The rate of copper II/zinc cementation from copper sulphate solutions in the absence and in the presence of methanol (CH3OH) and dimethyl sulphoxide (DMSO) has been studied and the reaction was found to follow first-order kinetics. The influence of several parameters on the course of the reaction, such as cylinder rotation speed, initial concentration of Cu ions, temperature and concentration o...

Some difficulties are encountered when simulating super-critical Reynolds number (Re) flow over curved surfaces of a building in a low speed boundary layer wind tunnel (BLWT) due to the sensitivity of the flow to Re. Surface roughness on the façade of the cylinder can affect the location of the separation point and the extent of the wake on the leeward face, upon which the wind-induced response...

In this article, computational results from boundary integral equations and their normal derivatives for the same test cases are compared. Both kinds of formulations are desingularized on their real boundary. The test cases are chosen as a uniform flow past a circular cylinder for both the Dirichlet and Neumann problems. The results indicate that the desingularized method for the standard bound...

The theory of creeping waves is developed by applying the Sommerfeld-Watson transformation on the normal-mode solution for acoustic scattering from an infinite elastic cylinder. Two types of radiating, circumferential waves emerge: (1) highly attenuated “Franz-type” waves with subsonic speeds, and (2) supersonic “Rayleigh-type” waves which are only slightly attenuated. The experimental study of...

The objective of this paper is to investigate the effect of fuel injection pressure on power performance and fuel consumption of diesel engine. In a diesel engine, fuel injection pressure is an important aspect of the engines’ power performance in order to obtain combustion treatment. The experiments in this paper are performed on a four-cylinder two-stroke direct injection diesel engine. The d...

Out of the handful of asteroids that have been imaged, some have distributions of blocks that are not easily explained. In this paper, we investigate the possibility that seismic shaking leads to the size sorting of particles in asteroids. In particular, we focus on the so-called Brazil nut effect (BNE) that separates large particles from small ones under vibrations. We study the BNE over a wid...

Valvetrain flexibility enables the optimization of the engine’s ability to breathe across the operating range, resulting in more efficient operation. The authors have shown the merit of improving volumetric efficiency via valvetrain flexibility to improve fuel efficiency at elevated engine speeds in the previous work. This study focuses on production viable solutions targeting similar volumetri...

machine harvesting of legumes in iran is not being done due to unsuitable variety of the plant, lack of farmers' technical knowledge and farms of small scale sizes.currently the plant is harvested by hand and carried to the thresher: yet application of these threshers is not common; they are few in number, and not very suitable for iran. this presentation shows the design and construction ...

Sanyo has originally introduced 6HP two-cylinder rotary compressors for packaged airconditioners in I 985. The concept of two-cylinder rotary compressor has been recently applied to room airconditioners(RACs) for the purpose of reducing vibration and noise of the unit. However. RACs are demanded to decrease the noise by lowering levels of the compressor noise. SanYo has newly developed the quie...

Laser-based in-cylinder diagnostics are well established in engine research. The requirement of large-scale optical accesses, however, makes the application expensive and time consuming. It furthermore limits the engine operation range to low loads and speeds. We introduce laser excitation and imaging optics with a minimal outer diameter of 10 mm (imaging optic) respectively 9 mm (excitation op...