An in-vitro flow study was conducted in a mildly atherosclerotic main coronary artery casting of man using sugar-water solutions simulating blood viscosity. Steady flow results indicated substantial increases in pressure drop, and thus flow resistance at the same Reynolds number, above those for Poiseuille flow by 30 to 100 percent in the physiological Reynolds number range from about 100 to 40...

We investigate menu distance, size, and related techniques to understand and optimize menu performance in VR. We show how user interaction using ray casting and Pointer-Attached-to-Menu (PAM) pointing techniques is affected by menu size and distance from users. Results show how selection angle – an angle to targets that depends on menu size and distance – relates to selection times. Mainly, inc...

Introduction: The aim of this study was to evaluate the effect of bridge orientation in casting machine on castability and quality of base metal castings. Methods: Three groups of patterns with different direction and lengths in casting machine were casted and then studied qualitatively and quantitatively using mean and standard deviation in table of frequency. Results: Larger nodules and poros...

The objective of this work was to introduce a novel method for refining the solidification microstructure. Traditional casting usually solidifies one homogeneous liquid by removing heat from liquid surface, by which the microstructure solely depends on the heat removal rate for the given alloy composition. The newly developed multi-liquid composite simultaneous casting concept raises an alterna...

Conventional sand casting processes often take many weeks or months to produce the tooling required for a casting, in particular the fabrication of sand core arrays for hollow features in a casting. SLS is already being applied to produce complex sand core geometries and reduce production times, but a new development of discretely laying down two different materials and removing one after sinte...

This paper attempts to investigate the influence of the microstructure and mechanical property changes on sand casting and permanent die casting alloys by grain refinement, modification combined action of both (Al– 3Ti–1B + Al–10Sr) and without grain refinement and modification effect. The microstructures of the castings are studied by optical microscopes. The microstructure and mechanical prop...

Two widely used jewellery investment casting alloys (platinum with 5 wt% ruthenium (Pt-5Ru) and platinum with 5 wt% cobalt (Pt-5Co)) suffer from poor castability and other drawbacks. In this work thermodynamic calculations of alloy properties were employed to optimise the alloy compositions. Segregation behaviour appeared to be important for the melting range. Scheil simulations were used to si...

A new group of synthetic resins (the ethoxyline or epoxide resins) has been widely accepted in industry during the last few years. These resins, thanks to their novel properties as adhesives and casting resins, are used in the modern manufacture of various kinds of apparatus, of electrical equipment, of automobiles, and of aircraft. They are usually supplied in the form of two reactive componen...

A full scale physical model of a thin slab caster with a four-hole design submerged entry nozzle (SEN) was constructed. On the basis of the dimensionless Reynolds and Froude similitude criteria, the fluid flow in a full-scale model is similar to that of the actual system and, hence, the data obtained from the water model can be applied to the actual system. In order to determine the optimum ope...

Abstract: structures in alloys. This method is based on pouring the melt through a small sized nozzle into a mould located at acertain height under the crucible. This simple method generates globular structures without using equipments such asimpellers, electromagnetic stirrers, ultrasonic probes and cooling slopes. Therefore it is cost effective. In the presentstudy, the effect of casting size...