Diphosphate coatings for protection of galvanized steel: quality control by impedance measurements

1984 ◽  
Vol 14 (4) ◽  
pp. 537-545 ◽  
Author(s):  
A. Jardy ◽  
R. Rosset ◽  
R. Wiart
Keyword(s):  
Quality Control ◽  
Galvanized Steel ◽  
Impedance Measurements ◽  
Steel Quality

scholarly journals Steel quality of rolling contact bearings produced by different manufacturers, used for mining equipment instrumentation

2021 ◽  
Vol 315 ◽  
pp. 03019
Author(s):  
Aleksandr Korotkov ◽  
Lidiya Korotkova ◽  
Stefan Voeth ◽  
Roman Solentsov
Keyword(s):  
Quality Control ◽  
Negative Impact ◽  
Bearing Steel ◽  
Operating Conditions ◽  
Rolling Contact ◽  
Mining Equipment ◽  
Operating Life ◽  
Premature Failure ◽  
Steel Quality

Severe operating conditions of mining equipment have a negative impact on the operating life of the rolling contact bearings used in such equipment. The main reasons for the premature failure of rolling contact bearings include, first of all, poor quality of the bearing steel as delivered and the defects of their subsequent heat treatment. The abovementioned reasons result in splitting of bearings, metal shelling and appearance of potholes on their tracks, as well as intense abrasive wear. Nevertheless, despite the importance of this issue, the quality of bearing steel, either as delivered or in finished bearings, is usually not under control.To solve this problem, the quality of bearing steel was studied, exemplified by the bearings of the Russian, Swedish (SKF) and Japanese (NSK) manufacturers, i.e., main suppliers of rolling contact bearings for mining equipment in Russia. The problem of bearing steel quality control was solved by developing a quality control methodology that took into account the state of the metal after metallurgical treatment and at the stage of bearing production. Based on this methodology, the main types of bearing steel defects affecting the mechanism of bearing failure are identified.It is found that the bearing steel quality of domestic manufacturers is highly competitive with foreign counterparts. A method of nondestructive control is also proposed for detecting possible microstructure defects in bearings, either as delivered or while in operation.

Quality Control of Silicone Hydrogel Contact Lenses by Impedance Spectroscopy

2014 ◽  
Vol 1626 ◽  
Author(s):  
M. Torres ◽  
K.S.V. Santhanam
Keyword(s):  
Quality Control ◽  
Phase Angle ◽  
Contact Lens ◽  
Contact Lenses ◽  
Electrochemical Impedance ◽  
Spectroscopic Method ◽  
Impedance Change ◽  
Impedance Measurements ◽  
Silicone Hydrogel ◽  
Silicone Hydrogels

ABSTRACTWe wish to propose an impedance spectroscopic method for the quality control of contact lenses by measuring the pore resistance. Silicone hydrogels are excellent materials for use as contact lenses and their on eye performance is dependent on salt intrusion characteristics which are related to the pore resistance and water uptake. When the contact lenses are placed on the eye, they are expected to permeate ions and molecules to maintain ocular health. The hydrogel pores control the permeability and can be viewed as a quality control parameter. Two models are considered here: in one, the contact lenses are considered as strong rigid films with no permeability. In another, the hydrogels are having ionic permeability. We designed a silicone hydrogel contact lens attachment holder that is amenable for electrochemical impedance measurements. The electrochemical impedance measurements were carried out in an inert medium of 0.1 M Na2SO4. The impedance measurement experimental parameters used were a) AC potential 10 mV rms b) frequency range 0.1-210 kHz and c) open circuit potential of 0.207 V. The impedance variation with frequency was constructed for a number of hydrogels. The ideally acceptable silicone hydrogel contact lenses showed an impedance change with frequency in a sigmoidal fashion with a characteristic phase angle (acceptable in the range of 70-75o). The hydrogel pore resistances for the acceptable contact lenses are in the range of 4.5-11 kΩ. When the impedance showed a linear decrease or no well defined phase angle, the contact lens is considered acting as an insulator-a test for rejection. A test of the model was done with several acceptable contact lenses in the market. This study revealed interesting aspects of the influence of pulsating electric field on the silicone hydrogels.

Digitization Possibilities for Steel Quality Control Using the Structure of Fracture

2021 ◽  
Vol 2021 (12) ◽  
pp. 1619-1624
Author(s):  
A. V. Kudrya ◽  
E. A. Sokolovskaya ◽  
V. P. Tang ◽  
M. I. Sergeyev
Keyword(s):  
Quality Control ◽  
Steel Quality

Steel quality control using the ARL quantometer

JOM ◽  
1958 ◽  
Vol 10 (12) ◽  
pp. 815-816
Author(s):  
H. C. Brown
Keyword(s):  
Quality Control ◽  
Steel Quality

Health communication ethics and CDC quality-control guidelines for information

2003 ◽  
Vol 118 (3) ◽  
pp. 193-196 ◽  
Author(s):  
Jeffrey W McKenna ◽  
Terry F Pechacek ◽  
Donna F Stroup
Keyword(s):  
Quality Control ◽  
Health Communication ◽  
Communication Ethics
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