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3D city models are a useful tool to analyze the solar potential of neighborhoods and cities. These models are built from buildings footprints and elevation measurements. Footprints are widely available, but elevation datasets remain expensive and time-consuming to acquire. Our hypothesis is that the GIS cadastral data can be used to build a 3D model automatically, so that generating complete cities 3D models can be done in a short time with already available data. We propose a method for the automatic construction of 3D models of cities and neighborhoods from 2D cadastral data and study their usefulness for solar analysis by comparing the results with those from a hand-built model. The results show that the accuracy in evaluating solar access on pedestrian areas and solar potential on rooftops with the automatic method is close to that from the hand-built model with slight differences of 3.4% and 2.2%, respectively. On the other hand, time saving with the automatic models is significant. A neighborhood of 400,000 m2 can be built up in 30 min, 50 times faster than by hand, and an entire city of 967 km2 can be built in 8.5 h.

This paper reports on laboratory studies into the ac impedance spectra of nickel–metal hydride and nickel–cadmium batteries, aiming at finding out possible correlation between electrical parameters, extracted directly from the high frequency region, and the battery state-of-charge (SoC). Impedance diagrams were recorded immediately after interrupting the dc charge, or discharge, current. The study revealed that the series resonance frequency, at which the dynamic cell behavior switches from an inductive character (Z″>0) to a capacitive one (Z″<0), varied monotonously as a function of state-of-charge. This behavior was reproducible after intermittent charge and discharge. Half-cell measurements were also conducted to associate the cell impedance with either processes occurring at the positive or negative plates.

Abstract Every day and innumerably, road vehicles of different types pass flat roadside-placed elements like stable or temporary traffic signs, noise barriers, charge devices, etc. The elements are exposed to a vehicle-specific flow and pressure field, i.e. to transient loads. In order to quantify the involved phenomena, full-scale experiments were performed for six different vehicle types and three sizes of square plates, which were aligned in three different configurations with respect to the vehicle׳s track. For the measurement of loads effecting the plate, the pressure multi-tapping technique was implemented with high temporal and spatial resolution. The experiments delivered a broad database for the proper quantification of vehicle induced loads on flat elements as a function of vehicle type, vehicle velocity and passing distance to the plate, element size as well as spatial plate alignment with respect to the vehicle.

This research studied the impacts of the environmental Kuznets curve and the determinants of economic growth for Visegrad countries from 1990 to 2018. This paper reflects on the effects of renewable and non-renewable energy, urban population, foreign direct investment, economic growth, and carbon dioxide emissions. According to our results, the panel of unit root tests showed that the variables under study are integrated into the first differences. Considering the empirical results for the environmental Kuznets curve, we observe that economic growth is positively correlated with pollution emissions; nevertheless, the squared income per capita is negatively impacted by carbon dioxide emissions. Energy consumption increases carbon emissions, and foreign direct investment confirms the pollution halo hypothesis. Therefore, the econometric results showed that renewable energy consumption promotes regional growth. Consequently, urban population and foreign direct investment positively correlate with economic growth.

In this paper the low frequency shielding behavior of shielded high voltage cables for electric vehicles is analyzed using analytical methods. First the basic theory on the operational modes and modeling of cables is presented. Measurements and numerical simulations are done to verify the models. The powertrain of an electric vehicle is investigated using the simulation models. A parametrical study determines the influence of parameters such as height and distance of the cables and gives information for an EMC compliant layout. The magnetic fields for different cable setups are calculated and compared with values from health protection standards.

Wholesale electricity markets can be organised into different types of markets-energy markets and ancillary services markets-that are cleared sequentially. The paper proposes a stochastic-optimisation model to obtain the distribution of the electricity resources of a generation firm among the different sequential markets within a wholesale electricity market. Market power is modelled by linear approximations of the residual-demand curves. In addition, the model obtains the bid curves of a generation firm that are submitted for every hourly period of each market comprising the sequence. A methodology to estimate the stochastic residual-demand curves for every hour of each market based on decision trees has been designed. The model has been developed for a Spanish utility to operate in the Spanish electricity market. A case study illustrates the performance of the proposed model.

Abstract A variety of novel, recyclable and reusable, construction materials has already been studied within literature during the past years, aiming at improving the overall energy efficiency ranking of the building envelope. However, several studies show that a delicate control of indoor climating elements can lead to a significant performance improvement by exploiting the building’s savings potential via smart adaptive HVAC regulation to exogenous uncertain disturbances (e.g. weather, occupancy). Building Optimization and Control (BOC) systems can be categorized into two different groups: centralized (requiring high data transmission rates at a central node from every corner of the overall system) and decentralized 1 (assuming an intercommunication among neighboring constituent systems). Moreover, both approaches can be further divided into two subcategories, respectively: model-assisted (usually introducing modeling oversimplifications) and model-free (typically presenting poor stability and very slow convergence rates). This paper presents the application of a novel, decentralized, agent-based , model-free BOC methodology (abbreviated as L4GPCAO) to a modern non-residential building (E.ON. Energy Research Center’s main building), equipped with controllable HVAC systems and renewable energy sources by utilizing the existing Building Management System (BES). The building testbed is located inside the RWTH Aachen University campus in Aachen, Germany. A combined rule criterion composed of the non-renewable energy consumption (NREC) and the thermal comfort index – aligned to international comfort standards – was adopted in all cases presented herein. Besides the limited availability of the specified building testbed, real-life experiments demonstrated operational effectiveness of the proposed approach in BOC applications with complex, emerging dynamics arising from the building’s occupancy and thermal characteristics. L4GPCAO outperformed the control strategy that was designed by the planers and system provider, in a conventional manner, requiring no more than five test days.

[EN] The service life of real construction elements is usually long, so the study of the behavior of cement-based materials with new pozzolanic additions in the very long term, after several hardening years, could be interesting. Here, the influence of using waste brick powder as 10% and 20% clinker substitution in microstructure and several durability-related parameters of mortars after 1500 hardening days (approximately 4 years) has been studied. According to the results obtained, the incorporation of brick powder overall improved the performance of mortars after 4 years, compared to reference mortars without addition, especially regarding the pore structure and chloride diffusion. This work was supported by the Conselleria de Educacion, Inves-tigacion, Cultura y Deporte (at present re-named as Conselleria de Innovacion, Universidades, Ciencia y Sociedad Digital) de la Generalitat Valenciana (Spain) [grant number GV/2019/070] ; and by the Agencia Nacional de Investigacion y Desarrollo de Chile (ANID) [grant number FONDECYT REGULAR 1211135]