Journals
2025 EN
Abdulsahib Ahmed Dhafer · Alkhafaji Dhirgham · Albayati Ibrahim M.
ABSTRACT Heat sinks dissipate heat from electronic components, and the increase in heat generation owing to technological advancements has prompted researchers to improve heat sink efficiency. The present study aims to improve heat sinks by high‐emissivity nanocoating where the coating is prepared using nanoparticles CuO and MWCNT at a rate of 6% in half a liter of Acrylic resin and solvents Xylene and Butyl acetate at a rate of 30%. After coating the heat sink, the emissivity was examined and it was (0.963) while it was before coating (0.202). The heat sink is examined inside a cubic cavity with a right surface containing heaters that give temperature at the same value as the thyristors (58.5°C, 90°C, and 112.5°C) and a cold left surface (30°C). The temperatures at the tip of each fin are measured before and after coating when they change with time and at a steady state. The results showed that the nanocoating significantly reduced the temperature compared to the uncoated condition with the improvement percentage at a heater temperature of 58.5°C ranging from 10% to 15% at 90°C ranging from 24% to 34% and at 112.5°C ranging from 23% to 35%. It is concluded that the nanocoating showed great effectiveness in improving the performance of the heat sink at all temperatures, but the maximum effectiveness was at high thermal loads.
Journals
2025 EN
Manthena V. R. · Bhad P. P. · Lamba N. K.
+2 more
ABSTRACT This study investigates the thermal behavior of a thick elliptical plate subjected to a moving laser heat‐source using a novel application of the time‐fractional heat conduction equation with the Caputo‐fractional derivative. By incorporating a long‐tail power kernel to account for the memory‐dependent heat flow, this approach provides a more accurate representation of heat transfer dynamics in functionally graded materials (FGMs) under transient conditions. The material properties of the elliptical annulus plate, including thermal conductivity, heat capacities, and Poisson's ratio, are axially graded to model ceramic–metal–based FGMs, specifically titanium carbide and nickel. Analytical solutions for the displacement and temperature distributions are derived using the extended Mathieu function, Laplace transform, and perturbation methods, while numerical methods are employed for stress computation. The study introduces a comprehensive framework to evaluate the influence of time‐fractional parameters on thermal, deformation, and stress profiles, offering enhanced predictive capabilities for high‐temperature applications in advanced material design. The novelty lies in the integration of fractional‐order modeling and a moving laser source, which provides deeper insights into the thermal–mechanical responses of FGMs, paving the way for optimized designs in thermal industries. The merit of this study lies in its innovative modeling approach, novel application to FGMs with elliptical geometry, and relevance to high‐temperature industrial applications. The integration of fractional calculus and moving heat sources represents a significant advancement in understanding and optimizing thermal behavior in advanced materials.
Journals
2025 EN
Alqahtani Zuhur · Abbas Ibrahim · ElBary Alaa A.
+1 more
ABSTRACT This study examines the thermo‐electro‐elastic responses of a long hollow cylindrical piezoelectric material due to a pulse heating flux on its surface. Formulations suggested by Lord and Shulman for generalized piezothermoelastic systems are used. The response of the vessel is modeled under axisymmetric conditions, leading to the formulation of three coupled governing equations: the motion, Maxwell and the energy formulations. The finite element approach is used to solve these equations numerically. The Newmark time‐marching methodology is used to derive the temporal evolution. The presentation of novel numerical results provides insights into the dynamic behaviors of the piezoelectric cylinder under transient heat settings. The responses of pulse heating flux and relaxation time on the coupling between mechanical, thermal and electrical fields are highlighted in this work, providing useful.
Journals
2025 EN
Alabdaly Ibrahim K. · Azzawi Itimad D. J. · Aldamook Amer
+1 more
ABSTRACT Free convection and entropy generation inside a complex annular pipe were vital for different applied thermal engineering systems. The current study investigated the thermal and flow characteristics inside a porous Cassini oval annular pipe, considering response surface methodology (RSM) joint with CFD. The multi‐objective optimum design was a novel consideration to improve heat transfer in terms of Nusselt number ( Nu m R ) and heat transfer rate ( QR ) with a reduction in entropy generation ( EnR ) and frictional losses ( SFCR ) under different design parameters, such as aspect ratio (0.08 ≤ AR ≤ 0.2), angular rotation (0° ≤ θ ≤ 90°), porosity (0.15 ≤ ɛ ≤ 0.95), and pore per inch (10 ≤ PPI ≤ 30). The main data indicate that the aim optimum design is achieved in the enhancement of Nu m R and QR by nearly 23.78 times and the reduction in SCFR by approximately 91.45% with appropriate EnR by about 1.0227 times. This demonstrate the resilience of design's hydrothermal performance under different applied operation temperatures (10 ≤ ΔT ≤ 30). Thus, the multi‐objective optimization function is a useful and novel proposed process for optimizing the hydrothermal and entropy performance of a porous Cassini oval annular pipe under several design and operation parameters.
Journals
2025 EN
Mourad Abdelrahman M. · El Moghazy Ibrahim M. M. · Hassan Ali A. M.
ABSTRACT As global energy demands rise and environmental concerns intensify, evaporative cooling systems emerge as a promising solution to reduce energy consumption and environmental impact. While some studies have demonstrated that air gap spacing between cooling pads improves the energy performance of direct evaporative cooling (DEC) systems, none have explored their exergy and economic performance. This study provides a comprehensive thermal, exergetic, and economic analysis of a DEC system across a broad range of operating circumstances, comparing configurations with and without an air gap between the cooling pads. Tests were carried out using water flow rates of 60 and 35 L/(min·m²) and air velocities ranging from 1 to 3 m/s, under constant inlet conditions of approximately 32°C−33°C dry‐bulb temperature and 28%−30% relative humidity. The results showed that the outlet air temperature decreased by 4%–6%, while heat and mass transfer flux increased by 8.2%–10%, leading to improved cooling efficiency. Performance evaluation criterion and water consumption criterion analyses identified a 200‐mm pad thickness with an air gap at a flow rate of 35 L/(min·m²) as the most thermally efficient configuration, striking a perfect equilibrium between thermal performance, power consumption, and water usage. Moreover, configurations with an air gap proved to be the most cost‐effective, reducing the specific total cost by 6%–9.6%. These findings highlight the potential of air gap configurations to enhance the sustainability and performance of DEC systems, offering an energy‐efficient cooling solution that is particularly suitable for environments with limited water resources.
Journals
2025 EN
Marie Mohamed · Qi Baolei · Elamer Ahmed A.
+2 more
Abstract This study investigates the influence of board gender diversity on the relationship between environmental, social, and governance (ESG) performance and corporate cash holdings in Chinese A‐share listed companies from 2015 to 2022. Our research shows that ESG performance is positively associated with cash holdings. Drawing on critical mass theory, the study finds a moderating effect of board gender diversity in the relationship between ESG performance and the cash‐holding relationship. Specifically, the study finds a negative relation between ESG performance and cash holdings with the presence of a single female board member. However, this relationship shifts to a highly positive association when three or more female directors are on the board, underscoring the significant impact of gender diversity. Further heterogeneity analysis reveals that firms with a younger age profile and a strong commitment to green innovation exhibit a negative relationship between ESG performance and cash holdings. These findings highlight the complex and dynamic nature of the ESG performance‐cash holdings relationship, which varies according to specific firm characteristics. Overall, this study offers valuable insights into the multifaceted dynamics of ESG factors, enhancing our understanding of their impact on corporate financial strategies.
Journals
2025 EN
Wani Mohammad Jibran Gul · Alamir Ibrahim Abdou · Ghazwani Musa
+3 more
ABSTRACT This study aims at investigating the contextual factors surrounding the nexus between economic development and environmental degradation by utilising the Environmental Kuznets Curve (EKC) hypothesis and incorporating CO 2 emissions indicator. The environmental quality, energy source, economic growth nexus evaluation is heavily dependent on the level of economic growth. The study examines impact of different levels of economic expansion following an Environmental Kuznets Curve (EKC) hypothesis across Middle East and North Africa (MENA). Additionally, the present study examines the asymmetrical relationship that exist between economic growth and green energy, and the environmental quality. The study employs panel data ranging from 1996 to 2020 in the context of MENA nations. Several econometric tests were employed, second generation unit root tests, CIPS and CADF, Westerlund cointegration test. This study extends prior studies by applying the Panel Non‐Linear Autoregressive Distributed Lag (PNARDL). The Westerlund test validates a long run association among the variable of the study. The EKC hypothesis is validated in the short run for the MENA countries. It also reveals that a positive and negative shocks to the green energy decreases CO 2 emissions. The positive shock to GDP results in an increase in CO 2 emissions. Moreover, the study revealed a negative and significant relationship between FDI and CO 2 emission. A positive and significant relationship was found between trade openness and CO 2 emissions. Our findings suggest that the MENA nations should switch to green energy sources to lessen the impact of non‐renewable energy consumption on the environment and promote sustainable development, since non‐renewable energy is believed to have the greatest impact on economic activity.
Journals
2025 EN
Hakimi Sevil · Allahqoli Leila · Alizadeh Maryam
+5 more
Abstract Background Obstetric violence (OBV), defined as mistreatment or abuse during childbirth, is a pervasive global issue, albeit with regional differences, affecting women's physical and emotional well‐being. Objectives The purpose of this systematic review and meta‐analysis is to assess the prevalence of OBV to identify risk factors associated with OBV and to make suggestions for improving maternal healthcare practices and policies. Search Strategy In a systematic review and meta‐analysis, we searched four electronic databases for studies published over 10 years up to 31 January 2024: Medline (PubMed), Scopus, Embase, and Web of Science (WOS). The search was conducted among English language papers using a carefully curated set of keywords. Selection Criteria We conducted a comprehensive review, including all observational reporting data on the prevalence of and risk factors associated with OBV, irrespective of geographical location. The studies included in the review were required to be published in peer‐reviewed. journals and available in the English language. Data Collection and Analysis The data of the studies were summarized in an Excel file (version 19) and analyzed using R (version 4.2.3). A meta‐analysis was performed to evaluate the pooled prevalence of and identify risk factors associated with OBV. Main Results The global prevalence of OBV estimated based on 25 studies, calculated with a random‐effects model, was 59% (95% confidence interval [CI] 0.48–0.70; I 2 = 99.5%). The most prevalent subdomain of OBV was non‐consented care (37%; 95% CI 0.23–0.50; I 2 = 99.7%). The following factors were found to be significantly associated with OBV: the presence of a midwife as skilled personnel beside the woman during childbirth (odds ratio [OR] [95% CI] = 0.4 [0.2–0.9]), which might reduce the likelihood of OBV; middle and high levels of income (OR [95% CI] = 0.5 [0.2–0.7]), which might also reduce the likelihood of OBV; and vaginal delivery (OR [95% CI] = 2.08 [1.1–3.08]), which is liable to increase the likelihood of OBV. Conclusion This systematic review and meta‐analysis highlights the considerable prevalence and multifaceted nature of OBV, underscoring the urgent need for interventions at multiple levels to address this pervasive issue and ensure respectful, safe, and dignified maternal healthcare for all women.
Journals
2025 EN
Sav Seher · Senay Ibrahim
ABSTRACT Using samples from Turkey and Germany, which at a country level differ along individualism–collectivism and vertical–horizontal focus, the present study, through measurement‐invariant scales and multigroup SEM analysis, found that vertical collectivism and vertical individualism, which generally predict reduced well‐being across groups and individuals, indicate unhealthy Big‐Five personality factor levels for individuals in a country only when the country sample scores higher on these dimensions. Horizontal focus linked with improved well‐being was more characteristic of the German than the Turkish sample and predicted adaptive personality factor levels linked with well‐being equally in both country samples. Individuals' cultural self‐construal deviance scores from their country sample mean did not produce any significant effects in any country sample. Both countries' individualism and collectivism predicted a healthy personality profile when connected with horizontal focus. The results show that cultural fit could be unhealthy when the cultural dimension (e.g., vertical focus) defining fit predicts reduced well‐being and aversive outcomes across individuals and societies, with implications for the subjective well‐being of individuals with a migration background in adapting to a host culture such as individuals of Turkish origin in Germany or Syrian refugees in Turkey.
Journals
2025 EN
ChristieNguyen Phuoc · Ahmed Ahmed A · Ibrahim Nourhan
+2 more
Introduction The coexistence of renal cell carcinoma and classic Hodgkin lymphoma is exceedingly rare, with only two documented cases. Here, we present the third case diagnosed in our institution. Case presentation A 46‐year‐old man presented with right flank pain, fever, mild pancytopenia, and renal mass on computed tomography scan, suggesting renal malignancy. Despite intravenous antibiotics and extensive workup for recurrent fever, his condition did not improve. A bone marrow biopsy revealed rare large EBV‐positive B cells. Surprisingly, imaging only showed minimal intraabdominal lymphadenopathy in the perinephric region. Subsequent surgery confirmed clear cell renal cell carcinoma in the kidney and scattered large, atypical cells consistent with classic Hodgkin lymphoma in the suprahilar lymph node. Conclusion This case presents a rare case of classic Hodgkin lymphoma occurring in the perirenal region. When clinicians encounter unexplained symptoms in patients with primary tumors, additional biopsies should be considered for possible secondary malignancy.