Thermal Asperities Sensitivity to Particles: Methodology and Test Results

2000 ◽  
Vol 123 (2) ◽  
pp. 376-379
Author(s):  
Larry Y. Wang ◽  
Mike Sullivan ◽  
Jim Chao
Keyword(s):  
Giant Magnetoresistance ◽  
Disk Drive ◽  
Test System ◽  
Test Method ◽  
Aluminum Silicate ◽  
Disk Interface ◽  
Carbon Overcoats ◽  
Sensor Temperature ◽  
Sensitivity Data ◽  
Read Signal

Thermal asperities (TA’s) are tribological events that cause repercussions for giant magnetoresistance (GMR) and MR heads in the hard disk drive industry. A TA is a read signal spike caused by sensor temperature rise due to contact with disk asperities or contaminant particles. TA events may cause GMR and MR heads to temporarily lose their reading capability, and may potentially damage the transducer. It is difficult to completely avoid particle contamination in hard drive applications. Hence it is necessary to design heads/media with a minimum TA sensitivity to particles. A test method for TA sensitivity to particles is needed. This work developed a test method for TA sensitivities to particles. The test system includes a CSS tester with TA detection capability, a chamber to contain the head/disk interface, a particle atomizer, and a particle counter. Aluminum silicate particles used in the test have sizes ranging from 0.2 to 1.0 μm. Particles are injected into the chamber during head scan for TA’s from ID to OD with adjustable air-borne concentrations in the chamber from 10×106 to 30×106particles/m3. TA counts of 30 scans are averaged to obtain reliable TA sensitivity data. Media with different lubricant thickness, different carbon overcoats, and different lubricant types are tested with this method. The results indicated that this methodology can effectively differentiate TA sensitivity to particles for the media studied.

Experimental Study of High-Speed Contact at Head-Disk Interface in a Magnetic Hard Disk

2005 ◽  
Author(s):  
Mingwu Bai ◽  
Stephen M. Hsu
Keyword(s):  
Acoustic Emission ◽  
High Speed ◽  
Hard Disk ◽  
Disk Drive ◽  
Test Method ◽  
Head Disk Interface ◽  
Emission Analysis ◽  
Disk Interface ◽  
Emission Signal ◽  
Carbon Overcoats

Tribological performance of the head-disk interface will have significant impact on the performance and durability of the hard disk drive. A high-speed contact test method has been developed for the purpose of evaluating nanometer-thick lubricant film/carbon overcoats materials on hard-disk surfaces. Four different thickness overcoats were used in high speed contact experiments. High speed contact force was calculated based on the calibration of acoustic emission signal by proposed ball dropping tests. Acoustic emission analysis, frequency spectrum analysis, and surface morphology imaging were used to analyze the deformation and fracture at high speed contacted area. The availability of an experimental technique enables effective screening of different material chemistries and lubricant combinations to improve the level of protection for hard disk technology.

scholarly journals Evaluation of a Preclinical Blood Test for Scrapie in Sheep Using Immunocapillary Electrophoresis

2006 ◽  
Vol 89 (3) ◽  
pp. 720-727 ◽  
Author(s):  
Roy Jackman ◽  
David J Everest ◽  
Mary Jo Schmerr ◽  
Mohammed Khawaja ◽  
Pat Keep ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Prion Protein ◽  
Clinical Signs ◽  
Test System ◽  
Buffy Coat ◽  
Infected Sheep ◽  
Test Method ◽  
Peptide Sequence ◽  
Transmissible Spongiform Encephalopathies ◽  
Blood Samples

Abstract An analytical method is described for detection of endogenous disease-associated prion protein in the buffy coat fraction from the blood of sheep infected with scrapie. The method has been improved and evaluated for its performance in the preclinical diagnosis of ovine transmissible spongiform encephalopathies. The test system uses a protocol for sample preparation that includes extraction and concentration and a test method that uses a liquid-phase competitive immunoassay for prion protein. Antibodies directed to a peptide sequence at the C-terminus of the prion protein (PrP) and a fluorescein-labeled peptide conjugate are used in the assay. Free zone capillary electrophoresis with laser-induced fluorescence for detection is used to separate the antibody-bound fluorescently labeled peptide and free labeled peptide. In this assay, the PrP competes with the fluorescently labeled peptide for limited antibody binding sites, which results in a reduction of the peak representing the immunocomplex of the antibody bound to the fluorescently labeled peptide. When blood samples from scrapie-infected sheep aged 712 months and of the scrapie-susceptible PrP genotypes VRQ/VRQ and VRQ/ARQ were analyzed, the abnormal PrP was found in blood samples. These results correlated with the post-mortem diagnosis of scrapie. The sheep were preclinical and appeared normal at the time of testing but later died with clinical disease approximately 12 months after testing. In older animals, and those with clinical signs, a smaller percentage of animals tested positive. This study has demonstrated that this technology can be used as a sensitive, rapid preclinical test to detect the disease-associated PrP in the blood of scrapie-infected sheep. Improvements in the extraction protocol and capillary electrophoresis conditions will enhance the robustness of this test.

The Research of IC Test Based on LTX-77 Test System

2014 ◽  
Vol 496-500 ◽  
pp. 1176-1179
Author(s):  
Li Tan ◽  
Yu Fang
Keyword(s):  
Test Object ◽  
Test System ◽  
Test Method ◽  
Test Results ◽  
Analog Ic ◽  
Test Platform ◽  
Logic Functions ◽  
Actual Test ◽  
Ic Test

LTX-77 test system is a large IC test system that is used for various kinds of analog IC, digital IC and analog digital mixed IC. It can be used to test DC parameters, AC parameters and logic functions. In the paper, the IC test platform is LTX-77 test system. IC ADC0804 was tested as the test object. The test method of IC is described in the view of actual test. The test results show that the test system is convenient and accurate, which has important practical value for IC manufacturers and users.

Design on Hierarchical Testing System for Unmanned Ground Vehicles

2011 ◽  
Vol 346 ◽  
pp. 817-822 ◽  
Author(s):  
Xin Li ◽  
Guang Ming Xiong ◽  
Yang Sun ◽  
Shao Bin Wu ◽  
Jian Wei Gong ◽  
...  
Keyword(s):  
Evaluation System ◽  
Test System ◽  
Unmanned Vehicles ◽  
Intelligent Vehicles ◽  
Test Method ◽  
Unmanned Ground Vehicles ◽  
Ground Vehicles ◽  
Test Environment ◽  
Test And Evaluation ◽  
Comprehensive Test

The test system for technical abilities of unmanned vehicles is gradually developed from the single test to comprehensive test. The pre-established test and evaluation system can promote the development of unmanned ground vehicles. The 2009 Future Challenge: Intelligent Vehicles and Beyond (FC’09) pushed China's unmanned vehicles out of laboratories. This paper proposed to design a more scientific and comprehensive test system for future competitions to better guide and regulate the development of China's unmanned vehicles. According to the design idea of stage by stage and level by level, the hierarchical test content from simple to advanced, from local to overall is designed. Then the hierarchic test environment is established according to the levels of test content. The test method based on multi-platform and multi-sensor is put forward to ensure the accuracy of test results. The testing criterion framework is set up to regulate future unmanned vehicle contests and to assess the unmanned vehicles scientifically and accurately.

Plant Constituents Interfering with Human Sex Hormone-Binding Globulin. Evaluation of a Test Method and Its Application to Urtica dioica Root Extracts

1995 ◽  
Vol 50 (1-2) ◽  
pp. 98-104 ◽  
Author(s):  
Dietmar Ganßer ◽  
Gerhard Spiteller
Keyword(s):  
Test System ◽  
Binding Activity ◽  
Urtica Dioica ◽  
Sex Hormone ◽  
Test Method ◽  
Sex Hormone Binding Globulin ◽  
Hormone Binding ◽  
Root Extracts ◽  
Plant Constituents ◽  
Octadecenoic Acids

Abstract A test system is described, which allows the search for compounds interfering with human sex hormone-binding globulin (SHBG) even in complex plant extracts. The method has been evaluated and applied to Urtica dioica root extracts. The lignan secoisolariciresinol (5) as well as a mixture of isomeric (11 E)-9,10,13-trihydroxy-11-octadecenoic and (10 E)-9 ,12,13-trihydroxy-10-octadecenoic acids (3 and 4, resp.) were demonstrated to reduce binding activity of human SHBG. Methylation of the mixture of 3 and 4 increased its activity about 10-fold.

Research on a Test Method of Dynamic Force of Jet Elements

2014 ◽  
Vol 574 ◽  
pp. 154-159 ◽  
Author(s):  
Zhong Yang ◽  
Xiao Xian Yao ◽  
Dong Xu Zhang
Keyword(s):  
Delay Time ◽  
Simple Structure ◽  
Mathematic Model ◽  
Test System ◽  
Processing Method ◽  
Test Method ◽  
Dynamic Force ◽  
Simple Method ◽  
Pendulum Test ◽  
Testing Condition

According to the characteristics of the dynamic force of jet elements, a kind of simple pendulum test system was presented. The dynamic jet force value was obtained indirectly by the acceleration value of the jet element under its force. The mathematic model of the test system was established and the test errors of the amplitude and delay time were analyzed. A processing method of dynamic force test data was presented based on the test curve and the parameters of amplitude and delay time were obtained. The result indicates that the test method can satisfy the testing requirements of dynamic force and it has advantages of simple structure, low demands of testing condition and simple method of data processing.

The Improved Friction Properties of Bonded MoS2 Films by MAO Treating of Al Substrate

2013 ◽  
Vol 275-277 ◽  
pp. 1911-1914 ◽  
Author(s):  
Han Jun Hu ◽  
Hui Zhou ◽  
Yu Gang Zheng ◽  
Kai Feng Zhang ◽  
Zhi Hua Wan
Keyword(s):  
Tribological Properties ◽  
Solid Lubricants ◽  
Ceramic Coatings ◽  
Test System ◽  
Test Method ◽  
Test Results ◽  
Specimen Test ◽  
Micro Arc Oxidation ◽  
A New Technique ◽  
Porous Microstructures

The bonded MoS2 films are widely used as solid lubricants in aerospace mechanisms due to their excellent tribological properties. Traditionally, the MoS2 was directly bonded on the Al substrate that was only treated by the technique named of sandblast. For improving the tribological properties of MoS2 films, micro arc oxidation (MAO) instead of sandblast was introduced as a new technique for treating of Al substrate. In this article, the tribological properties of MoS2 films which were bonded on different surface of Al substrate as mentioned above were discussed, respectively. It was concluded from the test results that the MoS2 films bonded on substrate treated by MAO have better tribological properties than those samples treated by sandblast. The endurance life against abrasion of the former is as high as twenty times of the latter by the stand test method of ball on disk using the UMT Multi-Specimen Test System. This test results could be illustrated by the following reasons. The first is the porous microstructures of MAO ceramic coatings on the Al substrate. The coatings have numerous pits to be good at increasing the binding force with the MoS2 films, and the pits can also provide a MoS2 lubricants reservoir during processes of friction. Both of them improved the MoS2 film’s ability of wear-protective. The second is that hardness of the coating is higher than the Al, and this ensures well wearing resistance, especially in practical application to big load-supporting moving parts, such as bearing, gear, etc…

A Comprehensive Test System for Precision Transmission Performance of CORT Reducer

2013 ◽  
Vol 333-335 ◽  
pp. 2448-2451
Author(s):  
Yong Li ◽  
Guang Ma ◽  
Yun De Shen ◽  
Tai Hong Cheng ◽  
Zhen Zhe Li ◽  
...  
Keyword(s):  
Performance Test ◽  
Velocity Ratio ◽  
Test System ◽  
Test Method ◽  
Transmission Performance ◽  
Test Bed ◽  
Comprehensive Test ◽  
Return Difference ◽  
And Control ◽  
Torque Angle

To meet the needs of test for compound oscillatory roller transmission (CORT) reducer, A comprehensive test system for precision transmission performance was designed, the test-bed structure and control principal of which were introduced. First, a transmission performance test method was proposed and focused on the transmission performance of velocity ratio, accuracy, and efficiency. Then, user interface based on LabVIEW program was designed, and the transmission performance of torque, angle, velocity, velocity ratio, return difference, efficiency could be displayed. Finally, measurement example on an E80 type CORT reducer has been made, and shows that the proposed test system is suitable for test for these reducers of high-precision drive, high stiffness, high load characteristics.

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