Growth Mechanism and Optical Properties of Nano and Microstructures of ZnO Obtained by Thermal Oxidation of Zinc Powders at Atmospheric Pressure

2019 ◽  
Vol 286 ◽  
pp. 33-39
Author(s):  
Carlos Bueno ◽  
Abraham Pacio ◽  
Edith Osorio ◽  
Jose Alberto Alvarado ◽  
David Maestre ◽  
...  
Keyword(s):  
Thermal Oxidation ◽  
Growth Mechanism ◽  
Atmospheric Pressure ◽  
Hollow Spheres ◽  
Emission Spectra ◽  
Green Emission ◽  
Bottom Surface ◽  
Deep Part ◽  
Experimental Conditions ◽  
Zinc Powders

ZnO Nano and microstructures were obtained by thermal oxidation using Zn powders as source. To achieve those structures, the Zn powders were annealed at 650°C and 750°C under oxygen environment and atmospheric pressure. SEM results show that these experimental conditions promote the formation of hollow spherical microstructures with nanowires and nano-swords in each sphere. As was observed, the nanostructures start growing from the bottom surface of the spheres unlike those that were reported recently. The EDS results clearly show that those hollow spheres in the deep part make a compound with Zn and the top surface is mainly composed of ZnO. CL emission spectra show a main green emission that belongs to the sphere’s bottom surface; this emission is correlated to the existing defects that are presented. These results could allow the prediction of a possible growth mechanism under specific conditions.

On the growth of copper oxide nanowires by thermal oxidation near the threshold temperature at atmospheric pressure

2021 ◽  
pp. 161130
Author(s):  
Calin Constantin Moise ◽  
Laura-Bianca Enache ◽  
Veronica Anastasoaie ◽  
Oana Andreea Lazar ◽  
Geanina Valentina Mihai ◽  
...  
Keyword(s):  
Copper Oxide ◽  
Thermal Oxidation ◽  
Atmospheric Pressure ◽  
Threshold Temperature ◽  
Oxide Nanowires

Growth Mechanism and Electrochemical Properties of Porous Hollow Tin Dioxide Nanospheres

NANO ◽  
2015 ◽  
Vol 10 (06) ◽  
pp. 1550087 ◽  
Author(s):  
Youwen Yang ◽  
Dongming Ma ◽  
Ting Cheng ◽  
Yuanhao Gao ◽  
Guanghai Li
Keyword(s):  
Growth Mechanism ◽  
Tin Dioxide ◽  
Ostwald Ripening ◽  
Lithium Ion ◽  
Average Diameter ◽  
Reversible Capacity ◽  
Cycling Performance ◽  
Experimental Conditions ◽  
Electrochemical Tests ◽  
Hydrolysis Method

Porous hollow SnO 2 nanospheres were prepared by means of enforced Sn 2+ hydrolysis method under hydrochloric acid medium. These hollow nanospheres with an average diameter of 220nm had a very thin shell thickness of about 40nm and were surrounded by elongated octahedral-like nanoparticles with the apex oriented outside. The experimental conditions, such as HCl content, reaction temperature and time directly dominated the morphology, structure and crystallinity of the obtained samples. A pre-oxidation-nucleation-growth mechanism and inside-out Ostwald-ripening method was proposed on the basis of the previous research and time-dependent experiments. Electrochemical tests showed that the porous hollow SnO 2 nanospheres exhibited improved cycling performance for anode materials of lithium-ion batteries, which retained a high reversible capacity of 540.0mAhg-1, and stable cyclic retention at 120th cycle.

Emission spectra of nitrous oxide supported acetylene flames at atmospheric pressure

Talanta ◽  
1967 ◽  
Vol 14 (7) ◽  
pp. 789-800 ◽  
Author(s):  
G.F. Kirkbright ◽  
M.K. Peters ◽  
T.S. West
Keyword(s):  
Nitrous Oxide ◽  
Atmospheric Pressure ◽  
Emission Spectra

scholarly journals Tunning CO2 Separation Performance of Ionic Liquids through Asymmetric Anions

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 413
Author(s):  
Bruna F. Soares ◽  
Daniil R. Nosov ◽  
José M. Pires ◽  
Andrey A. Tyutyunov ◽  
Elena I. Lozinskaya ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Atmospheric Pressure ◽  
Time Lag ◽  
Gas Permeation ◽  
Separation Performance ◽  
Experimental Conditions ◽  
Feed Pressure ◽  
Similar Chemical ◽  
Supported Ionic Liquid Membranes ◽  
Gas Separation Performance

This work aims to explore the gas permeation performance of two newly-designed ionic liquids, [C2mim][CF3BF3] and [C2mim][CF3SO2C(CN)2], in supported ionic liquid membranes (SILM) configuration, as another effort to provide an overall insight on the gas permeation performance of functionalized-ionic liquids with the [C2mim]+ cation. [C2mim][CF3BF3] and [C2mim][CF3SO2C(CN)2] single gas separation performance towards CO2, N2, and CH4 at T = 293 K and T = 308 K were measured using the time-lag method. Assessing the CO2 permeation results, [C2mim][CF3BF3] showed an undermined value of 710 Barrer at 293.15 K and 1 bar of feed pressure when compared to [C2mim][BF4], whereas for the [C2mim][CF3SO2C(CN)2] IL an unexpected CO2 permeability of 1095 Barrer was attained at the same experimental conditions, overcoming the results for the remaining ILs used for comparison. The prepared membranes exhibited diverse permselectivities, varying from 16.9 to 22.2 for CO2/CH4 and 37.0 to 44.4 for CO2/N2 gas pairs. The thermophysical properties of the [C2mim][CF3BF3] and [C2mim][CF3SO2C(CN)2] ILs were also determined in the range of T = 293.15 K up to T = 353.15 K at atmospheric pressure and compared with those for other ILs with the same cation and anion’s with similar chemical moieties.

Pretreatment of Blind Via Holes before Ni/Au and Cu Plating Applied with Atmospheric Pressure Plasma Jet

2005 ◽  
Vol 2 (3) ◽  
pp. 189-196 ◽  
Author(s):  
Yasushi Sawada ◽  
Keiichi Yamazaki ◽  
Noriyuki Taguchi ◽  
Tetsuji Shibata
Keyword(s):  
Atmospheric Pressure ◽  
Printed Circuit Board ◽  
Formation Rate ◽  
Plasma Processing ◽  
Atmospheric Pressure Plasma ◽  
Plasma Jet ◽  
Circuit Board ◽  
Bottom Surface ◽  
Printed Circuit ◽  
Via Holes

The effectiveness of atmospheric pressure (AP) plasma preprocessing before Ni/Au or Cu plating has been examined by applying it to a build-up printed circuit board (FR-4 grade) and polyimide-based flexible circuit film, both with blind via-holes (BVHs). The AP plasma applied with a dielectric barrier discharge is generated inside a 56 mm wide quartz vessel by an RF power generator using Ar-O2 gas mixture. One side of the vessel is open and the plasma jet is blown on the sample substrate transported 5 mm downward from the outlet of the vessel. The deposit failure rate of Ni/Au electroless deposit to 50 μm-diameter BVHs formed on a photo resist on the printed circuit board is 12.5% without preprocessing but is decreased to 0% after applying the AP plasma processing. As for 50 μm-diameter BVHs formed with a YAG laser on a polyimide-based flexible circuit film, the bump formation using electrolytic copper plating fails without preprocessing, but a 100% bump formation rate is achieved after applying AP plasma processing. It is presumed that the AP plasma processing improves the wetting property of the BVH walls and allows the plating solution to uniformly cover the entire wall surfaces without generating bubbles. The removal of organic substances attached to the BVH bottom surface also helps to improve the adherence of metal plating.

Preparation of Y4MgSi3O13:Tb3+,Ce3+ Green Emitting Phosphor for White Light Emitting Diodes and its Luminescence Study

2011 ◽  
Vol 415-417 ◽  
pp. 1333-1339
Author(s):  
Guo Hua Song ◽  
Bin Jiang ◽  
Jian Wen Miao ◽  
Bang Dong Ding
Keyword(s):  
Sol Gel ◽  
Emission Spectra ◽  
Green Emission ◽  
Green Phosphor ◽  
Preparation Temperature ◽  
Light Emitting ◽  
Optimal Doping ◽  
Optimal Doping Concentration ◽  
White Light Emitting Diodes ◽  
Luminescence Characteristics

The Y4MgSi3O13:Tb3+,Ce3+green phosphors are synthesized by sol-gel method, the preparation temperature, reduction atmosphere and luminescence characteristics of Y4MgSi3O13doped with single Ce3+ions and Ce3+,Tb3+ions have been studied. The excitation and emission spectra of phosphors is determined by fluorescence spectrophotometer. The results show that: luminous intensity of Y4MgSi3O13:Tb3+phosphors increased after doped with Ce3+ions and the optimal doping concentration of Ce3+is 0.04. Y3.94MgSi3O13: 0.02Tb3+,0.04Ce3+green phosphor has the best luminescence characteristics under reduction atmosphere(H2:N2=1:3) at 1000°C, the phosphor gives intense green emission at 550nm originating from the5D4→7F5transition of Tb3+ions.

The herring swimbladder: loss and gain of gas

1984 ◽  
Vol 64 (2) ◽  
pp. 441-459 ◽  
Author(s):  
J. H. S. Blaxter ◽  
R. S. Batty
Keyword(s):  
Pressure Vessel ◽  
Atmospheric Pressure ◽  
Juvenile Fish ◽  
Gas Diffusion ◽  
Sea Surface ◽  
Target Strength ◽  
Experimental Conditions ◽  
Neutral Buoyancy ◽  
Sea Bed ◽  
Ecological Implications

The herring is a physostome with no gas secretion mechanism in the swimbladder. The swimbladder volume was measured in fish from about 3–33 cm in length. It was rarely large enough to give the fish neutral buoyancy at the sea surface. Swimbladder volumes were also measured after periods of up to 1 week at pressures from 1·9 to 5·5 ATA (0·9–4·5atm above atmospheric pressure) in a laboratory pressure vessel and in a sub-surface cage in the sea. The swimbladder gas was lost within a few hours in the larval herring and in a few days in smaller juvenile fish; no change was found in older fish under experimental conditions. The findings were in accord with measurements of the guanine content of the swimbladder wall which was low in those fish which lost gas quickly. This supports the view that gas diffusion is limited by guanine crystals. While it seems likely that larger fish can exist for several weeks without the need to replenish the swimbladder gas some large spawning herring were caught at sea with empty swimbladders, suggesting a long stay near the sea bed. Analysis of swimbladder gas showed that oxygen tended to diffuse out more quickly than nitrogen. Behaviour experiments showed that fish with artificially emptied swimbladders could refill them by swallowing air at the surface, in some cases very quickly and efficiently. Fish with empty swimbladders and no access to the surface suffered a high mortality. The ecological implications of these results and their relevance to the interpretation of sonar ‘target strength’ measurements are discussed.

Electrical and spectral property of cold arc plasma at atmospheric pressure

2012 ◽  
Vol 78 (6) ◽  
pp. 617-620
Author(s):  
YUAN ZHONG-CAI ◽  
SHI JIA-MING ◽  
CHEN ZONG-SHENG ◽  
XU BO
Keyword(s):  
Atmospheric Pressure ◽  
Arc Discharge ◽  
Rotational Temperature ◽  
Molecular Nitrogen ◽  
Atmospheric Pressure Plasma ◽  
Emission Spectra ◽  
Optical Emission ◽  
Plasma Jet ◽  
Ambient Air ◽  
Arc Plasma

AbstractAn atmospheric pressure plasma jet is generated with a cold arc discharge in ambient air. The current-voltage characteristics and optical emission spectra of plasma discharges are investigated. The molecular nitrogen (N2), hydroxyl radical (OH), and oxygen atom (O) are observed and analyzed. Based on the best fit of the simulated spectra of N2 (C3∏u+ − B3∏g+) band and OH (A2∑+ − X2∏) band transition and the experimentally recorded spectra, the rotational temperature and the vibrational temperature of atmospheric pressure cold arc plasma jet (APCAPJ) are estimated.

Experimental Method for Determining the Damping Parameter of Spectral Lines Emitted by a Microwave Plasma at Atmospheric Pressure

2005 ◽  
Vol 59 (12) ◽  
pp. 1457-1464 ◽  
Author(s):  
I. Santiago ◽  
M. C. García ◽  
M. D. Calzada
Keyword(s):  
Line Profile ◽  
Atmospheric Pressure ◽  
Microwave Plasma ◽  
Argon Plasma ◽  
Spectral Lines ◽  
Experimental Conditions ◽  
Simple Method ◽  
Damping Parameter ◽  
Absorption Phenomenon ◽  
Parameter Values

In this work, a simple method for experimentally obtaining the value of the damping parameter or a-parameter of the spectral lines emitted by an argon plasma generated at atmospheric pressure is presented. The value of this coefficient indicates the proportion existing between the Lorentzian and Doppler components of the total line profile, which can be approximated to a Voigt function for our experimental conditions. The a-parameter values found were within the value interval recorded in the literature. The results obtained showed that the damping coefficient of the lines next to the fundamental level remains practically constant along the plasma column, whereas for the spectral lines involving high-lying levels, the a-parameter is sensitive to the changes in the electron density in the plasma. In this work it is also proved that the self-absorption phenomenon induces errors in the calculation of a, due to an increase in the broadening of the line profile produced by this phenomenon.

Synthesis and capacitive properties of carbonaceous sphere@MnO2 rattle-type hollow structures

2010 ◽  
Vol 25 (8) ◽  
pp. 1476-1484 ◽  
Author(s):  
Jintao Zhang ◽  
Jizhen Ma ◽  
Jianwen Jiang ◽  
X.S. Zhao
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Experimental Conditions ◽  
X Ray ◽  
Hollow Structures ◽  
Capacitive Properties

Carbonaceous sphere@MnO2 rattle-type hollow spheres were synthesized under mild experimental conditions. The as-prepared hollow structures were characterized using scanning electron microscope, transmission electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and nitrogen adsorption techniques. The characterization data showed the formation of rattle-type hollow structures with a mesoporous MnO2 shell and a carbonaceous sphere core. The composition and shell thickness of the hollow spheres can be controlled experimentally. The capacitive performance of the hollow structures was evaluated by using both cycle voltammetry and charge–discharge methods. The results demonstrated a specific capacitance as high as 184 F/g at a current density of 125 mA/g. The good electrocapacitive performance resulted from the mesoporous structure and high surface area of the MnO2-based hollow spheres.

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