Plasma oxidation of liquid precursors for complex metal oxides.

Clean energy production and storage are two of the most significant challenges in the 21st century currently limited by the discovery and development of new and advanced materials. Complex oxides and alloys made using earth-abundant elements will play a crucial role in technology development moving forward, however, current preparation techniques are limited by their inability to produce complex oxides and alloys with precise composition control at fast timescales. A concept was proposed to produce mixed metal oxides with composition control through the oxidation of liquid precursors via plasma oxidation. It was hypothesized that the oxidation process can be completed in fast timescales owing to the rapid heating and cooling of the plasma process. Even though the rapid timescales for oxidation can be understood through fast heating processes during plasma exposure, the mechanisms responsible for composition control are not immediately obvious. So, fundamental experiments were carried out to elucidate the nucleation and growth steps responsible for metastable non-stoichiometric oxide formation. Interrupted oxidation experiments completed within twenty seconds revealed the following steps during plasma exposure of liquid droplets: the nucleation of monometallic oxide phases from an amorphous nutrient, solid-state reaction into intermediate mixed oxide phase, and formation of metastable phase. Evidence also suggests the fast kinetics of the oxidation process depends on the enormous heat released from the recombinative reactions among plasma species present in the plasma. The viability of a select set of plasma-synthesized oxides were tested in energy conversion and storage technologies. The technique was successfully used to synthesize W0.99Ir0.01O3-δ alloy which showed high oxygen evolution reaction (OER) activity and stability in acid with an overvoltage reduction in the excess of 500 mV compared to the same composition prepared via standard thermal oxidation route. The structural dilution of iridium with earth-abundant tungsten will enable the efficient use of scarce iridium resources. In alkaline media OER, charge-transfer type double perovskite (La0.9Ca0.1Co0.5Ni0.5O3-δ) prepared via the rapid plasma method shows excellent activity rivaling best performing complex oxide electrocatalysts. Most importantly, the obtained experimental data, combined with density functional theory calculations allows for relating the high OER activity to the strong hybridization of the transition metal 3d and oxygen 2p bands. Again, this technique has been used to fabricate manganese-enriched nickel-manganese-cobalt (NMC) oxides. The resulting NMC materials were tested as cathodes in lithium ion battery and show competitive results compared with NMCs prepared through other routes. This dissertation presents a concept utilizing plasma oxidation of liquid precursors for composition control of complex oxides and alloys. The presented concept could expedite the accelerated discovery and development of advanced materials for energy conversion and storage. Furthermore, the underlying nucleation and growth mechanistic aspects for forming non-stoichiometric oxide phases will add scientific knowledge to our understanding of the synthesis of materials far from equilibrium

Investigation on the Importance of Medicinal Plants Used in Treating Ailments in Ekiti-State, Southwest Zone, Nigeria

The demograhic characteristcs of the respondents shown that 60 years old respondents shown better intrest in the identification and collection of medicinal plants to treat various ailments. 59.76% of the respondents were illeterates but the  vast experiences and the believe they have developed because of the effectiveness  of the medicinal plants made the use to be preffered in the study area. The study showed the identification and collection of 50 botanicals belonging to 29 families. The respondents were quiet familiar with the various diseases symptoms whereby 15 diseases such as malaria, typhoid fever, pains of divers kinds, hypertention, diabetics, dysentry, microbial diseases and several others were identified. 16 botanicals were found use as singly or an individual while 44 other botanicals belonging to 13 families were found used as a combination of two or more plants in a single herbal preparation. The  mode of preparation were mostly orally while the methods of preparation was mainly by infusion and decoction. However, the dosage and precaution were not scientifically proved.

Sero-prevalence and associated risk factors of Hepatitis B among adults attending selected government hospitals in Nigeria

Hepatitis B virus (HBV) infection is one of the major public health problems globally. This study aims to determine the frequency of occurrence of HBV infection and associated risk factors for acquisition of the disease in clinically-ill adult patients attending selected government hospitals in Ondo State, Nigeria. Seven hundred and sixty-seven (767) ill adult individuals attending five medical out-patient Departments of the hospitals who consented to the study were recruited for the investigation. A structured questionnaire which covered sociodemographic characteristics and risk factors were used for primary information. Positivity for HBV was determined using a quality assured commercial enzyme linked immunosorbent assay (ELISA) kit for the detection of Hepatitis B surface antigen (HBsAg). Of the 767 patients, 11.0% were positive for HBsAg. The prevalence rate for HBsAg positivity was higher in the males (13.5%) than the females (9.3%) (pv = 0.043). The study also revealed the highest prevalence rate of HBsAg infection among the age group 19 – 39 years with mean percentage of 17.5%. Alcohol consumption, history of HBV in the family, multiple sex partners, history of injections in road side chemist shops, and intake of traditional herbs showed significant association respectively (p < 0.05), however no significant association among individuals with history of HBV vaccination, blood transfusion and tattoo/tribal mark (p > 0.05). Conclusively, this study gives information on the prevalence rate of HBV in the community sampled to be 11.0%. This shows that HBV is endemic in Ondo State, Southwest Nigeria

Seroprevalence and associated risk factors of hepatitis E virus infection among pregnant women attending Maiduguri teaching hospital, Nigeria

Background: Hepatitis E Virus (HEV) is a major public health problem in developing countries and often fatal among pregnant women in the third trimester. Objectives: The study investigated the sero-prevalence and risk factors of HEV infection among pregnant women attendee of University of Maiduguri Teaching Hospital, Maiduguri, Nigeria. Methods: The cross-sectional study was carried out between 4th January 2016 to 30th May, 2016. One hundred and eighty blood samples from pregnant women who consented and enrolled for the study were analyzed for anti – HEV IgM using a quality assured commercial Enzyme Linked Immunosorbent Assay (ELISA) kit. Structured questionnaires were used to collate the sociodemographic characteristics and risk factor of study subjects. Results: Out of the 180 pregnant women sampled, the anti-HEV IgM seroprevalence of 13.3% was recorded.  The seroprevalence was significantly higher in the age range of 31 – 35 years (26.5%) and least in age range ≤ 20 years (4.9%) (p=0.009).  The highest seroprevalence was recorded in the third trimester 14.1% followed by second (p>0.05). After logistic regression, nature of toilet system, and source of water consumption were significant risk factors for active HEV infection (p˂0.05). Conclusion: Based on the 10.8 % pooled national prevalence of HEV infection in Nigeria, this study recorded a significantly high level of anti – HEV IgM seropositivity, an indication of recent and active HEV infection among pregnant women at the study area. Also, these infections are most among the pregnant women in their third trimester. HEV infection was related to personal, water and environmental hygiene

An assessment of geographical access and factors influencing travel time to emergency obstetric care in the urban state of Lagos, Nigeria

Previous efforts to estimate the travel time to comprehensive emergency obstetric care (CEmOC) in low- and middle-income countries (LMICs) have either been based on spatial models or self-reported travel time, both with known inaccuracies. The study objectives were to estimate more realistic travel times for pregnant women in emergency situations using Google Maps, determine system-level factors that influence travel time and use these estimates to assess CEmOC geographical accessibility and coverage in Lagos state, Nigeria. Data on demographics, obstetric history and travel to CEmOC facilities of pregnant women with an obstetric emergency, who presented between 1st November 2018 and 31st December 2019 at a public CEmOC facility were collected from hospital records. Estimated travel times were individually extracted from Google Maps for the period of the day of travel. Bivariate and multivariate analyses were used to test associations between travel and health system-related factors with reaching the facility >60 minutes. Mean travel times were compared and geographical coverage mapped to identify ‘hotspots’ of predominantly >60 minutes travel to facilities. For the 4005 pregnant women with traceable journeys, travel time ranges were 2–240 minutes (without referral) and 7–320 minutes (with referral). Total travel time was within the 60 and 120 minute benchmark for 80 and 96% of women, respectively. The period of the day of travel and having been referred were significantly associated with travelling >60 minutes. Many pregnant women living in the central cities and remote towns typically travelled to CEmOC facilities around them. We identified four hotspots from which pregnant women travelled >60 minutes to facilities. Mean travel time and distance to reach tertiary referral hospitals were significantly higher than the secondary facilities. Our findings suggest that actions taken to address gaps need to be contextualized. Our approach provides a useful guide for stakeholders seeking to comprehensively explore geographical inequities in CEmOC access within urban/peri-urban LMIC settings

An assessment of geographical access and factors influencing travel time to emergency obstetric care in the urban state of Lagos, Nigeria.

Previous efforts to estimate the travel time to comprehensive emergency obstetric care (CEmOC) in low- and middle-income countries (LMICs) have either been based on spatial models or self-reported travel time, both with known inaccuracies. The study objectives were to estimate more realistic travel times for pregnant women in emergency situations using Google Maps, determine system-level factors that influence travel time and use these estimates to assess CEmOC geographical accessibility and coverage in Lagos state, Nigeria. Data on demographics, obstetric history and travel to CEmOC facilities of pregnant women with an obstetric emergency, who presented between 1st November 2018 and 31st December 2019 at a public CEmOC facility were collected from hospital records. Estimated travel times were individually extracted from Google Maps for the period of the day of travel. Bivariate and multivariate analyses were used to test associations between travel and health system-related factors with reaching the facility >60 minutes. Mean travel times were compared and geographical coverage mapped to identify 'hotspots' of predominantly >60 minutes travel to facilities. For the 4005 pregnant women with traceable journeys, travel time ranges were 2-240 minutes (without referral) and 7-320 minutes (with referral). Total travel time was within the 60 and 120 minute benchmark for 80 and 96% of women, respectively. The period of the day of travel and having been referred were significantly associated with travelling >60 minutes. Many pregnant women living in the central cities and remote towns typically travelled to CEmOC facilities around them. We identified four hotspots from which pregnant women travelled >60 minutes to facilities. Mean travel time and distance to reach tertiary referral hospitals were significantly higher than the secondary facilities. Our findings suggest that actions taken to address gaps need to be contextualized. Our approach provides a useful guide for stakeholders seeking to comprehensively explore geographical inequities in CEmOC access within urban/peri-urban LMIC settings

A Computational Study on the Use of an Aluminium Metal Matrix Composite and Aramid as Alternative Brake Disc and Brake Pad Material

A computational model for the heat generation and dissipation in a disk brake during braking and the following release period has been formulated. The model simulates the braking action by investigating the thermal behaviour occurring on the disc and pad surfaces during this period. A comparative study was made between grey cast iron (GCI), asbestos, Aluminium metal matrix composite (AMC), and aramid as brake pad and disc materials. The braking process and following release period were simulated for four material combinations, GCI disc and Asbestos pad, GCI disc and Aramid pad, AMC disc and Asbestos pad, AMC disc and Aramid pad using COMSOL Multiphysics software. The results show similarity in thermal behaviour at the contact surface for the asbestos and aramid brake pad materials with a temperature difference of 1.8 K after 10 seconds. For the brake disc materials, the thermal behaviour was close, with the highest temperature difference being 9.6 K. The GCI had a peak temperature of 489 K at 1.2 seconds and AMC was 465.5 K but cooling to 406.4 K at 10 seconds, while the GCI was 394.7 K

Effect of Covid-19 on the Socio-Economic Well-Being of Households in Nigeria

This study investigated the effect of COVID-19 on the socio-economic well-being of households in Nigeria. The main objective is to investigate the effect of COVID-19 on households' income, employment, expenditure and savings in Ayobo-Ipaja Local Council Development Area of Lagos State, Nigeria. The descriptive non-experimental qualitative study used structured questionnaire to collect data from men and women of working ages between 25 and 65 in Ayobo-Ipaja. Convenience non-probability random sampling technique was used to select 384 participants. The data were analyzed using frequency, percentage, mean, standard deviation and chi-square test. The findings revealed that there are 186 (52.7%) male and 167 (47.3%) female who participated in the survey. 229 (64.9%) study participants were employed either in public or private establishments. 211(59.8%) earned less than N90,000, while 84(23.8%) earned more than N90,000, and at least 219 (62.0%) households were affected by COVID-19 outbreak. The chi-square results revealed that COVID-19 outbreak has significant effect on households' income, employment, expenditure and savings in Ayobo-Ipaja Local Council Development Area of Lagos State. 204 (57.8%) participants agreed that their daily/weekly/monthly earnings fell; 177 (50.1%) agreed that customers were restricted from patronizing their wares/goods/stocks; 240 (68%) opined that their family financial upkeep increased, and 235 (66.6%) suggest that their family lived on savings during the COVID-19 outbreak and lockdown. It is recommended that government should intensify policy efforts towards economic growth recovery and poverty alleviation programs for increased social inclusion by creating jobs and providing support for the vulnerable citizen

Changes in Lipid Profiles and Other Biochemical Parameters in HIV-1 Infected Patients Newly Commenced on HAART Regimen

Abnormalities of lipid metabolism are common in human immunodeficiency virus (HIV)-infected patients and tend to be accentuated in those receiving antiretroviral therapy, particularly with protease inhibitors (PIs). However, there is a dearth of information on serum lipid profiles and biochemical parameters among treatment-naive HIV-positive patients in our environment. We found that after 24 months of highly active antiretroviral therapy (HAART), there was a significant increase in serum lipids. After 24 months of HAART, renal impairment was associated with a low increase in mean HDL and a high increase in triglycerides (TG). In conclusion, abnormality of serum lipid is common and showed female preponderance among treatment-naive HIV patients in our environment. Patients with HIV infection on HAART should be screened for lipid disorders given their high prevalence as observed in this study, because of its potential for morbidity and mortality in patients on HAART