Search results for "ELECTRICITY"
showing 10 items of 1225 documents
Study of the pyroelectricity in LiIns2 crystal
2002
Abstract Pyroelectric current measurements performed on a LiInS2 monodomain single crystal show a linear variation of the current between 120 and 260 K. Near room temperature, a space charge relaxation screens pyroelectricity. The pyroelectric coefficient follows a linear thermal dependence leading to an extrapolated value of 6×10−10 C K−1 cm−2 at 300 K. As for other oxide-type pyroelectric compounds, this value is shown to be proportional to the electro-optic coefficient r333 of LiInS2.
Critical Exponents and Randomness in SrTiO3 : Ca
1994
Since its discovery, the SrTiO3: Ca system is known to exhibit a number of features which were thought to arise from an impurity induced disorder. Non-linear dielectric measurements are used to obtain a more quantitative insight into this disorder. For 0.001 < xCa < 0.05, it is found that the non-linear susceptibility diverges at low temperatures. This is similar to what was previously reported in the dielectric random system KTaO3: Na. A method is proposed to quantify the contribution of the disorder to the non-linearities. It is found that the deviation from a true ferroelectric behaviour is not enough to call the low-temperature phase of SrTiO3: Ca a glass one. The maximum non-linearity …
Comparative study of [001] surface relaxations of perovskite titanates
1998
Surface relaxations of the cubic perovskite SrTiO and BaTiO crystals have been studied in the framework of the shell model. The 33 positions of atoms in several surface layers embedded into the electrostatic field of the remainder of the crystal were calculated. Ti 4q , Sr 2q ,B a 2q and O 2y ions in six near-surface layers are displaced differently from their crystalline sites. Such effects create the so-called surface rumpling, a dipole moment and the electric field in the near-surface region. Calculated atomic displacements were compared with the LEED experimental data and showed good agreement. Our simulations have demonstrated that the cubic perovskite SrTiO crystals 3 reveal surface p…
In Situ Synthesis of Conducting Polymers: A Novel Approach toward Polymer Thermoelectrics
2020
The efficient conversion of thermal energy into electricity by means of durable and scalable solid-state thermoelectric devices has been a well stablished aim. Electrically conducting polymers have...
Thermal sensor based on a polymer nanofilm
2016
In this work, we have developed a thermal sensor based on poly(3,4 ethylenedioxythiophene) (PEDOT) nanofilms as thermoelectric material. The PEDOT nanofilms have been synthesized by the electrochemical polymerization method. The thicknesses of the films were around 120 nm. The doping level of PEDOT was controlled by chemical reduction using hydrazine. The achieved Seebeck coeficient is 40 uV/K. A PEDOT nanofilm was integrated into an electronic circuit that amplifies the voltage originated from the Seebeck effect. The temperature increment produced by a fingerprint touching the film is enough to switch on a light emitting diode. Peer Reviewed
LoRa-Based Sensor Node Energy Consumption with Data Compression
2021
In this paper simple temporal compression algorithms' efficiency to reduce LoRa-based sensor node energy consumption has been evaluated and measured. It is known that radio transmission is the most energy consuming operation in a wireless sensor node. In this paper three lightweight compression algorithms are implemented in an embedded LoRa platform to compress sensor data in on-line mode and the overall energy consumption is measured. Energy consumption is compared to the situation without implementing any compression algorithm. The results show that a simple compression algorithm is an effective method to improve the battery powered sensor node lifetime. Despite the radio transmission's h…
The Southern African Power Pool: An Electrifying Project with Untapped Potential
2017
This chapter turns to infrastructure and gives an outstanding analysis of regional electricity cooperation in the SADC within the framework of the Southern African Power Pool (SAPP). The author illustrates the regional power imbalances in terms of national electricity generation and consumption which fuel the SADC countries’ demand for a regional electricity market and an interconnected regional power grid. It becomes clear that the SAPP’s institutional design is strongly influenced by South Africa as the hub of the existing power network and largest electricity producer. Influence by external actors is supportive of regional electricity cooperation since the EU provides funding for the SAP…
Photovoltaic electricity scenario analysis in urban contests: an Italian case study
2012
Abstract This paper shows a methodology for the assessment of the photovoltaic potential in urban areas using Google Earth™ tool that provides either satellite images of the roofs of buildings or their number of floors by means of the Street View function. The applicability of the methodology has been tested on a selected urban area of the city of Palermo in the South of Italy. After classifying roofs according to the shape, orientation and pitch of buildings with different morphologies, the share of energy generated by the installable PV systems was evaluated with regard to the number of floors. Moreover the coverage of the electricity demand was investigated on the basis of the consumptio…
Forecasting Electricity Consumption and Production in Smart Homes through Statistical Methods
2022
Abstract Over the last years, a steady increase in both domestic electricity consumption and in the adoption of personal clean energy production systems has been observed worldwide. By analyzing energy consumption and production on photovoltaic panels mounted in a house, this work focuses on finding patterns in electrical energy consumption and devising a predictive model. Our goal is to find an accurate method to predict electrical energy consumption and production. Being able to anticipate how consumers will use energy in the near future, homeowners, companies and governments may optimize their behavior and the import and export of electricity. We evaluated the ARIMA and TBATS statistical…
Electricity Consumption Analysis of Tertiary Buildings: An Empirical Approach for Two University Campuses
2020
An empirical approach for the analysis of energy consumption of existing buildings of the tertiary sector is presented in this study. It allowed the organization and management of large amounts of data according to different timeframes and helped to focus on leading issues about energy uses, and dealt with compatibility with tariff structure. The analysis method, which implied a powerful graphical representation of the results, allowed us to detect critical issues in electricity energy management for public buildings and improve their energy performance. Furthermore, the authors proposed a set of electricity consumption indexes (ECIs) that gave useful insight into the main hotspots. The bas…