Search results for "Electricity"
showing 10 items of 1225 documents
LC-Polymers with Axial Chirality
1991
Abstract Liquid crystalline polymers with axial chirality are prepared. These polymers are chiral, not due to a single asymmetric carbon atom, but due to a larger molecular fragment, which is chiral as a whole. They exhibit cholesteric and chiral smectic C* phases. Dielectric spectroscopy proves strong ferroelectric properties in the chiral smectic C* phases of these polymers.
Postsynthetic Approach for the Rational Design of Chiral Ferroelectric Metal–Organic Frameworks
2017
International audience; Ferroelectrics (FEs) are materials of paramount importance with a wide diversity of applications. Herein, we propose a postsynthetic methodology for the smart implementation of ferroelectricity in chiral metal−organic frameworks (MOFs): following a single-crystal to single-crystal cation metathesis, the Ca2+ counterions of a preformed chiral MOF of formula Ca6II{CuII24[(S,S)-hismox]12(OH2)3}·212H2O (1), where hismox is a chiral ligand derived from the natural amino acid l-histidine, are replaced by CH3NH3+. The resulting compound, (CH3NH3)12{CuII24[(S,S)-hismox]12(OH2)3}·178H2O (2), retains the polar space group of 1 and is ferroelectric below 260 K. These results op…
Polymers, Ferroelectric Liquid Crystalline Elastomers
2002
Ferroelectric materials are a subclass of pyro- and piezoelectric materials. They are very rarely found in crystalline organic or polymeric materials because ferroelectric hysteresis requires enough molecular mobility to reorient molecular dipoles in space. So semicrystalline polyvinylidene fluoride (PVDF) is nearly the only known compound. On the contrary, ferroelectric behavior is very often observed in chiral liquid crystalline materials, both low molar mass and polymeric. Ferroelectric LC-elastomers represent an interesting class of material because they combine the ordering of liquid crystalline ferroelectric phases and the rubber elasticity of polymer networks. Switching of the electr…
Smart Micro-Grid Performance using Renewable Energy
2020
The aim of this research is to determine the performance of PV panels, wind turbines, battery storage and power imported from the grid to the system which will ensure a reliable energy supply, as well as the technical feasibility of a smart microgrid system. Indonesia’s renewable energy potential for electricity reaches 443 GW, where solar energy is the largest potential, namely 4.8 KWh m–2 or equivalent to 112 000 GWp, but only 10 MWp has been utilized. The most basic problem in this system, namely, the uncertainty of wind energy and solar energy, one of the most vital factors in the optimal size of a renewable energy-based smart microgrid system is the reliability of the system being buil…
Renewable Energy Technologies for Economic Development
2020
Indonesian villages are facing dangerous condition. Every year, young people are deserting the villages. To overcome this problem, Tangsi Jaya hamlet, West Java, has been provided with 18 kW micro-hydro to supply electricity both to the community and to Small Processing Center for ground coffee production. Results of cash flow analysis for ground coffee in Tangsi Jaya hamlet, with total investment of IDR 110 750 000 and discount rate of 18 % for 5 yr. Banyumeneng I hamlet, Yogyakarta with an investment cost IDR 95 000 000 and production cost of IDR 34 195 000 yr–1 and the interest rate of 14 % yr–1, the payback period was estimated to be 3 yr with ROI of 40 %. PEST analysics indicate that t…
Complex composite structures with integrated piezoelectric transducers
2016
International audience; Nowadays, in different industrial fields as transport or aerospace, a research effort is conducted to reduce the structural weight. One of the most promising solutions is the use of composite structures due to their high stiffness, their low mass density and their low damping factor. At the same time, there is an intensification of the operational dynamic environment and an increase of durability requirements. These different expectations seem to be contradictory. One solution to manage these points is to design and manufacture smart composite structures with a fully distributed set of integrated piezoelec-tric transducers. These structures are able to modify their m…
The reliability of spanish and german electricity forward prices. Databases and price discovery process
2021
Given the existence of different databases from different sources that offer information on forward electricity prices, the need to compare them arises to guarantee that research results and trading decisions based on them are not sensitive to the database used. We worked with forward electricity prices traded over the counter, closest month to maturity, covering the period from 2010 to 2016 for the Spanish over the counter (OTC) market, and from 2008 to 2016 for the German OTC market. The goal of this paper was to test whether there were significant discrepancies between the price series provided by two of the main agencies of financial information (Thomson Reuters and Bloomberg), as well …
Impact of Wind Electricity Forecasts on Bidding Strategies
2017
The change in the generation mix from conventional electricity sources to renewables has important implications for bidding behaviour and may have an impact on prices. The main goal of this work is to discover the role played by expected wind production, together with other relevant factors, in explaining the day-ahead market price through a data panel model. The Spanish market, given the huge increase in wind generation observed in the last decade, has been chosen for this study as a paradigmatic example. The results obtained suggest that wind power forecasts are a new key determinant for supply market participants when bidding in the day-ahead market. We also provide a conservative quanti…
Iontophoresis: electrorepulsion and electroosmosis.
2000
Over the last 10-15 years, the electrical enhancement of drug delivery across the skin has undergone intense investigation. During this period, considerable amounts of experimental data have been generated, and the successful enhancement of a diverse array of molecules has been achieved. Indeed, the commercial exploitation of the method can be envisaged within the next few years. Despite this progress, however, the mechanistic understanding of iontophoresis remains a challenging scientific question that is yet to be fully resolved. The routes of permeation under the influence of an applied electrical potential, and the molecular interactions of the transporting drug with these pathways, hav…
The energy policy in Spain: the case of the sector of the electricity
2016
In this article the recent electricity policy in Spain is analysed. Firstly, the paper study how the goals were established, afterword it explains the design of the economic policy and finally their results are hi-ghlighted. The article concludes by evaluating the results obtained, with reference to the initially established objectives and also the costs of the policies implemented