scholarly journals Structural Analysis of Superconductors at MTF: A Review

2018 ◽  
Vol 26 (43) ◽  
pp. 53-60
Author(s):  
Michal Skarba ◽  
Marcela Pekarčíková ◽  
Pavol Konopka ◽  
Jozef Mišík ◽  
Eva Cuninková
Keyword(s):  
Structural Analysis ◽  
Material Properties ◽  
Research Team ◽  
Lead Free ◽  
Electromagnetic Properties ◽  
Superconducting Tapes ◽  
Lead Free Solders ◽  
First Time ◽  
Properties Of Superconductors ◽  
Insight Into

Abstract The activities of the young STU MTF research team focused on the material properties of superconductors were reviewed for the first time. We performed structural analyses on multiple types of superconducting tapes in order to get deeper insight into the correlation between their structure and electromagnetic properties, both experimentally and by modelling. We also addressed the joining of tapes by lead-free solders.

Effect of aluminum content on structure, transport and mechanical properties of Sn-Zn eutectic lead free solder alloy rapidly solidified from melt.

2015 ◽  
Vol 10 (1) ◽  
pp. 2641-2648
Author(s):  
Rizk Mostafa Shalaby ◽  
Mohamed Munther ◽  
Abu-Bakr Al-Bidawi ◽  
Mustafa Kamal
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Lead Free ◽  
Al Alloy ◽  
Lead Free Solder ◽  
Pronounced Increase ◽  
Mass Unit ◽  
Size Refinement ◽  
Free Solder ◽  
Lead Free Solders

The greatest advantage of Sn-Zn eutectic is its low melting point (198 oC) which is close to the melting point. of Sn-Pb eutectic solder (183 oC), as well as its low price per mass unit compared with Sn-Ag and Sn-Ag-Cu solders. In this paper, the effect of 0.0, 1.0, 2.0, 3.0, 4.0, and 5.0 wt. % Al as ternary additions on melting temperature, microstructure, microhardness and mechanical properties of the Sn-9Zn lead-free solders were investigated. It is shown that the alloying additions of Al at 4 wt. % to the Sn-Zn binary system lead to lower of the melting point to 195.72 ˚C.  From x-ray diffraction analysis, an aluminium phase, designated α-Al is detected for 4 and 5 wt. % Al compositions. The formation of an aluminium phase causes a pronounced increase in the electrical resistivity and microhardness. The ternary Sn-9Zn-2 wt.%Al exhibits micro hardness superior to Sn-9Zn binary alloy. The better Vickers hardness and melting points of the ternary alloy is attributed to solid solution effect, grain size refinement and precipitation of Al and Zn in the Sn matrix.  The Sn-9%Zn-4%Al alloy is a lead-free solder designed for possible drop-in replacement of Pb-Sn solders.  

Shear Strength and Dsc Analysis of High-Temperature Solders

2013 ◽  
Vol 58 (2) ◽  
pp. 529-533 ◽  
Author(s):  
R. Koleňák ◽  
M. Martinkovič ◽  
M. Koleňáková
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Lead Free ◽  
Dsc Analysis ◽  
Ultrasonic Activation ◽  
Metallic Substrates ◽  
Cu Substrate ◽  
Lead Free Solders

The work is devoted to the study of shear strength of soldered joints fabricated by use of high-temperature solders of types Bi-11Ag, Au-20Sn, Sn-5Sb, Zn-4Al, Pb-5Sn, and Pb-10Sn. The shear strength was determined on metallic substrates made of Cu, Ni, and Ag. The strength of joints fabricated by use of flux and that of joints fabricated by use of ultrasonic activation without flux was compared. The obtained results have shown that in case of soldering by use of ultrasound (UT), higher shear strength of soldered joints was achieved with most solders. The highest shear strength by use of UT was achieved with an Au-20Sn joint fabricated on copper, namely up to 195 MPa. The lowest average values were achieved with Pb-based solders (Pb-5Sn and Pb-10Sn). The shear strength values of these solders used on Cu substrate varied from 24 to 27 MPa. DSC analysis was performed to determine the melting interval of lead-free solders.

TAMM HORSFALL PROTEIN: THE MEN BEHIND THE EPONYM

2019 ◽  
Vol 23 (2) ◽  
pp. 117-119 ◽  
Author(s):  
D. N. Paskalev ◽  
B. T. Galunska ◽  
D. Petkova-Valkova
Keyword(s):  
Viral Replication ◽  
Research Team ◽  
Molecular Mechanisms ◽  
Thick Ascending Limb ◽  
Rockefeller Institute ◽  
The Usa ◽  
Natural Inhibitor ◽  
Simplex Virus ◽  
First Time ◽  
New Protein

Tamm–Horsfall Protein (uromodulin) is named after Igor Tamm and Franc Horsfall Jr who described it for the first time in 1952. It is a glycoprotein, secreted by the cells in the thick ascending limb of the loop of Henle. This protein will perform a number of important pathophysiological functions, including protection against uroinfections, especially caused by E. Сoli, and protection against formation of calcium concernments in the kidney. Igor Tamm (1922-1995) is an outstanding cytologist, virologist and biochemist. He is one of the pioneers in the study of viral replication. He was born in Estonia and died in the USA. In 1964 he was elected for a professorship in Rockefeller Institute for Medical Research, where has been working continuously. Since 1959, he became a head of the virology lab established by his mentor and co-author Franc Horsfall. In the course of studies on the natural inhibitor of viral replication, Tamm and Horsfall isolated and characterized biochemically a new protein named after their names. Franc Lappin Horsfall Jr (1906-1971) was a well-known clinician and virologist with remarkable achievements in internal medicine. He was born and died in the USA. He worked in the Rockefeller Hospital from 1934 to 1960, then in the Center for Cancer Research at the Sloan-Kettering Institute. Here he was a leader of a research team studying the molecular mechanisms of immunity, the effects of chemotherapy with benzimidazole compounds (together with I. Tamm), coxsackie viruses, herpes simplex virus, etc. 

Aleksey Peshkov as an editor of Samarskaya Gazeta

2020 ◽  
pp. 128-138
Author(s):  
A. S. Bik-Bulatov
Keyword(s):  
Local History ◽  
Organizational Skills ◽  
First Time ◽  
New Evidence ◽  
Insight Into ◽  
Shed Light

The article uses little known letters of M. Gorky, many of which were published for the first time in 1997, as well as findings of Samara-based experts in local history to shed light on the writer’s work as editor-in-chief of the Samarskaya Gazeta newspaper in 1895. The researcher introduces hitherto unstudied reminiscences of the journalist D. Linyov (Dalin) about this period, which reference a letter by Gorky, now lost. The paper details a newly discovered episode of Gorky’s professional biography as a journalist: it concerns his campaign against a Samara ‘she-wolf,’ the madam of a local brothel A. Neucheva. Linyov’s reminiscences turn out to be an important and interesting source, offering an insight into the daily grind of the young editor Gorky, providing new evidence of his excellent organizational skills, and describing his moral and social stance. The author presents his work in the context of a recently initiated broader discussion about the need to map out all Russian periodicals for the period until 1917, as well as all research devoted to individual publications.

scholarly journals Comparative Study of Chemical Compositions and Antioxidant Capacities of Oils Obtained from 15 Macadamia (Macadamia integrifolia) Cultivars in China

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1031
Author(s):  
Xixiang Shuai ◽  
Taotao Dai ◽  
Mingshun Chen ◽  
Ruihong Liang ◽  
Liqing Du ◽  
...  
Keyword(s):  
Palmitoleic Acid ◽  
Linear Regression Analysis ◽  
Monounsaturated Fatty Acids ◽  
Multiple Linear Regression Analysis ◽  
Chemical Compositions ◽  
Macadamia Integrifolia ◽  
Antioxidant Capacities ◽  
Squalene Content ◽  
First Time ◽  
Insight Into

The planting area of macadamia in China accounted for more than one third of the world’s planted area. The lipid compositions, minor components, and antioxidant capacities of fifteen varieties of macadamia oil (MO) in China were comparatively investigated. All varieties of MO were rich in monounsaturated fatty acids, mainly including oleic acid (61.74–66.47%) and palmitoleic acid (13.22–17.63%). The main triacylglycerols of MO were first time reported, including 19.2–26.1% of triolein, 16.4–18.2% of 1-palmitoyl-2,3-dioleoyl-glycerol, and 11.9–13.7% of 1-palmitoleoyl-2-oleoyl-3-stearoyl-glycerol, etc. The polyphenol, α-tocotrienol and squalene content varied among the cultivars, while Fuji (791) contained the highest polyphenols and squalene content. Multiple linear regression analysis indicated the polyphenols and squalene content positively correlated with the antioxidant capacity. This study can provide a crucial directive for the breeding of macadamia and offer an insight into industrial application of MO in China.

scholarly journals Insight into the origin of SARS-CoV-2 through structural analysis of receptor recognition: a molecular simulation study

RSC Advances ◽  
2021 ◽  
Vol 11 (15) ◽  
pp. 8718-8729
Author(s):  
Jixue Sun ◽  
Meijiang Liu ◽  
Na Yang
Keyword(s):  
Molecular Dynamics ◽  
Structural Analysis ◽  
Molecular Dynamics Simulations ◽  
Molecular Simulation ◽  
Simulation Study ◽  
Receptor Recognition ◽  
Dynamics Simulations ◽  
Insight Into

The origin of SARS-CoV-2 through structural analysis of receptor recognition was investigated by molecular dynamics simulations.

Precursor engineering for high-quality Cs2AgBiBr6 films toward efficient lead-free double perovskite solar cells

2021 ◽  
Author(s):  
Ping Hou ◽  
Wenxiang Yang ◽  
Ning Wan ◽  
Zhi Fang ◽  
Jinju Zheng ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Control Sample ◽  
Double Perovskite ◽  
Lead Free ◽  
High Quality ◽  
Precursor Engineering ◽  
First Time

We report a facile BiBr3(DMSO)2 adduct process to produce high-quality Cs2AgBiBr6 films with large grains for the first time, which leads to an enhancement of over 40% on the PCE of Cs2AgBiBr6-based solar cells compared to that of the control sample.

scholarly journals Effects of Yttrium Addition on the Microstructure Evolution and Electrochemical Corrosion of SN-9zn Lead-Free Solders Al-Loy

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2549
Author(s):  
Wenchao Yang ◽  
Jun Mao ◽  
Yueyuan Ma ◽  
Shuyuan Yu ◽  
Hongping He ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Microstructure Evolution ◽  
Electrochemical Corrosion ◽  
Lead Free ◽  
Nacl Solution ◽  
Rich Phase ◽  
Yttrium Addition ◽  
Electrochemical Corrosion Behavior ◽  
Lead Free Solders ◽  
Addition Amount

Electrochemical corrosion behavior of ternary tin-zinc-yttrium (Sn-9Zn-xY) solder alloys were investigated in aerated 3.5 wt.% NaCl solution using potentiodynamic polarization techniques, and the microstructure evolution was obtained by scanning electron microscope (SEM). Eight different compositions of Sn-9Zn-xY (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.20, and 0.30 wt.%) were compared by melting. The experimental results show that when the content of Y reached 0.06 wt.%, the grain size of Zn-rich phase became the smallest and the effect of grain refinement was the best, but there was no significant effect on the melting point. With the increases of Y content, the spreading ratio first increased and then decreased. When the content of Y was 0.06 wt.%, the Sn-9Zn-0.06Y solder alloy had the best wettability on the Cu substrate, which was increased by approximately 20% compared with Sn-9Zn. Besides, the electrochemical corrosion experimental shows that the Y can improve the corrosion resistance of Sn-9Zn system in 3.5 wt.% NaCl solution, and the corrosion resistance of the alloy is better when the amount of Y added is larger within 0.02–0.30 wt.%. Overall considering all performances, the optimal performance can be obtained when the addition amount of Y is 0.06.

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