Search results for "020209 energy"
showing 10 items of 1300 documents
The social acceptance of airport expansion scenarios: A factorial survey experiment
2020
Abstract Against the background of growing aviation and protests against air traffic in many countries, we employ a factorial survey experiment to examine the social acceptance of airport expansion scenarios in two European cities located near the international airports of Frankfurt (Germany) and Zurich (Switzerland), respectively. In our experiment, respondents evaluated short descriptions of airport expansion scenarios that varied in several impact attributes. The experiment helps to disentangle to what extent environmental impacts (aircraft noise), economic impacts (job creation), participatory justice aspects (participation opportunities), and distributive justice aspects (noise distrib…
Les mobilités urbaines et leur impact sur l’exposition au bruit : simulation de scénarios prospectifs appliqués à la ville de Besançon
2015
Le modele MobiSim a teste le lien entre la modification de l’offre de transport et l’exposition au bruit dans ses dimensions spatiales et temporelles, le test etant applique a l’agglomeration de Besancon. C’est la desynchronisation des activites, le report modal et les changements dans les grilles horaires des transports collectifs qui produisent des effets reduisant ou bien augmentant l’exposition au bruit selon les lieux et les moments, les populations concernees etant elles-memes socialement diversifiees.
Performance Study of Twisted Darrieus Hydrokinetic Turbine With Novel Blade Design
2021
Abstract Twisted Darrieus water turbine is receiving growing attention for small-scale hydropower generation. Accordingly, the need for raised water energy conversion incentivizes researchers to focus on the blade shape optimization of twisted Darrieus turbine. In view of this, experimental analysis has been performed to appraise the efficiency of a spiral Darrieus water rotor in the present work. To better the performance parameters of the studied water rotor with twisted blades, three novel blade shapes, namely U-shaped blade, V-shaped blade, and W-shaped blade, have been numerically tested using a computational fluid dynamics three-dimensional numerical model. The maximum power coefficie…
Thermal response test analysis for U-pipe vertical borehole heat exchangers under groundwater flow conditions
2021
[EN] Conventional models used in the analysis of thermal response test data only consider conduction as heat transfer mechanism. In cases where presence of groundwater is detected, convection heat transmission plays an important role, so its influence must be determined in the calculation of the effective thermal conductivity, usually overestimated in these situations, increasing its value the higher the power injected and the time elapsed. In this work, based on the data collected in a borehole located at UPV (Valencia) in which have been carried out three thermal response tests with different characteristics, has been implemented a variation of the finite line source model introducing an …
3-Phase grid-connected building integrated photovoltaic system with reactive power control capability
2020
Abstract Recently, a tendency in the growing of grid-connected building integrated photovoltaic (BIPV) systems has been noticed in most countries. Hence, high penetration of PV power into the system network can be observed in many points in the network. This may cause severe problems on the distribution network due to the intermittent nature of PV systems. As a feasible solution, the reactive power capability of voltage source inverter in PV systems can be employed rather than approaching expensive grid infrastructures in the distribution network. The purpose of this study is to implement a 3-phase grid-connected (BIPV) system with reactive power control to regulate the system voltage and i…
Multifarious pretreatment strategies for the lignocellulosic substrates for the generation of renewable and sustainable biofuels: A review
2020
Abstract Currently major part of the world’s energy requirements is fulfilled by fossil resources. Severe economic and environmental problems along with their limited resources are still a major issue. Long-term environmental and commercial concern has focussed into huge research in the past decades to replace fossil fuels with renewable sources of energy. The main focus of energy research is lignocellulosic substrates, which seems to be the best for energy application due to easily availability, cost-effective and environment favourable production process. Therefore, lignocellulosic materials provide economical, environmental and energetic benefits with an alternative to traditional or hig…
Analysing the effects of power swing on wind farms using instantaneous impedances
2020
Abstract Most of the grid disturbances happen due to the presence of faults and power swing. This article focuses on power swing in view of the amount of penetration of renewable energy resources especially the wind farms. There are two sections. First section approached power swing by deriving a mathematical expression which would be able to track the locus of impedance in time domain and subsequently analyze resistance and reactance simultaneously with respect to time. It used a grid comprising of generator, transmission line and load. The derived expression was compared with a power swing generated using RTDS model and the results were analyzed in R-X plane. Second section analyses the i…
Dynamic mean absolute error as new measure for assessing forecasting errors
2018
Abstract Accurate wind power forecast is essential for grid integration, system planning, and electricity trading in certain electricity markets. Therefore, analyzing prediction errors is a critical task that allows a comparison of prediction models and the selection of the most suitable model. In this work, the temporal error and absolute magnitude error are simultaneously considered to assess the forecast error. The trade-off between both types of errors is computed, analyzed, and interpreted. Moreover, a new index, the dynamic mean absolute error, DMAE, is defined to measure the prediction accuracy. This index accounts for both error components: temporal and absolute. Real cases of wind …
Mechanical, thermal and acoustical characterizations of an insulating bio-based composite made from sunflower stalks particles and chitosan
2014
International audience; This study has for objective the determination of thermal, mechanical and acoustical properties of insulating bio-based composite made with chitosan and sunflower's stalks particles. An experimental design was established to find the size grading of particles, the ratio chitosan/sunflower particles and the stress of compaction influencing the thermal and mechanical properties. Composites with a thermal conductivity $(\kappa)$ of 0.056 W/m/K, a maximum stress $(\sigma_{\text{max}})$ of 2 MPa and an acoustic coefficient of absorption $(\alpha)$ of 0.2 were obtained with a ratio of chitosan of 4.3% (w/w) and a size grading of particles higher to 3 mm. These mechanical a…
Nano-magnetic potassium impregnated ceria as catalyst for the biodiesel production
2019
Abstract The main objective of this work comprises the investigation of biodiesel production from rapeseed oil using potassium impregnated Fe3O4-CeO2 nanocatalyst. The various concentration of potassium impregnated Fe3O4-CeO2 was screened for catalytic conversion of rapeseed oil to triglyceride methyl ester. The 25 wt % potassium impregnated Fe3O4-CeO2 nanocatalyst showed best biodiesel production. Nanocatalyst was characterized by FTIR, XRD, SEM, TEM, BET and Hammett indicator for basicity test. The characterization of biodiesel was performed with GC-MS, 1H and 13C NMR. Moreover, the optimum reaction parameters such as catalyst amount (wt %), oil to methanol ratio, reaction time and reacti…