scholarly journals Characterization of New Excimer Pumped UV Laser Dyes I. p-Terphenyls

1991 ◽  
Vol 11 (1) ◽  
pp. 49-62 ◽  
Author(s):  
D. J. Schneider ◽  
D. A. Landis ◽  
P. A. Fleitz ◽  
C. J. Seliskar ◽  
J. M. Kauffman ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Performance Characteristics ◽  
Laser Dyes ◽  
Uv Laser ◽  
Alternative Solvents

The performance characteristics of a series of new excimer pumped ultraviolet dyes are presented. Chemical structure modifications which influence dye performance are discussed. An evaluation of several alternative solvents shows that p-dioxane remains the solvent of choice based on dye performance. The influence of the cover gas in the dye circulator was examined and results are presented to show how dye performance can greatly depend on this factor.

scholarly journals Characterization of New Excimer Pumped UV Laser Dyes 3. P-Quinqui-, Sexi-, Octi- and Deciphenyls

1993 ◽  
Vol 13 (1) ◽  
pp. 19-28 ◽  
Author(s):  
C. J. Seliskar ◽  
D. A. Landis ◽  
J. M. Kauffman ◽  
M. A. Aziz ◽  
R. N. Steppel ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Laser Dyes ◽  
Uv Laser ◽  
Predictive Information ◽  
Good Linear ◽  
Phenyl Rings ◽  
Conversion Efficiencies ◽  
Linear Regressions

The spectroscopic and lasing characteristics of a series of 308 nm pumped p-oligophenylenes with five or more phenyl rings have been studied. Quantitative comparisons of the absorption spectra of these dyes with numerous other dyes in this class of compounds can be made by defining a parameter, theta, as the sum of the number of phenyl rings and the number of ring-bridges. Statistically good linear regressions result from the correlations of molar extinction with theta and from wavelength of absorbance with the reciprocal of theta. We find that these correlations provide good predictive information in deciding which dyes to attempt to synthesize for testing. The lasing characteristics of the dyes studied show that these dyes are amongst the best dyes in this class of dyes. Some of these dyes have exceptionally long lifetimes coupled with acceptable conversion efficiencies.

scholarly journals Characterization of New Excimer Pumped UV Laser Dyes 2. p-Quaterphenyls

1991 ◽  
Vol 11 (2) ◽  
pp. 99-107 ◽  
Author(s):  
P. A. Fleitz ◽  
C. J. Seliskar ◽  
R. N. Steppel ◽  
J. M. Kauffman ◽  
C. J. Kelly ◽  
...  
Keyword(s):  
Laser Dyes ◽  
Performance Parameters ◽  
Uv Laser ◽  
Chemical Structures ◽  
Better Than ◽  
Made In

New excimer-pumped laser dyes based on p-quaterphenyl are described and the associated performance parameters are presented. A discussion of the variations in the performance parameters found is made in terms of dye chemical structures. Most of the dyes studied are significantly better than the chosen reference dye BBQ. The best dye in the series (dye 3) is stabilized both by ring-alkylation and by ringbridging. The net effect is the production of a new dye with a lifetime ten times greater than that of the reference dye BBQ.

Preparation and Characterization of Soybean Oil-based Flame Retardant Rigid Polyurethane Foams Containing Phosphaphenanthrene Groups

2020 ◽  
Vol 17 (10) ◽  
pp. 760-771
Author(s):  
Qirui Gong ◽  
Niangui Wang ◽  
Kaibo Zhang ◽  
Shizhao Huang ◽  
Yuhan Wang
Keyword(s):  
Soybean Oil ◽  
Flame Retardant ◽  
Chemical Structure ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Limiting Oxygen Index ◽  
Rigid Polyurethane Foams ◽  
Degradation Activation Energy ◽  
Ft Ir

A phosphaphenanthrene groups containing soybean oil based polyol (DSBP) was synthesized by epoxidized soybean oil (ESO) and 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Soybean oil based polyol (HSBP) was synthesized by ESO and H2O. The chemical structure of DSBP and HSBP were characterized with FT-IR and 1H NMR. The corresponding rigid polyurethane foams (RPUFs) were prepared by mixing DSBP with HSBP. The results revealed apparent density and compression strength of RPUFs decreased with increasing the DSBP content. The cell structure of RPUFs was examined by scanning electron microscope (SEM) which displayed the cells as spherical or polyhedral. The thermal degradation and flame retardancy of RPUFs were investigated by thermogravimetric analysis, limiting oxygen index (LOI), and UL 94 vertical burning test. The degradation activation energy (Ea) of first degradation stage reduced from 80.05 kJ/mol to 37.84 kJ/mol with 80 wt% DSBP. The RUPF with 80 wt% DSBP achieved UL94 V-0 rating and LOI 28.3. The results showed that the flame retardant effect was mainly in both gas phase and condensed phase.

Optimization and characterization of flavonoids extracted from Cannabis sativa fibers

2021 ◽  
pp. 004051752110277
Author(s):  
Qilu Cui ◽  
Jiawei Li ◽  
Chongwen Yu
Keyword(s):  
Chemical Structure ◽  
Cannabis Sativa ◽  
Ethanol Concentration ◽  
Extraction Process ◽  
Test Results ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
Structure Surface ◽  
Degumming Process

In this paper, the extraction process of flavonoids from hemp fibers was studied. Response surface methodology (RSM) analysis of the extraction parameters indicated that optimized results would be ethanol concentration 76 vol.%, bath ratio 1:50, and reaction time 139 min; therefore, an optimal extraction rate of flavonoids of 0.2275% can be obtained. The chemical structure, surface morphology and element composition of flavonoid extracts were analyzed. The test results indicated that hemp extract contains flavonoids, which can be used to extract flavonoids from hemp fiber, so as to comprehensively develop hemp fiber and reduce the discharge of waste liquid in the traditional degumming process.

scholarly journals Isolation and chemical structure characterization of enzymatic lignin frompopulus deltoidswood

2013 ◽  
Vol 130 (1) ◽  
pp. 710-710
Author(s):  
Ali Abdulkhani ◽  
Alinaghi Karimi ◽  
Ahmad Mirshokraie ◽  
Yahya Hamzeh ◽  
Nathalie Marlin ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Structure Characterization

Experimental and theoretical characterization of the Cn=2,16- clusters produced by 337nm UV laser

2007 ◽  
Vol 445 (4-6) ◽  
pp. 147-151 ◽  
Author(s):  
Francisco Alberto Fernandéz-Lima ◽  
Cássia Ribeiro Ponciano ◽  
Enio Frota da Silveira ◽  
Marco Antonio Chaer Nascimento
Keyword(s):  
Uv Laser ◽  
Theoretical Characterization

Synthesis and Characterization of Alkeyl Imidazolium Ionic Liquids

2014 ◽  
Vol 1048 ◽  
pp. 452-455
Author(s):  
Qiang Wang ◽  
Shi Dong Wang ◽  
Ming Chen Qi ◽  
Shu Liang Zang
Keyword(s):  
Ionic Liquids ◽  
Chemical Structure ◽  
Direct Synthesis ◽  
Synthesis Method ◽  
Structure And Properties ◽  
Spectra Analysis ◽  
Infrared Spectrometer ◽  
Liquid Salts ◽  
Structure Of Matter

Two new imidazole ionic liquid salts, 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-allyl-3-methy-imidazolium hydrogen sulfate ([EMIM]HSO4), were synthesized with direct synthesis and two-step synthesis method, using a viscosity meter, PH meter, conductivity meter, densitometer, infrared spectrometer determined its chemical structure and properties. The results show that two ionic liquids in the range is slightly different, the trend is roughly same. As the temperature increases, the viscosity decreases, PH gradually increased, the density decreases slightly, can be regarded as constant, the conductivity gradually increased. Ionic liquids of the two IR spectra analysis show its structure and synthetic route consistent with the structure of matter.

Evaluation of the Effect of Ultraviolet Light Excitation during Characterization of Silicon Carbide Epitaxial Layers

2018 ◽  
Vol 924 ◽  
pp. 261-264
Author(s):  
Hrishikesh Das ◽  
Swapna Sunkari ◽  
Oener Akdik ◽  
Andrei Konstantinov ◽  
Krister Gumaelius ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Ultraviolet Light ◽  
Defect Detection ◽  
Uv Light ◽  
Surface Treatments ◽  
Uv Laser ◽  
Original State ◽  
Optimal Surface ◽  
Light Excitation

The scanning of Silicon Carbide (SiC) epitaxy wafers for defects by ultraviolet (UV) laser or lamps is widely prevalent. In this work, we document the effects of UV light excitation on the SiC epitaxy material. An increase in background photoluminescence (PL) is observed after repeated scans. The effect of this increase on defect detection is shown. Optimal surface treatments to recover the material back to the original state are demonstrated. Further, some surface treatments are proposed which reduce the effect of the UV light excitation and prevent to a large extent the rise in background PL.

Synthesis and characterization of novel sulfonated polyimide with varying chemical structure for fuel cell applications

2018 ◽  
Vol 319 ◽  
pp. 141-147 ◽  
Author(s):  
Khurram Liaqat ◽  
Wajid Rehman ◽  
Shaukat Saeed ◽  
Muhammad Waseem ◽  
Srosh Fazil ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Chemical Structure ◽  
Synthesis And Characterization ◽  
Sulfonated Polyimide
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