Accurate solutions of Colebrook-White’s friction factor formulae

Estimations of friction factor (Ff) in pipeline systems and fluid transport are essential ingredients in engineering fields and processes. In this paper explicit friction factor formulae (Fff) were proposed and evaluated with an aim of developing error free Fff. General Fff that relate Ff, Reynolds number (Re) and relative roughness (Rr) were proposed. Colebrook – White’s formula was used to compute different Ff for Re between 4 x 103 and 1.704 x 108, and Rr between 1.0 x 10-7 and 0.052 using Microsoft Excel Solver to fix the Fff. The fixed Fff were used to compute Ff for Re between 4 x 103 and 1.704 x 108 and Rr between 1.0 x 10-7 and 0.052. Accuracy of the fixed Fff was evaluated using relative error; model of selection (MSC) and Akaike Information Criterion (AIC) and compared with the previous Fff using Colebrook–White’s Ff as the reference. The study revealed that Ff estimated using the fixed Fff were the same as Ff estimated using Colebrook – White’s Fff. The fixed Fff provided the lowest relative error of (0.02 %; 0.06 % and 0.04 % ), the highest MSC (14.03; 12.42 and 13.07); and the lowest AIC (-73006; -64580 and -67982). The study concluded that modeling of Fff using numerical methods and Microsoft Excel Solver are better tools for estimating Ff in pipeline flow problems.Keywords: Friction factor, MSC; AIC; Reynolds number; Engineering Field; pipe flow, statistical method

The Effect of Climatic Factors on the Distribution and Abundance of Mosquito Vectors in Ekiti State

In warm and tropical climatic regions of the world, climatic factors have been associated with relative mosquito abundance and transmission of mosquito borne infections. The main objective of this study is to assess the change in seasonal abundance and distribution of mosquito vectors in relation to climate variables (rainfall, temperature and humidity). Mosquito samples were collected from randomly selected houses in all the Local Government Areas of the State using Aspirators, light trap and pyrethrum spray catch methods from July 2006 to June 2008. Species of Anopheles, Aedes and Culex mosquitoes were collected. Anopheles gambiae s.s had the highest number (43.5%) out the three malaria vectors found. For Aedes and Culex species collected, Aedes aegypti (37.6%) and Culex fatigans (37.1%) have the highest prevalence out of their sibling species. Temperature and Rainfall were highly correlated with the abundance of mosquito vectors. It was observed that relative humidity of at least 50- 55% prolong mosquito survival. The rainy season (March to October) recorded the highest number of mosquito vectors collection with the peak in the months of July and August while the lowest collection was in the month of February when there was little or no rains. The environmental and ecological factors including Human activities enhanced the breeding and abundance of these mosquito vectors. Keywords:  Culex fatigans; Aedes aegypti; Mosquito; rainfall; temperature; abundanc

Pathogenic Conditions of Cichlids in Natural and Man-Made Ponds in Ibadan

A total of 354 fishes from three different stations A,B and C belonging to the family cichlidae were examined for ecto and endo parasites. The cichlids harboured the larva trematode; clinostomum tilapiae, Neascus species and Acanthocephalans. From all the parasites, clinostomum tilapiae had the highest percentage of infection (66%) and the lowest percentage of infection was found in Euclinostomum (1%). There was significant difference in the percentage of infections at A&B, but at station C, there was no significant difference of all the fish hosts examined Oreochromis niloticus had the highest percentage level of infection 67% and the least percentage level of infection was found in Sarotherodon galilaeus 22.5%. Keywords- cichlids, Endoparasite, Ectoparasite, ponds, Ibadan

An evaluation of solutions to moment method of biochemical oxygen demand kinetics

This paper evaluated selected solutions of moment method in respect to Biochemical Oxygen Demand (BOD) kinetics with the aim of ascertain error free solution. Domestic - institutional wastewaters were collected two - weekly for three months from waste - stabilization ponds in Obafemi Awolowo University, Ile - Ife. BOD concentrations (BODc ) were determined daily for 8 days using standard method. The BODc were used to determine parameters in BOD kinetics ( ultimate BOD concentration and BOD removal rate) using Microsoft Excel Solver, non - linear regression (exponential) and least squares methods (three graphs). Accuracies of these solutions were evaluated using relative error, Akaike Information Criterion (AIC), and model of selection criterion (MSC). The study revealed that ultimate BOD c was in the range of 1368.7 to 860.6 mg/L and BODc removal rate was between - 0.139 and - 0.470 /d. The averages of MSC were 4.18; 0.01; 1.49, 1.28 and 1.61 for Microsoft Excel Solver, non - linear and three least square methods (graphs 1, 2 and 3) respectively. The result revealed that Microsoft Excel Solver provided an improved solution of moment method, and a good description of BODc removal trend based on MSC and AIC than the other solutions. The study concluded that Microsoft Excel Solver solution to the method is a valuable solution at higher confidence l evel based on lower values of AIC and high values of MSC. Keywords: Wastewater, Environmental Pollution Control, BODKinetic Parameters , Moment Method, Statistical Evaluatio

Persistence of Ebola virus RNA in some body fluids of Ebola virus disease (EVD) survivors – the Nigerian experience

Introduction: Ebola virus (EBOV) has been shown to persist in some body fluids of Ebola Virus Disease (EVD) survivors with implication for future transmission particularly in Nigeria where EVD was experienced for the first time in 2014. Thus, this paper was aimed at providing information on the duration of persistence of EBOV in Nigeria. Materials and Methods: Ten consenting EVD survivors were enrolled. Baseline specimens; urine and semen (males), urine and high vaginal swab (HVS) (females) were obtained within one month after discharge from the Ebola Treatment Centre (ETC) and subsequently every fortnight. Samples were analyzed using quantitative Real-Star Filovirus Screen RT-PCR kit 1.0 at the National Reference Laboratory in Lagos.Results: Ten EVD survivors comprising 4 (40%) males and 6 (60%) females with age ranges of 28 to >33 years (mean age: 33.0 ± 6.9 years) were evaluated. EBOV RNA was not detected in the urine of all the participants and HVS from the females. However, EBOV RNA was detected in the semen of all 4 (100%) male participants at baseline, and at 2 months after discharge from the ETC. Two men were still positive for EBOV RNA 4 months after discharge from the ETC despite persistent negative vireamia. Conclusions: Our data confirm that a negative viremia in the convalescent period is not predictive of the absence of the virus in semen. Despite an early clearance of the virus from the urine and HVS, there was persistence of EBOV RNA in semen of male survivors 4 months after recovery

Diversidad, intensidad y prevalencia de parásitos de los cíclidos en secciones contaminadas y no contaminadas de la Represa de Eleyele, Ibadan, Nigeria

This study aimed to investigate the diversity, intensity and prevalence of parasites in Cichlids. A total of 354 specimens of cichlids was sampled in polluted and unpolluted ends of Eleyele River, Ibadan, Nigeria and examined for parasites. The total prevalence was 57.34%. Recovered parasites were Clinostomum tilapiae, Euclinostomum heterostomum, Neascus, Allocreadium ghanensis, Phagicola longa, Alloglossidium corti and the acanthocephalan; Acanthogyrus tilapiae and Acanthella. Clinostomum tilapiae had higher prevalence and abundance (42.90%) with Allocreadium corti recording least abundance (0.49%). Tilapia zilli was the most abundant (41.53%) among the fish hosts but Oreochromis niloticus harboured the highest percentage of parasites (80.00%). The fish hosts in the polluted end of the river harboured the highest percentage of parasites (71.18%) against (43.50%) parasites recovered from the unpolluted end. There was a significant difference in the parasites harboured. Heavy infection with a broad number of parasites in fish hosts could reduce performance and productivity of the species, especially in fish farming.Un total de 354 especime­nes de ciclidos se muestrearon en los extremos contaminadas y no contaminadas del río Eleyele, Ibadan, Nigeria y se examinaron sus parásitos. El total de prevalencia fue del 57.34%. Los parásitos encon­trados fueron Clinostomum tilapiae, Euclinostomum heterostomum, Neascus, Allocreadium ghanensis, Phagicola longa, Alloglossidium corti y Acanthogyrus tilapiae, Acanthella. Clinostomum tilapiae tuvo la mayor prevalencia y abundancia (42.90%) y Allocreadium corti con la menor abundancia (0.49%). Tilapia zilli fue el más abundante (41.53%) entre los hospederos de los peces pero Oreochromis niloticus albergó el ma­yor porcentaje de parásitos (80%). Los hospederos de peces en el ex­tremo contaminado del río contienen el mayor porcentaje de parásitos (71.18%) contra (43.50%) de parásitos recuperados en el extremo no contaminado. Existe una diferencia significativa en los parásitos alber­gados. Una infección intensa con un amplio número de parásitos en peces hospederos podría reducir el rendimiento y la productividad de la especie, especialmente en la piscicultura

Prevalence and distribution of malaria, Pfcrt and Pfmdr 1 genes in patients attending FUT Health Centre, Akure, Nigeria

This research evaluated the distribution of malaria, Plasmodium falciparum chloroquine resistance transporter (Pfcrt) and Plasmodium falciparum multidrug resistant (Pfmdr1) mutant genes among patients attending FUTA Health Centre. The research was carried out between December 2015 and February 2016. One hundred and forty (1 4 0) patients coming for malaria test were examined out of which 74 (52.86%) were males and 66 (47.14%) were females. Malaria test was done by thick blood film microscopy and Polymerase Chain Reaction (PCR) technique. PCR technique was used to detect Pfcrt and Pfmdr1 mutant genes of P. falciparum. Information about sex, age, status and date of collection of each patient were collected. Pearson’s Chi-square test was used for analysis. Out of 140 blood samples that were tested, 100 (71%) were positive for malaria infection. The percentage distribution of malaria infection among male and female patients was 54 (72.97%) and 46 (69.70%) respectively with no significant difference (P = 0.668). The prevalence of Pfcrt (95%) and Pfmdr1 (45%) showed significant difference (P = 0.001). The research revealed high prevalence of Pfcrt and Pfmdr1 mutant genes of P. falciparum among patients which may be as a result of treatment of malaria with Chloroquine and other medication which the parasite have formed resistance against. It is therefore important to administer other malaria drugs apart from the drugs the parasite have formed resistance against

GIS malaria risk assessment of Akure North and South Local Government Areas, Ondo State, Nigeria

Malaria, a mosquito-borne, protozoan disease, is an important health problem of developing countries, especially Africa. The study was designed to map malaria risk areas within Akure North and South Local Government Areas of Ondo State. Health-based survey, larval survey, socio-economic survey, and Geographic Information System (GIS) were used in achieving the objectives of the study. Larvae of mosquitoes were collected from breeding sites across the study areas; information on reported malaria cases from year 2010 to 2013 were retrieved from primary health centres, while socio-economic data of the population were generated using questionnaires. Maps of dumpsites, rivers, primary health centres and land use/land cover of the areas were generated using a combination of field and satellite data in a GIS environment. Pearson’s chi-square was used to correlate variables. The results showed that the presence of anopheline larvae (18%) in the study areas and the socio-economic characteristics of the population were contributory factors to malaria infection. Environmental conditions of respondents were significant (p<0.05) when correlated with prevalence of malaria (62.4%). High prevalence of malaria and the presence of anopheline mosquitoes indicated that the entire study area is a malaria endemic zone as represented in the generated risk map. Therefore, it can be concluded that a change in environmental conditions and lifestyle choices can reduce the malaria endemicity. Areas with high altitude, presence of larvae, water bodies, dumpsites and other factors present higher risk of malaria and vice versa. The introduction of environmental sanitation could ensure that mosquito breeding grounds are eliminated through filling up  of depressions, disposing shells, discarding cans and earthen vessels appropriately.Keywords: GIS, malaria, risk map, mosquito, primary health centr