Gender Differences In Social Presence In Gender-Segregated And Blended Learning Environments In Saudi Arabia

The present study aimed to achieve one of the goals of the Saudi Arabia Vision 2030, which is the improvement of the quality of teaching approaches and learning outcomes. Additionally, the vision strives for equality among students in all educational institutions, including equality among men and women, who are mostly segregated in all aspects of life (e.g., education). One of the major issues in the online portion of blended learning environments is the lack of social presence. Therefore, the present study used a quantitative, cross-sectional survey design to investigate the influence of gender on the perception of social presence levels in gender- segregated and blended learning environments in Saudi Arabia. The findings of this study revealed that the independent variable (gender) had an insignificant impact on dependent variable (social presence levels) in single-gender segregated and blended learning environments. Moreover, gender was not related to any of social presence four constructs (social context, privacy, interactivity, and online communication). The discussion of this study revealed that COVID-19 pandemic and technology evolution in the last decade could be two major factors that impacted the results of this study. The implications of this study are also included in the discussion section

Risk Assessment Using Predictive Analytics

Purpose: This research paper uses design science methodology to develop and evaluate a predictive analytics model for audit risk assessment. This research therefore contributes to improving the accuracy and efficiency of audit risk assessment through predictive analytics.   Theoretical framework: This study involved developing and evaluating a predictive analytics model for audit risk assessment, with it being tested during the audit of a publicly listed Saudi company.   Design/methodology/approach: This study adopted the design science research methodology, which is a problem-solving approach that involves the creation of innovative solutions to practical problems. This methodology is particularly relevant for developing and evaluating predictive analytics models for audit risk assessment, because it provides a structured, systematic approach to the problem-solving process. In the context of this research paper, the design science research methodology was used to develop and evaluate a predictive analytics model for audit risk assessment.   Findings: The proposed predictive analytics model for audit risk assessment was found to be an effective tool for helping auditors to make informed decisions based on data analysis. The model accurately identifies high-risk factors associated with an organization, provides valuable insights for decision-making, and highlights areas of potential risk that may require further investigation.   Research, practical & social implications: Future research could explore several areas related to predictive analytics in audit risk assessment. One important area to investigate would be the impact of using predictive analytics on audit quality. The ethical implications of using predictive analytics in audit risk assessment and the potential biases that could affect a model’s accuracy are also important areas to explore.   Originality/value: This paper helps improve our understanding of how predictive analytics can be effectively applied to audit risk assessment and how design science methodology can be used to develop and evaluate predictive analytics models. Furthermore, this study provides insights about the effectiveness of predictive analytics for improving audit risk assessment, thus contributing to the existing literature on the topic

Nonparametric Tests for the Umbrella Alternative in a Mixed Design for Location

This paper further investigates existing test statistics proposed by Magel et al. (2010) for detecting umbrella alternatives when the peak is known, and the underlying design consists of a completely randomized design (CRD) and randomized complete block design (RCBD). Magel et al. (2010) assumed equal variance between the CRD and the RCBD portions for the power estimates that they conducted.  We investigate the powers of the tests compared to each other when testing for location in this design when the variance of the CRD portion is 2, 4, and 9 times larger than the variance of the RCBD portion. Underlying normal, t, and exponential distributions are considered as well as a variety of location shifts, and different ratios between the sample size in the CRD portion compared to the number of blocks in the RCBD portion

An examination of interaction quality in service encounters in the hotel industry : a customer perspective

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Applications of phase-field modeling in hydraulic fracture

Understanding the mechanisms behind the nucleation and propagation of cracks is of considerable interest in engineering application and design decisions. In many applications in the oil industry, complicated fracture geometries and propagation behaviors are encountered. As a result, the development of modeling approaches that can capture the physics of non-planar crack evolution while being computationally tractable is a critical challenge. The phase-field approach to fracture has been shown to be a powerful tool for simulating very complex fracture topologies, including the turning, splitting, and merging of cracks. In contrast to fracture models that explicitly track the crack surfaces, crack propagation and the evolution thereof arise out of the solution to a partial differential equation governing the evolution of a phase-field damage parameter. As such, the crack growth emerges naturally from solving the set of coupled differential equations linking the phase-field to other field quantities that can drive the fracture process. In the present model, the physics of flow through porous media and cracks is coupled with the mechanics of fracture. Darcy-type flow is modeled in the intact porous medium, which transitions to a Stokes-type flow regime within open cracks. This phase-field model is implemented to gain insights into the propagation behavior of fluid-injected cracks. One outstanding issue with phase-field fracture models is the decomposition of the strain energy required to ensure that compressive stress states do not cause crack propagation and damage evolution. In the present study, the proper representation of the strain energy function to reflect this fracture phenomenon is examined. The strain energy is constructed in terms of principle strains in such a way that it has two parts; the tensile and the compressive. A degradation function only applies to the tensile part enforcing that the crack is driven only by that part of the strain energy. We investigated the split operator proposed by Miehe et al. [1], and then proposed a split approach based on masonry-like material behavior [2, 3]. We have found that when using Miehe’s form for the strain energy function, cracks can propagate under compressive stresses. In contrast, the approach based on a masonry-like materials constitutive model we proposed ensures that cracks do not grow under compressive stresses. To demonstrate the capabilities of phase-field modeling for fluid-driven fractures, four general types of problems are simulated: 1) interactions of fluid-driven, natural, and proppant-filled cracks, 2) crack growth through different material layers, 3) fluid-driven crack growth under the influence of in-situ far-field stresses, and 4) crack interactions with inclusions. The simulations illustrate the capabilities of the phase-field model for capturing interesting and complex crack growth phenomena. To understand how fluid-driven cracks interact with inclusions, AlTammar et al. [4] performed experiments. Three tests with tough inclusions were performed to understand the effects of orientation angle, thickness, and material properties. Additionally, one test with a weak inclusion was performed to compare the results with those of the tough inclusion cases. The experiments show a clear tendency for the fluid-driven hydraulic fracture to cross thick natural fractures filled with materials weaker and softer than the matrix and to be diverted by thick natural fractures with tougher and stiffer filling materials. To replicate these experiments numerically and to gain a mechanistic understanding, in the present study, we ran simulations using phase-field modeling. Results from both the experiments and the simulations provide clear evidence that inclusion width, angle, material properties, and distance from the injection point affect the outcome of the crack evolution. Phase-field modeling was able to capture the trends of crack deflection/crossing in all the test cases. Finally, we extended the phase-field model has been extended to three dimensions and tested it on bench-mark problems. The first bench-mark problem is a compact test for a CT specimen. In this problem, the mechanical equations are only considered. The simulation shows that the CT specimen is split into two symmetric parts. The second bench-mark problem is a fluid-driven circular crack. The simulation for this problem shows that the crack grows in a radial direction.Engineering Mechanic

Tribological studies of bamboo fibre reinforced epoxy composites using a BOD technique

To reduce the emission of harmful materials into the ecosystem, researchers have been exploring the potential of manufacturing polymeric composites based on natural fibres. Although the large area of application of these materials has encouraged investigations of their performance under various loading conditions, less research has been conducted on their tribological behaviour. Hence, in this study, tribological tests were conducted on epoxy composites based on bamboo fibres. The wear performance of bamboo fibre reinforced epoxy was tested using various operating parameters, and the worn surfaces were examined using optical microscopy. The results revealed that the specific wear rate of the composites reduced since the epoxy was reinforced with bamboo fibres. Scanning electron microscopy analysis showed different wear mechanisms and damages

Effect of Fibre Content on Compressive and Flexural Properties of Coconut Fibre Reinforced Epoxy Composites

Coconut fibre reinforced polymer composites are gaining popularity in the field of engineering due to the many benefits that come with them such as low cost of production, easy fabrication, enhanced strength compared to other polymer composites. Of late, there has been an increase in the use of composites that are naturally based because they have many benefits. In line with this, the current research is focused on the mechanical properties of coconut fiber reinforced epoxy composites. The effect of the fibre content on the flexural and compressive characteristics of the epoxy composites was investigated. Chemical treatment of the coconut fibres was performed using 50% bleaching concertation. The composites were fabricated in random orientations withe fibre length of 10 mm as recommended by the literature. Scanning Electron Microscopy (SEM) was used to examine the fractured surfaces. The main findings are that the increase in the volume fraction of the coconut fibre in the epoxy composites increases the flexural and compressive strengths. SEM showed that the main failure mechanisms were brittle nature in the epoxy regions and pullout and breakage of fibres in the coconut region

Epoxy and polyester composites’ characteristics under tribological loading conditions

This research examines the friction and dry wear behaviours of glass fibre-reinforced epoxy (GFRE) and glass fibre-reinforced polyester (GFRP) composites. Three fibre orientations—parallel orientation (P–O), anti-parallel orientation (AP–O), and normal orientation (N–O)—and various sliding distances from 0–15 km were examined. The experiments were carried out using a block-on�ring configuration at room temperature, an applied load of 30 N, and a sliding velocity of 2.8 m/s. During the sliding, interface temperatures and frictional forces were captured and recorded. Worn surfaces were examined using scanning electron microscopy to identify the damage. The highest wear rates for GFRE composites occurred in those with AP–O fibres, while the highest wear rates for GFRP composites occurred in those with P–O fibres. At longer sliding distances, composites with P–O and N–O fibres had the lowest wear rates. The highest friction coefficient was observed for composites with N–O and P–O fibres at higher sliding speeds. The lowest friction coefficient value (0.25) was for composites with AP–O fibres. GFRP composites with P–O fibres had a higher wear rate than those with N–O fibres at the maximum speed

Investigating the lap shear adhesion of coir and glass-fibre reinforced epoxy bonding to mild steel with varying volume fractions

Bonding synthetic fibres to metals to improve strength, durability, and corrosion resistance is a prevalent practise in the automotive, marine, and aerospace industries. Lap shear adhesion, a measurement of the bonding strength between composites and metallic substrates, is essential for structural integrity. The emergence of natural fibre composites as sustainable alternatives to synthetic composites makes it essential to investigate their lap shear behaviour and the effect of fibre volume fraction on composite properties. This research investigates the adhesion behaviour of coir and glass fibre epoxy composites to mild steel. Coir fibres, which are known for their resilience and tenacity, were treated with an alkaline solution to improve their adhesion to the resin. Samples of lap shear adhesion were prepared in accordance with ASTM specifications, and tests were conducted using a tensile machine. Increasing the volume fraction of coir or glass fibres decreased the bond strength, as demonstrated by the results. Due to the fibres’ greater tensile strength and rigidity, glass fibre composites exhibited superior strength. However, under tensile loading conditions, coir fibres exhibited superior adhesion to mild steel surfaces. SEM micrographs confirmed that coir composites exhibit shear failure while glass composites exhibit fibre pull-out behaviour. This study concludes by highlighting the engineering potential of coir fibres, considering their natural properties and cost-effectiveness. It is necessary to further optimise the fiber-matrix interface and comprehend the mechanical behaviour of coir composites in order to maximise their effectiveness. To assure the long-term durability of composite-metal joints, surface preparation, adhesive type, application procedure, and environmental conditions must also be considered. At a content percentage of 10%, glass fibres exhibited 100% higher shear strength compared to coir fibres in epoxy composites. Conversely, coir fibres at 10% content demonstrated approximately 75% greater shear strength than the values obtained with 40% glass fibres. The failure mechanisms observed are delamination or fibre fracture in the bonding area under tensile and shear loading. Increasing the fibre volume fraction reduces bond strength. Factors such as limited space for the matrix, tension concentrations, and the mechanical properties of the fibres contribute to weakened bonds. Glass fibres have better strength and rigidity than coir fibres, affecting load transfer and adhesion. Interfacial bonding is crucial, and maintaining it becomes more difficult with higher fibre volume fractions, resulting in weakened bonds

Female health college students’ knowledge and attitude towards breast cancer

BackgroundBreast cancer is the most common cancer in women in Saudi Arabia and worldwide. It occurs at an earlier age in comparison with Western countries and account for 25.1 per cent of all newly diagnosed female cancers.AimsAim was to assess knowledge level of breast cancer risk factors, the symptoms, the signs and screening methods of early detection among female students at the health colleges. Additionally, to determine the attitude of students towards the breast cancer.Methods A cross-sectional study was carried out on a representative sample of female students at the health colleges in King Abdulaziz University, through stratified sampling with proportional allocation.Results More than 78 per cent of the students had good knowledge about the symptoms and signs of breast cancer, and 76.8 per cent of them had positive attitude towards believing and treatment of breast cancer. About 75.5 per cent of students mentioned mammography is an early screening method. However, the total score of insufficient knowledge about breast cancer risk factors was 57.5 per cent. Logistic regression analysis revealed that lower grades were the predictors of insufficient knowledge about breast cancer risk factors.ConclusionAlthough the students had a good knowledge about the symptoms and signs of breast cancer and they had positive attitude towards believing and treatment of breast cancer, for example, most of them will consult a doctor if they develop breast cancer and they will agree to perform mastectomy if she needed, they will see a doctor within one week if they have breast lump and they thought that the breast cancer is a curable disease. However, they had insufficient knowledge of some risk factors. So, we should focus on increasing the knowledge of risk factors among the students either through regular update teaching courses and methods or through health education workshop or campaigns