Recently, with the Chandra X-ray Telescope we have detected several local X-ray absorption lines along lines-of-sight towards distant quasars. These absorption lines are produced by warm/hot gas located in local intergalactic space and/or in our Galaxy. I will present our observations and discuss the origin of the X-ray absorption and its implications in probing the warm/hot component of local ...

Some activities for in-pool warm-ups have been evaluated. An historically important study was conducted by Carlile (1956). It was shown that the passive activity of tolerating a hot shower for as long as possible prior to performing a maximal 55-yard swim produced improved performances in all subjects significantly more than in a control group (no hot showers). A passive warm-up is possible if ...

the flow stress of steel depends significantly on microstructural changes taken place during hot deformation processes. in hot deformation processes, the flow stress of steel is influenced by two main metallurgical phenomena, i.e. recovery and recrystallization, along with its chemical composition and thermo-mechanical parameters. the final mechanical properties of steel are also determined by ...

In the beginning the surface of the Earth was extremely hot, because the Earth as we know it is the product of a collision between two planets, a collision that also created the Moon. Most of the heat within the very young Earth was lost quickly to space while the surface was still quite hot. As it cooled, the Earth's surface passed monotonically through every temperature regime between silicat...

in all engineering applications where solid surfaces slide on each other, friction plays an important role. it becomes even more important, particularly in metal forming processes where the two sliding materials are metallic. among forming processes, forging is an important process, because of improving material structure, mechanical properties and reducing production time. an inverse analysis ...

determination of critical points on hot stress-strain curve of metals is crucial in thermo-mechanical processes design. in this investigation a mathematical modeling is given to illustrate the behavior of metal during hot deformation processes such as hot rolling. the critical strain for the onset of dynamic recrystallization has been obtained as a function of strain at the maximum stress. in a...

In sheet metal forming processes with complex strain paths, a part is subjected to large plastic deformation. This severe plastic deformation leads to high plastic strain localization zones and subsequent accumulation of those strains. Then internal and superficial micro-defects and in other words ductile damage is created. This damage causes quality problems such as fracture. Therefore, design...