Influence Of Temperature Profile Research Articles

Influence of Temperature Profile on the Composition of Condensed Carbon in a Plasma Jet

Graphene materials are synthesized in a thermal plasma jet without using size forming catalysts. The synthesis was performed on a direct current plasma torch operating at 28–30 kW with a pressure of 100–710 Torr. The synthesis products are studied by electron microscopy, X-ray diffraction, and dynamic light scattering. It is found that structures formed in the plasma jet have a flake morphology regardless of the type of the carbon bearing source. Thermodynamic calculations testify a correlation between the temperature profile in the plasma jet and the composition of condensed carbon (redistribution between C60 and C80). The application areas of flaky structures are discussed.

Influence of Temperature Profile during Laser Welding of Aluminum Alloy 6061 T6 on Microstructure and Mechanical Properties

In the present study, laser welding was carried out with CO2 laser on a 2 mm thick aluminum alloy (6061-T6) sheet to study laser weldability of this heat-treatable aluminum alloy. Screening experiments were performed initially to enumerate the power density requirement for proper coupling of the laser with the material. Bead on plate experiments were conducted to recognize situation under which stable keyhole and welds with minimum defects (porosity and cracks) can be produced. Recognized process window (3 kW power, 4 m/min welding speed, and 18 L/min Helium flow rate) obtained from initial trial was used in butt welding experiment and the resulted weld was characterized by macroscopic and microscopic observation, microhardness study, and tensile test. The microstructure reveals porosity and crack-free welds and hardness data confirmed presence of heat-affected zone (HAZ) and huge drop in overall hardness after welding. After post-weld treatment (aging treatment), the hardness was increased marginally, but base hardness could not be achieved. Thermal profile experienced by the material during welding was calculated and it revealed that the mechanical properties of the material decreased due to temperature experienced by the material lead to loss of aging properties of the material.

73. Influence of temperature profile and CPA distribution on cryopreservation of native tissue

73. Influence of temperature profile and CPA distribution on cryopreservation of native tissue

Influence of temperature profile in an annular shaft kiln on calcination

The paper discusses an experimental measurement of the vertical temperature profile and kiln gas composition in an annular shaft kiln. The results obtained confirm that calcination in the kiln begins at a temperature between 820°C and 830°C. From energy balance, kiln gas composition and the samples of partially burned stones from the kiln the average heat transfer coefficient from kiln gases to the stones is determined, as well as the calcination distribution within the kiln. Modelling of the calcination process in an annular shaft kiln was performed on the basis of the measured temperature profile. The results of this model were in good agreement with those for samples of partially calcinated stones taken from the area of the lower and upper burners.

Aluminum-induced crystallization of amorphous silicon: Influence of temperature profiles

Annealing of amorphous silicon/aluminum layer stacks below the eutectic temperature leads to a layer exchange and concurrent crystallization of silicon. The resulting polycrystalline silicon layers are of great interest for large area thin film devices. This paper reports about the influence of annealing temperature profiles on the layer exchange process. It is shown that temperature profiles have pronounced influence on the nucleation process. The obtained results are helpful for a better understanding of the physics of the layer exchange process and for an improvement of the layer exchange process by allowing for a reduction of the process time with a simultaneous increase in grain size. It is shown in particular that the characteristic suppression of nucleation is caused by Si-depletion around the growing Si-grains.

Influence of temperature profile on solar acoustic modes

Solar global acoustic oscillations in a multilayer model of the solar atmosphere are studied in the plane-parallel geometry. Calculated frequencies of acoustic modes of the Sun are found to depend on parameters of the temperature profile used in the model. Larger influence on frequencies comes from values of the temperature gradient in the convection zone, and less influence from values of the thickness L of the transitional layer and from values of the ratio τ≡Tc/Tp of the coronal and the photospheric temperature, Tc and Tp, respectively. The uncertainties in determining these parameters can easily yield frequency shifts that are larger than the observational accuracy. This then indicates a possibility for a diagnostics of solar plasma based on known values of observed oscillation frequencies.

Comparison of High Field Characteristics of SiO2 and AIN Gate Insulators in 6H SiC MOS Capacitors

ABSTRACTUsing a fast ramp response technique, the high field characteristics, specifically the breakdown strength, of thermally grown silicon-dioxide (SiO2) and MOCVD grown aluminum-nitride (AIN), on n-type 6H-SiC epilayers is obtained as a function of three different processing conditions for the insulator growth. Significant improvement in the breakdown strength of thermally grown SiO2 after a 30 minute post annealing at 400°C in nitrogen ambient is reported. Further, the influence of temperature profile during the AIN growth on the breakdown strength is reported.

Detailed Model of the Afterglow Region of a Microwave Generated Oxygen Plasma

ABSTRACTA one dimensional mass continuity equation was used to model a low pressure, high radical concentration, non-isothermal oxygen afterglow reactor. The mathematics are very similar to those used to model flames. It was shown that the model, with no adjustable parameters, yielded very good agreement with experimental measures of O-atom flux. The model was manipulated to study the influence of temperature profile, pressure, homogeneous and heterogeneous kinetics, O-atom generation and flow rate on the afterglow plasma.

The Influence of Temperature Profile on Noise Propagation Outdoors

The Influence of Temperature Profile on Noise Propagation Outdoors

Influence of temperature profile on product yields in pyrolysis of hydrocarbon feedstock

Influence of temperature profile on product yields in pyrolysis of hydrocarbon feedstock