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Article Citation - WoS: 5Citation - Scopus: 6Analysis of the Effect of Propellant Temperature on Interior Ballistics Problem(Yildiz Technical Univ, 2018) Evci, C.; Isik, H.This study investigates the effect of conditioning temperature of double base propellants on the interior ballistic parameters such as burning gas temperature, barrel wall temperature, pressure and stresses generated in the barrel. Interior ballistic problem was solved employing experimental, numerical and analytical methods with a thermo-mechanical approach. Double base propellants were conditioned at different temperatures ( 52, 35, 21, 0, -20, -35, -54 degrees C). The maximum pressure in the barrel and projectile muzzle velocity were measured for all the propellants by conducting shooting tests with a special test barrel using 7.62x51 mm NATO ammunition. Vallier-Heydenreich method was employed to determine the transient pressure distribution along the barrel. The temperature of burnt gases was calculated by using Noble-Abel equation. The heat transfer analysis was done using the commercial software ANSYS to get the transient temperature and stress distributions. Temperature distribution through the barrel wall thickness was validated using a FLIR thermal imager. Radial, circumferential and axial stresses and corresponding equivalent Von Misses stresses were determined numerically and analytically. The results of the analytical solution for stress analysis validated the finite element solution of interior ballistic problem. Increasing the initial temperature of the propellant resulted in higher temperature and pressure inside the barrel which in turn increased the stresses in the barrel.Article Citation - WoS: 4An Eye-Controlled Wearable Communication and Control System for Als Patients: Smarteyes(Yildiz Technical Univ, 2017) Sumer, Emre; Uslu, I. Baran; Turker, MustafaALS (Amyotrophic Lateral Sclerosis) is a progressive neurodegenerative disease that involves the malfunctioning of motor neurons. The ability of the brain to initiate and control muscle movement is lost subsequent to death of motor neurons. People with ALS present the greatest challenge regarding communication issues. Besides, caring for a loved one with ALS is not an easy task. In this study, we developed an eye-controlled wearable system called "SmartEyes" which improves the life qualities of ALS patients and their caregivers by offering two important skills. The first skill is communicating through predefined voice messages generated by a computer and the second one is controlling several peripherals located in the patient's environment. The developed system is novel in that; the patients can easily vocalize their needs and requests with a few sequential eye movements. Moreover, they can control several household items including desk lamp, rolling curtain, television and air conditioner in the same way. The preliminary experiments showed that the performance of the system is satisfactory. The accuracy of the system commands based on pupil gaze direction was tested on several users and about an accuracy of 89% was achieved. It is believed that the developed system has attracted the patients' and their caregivers' interest very much and this is the main motivation in improving our system.
