Acrylonitrilebutadiene-styrene (ABS) thermoplastic is evaluated as a potential fuel for hybrid rocket motors and compared to the widely used fuel material Hydroxyl-Terminated Polybutadiene (HTPB). For this project Nitrous Oxide (N2O) is used as the matching oxidizer. ABS is widely mass-produced for non-combustion applications including household plumbing and structural materials. Analytical pre...

A go-kart is a four-wheel drive that lacks suspension system and differential unit due to the very low ground clearance usually employed for Formula E or 1 racing. Due absence of system, chassis should be rigid strong enough withstand impact loads, as well other support equipment. The present research focused on design, material selection, structural vibrational analysis chassis. For this, desi...

Abstract: A well-known challenge is to predict the transformations occurring during metal alloys welding aiming control weldment properties. Thus, this study presents a Thermo-Mechanical-Metallurgical model numerically thermal history, solid-state phase transformations, solidification microstructure and hardness distribution after of high strength low-alloy steels. The was implemented in an in-...

Gh. Amza, Z. Apostolescu, Faculty of Engineering and Management of Technological, Polytehnic University of Bucharest, Romania D. Dobrotă, Engineering Faculty, “Constantin Brâncuşi” University of Târgu-Jiu, Romania V. Petrescu, Engineering Faculty, Lucian Blaga University of Sibiu, Romania R. G. Albulescu, The Oil Company, Ploiesti, Romania Plating by welding in an ultrasonic field represents a ...

RESUMO O objetivo deste trabalho foi avaliar o efeito da aplicação de tratamento térmico alívio tensão (TTAT) e das temperaturas preaquecimento interpasse sobre a microestrutura, presença zonas parcialmente diluídas (ZPD), microdureza gradiente composição ao longo interface depósitos liga AWS E NiCrMo 3 os aços AISI 8630M 4130 aplicados por dois processos soldagem (GMAW PTA-P). Para isto foram ...

Mechanical properties of machined components are controlled by inducing phase transformations in the outer layer of the materials. Induction hardening is one such manufacturing process where the surface hardness is enhanced while the core is retained with the original structure and characteristics. In this study, a mathematical model had been developed to predict the hardness and the volume fra...

In this study, some mechanical properties of borided and unborided four steels were investigated. Boronizing of steels was performed by powder pack method at 1210 K for 4 h. The hardness of borides, boride layer thickness and room temperature tensile properties were measured and it was observed that hardness and tensile properties strongly depend on chemical composition of steels. In addition, ...

TeV J2032+4130 is the first extended very high energy gamma-ray source, which has remained enigmatic since its discovery, due to the lack of identification. We report here deep radio observations covering the TeV J2032+4130 field and revealing for the first time an extended and diffuse radio emission, as well as a remarkable population of compact radio sources. Some of these radio sources are i...