METHODS FOR REDUCING THE STRESS CONCENTRATION IN CYLINDRICAL SPECIMENS, AT AXIAL LOADING

The article presents specialized software methods for reducing stress concentration. Objects of study are cylindrical test specimens subjected to axial loading. Notching with different shapes and sizes on the specimens were formed to reduce the stresses in the endangered areas. The geometric parameters of notches identified through the specialized built-in modules to the ANSYS software. An analysis performed were to show the influence of stresses acting on the fatigue limit during different cycles. The results of the study were present in a graphical form.

REDUCTION OF THE STRESS CONCENTRATION FACTOR OF PRISMATIC SPECIMENS THROUGH THE USE OF TOPOLOGICAL OPTIMIZATION

The article presents studies related to the reduction of stress concentration acting on prismatic specimen subject to axial loading. Using ANSYS software, a topological optimization was performed which aims to reduce the stresses in the endangered areas. The aim of identification of the geometric parameters accomplished after the completion of topological optimization of the objective function is to minimize the stresses in the engaged areas. An analysis performed were to show the influence of stresses acting on the fatigue limit during different cycles. The results of the study were present in a graphical form.

Advantage of Animal Models with Metabolic Flexibility for Space Research Beyond Low Earth Orbit

As the worlds space agencies and commercial entities continue to expand beyond Low Earth Orbit (LEO), novel approaches to carry out biomedical experiments with animals are required to address the challenge of adaptation to space flight and new planetary environments. The extended time and distance of space travel along with reduced involvement of Earth-based mission support increases the cumulative impact of the risks encountered in space. To respond to these challenges, it becomes increasingly important to develop the capability to manage an organisms self-regulatory control system, which would enable survival in extraterrestrial environments. To significantly reduce the risk to animals on future long duration space missions, we propose the use of metabolically flexible animal models as pathfinders, which are capable of tolerating the environmental extremes exhibited in spaceflight, including altered gravity, exposure to space radiation, chemically reactive planetary environments and temperature extremes.In this report we survey several of the pivotal metabolic flexibility studies and discuss the importance of utilizing animal models with metabolic flexibility with particular attention given to the ability to suppress the organism's metabolism in spaceflight experiments beyond LEO. The presented analysis demonstrates the adjuvant benefits of these factors to minimize damage caused by exposure to spaceflight and extreme planetary environments. Examples of microorganisms and animal models with dormancy capabilities suitable for space research are considered in the context of their survivability under hostile or deadly environments outside of Earth. Potential steps toward implementation of metabolic control technology in spaceflight architecture and its benefits for animal experiments and manned space exploration missions are discussed

Environmental Enrichment in the ISS Rodent Habitat Hardware System

Responses of animals exposed to microgravity during in-space experiments were reviewed from NASAs and ESA available video recording archives. These documented observation of animal behavior, as well as the range and level of activities during spaceflight, clearly demonstrate that weightlessness conditions and the extreme novelty of the surroundings exert damaging psychological stresses on the inhabitants. In response to a recognized need for in-flight animals to improve their wellbeing we propose to reduce such stresses by shaping and interrelating structures and surroundings to satisfying vital physiological needs of inhabitants. Rodent Habitat Hardware System based housing facility incorporating a tubing network system, to maintain and monitor rodent health environment with advanced accessories has been proposed. The new tubing configuration was found suitable for further incorporation of innovative monitoring technology and accessories in the animal holding habitat unit which allow to monitor in real-time the most valuable health related biological parameter under weightlessness environment of spaceflight

Environmental Enrichment in the ISS Rodent Habitat Hardware System

Responses of animals exposed to microgravity during in-space experiments were observed via available video recording stored in the NASA Ames Life Sciences Data Archive. These documented observations of animal behavior, as well as the range and level of activities during spaceflight, demonstrate that weightlessness conditions and the extreme novelty of the surroundings may exert damaging psychological stresses on the inhabitants. In response to a recognized need for in-flight animals to improve their wellbeing we propose to reduce such stresses by shaping and interrelating structures and surroundings to satisfying vital physiological needs of inhabitants. A Rodent Habitat Hardware System (RHHS) based housing facility incorporating a tubing network system, to maintain and monitor rodent health environment with advanced accessories has been proposed. Placing mice in a tubing-configured environment creates more natural space-restricted nesting environment for rodents, thereby facilitating a more comfortable transition to living in microgravity. A sectional tubing structure of the RHHS environment will be more beneficial under microgravity conditions than the provision of a larger space area that is currently utilized. The new tubing configuration was found suitable for further incorporation of innovative monitoring technology and accessories in the animal holding habitat unit which allow to monitor in real-time monitoring of valuable health related biological parameters under weightlessness environment of spaceflight

Changes in the Surface Texture of Thermoplastic (Monomer-Free) Dental Materials Due to Some Minor Alterations in the Laboratory Protocol—Preliminary Study

Contemporary thermoplastic monomer-free prosthetic materials are widely used nowadays, and there are a great variety available on the market. These materials are of interest in terms of the improvement of the quality features of the removable dentures. The aim of this study is to establish how minimal changes in the laboratory protocol of polyamide prosthetic base materials influence the surface texture. Two polyamide materials intended for the fabrication of removable dentures bases were used—Perflex Biosens (BS) and VertexTM ThermoSens (TS). A total number of 20 coin-shaped samples were prepared. They were injected under two different modes—regular, as provided by the manufacturer, and modified, proposed by the authors of this study. Scanning electronic microscopy (SEM) under four magnifications—×1000, ×3000, ×5000, and ×10,000—was conducted. With minimal alterations to the melting temperature (5 °C) and the pressure (0.5 Bar), in Biosens, no changes in terms of surface improvement were found, whereas in ThermoSens, the surface roughness of the material significantly changed in terms of roughness reduction. By modifying the technological mode during injection molding, a smoother surface was achieved in one of the studied materials