scholarly journals Elastic Properties of a Polyimide Film Determined by Brillouin Scattering and Mechanical Techniques

1993 ◽  
Vol 308 ◽  
Author(s):  
R. Sai Kumar ◽  
Ivan K. Schuller ◽  
Sudha S. Kumar ◽  
A. Fartash ◽  
M. Grimsditch
Keyword(s):  
Elastic Properties ◽  
Brillouin Scattering ◽  
Direct Determination ◽  
Polyimide Film ◽  
Complete Characterization ◽  
Elastic Behavior ◽  
Complete Determination ◽  
Vibrating Membrane

ABSTRACTWe discuss here the complete determination of the elastic properties of a polyimide film using two experimental techniques. One technique employs the polymer film as a vibrating membrane and allows a direct determination of the ’macroscopic’ biaxial modulus. Brillouin scattering, which measures the elastic properties on a ∼ 100 μ scale, allows for a complete characterization of the elastic behavior. The results obtained by the two techniques are in agreement within the reported error bars.

Photoluminescence Excitation Spectroscopy of Carbon-Doped Gallium Nitride

1998 ◽  
Vol 537 ◽  
Author(s):  
E. E. Reuter ◽  
R. Zhang ◽  
T. F. Kuech ◽  
S. G. Bishop
Keyword(s):  
Complete Characterization ◽  
Photoluminescence Excitation ◽  
Yellow Luminescence ◽  
Broad Excitation Band ◽  
Carbon Doped ◽  
Sapphire Substrates ◽  
Red Luminescence ◽  
Unusual Shape

AbstractWe have done a comparative study of carbon-doped GaN and undoped GaN utilizing photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies in order to investigate deep levels involved in yellow luminescence (YL) and red luminescence (RL). When the GaN was excited by above-bandgap light, red luminescence (RL) centered at 1.82 eV was the dominant below-gap PL from undoped GaN, but carbon-doped GaN below-gap PL was dominated by yellow luminescence (YL) centered at 2.2 eV. When exciting PL below the band-gap with 2.4 eV light, undoped GaN had a RL peak centered at 1.5 eV and carbon-doped GaN had a RL peak centered at 1.65 eV. PLE spectra of carbon-doped GaN, detecting at 1.56 eV, exhibited a strong, broad excitation band extending from about 2.1 to 2.8 eV with an unusual shape that may be due to two or more overlapping excitation bands. This RL PLE band was not observed in undoped GaN. We also demonstrate that PL spectra excited by below gap light in GaN films on sapphire substrates are readily contaminated by 1.6-1.8 eV and 2.1-2.5 eV chromium-related emission from the substrate. A complete characterization of the Cr emission and excitation bands for sapphire substrates enables the determination of the excitation and detection wavelengths required to obtain GaN PL and PLE spectra that are free of contributions from substrate emission.

scholarly journals Complete characterization of the 3p Rydberg complex of a molecular ion: MgAr+. I. Observation of the Mg(3pσ)Ar+ B+ state and determination of its structure and dynamics

2020 ◽  
Vol 153 (7) ◽  
pp. 074310 ◽  
Author(s):  
Dominik Wehrli ◽  
Matthieu Génévriez ◽  
Stefan Knecht ◽  
Markus Reiher ◽  
Frédéric Merkt
Keyword(s):  
Complete Characterization ◽  
Molecular Ion ◽  
Structure And Dynamics

Instrumentation for wet steam

2004 ◽  
Vol 218 (8) ◽  
pp. 811-842 ◽  
Author(s):  
A Kleitz ◽  
J M Dorey
Keyword(s):  
Liquid Phase ◽  
Liquid Film ◽  
Direct Determination ◽  
Dispersed Phase ◽  
Wet Steam ◽  
Turbine Performance ◽  
Chemical Measurements ◽  
Formation And Evolution

This paper is devoted to the measuring methods and instrumentation used in the wet-steam area for both aerodynamics measurements (pressure, temperature and velocity) taking into account the interaction between the vapour and the liquid phase, and the characterization of the liquid phase itself (dispersed phase and liquid film). The development of suitable instrumentation is an important part in understanding the formation and evolution of the liquid phase but is now more and more oriented towards practical industrial concerns, such as the direct determination of turbine performance by measuring exhaust wetness or chemical measurements relating to erosion in the transition zone inside the turbine. Emphasis has been given to techniques suitable for use in actual turbines.

Sensor Placement for Angular Velocity Determination

2005 ◽  
Vol 128 (3) ◽  
pp. 543-547 ◽  
Author(s):  
Guy M. Genin ◽  
Joseph Genin
Keyword(s):  
Angular Velocity ◽  
Rigid Body ◽  
Velocity Vector ◽  
Constraint Equation ◽  
Complete Characterization ◽  
Angular Velocity Vector ◽  
Algebraic Constraint ◽  
Transducer Placement

Velocity transducer placement to uniquely determine the angular velocity of a rigid body is investigated. The angular velocity of a rigid body can be determined with no fewer than five properly placed velocity transducers, if no other types of sensors are present and no algebraic constraint equation involving the angular velocity vector can be written. Complete characterization of the velocity of a rigid body requires six transducers. Choice of transducer placement and orientation requires care, as suboptimal transducer placement can result in data from which the determination of a unique angular velocity vector is impossible. Conditions for successful transducer placement are established, and two examples of adequate transducer placement are presented: an Earth-penetrating projectile, and a bioengineering device for the measurement of head motion.

scholarly journals Isometric and Closed-Range Composition Operators between Bloch-Type Spaces

2011 ◽  
Vol 2011 ◽  
pp. 1-15
Author(s):  
Nina Zorboska
Keyword(s):  
Holomorphic Function ◽  
Composition Operators ◽  
Function Spaces ◽  
Complete Characterization ◽  
Closed Range ◽  
Different Types ◽  
Type Spaces ◽  
Range Determination

We present an overview of the known results describing the isometric and closed-range composition operators on different types of holomorphic function spaces. We add new results and give a complete characterization of the isometric univalently induced composition operators acting between Bloch-type spaces. We also add few results on the closed-range determination of composition operators on Bloch-type spaces and present the problems that are still open.

Simultaneous Determination of E, G and ν of Soft Hydrogels Using Theory of Elasticity

2009 ◽  
Author(s):  
Uday Chippada ◽  
Xue Jiang ◽  
Lulu Li ◽  
Rene Schloss ◽  
Bernard Yurke ◽  
...  
Keyword(s):  
Poisson’S Ratio ◽  
Theory Of Elasticity ◽  
Complete Characterization ◽  
Poisson's Ratio ◽  
Force Microscopy ◽  
Cellular Processes ◽  
Atomic Force ◽  
Significant Research

Hydrogels have been used as substrates by many researchers in the study of cellular processes. The mechanical properties of these gels play a significant role in the growth of the cells. Significant research using several methods like compression, indentation, atomic force microscopy and manipulation of beads has been performed in the past to characterize the stiffness of these substrates. However, most of the methods employed assume the gel to be incompressible, with a Poisson’s ratio of 0.5. However, Poisson’s ratio can differ from 0.5. Hence, a more complete characterization of the elastic properties of hydrogels requires that one experimentally obtain the value of at least two of the three quantities: Poisson’s ratio, shear modulus, and elastic modulus.

Complete Characterization of AlxGa1-xN/InxGa1-xN/GaN Devices by Sims

1997 ◽  
Vol 468 ◽  
Author(s):  
C. Huang ◽  
S. Mitha ◽  
J. W. Erickson ◽  
R. Clark-Phelps ◽  
Jack Sheng ◽  
...  
Keyword(s):  
Growth Rate ◽  
Reverse Engineering ◽  
Failure Analysis ◽  
Concurrent Engineering ◽  
Alloy Composition ◽  
Electronic Devices ◽  
Complete Characterization ◽  
Sims Analysis

ABSTRACTSIMS analysis was applied to the characterization of GaN, AlGaN/GaN and InGaN/GaN grown by MOCVD. Such characterization enables the control of purity and doping, and the determination of growth rate and alloy composition. The analysis can be performed on finished optoelectronic and electronic devices and this makes SIMS technique a powerful tool for failure analysis, reverse engineering, and concurrent engineering.

scholarly journals Quantitative Analysis of Portland Cement Clinker with Rietveld Refinement: Implications of the Amorphous Matter

2021 ◽  
Vol 5 (1) ◽  
pp. 75
Author(s):  
Georgios E. Christidis ◽  
Maria Dimitriadi ◽  
George Triantafyllou ◽  
Christos Tsoumeleas
Keyword(s):  
Portland Cement ◽  
Rietveld Method ◽  
Internal Standard ◽  
Complete Characterization ◽  
Cement Clinker ◽  
White Cement ◽  
Portland Cement Clinker ◽  
Amorphous Matter

Six ordinary Portland cement (OPC) clinkers and one white cement clinker were analyzed with the Rietveld method, using ZnO internal standard (IC), to determine the presence of amorphous matter (AM). All clinkers contain abundant AM and have lower silicate phase contents when compared with the same clinkers analyzed without IC, whereas the abundances of the aluminate and ferrate phases were not affected by AM. The white cement clinker had the highest AM content. Determination of AM is important for complete characterization of the OPC clinker and might contribute to a better understanding of the mechanical properties of the clinker.

scholarly journals Characterization of Clay of the Benin Used in Ruminale Feeding. Complete Determination of the Smectites Contained in These Clays

2015 ◽  
Vol 06 (11) ◽  
pp. 1322-1336
Author(s):  
Etienne Sagbo ◽  
Marielle Agbahoungbata ◽  
Wilfried Kangbode ◽  
Arthur Cakpo ◽  
Jacques Kinlehoume ◽  
...  
Keyword(s):  
Complete Determination
Sign in / Sign up

Export Citation Format

Share Document