An Ultrasonic Method for Measurement of Oil Films in Reciprocating Rubber O-ring Seals

2021 ◽  
pp. 107407
Author(s):  
Juanjuan Zhu ◽  
Xiangwei Li ◽  
Scott Beamish ◽  
Rob S Dwyer-Joyce
Keyword(s):  
2006 ◽  
Vol 137 ◽  
pp. 219-222 ◽  
Author(s):  
W. Marczak ◽  
T. Kowalska ◽  
M. Bucek ◽  
D. Piotrowski ◽  
M. Sajewicz
Keyword(s):  

2020 ◽  
Vol 2020 (1) ◽  
pp. 34-52
Author(s):  
Rafał Szymański

AbstractThe article is in line with the contemporary interests of companies from the aviation industry. It describes thermoplastic material and inspection techniques used in leading aviation companies. The subject matter of non-destructive testing currently used in aircraft inspections of composite structures is approximated and each of the methods used is briefly described. The characteristics of carbon preimpregnates in thermoplastic matrix are also presented, as well as types of thermoplastic materials and examples of their application in surface ship construction. The advantages, disadvantages and limitations for these materials are listed. The focus was put on the explanation of the ultrasonic method, which is the most commonly used method during the inspection of composite structures at the production and exploitation stage. Describing the ultrasonic method, the focus was put on echo pulse technique and the use of modern Phased Array heads. Incompatibilities most frequently occurring and detected in composite materials with thermosetting and thermoplastic matrix were listed and described. A thermoplastic flat composite panel made of carbon pre-impregnate in a high-temperature matrix (over 300°C), which was the subject of the study, was described. The results of non-destructive testing (ultrasonic method) of thermoplastic panel were presented and conclusions were drawn.


Author(s):  
J Downing ◽  
A Hook

Two steel substrate test panels were developed to represent common plate thicknesses found on naval vessels and scanned using the Babcock developed ultrasonic technique. One sample comprised of a series of slotted surface breaking flaws of varying widths and through thicknesses to represent fracturing/cracking. The inspection method detected simulated cracking to a depth of 2mm and 0.5mm in width. The second sample included numerous loss of wall thickness areas of varying diameters and through thicknesses, with the smallest detectable loss of wall thickness being 0.1mm at a 15mm diameter. After proving confidence in detection, there was a need to characterise flaws to provide support and ascertain a repair action. Samples were produced that were subjected to either impact or heat exposure to induce realistic representative damage. The practical ultrasonic method was successfully used to independently characterise between the samples, with induced de-laminations caused by blisters, and multi layered matrix cracking caused by varying levels of projectile impacts, due to their unique morphology.


Author(s):  
Shirley García ◽  
Thairon Reis ◽  
Auteliano Antunes dos Santos Junior

2020 ◽  
Vol 6 (3) ◽  
pp. 180-191
Author(s):  
Kavitha Chandrasekaran

Background:: In the long run, synthetic tints were found to be harmful to the chemicals. As a result natural tints have come to be used for their many intrinsic values. The main reason being, then availability of local plants as the main source of natural colorants. Their easy availability in the country being zero cost – effective and planted for other purposes are the main reasons for utilizing them as natural tints. Almost all the parts of the plants, namely stem, leaves, fruits, seeds, barks etc. are used for extracting natural colour. In addition, they are antimicrobial antifungal, insect – repellant deodorant, disinfectant having medicinal values. Methods:: Sweet Indrajao leaves were cleaned by washing with water and dried under direct sunlight and ground as fine powder. A fine strainer was used to remove the wastages. After all these processes, 1-kilogram leaves weighed 318 grams. Then, it is put in 75% ethanol 25% water and heated in a breaker which in kept over a water bath for 2 hours. After this, the contents were filtered and kept in a separate beaker. Bleached fleece draperies stained with stain extract were made to become wet and put into different stain baths which contain the required amount of stain extract and water. Acetic acid was added to it after 20 minutes. The fleece drapery was stained for about one hour at 60oC. The draperies thus stained were removed, squeezed, and put to treatment with metal salts without washing. Different metal salts were used for the treatment using 3% of any one of the chemical mordants like alum, stannous chloride, potassium dichromate, ferrous sulphate, nickel sulphate, copper sulphate and natural mordants such as myrobolan, turmeric, cow dung, Banana sap juice at 60oC for 30 minutes with MLR of 1:30. The stained draperies were washed repeatedly in all the three methods in water and dried in air. At last, the stained draperies were put to soap with soap solution at 60oC for 10 minutes. The draperies were repeatedly washed in water and dried under the sun. Results:: Sweet Indrajao leaves discharged colour easily in alcoholic water. The fleece draperies were stained with chemical and natural mordants. It was observed that the stain uptake was found to be good in post-mordanting method. Ultrasonication has clearly improved the stainability of the draperies at pH 3 and 3.5 values. The pH decreases the stain ability under both Conventional and Ultrasonic conditions. The colour strength increases with an increase in staining temperature in both cases of US and CH methods. Conclusion:: Sweet Indrajao.L has been found to have good ultrasonic potential as a stain plant. The stain uptake as well as the fastness properties of the fleece drapery were found to enhance when metal mordant was used in conjugation with ultra-sonication for the extract of Sweet Indrajao. It was also found that the enhancement of staining ability was better without mordant draperies. The dye extract showed good antibacterial activity against the three bacterial pathogens. Among the three bacterial pathogens, dye extract showed more effective against Escherichia coli pathogens and dye extract showed more effective against Aspergillus pathogens. Hence, the ultrasonic method of drapery staining may be appropriate and beneficial for society at large in future.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110118
Author(s):  
Zenan Chu ◽  
Tao Wang ◽  
Qiang He ◽  
Kai Zhao

To solve the problems of low processing efficiency and poor glass surface quality when using rare earth polishing powder to grind super-hard K9 glass. The potential, phase structure, surface morphology, and particle size distribution of the nano-rare earth polishing powder were characterized. Compare the evaluation indexes such as polishing efficiency, surface morphology, and contact angle after the polishing process is changed. The results of the comparative study show that the average surface roughness of the glass after heating ultrasonic polishing process is 0.9064 nm, the polishing rate reaches 0.748 μm/min, the average surface roughness of the glass without heating ultrasonic polishing process is 1.3175 nm, and the polishing rate reaches 0.586 μm/min, the ultrasonic assisted polishing process is superior to the conventional polishing process. The heating ultrasonic method provides experimental basis for precise and rapid processing.


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