Effect of process conditions on the quality of CdTe grown on InSb by organometallic epitaxy

1986 ◽  
Vol 49 (19) ◽  
pp. 1290-1292 ◽  
Author(s):  
S. K. Ghandhi ◽  
N. R. Taskar ◽  
I. B. Bhat
2014 ◽  
Vol 778-780 ◽  
pp. 230-233
Author(s):  
Yukimune Watanabe ◽  
Tsuyoshi Horikawa ◽  
Kiichi Kamimura

The carbonized layer for a buffer layer strongly influences the crystalline quality of the 3C-SiC epitaxial films on the Si substrates. The growth mechanism of the carbonized layer strongly depended on the process conditions. The surface of silicon substrate was carbonized under the pressure of 7.8 × 10-3 Pa or 7.8 × 10-2 Pa in this research. Under the relatively low pressure of 7.8 × 10-3 Pa, the carbonized layer was grown by the epitaxial mechanism. The crystal axis of the carbonized layer grown under this pressure was confirmed to coincide with the crystal axis of the Si substrate from the results of the selected area electron diffraction (SAED) analysis. Under the relatively high pressure condition of 7.8 × 10-2 Pa, the carbonized layer was grown by the diffusion mechanism. The result of the SAED pattern and the XTEM image indicated that this layer consisted of small grainy crystals and their crystal axes inclined against the growth direction. It was confirmed that the crystalline quality of the SiC film deposited on the carbonized layer grown by the epitaxial mechanism is better than that deposited on the layer grown by the diffusion mechanism.


2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000033-000036 ◽  
Author(s):  
M.H. Weng ◽  
A.D. Murphy ◽  
D.T. Clark ◽  
D.A. Smith ◽  
R.F. Thompson ◽  
...  

The potential to thermally grow SiO2 on silicon carbide has resulted in it becoming the technology of choice to realise high temperature CMOS circuits. The challenge to achieve a high quality gate stack relies on engineering the metal-insulator-semiconductor interfaces to enable reliable high temperature functionality. Here we describe the effect of different process conditions for the formation of the dielectric layer on the characteristics of the resulting devices. The operating characteristics at elevated temperatures depend critically on the quality of the gate stack. Therefore a systematic evaluation of the intrinsic properties of the gate stack and data from reliability tests are needed.


Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 683 ◽  
Author(s):  
Katia Vutova ◽  
Vania Vassileva ◽  
Vladislava Stefanova ◽  
Dinesh Amalnerkar ◽  
Takeshi Tanaka

This study reveals the efficiency of the electron beam processing of titanium technogenic material with a high level of impurities and the quality of the obtained metal in correlation to process parameters which are discussed. The influence of the beam power and melting time on the composition variation, morphologies, hardness of metal samples and mass losses is investigated. Based on the different technological parameters, the removal efficiency of impurities is also discussed, and the corresponding experiments are carried out in order to make a comparison. Different thermal process conditions are realized during the single-melt operation. Chemical and metallographic analyses are performed, and the results are discussed. The hardness of the titanium decreases by prolonging the time of the electron beam processing. A maximal overall removal efficiency of 99.975% is seen at 5.5 kW beam power for a 40 min melting time and the best purification of Ti (99.996%) is achieved.


2020 ◽  
Vol 166 ◽  
pp. 02004
Author(s):  
Volodymyr Peregudov ◽  
Ihor Hryhoriev ◽  
Serhii Joukov ◽  
Yulian Hryhoriev

Further development of the open mining works on the domestic enterprises will be accompanied by the worsening of mining-geological conditions and declining of the quality of iron ore raw materials. In the same time, the accumulated mining wastes, that can make the technogenic deposits, pass into one of the important sources of the mineral raw materials. Taking into account this thing, the development and implementation of the modern technological circuits of the technogenic deposit development is an actual calling for mining industry, and determination and optimization of process conditions of the technogenic deposit development – is the scientific task of this publication. The obtained results of studies of the optimum step value of the ore chute transfer during the technogenic deposit development can be used by design organizations and mining enterprises for designing works. The obtained methodology and the proposed mathematical dependencies will reduce the cost of mining of the technogenic deposit due to the reasonable timely transfer of the open ore chute.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Christina-Luise Roß ◽  
Kerstin Nielsen ◽  
Jorita Krieger ◽  
Marieke Hoffmann ◽  
Karen Sensel-Gunke ◽  
...  

Depending on the quality of the input substrates, process parameters, and postfermentation treatments, digestates may contain a broad spectrum of potentially toxic elements. We suspected that these contents may vary on a broad scale even under seemingly stable process conditions at the biogas plant. Digestates from four biogas plants were therefore continuously analyzed for their contents of phosphorus, nitrogen, cadmium, copper, lead, and zinc over a period of six years. The input substrates varied between the plants (e.g., cattle and pig slurry and rye and maize silage), but were the same for each plant over the whole period. The N : P ratio of the digestates ranged from 2 to 24, with the digestate coming from cofermentation of pig slurry and energy crops (“DG Pig”) having the widest range of N : P ratio over the years. Heavy metal loads of all digestates and during all evaluations did not exceed the limits set by European or German legislation, but as previously expected, showed a large variability especially if cattle or pig manure were used as substrates. Copper content of Cattle slurry before digestion was 897.7 mg kg−1 DM in one case, and zinc content of DG Pig reached 590.2 mg kg−1 DM also once during the investigation. As a result, we strongly recommend to monitor especially phosphorus, copper, and zinc contents in digestates very closely and in short intervals.


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5598
Author(s):  
Ana Carolina Mosca ◽  
Leonardo Menghi ◽  
Eugenio Aprea ◽  
Maria Mazzucotelli ◽  
Jose Benedito ◽  
...  

Due to the interest in identifying cost-effective techniques that can guarantee the microbiological, nutritional, and sensorial aspects of food products, this study investigates the effect of CO2 preservation treatment on the sensory quality of pomegranate juice at t0 and after a conservation period of four weeks at 4 °C (t28). The same initial batch of freshly squeezed non-treated (NT) juice was subjected to non-thermal preservation treatments with supercritical carbon dioxide (CO2), and with a combination of supercritical carbon dioxide and ultrasound (CO2-US). As control samples, two other juices were produced from the same NT batch: A juice stabilized with high pressure treatment (HPP) and a juice pasteurized at high temperature (HT), which represent an already established non-thermal preservation technique and the conventional thermal treatment. Projective mapping and check-all-that-apply methodologies were performed to determine the sensory qualitative differences between the juices. The volatile profile of the juices was characterized by gas chromatography-mass spectrometry. The results showed that juices treated with supercritical CO2 could be differentiated from NT, mainly by the perceived odor and volatile compound concentration, with a depletion of alcohols, esters, ketones, and terpenes and an increase in aldehydes. For example, in relation to the NT juice, limonene decreased by 95% and 90%, 1-hexanol decreased by 9% and 17%, and camphene decreased by 94% and 85% in the CO2 and CO2-US treated juices, respectively. Regarding perceived flavor, the CO2-treated juice was not clearly differentiated from NT. Changes in the volatile profile induced by storage at 4 °C led to perceivable differences in the odor quality of all juices, especially the juice treated with CO2-US, which underwent a significant depletion of all major volatile compounds during storage. The results suggest that the supercritical CO2 process conditions need to be optimized to minimize impacts on sensory quality and the volatile profile.


2016 ◽  
Vol 866 ◽  
pp. 196-200
Author(s):  
Sun Ho Jung ◽  
S. Lee ◽  
J. Lee

Band structures with pearlite and ferrite aligned as stripes can be created during the heat treatment of carbon steel. Since band structures undermine the mechanical quality of end products, it is highly important to select a process condition that will not create band structures as a result of heat treatment. This study verified the effect of temperature and cooling rate on the creation of band structures during heat treatment of 35MnB and 25Mn steel tubes for drive shafts and also considered the optimal process conditions to remove band structures or prevent their creation. The experimental results suggest that, during heat treatment of 35MnB and 25Mn steel tubes, it is most effective to ensure a cooling rate faster than furnace cooling in order to prevent band structures.


2010 ◽  
Vol 426-427 ◽  
pp. 589-592 ◽  
Author(s):  
Jun Li ◽  
Yong Wei Zhu ◽  
Dun Wen Zuo ◽  
Kui Lin ◽  
M. Li

Fixed abrasive lapping and polishing (FALP) is a new machining technology and was adopted to manufacture hard brittle materials and obtain the high productivity because of fixed abrasive. The preparation process of fixed abrasive pad (FAP) was described. FALP of K9 glass, mobile panel glass and Si were investigated with fixed 5-10 µm diamond abrasives. The effect on material removal rate (MRR) and surface quality of different materials was studied. The results show that in the same FALP process conditions, Si is the highest MRR and reaches 4428 nm/min, mobile panel glass is inferior to and K9 glass is the lowest. And surface quality of mobile panel glass that surface roughness Sa is 2.10 nm and little and less damages is the best, Si is followed and K9 glass is the worst. So FALP can obtain the higher MRR and reaches several micrometers per minute and the better quality that surface roughness Sa can reach nanometer level for different materials.


1996 ◽  
Vol 12 (3) ◽  
pp. 345-350 ◽  
Author(s):  
L. Tabil Jr. ◽  
S. Sokhansanj

2019 ◽  
Vol 10 (3) ◽  
pp. 207-218
Author(s):  
Lidiane Schmalfuss Valadão ◽  
Caroline Dos Santos Duarte ◽  
Pedro José Sanches Filho

The peach stone is considered an agroindustrial residue originating from the industrial process of peach in halves in syrup. It does not have an adequate destination, its final disposal is incorrect and may cause contamination in the environmental compartments. In this way, the burning of this raw material as biomass enables its reuse, besides adding value to the residue. Among the processes used for the application of this residue is the carbonization process, which allows to obtain co-products with higher added value, such as pyroligneous liquid, which represents a fraction of organic compounds condensed from the smoke emitted during carbonization. The quality of the liquid depends on the process conditions and the biomass used. Therefore, the objective of this study was to characterize the sample of pyrolignous liquid obtained from the carbonization of the peach stone, on an industrial scale, qualitative and semi quantitative. Preliminary characterization (pH, conductivity, color, density and contents of tar, organic matter and acidity) and a chemical characterization by gas chromatography coupled to mass spectrometry (GC-MS) were performed. The liquid presented satisfactory results for the physico-chemical evaluations. Regarding the qualitative determination, it was possible to identify 49 compounds. Highlighting the phenols, with 44.90% of the number of compounds, mainly methoxyphenols. These are compounds with significant added value and industrial importance, indicating their use as raw material in the production of polymer resins, among other purposes.


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