Fabrication of three-dimensional SiC-based ceramic micropatterns using a sequential micromolding-and-pyrolysis process

2006 ◽  
Vol 83 (11-12) ◽  
pp. 2475-2481 ◽  
Author(s):  
Tae Woo Lim ◽  
Sang Hu Park ◽  
Dong-Yol Yang ◽  
Tuan Anh Pham ◽  
Dong Hoon Lee ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Pyrolysis Process

scholarly journals Simulation of Wood Combustion in PATO Using a Detailed Pyrolysis Model Coupled to fireFoam

2021 ◽  
Vol 11 (22) ◽  
pp. 10570
Author(s):  
Hermes Scandelli ◽  
Azita Ahmadi-Senichault ◽  
Jean Lachaud ◽  
Franck Richard
Keyword(s):  
Three Dimensional ◽  
Chemical Species ◽  
Pyrolysis Process ◽  
Wood Combustion ◽  
Gaseous Species ◽  
Fire Propagation ◽  
Wood Pyrolysis ◽  
Pyrolysis Model ◽  
And Behavior ◽  
Pyrolysis Gases

The numerical simulation of fire propagation requires capturing the coupling between wood pyrolysis, which leads to the production of various gaseous species, and the combustion of these species in the flame, which produces the energy that sustains the pyrolysis process. Experimental and numerical works of the fire community are targeted towards improving the description of the pyrolysis process to better predict the rate of production and the chemical nature of the pyrolysis gases. We know that wood pyrolysis leads to the production of a large variety of chemical species: water, methane, propane, carbon monoxide and dioxide, phenol, cresol, hydrogen, etc. With the idea of being able to capitalize on such developments to study more accurately the physics of fire propagation, we have developed a numerical framework that couples a detailed three-dimensional pyrolysis model and fireFoam. In this article, we illustrate the capability of the simulation tool by treating the combustion of a wood log. Wood is considered to be composed of three phases (cellulose, hemicellulose and lignin), each undergoing parallel degradation processes leading to the production of methane and hydrogen. We chose to simplify the gas mixture for this first proof of concept of the coupling of a multi-species pyrolysis process and a flame. In the flame, we consider two separate finite-rate combustion reactions for methane and hydrogen. The flame evolves during the simulation according to the concentration of the two gaseous species produced from the material. It appears that introducing different pyrolysis species impacts the temperature and behavior of the flame.

The orbit of Pluto over a long interval of time

1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer
Keyword(s):  
Periodic Orbit ◽  
Numerical Integration ◽  
Restricted Problem ◽  
Three Dimensional ◽  
The Third ◽  
Circular Restricted Problem ◽  
Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

Ultrastructural Investigations of the Contractile Filaments of Amoebae

1974 ◽  
Vol 32 ◽  
pp. 188-189
Author(s):  
P.L. Moore
Keyword(s):  
Cytoplasmic Streaming ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Amoeboid Movement ◽  
Different Types ◽  
Chemical Conditions ◽  
Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

Structural organization of escherichia coli ribosomes as determined by immuno electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 166-167 ◽  
Author(s):  
G. Stöffler ◽  
R.W. Bald ◽  
J. Dieckhoff ◽  
H. Eckhard ◽  
R. Lührmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Ribosomal Proteins ◽  
Structural Organization ◽  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Spatial Arrangement ◽  
Small Subunit ◽  
Antibody Binding ◽  
Immuno Electron Microscopy

A central step towards an understanding of the structure and function of the Escherichia coli ribosome, a large multicomponent assembly, is the elucidation of the spatial arrangement of its 54 proteins and its three rRNA molecules. The structural organization of ribosomal components has been investigated by a number of experimental approaches. Specific antibodies directed against each of the 54 ribosomal proteins of Escherichia coli have been performed to examine antibody-subunit complexes by electron microscopy. The position of the bound antibody, specific for a particular protein, can be determined; it indicates the location of the corresponding protein on the ribosomal surface.The three-dimensional distribution of each of the 21 small subunit proteins on the ribosomal surface has been determined by immuno electron microscopy: the 21 proteins have been found exposed with altogether 43 antibody binding sites. Each one of 12 proteins showed antibody binding at remote positions on the subunit surface, indicating highly extended conformations of the proteins concerned within the 30S ribosomal subunit; the remaining proteins are, however, not necessarily globular in shape (Fig. 1).

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