Search results for "Operation"

Impact of anionic system modification on the desired properties for CuGa(S1−Se )2 solid solutions

2021

Abstract One of promising directions of the modern solar cells’ development is related to the use of the ternary chalcopyrite crystals (CuInS2, CuGaS2 etc.) and their solid solutions as efficient light absorbing layers. Unfortunately, so far there is no systematic research linking chemical composition to useful properties allowing their optimization to increase the efficiency of solar cells. Therefore, we report the results of the detailed theoretical studies of the structural, electronic, and optical properties for the series of CuGa(S1−xSex)2 solid solutions (x = 0, 0.25, 0.5, 0.75, 1) in the framework of the density functional theory. For this purpose, crystal structures are analyzed wit…

Integrated ternary bionanocomposites with superior mechanical performance via the synergistic role of graphene and plasma treated carbon nanotubes

2019

Abstract Herein, we prepared an integrated ternary bionanocomposite based on polylactic acid (PLA) as a host polymer and two different forms of carbon fillers, i.e. graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs), used simultaneously at extremely low concentrations, relying on the synergistic effect of CNT and graphene nanoreinforcement and a novel, multi-step procedure to achieve a high level dispersion. The results indicated that this multi-step approach allows stiffness increments up to +66%, with simultaneous enhancement of tensile strength (up to +44%), and elongation at break (up to +36%) with respect to neat PLA, by adding an extremely low content (0.5 wt%) of a hybrid comb…

Thermal Characterization of the Chip-Tool Interface When Using Coated Turning Inserts

2000

Abstract This paper reports some results of extensive experimental investigations of the thermal interactions between the coating/substrate and the moving surface of the chip. Semi-orthogonal cutting when bar turning a medium carbon steel and an austenitic stainless steel was carried out. Both flat-faced and grooved inserts coated with TiC, TiC/TiN, and TiC/Al 2 O 3 /TiN were tested. A standard K-type thermocouple embedded in the workpiece was used to convert measured efm's to the interfacial temperatures. In addition, the chiprake contact length and the area of contact were determined by using computer processing of scanned contact images. The minimum steady-state temperature at the interf…

Characterization of cryoprotectants ternary mixture according to cooling rates

2015

The Preparation and the Characterisation of some Ternary Titanium Oxide Pkotocatalysts.

1987

TiO 2 catalysts, of moderate surface areas and minimal porosities, containing various nominal quantities of iron have been prepared. E.s.r spectra indicate that Fe 3+ is well dispersed in coprecipitated samples, and in impregnated Tioxide samples, when the iron concentration is

Preparation and evaluation of butyl acrylate-based monolithic columns for CEC using ammonium peroxodisulfate as a chemical initiator.

2008

Acrylate-ester-based monoliths for CEC using peroxodisulfate as a chemical initiator were prepared. The influence of two ternary porogenic solvents on the physical and chromatographic properties of butyl acrylate monolithic stationary phases was investigated. The composition and the ratio of porogenic solvent were adjusted to obtain highly permeable rigid monoliths with adequate column efficiency. Among the prepared butyl acrylate monoliths, those polymerized from a ternary porogenic solvent of acetonitrile/ethanol/water exhibited the most promising performance with a minimum plate height for naphthalene of 10.5 microm and a bed permeability of 7.3 x 10(-14) m(2). A comparison in terms of e…

Optical and magnetic properties of ZnCoO thin films synthesized by electrodeposition

2008

Ternary Zn1−xCoxO crystalline films with different compositions were grown by electrodeposition. The Co content in the final compound is linked to the initial Co/Zn ratio in the starting solution. X-ray diffraction reveals a wurtzite structure for the Zn1−xCoxO films. Transmittance spectra show two effects proportional to Co content, a redshift of the absorption edge and three absorption bands, which are both interpreted to be due to the Co incorporated into the ZnO lattice. The amount of deposited charge was used to get a precise control of the film thickness. Magnetic measurements point out that Co(II) ions are isolated from each other, and consequently the films are paramagnetic. Francis…

Quaternary half-metallic Heusler ferromagnets for spintronics applications

2011

This work reports on three quaternary Heusler compounds NiFeMnGa, NiCoMnGa, and CuCoMnGa. In contrast to their ternary relatives, quaternary Heusler compounds are still rarely investigated. A very large pool of interesting materials lies thus idle waiting for exploration. The difficulty consists in choosing prospective compositions, and trial and error is elaborate and expensive. We have identified several candidates employing ab initioelectronic-structure calculations. The compounds were synthesized, and the structural and magnetic properties were investigated experimentally. CuCoMnGa is a quaternary Heusler compound; NiFeMnGa and NiCoMnGa are unreported half-metallic ferromagnetic materia…

CO2 to Liquid Fuels: Photocatalytic Conversion in a Continuous Membrane Reactor

2018

The photocatalytic reduction of CO, into value-added chemicals using sunlight is a promising approach to promote energy-bearing products, mitigating the adverse effects of anthropogenic CO2 emissions. In this work, exfoliated C3N4 was incorporated into Nafion matrix and used in a continuous photocatalytic reactor for converting CO2 into liquid fuels. Comprehensive structural and morphological diffuse reflectance spectroscopy (DRS), FT-IR, ATR-IR, and SEM measurements were performed for C3N4-loaded Nafion membrane and then compared with those of a Nafion membrane without any catalyst. The synergic effect of C3N4 organic catalyst embedded in a Nafion dense matrix and a continuous operating mo…

High voltage vacuum-processed perovskite solar cells with organic semiconducting interlayers

2020

In perovskite solar cells, the choice of appropriate transport layers and electrodes is of great importance to guarantee efficient charge transport and collection, minimizing recombination losses. The possibility to sequentially process multiple layers by vacuum methods offers a tool to explore the effects of different materials and their combinations on the performance of optoelectronic devices. In this work, the effect of introducing interlayers and altering the electrode work function has been evaluated in fully vacuum-deposited perovskite solar cells. We compared the performance of solar cells employing common electron buffer layers such as bathocuproine (BCP), with other injection mate…