Species Composition and Plasmodium falciparum Infection Rates of Anopheles gambiae s.l. Mosquitoes in Six Localities of Kwara State, North Central, Nigeria

Entomological data gathering is essential for monitoring malaria vector disease risks and selection of appropriate interventions for the protection of exposed human populations. This study assessed the relative abundance, species composition, and sporozoite infection rates of indoor resting An. gambiae s.l. malaria vectors in six communities across 3 Local Government Areas in Kwara State, Nigeria. Total number of mosquitoes collected by Pyrethrum Spray Catch method over a period of eighth months were correlated with rainfall values in the area. Plasmodium falciparum sporozoite infection rates and sibling species identification of collected An. gambiae s.l. mosquito samples were determined by ELISA and PCR respectively. Results showed a positive correlation (r = 0.639, p = 0.08) between rainfall and numbers of Anopheles mosquitoes in the study areas. The overall composition of the An. gambiae s.l sibling species in the collected samples from all the six communities showed the predominance of An. gambiae s.s 298 (75.3%) compared to An. coluzzii 94(23.7%) and An. arabiensis 4(1.0%). However, the sporozoite infection rate of An. coluzzii (22.3%) was higher compared to An. gambiae s.s (12.8%) and An. arabiensis (0%). Mean numbers of An. gambiae s.l mosquitoes were significantly higher in Ilorin west LGA compared to Asa (F = 17.81, P < 0.001) and Ilorin East LGAs (F = 22.81, P < 0.001). Sporozoite rates of both An. gambiae s.s and An. coluzzii sibling species were higher in Ilorin West communities (Aiyede 21%, Ogundele 32%) compared to Asa (Idi Emi 11.1%, Lasoju 5.1%) and Ilorin East (Oke Oyi 2.4%, Ote-efan 0%) communities. Prevalence of sporozoite-infected An. gambiae s.s and An. coluzzii indoors highlight the need for effective insecticide treated bed-nets interventions to protect the residents from malaria risks. Higher numbers of An. coluzzii in the swampy rice marshed Ilorin West LGA communities require larval source management as an additional strategy for effective malaria vector control

Simulations of air-water two-phase flow in an inclined pipe

Flow patterns depend on the mass flux and phase composition of the flow and also on the inclination angle of the tube. This work analyses the different flow patterns taking place in an inclined tube at 30 numerically. Both upward and downward flows are considered. The simulations of air-water flow in a pipe of diameter 0:051m and length 2m have been carried out using one-fluid model. The simulated flow patterns are slug, plug, stratified and bubbly flow. The calculated flow regimes are compared with data taken from the well-known Barnea flow pattern map. ANSYS-FLUENT 16.0 is used to solve the mass and momentum equations using second-order upwind scheme. The model takes into account the influence of gravitational force and the surface tension on the flow. A piecewise linear interface reconstruction based on Youngs's VOF is used. The simulation is carried out for the following combinations of superficial air velocities and superficial water velocities of (0.05, 0.1), (1.0,0.5) and (0.5,9.0) at an inclination angle of 30 and of (1.0, 0.1), (12,5) and (1.0,8.0) at an inclination angle of 30 . The volume fraction is predicted. To the authors’ knowledge, it is the first time that air-water flow as predicted by Barnea flow pattern map is being reproduced numerically and used to validate the VOF method. The results from FLUENT are compared with the experimental data from the well-known Barnea flow pattern map. The model predictions showed good agreement with experimental data obtained at both angles of inclination.Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .International centre for heat and mass transfer.American society of thermal and fluids engineers

A condensation heat transfer correlation for inclined smooth tubes

Correlation models for the prediction of condensation heat transfer performance of inclined smooth tubes are very scarce in literature. Most of the available models are limited to horizontal and vertical tube orientations. This paper presents a correlation model for the prediction of heat transfer coefficient during the convective condensation of R134a in a smooth inclined tube-in-tube condensing heat exchanger subject to diabatic conditions. The authors, in previous investigations presented the experimental data which have been used for the development of the proposed model. In this particular study, the test matrix comprises 260 data test points for inclination angles varying between -90 degrees (downward flow) and + 90 degrees (upward flow), for mass fluxes between 100 kg/m2s and 400 kg/m2s, mean vapour qualities between 0.1 and 0.9 at saturation temperature of 40°C. In the developed model, the effects of the independent variables such as mean vapour quality, mass flux and inclination are well captured. The proposed empirical model is in good agreement with the experimental data and performed better than the other models used for comparison.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

Production of pectinase enzyme from cheap plant materials (corn pomace, rice bran and peanut chaff) using Aspergillus niger.

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Dynamics of anopheline vector species composition and reported malaria cases during rain and dry seasons in two selected communities of Kwara State

Indoor resting mosquitoes were collected between November 2013 and May 2014 using Pyrethrum spray collection (PSC). The mosquitoes were identified using morphological keys and species specific polymerase chain reaction (PCR) assays. The species composition of members of the An. gambiae complex and reported malaria cases in the selected study communities were spatially mapped using Arc GIS software. A total of 645 mosquitoes were collected from the study sites and morphologically identified. This comprised of 598 (92%) Anopheles species, 42 (7%) Culex species and 5 (1%) Aedes species. One hundredand ninety-six An. gambiaes. l. samples were randomly selected and successfully identified by PCR. The composition of the mosquitoes species collected in Gaa Bolohunduro showed that a higher proportion 53 (64.6%) were An. arabiensis compared to lower proportions 5(6.1%) of An. coluzzii and 24 (29.3%) An. gambiae. In Osin, only 12 (10.5%) were An. arabiensis compared to 13 (11.4%) and 89 (78.1%) identified as An. coluzzii and An. gambiae respectively. The variation in the composition of members of the An. gambiaes. l. identified in Gaa Bolohunduro was not significant (p=0.070) compared to Osin (p=0.043). A weak correlation coefficient showed that the predominance of Anopheles in both communities was not dependent on rainfall, though variation in the members of the complex within the wet and dry season was significant (p<0.01). The sympatric occurrence and availability of An. gambiaes. s. and An. arabiensis during the dry and wet seasons corroborated the high malaria prevalence identified in Ilorin South. This suggests that both vectors will sustain malaria transmission in the study sites. Hence, a vector control strategy in these localities should be informed by the individual behaviour of each vector species identified.Keywords: Anopheles arabiensis, Anopheles coluzzi, Anopheles gambiae, distribution, composition, malaria cas

A numerical investigation of the heat transfer characteristics of water-based mango bark nanofluid flowing in a double-pipe heat exchanger

In this study, the heat transfer characteristics of a new class of nanofluids made from mango bark was numerically simulated and studied during turbulent flow through a double pipe heat exchanger. A range of volume fractions was considered for a particle size of 100 nm. A two-phase flow was considered using the mixture model. The mixture model governing equations of continuity, momentum, energy and volume fraction were solved using the finitevolume method. The results showed an increase of the Nusselt number by 68% for a Reynolds number of 5,000 and 45% for a Reynolds number of 13 000, and the heat transfer coefficient of the nanofluid was about twice that of the base fluid. In addition, the Nusselt number decreased by an average value of 0.76 with an increase of volume fraction by 1%. It was also found that there was a range of Reynolds numbers in which the trend of the average heat transfer coefficient of the nanofluid was completely reversed, and several plots showing zones of higher heat transfer which if taken advantage of in design will lead to higher heat transfer while avoiding other zones that have low heat transfer. It is hoped that these results will influence the thermal design of new heat exchangers.https://www.heliyon.comam2020Mechanical and Aeronautical Engineerin

Numerical investigation on the thermal-nanofluidic flow induced transverse and longitudinal vibrations of single and multi-walled branched nanotubes resting on nonlinear elastic foundations in a magnetic environment

Carbon nanotubes (CNTs) have attracted great attention due to their tremendous mechanical, thermal, structural and electrical properties leading to many promising applications. The unique and interesting properties of CNTs, such as their mechanical and electrical features, have fascinated industries and researchers to implement CNTs for production of different electromechanical devices. However, it is established that the phenomenon of buckling often occurs when CNTs are subjected to compressive loads and their frequencies under vibration are in order of Tera-Hz and Giga-Hz. Moreover, the profound dynamic behaviours of nanotube under the influences of slip when conveying fluid and magnetic field require a serious and meticulous study. Therefore, this study focuses on the vibration analysis of nanofluid-conveying embedded multi-walled branched nanotubes resting on Winkler-Pasternak foundation in a thermal-magnetic environment. Using Euler-Bernoulli theory, Hamilton's principle and nonlocal elasticity theory, fully coupled equations of motion governing the transverse and longitudinal vibrations of the nanotube are developed. Also, the equation of the deformation of the nanotubes as well as the pressure variation in the tubes are developed. Additionally, Navier-Stoke's equation and energy equation for the fluid and nanotube are coupled with the vibration models. The dynamics of the multi-walled carbon nanotubes when coupled with Navier-Stokes and energy equations require meticulous study as it is different from the usual assumption of plug flow. Therefore, in this present work, the developed coupled systems of nonlinear partial differential equations are solved using multi-dimensional numerical PDEs solvers coupled with PDE-tools in MATLAB. With the aids of the solutions, parametric studies were performed. The results indicate that increasing the downstream angle decreases the stability of the system. Also, the results obtained from the dynamic behaviour of the system indicate that the magnetic effect has an attenuating or damping effect of about 20 %. Furthermore, the plug flow assumption deviates from actual working processes by over 11 %. The analytical solutions verified and validated with existing analytical, numerical and experimental results. It is envisaged that the present study will give better insight into nanotubes design and serve as an index for subsequent works in the research area