Reacting System of Variable Viscosity on Mhd Mixed Convection over a Stratified Porous Wedge.

The reacting system of variable viscosity on MHD mixed convection over a stratified porous wedge has been studied in the presence of suction or injection. The wall of the wedge is embedded in a uniform Darcian porous medium in order to allow for possible fluid wall suction or injection and has a power-law variation of the wall temperature. An approximate numerical solution for the steady boundary-layer flow over a wall of the wedge has been obtained by solving the governing equation analytically and with the help of a computer program (MAPLE). The results were illustrated graphically and necessary conclusions were derived. Keywords: Reacting system, Variable viscosity, Magneto hydrodynamics (MHD), Mixed Convection, Porous Wedge, suction, injection, power-law, boundary layer flow.

Antimicrobial Activities of Ginger (Zingiber officinale) and Garlic (Allium Sativum) Against Selected Pathogenic Organisms

Garlic and ginger samples were collected and their bio active components were determined using standard methods. Bio active components of ginger were found to include Saponins, Glycosides, Akaloids, Flavonoids, Tannis, Terpernoides while garlic tested positive to only Cardiac glycosides. Pseudomonas aueroginosa, Klebsiella pneumonia, Staphylococcus aureus were the test organisms. Antimicrobial activities were tested on Klebsiella pnuemoniae, Staphyloccus aureus, and Pseudomonas aeroginosa using Antibiotic sensitivity disc and zone of clearance was highest with Ciprofloxacin but resistant with Meropenem and Cefuroxime sodium respectively. Kirby- Baucer method disc diffusion method was used to test the effectiveness of extracts against selected pathogenic bacteria. Pseudomonas aueroginosa was susceptible to various dilutions (10-1 – 10-7) of extracts of ginger and ethanol (51 – 15mm) but more susceptible to extracts of garlic and ethanol (59 – 22mm) and resistant to some dilutions of extracts of garlic and ginger in combination (18 – 0mm). Staphylococcus aureus was susceptible to garlic and ethanolic extracts (44 – 19mm), more susceptible to extracts of ginger and garlic in ethanol (51 – 19mm) but resistant to some dilutions of aqueous and ethanolic ginger extracts. Klebsiella pneumonia was resistant to both aqueous and ethanolic extracts at various dilutions singly and in combination. It is however susceptible to the extracts at 10-1 dilutions except in ginger warm aqueous extract and garlic cold aqueous extract where it is resistant. The study therefore prove the potency of ginger and garlic in treatment of certain pathogenic bacteria infections. Keywords: Pathogenic, garlic, ginger, extracts, zone of clearance. DOI: 10.7176/JBAH/12-24-01 Publication date: December 31st 2022

System Dynamics Simulation of Selected Composite Landfill Liners for Leachate Containment

The disposal of wastes through landfiling is becoming increasingly acceptable worldwide. Its attendant leachate pollution is however a source of concern to the 21st century environmental engineering researchers. This paper therefore focuses on the application of system dynamics modeling technique in simulating the breakthrough times of selected composite liners in order to determine their effectiveness in leachate containment. Four (4) composite liners were studied viz: High Density Polyethylene (HDPE) and Low Density Polyethylene (LDPE); Geotextile and Geonet; Geosynthetic Clay Liner (GCL) and Compacted Clay Liner (CCL); and Silt and Sand. Governing equations coded in Visual Basic computer programming language based on the principles of system dynamics modeling was applied in the determination of retention abilities of the selected liners. Notable properties of the liners like Hydraulic Conductivity, Permeability, Porosity and Hydraulic Head were employed in model validation. Other inputs include the Thickness, Placement Slope and Insertion Depth of the liners. The interrelationship of the properties and breakthrough times was determined through simulation processes using STELLA 9.1.4 software.of the composite liners studied, HDPE-LDPE combination was found to be the most effective with the longest breakthrough time. The Geotextile-Geonet combination however has the highest leakage rate. The study therefore recommends the use HDPE-LDPE liner combination for use in landfill leachate retention. Keywords: system dynamics, leachate, landfill, composite liner, breakthrough tim

Performance Evaluation of a Hybrid Fractional Carrier Frequency Offset Estimator in OFDM

The major drawback of the orthogonal frequency division multiplexing (OFDM) system is high sensitivity to synchronization errors caused by carrier frequency offsets (CFOs), which result in degradation in the bit error rate (BER) performance. This paper investigates the performance of a hybrid fractional carrier frequency offset estimator (FCFOE) for frequency synchronization in the OFDM system. The hybrid FCFOE exploits the pilots inserted within the OFDM symbol for channel estimation together with the information inherent in the cyclic prefix (CP), with a view to improving the estimation of the CP-based FCFOE. The performance of the developed hybrid FCFOE was evaluated in terms of the mean squared error (MSE) and bit error rate (BER) using OFDM-QPSK and OFDM-16QAM schemes it turn. The simulation results show that the hybrid FCFOE only gives slightly better performance over the CP-based FCFOE; but the performance enhancement of the hybrid FCFOE is noticeable in OFDM-16QAM. Keywords: Carrier frequency offset estimation, Hybrid, Orthogonal frequency division multiplexing, Synchronization, Maximum likelihood, Cross-correlation

Effect of semen extenders on the motility and viability of stored African Catfish ( Clarias gariepinus ) spermatozoa

This study assessed the effects of common extenders and diluents on the spermatozoa of African catfish ( Clarias gariepinus ), with the intent of obtaining a semen preservation protocol that can serve as a means of making fingerlings available to fish farmers all year round. Semen samples (milt) were pooled from mature broodstock males and pre-extension qualities were evaluated. Egg yolk, tomato juice and sodium citrate buffers were combined in four different trials and used to preserve obtained semen at temperatures of 5\ub0C and -40\ub0C for 8 days and 4 weeks respectively in different trials. Motility indices of extended, preserved, refrigerated and frozen semen were used to analyze the effect of the various combinations. Forward, progressive and rectilinear motion was employed as a significant measurement of the livability of extended sperm cells and the efficacy of the extender solution. The result of the study showed that the buffer (sodium citrate) on its own performed excellently well (sperm motility was 85%) in enhancing survival within the first 24-48 hours post extension; Semen extended with 20% tomato juice gave the best survival rate when stored at 5\ub0C, because the sperm cells were still viable by day 6 post- extension. Extender containing 20% egg yolk gave 70% motility while that containing 10% egg yolk mixed with 10% tomato juice gave 60% motility. However, motility decreased progressively as the period of storage increased. The results of the effect of freezing (at -40\ub0C) on motility revealed that no motility was observed in all the cryopreserved trials except the sample containing 10% egg yolk and 10% tomato juice, which recorded 10% post-thaw motility

Carryover effect on carcass characteristics of growing rabbits from does subjected to feed restriction during pregnancy with or without vitamin E inclusion

Several studies have been carried out on quantitative feed restriction and its impact on carcass characteristics of growing rabbits and findings concluded that feed restriction helps in reducing carcass fat deposition in growing rabbits. Feed restriction during breeding periods have been carried out extensively in pregnant rabbit does, however, the carryover effect on the carcass characteristics of growing rabbits from does subjected to such feeding regimen have not been examined. A total of one hundred and eighty (180) weaned rabbits harvested from rabbit does subjected to maternal feed restriction (0% and 15% feed restriction) at three pregnancy periods (15-19 days, 20-24 days and 25-29 days) with or without (+/-) vitamin E were profiled for this study. Kits were randomly assigned to 12 treatments of 5 replicates, each consisting of 3 rabbits per replicate. Data obtained for carcass weight, dressed weight, chest, back, hindlimb, forelimbs, loin, back, kidney, liver, spleen, lungs and heart; these were arranged in a 2×3×2 factorial arrangement. Significantly (p<0.05) higher carcass weight and dressing percentage were obtained for growing rabbit from does fed ad libitum during pregnancy. However, significant influence recorded for carcass and dressing percentage cannot be attributed solely to the treatment during gestation since all results obtained were within acceptable or recommended ranges for healthy rabbits. Therefore, it can be concluded that maternal feed restriction during pregnancy positively influence carcass yield and dressing percentage of growing rabbits from does subjected to feed restriction between 20 – 24 days with or without Vitamin E was influenced (p<0.05)

Pharyngo-cutaneous fistula post total-laryngectomy: A local experience

Background: Pharyngo-cutaneous fistula is a major complication of total laryngectomy. Despite its significant impact on the patients' nutrition and management outcome, there is lack of consensus for recognising high-risk patients and factors associated with fistula formation. Hence, this study was aimed at determining the incidence of pharyngocutaneous fistula and factors associated with fistula formation.Methods: A retrospective collection of data on all cases of laryngeal cancer diagnosed histologically and had total laryngectomy, in the  Otorhinolaryngology Department of a tertiary centre in Southwestern, Nigeria, from 2007 – 2016. The data collected includeage, gender, tumour stage, tracheostomy, adjuvant therapy extent of laryngectomy procedure and factors for pharyngo-cutaneous fistula.Results: Forty-two patients had total laryngectomy, male to female ratio was 7.4:1 and mean age was 52.3 ± 2.1 years. All patients had pathological diagnosis of stage 3 (83.3%) and stage 4 (16.7%) laryngeal cancer, respectively. The incidence of pharyngo-cutaneous fistula was11.9% and the factors related to fistula formation were prior radiotherapy treatment and diabetes. Age, gender, neck dissection procedures, site of primary tumor and emergency tracheostomy did not contribute to fistula formation. Spontaneous fistula closure was achieved in all cases except one patient who had surgical closure.Conclusion: Pharyngo-cutaneous fistula formation post-surgery is related to the presence of co-morbidities. The high percentage of spontaneous closure underscores the need for a conservative management approach. Keywords: Laryngeal Cancer, Laryngectomy, Neck dissection, Pharyngo-cutaneous fistula, Post-surgery, Radiotherap

Microbial population, identification and in vitro studies of West African Dwarf goats fed diets with or without urea treated corncob

Corncob is an agricultural by-product emanating from harvested maize which is considered as waste after maize seeds/grains are removed either in fresh or dry form. Effort can be made to fortify and utilise it as feed for ruminant animals using some substances. Thus, a study was conducted to evaluate microbial population, identification and in vitro studies of West African Dwarf (WAD) goats fed diets with or without urea treated corncob. Sixteen WAD goats of four animals/treatment were randomly allotted to four dietary treatments comprising of T1 (diet without urea treated corncob); T2 (diet with corncob treated with 1.5% urea); T3 (diet with corncob treated with 2% urea); and T4 (diet with corncob treated with 2.5% urea). The diets were fed for 12 weeks after which rumen liquor was collected from the animals for evaluations and in vitro studies. Data obtained were analysed using one-way ANOVA at 5% probability level. Results obtained revealed that bacteria population was highest (p<0.05) and lowest with values of 1.60 and 1.02×104cfu/ml, respectively for goats fed T3 and T2. Bacteria isolates common to all the treatments included Streptococcus faecalis and Eschericia coli; while Penicillin notatum was for fungi. TI had the highest significant (p<0.05) values for in vitro  parameters like gas production at 33rd, 42nd and 45th hours of incubation; dry matter digestibility (41.67%) and CO2 (15.00ml/200mg DM). It could be concluded from the study that inclusion of urea treated corncob generally improved microbial population, reduced value for CO2, whereas T1 had highest dry matter digestibility

Factors Influencing the Practice of Exclusive Breast Feeding in Rural Communities of Osun State, Nigeria.

This randomised cross-sectional study aims at identifying factors that influence the practice of Exclusive Breast-Feeding(EFB) in rural communities of Osun-State, Nigeria. The sample size consists of four hundred and eighty (480) nursing mothers drawn randomly from five (5) selected communities (Aayegbogbo,Ola, Isoko, Ilawo and Masifa). Data were analysed using simple percentage and chi-square at 0.05 level of significance. The study reveals a high percentage (80%) resistance to change from Inclusive Breast Feeding (IBF) to Exclusive Breast Feeding (EBF). The identified factors that influence the practice of EBF includes; nursing mother’s age, marital status, occupation, education, parity and financial status of the family. About 47% of the respondents who started EBF at birth stopped the practice in less than one month, only about 10% continued with EBF till 6 months. Perceived reason for not practising EBF is attributable to cultural factors. Generally, only 20% of the respondents practice EBF while majority (80%) do not. It was concluded that there is the need for midwives to intensify their health education on rural women which will address all issues of cultural barriers that militate against nursing mother from practising EBF Keywords: - Exclusive Breast Feeding, Factors Influencing, Rural Communities

The Fear of COVID-19 Infection and Its Correlates with Clinical Practice among Nigerian Dentists

Background: The COVID-19 pandemic was not without its consequences like fear and effect on the economy and health care systems, with dentists being at a high risk of contracting the infection. Objectives: The study aimed to assess the fear and risk of contracting the disease among Nigerian dentists. It also assessed a self-reported economic impact of the outbreak of COVID-19 disease on dental practices in Nigeria. Methods: An online cross-sectional survey was conducted among Nigerian dentists. The survey link was forwarded on social media platforms of Nigerian dentists. The questionnaire inquired about fear/anxiety, self-reported effect on clinic income, adequacy of knowledge on COVID-19, and use of N95 facemask, among others. The statistical level was set at 5%.  Results: A total of 314 dentists (184 males and 130 females) within the age range of 22 to 63 years responded. The majority (214; 68.2%), were confident about their knowledge of the COVID-19 disease. Almost all the participants (298; 94.9%) entertained fears of contracting the disease through practice and transmission to family members, while 54.1% strongly agreed that theN95 mask should be worn routinely. However, all (100.0%) reported an economic impact of the pandemic on dental practice. Conclusion: The fear of contracting COVID-19 infection was high among dentists. Therefore, adequate and regular use of protective and preventive measures such as N95 face mask should be a priority among dentists. Attention should be paid to constant medical evaluation to those at risk. &nbsp