INTELLIGENT ADVISORY SYSTEM FOR SUPPORTING COMPUTER-BASED AUTHENTICATION USERS

Authentication is one of the cornerstones of computer security systems today, and most users of computers interact withthese mechanisms on a daily basis. However, human factor has often been described as one of the weakest part of computersecurity as users of authentication are often identified to be the weakest link in the security chain. In related development ithas been demanding to merge usability with security in the choice of authentication method by computer users. To addressthe serious problem, this paper presents an intelligent advisory system based on artificial neural network that can assist usersof authentication systems on making decision on the authentication method that best suits them.Keywords: Intelligent, Advisory system, Authentication, Human Factor

Emergence and spread of two SARS-CoV-2 variants of interest in Nigeria.

Identifying the dissemination patterns and impacts of a virus of economic or health importance during a pandemic is crucial, as it informs the public on policies for containment in order to reduce the spread of the virus. In this study, we integrated genomic and travel data to investigate the emergence and spread of the SARS-CoV-2 B.1.1.318 and B.1.525 (Eta) variants of interest in Nigeria and the wider Africa region. By integrating travel data and phylogeographic reconstructions, we find that these two variants that arose during the second wave in Nigeria emerged from within Africa, with the B.1.525 from Nigeria, and then spread to other parts of the world. Data from this study show how regional connectivity of Nigeria drove the spread of these variants of interest to surrounding countries and those connected by air-traffic. Our findings demonstrate the power of genomic analysis when combined with mobility and epidemiological data to identify the drivers of transmission, as bidirectional transmission within and between African nations are grossly underestimated as seen in our import risk index estimates

Mathematical Modeling of a Flat Plate Solar Collector with Eutectic Salts as Phase Change Material

Solar energy is the most promising heat source for meeting energy demand without having negative impact on the environment. Solar energy is, however, intermittent in nature and time dependent energy source. In order to mitigate the intermittent supply of solar energy for water heating, the use of phase change material (PCM) comes into play. The PCM acts as a heat source for the solar heating system when the intensity of the solar radiation is low or no longer active.  Knowledge about the thermal effectiveness of solar collector with PCM is paramount. So, this study developed a mathematical model to evaluate the thermal behavior of a flat plate solar collector integrated with a phase change material (PCM). This mathematical model developed for the flat-plate with PCM was based upon the conservation and heat transfer equations and used to predict the thermal behavior of integrated phase change material in solar collector during thermal storage. The energy balance equations for the flat-plate heating components of the collector and PCM were formulated numerically. The model was used to investigate the effect of inlet water temperature, water mass flow rate, outlet water temperature and the melt fraction during charging and discharging modes at each of the respective nodes. A comparison was made with a collector with and without PCM. The results show that charging and discharging processes of PCM have multiple stages.  The addition of PCM in the first stage causes a decrease in temperature during charging and an increase during discharging. The highest water temperatures reached for the collector without and with a phase change material were approximately 51 and 74°C respectively Comparisons were also made between the simulated and experimental data for the solar water heater without and with PCM. Minimum inlet water temperatures of 41.54 and 36°C were observed for the simulated and experimental model while, 42.69 and 74°C were both recorded for outlet temperatures respectively, for solar water heater without PCM. For the solar water heater with PCM, the inlet temperatures for the simulation and experimental model were found to be 42°C and 56°C respectively. A maximum outlet water temperature of 108°C was obtained from the experimental model compared to 45°C obtained from    simulation.  The temperature of the hot water obtained was remarkable and sufficiently enough for many domestic and industrial applications. Finally, the solar water heating system with phase change materials finds useful application and acts as a renewable energy resource in regions where there is   inconsistent or poor sunlight