Insight into soot formed in coal combustion flame: Evolution of physiochemical structure, oxidation reactivity

Fuel ◽  
2022 ◽  
Vol 312 ◽  
pp. 122948
Author(s):  
Yishu Xu ◽  
Jingji Zhu ◽  
Xiaowei Liu ◽  
Jiuxin Qi ◽  
Huakun Wang ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Combustion Flame ◽  
Oxidation Reactivity ◽  
Insight Into

scholarly journals Ignition Studies on High-Vitrinite and High-Inertinite Coals Using TGA/DSC, DTIF, EFR, and 20 L Dust Explosive Chamber

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3601
Author(s):  
Wiesław Rybak ◽  
Wojciech Moroń ◽  
Janusz Wach
Keyword(s):  
Coal Dust ◽  
Dust Cloud ◽  
Petrographic Analysis ◽  
Petrographic Composition ◽  
Ignition Mechanism ◽  
Oxidation Reactivity ◽  
Ignition Characteristics ◽  
The Relationship ◽  
Insight Into ◽  
Fuel Stream

The aim of this work was to study the ignition behaviour of eight coals of different coal ranks, petrographic compositions, and places of origin. The research allows us to gain deeper insight into the ignition mechanism and the relationship between certain properties of coals and their behaviour during ignition. The methodology utilised standard fuel ASTM data, petrographic analysis, pyrolysis and oxidation reactivity, and ignition characteristics generated through lab-scale tests using various ignition measurement methods. The results show that, in the dust explosion, a homogeneous ignition of coal dust took place. The ignition potential was the highest for coals with a high content of liptinites and a low content of inertinites. The ranking of coals in terms of ignition potential under these conditions can be determined on the basis of the measurements of the devolatilization rate. During the combustion of coal dust in TGA/DSC, a dust cloud, and a pulverised fuel stream, the ignition of particles was performed according to a heterogeneous mechanism. The study showed that the reflectance index may be the most reliable method of predicting and comparing ignition temperatures of both vitrinite-rich and inertinite-rich coals. Due to the lack of regularity in the ignition temperatures of some coals, depending on the proportion of inertinites, the petrographic composition of coal cannot be used to predict ignition temperatures during the combustion of coal dust. The ranking of the coals according to their ignition potential can be determined using TGA/DSC.

Calibration problems in hydrogen luminosities

1966 ◽  
Vol 24 ◽  
pp. 322-330
Author(s):  
A. Beer
Keyword(s):  
Galactic Structure ◽  
B Stars ◽  
Insight Into

The investigations which I should like to summarize in this paper concern recent photo-electric luminosity determinations of O and B stars. Their final aim has been the derivation of new stellar distances, and some insight into certain patterns of galactic structure.

Stochasting modeling of planetary ring systems

1984 ◽  
Vol 75 ◽  
pp. 461-469 ◽  
Author(s):  
Robert W. Hart
Keyword(s):  
Maximum Entropy ◽  
Ring System ◽  
The Sun ◽  
Ultimate State ◽  
Interparticle Interactions ◽  
Ring Systems ◽  
First Order ◽  
Planetary Ring ◽  
Insight Into

ABSTRACTThis paper models maximum entropy configurations of idealized gravitational ring systems. Such configurations are of interest because systems generally evolve toward an ultimate state of maximum randomness. For simplicity, attention is confined to ultimate states for which interparticle interactions are no longer of first order importance. The planets, in their orbits about the sun, are one example of such a ring system. The extent to which the present approximation yields insight into ring systems such as Saturn's is explored briefly.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Radiation Damage Studies with the HVEM

1972 ◽  
Vol 30 ◽  
pp. 680-681
Author(s):  
J. J. Laidler ◽  
B. Mastel
Keyword(s):  
Radiation Damage ◽  
Stainless Steels ◽  
Volume Expansion ◽  
Austenitic Stainless Steels ◽  
Test Facility ◽  
Fast Breeder Reactors ◽  
Breeder Reactors ◽  
Under Construction ◽  
Development Laboratory ◽  
Insight Into

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.

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