The Determination of Flash Temperature in Intermittent Magnetic Head/Disk Contacts Using Magnetoresistive Heads: Part I—Model and Laser Simulation

1993 ◽  
Vol 115 (1) ◽  
pp. 170-178 ◽  
Author(s):  
Yufeng Li ◽  
Aric R. Kumaran
Keyword(s):  
Theoretical Model ◽  
Temperature Response ◽  
Sensitivity Coefficient ◽  
Flash Temperature ◽  
Magnetic Head ◽  
Response Characteristics ◽  
Power Intensity ◽  
Magnetoresistive Sensor ◽  
Laser Simulation ◽  
Magnetoresistive Heads

The feasibility of using a magnetoresistive magnetic head to determine the flash temperature of intermittent magnetic head/disk contacts is investigated. A finite difference model is developed to study the effects of the magnetoresistive sensor height, the contact power intensity and the contact duration on the temperature response characteristics of the magnetoresistive sensor. A pulsed neody-minum:yttrium-aluminum-garnet laser is used as the heat source to simulate the contact and verify the model. The simulation results agree well with the theoretical model. Based on the theoretical model and laser simulation, a temperature sensitivity coefficient ζ is proposed to determine the surface temperature rise.

The Determination of Flash Temperature in Intermittent Magnetic Head/Disk Contacts Using Magnetoresistive Heads: Part II—Experimental Investigation

1993 ◽  
Vol 115 (1) ◽  
pp. 179-184 ◽  
Author(s):  
Yufeng Li ◽  
Aric R. Kumaran
Keyword(s):  
Experimental Investigation ◽  
Temperature Sensitivity ◽  
Radial Direction ◽  
Flash Temperature ◽  
Magnetic Head ◽  
Magnetoresistive Sensor ◽  
Magnetoresistive Heads ◽  
Transient Contact ◽  
Spinning Speed

The flash temperature during intermittent head/disk contacts was measured using specially fabricated magnetoresistive heads. Microasperities were intentionally created on disk substrates, and ZrO2 was sputtered on disc surfaces as overcoat. It was found that with a disk spinning speed of 20 m/s, flash temperature could reach 50 to 100°C for transient contact (head was moving in disk radial direction), but less than 40°C for dwell on track contact (head was stationary). The contact times were in the range from submicroseconds to several microseconds, contact widths on the order of several micrometers, and temperature sensitivity coefficients in the range from 0.15 to 0.7 for a 2.5–μ high magnetoresistive sensor.

Study on characteristics of schottky temperature detector based on metal/n-ZnO/n-Si structures

2020 ◽  
Vol 12 ◽  
Author(s):  
Fang Wang ◽  
Jingkai Wei ◽  
Caixia Guo ◽  
Tao Ma ◽  
Linqing Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Measurement ◽  
Temperature Response ◽  
Large Temperature ◽  
Mems Devices ◽  
Temperature Range ◽  
Response Characteristics ◽  
High Temperature Measurement ◽  
Temperature Detector ◽  
Schottky Structure

Background: At present, the main problems of Micro-Electro-Mechanical Systems (MEMS) temperature detector focus on the narrow range of temperature detection, difficulty of the high temperature measurement. Besides, MEMS devices have different response characteristics for various surrounding temperature in the petrochemical and metallurgy application fields with high-temperature and harsh conditions. To evaluate the performance stability of the hightemperature MEMS devices, the real-time temperature measurement is necessary. Objective: A schottky temperature detector based on the metal/n-ZnO/n-Si structures is designed to measure high temperature (523~873K) for the high-temperature MEMS devices with large temperature range. Method: By using the finite element method (FEM), three different work function metals (Cu, Ni and Pt) contact with the n-ZnO are investigated to realize Schottky. At room temperature (298K) and high temperature (523~873K), the current densities with various bias voltages (J-V) are studied. Results: The simulation results show that the high temperature response power consumption of three schottky detectors of Cu, Ni and Pt decreases successively, which are 1.16 mW, 63.63 μW and 0.14 μW. The response temperature sensitivities of 6.35 μA/K, 0.78 μA/K, and 2.29 nA/K are achieved. Conclusion: The Cu/n-ZnO/n-Si schottky structure could be used as a high temperature detector (523~873K) for the hightemperature MEMS devices. It has a large temperature range (350K) and a high response sensitivity is 6.35 μA/K. Compared with traditional devices, the Cu/n-ZnO/n-Si Schottky structure based temperature detector has a low energy consumption of 1.16 mW, which has potential applications in the high-temperature measurement of the MEMS devices.

Thermocouple Response Characteristics in Deflagrating Low-Conductivity Materials

1971 ◽  
Vol 93 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Nam P. Suh ◽  
C. L. Tsai
Keyword(s):  
Theoretical Model ◽  
Gas Phase ◽  
Wire Diameter ◽  
Solid Propellants ◽  
Optimum Ratio ◽  
Response Characteristics ◽  
Bead Diameter ◽  
Double Base ◽  
Theoretical Results ◽  
Good Agreement

The transient thermocouple response characteristics in deflagrating low-conductivity materials with high temperature gradients were investigated theoretically and experimentally. The theoretical model considers the thermocouple bead and lead wires separately, and the two resulting partial differential equations are solved simultaneously by a finite difference technique. The experimental results are obtained by embedding various size thermocouple wires in double-base solid propellants and consequently measuring the temperature profiles and the surface temperatures. The theoretical model is used to predict the experimentally measured temperatures. There is good agreement. The experimentally measured values are smaller than the correct surface temperature, corresponding to the model prediction for zero wire diameter, by at least 20 percent even when 1/2-mil thermocouple wire is used. Both the experimental and theoretical results show a plateau when the thermocouple bead emerges from the solid into the gas phase. The theoretical results also show that there is an optimum ratio of. the thermocouple bead diameter to the wire diameter, which is found to be close to three

scholarly journals Experimental Study on Temperature Response Characteristics of Water-bearing Rock Mass during Mining

2013 ◽  
Vol 129 (7) ◽  
pp. 506-512
Author(s):  
Yang GAO ◽  
Yujing JIANG ◽  
Qingsong ZHANG ◽  
Bo LI ◽  
Lei YANG
Keyword(s):  
Experimental Study ◽  
Rock Mass ◽  
Temperature Response ◽  
Response Characteristics

scholarly journals Temperature response characteristics of enzyme thermistor using precisely thermostated bath.

1988 ◽  
Vol 14 (5) ◽  
pp. 695-698
Author(s):  
Noriaki Kaneki ◽  
Hiromitsu Sakai ◽  
Kennosuke Yokota ◽  
Takao Takeuchi ◽  
Koji Shimada ◽  
...  
Keyword(s):  
Temperature Response ◽  
Response Characteristics ◽  
Enzyme Thermistor

Theoretical Model for Lateral Inhibitory Interaction in the Human Retina

1969 ◽  
Vol 28 (1) ◽  
pp. 119-142 ◽  
Author(s):  
Willard L. Brigner
Keyword(s):  
Theoretical Model ◽  
Receptive Field ◽  
Horizontal Cell ◽  
Angular Size ◽  
Brightness Contrast ◽  
Human Retina ◽  
Inhibitory Interaction ◽  
Systematic Account ◽  
Response Characteristics ◽  
Simultaneous Brightness Contrast

Several models for lateral inhibitory interaction are available in the literature; however, these models are deficient in providing a systematic account of simultaneous brightness contrast for one or several of the following reasons: (1) no rational basis is presented for phenomenal black; (2) the mediation of lateral inhibitory interaction is generally attributed to the horizontal cells of the human retina, but there is no neuroanatomical evidence that the horizontal cell is present in the central-most fovea, although there is psychophysical evidence that lateral inhibitory interaction occurs in the central-most fovea; (3) the response characteristics of the receptive field have not been conceptually integrated into the models despite general theoretical agreement that the receptive field organization is meaningful for simultaneous brightness contrast. These deficiencies have prompted the development of the theoretical model presented here. In addition to integrating the foregoing empirical aspects of simultaneous brightness contrast, the model predicts that the magnitude of perceived brightness contrast will be greater at a corner than along an edge. Empirical data consistent with this prediction are presented. A further prediction that the perceived magnitude of brightness contrast will increase as the angular size of the corner decreases is tested. In a theoretical analysis, an approximation to the experimental results is obtained when contrast effects due both to the predicted effect of angle size and the well known effect of inducing-field area are considered.

Magnetic Head-Media Interface Temperatures: Part 1—Analysis

1987 ◽  
Vol 109 (2) ◽  
pp. 243-251 ◽  
Author(s):  
B. Bhushan
Keyword(s):  
The Other ◽  
Temperature History ◽  
Asperity Contact ◽  
Thermal Interaction ◽  
Flash Temperature ◽  
Magnetic Head ◽  
Temperature Variations ◽  
Sliding Surfaces ◽  
Basic Model ◽  
Asperity Contacts

A “generalized” thermal analysis is described to estimate the flash temperature during sliding when both surfaces are of more or less equal roughness or one surface is substantially smoother than the other. High- and low-speed cases are considered. The basic model includes surface-topography statistics, frictional conditions, and mechanical and thermal parameters. Temperature history during the life of an individual asperity contact is calculated, from which average temperatures of an asperity contact are calculated. Thermal interaction of neighboring asperity contacts is considered. Then, an analysis is presented to show how individual asperity temperatures should be averaged. Temperature variations perpendicular to the sliding surfaces are also analyzed. Throughout the analysis, closed-form equations are developed, which can be conveniently used in the design of any sliding interface.

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