Pricing Optimization and Control of Standalone Distributed Energy Generations

Martin Onyeka Okoye(마틴 온에카 오코에),Hak-Man Kim(김학만) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.7

Prevalence of high-risk HPV genotypes in sub-Saharan Africa according to HIV status: a 20-year systematic review

Jude Ogechukwu Okoye,Chukwudi Amaechi Ofodile,Oluwaseun Kelechi Adeleke,Okechi Obioma 한국역학회 2021 Epidemiology and Health Vol.43 No.-

OBJECTIVES: This review assessed the rate of high-risk human papillomavirus (HPV) infection among women living in sub-Saharan Africa. It also determined the prevalence of high-risk HPV (hrHPV) among human immunodeficiency virus (HIV) seropositive (HIV+) and seronegative (HIV-) women in sub-Saharan Africa, pre-2010 and post-2010. METHODS: In this systematic review, Google Scholar, PubMed Central, and Embase were searched to identify cohort and case-control studies that investigated the relationship between HIV and HPV infection. The database searches yielded 17 studies published between 1999 and 2018. RESULTS: In the general population, the prevalence of any HPV/multiple HPV infections was higher among HIV+ (53.6/22.6%) than among HIV- women (26.5/7.3%) with odds ratios of 3.22 and 3.71, respectively (95% confidence interval, 3.00 to 3.42 and 2.39 to 5.75, p<0.001). The prevalent HPV genotypes among HIV+ and HIV- women diagnosed with invasive cervical cancer (ICC) were HPV-16/18 and HPV-45. The prevalence of HPV-16, HPV-18, and HPV-45 was lower in 1999-2010 (3.8, 1.7, and 0.8%, respectively) than in 2011-2018 (19.1, 6.0, and 3.6%, respectively). Among women diagnosed with ICC, HIV+ women had a higher prevalence of HPV-56, HPV-31, and HPV-51 (7.3, 5.3, and 3.3%, respectively) than HIV- women (1.3, 2.2, and 0.4%, p<0.001, p=0.050, and p=0.013, respectively). CONCLUSIONS: The prevalence of HPV infection, multiple HPV infections, and non-vaccine HPV types were higher among HIV+ women than among HIV- women in sub-Saharan Africa. Although HIV infection influences the distribution of HPV types, this study suggests that cervical cancer incidence in sub-Saharan Africa is primarily driven by the prevalence of vaccine hrHPVs, especially HPV-16 and HPV-18.

Fischer–Tropsch synthesis: The effect of hydrophobicity on silica-supported iron catalysts

Chike George Okoye-Chine,Mahluli Moyo,Diane Hildebrandt 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.97 No.-

This work focuses on the effect of surface hydrophobicity of SiO2 supports on the performance ofSiO2-supported Fe catalysts during Fischer–Tropsch synthesis (FTS). Three different hydrophobized SiO2supports were synthesized by varying the amount of the dichlorodimethylsilane used for thehydrophobization of the hydrophilic mesoporous SiO2 gel. Fe metal of approximately 9 wt% was loadedon the hydrophilic SiO2, and three hydrophobized SiO2 supports by homogeneous depositionprecipitation. The wholly hydrophobized SiO2 surface improved the catalytic activity of Fe catalystsbecause the hydrophobized SiO2 increased the reducibility of the iron oxide and inhibited readsorption ofwater over the surface of the Fe catalyst, therefore creating more available active sites for the adsorptionof CO. Also, hydrophobized SiO2 decreased the CH4 selectivity and C2–C4 selectivity and increasedC5+ selectivity of the Fe catalysts due to the promotion of chain growth by the hydrophobized SiO2. Furthermore, the hydrophobized SiO2 decreased the CO2 selectivity of the Fe catalysts because thehydrophobized SiO2 hindered the readsorption of water over the surface of the Fe catalysts, which leadsto the inhibition of water gas shift reaction and subsequently the hindering of the CO2 formation.

Argument Alternation in Etulo

Adaobi Ngozi Okoye 세종대학교 언어연구소 2023 Journal of Universal Language Vol.24 No.1

Experiential verbs provide information on the type of stimulus experienced by an entity. The experiential verb class provides certain features across languages. One of the features concerns their ability to allow arguments to change positions in their occurrences as subjects and objects in sentential constructs without a resultant meaning change. The present study explores this verb class in Etulo, a Benue Congo language of the Niger-Congo language family. Specifically, this study attempts a description of the Etulo verbs that convey information about an entity’s experience. The features provided by the Etulo verbs are examined in line with cross linguistics features ascribed to experiential verbs. Data for the study were elicited from competent native Etulo speakers residing in Adi, Buruku local government area of Benue state, Nigeria. From the verbs examined, this study discovers that most Etulo experiential verbs allow their arguments to switch positions without any resultant change in meaning. The experiential verbs appear as predicates of involuntary activities, and additional arguments are obligatory for an animate experiencer. The study substantiates cross-linguistic findings on experiential verbs.

RSM and ANN Modeling for Production of Newbouldia Laevies Fibre and Recycled High Density Polyethylene Composite: Multi Objective Optimization Using Genetic Algorithm

Chidozie Chukwuemeka Nwobi-Okoye,Martins Kenechukwu Anyichie,Clement Uche Atuanya 한국섬유공학회 2020 Fibers and polymers Vol.21 No.4

In this study response surface methodology (RSM), artificial neural network (ANN) and non-dominated sortinggenetic algorithm-II (NSGA-II) were used for modeling and multi objective optimization of Newbouldia Laevies Fibre andrecycled high density polyethylene (RHDPE) composite for fiberboard application. The fiberboard properties optimized weremodulus of rupture (MOR), modulus of elasticity (MOE), internal bonding (IB), thickness swelling (TS) and waterabsorption (WA) whose values vary in response to changes in production process variables namely: Fibre/RHDPE (%), presspressure, press time and temperature. An experimental design using central composite design (CCD) was used to develop anRSM model for modeling the variations in physical and mechanical properties of the fiberboard in response to variations inprocess parameters. An ANN model was equally used to predict the properties of the fiberboard. Subsequently the ANN wasused as the fitness function for multi objective optimization of the fiberboard using NSGA-II. A comparative algorithm waslater developed with a traditional multi objective optimization algorithm known as desirability function using the RSMmodel. The results of the study showed that RSM and ANN effectively modeled the properties of the fiberboard. Theoptimized Pareto front of the NSGA-II algorithm was found to be an excellent design guide for practical applications of thecomposite. The superiority of NSGA-II algorithm over the desirability function as a multi objective optimization tool wasdemonstrated.

Advanced ceramic components: Materials, fabrication, and applications

Tunmise Ayode Otitoju,Patrick Ugochukwu Okoye,Guanting Chen,Yang Li,Martin Onyeka Okoye,San-xi Li 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.85 No.-

The global demand for ceramic materials with wide-ranging applications in the environment, precisiontools, biomedical, and electronics, and environmentalfields is on the increase. Several ceramic materialsand methods of fabrication have been developed with task-specific properties. The material, thefabrication methods, and processing conditions impel characteristics including corrosion-resistant,outstanding optical and electrical properties, hardness and anti-aging. In this review, various materialsfor the preparation of ceramics and ceramic composites components were investigated to demonstratethe contribution of the materials and different fabrication methods to the properties of the ceramicscomponents. The material properties, sintering temperature, casting technique, and pressure influencesthe ceramics grain size and porosity, which have an explicit effect on mechanical strength, corrosionresistant,and optical properties of the ceramic components. Thefinishing of the ceramic componentsinto a machinable shape requires careful attention to avoid defects. However, most conventionalfinishing methods are cost-intensive, hence, the need to commercialize 3-D printing for large scale andlong-run applications. It is hoped that this review would propagate wider research on low cost andenergy effective pathways to produce ceramics with dynamic properties, which can be applied in severalfields with outstanding performance.

Comparative Biological Activity of Synzygium aromaticum (L.) and Xylopia ethiopica on Rhizopetha dominica F. (Bostrychidae) and Sitophilus zeamais Motsch (Cuculionidae) in Maize Grains

Kemabonta Kehinde,Okoye Angela 한국응용곤충학회 2004 Journal of Asia-Pacific Entomology Vol.7 No.3

Powders obtained from dry ground leaves of Synzygium aromaticm (L) and Xylopia ethiopica were treated under laboratory conditions (26.4±3℃ and 70-79% r.h) for their abilities to protect grains from damage by adult Rhizopertha dominica F and Sitophilus zeamais Motsch. The adult insects were reared and tested on whole maize grains. The pow- ders were mixed with maize grains at different dosage levels ranging from 1-5% (wt/wt). S. aroma- ticum caused significantly higher mortality in the two insects than xylopia ethopica. Maize grains treated with 5% concentration of S. aromaticum caused 90 and 55% mortalities of S. zeamais and R. dominica respectively after 7 days, while X. ethiopica treated-grains caused 50 and 15% mor- talities respectively at the same time. Five % concentration of S. aromaticum inhibited F1 progeny production and adult emergence of Sitophilus zeamais. Significantly lower number of F1 adults of R. dominica emerged from grains treated with S. aromaticum when compared to adult emergence from X. ethiopica-treated grains. The powders signi- ficantly increased the developmental period of the two insects when compared to the control except in X. ethiopica that had no significant effect on S. zeamais.

Comparative Biological Activity of Synzygium aromaticum (L.) and Xylopia ethiopica on Rhizopetha dominica F. (Coleoptera: Bostrychidae) and Sitophilus zeamais Motsch (Coleoptera: Cuculionidae) in Maize Grains

Kehinde, Kemabonta,Angela, Okoye Korean Society of Applied Entomology 2004 Journal of Asia-Pacific Entomology Vol.7 No.3

Powders obtained from dry ground leaves of Synzygium aromaticm (L) and Xylopia ethiopica were treated under laboratory conditions (26.4$\pm\;3^{\circ}$ and 70-79% r.h) for their abilities to protect grains from damage by adult Rhizopertha dominica F and Sitophilus zeamais Motsch. The adult insects were reared and tested on whole maize grains. The powders were mixed with maize grains at different dosage levels ranging from 1-5% (wt/wt). S. aromaticum caused significantly higher mortality in the two insects than xylopia ethopica. Maize grains treated with 5% concentration of S. aromaticum caused 90 and 55% mortalities of S. zeamais and R. dominica respectively after 7 days, while X. ethiopica treated-grains caused 50 and 15% mortalities respectively at the same time. Five % concentration of S. aromaticum inhibited F1 progeny production and adult emergence of Sitophilus zeamais. Significantly lower number of F1 adults of R. dominica emerged from grains treated with S. aromaticum when compared to adult emergence from X. ethiopica-treated grains. The powders significantly increased the developmental period of the two insects when compared to the control except in X. ethiopica that had no significant effect on S. zeamais.

Effect of storage on the levels of sodium benzoate in soft drinks sold in some Nigerian market with exposure and health risk assessment

Joseph Segun Akolawole,Patrice Anthony Chudi Okoye,Daniel Omokpariola 환경독성보건학회 2022 환경독성보건학회지 Vol.37 No.4

Soft drinks consumption is still a controversial issue for public health and public policy, as the influence storage condition impacts taste, color and shelf life. In all, fifty (50) soft drinks samples, acquired from Enugu, Aba, Asaba, Onitsha and Owerri markets in Nigeria, were subjected to four different storage conditions namely: room temperature (RT), refrigerated (RF), 40 °C and 60 °C for 15 days after which they were analyzed for sodium benzoate concentration using HPLC – UV/Vis detector. The results showed on the average that at RT and RF, soft drinks from Aba had the highest concentration of sodium benzoate (98.7 mg/L and 112.9 mg/L) respectively while samples from Asaba had least concentration of 39.9 mg/L and 38.1 mg/L. At increased temperature of 40 °C, the concentration of sodium benzoate increased generally across the sample, while at 60 °C, the levels in all the samples analyzed were either reduced to less than 50% or below detection level, which suggest that degradation of sodium benzoate at this elevated temperature could result in benzene formation, which is a known carcinogen. Carcinogenic and non-carcinogenic risk assessment showed that children are at risk compared to adults due to higher sodium benzoate daily intake leading to high rate of hyperactivity in correlation to malaise.

Perceptions of the COVID-19 vaccine and willingness to receive vaccination among health workers in Nigeria

Oluseyi Ademola Adejumo,Olorunfemi Akinbode Ogundele,Cynthia Roli Madubuko,Rosena Olubanke Oluwafemi,Ogochukwu Chinedum Okoye,Kenechukwu Chukwuemeka Okonkwo,Sunday Samson Owolade,Oladimeji Adedeji Jun 질병관리본부 2021 Osong Public Health and Research Persptectives Vol.12 No.4

Objectives: The study aimed to examine health workers’ perceptions of the coronavirus disease 2019 (COVID-19) vaccine in Nigeria and their willingness to receive the vaccine when it becomes available.Methods: This multi-center cross-sectional study used non-probability convenience sampling to enroll 1,470 hospital workers aged 18 and above from 4 specialized hospitals. A structured and validated self-administered questionnaire was used for data collection. Data entry and analysis were conducted using IBM SPSS ver. 22.0.Results: The mean age of respondents was 40±6 years. Only 53.5% of the health workers had positive perceptions of the COVID-19 vaccine, and only slightly more than half (55.5%) were willing to receive vaccination. Predictors of willingness to receive the COVID-19 vaccine included having a positive perception of the vaccine (adjusted odds ratio [AOR], 4.55; 95% confidence interval [CI], 3.50−5.69), perceiving a risk of contracting COVID-19 (AOR, 1.50; 95% CI, 1.25–3.98), having received tertiary education (AOR, 3.50; 95% CI, 1.40−6.86), and being a clinical health worker (AOR, 1.25; 95% CI, 1.01−1.68).Conclusion: Perceptions of the COVID-19 vaccine and willingness to receive the vaccine were sub-optimal among this group. Educational interventions to improve health workers' perceptions and attitudes toward the COVID-19 vaccine are needed.