Effect of a Multiaxial Load of Reverse Torsion on Open-Cell Aluminum Foams Behavior.

As a main goal of this work, a novel generation of cellular materials has been developed and manufactured by the kelvin cell model to be offered for different multifunctional applications. These Open-Cell Aluminum Foams (OCAF) have 85% porosities of spherical-shaped pores with a diameter of 11 mm. Several foamed square-section specimens were used. This work investigated the impact of different new quasi-static biaxial loading complexities on the mechanical behavior of such foams. Thus, new S-profiled rigs were already designed for examining the behavior of tested foams under biaxial loading conditions with different reverse torsional components named ACTP-S. After testing, their high specific strength and high energy absorption abilities have been characterized. Thus, in addition to the reference uniaxial test, all other tests were conducted at a speed of 5 mm/min. Thus, the mechanical responses of this foam are affected by loading complexities which are simple uniaxial, intermediate-biaxial (Bi-45°), and sever-biaxial (Bi-60°). These results were compared to the classical Absorption using Compression-Torsion Plastique (ACTP) responses. It was concluded that the highest dissipated energy increases with the increase in loading path complexity. Note that the energy absorption of the foam is essentially governed by its collapse mode.

Musculoskeletal Symptoms Among Surgeons at a Tertiary Care Center: a Survey Based Study.

INTRODUCTION: Musculoskeletal (MSK) manifestations represent a common work-related physical complication that affect surgeons and impacts their life and the healthcare service negatively. AIM: The aim of this study was to determine the prevalence of work related MSK manifestations among surgeons in a tertiary care hospital and to identify the possible associated risk factors. METHODS: A Web-based self-administered cross-sectional survey was conducted. This study targeted all surgeons regardless of their nationalities, ages, genders, and marital statuses. The questionnaire assessed the participants' demographic data as well as musculoskeletal manifestations. RESULTS: Most respondents (80%) suffered from MSK manifestations that were related to performing surgeries. Back and neck areas represented the most affected body parts (71.1% and 59.8%, respectively). A significantly higher percentage of those with musculoskeletal manifestations practiced for 5-10 years (28.9%) (p = 0.006). CONCLUSION: MSK pain is common among Saudi surgeons in different specialties. More attention should be directed to improving the physical environments in which the surgeons are operating. Moreover, surgeons should be educated about the recommended ergonomic positions that can prevent or decrease their work related MSK manifestations.