Thermal Aspects of Grinding: The Case of Upgrinding

1999 ◽  
Vol 122 (4) ◽  
pp. 605-611 ◽  
Author(s):  
Marios D. Demetriou ◽  
Adrienne S. Lavine
Keyword(s):  
Experimental Data ◽  
Heat Generation ◽  
Opposite Direction ◽  
Thermal Model ◽  
Reasonable Agreement ◽  
Workpiece Temperature ◽  
Conventional Grinding

Conventional grinding is usually carried out in upgrinding mode, with the wheel moving in the opposite direction from the workpiece. In this paper, a thermal model is developed for upgrinding. This model is similar to our previous models of downgrinding in that the behavior of the workpiece, grains, fluid, and chips are all coupled. The model is used to compare the workpiece temperature rises in upgrinding and downgrinding, and to explore the effect of the location of heat generation. The model results are also compared with experimental data and are seen to yield reasonable agreement. Finally, the sensitivity of the results to some parameters which are not well known is explored. [S1087-1357(00)01002-9]

Heat Generation in Thermoplastic Spur Gears

1985 ◽  
Vol 107 (1) ◽  
pp. 31-36 ◽  
Author(s):  
D. Koffi ◽  
R. Gauvin ◽  
H. Yelle
Keyword(s):  
Heat Generation ◽  
Reasonable Agreement ◽  
Simplified Model ◽  
Temperature Sensitive ◽  
Spur Gears ◽  
Theoretical Line ◽  
Usual Case

Since thermoplastics are temperature-sensitive materials, heat generation in running spur gears is an important parameter. This paper presents two models for its evaluation, an exact one which considers all the parameters but needs a computer to solve the equations; then a simplified model. Both models take into account the contact outside the theoretical line of action which is the usual case with thermoplastic gears. Results for the simplified model are within reasonable agreement with the exact one.

Numerical Simulations as a Reliable Alternative for Landmine Explosion Studies: The AUTODYN Approach

2010 ◽  
Author(s):  
Stephanie Follett ◽  
Amer Hameed ◽  
S. Darina ◽  
John G. Hetherington
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Reasonable Agreement ◽  
Specific Impulse ◽  
Numerical Procedure ◽  
Ground Surface ◽  
Time Of Arrival ◽  
Linear Dynamics ◽  
Non Linear

In order to validate the numerical procedure, the explosion of a mine was recreated within the non-linear dynamics software, AUTODYN. Two models were created and analysed for the purposes of this study — buried and flush HE charge in sand. The explosion parameters — time of arrival, maximum overpressure and specific impulse were recorded at two stand-off distances above the ground surface. These parameters are then compared with LS-DYNA models and published experimental data. The results, presented in table format, are in reasonable agreement.

Thermal Model of a Thinned-Die Cooling System

2003 ◽  
Author(s):  
N. Boiadjieva ◽  
P. Koev
Keyword(s):  
Experimental Data ◽  
Thermal Model ◽  
Cooling System ◽  
Input Power ◽  
The Other ◽  
System Parameters ◽  
Air Intake ◽  
Optical Probing ◽  
Cooling Air ◽  
Better Than

For through-silicon optical probing of microprocessors, the heat generated by devices with power over 100W must be dissipated [1]. To accommodate optical probing, a seemingly elaborate cooling system that controls the microprocessor temperature from 60 to 100° C for device power up to 150W was designed [2]. The system parameters to achieve the desired thermal debug environment were cooling air temperature and air flow. A mathematical model was developed to determine both device temperature and input power. The 3-D heat equation that governs the temperature distribution was simplified to a case of a 1-D rod with one end at the device center and the other at the cooling air intake. Thus the cooling system was reduced to an analytical expression. From experimental data, we computed all coefficients in the model, then ran extensive tests to verify—the accuracy was better than 10% over the entire temperature and power ranges.

The thermodynamic properties of mixed phospholipid bilayers: a theoretical analysis

1984 ◽  
Vol 62 (8) ◽  
pp. 796-802 ◽  
Author(s):  
Maryse Mondat ◽  
A. Georgallas ◽  
D. A. Pink ◽  
M. J. Zuckermann
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Reasonable Agreement ◽  
Phospholipid Bilayers ◽  
Scanning Calorimetry ◽  
Phase Separations ◽  
Lipid Mixtures ◽  
Wide Range ◽  
Acyl Chains ◽  
Gel Phase

A theoretical model is presented with the intention of describing lateral phase separations in binary lipid mixtures in which the acyl chains of the components differ in their length. The model includes explicitly interactions between the acyl chains and between polar heads of the lipid molecules. Phase diagrams and thermodynamic properties of binary lipid mixtures were calculated using a wide range of interaction parameters. It is shown that the occurrence of immiscibility in the gel phase is related to the interactions between the polar heads of the lipid molecules. The calculated results for binary lipid mixtures are compared with the available experimental data. In particular, the calculated specific heat for dilauroyl phosphatidylcholine – distearoyl phosphatidylcholine is in reasonable agreement with experimental results obtained from differential scanning calorimetry measurements.

scholarly journals Spectral Fourier-microscopy of the periodic structures based on Ge2Sb2Te5

2021 ◽  
Vol 2103 (1) ◽  
pp. 012173
Author(s):  
A I Solomonov ◽  
S I Pavlov ◽  
P I Lazarenko ◽  
V V Kovalyuk ◽  
A D Golikov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Reasonable Agreement ◽  
Angular Resolution ◽  
Periodic Structures ◽  
Diffraction Gratings ◽  
Dispersion Curves ◽  
Reflection Spectra ◽  
Waveguide Modes ◽  
Periodic Gratings

Abstract The method of spectral Fourier microscopy was used to study the reflection spectra with an angular resolution of submicron periodic gratings based on amorphous and crystalline Ge2Sb2Te5. The form of the dispersion curves of quasi-waveguide modes in the structures under study was established. The experimental data were compared with the calculations of dispersion curves in synthesized diffraction gratings. Reasonable agreement between theoretical and experimental data was obtained.

Dynamical Theory for Simultaneous X-Ray Diffraction

1966 ◽  
Vol 10 ◽  
pp. 67-79
Author(s):  
P. Penning
Keyword(s):  
Experimental Data ◽  
Plane Wave ◽  
Quantitative Data ◽  
Reasonable Agreement ◽  
Dynamical Theory ◽  
Inversion Symmetry ◽  
Surprising Result ◽  
X Ray Diffraction ◽  
Wave Fields ◽  
X Ray

AbstractComplete dynamical solutions for three coupled plane-wave components in crystal structures with inversion symmetry have been found. After reviewing briefly the dynamical solutions for wave fields with two coupled plane-wave components, the results for the three-beam case are discussed in qualitative terms. Attention is paid to singular points and lines on the ω-surface, and to the attenuation of the mode-intensity because of absorption. The most surprising result is that in the case one of the reflections is forbidden (Umweganregung) the absorption is reduced in comparison with the adjoining two-beam cases. Experimental data are in reasonable agreement with the theory. Quantitative data are presented for a few three-beam cases of simultaneous diffraction of Cu Kα. radiation in germanium.

Thermal Modeling and Luminosity Characterization of a Plasma Display Panel

2007 ◽  
Author(s):  
Jeffry Kahn ◽  
Avram Bar-Cohen
Keyword(s):  
Heat Generation ◽  
Thermal Model ◽  
Temporal Variations ◽  
High Definition ◽  
3 Dimensional ◽  
Beneficial Effects ◽  
Large Size ◽  
Plasma Display ◽  
Graphite Heat ◽  
Color Analyzer

Plasma Display Panels (PDPs) are a popular technology for large size television displays. Screen inefficiencies, which result in significant localized heat generation, necessitate the use of advanced thermal management materials to reduce both the peak temperatures and the spatial temperature variations across the screen. In the current study, infrared thermography was used to obtain thermal maps of a typical, 42", high-definition PDP screen for different illumination patterns and for several configurations of externally controlled heaters, simulating PDP heat generation. The results were used to validate a 3-dimensional numerical thermal model of the PDP which was then used to predict the beneficial effects of anisotropic graphite heat spreaders on the temperature distribution of the PDP. In addition, a color analyzer was used to determine the spatial and temporal variations in luminosity across the PDP when operated continuously for 1750 hours with different illumination patterns. The thermal model and experimental luminosity characteristics are used to evaluate the deleterious effects of temperature on PDP performance.

The Thermal Emission of Iodine

1974 ◽  
Vol 52 (19) ◽  
pp. 1862-1871
Author(s):  
J. David Brown ◽  
George Burns
Keyword(s):  
Experimental Data ◽  
Shock Wave ◽  
Temperature Dependence ◽  
Electronic State ◽  
Reasonable Agreement ◽  
Thermal Emission ◽  
Electronic States ◽  
Excited Electronic States ◽  
Calculated Temperature ◽  
Calculated Temperature Dependence

The temperature dependence of emission from iodine, heated in a shock wave to 1000 K–2000 K, has been measured at 4550, 5550, 6950, 7550, and 7820 Å. Preliminary measurements of the emission at 6380 Å were also made. The temperature dependence of the emission was calculated at these wavelengths for transitions to the ground electronic state X(1Σg+) of iodine from the excited electronic states, A(3Π1u), (1Π1u), and [Formula: see text]. The calculated results are in a reasonable agreement with experimental data. For the banded emission due to the B → X transition, a theory of the temperature dependence of emission was developed. At 6950, 7550, and 7820 Å, the results of this theory agree with the experimental data thus identifying the B → X transition as the source of emission at these wavelengths. The temperature dependence of emission at 4550 Å is consistent with calculated temperature dependence for either (1Π1u) → X or [Formula: see text] transitions. The temperature dependence of the emission at 5550 Å is consistent with calculated temperature dependence for the above two transitions, as well as for the A(3Π1u) → X transition.

STUDIES OF THE LOCAL STRUCTURE AND THE g FACTORS FOR THE ORTHORHOMBICTi3+CENTER IN YAP

2007 ◽  
Vol 21 (12) ◽  
pp. 737-743 ◽  
Author(s):  
JI-ZI LIN ◽  
SHAO-YI WU ◽  
QIANG FU ◽  
HUA-MING ZHANG
Keyword(s):  
Experimental Data ◽  
Local Structure ◽  
Reasonable Agreement ◽  
Orthorhombic Symmetry ◽  
Cluster Approach ◽  
Orthorhombic Distortion ◽  
Large Anisotropy ◽  
G Factors

The local structure and the g factors for the orthorhombic Ti3+center in YAP are theoretically studied from the perturbation formulas of the g factors gx, gyand gzfor a 3d1ion in orthorhombic symmetry based on the cluster approach. The observed large anisotropy of the g factors may be attributed to the significant low-symmetrical (tetragonal and orthorhombic) distortion near the Al3+site occupied by the impurity Ti3+. The calculated g factors in this work show reasonable agreement with the experimental data.

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