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Proper minimal object

Given the first type of simulation, it is advantageous to be able to design a system of RO modules that can achieve the process objective at a minimal cost. A model has been iategrated iato a process simulation program to predict the stream matrix for a reverse osmosis process (132). In the area of waste minimization, the proper placement of RO modules is essential for achieving minimum waste at a minimum cost. Excellent details on how to create an optimal network of RO modules is available (96). [Pg.156]

Depending upon size and type of unit, the mounting may vary from simply bolting to the floor to attaching to a massive foundation designed specifically for the application. A proper foundation must (1) maintain the alignment and level of the compressor and its driver at the proper elevation, and (2) minimize vibration and prevent its transmission to adjacent building structures and machinery. There are five steps to accomplish the first objective ... [Pg.565]

The ceramic products obtained in the pyrolysis of the "combined" polymers have not been studied in detail, but some of them have been analyzed for C, N, and Si. The compositions of the ceramic materials obtained cover the range 1 Si3N4 + 3.3 to 6.6 SiC + 0.74 to 0.85 C. Thus, as expected, they are rich in silicon carbide and the excess Si which is obtained in the pyrolysis of the [(CH3SiH)x(CH3Si)y]n materials alone is not present, so that objective has been achieved. By proper adjustment of starting material ratios, we find that the excess carbon content can be minimized [11]. [Pg.153]

Difficulty 3 can be ameliorated by using (properly) finite difference approximation as substitutes for derivatives. To overcome difficulty 4, two classes of methods exist to modify the pure Newton s method so that it is guaranteed to converge to a local minimum from an arbitrary starting point. The first of these, called trust region methods, minimize the quadratic approximation, Equation (6.10), within an elliptical region, whose size is adjusted so that the objective improves at each iteration see Section 6.3.2. The second class, line search methods, modifies the pure Newton s method in two ways (1) instead of taking a step size of one, a line search is used and (2) if the Hessian matrix H(x ) is not positive-definite, it is replaced by a positive-definite matrix that is close to H(x ). This is motivated by the easily verified fact that, if H(x ) is positive-definite, the Newton direction... [Pg.202]

The main objective of the work to be described here is to design and synthesize new organic dielectric materials, and to develop new techniques to deposit these materials as thin, thermally stable films with very low dielectric constants, for use as ILDs. New dielectric materials must not only possess proper electrical, thermal, and mechanical properties but should also minimize or eliminate the use of solvents in this era of concern for environmental pollution. [Pg.277]

The principal objective of an O M program is to minimize exposure of aU building occupants to asbestos fibers. To accomplish this objective, an O M program includes work practices to (a) maintain ACM in good condition, (b) ensure proper cleanup of asbestos fibers previously released, (c) prevent further release of asbestos fibers, and (d) monitor the condition of ACM. [Pg.89]

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Law, also known as Superfund, passed in 1980 and amended by the Superfund Amendments and Reauthorization Act (SARA) of 1986 and later amendments, that governs federal response and compensation for unpermitted and uncontrolled releases, including threats of release, of hazardous substances to the environment. An unpermitted release is any release that is not properly regulated under other laws. An important focus of CERCLA/SARA is remediation of old, unpermitted waste disposal sites that are closed or inactive. Basic objectives of the Superfund program are to protect human health and the environment in a cost-effective manner, maintain this protection over time, and minimize the amounts of untreated waste in the environment. [Pg.363]

For an estimated vector of the three parameters, curves of Za and Z as a function of time can be calculated by the integration (if necessary, numerical) of Eqs. (22) and (23) and compared with the experimental results. An objective function can be minimized by suitable-least-squares calculations as the vector of parameters is varied according to the proper procedures (27,106,107). [Pg.364]

Because it is difficult to make any reasonable estimates of the costs of aU the different contributions to the production cost, we can consider in a general discussion only some simple scenarios and their possible combinations. Since the feed cost depends essentially on the value of the recovery yield, it can be minimized by either considering optimization procedures with a constraint of min-imrun recovery yield or maximizing the product of the production rate and the recovery yield. Another possibility is to minimize the operating costs, or the fixed costs. Most practical cases are intermediate between these two extremes and can be taken care of by a proper mixing of the two objective functions (see Section 18.4.4). [Pg.861]

Mitra et al. (1998) employed NSGA (Srinivas and Deb, 1994) to optimize the operation of an industrial nylon 6 semibatch reactor. The two objectives considered in this study were the minimization of the total reaction time and the concentration of the undesirable cyclic dimer in the polymer produced. The problem involves two equality constraints one to ensure a desired degree of polymerization in the product and the other, to ensure a desired value of the monomer conversion. The former was handled using a penalty function approach whereas the latter was used as a stopping criterion for the integration of the model equations. The decision variables were the vapor release rate history from the semibatch reactor and the jacket fluid temperature. It is important to note that the former variable is a function of time. Therefore, to encode it properly as a sequence of variables, the continuous rate history was discretized into several equally-spaced time points, with the first of these selected randomly between the two (original) bounds, and the rest selected randomly over smaller bounds around the previous generated value (so as... [Pg.75]

The plant economics almost always end up as costs on controller CVs or MVs or both. They tell the controller which variables to minimize and which ones to maximize to achieve the proper objective (e.g., increased profit, reduced cost, reduced environmental cost, and so forth). [Pg.1258]


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See also in sourсe #XX -- [ Pg.337 ]




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