Convergence of Periodic Wavetrains in the Limit of Large Wavelength.

1981 ◽  
Author(s):  
Jerry L. Bona
Keyword(s):  
Large Wavelength

Schiff base derivative doped chiral nematic liquid crystals with a large wavelength shift driven by temperature and light

2020 ◽  
Vol 8 (2) ◽  
pp. 561-566
Author(s):  
Lei Ren ◽  
Wanli He ◽  
Meiju Wei ◽  
Shiguang Luo ◽  
Daipeng Yao ◽  
...  
Keyword(s):  
Schiff Base ◽  
Liquid Crystals ◽  
Uv Light ◽  
Light Irradiation ◽  
Wavelength Shift ◽  
Uv Light Irradiation ◽  
Chiral Nematic ◽  
Base Derivative ◽  
Chiral Liquid Crystals ◽  
Large Wavelength

A chiral salicylaldehyde Schiff-base was successfully synthesized and was used to develop responsive chiral liquid crystals with large wavelength shift driven by temperature and UV light irradiation.

Large wavelength pulse propagation in curved elastic rods

1976 ◽  
Vol 59 (3) ◽  
pp. 557-563 ◽  
Author(s):  
T. Bryant Moodie ◽  
C. Rogers ◽  
D. L. Clements
Keyword(s):  
Pulse Propagation ◽  
Elastic Rods ◽  
Large Wavelength

scholarly journals Integral field spectroscopy with optical fibres

1995 ◽  
Vol 149 ◽  
pp. 209-218 ◽  
Author(s):  
C. Vanderriest
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Optical Fibres ◽  
Future Developments ◽  
Integral Field Spectroscopy ◽  
Field Spectroscopy ◽  
Large Telescopes ◽  
New Generation ◽  
Integral Field ◽  
Large Wavelength

AbstractAn efficient technique for obtaining complete spectral informations over moderately extended objects is to transform the geometry of their telescopic images to match a classical long ”slit” aperture. This anamorphosis is conveniently made with bundles of optical fibres. Such devices are especially useful when high spatial resolution and large wavelength coverage are required at the same time. We review the existing instruments based on this technique and present some typical results. We discuss also the future developments of integral field spectroscopy with optical fibres (visible or IR domains) for the new generation of very large telescopes.

scholarly journals Peristaltic motion of a Johnson-Segalman fluid in a planar channel

2003 ◽  
Vol 2003 (1) ◽  
pp. 1-23 ◽  
Author(s):  
T. Hayat ◽  
Y. Wang ◽  
A. M. Siddiqui ◽  
K. Hutter
Keyword(s):  
Characteristic Time ◽  
Numerical Solutions ◽  
Pressure Rise ◽  
Travelling Wave ◽  
Weissenberg Number ◽  
Planar Channel ◽  
Two Dimensional ◽  
Peristaltic Motion ◽  
Two Dimensional Flow ◽  
Large Wavelength

This paper is devoted to the study of the two-dimensional flow of a Johnson-Segalman fluid in a planar channel having walls that are transversely displaced by an infinite, harmonic travelling wave of large wavelength. Both analytical and numerical solutions are presented. The analysis for the analytical solution is carried out for small Weissenberg numbers. (A Weissenberg number is the ratio of the relaxation time of the fluid to a characteristic time associated with the flow.) Analytical solutions have been obtained for the stream function from which the relations of the velocity and the longitudinal pressure gradient have been derived. The expression of the pressure rise over a wavelength has also been determined. Numerical computations are performed and compared to the perturbation analysis. Several limiting situations with their implications can be examined from the presented analysis.

Dye lasers generating two wavelengths simultaneously with a large wavelength separation

1989 ◽  
Vol 54 (17) ◽  
pp. 1637-1638 ◽  
Author(s):  
Kazuhito Ishikawa ◽  
Shinzo Muto ◽  
Hidenori Matsuzawa
Keyword(s):  
Dye Lasers ◽  
Large Wavelength

scholarly journals Effect of charge separation on the stability of large wavelength fluctuations during spinodal decomposition

2003 ◽  
Vol 51 (6) ◽  
pp. 1517-1524 ◽  
Author(s):  
Catherine M. Bishop ◽  
R.Edwin García ◽  
W.Craig Carter
Keyword(s):  
Spinodal Decomposition ◽  
Charge Separation ◽  
The Stability ◽  
Large Wavelength

scholarly journals Analysis of ACAM Data for Trace Gas Retrievals during the 2011 DISCOVER-AQ Campaign

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
C. Liu ◽  
X. Liu ◽  
M. G. Kowalewski ◽  
S. J. Janz ◽  
G. González Abad ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Spectral Region ◽  
Total Ozone ◽  
Signal To Noise Ratio ◽  
Trace Gas ◽  
System Throughput ◽  
Signal To Noise ◽  
Ozone Profile ◽  
Blue Spectral Region ◽  
Large Wavelength

To improve the trace gas retrieval from Airborne Compact Atmospheric Mapper (ACAM) during the DSICOVER-AQ campaigns, we characterize the signal to noise ratio (SNR) of the ACAM measurement. From the standard deviations of the fitting residuals, the SNRs of ACAM nadir measurements are estimated to vary from ~300 at 310 nm to ~1000 in the blue spectral region; the zenith data are noisier due to reduced levels of illumination and lower system throughput and also show many more pixels with abrupt anomalous values; therefore, a new method is developed to derive a solar irradiance reference at the top of the atmosphere (TOA) from average nadir measurements, at instrument spectral resolution and including instrument calibration characteristics. Using this reference can significantly reduce fitting residuals and improve the retrievals. This approach derives an absolute reference for direct fitting algorithms involving radiative transfer calculations and thus can be applied to both aircraft and ground-based measurements. The comparison of ACAM radiance with simulations using coincident ozonesonde and OMI data shows large wavelength-dependent biases in ACAM data, varying from ~−19% at 310 nm to 5% at 360 nm. Correcting ACAM radiance in direct-fitting based ozone profile algorithm significantly improves the consistency with OMI total ozone.

scholarly journals Energy Transfer Between Yb3+- Mn2+ in Zn(Po3 ) 2 Glasses Giving Green, Red and Infrared Light

2020 ◽  
pp. 1-8
Author(s):  
C Flores J ◽  
◽  
J Hernández A ◽  
E Camarillo G ◽  
D Acosta N ◽  
...  
Keyword(s):  
Ion Pairs ◽  
Ion Concentration ◽  
Infrared Light ◽  
Electromagnetic Spectrum ◽  
Manganese Ion ◽  
Α Phase ◽  
Effective Option ◽  
Superexchange Coupling ◽  
Large Wavelength ◽  
Upconversion Process

The Yb3+-Mn2+codoped zinc metaphosphate glass gives rise to several processes such as upconversion, downshifting and double ion absorptions producing light from the visible to the IR wavelengths. These processes are possible since the Mn2+ and the Yb3+ ions replaces the Zn2+ ion in nanoparticles of the α phase of the compound Zn(PO3)2. An important result is that the α structure presence allows the formation of Yb3+-Mn2+ dimers, that gives rise to a superexchange coupling that allows an upconversion process from the IR to the red region of the electromagnetic spectrum. The experimental results also show that these dimers can couple to produce Yb3+ ion pairs that led to a cooperative emission in the green, around 500nm, coupling also the Mn2+ ions that in turn allows to produce a double absorption of this ions in the red region of the electromagnetic spectrum and as well a downshifting process conducting to the Yb3+ emission in the infrared. If the manganese ion concentration is higher than 10% most of these effects are masked. All these results make the material an effective option for different applications, due to the large wavelength variety that can be selected for excitation or emission

Oxygen Fluorescence as a Means for Temperature and Pressure Measurement

2003 ◽  
Author(s):  
Tadej Semenic ◽  
Ben Blake ◽  
Matthew Messana ◽  
Ivan Catton
Keyword(s):  
Air Temperature ◽  
Pressure Measurement ◽  
Laser Induced Fluorescence ◽  
Fluorescence Ratio ◽  
Broadband Laser ◽  
Temperature And Pressure ◽  
Xenon Flashlamp ◽  
The Cost ◽  
Large Wavelength

The application of interest in this work is the measurement of air temperature and pressure using broadband laser-induced fluorescence (LIF). Because of the cost, bulkiness, and operating complications of ArF lasers, a xenon flashlamp is used instead of LIF. The oxygen is excited by photons in the 185–200nm range. Large wavelength windows (100nm and 65nm) are used to reduce the fluctuations in the total measured fluorescence. A correlation between temperature and fluorescence ratio is developed with an error in fluorescence ratio of approximately ±1.3%, resulting in an error in temperature of ±1.35° C for temperatures from 25–50° C.

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