Akanu Ibiam, Federal Polytechnic Unwana

This work investigated the near stream behavior of a confined jet flow when passive rings were placed at the nozzle exit plane at different gap ratios ( β). β is the gap ( da) between the ring and the inner nozzle wall, normalized by the ring thickness (drc) and ranged from 0.2≤da/drc≤1.0. The results show that the shedding of vortices behind the ring depends strongly on β. The suppression of the vortices was complete and partially at β=0.2 and 0.6, respectively, but negligible at β=1.0. The vortex suppression was associated with flow deflection due to delayed separation. The normal Reynolds stress Uu at the center of the gap was 1.255m2s−2 at β=0.2 and 3.083e−5m2s−2 at β=1.0. The increase in stress across the gap at small β values enhanced the momentum transfer between the fluid layers. This sustained the flow on the ring surface against an adverse pressure gradient and delayed the flow separation. The ring generally suppressed the jet spread. However, the mean velocity spread suppression only correlated strongly with β at the nozzle exit because the negative forcing on the shear layer coherent structure by the wake vortices was local. At 0.3 nozzle diameter downstream of the origin, the velocity spread became independent of β because of the decay of the wake vortices.

Background and Objectives: Routine use of antibiotics for infectious diarrhea in children is associated with the risk of increasing antibiotic resistance in developing countries. This work aimed to study the predominant extended spectrum beta-lactamase (ESBL) genes among bacteria pathogens implicated in acute childhood gastroenteritis in a tertiary hospital in Nigeria. Materials and Methods: The stool samples of children diagnosed with acute gastroenteritis were collected. Isolation and identification of bacterial pathogens from the stool samples using standard microbiological and molecular sequencing methods. Pure cultures of the probable bacteria pathogens were subjected to antibiotics susceptibility profiling using the Kirby-Bauer Disk Diffusion Method and also screened for ESBL and AmpC using the Modified Double Disc Synergy Test. Primers for 5 different ESBL genes associated with beta-lactam antibiotic resistance were amplified and sequenced. Results: Out of the 62 isolates, the highest number of organisms identified within the isolates were Bacillus sp at 38.7% (24) followed by Alcaligenes sp at 37% (23). Resistance to cefepime and ceftazidime were recorded at 50.8% (30) each. Ceftriaxone and cefotaxime were resisted in 47.4% (28) of the isolates. Out of 34 isolates resistant to all the cephalosporins used, 41.2% (14) were ESBL-producing, of which blaCTXM-1 and blaCTXM-2 were detected in 85.7%, while blaTEM was seen in 64.3%. Conclusions: blaCTXM and blaTEM may be the predominant ESBL genes haboured in the bacteria pathogens implicated in the yearly incidence of acute childhood gastroenteritis in Nigeria. This may be due to the widespread use of antibiotics in treating this disease.

Passive radiative cooling presents a smart alternative energy solution to the increasing demand for energy, especially for thermal comfort, as it requires energy input while being environmentally friendly. Achieving cooling through radiation is, however, material dependent. This study investigates the seasonal performance of a radiative cooling arrangement for all-year cooling. A 2D mathematical model of a diurnal radiative cooler was developed from first principles based on thermal energy balance and was parameterized using the climatic data of Owerri, Nigeria, to evaluate the thermal performance of the cooler during the late Harmattan (January), early rainy (April), late rainy (September), and early Harmattan (November) seasons in the study location. The months so chosen and their peculiar climatic characteristics are representative of the four seasons that characterize the study location. The system showed appreciable cooling under direct sunlight in all the months, indicating that diurnal passive radiative cooling is feasible all year round. Sub-ambient temperature values of 5, 3, 3.4, and 5 °C were recorded for the months of January, April, September, and November, under solar irradiance of 1250, 1150, 950, and 1200 W/m² and cooling powers of 94, 107, 84, and 96 W/m², respectively.

Aluminium–silicon alloys are highly regarded for their lightweight and unique mechanical properties, making them crucial for various industrial applications. Achieving optimal mechanical behavior in Al-Si-based alloys necessitates meticulous control over their microstructure. The research investigated the impacts of heat treatment regimes on the microstructure of A356 hypoeutectic alloys by light optical microscope (OM), scanning electron microscope (SEM), and energy dispersive spectroscope (EDS). The alloy, produced via stir-casting, underwent homogenization at 540 °C/5 h, one-step (200 °C for 0.5–8 h (T1)) and two-step (T2 (200 °C/0.5 h/180 °C/0.5–8 h)), and T2L (200 °C/0.5 h/160 °C/0.5–8 h)) aging processes. The findings revealed significant microstructural changes due to heat treatment. Homogenization reduced the average grain size of eutectic silicon by 20.5%. The T1 treatment increased the grain size and changed the grain morphology with prolonged aging, negatively impacting the mechanical properties. The T2 and T2L treatments resulted in finer, more uniform grain structures. The T2L treatment produced the finest eutectic silicon and the most uniform grain distribution, indicating the superior potential for mechanical performance. Overall, this study underscores the importance of tailored heat treatment regimes to optimize the microstructure and enhance the structural sensitive properties of Al-Si alloys, benefiting automotive and aerospace industries.

Background Malaria remains a serious health challenge; thus, the need for continual improvements in treatment regimens and the adoption of new treatment guidelines to enhance case management is vital. We report trends in malaria case management over a 16-year period at the Jakiri Health Centre in Cameroon, an area that has been plagued with civil unrest since 2016. Methods Data were collected retrospectively from consultation, laboratory, and prescription registers and double entered into Excel. Analysis was conducted using SPSS statistics and Microsoft Excel. Results A total of 3,800 febrile patients visited the outpatient department (OPD), and 8,324 prescriptions were received by patients. Of these prescriptions, 11.6% (964) were anti-malarials, 3.5% (291) were ferrous sulfate (FS), 40.8% (3,396) were antibiotics (AB), and 44.1% (3,673) were analgesics. The antimalarials prescribed were artemisinin-based combination therapies (ACTs) 83.2% (802) and quinine (Q) 16.8% (162). No ACTs were prescribed between 2006 and 2011. The 5 to < 15 years age group received the highest proportion of ACTs (42.3%), followed by the 1 to < 5 years age group (31.8%). Males were more likely to be prescribed ACTs than females were (OR = 1.336, 95% CI 1.141–1.564; p < 0.0001). Between 2006 and 2013, the number of quinine prescriptions increased from 17.2% (21) in 2006 to a peak of 26.1% (30) in 2009 and progressively decreased to 0% between 2014 and 2019. Antibiotic prescription rates were high across all age groups. Analgesics were prescribed to all patients across age groups for malaria-positive patients. The prescription of antimalarials to malaria-negative patients was relatively low over time. Conclusion This study demonstrated that recommended malaria treatment guidelines have been adopted by the Jakiri Health Centre, which has transitioned from quinine as a first-line treatment to ACTs. ACTs were not used in the facility until 2012. The prevalence of malaria is still very high, and most anti-malaria treatments are appropriate. However, antibiotics and analgesics were found to be highly prescribed.

The COVID-19 pandemic has led to the introduction of unprecedented safety measures, one of them being physical distancing recommendations. Here, we assessed whether the pandemic has led to long-term effects on two important physical distancing aspects, namely interpersonal distance preferences and interpersonal touch behaviors. We analyzed nearly 14,000 individual cases from two large, cross-cultural surveys – the first conducted 2 years prior to the pandemic and the second during a relatively stable period of a decreased infection rate in May-June 2021. Preferred interpersonal distances increased by 54% globally during the COVID-19 pandemic. This increase was observable across all types of relationships, all countries, and was more pronounced in individuals with higher self-reported vulnerability to diseases. Unexpectedly, participants reported a higher incidence of interpersonal touch behaviors during than before the pandemic. We discuss our results in the context of prosocial and self-protection motivations that potentially promote different social behaviors.

Given increasing concerns about the environmental impact of heavy metal pollution, assessing the level of contamination in floodplain suspended sediments is an important task. Effective environmental management and the preservation of an ecosystem depend on understanding existing pollution levels and potential concerns in the future. For this reason, floodplain-suspended sediments from major industrialized cities in Southeast Nigeria were sampled and analyzed for heavy metal contents. The investigation was conducted to evaluate the immediate and long-term bioavailability and pollution status of heavy metals in receptor organisms. A five-step sequential extraction procedure was adopted to fractionate iron, manganese, copper, zinc, nickel, lead, cadmium, and chromium to determine the geochemical phases in which they were distributed. Generally, the heavy metals were partitioned in the following order: residual > > oxidizable > carbonate > reducible > exchangeable. This indicates that a significant portion of the metals was tightly bound to the soil matrix, rendering them not readily bioavailable to the biota, except over an extended period. The levels of heavy metals, except for lead and cadmium in specific areas, were below the saturation point in terms of their bioavailability. Furthermore, the pollution assessment indices, such as the geo-accumulation index, reflected high levels of cadmium, copper, and lead contamination. This suggests a potential ecotoxicological risk to organisms near the sampling sites. The sites were classified as moderate and high risk in terms of immediate and future risk assessment, respectively. Proper cleaning methods and potential site reclamation are imperative to minimize or contain these heavy metals in stable forms within urban areas to prevent bioaccumulation.

A BSTRACT Background Stakeholders have had a long-standing concern about the quality of Routine Immunisation (RI) data in Nigeria. Digital technology tools like Open Data Kit (ODK) can address this challenge by reducing errors and discrepancies in RI data. However, despite its use in various health promotion programs, ODK is yet to be implemented for RI data capture and transmission. Aim The purpose of this study is to explore stakeholders’ views regarding the use of ODK for RI data capture and transmission. Methods The study was conducted in Enugu State, using a qualitative research approach. Stakeholders in RI from Primary health facilities, local government quarters and Enugu state primary health care development agencies (ENS-PHCDA) were purposefully selected and interviewed. The analyses followed a thematic approach. Results The study found that the current method of RI data capture is challenged by delays, incomplete and inaccurate reporting. Stakeholders had a positive reception of a switch to ODK for RI data capture and transmission because they think it can address the challenges associated with the current method, which is partly paper-based. The desire to switch to ODK was based on the belief that it guarantees data safety, timely submission, and reduced error or inaccurate data; these views were informed by previous experience with ODK in other health promotion programs. Stakeholders also perceived that to effectively implement ODK for RI data capture and transmission, training must be properly organized and resources put in place. Conclusion The study provides new knowledge to pave the way for pilot implementation and integration of ODK for RI data capture and transmission in Enugu State, Nigeria.

A BSTRACT Background Despite the efforts invested in generating quality data for routine immunization (RI) in Nigeria, significant improvement is yet to be reported, largely due to the multiple reporting, summation, and data transfer processes associated with the current paper-based reporting system. Aim This study piloted the use of electronic capture and transmission of RI data using Open Data Kit (ODK) in selected health facilities in Enugu State to determine its effect on internal consistency, completeness, timeliness, and validity on RI data. Materials and Methods An intervention study adopting the implementation research approach was conducted in 12 local government areas (LGAs) in Enugu State, Nigeria: six intervention LGAs and six control LGAs. Four RI data sets were built into two ODK data collection tools and deployed in Android phones for RI data capture and transmission in 60 randomly selected primary health care centers (PHCs) from six intervention LGAs (10 PHC per LGA) for three months. A second set of 60 health facilities was randomly selected from another six different LGAs as a control. A total of 10,663 RI data captured within this period were processed and analyzed using Microsoft Excel and SPSS version 25. Results Only 49 (81.7%) of the 60 intervention PHCs transmitted RI data using the ODK, and the majority of the PHCs (81, 74.3%) were also from rural areas. RI data captured and transmitted using ODK had internal consistency in more health facilities where intervention had taken place (46, 93.9%) than in health facilities where the paper-based method was used (33, 55.0%), representing a 70.1% marginal increase in internal consistency. Internal consistency was significantly associated with intervention status (intervention and non-intervention sites) and location (urban/rural) at P value = 0.001 and 0.044, respectively. Data transmitted electronically using ODK were also 2.9 times more likely to have internal consistency than those captured and transmitted with the paper-based method ( P = 0.001). Data from urban areas were also 1.5 times more likely to have internal consistency than those from rural areas ( P = 0.011). Conclusion Despite its challenges, such as poor power supply, poor network coverage, and device specification and the capacity of health workers, electronic capture and transmission of RI data using ODK is effective in improving RI data internal consistency, completeness, and validity.

A BSTRACT Background Immunization data are critical for the effective delivery of immunization programs, health planning, and-decision-making. It can also help to identify gaps in vaccine coverage and service delivery. Immunization data quality is dependent on the quality of the collection process at individual health facilities and its transmission to an integrated system. Aim This study set out to appraise the quality of childhood routine immunization data across the different levels of transmission in selected health facilities in Enugu, Nigeria. Materials and Methods This was a cross-sectional, analytical study of the immunization data of two vaccine antigens in 103 health facilities across 10 local council areas offering routine immunization services in Enugu state. Accuracy, discrepancy consistency, completeness, and timeliness of the data for the year 2020, the study period, were determined using WHO data quality assessment tools. Results This study noted that childhood routine immunization data from health facilities to the state are inconsistent, incomplete, and untimely in the transmission. Accuracy ratios were 110 and 108, discrepancy -10 and -8 for BCG and Penta III, respectively, at the health facility level. These signify the underreporting of the two vaccine antigens. This pattern was observed to be reversed as the data were transmitted from the local councils to DHIS 2. Timeliness of reporting did not go beyond 65% for the entire year 2020, while the completeness of reporting was below 80% for the same period. Conclusion There were significant changes in childhood routine immunization data as it were transmitted across the different levels of the data management processes in the state. Routine immunization data from health facilities in the state are inconsistent, incomplete, and untimely in their transmission. This calls for interventions to improve data quality and make use of it in decision-making.

Peeled melon seeds are widely consumed and are export items for several countries. The present research was conducted to establish the appropriate packaging materials for nutrient retention and shelf stability of peeled melon seeds ( Citrullus lanatus ). Fresh melon seeds were peeled and stored in three packaging materials- (Hessian Brown Bag (HBB), Propylene Bag (GSB) and Transparent Polyethylene Bag (TPB) for three months. Functional properties, physiochemical properties and nutrient composition of the samples were determined at the onset and after 3 months using standard AOAC methods. There was no significant difference (p > 0.05) between the fresh and samples stored for 3 months in all the functional properties. Emulsion capacity decreased after 3 months, while emulsion stability increased. All the vitamins, minerals and approximate nutrients determined (except carbohydrates) decreased as the storage period increased. The indices of fat deterioration increased with the storage period. Both the storage period and the packaging material did not affect the magnesium and zinc contents; iron, manganese, vitamin B 6 and vitamin A contents decreased with storage period. Melon seeds packaged in Hessian bag retained the highest amount of nutrients and was the least susceptible to deterioration by fat rancidity.

Traditional irrigation control systems is characterized with inefficient management of water and often results in low water productivity index and reduced cultivation yield. In addition, insufficient water supply and high rate of water loss due to evapotranspiration increases plant stress which often affects its growth and development. Therefore, to address this issues, this paper is aimed at developing a model predictive control (MPC) strategy for water saving drip irrigation experiment that will regulate the soil moisture content within the desired field capacity and above the wilting point, while scheduling irrigation to replace the loss of water from soil and plant due to evapotranspiration in the greenhouse environment. The controller design involves a data driven predictive model identified and integrated with the MPC designer in MATLAB and thereafter exported in Simulink for simulation. The generate controller code was modified and deployed on a Raspberry Pi 4 controller to generate a pulse width modulated signal to drive the pump for the control water mixed with fertilizer. To achieve enhancement of controller an Internet of Things (IoT) integration was used for easy soil, weather, and plant monitoring which are used to update the MPC model for the irrigation control. The performance of the proposed MPC controller deployed drip irrigated Greenhouse(GH1) is benchmarked against an existing automatic evapotranspiration (ETo) model based controller in Greenhouse(GH2), with each greenhouse containing 80 poly bags of Cantaloupe plant with similar growth stage. The results obtained shows that, the proposed MPC-based irrigation system has higher water productivity index of 36.8 g/liters, good quality of fruit with average sweetness level of 13.5 Brix compared to automatic ETo-based irrigation system with 25.6 g/liters and 10.5 Brix respectively. However, the total mass of harvested fruit for ETo-based irrigation system is higher than MPC-based irrigation system by 21.7%. The performance of the proposed MPC controller was achieved through the integration of event based scheduling with IoT monitoring as well as inclusion of evapotranspiration effect in the plant dynamics.

Introduction With the use of recent therapeutic data, several methods for finding medications from untapped natural materials continue to advance research and development. The antioxidant and antianemic effects of ethanol leaf extracts of Telfairia occidentalis and Mucuna poggei in phenylhydrazine-induced anemia in Wister albino rats were investigated. Method A total of 54 male albino rats were randomly assigned to nine experimental groups (n = 6). Anemia was induced in groups 2 to 9 with 10 mg/kg body weight of phenylhydrazine. Group 1 (normal control) rats were administered normal saline only. Group 2 (anemic control) rats were untreated. Group 3 (standard controls) rats were treated with a standard multivitamin, groups 4, 5, and 6 rats were treated with varying doses of M. poggei leaf extract respectively, while groups 7, 8, and 9 rats were treated with similar doses of T. occidentalis leaf extract by oral intubation for 21 days. Results Earlier, the gas chromatography-mass spectrometry analysis indicated eighteen (18) and twenty-nine (29) active compounds present in M. poggei and T. occidentalis, respectively. More so, T. occidentalis and M. poggei were studied for their inhibitory potentials against 2,2-diphenyl-1 picrylhydrazyl-free radicals, nitric oxide, phosphomolybdenum, and ferric-reducing antioxidant power. M. poggei and T. occidentalis also showed the following trend of minerals Mg > Ca > Fe > Na > Zn > Mn > K and Mg > Fe > Ca > Na > K > Mn > Zn, respectively. The results also showed that the packed cell volume, red blood cells, and hemoglobin significantly (p < 0.05) decreased in anemic control rats compared with normal controls and were significantly (p < 0.05) increased on treatment with the leaf extracts. Catalase, superoxide dismutase, glutathione peroxidase activities, and glutathione levels significantly (p < 0.05) decreased in anemic control, compared with normal. However, these significantly (p < 0.05) increased on treatment with the leaf extracts in a dose-independent manner. Malondialdehyde levels took the reverse trend. Conclusion This study indicated that leaf extracts of M. poggei and T. occidentalis can be used in the management of anemia and oxidative stress-related complications

This study focused on the influence of relationship marketing on customer loyalty in chain fast food establishments in Umuahia, Abia State. Specifically, the study determined the influence of trust on brand attachment; relationship commitment on brand advocacy; service quality on customer patronage, and customer knowledge management on customer experience. Customers of chain fast food establishments in the study area formed the population while the sample size was made up of 200 customers drawn from chain fast food establishments operating in the study area. The research instrument used for data collection was a questionnaire. Descriptive and inferential statistics on SPSS version 23 were used to analyze the data generated. Findings revealed that trust has a positive influence on brand attachment (R=0.321); relationship commitment has a significant influence on brand advocacy (R=0.715); service quality has a positive influence on customer patronage (R=0.459); and customer knowledge management has a significant influence on customer experience (R=0.659, R2=0.435). In view of the findings, the study concluded that relationship marketing has a positive relationship with customer loyalty and therefore recommends that operators of chain fast food establishments should build trust, fulfill promises made to customers, target continuous improvement in service quality, and develop database and other social media platforms for proper customer knowledge management as all these contribute in developing a good relationship with the customers leading to customer loyalty.

The deployment of smart electricity meter (SEM) via the advanced metering infrastructure (AMI) has come under cyber-attacks as adversaries continue to exploit the communication links for possible evasion of electricity bill payments. Various detection models relying on energy consumption data offer a disadvantage of delayed detection and consequent huge financial losses before frauds are detected. Moreover, existing techniques mostly concentrate on detection of electricity thefts and rely on energy consumption data alone as the basis of theft perpetration whereas other potential parameters which could be exploited for electricity theft prevention exist in AMI. In this study, AMI parameters, which are indicative of electricity thefts are preselected and modelled for electricity theft prevention. First, a given AMI network is sectioned into zones with the selected parameters modelled to define security risks by formulated set of rules based on real-time scenarios. Fuzzy inference system is then employed to model the security risks to ascertain the compromised state of the monitored parameters at the defined scenarios. The result of the developed model at 50% weight of each of the modelled parameters with interdependencies show clear indications of the modelled parameters and their interactions in the determination of risks. The decisions on monitored parameters evaluated at every timestep reveal varied dense velocity behaviours for every scenario. The result is suitable for monitoring the AMI in reporting and/or disconnecting any compromised SEM within a considerable timestep before huge losses are incurred. Implementation of this scheme will contribute a significant success in the attempt to prevent electricity theft perpetration via the AMI.

This study improves on the conventional SODIS design to make it more effective and increase its acceptability. An improved SODIS was designed to allow polyethylene teraphalate (PET) bottles serving as reactors to be under approximately 97% sunrays’ cover, and with a provision for a heat absorber. The improved SODIS was tested for inactivation of microorganisms by loading it with eight PET bottles filled with water containing 105 to 107 CFU/100 ml of Escherichia coli. The test was conducted simultaneously with a conventional SODIS, consisting of an improvised rooftop arrangement, containing same quantity of water-filled bottles with same concentration of E. coli. The two systems were placed close to each other, and exposed to direct sunlight for seven hours each day, on six different days. Ambient temperature was measured with a general-purpose thermometer. The thermometer was inserted into one bottle on each system to measure (representative) temperature. At hourly time intervals, a bottle was taken out from each system for enumeration of E. coli concentration. Hourly ambient and bottle temperatures were read simultaneously. The improved SODIS achieved a temperature of 4 °C above ambient and 1 °C above the conventional SODIS. In all the experiment days, complete inactivation of E-coli below detectable limit (less than 1 CFU/100 ml) was achieved at the fourth hour of exposure to sunlight by the improved SODIS and sixth hour by the conventional SODIS. The inactivation rates, K, for E. coli were 0.53 and 0.46 for the improved SODIS and the conventional (rooftop) SODIS, respectively.

Background: Cereals are the most staple foods in human diet and the main components of the daily diet. This work was designed to determine the level of essential and non-essential elements, the in vitro bioavailability, interrelationship, and associated health risk in consumed cereal grains in Nigeria to assess their safety and wholesomeness. Methods: The contents of phytate, oxalate, and some major-, trace- and potentially toxic elements were determined in 36 samples of barley, maize, millet, rice, sorghum, and wheat marketed in Nigeria. Results: The data showed variable significant (p

The effect of calcining in either air (VSTO-A) or 5% H2/N2 (VSTO-H) on the thermoelectric performance of La and Sm co-doped A-site-deficient Sr1-3x/2Lax/2Smx/2TiO3-δ ceramics is reported. All calcined powders were sintered 6 h in 5% H2/N2 at 1773 K to ≥96% relative density. All peaks in X-ray diffraction patterns indexed as a cubic perovskite phase. Scanning electron microscopy revealed grain sizes ~14 and ~10 μm for VSTO-A and VSTO-H ceramics, respectively. x = 0.30 showed the lowest k (2.99 W/m.K at 973 K) for VSTO-A, whereas x = 0.20 had the lowest (2.67 W/m. K at 973 K) for the VSTO-H ceramics. x = 0.30 VSTO-A showed a thermoelectric figure of merit, ZT = 0.25 (at 973 K), whereas the maximum ZT = 0.30 (at 973 K) was achieved for x = 0.20 VSTO-H ceramics, demonstrating that thermoelectric properties are optimized when all processing is carried out in 5% H2/N2.

There is a growing body of work suggesting that social class stereotypes are amplified when people perceive higher levels of economic inequality—that is, the wealthy are perceived as more competent and assertive and the poor as more incompetent and unassertive. The present study tested this prediction in 32 societies and also examines the role of wealth‐based categorization in explaining this relationship. We found that people who perceived higher economic inequality were indeed more likely to consider wealth as a meaningful basis for categorization. Unexpectedly, however, higher levels of perceived inequality were associated with perceiving the wealthy as less competent and assertive and the poor as more competent and assertive. Unpacking this further, exploratory analyses showed that the observed tendency to stereotype the wealthy negatively only emerged in societies with lower social mobility and democracy and higher corruption. This points to the importance of understanding how socio‐structural features that co‐occur with economic inequality may shape perceptions of the wealthy and the poor.