The liquid metal flow and the solidification behaviours in a multi-cavity casting mould of two automotive cast parts were simulated in three dimensions. The commercial code, FLOW-3D® was used because it can track the front of the molten metal by a Volume of Fluid (VOF) method and allows complicated parts to be modeled by the Fractional Area/Volume Obstacle Representation (FAVOR) meth...

Conical shock waves are generated as sharp conical solid projectiles fly supersonically in the air. We study such conical shock waves in steady supersonic flow using isentropic Euler system. The stability of such attached conical shock waves for non-symmetrical conical projectile and non-uniform incoming supersonic flow are established. Meanwhile, the existence of the solution to the Euler syst...

a mathematical model of sorption of zirconium and hafnium cations mixture and elution of these ions from a cation exchange resin bed is developed. sulfuric acid is selected as the eluent for selective separation of zr and hf in a packed bed of dowex cation exchange resin. the column model is a dispersed plug flow model,and assumed to consist of randomly packed synthetic and spherical resin bead...

A pilot scale trickling filter and secondary sedimentation are used to evaluate the feasibility of this process for the treatment of raw dairy waste. The BOD in the raw waste of 252 to 1200 mg/l is reduced 50-73% by a single stage and a further 17-55% by sedimentation tank. Treatment efficiencies are determined at various waste strengths and influent flow rates. With a loading rate of 5-12 kg B...

background: in addition to the various human environmental issues, environmental hazards due to the industrial waste mismanagement are one of the country's major problems. this especially is more important in the provinces such as bakhtiari province where there have been concentration and diversity of the natural resources and a rapid growth of technology and industry in the recent years. metho...

A n experimental investigation of a solid–liquid dispersion pipe flow was conducted using a pulsed ultrasonic Doppler velocimeter. The solid phase was composed of buoyant particles dispersed in water. This particular two-phase flow was used to mimic the behaviour of ice–water flow. Four diagnostics were used to study the complex nature of the two-phase flow mixtures: mean velocity profiles, spa...

Background and purpose: The performance of full-scale moving bed biofilm reactor (MBBR) was evaluated as an alternative for upgrading of Kish Island Mirmohana wastewater treatment plant. In this study activated sludge process upgrade to MBBR process and different operating parameters were compared. Materials and Methods: Effect of upgrading on different parameters such as organic loading rate (...

This brief overview outlines the fundamental principles of flow cytometry with emphasis on DNA measurements and cell cycle analysis in human solid tumors. Type of material used, sampling processing procedures and methods of analysis of data are discussed. DNA ploidy and proliferative activity (S-phase fraction) are the two biological parameters commonly measured by DNA flow cytometric analysis....

This article reviews and summarizes recent work on flow-structural interaction in solid motors. This interaction is important because it can lead to rocket motor failure. In the first part of the document, an idealized model of the failure mechanism is developed to illustrate in simple terms how such an event can occur. In the second part of this article recently published numerical modeling wo...

We consider the problem of 2D supersonic flow onto a solid wedge, or equivalently in a concave corner formed by two solid walls. For mild corners, there are two possible steady state solutions, one with a strong and one with a weak shock emanating from the corner. The weak shock is observed in supersonic flights. A long-standing natural conjecture is that the strong shock is unstable in some se...