Recent publications
A large part of incident solar radiation on photovoltaic (PV) modules is converted into heat, leading to overheating and reduction of PV modules performance. The present work investigates the impact of rectangular aluminium fins (RAFs) and evaporative cooling represented by cotton wicks immersed water (CWWs) on the performance and thermal behaviour of the PV module. Results indicate that the evaporative cooling attained better cooling potential than RAFs, in which the PV module temperature was reduced by 22.3%, and the output power was enhanced by 73% thanks to continuous cooling of the PV module. A slight improvement in the PV module performance was observed with RAFs due to the increased heat transfer area, which reduced temperature by up to 6.7% and increased the output power of the PV module by up to 21.3 %. Exergy analysis shows a gradual increment of the electrical exergy and exergy efficiency using CWWs, which reduces the entropy generation of it more than RAFs. The study concluded that PV modules without cooling in hot climate areas may deteriorate their performance significantly.
Recently, photovoltaic technology applications have occupied a wide range in electric generation. The temperature rising higher than the operating temperature permissible is the weak point facing this technology, which significantly influences the performance of the photovoltaic cells. Using nanofluids as the coolant of photovoltaic (PV) modules is an effective method, circulating nanofluids in the heat exchanger attached to the backside of the PV module to absorb excess heat and enhance the performance of the PV module. The current work investigates using zirconium oxide (ZrO 2) nanofluid as a coolant at different volume concentrations (0.015 vol%, 0.025 vol%, 0.0275 vol%) in deionized (DI) water to reduce the temperature of the photovoltaic PV cells and then analyses the performance from the energy/exergy viewpoints. The results indicate that the PV module temperature was reduced by 10.2 °C when cooled by ZrO 2 nanofluid at 0.0275% volume concentration in DI water compared to the reference PV module, resulting in remarkable system energy and exergy enhancement. Besides, the cooling by DI water has decreased the PV module temperature by 5.1 °C. The overall efficiencies gradually increment with an increase in volume concentration by 8.9%, 18.8 % and 24.4%, respectively, compared with PV modules cooled by DI water. Using ZrO 2 nanofluids with 0.0275 vol% could enhance the exergy efficiency by 66.8% and reduce the exergy losses and entropy generation by 7% and 26%, respectively.
Hemophilias are the most common X-linked inherited blood diseases that, if not properly treated, can cause lifelong debilitations. The challenges and problems in babies differ from that in older kids and adults. Blood loss conditions continue to dominate as diagnostic triggers in children, but the locations of blood loss vary with age. The TNF-α-308 gene polymorphism in children with moderate to severe hemophilia correlates with genetic background and with the clinical phenotype of the cases. This study was a case control conducted in fifty hemophilic and fifty age- and sex-matched healthy cases from September 2020 to October 2021. Results; a significant change was found among positive and negative inhibitors regarding the number of factors eight exposure days >20 days (in positive inhibitors was 59.3% compared to adverse inhibitors 27.8%). Conclusion: The (TNF-)308 gene polymorphism is significantly correlated with inhibitor progress in severe Haemophilia A cases. TNF-Alpha gene might be of use as a biomarker as well possible immune response modulator in Haemophilia A patients receiving substitute treatment. Keywords: polymorphism, TNF-α -308Haemophilia, inhibitor, prophylaxis - intracranial hemorrhage and pediatrics.
Morus alba is a fast-growing shrub or medium-sized tree with a straight, cylindrical trunk. Medicinally, whole plants, leaves, fruits, branches, and roots have been employed. Google Scholar, PubMed, Scopus, and Web of Science were used to search for relevant material on the phytochemical components and pharmacologic and mechanism of action of the Morus alba. This was reviewed to assess important updates about Morus alba. The fruits of Morus alba have traditionally been used as an analgesic, anthelmintic, antibacterial, anti-rheumatic, diuretic, hypotensive, hypoglycemia, purgative, restorative, sedative tonic, and blood stimulant. Various plant parts were used as a cooling, sedating, diuretic, tonic, and astringent agent to treat nerve disorders. The plant contained tannins,
Nanotechnology applications have occupied a wide range in engineering applications and achieved distinctive performance due to their potential as a working fluid instead of conventional liquids due to their outstanding performance. Sustaining stable performance nanofluids for a longer time retaining their properties without clustering and nanoparticles aggregation in the base fluid represents a significant challenge that can influence nanofluid properties and thermal behaviour. This review highlights some important factors that influence the stability of nanofluids, such as the size, concentration ratio of nanoparticles, and the type of base fluid, in addition discussing the methods used to improve the stability of nanofluids, such as the effect of cluster formation of nanoparticles in the base fluid due to Brownian motion and the role of the surfactants in preventing or reducing the agglomeration of nanoparticles, zeta potential and pH in estimating nanofluids stability. The factors mentioned affect the thermophysical properties of nanoparticles in preparing nanofluids and enhance their performance. This review provides information which helps improve the wide range usability of nanofluids for preparing stable nanofluids with good thermophysical properties.
This paper presents a compact dual-band open-loop monopole MIMO antenna to serve 4G/5G applications. This antenna consists of two printed monopole antennas with very high isolation. Two enhancement techniques are utilized to improve the isolation between ports. Since each technique can provide high isolation of a single band, a combination of λ /4 slot and T-shape techniques are used to achieve high isolation of −19 dB and −35 dB at 2.4 GHz and 3.5 GHz, respectively. The proposed design has high efficiency, a low envelope correlation coefficient, and an acceptable level of realized gain (2.7 dBi and 2.2 dBi) at low and high bands. This design has been fabricated using low-profile printed circuit technology with a compact patch size of 50 × 25 mm ² based on an FR-4 substrate. Moreover, the simulation and measurement results are in good agreement.
This research examines the impact of firms’ decision-making, crisis management, and risk-taking behaviors on their sustainability and circular economy behaviors through the mediating role of their eco-innovation behavior in the energy industry in Iraq. Firms are exploring applicable mechanisms to increase green practices. This requires the industry to possess the essential skills to overcome the challenges that reduce sustainable activities. We applied a dual-stage structural equation modeling (PLS-SEM) and a multi-criteria decision-making (MCDM) approach to explore the linear relationships between variables, determine the weight of the criteria, and rank energy companies based on a circular economy. The online questionnaire was sent to 549 managers and heads of departments of Iraqi electric power companies. Out of these, 384 questionnaires were collected. The results indicate that firms’ crisis management, decision-making, and risk-taking behaviors are significantly and positively linked to their eco-innovation behavior. This study confirms the significant and positive impact of firms’ eco-innovation behavior on their sustainability and circular economy behaviors. Likewise, eco-innovation behavior has a fully mediating role. For the MCDM methods, ranking energy companies according to the circular economy can support policymakers’ decisions to renew contracts with leading companies in the ranking. Practitioners can also impose government regulations on low-ranked companies. Thus, governments can reduce the problems of greenhouse gas emissions and other environmental pollution.
Background and Objectives: The steady increase in the spread of multidrug-resistant Pseudomonas aeruginosa (MDR) has become a major threat to the global health systems, including Iraq. This study aimed to investigate the prevalence and the molecular basis of antibiotic resistance in Pseudomonas aeruginosa isolated from clinical and environmental samples.
Materials and Methods: Pseudomonas aeruginosa strains were identified by standard microbiological procedures followed by PCR confirmation. Antibiotic susceptibility testing, for 16 antimicrobials, was conducted according to the Clinical and Laboratory Standard Institute (CLSI) standardized by disk diffusion and VITEK 2 methods. Detection of beta-lactamases (ESBLs, AmpC and carbapenemase) activities and related encoding genes was performed by using phenotypic methods and PCR technique respectively.
Results: A total of 81 clinical specimens and 14 environmental samples were positive for P. aeruginosa. Antimicrobial susceptibility test showed high rates of resistance to antipseudomonal cephalosporines (74.74 to 98.95%), aztreonam (82.11%), antipseudomonal carbapenems (68.4%), piperacillin/tazobactam (69.5%) ciprofloxacin (71.6%), and aminoglycosides (69%), with emergence of resistance to colistin (7.4%) among tested P. aeruginosa. Among the tested isolates, 69 (72.63%) strains were MDR, of which 63 (91.3%) strains were extremely drug resistance (XDR). Most of the isolated strains harbored one or more of ESBL genes (blaSHV-2a, blaCTX-M-28, blaVEB-2, blaOXA-677, blaPER) with predominant blaOXA-677, but none of the MBLs (GIM, SIM, SPM, IMP) and AmpC (FOX) genes were detected.
Conclusion: The results highlighted a high prevalence rate of MDR and XDR and emergence of colistin resistance P. aeruginosa at Basra hospitals, Iraq.
Flood disasters are a natural occurrence around the world, resulting in numerous casualties. It is vital to develop an accurate flood forecasting and prediction model in order to curb damages and limit the number of victims. Water resource allocation, management, planning, flood warning and forecasting, and flood damage mitigation all benefit from rain forecasting. Prior to recent decades' worth of research, this domain demonstrated to be promising prospects in time series prediction tasks. Therefore, the main aim of this study is to build a forecasting model based on the exponential smoothing-long-short term memory (ES-LSTM) structure and recurrent neural networks (RNNs) for predicting hourly precipitation seasons; and classify the precipitation using an artificial neural network (ANN) model and decision tree (DT) algorithm. We employ the dataset from the Australian commonwealth office of meteorology named Historical Daily Weather dataset to test the effectiveness of the proposed model. The findings showed that the ES-LSTM and RNN had achieved 3.17 and 6.42 in terms of mean absolute percentage error (MAPE), respectively. Meanwhile , the ANN and DT models obtained a prediction accuracy rate of 96.65% and 84.0%, respectively. Finally, the outcomes revealed that ES-LSTM and ANN had achieved the best results compared to other models.
Nowadays, core/shell structures due to very high thermal and electrical conductivity are taken into account in the manufacture of many industrial sensors and catalysis. Ni–Al core/shell structures are known as one of the most practical materials due to their high chemical stabilities at elevated temperatures. Since the evaluation of the mechanical properties of the industrial core/shell catalysts is crucial, identification of the mechanism responsible for their plastic deformation has been a challenging issue. Accordingly, in this study, the mechanical properties and plastic deformation process of Ni–Al core/shell structures were investigated using the molecular dynamics method. The results showed that due to the high-stress concentration in the Ni/Al interface, the crystalline defects including dislocations and stacking faults nucleate from this region. It was also observed that with increasing temperature, yield strength and elastic modulus of the samples decrease. On the other hand, increasing the temperature promotes the heat-activated mechanisms, which reduces the density of dislocations and stacking faults in the material. Consequently, the obstacles in the slip path of the dislocations as well as dislocation locks are reduced, weakening the mechanical properties of the samples.
This paper investigates the behavior of cast-in headed anchors in early age concrete with different mixes and supplementary cementitious materials. A series of anchor pull-out tests of cast-in headed anchors were conducted using slag and fly ash as Supplementary Cementitious Materials (SCMs) and their amounts were varied from 0 to 50% for slag and 0 to 25% for fly ash of total cement content in concrete. The tests were conducted from 18 h to 28 days after concrete being casted. The results from the experiment were compared with the current theoretical model used in literatures and design standards to predict concrete cone failure for mature concrete to check their applicability for early age concrete with SCMs. Further, a comprehensive 3D finite element model was developed and verified against experimental results. The verified finite element model was used to conduct detailed parametric studies varying concrete and anchor properties. A detailed discussion on the anchorage behavior with different types and amount of SCMs based on findings of this study is presented in this paper. The concrete cone capacity method was found to be applicable for early age concrete with headed anchor with 40 mm effective depth and concrete strength as low as 3 MPa for anchors tested in this study.
Emergency remote teaching (ERT) has potential for transforming future instruction and learning across the K–12 educational domain. The study presented here evaluated empirical evidence from peer-reviewed literature pertaining to the challenges and opportunities experienced by teachers and students during the implementation of ERT prompted by the COVID-19 pandemic. To locate relevant reports and research, the authors explored three databases: Web of Science, ScienceDirect and Scopus. Based upon predefined selection criteria, they selected 51 studies for thematic and content analysis. Next, they developed a taxonomy which comprised three categories: (1) K–12 education responses to ERT; (2) educational inequality; and (3) learning outcomes. Using this taxonomy, the authors conducted a deep analysis and critical review to highlight multiple challenges and critical gaps in the literature surrounding ERT in K–12 education settings. Their review reveals innovative strategies for overcoming obstacles to technological readiness, online learning adaptation and teachers’ and students’ physical and mental health. This knowledge will be valuable to policymakers, researchers, practitioners and educational institutions in reducing the adverse effects of catastrophic situations on childhood education in the future.
This article presents the design, fabrication, and testing of three heat conduction apparatuses needed for engineering students. These devices are the axial heat transfer apparatus (AHTA), radial heat transfer apparatus (RHTA), and fin heat transfer apparatus (FHTA). These three devices allow students to undertake experiments in conduction heat transfer. The laboratory staff, with the help of third- and fourth-year classes, took this effective step to carry out experiments related to the heat transfer course. The use of surplus materials and locally available low-cost new instruments make them suitable for performing successful laboratory experiments at an affordable cost. The total cost of the three devices is 750 US$. Currently, the devices are in service and show excellent performance. The devices and experiments demonstrated in this work are simple and easy to create. Their design and fabrication are based on tools that are readily available in an engineering department. The experiments achieve important aspects in the study of heat transfer, which enhances students’ understanding of the conduction mechanism in solids.
COVID-19 spread rapidly around the world in 18 months, with various forms of variants caused by severe acute respiratory syndrome (SARS-CoV). This has put pressure on the world community and created an urgent need for understanding its early occurrence through rapid, simple, cheap, and yet highly accurate diagnosis. The most widely adopted method as of today is the real-time reverse-transcriptase polymerase chain reaction. This test has shown the potential for rapid testing, but unfortunately, the test is not rapid and, in some cases, displays false negatives or false positives. The nanomaterials play an important role in creating highly sensitive systems, and have been thought to significantly improve the performance of the SARSCoV-2 protocols. Several biosensors based on micro-and nano-sensors for SARS-CoV-2 detection have been reported, and they employ multi-dimensional hybrids on sensing surfaces with devices having different sizes and geometries. Zero-to-three-dimension nanomaterial hybrids on sensing surfaces, including nanofilm hybrids for SARS-CoV-2 detection, were employed with unprecedented sensitivity and accuracy. Furthermore, the sensors were nanofluidic and mediated high-performance SARS-CoV-2 detection. This breakthrough has brought the possibility of making a biosystem on a chip (Bio-SoC) for rapid, cheap, and point-of-care detection. This review summarises various advancements in nanomaterial-associated nanodevices and metasurface devices for detecting SARS-CoV-2.
Background
Head nurses are vital in understanding and encouraging knowledge sharing among their followers. However, few empirical studies have highlighted their contribution to knowledge-sharing behaviour in Online Health Communities (OHCs). In addition, scant literature has examined the moderating role of knowledge self-efficacy in this regard.
Purposes
This study examines the moderating role of self-efficacy between the association of four selected individual factors of head nurses (i.e., Trust, Reciprocity, Reputation, and Ability to Share) and their knowledge-sharing behaviour in OHCs in Jordan.
Method
The data were obtained by using a self-reported survey from 283 head nurses in 22 private hospitals in Jordan. A moderation regression analysis using a structural equation modelling approach (i.e. Smart PLS-SEM, Version 3) was utilised to evaluate the study’s measurement and structural model.
Results
Knowledge self-efficacy moderates the relationship between the three individual factors (i.e., Trust, Reciprocity, and Reputation) and knowledge-sharing behaviours. However, self-efficacy did not moderate the relationship between the ability to share and knowledge-sharing behaviours.
Implications
This study contributes to understanding the moderating role of knowledge self-efficacy among head nurses in online healthcare communities. Moreover, this study provides guidelines for head nurses to become active members in knowledge sharing in OHCs. The findings of this study offer a basis for further research on knowledge sharing in the healthcare sector.
In this study, we set up and analyze a cancer growth model that integrates a chemotherapy drug with the impact of vitamins in boosting and strengthening the immune system. The aim of this study is to determine the minimal amount of treatment required to eliminate cancer, which will help to reduce harm to patients. It is assumed that vitamins come from organic foods and beverages. The chemotherapy drug is added to delay and eliminate tumor cell growth and division. To that end, we suggest the tumor-immune model, composed of the interaction of tumor and immune cells, which is composed of two ordinary differential equations. The model's fundamental mathematical properties, such as positivity, boundedness, and equilibrium existence, are examined. The equilibrium points' asymptotic stability is analyzed using linear stability. Then, global stability and persistence are investigated using the Lyapunov strategy. The occurrence of bifurcations of the model, such as of trans-critical or Hopf type, is also explored. Numerical simulations are used to verify the theoretical analysis. The Runge-Kutta method of fourth order is used in the simulation of the model. The analytical study and simulation findings show that the immune system is boosted by regular vitamin consumption, inhibiting the growth of tumor cells. Further, the chemotherapy drug contributes to the control of tumor cell progression. Vitamin intake and chemotherapy are treated both individually and in combination, and in all situations, the minimal level required to eliminate the cancer is determined.
Overcoming the issue of photovoltaic (PV) module productivity at high temperatures is one of the most critical obstacles facing its use. PV cells are made of silicon, which loses its properties at high temperatures, degrading the PV module work. The present research compares cotton wicks integrated with rectangular aluminium fins (CWIRAFs) submerged in water as passive cooling with an absorbing plate and copper pipes attached at the PV module backside as active cooling. Compared with the PV module without cooling, CWIRAFs have better performance with the PV module than active cooling owing to evaporative cooling and increased heat dissipation area represented by wet cotton bristles integrated. The PV module is exposed to significant performance degradation without cooling in hot climate conditions. As a result, using CWIRAFs with the PV module had reduced the temperature by 31.4%, increased the power by up to 66.6%, and increased the electrical efficiency from 3.12 to 8.6%. Active cooling methods have reduced the PV temperature by 20.8%, increased the power by 56.7%, and enhanced electrical efficiency by 7.9%. Removing excess heat from the backside of the PV module via circulating water has improved the thermal efficiency and overall efficiency of the PVT system by about 26.3 and 34.2%, respectively.
The information obtained from external sources within the cloud and the resulting computations are not always reliable. This is attributed to the absence of tangible regulations and information management on the part of the information owners. Although numerous techniques for safeguarding and securing external information have been developed, security hazards in the cloud are still problematic. This could potentially pose a significant challenge to the effective adoption and utilization of cloud technology. In terms of performance, many of the existing solutions are affected by high computation costs, particularly in terms of auditing. In order to reduce the auditing expenses, this paper proposes a well-organised, lightweight system for safeguarding information through enhanced integrity checking. The proposed technique implements a cryptographic hash function with low-cost mathematic operations. In addition, this paper explores the role of a semi-trusted server with regard to smart device users. This facilitates the formal management of information prior to distribution through the IoT-cloud system. Essentially, this facilitates the validation of the information stored and exchanged in this environment. The results obtained show that the proposed system is lightweight and offers features such as a safeguarding capability, key management, privacy, decreased costs, sufficient security for smart device users, one-time key provision, and high degree of accuracy. In addition, the proposed method exhibits lower computation complexity and storage expenses compared with those of other techniques such as bilinear map-based systems.
As practical research, this study assesses the resistance of the radially-graded graphene-platelets reinforced (RG-GPLR) nanocomposite annular sector plates against thermal shock. Three-dimensional declaration of the elasticity theory is the base for defining the governing equations of the system. Discrete singular convolution technique (DSCT) is applied as an efficient solution to determine the stress and defection variation of the clamped plate against the instantaneous thermal shock. For the first time, this study considers the effect of thermal shock induced by the radical temperature gradient, heat flux, and the mixed form. Laplace transform combined with the extended Dubner and Abate's technique to find the time history of the system's thermomechanical behavior. The accuracy of the solution is inspected through a comparative analysis between the present and published studies’ results. As a valuable outcome, it is revealed that the fluctuations of the system's response around their ultimate constant values would be damped faster when the applied heat flux is higher.
Non-alcoholic fatty liver disease (NAFLD) is the term for a range of conditions caused by a build-up of fat in the liver. The goal of the study was to determine the link between lipid damage (MDA), enzymatic and non-enzymatic antioxidants, and various biochemical indicators in patients with NAFLD who had diabetes and obese adults. This study included comparison 100 patients and healthy control group, aged 18 to 75 years while BMI range from 15.9 to 50.9 Kg/m2. Enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)); non-enzymatic antioxidants (GSH, vit E and direct and total bilirubin); lipid damage (malondialdehyde (MDA)), and biochemical markers ( liver enzyme ( ALT, AST & ALP), glucose, Albumin and lipid profile in the serum samples were measured . The NAFLD with DM and obese adult showed increasing of glucose, BMI, ALT, AST, ALP, T. CHOL, LDL, TG, VLDL, SOD and CAT levels excepted HDL. It showed a decreasing. Whereas decrease of Vitamin E and ALB levels compared to control group. Our findings show that the serum enzymatic anti-oxidant , non-enzymatic anti-oxidant, dyslipidemia and liver disfunction and vitamin E decrease are tightly and independently related to NAFLD with diabetes and obese adult status.
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Information
Address
Al-Zubair Street, 00964, Az Zubayr, Basra & Thi -Qar, Iraq
Head of institution
Rabee Hashim Alabbasi
Website
www.stu.edu.iq