Mathematical programming model for heat exchanger design through optimization of partial objectives

Mathematical programming can be used for the optimal design of shell-and-tube heat exchangers (STHEs). This paper proposes a mixed integer non-linear programming (MINLP) model for the design of STHEs, following rigorously the standards of the Tubular Exchanger Manufacturers Association (TEMA). Bell–Delaware Method is used for the shell-side calculations. This approach produces a large and non-convex model that cannot be solved to global optimality with the current state of the art solvers. Notwithstanding, it is proposed to perform a sequential optimization approach of partial objective targets through the division of the problem into sets of related equations that are easier to solve. For each one of these problems a heuristic objective function is selected based on the physical behavior of the problem. The global optimal solution of the original problem cannot be ensured even in the case in which each of the sub-problems is solved to global optimality, but at least a very good solution is always guaranteed. Three cases extracted from the literature were studied. The results showed that in all cases the values obtained using the proposed MINLP model containing multiple objective functions improved the values presented in the literature.

The regulation of professional advertising practices in Spain, 1988–2013

From the perspective of the sociology of professions, every professional activity should have its own clearly circumscribed and regulated sphere of action. Such an articulation facilitates the regulation of the production of a given profession as well as the way in which it is practiced. The purpose of the research reported here was to provide a comprehensive review and evaluation of the regulatory framework governing the advertising sector in Spain. To this end, the authors analysed external regulatory legislation and self-regulatory codes extracted from the data base of the Asociación para la Autoregulación de la Comunicación Comercial (Autocontrol) that had been enacted or adopted between 1988, the year that Law 11/1998 on General Telecommunications entered into force, and 2003 as well as other relevant documents retrieved from the Boletin Oficial del Estado (BOE) pertaining to the same period. Findings indicate that although there has been a groundswell of legislation governing advertising practices in Spain since 1988, especially at the regional level, lawmakers have focused on the content of advertising messages and shown very little interest in regulating the professions of advertising and public relations. Furthermore, Spanish legislation enacted in 2003 and EU policies appear to have encouraged the adoption of voluntary codes of ethics. Sectors traditionally subject to mandatory advertising regulation, either due to the vulnerability of their target audiences or the potential impact of their commercial messages on public health or the environment, are more likely to develop self-regulatory codes of conduct than others