The current understanding of mechanical feedback is reviewed by evaluating the standard, adiabatic model for shell formation and evolution. This model is relevant to phenomena ranging from individual stellar-wind bubbles to galactic superwinds, forming the basis for our understanding of the multiphase ISM, IGM, and galactic evolutionary processes. Although significant discrepancies between the ...

Plates of 3–5 mm in thickness were extracted from an AZ91D ingot and then butt joints of the plates were produced using tungsten inert gas (TIG) welding method. The TIG arc was also used to deposit welding beads on some of the thin plates. No cracking was found in the butt joints. However, hot cracking was always observed to propagate from the heat affected zone (HAZ) under the welding bead int...

Due to their low gravitational energies, dwarf galaxies are greatly exposed to energetical influences from internal and external sources. By means of chemodynamical models we show that their star formation is inherently self-regulated, that peculiar abundance ratios can only be achieved assuming different star-formation episodes and that evaporation of interstellar clouds embedded in a hot phas...

Introduction When the grinding wheel specifications are properly chosen, a SiC grinding wheel performs remarkably well for grinding partially stabilized MgO-ZrO2 ceramics (MgO-PSZ). Rather surprisingly, the highest Gratios are obtained at higher grinding rates for the SiC wheel. This, and the fact that SiC grinding wheels can be readily shaped for use in precision cylindrical form grinding, has...

In recent years, in order to reducing die design and manufacturing costs, Multi point forming technique has gained an increasing interest because of its high flexibility. In this process, the conventional fixed shape solid die sets are replaced with a pair of opposite matrices of controllable elements. In this paper, the fundamental principles of multi-point forming was described and the possib...

The most common issues in sheet metal stamping are progression design, transfer design, thickness control, wrinkling, thinning, tearing, spring-back and die-wear. An innovative methodology has been developed to analyze these aspects using a non-linear finite element approach with 3D Solid elements instead of the more traditional Shell elements. This leads to the most accurate result, and allows...

Abstract Flashless forging is classified as a precise metal forming technology. The main advantages of this technology are the reduction flash allowance and shortening manufacturing time by eliminating trimming operation. article presents process one-step stepped shaft made aluminum with use split dies. was carried out in cold hot metal-forming conditions. analyzed numerically using Simufact Fo...

We present first results concerning the metallicities and stellar populations of galaxies formed in a cosmologically motivated simulation. The calculations include dark matter, gas dynamics, radiation processes, star formation, supernovae feedback, and metal enrichment. A rotating, overdense sphere with a mass of 8 1011 M serves as initial model. Converging and Jeans unstable regions are allowe...

Young massive star-forming regions are known to produce hot molecular gas cores (HMCs) with a rich chemistry. While this chemistry is interesting in itself, it also allows to investigate important physical parameters. I will present recent results obtained with high-angular-resolution interferometers disentangling the small-scale structure and complexity of various molecular gas components. Ear...