Integration of modular process simulators under the Generalized Disjunctive Programming framework for the structural flowsheet optimization

The optimization of chemical processes where the flowsheet topology is not kept fixed is a challenging discrete-continuous optimization problem. Usually, this task has been performed through equation based models. This approach presents several problems, as tedious and complicated component properties estimation or the handling of huge problems (with thousands of equations and variables). We propose a GDP approach as an alternative to the MINLP models coupled with a flowsheet program. The novelty of this approach relies on using a commercial modular process simulator where the superstructure is drawn directly on the graphical use interface of the simulator. This methodology takes advantage of modular process simulators (specially tailored numerical methods, reliability, and robustness) and the flexibility of the GDP formulation for the modeling and solution. The optimization tool proposed is successfully applied to the synthesis of a methanol plant where different alternatives are available for the streams, equipment and process conditions.

Multi-objective adaptive evolutionary strategy for tuning compilations

Tuning compilations is the process of adjusting the values of a compiler options to improve some features of the final application. In this paper, a strategy based on the use of a genetic algorithm and a multi-objective scheme is proposed to deal with this task. Unlike previous works, we try to take advantage of the knowledge of this domain to provide a problem-specific genetic operation that improves both the speed of convergence and the quality of the results. The evaluation of the strategy is carried out by means of a case of study aimed to improve the performance of the well-known web server Apache. Experimental results show that a 7.5% of overall improvement can be achieved. Furthermore, the adaptive approach has shown an ability to markedly speed-up the convergence of the original strategy.

MINLP Model for the Synthesis of Heat Exchanger Networks with Handling Pressure of Process Streams

This paper introduces a new mathematical model for the simultaneous synthesis of heat exchanger networks (HENs), wherein the handling pressure of process streams is used to enhance the heat integration. The proposed approach combines generalized disjunctive programming (GDP) and mixed-integer nonlinear programming (MINLP) formulation, in order to minimize the total annualized cost composed by operational and capital expenses. A multi-stage superstructure is developed for the HEN synthesis, assuming constant heat capacity flow rates and isothermal mixing, and allowing for streams splits. In this model, the pressure and temperature of streams must be treated as optimization variables, increasing further the complexity and difficulty to solve the problem. In addition, the model allows for coupling of compressors and turbines to save energy. A case study is performed to verify the accuracy of the proposed model. In this example, the optimal integration between the heat and work decreases the need for thermal utilities in the HEN design. As a result, the total annualized cost is also reduced due to the decrease in the operational expenses related to the heating and cooling of the streams.

Use of Tablet Pcs in Higher Education: A new Strategy for Training Engineers in European Bachelors and Masters Programmes

The use of technology in classrooms in Spanish universities has been following an upward path, and in many cases technological devices are substituting other materials that until now have been used, such as books, notebooks and so on. Step by step in higher education, more of these latest generationdevices are being used, and are providing significant improvements in training. Nowadays, there are Spanish universities that use tablets, a device with multiple applications for teaching as well as for students to study differently. They are definitely a notable innovation that will gradually become incorporated into university life. Tablet PCs make teaching more dynamic and available to students through the use of up to date digital materials, something which is key in training engineers. This paper presents their different functions employed in three Spanish universities to support teachingin engineering degrees and masters using the tablet PC, and their impact on the training process. Possible uses in specific programs like the Erasmus Masters Programmes are also assessed. The main objective of using tabletsis to improve the academic performance of students through the use of technology.

Technology Language and Frankenstein Strategy

Teaching architecture is experiencing a moment of opportunity. New methods, like constructivist pedagogy, based on complexity and integration are yet to be explored. In this context of opportunity teaching architecture has a duty to integrate complexity in their curriculum. Teaching methods should also assume inherent indeterminacy and contingency of all complex process. If we accept this condition as part of any teaching method, the notion of truth or falsehood it becomes irrelevant. In this regard it could focus on teaching to contingency of language. Traditionally, technology is defined as the language of science. If we assume contingency as one of the characteristics of language, we could say that technology is also contingent. Therefore we could focus technology teaching to redefine its own vocabulary. So, redefining technological vocabulary could be an area of opportunity for education in architecture. The student could redefine their own tools, technology, to later innovate with them. First redefine the vocabulary, the technology, and then construct the new language, the technique. In the case of Building Technology subjects, it should also incorporate a more holistic approach for enhancing interdisciplinary transfer. Technical transfer, either from nature or other technologies to the field of architecture, is considered as a field of great educational possibilities. Evenmore, student get much broader technical approach that transgresses the boundaries of architectural discipline.