Towards Characterization of Soot Morphology, Composition, and Optical Properties From Large Pool Fires

2002 ◽  
Author(s):  
Jill Suo-Anttila ◽  
Patrick Drozda ◽  
Louis Gritzo ◽  
Mun Young Choi
Keyword(s):  
Optical Properties ◽  
Morphological Properties ◽  
Pool Fires ◽  
Flame Zone ◽  
Large Pool ◽  
Transmission Electron ◽  
Soot Morphology ◽  
Large Fires ◽  
Insight Into

The thermal hazard posed by large hydrocarbon fires is dominated by the radiative emission from high temperature soot. Since the optical and morphological properties of soot are not well known, especially in the infrared, efforts to characterize these properties are underway. Measurements of optical properties and morphology in large fires are important in heat transfer calculations, interpretation of laser-based diagnostics, and to build revised soot property models for fire field models. This research utilizes extractive measurement diagnostics to characterize soot morphology, composition, and optical properties in pool fires. The fires of interest are realistic in size, and considerably larger than recent studies, from transitionally turbulent to fully turbulent JP-8 pool fires. For measurement of the extinction coefficient, soot extracted from the flame zone is transported to a transmission cell where measurements are made using both visible and infrared lasers. Soot morphological properties are obtained by analysis via transmission electron microscopy of soot samples obtained thermophoretically within the flame zone, overfire region, and in the transmission cell. Soot composition, including carbon-to-hydrogen ration and PAH concentration, is obtained by analysis of soot collected on filters. In addition to providing insight into optical properties, soot samples obtained allow researchers to determine that the soot morphology is not affected by the transport to the transmission cell. This paper describes the diagnostics and presents some preliminary data for soot morphology, composition, and optical properties measurements within the flame zone of pool fires.

scholarly journals An Efficient and Novel Ammonia Sensor Based on Polypyrrole/Tin Oxide/MWCNT Nanocomposite

2020 ◽  
Vol 32 (6) ◽  
pp. 1505-1510
Author(s):  
Ahmad Husain ◽  
Mohd Urooj Shariq ◽  
Anees Ahmad
Keyword(s):  
Electron Microscopy ◽  
Tin Oxide ◽  
Charge Carriers ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Ammonia Sensing ◽  
Transmission Electron ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

In present study, the synthesis and characterization of a novel polypyrrole (PPy)/tin oxide (SnO2)/MWCNT nanocomposite along with pristine polypyrrole is reported. These materials have been studied for their structural and morphological properties by FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. PPy/SnO2/MWCNT nanocomposite has been converted into a pellet-shaped sensor, and its ammonia sensing studies were carried out by calculating the variation in the DC electrical conductivity at different concentration of ammonia ranging from 10 to 1500 ppm. The sensing response of the sensor was determined at 1500, 1000, 500, 200, 100 and 10 ppm and found to be 70.4, 66.1, 62.2, 55.4, 50.8 and 39.7%, respectively The sensor showed a complete reversibility at lower concentrations along with excellent selectivity and stability. Finally, a sensing mechanism was also proposed involving polarons (charge carriers) of polypyrrole and lone pairs of ammonia molecules

scholarly journals Characterization of monoclonal IgG cryoglobulins: fine-structural and morphological analysis

Blood ◽  
1987 ◽  
Vol 69 (2) ◽  
pp. 677-681 ◽  
Author(s):  
DN Podell ◽  
CH Packman ◽  
J Maniloff ◽  
GN Abraham
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Morphological Analysis ◽  
Vascular Occlusion ◽  
Molecular Clusters ◽  
Morphological Properties ◽  
Transmission Electron ◽  
Thin Walled ◽  
Scanning Electron

Abstract The morphology of the amorphous, gelatinous, and crystalline varieties of monoclonal IgG cryoglobulins was analyzed by light and transmission and scanning electron microscopy. Each cryoglobulin had a characteristic fine structure that correlated with its gross morphology. Transmission electron microscopy showed that the amorphous precipitates were random and disorganized molecular clumps. In contrast, cryogels were thin-walled, well-organized, and hydrated strawlike clusters, whereas cryocrystals formed tightly compacted, highly structured molecular clusters. Crystals that formed in blood produced rouleaux, and analysis by scanning electron microscopy indicated that the crystals could form thick-walled, branching, macromolecular nets that could physically trap cells. The morphological properties provided visual impressions by which cryoglobulins could cause clinical disease secondary to vascular occlusion produced by self- associated IgG cryoglobulin molecules.

Characterization of optical properties of the dislocations in GaN films using transmission electron microscopy cathodoluminescence

2012 ◽  
Vol 18 (S2) ◽  
pp. 1840-1841
Author(s):  
S. Kim ◽  
J. Lee ◽  
B. Koo ◽  
Y. Kim ◽  
J. Choi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Properties ◽  
Transmission Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Structural Characterization of Crystalline Si-C-N Films

1997 ◽  
Vol 498 ◽  
Author(s):  
E. G. Wang ◽  
Cheng-Zhang Wang ◽  
Changfeng Chen ◽  
Yan Chen
Keyword(s):  
Electron Microscopy ◽  
Structural Characterization ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Hot Filament ◽  
Microscopy Images ◽  
Insight Into

ABSTRACTHigh quality crystalline Si-C-N films on silicon substrate have been synthesized by bias-assisted hot filament chemical vapor deposition (CVD) using a gas mixture of nitrogen and methane. Scanning electron microscopy images show that the Si-C-N clusters are composed of many columnar crystals with hexagonal facets. X-ray diffraction and transmission electron microscopy analyses confirm the formation of Si-C-N crystals with lattice parameters a=7.06Å and c=2.72Å. First principles calculations are performed for β-Si3–nCnN4 (n=0,1,2,3). The calculated results support the experimental structural characterization and provide further insight into the property of the system. With increasing amount of C substitution, the bulk modulus progressively increases to 4.44 Mbar, comparable to that of diamond (4.43 Mbar), and both a and c are reduced but the ratio c/a shows little variation.

scholarly journals Characterization of a Latent Virus-Like Infection of Symbiotic Zooxanthellae

2007 ◽  
Vol 73 (9) ◽  
pp. 2976-2981 ◽  
Author(s):  
Jayme Lohr ◽  
Colin B. Munn ◽  
William H. Wilson
Keyword(s):  
Uv Light ◽  
Latent Virus ◽  
Thin Sections ◽  
Virus Like Particles ◽  
Transmission Electron ◽  
Uv Irradiance ◽  
Virus System ◽  
Insight Into

ABSTRACT A latent virus-like agent, which we designated zooxanthella filamentous virus 1 (ZFV1), was isolated from Symbiodinium sp. strain CCMP 2465 and characterized. Transmission electron microscopy and analytical flow cytometry revealed the presence of a new group of distinctive filamentous virus-like particles after exposure of the zooxanthellae to UV light. Examination of thin sections of the zooxanthellae revealed the formation and proliferation of filamentous virus-like particles in the UV-induced cells. Assessment of Symbiodinium sp. cultures was used here as a model to show the effects of UV irradiance and induction of potential latent viruses. The unique host-virus system described here provides insight into the role of latent infections in zooxanthellae through environmentally regulated viral induction mechanisms.

Microstructural characterization of Al98.5wt. %Si1.0wt. %Cu0.5wt. % on chemical-vapor-deposited W

1993 ◽  
Vol 8 (5) ◽  
pp. 1001-1009 ◽  
Author(s):  
Carey A. Pico ◽  
Tom D. Bonifield
Keyword(s):  
Substrate Temperature ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Morphological Properties ◽  
Sintering Process ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Chemical Vapor Deposited ◽  
Lower Temperature

The microstructural and morphological properties of thin (6000 Å) Al98.5wt. %Si1.0wt. %Cu0.5wt. % films on chemical-vapor-deposited tungsten-coated substrates have been characterized as functions of substrate temperature during deposition and a postdeposition sinter. Scanning electron and transmission electron microscopic investigations show these properties can be categorized with respect to the substrate temperature during deposition. The Al98.5wt. %Si1.0wt. %Cu0.5wt. % films deposited on substrates heated at temperatures ≤200 °C are rough and are comprised of rounded grains. For deposition on substrates heated at ≤300 °C, the films are smooth. Large voids and small precipitates (presumably Al2Cu) are present in the films deposited at 400 °C. The films retain their as-deposited texture during a 450 °C sinter. Precipitates and evidence of W interactions occur in the sintered films deposited on the lower temperature substrates. In addition, the shapes of thermal hillocks and mesa-like protrusions that form during the sintering process are influenced by the films' as-deposited morphologies.

Effects of a Post-Oxidation Annealing in Nitrous Oxide on the Morphological and Electrical Properties of SiO2/4H-SiC Interfaces

2013 ◽  
Vol 740-742 ◽  
pp. 719-722 ◽  
Author(s):  
Lukas K. Swanson ◽  
Patrick Fiorenza ◽  
Filippo Giannazzo ◽  
Fabrizio Roccaforte
Keyword(s):  
Nitrous Oxide ◽  
Electrical Characterization ◽  
Mos Capacitors ◽  
Flat Interface ◽  
Transmission Electron ◽  
Nanoscale Characterization ◽  
Atomically Flat ◽  
Density Of Interface States ◽  
Insight Into

This work reports on the morphological, structural and electrical effects of a nitrous oxide (N2O) ambient post-oxidation annealing (POA) of the SiO2/4H-SiC interface. In particular, a conventional electrical characterization of MOS capacitors showed that nitrous oxide POA reduces the presence of both fixed oxide charge and the density of interface states. A local atomically flat interface was observed by transmission electron microscopy with only a moderate step bunching observed at a macroscopic scale. A novel nanoscale characterization approach via scanning spreading resistance microscopy resolved local electrical changes induced at the SiC surface exposed to N2O POA. This result subsequently revealed additional insight into the mechanism for the improved device performance subjected to N2O POA treatment.

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