite. The biotite phenocrysts contain up to 6.2 wt. % BaO and 9.8 wt. % TiO2. The BaO content of electron-microprobe mica is positively correlated with the Al2O3, TiO2, and FeO contents, and negatively correlated with the SiO2, K2O, and MgO contents. Ba and Ti rich micas are generally found in in SiO2 deficient rocks, whereas Ba and Ti bearing mica in this study occur in silica-saturated rocks. Most of the phenocrysts analysed have deficiencies in their octahedral and interlayer sites. Deficiencies in the octahedral sites may arise from the Ti vacancy and partly the Ti tschermakite substitution. On the other hand, deficiencies in the interlayer-site are due to the replacement of K by Ba. The substitution mechanism in the Upper Benue valley mica is characterized by Ba + 2Ti + 3Al =(K + Na + Ca) + 3(Mg + Fe + Mn) + 3Si, with an excellent correlation coefficient. Biotite compositions from the Upper Benue valley area fall between the quartz-fayalite-magnetite (QFM) and nickel-nickel-oxide (NNO) oxygen fugacity buffers. All these show that Upper Benue valley mica with high Ba and Ti contents may be formed from magmas rich in these elements.Keywords: Benue valley, trachyte, biotite, mineral chemistry, enrichment
Procedia PDF Downloads 29863 Physical Activity Participation Levels as Correlates of Cardiorespiratory Fitness of Senior High School Teachers in the Dormaa East District
Authors: Isaac Yeboah, Emmanuel Osei Sarpong
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Physical activity (PA) is considered the best preventative tool for maintaining physical health and extending lifespan because it offers a range of benefits. However, for people to benefit from physical activity, it must be done at a level that can enhance fitness, health, and overall well-being. Therefore, this study aimed to determine the link between physical activity participation levels and cardiorespiratory fitness (CRF). The study employed the descriptive correlational design. The census sampling technique included all 190-teaching staff from the two senior high schools in the Dormaa East District. An adapted International Physical Activity Questionnaire (IPAQ) and standardized physical fitness tests were used for data collection. Descriptive statistics of frequency counts and percentages were used to answer the research questions while inferential statistics of Pearson Product Moment Correlation and the independent sample t-test were used to test hypotheses one and two respectively. A moderately negative (r = -.156) relationship existed between physical activity participation levels and CRF. Female teachers demonstrated a statistically significant value (p = .045) than males. The study concluded that the reported physical activity levels of the teachers did not reflect their CRF. The implication is that either the participants overestimated their physical activity participation levels, or the intensity of the activities was not high enough to affect physiological changes. For the teachers' CRF to improve, it was suggested, among other things, that regular physical activity sessions of the appropriate mixes of FITT be organized.Keywords: physical activity, participation levels, cardiorespiratory fitness, sedentary lifestyle, teachers
Procedia PDF Downloads 7062 Hydrogeophysical Investigations of Groundwater Resources and Demarcation of Saltwater-Freshwater Interface in Kilwa Kisiwani Island, Se Tanzania
Authors: Simon R. Melchioly, Ibrahimu C. Mjemah, Isaac M. Marobhe
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The main objective of this research was to identify new potential sources of groundwater resources using geophysical methods and also to demarcate the saltwater - freshwater interface. Kilwa Kisiwani Island geologically is covered mostly by Quaternary alluvial sediments, sand, and gravel. The geophysical techniques employed during the research include Vertical Electrical Sounding (VES), Earth Resistivity Tomography (ERT), and Transient Electromagnetics (TEM). Two-dimensional interpolated geophysical results show that there exist freshwater lenses formations that are potential aquifers on the Island with resistivity values ranging from 11.68 Ωm to 46.71 Ωm. These freshwater lenses are underlain by formation with brackish water in which the resistivity values are varying between 3.89 Ωm and 1.6 Ωm. Saltwater with resistivity less than 1 Ωm is found at the bottom being overlaid by brackish saturated formation. VES resistivity results show that 89% (16 out of 18) of the VES sites are potential for groundwater resources drilling while TEM results indicate that 75% (12 out of 16) of TEM sites are potential for groundwater borehole drilling. The recommended drilling depths for potential sites in Kilwa Kisiwani Island show that the maximum depth is 25 m and the minimum being 10 m below ground surface. The aquifer structure in Kilwa Kisiwani Island is a shallow, unconfined freshwater lenses floating above the seawater and the maximum thickness of the aquifer is 25 m for few selected VES and TEM sites while the minimum thickness being 10 m.Keywords: groundwater, hydrogeophysical, Kilwa Kisiwani, freshwater, saltwater, resistivity
Procedia PDF Downloads 20161 Intensity Analysis to Link Changes in Land-Use Pattern in the Abuakwa North and South Municipalities, Ghana, from 1986 to 2017
Authors: Isaac Kwaku Adu, Jacob Doku Tetteh, John Joseph Puthenkalam, Kwabena Effah Antwi
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The continuous increase in population implies increase in food demand. There is, therefore, the need to increase agricultural production and other forest products to ensure food security and economic development. This paper employs the three-level intensity analysis to assess the total change of land-use in two-time intervals (1986-2002 and 2002-2017), the net change and swap as well as gross gains and losses in the two intervals. The results revealed that the overall change in the 31-year period was greater in the second period (2002-2017). Agriculture and forest categories lost in the first period while the other land class gained. However, in the second period agriculture and built-up increased greatly while forest, water bodies and thick bushes/shrubland experienced loss. An assessment revealed a reduction of forest in both periods but was greater in the second period and expansion of agricultural land was recorded as population increases. The pixels gaining built-up targeted agricultural land in both intervals, it also targeted thick bushes/shrubland and waterbody in the second period only. Built-up avoided forest in both intervals as well as waterbody and thick bushes/shrubland. To help in developing the best land-use strategies/policies, a further validation of the social factors is necessary.Keywords: agricultural land, forest, Ghana, land-use, intensity analysis, remote sensing
Procedia PDF Downloads 15660 The “Bright Side” of COVID-19: Effects of Livestream Affordances on Consumer Purchase Willingness: Explicit IT Affordances Perspective
Authors: Isaac Owusu Asante, Yushi Jiang, Hailin Tao
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Live streaming marketing, the new electronic commerce element, became an optional marketing channel following the COVID-19 pandemic. Many sellers have leveraged the features presented by live streaming to increase sales. Studies on live streaming have focused on gaming and consumers’ loyalty to brands through live streaming, using interview questionnaires. This study, however, was conducted to measure real-time observable interactions between consumers and sellers. Based on the affordance theory, this study conceptualized constructs representing the interactive features and examined how they drive consumers’ purchase willingness during live streaming sessions using 1238 datasets from Amazon Live, following the manual observation of transaction records. Using structural equation modeling, the ordinary least square regression suggests that live viewers, new followers, live chats, and likes positively affect purchase willingness. The Sobel and Monte Carlo tests show that new followers, live chats, and likes significantly mediate the relationship between live viewers and purchase willingness. The study introduces a new way of measuring interactions in live streaming commerce and proposes a way to manually gather data on consumer behaviors in live streaming platforms when the application programming interface (API) of such platforms does not support data mining algorithms.Keywords: livestreaming marketing, live chats, live viewers, likes, new followers, purchase willingness
Procedia PDF Downloads 8259 Indigenous Knowledge Management: Towards Identification of Challenges and Opportunities in Developing Countries
Authors: Desmond Chinedu Oparaku, Emmanuel Uwazie Anyanwu, Oyemike Victor Benson, Ogbonna Isaac-Nnadimele
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The purpose of this paper is to provide a theoretical discourse that highlights the challenges associated with management of indigenous knowledge with reference to developing countries. Literature review and brainstorming were used to collect relevant data and draw inferences. The findings indicate that non-existence of indigenous knowledge management policy (IKMP), low level of partnership drive among library and information services providers, non-uniformity of format and content of indigenous knowledge, inadequate funding, and lack of access to ICTs, lack of indigenous people with indigenous expertise and hoarding of knowledge as challenges to indigenous knowledge management. The study is based on literature review and information gathered through brain storming with professional colleagues the geographic scope as developing countries. The study has birth several implication based on the findings made. Professionally, it has necessitated the need for formulating a viable indigenous knowledge management policy (IKMP), creating of collaborative network through partnership, and integration of ICTs to indigenous knowledge management practices by libraries in developing countries etc. The originality of this paper is revealed in its capability as serving as an eye opener to librarians on the need for preserving and managing indigenous knowledge in developing countries. It further unlocks the possibilities of exploring empirical based researches to substantiate the theoretical issues raised in this paper. The findings may be used by library managers to improve indigenous knowledge management (IKM).Keywords: developing countries, ICTs, indigenous knowledge, knowledge management
Procedia PDF Downloads 34258 Reducing Uncertainty in Climate Projections over Uganda by Numerical Models Using Bias Correction
Authors: Isaac Mugume
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Since the beginning of the 21st century, climate change has been an issue due to the reported rise in global temperature and changes in the frequency as well as severity of extreme weather and climatic events. The changing climate has been attributed to rising concentrations of greenhouse gases, including environmental changes such as ecosystems and land-uses. Climatic projections have been carried out under the auspices of the intergovernmental panel on climate change where a couple of models have been run to inform us about the likelihood of future climates. Since one of the major forcings informing the changing climate is emission of greenhouse gases, different scenarios have been proposed and future climates for different periods presented. The global climate models project different areas to experience different impacts. While regional modeling is being carried out for high impact studies, bias correction is less documented. Yet, the regional climate models suffer bias which introduces uncertainty. This is addressed in this study by bias correcting the regional models. This study uses the Weather Research and Forecasting model under different representative concentration pathways and correcting the products of these models using observed climatic data. This study notes that bias correction (e.g., the running-mean bias correction; the best easy systematic estimator method; the simple linear regression method, nearest neighborhood, weighted mean) improves the climatic projection skill and therefore reduce the uncertainty inherent in the climatic projections.Keywords: bias correction, climatic projections, numerical models, representative concentration pathways
Procedia PDF Downloads 12257 Ghanaian Men and the Performance of Masculinity: Negotiating Gender-Based Violence in Contemporary Ghana
Authors: Isaac Dery
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Masculinity studies have gained much purchase globally in recent decades, especially the sense in which they have produced discursive space for interdisciplinary investigations. In the light of this, there is increasing consensus among commentators that different masculinities co-exist within a particular social space. There is also a growing recognition and awareness of the merits in examining the conceptual underpinnings of masculinity (especially hegemonic masculinity) its variously contested meanings, and values, and how it contributes to violent behaviours by men. The consequences of hegemonic masculinity and its violent and traumatic impacts on men and women have been evident. The emerging call to imagine more egalitarian and complex masculinities among men has been at the centre of various discussions on the fight against violence. Some theorists argue that this violence emanates from men’s drive to live up to impossible ideals of “masculinity.” Seeking to make the connections between masculinity and gender-based violence, this paper discusses the imperative and possibilities of engaging men/boys as key actors in the campaign against violence. It is worth re-examining the ways in which men’s embodiment and performance of dangerous masculinities contribute towards violence. This paper therefore argues that empowering men to understand the implications of certain behaviours is the key in an attempt to arrest violence and its traumatic cost. This paper is situated within the thesis that there is a relationship between men’s embodiment and performance of dominant forms of masculinities, on the one hand, and violence against women and other men, on the other. Based on research conducted in northern Ghana on domestic violence, it is the argument of this paper that in order to contain violence against women, conditions of gender construction need to be problematized in a manner that will transform fundamental understandings of gender relations in society.Keywords: violence against women, masculinities, Ghana, gender
Procedia PDF Downloads 50256 Saponins from the Fruits of Solanum anguivi Reverse Hyperglycemia, Hyperlipidemia and Increase Antioxidant Status in Stretozotocin Induced Diabetic Rats
Authors: Isaac Gbadura Adanlawo, Olusola Olalekan Elekofehinti
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This work investigated the antihyperglycemic, antioxidant and antihyperlipidemic effects of saponins from the fruit of Solanum anguivi, a plant generally used in folk medicine to treat diabetes and hypertension and to compare its effect with metformin in streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in albino rats by administration of STZ (65 mg/kg) intraperitoneally. Saponin (40 and 100 mg/kg) was administered by oral gavage once daily for 21 days. Metformin (200 mg/kg b.w.) was administered as the positive control. The effect of saponin on blood glucose, serum lipids and enzymatic antioxidants defense systems, like superoxide dismutase (SOD), catalase (CAT), as well as MDA levels in serum, liver and pancreas were studied. Saponins from S. anguivi fruits reduced the blood glucose, total cholesterol (TC), triglycerides (TG) and low-density lipoprotein (LDL) levels in STZ-diabetic rats. They also significantly abolished the increase in MDA level in serum, liver and pancreas of diabetic rats. The activities of SOD and CAT in serum, liver and pancreas were significantly increased as well as concentration of HDL in the serum. Metformin had the same effect as saponin but saponins seems to be more potent in reducing serum TC, TG, LDL, and MDA, and increasing SOD and CAT. Conclusions: These results suggest that saponins from S. anguivi fruits have anti-diabetic and antihypercholesterolemic, antihypertriglyceridemic antiperoxidative activities mediated through their antioxidant properties. Also, saponins appeared to have more hypolipidemic, antiperoxidative and antioxidant activity than metformin.Keywords: saponin, diabetes, metformin, streptozotocin, Solanum anguivi
Procedia PDF Downloads 47855 Emerging Cyber Threats and Cognitive Vulnerabilities: Cyberterrorism
Authors: Oludare Isaac Abiodun, Esther Omolara Abiodun
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The purpose of this paper is to demonstrate that cyberterrorism is existing and poses a threat to computer security and national security. Nowadays, people have become excitedly dependent upon computers, phones, the Internet, and the Internet of things systems to share information, communicate, conduct a search, etc. However, these network systems are at risk from a different source that is known and unknown. These network systems risk being caused by some malicious individuals, groups, organizations, or governments, they take advantage of vulnerabilities in the computer system to hawk sensitive information from people, organizations, or governments. In doing so, they are engaging themselves in computer threats, crime, and terrorism, thereby making the use of computers insecure for others. The threat of cyberterrorism is of various forms and ranges from one country to another country. These threats include disrupting communications and information, stealing data, destroying data, leaking, and breaching data, interfering with messages and networks, and in some cases, demanding financial rewards for stolen data. Hence, this study identifies many ways that cyberterrorists utilize the Internet as a tool to advance their malicious mission, which negatively affects computer security and safety. One could identify causes for disparate anomaly behaviors and the theoretical, ideological, and current forms of the likelihood of cyberterrorism. Therefore, for a countermeasure, this paper proposes the use of previous and current computer security models as found in the literature to help in countering cyberterrorismKeywords: cyberterrorism, computer security, information, internet, terrorism, threat, digital forensic solution
Procedia PDF Downloads 9754 Design of a Thrust Vectoring System for an Underwater ROV
Authors: Isaac Laryea
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Underwater remote-operated vehicles (ROVs) are highly useful in aquatic research and underwater operations. Unfortunately, unsteady and unpredictable conditions underwater make it difficult for underwater vehicles to maintain a steady attitude during motion. Existing underwater vehicles make use of multiple thrusters positioned at specific positions on their frame to maintain a certain pose. This study proposes an alternate way of maintaining a steady attitude during horizontal motion at low speeds by making use of a thrust vector-controlled propulsion system. The study began by carrying out some preliminary calculations to get an idea of a suitable shape and form factor. Flow simulations were carried out to ensure that enough thrust could be generated to move the system. Using the Lagrangian approach, a mathematical system was developed for the ROV, and this model was used to design a control system. A PID controller was selected for the control system. However, after tuning, it was realized that a PD controller satisfied the design specifications. The designed control system produced an overshoot of 6.72%, with a settling time of 0.192s. To achieve the effect of thrust vectoring, an inverse kinematics synthesis was carried out to determine what angle the actuators need to move to. After building the system, intermittent angular displacements of 10°, 15°, and 20° were given during bench testing, and the response of the control system as well as the servo motor angle was plotted. The final design was able to move in water but was not able to handle large angular displacements as a result of the small angle approximation used in the mathematical model.Keywords: PID control, thrust vectoring, parallel manipulators, ROV, underwater, attitude control
Procedia PDF Downloads 7353 Bio-Heat Transfer in Various Transcutaneous Stimulation Models
Authors: Trevor E. Davis, Isaac Cassar, Yi-Kai Lo, Wentai Liu
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This study models the use of transcutaneous electrical nerve stimulation on skin with a disk electrode in order to simulate tissue damage. The current density distribution above a disk electrode is known to be a dynamic and non-uniform quantity that is intensified at the edges of the disk. The non-uniformity is subject to change through using various electrode geometries or stimulation methods. One of these methods known as edge-retarded stimulation has shown to reduce this edge enhancement. Though progress has been made in modeling the behavior of a disk electrode, little has been done to test the validity of these models in simulating the actual heat transfer from the electrode. This simulation uses finite element software to couple the injection of current from a disk electrode to heat transfer described by the Pennesbioheat transfer equation. An example application of this model is studying an experimental form of stimulation, known as edge-retarded stimulation. The edge-retarded stimulation method will reduce the current density at the edges of the electrode. It is hypothesized that reducing the current density edge enhancement effect will, in turn, reduce temperature change and tissue damage at the edges of these electrodes. This study tests this hypothesis as a demonstration of the capabilities of this model. The edge-retarded stimulation proved to be safer after this simulation. It is shown that temperature change and the fraction of tissue necrosis is much greater in the square wave stimulation. These results bring implications for changes of procedures in transcutaneous electrical nerve stimulation and transcutaneous spinal cord stimulation as well.Keywords: bioheat transfer, electrode, neuroprosthetics, TENS, transcutaneous stimulation
Procedia PDF Downloads 24052 The Post-Colonial Yoruba Poets as Agents of Political and Economic Emancipation in Nigeria
Authors: Isaac Alonge Olusola
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One of the major peculiarities of man is the ability to communicate and interact with language. The original Yoruba society, before the advent of the Europeans, was purely oral. That is the major means of inter- personal communication was through speaking. The abolition of slave trade by Britain marked the beginning of development of Yoruba alphabet and introduction of writing around 1800. However, most of the writing was Christian religion-focused. Later, the introduction of British colonial rule led to the introduction of writing that dwelt on political and economic emancipation. On October 1, 1960, Nigeria was granted independence by the British colonial masters and self-rule started in Nigeria. Unfortunately, the military and civilian administrations brought about political and economic oppression instead of comfort. The discomfort brought about by Nigerian political and military rulers turned the Yoruba poets to activists, reactionaries and critics. This paper will give a brief preamble on the history of Nigeria and how she got her political independence from the British in 1960. It will thereafter go further to mention some political and economic hardship brought about by Nigerian leaders. Using literary theories called semiotics and structuralism, the reactions and criticisms of some Yoruba poets will be mentioned and analyzed vis-à-vis the counter reactions of the governments in power. Moreover, the paper will bring about a conclusion on how to create a conducive atmosphere for the Yoruba poets to operate in Nigeria. Finally, suggestions will be offered on how the Nigerian government and Yoruba poets can co-exist positively to bring about a better standard of living to Nigerians and also promote good governanceKeywords: Yoruba, Yoruba language, Yoruba poets, political leaders
Procedia PDF Downloads 14151 Synthesis of Zeolites from Bauxite and Kaolin: Effect of Synthesis Parameters on Competing Phases
Authors: Bright Kwakye-Awuah, Elizabeth Von-Kiti, Isaac Nkrumah, Baah Sefa-Ntiri, Craig D. Williams
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Bauxite and kaolin from Ghana Bauxite Company mine site were used to synthesize zeolites. Bauxite served as the alumina source and kaolin the silica source. Synthesis variations include variation of aging time at constant crystallization time and variation of crystallization times at constant aging time. Characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX) and Fourier transform infrared spectroscopy (FTIR) were employed in the characterization of the raw samples as well as the synthesized samples. The results obtained showed that the transformations that occurred and the phase of the resulting products were coordinated by the aging time, crystallization time, alkaline concentration and Si/Al ratio of the system. Zeolites A, X, Y, analcime, Sodalite, and ZK-14 were some of the phases achieved. Zeolite LTA was achieved with short crystallization times of 3, 5, 18 and 24 hours and a maximum aging of 24 hours. Zeolite LSX was synthesized with 24 hr aging followed with 24 hr hydrothermal treatment whilst zeolite Y crystallized after 48 hr of aging and 24 hr crystallization. Prolonged crystallization time produced a mixed phased product. Prolonged aging times, on the other hand, did not yield any zeolite as the sample was amorphous. Increasing the alkaline content of the reaction mixture above 5M introduced sodalite phase in the final product. The properties of the final products were comparable to zeolites synthesized from pure chemical reagents.Keywords: bauxite, kaolin, aging, crystallization, zeolites
Procedia PDF Downloads 22150 Modelling Exchange-Rate Pass-Through: A Model of Oil Prices and Asymmetric Exchange Rate Fluctuations in Selected African Countries
Authors: Fajana Sola Isaac
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In the last two decades, we have witnessed an increased interest in exchange rate pass-through (ERPT) in developing economies and emerging markets. This is perhaps due to the acknowledged significance of the pattern of exchange rate pass-through as a key instrument in monetary policy design, principally in retort to a shock in exchange rate in literature. This paper analyzed Exchange Rate Pass-Through by A Model of Oil Prices and Asymmetric Exchange Rate Fluctuations in Selected African Countries. The study adopted A Non-Linear Autoregressive Distributed Lag approach using yearly data on Algeria, Burundi, Nigeria and South Africa from 1986 to 2022. The paper found asymmetry in exchange rate pass-through in net oil-importing and net oil-exporting countries in the short run during the period under review. An ERPT exhibited a complete pass-through in the short run in the case of net oil-importing countries but an incomplete pass-through in the case of the net oil-exporting countries that were examined. An extended result revealed a significant impact of oil price shock on exchange rate pass-through to domestic price in the long run only for net oil importing countries. The Wald restriction test also confirms the evidence of asymmetric with the role of oil price acting as an accelerator to exchange rate pass-through to domestic price in the countries examined. The study found the outcome to be very useful for gaining expansive knowledge on the external shock impact on ERPT and could be of critical value for national monetary policy decisions on inflation targeting, especially for countries examined and other developing net oil importers and exporters.Keywords: pass through, exchange rate, ARDL, monetary policy
Procedia PDF Downloads 8049 A Comparative Analysis of the Performance of COSMO and WRF Models in Quantitative Rainfall Prediction
Authors: Isaac Mugume, Charles Basalirwa, Daniel Waiswa, Mary Nsabagwa, Triphonia Jacob Ngailo, Joachim Reuder, Sch¨attler Ulrich, Musa Semujju
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The Numerical weather prediction (NWP) models are considered powerful tools for guiding quantitative rainfall prediction. A couple of NWP models exist and are used at many operational weather prediction centers. This study considers two models namely the Consortium for Small–scale Modeling (COSMO) model and the Weather Research and Forecasting (WRF) model. It compares the models’ ability to predict rainfall over Uganda for the period 21st April 2013 to 10th May 2013 using the root mean square (RMSE) and the mean error (ME). In comparing the performance of the models, this study assesses their ability to predict light rainfall events and extreme rainfall events. All the experiments used the default parameterization configurations and with same horizontal resolution (7 Km). The results show that COSMO model had a tendency of largely predicting no rain which explained its under–prediction. The COSMO model (RMSE: 14.16; ME: -5.91) presented a significantly (p = 0.014) higher magnitude of error compared to the WRF model (RMSE: 11.86; ME: -1.09). However the COSMO model (RMSE: 3.85; ME: 1.39) performed significantly (p = 0.003) better than the WRF model (RMSE: 8.14; ME: 5.30) in simulating light rainfall events. All the models under–predicted extreme rainfall events with the COSMO model (RMSE: 43.63; ME: -39.58) presenting significantly higher error magnitudes than the WRF model (RMSE: 35.14; ME: -26.95). This study recommends additional diagnosis of the models’ treatment of deep convection over the tropics.Keywords: comparative performance, the COSMO model, the WRF model, light rainfall events, extreme rainfall events
Procedia PDF Downloads 26248 Bioethanol Production from Wild Sorghum (Sorghum arundinacieum) and Spear Grass (Heteropogon contortus)
Authors: Adeyinka Adesanya, Isaac Bamgboye
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There is a growing need to develop the processes to produce renewable fuels and chemicals due to the economic, political, and environmental concerns associated with fossil fuels. Lignocellulosic biomass is an excellent renewable feedstock because it is both abundant and inexpensive. This project aims at producing bioethanol from lignocellulosic plants (Sorghum Arundinacieum and Heteropogon Contortus) by biochemical means, computing the energy audit of the process and determining the fuel properties of the produced ethanol. Acid pretreatment (0.5% H2SO4 solution) and enzymatic hydrolysis (using malted barley as enzyme source) were employed. The ethanol yield of wild sorghum was found to be 20% while that of spear grass was 15%. The fuel properties of the bioethanol from wild sorghum are 1.227 centipoise for viscosity, 1.10 g/cm3 for density, 0.90 for specific gravity, 78 °C for boiling point and the cloud point was found to be below -30 °C. That of spear grass was 1.206 centipoise for viscosity, 0.93 g/cm3 for density 1.08 specific gravity, 78 °C for boiling point and the cloud point was also found to be below -30 °C. The energy audit shows that about 64 % of the total energy was used up during pretreatment, while product recovery which was done manually demanded about 31 % of the total energy. Enzymatic hydrolysis, fermentation, and distillation total energy input were 1.95 %, 1.49 % and 1.04 % respectively, the alcoholometric strength of bioethanol from wild sorghum was found to be 47 % and the alcoholometric strength of bioethanol from spear grass was 72 %. Also, the energy efficiency of the bioethanol production for both grasses was 3.85 %.Keywords: lignocellulosic biomass, wild sorghum, spear grass, biochemical conversion
Procedia PDF Downloads 23647 Investigating The Effect Of Convection On The Rating Of Buried Cables Using The Finite Element Method
Authors: Sandy J. M. Balla, Jerry J. Walker, Isaac K. Kyere
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The heat transfer coefficient at the soil–air interface is important in calculating underground cable ampacity when convection occurs. Calculating the heat transfer coefficient accurately is complex because of the temperature variations at the earth's surface. This paper presents the effect of convection heat flow across the ground surface on the rating of three single-core, 132kV, XLPE cables buried underground. The Finite element method (FEM) is a numerical analysis technique used to determine the cable rating of buried cables under installation conditions that are difficult to support when using the analytical method. This study demonstrates the use of FEM to investigate the effect of convection on the rating ofburied cables in flat formation using QuickField finite element simulation software. As a result, developing a model to simulate this type of situation necessitates important considerations such as the following boundary conditions: burial depth, soil thermal resistivity, and soil temperature, which play an important role in the simulation's accuracy and reliability. The results show that when the ground surface is taken as a convection interface, the conductor temperature rises and may exceed the maximum permissible temperature when rated current flows. This is because the ground surface acts as a convection interface between the soil and the air (fluid). This result correlates and is compared with the rating obtained using the IEC60287 analytical method, which is based on the condition that the ground surface is an isotherm.Keywords: finite element method, convection, buried cables, steady-state rating
Procedia PDF Downloads 13146 Phyllantus nuriri Protect against Fe2+ and SNP Induced Oxidative Damage in Mitochondrial Rich Fractions of Rats Brain
Authors: Olusola Olalekan Elekofehinti, Isaac Gbadura Adanlawo, Joao Batista Teixeira Rocha
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We evaluated the potential neuroprotective effect of Phyllantus nuriri against Fe2+ and SNP induced oxidative stress in mitochondria of rats brain. Cellular viability was assessed by MTT reduction, reactive oxygen species (ROS) generation was measured using the probe 2,7-dichlorofluorescein diacetate (DCFH-DA). Glutathione content was measured using dithionitrobenzoic acid (DTNB). Fe2+ (10µM) and SNP (5µM) significantly decreased mitochondrial activity, assessed by MTT reduction assay, in a dose-dependent manner, this occurred in parallel with increased glutathione oxidation, ROS production and lipid peroxidation end-products (thiobarbituric acid reactive substances, TBARS). The co-incubation with methanolic extract of Phyllantus nuriri (10-100 µg/ml) reduced the disruption of mitochondrial activity, gluthathione oxidation, ROS production as well as the increase in TBARS levels caused by both Fe2+ and SNP in a dose dependent manner. HPLC analysis of the extract revealed the presence of gallic acid (20.54±0.01), caffeic acid (7.93±0.02), rutin (25.31±0.05), quercetin (31.28±0.03) and kaemferol (14.36±0.01). This result suggests that these phytochemicals account for the protective actions of Phyllantus nuriri against Fe2+ and SNP -induced oxidative stress. Our results show that Phyllantus nuriri consist important bioactive molecules in the search for an improved therapy against the deleterious effects of Fe2+, an intrinsic producer of reactive oxygen species (ROS), that leads to neuronal oxidative stress and neurodegeneration.Keywords: Phyllantus niruri, neuroprotection, oxidative stress, mitochondria, synaptosome
Procedia PDF Downloads 36045 Data and Biological Sharing Platforms in Community Health Programs: Partnership with Rural Clinical School, University of New South Wales and Public Health Foundation of India
Authors: Vivian Isaac, A. T. Joteeshwaran, Craig McLachlan
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The University of New South Wales (UNSW) Rural Clinical School has a strategic collaborative focus on chronic disease and public health. Our objectives are to understand rural environmental and biological interactions in vulnerable community populations. The UNSW Rural Clinical School translational model is a spoke and hub network. This spoke and hub model connects rural data and biological specimens with city based collaborative public health research networks. Similar spoke and hub models are prevalent across research centers in India. The Australia-India Council grant was awarded so we could establish sustainable public health and community research collaborations. As part of the collaborative network we are developing strategies around data and biological sharing platforms between Indian Institute of Public Health, Public Health Foundation of India (PHFI), Hyderabad and Rural Clinical School UNSW. The key objective is to understand how research collaborations are conducted in India and also how data can shared and tracked with external collaborators such as ourselves. A framework to improve data sharing for research collaborations, including DNA was proposed as a project outcome. The complexities of sharing biological data has been investigated via a visit to India. A flagship sustainable project between Rural Clinical School UNSW and PHFI would illustrate a model of data sharing platforms.Keywords: data sharing, collaboration, public health research, chronic disease
Procedia PDF Downloads 45144 Protective Effect of Saponin Extract from the Root of Garcinia kola (Bitter Kola) against Paracetamol-Induced Hepatotoxicity in Albino Rats
Authors: Alli Smith Yemisi Rufina, Adanlawo Isaac Gbadura
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Liver disorders are one of the major problems of the world. Despite its frequent occurrence, high morbidity, and high mortality, its medical management is currently inadequate. This study was designed to evaluate the Hepatoprotective effect of saponin extract of the root of Garcinia kola on the integrity of the liver of paracetamol induced Wistar albino rats. Twenty-five male adult Wistar albino rats were divided into five (5) groups. Group I, was the Control group that received distilled water only, group II was the negative control that received 2 g/kg of paracetamol on the 13th day, and group III, IV, and V were pre-treated with 100, 200 and 400 mg/kg of the saponin extract before inducing the liver damage on the 13th day with 2 g/kg of paracetamol. Twenty-four hours after administration, the rats were sacrificed, and blood samples were collected. The serum Alanine Transaminase (ALT), Aspartate Transaminase (AST), Alkaline Phosphatase (ALP) activities, Bilirubin and Conjugated Bilirubin, Glucose and Protein concentrations were evaluated. The liver was fixed immediately in Formalin and was processed and stained with Haematoxylin and Eosin (H&E). Administration of saponin extract from the root of Garcinia kola significantly decreased paracetamol induced elevated enzymes in the test group. Also, histological observations showed that saponin extract of the root of Garcinia kola exhibited a significant liver protection against the toxicant as evident by the cells trying to return to normal. Saponin extract from the root of Garcinia kola indicated a protection of the structural integrity of the hepatocytic cell membrane and regeneration of the damaged liver.Keywords: hepatoprotective, liver damage, Garcinia kola, saponin, paracetamol
Procedia PDF Downloads 26143 Developing Stability Monitoring Parameters for NIPRIMAL®: A Monoherbal Formulation for the Treatment of Uncomplicated Malaria
Authors: Ekere E. Kokonne, Isimi C. Yetunde, Okoh E. Judith, Okafor E. Ijeoma, Ajeh J. Isaac, Olobayo O. Kunle, Emeje O. Martins
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NIPRIMAL® is a mono herbal formulation of Nauclea latifolia used in the treatment of malaria. The stability of extracts made from plant material is essential to ensure the quality, safety and efficacy of the finished product. This study assessed the stability of the formulation under three different storage conditions; normal room temperature, infrared and under refrigeration. Differential Scanning Calorimetry (DSC) and Thin Layer Chromatography (TLC) were used to monitor the formulations. The DSC analysis was done from 0oC to 350oC under the three storage conditions. Results obtained indicate that NIPRIMAL® was stable at all the storage conditions investigated. Thin layer chromatography (TLC) after 6 months showed there was no significant difference between retention factor (RF) values for the various storage conditions. The reference sample had four spots with RF values of 0.47, 0.68, 0.76, 0.82 respectively and these spots were retained in the test formulations with corresponding RF values were after 6 months at room temperature and refrigerated temperature been 0.56, 0.73, 0.80, 0.92 and 0.47, 0.68, 0.76, 0.82 respectively. On the other hand, the RF values (0.55, 0.74, 0.77, 0.93) obtained under infrared after 1 month varied slightly from the reference. The sample exposed to infrared had a lower heat capacity compared to that stored under room temperature or refrigeration. A combination of TLC and DSC measurements has been applied for assessing the stability of NIPRIMAL®. Both methods were found to be rapid, sensitive and reliable in determining its stability. It is concluded that NIPRIMAL® can be stored under any of the tested conditions without degradation. This study is a major contribution towards developing appropriate stability monitoring parameters for herbal products.Keywords: differential scanning calorimetry, formulation, NIPRIMAL®, stability, thin layer hromatography
Procedia PDF Downloads 25742 A Sentence-to-Sentence Relation Network for Recognizing Textual Entailment
Authors: Isaac K. E. Ampomah, Seong-Bae Park, Sang-Jo Lee
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Over the past decade, there have been promising developments in Natural Language Processing (NLP) with several investigations of approaches focusing on Recognizing Textual Entailment (RTE). These models include models based on lexical similarities, models based on formal reasoning, and most recently deep neural models. In this paper, we present a sentence encoding model that exploits the sentence-to-sentence relation information for RTE. In terms of sentence modeling, Convolutional neural network (CNN) and recurrent neural networks (RNNs) adopt different approaches. RNNs are known to be well suited for sequence modeling, whilst CNN is suited for the extraction of n-gram features through the filters and can learn ranges of relations via the pooling mechanism. We combine the strength of RNN and CNN as stated above to present a unified model for the RTE task. Our model basically combines relation vectors computed from the phrasal representation of each sentence and final encoded sentence representations. Firstly, we pass each sentence through a convolutional layer to extract a sequence of higher-level phrase representation for each sentence from which the first relation vector is computed. Secondly, the phrasal representation of each sentence from the convolutional layer is fed into a Bidirectional Long Short Term Memory (Bi-LSTM) to obtain the final sentence representations from which a second relation vector is computed. The relations vectors are combined and then used in then used in the same fashion as attention mechanism over the Bi-LSTM outputs to yield the final sentence representations for the classification. Experiment on the Stanford Natural Language Inference (SNLI) corpus suggests that this is a promising technique for RTE.Keywords: deep neural models, natural language inference, recognizing textual entailment (RTE), sentence-to-sentence relation
Procedia PDF Downloads 34941 An Estimation of Rice Output Supply Response in Sierra Leone: A Nerlovian Model Approach
Authors: Alhaji M. H. Conteh, Xiangbin Yan, Issa Fofana, Brima Gegbe, Tamba I. Isaac
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Rice grain is Sierra Leone’s staple food and the nation imports over 120,000 metric tons annually due to a shortfall in its cultivation. Thus, the insufficient level of the crop's cultivation in Sierra Leone is caused by many problems and this led to the endlessly widening supply and demand for the crop within the country. Consequently, this has instigated the government to spend huge money on the importation of this grain that would have been otherwise cultivated domestically at a cheaper cost. Hence, this research attempts to explore the response of rice supply with respect to its demand in Sierra Leone within the period 1980-2010. The Nerlovian adjustment model to the Sierra Leone rice data set within the period 1980-2010 was used. The estimated trend equations revealed that time had significant effect on output, productivity (yield) and area (acreage) of rice grain within the period 1980-2010 and this occurred generally at the 1% level of significance. The results showed that, almost the entire growth in output had the tendency to increase in the area cultivated to the crop. The time trend variable that was included for government policy intervention showed an insignificant effect on all the variables considered in this research. Therefore, both the short-run and long-run price response was inelastic since all their values were less than one. From the findings above, immediate actions that will lead to productivity growth in rice cultivation are required. To achieve the above, the responsible agencies should provide extension service schemes to farmers as well as motivating them on the adoption of modern rice varieties and technology in their rice cultivation ventures.Keywords: Nerlovian adjustment model, price elasticities, Sierra Leone, trend equations
Procedia PDF Downloads 23540 Electronic Government around the World: Key Information and Communication Technology Indicators
Authors: Isaac Kofi Mensah
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Governments around the world are adopting Information and Communication Technologies (ICTs) because of the important opportunities it provides through E-government (EG) to modernize government public administration processes and delivery of quality and efficient public services. Almost every country in the world is adopting ICT in its public sector administration (EG) to modernize and change the traditional process of government, increase citizen engagement and participation in governance, as well as the provision of timely information to citizens. This paper, therefore, seeks to present the adoption, development and implementation of EG in regions globally, as well as the ICT indicators around the world, which are making EG initiatives successful. Europe leads the world in its EG adoption and development index, followed by the Americas, Asia, Oceania and Africa. There is a gradual growth in ICT indicators in terms of the increase in Internet access and usage, increase in broadband penetration, an increase of individuals using the Internet at home and a decline in fixed telephone use, while the mobile cellular phone has been on the increase year-on-year. Though the lack of ICT infrastructure is a major challenge to EG adoption and implementation around the world, in Africa it is very pervasive, hampering the expansion of Internet access and provision of broadband, and hence is a barrier to the successful adoption, development, and implementation of EG initiatives in countries on the continent. But with the general improvement and increase in ICT indicators around the world, it provides countries in Europe, Americas, Asia, Arab States, Oceania and Africa with the huge opportunity to enhance public service delivery through the adoption of EG. Countries within these regions cannot fail their citizens who desire to enjoy an enhanced and efficient public service delivery from government and its many state institutions.Keywords: e-government development index, e-government, indicators, information and communication technologies (ICTs)
Procedia PDF Downloads 303