The sensitivity of GCC firms’ stock returns to exchange rate, interest rate, and oil price volatility

This study seeks to investigate the sensitivity of stock returns to exchange rate, interest rate and oil price volatility in the Gulf Cooperation Council (GCC) countries. It employs both the multivariate ordinary least square (OLS) regression and the exponential generalized autoregressive conditional heteroscedastic in mean (EGARCH-M) models to analyse the data collected from Bloomberg and Datastream on the GCC countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and United Arab Emirates) for the period January 2007 to June 2012. The study shows that stock returns in GCC countries are influenced by the exchange rate risk, interest rate risk and oil price risk. However, the exposure is highest for exchange rate risk and lowest for interest rate risk. While the effects of these risks were mixed, overall, exchange rate risk and oil price risk showed a positive and significant relationship as compared to the interest rate risk that showed a negative significant effect on firm values. The level of the effect of these risks also differed from country to country. Further, foreign operations and firm size had a significant influence on the extent of the firms’ exposure to all the three risks. The study findings suggest that the volatility of stock returns affected by changes in the risk factors could indicate non-prioritisation of risk management by firms. This has implications in terms of consideration of the long-term exposure of firms to these three risks and thus, the need for effective risk management strategies

Hydrodynamic performance comparison between the outflow of the breakwater oscillating water column (OWC's) devices and offshore OWC device attached to an offshore structure by using Computational Fluid Dynamics (CFD) analysis.

The oscillating water column (OWC) Device is a type of wave energy converters (WEC), as it intends to transform energy from wave energy at sea into electricity by using the wave heaving to move confined air and thus drive an air turbine to generate the power. Furthermore, this thesis manages the hydrodynamic analysis of two types of the oscillating water column (OWC) devices that are gliding freely in limited profundity waters and presented in the activity of standard surface waves. The hydrodynamic analysis, the comparison was made by applying the technique of Computational Fluid Dynamics (CFD) analysis. The significant agreement that CFD is an extremely encouraging device that an originator can utilize it to explore and survey gadget survivability under various conditions upon further approvals in different wave conditions, This method provided an efficient tool for complete hydrodynamic analysis of these devices, the hydrodynamic pressure Parameters; and by using the inputs of wave’s characteristics in the Arabian Gulf Area which have an average historical wave height of 1m. The OWC chamber model used in previous experiments has detailed that it is for the breakwater and for the offshore OWC using the inner diameter, which achieves the same cross-sectional area with the breakwater chamber. A numerical model and Numerical Wave Tank (NWT) established to evaluate the interaction of an OWC with the water in different cases of different depths of the sea. ANSYS is used here to find the effects of the water surface in and around the central column, breakwater-mounted OWC, and calculate the equations of Navier-Stokes to get the vertical component of air entering and exiting the vent of the OWC. After modeling and analysis of the output flow, we got to conclusions for the hydrodynamic performance of the breakwater chamber shows higher efficiency than the open ocean fixed OWC, in addition to that the variation of the energy with the wave steepness.Chapter 1.Introduction 1 1.1. Introduction 1 1.2. Forces acting on an OWC 2 1.3. Classification of OWCs by location and shape 3 1.3.1. Location of OWCs 4 1.4. Power take-off for OWC-WEC 7 1.4.1. Rectifying airflow using valves 8 1.4.2. The Wells turbine 8 Chapter 2.Theory behind OWC 11 2.1. Theory 11 2.2. Wave Theoretical Considerations 11 2.3. Wave Small Amplitude Theory 12 2.4. Wave Velocity and Wave Classification 13 2.5. Higher-Order Theories 15 2.5.1. General 15 2.5.2. OWC Efficiency 18 2.6. Research Background 25 Chapter 3.CFD modeling and analysis 26 3.1. Research contents 26 3.2. Research Goals 26 3.3. Modeling and Analysis 27 3.3.1. Numerical Wave Tank 28 3.3.2. Validation of Wave Propagation 37 3.3.3. OWC Numerical Analysis 41 3.3.4. Summarized efficiency equations 43 3.4. Performance of the OWC in a real sea 44 3.4.1. Describing real seas 45 3.4.2. Irregular waves Performance 47 3.4.3. Annual performance 49 3.5. Review of the Modelling 57 3.5.1. Impulse Functions and Mechanical Oscillators 57 3.5.2. Methods of Boundary Element and Diffraction 58 3.5.3. Investigations for Computational Fluid Dynamics 60 3.6. Summary 65 Chapter 4.The Comparative evaluation of analysis results 66 4.1. Hydrodynamics 66 4.1.1. Modeling 66 4.1.2. Major findings 75 4.1.3. Importance 75 4.1.4. Limitations 75 4.2. Time-domain modeling 76 4.2.1. Time-Domain Modeling Main Findings 76 4.2.2. The time-domain modeling Importance 77 4.2.3. Limitations 78 4.3. Computational fluid dynamics 80 4.4. Fluent Results 84 Chapter 5.Discussion 89 5.1. Discussions 89 Chapter 6.Conclusions 95 6.1. Numerical Wave Tank NWT 95 6.2. Parametric Simulations of the OWC 96 6.3. Practical Modeling of the OWC 97 6.4. Limitations 98 Acknowledgment 100 References 100Docto

Workability and compressive strength of eco-friendly concrete based on waste ceramic particles

Eco-materials are becoming the one of the important matters to be addressed in industries and academics owing to reduce the impact of synthetic materials on environment. On the other hand, waste materials have becoming an equal important matter in term of disposal and their impact on environment. In civil engineering, exploring any potential eco-materials for structural components is the ambition of many engineering and environmental researchers. In this project, an attempt is made to explore the potential of using waste ceramic particles in concrete. The structure and the compressive characteristics of the developed materials with different waste ceramic particle percent are investigated. Different concrete samples were prepared and tested. The failure mechanisms were determined after the completion of the experiments. The optimum percent of waste ceramic particles in concreate were determined from workability, compressive strength and structure of the concrete. Compressive strength of the developed concretes were tested at different curing duration of 7, 14 and 28 days. Visual examination and scanning electron microscope were used to observe the failure mechanism. The experimental results were in high agreement with the published recent and related works. The content of the waste ceramic particle controlled all the characteristics of the ceramics, i.e. workability, compressive strength, and the structure. Increase in the content of the waste ceramic particles deteriorate the strength of the concrete especially at content of above 25 wt. %. Despite of that the reduction in the strength at low percent of waste ceramic particle were within the industrial recommended ranges. Also, from environmental point of view, a promising results are identified and 25 wt % of waste ceramic particles in concrete is highly recommend. The failure of the concreate was commonly due to the crack generation and/or propagation in the bonding region of the particles and the cement. At high percent of waste ceramic particles, there is micro- and mac-cracks propagated which resulted in the poor performance of the concreate at this high percent of particle

The effects of a burnout prevention programme on mental health nurses in the Kingdom of Saudi Arabia (KSA)

Burnout is a common problem among mental health professionals, particularly mental health nurses. High levels of burnout result in job dissatisfaction, rapid turnover of staff, physical and psychological discomfort, and reduction in the quality of patient care. While there is an abundance of research relating to burnout per se, there is a lack of research regarding burnout among mental health nurses in Saudi Arabia, and more specifically of the impact a burnout prevention programme might have on those experiencing high levels of work related stress. In starting to address this gap, the aim of this study was to identify the level of burnout, predictors of burnout, and measure the effects of a burnout prevention programme on mental health nurses working in Saudi Arabia. A quasi-experimental design was used to test the effectiveness of a two-day burnout prevention workshop offered to mental health nurses working in Saudi Arabia. The sample was drawn from the Al-Amal Complex for Mental Health at two sites; Riyadh and Ara'r, the former providing the intervention group, the latter the control group. The workshop consisted of providing information about burnout, as well as strategies to decrease stress. A demographic questionnaire, as well as the Maslach Burnout Inventory (MBI), was used to collect data immediately before conducting the workshop and at one, three and six month intervals after participants had completed the workshop. Data were analysed using the latest version of SPSS. Means, standard deviations, frequencies and percentages were used to describe the sample and levels of burnout experienced by the nurses. A t-test, ANOVA, Multiple linear regression and chi squared were used to measure the effect of the workshop before and at three intervals after the nurses were exposed to the burnout prevention programme. Findings indicate the burnout prevention programme was effective with a significant reduction being reported one month after the intervention. However, although not returning to baseline scores, an increase in the burnout score was again observed after 6 months, indicating a need to continue with the programme at reasonable intervals. However, the overall efficacy of the burnout reduction programme is evident within this study as there was a significant reduction in burnout among mental health nurses working in Saudi Arabia. Importance and Relevance This research was carried out to address burnout levels by introducing a burnout prevention programme and measuring the effects of such on mental health nurses working in Saudi Arabia. Additionally, predictive factors of burnout for this target geoup were also identified. This is the first of study within Saudi Arabia

Predicting effect of emotional-social intelligence on academic achievement of nursing students

Background. Academic achievement refers to the extent to which a learner, instructor or institution has accomplished their short- or long-term educational goals. There are inconclusive results about the individual factors that successfully predict academic performance. Emotional intelligence has been a popular topic in the field of higher educational learning. Several research reports have shown that emotional intelligence is one of the factors that successfully predicts students’ academic achievement.Objectives. To examine the relationship between emotional-social intelligence (ESI) and self-reported academic achievement among nursing students.Methods. A descriptive-comparative approach was used. The study was carried out on 127 nursing students from different academic levels. The study used two tools, namely an ESI questionnaire and an academic achievement scale.Results. The females had statistically significant higher means than the males in their scores on the ESI questionnaire (p=0.042) and interpersonal competencies (p=0.003). There were positive correlations between ESI score, its five components and students’ self-reported academic achievement.Conclusion. The outcome of this study suggests that educational planners and academicians should embrace emotional intelligence-developing courses at college and university levels

Osseointegration effects of local release of strontium ranelate from implant surfaces in rats

BACKGROUND: Numerous studies have reported the beneficial effects of strontium on bone growth, particularly by stimulating osteoblast proliferation and differentiation. Thus, strontium release around implants has been suggested as one possible strategy to enhance implant osseointegration. AIM: This study aimed to evaluate whether the local release of strontium ranelate (Sr-ranelate) from implants coated with mesoporous titania could improve bone formation around implants in an animal model. MATERIALS AND METHODS: Mesoporous titania (MT) thin coatings were formed utilizing the evaporation induced self-assembly (EISA) method using Pluronic (P123) with or without the addition of poly propylene glycol (PPG) to create materials with two different pore sizes. The MT was deposited on disks and mini-screws, both made of cp Ti grade IV. Scanning electron microscopy (SEM) was performed to characterize the MT using a Leo Ultra55 FEG instrument (Zeiss, Oberkochen, Germany). The MT was loaded with Sr-ranelate using soaking and the drug uptake and release kinetics to and from the surfaces were evaluated using quartz crystal microbalance with dissipation monitoring (QCM-D) utilizing a Q-sense E4 instrument. For the in vivo experiment, 24 adult rats were analyzed at two time points of implant healing (2 and 6 weeks). Titanium implants shaped as mini screws were coated with MT films and divided into two groups; supplied with Sr-ranelate (test group) and without Sr-ranelate (control group). Four implants (both test and control) were inserted in the tibia of each rat. The in vivo study was evaluated using histomorphometric analyses of the implant/bone interphase using optical microscopy. RESULTS: SEM images showed the successful formation of evenly distributed MT films covering the entire surface with pore sizes of 6 and 7.2 nm, respectively. The QCM-D analysis revealed an absorption of 3300 ng/cm2 of Sr-ranelate on the 7.2 nm MT, which was about 3 times more than the observed amount on the 6 nm MT (1200 ng/cm2). Both groups showed sustained release of Sr-ranelate from MT coated disks. The histomorphometric analysis revealed no significant differences in bone implant contact (BIC) and bone area (BA) between the implants with Sr-ranelate and implants in the control groups after 2 and 6 weeks of healing (BIC with a p-value of 0.43 after 2 weeks and 0.172 after 6 weeks; BA with a p-value of 0.503 after 2 weeks, and 0.088 after 6 weeks). The mean BIC and BA values within the same group showed significant increase among all groups between 2 and 6 weeks. CONCLUSION: This study could not confirm any positive effects of Sr-ranelate on implant osseointegration

Pattern of Congenital Dislocation of the Hip in Arar City, Northern Saudi Arabia

Background: Developmental dysplasia of the hip (DDH) is one of the most widely discussed abnormalities in neonates. The etiology of DDH is unknown. There are many insights, however, from epidemiologic/demographic information. Aim of the study: To determine the incidence, risk factors and treatment modalities of congenital dislocation of the hip (CDH) in Arar city, Northern Saudi Arabia. Methods: This is prospective study involve 955(19100hips) infants referred to Arar central hospital. During the period from 1 January 2014, to 31 December 2016, each infant was evaluated by history taking, clinical and sonographic examination for hip abnormality. Results: The incidence of (CDH) was 3.1% (73.3% were females), 70.0% of the affected had positive family history and in 46.7% there was consanguinity between parents. In 80.0% there was regular follow up during pregnancy. 16.7% had history of oligohydramnios. Breech presentation was found in 26.7% and 15.0% delivered by caesarian section. First born children constituted 25.0%. The left hip joint was more affected( 41.6%) , the right hip joint affected in  28.3% and bilateral CDH were involved in 13.3%. In the studied cases, 40.0% of the infants were treated surgically, 30% conservatively, 16% by both and 14% were referred to higher centers. Conclusion and recommendations: CDH in Arar, Central hospital and by inference in Northern region of Saudi Arabia was found to be 3.1%. Awareness programs, routine neonatal hip joint examination at birth and up to one year of age as well as ultrasound examination of pelvis in high-risk babies are strongly recommended

Flow structure and heat transfer of jet impingement on a rib-roughened flat plate

The jet impingement technique is an effective method to achieve a high heat transfer rate and is widely used in industry. Enhancing the heat transfer rate even minimally will improve the performance of many engineering systems and applications. In this numerical study, the convective heat transfer process between orthogonal air jet impingement on a smooth, horizontal surface and a roughened uniformly heated flat plate is studied. The roughness element takes the form of a circular rib of square cross-section positioned at different radii around the stagnation point. At each location, the effect of the roughness element on heat transfer rate was simulated for six different heights and the optimum rib location and rib dimension determined. The average Nusselt number has been evaluated within and beyond the stagnation region to better quantify the heat transfer advantages of ribbed surfaces over smooth surfaces. The results showed both flow and heat transfer features vary significantly with rib dimension and location on the heated surface. This variation in the streamwise direction included both augmentation and decrease in heat transfer rate when compared to the baseline no-rib case. The enhancement in normalized averaged Nusselt number obtained by placing the rib at the most optimum radial location R/D = 2 was 15.6% compared to the baseline case. It was also found that the maximum average Nusselt number for each location was achieved when the rib height was close to the corresponding boundary layer thickness of the smooth surface at the same rib position

Recent advances in the Biosynthesis of Zirconium Oxide Nanoparticles and their Biological Applications

أثار أكسيد الزركونيوم  ZrO2  اهتمام الباحثين في جميع أنحاء العالم، لا سيما منذ تطوير طرق لتصنيع جزيئات بحجم النانو. تم تحفيز الدراسة المكثفة في تكوين الجسيمات النانوية باستخدام تقنيات تركيبية مختلفة، بالإضافة إلى استخداماتها المحتملة، من خلال كفاءتها الضوئية العالية، وفجوة النطاق العريض، وطاقة ربط الأكسيتون العالية. في تغليف المواد الغذائية، يمكن استخدام الجسيمات النانوية لثاني أكسيد الزركونيوم كعوامل مضادة للميكروبات ومضادة للسرطان. استجابةً للاهتمام المتزايد بـ nano ZrO2 ، ابتكر الباحثون وطوروا طرقًا لتركيب الجسيمات النانوية. تم مؤخرًا إنشاء مركبات ZrO2 النانوية ذات الأشكال المختلفة باستخدام طرق بيولوجية ("الكيمياء الخضراء"). تساهم كل من الميكروبات والنباتات في إنتاج الزركونيا في المختبر. يتم توفير عوامل التثبيت بواسطة الجزيئات الحيوية الموجودة في المستخلصات النباتية، بينما يتم توفير الإنزيمات بواسطة الكائنات الحية الدقيقة كعوامل للتغطية والتثبيت (داخل الخلايا أو خارج الخلية). من الممكن تحليل الجسيمات النانوية المنتجة باستخدام مجموعة متنوعة من الأساليب التحليلية، بما في ذلك التحليل الطيفي للأشعة فوق البنفسجية المرئية، وحيود الأشعة السينية (XRD) ، والمجهر الإلكتروني للإرسال (TEM) ، والتحليل الطيفي للأشعة تحت الحمراء (FT-IR). عند تطبيقها على البكتيريا (موجبة الجرام وسالبة الجرام) والفطريات، تظهر ZrO2NPs قدرات واعدة مضادة للجراثيم. تعتبر الخلايا الطبيعية والخبيثة حساسة للجسيمات النانوية ZrO2 ، والتي يمكن تفسيرها من خلال توليد الأكسجين التفاعلي (ROS). يناقش هذا العمل ويصف الطرق العديدة لإنتاج جسيمات ZrO2 النانوية، بالإضافة إلى خصائصها وإمكانيات التطبيق المختلفة.A critical milestone in nano-biotechnology is establishing reliable and ecological friendly methods for fabricating metal oxide NPs. Because of their great biodegradable, electrical, mechanical, and optical qualities, zirconia NPs (ZrO2NPs) attract much interest among all zirconia NPs (ZrO2NPs). Zirconium oxide (ZrO2) has piqued the interest of researchers throughout the world, particularly since the development of methods for the manufacture of nano-sized particles. An extensive study into the creation of nanoparticles utilizing various synthetic techniques and their potential uses has been stimulated by their high luminous efficiency, wide bandgap, and high exciton binding energy. Zirconium dioxide nanoparticles may be used as antimicrobial and anticancer agents in food packaging. In response to the growing interest in nano ZrO2, researchers invented and developed methods for synthesizing nanoparticles. ZrO2 nanocomposites with various morphologies have recently been created using biological (green chemistry) methods. Microbes and plants both contribute to the production of zirconia in the laboratory. Capping and stabilizing agents are provided by the biomolecules found in plant extracts, whereas microorganisms provide enzymes as capping and stabilizing agents (intracellular or extracellular). It is possible to analyze the nanoparticles produced using a variety of analytical approaches, including ultraviolet-visible spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). When applied to bacteria (both Gram-positive and Gram-negative) and fungi, ZrO2NPs show promising antibacterial capabilities. Normal and malignant cells are sensitive to ZrO2 nanoparticles, which can be explained by the generation of reactive oxygen (ROS). This work discusses and describes many ways of producing ZrO2 nanoparticles, their properties, and various application possibilities