Modeling the Effect of Contact and Seepage Forces at Equilibrium on the Failure of Water Borehole

There have been records of failures and quicksand conditions in boreholes in recent times impeding the performance and operation of boreholes which may have resulted from various factors ranging from construction problems, drilling inaccuracies, fitting and installation problems, some chemical effects within the aquifer medium etc, but it has been ignored that a factor of great benefit to the operation of water boreholes; seepage force could get to a considerable which becomes unsafe for the well operation thereby causing dislodgement of sand particles and sandstones resulting boiling. This research work has investigated the contribution of contact force and seepage force to the failure of boreholes. This necessitated the use of combined finite-discrete element method to generate model expressions from contact and seepage forces considered to be the major forces contributing to the flow of fluid through soil mass and boiling or quicksand effect results when seepage force becomes more in effect under critical hydraulic gradient and / or critical hydraulic head. A mathematical/laboratory model was used and an expression for calculating the critical hydraulic head causing critical seepage deduced as = and the equilibrium model has deduced an expression for the safe hydraulic head during well pumping as =. These have been verified using a laboratory investigation; borehole prototype well failure test. It has been established that there is strong agreement between model result and the laboratory study result from the correlation analysis conducted which has shown correlations of 1.00975 and 0.989879999701 for the critical state condition and equilibrium state condition respectively. For purposes of future calculations, borehole performance monitoring and designs, the standard critical hydraulic head of the system from Table 3 and Fig.7 is 2.92E-8 which has the strongest agreement with 2.59E-8 of the laboratory study with a deviation of 3.3E-9. The deduced models can be used to design and monitor the performance of boreholes. For safe pumping and corresponding yield in the bore hole system, inter-granular force between granular particles should equal the seepage force and this is achieved by ensuring that the deduced model expression is used to determine the safe hydraulic head. Finally, irrespective of the fact that an increase in hydraulic head increases discharge, the system should be operated at a head safe for the performance of the well and as long as the model hydraulic head expression deduced is used under the above conditions, safe pumping can be achieved at any voltage between 150volts and 240volts.http://dx.doi.org/10.4314/njt.v34i3.3

Agile gravitational search algorithm for cyber-physical path-loss modelling in 5G connected autonomous vehicular network

Based on the characteristics of the 5 G standard defined in Release 17 by 3GPP and that of the emerging Beyond 5 G (or the so-called 6 G) network, cyber-physical systems (CPSs) used in smart transport network infrastructures, such as connected autonomous vehicles (CAV), will significantly depend on the cellular networks. The 5 G and Beyond 5 G (or 6 G) will operate over millimetre-wave (mmWave) bands. These network standards require suitable path loss (PL) models to guarantee effective communication over the network standards of CAV. The existing PL models suffer heavy signal losses and interferences at mmWave bands and may not be suitable for cyber-physical (CP) signal propagation. This paper develops an Agile Gravitational Search Algorithm (AGSA) that mitigates the PL and signal interference problems in the 5G–NR network for CAV. On top of that, a modified Okumura-Hata model (OHM) suitable for deployment in CP terrestrial mobile networks is derived for the CAV-CPS application. These models are tested on the real-world 5 G infrastructure. Results from the simulated models are compared with measured data for the modified, enhanced model and four other existing models. The comparative evaluation shows that the modified OHM and AGSA performed better than existing OHM, COST, and ECC-33 models by 90%. Also, the modified OHM demonstrated reduced signal interference compared to the existing models. In terms of optimisation validation, the AGSA scheme outperforms the Genetic algorithm, Particle Swarm Optimisation, and OHM models by at least 57.43%. On top of that, the enhanced AGSA outperformed existing PL (i.e., Okumura, Egli, Ericson 999, and ECC-33 models) by at least 67%, thus presenting the potential for efficient service provisioning in 5G-NR driverless car applications

Heterogeneous cyber-physical network coexistence through interference contribution rate and uplink power control algorithm (ICR-UPCA) in 6G edge cells

Optimizing power control for interference mitigation at the network cell edge is pivotal in enhancing capacity within a heterogeneous cyber-physical infrastructure, such as smart cities, manufacturing, healthcare, energy grids, transportation, and agriculture, among others. In this paper, we consider the intricate dynamics of Internet of Things (IoT) 5/6G edge users, with a particular focus on the Interference Contribution Rate (ICR), where macro and femtocells are critical network infrastructures. Existing approaches has drawbacks such as computational complexity, overhead, and co-channel interference, among others. However, to fully address interference challenges from the coexistence of diverse network hierarchies, preserving the Quality of Service for femtocell users is prioritized. The paper concurrently enhances the handoff mechanism of cell edge users in the macro cell network. A two-tier heterogeneous network (HetNet) is utilized to initially assess the contribution of edge user equipment (UE) to interference levels during its active state while quantifying it as ICR. Game theory is used to formulate a cohesive model for the coexistence of macro cell (MUE) and femtocell users (FUE). ICR-based uplink power control and reference signal received quality (RSRQ)-based handoff algorithms are deployed to regulate interference levels and enhance the Signal-to-Interference-Noise Ratio (SINR) of the MUE at the cell edge. This is achieved through coordinated transmit power adjustments by both user types. Results indicate a 6.67 % channel capacity loss (interference tolerance) by the FUE, leading to a 12.5 % improvement, translating to approximately 4 Mbps and 1 Mbps channel enhancements, respectively. The MUE and FUE can effectively coordinate power control with minimal overhead, accepting compromises in network channel quality. This approach facilitates improved MUE data access rates while ensuring the preservation of FUE. We show that interference is successfully mitigated through power control in heterogeneous networks with lower computational complexity

A computational fractional order model for optimal control of wearable healthcare monitoring devices for maternal health

The post-COVID-19 landscape has propelled the global telemedicine sector to a projected valuation of USD 91.2 billion by 2022, with a remarkable compounded annual growth rate (CAGR) of 18.6% from 2023 to 2030. This paper introduces an analytical wearable healthcare monitoring device (WHMD) designed for the timely detection and seamless transmission of crucial health vitals to telemedical cloud agents. The fractional order modeling approach is employed to delineate the efficacy of the WHMD in pregnancy-related contexts. The Caputo fractional calculus framework is harnessed to show the device potential in capturing and communicating vital health data to medical experts precisely at the cloud layer. Our formulation establishes the fractional order model's positivity, existence, and uniqueness, substantiating its mathematical validity. The investigation comprises two major equilibrium points: the disease-free equilibrium and the equilibrium accounting for disease presence, both interconnected with the WHMD. The paper explores the impact of integrating the WHMD during pregnancy cycles. Analytical findings show that the basic reproduction number remains below unity, showing the WHMD efficacy in mitigating health complications. Furthermore, the fractional multi-stage differential transform method (FMSDTM) facilitates optimal control scenarios involving WHMD utilisation among pregnant patients. The proposed approach exhibits robustness and conclusively elucidates the dynamic potential of WHMD in supporting maternal health and disease control throughout pregnancy. This paper significantly contributes to the evolving landscape of analytical wearable healthcare research, highlighting the critical role of WHMDs in safeguarding maternal well-being and mitigating disease risks in edge reconfigurable health architectures

Depression and physical activity in a sample of nigerian adolescents: levels, relationships and predictors

<p>Abstract</p> <p>Background</p> <p>Physical inactivity is related to many morbidities but the evidence of its link with depression in adolescents needs further investigation in view of the existing conflicting reports.</p> <p>Methods</p> <p>The data for this cross-sectional study were collected from 1,100 Nigerian adolescents aged 12-17 years. Depressive symptomatology and physical activity were assessed using the Children's Depression Inventory (CDI) and the Physical Activity Questionnaire-Adolescent version (PAQ-A) respectively. Independent t tests, Pearson's Moment Correlation and Multi-level logistic regression analyses for individual and school area influences were carried out on the data at p < 0.05.</p> <p>Results</p> <p>The mean age of the participants was 15.20 ± 1.435 years. The prevalence of mild to moderate depression was 23.8%, definite depression was 5.7% and low physical activity was 53.8%. More severe depressive symptoms were linked with lower levels of physical activity (r = -0.82, p < 0.001) and moderate physical activity was linked with reduced risk of depressive symptoms (OR = 0.42, 95% CI = 0.29-0.71). The odds of having depressive symptoms were higher in older adolescents (OR = 2.16, 95% CI = 1.81-3.44) and in females (OR = 2.92, 95% CI = 1.82-3.54). Females had a higher risk of low physical activity than male adolescents (OR = 2.91, 95% CI = 1.51-4.26). Being in Senior Secondary class three was a significant predictor of depressive symptoms (OR = 3.4, 95% CI = 2.55-4.37) and low physical activity.</p> <p>Conclusions</p> <p>A sizable burden of depression and low physical activity existed among the studied adolescents and these were linked to both individual and school factors. Future studies should examine the effects of physical activity among clinical samples of adolescents with depression.</p

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Pharmacokinetics Of Artemether-Lumefantrine Combination Therapy In Malaria Chemotherapy

Objectives: The therapeutic effects of artemether monotherapy compared to artemether-lumefantrine combined therapy in malaria based on their pharmacokinetic parameters such as absorption, elimination constants, area under the curve, bioavailability, volume of distribution and half-lives were investigated. Methods: Design was by single blind technique at Our Lady of Lourdes Hospital, Ihiala, Anambra State, Nigeria. Presence and concentration of Plasmodium falciparum in the patients' blood were confirmed by microscopy. Analysis of blood samples for drug. Concentration was by high performance liquid chromatography (hplc). Results: Results showed that peak serum concentration (Cmax) was 12.22±0.11µg for monotherapy and 82±0.8µg for combination therapy Area under the curve (AUC) was 756±0.11µ h-1ml-1for monotherapy and 415±0.11µh-1ml-1 for combination therapy. Apparent volume of distribution (Vd) was 317±0.5ml for monotherapy and 23±0.1ml for combination therapy. Bioavailability (f) was 0.4±0.00 for monotherapy and 0.12±0.00 for combination therapy. Absorption rate constant (Ka) was 18±0.11 h-1 for monotherapy and 15±0.11 h-1 for combination therapy. Elimination rate constant (Kel) was 0.33±0.00 h-1 for monotherapy and 0.29±0.00 h-1 for combination therapy, since elimination constant calculates half-lives of the drugs. Conclusion: Results indicate significant differences between the pharmacokinetic parameters employed, particularly of artemether (2.1±0.03) as control with short elimination half-life and artemether – lumefartrine (2.3±0.01h-1) with longer elimination half-life. These significant variations might be attributed to the enhanced effect of the combined drugs possibly due to synergistic effect. Keywords: Pharmacokinetics, Artemether, Lumefantrine, Monotherapy, combination therapy, Plasmodium falciparum.Tropical Journal of Medical Research Vol. 12 (1) 2008: pp. 9-1

The effect of L-Ascorbic acid on the choline chloride toxicity in mice

No Abstract

Investigation Into The Antibacterial And Antidiarrhoeal Properties Of Water And Ethanolic Extracts Of Psidium Guava Leaves

Objective: The water extract (WE) and ethanol extract (EE) of Psidium guava Leaf were carried out for antibacterial and antidiarrhoeal effects using patients stool and animal models. The antibacterial sensitivity tests were based on their zone of inhibition for six species of bacteria which include: Aeromonas hydrophila, 22±4mm; Pseudomonas aeruginosa 18±2mm; Shigella dysenteriae, 17±1mm; Bacillus subtilis, 16±3mm; Staphylococcus aureus, 13±1mm; and Escherichia coli, 12±2mm. Result: Their minimum inhibitory concentration, MIC, and minimum bactericidal concentration, MBC, were respectively: Aeromonas hydrophila, 3mg/ml and 5mg/ml; Pseudomonas aeruginosa, 6mg/ml and 9mg/ml; Bacillus subtilis, 25mg/ml and 40mg/ml; Staphylococcus aureus, 50mg/ml and 84mg/ml; while Escherichia coil gave 100mg/ml and 132mg/ml, respectively. Antidiarrhoeal effect of both the water and ethanol extracts, compared with the standard drug diphenoxylate was, clearly showed significant reduction in faecal output and protection from castor oil – induced diarrhoea in the albino rat. Conclusion: The extracts also significantly (