Search

Orientation: Success is a common goal in both personal and professional life, and wise leadership is key to achieving it. Effective leadership guides and motivates teams, driving them toward success and excellence. Research purpose: This study examines wise leadership in Oman’s government sector, using Hassi and Storti’s theoretical frameworks. It explores dimensions such as Intellectual Shrewdness, Spurring Action, Moral Conduct, and Cultivating Humility to improve employee awareness and perception. Motivation for the study: To assess wise leadership qualities across different dimensions and demographic groups to identify strengths and areas for improvement in leadership practices. Research approach/design and method: A descriptive method was employed, and a questionnaire was used as a data gathering tool. The data were analysed by several techniques including T-tests, ANOVA and descriptive statistics. Data were anonymously collected from 300 respondents across the Ministry of Labour, Ministry of Information and Taxation Authority, representing diverse demographic profiles and organisational ranks. Main findings: The findings highlight that practical wisdom is vital for organisational resilience, effective communication, and societal well-being in complex governance. While there is broad agreement on key leadership traits, minor discrepancies suggest challenges in applying theoretical ideals, especially concerning vulnerability and humility. Practical/managerial implications: Providing a detailed look at employees’ views on wise leadership and the impact of personal characteristics on these perceptions. Contribution/value-add: Provides a comprehensive view of employees’ perceptions of wise leadership and how personal characteristics influence these perceptions.

Abstract Liquid jet pumps are widely used in various industrial applications for fluid mixing, circulation, and transport. The efficiency and performance of liquid jet pumps play a crucial role in determining their overall effectiveness and economic viability. The performance of liquid jet pumps is primarily affected by parameters such as motive fluid pressure, nozzle design, and entrainment ratio. Liquid jet pumps exhibit a notable drawback in terms of comparatively lower efficiency when compared to alternative pump types. The reduced overall efficiency of liquid jet pumps stems primarily from energy dissipation incurred during the entrainment process. To address this obstacle, a water-water loop system was implemented in conjunction with a liquid jet pump, followed by the introduction of drag-reducing polymers (DRPs) into the suction flow of the liquid jet pump using a specific configuration. This configuration led to a significant reduction in drag within the liquid jet pump, raising its efficiency in some cases from 13.8% to 26.7% with a drag reduction of 46%, subsequently improving its overall performance. The resulting enhancement was evaluated using various efficiency models documented in the existing literature to comprehensively assess the overall performance of the liquid jet pump. A new interpretation of jet pump efficiency has been shared, along with a comparison of the various efficiencies.

Matching between low-voltage high-current capacity battery/fuel cell with high-voltage low-current motors in electric vehicles (EVs) requires paralleling-connection multi-stage power electronic converter with accurate modeling and control system. For high-voltage low-current drives of EVs with high-boosting/bucking gain, single-stage single-arm DC/DC converters suffer from unstable output voltage and the impractical choice of charging/discharging elements. Therefore, a multi-stage multi-arm DC/DC converter is researched to solve the problems of high boosting/bucking gain and minimized the voltage and current ripples. This paper presents parametric sizing, dynamic modeling, and analysis of all logical operational modes for a new high-gain DC/DC converter suitable for deployment in EV applications. The proposed topology composes of three-stage interleaved-input composed of cascaded two stages and double float-output as a third stage with bidirectional current capability. In this study, parametric design, and sizing for the three stages are performed according to the prerequisite ratings. Then, an analysis is conducted on rules of operating the DC/DC converter along with a discussion on considerations taken into account for such a critical design. An investigation of the dynamic behavior of the suggested DC/DC converter is carried out through a state-space model with switches’ states. Furthermore, a simulation and measurement-based validation of the derived mathematical models are conducted. The theoretical based analysis, design, and boosting gains are confirmed through a constructed and tested prototype given data on power supply and load utilization. A discussion on the choice of semiconductor equipment and reactive elements is provided for the proposed DC/DC converter. The experimental results show that the three stages can be used in a separate mode or in a cascaded booster.

PURPOSEEarly-onset colorectal cancer (EOCRC) is a rising health problem. The incidence of EOCRC has increased over the past 2 decades all over the world. Reports from Egypt since the 1990s have reported a higher incidence among young populations with no identifiable risk factors. The aim of this study was to assess EOCRC in Egypt regarding incidence, characteristics, treatment pattern, and survival compared with average age onset and elderly patients.MATERIALS AND METHODSThis was a retrospective, record-based, cohort study combining data from four different cancer centers in Egypt. We grouped patients according to age into three categories: the EOCRC group for patients age ≤45 years and the average age onset and elderly cancer group (for patients age ≥65 years).RESULTSThe study included 1,310 patients with histopathologically proven colorectal cancer, representing four different geographical areas in Egypt. Patients with EOCRC represented 42.4% of the study population. Female patients were 50.6% among the EOCRC group and 52.5% among the average age group. Rectal tumors were significantly higher in EOCRC (54.7% v 40.6%; P < .001). There was no significant difference between both groups regarding the tumor stage at presentation, obstruction, or presence of metastases at presentation. Patients with EOCRC had a significantly higher rate of peritoneum/adnexa metastases than the average age ones (12.3% in EOCRC v 6.9% in the average age group; P < .001). No statistically significant differences between EOCRC and average age groups in both disease-free survival and overall survival were reported.CONCLUSIONA comprehensive framework for the study of EOCRC is required in Egypt as well as a genomic analysis to identify possible underlying genetic alterations responsible for the high incidence of EOCRC.

The primary focus of this research is to create a precise, yet straightforward drift-flux model tailored for water-gas flow in variously angled pipes. This model is pivotal in estimating the volumetric flow rate of each phase in two-phase pipe flow scenarios. The proposed correlation is developed using twenty-two different (4367 data points) sources with a wide range of input data with different flow patterns. The drift-flux model created in this study underwent validation through the use of experimental data previously documented in the literature. Results indicate this model's stability and practicality, achieving 94.7 % accuracy within a margin of error of ±20 % for the chosen datasets. Furthermore, when compared against several drift-flux models, this newly proposed model consistently outperformed them across a liquid holdup range of 0.01–1. A comparative analysis with the state-of-the-art Unified Model underscores the accuracy of the proposed drift-flux model, highlighting its performance across diverse inclination angles and flow regimes. The proposed model demonstrates excellent predictive accuracy, particularly in vertical flow scenarios. Extending the scope of the study, further research could focus on the application of the developed drift-flux model to other fluid combinations and flow conditions, as well as its integration with mechanistic modeling and computational fluid dynamics simulations to provide more comprehensive insights into the behavior of two-phase flow in pipes with different inclination angles, enhancing the model predictive ability and operational range.

Background: Invasive fungal infections (IFIs) contribute to significant morbidity and mortality among patients with haemato-oncological conditions, seriously ill hospitalised patients and those in intensive care (ICU). We surveyed for the World Health Organization-recommended essential diagnostic tests for IFIs in these risk groups in Africa. Methods: The Global Action For Fungal Infections (GAFFI) evaluated the different levels of access to both diagnostics for IFIs for populations in Africa, with the aim of building a comparative dataset and a publicly available interactive map. Data was collected through a validated questionnaire administered to a country leader in relevant topics (i.e., HIV, laboratory coordination) and/or Ministry of Health representatives and followed up with 2 rounds of validation by video calls, and later confirmation by email of findings. Results: Initial data was collected from 48 African countries covering 99.65 % of the population. Conventional diagnostics such as blood cultures, direct microscopy and histopathology were often used for diagnosis of IFIs in more than half of the facilities. Bronchoscopy was rarely done or not done in 20 countries (population 649 million). In over 40 African countries (population >850 million), Aspergillus antigen testing was never performed in either the public or private sectors. Computed tomography (CT) imaging is routinely used in 27 (56 %) of countries in the public sector and 21 44 %) in the private sector. However, magnetic resonance imaging remains relatively uncommon in most African countries. Conclusions: There are critical gaps in the availability of essential diagnostics for IFIs in Africa, particularly Aspergillus antigen testing and modern medical imaging modalities. Early diagnosis and commencement of targeted therapy of IFIs are critical for optimal outcomes from complex cancer therapies.

Abstract Frictional pressure drop has been grasping the attention of many industrial applications associated with multi-phase and academia. Alongside the United Nations, the 2030 Agenda for Sustainable Development calls for the exigency of giving attention to economic growth, a considerable reduction in power consumption is necessary to co-up with this vision and to adhere to energy-efficient practices. Thereinto, drag-reducing polymers (DRPs), which do not require additional infrastructure, are a much better option for increasing energy efficiency in a series of critical industrial applications. Therefore, this study evaluates the effects of two DRPs—polar water-soluble polyacrylamide (DRP-WS) and nonpolar oil-soluble polyisobutylene (DRP-OS)—on energy efficiency for single-phase water and oil flows, two-phase air–water and air-oil flows, and three-phase air–oil–water flow. The experiments were conducted using two different pipelines; horizontal polyvinyl chloride with an inner diameter of 22.5 mm and horizontal stainless steel with a 10.16 mm internal diameter. The energy-efficiency metrics are performed by investigating the head loss, percentage saving in energy consumption (both per unit pipe length), and throughput improvement percentage (%TI). The larger pipe diameter was used in experiments for both DRPs, and it was discovered that despite the type of flow or variations in liquid and air flow rates, there was a reduction in head loss, an increase in energy savings, and an increase in the throughput improvement percentage. In particular, DRP-WS is found to be more promising as an energy saver and the consequent savings in the infrastructure cost. Hence, equivalent experiments of DRP-WS in two-phase air–water flow using a smaller pipe diameter show that the head loss drastically increases. However, the percentage saving in power consumption and throughput improvement percentage is significantly compared with that found in the larger pipe. Thus, this study found that DRPs can improve energy efficiency in various industrial applications, with DRP-WS being particularly promising as an energy saver. However, the effectiveness of these polymers may vary depending on the flow type and pipe diameter.

Abstract Background Patients who develop severe illness due to COVID-19 are more likely to be admitted to hospital and acquire bacterial co-infections, therefore the WHO recommends empiric treatment with antibiotics. Few reports have addressed the impact of COVID-19 management on emergence of nosocomial antimicrobial resistance (AMR) in resource constrained settings. This study aimed to ascertain whether being admitted to a COVID-19 ward (with COVID-19 infection) compared to a non-COVID-19 ward (as a COVID-19 negative patient) was associated with a change in the prevalence of bacterial hospital acquired infection (HAI) species or resistance patterns, and whether there were differences in antimicrobial stewardship (AMS) and infection prevention and control (IPC) guidelines between COVID-19 and non-COVID-19 wards. The study was conducted in Sudan and Zambia, two resource constrained settings with differing country-wide responses to COVID-19. Methods Patients suspected of having hospital acquired infections were recruited from COVID-19 wards and non-COVID-19 wards. Bacteria were isolated from clinical samples using culture and molecular methods and species identified. Phenotypic and genotypic resistance patterns were determined by antibiotic disc diffusion and whole genome sequencing. Infection prevention and control guidelines were analysed for COVID-19 and non-COVID-19 wards to identify potential differences. Results 109 and 66 isolates were collected from Sudan and Zambia respectively. Phenotypic testing revealed significantly more multi-drug resistant isolates on COVID-19 wards in both countries (Sudan p = 0.0087, Zambia p = 0.0154). The total number of patients with hospital acquired infections (both susceptible and resistant) increased significantly on COVID-19 wards in Sudan, but the opposite was observed in Zambia (both p = ≤ 0.0001). Genotypic analysis showed significantly more β-lactam genes per isolate on COVID-19 wards (Sudan p = 0.0192, Zambia p = ≤ 0.0001). Conclusions Changes in hospital acquired infections and AMR patterns were seen in COVID-19 patients on COVID-19 wards compared to COVID-19 negative patients on non-COVID-19 wards in Sudan and Zambia. These are likely due to a potentially complex combination of causes, including patient factors, but differing emphases on infection prevention and control, and antimicrobial stewardship policies on COVID-19 wards were highlighted.

Decimal arithmetic gains its importance in different applications in the fields of finance and scientific applications. The approach of running decimal arithmetic over binary hardware requires conversions from decimal to binary and from binary to decimal. These conversions produce inexact results that impose financial losses for companies. Therefore, the need for decimal hardware is of high importance. This work proposes decimal addition circuits and presents their realization in complementary metal-oxide semiconductor (CMOS) technology. LTSPICE SPICE simulator software is used to simulate and verify the functionality of the proposed circuits. The circuits are simulated using $45nm$ , $65nm$ , and $180nm$ technologies and compared against existing works in the literature. Due to the lack of existing work in literature and for purpose of comparison, this work also designed five different BCD adders using different existing binary adders in literature. The experimental results show that proposed decimal adder achieves better performance comparing to the other works. For example, for 3-digit operands, the proposed adder shows a power delay product (PDP), in femtojoule (fJ), of $13.88~fJ$ comparing to $25.38~fJ$ , $16.01~fJ$ , $15.24~fJ$ , $27.49~fJ$ , and $27.77~fJ$ PDP for other works.

Abstract This paper introduces the application of the variants of the Grey Wolf Optimisation algorithm for the sake of assessing unknown parameters of Proton Exchange Membrane Fuel Cells models. Three versions of Grey Wolf Optimisation algorithm are applied: Conventional Grey Wolf Optimisation, Improved Grey Wolf Optimisation based on dimension learning‐based hunting, and Selective Opposition‐based Grey Wolf Optimisation. Moreover, Optimisation algorithms of Ant Lion Optimiser, Atom search optimisation, Dragonfly algorithm, and Multi‐Verse Optimiser have been applied to estimate the parameters of Proton Exchange Membrane Fuel Cells models for the validation purpose. These algorithms are applied to three commercial Proton Exchange Membrane Fuel Cells stacks: BCS 500W‐PEM, 500W‐SR‐12PEM and 250W‐stack. The analyses are executed considering several operational circumstances. Sum of square errors value of the results based on parameters estimation and those experimentally tested are calculated. The objective function is chosen as sum of square errors value. The results are compared with those obtained using well‐known methods in the literature to validate the effectiveness of the proposed methods. It is noticeable that the simulated I‐V curves momentously match the datasheet curves for all the studied cases. In addition, considering the accuracy of the solution and the convergence speed, the Proton Exchange Membrane Fuel Cells model based on the Improved Grey Wolf Optimisation algorithm excels all other algorithms. Based on the simulation results, the Improved Grey Wolf Optimisation algorithm can improve the optimisation efficiency to 99.97 for the 250 W stack while the efficiency with Grey Wolf Optimisation and Selective Opposition‐based Grey Wolf Optimisation are 98.83 and 98.84, respectively, for the 250 W stack case study.

Researchers are paying attention to the current trend of electric vehicles (EVs), but there are not many places to charge them and serve as electric vehicle charging stations (EVCSs). In order to prevent the lack of EVCS for battery EVs (BEVs) on any road with all modes of operation, this paper proposed the design of a novel configuration and control structures for the isolated charging station (ICS) based on the solar PV system for efficient energy utilization to charge battery EVs (BEVs) with flexible double function cascaded converter (MPPT and DC-link voltage regulation). This was done with the aid of a battery energy storage system (BESS) as a backup/auxiliary source. The PV system is reliant on solar radiation and the daily load profile. Therefore, the BESS is employed to provide continuous power to BEVs and overcome PV’s intermittent nature. The cascaded converter is used to achieve the MPP and to regulate the DC-link voltage to its reference value (100 V), while the buck-boost matching bidirectional DC-DC voltage converters (MBDVCs) are used for charging and discharging mode/buck and boost mode, respectively, of BEVs and BESSs. Additionally, the MBDVCs are used as an interface between the ICS sources with the load through the developed control systems. The outcomes of various operating modes show that the system functions effectively. To verify the system performance, the MATLAB/Simulink application builds the system setup.

هدفت الدراسة إلى معرفة أثر الابتكار الاجتماعي في العلاقة بين التوجه الاستراتيجي والكفاءة في القطاع الصناعي بولاية الخرطوم، إلا إن قلة الدراسات التي تناولت محددات الابتكار الاجتماعي خاصة في الدول النامية. تم بناء نموذج الدراسة وفرضياتها بناء على دراسات سابقة في تطوير مقاييس الدراسة تم الاعتماد على المنهج الوصفي التحليلي وعلى العينة غير الاحتمالية /ميسرة وذلك لأنه تم توزيعها على فئة المديرين بمختلف مستوياتهم الوظيفية وتم تصميم اداة لجمع البيانات الاولية (الاستبانة)، وكان العدد الكلى الموزع (384) استبانة، حيث تم توزيعها على عدد (96) مؤسسة صناعية سودانية عاملة بولاية الخرطوم بنسبة استرداد بلغت (87%) وتم استخدام برنامج الحزم الاحصائية (SPSS) و(اموس23) لتحليل البيانات. تم استخدام أسلوب تحليل المسار ونمذجة المعادلة البنائية لاختبار فرضياتها، وقد توصلت الدراسة إلى استنتاجات أهمها الابتكار الاجتماعي لا يتوسط العلاقة الايجابية بين التوجه التكنولوجي والكفاءة بينما يوجد أثر إيجابي الابتكار الاجتماعي على الكفاءة واختتم البحث بمجموعة من التوصيات كان اهمها ضرورة الاهتمام في الابداع والسلوك الاجتماعي والفاعلية لما لها من أهمية في تحسين أداء المؤسسة المبحوثة، وبناء على نتائج الدراسة تمت مناقشة نتائج الدراسة وكذلك التأثير النظري والتطبيقي وأيضا تم تقديم توصيات واقتراح بحوث مستقبلية.

The aim of this research is to investigate the effects of rheological models of shear-thinning fluids and their estimated parameters on the predictions of laminar, transitional, and turbulent flow. The investigation was carried out through experimental and computational fluid dynamics (CFD) studies in horizontal pipes (diameters of 19.1 mm and 76.2 mm). Six turbulent models using Reynolds averaged Navier–Stokes equations in CFD_ANSYS Fluent 19.0 were examined in a 3D simulation followed by comparison studies between numerical and experimental results. Regarding results of laminar regions in power-law rheology models, Metzner and Reed presented the best fit for the pressure loss and transitional velocity. For the turbulent region, correlations observed by Wilson and Thomas as well as Dodge and Matzner had good agreement with the experimental results. For Herschel–Bulkley fluids, pressure losses and transitional regions based on a yielded region were examined and compared to the experimental results and the modified Slatter Reynolds number, where the results provided good estimation. For both pipe diameters, the Slatter model was the best fit for pressure losses of Herschel–Bulkley fluids in the turbulent regime. Furthermore, when comparing k-omega and k-epsilon turbulence models to the power-law behaviour, numerical studies delivered the most accurate results with fluids that have a higher behaviour index. However, the error percentage significantly increased at a higher shear rate in the Herschel–Bulkley fluids with a greater yield stress effect. Moreover, the modified Herschel–Bulkley viscosity function by Papanastasiou was implemented in the current CFD study. This function was numerically stabilized, devoid of discontinuity at a low strain rate, and more effective in transitional regions.

This paper presents a comprehensive experimental investigation concerning the effect of drag reducing polymers (DRP) on enhancing the throughput and reducing the pressure drop for a horizontal pipe carrying two-phase flow of air and water mixture. Moreover, the ability of these polymer entanglements to damp turbulence waves and changing the flow regime has been tested at various conditions, and a clear observation showed that the maximum drag reduction always occurs when the highly fluctuated waves were reduced effectively by DRP (and that, accordingly, phase transition (flow regime changed) appeared. This may also help in improving the separation process and enhancing the separator performance. The present experimental set-up has been constructed using a test section of 1.016-cm ID; an acrylic tube section was used to enable visual observations of the flow patterns. A new injection technique has been utilized and, with the use of different injection rates of DRP, the results have shown that the reduction in pressure drop occurred in all flow configurations. Furthermore, different empirical correlations have been developed which improve the ability to predict the pressure drop after the addition of DRP. The correlations showed low discrepancy for a wide range of water and air flow rates.

Residential and commercial buildings consume over a third of the world's total energy. The residential sector accounts for most energy use in the Gaza Strip, necessitating the development of feasible energy-saving techniques. Herein, a simulation-based study has been prepared to examine the integration of some practical passive design strategies into a generic residence. The study aims to optimize thermal performance by minimizing the building's cooling loads. A detailed examination is conducted for the literature on similar research and passive design techniques to investigate a city's state and climate. Three passive parameters, namely, shading devices, natural ventilation, and thermal insulation, were investigated using Climate Consultant and IESve as assessment software. Accordingly, their impacts on the building's indoor temperature and cooling load were evaluated. The findings suggest that the implementation of such passive design parameters can reduce energy consumption by 9.89 kW, representing 59% of the total energy consumption of the building. Such integration in residential buildings could be significant in cities with limited natural resources and would guide architects, designers, engineers towards the potential of passive measures in building design.