Retention of At-Risk Students: a Case Study from a Tertiary Education Institution in the Middle East

This study investigates the engagement and retention of higher education students in the Middle East. It focuses on a group of students who have been identified as ‘at-risk’ of leaving before completing their course in a government-funded tertiary education institution, one of a group of 17 male and female colleges spread across one country in the Middle East. The study reflects growing concern over the need to improve students’ retention and success levels in this part of the world and contributes theoretically and practically to the field. More specifically, it addresses two research questions: 1) What are the main reasons for poor student engagement and retention in this context? and 2) How can faculty through their formal and informal interaction with students contribute to the retention and engagement of at-risk students? An interpretive method of inquiry was adopted and conducted through a qualitative case study focusing on a single institution. The empirical data were collected through focus groups with students and staff. The focus groups were conducted in Arabic with students, and English with teachers, reflecting the linguistic preferences of the participants. The qualitative focus group data were analysed thematically and then considered in relation to existing institutional quantitative data. This process helped triangulate and extend the qualitative data findings to enhance the validity of this investigation. The study was informed by existing literature on student persistence regarding course completion. To develop a theoretical framework, Tinto's model of departure (1975) was utilised initially, as it recognises the importance of both social and academic integration, and the contribution of the attributes that students bring with them to the institution, such as prior education and personal circumstances. The second phase of the empirical work homed in on the role of academic staff in contributing to the engagement and success of students. Findings from the case study research reaffirmed the consensus in the literature that retention is a multidimensional issue; students leave for a range of reasons (Sanders et al., 2016). The thematic analysis of the empirical data identified additional issues that contribute to early departure, which are specific to the cultural and geographical context of the Middle East. Following on from this, a new conceptual model for students’ engagement and retention in the Middle East, which identifies practical ways to improve the outcomes of students in this part of the world, is presented

Span morphing using the GNATSpar wing

Rigid wings usually fly at sub-optimal conditions generating unnecessary aerodynamic loses represented in flight time, fuel consumption, and unfavourable operational characteristics. High aspect ratio wings have good range and fuel efficiency, but lack manoeuvrability. On the other hand, low aspect ratio wings fly faster and are more manoeuvrable, but have poor aerodynamic performance. Span morphing technology allows integrating both features in a single wing design and allows continuously adjusting the wingspan to match the instantaneous flight conditions and mission objectives. This paper develops, a novel span morphing concept, the Gear driveN Autonomous Twin Spar (GNATSpar) for a mini-UAV. The GNATSpar can be used to achieve span extensions up to 100% but for demonstration purposes it is used here to achieve span extensions up to 20% to reduce induced drag and increase flight endurance. The GNATSpar is superior to conventional telescopic and articulated structures as it uses the space available in the opposite sides of the wing instead of relying on overlapping structures and bearings. In addition, it has a self-locking actuation mechanism due to the low lead angle of the driving worm gear. Following the preliminary aero-structural sizing of the concept, a physical prototype is developed and tested in the 7?×5? wind-tunnel at the University of Southampton. Finally, benefits and drawbacks of the design are highlighted and analysed

The use of acoustic emission for damage assessment of composite materials and life prediction under spectrum fatigue loading

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PE-HD fatigue damage accumulation under variable loading based on various damage models

Despite numerous studies on fatigue of polymer materials under variable loading, there is little work on highdensity polyethylene (PE-HD). In this context, an experimental analysis for determining the fatigue strength of PE-100, under constant and variable amplitude loading is presented. Further, the cumulative fatigue damage behavior of PE-100 was experimentally investigated. First, the fatigue curve (S-N: stress vs. number of cycles) was obtained in order to establish the fatigue life of PE-100 subjected to constant stress amplitude. Secondly, Miner’s fatigue rule as well as stress-based and energy-based fatigue damage models were used to estimate the cumulative variable amplitude fatigue damage. Comparison between predictions and experimental results showed different trends depending on the choice of prediction model used implying careful fatigue damage consideration when designing under variable amplitude loading

The Effect of Alkaline Treatment on Mechanical Performance of Natural Fibers-reinforced Plaster: Optimization Using RSM

In the last decades, eco-friendly materials are playing an interesting role. Particularly, many studies deal with the use of natural fibers as a replacement to synthetic fibers in the plaster matrix. This study has examined the flexural properties of treated natural sisal, flax and jute fibers with different concentrations of NaOH (1.5%, 2% and 4%) and fiber length (5, 10 and 20 mm) reinforced plaster mortars. In this study, the effect of experimental parameters was determined by using analysis of variance ANOVA test. In addition, the response surface methodology (RSM) and desirability function (DF) are also used to optimize the output responses with maximizing the flexural properties. Finally, the experimental results are in good agreement with those obtained statistically

Span morphing using the GNAT spar for a mini-UAV: designing and testing

Rigid wings usually fly at sub-optimal conditions which generates unnecessary aerodynamic loses represented in flight time, fuel consumption, and unfavourable operational characteristics. Large wingspans allow for good range and fuel efficiency, but lack manoeuvrability; on the other hand, low aspect ratio wings fly faster and are more manoeuvrable, but suffer from poor aerodynamic performance. Span morphing technology allows integrating both features in a single wing design and allows continuously adjusting the wingspan to match the instantaneous flight conditions and mission objectives. This paper develops a novel span morphing concept called the Gear driveN Autonomous Twin (GNAT) spar for a mini-UAV. The GNAT spar allows span extension up to 25% of the original span to reduce induced drag and increase flight endurance. The GNAT is superior to conventional telescopic structures as it uses the extra space available in the other side of the wing instead of relying on overlapping structures associated with telescopic spars. In addition, it has a self-locking capability due to the low lead angle of the driving worm gear of its actuation mechanism. Aero-structural sizing and design of the concept is performed using low fidelity aerodynamics (XFLR5) and high-fidelity FE solver (SolidWorks). Furthermore a physical prototype of the concept is developed, followed by the integration of Latex flexible skin to provide the aerodynamic shape of the wing. Following from this, the design of robust control system using the Arduino Uno R3 microcontroller is discussed. Finally, benefits and drawbacks of the design are highlighted and analysed

Twist morphing using the variable cross section spar: a feasibility study

This paper presents the variable cross section spar (VCSpar) concept that facilitates varying the shear center position relative to the aerodynamic center, allowing the external aerodynamic loads to twist the structure and maintain its deformed shape. The VCSpar is considered in this paper as integrated within the wing of a representative unmanned aerial vehicle (UAV) to enhance its flight performance and control authority. A preliminary design study was conducted to assess the potential benefits of the concept using a low-fidelity design tool. Then, aeroelastic modeling of the concept was performed where the VCSpar was modeled as a two-dimensional equivalent aerofoil using bending and torsion shape functions to express the equations of motion in terms of the twist angle and plunge displacement at the wingtip. The aerodynamic lift and moment acting on the equivalent aerofoil were modeled using Theodorsen’s unsteady aerodynamic theory. A low-dimensional state-space representation of an empirical Theodorsen’s transfer function was adopted to allow time-domain analyses