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Electric vehicles (EVs) are considered a substitute for fossil-fueled vehicles due to rising fossil fuel prices and accompanying environmental concerns, and their use is predicted to increase dramatically shortly. However, the widespread use of EVs and their large-scale integration into the energy system will present several operational and technological hurdles. In the energy industry, an innovative solution known as the EVs smart parking lot (SPL) is introduced to handle EV charging and discharging electricity and energy supply challenges. This paper investigates social equity access and mobile charging stations (MCSs) for EVs, where the owner of MCSs is the EV parking lot. Accordingly, a new self-scheduling model for SPLs is presented in this paper that incorporates scheduling of the MCSs as temporary charging infrastructures while considering social equity access and optimizes SPL energy generation and storage schedule. The main objectives of this research are to (i) develop MCSs accessibility measures and quantify the equity impacts of MCSs locations by modeling prioritized demand based on several indices; (ii) determine the optimal set-points of SPL components (i.e., combined heat and power (CHP), photovoltaic system, electrical and heat-energy storage, and MCSs) to manage electrical peak demand and to maximize the economic benefits of SPLs. Results indicate that the proposed demand prioritization function model can meet the required EV charging demands for prioritized events, and the self-scheduling model for SPLs satisfies the charging demand of the EVs in the SPL location. Also, the social equity access to the EV charging stations is satisfied by analyzing the operation of MCSs around the prioritized demand of the prioritized events and social equity access indices.

Artículos en revistas Security-constrained unit commitment (SCUC) problem is one of the necessary tools for system operators to make operational planning and real-time operation. The internalization of transmission-network and security constraints (e.g. N-1 criterion) could lead to different decisions in the generation dispatch. However, the computational burden of this problem is challenging mainly due to its inherent large problem size. Therefore, this paper proposes an N-1 security constrained formulation based on the Line Outage Distribution Factors (LODF) instead of the one based on Injection Sensitivity Factors (ISF). This formulation is at the same time more compact than analogous formulations for contingency constraints; hence, it presents a lower computational burden. The computational efficiency of the proposed formulation is shown by solving the SCUC of the IEEE 118 bus system with LODF and ISF. Additionally, an iterative methodology for filtering the active N-1 congestion constraints is detailed, and its implementation for large-scale systems is described. The results show that the proposed filter reduces the computational time by approximately 70% in comparison to the complete formulation of N-1 constraints in SCUC. info:eu-repo/semantics/publishedVersion

Abstract The use of phase change materials (PCMs) for thermal storage in buildings was one of the first applications studied, together with typical storage tanks. An interesting possibility in building application is the impregnation of PCMs into porous construction materials, such as plasterboard or concrete, to increase thermal mass. The thermal improvements in a building due to the inclusion of PCMs depend on the climate, design and orientation of the construction, but also to the amount and type of PCM. Therefore, these projects require a complete simulation of the thermal behaviour of the designed space in the conditions of use established a priori. In this paper a simple methodology for the energetic simulation of buildings including elements with PCMs using the program TRNSYS is presented and validated. This procedure does not aim a simulation of the real transfer processes inside the materials with PCM, but to evaluate the influence of walls/ceiling/floor with PCM in the whole energy balance of a building. The key parameter in the simulations is the equivalent heat transfer coefficient which has to be determined for each material. Experimental evaluation of the coefficient is presented. The methodology is applied in a building such as a prototype room built with concrete panels with PCM.

Changes in weather patterns pose a threat to the serviceability and long-term performance of roads, and porous asphalt (PA) roads are particularly sensitive to the freezing-thawing (FT) phenomenon. The main objective of this research is to assess the impact of climate change, particularly freezing and thawing cycles, on PA. Climate models predict changes in air temperature, not pavement temperature. To predict the climate change impact on pavements performance, this requires first establishing a relationship between air and road temperature and a correlation between pavement performance and FT cycles. This project focuses on the Netherlands, where PA pavement use has become mandatory, and recent severe winters have increased the discussion about the cold weather performance of porous asphalt and the potential challenges of changing winter weather patterns. When considering long-term changes in climate, the cost impacts of freeze-thaw on PA pavement are predicted to vary regionally and in most areas reach a point in the middle of the century when a reactive wait-and-see approach is more advantageous than proactive adaptation. Further research is suggested to refine the relationship between observed damage and freeze-thaw impacts on PA pavement.

An experiment in open-top chambers was carried out in summer 2008 in Curno (northern Italy) in order to study the effects of ozone and drought stress on net photosynthesis, growth and stable isotope partitioning on cuttings of an ozone-sensitive poplar clone (Oxford). The biomass (as dry weight) of stems, leaves and roots was assessed five times during the growing season on a set of plants intended for destructive measurements (set 1). Another set of plants (set 2) was used for repeated measurements (net photosynthesis) and then destroyed at the end of the experiment. The dry weight of the stems in set 1 plants was calculated using allometric relations. The results showed that drought stress had a strong effect on all the parameters assessed. Ozone did not have any effect on biomass allocation in woody stems and stable isotope composition but reduced root/shoot ratios and caused loss of leaves during the growing season. The loss of leaves in the lower part of the crown was partly recovered with the emission of new young leaves in the upper part, thus restoring the overall photosynthetic apparatus. We conclude that the metabolic costs suffered to repair damage and support growth, and the reduction in starch reserves in the roots can compromise growth and the capacity to cope with stress factors in subsequent years.

Artículos en revistas This paper presents the principles of a centralized underfrequency load-shedding (UFLS) scheme based on a frequency stability boundary curve suitable for small isolated power systems. The centralized UFLS scheme is illustrated in case of two small isolated Spanish power systems. info:eu-repo/semantics/publishedVersion

Antiprotons have been suggested as a possibly superior modality for radiotherapy, due to the energy released when antiprotons annihilate, which enhances the Bragg peak and introduces a high-LET component to the dose. However, concerns are expressed about the inferior lateral dose distribution caused by the annihilation products.We use the Monte Carlo code FLUKA to generate depth-dose kernels for protons, antiprotons, and carbon ions. Using these we then build virtual treatment plans optimized according to ICRU recommendations for the different beam modalities, which then are recalculated with FLUKA. Dose-volume histograms generated from these plans can be used to compare the different irradiations.The enhancement in physical and possibly biological dose from annihilating antiprotons can significantly lower the dose in the entrance channel; but only at the expense of a diffuse low dose background from long-range secondary particles. Lateral dose distributions are improved using active beam delivery methods, instead of flat fields.Dose-volume histograms for different treatment scenarios show that antiprotons have the potential to reduce the volume of normal tissue receiving medium to high dose, however, in the low dose region antiprotons are inferior to both protons and carbon ions. This limits the potential usage to situations where dose to normal tissue must be reduced as much as possible.

Enhanced weathering (EW) is one of the most promising negative emissions technologies urgently needed to limit global warming to at least below 2 °C, a goal recently reaffirmed at the UN Global Climate Change conference (i.e., COP26). EW relies on the accelerated dissolution of crushed silicate rocks applied to soils and is considered a sustainable solution requiring limited technology. While EW has a high theoretical potential of sequestering CO2, research is still needed to provide accurate estimates of carbon (C) sequestration when applying different silicate materials across distinct climates and major soil types in combination with a variety of plants. Here we elaborate on fundamental advances that must be addressed before EW can be extensively adopted. These include identifying the most suitable environmental conditions, improving estimates of field dissolution rates and efficacy of CO2 removal, and identifying alternative sources of silicate materials to meet future EW demands. We conclude with considerations on the necessity of integrated modeling-experimental approaches to better coordinate future field experiments and measurements of CO2 removal, as well as on the importance of seamlessly coordinating EW with cropland and forest management.