Nano Cuprous Oxides Film Prepared by Magnetron Sputtering

2004 ◽  
Vol 822 ◽  
Author(s):  
Yang-Ming Lu ◽  
Jun-Yuan Chen ◽  
Tzuu-Shaang Wey
Keyword(s):  
Substrate Temperature ◽  
Flow Rate ◽  
Cuprous Oxide ◽  
Rate Ratio ◽  
Single Phase ◽  
Flow Rate Ratio ◽  
Argon Flow Rate ◽  
Practical Applications ◽  
Argon Flow ◽  
Pure Cu

AbstractCuprous oxide (Cu2O) is a direct-gap semiconductor with band-gap energy of 2.0 eV and has been extensively investigated as a candidate for a photovoltaic material. However, practical applications have not been achieved to date due to the difficulty in controlling its physical properties. We have investigated the controllability of the formation of pure Cu2O thin films deposited by the reactive DC sputtering method and analysis by XPS and Raman spectrometer to identify the Cu+1 in the cuprous oxide. The formation of pure Cu2O films is not only dependent on the substrate temperature but also strongly effected by the oxygen and argon flow rate ratio. When the substrate temperature was kept constant at 100°C and varied the oxygen and argon flow rate ratio from 3ml/min to 10ml/min, it is found a mixture of Cu2O and CuO phases is formed. At the flow rate of oxygen to 5ml/min, the pure and single phase of Cu2O is formed. Further increasing the oxygen flow rate, the phase is changed to be the CuO phase. The crystallity is improved as increasing the substrate temperature. The electrical resistivity of Cu2O obtained in this study is about 316 ohm-cm at 100°C substrate temperature and 2.66Pa condition. The dependence of cupper oxides resistivity is not only on the substrate temperature and reactive gases but also on the sputter pressure. Because the characteristic resistivity values change with sputter pressure variation due to different phase compositions forming in the films. The lowest resistivity of Cu2O film is obtained when the Cu2O single phase exists in the films.

Ag-coated cotton fabric as ultrasensitive and flexible SERS substrate

2021 ◽  
pp. 152808372110277
Author(s):  
Xueyan Bian ◽  
Jiangtao Xu ◽  
Yi Pu ◽  
Jing Yang ◽  
Ka-lam Chiu ◽  
...  
Keyword(s):  
Cotton Fabric ◽  
Flow Rate ◽  
Ag Nanoparticles ◽  
Fdtd Method ◽  
Raman Signal ◽  
Enhancement Effect ◽  
Sers Substrate ◽  
Argon Flow Rate ◽  
Practical Applications ◽  
Argon Flow

Surface enhanced Raman scattering (SERS) has proven to be increasingly valuable as an analytical tool since this phenomenon was first observed in 1973. However, challenges still exist to ensure their ability to access targeted analytes and adequate levels of sensitivity to them on irregular surfaces. Herein, silver (Ag) nanoparticles are deposited onto cotton fabric through magnetron sputtering to develop a flexible and ultrasensitive SERS-active substrate. To obtain a better enhancement effect, Ag nanoparticles of different sizes are produced by controlling the argon flow rate and the sputtering time. The finite-difference time-domain (FDTD) method and Raman mapping are used to explain the process behind Raman signal enhancement. The cotton fabric sample with Ag nanoparticles deposited at an argon flow rate of 200  sccm (labelled as AC-200) shows a high enhancement factor (EF) of 104 with a Methylene blue (MB) solution of 10−3 M, stability with a related standard deviation (RSD) of 1.03%, excellent reproducibility with an RSD of 1.92% and high sensitivity with 10−9 M of MB solution. Therefore, AC-200 demonstrates exceptional SERS signal reproducibility and stability for different types of chemical analytes and has the potential to be used in future practical applications.

Determination of flow rate ratio for plate valve operating in two-phase medium

1989 ◽  
Vol 25 (7) ◽  
pp. 394-396
Author(s):  
V. E. Shcherba ◽  
I. S. Berezin ◽  
S. S. Danilenko ◽  
I. E. Titov ◽  
P. P. Filippov
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Flow Rate Ratio ◽  
Two Phase ◽  
Plate Valve ◽  
Phase Medium

Effect of the argon/monomer flow-rate ratio on the flowability trend of PECVD-processed micropowder

2017 ◽  
Vol 328 ◽  
pp. 480-487 ◽  
Author(s):  
V.R. Giampietro ◽  
M. Gulas ◽  
P. Rudolf von Rohr
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Flow Rate Ratio

PHOTO-CATALYTIC ACTIVITY AND PHOTO-ABSORPTION OF PLASMA-SPRAYED NANO-STRUCTURED TiO2 COATINGS

2010 ◽  
Vol 24 (31) ◽  
pp. 6115-6127 ◽  
Author(s):  
MARYAMOSSADAT BOZORGTABAR ◽  
MEHDI SALEHI ◽  
MOHAMMADREZA RAHIMIPOUR ◽  
MOHAMMADREZA JAFARPOUR
Keyword(s):  
Catalytic Activity ◽  
Flow Rate ◽  
Test Chamber ◽  
Catalytic Efficiency ◽  
Surface Characteristics ◽  
Catalytic Performance ◽  
Atmospheric Plasma ◽  
Argon Flow Rate ◽  
Photo Catalytic Activity ◽  
Argon Flow

Titanium dioxide coatings were deposited by utilizing atmospheric plasma-spraying system. The agglomerated P25/20 nano-powder and different spraying parameters (e.g., Argon flow rate and spray distance) were used to determine their influences on the microstructure, crystalline structure, photo-absorption, and photo-catalytic performance of the coatings. The microstructure and phases of as-sprayed TiO 2 coatings were characterized by scanning electron microscope SEM and X-ray diffraction, respectively. Surface characteristics were investigated by Fourier Transform Infrared. Photo-catalytic efficiency of the elaborated samples was also determined in an environmental test chamber set-up and evaluated from the conversion rate of ethanol. The photo-absorption was determined by UV–Vis spectrophotometer. The as-sprayed TiO2 coating was photo-catalytically reactive for the degradation of ethanol. The photo-catalytic activity was influenced by spray conditions. It is found that the photo-catalytic activity is significantly influenced by anatase content, surface area, and surface state. The results showed that the argon flow rate has an influence on the microstructure, anatase content, and photo-catalytic activity of the TiO 2 coatings.

Effects of Respiration and Gravity on Infradiaphragmatic Venous Flow in Normal and Fontan Patients

Circulation ◽  
2000 ◽  
Vol 102 (suppl_3) ◽  
Author(s):  
Tain-Yen Hsia ◽  
Sachin Khambadkone ◽  
Andrew N. Redington ◽  
Francesco Migliavacca ◽  
John E. Deanfield ◽  
...  
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Venous Return ◽  
Fontan Circulation ◽  
Flow Rate Ratio ◽  
Venous Flow ◽  
Beneficial Effects ◽  
In Series ◽  
Expiratory Flow ◽  
Fontan Patients

Background —In the Fontan circulation, pulmonary and systemic vascular resistances are in series. The implications of this unique arrangement on infradiaphragmatic venous physiology are poorly understood. Methods and Results —We studied the effects of respiration and gravity on infradiaphragmatic venous flows in 20 normal healthy volunteers (control) and 48 Fontan patients (atriopulmonary connection [APC] n=15, total cavopulmonary connection [TCPC] n=30). Hepatic venous (HV), subhepatic inferior vena caval (IVC), and portal venous (PV) flow rates were measured with Doppler ultrasonography during inspiration and expiration in both the supine and upright positions. The inspiratory-to-expiratory flow rate ratio was calculated to reflect the effect of respiration, and the supine-to-upright flow rate ratio was calculated to assess the effect of gravity. HV flow depended heavily on inspiration in TCPC compared with both control and APC subjects (inspiratory-to-expiratory flow rate ratio 3.4, 1.7, and 1.6, respectively; P <0.0001). Normal PV flow was higher in expiration, but this effect was lost in TCPC and APC patients (inspiratory-to-expiratory flow rate ratio 0.8, 1.0, and 1.1, respectively; P =0.01). The respiratory influence on IVC flow was the same in all groups. Gravity decreased HV flow more in APC than in TCPC patients (supine-to-upright flow rate ratio 3.2 versus 2.1, respectively; P <0.04) but reduced PV flow equally in all groups. Conclusions —Gravity and respiration have important influences on infradiaphragmatic venous return in Fontan patients. Although gravity exerts a significant detrimental effect on lower body venous return, which is more marked in APC than in TCPC patients, the beneficial effects of respiration in TCPC patients are mediated primarily by an increase in HV flow. These effects may have important short- and long-term implications for the hemodynamics of the Fontan circulation.

scholarly journals Numerical and experimental investigation on the depressurization capacity of a new type of depressure-dominated jet mill bit

2020 ◽  
Vol 17 (6) ◽  
pp. 1602-1615
Author(s):  
Xu-Yue Chen ◽  
Tong Cao ◽  
Kai-An Yu ◽  
De-Li Gao ◽  
Jin Yang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Area Ratio ◽  
Low Flow ◽  
Flow Rate Ratio ◽  
Cuttings Transport ◽  
Horizontal Drilling ◽  
Hole Cleaning ◽  
Bottom Hole ◽  
New Type

AbstractEfficient cuttings transport and improving rate of penetration (ROP) are two major challenges in horizontal drilling and extended reach drilling. A type of jet mill bit (JMB) may provide an opportunity to catch the two birds with one stone: not only enhancing cuttings transport efficiency but also improving ROP by depressuring at the bottom hole. In this paper, the JMB is further improved and a new type of depressure-dominated JMB is presented; meanwhile, the depressurization capacity of the depressure-dominated JMB is investigated by numerical simulation and experiment. The numerical study shows that low flow-rate ratio helps to enhance the depressurization capacity of the depressure-dominated JMB; for both depressurization and bottom hole cleaning concern, the flow-rate ratio is suggested to be set at approximately 1:1. With all other parameter values being constant, lower dimensionless nozzle-to-throat-area ratio may result in higher depressurization capacity and better bottom hole cleaning, and the optimal dimensionless nozzle-to-throat-area ratio is at approximately 0.15. Experiments also indicate that reducing the dimensionless flow-rate ratio may help to increase the depressurization capacity of the depressure-dominated JMB. This work provides drilling engineers with a promising tool to improve ROP.

The Characteristics of CH4-Vapor Catalytic Reforming Reaction Considering CO2 and CH4 Reaction in the Micro-Chamber

2007 ◽  
Author(s):  
Jing-Yu Ran ◽  
Li-Xiang Niu ◽  
Qiang Tang ◽  
Li Zhang
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rate Ratio ◽  
Reaction System ◽  
Conversion Ratio ◽  
Flow Rate Ratio ◽  
Ni Catalyst ◽  
Complex Reaction ◽  
Catalytic Reforming

Methane and vapor catalytic-reaction is a complex reaction system, and especially CH4/CO2 reaction has an important influence to the methane/vapor reforming reaction. In this paper, the reaction character for methane and vapor catalytic reforming reaction in the micro-chamber wall with Ni catalyst is numerically investigated. The results show that the CH4/CO2 reaction has a vital influence on reactive characteristics in the different H2O/CH4 mole ratio and the mass flow-rate. With increasing the H2O/CH4 mole ratio, the concentration of H2 and CO2 increases, the concentration of CO increases and then decreases, but if the H2O/CH4 mole ratio is more than 2.5, the result is different. The reaction efficiency will descend while the flow-rate increases. The results also display that the methane conversion ratio, the vapor conversion ratio, and the hydrogen concentrations can be up to 81.73%, 69.42%, and 4.29%, while the H2O/CH4 mole ratio, flow-rate and methane/vapor mass flow-rate ratio are 2.5, 7 g/h and 0.1 respectively.

scholarly journals Physical Simulation of Molten Steel Homogenization and Slag Entrapment in Argon Blown Ladle

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 479 ◽  
Author(s):  
Yang ◽  
Jin ◽  
Zhu ◽  
Dong ◽  
Lin ◽  
...  
Keyword(s):  
Flow Rate ◽  
Molten Steel ◽  
Physical Simulation ◽  
Mixing Time ◽  
Water Model ◽  
Steel Ladle ◽  
Argon Flow Rate ◽  
Argon Flow ◽  
Slag Thickness ◽  
Slag Entrapment

Argon stirring is one of the most widely used metallurgical methods in the secondary refining process as it is economical and easy, and also an important refining method in clean steel production. Aiming at the issue of poor homogeneity of composition and temperature of a bottom argon blowing ladle molten steel in a Chinese steel mill, a 1:5 water model for 110 t ladle was established, and the mixing time and interface slag entrainment under the different conditions of injection modes, flow rates and top slag thicknesses were investigated. The flow dynamics of argon plume in steel ladle was also discussed. The results show that, as the bottom blowing argon flow rate increases, the mixing time of ladle decreases; the depth of slag entrapment increases with the argon flow rate and slag thickness; the area of slag eyes decreases with the decrease of the argon flow rate and increase of slag thickness. The optimum argon flow rate is between 36–42 m3/h, and the double porous plugs injection mode should be adopted at this time.

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