Rotary Evaporator
Rotary evaporators are a common feature in most undergraduate laboratories. Their primary purpose is to remove solvent following a reflux, perhaps before crystallization of a reaction product. To operate the evaporator, we place the reaction solution in a raound-bottomed flask while pressure inside the evaporator is decreased to about 1/30 x p0. The flask is then rotated. The solvent evaporates more easily at this low pressure than at p0 . The solvent removed under vacuum is trapped by a consider and collected for easy re-use, or disposal in an environmentally sensitive way.
(Monk P. M. S., Physical Chemistry: Understanding Our Chemical World, 2004, p.188)
Cell Formation Approach
In this approach the Jaccard similarity coefficient is first calculated between each machine pair of machines. Next, agraph is defined where each vertex represents a machine and the edges represent the relationships between the machines. An edge connects two vertices in the graph only is the similarity coefficient for the machine pair is greater than some threshold value. Finally machine cells are formed by locating maximal “cliques” (a maximal coplete subgraph) or near cliques and merging them together. In CM terminology, a clique is a group of machines in which every pair is related with a similarity coefficient greater than the specified threshold value.
(Suresh C. N., Kay J. M., Group Technology and Cellular Manufacturing, p.144)
Sectioning Method
Sectioning method is one of useful measurement tecnique for 3D profile measurement. It is insensitive to the surface optical property of 3D objects, has scarcely any demand on surrounding. So it can hold good to complex profile 3D object, which other techniques are invalidation. We design a shape measurement system which has 3600 measurement range and multi-resolution measurement property on the blade of aviation engine measurement demand. It can measure whole profile and the entering and ending edge partial detail of the blade with high precision at the same time.
(Xiong C., Liu H., Huang Y., Xiong Y., Intelligent Robotics And Applications,2008, p.762)
A Layered Structure
A Layered Structure has been considered by many investigators. A variety of tecniques has been introduced. Among these normal incidence longitudinal waves can be applied in the low frequency regime, and the transmitted and/or reflected signals can be used for the evaluation of a layered medium. A referenced signal has to be introduced in order to calibrate the evaluation. A self-compensating tecnique has been proposed to evaluate a layered structure, in that a ratio of transmission and reflection coefficients has been used. In order to effectively deduce the parameters of a layered structure, the sensitivity of the ratio of transmission and reflection coefficients of a layered structure to variation of the parameters and the distirbution of minima in an error surface.
(Chenng A., Achenbach J. D., Rewiev of Progress in Quantitative Nondestructive Evaluation,2002,p.1815)
rotary evaporator had been written before
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