Sami Shamoon College of Engineering

BackgroundFlight attendants (FAs) are subject to unique occupational demands, increasing their risk of developing work-related musculoskeletal pain (WRMSP). WRMSP is influenced by physical, psychosocial, and demographic factors that may change over time due to evolving work environments and practices.ObjectivesCompare the prevalence of FAs' WRMSP in 2016 vs 2024; Identify key physical and psychosocial predictors of WRMSP in each period; explore implications for ergonomic interventions and health promotion strategies tailored to the aviation work environment.MethodsTwo cross-sectional cohorts of FAs, from 2016 (n = 94) and 2024 (n = 89), completed identical, validated questionnaires using the same sampling frame. Surveys covered demographics, occupational tasks, region-specific pain, and psychosocial factors.ResultsArm and hand pain were less prevalent in 2024. Logistic regressions showed higher odds of neck pain in 2024 associated with stress, attitudes, and satisfaction, but markedly lower odds of arm pain across psychosocial and task factors. Lower back pain was less predicted in 2024 when satisfaction was considered. Across both years, hand pain increased with workload and oven-loading but decreased with age and authority; finger pain rose with effort; upper back pain with BMI and time pressure; shoulder pain with dissatisfaction; elbow pain with standing.ConclusionsTechnological and organizational changes appear to have contributed to reduced arm and hand pain and to lower back pain being less predicted in 2024, while psychosocial stressors were linked to increased neck pain, underscoring the dual impact of ergonomic improvements and persistent organizational pressures on WRMSP.

Previous studies have shown a clear correlation between the value of the human ZP shear modulus and implantation potential. Nevertheless, the mechanical response of the ZP changes following fertilization due to a phenomenon termed Zona hardening were not demonstrated. The current study investigated the Zona hardening phenomenon using a computational approach based on oocyte specific clinical data taken from IVF procedures. By analysis of ZP deformation before and after fertilization the value of the ZP shear modulus was estimated. The results clearly show an increase in ZP shear modulus by an average factor of 1.768 ± 0.83 which is consistent with past studies. There is, however, great variability in the amount of Zona hardening for the different oocytes analyzed. It is shown, that while the value of the ZP shear modulus before fertilization is well correlated with embryo implantation potential, strengthening past observations, the ZP shear modulus estimated at days 2-3 after oocyte retrieval is not correlated with implantation.

This study presents the development of a heterogeneous photoelectrochemical system using the known water oxidation catalyst [Ru(tpy)(bpy)(OH2)](ClO4)2 (tpy = 2,2′:6′,2″-terpyridine, bpy = 2,2′-bipyridyl), which was patterned on meta-chemical surface (MCS) electrodes, using the DPN (dip-pen nanolithography) technique. The MCS electrodes demonstrate higher currents and turnover frequencies (kcat) compared to their coated counterparts and the homogeneous system under dark conditions and 475 nm illumination, pointing out higher efficiency in water oxidation. The results highlight the effectiveness of MCS electrodes in improving electrode performance (kcat equal to 1903 s–1 and 989 s–1 at dark and light conditions, respectively). These results advance the continuous development of water-splitting technologies and help advance hydrogen as a practical alternative energy source.

It is well known that fixed-frequency constant-coupling series(capacitor)-series(capacitor) (S(C)-S(C)) compensated inductive wireless power transfer links (IWPTL) may be designed to operate with load-independent voltage gain (LIVG) within bounds dictated by parameters of the loosely coupled transformer (LCT). Lately, it has been shown that these bounds may be extended by employing series(inductor)-series(capacitor) (S(L)-S(C)) or series(capacitor)-series(inductor) (S(C)-S(L)) compensation networks, allowing attaining arbitrary LIVG at the expense of utilizing full-rating inductors as compensation elements. This work proposes a design method allowing to simultaneously attain arbitrary LIVG with S(C)-S(C) compensated IWPTL and minimize inverter VA rating. The revealed methodology is validated in PSIM simulation and experiments.

Studies for more than two decades have uncovered a variety of difficulties and misconceptions that novice programmers have with object-oriented programming (OOP). Particularly challenging are the threshold concepts of program dynamics. Studies show that engaging learning approaches may be helpful. One such approach is that of capitalizing on errors, which has been successfully applied in mathematics and physics education. The learning-from-errors approach embedded in an OOP course may improve novices’ comprehension of OOP program dynamics notions and promote the embedment of such an approach in teaching. An instructional approach capitalizing on cognitive conflicts and conflict resolution was designed, applied, and evaluated. The approach involved declarative specifications of the fundamental, challenging notions of object creation and object access. The specifications embodied the mental models at which the instruction was aimed. Focused learning-from-errors activities based on minimalism principles were developed and applied. A comparative evaluation of an experimental group and a control group showed that the experimental-group students were more successful, particularly with the assimilation of the notions of object creation, object identifiers, static elements, and encapsulation. The learning-from-errors approach may be applied in additional domains, including other programming paradigms.

Quasi-one-dimensional systems with multiple conduction channels are essential for describing a range of physical phenomena. In this paper, we analyse transport in wires where electrons are subject to arbitrary number of strong multi-particle backscattering terms. We present an exact calculation of the system’s scattering matrix and derive a formula for the two-terminal conductance. We find the conductance is reduced from its ideal value by a term corresponding to the projection of current fields onto the subspace of integer-valued vectors characterising the gapped channels created by the perturbations. Applying this result, we establish the minimal model required to reproduce the recently observed, yet unexplained, fractional conductance plateaus with even denominators.