Ángel M. Costa

New Climatic Indicators for Improving Urban Sprawl: A Case Study of Tehran City

In the modern world, the fine balance and delicate relationship between human society and the environment in which we exist has been affected by the phenomena of urbanisation and urban development. Today, various environmental factors give rise to horizontal dispersion, spread and growth of cities. One of the most important results of this is climatic change which is directly affected by the urban sprawl of every metropolis. The aim of this study is to identify the relationship between the various horizontally distributed components of Tehran city and changes in essential microclimate clusters, by means of the humidex index. Results showed that, when the humidex was calculated for each of the obtained clusters, it was evident that it had increased with time, in parallel with Shannon’s entropy, as a consequence of the average temperature and relative humidity of each cluster. At the same time, results have shown that both temperature and relative humidity of the study area are related with urban sprawl, urbanisation and development, as defined by Shannon’s entropy and, in consequence, with humidex. In consequence, this new concept must be considered in future research works to predict and control urban sprawl and microclimate conditions in cities.

Effect of climate change on outdoor thermal comfort in humid climates

BackgroundGalicia, in northwest Spain, experiences warm summers and winters. However, the higher relative humidity that prevails the whole year through and the location of the summer hot points are related to real weather heat stroke in the hottest season. However, Planet Global Heating was recently analyzed for the climate in Galicia. Climate change was found to be able to trigger effects that involve a new situation with new potential regions of risk. In this paper, 50 weather stations were selected to sample the weather conditions in this humid region, over the last 10 years. From these results, new regions with a potential for heat stroke risk in the next 20 years were identified using the humidex index.ResultsResults reveal that during the last 10 years, the winter season presents more comfortable conditions, whereas the summer season presents the highest humidex value. Further, the higher relative humidity throughout the whole year reveals that the humidex index clearly depends upon the outdoor temperature.ConclusionsGlobal Planet Heating shows a definite effect on the outdoor comfort conditions reaching unbearable degrees in the really hottest zones. Therefore, this effect will clearly influence tourism and risk prevention strategies in these areas.

New procedure for wind farm maintenance

Purpose – Conditions monitoring system (CMS) is a tool for describing the present condition of the components of a system. To achieve this objective, there is a need to develop an efficient fault prediction algorithm. This paper seeks to address this issue.Design/methodology/approach – The paper analyses four real wind farms with control charts of indices derived from UNE EN15341:2008 standard indicators, as the main CMS algorithm to define which index must be considered for improving wind farm maintenance and related costs.Findings – The findings show that climatic conditions are related to maintenance cost indices. Employing the statistical control process of various wind energy converter (WEC) indices proposed by wind farm operators is an adequate procedure to monitor and control wind farm performance. In particular, only the maintenance cost index and the hourly maintenance cost index presented a clear relationship with respect to weather conditions.Practical implications – Climatic conditions must fo...

A New Way to Improve Subject Selection in Engineering Degree Studies

In recent years, different Spanish degree studies are being changed and rearranged in accordance with the European Education System (EES) and the Bologna declaration. At that time there was no tool or methodology to define the manner in which different subjects of a degree had to be studied, for better improvement of knowledge. At present, research studies a new method to define the order in which each subject must be studied in different engineering degrees, with the objective of improving the actual studies to a new type, a type more adjusted to real situations. To do this, different statistical studies on electrical and electronic engineering from the University of A Coruna were evaluated. The main results showed a clear relationship between the marks when accessing the degree and the final average marks after completion of the entire degree. Furthermore, different models were obtained to define the relationship between the marks in the first and second courses as compared with the last one. Finally, it was concluded that more professional subjects depend not only on the previous subjects, but also on the same subjects in the last course, as in the case of electrical machines II. This new procedure had to be proposed in future degree adaptation processes, to improve the quality of university studies.

A new modelling procedure of the engine room ventilation system for work risk prevention and energy saving

Maritime transport is one of the primary international objectives for energy saving and pollution reduction, in agreement with the International Maritime Organization. Within the most interesting energy-saving topics, the ventilation system of the engine room must be highlighted, which represents about 5% of the nominal power of a modern ship. Nevertheless, its energetic optimization is not simple and must consider also work risk criteria, since the engine room is the hottest and, in consequence, one of the hazardous places in the ship. In this research, a complete three-dimensional computational fluid dynamics model of the engine room of a real ship has been developed in order to identify the hottest places and fully characterize their thermal conditions. On the basis of this analysis, a mathematical model of the maximum working time allowed has been defined, which can be directly used to design an efficient control algorithm for the ventilation system. In a complementary way, the minimum time required to rest in the control engine room to release the cumulated heat has also been analysed, in order to optimize its set-point conditions.

Development of VBA Based Ship Technical Corrective Management System for Marine Engineers

Recent research works aim at developing an advanced tool, based on expert system principles to solve ship auxiliary machinery troubleshooting (Cebi et al., 2009). In a broad sense, expert systems are computer applications, which embody some/no algorithmic expertise to solve certain types of problems. An expert system, also known as knowledge based system, is a computer program that contains the knowledge and analytical skills of one or more human experts, related to a specific subject. In this sense, some advantages common to most computer systems could include the following (Garcia, 2003): • Control over maintenance activity. • Control over spending. • Facility or consulting history. • Easy to obtain ratios and indicators. Some disadvantages would be: • High initial investment in equipment and programs and manpower for the implementation. • Bureaucratic system. • Increased staff dedicated to indirectly unproductive tasks. • The information provided is often not sufficiently reliable. An example of expert system is the SHIPAMTsolver (Cebi et al., 2009). This system was developed based on PRO-LOG language. It was developed utilizing a considerable amount of information and collected data on the different types of ships machinery systems, system failures, system indicators, and troubleshooting methods through textbooks, handbooks, and interviews with chief engineers who are the marine experts on ship marine system. Nowadays, maintenance activity in ships is proposed to be developed with GMAO (computer maintenance management system) software (Louit et al., 2009; harris et al., 1999; and Vosniakos and Wang, 1999). To analyze the obtained data with this software, it is evident that for an adequate resolution of each problem, an adequate model selection to determine the time taken for a particular component or system to reach failure is essential, which can in turn lead to wrong conclusions and decisions. The gap between researchers