Fire growth using minimum travel time methods

2002 ◽  
Vol 32 (8) ◽  
pp. 1420-1424 ◽  
Author(s):  
Mark A Finney

Fire-growth modeling on complex landscapes can be approached as a search for the minimum time for fire to travel among nodes in a two-dimensional network. The paths producing minimum travel time between nodes are then interpolated to reveal the fire perimeter positions at an instant in time. These fire perimeters and their fire behavior characteristics (e.g., spread rate, fireline intensity) are essentially identical to the products of perimeter expansion techniques. Travel time methods offer potential advantages for some kinds of modeling applications, because they are more readily parallelized for computation than methods for expanding fire fronts and require no correction for crossed fronts or merging separate fires.

2003 ◽  
Vol 12 (2) ◽  
pp. 167 ◽  
Author(s):  
Mark A. Finney

An approach is presented for approximating the expected spread rate of fires that burn across 2-dimensional landscapes with random fuel patterns. The method calculates a harmonic mean spread rate across a small 2-dimensional grid that allows the fire to move forward and laterally. Within this sample grid, all possible spatial fuel arrangements are enumerated and the spread rate of an elliptical fire moving through the cells is found by searching for the minimum travel time. More columns in the sample grid are required for accurately calculating expected spread rates where very slow-burning fuels are present, because the fire must be allowed to move farther laterally around slow patches. This calculation can be used to estimate fire spread rates across spatial fuel mixtures provided that the fire shape was determined from wind and slope. Results suggest that fire spread rates on random landscapes should increase with fire size and that random locations of fuel treatments would be inefficient in changing overall fire growth rates.


2014 ◽  
Vol 70 (12) ◽  
pp. o1252-o1252 ◽  
Author(s):  
Rodolfo Moreno-Fuquen ◽  
Diego F. Sánchez ◽  
Javier Ellena

In the title compound, C10H6N4O5S, the mean plane of the non-H atoms of the central amide fragment C—N—C(=O)—C [r.m.s. deviation = 0.0294 Å] forms dihedral angles of 12.48 (7) and 46.66 (9)° with the planes of the thiazole and benzene rings, respectively. In the crystal, molecules are linked by N—H...O hydrogen bonds, forming chains along [001]. In addition, weak C—H...O hydrogen bonds link these chains, forming a two-dimensional network, containingR44(28) ring motifs parallel to (100).


Author(s):  
Dong Liu

Solvothermal reaction between Cd(NO3)2, 1,4-phenylenediacetate (1,4-PDA) and 1,3-bis(pyridin-4-yl)propane (bpp) afforded the title complex, [Cd(C10H8O4)(C13H14N2)]n. Adjacent carboxylate-bridged CdIIions are related by an inversion centre. The 1,4-PDA ligands adopt acisconformation and connect the CdIIions to form a one-dimensional chain extending along thecaxis. These chains are in turn linked into a two-dimensional network through bpp bridges. The bpp ligands adopt ananti–gaucheconformation. From a topological point of view, each bpp ligand and each pair of 1,4-PDA ligands can be considered as linkers, while the dinuclear CdIIunit can be regarded as a 6-connecting node. Thus, the structure can be simplified to a two-dimensional 6-connected network.


2014 ◽  
Vol 70 (8) ◽  
pp. o875-o876 ◽  
Author(s):  
Naresh Sharma ◽  
Goutam Brahmachari ◽  
Bubun Banerjee ◽  
Rajni Kant ◽  
Vivek K. Gupta

In the title compound, C17H18N4O4, the dihedral angle between the benzene ring and 2,4-dihydropyrano[2,3-c]pyrazole ring system is 89.41 (7)°. The pyran moiety adopts a strongly flattened boat conformation. In the crystal, molecules are linked by N—H...N, N—H...O, C—H...N and C—H...O hydrogen bonds into an infinite two-dimensional network parallel to (110). There are π–π interactions between the pyrazole rings in neighbouring layers [centroid–centroid distance = 3.621 (1) Å].


1991 ◽  
Vol 44 (12) ◽  
pp. 1783 ◽  
Author(s):  
XM Chen ◽  
TCW Mak

The complex silver(I) 3-carboxylato-1-pyridinioacetate monohydrate, [Ag{C5H4(COO)NCH2.COO}]n.nH2O, crystallizes in space group P21/c (No. 14), with Z-4, a 12.233(6), b 5.049(1), c 14.418(7)Ǻ, and β 94.96(4)°; the structure was refined to RF -0.057 for 1721 observed [I ≥ 3σ(I)] Mo Kα data. The silver(I) atom is coordinated by four carboxylato oxygen atoms in a distorted tetrahedral environment [Ag-O 2.284(5)-2.570(5)Ǻ]. The tridentate acetato group bridges the Ag1 atoms into a zigzag chain featuring an uncommon [Ag2( carboxylato -O,O′)(carboxylato-μ-1,1-O)] six- membered ring, and the coordination sphere about each metal centre is completed by the unidentate aromatic carboxylato group, resulting in a two-dimensional network in the solid. The lattice water molecule forms hydrogen bonds with the uncoordinated oxygen atom of the aromatic carboxylato group [2.755(9)Ǻ] and the coordinated oxygen atom of the acetato group [2.936(9)Ǻ].


2012 ◽  
Vol 68 (6) ◽  
pp. o1601-o1602 ◽  
Author(s):  
Fadila Berrah ◽  
Sofiane Bouacida ◽  
Hayet Anana ◽  
Thierry Roisnel

The asymmetric unit includes two crystallographically independent equivalents of the title salt, C6H7N2O2 +·ClO4 −. The cations and anions form separate layers alternating along the c axis, which are linked by N—H...O, O—H...O and C—H...O hydrogen bonds into a two-dimensional network parallel to (100). Further C—H...O contacts connect these layers, forming a three-dimensional network, in which R 4 4(20) rings and C 2 2(11) infinite chains can be identified.


2012 ◽  
Vol 68 (6) ◽  
pp. o1733-o1733
Author(s):  
Qian Xu

In the structure of the title molecular salt, 2C6H14N+·C10H6O6S2 2−, the asymmetric unit consists of one 2-methylpiperidinium cation and one-half of a naphthalene-1,5-disulfonate anion; the anion lies across a centre of symmetry. In the crystal, the cations and anions are linked through N—H...O hydrogen bonds, forming a two-dimensional network.


2013 ◽  
Vol 69 (11) ◽  
pp. o1632-o1632
Author(s):  
Hakima Chicha ◽  
El Mostapha Rakib ◽  
Latifa Bouissane ◽  
Mohamed Saadi ◽  
Lahcen El Ammari

In the title compound, C14H12ClN3O3S, the fused five- and six-membered rings are folded slightly along the common edge, forming a dihedral angle of 3.2 (1)°. The mean plane through the indazole system makes a dihedral angle of 30.75 (7)° with the distant benzene ring. In the crystal, N—H...O hydrogen bonds link the molecules, forming a two-dimensional network parallel to (001).


Author(s):  
Konstantin V. Domasevitch

In the title compound, C20H30O2, one of the two crystallographically independent molecules lies across a centre of inversion and the other resides in a general position (Z′ = 1.5). The supramolecular structure exists as an unusual two-dimensional network incorporating centrosymmetric hexameric hydrogen-bonded alcohol (OH)6clusters [O...O = 2.6637 (12)–2.6993 (12) Å] as the net nodes. The hexamers adopt a chair conformation [O...O...O = 106.55 (4)–115.81 (4)°] and are connected into a network with a square-grid topology (44) by a combination of single and double 1,1′-biadamantanediyl links. The bulky aliphatic groups appear to require specific hexagonal packing and so generate distinct noncovalent hydrophobic layers, which are essential for the stabilization of the hexameric alcohol array rather than the formation of the more commonly encountered tetramer-based arrays.


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