Experimental Design of a Prescribed Burn Instrumentation

Observational data collected during experiments, such as the planned Fire and Smoke Model Evaluation Experiment (FASMEE), are critical for progressing and transitioning coupled fire-atmosphere models like WRF-SFIRE and WRF-SFIRE-CHEM into operational use. Historical meteorological data, representing typical weather conditions for the anticipated burn locations and times, have been processed to initialize and run a set of simulations representing the planned experimental burns. Based on an analysis of these numerical simulations, this paper provides recommendations on the experimental setup that include the ignition procedures, size and duration of the burns, and optimal sensor placement. New techniques are developed to initialize coupled fire-atmosphere simulations with weather conditions typical of the planned burn locations and time of the year. Analysis of variation and sensitivity analysis of simulation design to model parameters by repeated Latin Hypercube Sampling are used to assess the locations of the sensors. The simulations provide the locations of the measurements that maximize the expected variation of the sensor outputs with the model parameters.Comment: 35 pages, 4 tables, 28 figure

Design Analysis of a Combined Optical-LADAR Deep-Space Surveillance Satellite

This research determines the performance requirements of a combined optical LADAR space-based system in order to detect and track deep-space satellites from a near-earth orbit satellite. The research derives the necessary equations to compare both direct and heterodyne detection techniques. The selection of the candidate laser systems is based on current space developed LADAR technology. The selection of the detector, detector size, and optic size are determined in order to maximize the signal-to-noise ratio. The analysis includes the effects of beam truncation, obscuration, pixel geometry, and background radiance. The results indicate that the direct detection technique with a GaA1As semiconductor laser and a charge-couple device detector provided the best signal-to-noise ratio for the range selected. In addition, the visible detection capability of the smallest entrance pupil system is compared with that of GEODSS. For the parameters chosen, the results indicate that this system should, on average, be able to detect objects of smaller size than GEODSS

FINANCING LOCAL DEVELOPMENT

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Field theoretic calculation of scalar turbulence

The cascade rate of passive scalar and Bachelor's constant in scalar turbulence are calculated using the flux formula. This calculation is done to first order in perturbation series. Batchelor's constant in three dimension is found to be approximately 1.25. In higher dimension, the constant increases as $d^{1/3}$.Comment: RevTex4, publ. in Int. J. Mod. Phy. B, v.15, p.3419, 200

Long-range Ni/Mn structural order in epitaxial double perovskite La2NiMnO6 thin films

We report and compare the structural, magnetic, and optical properties of ordered La2NiMnO6 thin films and its disordered LaNi0.5Mn0.5O3 counterpart. An x-ray diffraction study reveals that the B-site Ni/Mn ordering induces additional XRD reflections as the crystal symmetry is transformed from a pseudocubic perovskite unit cell in the disordered phase to a monoclinic form with larger lattice parameters for the ordered phase. Polarized Raman spectroscopy studies reveal that the ordered samples are characterized by additional phonon excitations that are absent in the disordered phase. The appearance of these additional phonon excitations is interpreted as the clearest signature of Brillouin zone folding as a result of the long-range Ni/Mn ordering in La2NiMnO6. Both ordered and disordered materials display a single ferromagnetic-to-paramagnetic transition. The ordered films display also a saturation magnetization close to 4.8 mB/f.u. and a transition temperature (FM-TC) around 270 K, while the disordered ones have only a 3.7 mB/f.u. saturation magnetization and a FM-TC around 138 K. The differences in their magnetic behaviours are understood based on the distinct local electronic configurations of their Ni/Mn cations.Comment: 15 pages, 5 fig

Phase formation, phonon behavior, and magnetic properties of novel ferromagnetic La3BAlMnO9 (B = Co or Ni) triple perovskites

In the quest for novel magnetoelectric materials, we have grown, stabilized and explored the properties of La3BAlMnO9 (B = Co or Mn) thin films. In this paper, we report the influence of the growth parameters that promote B/Al/Mn ordering in the pseudo-cubic unit cell and their likely influence on the magnetic and multiferroic properties. The temperature dependence of the magnetization shows that La3CoAlMnO9 is ferromagnetic up to 190 K while La3NiAlMnO9 shows a TC of 130 K. The behavior of these films are compared and contrasted with related La2BMnO6 double perovskites. It is observed that the insertion of AlO6 octahedra between CoO6 and MnO6 suppresses significantly the strength of the superexchange interaction, spin-phonon and spin-polar coupling.Comment: 13 pages, 3 fig

Multi-locus phylogeny of Pleosporales: a taxonomic, ecological and evolutionary re-evaluation

Five loci, nucSSU, nucLSU rDNA, TEF1, RPB1 and RPB2, are used for analysing 129 pleosporalean taxa representing 59 genera and 15 families in the current classification of Pleosporales. The suborder Pleosporineae is emended to include four families, viz. Didymellaceae, Leptosphaeriaceae, Phaeosphaeriaceae and Pleosporaceae. In addition, two new families are introduced, i.e. Amniculicolaceae and Lentitheciaceae. Pleomassariaceae is treated as a synonym of Melanommataceae, and new circumscriptions of Lophiostomataceae s. str, Massarinaceae and Lophiotrema are proposed. Familial positions of Entodesmium and Setomelanomma in Phaeosphaeriaceae, Neophaeosphaeria in Leptosphaeriaceae, Leptosphaerulina, Macroventuria and Platychora in Didymellaceae, Pleomassaria in Melanommataceae and Bimuria, Didymocrea, Karstenula and Paraphaeosphaeria in Montagnulaceae are clarified. Both ecological and morphological characters show varying degrees of phylogenetic significance. Pleosporales is most likely derived from a saprobic ancestor with fissitunicate asci containing conspicuous ocular chambers and apical rings. Nutritional shifts in Pleosporales likely occured from saprotrophic to hemibiotrophic or biotrophic

Typologie morpho-génétique des marelles du marais littoral de la baie de Kangiqsualujjuaq, estuaire du George, Québec nordique

Des marées d'un très grand marnage (12 m aux vives-eaux) caractérisent l'estuaire du George. Dans la partie supérieure des marais littoraux, la faible fréquence des submersions et l'importance des surfaces à découvert permettent la croissance de gel intertidal sous forme de buttes de pergélisol et de gel saisonnier épais. Sur le marais littoral de la baie de Kangiqsualujjuaq, la dynamique du gel intertidal, l'activité glacielle et l'action sédimentaire des vagues, de la marée et de l'eau de ruissellement sont responsables de la formation et du développement de plus de 170 marelles littorales. On peut distinguer 10 types de marelles se répartissant selon le gradient inondation sur le marais, qui se divise topographiquement en marais inférieur, en marais supérieur sans gel intertidal et en marais supérieur avec gel intertidal. Les marelles créées par l'action du gel se trouvent dans les parties les plus hautes du marais qui sont protégées de l'action des vagues et des glaces flottantes. Les marelles produites par la dynamique sédimentaire de la baie se situent dans les secteurs exposés aux agents littoraux, surtout dans l'axe de l'ouverture de la baie sur l'estuaire. Le régime de température et de salinité des marelles dépend de facteurs externes, comme la fréquence de submersion par la marée ou les précipitations, mais également de facteurs internes, comme la situation topographique et la morphologie des bassins.Very large spring tides with a range of 12 m characterize the George River Estuary. In the upper marsh, unfrequent tidal covering and significant unsheltered areas permit the development of small mounds and heaved marsh surfaces. In the Kangiqsualujjuaq salt marsh, processes related to intertidal ground frost, shore-ice processes and sedimentological processes due to waves, tidal currents and overland flow are responsible of the existence of 170 pans. Ten types of pans are defined. They are distributed along the intertidal topographical gradient including three zones : lower marsh, upper marsh without frost and upper marsh underlain by permafrost. Pans formed by processes related to permafrost are located at the highest parts on the intertidal zone in areas sheltered from waves and ice drifting. Pans originating from hydraulic and sedimentological processes are concentrated in exposed sites that lie opposite of the opening of the bay. Temperature and salinity regimes of the pans depend on the frequency of tidal submersions and precipitations, as well as on topographic situation and basin morphology.Gezeiten mit sehr hoher Fluthôhe (12 m Springtiden) charakterisieren die Mundung des George-Flusses. Im oberen Teil der Kusten-Moraste ermoglichen die geringe Ùberschwemmungs-frequenz und erhebliche ungeschutzte Oberflachen die Zunahme von Gezeitenfrost in Form von Dauerfrost-Hugeln und von dichtem, saisonbedingtem Frost. Auf dem Kiisten-Morast der Bucht von Kangiqsualujjuaq sind die Dynamik des Frosts zwischen den Gezeiten, die Frost-Aktivitàt und die sedimentologische Wirkung der Wellen, der Gezeiten und des rieselnden Wassers verantwortlich fur die Bildung und Entwicklung von mehr als 170 kleinen Kusten-Pfuhlen. Man kann 10 Typen von kleinen Pfuhlen unterscheiden, die sich entsprechend dem Ùberschwemmungsgefàlle ùber den Morast verteilen, welcher sich topographisch in unteren Morast, hôheren Morast ohne Zwischengezeitenfrost und hôheren Morast mit Zwischengezeitenfrost teilt. Die kleinen, durch Frostwirkung geformten Pfùhle befinden sich in den hôchsten Teilen des Morasts, die vom Einflup der Wellen und des Treibeises geschùtzt sind. Die durch die Sediment-Dynamik der Bucht geschaffenen kleinen Pfùhle befinden sich in den Abschnitten, die den Einflussen der Kuste ausgesetzt sind, vor allem in der Achse der Ôffnung der Bucht auf die Flufi-Mundung. Das System der Temperatur und des Salzgehalts der kleinen Pfùhle hàngt von âuperen Faktoren ab, wie die Hàufigkeit der Uberschwemmung durch die Flut oder die Niederschlàge, aber auch von inneren Faktoren, wie die topographische Lage und die Morphologie der Becken

Calculation of renormalized viscosity and resistivity in magnetohydrodynamic turbulence

A self-consistent renormalization (RG) scheme has been applied to nonhelical magnetohydrodynamic turbulence with normalized cross helicity $\sigma_c =0$ and $\sigma_c \to 1$. Kolmogorov's 5/3 powerlaw is assumed in order to compute the renormalized parameters. It has been shown that the RG fixed point is stable for $d \ge d_c \approx 2.2$. The renormalized viscosity $\nu^*$ and resistivity $\eta^*$ have been calculated, and they are found to be positive for all parameter regimes. For $\sigma_c=0$ and large Alfv\'{e}n ratio (ratio of kinetic and magnetic energies) $r_A$, $\nu^*=0.36$ and $\eta^*=0.85$. As $r_A$ is decreased, $\nu^*$ increases and $\eta^*$ decreases, untill $r_A \approx 0.25$ where both $\nu^*$ and $\eta^*$ are approximately zero. For large $d$, both $\nu^*$ and $\eta^*$ vary as $d^{-1/2}$. The renormalized parameters for the case $\sigma_c \to 1$ are also reported.Comment: 19 pages REVTEX, 3 ps files (Phys. Plasmas, v8, 3945, 2001