نتایج جستجو برای: shielding gas

تعداد نتایج: 253666  

Journal: :Dental materials journal 2012
Yasuko Takayama Rie Nomoto Hiroyuki Nakajima Chikahiro Ohkubo

The purpose of this study was to evaluate the effects of the rate of argon gas flow on joint strength in the laser-welding of cast metal plates and to measure the porosity. Two cast plates (Ti and Co-Cr alloy) of the same metal were abutted and welded together. The rates of argon gas flow were 0, 5 and 10 L/min for the Co-Cr alloy, and 5 and 10 L/min for the Ti. There was a significant differen...

2011

The information system is a coherently structured assembly, made of electronic computing and communication equipments, software, processes, automated and manual procedures, used as automatic data processing tool within a field of activity. In the process of welding in shielding gas environment with fusible electrode, there are used either inert or active gases. Therefore, we make the distinctio...

Journal: :Microelectronics Reliability 2011
A. Pequegnat H. J. Kim M. Mayer Y. Zhou J. Persic J. T. Moon

0026-2714/$ see front matter 2010 Elsevier Ltd. A doi:10.1016/j.microrel.2010.02.023 * Corresponding author. E-mail address: [email protected] (A. Peque The development of novel Cu wires for thermosonic wire bonding is time consuming and the effects of shielding gas on the electrical flame off (EFO) process is not fully understood. An online method is used in this study for characterizing C...

In this research, geometrical structures of armchair single walled boron nitride nanotube (SWBNNT) and armchair single walled aluminum nitride nanotube (SWAlNNT) were optimized by Density Functional Theory (DFT) in the gas phase, both having the same length of 5 angstrom and n=9, m=9. B3LYP/6-31G* level of theory have been used to determine and compare electronic properties, n...

F. Mollaamin S. M. Sadat Choobeh

A cluster model for active site of nanotube (C48) was presented and investigated the geometricstructure and thermochemical parameters. Quantum-mechanical calculations were performed at theHF / 510-30, 6-310, 6-3 IG• and 6-310" levels of theory in the gas phase and three solvents atfour temperatures. Also, nuclear shielding parameters of the active site of nanotube have been takeninto account us...

In this research, geometrical structures of armchair single walled boron nitride nanotube (SWBNNT) and armchair single walled aluminum nitride nanotube (SWAlNNT) were optimized by Density Functional Theory (DFT) in the gas phase, both having the same length of 5 angstrom and n=9, m=9. B3LYP/6-31G* level of theory have been used to determine and compare electronic properties, n...

2012
S. W. CAMPBELL A. M. GALLOWAY N. A. MCPHERSON

Shielding gases are fundamental to the operation of the gas metal arc welding (GMAW) process and there are a number commonly used, each with its own specific properties, i.e., ionization potential, which creates unique arc characteristics (Refs. 1–7). Shielding gases are also commonly used in a variety of premixed combinations of two or more gases in order to take advantage of the beneficial pr...

Journal: :Physical chemistry chemical physics : PCCP 2017
Liuxie Liu Laicai Li Quan Li Qun Zeng

Shielding effects of a nanocage can be determined by the field felt by an encapsulated noble gas (NG) atom. Using the polarizability distributions about NG endohedral fullerenes (NGEFs), a new scheme based on the local polarizability of the NG is introduced to detect the shielding effects of fullerenes, using density functional theory calculations and Hirshfeld population analysis. For large ca...

Journal: :journal of physical and theoretical chemistry 0
farideh keshavarz rezaei -

the physical and chemical properties of pyrazole and pyrazoline molecules were theoreticallystudied by gaussian 03, software with nmr and molecular orbital calculations at b3lyp/6-31g andb3lyp/6-31+g(d) levels, in gas phase and solution. in this study a comparison effect of threesolvents with different dielectric constants on pyrazole and pyrazoline molecules in aspect energyinteraction between...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2015
jamshid najafpour ali akbar salari forouzan zonouzi mohammad porghamdaryasari

hartree-fock (hf) and density functional theory (dft) methods employed to study the effect of conformational change on the 13c chemical shifts of 6-mono axial and equatorial substituted and 6,7-di axial-axial, equatorial-equatorial and axial-equatorial substitutedderivatives of 5,6,7,8-tetrahydrodibenzo[a,c]cyclo-octene. the geometry of the conformers have been optimized in the gas phase employ...

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