Inert Gas
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ACS Omega ◽  
2021 ◽  
Author(s):  
Chengjie Bai ◽  
Shi Li ◽  
Tong Chen ◽  
Xiaoxiao Chen ◽  
Wenjing Meng ◽  
...  

2021 ◽  
Vol 78 (3) ◽  
pp. 24-33
Author(s):  
A.U. Aldiyarov ◽  
◽  
D.Y. Sokolov ◽  
A. Z. Tychengulova ◽  
D. Yerezhep ◽  
...  

It is known that by changing the concentration in an inert medium, it is possible to form clusters of various sizes of any substance by condensing them on a cold substrate from the gas phase. Traditionally, such systems are presented by molecular cryocrystals. This paper demonstrates the results of IR spectro­metric studies of cryovacuum condensates of ethanol mixture with nitrogen. The main task of this study is to explain the complex, most often, ambiguous behavior of thin films of ethanol cryovacuum conden­sates in the process of its co­condensation with nitrogen. For this purpose, vibrational spectroscopy of cryodeposited thin films of “ethanol in nitrogen” mixtures in various concentration ratios was performed. The objects of research are thin films of cryocondensates of ethanol mixture with inert gas (N2). The sam­ples were condensed at the temperature T = 16 K. The pressure of the gas phase of the mixture during cryocondensation was kept at P = 10­5 Torr. The range of ethanol concentrations in the mixtures varied from 3% to 90%. The spectral range of measurements was considered in 400­-4200 1/cm. It is assumed that the change in the concentration of ethanol in the mixture leads to the formation of various cluster compositions of ethanol molecules dissolved in an inert medium.


2021 ◽  
pp. 161863
Author(s):  
Nicola Patelli ◽  
Francesco Cugini ◽  
Di Wang ◽  
Samuele Sanna ◽  
Massimo Solzi ◽  
...  

2021 ◽  
Vol 6 (2) ◽  
pp. 12-22
Author(s):  
Ahmad Zayadi ◽  
Sungkono ◽  
Cahyono HP

X-Ray Radiographic Analysis of Aisi 304 Stainless Steel Plate Joints From Inert Gas Tungsten Welding Results with 40 – 60 Ampere Current. Metal welding process is one of the main processes in machine construction. The quality of welded joints determines the strength and toughness of a machine construction. The quality of welded joints of installed construction can be determined by the non-destructive test method using X-ray radiography equipment. This study aims to obtain a butt joint obtained from TIG welding of AISI 304 stainless steel plate with a current of 40 - 60 A, identification of defects in the 1G butt joint, and analysis of the quality of the weld joint. The research method used is testing of welded joints using X-ray radiography which refers to the ASME V article II standard and the connection quality refers to ASME section IX. The results showed that TIG welding with a current of 60 Ampere produced a butt joint butt joint that was penetrated and there was no gap between the plates, whereas with a current of 40 A and 50 A the weld joint was not see-through but there was still a gap between the plates. Incomplete penetration weld defects were found in the welded SS 304 plate joints with a current of 40 A. Welded porosity defects were found in the welded SS 304 plate joints with a current of 50 A. Weld defects were not found in the SS 304 plate joints with a current of 60 A. Butt joint connections TIG welded SS 304 plate with the best current of 60 A compared to the current of 40 A and 50 A.


Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2930
Author(s):  
Donghwi Kim ◽  
Youngjae Ryu ◽  
Ju-Heon Lee ◽  
Sung Woon Cha

Injection research using aluminum flakes has been conducted to realize metallic textures on the surface of plastic products. Several studies have focused on the effect of the orientation and quality of the flakes when using conventional injection molding methods; however, limited studies have focused on the foam injection molding method. In this study, we examined the orientation of aluminum flakes through foam injection with an inert gas and observed the changes in texture using a spectrophotometer and a gloss meter. The mechanical properties were also studied because the rigidity of the product, which is affected by the weight reduction that occurs during foaming, is an important factor. The results demonstrate that under foam injection molding, reflectance and gloss increased by 6% and 7 GU, respectively, compared to those obtained using conventional injection molding; furthermore, impact strength and flexural modulus increased by 62% and 15%, respectively. The results of this research can be applied to incorporate esthetic improvements to products and to develop functional parts.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4884
Author(s):  
Qihao Chen ◽  
Chengcheng Wang ◽  
Yihao Wang ◽  
Jiahui Wang ◽  
Sanbao Lin ◽  
...  

Ultrasonic energy is introduced into the Metal Inert Gas (MIG) welding arc and weld pool by superposition of an ultrasonic frequency current. In this study, the arc shape, arc energy, and ultrasonic energy that responded to ultrasonic excitation voltage and frequency is investigated. The comprehensive influence of arc and ultrasonic energy on weld formation, microstructure, and mechanical properties is further studied. The arc and ultrasonic energy are analyzed by using a high-speed camera and microphone, respectively. The results showed that the arc width increased, and the arc energy density decreased after the superposition of ultrasonic current. The arc height could be compressed under certain ultrasonic excitation parameters. The ultrasonic excitation voltage and frequency had a direct influence on the ultrasonic energy. The arc height, arc energy density, and ultrasonic energy together determined the weld width. Ultrasound could effectively refine the microstructure of the weld zone and fusion zone but had little effect on the heat-affected zone. Ultrasound improved the hardness of the joint by refining the grain and the second phase. The joint hardness was the highest when the ultrasonic excitation voltage was 100 V, and the frequency was 30 kHz.


2021 ◽  
Vol 6 (5) ◽  
pp. 141-145
Author(s):  
F. O. Uwoghiren ◽  
A. Ozigagun

The heat affected zone and arc length parameters have a vital role to play in determining the integrity of a weld structure. The cooks distance is a statistical diagnostic employed in this study to select the best optimum combination of welding process parameters. Mild steel plate was the choice material used to produce the weld specimen, which was welded with the Tungsten inert gas method. The RSM model was used to develop an optimal solution that can explain the behavior of the welded joint with respect to the heat affected zone and arc length, different diagnostic techniques were employed which includes the normal probability plot and cooks distance plot. The model developed has sufficient merit as the results obtained shows that the cooks distance values is within the range of 0 and 1 indicating the absence of outlier in the data making the optimal solution highly acceptable.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4759
Author(s):  
Marina Ol’khovich ◽  
Angelica Sharapova ◽  
Svetlana Blokhina ◽  
German Perlovich

A temperature dependence of saturated vapor pressure of isavuconazole (IVZ), an antimycotic drug, was found by using the method of inert gas-carrier transfer and the thermodynamic functions of sublimation were calculated at a temperature of 298.15 K. The value of the compound standard molar enthalpy of sublimation was found to be 138.1 ± 0.5 kJ·mol−1. The IVZ thermophysical properties—melting point and enthalpy—equaled 302.7 K and 29.9 kJ mol−1, respectively. The isothermal saturation method was used to determine the drug solubility in seven pharmaceutically relevant solvents within the temperature range from 293.15 to 313.15 K. The IVZ solubility in the studied solvents increased in the following order: buffer pH 7.4, buffer pH 2.0, buffer pH 1.2, hexane, 1-octanol, 1-propanol, ethanol. Depending on the solvent chemical nature, the compound solubility varied from 6.7 × 10−6 to 0.3 mol·L−1. The Hansen s approach was used for evaluating and analyzing the solubility data of drug. The results show that this model well-described intermolecular interactions in the solutions studied. It was established that in comparison with the van’t Hoff model, the modified Apelblat one ensured the best correlation with the experimental solubility data of the studied drug. The activity coefficients at infinite dilution and dissolution excess thermodynamic functions of IVZ were calculated in each of the solvents. Temperature dependences of the compound partition coefficients were obtained in a binary 1-octanol/buffer pH 7.4 system and the transfer thermodynamic functions were calculated. The drug distribution from the aqueous solution to the organic medium was found to be spontaneous and entropy-driven.


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