scholarly journals Semi-Automatic Apparatus for Measuring Wetting Properties at High Temperatures

2017 ◽  
Vol 24 (1) ◽  
pp. 175-184 ◽  
Author(s):  
Marcin Bąkała ◽  
Rafał Wojciechowski ◽  
Dominik Sankowski ◽  
Adam Rylski

Abstract Determination of the physico-chemical interactions between liquid and solid substances is a key technological factor in many industrial processes in metallurgy, electronics or the aviation industry, where technological processes are based on soldering/brazing technologies. Understanding of the bonding process, reactions between materials and their dynamics enables to make research on new materials and joining technologies, as well as to optimise and compare the existing ones. The paper focuses on a wetting force measurement method and its practical implementation in a laboratory stand – an integrated platform for automatic wetting force measurement at high temperatures. As an example of using the laboratory stand, an analysis of Ag addition to Cu-based brazes, including measurement of the wetting force and the wetting angle, is presented.

2013 ◽  
Vol 18 (2-3) ◽  
pp. 33-41
Author(s):  
Dominik Sankowski ◽  
Marcin Bakala ◽  
Rafał Wojciechowski

Abstract The good quality of several manufactured components frequently depends on solidliquid interactions existing during processing. Nowadays, the research in material engineering focuses also on modern, automatic measurement methods of joining process properties, i.a. wetting force and surface tension, which allows for quantitative determination of above mentioned parameters. In the paper, the brazes’ dynamic properties in high-temperatures’ measurement methodology and the stand for automatic determination of braze’s properties, constructed and implmented within the research grant nr KBN N N519 441 839 - An integrated platform for automatic measurement of wettability and surface tension of solders at high temperatures, are widely described


2003 ◽  
Vol 18 (6) ◽  
pp. 1420-1428 ◽  
Author(s):  
Hsiu-yu Chang ◽  
Sinn-wen Chen ◽  
David Shan-hill Wong ◽  
Hsiu-Feng Hsu

Wetting properties of lead-free solders, Sn–0.7 wt.% Cu and Sn–3.5 wt.% Ag, pure Sn, and conventional Sn–40 w.t% Pb on Ni, Cu, and Ag substrates at 250 and 240 °C were determined by using a wetting balance technique. Wetting times and wetting forces were determined directly from the wetting curves, and surface tensions of molten solders were calculated from the wetting force measurements. A statistic tool, analysis of variance (ANOVA), was used to analyze the experimental results. By using the wetting time as an indication, it was found that Sn–Pb exhibited the best wetting followed by Sn–Ag, Sn–Cu, and Sn, in that order. A very significant but frequently ignored issue is that most solders react with substrates, and the molten solders are not in contact with the original substrates but rather with intermetallic compounds. On the basis of theoretical analysis and experimental observations, it was concluded that the withdrawing forces and the surface tensions of the molten solders determined by the present technique are not significantly affected by the interfacial reactions if the interfacial reactions are not too excessive. However, wetting times are strong functions of both solders and substrates and the interfacial reactions between them.


2014 ◽  
Vol 45 (1) ◽  
pp. 3-20 ◽  
Author(s):  
Ivan Vladimirovich Egorov ◽  
Boris Evgen'evich Zhestkov ◽  
Vladimir Viktorovich Shvedchenko

2019 ◽  
Vol 15 (4) ◽  
pp. 312-318
Author(s):  
Shuoye Yang

Background: The therapeutic ability and application of antifungal peptide (APs) are limited by their physico-chemical and biological properties, the nano-liposomal encapsulation would improve the in vivo circulation and stability. </P><P> Objective: To develop a long-circulating liposomal delivery systems encapsulated APs-CGA-N12 with PEGylated lipids and cholesterol, and investigated through in vivo pharmacokinetics. Methods: The liposomes were prepared and characterized, a rapid and simple liquid chromatographytandem mass spectrometry (LC-MS/MS) assay was developed for the determination of antifungal peptide in vivo, the pharmacokinetic characteristics of APs liposomes were evaluated in rats. Results: Liposomes had a large, unilamellar structure, particle size and Zeta potential ranged from 160 to 185 nm and -0.55 to 1.1 mV, respectively. The results indicated that the plasma concentration of peptides in reference solutions rapidly declined after intravenous administration, whereas the liposomeencapsulated ones showed slower elimination. The AUC(0-∞) was increased by 3.0-fold in liposomes in comparison with standard solution (20 mg·kg-1), the half-life (T1/2) was 1.6- and 1.5-fold higher compared to the reference groups of 20 and 40 mg·kg-1, respectively. Conclusion: Therefore, it could be concluded that liposomal encapsulation effectively improved the bioavailability and pharmacokinetic property of antifungal peptides.


2011 ◽  
Vol 17 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Nada Babovic ◽  
Dejan Markovic ◽  
Vojkan Dimitrijevic ◽  
Dragan Markovic

This paper shows the results obtained in field analysis performed at the Tamis River, starting from the settlement Jasa Tomic - border between Serbia and Romania to Pancevo - confluence of Tamis into the Danube. The Tamis is a 359 km long river rising in the southern Carpathian Mountains. It flows through the Banat region and flows into the Danube near Pancevo. During the years the water quality of the river has severely deteriorated and badly affected the environment and the river ecosystem. In situ measurements enabled determination of physico-chemical parameters of water quality of the Tamis River on every 400 m of the watercourse, such as: water temperature, pH value, electrical conductivity, contents of dissolved oxygen and oxygen saturation. The main reason of higher pollution of Tamis is seen in connection to DTD hydro system. Sampling was performed at 7 points with regard to color, turbidity, total hardness, alkalinity, concentration of ammonium nitrogen, nitrite nitrogen, nitrate nitrogen, iron, chlorides and sulphates in samples. The aim of the present work was to evaluate water quality in the Tamis River taking into account significant pollution, which originates from settlements, industry and agriculture, and to suggest appropriate preventive measures to further pollution decreasing of the river's water.


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