Energy Management Strategies based on efficiency map for Fuel Cell Hybrid Vehicles

The addition of a fast auxiliary power source like a supercapacitor bank in fuel cell-based vehicles has a great potential because permits a significant reduction of the hydrogen consumption and an improvement of the vehicle efficiency. The Energy Management Strategies, commanding the power split between the power sources in the hybrid arrangement to fulfil the power requirement, perform a fundamental role to achieve this objective. In this work, three strategies based on the knowledge of the fuel cell efficiency map are proposed. These strategies are attractive due to the relative simplicity of the real time implementation and the good performance. The strategies are tested both in a simulation environment and in an experimental setup using a 1.2-kW PEM fuel cell. The results, in terms of hydrogen consumption, are compared with an optimal case, which is assessed trough an advantageous technique also introduced in this work and with a pure fuel cell vehicle as well. This comparative reveals high efficiency and good performance, allowing to save up to 26% of hydrogen in urban scenarios.     

Tunable shapes in supported metal nanoparticles: From nanoflowers to nanocubes

The facile preparation of a range of supported nanoparticles on porous materials was successfully accomplished through the use of a range of environmentally friendly protocols including a modified impregnation/reduction methodology, ultrasounds and microwave irradiation. Materials were characterised by transmission electron microscopy (TEM) and XPS. Different morphologies including conventional nanospheres, nanoflower aggregates, nanorod-like structures and nanocubes were achieved under different conditions. The reported supported nanoparticles are envisaged to have interesting applications in various areas including catalysis, optics and sensors.     

On the structure of generalized toric codes

Toric codes are obtained by evaluating rational functions of a nonsingular toric variety at the algebraic torus. One can extend toric codes to the so-called generalized toric codes. This extension consists of evaluating elements of an arbitrary polynomial algebra at the algebraic torus instead of a linear combination of monomials whose exponents are rational points of a convex polytope. We study their multicyclic and metric structure, and we use them to express their dual and to estimate their minimum distance.     

An investigation of wash-off controlling parameters at urban and commercial monitoring sites.

The relationship between the parameters of the wash-off function and the controlling hydrologic variables are investigated in this paper, assuming that the pollutant generation process basically depends on the watershed rainfall-runoff response characteristics. Data collected during an intense monitoring program carried out by the Department of Environmental Engineering of the University of Genova (Italy) within a residential area, an auto dismantler facility, a tourism terminal and a urban waste truck depot are used to this aim. The observed runoff events are classified into different TSS mass delivery processes and the occurrence of the first flush phenomenon is also investigated. The correlation between the mathematical parameters describing the exponential process and the hydrological parameters of the corresponding rainfall-runoff event is analysed: runoff parameters and in particular the maximum flow discharge over the time of concentration of the drainage network are proposed as the controlling factor for the total mass of pollutant that is made available for wash-off during each runoff event.     

Cost and Schedule Monitoring of Industrial Building Projects: Case Study

Performance measurement is a helpful tool for taking corrective actions and controlling a project as far as this enables accurate time and cost forecasts during the first stages of the construction effort when the management team still has opportunities to make adjustments. This paper overcomes the dilemma of practicability and predictability of traditional estimates at completion based on early progress measurement by presenting the empirical results from the construction project of an industrial facility. The case may be a reference practice for assessing time and cost performance measurement of any building, whose layout can be reasonably partitioned into repeatable portions. In such circumstances, an effectively-managed traditional earned value method and appropriate metrics for computing performance provide project managers with accurate forecasts as useful tools for successful project management and control.     

New technologies and regional growth: the case of Andalucía

This paper studies the contribution of information and communication technologies (ICT) to economic and labour productivity growth in Andalucía (Spain) between 1995 and 2004. We find that, for the period under study, ICT assets only modestly improved total market GVA growth but did significantly improve that of ICT-intensive sectors. Although our analysis shows that ICT-intensive sectors are highly productive in comparison with non-intensive (less intensive) ones, we conclude that it is too early to detect the potential advantages of ICT use in the Andalusian marketplace, especially in comparison to most developed economies.     

Frequency domain methods applied to forecasting electricity markets

The changes taking place in electricity markets during the last two decades have produced an increased interest in the problem of forecasting, either load demand or prices. Many forecasting methodologies are available in the literature nowadays with mixed conclusions about which method is most convenient. This paper focuses on the modeling of electricity market time series sampled hourly in order to produce short-term (1 to 24 h ahead) forecasts. The main features of the system are that (i) models are of an Unobserved Component class that allow for signal extraction of trend, diurnal, weekly and irregular components; (ii) its application is automatic, in the sense that there is no need for human intervention via any sort of identification stage; (iii) the models are estimated in the frequency domain; and (iv) the robustness of the method makes possible its direct use on both load demand and price time series. The approach is thoroughly tested on the PJM interconnection market and the results improve on classical ARIMA models.     

Exergy recovery in regasification facilities – Cold utilization: A modular unit

The paper deals with the problem of cold recovery for direct utilization both in the site of regasification facility and far from it.A modular LNG regasification unit is proposed having the regasification capacity of 2 billion standard cubic meters/year of gas. The modular plant is based on use of a power cycle working with ethane or ethylene which allows operation of cold energy transfer, contained in LNG to be regasified, in a range of temperatures suitable for multipurpose use of cold, reducing regasification process irreversibility. Some electric energy is produced by the power cycle, but the own mission of modular unit proposed is addressed to deliver cold suitable for industrial and commercial use in the proper temperature range. The option considers, also, the use of carbon dioxide as a secondary fluid for transfer of cold from regasification site to far end users. This option seems very attractive due to expected wide future exploitation of LNG regasification in the world.Results of a detailed thermodynamic and economic analysis demonstrate the suitability of the proposal.     

Crystallization kinetics of iPP: Influence of operating conditions and molecular parameters

An analysis of the crystallization kinetics of different grades of isotactic polypropylene (iPP) is here presented. To describe the crystallization kinetics as a function of molecular and operating parameters, the methodological path followed was the preparation of quenched samples of known cooling histories, calorimetric crystallization isotherms tests, differential scanning calorimetry cooling ramps, wide angle X‐ray diffraction (WAXD) measurements, and density determination. The WAXD analysis performed on the quenched iPP samples confirmed that during the fast cooling at least a crystalline structure and a mesomorphic one form. The diffractograms were analyzed by a deconvolution procedure, to identify the relationship between the cooling history and the distribution of the crystalline phases. The whole body of results (including calorimetric ones) provides a wide basis for the identification of a crystallization model suitable to describe solidification in polymer‐processing operations, based on the Kolmogoroff–Avrami–Evans nonisothermal approach. The kinetic parameters, determined for all the materials, are discussed, highlighting the effect of molecular parameters on the crystallization kinetics: molecular mass and distribution, tacticity, nucleating agents, and ethylene units content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1358–1367, 2007