Light emission of electroluminescent lamps under different operating conditions

2012 ◽  
Author(s):  
Walter Kaiser ◽  
Ricardo P. Marques ◽  
Alexander F. Correa
Keyword(s):  
Light Emission ◽  
Operating Conditions

scholarly journals Effect of Fabric Integration on the Physical and Optical Performance of Electroluminescent Fibers for Lighted Textile Applications

Fibers ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 50
Author(s):  
Alyssa Martin ◽  
Adam Fontecchio
Keyword(s):  
Mechanical Properties ◽  
Light Emission ◽  
Operating Conditions ◽  
Device Performance ◽  
Optical Performance ◽  
Limited Information ◽  
Light Emitting ◽  
Practical Applications ◽  
The Past ◽  
Device Efficiency

The advent of electroluminescent (EL) fibers, which emit light in response to an applied electric field, has opened the door for fabric-integrated light emission and displays in textiles. However, there have been few technical publications over the past few years about the performance of these light emitting fibers inside functional fabrics. Thus, there is limited information on the effect of integration on the physical and optical performance of such devices. In this work, alternating current powder-based EL (ACPEL) fibers were evaluated under a range of operating conditions both inside and outside of a knit matrix to understand how the EL fiber device performance changed inside a functional fabric. The device efficiency, adjustable brightness, and mechanical properties of these fibers are presented. The effects of fabric integration on the light-emitting fibers as well as the supporting knit fabric are discussed as they relate to the practical applications of this technology.

Light Emission of Electroluminescent Lamps Under Different Operating Conditions

2013 ◽  
Vol 49 (5) ◽  
pp. 2361-2369 ◽  
Author(s):  
Walter Kaiser ◽  
Ricardo Paulino Marques ◽  
Alexander Fernandez Correa
Keyword(s):  
Light Emission ◽  
Operating Conditions

Arc Voltage Fluctuations as an Indication of Spray Torch Anode Condition

1997 ◽  
Author(s):  
Z. Duan ◽  
L. Beall ◽  
M.P. Planche ◽  
J. Heberlein ◽  
E. Pfender ◽  
...  
Keyword(s):  
Light Emission ◽  
Acoustic Emissions ◽  
Plasma Jet ◽  
Deposition Process ◽  
Operating Conditions ◽  
Clear Correlation ◽  
Voltage Fluctuations ◽  
Arc Voltage ◽  
On Line ◽  
Anode Erosion

Abstract Arc voltage fluctuations of a plasma spray torch are primarily an indication of the movement of the arc attachment inside the anode nozzle. These fluctuation have been shown to influence the deposition process. In order to detect changes in the operating conditions which affect coating quality, a method has been developed for on-line analysis of these fluctuations. Voltage fluctuation have been recorded together with light emission fluctuations and with acoustic emissions from the plasma jet and analyzed on-line using a workstation operating with the LabView environment. Anodes with different wear characteristics have been examined in this study. A clear correlation has been found between the changes in the dominant frequencies of all three signals and the conditions of the torch anode and the coating properties. Appearance of a group of frequency peaks in the 2 to 5 kHz range indicates a more unstable plasma jet and is correlated with anode erosion and increased coating porosity. The results of this study provide us with a convenient method to detect coating deterioration due to anode erosion.

Thermally-excited fluorescence of strontium products for in-cylinder temperature diagnostics in internal combustion engines

2020 ◽  
pp. 146808742097455
Author(s):  
Ivan Tibavinsky ◽  
Ahmet Mazacioglu ◽  
Volker Sick
Keyword(s):  
Alkali Metal ◽  
Internal Combustion Engines ◽  
Light Emission ◽  
Diagnostic Technique ◽  
Energy Difference ◽  
Operating Conditions ◽  
Temperature Measurements ◽  
Thermal Excitation ◽  
Gas Temperature ◽  
Analysis Model

A new optical diagnostic technique for burned gas temperature measurements was introduced using visible thermally-excited fluorescence of strontium monohydroxide (SrOH). The technique is a significant improvement over previously developed alkali metal-based techniques in that it requires only one tracer substance, strontium acetylacetonate in ethanol, compared to two or three alkali metal precursors. Combustion of the precursor forms 1.5 to 12 ppm SrOH, depending on equivalence ratio, and thermal excitation leads to visible light emission. For the purpose of temperature measurements, multiple emission bands were spectrally resolved and recorded with an intensified camera coupled to a spectrometer during experiments in an optical spark-ignited direct-injected engine. A hybrid experimental and computational approach was taken to validate the feasibility of SrOH based temperature measurements as well as to determine missing spectroscopic information. To that end, emission spectra were recorded for equivalence ratios ranging from lean to rich, and GT Power simulations provided a calibration base for burned gas temperatures. The optical engine was operated with early injection leading to near-homogenous mixing prior to ignition. It was confirmed that the measured data follow relationships consistent with a Boltzmann distribution of excited states populations. Furthermore, the experimentally determined energy difference between the excited [Formula: see text] and [Formula: see text] states of SrOH that form the basis of the temperature evaluation was found to be in good agreement with literature data. The calibrated analysis model then allowed to process spectra from over 400 single engine cycles from 10 runs with four different operating conditions to determine instantaneous burned gas temperatures. Average temperatures ranged from 1759 to 2490 K with standard deviations of 46–122 K. Variations were higher for more marginal fuel conditions. Self-absorption of the emission signals was characterized and would lead to a temperature error of no more than 0.5%.

Renilla Bioluminescence: A Morphologic Approach to the Location of Photocytes

1974 ◽  
Vol 32 ◽  
pp. 208-209
Author(s):  
Ben O. Spurlock ◽  
Milton J. Cormier
Keyword(s):  
Excited State ◽  
Ground State ◽  
Molecular Basis ◽  
Light Emission ◽  
Chemical Basis ◽  
Electronic Excited State ◽  
Colonial Form ◽  
The Common ◽  
Eighteenth And Nineteenth Centuries ◽  
Catalyzed Oxidation

The phenomenon of bioluminescence has fascinated layman and scientist alike for many centuries. During the eighteenth and nineteenth centuries a number of observations were reported on the physiology of bioluminescence in Renilla, the common sea pansy. More recently biochemists have directed their attention to the molecular basis of luminosity in this colonial form. These studies have centered primarily on defining the chemical basis for bioluminescence and its control. It is now established that bioluminescence in Renilla arises due to the luciferase-catalyzed oxidation of luciferin. This results in the creation of a product (oxyluciferin) in an electronic excited state. The transition of oxyluciferin from its excited state to the ground state leads to light emission.

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

Scanning luminescence x-ray microscopy: Progress toward selective staining using microspheres

1994 ◽  
Vol 52 ◽  
pp. 74-75
Author(s):  
C. Jacobsen ◽  
J. Fu ◽  
S. Mayer ◽  
Y. Wang ◽  
S. Williams
Keyword(s):  
Visible Light ◽  
Active Sites ◽  
Light Emission ◽  
Chinese Hamster ◽  
Polystyrene Spheres ◽  
Good Resistance ◽  
X Ray ◽  
Selective Staining ◽  
Visible Light Emission ◽  
Specific Labelling

In scanning luminescence x-ray microscopy (SLXM), a high resolution x-ray probe is used to excite visible light emission (see Figs. 1 and 2). The technique has been developed with a goal of localizing dye-tagged biochemically active sites and structures at 50 nm resolution in thick, hydrated biological specimens. Following our initial efforts, Moronne et al. have begun to develop probes based on biotinylated terbium; we report here our progress towards using microspheres for tagging.Our initial experiments with microspheres were based on commercially-available carboxyl latex spheres which emitted ~ 5 visible light photons per x-ray absorbed, and which showed good resistance to bleaching under x-ray irradiation. Other work (such as that by Guo et al.) has shown that such spheres can be used for a variety of specific labelling applications. Our first efforts have been aimed at labelling ƒ actin in Chinese hamster ovarian (CHO) cells. By using a detergent/fixative protocol to load spheres into cells with permeabilized membranes and preserved morphology, we have succeeded in using commercial dye-loaded, spreptavidin-coated 0.03μm polystyrene spheres linked to biotin phalloidon to label f actin (see Fig. 3).

Slow-scan CCD cameras and low-dose High-Resolution Electron Microscopy: Direct and quantitative

1994 ◽  
Vol 52 ◽  
pp. 412-413
Author(s):  
M. Pan
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structural Damage ◽  
Low Dose ◽  
Dynamic Range ◽  
High Resolution Electron Microscopy ◽  
Operating Conditions ◽  
Digital Data ◽  
Ccd Cameras ◽  
Resolution Electron

It has been known for many years that materials such as zeolites, polymers, and biological specimens have crystalline structures that are vulnerable to electron beam irradiation. This radiation damage severely restrains the use of high resolution electron microscopy (HREM). As a result, structural characterization of these materials using HREM techniques becomes difficult and challenging. The emergence of slow-scan CCD cameras in recent years has made it possible to record high resolution (∽2Å) structural images with low beam intensity before any apparent structural damage occurs. Among the many ideal properties of slow-scan CCD cameras, the low readout noise and digital recording allow for low-dose HREM to be carried out in an efficient and quantitative way. For example, the image quality (or resolution) can be readily evaluated on-line at the microscope and this information can then be used to optimize the operating conditions, thus ensuring that high quality images are recorded. Since slow-scan CCD cameras output (undistorted) digital data within the large dynamic range (103-104), they are ideal for quantitative electron diffraction and microscopy.

Simulation and Contrast Analysis of tem Images of Cracks

1990 ◽  
Vol 48 (1) ◽  
pp. 578-579
Author(s):  
D. Goyal ◽  
A. H. King
Keyword(s):  
Displacement Vector ◽  
Crack Tip ◽  
Perfect Crystal ◽  
Operating Conditions ◽  
Displacement Fields ◽  
Fringe Contrast ◽  
Orthogonal Geometry ◽  
Moire Fringe ◽  
Moiré Fringe

TEM images of cracks have been found to give rise to a moiré fringe type of contrast. It is apparent that the moire fringe contrast is observed because of the presence of a fault in a perfect crystal, and is characteristic of the fault geometry and the diffracting conditions in the TEM. Various studies have reported that the moire fringe contrast observed due to the presence of a crack in an otherwise perfect crystal is distinctive of the mode of crack. This paper describes a technique to study the geometry and mode of the cracks by comparing the images they produce in the TEM because of the effect that their displacement fields have on the diffraction of electrons by the crystal (containing a crack) with the corresponding theoretical images. In order to formulate a means of matching experimental images with theoretical ones, displacement fields of dislocations present (if any) in the vicinity of the crack are not considered, only the effect of the displacement field of the crack is considered.The theoretical images are obtained using a computer program based on the two beam approximation of the dynamical theory of diffraction contrast for an imperfect crystal. The procedures for the determination of the various parameters involved in these computations have been well documented. There are three basic modes of crack. Preliminary studies were carried out considering the simplest form of crack geometries, i. e., mode I, II, III and the mixed modes, with orthogonal crack geometries. It was found that the contrast obtained from each mode is very distinct. The effect of variation of operating conditions such as diffracting vector (), the deviation parameter (ω), the electron beam direction () and the displacement vector were studied. It has been found that any small change in the above parameters can result in a drastic change in the contrast. The most important parameter for the matching of the theoretical and the experimental images was found to be the determination of the geometry of the crack under consideration. In order to be able to simulate the crack image shown in Figure 1, the crack geometry was modified from a orthogonal geometry to one with a crack tip inclined to the original crack front. The variation in the crack tip direction resulted in the variation of the displacement vector also. Figure 1 is a cross-sectional micrograph of a silicon wafer with a chromium film on top, showing a crack in the silicon.

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