Search results for " conversion"

An over-the-distance wireless battery charger based on RF energy harvesting

2017

An RF powered receiver silicon IC (integrated circuit) for RF energy harvesting is presented as wireless battery charger. This includes an RF-to-DC energy converter specifically designed with a sensitivity of -18.8 dBm and an energy conversion efficiency of ∼45% at 900 MHz with a transmitting power of 0.5 W in free space. Experimental results concerned with remotely battery charging using a complete prototype working in realistic scenarios will be shown.

Concepts for medium-high to high temperature thermoelectric heat-to-electricity conversion: a review of selected materials and basic considerations o…

2015

Within the last decade, novel materials concepts and nanotechnology have resulted in a great increase of the conversion efficiency of thermoelectric materials. Despite this, a mass market for thermoelectric heat-to-electricity conversion is yet to be opened up. One reason for this is that the transfer of the lab records into fabrication techniques which enable thermoelectric generator modules is very challenging. By closing the gap between record lab values and modules, broad industrial applications may become feasible. In this review, we compare three classes of materials, all designed for medium-high to high temperature applications in the field of waste heat recovery: skutterudites, half…

Electrochemical conversion of carbon dioxide: effect of the cell and of the operating parameters on the performances of the process.

2017

Recycling technologies of CO2 allow to introduce renewable energy in the chemical and energy chain, storing a renewable energy in the chemical form. In this context, electrochemical conversion of CO2 is considered one of the more interesting approaches, using excess electric energy from intermittent renewable sources. (1) Furthermore, products can be selectively controlled by changing the operating conditions of electrolysis. In particular, in the last years, an increasing attention has been devoted to the electrochemical conversion of CO2 to formic acid or formate in water. (2,3,4) The main hurdle of the reduction of CO2 from water solution is the low CO2 solubility in water. In this work,…

A 3-week post-weaning restricted feeding as alternative to an ad libitum antibiotic-medicated feed: Effects on growth, carcass and meat of rabbits di…

2022

In this investigation, the impact of a 3-week post-weaning restricted feeding (RF) using an antibiotic-free feed, applied to rabbits from 36 to 56 days of age to preserve their health status as alternative to an ad libitum medicated feed with antibiotics (AMF), was verify in relation to rabbit genotype and slaughter age (SA). The RF and AMF treatments were compared evaluating their effects on feed intake, growth, mortality, carcass and meat quality of rabbits of two genotypes, Italian White purebred (IWP) and hybrid Hycole×IWP crossbred (HIWC), slaughtered at 78 or 92 days of age to obtain light or heavy carcasses. At 36 days of age, 256 weaned rabbits of both sexes were divided into 4 homo…

Improving the efficiency of a standard compliant wireless battery charger

2012

In this paper, a wireless charger for portable electronics devices is presented. A power transmitter, also known as the magnetic pad, and a power receiver are magnetically coupled. A receiver architecture which improves the power conversion efficiency is proposed. All advantages brought by the proposed architecture are discussed and standard constraints are presented as well. The receiver is fully standard-compliant. A wireless station for mobile application is designed and tested. Simulation and experimental results are compared. As shown by experimental results, thanks to the proposed architecture the power conversion efficiency of the receiver section is really close to a unit value. Pow…

Conversion of carbohydrates into 5-HMF in Deep Eutectic Solvents under mild reaction conditions

Impact of hydroxy and octyloxy substituents of phenothiazine based dyes on the photovoltaic performance

2013

Two novel organic dyes containing hydroxy and octyloxy substituents onto a phenothiazine skeleton were synthesized and their effects on the photovoltaic performance were studied. Hydroxy acts as an ancillary anchoring unit along with the carboxylic group, while the phenothiazine modified moiety acts as an electron donor. The photophysical and electrochemical studies revealed that maximum absorbance of the dye with the hydroxy group in the solution was blue shifted and its band gap increased, indicating that donor acceptor strength was reduced as compared to the octyloxy substituted dye. Furthermore, electron lifetime of the organic dye with the hydroxy moiety was shorter due to smaller resi…

Nonfullerene Polymer Solar Cells Reaching a 9.29% Efficiency Using a BODIPY-Thiophene Backboned Donor Material

2018

A conjugated polymer donor containing BODIPY-thiophene dyads in the backbone, P(BdP-EHT), combined with a low bandgap nonfullerene acceptor (SMDPP) consisting of carbazole and diketopyrrolopyrrole units linked with a tetracyanobutadiene acceptor π-linker, was used to design bulk heterojunction polymer solar cells. After the optimization of the donor to acceptor weight ratio and solvent vapor annealing of the P(BdP-EHT):SMDPP active layer, the resulting polymer solar cell showed an overall power conversion efficiency of 9.29%, which is significantly higher than that for the polymer solar cell based on PC71BM (7.41%) processed under identical conditions. This improved power conversion efficie…

The adoption of the Euro by Romania

2013

As Romania has joined the European Union, the European currency must be adopted even though it may raise some problems regarding conversion, the impact on goods and services expenses on the interior market having a direct effect on the population and the national economy because we don’t know which the trajectory of the Euro will be. This paper takes a look at the advantages and disadvantages of the adoption of the unique currency in our country taking into account the time factor and the behaviour we must have regarding the Euro, establishing the issues we must take a close look at when the initial term of adoption must be respected.

Theoretical analysis of the optimum energy band gap of semiconductors for fabrication of solar cells for applications in higher latitudes locations

2005

In this work some results of theoretical analysis on the selection of optimum band gap semiconductor absorbers for application in either single or multijunction (up to five junctions) solar cells are presented. For calculations days have been taken characterized by various insolation and ambient temperature conditions defined in the draft of the IEC 61836 standard (Performance testing and energy rating of terrestrial photovoltaic modules) as a proposal of representative set of typical outdoor conditions that may influence performance of photovoltaic devices. Besides various irradiance and ambient temperature ranges, these days additionally differ significantly regarding spectral distributio…