in general, the objective of distillation control is to maintain the desired products quality. in this paper, the performances of different one point control strategies for an aromatic distillation column have been compared through dynamic simulation. these methods are: a) composition control using measured composition directly. this method sufferes from large sampling delay of measuring device...

INTRODUCTION An accurate and passive fit of implant framework prosthesis, as well as the successful surgical operation is suggested as one of the critical requirements for long-term implant success. OBJECTIVE The purpose of this in vitro study was to evaluate the accuracy of the master cast using open tray impression technique with conventional and novel splinting materials. METHODOLOGY A m...

The simulation of batch distillation columns during start-up operations is a very challenging modelling problem because of the complex dynamic behaviour. Only few rigorous models for distillation columns start-up are available in literature and generally required a lot of parameters related to tray or pack geometry. On an industrial viewpoint, such a complexity penalizes the achievement of a fa...

The use of robotics in food industry is becoming more popular in recent years. The trend seems to continue as long as the robotics technology meets diverse and challenging needs of the food producers. Rapid developments in digital computers and control systems technologies have significant impact in robotics like any other engineering fields. By utilizing new hardware and software tools, design...

Increasing competition in the process industries enforces the application of mathematical simulation techniques both in the design phase and in the operating phase of a plant. The basic apparatus for separation processes is the distillation column. Its rigorous (tray by tray) mathematical modelling results in a system of simultaneous nonlinear equations (algebraic in the steady-state case, diff...

INTRODUCTION It is unknown how the use of a light-cured acrylic resin is appreciated over the traditional chemically cured resins for the construction of custom trays in a teaching environment. OBJECTIVE To evaluate the acceptance of light-cured acrylic resin for custom trays by dental students. METHOD A questionnaire addressing the use and handling properties of both light-cured (Megatray,...

PURPOSE To evaluate the dimensional accuracy of the resultant (duplicative) casts made from two different impression materials (polyvinyl siloxane and polyether) in parallel and angulated implants. MATERIALS AND METHODS Three definitive master casts (control groups) were fabricated in dental stone with three implants, placed at equi-distance. In first group (control), all three implants were ...

The effect of the outlet weir height on sieve tray performance is described in this paper. The studies were made to investigate the effect of the outlet weir height on sieve tray mass transfer efficiency and hydraulic performance. Tests were conducted in the 1.22 m diameter section of the Fractionation Research, Inc. (FRI) low-pressure column. Sieve trays with nominal hole areas of 14%, 13%, an...

In recent years, many dental professionals have changed their philosophy regarding the use of trays with at-home bleaching regimens. However, facts do not change--and successful vital tooth bleaching still occurs only when tooth surfaces are in direct contact with the appropriate concentration of active whitening agent for a specific amount of time. Because the science of tooth whitening is sti...