We have developed a new numerical code to study the evolution of distorted, rotating black holes. We discuss the numerical methods and gauge conditions we developed to evolve such spacetimes. The code has been put through a series of tests, and we report on (a) results of comparisons with codes designed to evolve non-rotating holes, (b) evolution of Kerr spacetimes for which analytic properties...

this paper concerns the design and analysis, of a ball type continuously variable transmission, (b-cvt). this b-cvt has a simple kinematic structure, and same as a toroidal cvt, transmits power by friction on the contact points between input and output discs, that are connected to each other by balls. after, a brief introduction of our b-cvt structure, the performance and traction efficiency of...

Since tubes have numerous industrial applications, different attempts are focused on the Severe Plastic Deformation (SPD) processes of tubes. As an illustration, Tube Channel Pressing (TCP) is an attractive process for this purpose since it can be used for processing of different sizes of tubes. However, more attempts are needed to improve the outcomes of TCP. For example, imposing of greater s...

Finite element simulation of stretch flanging process was carried out in order to investigate the effect of process parameters on maximum thinning (%) in stretch flanging process. Influences of initial flange length, punch die clearance, width of sheet metal blank and blank holding force were investigated on maximum thinning (%). Finite element simulation was done using FEM software package ABA...

in this work, the steady and laminar mixed convection of nanofluid in horizontal concentric annulus withrotating inner cylinder is investigated numerically. the inner and outer cylinders are kept at constanttemperature ti and to respectively, where ti>to. the annular space is filled with alumina-water nanofluid.the governing equations with the corresponded boundary conditions in the polar coord...

designing and manufacturing the multiple jets simulator and experimental investigation of the multiple jets in crossflow at low velocity ratios have been studied together with design and build a low-speed wind tunnel. a specific rake is used to determine the flow field pressure and changes in static pressure measured by pressure taps in the near field of the jets. there are generally three regi...

In diesem Beitrag präsentieren wir die Artefaktkarte, eine Verbindung aus einem angereicherten Glossar und einer Karte der Arbeitsumgebung. Die Artefaktkarte macht den Kontext der Arbeit unabhängig von der tatsächlichen Arbeitsumgebung verfügbar und das in konkreter Form, situiert und nahezu vollständig. Sie ermöglicht, notwendige Erhebungen zügig und strukturiert Weise durchzuführen, und unter...

and the sixtieth birthday of Dr. Heinrich Meng to whom it owes so much. The editor acknowledges also the stimulating influence by the International Congress held in London in 1948. The majority of the forty-three contributions deals with problems of social psychology and psychiatry; and the rest (in fact the two introductory sections) discuss a few selected problems of psycho-analysis and medic...

There are several method for forming bulk material, such as forging, rolling and extrusion. Every of these methods have advantages and dis-advantages of their selves. Forging process is one of the most common of them that include a die, press and in some case heater with controlling system, and has a special place in automotive, military and aerospace industries due uniformity of the final prod...

The assessment of the influence of the work-hardening of material on the optimum die profile and drawing force  in rod drawing process is the main objective of the present paper. The upper bound solution, based on the assumption of perfect plasticity, has been extended to consider the work-hardening of the material during the rod drawing process through curved dies. Analytical results of drawin...