Methods of tests for paints; determination of resistance to water (water immersion method)

2015 ◽  
2005 ◽  
Vol 59 (1-2) ◽  
pp. 32-35
Author(s):  
Slavica Mihajlovic ◽  
Zivko Sekulic ◽  
Milan Petrov

The results of laboratory investigations of the possibility to obtain coated limestone for the production of PVC-products are presented in this paper. Limestone from the "Vencac" deposit (Arandjelovac, Serbia and Montenegro) was used as the raw material. The investigations were carried out in two phases: obtaining the coated limestone and determination of the degree of coating. The results of the investigations showed that successful coating of the surface of the limestone particles with Ca-stearate (Ca-stearate content 3%) was achieved in a vibro mill with rings and the obtained degree of coating was higher than 95%. The coating degree was determined in transmitted light by a polarization microscope applying the immersion method (water immersion).


2009 ◽  
Vol 3 (4) ◽  
pp. 191-196 ◽  
Author(s):  
Sanja Martinovic ◽  
Jelena Majstrovic ◽  
Velislav Vidojkovic ◽  
Tatjana Volkov-Husovic

The low cement high alumina castable (LCC) studied in this paper was synthesised, cured and then treated at different sintering temperatures. Since any inhomogeneity introduced during the castable preparation can remain inside the material degrading its properties and therefore the quality during service life, particular attention was given to the processing procedure in order to produce the material with the optimum characteristics. Composition of the castable regarding particle size distribution was adjusted according to the Andreassen's packing model. The samples were sintered at 1100, 1300 and 1600?C for three hours. Influence of the different sintering temperatures on the castable properties is discussed. Compressive and flexural strengths were determined by destructive testing method, while the water immersion method was used for determination of the bulk density and the water absorption. Changes of elastic properties and microstructure (porosity) were observed by the non-destructive testing methods, ultrasonic measurements and image analysis. Based on the results, it can be concluded that sintering temperature has strong influence on the properties of the LCC. Exceptionally good properties were obtained for the sample sintered at 1600?C, but it should be highlighted that the samples treated at 1100 and 1300?C were provided with good properties, too. This should not be neglected because of the energy saving importance, in cases where the material sintered at lower temperature satisfies the application requirements. .


1986 ◽  
Vol 23 (8) ◽  
pp. 1068-1074 ◽  
Author(s):  
T. W. Melnyk ◽  
A. M. M. Skeet

A modified technique for the determination of the connected porosity of rocks by the water immersion method has been developed and tested. The technique is recommended for rocks with porosity less than 0.05. The major modifications to the technique include saturation of the sample under vacuum conditions and determination of the water-saturated but surface-dry weight from a drying curve.Porosity measurements on 48 granitic samples showed that the technique is reproducible within a 95% confidence range of ±4% of the mean value. However, the possibility of spatial variation of porosity must be taken into account in assigning uncertainties to the measured values.


Author(s):  
Manju Gari ◽  
Kumari Ranjeeta ◽  
Lakhan Majhee ◽  
Akhilesh Kumar ◽  
Sumit Kumar Mahato

Background: Pain is the most common reason patients seek medical care. Increased level of monoamines (serotonin and norepinephrine) in synaptic clefts lead to changes in pain threshold and induce antinociception. The study was carried out to evaluate antinociceptive effect of paroxetine in albino rats and to probe into its possible mechanism of action. The study was carried out to evaluate anti-nociceptive effect of paroxetine in albino rats.Methods: Male Albino rats of average weight 150-240gms were used. The drugs used were paroxetine 5mg/Kg, pethidine 5mg/kg (standard drug). Anti-nociceptive effect tested by using thermal method i.e. Tail flick response and Tail warm water immersion method.Results: In this study, Anti-nociceptive effect of respective drugs were measured by using two methods i.e. tail flick test and tail warm water immersion method at 0 min., 30 min., 60 min. and 90min.after administration of drugs. Reaction time started to increase from baseline at 0 min. and peak effect was seen at 60 min. then it started to decrease at 90 min. in almost all the groups except in control group.Conclusions: Paroxetine have significant analgesic effect in acute pain, which may be mediated via central and peripheral mechanisms. Efficacy of Paroxetine is almost equal to that of standard drug pethidine in acute pain management.


Author(s):  
Yasuhiro Yuguchi ◽  
Taiji Hirasawa

This paper describes development and application of Phased Array Ultrasonic Testing (UT) and Remotely Operated Vehicles (ROV) for In-Vessel Internals Inspection. Stress Corrosion Crack (SCC) on reactor internals is one of the most important issues since 1990s, and demand to inspect the reactor internals is increasing. Instrument manufactures and inspection venders have developed and applied 1) Phased Array UT technologies and technique as one of our Non-Destructive Examination (NDE) technologies, 2) several kinds of ROVs and special tools for probe delivery and positioning. They are available and effective in In-Vessel Inspection (IVI) and maintenance, which shall be conducted in the narrow room under water. Furthermore, the UT technique for Alloy 182 weld that used to be difficult to detect and size flaws was developed and deployed in the BWR IVI. UT experiences in reactor vessels are increasing in recent years. An immersion technique by Phased Array UT is a key to perform the In-vessel UT on a complex geometric surface to be inspected, and to achieve very wide accessible range by ROVs or simple special tools efficiently. Advantages of the water immersion method and a ROV development result are shown in this paper. Particularly, TOSHIBA developed a flat type ROV for Shroud (Shroud ROV), which can be held against the surface of the shroud by thrusting propellers and scan mechanically through narrow gap within 2 inches {50mm}. The ROV’s positioning accuracy and applications for Shroud UT are shown. As the field experience, this introduces the UT results for CRD Stub tube Alloy 182 weld that is located on the vessel bottom head in Hamaoka UNIT 1 of Chubu Electric Power Company in Japan. An axial SCC flaw was detected by underwater visual testing, after the CRD stub tube leakage was detected. Then UT examination for the flaw was accomplished on the Alloy 182 weld in the vessel. We evaluated that the flaw penetrated into the weld metal of the CRD stub tube-pat weld and didn’t propagate into the low alloy of Reactor Pressure Vessel base metal. After UT sizing, the CRD stub tube was removed and replaced. The examination result was proven to have a good agreement with the actual crack depth. As a result, the efficiency of our Phased Array Technique was confirmed. As the other immersion method application, UT coverage example and accessible range for Shroud inspection are shown.


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