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Online since: May 2016
Authors: Francesco La Via, Massimo Camarda, Grazia Litrico, Nicolo Piluso, Stefania Privitera
The electrical behaviour of these defects impact the overall quality of the SiC devices, e.g. it is known that Single Shockley stacking faults (SSSF) act as recombination centres and expand during forward bias in bipolar devices, resulting in an increase of the on-state resistance [1]; SF can significantly scatter propagating electron waves increasing both the resistance and the Schottky-barrier in n-doped SiC films [4]; point defects, mainly Z1/2 and EH6/7, induce a reduction of the minority carrier lifetime [5] and an increase of the leakage currents in Schottky diodes [6].
Based on data reported in literature [7,10], such a defect corresponds to the 4SSF.
The PL signal is almost constant along the defect, whilst the PC is strongly asymmetric, with deep reduction on one side and graded variation on the other side.
The lifetime reduction is strongly dependent on the type of defect: the 4SSF is a more effective recombination center than a bar defect, with a photoluminescence peak at 2.92 eV.
Based on data reported in literature [7,10], such a defect corresponds to the 4SSF.
The PL signal is almost constant along the defect, whilst the PC is strongly asymmetric, with deep reduction on one side and graded variation on the other side.
The lifetime reduction is strongly dependent on the type of defect: the 4SSF is a more effective recombination center than a bar defect, with a photoluminescence peak at 2.92 eV.
Online since: November 2011
Authors: Hong Yan Hao, Yan Qing Wu, Qing Shan Ji
The design and adjustment of the generator and of the excitation equipment permit continuous changes of the terminal voltage in the range of ±5% rated voltage via the setpoint selector under steady-state conditions and at loads varying from no load to rated load and power factors from 0.8 to unity unless specified otherwise on the rating plate, If several rated voltage and frequencies are indicated on the rating plate, the above data apply to each of the rates voltages stated.
Regarding generators with current transformer for droop compensation, potentiometer S in the regulator is adjusted so that there is no reduction in the generator voltage at unity p .f . but a 6% reduction at aero p. f.
The corresponding voltage reduction at 0.8 p. f. is 3.6%.
Regarding generators with current transformer for droop compensation, potentiometer S in the regulator is adjusted so that there is no reduction in the generator voltage at unity p .f . but a 6% reduction at aero p. f.
The corresponding voltage reduction at 0.8 p. f. is 3.6%.
Online since: June 2011
Authors: Toshio Hirao, Takeshi Ohshima, Li Cai, Hiroaki Yano, Zong Fan Duan, Hideharu Takayanagi, Hideharu Ueki, Yasushiro Nishioka
The comparison of these data suggests that the drain current decreased almost 70% when the total-dose reached 1200 Gy (Si).
For the OTFT with PI gate insulator, nearly 40 % reduction of drain current IDS was observed after a total-dose of 1200 Gy (Si).
Positive oxide-trapped charge buildup dominates at low radiation levels and result in the reduction of threshold voltage.
This reduction in the mobility is consistent with a large increase in the amount of interface state density.
For the OTFT with PI gate insulator, nearly 40 % reduction of drain current IDS was observed after a total-dose of 1200 Gy (Si).
Positive oxide-trapped charge buildup dominates at low radiation levels and result in the reduction of threshold voltage.
This reduction in the mobility is consistent with a large increase in the amount of interface state density.
Online since: January 2013
Authors: Sudin Izman, Raden Dadan Ramdan, Rochim Suratman, Joy Rizki Pangestu Djuansjah, Esah Hamzah
These are sample without cold rolling treatment and 4 cold rolled samples that treated at 4 different reductions of thickness level, 10, 20, 30 and 40% respectively.
Fig. 2 Surface roughness data (Ra) sample after thermal-oxidation process (a) (b) Fig. 3 Grain structure of sample without (a) and with (b) cold rolling treatment Anodizing samples.
In addition, Figure 6 shows surface texture before and after anodizing for cold-rolled sample with 40% reduction in thickness.
Fig.4 Cross-section micrograph for sample after anodizing, (a) Sample without cold-rolling treatment, (b) sample with cold rolling treatment Fig.5 Comparison of surface roughness before and after anodizing process 500nm 0 -400nm (a) (b) Fig. 6 Texture contour of oxide layer before (a) and after (b) anodizing (Cold rolled sample with 40% reduction in thickness) Summary The effect of cold-rolling treatment of titanium alloys substrate on the characteristics of titanium oxide layer by thermal electro-chemical anodizing processes was evaluated.
Fig. 2 Surface roughness data (Ra) sample after thermal-oxidation process (a) (b) Fig. 3 Grain structure of sample without (a) and with (b) cold rolling treatment Anodizing samples.
In addition, Figure 6 shows surface texture before and after anodizing for cold-rolled sample with 40% reduction in thickness.
Fig.4 Cross-section micrograph for sample after anodizing, (a) Sample without cold-rolling treatment, (b) sample with cold rolling treatment Fig.5 Comparison of surface roughness before and after anodizing process 500nm 0 -400nm (a) (b) Fig. 6 Texture contour of oxide layer before (a) and after (b) anodizing (Cold rolled sample with 40% reduction in thickness) Summary The effect of cold-rolling treatment of titanium alloys substrate on the characteristics of titanium oxide layer by thermal electro-chemical anodizing processes was evaluated.
Online since: November 2012
Authors: Yoshinori Kobayashi, Toshitaka Oka, Kanehisa Hattori, Seiichi Saiki, Yoshihiro Watanabe, Masato Yamawaki, Hamdy F.M. Mohamed
Experimental and data analysis
The sample was ultra high molecular weight polyethylene (UHMWPE).
Similarly to the present results of UHMWPE, the fast reduction of the ortho-positronium formation at low doses is observed, which is followed by leveling off at higher doses.
The rapid reduction of Ps formation at low doses is attributed to the trapping of mobile positrons by defects produced by the irradiation, prohibiting the re-entering of the positrons into the blob.
With the reduction in mechanical properties, ortho-positronium lifetime is shortened.
Similarly to the present results of UHMWPE, the fast reduction of the ortho-positronium formation at low doses is observed, which is followed by leveling off at higher doses.
The rapid reduction of Ps formation at low doses is attributed to the trapping of mobile positrons by defects produced by the irradiation, prohibiting the re-entering of the positrons into the blob.
With the reduction in mechanical properties, ortho-positronium lifetime is shortened.
Online since: June 2014
Authors: Yan Ma, Yan Ze Xu, Chen Lin Lu, Shu Yu Zhang
The conventional sintering costs long time and huge amounts of energy and lead oxide volatilization during high temperature sintering leads to reduction of density and strength.
Results and Discussion Tab.1 Mass reduction of samples Sample Mass(mg) reduction proportion(%) before sintering after sintering difference Method One 2943.32 2939.74 3.58 0.12163 Method Two 2957.95 2957.92 0.03 0.00101 conventional sinter 2993.53 2978.55 14.98 0.50041 The mass of products is the average value of a series samples tested repeatedly.
As can be seen from the data in the Tab.1, the losing mass of conventional processing is remarkably larger than that of microwave methods.
Results and Discussion Tab.1 Mass reduction of samples Sample Mass(mg) reduction proportion(%) before sintering after sintering difference Method One 2943.32 2939.74 3.58 0.12163 Method Two 2957.95 2957.92 0.03 0.00101 conventional sinter 2993.53 2978.55 14.98 0.50041 The mass of products is the average value of a series samples tested repeatedly.
As can be seen from the data in the Tab.1, the losing mass of conventional processing is remarkably larger than that of microwave methods.
Online since: December 2014
Authors: Claudinei dos Santos, Jefferson Fabrício Cardoso Lins, Alexandre Fernandes Habibe, Durval Rodrigues, José C. Minatti, Luis Alberto dos Santos
Fig. 1 – XRD patterns of the Co-Cr-Mo alloy milled at different times and ball powder relations
The calculation of the crystallite size in proportion balls powder is shown in Figure 2, demonstrating that the crystallite size ranging from 6nm to 10nm, in a time of 60 minutes of grinding, which indicates a reduction of 40% due the change in balls powder ratio.
Increasing the ball-powder ratio of 4:1 to 10:1 leads to a higher degree of agglomeration, however not reflected in increased reduction of the atomic disorder of the crystals, identified by the decrease in crystallite size.
There was a reduction in crystallite size on the order of 40% after 60 minutes of grinding to powder ratios of 4:1 to 10:1.
[5] JCPDS-International Centre for Diffraction Data (2000), Advances in X-Ray Analysis
Increasing the ball-powder ratio of 4:1 to 10:1 leads to a higher degree of agglomeration, however not reflected in increased reduction of the atomic disorder of the crystals, identified by the decrease in crystallite size.
There was a reduction in crystallite size on the order of 40% after 60 minutes of grinding to powder ratios of 4:1 to 10:1.
[5] JCPDS-International Centre for Diffraction Data (2000), Advances in X-Ray Analysis
Online since: February 2017
Authors: Nik Hisyamudin Muhd Nor, Fariza Mohamad, Nabiah binti Zinal, Nurliyana binti Mohamad Arifin, Masanobu Izaki, Kah Hao Cheong, Asyikin Sasha binti Mohd Hanif
Cyclic voltammorgram (CV) measurement was used to investigate the reduction process under controlled parameters.
Until to date, the reported work of n-Cu2O is more focus on the construction of homojunction, there are lack data on parameter optimization and also the structural and morphological properties [11, 13].
The graphs shown were only the reduction part of the cyclic voltammmetry measurement.
Based on Fig. 1 and Fig. 2, temperature at 30, 50 and 60℃ seem to have possibility for deposition since there are reduction region of Cu2O.
The region of reduction process is believed to be 2Cu+ + 2OH-àCu2O + H2O (1) However, for pH 5.5 and 6.5, both at 30℃ were not taken for deposition.
Until to date, the reported work of n-Cu2O is more focus on the construction of homojunction, there are lack data on parameter optimization and also the structural and morphological properties [11, 13].
The graphs shown were only the reduction part of the cyclic voltammmetry measurement.
Based on Fig. 1 and Fig. 2, temperature at 30, 50 and 60℃ seem to have possibility for deposition since there are reduction region of Cu2O.
The region of reduction process is believed to be 2Cu+ + 2OH-àCu2O + H2O (1) However, for pH 5.5 and 6.5, both at 30℃ were not taken for deposition.
Online since: January 2013
Authors: Xing Guo Zhao, Jing Xia Zheng, Jin Bo Xue, Wei Liang
Flaky ZnO thin films were electrodeposited from an aqueous solution of zinc nitrate (Zn(NO3)2) as electrolyte on ITO glass substrate by cathodic reduction method The effect of electrolyte concentration on the structure, morphology and optical properties of ZnO thin films were studied by X-ray diffraction, scanning electron microscopy and UV-Vis spectrometer.
In our study, flaky ZnO thin films were electrodeposited from an aqueous solution of Zn(NO3)2 as electrolyte onto ITO covered glass substrates by cathodic reduction method without any surfactants.
To confirm optical band gap, the absorption data of the samples are conducted to make the relation curve as shown in Fig. 4.
(4) Site ZnO Zn2+ absorption ZnO 2e- NO3- Zn2+ electron transfer ZnO ZnO formation NO2- Fig. 5 The illustration of the electrodeposition of ZnO in Zn(NO3)2 bath Conclusion A facile and low cost synthetic process (cathodic reduction method) to prepare ZnO films in the aqueous solution at low temperature, 70 ℃ without any surfactants is presented, and the reaction mechanism has been discussed systematically.
Levy-Clement, et al., Role of chloride ions on electrochemical deposition of ZnO nanowire arrays from O2 reduction, J.
In our study, flaky ZnO thin films were electrodeposited from an aqueous solution of Zn(NO3)2 as electrolyte onto ITO covered glass substrates by cathodic reduction method without any surfactants.
To confirm optical band gap, the absorption data of the samples are conducted to make the relation curve as shown in Fig. 4.
(4) Site ZnO Zn2+ absorption ZnO 2e- NO3- Zn2+ electron transfer ZnO ZnO formation NO2- Fig. 5 The illustration of the electrodeposition of ZnO in Zn(NO3)2 bath Conclusion A facile and low cost synthetic process (cathodic reduction method) to prepare ZnO films in the aqueous solution at low temperature, 70 ℃ without any surfactants is presented, and the reaction mechanism has been discussed systematically.
Levy-Clement, et al., Role of chloride ions on electrochemical deposition of ZnO nanowire arrays from O2 reduction, J.
Online since: October 2015
Authors: Farah Nora Aznieta Abd Aziz, Arafa Suleiman Juma, M.N. Noor Azline
Results show that the reduction in compressive strength is greater with the higher cement replacement level for all concretes particularly for POFA binary concretes.
Thus it is necessary to find an alternative way to utilize this wastage, which has various indirect benefits such as reduction in the dumped waste and environment sustainability.
Result and Discussion POFA Binary Concrete According to obtained data in Figure 1, it was observed that POFA decreased the compressive strength of concrete with increasing POFA content compared to PC concrete for all w/b ratios.
The reason for the reduction in compressive strength of POFA binary may be attributed to the effect of PC dilution, which decreases the CH supply and increases the effective water (due to the reduced in PC level) in the mix [14].
However, the strength reduction was increased with increasing POFA level at 45%.
Thus it is necessary to find an alternative way to utilize this wastage, which has various indirect benefits such as reduction in the dumped waste and environment sustainability.
Result and Discussion POFA Binary Concrete According to obtained data in Figure 1, it was observed that POFA decreased the compressive strength of concrete with increasing POFA content compared to PC concrete for all w/b ratios.
The reason for the reduction in compressive strength of POFA binary may be attributed to the effect of PC dilution, which decreases the CH supply and increases the effective water (due to the reduced in PC level) in the mix [14].
However, the strength reduction was increased with increasing POFA level at 45%.