A Shortcut Method for Estimating the HETP of Structured Packed Distillation Columns at Elevated Pressure

A shortcut model is developed for predicting the HETP of a structured packed distillation column operating at elevated pressure. The proposed model incorporates the geometrical parameters of the packing, physical properties of the vapor and liquid phases, and the hydrodynamics of the two‐phase flow. The proposed model is tested and validated by comparing the predicted results with the present experimental data and some published HETP data. The results show that the proposed model can predict the experimental data with a deviation smaller than 20 %.     

Nitrogen management in reservoir catchments through constructed wetland systems.

In this study, nitrogen removal was investigated in pilot-scale subsurface flow (SSF) and in free water surface flow (FWS) constructed wetlands installed in the campus of TUBITAK-Marmara Research Center, Gebze, near Istanbul, Turkey. The main purposes of this study are to apply constructed wetlands for the protection of water reservoirs and to reuse wastewater. Experiments were carried out at continuous flow reactors. The effects of the type of plants on the removal were investigated by using emergent (Canna, Cyperus, Typhia spp., Phragmites spp., Juncus, Poaceae, Paspalum and Iris.), submerged (Elodea, Egeria) and floating (Pistia, Salvina and Lemna) marsh plants at different conditions. During the study period HLRs were 30, 50, 70, 80 and 120 L m(2)d(-1) respectively. The average annual NH4-N, NO(3)-N, organic N and TN treatment efficiencies in SSF and FWS wetlands are 81% and 68%, 37% and 49%, 75% and 68%, 47% and 53%, respectively. Nitrification, denitrification and ammonification rate constant (k20) values in SSF and FNS systems have been found as 0.898 d(-1) and 0.541 d(-1), 0.488 d(-1) and 0.502 d(-1), 0.986 d(-1) and 0.908 respectively. Two types of the models (first-order plug flow and multiple regression) were tried to estimate the system performances.     

Economical technology for cryoproduct storage and delivery

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 11, pp. 22–23, November, 1992.     

Y Zeolite as a component of catalysts for hydrotreating petroleum fractions

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3, pp. 7–12, March, 1991.     

Segmented force plate (SFP) software package for clinical use

A gait analysis system is described. It is designed for clinical use as well as research purposes. The system is simple to operate and can be used by non-computer specialist. The design philosophy is straightforward and allows for easy adaptation to other systems. Samples of the output are presented.     

Designing screens for people to use easily

The use of interactive computer systems is expanding rapidly. In many applications users can communicate directly with computer-based systems through an interactive dialogue at a display terminal. However, this direct form of communication has created problems. Whereas early users of on-line systems were skilled computer professionals, today's users may have little or no training in computer technology. How then does this group communicate effectively with a computer systems?

The answer is that many users communicate only with considerable difficulty. The result is that the effectiveness of many systems is very much less than expected. The reason for this is simple: these systems are not very good at communicating with their users.

The most common communications bridge between a person and a computer system is a display screen. A well-designed screen format can enhance user productivity, eliminate or reduce user input errors, and promote end user satisfaction. A poorly designed screen has the opposite effect: it will decrease human processing speed, provoke user mistakes, and complicate computer operations.

Screen design requires the same care as designing the overall application. It employs the same techniques as planning and preparing good user documents. Screens, like documents, must be easy to understand and easy to use. To achieve these objectives, screen designers must make good choices regarding three ease-of-use parameters: format; screen content and layout; and style. This paper describes how standards may be established for each of these parameters in a proposed application or system. Futher, an interactive tutorial computer program has been developed (using Bricklin's DEMO program) which may be used to illustrate the application of these standards.     

Technology of secondary purification by means of short-cycle unheated adsorption

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 2, pp. 39–40, February, 1995.     

Kinetic study of the reaction between molybdenum trioxide and gaseous carbon tetrachloride

The kinetics of the chlorination reaction of molybdenum trioxide with gaseous carbon tetrachloride has been studied at temperatures between 713 and 753 K. The effects of temperature, reaction time, residence time and gaseous reactant concentration on conversion were studied throughout the reaction. In all cases, there was an increase in conversion when the above operating variables were increased. The kinetic model proposed is consistent with and correlates the experimental data. In the range studied for the different variables, the step that controls the rate of reaction is the surface chemical reaction. Values of the rate constant and the activation energy were estimated.