Sample records for initiation burn model

  1. MESOSCALE MODELING OF DEFLAGRATION-INDUCED DECONSOLIDATION IN POLYMER-BONDED EXPLOSIVES

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Springer, H K; Glascoe, E A; Reaugh, J E

    Initially undamaged polymer-bonded explosives can transition from conductive burning to more violent convective burning via rapid deconsolidation at higher pressures. The pressure-dependent infiltration of cracks and pores, i.e., damage, by product gases at the burn-front is a key step in the transition to convective burning. However, the relative influence of pre-existing damage and the evolution of deflagration-induced damage during the transition to convective burning is not well understood. The objective of this study is to investigate the role of microstructure and initial pressurization on deconsolidation. We performed simulations using the multi-physics hydrocode, ALE3D. HMX-Viton A served as our model explosive.more » A Prout-Tompkins chemical kinetic model, Vielle's Law pressure-dependent burning, Gruneisen equation-of-state, and simplified strength model were used for the HMX. The propensity for deconsolidation increased with increasing defect size and decreasing initial pressurization, as measured by the increase in burning surface area. These studies are important because they enable the development of continuum-scale damage models and the design of inherently safer explosives.« less

  2. Combustion of a Polymer (PMMA) Sphere in Microgravity

    NASA Technical Reports Server (NTRS)

    Yang, Jiann C.; Hamins, Anthony; Donnelly, Michelle K.

    1999-01-01

    A series of low gravity, aircraft-based, experiments was conducted to investigate the combustion of supported thermoplastic polymer spheres under varying ambient conditions. The three types of thermoplastic investigated were polymethylmethacrylate (PMMA), polypropylene (PP). and polystyrene (PS). Spheres with diameters ranging from 2 mm to 6.35 mm were tested. The total initial pressure varied from 0.05 MPa to 0. 15 MPa whereas the ambient oxygen concentration varied from 19 % to 30 % (by volume). The ignition system consisted of a pair of retractable energized coils. Two CCD cameras recorded the burning histories of the spheres. The video sequences revealed a number of dynamic events including bubbling and sputtering, as well as soot shell formation and break-up during combustion of the spheres at reduced gravity. The ejection of combusting material from the burning spheres represents a fire hazard that must be considered at reduced gravity. The ejection process was found to be sensitive to polymer type. All average burning rates were measured to increase with initial sphere diameter and oxygen concentration, whereas the initial pressure had little effect. The three thermoplastic types exhibited different burning characteristics. For the same initial conditions, the burning rate of PP was slower than PMMA, whereas the burning rate of PS was comparable to PMMA. The transient diameter of the burning thermoplastic exhibited two distinct periods: an initial period (enduring approximately half of the total burn duration) when the diameter remained approximately constant, and a final period when the square of the diameter linearly decreased with time. A simple homogeneous two-phase model was developed to understand the changing diameter of the burning sphere. Its value is based on a competition between diameter reduction due to mass loss from burning and sputtering, and diameter expansion due to the processes of swelling (density decrease with heating) and bubble growth. The model relies on empirical parameters for input, such as the burning rate and the duration of the initial and final burning periods.

  3. Numerical computation of Pop plot

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Menikoff, Ralph

    The Pop plot — distance-of-run to detonation versus initial shock pressure — is a key characterization of shock initiation in a heterogeneous explosive. Reactive burn models for high explosives (HE) must reproduce the experimental Pop plot to have any chance of accurately predicting shock initiation phenomena. This report describes a methodology for automating the computation of a Pop plot for a specific explosive with a given HE model. Illustrative examples of the computation are shown for PBX 9502 with three burn models (SURF, WSD and Forest Fire) utilizing the xRage code, which is the Eulerian ASC hydrocode at LANL. Comparisonmore » of the numerical and experimental Pop plot can be the basis for a validation test or as an aid in calibrating the burn rate of an HE model. Issues with calibration are discussed.« less

  4. Large-Scale Aerosol Modeling and Analysis

    DTIC Science & Technology

    2010-09-30

    Application of Earth Sciences Products” supports improvements in NAAPS physics and model initialization. The implementation of NAAPS, NAVDAS-AOD, FLAMBE ...Forecasting of Biomass-Burning Smoke: Description of and Lessons From the Fire Locating and Modeling of Burning Emissions ( FLAMBE ) Program, IEEE Journal of

  5. Aspects of Cool-Flame Supported Droplet Combustion in Microgravity

    NASA Technical Reports Server (NTRS)

    Nayagam, Vedha; Dietrich, Daniel L.; Williams, Forman A.

    2015-01-01

    Droplet combustion experiments performed on board the International Space Station have shown that normal-alkane fuels with negative temperature coefficient (NTC) chemistry can support quasi-steady, low-temperature combustion without any visible flame. Here we review the results for n-decane, n-heptane, and n-octane droplets burning in carbon dioxidehelium diluted environments at different pressures and initial droplet sizes. Experimental results for cool-flame burning rates, flame standoff ratios, and extinction diameters are compared against simplified theoretical models of the phenomenon. A simplified quasi-steady model based on the partial-burning regime of Lin predicts the burning rate, and flame standoff ratio reasonably well for all three normal alkanes. The second-stage cool-flame burning and extinction following the first-stage hot-flame combustion, however, shows a small dependence on the initial droplet size, thus deviating from the quasi-steady results. An asymptotic model that estimates the oxygen depletion by the hot flame and its influence on cool-flame burning rates is shown to correct the quasi-steady results and provide a better comparison with the measured burning-rate results.This work was supported by the NASA Space Life and Physical Sciences Research and Applications Program and the International Space Station Program.

  6. Characteristics code for shock initiation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Partom, Y.

    1986-10-01

    We developed SHIN, a characteristics code for shock initiation studies. We describe in detail the equations of state, reaction model, rate equations, and numerical difference equations that SHIN incorporates. SHIN uses the previously developed surface burning reaction model which better represents the shock initiation process in TATB, than do bulk reaction models. A large number of computed simulations prove the code is a reliable and efficient tool for shock initiation studies. A parametric study shows the effect on build-up and run distance to detonation of (1) type of boundary condtion, (2) burning velocity curve, (3) shock duration, (4) rise timemore » in ramp loading, (5) initial density (or porosity) of the explosive, (6) initial temperature, and (7) grain size. 29 refs., 65 figs.« less

  7. Reacting Chemistry Based Burn Model for Explosive Hydrocodes

    NASA Astrophysics Data System (ADS)

    Schwaab, Matthew; Greendyke, Robert; Steward, Bryan

    2017-06-01

    Currently, in hydrocodes designed to simulate explosive material undergoing shock-induced ignition, the state of the art is to use one of numerous reaction burn rate models. These burn models are designed to estimate the bulk chemical reaction rate. Unfortunately, these models are largely based on empirical data and must be recalibrated for every new material being simulated. We propose that the use of an equilibrium Arrhenius rate reacting chemistry model in place of these empirically derived burn models will improve the accuracy for these computational codes. Such models have been successfully used in codes simulating the flow physics around hypersonic vehicles. A reacting chemistry model of this form was developed for the cyclic nitramine RDX by the Naval Research Laboratory (NRL). Initial implementation of this chemistry based burn model has been conducted on the Air Force Research Laboratory's MPEXS multi-phase continuum hydrocode. In its present form, the burn rate is based on the destruction rate of RDX from NRL's chemistry model. Early results using the chemistry based burn model show promise in capturing deflagration to detonation features more accurately in continuum hydrocodes than previously achieved using empirically derived burn models.

  8. Infection Casualty Estimation (ICE) Model: Predicting Sepsis in Nuclear Detonation Burn Patient Populations using Procalcitonin as a Biomarker

    DTIC Science & Technology

    2017-06-06

    environments may be injured or killed from the primary blast wave, thermal pulse and ionizing radiation . Burn casualties surviving the initial blast wave are...32]/1.8 degree Celsius (oC) degree Fahrenheit (oF) [T(oF) + 459.67]/1.8 kelvin (K) Radiation activity of radionuclides [curie (Ci)] 3.7 × 1010...develop casualty estimation models for improvised nuclear device (IND) scenarios. The HSRDIPT team has developed health effects models of radiation , burn

  9. Modeling Smoke Plume-Rise and Dispersion from Southern United States Prescribed Burns with Daysmoke.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Achtemeier, Gary, L.; Goodrick, Scott, A.; Liu, Yongqiang

    2011-08-19

    We present Daysmoke, an empirical-statistical plume rise and dispersion model for simulating smoke from prescribed burns. Prescribed fires are characterized by complex plume structure including multiple-core updrafts which makes modeling with simple plume models difficult. Daysmoke accounts for plume structure in a three-dimensional veering/sheering atmospheric environment, multiple-core updrafts, and detrainment of particulate matter. The number of empirical coefficients appearing in the model theory is reduced through a sensitivity analysis with the Fourier Amplitude Sensitivity Test (FAST). Daysmoke simulations for 'bent-over' plumes compare closely with Briggs theory although the two-thirds law is not explicit in Daysmoke. However, the solutions for themore » 'highly-tilted' plume characterized by weak buoyancy, low initial vertical velocity, and large initial plume diameter depart considerably from Briggs theory. Results from a study of weak plumes from prescribed burns at Fort Benning GA showed simulated ground-level PM2.5 comparing favorably with observations taken within the first eight kilometers of eleven prescribed burns. Daysmoke placed plume tops near the lower end of the range of observed plume tops for six prescribed burns. Daysmoke provides the levels and amounts of smoke injected into regional scale air quality models. Results from CMAQ with and without an adaptive grid are presented.« less

  10. Comparison Between Surf and Multi-Shock Forest Fire High Explosive Burn Models

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Greenfield, Nicholas Alexander

    PAGOSA1 has several different burn models used to model high explosive detonation. Two of these, Multi-Shock Forest Fire and Surf, are capable of modeling shock initiation. Accurately calculating shock initiation of a high explosive is important because it is a mechanism for detonation in many accident scenarios (i.e. fragment impact). Comparing the models to pop-plot data give confidence that the models are accurately calculating detonation or lack thereof. To compare the performance of these models, pop-plots2 were created from simulations where one two cm block of PBX 9502 collides with another block of PBX 9502.

  11. Initial fuel temperature effects on burning rate of pool fire.

    PubMed

    Chen, Bing; Lu, Shou-Xiang; Li, Chang-Hai; Kang, Quan-Sheng; Lecoustre, Vivien

    2011-04-15

    The influence of the initial fuel temperature on the burning behavior of n-heptane pool fire was experimentally studied at the State Key Laboratory of Fire Science (SKLFS) large test hall. Circular pool fires with diameters of 100mm, 141 mm, and 200 mm were considered with initial fuel temperatures ranging from 290 K to 363 K. Burning rate and temperature distributions in fuel and vessel wall were recorded during the combustion. The burning rate exhibited five typical stages: initial development, steady burning, transition, bulk boiling burning, and decay. The burning rate during the steady burning stage was observed to be relatively independent of the initial fuel temperature. In contrast, the burning rate of the bulk boiling burning stage increases with increased initial fuel temperature. It was also observed that increased initial fuel temperature decreases the duration of steady burning stage. When the initial temperature approaches the boiling point, the steady burning stage nearly disappears and the burning rate moves directly from the initial development stage to the transition stage. The fuel surface temperature increases to its boiling point at the steady burning stage, shortly after ignition, and the bulk liquid reaches boiling temperature at the bulk boiling burning stage. No distinguished cold zone is formed in the fuel bed. However, boiling zone is observed and the thickness increases to its maximum value when the bulk boiling phenomena occurs. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Building a balanced scorecard for a burn center.

    PubMed

    Wachtel, T L; Hartford, C E; Hughes, J A

    1999-08-01

    The Balanced Scorecard provides a model that can be adapted to the management of any burn center, burn service or burn program. This model enables an organization to translate its mission and vision into specific strategic objectives across the four perspective: (1) the financial perspective; (2) the customer service perspective; (3) the internal business perspective; and (4) the growth and learning perspective. Once the appropriate objectives are identified, the Balanced Scorecard guides the organization to develop reasonable performance measures and establishes targets, initiatives and alternatives to meet programmatic goals and pursue longer-term visionary improvements. We used the burn center at the University of Colorado Health Sciences Center to test whether the Balanced Scorecard methodology was appropriate for the core business plan of a healthcare strategic business unit (i.e. a burn center).

  13. Model assessing the impact of biomass burning on air quality and photochemistry in Mexico City

    Treesearch

    W. Lei; G. Li; C. Wiedinmyer; R. J. Yokelson; L. T. Molina

    2010-01-01

    Biomass burning is a major global emission source for trace gases and particulates. Various multi-platform measurements during the Mexico City Metropolitan Area (MCMA)-2003 and Megacity Initiative: Local and Global Research Observations (MILAGRO)-2006 campaigns suggest significant influences of biomass burning (BB) on air quality in Mexico City during the dry season,...

  14. Propagation of Cutaneous Thermal Injury: A Mathematical Model

    PubMed Central

    Xue, Chuan; Chou, Ching-Shan; Kao, Chiu-Yen; Sen, Chandan K.; Friedman, Avner

    2012-01-01

    Cutaneous burn wounds represent a significant public health problem with 500,000 patients per year in the U.S. seeking medical attention. Immediately after skin burn injury, the volume of the wound burn expands due to a cascade of chemical reactions, including lipid peroxidation chain reactions. Based on these chemical reactions, the present paper develops for the first time a three-dimensional mathematical model to quantify the propagation of tissue damage within 12 hours post initial burn. We use the model to investigate the effect of supplemental antioxidant vitamin E for stopping the propagation. We show, for example, that if the production rate of vitamin E is increased, post burn, by five times the natural production in a healthy tissue, then this would slow down the lipid peroxide propagation by at least 50%. Our model is formulated in terms of differential equations, and sensitivity analysis is performed on the parameters to ensure the robustness of the results. PMID:22211391

  15. A numerical modeling investigation of erosion and debris flows following the 2016 Fish Fire in the San Gabriel Mountains, CA, USA

    NASA Astrophysics Data System (ADS)

    Tang, H.; McGuire, L.; Rengers, F. K.; Kean, J. W.; Staley, D. M.

    2017-12-01

    Wildfire significantly changes the hydrological characteristics of soil for a period of several years and increases the likelihood of flooding and debris flows during high-intensity rainfall in steep watersheds. Hazards related to post-fire flooding and debris flows increase as populations expand into mountainous areas that are susceptible to wildfire, post-wildfire flooding, and debris flows. However, our understanding of post-wildfire debris flows is limited due to a paucity of direct observations and measurements, partially due to the remote locations where debris flows tend to initiate. In these situations, numerical modeling becomes a very useful tool for studying post-wildfire debris flows. Research based on numerical modeling improves our understanding of the physical mechanisms responsible for the increase in erosion and consequent formation of debris flows in burned areas. In this contribution, we study changes in sediment transport efficiency with time since burning by combining terrestrial laser scanning (TLS) surveys of a hillslope burned during the 2016 Fish Fire with numerical modeling of overland flow and sediment transport. We also combine the numerical model with measurements of debris flow timing to explore relationships between post-wildfire rainfall characteristics, soil infiltration capacity, hillslope erosion, and debris flow initiation at the drainage basin scale. Field data show that an initial rill network developed on the hillslope, and became more efficient over time as the overall rill density decreased. Preliminary model results suggest that this can be achieved when flow driven detachment mechanisms dominate and raindrop-driven detachment is minimized. Results also provide insight into the hydrologic and geomorphic conditions that lead to debris flow initiation within recently burned areas.

  16. Influence of Initial Moisture Content on Heat and Moisture Transfer in Firefighters' Protective Clothing

    PubMed Central

    He, Song

    2017-01-01

    This paper presents a model for heat and moisture transfer through firefighters' protective clothing (FPC) during radiation exposure. The model, which accounts for air gaps in the FPC as well as heat transfer through human skin, investigates the effect of different initial moisture contents on the thermal insulation performance of FPC. Temperature, water vapor density, and the volume fraction of liquid water profiles were monitored during the simulation, and the heat quantity absorbed by water evaporation was calculated. Then the maximum durations of heat before the wearer acquires first- and second-degree burns were calculated based on the bioheat transfer equation and the Henriques equation. The results show that both the moisture weight in each layer and the total moisture weight increase linearly within a given environmental humidity level. The initial moisture content in FPC samples significantly influenced the maximum water vapor density. The first- and second-degree burn injury time increase 16 sec and 18 sec when the RH increases from 0% to 90%. The total quantity of heat accounted for by water evaporation was about 10% when the relative humidity (RH) is 80%. Finally, a linear relationship was identified between initial moisture content and the human skin burn injury time before suffering first- and second-degree burn injuries. PMID:28466066

  17. Influence of Initial Moisture Content on Heat and Moisture Transfer in Firefighters' Protective Clothing.

    PubMed

    Huang, Dongmei; He, Song

    2017-01-01

    This paper presents a model for heat and moisture transfer through firefighters' protective clothing (FPC) during radiation exposure. The model, which accounts for air gaps in the FPC as well as heat transfer through human skin, investigates the effect of different initial moisture contents on the thermal insulation performance of FPC. Temperature, water vapor density, and the volume fraction of liquid water profiles were monitored during the simulation, and the heat quantity absorbed by water evaporation was calculated. Then the maximum durations of heat before the wearer acquires first- and second-degree burns were calculated based on the bioheat transfer equation and the Henriques equation. The results show that both the moisture weight in each layer and the total moisture weight increase linearly within a given environmental humidity level. The initial moisture content in FPC samples significantly influenced the maximum water vapor density. The first- and second-degree burn injury time increase 16 sec and 18 sec when the RH increases from 0% to 90%. The total quantity of heat accounted for by water evaporation was about 10% when the relative humidity (RH) is 80%. Finally, a linear relationship was identified between initial moisture content and the human skin burn injury time before suffering first- and second-degree burn injuries.

  18. The Synthesis of 44Ti and 56Ni in Massive Stars

    NASA Astrophysics Data System (ADS)

    Chieffi, Alessandro; Limongi, Marco

    2017-02-01

    We discuss the influence of rotation on the combined synthesis of {}44{Ti} and {}56{Ni} in massive stars. While {}56{Ni} is significantly produced by both complete and incomplete explosive Si burning, {}44{Ti} is mainly produced by complete explosive Si burning, with a minor contribution (in standard non-rotating models) from incomplete explosive Si burning and O burning (both explosive and hydrostatic). We find that, in most cases, the thickness of the region exposed to incomplete explosive Si burning increases in rotating models (initial velocity, v ini = 300 km s-1) and since {}56{Ni} is significantly produced in this zone, the fraction of mass coming from the complete explosive Si burning zone necessary to get the required amount of {}56{Ni} reduces. Therefore the amount of {}44{Ti} ejected for a given fixed amount of {}56{Ni} decreases in rotating models. However, some rotating models at [Fe/H] = -1 develop a very extended O convective shell in which a consistent amount of {}44{Ti} is formed, preserved, and ejected in the interstellar medium. Hence a better modeling of the thermal instabilities (convection) in the advanced burning phases together with a critical analysis of the cross sections of the nuclear reactions operating in O burning are relevant for the understanding of the synthesis of {}44{Ti}.

  19. The First 3D Simulations of Carbon Burning in a Massive Star

    NASA Astrophysics Data System (ADS)

    Cristini, A.; Meakin, C.; Hirschi, R.; Arnett, D.; Georgy, C.; Viallet, M.

    2017-11-01

    We present the first detailed three-dimensional hydrodynamic implicit large eddy simulations of turbulent convection for carbon burning. The simulations start with an initial radial profile mapped from a carbon burning shell within a 15 M⊙ stellar evolution model. We considered 4 resolutions from 1283 to 10243 zones. These simulations confirm that convective boundary mixing (CBM) occurs via turbulent entrainment as in the case of oxygen burning. The expansion of the boundary into the surrounding stable region and the entrainment rate are smaller at the bottom boundary because it is stiffer than the upper boundary. The results of this and similar studies call for improved CBM prescriptions in 1D stellar evolution models.

  20. Determination of deuterium–tritium critical burn-up parameter by four temperature theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nazirzadeh, M.; Ghasemizad, A.; Khanbabei, B.

    Conditions for thermonuclear burn-up of an equimolar mixture of deuterium-tritium in non-equilibrium plasma have been investigated by four temperature theory. The photon distribution shape significantly affects the nature of thermonuclear burn. In three temperature model, the photon distribution is Planckian but in four temperature theory the photon distribution has a pure Planck form below a certain cut-off energy and then for photon energy above this cut-off energy makes a transition to Bose-Einstein distribution with a finite chemical potential. The objective was to develop four temperature theory in a plasma to calculate the critical burn up parameter which depends upon initialmore » density, the plasma components initial temperatures, and hot spot size. All the obtained results from four temperature theory model are compared with 3 temperature model. It is shown that the values of critical burn-up parameter calculated by four temperature theory are smaller than those of three temperature model.« less

  1. A trajectory modeling investigation of the biomass burning-tropical ozone relationship

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.; Thompson, Anne M.; Mcnamara, Donna P.; Schoeberl, Mark R.; Lait, Leslie R.; Newman, Paul A.; Justice, Christopher O.; Kendall, Jacqueline D.

    1994-01-01

    The hypothesis that tropical total O3 maxima seen by the TOMS satellite derive from African biomass burning has been tested using isentropic trajectory analyses with global meteorological data fields. Two case studies from the 1989 biomass burning season demonstrate that a large fraction of the air arriving at the location of TOMS O3 maxima passed over regions of intense burning. Other trajectories initiated at a series of points over Africa and the Atlantic suggest flight strategies for field studies to be conducted in September 1992.

  2. Shock Detector for SURF model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Menikoff, Ralph

    2016-01-11

    SURF and its extension SURFplus are reactive burn models aimed at shock initiation and propagation of detonation waves in high explosives. A distinctive feature of these models is that the burn rate depends on the lead shock pressure. A key part of the models is an algorithm to detect the lead shock. Typically, shock capturing hydro algorithms have small oscillations behind a shock. Here we investigate how well the shock detection algorithm works for a nearly steady propagating detonation wave in one-dimension using the Eulerian xRage code.

  3. A mesoscopic reaction rate model for shock initiation of multi-component PBX explosives.

    PubMed

    Liu, Y R; Duan, Z P; Zhang, Z Y; Ou, Z C; Huang, F L

    2016-11-05

    The primary goal of this research is to develop a three-term mesoscopic reaction rate model that consists of a hot-spot ignition, a low-pressure slow burning and a high-pressure fast reaction terms for shock initiation of multi-component Plastic Bonded Explosives (PBX). Thereinto, based on the DZK hot-spot model for a single-component PBX explosive, the hot-spot ignition term as well as its reaction rate is obtained through a "mixing rule" of the explosive components; new expressions for both the low-pressure slow burning term and the high-pressure fast reaction term are also obtained by establishing the relationships between the reaction rate of the multi-component PBX explosive and that of its explosive components, based on the low-pressure slow burning term and the high-pressure fast reaction term of a mesoscopic reaction rate model. Furthermore, for verification, the new reaction rate model is incorporated into the DYNA2D code to simulate numerically the shock initiation process of the PBXC03 and the PBXC10 multi-component PBX explosives, and the numerical results of the pressure histories at different Lagrange locations in explosive are found to be in good agreements with previous experimental data. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Optimization of Equation of State and Burn Model Parameters for Explosives

    NASA Astrophysics Data System (ADS)

    Bergh, Magnus; Wedberg, Rasmus; Lundgren, Jonas

    2017-06-01

    A reactive burn model implemented in a multi-dimensional hydrocode can be a powerful tool for predicting non-ideal effects as well as initiation phenomena in explosives. Calibration against experiment is, however, critical and non-trivial. Here, a procedure is presented for calibrating the Ignition and Growth Model utilizing hydrocode simulation in conjunction with the optimization program LS-OPT. The model is applied to the explosive PBXN-109. First, a cylinder expansion test is presented together with a new automatic routine for product equation of state calibration. Secondly, rate stick tests and instrumented gap tests are presented. Data from these experiments are used to calibrate burn model parameters. Finally, we discuss the applicability and development of this optimization routine.

  5. Study of Burn Scar Extraction Automatically Based on Level Set Method using Remote Sensing Data

    PubMed Central

    Liu, Yang; Dai, Qin; Liu, JianBo; Liu, ShiBin; Yang, Jin

    2014-01-01

    Burn scar extraction using remote sensing data is an efficient way to precisely evaluate burn area and measure vegetation recovery. Traditional burn scar extraction methodologies have no well effect on burn scar image with blurred and irregular edges. To address these issues, this paper proposes an automatic method to extract burn scar based on Level Set Method (LSM). This method utilizes the advantages of the different features in remote sensing images, as well as considers the practical needs of extracting the burn scar rapidly and automatically. This approach integrates Change Vector Analysis (CVA), Normalized Difference Vegetation Index (NDVI) and the Normalized Burn Ratio (NBR) to obtain difference image and modifies conventional Level Set Method Chan-Vese (C-V) model with a new initial curve which results from a binary image applying K-means method on fitting errors of two near-infrared band images. Landsat 5 TM and Landsat 8 OLI data sets are used to validate the proposed method. Comparison with conventional C-V model, OSTU algorithm, Fuzzy C-mean (FCM) algorithm are made to show that the proposed approach can extract the outline curve of fire burn scar effectively and exactly. The method has higher extraction accuracy and less algorithm complexity than that of the conventional C-V model. PMID:24503563

  6. Recent Biomass Burning in the Tropics and Related Changes in Tropospheric Ozone

    NASA Technical Reports Server (NTRS)

    Ziemke; Chandra, J. R. S.; Duncan, B. N.; Schoeberl, M. R.; Torres, O.; Damon, M. R.; Bhartia, P. K.

    2009-01-01

    Biomass burning is an important source of chemical precursors of tropospheric ozone. In the tropics, biomass burning produces ozone enhancements over broad regions of Indonesia, Africa, and South America including Brazil. Fires are intentionally set in these regions during the dry season each year to clear cropland and to clear land for human/industrial expansion. In Indonesia enhanced burning occurs during dry El Nino conditions such as in 1997 and 2006. These burning activities cause enhancement in atmospheric particulates and trace gases which are harmful to human health. Measurements from the Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) from October 2004-November 2008 are used to evaluate the effects of biomass burning on tropical tropospheric ozone. These measurements show sizeable decreases approx.15-20% in ozone in Brazil during 2008 compared to 2007 which we attribute to the reduction in biomass burning. Three broad biomass burning regions in the tropics (South America including Brazil, western Africa, and Indonesia) were analyzed in the context of OMI/MLS measurements and the Global Modeling Initiative (GMI) chemical transport model developed at Goddard Space Flight Center. The results indicate that the impact of biomass burning on ozone is significant within and near the burning regions with increases of approx.10-25% in tropospheric column ozone relative to average background concentrations. The model suggests that about half of the increases in ozone from these burning events come from altitudes below 3 km. Globally the model indicates increases of approx.4-5% in ozone, approx.7-9% in NO, (NO+NO2), and approx.30-40% in CO.

  7. Ballistically Initiated Fire Ball Generation Using M&S: Innovation Grant (Briefing Charts)

    DTIC Science & Technology

    2012-01-26

    isotropic in nature Phenomenological models for explosives initiation. – HVRB, forest fire etc. Equation of state – Ideal gas, Mie-Gruneisen, JWL ...perfectly plastic description • EOS • Mie Gruneisen • JWL for explosive • Phenomenological Model for EFP • High Explosive input for programmed burn

  8. The treatment of mixing in core helium-burning models - III. Suppressing core breathing pulses with a new constraint on overshoot

    NASA Astrophysics Data System (ADS)

    Constantino, Thomas; Campbell, Simon W.; Lattanzio, John C.

    2017-12-01

    Theoretical predictions for the core helium burning phase of stellar evolution are highly sensitive to the uncertain treatment of mixing at convective boundaries. In the last few years, interest in constraining the uncertain structure of their deep interiors has been renewed by insights from asteroseismology. Recently, Spruit proposed a limit for the rate of growth of helium-burning convective cores based on the higher buoyancy of material ingested from outside the convective core. In this paper we test the implications of such a limit for stellar models with a range of initial mass and metallicity. We find that the constraint on mixing beyond the Schwarzschild boundary has a significant effect on the evolution late in core helium burning, when core breathing pulses occur and the ingestion rate of helium is fastest. Ordinarily, core breathing pulses prolong the core helium burning lifetime to such an extent that models are at odds with observations of globular cluster populations. Across a wide range of initial stellar masses (0.83 ≤ M/M⊙ ≤ 5), applying the Spruit constraint reduces the core helium burning lifetime because core breathing pulses are either avoided or their number and severity reduced. The constraint suggested by Spruit therefore helps to resolve significant discrepancies between observations and theoretical predictions. Specifically, we find improved agreement for R2 (the observed ratio of asymptotic giant branch to horizontal branch stars in globular clusters), the luminosity difference between these two groups, and in asteroseismology, the mixed-mode period spacing detected in red clump stars in the Kepler field.

  9. The wound/burn guidelines - 6: Guidelines for the management of burns.

    PubMed

    Yoshino, Yuichiro; Ohtsuka, Mikio; Kawaguchi, Masakazu; Sakai, Keisuke; Hashimoto, Akira; Hayashi, Masahiro; Madokoro, Naoki; Asano, Yoshihide; Abe, Masatoshi; Ishii, Takayuki; Isei, Taiki; Ito, Takaaki; Inoue, Yuji; Imafuku, Shinichi; Irisawa, Ryokichi; Ohtsuka, Masaki; Ogawa, Fumihide; Kadono, Takafumi; Kawakami, Tamihiro; Kukino, Ryuichi; Kono, Takeshi; Kodera, Masanari; Takahara, Masakazu; Tanioka, Miki; Nakanishi, Takeshi; Nakamura, Yasuhiro; Hasegawa, Minoru; Fujimoto, Manabu; Fujiwara, Hiroshi; Maekawa, Takeo; Matsuo, Koma; Yamasaki, Osamu; Le Pavoux, Andres; Tachibana, Takao; Ihn, Hironobu

    2016-09-01

    Burns are a common type of skin injury encountered at all levels of medical facilities from private clinics to core hospitals. Minor burns heal by topical treatment alone, but moderate to severe burns require systemic management, and skin grafting is often necessary also for topical treatment. Inappropriate initial treatment or delay of initial treatment may exert adverse effects on the subsequent treatment and course. Therefore, accurate evaluation of the severity and initiation of appropriate treatment are necessary. The Guidelines for the Management of Burn Injuries were issued in March 2009 from the Japanese Society for Burn Injuries as guidelines concerning burns, but they were focused on the treatment for extensive and severe burns in the acute period. Therefore, we prepared guidelines intended to support the appropriate diagnosis and initial treatment for patients with burns that are commonly encountered including minor as well as moderate and severe cases. Because of this intention of the present guidelines, there is no recommendation of individual surgical procedures. © 2016 Japanese Dermatological Association.

  10. Quantifying soil burn severity for hydrologic modeling to assess post-fire effects on sediment delivery

    NASA Astrophysics Data System (ADS)

    Dobre, Mariana; Brooks, Erin; Lew, Roger; Kolden, Crystal; Quinn, Dylan; Elliot, William; Robichaud, Pete

    2017-04-01

    Soil erosion is a secondary fire effect with great implications for many ecosystem resources. Depending on the burn severity, topography, and the weather immediately after the fire, soil erosion can impact municipal water supplies, degrade water quality, and reduce reservoirs' storage capacity. Scientists and managers use field and remotely sensed data to quickly assess post-fire burn severity in ecologically-sensitive areas. From these assessments, mitigation activities are implemented to minimize post-fire flood and soil erosion and to facilitate post-fire vegetation recovery. Alternatively, land managers can use fire behavior and spread models (e.g. FlamMap, FARSITE, FOFEM, or CONSUME) to identify sensitive areas a priori, and apply strategies such as fuel reduction treatments to proactively minimize the risk of wildfire spread and increased burn severity. There is a growing interest in linking fire behavior and spread models with hydrology-based soil erosion models to provide site-specific assessment of mitigation treatments on post-fire runoff and erosion. The challenge remains, however, that many burn severity mapping and modeling products quantify vegetation loss rather than measuring soil burn severity. Wildfire burn severity is spatially heterogeneous and depends on the pre-fire vegetation cover, fuel load, topography, and weather. Severities also differ depending on the variable of interest (e.g. soil, vegetation). In the United States, Burned Area Reflectance Classification (BARC) maps, derived from Landsat satellite images, are used as an initial burn severity assessment. BARC maps are classified from either a Normalized Burn Ratio (NBR) or differenced Normalized Burned Ratio (dNBR) scene into four classes (Unburned, Low, Moderate, and High severity). The development of soil burn severity maps requires further manual field validation efforts to transform the BARC maps into a product more applicable for post-fire soil rehabilitation activities. Alternative spectral indices and modeled output approaches may prove better predictors of soil burn severity and hydrologic effects, but these have not yet been assessed in a model framework. In this project we compare field-verified soil burn severity maps to satellite-derived and modeled burn severity maps. We quantify the extent to which there are systematic differences in these mapping products. We then use the Water Erosion Prediction Project (WEPP) hydrologic soil erosion model to assess sediment delivery from these fires using the predicted and observed soil burn severity maps. Finally, we discuss differences in observed and predicted soil burn severity maps and application to watersheds in the Pacific Northwest to estimate post-fire sediment delivery.

  11. Development of a reactive burn model based on an explicit viscoplastic pore collapse model

    NASA Astrophysics Data System (ADS)

    Bouton, E.; Lefrançois, A.; Belmas, R.

    2017-01-01

    The aim of this study is to develop a reactive burn model based upon a microscopic hot spot model to compute the shock-initiation of pressed TATB high explosives. Such a model has been implemented in a lagrangian hydrodynamic code. In our calculations, 8 pore radii, ranging from 40 nm to 0.63 μm, have been taken into account and the porosity fraction associated to each void radius has been deduced from the Ultra-Small-Angle X-ray Scattering measurements (USAXS) for PBX-9502. The last parameter of our model is a burn rate that depends on three variables. The first two are the reaction progress variable and the lead shock pressure, the last one is the chemical reaction site number produced in the flow and calculated by the microscopic model. This burn rate has been calibrated by fitting pressure, velocity profiles and run distances to detonation. As the computed results are in close agreement with the measured ones, this model is able to perform a wide variety of numerical simulations including single, double shock waves and the desensitization phenomenon.

  12. Establishing a Reproducible Hypertrophic Scar following Thermal Injury: A Porcine Model

    PubMed Central

    Rapp, Scott J.; Rumberg, Aaron; Visscher, Marty; Billmire, David A.; Schwentker, Ann S.

    2015-01-01

    Background: Our complete understanding of hypertrophic scarring is still deficient, as portrayed by the poor clinical outcomes when treating them. To address the need for alternative treatment strategies, we assess the swine animal burn model as an initial approach for immature scar evaluation and therapeutic application. Methods: Thermal contact burns were created on the dorsum of 3 domestic swine with the use of a branding iron at 170°F for 20 seconds. Deep partial-thickness burns were cared for with absorptive dressings over 10 weeks and wounds evaluated with laser and negative pressure transduction, histology, photographic analysis, and RNA isolation. Results: Overall average stiffness (mm Hg/mm) increased and elasticity (mm) decreased in the scars from the initial burn injury to 8 weeks when compared with normal skin (P < 0.01). Scars were thicker, more erythematous, and uniform in the caudal dorsum. The percent change of erythema in wounds increased from weeks 6 to 10. Histology demonstrated loss of dermal papillae, increased myofibroblast presence, vertically oriented vessels, epidermal and dermal hypercellularity, and parallel-layered collagen deposition. Immature scars remained elevated at 10 weeks, and minimal RNA was able to be isolated from the tissue. Conclusions: Deep partial-thickness thermal injury to the back of domestic swine produces an immature hypertrophic scar by 10 weeks following burn with thickness appearing to coincide with the location along the dorsal axis. With minimal pig to pig variation, we describe our technique to provide a testable immature scar model. PMID:25750848

  13. Astaxanthin protects against early burn-wound progression in rats by attenuating oxidative stress-induced inflammation and mitochondria-related apoptosis

    PubMed Central

    Fang, Quan; Guo, Songxue; Zhou, Hanlei; Han, Rui; Wu, Pan; Han, Chunmao

    2017-01-01

    Burn-wound progression can occur in the initial or peri-burn area after a deep burn injury. The stasis zone has a higher risk of deterioration mediated by multiple factors but is also considered salvageable. Astaxanthin (ATX), which is extracted from some marine organisms, is a natural compound with a strong antioxidant effect that has been reported to attenuate organ injuries caused by traumatic injuries. Hence, we investigated the potential effects of ATX on preventing early burn-wound progression. A classic “comb” burn rat model was established in this study for histological and biological assessments, which revealed that ATX, particularly higher doses, alleviated histological deterioration in the stasis zone. Additionally, we observed dose-dependent improvements in oxidative stress and the release of inflammatory mediators after ATX treatment. Furthermore, ATX dose-dependently attenuated burn-induced apoptosis in the wound areas, and this effect was accompanied by increases in Akt and Bad phosphorylation and a downregulation of cytochrome C and caspase expression. In addition, the administration of Ly 294002 further verified the effect of ATX. In summary, we demonstrated that ATX protected against early burn-wound progression in a rat deep-burn model. This protection might be mediated by the attenuation of oxidative stress-induced inflammation and mitochondria-related apoptosis. PMID:28128352

  14. Burns education for non-burn specialist clinicians in Western Australia.

    PubMed

    McWilliams, Tania; Hendricks, Joyce; Twigg, Di; Wood, Fiona

    2015-03-01

    Burn patients often receive their initial care by non-burn specialist clinicians, with increasingly collaborative burn models of care. The provision of relevant and accessible education for these clinicians is therefore vital for optimal patient care. A two phase design was used. A state-wide survey of multidisciplinary non-burn specialist clinicians throughout Western Australia identified learning needs related to paediatric burn care. A targeted education programme was developed and delivered live via videoconference. Pre-post-test analysis evaluated changes in knowledge as a result of attendance at each education session. Non-burn specialist clinicians identified numerous areas of burn care relevant to their practice. Statistically significant differences between perceived relevance of care and confidence in care provision were reported for aspects of acute burn care. Following attendance at the education sessions, statistically significant increases in knowledge were noted for most areas of acute burn care. Identification of learning needs facilitated the development of a targeted education programme for non-burn specialist clinicians. Increased non-burn specialist clinician knowledge following attendance at most education sessions supports the use of videoconferencing as an acceptable and effective method of delivering burns education in Western Australia. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  15. Internal and Surface Phenomena in Heterogenous Metal Combustion

    NASA Technical Reports Server (NTRS)

    Dreizin, Edward L.

    1997-01-01

    The phenomenon of gas dissolution in burning metals was observed in recent metal combustion studies, but it could not be adequately explained by the traditional metal combustion models. The research reported here addresses heterogeneous metal combustion with emphasis on the processes of oxygen penetration inside burning metal and its influence on the metal combustion rate, temperature history, and disruptive burning. The unique feature of this work is the combination of the microgravity environment with a novel micro-arc generator of monodispersed metal droplets, ensuring repeatable formation and ignition of uniform metal droplets with a controllable initial temperature and velocity. Burning droplet temperature is measured in real time with a three wavelength pyrometer. In addition, particles are rapidly quenched at different combustion times, cross-sectioned, and examined using SEM-based techniques to retrieve the internal composition history of burning metal particles. When the initial velocity of a spherical particle is nearly zero, the microgravity environment makes it possible to study the flame structure, the development of flame nonsymmetry, and correlation of the flame shape with the heterogeneous combustion processes.

  16. Burn injury models of care: A review of quality and cultural safety for care of Indigenous children.

    PubMed

    Fraser, Sarah; Grant, Julian; Mackean, Tamara; Hunter, Kate; Holland, Andrew J A; Clapham, Kathleen; Teague, Warwick J; Ivers, Rebecca Q

    2018-05-01

    Safety and quality in the systematic management of burn care is important to ensure optimal outcomes. It is not clear if or how burn injury models of care uphold these qualities, or if they provide a space for culturally safe healthcare for Indigenous peoples, especially for children. This review is a critique of publically available models of care analysing their ability to facilitate safe, high-quality burn care for Indigenous children. Models of care were identified and mapped against cultural safety principles in healthcare, and against the National Health and Medical Research Council standard for clinical practice guidelines. An initial search and appraisal of tools was conducted to assess suitability of the tools in providing a mechanism to address quality and cultural safety. From the 53 documents found, 6 were eligible for review. Aspects of cultural safety were addressed in the models, but not explicitly, and were recorded very differently across all models. There was also limited or no cultural consultation documented in the models of care reviewed. Quality in the documents against National Health and Medical Research Council guidelines was evident; however, description or application of quality measures was inconsistent and incomplete. Gaps concerning safety and quality in the documented care pathways for Indigenous peoples' who sustain a burn injury and require burn care highlight the need for investigation and reform of current practices. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

  17. Quantifying bacterial transfer from patients to staff during burns dressing and bed changes: implications for infection control.

    PubMed

    Bache, Sarah E; Maclean, Michelle; Gettinby, George; Anderson, John G; MacGregor, Scott J; Taggart, Ian

    2013-03-01

    Routine nursing activities such as dressing/bed changes increase bacterial dispersal from burns patients, potentially contaminating healthcare workers (HCW) carrying out these tasks. HCW thus become vectors for transmission of nosocomial infection between patients. The suspected relationship between %total body surface area (%TBSA) of burn and levels of bacterial release has never been fully established. Bacterial contamination of HCW was assessed by contact plate samples (n=20) from initially sterile gowns worn by the HCW during burns patient dressing/bed changes. Analysis of 24 gowns was undertaken and examined for relationships between %TBSA, time taken for activity, and contamination received by the HCW. Relationships between size of burn and levels of HCW contamination, and time taken for the dressing/bed change and levels of HCW contamination were best described by exponential models. Burn size correlated more strongly (R(2)=0.82, p<0.001) than time taken (R(2)=0.52, p<0.001), with levels of contamination received by the HCW. Contamination doubled with every 6-9% TBSA increase in burn size. Burn size was used to create a model to predict bacterial contamination received by a HCW carrying out bed/dressing changes. This may help with the creation of burn-specific guidelines on protective clothing worn by HCW caring for burns patients. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  18. Calibrating reaction rates for the CREST model

    NASA Astrophysics Data System (ADS)

    Handley, Caroline A.; Christie, Michael A.

    2017-01-01

    The CREST reactive-burn model uses entropy-dependent reaction rates that, until now, have been manually tuned to fit shock-initiation and detonation data in hydrocode simulations. This paper describes the initial development of an automatic method for calibrating CREST reaction-rate coefficients, using particle swarm optimisation. The automatic method is applied to EDC32, to help develop the first CREST model for this conventional high explosive.

  19. Hot soup! Correlating the severity of liquid scald burns to fluid and biomedical properties.

    PubMed

    Loller, Cameron; Buxton, Gavin A; Kerzmann, Tony L

    2016-05-01

    Burns caused by hot drinks and soups can be both debilitating and costly, especially to pediatric and geriatric patients. This research is aimed at better understanding the fluid properties that can influence the severity of skin burns. We use a standard model which combines heat transfer and biomedical equations to predict burn severity. In particular, experimental data from a physical model serves as the input to our numerical model to determine the severity of scald burns as a consequence of actual fluid flows. This technique enables us to numerically predict the heat transfer from the hot soup into the skin, without the need to numerically estimate the complex fluid mechanics and thermodynamics of the potentially highly viscous and heterogeneous soup. While the temperature of the soup is obviously is the most important fact in determining the degree of burn, we also find that more viscous fluids result in more severe burns, as the slower flowing thicker fluids remain in contact with the skin for longer. Furthermore, other factors can also increase the severity of burn such as a higher initial fluid temperature, a greater fluid thermal conductivity, or a higher thermal capacity of the fluid. Our combined experimental and numerical investigation finds that for average skin properties a very viscous fluid at 100°C, the fluid must be in contact with the skin for around 15-20s to cause second degree burns, and more than 80s to cause a third degree burn. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  20. Should early amputation impact initial fluid therapy algorithms in burns resuscitation? A retrospective analysis using 3D modelling.

    PubMed

    Staruch, Robert M T; Beverly, A; Lewis, D; Wilson, Y; Martin, N

    2017-02-01

    While the epidemiology of amputations in patients with burns has been investigated previously, the effect of an amputation on burn size and its impact on fluid management have not been considered in the literature. Fluid resuscitation volumes are based on the percentage of the total body surface area (%TBSA) burned calculated during the primary survey. There is currently no consensus as to whether the fluid volumes should be recalculated after an amputation to compensate for the new body surface area. The aim of this study was to model the impact of an amputation on burn size and predicted fluid requirement. A retrospective search was performed of the database at the Queen Elizabeth Hospital Birmingham Regional Burns Centre to identify all patients who had required an early amputation as a result of their burn injury. The search identified 10 patients over a 3-year period. Burn injuries were then mapped using 3D modelling software. BurnCase3D is a computer program that allows accurate plotting of burn injuries on a digital mannequin adjusted for height and weight. Theoretical fluid requirements were then calculated using the Parkland formula for the first 24 h, and Herndon formula for the second 24 h, taking into consideration the effects of the amputation on residual burn size. This study demonstrated that amputation can have an unpredictable effect on burn size that results in a significant deviation from predicted fluid resuscitation volumes. This discrepancy in fluid estimation may cause iatrogenic complications due to over-resuscitation in burn-injured casualties. Combining a more accurate estimation of postamputation burn size with goal-directed fluid therapy during the resuscitation phase should enable burn care teams to optimise patient outcomes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  1. Improving Long-term Post-wildfire hydrologic simulations using ParFlow

    NASA Astrophysics Data System (ADS)

    Lopez, S. R.; Kinoshita, A. M.

    2015-12-01

    Wildfires alter the natural hydrologic processes within a watershed. After vegetation is burned, the combustion of organic material and debris settles into the soil creating a hydrophobic layer beneath the soil surface with varying degree of thickness and depth. Vegetation regrowth rates vary as a function of radiative exposure, burn severity, and precipitation patterns. Hydrologic models used by the Burned Area Emergency Response (BAER) teams use input data and model calibration constraints that are generally either one-dimensional, empirically-based models, or two-dimensional, conceptually-based models with lumped parameter distributions. These models estimate runoff measurements at the watershed outlet; however, do not provide a distributed hydrologic simulation at each point within the watershed. This work uses ParFlow, a three-dimensional, distributed hydrologic model to (1) correlate burn severity with hydrophobicity, (2) evaluate vegetation recovery rate on water components, and (3) improve flood prediction for managers to help with resource allocation and management operations in burned watersheds. ParFlow is applied to Devil Canyon (43 km2) in San Bernardino, California, which was 97% burned in the 2003 Old Fire. The model set-up uses a 30m-cell size resolution over a 6.7 km by 6.4 km lateral extent. The subsurface reaches 30 m and is assigned a variable cell thickness. Variable subsurface thickness allows users to explicitly consider the degree of recovery throughout the stages of regrowth. Burn severity maps from remotely sensed imagery are used to assign initial hydrophobic layer parameters and thickness. Vegetation regrowth is represented with satellite an Enhanced Vegetation Index. Pre and post-fire hydrologic response is evaluated using runoff measurements at the watershed outlet, and using water component (overland flow, lateral flow, baseflow) measurements.

  2. Endothelial necrosis at 1h post-burn predicts progression of tissue injury

    PubMed Central

    Hirth, Douglas; McClain, Steve A.; Singer, Adam J.; Clark, Richard A.F.

    2013-01-01

    Burn injury progression has not been well characterized at the cellular level. To define burn injury progression in terms of cell death, histopathologic spatiotemporal relationships of cellular necrosis and apoptosis were investigated in a validated porcine model of vertical burn injury progression. Cell necrosis was identified by High Mobility Group Box 1 protein and apoptosis by Caspase 3a staining of tissue samples taken 1h, 24h and 7 days post-burn. Level of endothelial cell necrosis at 1h was predictive of level of apoptosis at 24h (Pearson's r=0.87) and of level of tissue necrosis at 7 days (Pearson's r=0.87). Furthermore, endothelial cell necrosis was deeper than interstitial cell necrosis at 1h (p<0.001). Endothelial cell necrosis at 1h divided the zone of injury progression (Jackson's zone of stasis) into an upper subzone with necrotic endothelial cells and initially viable adnexal and interstitial cells at 1h that progressed to necrosis by 24h, and a lower zone with initially viable endothelial cells at 1h, but necrosis and apoptosis of all cell types by 24h. Importantly, this spatiotemporal series of events and rapid progression resembles myocardial infarction and stroke, and implicates mechanisms of these injuries, ischemia, ischemia reperfusion, and programmed cell death, in burn progression. PMID:23627744

  3. Model of ASTM Flammability Test in Microgravity: Iron Rods

    NASA Technical Reports Server (NTRS)

    Steinberg, Theodore A; Stoltzfus, Joel M.; Fries, Joseph (Technical Monitor)

    2000-01-01

    There is extensive qualitative results from burning metallic materials in a NASA/ASTM flammability test system in normal gravity. However, this data was shown to be inconclusive for applications involving oxygen-enriched atmospheres under microgravity conditions by conducting tests using the 2.2-second Lewis Research Center (LeRC) Drop Tower. Data from neither type of test has been reduced to fundamental kinetic and dynamic systems parameters. This paper reports the initial model analysis for burning iron rods under microgravity conditions using data obtained at the LERC tower and modeling the burning system after ignition. Under the conditions of the test the burning mass regresses up the rod to be detached upon deceleration at the end of the drop. The model describes the burning system as a semi-batch, well-mixed reactor with product accumulation only. This model is consistent with the 2.0-second duration of the test. Transient temperature and pressure measurements are made on the chamber volume. The rod solid-liquid interface melting rate is obtained from film records. The model consists of a set of 17 non-linear, first-order differential equations which are solved using MATLAB. This analysis confirms that a first-order rate, in oxygen concentration, is consistent for the iron-oxygen kinetic reaction. An apparent activation energy of 246.8 kJ/mol is consistent for this model.

  4. The Impact of Media Reporting on the Emergence of Charcoal Burning Suicide in Taiwan

    PubMed Central

    Chen, Ying-Yeh; Chen, Feng; Gunnell, David; Yip, Paul S. F.

    2013-01-01

    We investigated the association of the intensity of newspaper reporting of charcoal burning suicide with the incidence of such deaths in Taiwan during 1998–2002. A counting process approach was used to estimate the incidence of suicides and intensity of news reporting. Conditional Poisson generalized linear autoregressive models were performed to assess the association of the intensity of newspaper reporting of charcoal burning and non-charcoal burning suicides with the actual number of charcoal burning and non-charcoal burning suicides the following day. We found that increases in the reporting of charcoal burning suicide were associated with increases in the incidence of charcoal burning suicide on the following day, with each reported charcoal burning news item being associated with a 16% increase in next day charcoal burning suicide (p<.0001). However, the reporting of other methods of suicide was not related to their incidence. We conclude that extensive media reporting of charcoal burning suicides appears to have contributed to the rapid rise in the incidence of the novel method in Taiwan during the initial stage of the suicide epidemic. Regulating media reporting of novel suicide methods may prevent an epidemic spread of such new methods. PMID:23383027

  5. Burns teaching in UK medical schools: Is it enough?

    PubMed

    Zinchenko, Ruslan; Perry, Fiona M; Dheansa, Baljit S

    2016-02-01

    Burns are frequently seen and managed in non-specialist settings. The crowding of the UK medical undergraduate curriculum may have resulted in the reduction of teaching on burns. To determine the burns education experience and the level of competence among UK final year medical students in assessing and acutely managing patients with burns. An online questionnaire was circulated among UK final year medical students. There was a total of 348 respondents. The majority of the respondents (70%) have not received any specific teaching on how to manage patients with burns. Nearly two-thirds of the students (66%) have never seen a patient being managed for burns throughout their training. Over 90% of respondents stated that they would not feel confident in initially managing a burn in the emergency department. The majority of the respondents (57%) have not heard of the criteria for referring a burns patient for further specialist management. There was almost universal agreement about the importance of knowing how to manage a burn initially. There seems to be a lack of consistent undergraduate training in burns management and final year students lack the experience and knowledge to initially manage burns. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  6. Development of a reactive burn model based upon an explicit visco-plastic pore collapse model

    NASA Astrophysics Data System (ADS)

    Bouton, Eric; Lefrançois, Alexandre; Belmas, Robert

    2015-06-01

    Our aim in this study is to develop a reactive burn model based upon a microscopic hot spot model to compute the initiation and shock to detonation of pressed TATB explosives. For the sake of simplicity, the hot spots are supposed to result from the viscoplastic collapse of spherical micro-voids inside the composition. Such a model has been incorporated in a lagrangian hydrodynamic code. In our calculations, 8 different pore diameters, ranging from 100 nm to 1.2 μm, have been taken into account and the porosity associated to each pore size has been deduced from the PBX-9502 void distribution derived from the SAXS. The last ingredient of our model is the burn rate that depends on two main variables. The first one is the shock pressure as proposed by the developers of the CREST model. The second one is the number of effective chemical reaction sites calculated by the microscopic model. Furthermore, the function of the reaction progress variable of the burn rate is similar to that in the SURF model proposed by Menikoff. Our burn rate has been calibrated by using pressure profile, material velocities wave forms obtained with embedded particle velocity gauges and run distance to detonation. The comparison between the numerical and experimental results is really good and sufficient to perform a wide variety of simulations including single, double shock waves and the desensitization phenomenon. In conclusion, future works are described.

  7. Numerical and experimental study of thermal explosions in LX-10 and PBX 9501: Influence of thermal damage on deflagration processes

    NASA Astrophysics Data System (ADS)

    Tringe, J. W.; Kercher, J. R.; Springer, H. K.; Glascoe, E. A.; Levie, H. W.; Hsu, P.; Willey, T. M.; Molitoris, J. D.

    2013-07-01

    We employ in-situ flash x-ray imaging, together with a detailed multiphase convective burn model, to demonstrate how explosives' binder characteristics influence the burning processes in thermal explosions. Our study focuses on the HMX-based explosives LX-10 and PBX 9501. While the HMX (cyclotetramethylene-tetranitramine) crystallite size distributions for these two explosives are nearly identical before heating, our experiments and simulations indicate that after heating, variations result due to differences in binder composition. Post-ignition flash x-ray images reveal that the average density decreases at late times more rapidly in PBX 9501 than LX-10, suggesting a faster conductive burning rate in PBX-9501. Heated permeability measurements in LX-10 and PBX 9501 demonstrate that the binder system characteristics influence the evolution of connected porosity. Once ignited, connected porosity provides pathways for product gas heating ahead of the reaction front and additional surface area for burning, facilitating the transition from conductive to convective burning modes. A multiphase convective burn model implemented in the ALE3D code is used to better understand the influence on burn rates of material properties such as porosity and effective thermally damaged particle size. In this context, particles are defined as gas-impermeable binder-coated crystallites and agglomerations with a set of effective radii reff. Model results demonstrate quantitative agreement with containment wall velocity for confined PBX 9501 and LX-10, and qualitative agreement with density as a function of position in the burning explosive. The model predicts a decrease in post-ignition containment wall velocity with larger radii in reff. These experimental data and model results together provide insight into the initiation and propagation of the reaction wave that defines the convective burn front in HMX-based explosives, a necessary step toward predicting violence under a broad range of conditions.

  8. Runoff-generated debris flows: observations and modeling of surge initiation, magnitude, and frequency

    USGS Publications Warehouse

    Kean, Jason W.; McCoy, Scott W.; Tucker, Gregory E.; Staley, Dennis M.; Coe, Jeffrey A.

    2013-01-01

    Runoff during intense rainstorms plays a major role in generating debris flows in many alpine areas and burned steeplands. Yet compared to debris flow initiation from shallow landslides, the mechanics by which runoff generates a debris flow are less understood. To better understand debris flow initiation by surface water runoff, we monitored flow stage and rainfall associated with debris flows in the headwaters of two small catchments: a bedrock-dominated alpine basin in central Colorado (0.06 km2) and a recently burned area in southern California (0.01 km2). We also obtained video footage of debris flow initiation and flow dynamics from three cameras at the Colorado site. Stage observations at both sites display distinct patterns in debris flow surge characteristics relative to rainfall intensity (I). We observe small, quasiperiodic surges at low I; large, quasiperiodic surges at intermediate I; and a single large surge followed by small-amplitude fluctuations about a more steady high flow at high I. Video observations of surge formation lead us to the hypothesis that these flow patterns are controlled by upstream variations in channel slope, in which low-gradient sections act as “sediment capacitors,” temporarily storing incoming bed load transported by water flow and periodically releasing the accumulated sediment as a debris flow surge. To explore this hypothesis, we develop a simple one-dimensional morphodynamic model of a sediment capacitor that consists of a system of coupled equations for water flow, bed load transport, slope stability, and mass flow. This model reproduces the essential patterns in surge magnitude and frequency with rainfall intensity observed at the two field sites and provides a new framework for predicting the runoff threshold for debris flow initiation in a burned or alpine setting.

  9. Mesoscale Modeling of Deflagration-Induced Deconsolidation in Polymer-Bonded Explosives

    NASA Astrophysics Data System (ADS)

    Springer, H. Keo; Reaugh, J. E.; Glascoe, E. A.; Kercher, J. R.; Friedman, G.

    2011-06-01

    Initially intact polymer-bonded explosives can transition from conductive burning to more violent convective burning via rapid deconsolidation at higher pressures. The pressure-dependent infiltration of cracks and pores, i.e., damage, by product gases at the burn-front is a key step in the transition to convective burning. However, the relative influence of pre-existing damage and deflagration-induced damage on the transition to convective burning is not well understood. The objective of this study is to investigate the role of explosive constituent properties, microstructure, and deflagration velocity on deconsolidation. We performed simulations using the multi-physics hydrocode, ALE3D. HMX was used as the model energetic grain. We used a JWL form for the unreacted and reacted equation-of-state of the HMX. Simplified strength and failure models were used for the HMX and the binder. The propensity for deconsolidation increased with increasing grain volume fraction, increasing porosity, decreasing binder strength, and increasing deflagration velocity. These studies are important because they enable the development of deflagration-induced damage models, as well as the design of inherently safer explosives. This work performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344. This work was funded by the Joint DoD/DOE Munitions Technology Development Program.

  10. Initial Observations on the Burning of an Ethanol Droplet in Microgravity

    NASA Technical Reports Server (NTRS)

    Kazakov, Andrei; Urban, Bradley; Conley, Jordan; Dryer, Frederick L.; Ferkul, Paul (Technical Monitor)

    1999-01-01

    Combustion of liquid ethanol represents an important system both from fundamental and practical points of view, Ethanol is currently being used as an additive to gasoline in order to reduce carbon monoxide and particulate emissions as well as to improve the fuel octane rating. A detailed physical understanding of liquid ethanol combustion is therefore necessary to achieve an optimal performance of such fuel blends in practical conditions. Ethanol is also a relatively simple model compound suitable for investigation of important combustion characteristics typical of more complex fuels. In particular, ethanol has been proposed for studies of sooting behavior during droplet burning. The sooting nature of ethanol has pressure sensitivities similar to that of n-heptane, but shifted to a higher range of pressures (1-3 atm). Additionally, liquid ethanol is miscible with water produced during its combustion forming mixtures with azeotropic behavior, a phenomenon important for understanding multi-component, liquid fuel combustion. In this work, we present initial results obtained in a series of recent space-based experiments and develop a detailed model describing the burning of ethanol droplet in microgravity.

  11. In view of standardization: comparison and analysis of initial management of severely burned patients in Germany, Austria and Switzerland.

    PubMed

    Münzberg, Matthias; Ziegler, Benjamin; Fischer, Sebastian; Wölfl, Christoph Georg; Grützner, Paul Alfred; Kremer, Thomas; Kneser, Ulrich; Hirche, Christoph

    2015-02-01

    Initial treatment of severely injured patients in German speaking trauma centers follows precise sequences. Several guidelines and training courses ensure a constant quality in providing evidence-based treatment for these patients. Similar standards, algorithms and guidelines for the treatment of severely burned patients are lacking. This raises the question about the current standard of care for burn victims in German speaking burn centers. In order to achieve standardization, as a first step this study surveys principles of burn room organization and management in these burn centers. A questionnaire including 40 questions regarding burn room organization, personnel structure and qualification, infrastructural conditions and quality management was developed and sent to 21 level one burn centers in Germany, Austria and Switzerland. The rate of returned questionnaires was 81%. The analysis revealed varying personnel and infrastructural conditions in participating burn centers. Indications for admission to the burn room and admission procedures itself are different throughout surveyed hospitals. Individual standard operating procedure (SOP) for burn trauma admissions was available in most burn centers and nearly all participants register their burn trauma cases using an in-house burn register. The survey suggests a lack of standardization in personnel structure, infrastructure and treatment approach for the initial clinical care of severely burned patients in burn centers across the German speaking countries. Further evaluation of existing protocols and international standards in burn care is inevitable to develop standardized guidelines for burn care and to improve quality of care. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  12. Topically applied metal chelator reduces thermal injury progression in a rat model of brass comb burn.

    PubMed

    Wang, Cheng Z; Ayadi, Amina El; Goswamy, Juhi; Finnerty, Celeste C; Mifflin, Randy; Sousse, Linda; Enkhbaatar, Perenlei; Papaconstantinou, John; Herndon, David N; Ansari, Naseem H

    2015-12-01

    Oxidative stress may be involved in the cellular damage and tissue destruction as burn wounds continues to progress after abatement of the initial insult. Since iron and calcium ions play key roles in oxidative stress, this study tested whether topical application of Livionex formulation (LF) lotion, that contains disodium EDTA as a metal chelator and methyl sulfonyl methane (MSM) as a permeability enhancer, would prevent or reduce burns. We used an established brass comb burn model with some modifications. Topical application of LF lotion was started 5 min post-burn, and repeated every 8 h for 3 consecutive days. Rats were euthanized and skin harvested for histochemistry and immunohistochemistry. Formation of protein adducts of 4-hydroxynonenal (HNE), malonadialdehyde (MDA) and acrolein (ACR) and expression of aldehyde dehydrogenase (ALDH) isozymes, ALDH1 and ALDH2 were assessed. LF lotion-treated burn sites and interspaces showed mild morphological improvement compared to untreated burn sites. Furthermore, the lotion significantly decreased the immunostaining of lipid aldehyde-protein adducts including protein -HNE, -MDA and -ACR adducts, and restored the expression of aldehyde dehydrogenase isozymes in the unburned interspaces. This data, for the first time, demonstrates that a topically applied EDTA-containing lotion protects burns progression with a concomitant decrease in the accumulation of reactive lipid aldehydes and protection of aldehyde dehydrogenase isozymes. Present studies are suggestive of therapeutic intervention of burns by this novel lotion. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  13. Topically Applied Metal Chelator Reduces Thermal Injury Progression in a Rat Model of Brass Comb Burn

    PubMed Central

    Wang, Cheng Z.; El Ayadi, Amina; Goswamy, Juhi; Finnerty, Celeste C.; Mifflin, Randy; Sousse, Linda; Enkhbaatar, Perenlei; Papaconstantinou, John; Herndon, David N.; Ansari, Naseem H.

    2016-01-01

    Oxidative stress may be involved in the cellular damage and tissue destruction as burn wounds continues to progress after abatement of the initial insult. Since iron and calcium ions play key roles in oxidative stress, this study tested whether topical application of Livionex formulation (LF) lotion, that contains disodium EDTA as a metal chelator and methyl sulfonyl methane (MSM) as a permeability enhancer, would prevent or reduce burn injury. Methods We used an established brass comb burn model with some modifications. Topical application of LF lotion was started 5 minutes post-burn, and repeated every 8 hours for 3 consecutive days. Rats were euthanized and skin harvested for histochemistry and immunohistochemistry. Formation of protein adducts of 4-hydroxynonenal (HNE), malonadialdehyde (MDA) and acrolein (ACR) and expression of aldehyde dehydrogenase (ALDH) isozymes, ALDH1 and ALDH2 were assessed. Results LF lotion-treated burn sites and interspaces showed mild morphological improvement compared to untreated burn sites. Furthermore, the lotion significantly decreased the immunostaining of lipid aldehyde-protein adducts including protein -HNE, -MDA and -ACR adducts, and restored the expression of aldehyde dehydrogenase isozymes in the unburned interspaces. Conclusion This data, for the first time, demonstrates that a topically applied EDTA-containing lotion protects burn injury progression with a concomitant decrease in the accumulation of reactive lipid aldehydes and protection of aldehyde dehydrogenase isozymes. Present studies are suggestive of therapeutic intervention of burn injury by this novel lotion. PMID:26392023

  14. Systematic care management: a comprehensive approach to catastrophic injury management applied to a catastrophic burn injury population--clinical, utilization, economic, and outcome data in support of the model.

    PubMed

    Kucan, John; Bryant, Ernest; Dimick, Alan; Sundance, Paula; Cope, Nathan; Richards, Reginald; Anderson, Chris

    2010-01-01

    The new standard for successful burn care encompasses both patient survival and the burn patient's long-term quality of life. To provide optimal long-term recovery from catastrophic injuries, including catastrophic burns, an outcome-based model using a new technology called systematic care management (SCM) has been developed. SCM provides a highly organized system of management throughout the spectrum of care that provides access to outcome data, consistent oversight, broader access to expert providers, appropriate allocation of resources, and greater understanding of total costs. Data from a population of 209 workers' compensation catastrophic burn cases with a mean TBSA of 27.9% who were managed under the SCM model of care were analyzed. The data include treatment type, cost, return to work, and outcomes achieved. Mean duration of management to achieve all guaranteed outcomes was 20 months. Of the 209 injured workers, 152 (72.7%) achieved sufficient recovery to be released to return to work, of which 97 (46.8%) were both released and competitively employed. Assessment of 10 domains of functional independence indicated that 47.2% of injured workers required total assistance at initiation of SCM. However, at termination of SCM, 84% of those injured workers were fully independent in the 10 functional activities. When compared with other burn research outcome data, the results support the value of the SCM model of care.

  15. Disaster planning: the basics of creating a burn mass casualty disaster plan for a burn center.

    PubMed

    Kearns, Randy D; Conlon, Kathe M; Valenta, Andrea L; Lord, Graydon C; Cairns, Charles B; Holmes, James H; Johnson, Daryhl D; Matherly, Annette F; Sawyer, Dalton; Skarote, Mary Beth; Siler, Sean M; Helminiak, Radm Clare; Cairns, Bruce A

    2014-01-01

    In 2005, the American Burn Association published burn disaster guidelines. This work recognized that local and state assets are the most important resources in the initial 24- to 48-hour management of a burn disaster. Historical experiences suggest there is ample opportunity to improve local and state preparedness for a major burn disaster. This review will focus on the basics of developing a burn surge disaster plan for a mass casualty event. In the event of a disaster, burn centers must recognize their place in the context of local and state disaster plan activation. Planning for a burn center takes on three forms; institutional/intrafacility, interfacility/intrastate, and interstate/regional. Priorities for a burn disaster plan include: coordination, communication, triage, plan activation (trigger point), surge, and regional capacity. Capacity and capability of the plan should be modeled and exercised to determine limitations and identify breaking points. When there is more than one burn center in a given state or jurisdiction, close coordination and communication between the burn centers are essential for a successful response. Burn surge mass casualty planning at the facility and specialty planning levels, including a state burn surge disaster plan, must have interface points with governmental plans. Local, state, and federal governmental agencies have key roles and responsibilities in a burn mass casualty disaster. This work will include a framework and critical concepts any burn disaster planning effort should consider when developing future plans.

  16. Delayed prescribed burning in a seedling and sapling Longleaf Pine plantation in Louisiana

    Treesearch

    James D. Haywood

    2002-01-01

    To examine the effects of delaying prescribed burning for several years, I initiated five treatments in a 5- to 6-year-old longleaf pine stand: a check of no control; biennial hardwood control by directed chemical application; and biennial burning in either early March, May, or July. After the initial burns, longleaf pine survival decreased from 82 percent in February...

  17. Biomass Burning: The Cycling of Gases and Particulates from the Biosphere to the Atmosphere

    NASA Astrophysics Data System (ADS)

    Levine, J. S.

    2003-12-01

    Biomass burning is both a process of geochemical cycling of gases and particulates from the biosphere to the atmosphere and a process of global change. In the preface to the book, One Earth, One Future: Our Changing Global Environment (National Academy of Sciences, 1990), Dr. Frank Press, the President of the National Academy of Sciences, writes: "Human activities are transforming the global environment, and these global changes have many faces: ozone depletion, tropical deforestation, acid deposition, and increased atmospheric concentrations of gases that trap heat and may warm the global climate."It is interesting to note that all four global change "faces" identified by Dr. Press have a common thread - they are all caused by biomass burning.Biomass burning or vegetation burning is the burning of living and dead vegetation and includes human-initiated burning and natural lightning-induced burning. The bulk of the world's biomass burning occurs in the tropics - in the tropical forests of South America and Southeast Asia and in the savannasof Africa and South America. The majority of the biomass burning, primarily in the tropics (perhaps as much as 90%), is believed to be human initiated for land clearing and land-use change. Natural fires triggered by atmospheric lightning only accounts for ˜10% of all fires (Andreae, 1991). As will be discussed, a significant amount of biomass burning occurs in the boreal forests of Russia, Canada, and Alaska.Biomass burning is a significant source of gases and particulates to the regional and global atmosphere (Crutzen et al., 1979; Seiler and Crutzen, 1980; Crutzen and Andreae, 1990; Levine et al., 1995). Its burning is truly a multidiscipline subject, encompassing the following areas: fire ecology, fire measurements, fire modeling, fire combustion, remote sensing, fire combustion gaseous and particulate emissions, the atmospheric transport of these emissions, and the chemical and climatic impacts of these emissions. Recently, a series of dedicated books have documented much of our understanding of biomass burning in different ecosystems. These volumes include: Goldammer (1990), Levine (1991, 1996a, b), Crutzen and Goldammer (1993), Goldammer and Furyaev (1996), van Wilgen et al. (1997), Kasischke and Stocks (2000), Innes et al. (2000), and Eaton and Radojevic (2001).

  18. Pine Oil Effects on Chemical and Thermal Injury in Mice and Cultured Mouse Dorsal Root Ganglion Neurons

    PubMed Central

    Clark, SP; Bollag, WB; Westlund, KN; Ma, F; Falls, G; Xie, D; Johnson, M; Isales, CM; Bhattacharyya, MH

    2013-01-01

    A commercial resin-based pine oil derived from Pinus palustris and Pinus elliottii was the major focus of this investigation. Extracts of pine resins, needles and bark are folk medicines commonly used to treat skin ailments, including burns. The American Burn Association estimates that 500,000 people with burn injuries receive medical treatment each year; one-half of US burn victims are children, most with scald burns. This systematic study was initiated as follow-up to personal anecdotal evidence acquired over more than 10 years by MH Bhattacharyya regarding pine oil’s efficacy for treating burns. The results demonstrate that pine oil counteracted dermal inflammation in both a mouse ear model of contact irritant-induced dermal inflammation and a 2nd degree scald burn to the mouse paw. Furthermore, pine oil significantly counteracted the tactile allodynia and soft tissue injury caused by the scald burn. In mouse dorsal root ganglion (DRG) neuronal cultures, pine oil added to the medium blocked ATP-activated, but not capsaicin-activated, pain pathways, demonstrating specificity. These results together support the hypothesis that a pine-oil-based treatment can be developed to provide effective in-home care for 2nd degree burns. PMID:23595692

  19. A One-Dimensional Global-Scaling Erosive Burning Model Informed by Blowing Wall Turbulence

    NASA Technical Reports Server (NTRS)

    Kibbey, Timothy P.

    2014-01-01

    This paper makes no attempt to comprehensively review erosive burning models or the data collected in pursuit of them; the interested reader could begin with Landsbaum for a historical summary. However, a discussion and comparison to recent work by McDonald and Rettenmaier and Heister will be included, along with data generated by Strand, et. al. Suffice it to say that the search for a way to predict erosive burning in any size motor with formulas cleanly applicable to a typical 1D ballistics analysis has been long thwarted. Some models were based on testing that failed to adequately simulate the solid rocket motor environment. In most cases, no real-time burn rate measurement was available. Two popular models, even when calibrated to recent motor-like real-time burn rate data obtained by Furfaro, were shown by McMillin to be inadequate at modeling erosive burning in the Space Shuttle Reusable Solid Rocket Motor (RSRM), the Space Launch Systems' Five-Segment RSRM (RSRMV), and the five-segment Engineering Test Motor (ETM)-3. Subsequently to the data cited from Strand and Furfaro, additional motors of the same kind as Furfaro's were tested with RSRMV propellant, utilizing 7 segments per motor and 3 throat sizes. By measuring propellant web thickness with ultrasonic gages, the burn rate was determined at cross-flow Mach numbers up to Mach 0.8. Furthermore, because of the different throat sizes in otherwise identical motors, this provides a unique look at the effect of pressure and base burn rate on the erosive response. Figure 1 shows example of the data pertaining to the high Mach motor, where the port area is initially less than the throat area. The burn rate data was processed using a smoothing method developed to reduce the noise without too severely introducing end effects that limit the range of useful data. Then, an empirical ballistics scheme was used to estimate the flow condition based on the burn rate measurements and pressure measured between each segment.

  20. Propagation of Reactions in Thermally-damaged PBX-9501

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tringe, J W; Glascoe, E A; Kercher, J R

    A thermally-initiated explosion in PBX-9501 (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) is observed in situ by flash x-ray imaging, and modeled with the LLNL multi-physics arbitrary-Lagrangian-Eulerian code ALE3D. The containment vessel deformation provides a useful estimate of the reaction pressure at the time of the explosion, which we calculate to be in the range 0.8-1.4 GPa. Closely-coupled ALE3D simulations of these experiments, utilizing the multi-phase convective burn model, provide detailed predictions of the reacted mass fraction and deflagration front acceleration. During the preinitiation heating phase of these experiments, the solid HMX portion of the PBX-9501 undergoes a {beta}-phase to {delta}-phase transition which damages the explosivemore » and induces porosity. The multi-phase convective burn model results demonstrate that damaged particle size and pressure are critical for predicting reaction speed and violence. In the model, energetic parameters are taken from LLNL's thermochemical-kinetics code Cheetah and burn rate parameters from Son et al. (2000). Model predictions of an accelerating deflagration front are in qualitative agreement with the experimental images assuming a mode particle diameter in the range 300-400 {micro}m. There is uncertainty in the initial porosity caused by thermal damage of PBX-9501 and, thus, the effective surface area for burning. To better understand these structures, we employ x-ray computed tomography (XRCT) to examine the microstructure of PBX-9501 before and after thermal damage. Although lack of contrast between grains and binder prevents the determination of full grain size distribution in this material, there are many domains visible in thermally damaged PBX-9501 with diameters in the 300-400 {micro}m range.« less

  1. Benchmarks for multidimensional recovery after burn injury in young adults: the development, validation, and testing of the American Burn Association/Shriners Hospitals for Children young adult burn outcome questionnaire.

    PubMed

    Ryan, Colleen M; Schneider, Jeffrey C; Kazis, Lewis E; Lee, Austin; Li, Nien-Chen; Hinson, Michelle; Bauk, Helena; Peck, Michael; Meyer, Walter J; Palmieri, Tina; Pidcock, Frank S; Reilly, Debra; Tompkins, Ronald G

    2013-01-01

    Although data exist on burn survival, there are little data on long-term burn recovery. Patient-centered health outcomes are useful in monitoring and predicting recovery and evaluating treatments. An outcome questionnaire for young adult burn survivors was developed and tested. This 5-year (2003-2008) prospective, controlled, multicenter study included burned and nonburned adults ages 19 to 30 years. The Young Adult Burn Outcome Questionnaires were completed at initial contact, 10 days, and 6 and 12 months. Factor analysis established construct validity. Reliability assessments used Cronbach α and test-retest. Recovery patterns were investigated using generalized linear models, with generalized estimating equations using mixed models and random effects. Burned (n = 153) and nonburned subjects (n = 112) completed 620 questionnaires (47 items). Time from injury to first questionnaire administration was 157 ± 36 days (mean ± SEM). Factor analysis included 15 factors: Physical Function, Fine Motor Function, Pain, Itch, Social Function Limited by Physical Function, Perceived Appearance, Social Function Limited by Appearance, Sexual Function, Emotion, Family Function, Family Concern, Satisfaction With Symptom Relief, Satisfaction With Role, Work Reintegration, and Religion. Cronbach α ranged from 0.72 to 0.92, with 11 scales >0.8. Test-retest reliability ranged from 0.29 to 0.94, suggesting changes in underlying health status after burns. Recovery curves in five domains, Itch, Perceived Appearance, Social Function Limited by Appearance, Family Concern, and Satisfaction with Symptom Relief, remained below the reference group at 24 months. The Young Adult Burn Outcome Questionnaire is a reliable and valid instrument for multidimensional functional outcomes assessment. Recovery in some domains was incomplete.

  2. Black Carbon in the Arctic: Assessment of and efforts to reduce black carbon emissions from wildfires and agricultural burning in Russia

    NASA Astrophysics Data System (ADS)

    Kinder, B.; Hao, W. M.; Larkin, N. K.; McCarty, G.; O'neal, K. J.; Gonzalez, O.; Luxenberg, J.; Rosenblum, M.; Petkov, A.

    2011-12-01

    Black carbon and other short-lived climate forcers exert a warming effect on the climate but remain in the atmosphere for short time periods when compared to carbon dioxide. Black carbon is a significant contributor to increasing temperatures in the Arctic region, which has warmed at twice the global rate over the past 100 years. Black carbon warms the Arctic by absorbing incoming solar radiation while in the atmosphere and, when deposited onto Arctic ice, leading to increased atmospheric temperatures and snow and ice melt. Black carbon remains in the atmosphere for a short time period ranging from days to weeks; therefore, local atmospheric conditions at the time of burning determine the amount of black carbon transport to the Arctic. Most black carbon transport and deposition in the Arctic results from the occurrence of wildfires, prescribed forest fires, and agricultural burning at latitudes greater than 40 degrees north latitude. Wildfire affects some 10-15 million hectares of forest, forest steppe, and grasslands in Russia each year. In addition to wildfire, there is widespread cropland burning in Russia occurring in the fall following harvest and in the spring prior to tilling. Agricultural burning is common practice for crop residue removal as well as suppression of weeds, insects and residue-borne diseases. The goal of the United States Department of Agriculture (USDA) Black Carbon Initiative is to assess black carbon emissions from agricultural burning and wildfires in Russia and explore practical options and opportunities for reducing emissions from these two sources. The emissions assessment combines satellite-derived burned area measurements of forest and agricultural fires, burn severity information, ancillary geospatial data, vegetation and land cover maps, fuels data, fire emissions data, fire/weather relationship information, and smoke transport models to estimate black carbon transport and deposition in the Arctic. The assessment addresses necessary improvements to fire and burned area detection algorithms to improve agricultural burned area mapping accuracy. Efforts to explore practical options for reducing black carbon emissions from wildfires and agricultural burning in Russia have been focused on designing community-based fire prevention and education programs in Siberia and the Russia Far East, two regions prone to frequent human-caused fires. The initiative also seeks to identify practical alternatives to reduce black carbon emissions from agricultural burning and to help promote these alternatives through outreach to farmers and other agricultural organizations. This submission will explore the initial findings and results of the emissions assessment and discuss the progress and challenges associated with implementation of local-level fire prevention and mitigation efforts in Russia. The results of this initiative will help inform future policy and management tools to address black carbon emissions from wildfires and agricultural burning in Russia and perhaps additional interested countries.

  3. Debris flow initiation by runoff in a recently burned basin: Is grain-by-grain sediment bulking or en masse failure to blame?

    NASA Astrophysics Data System (ADS)

    McGuire, Luke A.; Rengers, Francis K.; Kean, Jason W.; Staley, Dennis M.

    2017-07-01

    Postwildfire debris flows are frequently triggered by runoff following high-intensity rainfall, but the physical mechanisms by which water-dominated flows transition to debris flows are poorly understood relative to debris flow initiation from shallow landslides. In this study, we combined a numerical model with high-resolution hydrologic and geomorphic data sets to test two different hypotheses for debris flow initiation during a rainfall event that produced numerous debris flows within a recently burned drainage basin. Based on simulations, large volumes of sediment eroded from the hillslopes were redeposited within the channel network throughout the storm, leading to the initiation of numerous debris flows as a result of the mass failure of sediment dams that built up within the channel. More generally, results provide a quantitative framework for assessing the potential of runoff-generated debris flows based on sediment supply and hydrologic conditions.

  4. Debris flow initiation by runoff in a recently burned basin: Is grain-by-grain sediment bulking or en masse failure to blame?

    USGS Publications Warehouse

    McGuire, Luke; Rengers, Francis K.; Kean, Jason W.; Staley, Dennis M.

    2017-01-01

    Postwildfire debris flows are frequently triggered by runoff following high-intensity rainfall, but the physical mechanisms by which water-dominated flows transition to debris flows are poorly understood relative to debris flow initiation from shallow landslides. In this study, we combined a numerical model with high-resolution hydrologic and geomorphic data sets to test two different hypotheses for debris flow initiation during a rainfall event that produced numerous debris flows within a recently burned drainage basin. Based on simulations, large volumes of sediment eroded from the hillslopes were redeposited within the channel network throughout the storm, leading to the initiation of numerous debris flows as a result of the mass failure of sediment dams that built up within the channel. More generally, results provide a quantitative framework for assessing the potential of runoff-generated debris flows based on sediment supply and hydrologic conditions.

  5. Burn disaster response planning: an urban region's approach.

    PubMed

    Yurt, Roger W; Lazar, Eliot J; Leahy, Nicole E; Cagliuso, Nicholas V; Rabbitts, Angela C; Akkapeddi, Vijay; Cooper, Arthur; Dajer, Antonio; Delaney, Jack; Mineo, Frank P; Silber, Steven H; Soloff, Lewis; Magbitang, Kevin; Mozingo, David W

    2008-01-01

    The objective of this study was to describe a draft response plan for the tiered triage, treatment, or transportation of 400 adult and pediatric victims (50/million population) of a burn disaster for the first 3 to 5 days after injury using regional resources. Review of meeting minutes and the 11 deliverables of the draft response plan was performed. The draft burn disaster response plan developed for NYC recommended: 1) City hospitals or regional burn centers within a 60-mile distance be designated as tiered Burn Disaster Receiving Hospitals (BDRH); 2) these hospitals be divided into a four-tier system, based on clinical resources; and 3) burn care supplies be provided to Tier 3 nonburn centers. Existing burn center referral guidelines were modified into a hierarchical BDRH matrix, which would vector certain patients to local or regional burn centers for initial care until capacity is reached; the remainder would be cared for in nonburn center facilities for up to 3 to 5 days until a city, regional, or national burn bed becomes available. Interfacility triage would be coordinated by a central team. Although recommendations for patient transportation, educational initiatives for prehospital and hospital providers, city-wide, interfacility or interagency communication strategies and coordination at the State or Federal levels were outlined, future initiatives will expound on these issues. An incident resulting in critically injured burn victims exceeding the capacity of local and regional burn center beds may be a reality within any community and warrants a planned response. To address this possibility within New York City, an initial draft of a burn disaster response has been created. A scaleable plan using local, state, regional, or federal health care and governmental institutions was developed.

  6. Quantitative long term measurements of burns in a rat model using spatial frequency domain imaging and laser speckle imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Ponticorvo, Adrien; Rowland, Rebecca A.; Baldado, Melissa L.; Kennedy, Gordon T.; Saager, Rolf B.; Choi, Bernard; Durkin, Anthony J.

    2016-04-01

    The ability to accurately assess burn wound severity in a timely manner is a critical component of wound management as it dictates the course of treatment. While full thickness and superficial burns can be easily diagnosed through visual inspection, burns that fall in between these categories are difficult to classify. Additionally, the ability to better quantify different stages of wound healing from a burn of any severity would be important for evaluating the efficacy of different treatment options. Here we present a longitudinal (28 day) study that employs spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) as non-invasive technologies to characterize in-vivo burn wounds and healing in a murine model. Burn wounds were created using an established technique of a brass comb heated to a given temperature and applied for a set amount of time. They were imaged immediately after the initial injury and then at 2, 4, 7, 14, 21, and 28 days following the injury. Biopsies were taken on the day of the injury in order to verify the extent of the burn damage as well as at different time points after the injury in order to visualize different stages of inflammation and healing. The results of this study suggest that the reduced scattering coefficient measured using SFDI and blood flow as measured using LSI have the potential to provide useful metrics for quantifying the severity of burn injuries as well as track the different stages associated with wound healing progression.

  7. Prehospital treatment of burns: a qualitative study of experiences, perceptions and reactions of victims.

    PubMed

    Sadeghi Bazargani, H; Fouladi, N; Alimohammadi, H; Sadeghieh Ahari, S; Agamohammadi, M; Mohamadi, R

    2013-08-01

    The manner in which burns are initially managed, at an incident scene, can affect the extent and depth of burn wounds and their final prognosis. The aim of this study was to understand people's experiences, perceptions and reactions towards the initial management of burns and fire accidents in Ardabil Province, Iran. In a qualitative study, 48 burn victims accompanied by their caregivers were enrolled. Focus group discussion (FGD) was used to collect data. All the interviews were recorded, transcribed and analysed using content analysis method. Four categories of information were retrieved in this study, including fire control, scald and burn wound management, seeking medical consultation and severity indicators. Uncertainty regarding what to do when someone catches fire was an evident finding that was explored through the discussions. The results revealed that transferring the patient to the hospital most often takes place after initial treatments administered at home. People believed that cooling a burn wound for a time longer than a few seconds may harm the wound. A strong belief in the efficacy of traditional remedies was disclosed when the statements of participants revealed that traditional or home-made remedies were widely used either to control pain immediately after burn and later during the wound repair process to accelerate the repair or to control the infection and prevent oedema and scar. Among these remedies, pennyroyal and grated potatoes seemed to be the most popular ones. Pennyroyal was thought to prevent infection and potatoes were used to relieve pain. People doubted the capability of health-care workers who work in rural health houses. People considered electrical burns and burns on the chest to be the most severe types of burns. Inappropriate perceptions regarding initial management of burns existed among the participants that should be addressed in future quantitative research or through developing programmes on secondary prevention of burns. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  8. Economic Spillovers From Public Investments in Medical Countermeasures: A Case Study of a Burn Debridement Product.

    PubMed

    Farahati, Farah; Nystrom, Scott; Howell, David R; Jaffe, Richard

    2017-12-01

    The US federal government invests in the development of medical countermeasures for addressing adverse health effects to the civilian population from chemical, biological, and radiological or nuclear threats. We model the potential economic spillover effects in day-to-day burn care for a federal investment in a burn debridement product for responding to an improvised nuclear device. We identify and assess 4 primary components for projecting the potential economic spillover benefits of a burn debridement product: (1) market size, (2) clinical effectiveness and cost-effectiveness, (3) product cost, and (4) market adoption rates. Primary data sources were the American Burn Association's 2015 National Burn Repository Annual Report of Data and published clinical studies used to gain European approval for the burn debridement product. The study results showed that if approved for use in the United States, the burn debridement product has potential economic spillover benefits exceeding the federal government's initial investment of $24 million a few years after introduction into the burn care market. Economic spillover analyses can help to inform the prioritizing of scarce resources for research and development of medical countermeasures by the federal government. Future federal medical countermeasure research and development investments could incorporate economic spillover analysis to assess investment options. (Disaster Med Public Health Preparedness. 2017;11:711-719).

  9. SURFplus Model Calibration for PBX 9502

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Menikoff, Ralph

    2017-12-06

    The SURFplus reactive burn model is calibrated for the TATB based explosive PBX 9502 at three initial temperatures; hot (75 C), ambient (23 C) and cold (-55 C). The CJ state depends on the initial temperature due to the variation in the initial density and initial specific energy of the PBX reactants. For the reactants, a porosity model for full density TATB is used. This allows the initial PBX density to be set to its measured value even though the coeffcient of thermal expansion for the TATB and the PBX differ. The PBX products EOS is taken as independent ofmore » the initial PBX state. The initial temperature also affects the sensitivity to shock initiation. The model rate parameters are calibrated to Pop plot data, the failure diameter, the limiting detonation speed just above the failure diameters, and curvature effect data for small curvature.« less

  10. What Fraction of Global Fire Activity Can Be Forecast Using Sea Surface Temperatures?

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Randerson, J. T.; Morton, D. C.; Andela, N.; Giglio, L.

    2015-12-01

    Variations in sea surface temperatures (SSTs) can influence climate dynamics in local and remote land areas, and thus influence fire-climate interactions that govern burned area. SST information has been recently used in statistical models to create seasonal outlooks of fire season severity in South America and as the initial condition for dynamical model predictions of fire activity in Indonesia. However, the degree to which large-scale ocean-atmosphere interactions can influence burned area in other continental regions has not been systematically explored. Here we quantified the amount of global burned area that can be predicted using SSTs in 14 different oceans regions as statistical predictors. We first examined lagged correlations between GFED4s burned area and the 14 ocean climate indices (OCIs) individually. The maximum correlations from different OCIs were used to construct a global map of fire predictability. About half of the global burned area can be forecast by this approach 3 months before the peak burning month (with a Pearson's r of 0.5 or higher), with the highest levels of predictability in Central America and Equatorial Asia. Several hotspots of predictability were identified using k-means cluster analysis. Within these regions, we tested the improvements of the forecast by using two OCIs from different oceans. Our forecast models were based on near-real-time SST data and may therefore support the development of new seasonal outlooks for fire activity that can aid the sustainable management of these fire-prone ecosystems.

  11. Is initiating tanning bed use as a minor associated with increased risky tanning behaviors and burning? An exploratory study.

    PubMed

    Seidenberg, Andrew B; Noar, Seth M; Sontag, Jennah M

    2017-12-01

    Tanning bed use is most common among youth and young adults, and is associated with an increased risk of skin cancer. Recently, numerous states have adopted restrictions on minors' access to tanning beds; however, little has been reported on how such policies may impact tanning behaviors and burning. The purpose of this study was to examine the associations between age of indoor tanning initiation and risky tanning behaviors and burning. Female students (n=567) attending a large southeastern public university completed a questionnaire (spring of 2015) assessing tanning bed use history, including age of initiation. The analytic sample was limited to participants reporting past year indoor tanning (n=134). Multivariable logistic regression was used to compare the odds of risky tanning behaviors and burning among those initiating indoor tanning before and after their 18th birthday. Participants initiating indoor tanning as a minor had significantly (ps<0.05) greater odds of using a tanning bed 10 or more times in the previous year, typically indoor tanning for ≥10min, ever indoor tanning without wearing goggles, and ever fallen asleep inside a tanning bed. Further, those that initiated as a minor had significantly greater odds of ever burning from indoor tanning (p<0.05). Indoor tanning initiation as a minor was associated with several risky tanning behaviors and burning. Youth access restrictions may help reduce the harms caused by tanning beds. Copyright © 2017. Published by Elsevier Inc.

  12. The multispecies modeling of the premixed, laminar steady-state ozone flame

    NASA Technical Reports Server (NTRS)

    Heimerl, J. M.; Coffee, T. P.

    1980-01-01

    Species dependent kinetic, transport and thermodynamic coefficients were employed in a one dimensional model of the premixed, laminar, steady state ozone flame. Convenient expressions for these coefficients are reported. They are based on independent measurements, no arbitrary parameters are used. The governing equations are solved using a relaxation technique and the partial differential equation package, PDECOL. Species and temperature profiles and the burning velocities are found over the range of initial ozone mole fraction of 0.25 to 1.00. The computed burning velocities are no more than 30% greater than the measurements of Streng and Grosses. Comparison with the computed results of Warnatz shows agreement within + or - 12%, even though quite different expressions for some of the kinetic coefficients were used. These differences are most obvious in the atomic oxygen and temperature profiles at an initial ozone mole fraction of unity.

  13. 40 CFR 60.2953 - What information must I submit prior to initial startup?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... initial startup? 60.2953 Section 60.2953 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... initial startup? You must submit the information specified in paragraphs (a) through (e) of this section prior to initial startup. (a) The type(s) of waste to be burned. (b) The maximum design waste burning...

  14. 40 CFR 60.2953 - What information must I submit prior to initial startup?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... initial startup? 60.2953 Section 60.2953 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... initial startup? You must submit the information specified in paragraphs (a) through (e) of this section prior to initial startup. (a) The type(s) of waste to be burned. (b) The maximum design waste burning...

  15. 40 CFR 60.2953 - What information must I submit prior to initial startup?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... initial startup? 60.2953 Section 60.2953 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... initial startup? You must submit the information specified in paragraphs (a) through (e) of this section prior to initial startup. (a) The type(s) of waste to be burned. (b) The maximum design waste burning...

  16. In view of standardization Part 2: Management of challenges in the initial treatment of burn patients in Burn Centers in Germany, Austria and Switzerland.

    PubMed

    Ziegler, Benjamin; Hirche, Christoph; Horter, Johannes; Kiefer, Jurij; Grützner, Paul Alfred; Kremer, Thomas; Kneser, Ulrich; Münzberg, Matthias

    2017-03-01

    Initial therapy of severe burns in specialized burn trauma centers is a challenging task faced by the treating multi-professional and interdisciplinary team. A lack of consistent operating procedures and varying structural conditions was recently demonstrated in preliminary data of our group. These results raised the question on how specific treatment measures in acute burn care are met in the absence of standardized guidelines. A specific questionnaire containing 57 multiple-choice questions was sent to all 22 major burn centers in Germany, Austria and Switzerland. The survey included standards of airway management and ventilation, fluid management and circulation, body temperature monitoring and management, topical burn wound treatment and a microbiological surveillance. Additionally, the distribution of standardized course systems was covered. 17 out of 22 questionnaires (77%) were returned completed. Regarding volume resuscitation, results showed a similar approach in estimating initial fluid while discrepancies persisted in the use of colloidal fluid and human albumin. Elective tracheostomy and the need for bronchoscopy with suspected inhalation injury were the most controversial issues revealed by the survey. Topical treatment of burned body surface also followed different principles regarding the use of synthetic epidermal skin substitutes or enzymatic wound debridement. Less discrepancy was found in basic diagnostic measures, body temperature management, estimation of the extent of burns and microbiological surveillance. While many burn-related issues are clearly not questionable and managed in a similar way in most participating facilities, we were able to show that the most contentious issues in burn trauma management involve initial volume resuscitation, management of inhalation trauma and topical burn wound treatment. Further research is required to address these topics and evaluate a potential superiority of a regime in order to increase the level of evidence. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  17. Fire hazard after prescribed burning in a gorse shrubland: implications for fuel management.

    PubMed

    Marino, Eva; Guijarro, Mercedes; Hernando, Carmen; Madrigal, Javier; Díez, Carmen

    2011-03-01

    Prescribed burning is commonly used to prevent accumulation of biomass in fire-prone shrubland in NW Spain. However, there is a lack of knowledge about the efficacy of the technique in reducing fire hazard in these ecosystems. Fire hazard in burned shrubland areas will depend on the initial capacity of woody vegetation to recover and on the fine ground fuels existing after fire. To explore the effect that time since burning has on fire hazard, experimental tests were performed with two fuel complexes (fine ground fuels and regenerated shrubs) resulting from previous prescribed burnings conducted in a gorse shrubland (Ulex europaeus L.) one, three and five years earlier. A point-ignition source was used in burning experiments to assess ignition and initial propagation success separately for each fuel complex. The effect of wind speed was also studied for shrub fuels, and several flammability parameters were measured. Results showed that both ignition and initial propagation success of fine ground fuels mainly depended on fuel depth and were independent of time since burning, although flammability parameters indicated higher fire hazard three years after burning. In contrast, time since burning increased ignition and initial propagation success of regenerated shrub fuels, as well as the flammability parameters assessed, but wind speed had no significant effect. The combination of results of fire hazard for fine ground fuels and regenerated shrubs according to the variation in relative coverage of each fuel type after prescribed burning enabled an assessment of integrated fire hazard in treated areas. The present results suggest that prescribed burning is a very effective technique to reduce fire hazard in the study area, but that fire hazard will be significantly increased by the third year after burning. These results are valuable for fire prevention and fuel management planning in gorse shrubland areas. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Investigation of critical burning of fuel droplets

    NASA Technical Reports Server (NTRS)

    Allison, C. B.; Canada, G. S.; Faeth, G. M.

    1972-01-01

    Measurements were made on the burning of liquid hydrazine, MMH, and UDMH in a combustion gas environment. The experimental range of these tests involved gas temperatures of 1660-2530 K, oxygen concentrations of 0-42% by mass and droplet diameters (employing both droplets and porous spheres) of 0.11-1.91 cm. at atmospheric pressure. A simplified hybrid combustion theory was developed which was found to correlate the present results as well as the experimental measurements of other investigators. Measurements were also made of the monopropellant strand burning rates and liquid surface temperatures of a number of nitrate ester fuels and hydrazine at elevated pressures. The temperature measurements for the nitrate esters were found to be in good agreement with a theoretical model which allowed for gas solubility in the liquid phase at high pressures. Experimental results were also obtained on the burning rates and liquid surface temperatures of a number of paraffin and alcohol fuels burning in air pressures up to 72 atm. For these tests, the fuels were burned from porous spheres in a natural convection environment. Initial findings on a pressurized flat flame burner are also described as well as the design of an oscillatory combustion apparatus to test the response of burning liquid fuels.

  19. The Fire Locating and Modeling of Burning Emissions (FLAMBE) Project

    NASA Astrophysics Data System (ADS)

    Reid, J. S.; Prins, E. M.; Westphal, D.; Richardson, K.; Christopher, S.; Schmidt, C.; Theisen, M.; Eck, T.; Reid, E. A.

    2001-12-01

    The Fire Locating and Modeling of Burning Emissions (FLAMBE) project was initiated by NASA, the US Navy and NOAA to monitor biomass burning and burning emissions on a global scale. The idea behind the mission is to integrate remote sensing data with global and regional transport models in real time for the purpose of providing the scientific community with smoke and fire products for planning and research purposes. FLAMBE is currently utilizing real time satellite data from GOES satellites, fire products based on the Wildfire Automated Biomass Burning Algorithm (WF_ABBA) are generated for the Western Hemisphere every 30 minutes with only a 90 minute processing delay. We are currently collaborating with other investigators to gain global coverage. Once generated, the fire products are used to input smoke fluxes into the NRL Aerosol Analysis and Prediction System, where advection forecasts are performed for up to 6 days. Subsequent radiative transfer calculations are used to estimate top of atmosphere and surface radiative forcing as well as surface layer visibility. Near real time validation is performed using field data collected by Aerosol Robotic Network (AERONET) Sun photometers. In this paper we fully describe the FLAMBE project and data availability. Preliminary result from the previous year will also be presented, with an emphasis on the development of algorithms to determine smoke emission fluxes from individual fire products. Comparisons to AERONET Sun photometer data will be made.

  20. Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; Olson, R. E.; Cobble, J. A.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Parra-Vasquez, N. A. G.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

    2016-05-01

    Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Work is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. The ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.

  1. Fiber Supported Droplet Combustion-2 (FSDC-2)

    NASA Technical Reports Server (NTRS)

    Colantonio, Renato; Dietrich, Daniel; Haggard, John B., Jr.; Nayagan, Vedha; Dryer, Frederick L.; Shaw, Benjamin D.; Williams, Forman A.

    1998-01-01

    Experimental results for the burning characteristics of fiber supported, liquid droplets in ambient Shuttle cabin air (21% oxygen, 1 bar pressure) were obtained from the Glove Box Facility aboard the STS-94/MSL-1 mission using the Fiber Supported Droplet Combustion - 2 (FSDC-2) apparatus. The combustion of individual droplets of methanol/water mixtures, ethanol, ethanol/water azeotrope, n-heptane, n-decane, and n-heptane/n-hexadecane mixtures were studied in quiescent air. The effects of low velocity, laminar gas phase forced convection on the combustion of individual droplets of n-heptane and n-decane were investigated and interactions of two droplet-arrays of n-heptane and n-decane droplets were also studied with and without gas phase convective flow. Initial diameters ranging from about 2mm to over 6mm were burned on 80-100 micron silicon fibers. In addition to phenomenological observations, quantitative data were obtained in the form of backlit images of the burning droplets, overall flame images, and radiometric combustion emission measurements as a function of the burning time in each experiment. In all, 124 of the 129 attempted experiments (or about twice the number of experiments originally planned for the STS-94/MSL-1 mission) were conducted successfully. The experimental results contribute new observations on the combustion properties of pure alkanes, binary alkane mixtures, and simple alcohols for droplet sizes not studied previously, including measurements on individual droplets and two-droplet arrays, inclusive of the effects of forced gas phase convection. New phenomena characterized experimentally for the first time include radiative extinction of droplet burning for alkanes and the "twin effect" which occurs as a result of interactions during the combustion of two-droplet arrays. Numerical modeling of isolated droplet combustion phenomenon has been conducted for methanol/water mixtures, n-heptane, and n-heptane/n-hexadecane mixtures, and results compare quantitatively with those found experimentally for methanol/water mixtures. Initial computational results qualitatively predict experimental results obtained for isolated n-heptane and n-heptane/n-hexadecane droplet combustion, although the effects of sooting are not yet included in the modeling work. Numerical modeling of ethanol and ethanol/water droplet burning is under development. Considerable data remain to be fully analyzed and will provide a large database for comparisons with further numerical and analytical modeling and development of future free droplet experiments aboard space platforms.

  2. SURF Model Calibration Strategy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Menikoff, Ralph

    2017-03-10

    SURF and SURFplus are high explosive reactive burn models for shock initiation and propagation of detonation waves. They are engineering models motivated by the ignition & growth concept of high spots and for SURFplus a second slow reaction for the energy release from carbon clustering. A key feature of the SURF model is that there is a partial decoupling between model parameters and detonation properties. This enables reduced sets of independent parameters to be calibrated sequentially for the initiation and propagation regimes. Here we focus on a methodology for tting the initiation parameters to Pop plot data based on 1-Dmore » simulations to compute a numerical Pop plot. In addition, the strategy for tting the remaining parameters for the propagation regime and failure diameter is discussed.« less

  3. 40 CFR 63.7530 - How do I demonstrate initial compliance with the emission limits and work practice standards?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Fuel Analyses, and Initial Compliance Requirements § 63.7530 How do I demonstrate initial compliance... this section, and Tables 5 and 7 to this subpart OR conducting initial fuel analyses to determine... in one of the liquid fuel subcategories that burn only fossil fuels and other gases and do not burn...

  4. The status of statewide burn prevention legislation.

    PubMed

    Hammond, J

    1993-01-01

    Successful programs in injury prevention can focus on changing an individual's attitude and behavior or on creating and amending the environment to reduce the likelihood of injury. To investigate the latter approach as it pertains to burn prevention, the American Burn Association Burn Prevention Committee catalogued statewide legislation (as opposted to county or municipal ordinances) in major areas of burn and fire prevention. Burn reporting was generally viewed by state fire marshals as a means to apprehend arsonists or investigate child abuse, as opposed to collect demographic data for injury prevention. Smoke detectors are mandated in new residential construction by the majority of states; however, one in six still leave this to local initiatives. Sprinkler systems have generally not been addressed by state legislation. The committee concludes that pursuing statewide legislative agendas as an area of burn and injury prevention is open to further initiatives.

  5. Foot burns: epidemiology and management.

    PubMed

    Hemington-Gorse, S; Pellard, S; Wilson-Jones, N; Potokar, T

    2007-12-01

    This is a retrospective study of the epidemiology and management of isolated foot burns presenting to the Welsh Centre for Burns from January 1998 to December 2002. A total of 289 were treated of which 233 were included in this study. Approximately 40% were in the paediatric age group and the gender distribution varied dramatically for adults and children. In the adult group the male:female ratio was 3.5:1, however in the paediatric group the male:female ratio was more equal (1.6:1). Scald burns (65%) formed the largest group in children and scald (35%) and chemical burns (32%) in adults. Foot burns have a complication rate of 18% and prolonged hospital stay. Complications include hypertrophic scarring, graft loss/delayed healing and wound infection. Although isolated foot burns represent a small body surface area, over half require treatment as in patients to allow for initial aggressive conservative management of elevation and regular wound cleansing to avoid complications. This study suggests a protocol for the initial acute management of foot burns. This protocol states immediate referral of all foot burns to a burn centre, admission of these burns for 24-48 h for elevation, regular wound cleansing with change of dressings and prophylactic antibiotics.

  6. Air Quality Impact from Biomass Burning in Northern Sub-Saharan Africa (NSSA).

    NASA Astrophysics Data System (ADS)

    Damoah, R.; Ichoku, C. M.; Ellison, L.

    2016-12-01

    Biomass burning (BB) is one of the major sources of troposheric ozone (O3) precursors such as nitrogen oxides (NOx), carbon monoxides (CO), and non-methane volatile organics compounds (NMVOCs) as well as primary aerosols such as organic carbon (OC) and black carbon (BC). These emissions do not only affect air quality locally, but also on continental to hemispheric scales through long-range transport. It is estimated that about 350 Million hectares of land burn globally every year of which 54 % are in Africa. The northern sub-Saharan African (NSSA) region (0 - 20N, 20W - 55E) is known to show one of the highest biomass burning rates (in terms of per unit land area) among all regions of the world. This is due to the high concentration and frequency of fires in this region. In 2016 a newly installed AERONET ( ) sun photometer at All Nations University College (6.2N, 0.3W) within our study region recorded enhanced aerosol optical depth presume to be triggered by smoke from fires. We will discuss sources of this enhancement as well results obtained from NASA's Global Modeling Initiative Chemistry and Transport Model (GMI-CTM), to quantify the impact on air quality by biomass burning.

  7. 40 CFR 60.2195 - What information must I submit prior to initial startup?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... initial startup? 60.2195 Section 60.2195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY..., 2001 Recordkeeping and Reporting § 60.2195 What information must I submit prior to initial startup? You... startup. (a) The type(s) of waste to be burned. (b) The maximum design waste burning capacity. (c) The...

  8. 40 CFR 60.2195 - What information must I submit prior to initial startup?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... initial startup? 60.2195 Section 60.2195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY..., 2001 Recordkeeping and Reporting § 60.2195 What information must I submit prior to initial startup? You... startup. (a) The type(s) of waste to be burned. (b) The maximum design waste burning capacity. (c) The...

  9. 40 CFR 60.2195 - What information must I submit prior to initial startup?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... initial startup? 60.2195 Section 60.2195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY..., 2001 Recordkeeping and Reporting § 60.2195 What information must I submit prior to initial startup? You... startup. (a) The type(s) of waste to be burned. (b) The maximum design waste burning capacity. (c) The...

  10. A foundation for initial attack simulation: the Fried and Fried fire containment model

    Treesearch

    Jeremy S. Fried; Burton D. Fried

    2010-01-01

    The Fried and Fried containment algorithm, which models the effect of suppression efforts on fire growth, allows simulation of any mathematically representable fire shape, provides for "head" and "tail" attack tactics as well as parallel attack (building fireline parallel to but at some offset distance from the free-burning fire perimeter, alone and...

  11. Mesa Isochrones and Stellar Tracks (MIST). I. Solar-scaled Models

    NASA Astrophysics Data System (ADS)

    Choi, Jieun; Dotter, Aaron; Conroy, Charlie; Cantiello, Matteo; Paxton, Bill; Johnson, Benjamin D.

    2016-06-01

    This is the first of a series of papers presenting the Modules for Experiments in Stellar Astrophysics (MESA) Isochrones and Stellar Tracks (MIST) project, a new comprehensive set of stellar evolutionary tracks and isochrones computed using MESA, a state-of-the-art open-source 1D stellar evolution package. In this work, we present models with solar-scaled abundance ratios covering a wide range of ages (5≤slant {log}({Age}) [{year}]≤slant 10.3), masses (0.1≤slant M/{M}⊙ ≤slant 300), and metallicities (-2.0≤slant [{{Z}}/{{H}}]≤slant 0.5). The models are self-consistently and continuously evolved from the pre-main sequence (PMS) to the end of hydrogen burning, the white dwarf cooling sequence, or the end of carbon burning, depending on the initial mass. We also provide a grid of models evolved from the PMS to the end of core helium burning for -4.0≤slant [{{Z}}/{{H}}]\\lt -2.0. We showcase extensive comparisons with observational constraints as well as with some of the most widely used existing models in the literature. The evolutionary tracks and isochrones can be downloaded from the project website at http://waps.cfa.harvard.edu/MIST/.

  12. A phase II prospective, non-comparative assessment of a new silver sodium carboxymethylcellulose (AQUACEL(®) Ag BURN) glove in the management of partial thickness hand burns.

    PubMed

    Duteille, Franck; Jeffery, Steven L A

    2012-11-01

    Nylon-reinforced silver sodium carboxymethylcellulose (AQUACEL(®) Ag BURN) dressings were developed to be pliable and conforming for the management of partial-thickness burns. This study evaluated the AQUACEL(®) Ag BURN glove for the management of hand burns. This 21-day, phase II, prospective, non-comparative study included 23 patients with partial-thickness hand burn of at least two fingers. The AQUACEL(®) Ag BURN glove was applied to one hand and could remain in place up to 21 days until clinically indicated to change the glove. Dressings were evaluated 1, 2, 4, 6, 8, 14, and 21 days after initial application. Safety was the primary study endpoint. Sixteen (70%) hand burns re-epithelialized fully over a mean of 15.6 days. Initial application was easy/very easy for 20 (87%) patients. Mean time for initial dressing application was 5.4 min. At final evaluation, most patients gave ratings of excellent/good for conformability (91%), overall glove performance (74%), and appropriateness of sizes (83%). Mean pain score from 0 (none) to 10 (worst imaginable) was 3.43 at baseline; during the study, mean scores were 1.15 at rest and 2.29 during movement. Of 61 glove removals, most (72%) were easy/very easy, and 12% had fallen off. Adverse events (wound site or elsewhere) occurred in 15 (65%) patients. Treatment-related adverse events were wound pain (17%), maceration (9%), and stiff fingers (4%). The AQUACEL(®) Ag BURN glove was well tolerated in the management of partial-thickness hand burn. Many patients used only one glove. When glove changes were required, they were usually quick and easy. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  13. The importance of plume rise on the concentrations and atmospheric impacts of biomass burning aerosol

    NASA Astrophysics Data System (ADS)

    Walter, Carolin; Freitas, Saulo R.; Kottmeier, Christoph; Kraut, Isabel; Rieger, Daniel; Vogel, Heike; Vogel, Bernhard

    2016-07-01

    We quantified the effects of the plume rise of biomass burning aerosol and gases for the forest fires that occurred in Saskatchewan, Canada, in July 2010. For this purpose, simulations with different assumptions regarding the plume rise and the vertical distribution of the emissions were conducted. Based on comparisons with observations, applying a one-dimensional plume rise model to predict the injection layer in combination with a parametrization of the vertical distribution of the emissions outperforms approaches in which the plume heights are initially predefined. Approximately 30 % of the fires exceed the height of 2 km with a maximum height of 8.6 km. Using this plume rise model, comparisons with satellite images in the visible spectral range show a very good agreement between the simulated and observed spatial distributions of the biomass burning plume. The simulated aerosol optical depth (AOD) with data of an AERONET station is in good agreement with respect to the absolute values and the timing of the maximum. Comparison of the vertical distribution of the biomass burning aerosol with CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) retrievals also showed the best agreement when the plume rise model was applied. We found that downwelling surface short-wave radiation below the forest fire plume is reduced by up to 50 % and that the 2 m temperature is decreased by up to 6 K. In addition, we simulated a strong change in atmospheric stability within the biomass burning plume.

  14. Antimicrobial Blue Light Therapy for Multidrug-Resistant Acinetobacter baumannii Infection in a Mouse Burn Model: Implications for Prophylaxis and Treatment of Combat-related Wound Infections

    PubMed Central

    Zhang, Yunsong; Zhu, Yingbo; Gupta, Asheesh; Huang, Yingying; Murray, Clinton K.; Vrahas, Mark S.; Sherwood, Margaret E.; Baer, David G.; Hamblin, Michael R.; Dai, Tianhong

    2014-01-01

    In this study, we investigated the utility of antimicrobial blue light therapy for multidrug-resistant Acinetobacter baumannii infection in a mouse burn model. A bioluminescent clinical isolate of multidrug-resistant A. baumannii was obtained. The susceptibility of A. baumannii to blue light (415 nm)–inactivation was compared in vitro to that of human keratinocytes. Repeated cycles of sublethal inactivation of bacterial by blue light were performed to investigate the potential resistance development of A. baumannii to blue light. A mouse model of third degree burn infected with A. baumannii was developed. A single exposure of blue light was initiated 30 minutes after bacterial inoculation to inactivate A. baumannii in mouse burns. It was found that the multidrug-resistant A. baumannii strain was significantly more susceptible than keratinocytes to blue light inactivation. Transmission electron microscopy revealed blue light–induced ultrastructural damage in A. baumannii cells. Fluorescence spectroscopy suggested that endogenous porphyrins exist in A. baumannii cells. Blue light at an exposure of 55.8 J/cm2 significantly reduced the bacterial burden in mouse burns. No resistance development to blue light inactivation was observed in A. baumannii after 10 cycles of sublethal inactivation of bacteria. No significant DNA damage was detected in mouse skin by means of a skin TUNEL assay after a blue light exposure of 195 J/cm2. PMID:24381206

  15. High pressure droplet burning experiments in reduced gravity

    NASA Technical Reports Server (NTRS)

    Chauveau, Christian; Goekalp, Iskender

    1995-01-01

    A parametric investigation of single droplet gasification regimes is helpful in providing the necessary physical ideas for sub-grid models used in spray combustion numerical prediction codes. A research program has been initiated at the LCSR to explore the vaporization regimes of single and interacting hydrocarbon and liquid oxygen droplets under high pressure conditions. This paper summarizes the status of the LCSR program on the high pressure burning of single fuel droplets; recent results obtained under normal and reduced gravity conditions with suspended droplets are presented. In the work described here, parabolic flights of the CNES Caravelle is used to create a reduced gravity environment of the order of 10(exp -2) g(sub O). For all the droplet burning experiments reported here, the suspended droplet initial diameters are scattered around 1.5 mm; and the ambient air temperature is 300 K. The ambient pressure is varied between 0.1 MPa and 12 MPa. Four fuels are investigated: methanol (Pc = 7.9 MPa), n-heptane (Pc = 2.74 MPa), n-hexane (Pc = 3.01 MPa) and n-octane (Pc = 2.48 MPa).

  16. The changing strength and nature of fire-climate relationships in the northern Rocky Mountains, U.S.A., 1902-2008

    USGS Publications Warehouse

    Littell, Jeremy

    2015-01-01

    Time-varying fire-climate relationships may represent an important component of fire-regime variability, relevant for understanding the controls of fire and projecting fire activity under global-change scenarios. We used time-varying statistical models to evaluate if and how fire-climate relationships varied from 1902-2008, in one of the most flammable forested regions of the western U.S.A. Fire-danger and water-balance metrics yielded the best combination of calibration accuracy and predictive skill in modeling annual area burned. The strength of fire-climate relationships varied markedly at multi-decadal scales, with models explaining < 40% to 88% of the variation in annual area burned. The early 20th century (1902-1942) and the most recent two decades (1985-2008) exhibited strong fire-climate relationships, with weaker relationships for much of the mid 20th century (1943-1984), coincident with diminished burning, less fire-conducive climate, and the initiation of modern fire fighting. Area burned and the strength of fire-climate relationships increased sharply in the mid 1980s, associated with increased temperatures and longer potential fire seasons. Unlike decades with high burning in the early 20th century, models developed using fire-climate relationships from recent decades overpredicted area burned when applied to earlier periods. This amplified response of fire to climate is a signature of altered fire-climate-relationships, and it implicates non-climatic factors in this recent shift. Changes in fuel structure and availability following 40+ yr of unusually low fire activity, and possibly land use, may have resulted in increased fire vulnerability beyond expectations from climatic factors alone. Our results highlight the potential for non-climatic factors to alter fire-climate relationships, and the need to account for such dynamics, through adaptable statistical or processes-based models, for accurately predicting future fire activity.

  17. The Changing Strength and Nature of Fire-Climate Relationships in the Northern Rocky Mountains, U.S.A., 1902-2008

    PubMed Central

    Higuera, Philip E.; Abatzoglou, John T.; Littell, Jeremy S.; Morgan, Penelope

    2015-01-01

    Time-varying fire-climate relationships may represent an important component of fire-regime variability, relevant for understanding the controls of fire and projecting fire activity under global-change scenarios. We used time-varying statistical models to evaluate if and how fire-climate relationships varied from 1902-2008, in one of the most flammable forested regions of the western U.S.A. Fire-danger and water-balance metrics yielded the best combination of calibration accuracy and predictive skill in modeling annual area burned. The strength of fire-climate relationships varied markedly at multi-decadal scales, with models explaining < 40% to 88% of the variation in annual area burned. The early 20th century (1902-1942) and the most recent two decades (1985-2008) exhibited strong fire-climate relationships, with weaker relationships for much of the mid 20th century (1943-1984), coincident with diminished burning, less fire-conducive climate, and the initiation of modern fire fighting. Area burned and the strength of fire-climate relationships increased sharply in the mid 1980s, associated with increased temperatures and longer potential fire seasons. Unlike decades with high burning in the early 20th century, models developed using fire-climate relationships from recent decades overpredicted area burned when applied to earlier periods. This amplified response of fire to climate is a signature of altered fire-climate-relationships, and it implicates non-climatic factors in this recent shift. Changes in fuel structure and availability following 40+ yr of unusually low fire activity, and possibly land use, may have resulted in increased fire vulnerability beyond expectations from climatic factors alone. Our results highlight the potential for non-climatic factors to alter fire-climate relationships, and the need to account for such dynamics, through adaptable statistical or processes-based models, for accurately predicting future fire activity. PMID:26114580

  18. The Changing Strength and Nature of Fire-Climate Relationships in the Northern Rocky Mountains, U.S.A., 1902-2008.

    PubMed

    Higuera, Philip E; Abatzoglou, John T; Littell, Jeremy S; Morgan, Penelope

    2015-01-01

    Time-varying fire-climate relationships may represent an important component of fire-regime variability, relevant for understanding the controls of fire and projecting fire activity under global-change scenarios. We used time-varying statistical models to evaluate if and how fire-climate relationships varied from 1902-2008, in one of the most flammable forested regions of the western U.S.A. Fire-danger and water-balance metrics yielded the best combination of calibration accuracy and predictive skill in modeling annual area burned. The strength of fire-climate relationships varied markedly at multi-decadal scales, with models explaining < 40% to 88% of the variation in annual area burned. The early 20th century (1902-1942) and the most recent two decades (1985-2008) exhibited strong fire-climate relationships, with weaker relationships for much of the mid 20th century (1943-1984), coincident with diminished burning, less fire-conducive climate, and the initiation of modern fire fighting. Area burned and the strength of fire-climate relationships increased sharply in the mid 1980s, associated with increased temperatures and longer potential fire seasons. Unlike decades with high burning in the early 20th century, models developed using fire-climate relationships from recent decades overpredicted area burned when applied to earlier periods. This amplified response of fire to climate is a signature of altered fire-climate-relationships, and it implicates non-climatic factors in this recent shift. Changes in fuel structure and availability following 40+ yr of unusually low fire activity, and possibly land use, may have resulted in increased fire vulnerability beyond expectations from climatic factors alone. Our results highlight the potential for non-climatic factors to alter fire-climate relationships, and the need to account for such dynamics, through adaptable statistical or processes-based models, for accurately predicting future fire activity.

  19. 40 CFR Table 4 to Subpart Eeee of... - Summary of Reporting Requirements

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... Waste management plan; and § 60.2952. v. Anticipated date of initial startup. § 60.2952. 2. Startup notification a. Prior to initial startup i. Types of waste to be burned;ii. Maximum design waste burning... petition for site-specific operating limits; and § 60.2953. v. Anticipated date of initial startup. § 60...

  20. 40 CFR Table 4 to Subpart Eeee of... - Summary of Reporting Requirements

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Waste management plan; and § 60.2952. v. Anticipated date of initial startup. § 60.2952. 2. Startup notification a. Prior to initial startup i. Types of waste to be burned;ii. Maximum design waste burning... petition for site-specific operating limits; and § 60.2953. v. Anticipated date of initial startup. § 60...

  1. 40 CFR Table 4 to Subpart Eeee of... - Summary of Reporting Requirements

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... Waste management plan; and § 60.2952. v. Anticipated date of initial startup. § 60.2952. 2. Startup notification a. Prior to initial startup i. Types of waste to be burned;ii. Maximum design waste burning... petition for site-specific operating limits; and § 60.2953. v. Anticipated date of initial startup. § 60...

  2. 40 CFR Table 4 to Subpart Eeee of... - Summary of Reporting Requirements

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Waste management plan; and § 60.2952. v. Anticipated date of initial startup. § 60.2952. 2. Startup notification a. Prior to initial startup i. Types of waste to be burned;ii. Maximum design waste burning... petition for site-specific operating limits; and § 60.2953. v. Anticipated date of initial startup. § 60...

  3. 40 CFR Table 4 to Subpart Eeee of... - Summary of Reporting Requirements

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Waste management plan; and § 60.2952. v. Anticipated date of initial startup. § 60.2952. 2. Startup notification a. Prior to initial startup i. Types of waste to be burned;ii. Maximum design waste burning... petition for site-specific operating limits; and § 60.2953. v. Anticipated date of initial startup. § 60...

  4. Effects of drop freezing on microphysics of an ascending cloud parcel under biomass burning conditions

    NASA Astrophysics Data System (ADS)

    Diehl, K.; Simmel, M.; Wurzler, S.

    There is some evidence that the initiation of warm rain is suppressed in clouds over regions with vegetation fires. Thus, the ice phase becomes important as another possibility to initiate precipitation. Numerical simulations were performed to investigate heterogeneous drop freezing for a biomass-burning situation. An air parcel model with a sectional two-dimensional description of the cloud microphysics was employed with parameterizations for immersion and contact freezing which consider the different ice nucleating efficiencies of various ice nuclei. Three scenarios were simulated resulting to mixed-phase or completely glaciated clouds. According to the high insoluble fraction of the biomass-burning particles drop freezing via immersion and contact modes was very efficient. The preferential freezing of large drops followed by riming (i.e. the deposition of liquid drops on ice particles) and the evaporation of the liquid drops (Bergeron-Findeisen process) caused a further decrease of the liquid drops' effective radius in higher altitudes. In turn ice particle sizes increased so that they could serve as germs for graupel or hailstone formation. The effects of ice initiation on the vertical cloud dynamics were fairly significant leading to a development of the cloud to much higher altitudes than in a warm cloud without ice formation.

  5. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Coble, Jamie; Orton, Christopher; Schwantes, Jon

    Abstract—The Multi-Isotope Process (MIP) Monitor provides an efficient approach to monitoring the process conditions in used nuclear fuel reprocessing facilities to support process verification and validation. The MIP Monitor applies multivariate analysis to gamma spectroscopy of reprocessing streams in order to detect small changes in the gamma spectrum, which may indicate changes in process conditions. This research extends the MIP Monitor by characterizing a used fuel sample after initial dissolution according to the type of reactor of origin (pressurized or boiling water reactor), initial enrichment, burn up, and cooling time. Simulated gamma spectra were used to develop and test threemore » fuel characterization algorithms. The classification and estimation models employed are based on the partial least squares regression (PLS) algorithm. A PLS discriminate analysis model was developed which perfectly classified reactor type. Locally weighted PLS models were fitted on-the-fly to estimate continuous fuel characteristics. Burn up was predicted within 0.1% root mean squared percent error (RMSPE) and both cooling time and initial enrichment within approximately 2% RMSPE. This automated fuel characterization can be used to independently verify operator declarations of used fuel characteristics and inform the MIP Monitor anomaly detection routines at later stages of the fuel reprocessing stream to improve sensitivity to changes in operational parameters and material diversions.« less

  6. Photoacoustic diagnosis of edema in rat burned skin

    NASA Astrophysics Data System (ADS)

    Yoshida, Ken; Sato, Shunichi; Hatanaka, Kosuke; Saitoh, Daizoh; Ashida, Hiroshi; Sakamoto, Toshihisa; Obara, Minoru

    2010-02-01

    Diagnosis of edema, abnormal accumulation of water in tissue, is important for managing various traumatic injuries and diseases. However, there is no established method for real-time, noninvasive monitoring of edema. In severe extensive burn injuries, edema develops both topically and systemically due to the increased permeability of blood vessels. In this study, we examined photoacoustic (PA) monitoring of edema formed in rat burn models. Deep dermal burn with a 20% total body surface area was made in the dorsal skin of rats. Burn and its adjacent nonburn tissues were irradiated with 6-ns light pulses at 1430 nm, which is one of the absorption peak wavelengths of water in the near infrared. The PA signal amplitude increased until 12 - 24 hr postburn, and thereafter it gradually decreased to its initial level; the latter phase (after 24 hr postburn) coincided with a diuretic phase in the rats. There was a significant correlation between the PA signal amplitudes and water contents in the tissue measured by wet/dry weight method. These findings demonstrate the validity of PA measurement for real-time, noninvasive monitoring of edema.

  7. Satellite Remote Sensing of Atmospheric Pollution: the Far-Reaching Impact of Burning in Southern Africa

    NASA Technical Reports Server (NTRS)

    Fishman, Jack; Al-Saadi, Jassim A.; Neil, Doreen O.; Creilson, John K.; Severance, Kurt; Thomason, Larry W.; Edwards, David R.

    2008-01-01

    When the first observations of a tropospheric trace gas were obtained in the 1980s, carbon monoxide enhancements from tropical biomass burning dominated the observed features. In 2005, an active remote-sensing system to provide detailed information on the vertical distribution of aerosols and clouds was launched, and again, one of the most imposing features observed was the presence of emissions from tropical biomass burning. This paper presents a brief overview of space-borne observations of the distribution of trace gases and aerosols and how tropical biomass burning, primarily in the Southern Hemisphere, has provided an initially surprising picture of the distribution of these species and how they have evolved from prevailing transport patterns in that hemisphere. We also show how interpretation of these observations has improved significantly as a result of the improved capability of trajectory modeling in recent years and how information from this capability has provided additional insight into previous measurements form satellites. Key words: pollution; biomass burning; aerosols; tropical trace gas emissions; Southern Hemisphere; carbon monoxide.

  8. The inter-rater reliability of estimating the size of burns from various burn area chart drawings.

    PubMed

    Wachtel, T L; Berry, C C; Wachtel, E E; Frank, H A

    2000-03-01

    The accuracy and variability of burn size calculations using four Lund and Browder charts currently in clinical use and two Rule of Nine's diagrams were evaluated. The study showed that variability in estimation increased with burn size initially, plateaued in large burns and then decreased slightly in extensive burns. The Rule of Nine's technique often overestimates the burn size and is more variable, but can be performed somewhat faster than the Lund and Browder method. More burn experience leads to less variability in burn area chart drawing estimates. Irregularly shaped burns and burns on the trunk and thighs had greater variability than less irregularly shaped burns or burns on more defined anatomical parts of the body.

  9. OPTRAN- OPTIMAL LOW THRUST ORBIT TRANSFERS

    NASA Technical Reports Server (NTRS)

    Breakwell, J. V.

    1994-01-01

    OPTRAN is a collection of programs that solve the problem of optimal low thrust orbit transfers between non-coplanar circular orbits for spacecraft with chemical propulsion systems. The programs are set up to find Hohmann-type solutions, with burns near the perigee and apogee of the transfer orbit. They will solve both fairly long burn-arc transfers and "divided-burn" transfers. Program modeling includes a spherical earth gravity model and propulsion system models for either constant thrust or constant acceleration. The solutions obtained are optimal with respect to fuel use: i.e., final mass of the spacecraft is maximized with respect to the controls. The controls are the direction of thrust and the thrust on/off times. Two basic types of programs are provided in OPTRAN. The first type is for "exact solution" which results in complete, exact tkme-histories. The exact spacecraft position, velocity, and optimal thrust direction are given throughout the maneuver, as are the optimal thrust switch points, the transfer time, and the fuel costs. Exact solution programs are provided in two versions for non-coplanar transfers and in a fast version for coplanar transfers. The second basic type is for "approximate solutions" which results in approximate information on the transfer time and fuel costs. The approximate solution is used to estimate initial conditions for the exact solution. It can be used in divided-burn transfers to find the best number of burns with respect to time. The approximate solution is useful by itself in relatively efficient, short burn-arc transfers. These programs are written in FORTRAN 77 for batch execution and have been implemented on a DEC VAX series computer with the largest program having a central memory requirement of approximately 54K of 8 bit bytes. The OPTRAN program were developed in 1983.

  10. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Menikoff, Ralph

    SURFplus is a reactive burn model for high explosives aimed at modelling shock initiation and propagation of detonation waves. It utilizes the SURF model for the fast hot-spot reaction plus a slow reaction for the energy released by carbon clustering. A feature of the SURF model is that there is a partially decoupling between burn rate parameters and detonation wave properties. Previously, parameters for PBX 9502 that control shock ini- tiation had been calibrated to Pop plot data (distance-of-run to detonation as a function of shock pressure initiating the detonation). Here burn rate parameters for the high pres- sure regimemore » are adjusted to t the failure diameter and the limiting detonation speed just above the failure diameter. Simulated results are shown for an uncon ned rate stick when the 9502 diameter is slightly above and slightly below the failure diameter. Just above the failure diameter, in the rest frame of the detonation wave, the front is sonic at the PBX/air interface. As a consequence, the lead shock in the neighborhood of the interface is supported by the detonation pressure in the interior of the explosive rather than the reaction immediately behind the front. In the interior, the sonic point occurs near the end of the fast hot-spot reaction. Consequently, the slow carbon clustering reaction can not a ect the failure diameter. Below the failure diameter, the radial extent of the detonation front decreases starting from the PBX/air interface. That is, the failure starts at the PBX boundary and propagates inward to the axis of the rate stick.« less

  11. Allocating resources to large wildland fires: a model with stochastic production rates

    Treesearch

    Romain Mees; David Strauss

    1992-01-01

    Wildland fires that grow out of the initial attack phase are responsible for most of the damage and burned area. We model the allocation of fire suppression resources (ground crews, engines, bulldozers, and airdrops) to these large fires. The fireline at a given future time is partitioned into homogeneous segments on the basis of fuel type, available resources, risk,...

  12. Wildfire-related debris-flow initiation processes, Storm King Mountain, Colorado

    USGS Publications Warehouse

    Cannon, S.H.; Kirkham, R.M.; Parise, M.

    2001-01-01

    A torrential rainstorm on September 1, 1994 at the recently burned hillslopes of Storm King Mountain, CO, resulted in the generation of debris flows from every burned drainage basin. Maps (1:5000 scale) of bedrock and surficial materials and of the debris-flow paths, coupled with a 10-m Digital Elevation Model (DEM) of topography, are used to evaluate the processes that generated fire-related debris flows in this setting. These evaluations form the basis for a descriptive model for fire-related debris-flow initiation. The prominent paths left by the debris flows originated in 0- and 1st-order hollows or channels. Discrete soil-slip scars do not occur at the heads of these paths. Although 58 soil-slip scars were mapped on hillslopes in the burned basins, material derived from these soil slips accounted for only about 7% of the total volume of material deposited at canyon mouths. This fact, combined with observations of significant erosion of hillslope materials, suggests that a runoff-dominated process of progressive sediment entrainment by surface runoff, rather than infiltration-triggered failure of discrete soil slips, was the primary mechanism of debris-flow initiation. A paucity of channel incision, along with observations of extensive hillslope erosion, indicates that a significant proportion of material in the debris flows was derived from the hillslopes, with a smaller contribution from the channels. Because of the importance of runoff-dominated rather than infiltration-dominated processes in the generation of these fire-related debris flows, the runoff-contributing area that extends upslope from the point of debris-flow initiation to the drainage divide, and its gradient, becomes a critical constraint in debris-flow initiation. Slope-area thresholds for fire-related debris-flow initiation from Storm King Mountain are defined by functions of the form Acr(tan ??)3 = S, where Acr is the critical area extending upslope from the initiation location to the drainage divide, and tan ?? is its gradient. The thresholds vary with different materials. ?? 2001 Elsevier Science B.V. All rights reserved.

  13. Ecological and sampling constraints on defining landscape fire severity

    USGS Publications Warehouse

    Key, C.H.

    2006-01-01

    Ecological definition and detection of fire severity are influenced by factors of spatial resolution and timing. Resolution determines the aggregation of effects within a sampling unit or pixel (alpha variation), hence limiting the discernible ecological responses, and controlling the spatial patchiness of responses distributed throughout a burn (beta variation). As resolution decreases, alpha variation increases, extracting beta variation and complexity from the spatial model of the whole burn. Seasonal timing impacts the quality of radiometric data in terms of transmittance, sun angle, and potential contrast between responses within burns. Detection sensitivity candegrade toward the end of many fire seasons when low sun angles, vegetation senescence, incomplete burning, hazy conditions, or snow are common. Thus, a need exists to supersede many rapid response applications when remote sensing conditions improve. Lag timing, or timesince fire, notably shapes the ecological character of severity through first-order effects that only emerge with time after fire, including delayed survivorship and mortality. Survivorship diminishes the detected magnitude of severity, as burned vegetation remains viable and resprouts, though at first it may appear completely charred or consumed above ground. Conversely, delayed mortality increases the severity estimate when apparently healthy vegetation is in fact damaged by heat to the extent that it dies over time. Both responses dependon fire behavior and various species-specific adaptations to fire that are unique to the pre-firecomposition of each burned area. Both responses can lead initially to either over- or underestimating severity. Based on such implications, three sampling intervals for short-term burn severity are identified; rapid, initial, and extended assessment, sampled within about two weeks, two months, and depending on the ecotype, from three months to one year after fire, respectively. Spatial and temporal conditions of sampling strategies constrain data quality and ecological information obtained about fire severity. Though commonly overlooked, such considerations determine the objectives and hypotheses that are appropriate for each application, and are especially important when building comparative studies or long-term reference databases on fire severity.

  14. Comparing the reported burn conditions for different severity burns in porcine models: a systematic review.

    PubMed

    Andrews, Christine J; Cuttle, Leila

    2017-12-01

    There are many porcine burn models that create burns using different materials (e.g. metal, water) and different burn conditions (e.g. temperature and duration of exposure). This review aims to determine whether a pooled analysis of these studies can provide insight into the burn materials and conditions required to create burns of a specific severity. A systematic review of 42 porcine burn studies describing the depth of burn injury with histological evaluation is presented. Inclusion criteria included thermal burns, burns created with a novel method or material, histological evaluation within 7 days post-burn and method for depth of injury assessment specified. Conditions causing deep dermal scald burns compared to contact burns of equivalent severity were disparate, with lower temperatures and shorter durations reported for scald burns (83°C for 14 seconds) compared to contact burns (111°C for 23 seconds). A valuable archive of the different mechanisms and materials used for porcine burn models is presented to aid design and optimisation of future models. Significantly, this review demonstrates the effect of the mechanism of injury on burn severity and that caution is recommended when burn conditions established by porcine contact burn models are used by regulators to guide scald burn prevention strategies. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  15. Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Murphy, T. J.; Douglas, M. R.; Fincke, J. R.

    Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Workmore » is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. Lastly, the ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.« less

  16. Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

    DOE PAGES

    Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; ...

    2016-05-26

    Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Workmore » is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. Lastly, the ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.« less

  17. Turbulent flame propagation and combustion in spark ignition engines

    NASA Technical Reports Server (NTRS)

    Beretta, G. P.; Rashidi, M.; Keck, J. C.

    1983-01-01

    Pressure measurements synchronized with high-speed motion-picture records of flame propagation have been made in a transparent-piston engine. The data show that the initial expansion speed of the flame front is close to that of a laminar flame. As the flame expands, its speed rapidly accelerates to a quasi-steady value comparable with that of the turbulent velocity fluctuations in the unburned gas. During the quasi-steady propagation phase, a significant fraction of the gas behind the visible front is unburned. Final burnout of the charge may be approximated by an exponential decay in time. The data have been analyzed in a model-independent way to obtain a set of empirical equations for calculating mass burning rates in spark-ignition engines. The burning equations contain three parameters: the laminar burning speed, a characteristic speed (uT), and a characteristic length (lT). The laminar burning speed is known from laboratory measurements. Tentative correlations relating uT and lT to engine geometry and operating variables have been derived from the engine data.

  18. Burns - resources

    MedlinePlus

    Resources - burns ... The following organizations are good resources for information on burns : Burns Recovered -- brsg.org Model Systems Knowledge Translation Center - Burn Model Systems -- www.msktc.org/burn http:// ...

  19. On beyond the standard model for high explosives: challenges & obstacles to surmount

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Menikoff, Ralph Ds

    2009-01-01

    Plastic-bonded explosives (PBX) are heterogeneous materials. Nevertheless, current explosive models treat them as homogeneous materials. To compensate, an empirically determined effective burn rate is used in place of a chemical reaction rate. A significant limitation of these models is that different burn parameters are needed for applications in different regimes; for example, shock initiation of a PBX at different initial temperatures or different initial densities. This is due to temperature fluctuations generated when a heterogeneous material is shock compressed. Localized regions of high temperatures are called hot spots. They dominate the reaction for shock initiation. The understanding of hot spotmore » generation and their subsequent evolution has been limited by the inability to measure transients on small spatial ({approx} 1 {micro}m) and small temporal ({approx} 1 ns) scales in the harsh environment of a detonation. With the advances in computing power, it is natural to try and gain an understanding of hot-spot initiation with numerical experiments based on meso-scale simulations that resolve material heterogeneities and utilize realistic chemical reaction rates. However, to capture the underlying physics correctly, such high resolution simulations will require more than fast computers with a large amount of memory. Here we discuss some of the issues that need to be addressed. These include dissipative mechanisms that generate hot spots, accurate thermal propceties for the equations of state of the reactants and products, and controlling numerical entropy error from shock impedance mismatches at material interfaces. The later can generate artificial hot spots and lead to premature reaction. Eliminating numerical hot spots is critical for shock initiation simulations due to the positive feedback between the energy release from reaction and the hydrodynamic flow.« less

  20. Measurements of Background and Polluted Air in Rural Regions of Rwanda

    NASA Astrophysics Data System (ADS)

    DeWitt, L.; Gasore, J.; Prinn, R. G.; Potter, K. E.

    2015-12-01

    Rwanda, a mountainous nation in Equatorial East Africa, is one of the least-urbanized nations in Africa. The majority of the population are subsistence farmers, and major sources of air pollution (e.g., particulates, greenhouse gases) in Rwanda include agricultural burning and cookstoves in rural areas, and older diesel vehicles and mototaxis in cities. Currently, initiatives to supply efficient cookstoves, development of cleaner-burning fuel from recycled agricultural waste, and new regulations on vehicle emissions and importation are underway. These initiatives seek to help Rwanda grow in the greenest way possible, to mitigate negative health and climate effects of development; however, little ambient data on air quality is available in different regions of Rwanda for a baseline study before and benefits study after these initiatives. The Rwanda Climate Observatory, located on the summit of Mt. Mugogo (-1.5833°, 29.5667°), a 2.5 km peak, has recently begun measurements of black carbon (BC) aerosol concentration and O3 and CO gas concentrations. BC measurements were performed with a 7-wavelength Magee Scientific aethalometer and the aethalometer model was used to calculate the influence of fossil fuel and biomass burning sources on BC concentrations. CO and O3 measurements were used in conjunction with BC aerosol data, and HYSPLIT back trajectories were also used to help discriminate between periods of heavy burning and periods of regional influence from traffic and general cookfire emissions. Since Mt. Mugogo is in a rural area, this station captures a snapshot of regional background pollution away from high anthropogenic influence. The nearby households and fields also allow case studies of household and crop burning during localized events and help quanitfy potential daily exposure to particulates and climate-forcing emissions in remote areas of this developing country. We will present time series of the BC, O3, CO and insolation measurements at Mt. Mugogo, and interpret them in terms of sources, circulation, air chemistry and physics, and sinks.

  1. Antimicrobial blue light therapy for multidrug-resistant Acinetobacter baumannii infection in a mouse burn model: implications for prophylaxis and treatment of combat-related wound infections.

    PubMed

    Zhang, Yunsong; Zhu, Yingbo; Gupta, Asheesh; Huang, Yingying; Murray, Clinton K; Vrahas, Mark S; Sherwood, Margaret E; Baer, David G; Hamblin, Michael R; Dai, Tianhong

    2014-06-15

    In this study, we investigated the utility of antimicrobial blue light therapy for multidrug-resistant Acinetobacter baumannii infection in a mouse burn model. A bioluminescent clinical isolate of multidrug-resistant A. baumannii was obtained. The susceptibility of A. baumannii to blue light (415 nm)-inactivation was compared in vitro to that of human keratinocytes. Repeated cycles of sublethal inactivation of bacterial by blue light were performed to investigate the potential resistance development of A. baumannii to blue light. A mouse model of third degree burn infected with A. baumannii was developed. A single exposure of blue light was initiated 30 minutes after bacterial inoculation to inactivate A. baumannii in mouse burns. It was found that the multidrug-resistant A. baumannii strain was significantly more susceptible than keratinocytes to blue light inactivation. Transmission electron microscopy revealed blue light-induced ultrastructural damage in A. baumannii cells. Fluorescence spectroscopy suggested that endogenous porphyrins exist in A. baumannii cells. Blue light at an exposure of 55.8 J/cm(2) significantly reduced the bacterial burden in mouse burns. No resistance development to blue light inactivation was observed in A. baumannii after 10 cycles of sublethal inactivation of bacteria. No significant DNA damage was detected in mouse skin by means of a skin TUNEL assay after a blue light exposure of 195 J/cm(2). © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Validation of the Zürich burn-biofilm model.

    PubMed

    Guggenheim, Merlin; Thurnheer, Thomas; Gmür, Rudolf; Giovanoli, Pietro; Guggenheim, Bernhard

    2011-11-01

    Despite advances in the use of topical and parenteral antimicrobial therapy and the practice of early tangential burn-wound excision, bacterial infection remains a major problem in the management of burn victims today. The purpose of this study was to design and evaluate a polyspecies biofilm model with bacteria known to cause severe infections in burn patients. The model is simple to prepare, maintain and analyse, and allows for short-term exposure to antimicrobials. Initial experiments showed that it was impossible to establish balanced polyspecies biofilms with an inoculum of Gram-positive and -negative bacteria. After 64.5 h of incubation, the Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) had suppressed the Gram-positives (Enterococcus faecalis, Staphylococcus aureus and Streptococcus intermedius). However, adding the Gram-negative bacteria after 41.5 h to an established biofilm of Gram-positives resulted in a balanced microbial consortium. After 64.5 h, all species were present in high numbers (10(7) to 10(8) colony forming units (CFU) per biofilm). Multiple repetitions showed high reproducibility of biofilm formation without significant differences between and within experiments. Combined fluorescence in situ hybridisation/confocal laser scanning microscopy (FISH/CLSM) analyses, for which biofilms had to be grown on a different non-flexible substrate (hydroxy apatite), revealed that, by 41.5 h, the biofilm consisted of an almost confluent layer of bacteria firmly adherent to the substratum. After 64.5 h (22 h after the addition of the Gram negatives), the biofilm consisted of a confluent mixture of single cells, an abundance of galaxies of bacteria with small lacunae and large amounts of extracellular matrix polysaccharides. The polyspecies biofilm model contains the most prevalent burn-associated Gram-positive and Gram-negative bacterial pathogens and mimics the Gram-negative shift observed in vivo. It shows excellent reproducibility. It should allow adaptation to the bacterial spectrum prevalent in different burn centres and lead to a much more reliable investigation of the efficiency of topical antimicrobial agents than models operating with planktonic bacteria. The experiments further open up the perspective to create an in vivo model using these biofilms as infectious agents. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

  3. Properties of Deflagration Fronts and Models for Type IA Supernovae

    NASA Astrophysics Data System (ADS)

    Domínguez, I.; Höflich, P.

    2000-01-01

    Detailed models of the explosion of a white dwarf that include self-consistent calculations of the light curve and spectra provide a link between observational quantities and the underlying explosion model. These calculations assume spherical geometry and are based on parameterized descriptions of the burning front. Recently, the first multidimensional calculations for nuclear burning fronts have been performed. Although a fully consistent treatment of the burning fronts is beyond the current state of the art, these calculations provide a new and better understanding of the physics. Several new descriptions for flame propagation have been proposed by Khokhlov et al. and Niemeyer et al. Using various descriptions for the propagation of a nuclear deflagration front, we have studied the influence on the results of previous analyses of Type Ia supernovae, namely, the nucleosynthesis and structure of the expanding envelope. Our calculations are based on a set of delayed detonation models with parameters that give a good account of the optical and infrared light curves and of the spectral evolution. In this scenario, the burning front first propagates in a deflagration mode and subsequently turns into a detonation. The explosions and light curves are calculated using a one-dimensional Lagrangian radiation-hydro code including a detailed nuclear network. We find that the results of the explosion are rather insensitive to details of the description of the deflagration front, even if its speed and the time from the transition to detonation differ almost by a factor of 2. For a given white dwarf (WD) and a fixed transition density, the total production of elements changes by less than 10%, and the distribution in the velocity space changes by less than 7%. Qualitatively, this insensitivity of the final outcome of the explosion to the details of the flame propagation during the (slow) deflagration phase can be understood as follows: for plausible variations in the speed of the turbulent deflagration, the duration of this phase is several times longer than the sound crossing time in the initial WD. Therefore, the energy produced during the early nuclear burning can be redistributed over the entire WD, causing a slow preexpansion. In this intermediate state, the WD is still bound but its binding energy is reduced by the amount of nuclear energy. The expansion ratio depends mainly on the total amount of burning during the deflagration phase. Consequently, the conditions are very similar under which nuclear burning takes place during the subsequent detonation phase. In our example, the density and temperature at the burning front changes by less than 3%, and the expansion velocity changes by less than 10%. The burning conditions are very close to previous calculations which used a constant deflagration velocity. Based on a comparison with observations, those required low deflagration speeds (~2%-3% of the speed of sound). Exceptions to the similarity are the innermost layers of ~0.03-0.05 Msolar. Still, nuclear burning is in nuclear statistical equilibrium, but the rate of electron capture is larger for the new descriptions of the flame propagation. Consequently, the production of very neutron-rich isotopes is increased. In our example, close to the center Ye is about 0.44, compared to 0.46 in the model with constant deflagration speed. This increases the 48Ca production by more than a factor of 100 to 3.E-6 Msolar. Conclusions from previous analyses of light curves and spectra on the properties of the WD and the explosions will not change, and even with the new descriptions, the delayed detonation scenario is consistent with the observations. Namely, the central density results with respect to the chemical structure of the progenitor and the transition density from deflagration to detonation do not change. The reason for this similarity is the fact that the total amount of burning during the long deflagration phase determines the restructuring of the WD prior to the detonation. Therefore, we do not expect that the precise, microphysical prescription for the speed of a subsonic burning front has a significant effect on the outcome. However, at the current level of uncertainties for the burning front, the relation between properties of the burning front and of the initial white dwarf cannot be obtained from a comparison between observation and theoretical predictions by one-dimensional models. Multidimensional calculations are needed (1) to get inside the relations between model parameters such as central density and properties of the deflagration front and its relation to the transition density between deflagration and detonation and (2) to make use of information on asphericity that is provided by polarization measurements. These questions are essential to test, estimate, and predict some of the evolutionary effects of SNe Ia and their use as cosmological yardsticks.

  4. Ignition of an organic water-coal fuel droplet floating in a heated-air flow

    NASA Astrophysics Data System (ADS)

    Valiullin, T. R.; Strizhak, P. A.; Shevyrev, S. A.; Bogomolov, A. R.

    2017-01-01

    Ignition of an organic water-coal fuel (CWSP) droplet floating in a heated-air flow has been studied experimentally. Rank B2 brown-coal particles with a size of 100 μm, used crankcase Total oil, water, and a plasticizer were used as the main CWSP components. A dedicated quartz-glass chamber has been designed with inlet and outlet elements made as truncated cones connected via a cylindrical ring. The cones were used to shape an oxidizer flow with a temperature of 500-830 K and a flow velocity of 0.5-5.0 m/s. A technique that uses a coordinate-positioning gear, a nichrome thread, and a cutter element has been developed for discharging CWSP droplets into the working zone of the chamber. Droplets with an initial size of 0.4 to 2.0 mm were used. Conditions have been determined for a droplet to float in the oxidizer flow long enough for the sustainable droplet burning to be initiated. Typical stages and integral ignition characteristics have been established. The integral parameters (ignition-delay times) of the examined processes have been compared to the results of experiments with CWSP droplets suspended on the junction of a quick-response thermocouple. It has been shown that floating fuel droplets ignite much quicker than the ones that sit still on the thermocouple due to rotation of an CWSP droplet in the oxidizer flow, more uniform heating of the droplet, and lack of heat drainage towards the droplet center. High-speed video recording of the peculiarities of floatation of a burning fuel droplet makes it possible to complement the existing models of water-coal fuel burning. The results can be used for a more substantiated modeling of furnace CWSP burning with the ANSYS, Fluent, and Sigma-Flow software packages.

  5. Turbulent Nuclear Burning of Carbon Fuel in Double-Degenerate White Dwarfs

    NASA Astrophysics Data System (ADS)

    Mozumdar, Pritom; Fisher, Robert

    2018-01-01

    Type Ia supernovae (SNe Ia) are of interest as standardizable cosmological candles, though their stellar progenitors are still poorly understood. The double-degenerate (DD) channel is promising, but the mechanism for the explosion remains a matter of active investigation. A long-standing problem in modeling SNe Ia is the fact that 3D simulations leave the length scales crucial for a possible detonation unresolved. In this work, we have performed local 3D hydrodynamical adaptive mesh refinement simulations of driven turbulence for various initial conditions characteristic of the DD scenario, which are capable of capturing length scales relevant to the Zel’dovich gradient mechanism. Because the carbon burning rate is highly sensitive to temperature in this regime, we demonstrate that turbulence can dramatically enhance the nuclear burning rate, and we investigate the connection to a possible detonation.

  6. Boron and Poloxamer (F68 and F127) Containing Hydrogel Formulation for Burn Wound Healing.

    PubMed

    Demirci, Selami; Doğan, Ayşegül; Karakuş, Emre; Halıcı, Zekai; Topçu, Atila; Demirci, Elif; Sahin, Fikrettin

    2015-11-01

    Burn injuries, the most common and destructive forms of wounds, are generally accompanied with life-threatening infections, inflammation, reduced angiogenesis, inadequate extracellular matrix production, and lack of growth factor stimulation. In the current study, a new antimicrobial carbopol-based hydrogel formulated with boron and pluronic block copolymers was evaluated for its healing activity using in vitro cell culture techniques and an experimental burn model. Cell viability, gene expression, and wound healing assays showed that gel formulation increased wound healing potential. In vitro tube-like structure formation and histopathological examinations revealed that gel not only increased wound closure by fibroblastic cell activity, but also induced vascularization process. Moreover, gel formulation exerted remarkable antimicrobial effects against bacteria, yeast, and fungi. Migration, angiogenesis, and contraction-related protein expressions including collagen, α-smooth muscle actin, transforming growth factor-β1, vimentin, and vascular endothelial growth factor were considerably enhanced in gel-treated groups. Macrophage-specific antigen showed an oscillating expression at the burn wounds, indicating the role of initial macrophage migration to the wound site and reduced inflammation phase. This is the first study indicating that boron containing hydrogel is able to heal burn wounds effectively. The formulation promoted burn wound healing via complex mechanisms including stimulation of cell migration, growth factor expression, inflammatory response, and vascularization.

  7. Emissions from Open Burning of Simulated Military Waste from Forward Operating Bases

    EPA Science Inventory

    Emissions from open burning of simulated military waste from forward operating bases (FOBs) were extensively characterized as an initial step in assessing potential inhalation exposure of FOB personnel and future disposal alternatives. Emissions from two different burning scenar...

  8. The effect of burn injury on CD8+ and CD4+ T cells in an irradiation model of homeostatic proliferation.

    PubMed

    Buchanan, Ian B; Maile, Robert; Frelinger, Jeffrey A; Fair, Jeffrey H; Meyer, Anthony A; Cairns, Bruce A

    2006-11-01

    Homeostatic proliferation of T cells has recently been shown to be an important mechanism in the host response to infection. However, its role in the T cell response to burn injury is unknown. In this study, we examine the effect of burn injury on CD4+ and CD8+ T cell homeostatic proliferation after irradiation. Wild-type C57BL/6 female mice were irradiated with six grays ionizing radiation and 48 hours later, syngeneic whole splenocytes or purified CD4+ or CD8+ T cells labeled with carboxy-fluorescein diacetate, succinimidyl ester were adoptively transferred. Two days later, mice underwent a 20% burn injury, followed by splenocyte harvest 3 and 10 days after injury. Burn mice demonstrate increased splenic cellularity and CD8+ T cell proliferation after adoptive transfer of either purified CD8+ cells or whole spleen populations compared with unburned (sham) mice. In contrast, CD4+ T cell proliferation after burn injury is unchanged after adoptive transfer of whole spleen cells and drastically decreased after adoptive transfer of a purified CD4+ population compared with sham mice. Ten days after burn injury CD8+ T cells continue to demonstrate greater proliferation than CD4+ T cells. CD8+ T cells are more robust than CD4+ T cells in their proliferative response after burn injury. In addition, CD8+ T cell proliferation appears less reliant on other immune cells than purified CD4+ T cell proliferation. These data reiterate the importance of CD8+ T cells in the initial immune response to burn injury.

  9. Titanium subhydride potassium perchlorate (TiH1.65/KClO4) burn rates from hybrid closed bomb-strand burner experiments.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cooper, Marcia A.; Oliver, Michael S.

    2012-08-01

    A hybrid closed bomb-strand burner is used to measure the burning behavior of the titanium subhydride potassium perchlorate pyrotechnic with an equivalent hydrogen concentration of 1.65. This experimental facility allows for simultaneous measurement of the closed bomb pressure rise and pyrotechnic burn rate as detected by electrical break wires over a range of pressures. Strands were formed by pressing the pyrotechnic powders to bulk densities between 60% and 90% theoretical maximum density. The burn rate dependance on initial density and vessel pressure are measured. At all initial strand densities, the burn is observed to transition from conductive to convective burningmore » within the strand. The measured vessel pressure history is further analyzed following the closed bomb analysis methods developed for solid propellants.« less

  10. Understory Plant Community Response to Season of Burn in Natural Longleaf Pine Forests

    Treesearch

    John S. Kush; Ralph S. Meldahl; William D. Boyer

    2000-01-01

    A season of burn study was initiated in 1973 on the Escambia Experimental Forest, near Brewton, Alabama. All study plots were established in the 14-year-old longleaf pine (Pinus palustris) stands. Treatments consisted of biennial burns in winter, spring, and summer, plus a no-burn check. Objectives of the current study were to determine...

  11. Effects of seasonal prescribved fires on residual overstory trees in oak-dominate shelterwood stands

    Treesearch

    Patrick H. Brose; David H. Van Lear

    1999-01-01

    A study was initiated in 1994 to evaluate the degree of bole damage and crown decline residual overstory trees would experience because of prescribed burning of shelterwood stands. Three oak-dominated shelterwood stands, partially harvested 2 to 4 yr earlier, were divided into four treatments (unburned control, spring burn, summer burn, and winter burn). Fifteen...

  12. Beneficial Effects of Hydrogen-Rich Saline on Early Burn-Wound Progression in Rats

    PubMed Central

    Guo, Song Xue; Jin, Yun Yun; Fang, Quan; You, Chuan Gang; Wang, Xin Gang; Hu, Xin Lei; Han, Chun-Mao

    2015-01-01

    Introduction Deep burn wounds undergo a dynamic process known as wound progression that results in a deepening and extension of the initial burn area. The zone of stasis is more likely to develop more severe during wound progression in the presence of hypoperfusion. Hydrogen has been reported to alleviate injury triggered by ischaemia/reperfusion and burns in various organs by selectively quenching oxygen free radicals. The aim of this study was to investigate the possible protective effects of hydrogen against early burn-wound progression. Methods Deep-burn models were established through contact with a boiled, rectangular, brass comb for 20 s. Fifty-six Sprague-Dawley rats were randomly divided into sham, burn plus saline, and burn plus hydrogen-rich saline (HS) groups with sacrifice and analysis at various time windows (6 h, 24 h, 48 h) post burn. Indexes of oxidative stress, apoptosis and autophagy were measured in each group. The zone of stasis was evaluated using immunofluorescence staining, ELISA, and Western blot to explore the underlying effects and mechanisms post burn. Results The burn-induced increase in malondialdehyde was markedly reduced with HS, while the activities of endogenous antioxidant enzymes were significantly increased. Moreover, HS treatment attenuated increases in apoptosis and autophagy postburn in wounds, according to the TUNEL staining results and the expression analysis of Bax, Bcl-2, caspase-3, Beclin-1 and Atg-5 proteins. Additionally, HS lowered the level of myeloperoxidase and expression of TNF-α, IL-1β, and IL-6 in the zone of stasis while augmenting IL-10. The elevated levels of Akt phosphorylation and NF-κB p65 expression post burn were also downregulated by HS management. Conclusion Hydrogen can attenuate early wound progression following deep burn injury. The beneficial effect of hydrogen was mediated by attenuating oxidative stress, which inhibited apoptosis and inflammation, and the Akt/NF-κB signalling pathway may be involved in regulating the release of inflammatory cytokines. PMID:25874619

  13. Burn leads to long-term elevated admissions to hospital for gastrointestinal disease in a West Australian population based study.

    PubMed

    Stevenson, Andrew W; Randall, Sean M; Boyd, James H; Wood, Fiona M; Fear, Mark W; Duke, Janine M

    2017-05-01

    While the most obvious impact of burn is on the skin, systemic responses also occur after burn, including intestinal inflammation. The objective of this study was to assess if burns are associated with increased long-term admissions for gastrointestinal diseases. A population-based longitudinal study using linked hospital morbidity and death data from Western Australia was undertaken of adults aged at least 15 years when hospitalized for a first burn (n=20,561) in 1980-2012. A frequency matched non-injury comparison cohort was randomly selected from Western Australia's birth registrations and electoral roll (n=80,960). Crude admission rates and summed days in hospital for digestive diseases were calculated. Negative binomial and Cox proportional hazards regression modeling were used to generate incidence rate ratios (IRR) and hazard ratios (HR), respectively. After adjustment for demographic factors and pre-existing health status, the burn cohort had 1.54 times (95% confidence interval (CI): 1.47-1.62) as many admissions and almost three times the number of days in hospital with a digestive system diagnosis (IRR, 95% CI: 2.90, 2.60-3.25) than the uninjured cohort. Significantly elevated adjusted post-burn incident rates were identified, with the risk decreasing with increasing time: in the first month (HR, 95% CI: 3.02, 1.89-4.82), from one month to five years (HR, 95% CI: 1.42, 1.31-1.54), and from five to twenty years after burn (HR, 95% CI: 1.13, 1.06-1.20). Findings of increased hospital admission rates and prolonged length of hospital stay for gastrointestinal diseases in the burn cohort provide evidence to support that burns have effects that persist long after the initial injury. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  14. Compliance with nutrition support guidelines in acutely burned patients.

    PubMed

    Holt, Brennen; Graves, Caran; Faraklas, Iris; Cochran, Amalia

    2012-08-01

    Adequate and timely provision of nutritional support is a crucial component of care of the critically ill burn patient. The goal of this study was to assess a single center's consistency with Society of Critical Care Medicine/American Society for Parenteral and Enteral Nutrition (SCCM/ASPEN) guidelines for nutritional support in critically ill patients. Acutely burned patients >45kg in weight admitted to a regional burn center during a two-year period and who required 5 or more days of full enteral nutritional support were eligible for inclusion in this retrospective review. Specific outcomes evaluated include time from admission to feeding tube placement and enteral feeding initiation and percent of nutritional goal received within the first week of hospital stay. Descriptive statistics were used for all analyses. IRB approval was obtained. Thirty-seven patients were included in this retrospective review. Median age of patients was 44.9 years (IQR: 24.2-55.1), and median burn injury size was 30% (IQR: 19-47). Median time to feeding tube placement was 31.1h post admission (IQR: 23.6-50.2h), while median time to initiation of EN was 47.9h post admission (IQR: 32.4-59.9h). The median time required for patients to reach 60% of caloric goal was 3 days post-admission (IQR: 3-4.5). The median time for initiation of enteral nutrition was within the SCCM/ASPEN guidelines for initial nutrition in the critically ill patient. This project identified a 16h time lag between placement of enteral access and initiation of enteral nutrition. Development of a protocol for feeding tube placement and enteral nutrition management may optimize early nutritional support in the acutely injured burn patient. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  15. Properties of convective oxygen and silicon burning shells in supernova progenitors

    NASA Astrophysics Data System (ADS)

    Collins, Christine; Müller, Bernhard; Heger, Alexander

    2018-01-01

    Recent 3D simulations have suggested that convective seed perturbations from shell burning can play an important role in triggering neutrino-driven supernova explosions. Since isolated simulations cannot determine whether this perturbation-aided mechanism is of general relevance across the progenitor mass range, we here investigate the pertinent properties of convective oxygen and silicon burning shells in a broad range of pre-supernova stellar evolution models. We find that conditions for perturbation-aided explosions are most favourable in the extended oxygen shells of progenitors between about 16 and 26 solar masses, which exhibit large-scale convective overturn with high convective Mach numbers. Although the highest convective Mach numbers of up to 0.3 are reached in the oxygen shells of low-mass progenitors, convection is typically dominated by small-scale modes in these shells, which implies a more modest role of initial perturbations in the explosion mechanism. Convective silicon burning rarely provides the high Mach numbers and large-scale perturbations required for perturbation-aided explosions. We also find that about 40 per cent of progenitors between 16 and 26 solar masses exhibit simultaneous oxygen and neon burning in the same convection zone as a result of a shell merger shortly before collapse.

  16. Ural-Tweed Bighorn Sheep Wildlife Mitigation Project, 1986 Annual Report.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yde, Chris A.; Summerfield, Bob; Young, Lewis

    This report summarizes the results of the project activities from September 1, 1984 to December 31, 1986. To date, habitat treatments have been initiated on eight areas. The treatments include selective slash and burn, prescribed fire and fertilization. Inclement weather precluded the completion of the prescribed burns scheduled during fall 1985 and fall 1986. The lower Stonehill prescribed fire was rescheduled from fall 1985 to spring 1986 with the burn accomplished, producing varied results. Extensive pretreatment vegetative information has been collected from all units scheduled for habitat manipulations. Additionally, future projects have been delineated for other areas frequented by bighornmore » sheep. Ten adult bighorn sheep (5 ewes and 5 rams) have been fitted with radio transmitters. Systematic aerial and ground surveys were utilized to monitor the movements and seasonal habitat preferences of the instrumented sheep. Age and sex information was gathered whenever possible to aid in the development of a population model, Monthly pallet group collections were initiated in May 1985 to provide samples for 2.6 diaminopimetic acid (DAPA), food habits and lungworm larvae analysis. The majority of the data analysis is ongoing and will be presented in later reports.« less

  17. 78 FR 7860 - Initial Research on the Long-Term Health Consequences of Exposure to Burn Pits in Iraq and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    ... design features. Existing research studies, such as the Million Veteran Program, the Cooperative Studies..., study designs, research and evaluation protocols, and results from burn pit emissions research. VA has... DEPARTMENT OF VETERANS AFFAIRS Initial Research on the Long-Term Health Consequences of Exposure...

  18. The Hand Burn Severity (HABS) score: A simple tool for stratifying severity of hand burns.

    PubMed

    Bache, Sarah E; Fitzgerald O'Connor, Edmund; Theodorakopoulou, Evgenia; Frew, Quentin; Philp, Bruce; Dziewulski, Peter

    2017-02-01

    Hand burns represent a unique challenge to the burns team due to the intricate structure and unrivalled functional importance of the hand. The initial assessment and prognosis relies on consideration of the specific site involved as well as depth of the burn. We created a simple severity score that could be used by referring non-specialists and researchers alike. The Hand Burn Severity (HABS) score stratifies hand burns according to severity with a numerical value of between 0 (no burn) and 18 (most severe) per hand. Three independent assessors scored the photographs of 121 burned hands of 106 adult and paediatric patients, demonstrating excellent inter-rater reliability (r=0.91, p<0.0001 on testing with Lin's correlation coefficient). A significant relationship was shown between the HABS score and a reliable binary outcome of the requirement for surgical excision on Mann-Whitney U testing (U=152; Z=9.8; p=0.0001). A receiver operator characteristic (ROC) curve analysis found a cut off score of 5.5, indicating that those with a HABS score below 6 did not require an operation, whereas those with a score above 6 did. The HABS score was shown to be more sensitive and specific that assessment of burn depth alone. The HABS score is a simple to use tool to stratify severity at initial presentation of hand burns which will be useful when referring, and when reporting outcomes. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  19. The Marble Experiment: Overview and Simulations

    NASA Astrophysics Data System (ADS)

    Douglas, M. R.; Murphy, T. J.; Cobble, J. A.; Fincke, J. R.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Olson, R. E.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

    2015-11-01

    The Marble ICF platform has recently been launched on both OMEGA and NIF with the goal to investigate the influence of heterogeneous mix on fusion burn. The unique separated reactant capsule design consists of an ``engineered'' CH capsule filled with deuterated plastic foam that contains pores or voids that are filled with tritium gas. Initially the deuterium and tritium are separated, but as the implosion proceeds, the D and T mix, producing a DT signature. The results of these experiments will be used to inform a probability density function (PDF) burn modelling approach for un-resolved cell morphology. Initial targets for platform development have consisted of either fine-pore foams or gas mixtures, with the goal to field the engineered foams in 2016. An overview of the Marble experimental campaign will be presented and simulations will be discussed. This work is supported by US DOE/NNSA, performed at LANL, operated by LANS LLC under contract DE-AC52-06NA25396.

  20. Analysis of compaction shock interactions during DDT of low density HMX

    NASA Astrophysics Data System (ADS)

    Rao, Pratap T.; Gonthier, Keith A.

    2017-01-01

    Deflagration-to-Detonation Transition (DDT) in confined, low density granular HMX occurs by a complex mechanism that involves compaction shock interactions within the material. Piston driven DDT experiments indicate that detonation is abruptly triggered by the interaction of a strong combustion-supported secondary shock and a piston-supported primary (input) shock, where the nature of the interaction depends on initial packing density and primary shock strength. These interactions influence transition by affecting dissipative heating within the microstructure during pore collapse. Inert meso-scale simulations of successive shock loading of low density HMX are performed to examine how dissipation and hot-spot formation are affected by the initial density, and the primary and secondary shock strengths. This information is used to formulate an ignition and burn model for low density HMX that accounts for the effect of shock densensitization on burn. Preliminary DDT predictions are presented that illustrate how primary shock strength affects the transition mechanism.

  1. Fates of the most massive primordial stars

    NASA Astrophysics Data System (ADS)

    Chen, Ke-Jung; Heger, Alexander; Almgren, Ann; Woosley, Stan

    2012-09-01

    We present our results of numerical simulations of the most massive primordial stars. For the extremely massive non-rotating Pop III stars over 300Msolar, they would simply die as black holes. But the Pop III stars with initial masses 140 - 260Msolar may have died as gigantic explosions called pair-instability supernovae (PSNe). We use a new radiation-hydrodynamics code CASTRO to study evolution of PSNe. Our models follow the entire explosive burning and the explosion until the shock breaks out from the stellar surface. In our simulations, we find that fluid instabilities occurred during the explosion. These instabilities are driven by both nuclear burning and hydrodynamical instability. In the red supergiant models, fluid instabilities can lead to significant mixing of supernova ejecta and alter the observational signature.

  2. The organisation of critical care for burn patients in the UK: epidemiology and comparison of mortality prediction models.

    PubMed

    Toft-Petersen, A P; Ferrando-Vivas, P; Harrison, D A; Dunn, K; Rowan, K M

    2018-05-15

    In the UK, a network of specialist centres has been set up to provide critical care for burn patients. However, some burn patients are admitted to general intensive care units. Little is known about the casemix of these patients and how it compares with patients in specialist burn centres. It is not known whether burn-specific or generic risk prediction models perform better when applied to patients managed in intensive care units. We examined admissions for burns in the Case Mix Programme Database from April 2010 to March 2016. The casemix, activity and outcome in general and specialist burn intensive care units were compared and the fit of two burn-specific risk prediction models (revised Baux and Belgian Outcome in Burn Injury models) and one generic model (Intensive Care National Audit and Research Centre model) were compared. Patients in burn intensive care units had more extensive injuries compared with patients in general intensive care units (median (IQR [range]) burn surface area 16 (7-32 [0-98])% vs. 8 (1-18 [0-100])%, respectively) but in-hospital mortality was similar (22.8% vs. 19.0%, respectively). The discrimination and calibration of the generic Intensive Care National Audit and Research Centre model was superior to the revised Baux and Belgian Outcome in Burn Injury burn-specific models for patients managed on both specialist burn and general intensive care units. © 2018 The Association of Anaesthetists of Great Britain and Ireland.

  3. Computer Program Applications to Tactical Missile Conceptual Design.

    DTIC Science & Technology

    1981-06-01

    initialized at a potential maximum of 1.25 inches/second (Ref. 21 and is allowed to decrease to arrive at a compati- ble burn area and web thickness...the same restrictions. The burn rate starts at 0.45 inches/sec- ond (Ref. 21 and is decreased to provide an acceptable web thickness and burn area. The...0.45 inches/sec- ond to provide a proper web thickness. "THE.SUSTAINER MOTOR HAS AN END BURNING GRAIN." The required burn area for the sustainer was

  4. Modeling carbon-nutrient interactions during the early recovery of tundra after fire.

    PubMed

    Jiang, Yueyang; Rastetter, Edward B; Rocha, Adrian V; Pearce, Andrea R; Kwiatkowski, Bonnie L; Shaver, Gaius R

    2015-09-01

    Fire frequency has dramatically increased in the tundra of northern Alaska, USA, which has major implications for the carbon budget of the region and the functioning of these ecosystems, which support important wildlife species. We investigated the postfire succession of plant and soil carbon (C), nitrogen (N), and phosphorus (P) fluxes and stocks along a burn severity gradient in the 2007 Anaktuvuk River fire scar in northern Alaska. Modeling results indicated that the early regrowth of postfire tundra vegetation was limited primarily by its canopy photosynthetic potential, rather than nutrient availability, because of the initially low leaf area and relatively high inorganic N and P concentrations in soil. Our simulations indicated that the postfire recovery of tundra vegetation was sustained predominantly by the uptake of residual inorganic N (i.e., in the remaining ash), and the redistribution of N and P from soil organic matter to vegetation. Although residual nutrients in ash were higher in the severe burn than the moderate burn, the moderate burn recovered faster because of the higher remaining biomass and consequent photosynthetic potential. Residual nutrients in ash allowed both burn sites to recover and exceed the unburned site in both aboveground biomass and production five years after the fire. The investigation of interactions among postfire C, N, and P cycles has contributed to a mechanistic understanding of the response of tundra ecosystems to fire disturbance. Our study provided insight on how the trajectory of recovery of tundra from wildfire is regulated during early succession.

  5. Dredge-up and Envelope Burning in Intermediate-Mass Giants of Very Low Metallicity

    NASA Astrophysics Data System (ADS)

    Herwig, Falk

    2004-04-01

    The evolution of intermediate-mass stars at very low metallicity during their final thermal pulse asymptotic giant branch (AGB) phase is studied in detail. As representative examples, models with initial masses of 4 and 5Msolar and with a metallicity of Z=0.0001 ([Fe/H]~-2.3) are discussed. The one-dimensional stellar structure and evolution model includes time- and depth-dependent overshooting motivated by hydrodynamic simulations, as well as a full nuclear network and time-dependent mixing. Particular attention is given to high time and space resolution to avoid numerical artifacts related to third dredge-up and hot bottom burning predictions. The model calculations predict very efficient third dredge-up that mixes the envelope with the entire intershell layer or a large fraction thereof and in some cases penetrates into the C/O core below the He shell. In all cases primary oxygen is mixed into the envelope. The models predict efficient envelope burning during the interpulse phase. Depending on the envelope-burning temperature, oxygen is destroyed to varying degrees. The combined effect of dredge-up and envelope burning does not lead to any significant oxygen depletion in any of the cases considered in this study. The large dredge-up efficiency in our model is closely related to the particular properties of the H shell during the dredge-up phase in low-metallicity very metal-poor stars, which is followed here over many thermal pulses. During the dredge-up phase, the temperature just below the convective boundary is large enough for protons to burn vigorously when they are brought into the C-rich environment below the convection boundary by the time- and depth-dependent overshooting. H-burning luminosities of 105 to ~2×106Lsolar are generated. C, and to lesser degree O, is transformed into N in this dredge-up overshooting layer and enters the envelope. The global effect on the CNO abundance is similar to that of hot bottom burning. If the overshoot efficiency is larger, then dredge-up H burning causes a further increase in the dredge-up efficiency. After some thermal pulses, the dredge-up proceeds through the He shell and into the CO core beneath. Then neutrons may not be released from 13C in radiative conditions during the interpulse phase because of the scarcity of α-particles for the 13C(α,n)16O reactions. Conditions for the s-process are discussed qualitatively. The abundance evolution of H, He, C, N, O, and Na is described. Finally, the model predictions for sodium and oxygen are compared with observed abundances. The notion that massive AGB stars are the origin of the O-Na abundance anticorrelation in globular cluster giants is not consistent with the model predictions of this study. The abundance of the C-rich extremely metal-poor binaries LP 625-44, CS 29497-030, and HE 0024-2523 is discussed.

  6. 40 CFR 63.7530 - How do I demonstrate initial compliance with the emission limits and work practice standards?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Pollutants for Industrial, Commercial, and Institutional Boilers and Process Heaters Testing, Fuel Analyses... 5 and 7 to this subpart OR conducting initial fuel analyses to determine emission rates and... fuel subcategories that burn only fossil fuels and other gases and do not burn any residual oil must...

  7. A Computer Program to Evaluate Experimental Therapies for Treating Burned Patients

    PubMed Central

    Flora, Jairus D.; Flora, Sharyl Ann

    1980-01-01

    Determining the worth of new therapies for burn patients has been difficult because of the rarity of the burn injury and the disparate survival chances associated with different sizes of burns. Recently a burn survival model has been developed that estimates the risk of death from a burn as a function of the patient's age, sex, area of full thickness (third degree) burn, area of partial thickness burn, involvement of the perineum, and time from burn to admission. An alternative risk model uses the total area burned in place of the areas of partial thickness burn and full thickness burn, and is appropriate if the amount of full thickness burn is not determined accurately. This paper describes a program that uses these risk models to correct or standardize for demographic and severity factors, then, after that adjustment, tests whether a group of burn patients who received a new or experimental therapy shows a significantly better survival rate than that predicted by a baseline model. The program is a simple one written in Fortran for easy adaptation to other computer systems.

  8. Relations between soil hydraulic properties and burn severity

    USGS Publications Warehouse

    Moody, John A.; Ebel, Brian A.; Nyman, Petter; Martin, Deborah A.; Stoof, Cathelijne R.; McKinley, Randy

    2015-01-01

    Wildfire can affect soil hydraulic properties, often resulting in reduced infiltration. The magnitude of change in infiltration varies depending on the burn severity. Quantitative approaches to link burn severity with changes in infiltration are lacking. This study uses controlled laboratory measurements to determine relations between a remotely sensed burn severity metric (dNBR, change in normalised burn ratio) and soil hydraulic properties (SHPs). SHPs were measured on soil cores collected from an area burned by the 2013 Black Forest fire in Colorado, USA. Six sites with the same soil type were selected across a range of burn severities, and 10 random soil cores were collected from each site within a 30-m diameter circle. Cumulative infiltration measurements were made in the laboratory using a tension infiltrometer to determine field-saturated hydraulic conductivity, Kfs, and sorptivity, S. These measurements were correlated with dNBR for values ranging from 124 (low severity) to 886 (high severity). SHPs were related to dNBR by inverse functions for specific conditions of water repellency (at the time of sampling) and soil texture. Both functions had a threshold value for dNBR between 124 and 420, where Kfs and S were unchanged and equal to values for soil unaffected by fire. For dNBRs >~420, the Kfs was an exponentially decreasing function of dNBR and S was a linearly decreasing function of dNBR. These initial quantitative empirical relations provide a first step to link SHPs to burn severity, and can be used in quantitative infiltration models to predict post-wildfire infiltration and resulting runoff.

  9. Assessment of fire-damaged mesquite trees 8 years following an illegal burn

    Treesearch

    Gerald J. Gottfried; Peter F. Ffolliott; Pablo Garcia; Diego Valdez-Zamudio; Akram Al-Khouri

    2003-01-01

    Effects of an illegal burn on the Santa Rita Experimental Range on mesquite (Prosopis velutina) survival in the semidesert grass-shrub ecosystem was initially assessed in terms of firedamage classes 18 months after the fire and again 8 years after the burn. While many of the mesquite trees on the burned site were damaged by the fire, some of the trees appear to have...

  10. Risk factors for peri-traumatic distress and appearance concerns in burn-injured inpatients identified by a screening tool

    PubMed Central

    Oaie, Ecaterina; Piepenstock, Emma; Williams, Lisa

    2018-01-01

    Introduction: Psychosocial screening of burn-injured patients is a National Burn Care Guideline and is increasingly used to identify individuals most in need of support. It can also generate data that can inform our understanding of patient reported concerns following a burn injury. Method: As part of routine care, 461 patients admitted to a burns unit were screened soon after admission using a psychosocial screen designed by the service. The questionnaire included items on pre-existing social support, coping, emotional and psychological difficulties, as well as current trauma symptoms and current level of concern about changed appearance following the burn. Results: Overall, patients reported low levels of appearance concerns (mean 3.7/10) and trauma symptoms (18% reporting flashbacks) in the initial days following a burn injury. In those who did report concerns, there were some significant associations with demographic and other variables. Patients who experienced flashbacks were younger and had a larger total body surface area (TBSA) burn. Higher levels of appearance concern were associated with younger women, larger TBSA and facial burns. However, the relationships found were weak and frequently confounded by other factors. Conclusion: Overall, the findings indicate that initial trauma symptoms and appearance concerns are not inevitable in this group and there is no substitute for screening in identifying who is most at risk. PMID:29873338

  11. Analysis and mapping of post-fire hydrologic hazards for the 2002 Hayman, Coal Seam, and Missionary Ridge wildfires, Colorado

    USGS Publications Warehouse

    Elliott, J.G.; Smith, M.E.; Friedel, M.J.; Stevens, M.R.; Bossong, C.R.; Litke, D.W.; Parker, R.S.; Costello, C.; Wagner, J.; Char, S.J.; Bauer, M.A.; Wilds, S.R.

    2005-01-01

    Wildfires caused extreme changes in the hydrologic, hydraulic, and geomorphologic characteristics of many Colorado drainage basins in the summer of 2002. Detailed assessments were made of the short-term effects of three wildfires on burned and adjacent unburned parts of drainage basins. These were the Hayman, Coal Seam, and Missionary Ridge wildfires. Longer term runoff characteristics that reflect post-fire drainage basin recovery expected to develop over a period of several years also were analyzed for two affected stream reaches: the South Platte River between Deckers and Trumbull, and Mitchell Creek in Glenwood Springs. The 10-, 50-, 100-, and 500-year flood-plain boundaries and water-surface profiles were computed in a detailed hydraulic study of the Deckers-to-Trumbull reach. The Hayman wildfire burned approximately 138,000 acres (216 square miles) in granitic terrain near Denver, and the predominant potential hazard in this area is flooding by sediment-laden water along the large tributaries to and the main stem of the South Platte River. The Coal Seam wildfire burned approximately 12,200 acres (19.1 square miles) near Glenwood Springs, and the Missionary Ridge wildfire burned approximately 70,500 acres (110 square miles) near Durango, both in areas underlain by marine shales where the predominant potential hazard is debris-flow inundation of low-lying areas. Hydrographs and peak discharges for pre-burn and post-burn scenarios were computed for each drainage basin and tributary subbasin by using rainfall-runoff models because streamflow data for most tributary subbasins were not available. An objective rainfall-runoff model calibration method based on nonlinear regression and referred to as the ?objective calibration method? was developed and applied to rainfall-runoff models for three burned areas. The HEC-1 rainfall-runoff model was used to simulate the pre-burn rainfall-runoff processes in response to the 100-year storm, and HEC-HMS was used for runoff hydrograph generation. Post-burn rainfall-runoff parameters were determined by adjusting the runoff-curve numbers on the basis of a weighting procedure derived from the U.S. Soil Conservation Service (now the National Resources Conservation Service) equation for precipitation excess and the effect of burn severity. This weighting procedure was determined to be more appropriate than simple area weighting because of the potentially marked effect of even small burned areas on the runoff hydrograph in individual drainage basins. Computed water-peak discharges from HEC-HMS models were increased volumetrically to account for increased sediment concentrations that are expected as a result of accelerated erosion after burning. Peak discharge estimates for potential floods in the South Platte River were increased by a factor that assumed a volumetric sediment concentration (Cv) of 20 percent. Flood hydrographs for the South Platte River and Mitchell Creek were routed down main-stem channels using watershed-routing algorithms included in the HEC-HMS rainfall-runoff model. In areas subject to debris flows in the Coal Seam and Missionary Ridge burned areas, debris-flow discharges were simulated by 100-year rainfall events, and the inflow hydrographs at tributary mouths were simulated by using the objective calibration method. Sediment concentrations (Cv) used in debris-flow simulations were varied through the event, and were initial Cv 20 percent, mean Cv approximately 31 percent, maximum Cv 48 percent, Cv 43 percent at the time of the water hydrograph peak, and Cv 20 percent for the duration of the event. The FLO-2D flood- and debris-flow routing model was used to delineate the area of unconfined debris-flow inundation on selected alluvial fan and valley floor areas. A method was developed to objectively determine the post-fire recovery period for the Hayman and Coal Seam burned areas using runoff-curve numbers (RCN) for all drainage basins for a 50-year period. A

  12. Gasdynamic modeling and parametric study of mesoscale internal combustion swing engine/generator systems

    NASA Astrophysics Data System (ADS)

    Gu, Yongxian

    The demand of portable power generation systems for both domestic and military applications has driven the advances of mesoscale internal combustion engine systems. This dissertation was devoted to the gasdynamic modeling and parametric study of the mesoscale internal combustion swing engine/generator systems. First, the system-level thermodynamic modeling for the swing engine/generator systems has been developed. The system performance as well as the potentials of both two- and four-stroke swing engine systems has been investigated based on this model. Then through parameterc studies, the parameters that have significant impacts on the system performance have been identified, among which, the burn time and spark advance time are the critical factors related to combustion process. It is found that the shorter burn time leads to higher system efficiency and power output and the optimal spark advance time is about half of the burn time. Secondly, the turbulent combustion modeling based on levelset method (G-equation) has been implemented into the commercial software FLUENT. Thereafter, the turbulent flame propagation in a generic mesoscale combustion chamber and realistic swing engine chambers has been studied. It is found that, in mesoscale combustion engines, the burn time is dominated by the mean turbulent kinetic energy in the chamber. It is also shown that in a generic mesoscale combustion chamber, the burn time depends on the longest distance between the initial ignition kernel to its walls and by changing the ignition and injection locations, the burn time can be reduced by a factor of two. Furthermore, the studies of turbulent flame propagation in real swing engine chambers show that the combustion can be enhanced through in-chamber turbulence augmentation and with higher engine frequency, the burn time is shorter, which indicates that the in-chamber turbulence can be induced by the motion of moving components as well as the intake gas jet flow. The burn time for current two-stroke swing engine is estimated as about 2.5 ms, which can be used in the prescribed burned mass fraction profile that follows the Wiebe's function. Finally, a 2D CFD code for compressible flow has been developed to study wave interactions in the engine and header system. It is found that with realistic working conditions, for a two-stroke swing engine, certain expansion waves can be created by the exhaust gas flows and the chamber pressure can reach as low as 5 psi below one atmosphere, which helps fill fresh reactant charge. The results also show that to obtain appropriate header tuning for the current two-stroke swing engine, the length of the header neck is about 40 cm.

  13. Steel Primer Chamber Assemblies for Dual Initiated Pyrovalves

    NASA Technical Reports Server (NTRS)

    Guemsey, Carl S.; Mizukami, Masashi; Zenz, Zac; Pender, Adam A.

    2009-01-01

    A solution was developed to mitigate the potential risk of ignition failures and burn-through in aluminum primer chamber assemblies on pyrovalves. This was accomplished by changing the assembly material from aluminum to steel, and reconfiguration of flame channels to provide more direct paths from initiators to boosters. With the geometric configuration of the channels changed, energy is more efficiently transferred from the initiators to the boosters. With the alloy change to steel, the initiator flame channels do not erode upon firing, eliminating the possibility of burn-through. Flight qualification tests have been successfully passed.

  14. Ammunition Suite for the FCS Multi-role Armament and Ammunition System (MRAAS)

    DTIC Science & Technology

    2001-06-20

    Cards Large Scale Gap Test (LSGT) Exploding Foil Initiator ( EFI ) Effort 19 Slow Burning Layer Fast Burning Layer FASTCORE Nitramines ETPEs RDX CL20...Center Burst Charge 48 M80 Grenades With Center Burst Charge ü Trade off performance with size, weight, etc. ü Develop initial space claim for...submunition ü Dynamic Analysis of projectile for different submunitions MRAAS Trades underway • Accomplishments – Initial meetings with TRADOC, Ft Knox and Ft

  15. Understanding Changes in Modeled Land Surface Characteristics Prior to Lightning-Initiated Holdover Fire Breakout

    NASA Technical Reports Server (NTRS)

    Schultz, Christopher J.; Case, Jonathan L.; Hain, Christopher R.; White, Kristopher; Wachter, J. Brent; Nauslar, Nicholas; MacNamara, Brittany

    2018-01-01

    Lightning initiated wildfires are only 16% of the total number of wildfires within the United States, but account for 56% of the acreage burned. One of the challenges with lightning-initiated wildfires is their ability to "holdover" which means smolder for up to 2+ weeks before breaking out into a full fledged fire. This work helps characterize the percentage of holdover events due to lightning, and helps quantify changes in the land surface characteristics to help understand trends in soil moisture and vegetation stress that potentially contribute to the fire breaking out into a full wildfire.

  16. Vegetation response to prescribed fire in the Kenai Mountains, Alaska.

    Treesearch

    Tina V. Boucher

    2003-01-01

    Between 1977 and 1997, 4000 ha were burned to promote regeneration of tree and shrub species used for browse by moose (Alces alces) in the Kenai Mountains. Species composition was documented along burned and unburned transects at 17 prescribed burn sites. Relationships among initial vegetation composition, physical site characteristics, browse...

  17. Effects of burn with and without Escherichia coli infection in rats on intestinal vs. splenic T-cell responses.

    PubMed

    Ravindranath, T; Al-Ghoul, W; Namak, S; Fazal, N; Durazo-Arvizu, R; Choudhry, M; Sayeed, M M

    2001-12-01

    To evaluate the effect of burn injury with and without an Escherichia coliseptic complication on T-cell proliferation, interleukin-2 production, and Ca(2+) signaling responses in intestinal Peyer's patch and splenic T cells. Prospective, randomized, sham-controlled animal study. University medical center research laboratory. Adult male Sprague-Dawley rats. Rats were subjected to a 30% total body surface area, full skin thickness burn. Infection in rats was induced via intraperitoneal inoculation of E. coli, 10(9) colony forming units/kg, with or without a prior burn. Rat Peyer's patch and splenic T lymphocytes were isolated by using a nylon wool cell purification protocol. T-cell proliferation, interleukin-2 production, and Ca(2+) signaling responses were measured after stimulation of cells with the mitogen, concanavalin A. T-cell proliferation was determined by measuring incorporation of (3)H-thymidine into T-cell cultures. Interleukin-2 production by T-cell cultures was measured by using enzyme-linked immunosorbent assay. Intracellular T-cell Ca2(+ )concentration, [Ca(2+)](i), was measured by the use of Ca(2+)-specific fluorescent label, fura-2, and its fluorometric quantification. [Ca(2+)](i) was also evaluated by the use of digital video imaging of fura-2 loaded individual T cells. T-cell proliferation and interleukin-2 production were suppressed substantially in both Peyer's patch and splenic T cells 3 days after either the initial burn alone or burn followed by the E. coli inoculation at 24 hrs after the initial burn. There seemed to be no demonstrable additive effects of E. coli infection on the effects produced by burn injury alone. The T-cell proliferation and interleukin-2 production suppressions with burn or burn-plus-infection insults were correlated with attenuated Ca(2+) signaling. E. coli infection alone suppressed T-cell proliferation in Peyer's patch but not in splenic T cells at 2 days postbacterial inoculation; E. coli infection had no effect on Peyer's patch or splenic T cells at 1 day postinjury. On the other hand, burn injury alone caused a substantial T-cell proliferative suppression at 2 days postburn in both Peyer's patch and splenic cells and a significant suppression in T-cell proliferation on day 1 postburn in Peyer's patch but not in the spleen. An initial burn injury suppressed T-cell proliferation at a level that it would not be further affected by a subsequent infection even if the infection by itself has the potential of suppressing T-cell proliferation. An earlier onset of T-cell suppression in Peyer's patch cells than in the spleen with burn could be attributable to an initial hypoperfusion-related intestinal mucosal tissue injury. Overall, our study supports the concept that burn injury per se can significantly suppress T-cell mediated immunity and that the intestine is an early tissue site of such suppression.

  18. Special considerations in paediatric burn patients

    PubMed Central

    Sharma, Ramesh Kumar; Parashar, Atul

    2010-01-01

    Burn injuries are a major cause of morbidity and mortality in children. In India, the figure constitutes about one-fourth of the total burn accidents. The management of paediatric burns can be a major challenge for the treating unit. One has to keep in mind that “children are not merely small adults”; there are certain features in this age group that warrant special attention. The peculiarities in the physiology of fluid and electrolyte handling, the uniqueness of the energy requirement and the differences in the various body proportions in children dictate that the paediatric burn management should be taken with a different perspective than for adults. This review article would deal with the special situations that need to be addressed while treating this special class of thermal injuries. We must ensure that not only the children survive the initial injury, but also the morbidity and complications are minimized. If special care is taken during the initial management of paediatric burn injuries, these children can be effectively integrated into the society as very useful and productive members. PMID:21321657

  19. Apollo 16, LM-11 ascent propulsion system final flight evaluation

    NASA Technical Reports Server (NTRS)

    Griffin, W. G.

    1974-01-01

    The duty cycle for the LM-11 APS consisted of two firings, an ascent stage liftoff from the lunar surface, and the terminal phase initiation (TPI) burn. APS performance for the first firing was evaluated and found to be satisfactory. No propulsion data were received from the second APS burn; however, all indications were that the burn was nominal. Engine ignition for the APS lunar liftoff burn occured at the Apollo elapsed time (AET) of 175:31:47.9 (hours:minutes:seconds). Burn duration was 427.7 seconds.

  20. Promoted Metals Combustion at Ambient and Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Engel, Carl D.; Herald, Stephen D.; Davis, S. Eddie

    2005-01-01

    Promoted combustion testing of materials, Test 17 of NASA STD-6001, has been used to assess metal propensity to burn in oxygen rich environments. An igniter is used at the bottom end of a rod to promote ignition, and if combustion is sustained, the burning progresses from the bottom to the top of the rod. The physical mechanisms are very similar to the upward flammability test, Test 1 of NASA STD-6001. The differences are in the normal environmental range of pressures, oxygen content, and sample geometry. Upward flammability testing of organic materials can exhibit a significant transitional region between no burning to complete quasi-state burning. In this transitional region, the burn process exhibits a probabilistic nature. This transitional region has been identified for metals using the promoted combustion testing method at ambient initial temperatures. The work given here is focused on examining the transitional region and the quasi-steady burning region both at conventional ambient testing conditions and at elevated temperatures. A new heated promoted combustion facility and equipment at Marshall Space Flight Center have just been completed to provide the basic data regarding the metals operating temperature limits in contact with oxygen rich atmospheres at high pressures. Initial data have been obtained for Stainless Steel 304L, Stainless Steel 321, Haynes 214, and Inconel 718 at elevated temperatures in 100-percent oxygen atmospheres. These data along with an extended data set at ambient initial temperature test conditions are examined. The pressure boundaries of acceptable, non-burning usage is found to be lowered at elevated temperature.

  1. Patient experiences of burn scars in adults and children and development of a health-related quality of life conceptual model: A qualitative study.

    PubMed

    Simons, Megan; Price, Nathaniel; Kimble, Roy; Tyack, Zephanie

    2016-05-01

    The aim of this study was to understand the impact of burn scars on health-related quality of life (HRQOL) from the perspective of adults and children with burn scars, and caregivers to inform the development of a conceptual model of burn scar HRQOL. Twenty-one participants (adults and children) with burn scars and nine caregivers participated in semi-structured, face-to-face interviews between 2012 and 2013. During the interviews, participants were asked to describe features about their (or their child's) burn scars and its impact on everyday life. Two coders conducted thematic analysis, with consensus achieved through discussion and review with a third coder. The literature on HRQOL models was then reviewed to further inform the development of a conceptual model of burn scar HRQOL. Five themes emerged from the qualitative data: 'physical and sensory symptoms', 'impact of burn scar interventions', 'impact of burn scar symptoms', 'personal factors' and 'change over time'. Caregivers offered further insights into family functioning after burn, and the impacts of burn scars and burn scar interventions on family life. In the conceptual model, symptoms (sensory and physical) of burn scars are considered proximal to HRQOL, with distal indicators including functioning (physical, emotional, social, cognitive), individual factors and the environment. Overall quality of life was affected by HRQOL. Understanding the impact of burn scars on HRQOL and the development of a conceptual model will inform future burn scar research and clinical practice. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  2. The Carbon Monoxide Tape Recorder

    NASA Technical Reports Server (NTRS)

    Schoeberl, M. R.; Duncan, B. N.; Douglass, A. R.; Waters, J.; Livesey, N.; Read, W.; Filipiak, M.

    2006-01-01

    Using Aura MLS data we have identified the stratospheric tape recorder in carbon monoxide (CO). Unlike the water vapor tape recorder, which is controlled by upper troposphere processes, the CO tape recorder is linked to seasonal biomass burning. Since CO has a lifetime of only a few months, the CO tape recorder barely extends above 20 km. The tape head for CO appears to be close to 360K near the same location as the water vapor tape head [Read et al, 20041. Both tape heads are below the equatorial cold point tropopause but above the base of the tropical tropopause layer. The tape recorder signal becomes more distinct from 360K to 380K suggesting that convective detrainment of plays a decreasingly important role with altitude. The Global Modeling Initiative chemical transport model forced by the climatology of biomass burning reproduces the CO tape recorder.

  3. A protocol for resuscitation of severe burn patients guided by transpulmonary thermodilution and lactate levels: a 3-year prospective cohort study.

    PubMed

    Sánchez, Manuel; García-de-Lorenzo, Abelardo; Herrero, Eva; Lopez, Teresa; Galvan, Beatriz; Asensio, María; Cachafeiro, Lucia; Casado, Cesar

    2013-08-15

    The use of urinary output and vital signs to guide initial burn resuscitation may lead to suboptimal resuscitation. Invasive hemodynamic monitoring may result in over-resuscitation. This study aimed to evaluate the results of a goal-directed burn resuscitation protocol that used standard measures of mean arterial pressure (MAP) and urine output, plus transpulmonary thermodilution (TPTD) and lactate levels to adjust fluid therapy to achieve a minimum level of preload to allow for sufficient vital organ perfusion. We conducted a three-year prospective cohort study of 132 consecutive critically burned patients. These patients underwent resuscitation guided by MAP (>65 mmHg), urinary output (0.5 to 1 ml/kg), TPTD and lactate levels. Fluid therapy was adjusted to achieve a cardiac index (CI) >2.5 L/minute/m² and an intrathoracic blood volume index (ITBVI) >600 ml/m2, and to optimize lactate levels. Statistical analysis was performed using mixed models. We also used Pearson or Spearman methods and the Mann-Whitney U-test. A total of 98 men and 34 women (mean age, 48 ± 18 years) was studied. The mean total body surface area (TBSA) burned was 35% ± 22%. During the early resuscitation phase, lactate levels were elevated (2.58 ± 2.05 mmol/L) and TPTD showed initial hypovolemia by the CI (2.68 ± 1.06 L/minute/m²) and the ITBVI (709 ± 254 mL/m²). At 24 to 32 hours, the CI and lactic levels were normalized, although the ITBVI remained below the normal range (744 ± 276 ml/m²). The mean fluid rate required to achieve protocol targets in the first 8 hours was 4.05 ml/kg/TBSA burned, which slightly increased in the next 16 hours. Patients with a urine output greater than or less than 0.5 ml/kg/hour did not show differences in heart rate, mean arterial pressure, CI, ITBVI or lactate levels. Initial hypovolemia may be detected by TPTD monitoring during the early resuscitation phase. This hypovolemia might not be reflected by blood pressure and hourly urine output. An adequate CI and tissue perfusion can be achieved with below-normal levels of preload. Early resuscitation guided by lactate levels and below-normal preload volume targets appears safe and avoids unnecessary fluid input.

  4. Effects of burn location and investigator on burn depth in a porcine model.

    PubMed

    Singer, Adam J; Toussaint, Jimmy; Chung, Won Taek; Thode, Henry C; McClain, Steve; Raut, Vivek

    2016-02-01

    In order to be useful, animal models should be reproducible and consistent regardless of sampling bias, investigator creating burn, and burn location. We determined the variability in burn depth based on biopsy location, burn location and investigator in a porcine model of partial thickness burns. 24 partial thickness burns (2.5 cm by 2.5 cm each) were created on the backs of 2 anesthetized pigs by 2 investigators (one experienced, one inexperienced) using a previously validated model. In one of the pigs, the necrotic epidermis covering each burn was removed. Five full thickness 4mm punch biopsies were obtained 1h after injury from the four corners and center of the burns and stained with Hematoxylin and Eosin and Masson's trichrome for determination of burn depth by a board certified dermatopathologist blinded to burn location and investigator. Comparisons of burn depth by biopsy location, burn location and investigator were performed with t-tests and ANOVA as appropriate. The mean (SD) depth of injury to blood vessels (the main determinant of burn progression) in debrided and non-debrided pigs pooled together was 1.8 (0.3)mm, which included 75% of the dermal depth. Non-debrided burns were 0.24 mm deeper than debrided burns (P<0.001). Burn depth increased marginally from cephalic to caudal in non-debrided burns, but showed no statistical differences for these locations, in debrided burns. Additionally, there were also no statistical differences in burn depths from midline to lateral in either of these burn types. Burn depth was similar for both investigators and among biopsy locations. Burn depth was greater for caudal locations in non-debrided burns and overall non-debrided burns were deeper than debrided burns. However, burn depth did not differ based on investigator, biopsy site, and medial-lateral location. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  5. A Burke-Schumann Analysis of Dual-Flame Structure Supported by a Burning Droplet

    NASA Technical Reports Server (NTRS)

    Nayagam, V.; Dietrich, D.; Williams, F. A.

    2016-01-01

    Droplet combustion experiments carried out onboard the International Space Station (ISS), using pure fuels and fuel mixtures, have shown that quasi-steady burning can be sustained by a non-traditional flame configuration, namely a "cool flame" burning in the "partial-burning" regime where both fuel and oxygen leak through the low-temperature controlled flame-sheet. Recent experiments involving large, bi-component fuel (n-decane and hexanol, 50/50 by volume) droplets at elevated pressures show that the visible, hot flame becomes extremely weak while the burning rate remains relatively high, suggesting the possibility of simultaneous presence of "cool" and "hot" flames of roughly equal importance. The radiant output from these bi-component droplets is relatively high and cannot be accounted for only by the presence of a visible hot-flame. In this analysis we explore the theoretical possibility of a dual-flame structure, where one flame lies close to the droplet surface called the "cool-flame," and other farther away from the droplet surface, termed the "hot-flame." A Burke-Schumann analysis of this dual-structure seems to indicate such flame structures are possible over a narrow range of initial conditions. Theoretical results can be compared against available experimental data for pure and bi-component fuel droplet combustion to test how realistic the model may be.

  6. Impact of Early Inpatient Rehabilitation on Adult Burn Survivors' Functional Outcomes and Resource Utilization.

    PubMed

    Gomez, Manuel; Tushinski, Morris; Jeschke, Marc G

    On July 2012, a rehabilitation hospital merged with a trauma center where the regional burn center is located. That rehabilitation center provides the only burn rehabilitation program in our region. The objective of this study was to determine if earlier initiation of inpatient rehabilitation after merger had an effect on burn survivors' functional outcomes and resource utilization. A retrospective review of electronic data of burn survivors' functional outcomes (functional independence measure [FIM] ratings on admission, at discharge, and percent change), and resource utilization (waiting time for rehab, burn center length of stay [LOS], rehab LOS, physiotherapy and occupational therapy rehabilitation workload [RehabWorkload], and discharge destination) was undertaken. Adult burn survivors who required inpatient rehabilitation and were transferred from the burn center to the inpatient rehabilitation service before the merger (July 2010-June 2012) were compared with those transferred after the merger (July 2012-June 2014). One hundred thirty-eight burn survivors were transferred from the burn center to the inpatient rehabilitation service during the study period. Sixty (43.5%) were transferred before and 78 (56.5%) were transferred after the merger. There were 97 (70.3%) men and 41 (29.7%) women with a mean age of 47.9 ± 17.9 years. TBSA burn was 24.2 ± 16.9%, and full thickness burn was 13.1 ± 16.4%. The etiology of these burns were flame (72.5%), scald (19.6%), electrical (5.1%), chemical (2.2%), and contact (0.7%). Patients in both groups had similar age, inhalation injury, TBSA, full thickness burn, FIM ratings, RehabWorkload, and burn etiology. Patients transferred before the merger had significantly more chemical burns (5% vs 0%, P = .046), and more work-related burns (26.7% vs 7.7%, P = .004). Patients transferred after the merger had significantly shorter burn center LOS (28.5 ± 20.9 days vs 38.8 ± 34.2 days, P = .043), and shorter waiting time for rehab (0.7 ± 1.1 days vs 1.5 ± 2.3 days, P = .010) than patients transferred before the merger. Early initiation of inpatient rehabilitation, after the burn center and the inpatient rehabilitation service were located in the same hospital, improved burn survivors' resource utilization.

  7. Brazil Fire Characterization and Burn Area Estimation Using the Airborne Infrared Disaster Assessment (AIRDAS) System

    NASA Technical Reports Server (NTRS)

    Brass, J. A.; Riggan, P. J.; Ambrosia, V. G.; Lockwood, R. N.; Pereira, J. A.; Higgins, R. G.; Peterson, David L. (Technical Monitor)

    1995-01-01

    Remotely sensed estimations of regional and global emissions from biomass combustion have been used to characterize fire behavior, determine fire intensity, and estimate burn area. Highly temporal, low resolution satellite data have been used to calculate estimates of fire numbers and area burned. These estimates of fire activity and burned area have differed dramatically, resulting in a wide range of predictions on the ecological and environmental impacts of fires. As part of the Brazil/United States Fire Initiative, an aircraft campaign was initiated in 1992 and continued in 1994. This multi-aircraft campaign was designed to assist in the characterization of fire activity, document fire intensity and determine area burned over prescribed, agricultural and wildland fires in the savanna and forests of central Brazil. Using a unique, multispectral scanner (AIRDAS), designed specifically for fire characterization, a variety of fires and burned areas were flown with a high spatial and high thermal resolution scanner. The system was used to measure flame front size, rate of spread, ratio of smoldering to flaming fronts and fire intensity. In addition, long transects were flown to determine the size of burned areas within the cerrado and transitional ecosystems. The authors anticipate that the fire activity and burned area estimates reported here will lead to enhanced information for precise regional trace gas prediction.

  8. Serum albumin levels in burn people are associated to the total body surface burned and the length of hospital stay but not to the initiation of the oral/enteral nutrition

    PubMed Central

    Pérez-Guisado, Joaquín; de Haro-Padilla, Jesús M; Rioja, Luis F; DeRosier, Leo C; de la Torre, Jorge I

    2013-01-01

    Objective: Serum albumin levels have been used to evaluate the severity of the burns and the nutrition protein status in burn people, specifically in the response of the burn patient to the nutrition. Although it hasn’t been proven if all these associations are fully funded. The aim of this retrospective study was to determine the relationship of serum albumin levels at 3-7 days after the burn injury, with the total body surface area burned (TBSA), the length of hospital stay (LHS) and the initiation of the oral/enteral nutrition (IOEN). Subject and methods: It was carried out with the health records of patients that accomplished the inclusion criteria and were admitted to the burn units at the University Hospital of Reina Sofia (Córdoba, Spain) and UAB Hospital at Birmingham (Alabama, USA) over a 10 years period, between January 2000 and December 2009. We studied the statistical association of serum albumin levels with the TBSA, LHS and IOEN by ANOVA one way test. The confidence interval chosen for statistical differences was 95%. Duncan’s test was used to determine the number of statistically significantly groups. Results: Were expressed as mean±standard deviation. We found serum albumin levels association with TBSA and LHS, with greater to lesser serum albumin levels found associated to lesser to greater TBSA and LHS. We didn’t find statistical association with IOEN. Conclusion: We conclude that serum albumin levels aren’t a nutritional marker in burn people although they could be used as a simple clinical tool to identify the severity of the burn wounds represented by the total body surface area burned and the lenght of hospital stay. PMID:23875122

  9. Serum albumin levels in burn people are associated to the total body surface burned and the length of hospital stay but not to the initiation of the oral/enteral nutrition.

    PubMed

    Pérez-Guisado, Joaquín; de Haro-Padilla, Jesús M; Rioja, Luis F; Derosier, Leo C; de la Torre, Jorge I

    2013-01-01

    Serum albumin levels have been used to evaluate the severity of the burns and the nutrition protein status in burn people, specifically in the response of the burn patient to the nutrition. Although it hasn't been proven if all these associations are fully funded. The aim of this retrospective study was to determine the relationship of serum albumin levels at 3-7 days after the burn injury, with the total body surface area burned (TBSA), the length of hospital stay (LHS) and the initiation of the oral/enteral nutrition (IOEN). It was carried out with the health records of patients that accomplished the inclusion criteria and were admitted to the burn units at the University Hospital of Reina Sofia (Córdoba, Spain) and UAB Hospital at Birmingham (Alabama, USA) over a 10 years period, between January 2000 and December 2009. We studied the statistical association of serum albumin levels with the TBSA, LHS and IOEN by ANOVA one way test. The confidence interval chosen for statistical differences was 95%. Duncan's test was used to determine the number of statistically significantly groups. Were expressed as mean±standard deviation. We found serum albumin levels association with TBSA and LHS, with greater to lesser serum albumin levels found associated to lesser to greater TBSA and LHS. We didn't find statistical association with IOEN. We conclude that serum albumin levels aren't a nutritional marker in burn people although they could be used as a simple clinical tool to identify the severity of the burn wounds represented by the total body surface area burned and the lenght of hospital stay.

  10. Influence of Fire on Oak Seedlings and Saplings in Southern Oak Woodland on the Santa Rosa Plateau Preserve, Riverside County, California

    Treesearch

    Earl W. Lathrop; Chris D. Osborne

    1991-01-01

    One wildfire and two prescription burns were monitored at 15 oak seedling/sapling regeneration sites and at four non-burned comparison sites to study the effect of fire on seedlings and saplings of Quercus engelmannii (Engelmann oak) and Q. agrifolia (coast live oak). The number of initial topkilled seedlings and saplings, initial...

  11. Animal models in burn research.

    PubMed

    Abdullahi, A; Amini-Nik, S; Jeschke, M G

    2014-09-01

    Burn injury is a severe form of trauma affecting more than 2 million people in North America each year. Burn trauma is not a single pathophysiological event but a devastating injury that causes structural and functional deficits in numerous organ systems. Due to its complexity and the involvement of multiple organs, in vitro experiments cannot capture this complexity nor address the pathophysiology. In the past two decades, a number of burn animal models have been developed to replicate the various aspects of burn injury, to elucidate the pathophysiology, and to explore potential treatment interventions. Understanding the advantages and limitations of these animal models is essential for the design and development of treatments that are clinically relevant to humans. This review aims to highlight the common animal models of burn injury in order to provide investigators with a better understanding of the benefits and limitations of these models for translational applications. While many animal models of burn exist, we limit our discussion to the skin healing of mouse, rat, and pig. Additionally, we briefly explain hypermetabolic characteristics of burn injury and the animal model utilized to study this phenomena. Finally, we discuss the economic costs associated with each of these models in order to guide decisions of choosing the appropriate animal model for burn research.

  12. Animal Models in Burn Research

    PubMed Central

    Abdullahi, A.; Amini-Nik, S.; Jeschke, M.G

    2014-01-01

    Burn injury is a severe form of trauma affecting more than two million people in North America each year. Burn trauma is not a single pathophysiological event but a devastating injury that causes structural and functional deficits in numerous organ systems. Due to its complexity and the involvement of multiple organs, in vitro experiments cannot capture this complexity nor address the pathophysiology. In the past two decades, a number of burn animal models have been developed to replicate the various aspects of burn injury; to elucidate the pathophysiology and explore potential treatment interventions. Understanding the advantages and limitations of these animal models is essential for the design and development of treatments that are clinically relevant to humans. This review paper aims to highlight the common animal models of burn injury in order to provide investigators with a better understanding of the benefits and limitations of these models for translational applications. While many animal models of burn exist, we limit our discussion to the skin healing of mouse, rat, and pig. Additionally, we briefly explain hypermetabolic characteristics of burn injury and the animal model utilized to study this phenomena. Finally, we discuss the economic costs associated with each of these models in order to guide decisions of choosing the appropriate animal model for burn research. PMID:24714880

  13. Predictors of functional independence, quality of life, and return to work in patients with burn injuries in mainland China.

    PubMed

    Tang, Dan; Li-Tsang, Cecilia W P; Au, Ricky K C; Shen, Xia; Li, Kui-Cheng; Yi, Xian-Feng; Liao, Lin-Rong; Cao, Hai-Yan; Feng, Ya-Nan; Liu, Chuan-Shun

    2016-01-01

    Burn injury may be associated with long-term rehabilitation and disability, while research studies on the functional performance after injuries, quality of life (QOL), and abilities to return to work of burn patients are limited. These outcomes are related not just to the degree and nature of injuries, but also to the socio-economical background of the society. This study aimed to identify the factors which might affect burn patients' abilities to reintegrate back to the society based on a sample in mainland China. A retrospective study was conducted to collect data of demographic characteristics, medical data about burn injuries, physical and psychological status, and self-perceived QOL at the initial phase and upon discharge from a rehabilitation hospital, timing of rehabilitation, and duration of rehabilitation intervention. Four hundred fifteen patients with burn injuries were recruited in the study. Multiple linear regression and logistic regression were used to obtain a model to predict the functional abilities and the perceived QOL at discharge and their changes during rehabilitation, as well as the post-injury work status within 6 months after discharge. The functional performance at discharge and its change were significantly predicted by the functional abilities and QOL at the admission, duration of treatment, timing of rehabilitation, payer source, and total body surface area burned. The perceived QOL at discharge and its change were significantly predicted by the baseline QOL at admission and duration of treatment. The significant predictors of work status within 6 months post-discharge included age, education, payer source, total body surface area burned, perceived QOL, and bodily pain at admission. The present study identified a number of factors affecting the rehabilitation outcomes of people with burn injuries. Identification of these predictors may help clinicians assess the rehabilitation potential of burn survivors and assist in resource allocation. Policy makers should ensure that resources are adequate to improve the outcomes based on these factors.

  14. Smoke emissions due to burning of green waste in the Mediterranean area: Influence of fuel moisture content and fuel mass

    NASA Astrophysics Data System (ADS)

    Tihay-Felicelli, V.; Santoni, P. A.; Gerandi, G.; Barboni, T.

    2017-06-01

    The aim of this study was to investigate emission characteristics in relation to differences in fuel moisture content (FMC) and initial dry mass. For this purpose, branches and twigs with leaves of Cistus monspeliensis were burned in a Large Scale Heat Release apparatus coupled to a Fourier Transform Infrared Spectrometer. A smoke analysis was conducted and the results highlighted the presence of CO2, H2O, CO, CH4, NO, NO2, NH3, SO2, and non-methane organic compounds (NMOC). CO2, NO, and NO2 species are mainly released during flaming combustion, whereas CO, CH4, NH3, and NMOC are emitted during both flaming and smoldering combustion. The emission of these compounds during flaming combustion is due to a rich fuel to air mixture, leading to incomplete combustion. The fuel moisture content and initial dry mass influence the flame residence time, the duration of smoldering combustion, the combustion efficiency, and the emission factors. By increasing the initial dry mass, the emission factors of NO, NO2, and CO2 decrease, whereas those of CO and CH4 increase. The increase of FMC induces an increase of the emission factors of CO, CH4, NH3, NMOC, and aerosols, and a decrease of those of CO2, NO, and NO2. Increasing fuel moisture content reduces fuel consumption, duration of smoldering, and peak heat release rate, but simultaneously increases the duration of propagation within the packed bed, and the flame residence time. Increasing the initial dry mass, causes all the previous combustion parameters to increase. These findings have implications for modeling biomass burning emissions and impacts.

  15. A rare case of failed healing in previously burned skin after a secondary burns.

    PubMed

    Goldie, Stephen J; Parsons, Shaun; Menezes, Hana; Ives, Andrew; Cleland, Heather

    2017-01-01

    Patients presenting with large surface area burns are common in our practice; however, patients with a secondary large burn on pre-existing burn scars and grafts are rare and not reported. We report on an unusual case of a patient sustaining a secondary large burn to areas previously injured by a burn from a different mechanism. We discuss the potential implications when managing a case like this and suggest potential biological reasons why the skin may behave differently. Our patient was a 33-year-old man who presented with a 5% TBSA burn on skin scarred by a previous 40% total body surface area (TBSA) burn and skin grafts. Initially assessed as superficial partial thickness in depth, the wounds were treated conservatively with dressings; however, they failed to heal and became infected requiring surgical management. Burns sustained in areas of previous burn scars and grafts may behave differently to normal patterns of healing, requiring more aggressive management and surgical intervention at an early stage.

  16. Reburn severity in managed and unmanaged vegetation in a large wildfire

    PubMed Central

    Thompson, Jonathan R.; Spies, Thomas A.; Ganio, Lisa M.

    2007-01-01

    Debate over the influence of postwildfire management on future fire severity is occurring in the absence of empirical studies. We used satellite data, government agency records, and aerial photography to examine a forest landscape in southwest Oregon that burned in 1987 and then was subject, in part, to salvage-logging and conifer planting before it reburned during the 2002 Biscuit Fire. Areas that burned severely in 1987 tended to reburn at high severity in 2002, after controlling for the influence of several topographical and biophysical covariates. Areas unaffected by the initial fire tended to burn at the lowest severities in 2002. Areas that were salvage-logged and planted after the initial fire burned more severely than comparable unmanaged areas, suggesting that fuel conditions in conifer plantations can increase fire severity despite removal of large woody fuels. PMID:17563370

  17. Persistent Influences of the 2002 Hayman Fire on Stream Nitrate and Dissolved Organic Carbon

    NASA Astrophysics Data System (ADS)

    Rhoades, C.; Pierson, D. N.; Fegel, T. S., II; Chow, A. T.; Covino, T. P.

    2016-12-01

    Large, high severity wildfires alter the physical and biological conditions that determine how watersheds retain and release nutrients and regulate stream water quality. For five years after the 2002 Hayman Fire burned in Colorado conifer forests, stream nitrate concentrations and export increased steadily in watersheds with extensive high-severity burning. Stream temperature and turbidity also increased in relation to the extent of high-severity burning and remained elevated above background levels throughout the initial five year post-fire period. Our recent sampling documents that 14 years after the Hayman Fire stream nitrate remains an order of magnitude higher in extensively-burned (35-90%) compared to unburned watersheds (0.2 vs 2.8 mg L-1). Nitrate represents 83% of the total dissolved N in extensively-burned watersheds compared to 29% in unburned watersheds. In contrast, dissolved organic carbon (DOC), was highest in watersheds that burned to a moderate extent (10-20%) and lowest in those with extensive burning. Catchments with a moderate extent burned had DOC concentrations 2.5 and 1.7 times more than those with extensive burning and unburned catchments, respectively. Peak concentrations of DOC and nitrate track the rising limb of the streamflow hydrograph and reach a maximum in May, but patterns among burn extent categories were seasonally consistent. Current riparian conditions are linked to stream nitrate in burned watersheds. For example, stream nitrate increases proportionally to the extent of riparian zones with low shrub cover (R2 = 0.76). We found signs of watershed recovery compared to the initial post-fire period; stream temperature and turbidity remained elevated in extensively burned catchments, but increases were only significant during the spring season. The persistent stream nitrate concentrations as well as the relation between riparian cover and post-fire stream nitrate may help prioritize restoration planting efforts and mitigate chronic, elevated nitrate export from burned watersheds.

  18. Resuscitation burn card--a useful tool for burn injury assessment.

    PubMed

    Malic, C C; Karoo, R O S; Austin, O; Phipps, A

    2007-03-01

    It is well recognised that the initial assessment of body surface area affected by a burn is often over estimated in Accident and Emergency Departments. A useful aide-memoir in the acute setting is Wallace's "rule of nines" or using the patients' palmar surface of the hand, which approximates 1% of the total body surface area, as a method of assessment. Unfortunately, as with every system, limitations apply. Factors such as patient size and the interpretation of what is exactly the 'palmar surface' may significantly influence burn size estimations and subsequently fluid resuscitation. Our aim is to develop a simple, quick and easy reproducible method of calculating burn injuries for medical professionals in the acute setting. Worldwide, the dimensions of a credit card are standardized (8.5 cm x 5.3 cm), thus producing a surface area of 45 cm2. We created a resuscitation burn card (RBC) using these exact same proportions, upon which a modified body surface area (BSA) nomogram was printed. Knowing the patient height and weight, we calculated the surface area of the card as percentage of total body surface area (TBSA). On the opposite site of the RBC, a Lund and Browder chart was printed, as well as the Parkland formula and a formula to calculate paediatric burn fluid requirements. The plastic, flexible RBC conformed well to the body contour and was designed for single use. We used the resuscitation burn card in the initial assessment of simulated burns in a Regional Burn Centre and in an Accident and Emergency Department. The information present on the card was found to be clear and straightforward to use. The evaluation of burn extent was found to be more accurately measured than the estimation obtained without the RBC. The resuscitation burn card can be a valuable tool in the hands of less experienced medical professionals for the early assessment and fluid resuscitation of a burn.

  19. Early Enteral Nutrition in Burns: Compliance With Guidelines and Associated Outcomes in a Multicenter Study

    PubMed Central

    Mosier, Michael J.; Pham, Tam N.; Klein, Matthew B.; Gibran, Nicole S.; Arnoldo, Brett D.; Gamelli, Richard L.; Tompkins, Ronald G.; Herndon, David N.

    2013-01-01

    Early nutritional support is an essential component of burn care to prevent ileus, stress ulceration, and the effects of hypermetabolism. The American Burn Association practice guidelines state that enteral feedings should be initiated as soon as practical. The authors sought to evaluate compliance with early enteral nutrition (EN) guidelines, associated complications, and hospitalization outcomes in a prospective multicenter observational study. They conducted a retrospective review of mechanically ventilated burn patients enrolled in the prospective observational multicenter study “Inflammation and the Host Response to Injury.” Timing of initiation of tube feedings was recorded, with early EN defined as being started within 24 hours of admission. Univariate and multivariate analyses were performed to distinguish barriers to initiation of EN and the impact of early feeding on development of multiple organ dysfunction syndrome, infectious complications, days on mechanical ventilation, intensive care unit (ICU) length of stay, and survival. A total of 153 patients met study inclusion criteria. The cohort comprised 73% men, with a mean age of 41 ± 15 years and a mean %TBSA burn of 46 ± 18%. One hundred twenty-three patients (80%) began EN in the first 24 hours and 145 (95%) by 48 hours. Age, sex, inhalation injury, and full-thickness burn size were similar between those fed by 24 hours vs after 24 hours, except for higher mean Acute Physiology and Chronic Health Evaluation II scores (26 vs 23, P = .03) and smaller total burn size (44 vs 54% TBSA burn, P = .01) in those fed early. There was no significant difference in rates of hyperglycemia, abdominal compartment syndrome, or gastrointestinal bleeding between groups. Patients fed early had shorter ICU length of stay (adjusted hazard ratio 0.57, P = 0.03, 95% confidence interval 0.35–0.94) and reduced wound infection risk (adjusted odds ratio 0.28, P = 0.01, 95% confidence interval 0.10–0.76). The investigators have found early EN to be safe, with no increase in complications and a lower rate of wound infections and shorter ICU length of stay. Across institutions, there has been high compliance with early EN as part of the standard operating procedure in this prospective multicenter observational trial. The investigators advocate that initiation of EN by 24 hours be used as a formal recommendation in nutrition guidelines for severe burns, and that nutrition guidelines be actively disseminated to individual burn centers to permit a change in practice. PMID:21116188

  20. LANDSAT digital analysis of the initial recovery of the Kokolik River tundra fire area, Alaska

    NASA Technical Reports Server (NTRS)

    Hall, D. K.; Ormsby, J. P.; Johnson, L.; Brown, J. (Principal Investigator)

    1979-01-01

    The author has identified the following significant results. Considerable regrowth of vegetation was observed between August 1977 and August 1978, both in the field and through analysis of LANDSAT near infrared digital data. The spectral reflectances in the burned areas were found to increase with the age of the burn in a one year period due to vegetation regrowth. Regrowth was particularly evident in the lightly burned portions of the burned area. Image analysis techniques using the AOIPS system permitted delineation of burn severity categories. The conditions and type of ground cover prior to the fire influenced the severity of burning, as did the direction of the winds while the burning was in progress as determined from field and LANDSAT observations. More severe burning was induced by winds blowing in the northeastern and southeastern portions of the burned area.

  1. Development of a Consistent and Reproducible Porcine Scald Burn Model

    PubMed Central

    Kempf, Margit; Kimble, Roy; Cuttle, Leila

    2016-01-01

    There are very few porcine burn models that replicate scald injuries similar to those encountered by children. We have developed a robust porcine burn model capable of creating reproducible scald burns for a wide range of burn conditions. The study was conducted with juvenile Large White pigs, creating replicates of burn combinations; 50°C for 1, 2, 5 and 10 minutes and 60°C, 70°C, 80°C and 90°C for 5 seconds. Visual wound examination, biopsies and Laser Doppler Imaging were performed at 1, 24 hours and at 3 and 7 days post-burn. A consistent water temperature was maintained within the scald device for long durations (49.8 ± 0.1°C when set at 50°C). The macroscopic and histologic appearance was consistent between replicates of burn conditions. For 50°C water, 10 minute duration burns showed significantly deeper tissue injury than all shorter durations at 24 hours post-burn (p ≤ 0.0001), with damage seen to increase until day 3 post-burn. For 5 second duration burns, by day 7 post-burn the 80°C and 90°C scalds had damage detected significantly deeper in the tissue than the 70°C scalds (p ≤ 0.001). A reliable and safe model of porcine scald burn injury has been successfully developed. The novel apparatus with continually refreshed water improves consistency of scald creation for long exposure times. This model allows the pathophysiology of scald burn wound creation and progression to be examined. PMID:27612153

  2. The potential association of later initiation of oral/enteral nutrition on euthyroid sick syndrome in burn patients.

    PubMed

    Pérez-Guisado, Joaquín; de Haro-Padilla, Jesús M; Rioja, Luis F; Derosier, Leo C; de la Torre, Jorge I

    2013-01-01

    Objective. The aim of this study was to determine if early initiation of oral/enteral nutrition in burn patients minimizes the drop in fT3 levels, reduces the potential for euthyroid sick syndrome (ESS), and shortens the length of hospital stay (LHS). Subjects and Methods. We retrospectively evaluated the statistical association of serum fT3, fT4, and TSH at the first (2nd-5th day) and second sample collection (9th-12th day) after the burn injury in 152 burn patients. Three groups were established depending on time of initiation of the oral/enteral nutrition: <24 h before the injury (Group 1), 24-48 h after the injury (Group 2), and >48 h after the injury (Group 3). Results. They were expressed as mean ± standard deviation. We found that LHS and the fT3 levels were statistically different in the 3 groups. The LHS (in days) was, respectively, in each group, 16.77 ± 4.56, 21.98 ± 4.86, and 26.06 ± 5.47. Despite the quantifiable drop in fT3, ESS was present only at the first sample collection (2.61 ± 0.92 days) in Group 3, but there was no group with ESS at the second sample collection (9.89 ± 1.01 days). Our data suggest that early initiation of nutritional supplementation decreases the length of hospitalization and is associated with decreasing fT3 serum concentration depression. Conclusion. Early initiation of oral/enteral nutrition counteracts ESS and improves the LHS in burn patients.

  3. Dual therapeutic functions of F-5 fragment in burn wounds: preventing wound progression and promoting wound healing in pigs.

    PubMed

    Bhatia, Ayesha; O'Brien, Kathryn; Chen, Mei; Wong, Alex; Garner, Warren; Woodley, David T; Li, Wei

    2016-01-01

    Burn injuries are a leading cause of morbidity including prolonged hospitalization, disfigurement, and disability. Currently there is no Food and Drug Administration-approved burn therapeutics. A clinical distinction of burn injuries from other acute wounds is the event of the so-called secondary burn wound progression within the first week of the injury, in which a burn expands horizontally and vertically from its initial boundary to a larger area. Therefore, an effective therapeutics for burns should show dual abilities to prevent the burn wound progression and thereafter promote burn wound healing. Herein we report that topically applied F-5 fragment of heat shock protein-90α is a dual functional agent to promote burn wound healing in pigs. First, F-5 prevents burn wound progression by protecting the surrounding cells from undergoing heat-induced caspase 3 activation and apoptosis with increased Akt activation. Accordingly, F-5-treated burn and excision wounds show a marked decline in inflammation. Thereafter, F-5 accelerates burn wound healing by stimulating the keratinocyte migration-led reepithelialization, leading to wound closure. This study addresses a topical agent that is capable of preventing burn wound progression and accelerating burn wound healing.

  4. Stellar evolution of high mass based on the Ledoux criterion for convection

    NASA Technical Reports Server (NTRS)

    Stothers, R.; Chin, C.

    1972-01-01

    Theoretical evolutionary sequences of models for stars of 15 and 30 solar masses were computed from the zero-age main sequence to the end of core helium burning. During the earliest stages of core helium depletion, the envelope rapidly expands into the red-supergiant configuration. At 15 solar mass, a blue loop on the H-R diagram ensues if the initial metals abundance, initial helium abundance, or C-12 + alpha particle reaction rate is sufficiently large, or if the 3-alpha reaction rate is sufficiently small. These quantities affect the opacity of the base of the outer convection zone, the mass of the core, and the thermal properties of the core. The blue loop occurs abruptly and fully developed when the critical value of any of these quantities is exceeded, and the effective temperature range and fraction of the lifetime of core helium burning during the slow phase of the blue loop vary surprisingly little. At 30 solar mass no blue loop occurs for any reasonable set of input parameters.

  5. 40 CFR 63.6590 - What parts of my plant does this subpart cover?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... initial notification requirements: (i) Existing spark ignition 2 stroke lean burn (2SLB) stationary RICE... spark ignition 4 stroke lean burn (4SLB) stationary RICE with a site rating of more than 500 brake HP... spark ignition 4 stroke rich burn (4SRB) stationary RICE with a site rating of less than or equal to 500...

  6. 40 CFR 63.11211 - How do I demonstrate initial compliance with the emission limits?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Table 4 to this subpart, conducting a fuel analysis for each type of fuel burned in your boiler... evaluations according to § 63.11224. For affected boilers that burn a single type of fuel, you are exempted from the compliance requirements of conducting a fuel analysis for each type of fuel burned in your...

  7. Effects of prescribed burning on vegetation and fuel loading in three east Texas state parks

    Treesearch

    Sandra Rideout; Brian P. Oswald

    2002-01-01

    This study was conducted to evaluate the initial effectiveness of prescribed burning in the ecological restoration of forests within selected parks in east Texas. Twenty-four permanent plots were installed to monitor fuel loads, overstory, sapling, seedling, shrub and herbaceous layers within burn and control units of Mission Tejas, Tyler and Village Creek state parks...

  8. 40 CFR 63.11211 - How do I demonstrate initial compliance with the emission limits?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Table 4 to this subpart, conducting a fuel analysis for each type of fuel burned in your boiler... evaluations according to § 63.11224. For affected boilers that burn a single type of fuel, you are exempted from the compliance requirements of conducting a fuel analysis for each type of fuel burned in your...

  9. A burn center paradigm to fulfill deferred consent public disclosure and community consultation requirements for emergency care research.

    PubMed

    Blackford, Martha G; Falletta, Lynn; Andrews, David A; Reed, Michael D

    2012-09-01

    To fulfill Food and Drug Administration and Department of Health and Human Services emergency care research informed consent requirements, our burn center planned and executed a deferred consent strategy gaining Institutional Review Board (IRB) approval to proceed with the clinical study. These federal regulations dictate public disclosure and community consultation unique to acute care research. Our regional burn center developed and implemented a deferred consent public notification and community consultation paradigm appropriate for a burn study. Published accounts of deferred consent strategies focus on acute care resuscitation practices. We adapted those strategies to design and conduct a comprehensive public notification/community consultation plan to satisfy deferred consent requirements for burn center research. To implement a robust media campaign we engaged the hospital's public relations department, distributed media materials, recruited hospital staff for speaking engagements, enlisted community volunteers, and developed initiatives to inform "hard-to-reach" populations. The hospital's IRB determined we fulfilled our obligation to notify the defined community. Our communication strategy should provide a paradigm other burn centers may appropriate and adapt when planning and executing a deferred consent initiative. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  10. Edge-preserving data assimilation for fire monitoring using optical data

    NASA Astrophysics Data System (ADS)

    Gomez-Dans, Jose; Lewis, Philip; Disney, Mathias; Roy, David; Quaife, Tristan; Wooster, Martin

    2013-04-01

    Monitoring fire using optical data from moderate spatial resolution sensors is in essence a change detection process, where changes in reflectance (or a vegetation index) within two dates or periods are interpreted as fires if the change meets a number of spectral rules. A major challenge in any of these algorithms is accounting for angular effects due to different acquistion/illumination geometry. The MODIS Coll5 algorithm for example, uses linear kernel models to forward predict observations, and based on a statistical test, decides whether a change has occurred and labels it as a potential fire. While the algorithm is successful in many regions, it has problems dealing with cloudy periods, and with limitations in the available observations. In this work, we propose a new approach based on (i) a more advanced signal tracking method using edge-preserving data assimilation techniques and (ii) an interpretation of the change signal using a spectral linear model. The signal tracking approach uses linear kernel models, but solves for them using regularisation in time as a prior. This allows for a transfer of information from data rich periods to other periods where data may be more sparse. To minimise information leaking over the actual fire, we implement an edge-preserving mechanism that limits the information transfer over the disturbance. The result of this is a complete time series of surface reflectance acquired with a constant geometry. Note that the system provides complete uncertainty estimates of the parameters, taking into account the initial level of uncertainty in the observations of surface reflectance. A second stage interprets post-fire reflectance as a mixture of a "typical burn signal" and an unburned component, which we assume to be the pre-fire reflectance. We propose a simple spectral model for the burn signal, a constrained quadratic function. This model is appropriate for a number of burned material spectrum. We demonstrate using the MODIS burned area product that the approach provides useful complementary information about fires, describing the spectral nature of the burn signal, as well as providing information on potentially the impact of the fire in the pixel. Both approaches are then combined into a multispectral burned area algorithm with MODIS land surface observations. We test the performance of the proposed method, compare to other well-established products, and show some of the shortcomings of the proposed algorithm.

  11. Standardization of deep partial-thickness scald burns in C57BL/6 mice

    PubMed Central

    Medina, Jorge L; Fourcaudot, Andrea B; Sebastian, Eliza A; Shankar, Ravi; Brown, Ammon W; Leung, Kai P

    2018-01-01

    Mouse burn models are used to understand the wound healing process and having a reproducible model is important. The different protocols used by researchers can lead to differences in depth of partial-thickness burn wounds. Additionally, standardizing a protocol for mouse burns in the laboratory for one strain may result in substantially different results in other strains. In our current study we describe the model development of a deep partial-thickness burn in C57BL/6 mice using hot water scalding as the source of thermal injury. As part of our model development we designed a template with specifications to allow for even contact of bare mouse skin (2×3 cm) with hot water while protecting the rest of the mouse. Burn depth was evaluated with H&E, Masson’s trichrome, and TUNEL staining. Final results were validated with pathology analysis. A water temperature of 54°C with a scalding time of 20 seconds produced consistent deep partial-thickness burns with available equipment described. Other than temperature and time, factors such as template materials and cooling steps after the burn could affect the uniformity of the burns. These findings are useful to burn research by providing some key parameters essential for researchers to simplify the development of their own mouse burn models. PMID:29755839

  12. Response of advance reproduction of oaks and associated species to repeated prescribed fires in upland oak-hickory forests, Missouri

    Treesearch

    Zhaofei Fan; Zhongqiu Ma; Daniel C. Dey; Scott D. Roberts

    2012-01-01

    The Chilton Creek prescribed burn project was initiated in 1996 by The Nature Conservancy (TNC) to restore native oak woodlands and test the effect of frequent, low intensity surface fires conducted in the dormant season (March-April) on upland oak-hickory forests in the Ozarks of Missouri. Burning treatments on five sites totaling 1000 ha were initiated in 1998. The...

  13. Emissions from open burning of simulated military waste from forward operating bases.

    PubMed

    Aurell, Johanna; Gullett, Brian K; Yamamoto, Dirk

    2012-10-16

    Emissions from open burning of simulated military waste from forward operating bases (FOBs) were extensively characterized as an initial step in assessing potential inhalation exposure of FOB personnel and future disposal alternatives. Emissions from two different burning scenarios, so-called "burn piles/pits" and an air curtain burner/"burn box", were compared using simulated FOB waste from municipal and commercial sources. A comprehensive array of emissions was quantified, including CO(2), PM(2.5), volatile organic compounds (VOCs), polyaromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins and -furans (PCDDs/PCDFs), polybrominated dibenzodioxins and -furans (PBDDs/PBDFs), and metals. In general, smoldering conditions in the burn box and the burn pile led to similar emissions. However, when the burn box underwent periodic waste charging to maintain sustained combustion, PM(2.5), VOCs, and PAH emissions dropped considerably compared to smoldering conditions and the overall burn pile results. The PCDD/PCDF and PBDD/PBDF emission factors for the burn piles were 50 times higher than those from the burn box likely due to the dominance of smoldering combustion in the burn piles.

  14. Gamma Ray Imaging of Inertial Confinement Fusion Experiments

    NASA Astrophysics Data System (ADS)

    Wilde, Carl; Volegov, Petr; Geppert-Kleinrath, Verena; Danly, Christopher; Merrill, Frank; Simpson, Raspberry; Fittinghoff, David; Grim, Gary; NIF Nuclear Diagnostic Team Team; Advanced Imaging Team Team

    2016-10-01

    Experiments consisting of an ablatively driven plastic (CH) shell surrounding a deuterium tritium (DT) fuel region are routinely performed at the National Ignition Facility (NIF). Neutrons produced in the burning fuel in-elastically scatter with carbon atoms in the plastic shell producing 4.4 MeV gamma rays. Providing a spatially resolved distribution of the origin of these gammas can inform models of ablator physics and also provide a bounding volume for the cold fuel (un-burned DT fuel) region. Using the NIF neutron imaging system hardware, initial studies have been performed of the feasibility of imaging these gamma rays. A model of the system has been developed to inform under which experimental conditions this measurement can be made. Presented here is an analysis of the prospects for this diagnostic probe and a proposed set of modifications to the NIF neutron imaging line-of-site to efficiently enable this measurement.

  15. Semi-analytic model of plasma-jet-driven magneto-inertial fusion

    DOE PAGES

    Langendorf, Samuel J.; Hsu, Scott C.

    2017-03-01

    A semi-analytic model for plasma-jet-driven magneto-inertial fusion is presented here. Compressions of a magnetized plasma target by a spherically imploding plasma liner are calculated in one dimension (1D), accounting for compressible hydrodynamics and ionization of the liner material, energy losses due to conduction and radiation, fusion burn and alpha deposition, separate ion and electron temperatures in the target, magnetic pressure, and fuel burn-up. Results show 1D gains of 3–30 at spherical convergence ratio <15 and 20–40 MJ of liner energy, for cases in which the liner thickness is 1 cm and the initial radius of a preheated magnetized target ismore » 4 cm. Some exploration of parameter space and physics settings is presented. The yields observed suggest that there is a possibility of igniting additional dense fuel layers to reach high gain.« less

  16. Effect of propellant deformation on ignition and combustion processes in solid propellant cracks

    NASA Technical Reports Server (NTRS)

    Kumar, M.; Kuo, K. K.

    1980-01-01

    A comprehensive theoretical model was formulated to study the development of convective burning in a solid propellant crack which continually deforms due to burning and pressure loading. In the theoretical model, the effect of interrelated structural deformation and combustion processes was taken into account by considering (1) transient, one dimensional mass, momentum, and energy conservation equations in the gas phase; (2) a transient, one dimensional heat conduction equation in the solid phase; and (3) quasi-static deformation of the two dimensional, linear viscoelastic propellant crack caused by pressure loading. Partial closures may generate substantial local pressure peaks along the crack, implying a strong coupling between chamber pressurization, crack combustion, and propellant deformation, especially when the cracks are narrow and the chamber pressurization rates high. The maximum pressure in the crack cavity is generally higher than that in the chamber. The initial flame-spreading process is not affected by propellant deformation.

  17. Preventing Scars after Injury with Partial Irreversible Electroporation

    PubMed Central

    Golberg, Alexander; Villiger, Martin; Khan, Saiqa; Quinn, Kyle P.; Lo, William C. Y.; Bouma, Brett E.; Mihm, Martin C.; Austen, William G.; Yarmush, Martin L.

    2017-01-01

    Preventing the formation of hypertrophic scars, especially those that are a result of major trauma or burns, would have enormous impact in the fields of regenerative and trauma medicine. In this report, we introduce a non-invasive method to prevent scarring based on non-thermal partial irreversible electroporation. Contact burn injuries in rats were treated with varying treatment parameters to optimize the treatment protocol. Scar surface area and structural properties of the scar were assessed with histology and non-invasive, longitudinal imaging with polarization-sensitive optical coherence tomography. We found that partial irreversible electroporation using 200 pulses of 250 V and 70 μs duration, delivered at 3 Hz every 20 days during a total of five therapy sessions after the initial burn injury resulted in a 57.9% reduction of the scar area in comparison with untreated scars and structural features approaching those of normal skin. Noteworthy, unlike humans, rats do not develop hypertrophic scars. Therefore, the use of a rat animal model is the limiting factor of this work. PMID:27393126

  18. Prediction of Fracture Initiation in Hot Compression of Burn-Resistant Ti-35V-15Cr-0.3Si-0.1C Alloy

    NASA Astrophysics Data System (ADS)

    Zhang, Saifei; Zeng, Weidong; Zhou, Dadi; Lai, Yunjin

    2015-11-01

    An important concern in hot working of metals is whether the desired deformation can be accomplished without fracture of the material. This paper builds a fracture prediction model to predict fracture initiation in hot compression of a burn-resistant beta-stabilized titanium alloy Ti-35V-15Cr-0.3Si-0.1C using a combined approach of upsetting experiments, theoretical failure criteria and finite element (FE) simulation techniques. A series of isothermal compression experiments on cylindrical specimens were conducted in temperature range of 900-1150 °C, strain rate of 0.01-10 s-1 first to obtain fracture samples and primary reduction data. Based on that, a comparison of eight commonly used theoretical failure criteria was made and Oh criterion was selected and coded into a subroutine. FE simulation of upsetting experiments on cylindrical specimens was then performed to determine the fracture threshold values of Oh criterion. By building a correlation between threshold values and the deforming parameters (temperature and strain rate, or Zener-Hollomon parameter), a new fracture prediction model based on Oh criterion was established. The new model shows an exponential decay relationship between threshold values and Zener-Hollomon parameter (Z), and the relative error of the model is less than 15%. This model was then applied successfully in the cogging of Ti-35V-15Cr-0.3Si-0.1C billet.

  19. Thermal Model of the Promoted Combustion Test

    NASA Technical Reports Server (NTRS)

    Jones, Peter D.

    1996-01-01

    Flammability of metals in high pressure, pure oxygen environments, such as rocket engine turbopumps, is commonly evaluated using the Promoted Combustion Test (PCT). The PCT emphasizes the ability of an ignited material to sustain combustion, as opposed to evaluating the sample's propensity to ignite in the first place. A common arrangement is a rod of the sample material hanging in a chamber in which a high pressure, pure oxygen environment is maintained. An igniter of some energetically combusting material is fixed to the bottom of the rod and fired. This initiates combustion, and the sample burns and melts at its bottom tip. A ball of molten material forms, and this ball detaches when it grows too large to be supported by surface tension with the rod. In materials which do not sustain combustion, the combustion then extinguishes. In materials which do sustain combustion, combustion re-initiates from molten residue left on the bottom of the rod, and the melt ball burns and grows until it detaches again. The purpose of this work is development of a PCT thermal simulation model, detailing phase change, melt detachment, and the several heat transfer modes. Combustion is modeled by a summary rate equation, whose parameters are identified by comparison to PCT results. The sensitivity of PCT results to various physical and geometrical parameters is evaluated. The identified combustion parameters may be used in design of new PCT arrangements, as might be used for flammability assessment in flow-dominated environments. The Haynes 214 nickel-based superalloy, whose PCT results are applied here, burns heterogeneously (fuel and oxidizer are of different phases; combustion takes place on the fuel surface). Heterogeneous combustion is not well understood. (In homogeneous combustion, the metal vaporizes, and combustion takes place in an analytically treatable cloud above the surface). Thermal modeling in heterogeneous combustion settings provides a means for linking test results more directly to detailed combustion mechanics, leading to improved data analysis, and improved understanding of heterogeneous combustion phenomena.

  20. Internal Flow Analysis of Large L/D Solid Rocket Motors

    NASA Technical Reports Server (NTRS)

    Laubacher, Brian A.

    2000-01-01

    Traditionally, Solid Rocket Motor (SRM) internal ballistic performance has been analyzed and predicted with either zero-dimensional (volume filling) codes or one-dimensional ballistics codes. One dimensional simulation of SRM performance is only necessary for ignition modeling, or for motors that have large length to port diameter ratios which exhibit an axial "pressure drop" during the early burn times. This type of prediction works quite well for many types of motors, however, when motor aspect ratios get large, and port to throat ratios get closer to one, two dimensional effects can become significant. The initial propellant grain configuration for the Space Shuttle Reusable Solid Rocket Motor (RSRM) was analyzed with 2-D, steady, axi-symmetric computational fluid dynamics (CFD). The results of the CFD analysis show that the steady-state performance prediction at the initial burn geometry, in general, agrees well with 1-D transient prediction results at an early time, however, significant features of the 2-D flow are captured with the CFD results that would otherwise go unnoticed. Capturing these subtle differences gives a greater confidence to modeling accuracy, and additional insight with which to model secondary internal flow effects like erosive burning. Detailed analysis of the 2-D flowfield has led to the discovery of its hidden 1-D isentropic behavior, and provided the means for a thorough and simplified understanding of internal solid rocket motor flow. Performance parameters such as nozzle stagnation pressure, static pressure drop, characteristic velocity, thrust and specific impulse are discussed in detail and compared for different modeling and prediction methods. The predicted performance using both the 1-D codes and the CFD results are compared with measured data obtained from static tests of the RSRM. The differences and limitations of predictions using ID and 2-D flow fields are discussed and some suggestions for the design of large L/D motors and more critically, motors with port to throat ratios near one, are covered.

  1. Sources, Transport, and Climate Impacts of Biomass Burning Aerosols

    NASA Technical Reports Server (NTRS)

    Chin, Mian

    2010-01-01

    In this presentation, I will first talk about fundamentals of modeling of biomass burning emissions of aerosols, then show the results of GOCART model simulated biomass burning aerosols. I will compare the model results with observations of satellite and ground-based network in terms of total aerosol optical depth, aerosol absorption optical depth, and vertical distributions. Finally the long-range transport of biomass burning aerosols and the climate effects will be addressed. I will also discuss the uncertainties associated with modeling and observations of biomass burning aerosols

  2. Post-fire burn severity and vegetation response following eight large wildfires across the Western United States

    Treesearch

    Leigh B. Lentile; Penelope Morgan; Andrew T. Hudak; Michael J. Bobbitt; Sarah A. Lewis; Alistair M. S. Smith; Peter R. Robichaud

    2007-01-01

    Vegetation response and burn severity were examined following eight large wildfires that burned in 2003 and 2004: two wildfires in California chaparral, two each in dry and moist mixed-conifer forests in Montana, and two in boreal forests in interior Alaska. Our research objectives were: 1) to characterize one year post-fire vegetation recovery relative to initial fire...

  3. Twenty Years of Prescribed Burning Influence the Development of Direct-Seeded Longleaf Pine on a Wet Pine Site in Louisiana

    Treesearch

    James D. Haywood; Harold E. Grelen

    2000-01-01

    Prescribed burning treatments were applied over a 20 yr period in a commonly randomized field study to determine the effects of various fire regimes on vegetation in a direct seeded standof longleaf pine (Pinus palustris Mill.). Seeding was done in November 1968. The study area was broadcast-burned about 16 months after seeding. The initial...

  4. First results from a large, multi-platform study of trace gas and particle emissions from biomass burning

    Treesearch

    I. R. Burling; R. J. Yokelson; S. K. Akagi; T. J. Johnson; D. W. Griffith; Shawn Urbanski; J. W. Taylor; J. S. Craven; G. R. McMeeking; J. M. Roberts; C. Warneke; P. R. Veres; J. A. de Gouw; J. B. Gilman; W. C. Kuster; WeiMin Hao; D. Weise; H. Coe; J. Seinfeld

    2010-01-01

    We report preliminary results from a large, multi-component study focused on North American biomass burning that measured both initial emissions and post-emission processing. Vegetation types burned were from the relatively less-studied temperate region of the US and included chaparral, oak savanna, and mixed conifer forest from the southwestern US, and pine understory...

  5. 40 CFR 63.7510 - What are my initial compliance requirements and by what date must I conduct them?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... subpart, conducting a fuel analysis for each type of fuel burned in your boiler or process heater... sources that burn a single type of fuel, you are exempted from the compliance requirements of conducting a fuel analysis for each type of fuel burned in your boiler or process heater according to § 63.7521 and...

  6. 40 CFR 63.7510 - What are my initial compliance requirements and by what date must I conduct them?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... subpart, conducting a fuel analysis for each type of fuel burned in your boiler or process heater... sources that burn a single type of fuel, you are exempted from the compliance requirements of conducting a fuel analysis for each type of fuel burned in your boiler or process heater according to § 63.7521 and...

  7. 40 CFR 62.14815 - What are the emission limitations for air curtain incinerators that burn 100 percent wood wastes...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air curtain incinerators that burn 100 percent wood wastes, clean lumber and/or yard waste? 62.14815... Before November 30, 1999 Air Curtain Incinerators That Burn 100 Percent Wood Wastes, Clean Lumber And/or... percent wood wastes, clean lumber and/or yard waste? (a) After the date the initial test for opacity is...

  8. 40 CFR 62.14815 - What are the emission limitations for air curtain incinerators that burn 100 percent wood wastes...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... air curtain incinerators that burn 100 percent wood wastes, clean lumber and/or yard waste? 62.14815... Before November 30, 1999 Air Curtain Incinerators That Burn 100 Percent Wood Wastes, Clean Lumber And/or... percent wood wastes, clean lumber and/or yard waste? (a) After the date the initial test for opacity is...

  9. 40 CFR 63.7530 - How do I demonstrate initial compliance with the emission limits and work practice standards?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) of this section. (i) You must determine the fuel type or fuel mixture that you could burn in your... for HCl, you must determine the fraction of the total heat input for each fuel type burned (Qi) based... of each fuel type burned (Ci). (iii) You must establish a maximum chlorine input level using Equation...

  10. Biomass Burning Data and Information

    Atmospheric Science Data Center

    2015-04-21

    Biomass Burning Data and Information This data set represents ... geographical and temporal distribution of total amount of biomass burned. These data may be used in general circulation models (GCMs) and ... models of the atmosphere. Project Title:  Biomass Burning Discipline:  Tropospheric Composition ...

  11. Dual therapeutic functions of F-5 fragment in burn wounds: preventing wound progression and promoting wound healing in pigs

    PubMed Central

    Bhatia, Ayesha; O’Brien, Kathryn; Chen, Mei; Wong, Alex; Garner, Warren; Woodley, David T.; Li, Wei

    2016-01-01

    Burn injuries are a leading cause of morbidity including prolonged hospitalization, disfigurement, and disability. Currently there is no Food and Drug Administration-approved burn therapeutics. A clinical distinction of burn injuries from other acute wounds is the event of the so-called secondary burn wound progression within the first week of the injury, in which a burn expands horizontally and vertically from its initial boundary to a larger area. Therefore, an effective therapeutics for burns should show dual abilities to prevent the burn wound progression and thereafter promote burn wound healing. Herein we report that topically applied F-5 fragment of heat shock protein-90α is a dual functional agent to promote burn wound healing in pigs. First, F-5 prevents burn wound progression by protecting the surrounding cells from undergoing heat-induced caspase 3 activation and apoptosis with increased Akt activation. Accordingly, F-5–treated burn and excision wounds show a marked decline in inflammation. Thereafter, F-5 accelerates burn wound healing by stimulating the keratinocyte migration-led reepithelialization, leading to wound closure. This study addresses a topical agent that is capable of preventing burn wound progression and accelerating burn wound healing. PMID:27382602

  12. Cool-flame Extinction During N-Alkane Droplet Combustion in Microgravity

    NASA Technical Reports Server (NTRS)

    Nayagam, Vedha; Dietrich, Daniel L.; Hicks, Michael C.; Williams, Forman A.

    2014-01-01

    Recent droplet combustion experiments onboard the International Space Station (ISS) have revealed that large n-alkane droplets can continue to burn quasi-steadily following radiative extinction in a low-temperature regime, characterized by negative-temperaturecoefficient (NTC) chemistry. In this study we report experimental observations of n-heptane, n-octane, and n-decane droplets of varying initial sizes burning in oxygen/nitrogen/carbon dioxide and oxygen/helium/nitrogen environments at 1.0, 0.7, and 0.5 atmospheric pressures. The oxygen concentration in these tests varied in the range of 14% to 25% by volume. Large n-alkane droplets exhibited quasi-steady low-temperature burning and extinction following radiative extinction of the visible flame while smaller droplets burned to completion or disruptively extinguished. A vapor-cloud formed in most cases slightly prior to or following the "cool flame" extinction. Results for droplet burning rates in both the hot-flame and cool-flame regimes as well as droplet extinction diameters at the end of each stage are presented. Time histories of radiant emission from the droplet captured using broadband radiometers are also presented. Remarkably the "cool flame" extinction diameters for all the three n-alkanes follow a trend reminiscent of the ignition delay times observed in previous studies. The similarities and differences among the n-alkanes during "cool flame" combustion are discussed using simplified theoretical models of the phenomenon

  13. Contributions of Kansas rangeland burning to ambient O3: Analysis of data from 2001 to 2016.

    PubMed

    Liu, Zifei; Liu, Yang; Murphy, James P; Maghirang, Ronaldo

    2018-03-15

    Prescribed range/pasture burning is a common practice in Kansas to enhance the nutritional value of native grasses and control invading weeds, trees, and brush. A major concern associated with the burning is the contribution of smoke to elevated ground level ambient ozone (O 3 ). The objective of this study is to estimate contributions of Kansas rangeland burning to ambient O 3 mixing ratios through regression analysis (1) between observed O 3 data and available satellite burn activity data from 2001 to 2016; and (2) between observed O 3 data and the smoke contributions to PM 2.5 which were resolved from receptor modeling. Positive correlations were observed between ambient O 3 levels and the acres burned each year estimated from satellite imagery. When burned acres in April were larger than or equal to 1.9 million, O 3 >70ppb occurred at least at one of the ten monitoring sites in Kansas. Statistical regression models of daily maximum 8-hour O 3 mixing ratios were developed at each of the ten monitoring sites using meteorological predictors. The O 3 model residuals that were not explained by the meteorological effect models were affected by PM 2.5 contributors including sulfate/industrial sources and emissions that generated secondary organic particles, such as rangeland burning, which were derived from receptor modeling. The average O 3 model residual on the high O 3 days in April was 21±9ppb, which was likely associated with smoke emissions from burning. Research will continue to obtain daily satellite burn activity data and to correlate burn data with daily O 3 data, so that modeling of O 3 levels can be improved under influences of daily burn activities. Less frequency of high O 3 days was observed in April since 2011, which may be partly due to implementation of the Flint Hills Smoke Management Plan which promoted better timing of burns. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Oppositional Defiant Disorder toward Adults and Oppositional Defiant Disorder toward Peers: Initial Evidence for Two Separate Constructs

    ERIC Educational Resources Information Center

    Taylor, Ted K.; Burns, G. Leonard; Rusby, Julie C.; Foster, E. Michael

    2006-01-01

    Confirmatory factor analysis of 25 items on the Child and Adolescent Disruptive Behavior Inventory (CADBI, Version 2.3; G. L. Burns, T. K. Taylor, & J. C. Rusby, 2001) was conducted on teacher ratings of 824 kindergarten children and replicated on 534 children. Model fit was improved when correcting for 2 method effects: (a) adjacent items and…

  15. White dwarf models for type 1 supernovae and quiet supernovae, and presupernova evolution

    NASA Technical Reports Server (NTRS)

    Nomoto, K.

    1980-01-01

    Supernova mechanisms in accreting white dwarfs are considered with emphasis on deflagration as a plausible mechanism for producing Type I supernovae and electron captures to form quiet supernovae leaving neutron stars. These outcomes depend on accretion rate of helium, initial mass and composition of the white dwarf. The various types of hydrogen shell burning in the presupernova stage are also discussed.

  16. Returning fire to Ozark Highland forest ecosystems: Effects on advance regeneration

    Treesearch

    Daniel C. Dey; George Hartman

    2005-01-01

    In mature forests of the Ozark Highlands, MO, USA, we evaluated fire effects on the survival and growth of tree seedlings and saplings (i.e., advance regeneration), and used this information to develop species-specific models that predict the probability of survival based on initial tree size and number of times burned. A 1000 ha forest area was divided into five units...

  17. Novel burn device for rapid, reproducible burn wound generation.

    PubMed

    Kim, J Y; Dunham, D M; Supp, D M; Sen, C K; Powell, H M

    2016-03-01

    Scarring following full thickness burns leads to significant reductions in range of motion and quality of life for burn patients. To effectively study scar development and the efficacy of anti-scarring treatments in a large animal model (female red Duroc pigs), reproducible, uniform, full-thickness, burn wounds are needed to reduce variability in observed results that occur with burn depth. Prior studies have proposed that initial temperature of the burner, contact time with skin, thermal capacity of burner material, and the amount of pressure applied to the skin need to be strictly controlled to ensure reproducibility. The purpose of this study was to develop a new burner that enables temperature and pressure to be digitally controlled and monitored in real-time throughout burn wound creation and compare it to a standard burn device. A custom burn device was manufactured with an electrically heated burn stylus and a temperature control feedback loop via an electronic microstat. Pressure monitoring was controlled by incorporation of a digital scale into the device, which measured downward force. The standard device was comprised of a heat resistant handle with a long rod connected to the burn stylus, which was heated using a hot plate. To quantify skin surface temperature and internal stylus temperature as a function of contact time, the burners were heated to the target temperature (200±5°C) and pressed into the skin for 40s to create the thermal injuries. Time to reach target temperature and elapsed time between burns were recorded. In addition, each unit was evaluated for reproducibility within and across three independent users by generating burn wounds at contact times spanning from 5 to 40s at a constant pressure and at pressures of 1 or 3lbs with a constant contact time of 40s. Biopsies were collected for histological analysis and burn depth quantification using digital image analysis (ImageJ). The custom burn device maintained both its internal temperature and the skin surface temperature near target temperature throughout contact time. In contrast, the standard burner required more than 20s of contact time to raise the skin surface temperature to target due to its quickly decreasing internal temperature. The custom burner was able to create four consecutive burns in less than half the time of the standard burner. Average burn depth scaled positively with time and pressure in both burn units. However, the distribution of burn depth within each time-pressure combination in the custom device was significantly smaller than with the standard device and independent of user. The custom burn device's ability to continually heat the burn stylus and actively control pressure and temperature allowed for more rapid and reproducible burn wounds. Burns of tailored and repeatable depths, independent of user, provide a platform for the study of anti-scar and other wound healing therapies without the added variable of non-uniform starting injury. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  18. Novel burn device for rapid, reproducible burn wound generation

    PubMed Central

    Kim, J.Y.; Dunham, D.M.; Supp, D.M.; Sen, C.K.; Powell, H.M.

    2016-01-01

    Introduction Scarring following full thickness burns leads to significant reductions in range of motion and quality of life for burn patients. To effectively study scar development and the efficacy of anti-scarring treatments in a large animal model (female red Duroc pigs), reproducible, uniform, full-thickness, burn wounds are needed to reduce variability in observed results that occur with burn depth. Prior studies have proposed that initial temperature of the burner, contact time with skin, thermal capacity of burner material, and the amount of pressure applied to the skin need to be strictly controlled to ensure reproducibility. The purpose of this study was to develop a new burner that enables temperature and pressure to be digitally controlled and monitored in real-time throughout burn wound creation and compare it to a standard burn device. Methods A custom burn device was manufactured with an electrically heated burn stylus and a temperature control feedback loop via an electronic microstat. Pressure monitoring was controlled by incorporation of a digital scale into the device, which measured downward force. The standard device was comprised of a heat resistant handle with a long rod connected to the burn stylus, which was heated using a hot plate. To quantify skin surface temperature and internal stylus temperature as a function of contact time, the burners were heated to the target temperature (200 ± 5 °C) and pressed into the skin for 40 s to create the thermal injuries. Time to reach target temperature and elapsed time between burns were recorded. In addition, each unit was evaluated for reproducibility within and across three independent users by generating burn wounds at contact times spanning from 5 to 40 s at a constant pressure and at pressures of 1 or 3 lbs with a constant contact time of 40 s. Biopsies were collected for histological analysis and burn depth quantification using digital image analysis (ImageJ). Results The custom burn device maintained both its internal temperature and the skin surface temperature near target temperature throughout contact time. In contrast, the standard burner required more than 20 s of contact time to raise the skin surface temperature to target due to its quickly decreasing internal temperature. The custom burner was able to create four consecutive burns in less than half the time of the standard burner. Average burn depth scaled positively with time and pressure in both burn units. However, the distribution of burn depth within each time-pressure combination in the custom device was significantly smaller than with the standard device and independent of user. Conclusions The custom burn device's ability to continually heat the burn stylus and actively control pressure and temperature allowed for more rapid and reproducible burn wounds. Burns of tailored and repeatable depths, independent of user, provide a platform for the study of anti-scar and other wound healing therapies without the added variable of non-uniform starting injury. PMID:26803369

  19. Multivariate analysis of gamma spectra to characterize used nuclear fuel

    DOE PAGES

    Coble, Jamie; Orton, Christopher; Schwantes, Jon

    2017-01-17

    The Multi-Isotope Process (MIP) Monitor provides an efficient means to monitor the process conditions in used nuclear fuel reprocessing facilities to support process verification and validation. The MIP Monitor applies multivariate analysis to gamma spectroscopy of key stages in the reprocessing stream in order to detect small changes in the gamma spectrum, which may indicate changes in process conditions. This research extends the MIP Monitor by characterizing a used fuel sample after initial dissolution according to the type of reactor of origin (pressurized or boiling water reactor; PWR and BWR, respectively), initial enrichment, burn up, and cooling time. Simulated gammamore » spectra were used in this paper to develop and test three fuel characterization algorithms. The classification and estimation models employed are based on the partial least squares regression (PLS) algorithm. A PLS discriminate analysis model was developed which perfectly classified reactor type for the three PWR and three BWR reactor designs studied. Locally weighted PLS models were fitted on-the-fly to estimate the remaining fuel characteristics. For the simulated gamma spectra considered, burn up was predicted with 0.1% root mean squared percent error (RMSPE) and both cooling time and initial enrichment with approximately 2% RMSPE. Finally, this approach to automated fuel characterization can be used to independently verify operator declarations of used fuel characteristics and to inform the MIP Monitor anomaly detection routines at later stages of the fuel reprocessing stream to improve sensitivity to changes in operational parameters that may indicate issues with operational control or malicious activities.« less

  20. Multivariate analysis of gamma spectra to characterize used nuclear fuel

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Coble, Jamie; Orton, Christopher; Schwantes, Jon

    The Multi-Isotope Process (MIP) Monitor provides an efficient means to monitor the process conditions in used nuclear fuel reprocessing facilities to support process verification and validation. The MIP Monitor applies multivariate analysis to gamma spectroscopy of key stages in the reprocessing stream in order to detect small changes in the gamma spectrum, which may indicate changes in process conditions. This research extends the MIP Monitor by characterizing a used fuel sample after initial dissolution according to the type of reactor of origin (pressurized or boiling water reactor; PWR and BWR, respectively), initial enrichment, burn up, and cooling time. Simulated gammamore » spectra were used in this paper to develop and test three fuel characterization algorithms. The classification and estimation models employed are based on the partial least squares regression (PLS) algorithm. A PLS discriminate analysis model was developed which perfectly classified reactor type for the three PWR and three BWR reactor designs studied. Locally weighted PLS models were fitted on-the-fly to estimate the remaining fuel characteristics. For the simulated gamma spectra considered, burn up was predicted with 0.1% root mean squared percent error (RMSPE) and both cooling time and initial enrichment with approximately 2% RMSPE. Finally, this approach to automated fuel characterization can be used to independently verify operator declarations of used fuel characteristics and to inform the MIP Monitor anomaly detection routines at later stages of the fuel reprocessing stream to improve sensitivity to changes in operational parameters that may indicate issues with operational control or malicious activities.« less

  1. The Incidence of Burns Among Sex-Trafficking Victims in India

    PubMed Central

    Rahman, Nadia; Sinha, Indranil; Husain, Fatima; Shah, Ajul; Patel, Anup

    2014-01-01

    Sex trafficking remains a flagrant violation of human rights, creating many public health concerns. During the initiation period, these victims experience acts of violence including gang rapes, subjecting them to traumatic injuries that include burns. Furthermore, lack of access to health care, particularly surgical, keeps them from receiving treatment for these functionally debilitating contractures caused by burns. This piece provides an overview of burns among sex-trafficked victims in India and the efforts by Cents of Relief to address the associated surgical burden of disease. PMID:25191142

  2. A Minimum (Delta)V Orbit Maintenance Strategy for Low-Altitude Missions Using Burn Parameter Optimization

    NASA Technical Reports Server (NTRS)

    Brown, Aaron J.

    2011-01-01

    Orbit maintenance is the series of burns performed during a mission to ensure the orbit satisfies mission constraints. Low-altitude missions often require non-trivial orbit maintenance (Delta)V due to sizable orbital perturbations and minimum altitude thresholds. A strategy is presented for minimizing this (Delta)V using impulsive burn parameter optimization. An initial estimate for the burn parameters is generated by considering a feasible solution to the orbit maintenance problem. An example demonstrates the dV savings from the feasible solution to the optimal solution.

  3. Methanol Droplet Combustion in Oxygen-Inert Environments in Microgravity

    NASA Technical Reports Server (NTRS)

    Nayagam, Vedha; Dietrich, Daniel L.; Hicks, Michael C.; Williams, Forman A.

    2013-01-01

    The Flame Extinguishment (FLEX) experiment that is currently underway in the Combustion Integrated Rack facility onboard the International Space Station is aimed at understanding the effects of inert diluents on the flammability of condensed phase fuels. To this end, droplets of various fuels, including alkanes and alcohols, are burned in a quiescent microgravity environment with varying amounts of oxygen and inert diluents to determine the limiting oxygen index (LOI) for these fuels. In this study we report experimental observations of methanol droplets burning in oxygen-nitrogen-carbon dioxide and oxygen-nitrogen-helium gas mixtures at 0.7 and 1 atmospheric pressures. The initial droplet size varied between approximately 1.5 mm and 4 mm to capture both diffusive extinction brought about by insufficient residence time at the flame and radiative extinction caused by excessive heat loss from the flame zone. The ambient oxygen concentration varied from a high value of 30% by volume to as low as 12%, approaching the limiting oxygen index for the fuel. The inert dilution by carbon dioxide and helium varied over a range of 0% to 70% by volume. In these experiments, both freely floated and tethered droplets were ignited using symmetrically opposed hot-wire igniters and the burning histories were recorded onboard using digital cameras, downlinked later to the ground for analysis. The digital images yielded droplet and flame diameters as functions of time and subsequently droplet burning rate, flame standoff ratio, and initial and extinction droplet diameters. Simplified theoretical models correlate the measured burning rate constant and the flame standoff ratio reasonably well. An activation energy asymptotic theory accounting for time-dependent water dissolution or evaporation from the droplet is shown to predict the measured diffusive extinction conditions well. The experiments also show that the limiting oxygen index for methanol in these diluent gases is around 12% to 13% oxygen by volume.

  4. AmeriFlux US-An2 Anaktuvuk River Moderate Burn

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hobbie, John; Rocha, Adrian; Shaver, Gaius

    This is the AmeriFlux version of the carbon flux data for the site US-An2 Anaktuvuk River Moderate Burn. Site Description - The Anaktuvuk River fire on the North Slope of Alaska started on July 16, 2007 by lightning. It continued until the end of September when nearby lakes had already frozen over and burned >256,000 acres, creating a mosaic of patches that differed in burn severity. The Anaktuvuk River Severe Burn, Moderate Burn, and Unburned sites are 40 km to the west of the nearest road and were selected in late May 2008 to determine the effects of the firemore » on carbon, water, and energy exchanges during the growing season. Because the fire had burned through September of the previous year, initial deployment of flux towers occurred prior to any significant vegetative regrowth, and our sampling campaign captured the full growing season in 2008. The Moderate Burn site consisted of a large area with small patches of completely and partially burned tundra intermixed across the landscape.« less

  5. Critical issues in burn care.

    PubMed

    Holmes, James H

    2008-01-01

    Burn care, especially for serious burn injuries, represents a considerable challenge for the healthcare system. The American Burn Association has established a number of strategies for the management of burn patients and dedicates its efforts and resources to promoting and supporting burn-related research, education, care, rehabilitation, and prevention, often in collaboration with other organizations. The American Burn Association has recommended that patients with serious burns be referred to a designated burn center, ie, a hospital outfitted with specialized personnel and equipment dedicated to burn care. Burn centers have been operational for over 50 years, but the complexity and costs of providing specialized burn care have given rise to a number of critical administrative and political issues. These include logistical limitations imposed by the uneven national distribution of burn centers and a potential shortage of burn beds, both during everyday conditions and in the event of a mass disaster. Burn surgeon shortages have also been identified, stemming, in part, from a lack of specialized burn care training opportunities. There is currently a lack of quality outcome data to support evidence-based recommendations for burn care, and burn care centers are compromised by problems obtaining reimbursement for the care of uninsured and publicly insured out-of-state burn patients. Initiatives are underway to maintain efficient burn care facilities that are fully funded, easily accessible, and most importantly, provide optimal, evidence-based care on a daily basis, and are well-equipped to handle a surge of patients during a disaster situation.

  6. Biomass burning influence on high latitude tropospheric ozone and reactive nitrogen in summer 2008: a multi-model analysis based on POLMIP simulations

    NASA Astrophysics Data System (ADS)

    Arnold, S. R.; Emmons, L. K.; Monks, S. A.; Law, K. S.; Ridley, D. A.; Turquety, S.; Tilmes, S.; Thomas, J. L.; Bouarar, I.; Flemming, J.; Huijnen, V.; Mao, J.; Duncan, B. N.; Steenrod, S.; Yoshida, Y.; Langner, J.; Long, Y.

    2014-09-01

    We have evaluated tropospheric ozone enhancement in air dominated by biomass burning emissions at high laititudes (> 50˚ N) in July 2008, using 10 global chemical transport model simulations from the POLMIP multi-model comparison exercise. In model air masses dominated by fire emissions, Δ O3/ΔCO values ranged between 0.039 and 0.196 ppbv ppbv-1 (mean: 0.113 ppbv ppbv-1) in freshly fire-influenced air, and between 0.140 and 0.261 ppbv ppbv-1 (mean: 0.193 ppbv) in more aged fire-influenced air. These values are in broad agreement with the range of observational estimates from the literature. Model ΔPAN/ΔCO enhancement ratios show distinct groupings according to the meteorological data used to drive the models. ECMWF-forced models produce larger ΔPAN/ΔCO values (4.44-6.28 pptv ppbv-1) than GEOS5-forced models (2.02-3.02 pptv ppbv-1), which we show is likely linked to differences efficiency of vertical transport during poleward export from mid-latitude source regions. Simulations of a large plume of biomass burning and anthropogenic emissions exported from Asia towards the Arctic using a Lagrangian chemical transport model show that 4 day net ozone change in the plume is sensitive to differences in plume chemical composition and plume vertical position among the POLMIP models. In particular, Arctic ozone evolution in the plume is highly sensitive to initial concentrations of PAN, as well as oxygenated VOCs (acetone, acetaldehyde), due to their role in producing the peroxyacetyl radical PAN precursor. Vertical displacement is also important due to its effects on the stability of PAN, and subsequent effect on NOx abundance. In plumes where net ozone production is limited, we find that the lifetime of ozone in the plume is sensitive to hydrogen peroxide loading, due to the production of HO2 from peroxide photolysis, and the key role of HO2 + O3 in controlling ozone loss. Overall, our results suggest that emissions from biomass burning lead to large-scale photochemical enhancement in high latitude tropospheric ozone during summer.

  7. Biomass burning influence on high-latitude tropospheric ozone and reactive nitrogen in summer 2008: a multi-model analysis based on POLMIP simulations

    NASA Astrophysics Data System (ADS)

    Arnold, S. R.; Emmons, L. K.; Monks, S. A.; Law, K. S.; Ridley, D. A.; Turquety, S.; Tilmes, S.; Thomas, J. L.; Bouarar, I.; Flemming, J.; Huijnen, V.; Mao, J.; Duncan, B. N.; Steenrod, S.; Yoshida, Y.; Langner, J.; Long, Y.

    2015-06-01

    We have evaluated tropospheric ozone enhancement in air dominated by biomass burning emissions at high latitudes (> 50° N) in July 2008, using 10 global chemical transport model simulations from the POLMIP multi-model comparison exercise. In model air masses dominated by fire emissions, ΔO3/ΔCO values ranged between 0.039 and 0.196 ppbv ppbv-1 (mean: 0.113 ppbv ppbv-1) in freshly fire-influenced air, and between 0.140 and 0.261 ppbv ppbv-1 (mean: 0.193 ppbv) in more aged fire-influenced air. These values are in broad agreement with the range of observational estimates from the literature. Model ΔPAN/ΔCO enhancement ratios show distinct groupings according to the meteorological data used to drive the models. ECMWF-forced models produce larger ΔPAN/ΔCO values (4.47 to 7.00 pptv ppbv-1) than GEOS5-forced models (1.87 to 3.28 pptv ppbv-1), which we show is likely linked to differences in efficiency of vertical transport during poleward export from mid-latitude source regions. Simulations of a large plume of biomass burning and anthropogenic emissions exported from towards the Arctic using a Lagrangian chemical transport model show that 4-day net ozone change in the plume is sensitive to differences in plume chemical composition and plume vertical position among the POLMIP models. In particular, Arctic ozone evolution in the plume is highly sensitive to initial concentrations of PAN, as well as oxygenated VOCs (acetone, acetaldehyde), due to their role in producing the peroxyacetyl radical PAN precursor. Vertical displacement is also important due to its effects on the stability of PAN, and subsequent effect on NOx abundance. In plumes where net ozone production is limited, we find that the lifetime of ozone in the plume is sensitive to hydrogen peroxide loading, due to the production of HOx from peroxide photolysis, and the key role of HO2 + O3 in controlling ozone loss. Overall, our results suggest that emissions from biomass burning lead to large-scale photochemical enhancement in high-latitude tropospheric ozone during summer.

  8. Single Droplet Combustion of Decane in Microgravity: Experiments and Numerical Modeling

    NASA Technical Reports Server (NTRS)

    Dietrich, D. L.; Struk, P. M.; Ikegam, M.; Xu, G.

    2004-01-01

    This paper presents experimental data on single droplet combustion of decane in microgravity and compares the results to a numerical model. The primary independent experiment variables are the ambient pressure and oxygen mole fraction, pressure, droplet size (over a relatively small range) and ignition energy. The droplet history (D(sup 2) history) is non-linear with the burning rate constant increasing throughout the test. The average burning rate constant, consistent with classical theory, increased with increasing ambient oxygen mole fraction and was nearly independent of pressure, initial droplet size and ignition energy. The flame typically increased in size initially, and then decreased in size, in response to the shrinking droplet. The flame standoff increased linearly for the majority of the droplet lifetime. The flame surrounding the droplet extinguished at a finite droplet size at lower ambient pressures and an oxygen mole fraction of 0.15. The extinction droplet size increased with decreasing pressure. The model is transient and assumes spherical symmetry, constant thermo-physical properties (specific heat, thermal conductivity and species Lewis number) and single step chemistry. The model includes gas-phase radiative loss and a spherically symmetric, transient liquid phase. The model accurately predicts the droplet and flame histories of the experiments. Good agreement requires that the ignition in the experiment be reasonably approximated in the model and that the model accurately predict the pre-ignition vaporization of the droplet. The model does not accurately predict the dependence of extinction droplet diameter on pressure, a result of the simplified chemistry in the model. The transient flame behavior suggests the potential importance of fuel vapor accumulation. The model results, however, show that the fractional mass consumption rate of fuel in the flame relative to fuel vaporized is close to 1.0 for all but the lowest ambient oxygen mole fractions.

  9. Sensitivity of the Plume Rise Model in the estimation of biomass burning plume injection heights in South America

    NASA Astrophysics Data System (ADS)

    Ferrada, Gonzalo A.; Freitas, Saulo; Pereira, Gabriel; Paugam, Ronan

    2017-04-01

    This study had the aim to evaluate the new developments on the Plume Rise Model (PRM), embedded into the Brazilian developments on the Regional Atmospheric Modelling System (BRAMS). PRM computes the biomass burning plume injection heights and returns that information to the host model. Then, the atmospheric model releases all the fire emissions at this height. New developments are based on the initialization data used by the PRM, using fire size and fire radiative power (FRP) from remote sensing. The main difference between the two new versions is the conversion parameter (β) used to convert from FRP to the plume convective flux. In addition, a new scheme to generate daily fire emission fluxes is offered using the fire radiative energy (computed from remote sensing) in the Brazilian Biomass Burning Emission Model (3BEM-FRE). Model results using the three versions of the PRM are compared with observed airborne CO and O3 data from the SAMBBA campaign, which took place in southern Amazonia and Cerrado (savanna-like) regions in September 2012. Results show that improvements in both 3BEM-FRE and PRM models, had a better performance in the vertical and horizontal reproduction of CO and O3 than the original versions of them, especially in the middle and upper troposphere. Nevertheless, with some difficulty to reproduce the emissions by the end of the campaign, probably due to the cumulus parameterization used, which overestimated the precipitation in the region of study. Also, developments made in the 3BEM model show better agreement with the observed remote sensing data of daily fire emissions than the original version of it in the Amazon region, but with some difficulty in the Cerrado.

  10. Infiltration and runoff generation processes in fire-affected soils

    USGS Publications Warehouse

    Moody, John A.; Ebel, Brian A.

    2014-01-01

    Post-wildfire runoff was investigated by combining field measurements and modelling of infiltration into fire-affected soils to predict time-to-start of runoff and peak runoff rate at the plot scale (1 m2). Time series of soil-water content, rainfall and runoff were measured on a hillslope burned by the 2010 Fourmile Canyon Fire west of Boulder, Colorado during cyclonic and convective rainstorms in the spring and summer of 2011. Some of the field measurements and measured soil physical properties were used to calibrate a one-dimensional post-wildfire numerical model, which was then used as a ‘virtual instrument’ to provide estimates of the saturated hydraulic conductivity and high-resolution (1 mm) estimates of the soil-water profile and water fluxes within the unsaturated zone.Field and model estimates of the wetting-front depth indicated that post-wildfire infiltration was on average confined to shallow depths less than 30 mm. Model estimates of the effective saturated hydraulic conductivity, Ks, near the soil surface ranged from 0.1 to 5.2 mm h−1. Because of the relatively small values of Ks, the time-to-start of runoff (measured from the start of rainfall),  tp, was found to depend only on the initial soil-water saturation deficit (predicted by the model) and a measured characteristic of the rainfall profile (referred to as the average rainfall acceleration, equal to the initial rate of change in rainfall intensity). An analytical model was developed from the combined results and explained 92–97% of the variance of  tp, and the numerical infiltration model explained 74–91% of the variance of the peak runoff rates. These results are from one burned site, but they strongly suggest that  tp in fire-affected soils (which often have low values of Ks) is probably controlled more by the storm profile and the initial soil-water saturation deficit than by soil hydraulic properties.

  11. Role of burning season on initial understory vegetation response to prescribed fire in a mixed conifer forest

    Treesearch

    Eric E. Knapp; Dylan W. Schwilk; Jeffrey M. Kane; Jon E. Keeley

    2007-01-01

    Although the majority of fires in the western United States historically occurred during the late summer or early fall when fuels were dry and plants were dormant or nearly so, early-season prescribed burns are often ignited when fuels are still moist and plants are actively growing. The purpose of this study was to determine if burn season influences postfire...

  12. 40 CFR 63.7510 - What are my initial compliance requirements and by what date must I conduct them?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for each type of fuel burned in your boiler or process heater according to § 63.7521 and Table 6 to... conducting CMS performance evaluations according to § 63.7525. For affected sources that burn a single type... each type of fuel burned in your boiler or process heater according to § 63.7521 and Table 6 to this...

  13. 40 CFR 63.7510 - What are my initial compliance requirements and by what date must I conduct them?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for each type of fuel burned in your boiler or process heater according to § 63.7521 and Table 6 to... conducting CMS performance evaluations according to § 63.7525. For affected sources that burn a single type... each type of fuel burned in your boiler or process heater according to § 63.7521 and Table 6 to this...

  14. 40 CFR 63.7510 - What are my initial compliance requirements and by what date must I conduct them?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for each type of fuel burned in your boiler or process heater according to § 63.7521 and Table 6 to... conducting CMS performance evaluations according to § 63.7525. For affected sources that burn a single type... each type of fuel burned in your boiler or process heater according to § 63.7521 and Table 6 to this...

  15. Understanding and predicting the dynamics of tokamak discharges during startup and rampdown

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jackson, G. L.; Politzer, P. A.; Humphreys, D. A.

    Understanding the dynamics of plasma startup and termination is important for present tokamaks and for predictive modeling of future burning plasma devices such as ITER. We report on experiments in the DIII-D tokamak that explore the plasma startup and rampdown phases and on the benchmarking of transport models. Key issues have been examined such as plasma initiation and burnthrough with limited inductive voltage and achieving flattop and maximum burn within the technical limits of coil systems and their actuators while maintaining the desired q profile. Successful rampdown requires scenarios consistent with technical limits, including controlled H-L transitions, while avoiding verticalmore » instabilities, additional Ohmic transformer flux consumption, and density limit disruptions. Discharges were typically initiated with an inductive electric field typical of ITER, 0.3 V/m, most with second harmonic electron cyclotron assist. A fast framing camera was used during breakdown and burnthrough of low Z impurity charge states to study the formation physics. An improved 'large aperture' ITER startup scenario was developed, and aperture reduction in rampdown was found to be essential to avoid instabilities. Current evolution using neoclassical conductivity in the CORSICA code agrees with rampup experiments, but the prediction of the temperature and internal inductance evolution using the Coppi-Tang model for electron energy transport is not yet accurate enough to allow extrapolation to future devices.« less

  16. A Burning Rate Emulator (BRE) for Study in Microgravity

    NASA Technical Reports Server (NTRS)

    Markan, A.; Sunderland, P. B.; Quintiere, J. G.; DeRis, J.; Stocker, D. P.

    2015-01-01

    A gas-fueled burner, the Burning Rate Emulator (BRE), is used to emulate condensed-phase fuel flames. The design has been validated to easily measure the burning behavior of condensed-phase fuels by igniting a controlled stream of gas fuel and diluent. Four properties, including the heat of combustion, the heat of gasification, the surface temperature, and the laminar smoke point, are assumed to be sufficient to define the steady burning rate of a condensed-phase fuel. The heat of gasification of the fuel is determined by measuring the heat flux and the fuel flow rate. Microgravity BRE tests in the NASA 5.2 s drop facility have examined the burning of pure methane and ethylene (pure and 50 in N2 balance). Fuel flow rates, chamber oxygen concentration and initial pressure have been varied. Two burner sizes, 25 and 50 mm respectively, are chosen to examine the nature of initial microgravity burning. The tests reveal bubble-like flames that increase within the 5.2s drop but the heat flux received from the flame appears to asymptotically approach steady state. Portions of the methane flames appear to locally detach and extinguish at center, while its shape remains fixed, but growing. The effective heat of gasification is computed from the final measured net heat flux and the fuel flow rate under the assumption of an achieved steady burning. Heat flux (or mass flux) and flame position are compared with stagnant layer burning theory. The analysis offers the prospect of more complete findings from future longer duration ISS experiments.

  17. Scar formation following excisional and burn injuries in a red Duroc pig model.

    PubMed

    Blackstone, Britani N; Kim, Jayne Y; McFarland, Kevin L; Sen, Chandan K; Supp, Dorothy M; Bailey, J Kevin; Powell, Heather M

    2017-08-01

    Scar research is challenging because rodents do not naturally form excessive scars, and burn depth, size, and location cannot be controlled in human longitudinal studies. The female, red Duroc pig model has been shown to form robust scars with biological and anatomical similarities to human hypertrophic scars. To more closely mimic the mode of injury, recreate the complex chemical milieu of the burn wound environment and enhance scar development, an animal model of excessive burn-induced scarring was developed and compared with the more commonly used model, which involves excisional wounds created via dermatome. Standardized, full-thickness thermal wounds were created on the dorsum of female, red Duroc pigs. Wounds for the dermatome model were created using two different total dermatome settings: ∼1.5 mm and ≥ 1.9 mm. Results from analysis over 150 days showed that burn wounds healed at much slower rate and contracted more significantly than dermatome wounds of both settings. The burn scars were hairless, had mixed pigmentation, and displayed fourfold and twofold greater excess erythema values, respectively, compared with ∼1.5 mm and ≥ 1.9 mm deep dermatome injuries. Burn scars were less elastic, less pliable, and weaker than scars resulting from excisional injuries. Decorin and versican gene expression levels were elevated in the burn group at day 150 compared with both dermatome groups. In addition, transforming growth factor-beta 1 was significantly up-regulated in the burn group vs. the ∼1.5 mm deep dermatome group at all time points, and expression remained significantly elevated vs. both dermatome groups at day 150. Compared with scars from dermatome wounds, the burn scar model described here demonstrates greater similarity to human hypertrophic scar. Thus, this burn scar model may provide an improved platform for studying the pathophysiology of burn-related hypertrophic scarring, investigating current anti-scar therapies, and development of new strategies with greater clinical benefit. © 2017 by the Wound Healing Society.

  18. Detection of Circulating Mucorales DNA in Critically Ill Burn Patients: Preliminary Report of a Screening Strategy for Early Diagnosis and Treatment.

    PubMed

    Legrand, Matthieu; Gits-Muselli, Maud; Boutin, Louis; Garcia-Hermoso, Dea; Maurel, Véronique; Soussi, Sabri; Benyamina, Mourad; Ferry, Axelle; Chaussard, Maïté; Hamane, Samia; Denis, Blandine; Touratier, Sophie; Guigue, Nicolas; Fréalle, Emilie; Jeanne, Mathieu; Shaal, Jean-Vivien; Soler, Charles; Mimoun, Maurice; Chaouat, Marc; Lafaurie, Matthieu; Mebazaa, Alexandre; Bretagne, Stéphane; Alanio, Alexandre

    2016-11-15

     Invasive wound mucormycosis (IWM) is associated with an extremely poor outcome among critically ill burn patients. We describe the detection of circulating Mucorales DNA (cmDNA) for the early diagnosis of IWM in those patients and report the potential value of detecting cmDNA for treatment guidance.  Severely ill burn patients admitted to our tertiary referral center between October 2013 and February 2016 were included. Retrospective plasma samples were tested for the presence of cmDNA by quantitative real-time polymerase chain reaction (qPCR). Patients were then prospectively screened twice a week, and liposomal amphotericin-B therapy initiated based on a positive qPCR. The primary endpoint was the time between cmDNA detection and standard diagnosis. Secondary endpoints were the time from cmDNA detection and treatment initiation and mortality.  Seventy-seven patients (418 samples) were included. The average age was 46 (28-60) years, abbreviated burn severity index was 8 (7-10), and simplified acute physiology score was 33 (23-46). The total body surface area was 33% (22%-52%). cmDNA was detected 11 (4.5-15) days before standard diagnosis. The in-hospital mortality was 62% for patients with IWM and 24% for those without (P = .03). The mortality due to IWM was 80% during period A and 33% during period B (P = .46).  This study suggests that the detection of cmDNA allows earlier diagnosis of IWM in severely ill burn patients and earlier initiation of treatment. Further studies are needed to confirm the impact of earlier treatment initiation on patient outcome. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  19. 49 CFR 173.50 - Class 1-Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... insensitive that there is very little probability of initiation or of transition from burning to detonation under normal conditions of transport. 1 The probability of transition from burning to detonation is... contain only extremely insensitive detonating substances and which demonstrate a negligible probability of...

  20. EMISSIONS FROM BURNING CABINET MAKING SCRAPS

    EPA Science Inventory

    The report gives results of an initial determination of differences in missions when burning ordinary cordwood compared to kitchen cabinet making scraps. he tests were performed in an instrumented woodstove testing laboratory on a stove that simulated units observed in use at a k...

  1. Modeling hydrologic and geomorphic hazards across post-fire landscapes using a self-organizing map approach

    USGS Publications Warehouse

    Friedel, Michael J.

    2011-01-01

    Few studies attempt to model the range of possible post-fire hydrologic and geomorphic hazards because of the sparseness of data and the coupled, nonlinear, spatial, and temporal relationships among landscape variables. In this study, a type of unsupervised artificial neural network, called a self-organized map (SOM), is trained using data from 540 burned basins in the western United States. The sparsely populated data set includes variables from independent numerical landscape categories (climate, land surface form, geologic texture, and post-fire condition), independent landscape classes (bedrock geology and state), and dependent initiation processes (runoff, landslide, and runoff and landslide combination) and responses (debris flows, floods, and no events). Pattern analysis of the SOM-based component planes is used to identify and interpret relations among the variables. Application of the Davies-Bouldin criteria following k-means clustering of the SOM neurons identified eight conceptual regional models for focusing future research and empirical model development. A split-sample validation on 60 independent basins (not included in the training) indicates that simultaneous predictions of initiation process and response types are at least 78% accurate. As climate shifts from wet to dry conditions, forecasts across the burned landscape reveal a decreasing trend in the total number of debris flow, flood, and runoff events with considerable variability among individual basins. These findings suggest the SOM may be useful in forecasting real-time post-fire hazards, and long-term post-recovery processes and effects of climate change scenarios.

  2. Community integration after burn injuries.

    PubMed

    Esselman, P C; Ptacek, J T; Kowalske, K; Cromes, G F; deLateur, B J; Engrav, L H

    2001-01-01

    Evaluation of community integration is a meaningful outcome criterion after major burn injury. The Community Integration Questionnaire (CIQ) was administered to 463 individuals with major burn injuries. The CIQ results in Total, Home Integration, Social Integration, and Productivity scores. The purposes of this study were to determine change in CIQ scores over time and what burn injury and demographic factors predict CIQ scores. The CIQ scores did not change significantly from 6 to 12 to 24 months postburn injury. Home integration scores were best predicted by sex and living situation; Social Integration scores by marital status; and Productivity scores by functional outcome, burn severity, age, and preburn work factors. The data demonstrate that individuals with burn injuries have significant difficulties with community integration due to burn and nonburn related factors. CIQ scores did not improve over time but improvement may have occurred before the initial 6-month postburn injury follow-up in this study.

  3. Numerical Simulation of Shock-Dispersed Fuel Charges

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bell, John B.; Day, Marcus; Beckner, Vincent

    Successfully attacking underground storage facilities for chemical and biological (C/B) weapons is an important mission area for the Department of Defense. The fate of a C/B agent during an attack depends critically on the pressure and thermal environment that the agent experiences. The initial environment is determined by the blast wave from an explosive device. The byproducts of the detonation provide a fuel source that burn when mixed with oxidizer (after burning). Additional energy can be released by the ignition of the C/B agent as it mixes with the explosion products and the air in the chamber. Hot plumes ventingmore » material from any openings in the chamber can provide fuel for additional energy release when mixed with additional oxidizer. Assessment of the effectiveness of current explosives as well as the development of new explosive systems requires a detailed understanding of all of these modes of energy release. Using methodologies based on the use of higher-order Godunov schemes combined with Adaptive Mesh Refinement (AMR), implemented in a parallel adaptive framework suited to the massively parallel computer systems provided by the DOD High-Performance Computing Modernization program, we use a suite of programs to develop predictive models for the simulation of the energetics of blast waves, deflagration waves and ejecta plumes. The programs use realistic reaction kinetic and thermodynamic models provided by standard components (such as CHEMKIN) as well as other novel methods to model enhanced explosive devices. The work described here focuses on the validation of these models against a series of bomb calorimetry experiments performed at the Ernst-Mach Institute. In this paper, we present three-dimensional simulations of the experiments, examining the explosion dynamics and the role of subsequent burning on the explosion products on the thermal and pressure environment within the calorimeter. The effects of burning are quantified by comparing two sets of computations, one in which the calorimeter is filled with nitrogen so there is no after burning and a second in which the calorimeter contains air.« less

  4. Recent Advances In Science Support For Isolated Droplet Combustion Experiments

    NASA Technical Reports Server (NTRS)

    Dryer, F. L.; Kazakov, A.; Urban, B. D.; Kroenlein, K.

    2003-01-01

    In a joint program involving Prof. F.A. Williams of the University of California, San Diego and Dr. V. Nayagam of the National Center for Microgravity Research, the combustion characteristics of isolated liquid fuel droplets of n-heptane, n-decane, methanol, methanol-water, ethanol and ethanol-water having initial diameters between about 1 mm and 6 mm continues to be investigated. The objectives of the work are to improve fundamental knowledge of droplet combustion dynamics for pure fuels and fuel-water mixtures through microgravity experiments and theoretical analyses. The Princeton contributions support the engineering design, data analysis, and data interpretation requirements for the study of initially single component, spherically symmetric, isolated droplet combustion studies through experiments and numerical modeling. UCSD contributions are described in a companion communication in this conference. The Princeton effort also addresses the analyses of Fiber Supported Droplet Combustion (FSDC) experiments conducted with the above fuels and collaborative work with others who are investigating droplet combustion in the presence of steady convection. A thorough interpretation of droplet burning behavior for n-heptane and n-decane over a relatively wide range of conditions also involves the influences of sooting on the combustion behavior, and this particular aspect on isolated burning of droplets is under consideration in a collaborative program underway with Drexel University. This collaboration is addressed in another communication at this conference. The one-dimensional, time-dependent, numerical modeling approach that we have continued to evolve for analyzing isolated, quiescent droplet combustion data has been further applied to investigate several facets of isolated droplet burning of simple alcohols, n-heptane, and n-decane. Some of the new results are described below.

  5. Expression and activity levels of chymase in mast cells of burn wound tissues increase during the healing process in a hamster model.

    PubMed

    Dong, Xianglin; Xu, Tao; Ma, Shaolin; Wen, Hao

    2015-06-01

    The present study aimed to investigate the changes in the expression levels and activity of mast cell chymase in the process of burn wound healing in a hamster model of deep second-degree burn. The hamster model was established by exposing a ~3 cm diameter area of bare skin to hot water (75°C) for 0, 6, 8, 10 or 12 sec. Tissue specimens were collected 24 h after burning and histological analysis revealed that hot water contact for 12 sec was required to produce a deep second-degree burn. Quantitative polymerase chain reaction and a radioimmunoassay were used to the determine changes in chymase mRNA expression levels and activity. The mRNA expression levels and activity of chymase were increased in the burn wound tissues when compared with the normal skin. However, no statistically significant differences were observed in mast cell chymase activity amongst the various post-burn stages. Chymase mRNA expression levels peaked at day 1 post-burn, subsequently decreasing at days 3 and 7 post-burn and finally increasing again at day 14 post-burn. In summary, a hamster model of deep second-degree burn can be created by bringing the skin into contact with water at 75°C for 12 sec. Furthermore, the mRNA expression levels and activity of chymase in the burn wound tissues increased when compared with those in normal skin tissues.

  6. Expression and activity levels of chymase in mast cells of burn wound tissues increase during the healing process in a hamster model

    PubMed Central

    DONG, XIANGLIN; XU, TAO; MA, SHAOLIN; WEN, HAO

    2015-01-01

    The present study aimed to investigate the changes in the expression levels and activity of mast cell chymase in the process of burn wound healing in a hamster model of deep second-degree burn. The hamster model was established by exposing a ~3 cm diameter area of bare skin to hot water (75°C) for 0, 6, 8, 10 or 12 sec. Tissue specimens were collected 24 h after burning and histological analysis revealed that hot water contact for 12 sec was required to produce a deep second-degree burn. Quantitative polymerase chain reaction and a radioimmunoassay were used to the determine changes in chymase mRNA expression levels and activity. The mRNA expression levels and activity of chymase were increased in the burn wound tissues when compared with the normal skin. However, no statistically significant differences were observed in mast cell chymase activity amongst the various post-burn stages. Chymase mRNA expression levels peaked at day 1 post-burn, subsequently decreasing at days 3 and 7 post-burn and finally increasing again at day 14 post-burn. In summary, a hamster model of deep second-degree burn can be created by bringing the skin into contact with water at 75°C for 12 sec. Furthermore, the mRNA expression levels and activity of chymase in the burn wound tissues increased when compared with those in normal skin tissues. PMID:26136958

  7. Using Logistic Regression to Predict the Probability of Debris Flows in Areas Burned by Wildfires, Southern California, 2003-2006

    USGS Publications Warehouse

    Rupert, Michael G.; Cannon, Susan H.; Gartner, Joseph E.; Michael, John A.; Helsel, Dennis R.

    2008-01-01

    Logistic regression was used to develop statistical models that can be used to predict the probability of debris flows in areas recently burned by wildfires by using data from 14 wildfires that burned in southern California during 2003-2006. Twenty-eight independent variables describing the basin morphology, burn severity, rainfall, and soil properties of 306 drainage basins located within those burned areas were evaluated. The models were developed as follows: (1) Basins that did and did not produce debris flows soon after the 2003 to 2006 fires were delineated from data in the National Elevation Dataset using a geographic information system; (2) Data describing the basin morphology, burn severity, rainfall, and soil properties were compiled for each basin. These data were then input to a statistics software package for analysis using logistic regression; and (3) Relations between the occurrence or absence of debris flows and the basin morphology, burn severity, rainfall, and soil properties were evaluated, and five multivariate logistic regression models were constructed. All possible combinations of independent variables were evaluated to determine which combinations produced the most effective models, and the multivariate models that best predicted the occurrence of debris flows were identified. Percentage of high burn severity and 3-hour peak rainfall intensity were significant variables in all models. Soil organic matter content and soil clay content were significant variables in all models except Model 5. Soil slope was a significant variable in all models except Model 4. The most suitable model can be selected from these five models on the basis of the availability of independent variables in the particular area of interest and field checking of probability maps. The multivariate logistic regression models can be entered into a geographic information system, and maps showing the probability of debris flows can be constructed in recently burned areas of southern California. This study demonstrates that logistic regression is a valuable tool for developing models that predict the probability of debris flows occurring in recently burned landscapes.

  8. Development of Erosive Burning Models for CFD Predictions of Solid Rocket Motor Internal Environments

    NASA Technical Reports Server (NTRS)

    Wang, Qun-Zhen

    2003-01-01

    Four erosive burning models, equations (11) to (14). are developed in this work by using a power law relationship to correlate (1) the erosive burning ratio and the local velocity gradient at propellant surfaces; (2) the erosive burning ratio and the velocity gradient divided by centerline velocity; (3) the erosive burning difference and the local velocity gradient at propellant surfaces; and (4) the erosive burning difference and the velocity gradient divided by centerline velocity. These models depend on the local velocity gradient at the propellant surface (or the velocity gradient divided by centerline velocity) only and, unlike other empirical models, are independent of the motor size. It was argued that, since the erosive burning is a local phenomenon occurring near the surface of the solid propellant, the erosive burning ratio should be independent of the bore diameter if it is correlated with some local flow parameters such as the velocity gradient at the propellant surface. This seems to be true considering the good results obtained by applying these models, which are developed from the small size 5 inch CP tandem motor testing, to CFD simulations of much bigger motors.

  9. Early anticoagulation therapy for severe burns complicated by inhalation injury in a rabbit model

    PubMed Central

    Fu, Zhong-Hua; Guo, Guang-Hua; Xiong, Zhen-Fang; Liao, Xincheng; Liu, Ming-Zhuo; Luo, Jinhua

    2017-01-01

    The aim of the present study was to determine the effects of early anticoagulation treatment on severe burns complicated by inhalation injury in a rabbit model. Under anesthetization, an electrical burns instrument (100°C) was used to scald the backs of rabbits for 15 sec, which established a 30% III severe burns model. Treatment of the rabbits with early anticoagulation effectively improved the severe burns complicated by inhalation injury-induced lung injury, reduced PaO2, PaCO2 and SPO2 levels, suppressed the expression of tumor necrosis factor-α, interleukin (IL)-1β and IL-6, and increased the activity of IL-10. In addition, it was found that early anticoagulation treatment effectively suppressed the activities of caspase-3 and caspase-9, upregulated the protein expression of vascular endothelial growth factor (VEGF) and decreased the protein expression of protease-activated receptor 1 (PAR1) in the severe burns model. It was concluded that early anticoagulation treatment affected the severe burns complicated by inhalation injury in a rabbit model through the upregulation of VEGF and downregulation of PAR1 signaling pathways. Thus, early anticoagulation is a potential therapeutic option for severe burns complicated by inhalation injury. PMID:28944866

  10. [Major Burn Trauma Management and Nursing Care].

    PubMed

    Lo, Shu-Fen

    2015-08-01

    Major burn injury is one of the most serious and often life-threatening forms of trauma. Burn patients not only suffer from the physical, psychological, social and spiritual impacts of their injury but also experience considerable changes in health-related quality of life. This paper presents a review of the literature on the implications of previous research and clinical care guidelines related to major burn injuries in order to help clinical practice nurses use evidence-based care guidelines to respond to initial injury assessments, better manage the complex systemic response to these injuries, and provide specialist wound care, emotional support, and rehabilitation services.

  11. Measurement and reactive burn modeling of the shock to detonation transition for the HMX based explosive LX-14

    NASA Astrophysics Data System (ADS)

    Jones, J. D.; Ma, Xia; Clements, B. E.; Gibson, L. L.; Gustavsen, R. L.

    2017-06-01

    Gas-gun driven plate-impact techniques were used to study the shock to detonation transition in LX-14 (95.5 weight % HMX, 4.5 weight % estane binder). The transition was recorded using embedded electromagnetic particle velocity gauges. Initial shock pressures, P, ranged from 2.5 to 8 GPa and the resulting distances to detonation, xD, were in the range 1.9 to 14 mm. Numerical simulations using the SURF reactive burn scheme coupled with a linear US -up / Mie-Grueneisen equation of state for the reactant and a JWL equation of state for the products, match the experimental data well. Comparison of simulation with experiment as well as the ``best fit'' parameter set for the simulations is presented.

  12. The treatment effect of the burn wound healing by electrolytic-reduction ion water lotion combination therapy. Part 2: Two degree burn of forearm to the dorsum of the hand.

    PubMed

    Shu, Tetsuo; Okajima, Masahiro; Wada, Yuko; Shimokawa, Ken-ichi; Ishii, Fumiyoshi

    2010-10-01

    Patient 1: A 1-year-and-3-month-old boy suffered a burn injury extending from the left forearm to hand due to boiling water. An extensive skin defect from the left forearm to the dorsum of the hand was observed, and an IIb-III degree burn was diagnosed. Treatment of the burn was started with the application of electrolytic-reduction ion water (ERI) lotion, antibiotic/steroid combination ointment, and vitamin A/E ointment with wrap therapy. Two days after the initiation of therapy, redness and swelling were still observed despite a slight decrease in swelling. After 21 days, skin redness decreased, and there was no functional impairment. After 74 days, the skin color was almost normal, and no functional impairment was observed, showing a favorable course. Patient 2: An 8.5-month-old girl suffered a burn injury extending from the fingers to dorsum of the right hand and right wrist due to boiling water. There was an extensive skin defect accompanied by bulla formation extending from the fingers and dorsum of the right hand. An II-degree burn was diagnosed. Treatment of the burn was started treatment similar to the Patient 1. Bulla decreased, but redness and swelling were still present 2-8 days after the initiation of therapy. After 16-25 days, both skin redness and swelling decreased. After 30 days, the epithelialization of the dorsum of the hand had almost completed. After 60 days, the skin color was nearly normal, and there was no functional impairment, showing a favorable course. In these patients, burn wounds completely healed without hypertrophic or keloid scar formation or pigmentation. These results suggest that extensive II-III burns can be adequately treated by this topical therapy.

  13. Sugarcane cultural practices to increase profits

    USDA-ARS?s Scientific Manuscript database

    Multiple experiments were initiated in an effort to reduce costs, increase ratooning, and maximize profits. A new method of mechanical removal using a modified rake produced yields similarly to burning, with both yielding an additional 1000 lbs/A than full retention. Where burning was not an option,...

  14. Total inpatient treatment costs in patients with severe burns: towards a more accurate reimbursement model.

    PubMed

    Mehra, Tarun; Koljonen, Virve; Seifert, Burkhardt; Volbracht, Jörk; Giovanoli, Pietro; Plock, Jan; Moos, Rudolf Maria

    2015-01-01

    Reimbursement systems have difficulties depicting the actual cost of burn treatment, leaving care providers with a significant financial burden. Our aim was to establish a simple and accurate reimbursement model compatible with prospective payment systems. A total of 370 966 electronic medical records of patients discharged in 2012 to 2013 from Swiss university hospitals were reviewed. A total of 828 cases of burns including 109 cases of severe burns were retained. Costs, revenues and earnings for severe and nonsevere burns were analysed and a linear regression model predicting total inpatient treatment costs was established. The median total costs per case for severe burns was tenfold higher than for nonsevere burns (179 949 CHF [167 353 EUR] vs 11 312 CHF [10 520 EUR], interquartile ranges 96 782-328 618 CHF vs 4 874-27 783 CHF, p <0.001). The median of earnings per case for nonsevere burns was 588 CHF (547 EUR) (interquartile range -6 720 - 5 354 CHF) whereas severe burns incurred a large financial loss to care providers, with median earnings of -33 178 CHF (30 856 EUR) (interquartile range -95 533 - 23 662 CHF). Differences were highly significant (p <0.001). Our linear regression model predicting total costs per case with length of stay (LOS) as independent variable had an adjusted R2 of 0.67 (p <0.001 for LOS). Severe burns are systematically underfunded within the Swiss reimbursement system. Flat-rate DRG-based refunds poorly reflect the actual treatment costs. In conclusion, we suggest a reimbursement model based on a per diem rate for treatment of severe burns.

  15. Preliminary Assessment Of The Burning Dynamics Of Jp8 Droplets In Microgravity

    NASA Technical Reports Server (NTRS)

    Bae, J. H.; Avedisian, C. T.

    2003-01-01

    In this report we present new data for fuel droplet combustion in microgravity to examine the influence of ambient gas and fuel composition on flame structure and sooting dynamics for droplets with initial diameters in the range of 0.4mm to 0.5mm. The fuels are JP8 (a kerosene derivative) and nonane. The ambient gas is air and a mixture of 30% oxygen and 70% helium, the latter having been examined for burning under conditions where soot formation is minimal. Some data at elevated pressures are also reported. The burning process shows a nonlinear D2 progression which is independent of soot formation as burning in a helium inert showed the same nonlinear trend. Flames were proportionally farther from the droplet surface in helium than they were in air. A nondimensional parameter is presented that consolidates the three standoff distances for the droplet, flame and soot shell diameters within the initial diameter ranges examined.

  16. Reliability enhancement through optimal burn-in

    NASA Astrophysics Data System (ADS)

    Kuo, W.

    1984-06-01

    A numerical reliability and cost model is defined for production line burn-in tests of electronic components. The necessity of burn-in is governed by upper and lower bounds: burn-in is mandatory for operation-critical or nonreparable component; no burn-in is needed when failure effects are insignificant or easily repairable. The model considers electronic systems in terms of a series of components connected by a single black box. The infant mortality rate is described with a Weibull distribution. Performance reaches a steady state after burn-in, and the cost of burn-in is a linear function for each component. A minimum cost is calculated among the costs and total time of burn-in, shop repair, and field repair, with attention given to possible losses in future sales from inadequate burn-in testing.

  17. 77 FR 18297 - Air Traffic Noise, Fuel Burn, and Emissions Modeling Using the Aviation Environmental Design Tool...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ... Integrated Routing System-- NIRS].'' The FAA developed the AEDT 2a to model aircraft noise, fuel burn, and... operations schedule. These data are used to compute aircraft noise, fuel burn and emissions simultaneously... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Noise, Fuel Burn, and...

  18. Evaluating post-wildfire hydrologic recovery using ParFlow in southern California

    NASA Astrophysics Data System (ADS)

    Lopez, S. R.; Kinoshita, A. M.; Atchley, A. L.

    2016-12-01

    Wildfires are naturally occurring hazards that can have catastrophic impacts. They can alter the natural processes within a watershed, such as surface runoff and subsurface water storage. Generally, post-fire hydrologic models are either one-dimensional, empirically-based models, or two-dimensional, conceptually-based models with lumped parameter distributions. These models are useful in providing runoff measurements at the watershed outlet; however, do not provide distributed hydrologic simulation at each point within the watershed. This research demonstrates how ParFlow, a three-dimensional, distributed hydrologic model can simulate post-fire hydrologic processes by representing soil burn severity (via hydrophobicity) and vegetation recovery as they vary both spatially and temporally. Using this approach, we are able to evaluate the change in post-fire water components (surface flow, lateral flow, baseflow, and evapotranspiration). This model is initially developed for a hillslope in Devil Canyon, burned in 2003 by the Old Fire in southern California (USA). The domain uses a 2m-cell size resolution over a 25 m by 25 m lateral extent. The subsurface reaches 2 m and is assigned a variable cell thickness, allowing an explicit consideration of the soil burn severity throughout the stages of recovery and vegetation regrowth. Vegetation regrowth is incorporated represented by satellite-based Enhanced Vegetation Index (EVI) products. The pre- and post-fire surface runoff, subsurface storage, and surface storage interactions are evaluated and will be used as a basis for developing a watershed-scale model. Long-term continuous simulations will advance our understanding of post-fire hydrological partitioning between water balance components and the spatial variability of watershed processes, providing improved guidance for post-fire watershed management.

  19. Double-detonation Sub-Chandrasekhar Supernovae: Synthetic Observables for Minimum Helium Shell Mass Models

    NASA Astrophysics Data System (ADS)

    Kromer, M.; Sim, S. A.; Fink, M.; Röpke, F. K.; Seitenzahl, I. R.; Hillebrandt, W.

    2010-08-01

    In the double-detonation scenario for Type Ia supernovae, it is suggested that a detonation initiates in a shell of helium-rich material accreted from a companion star by a sub-Chandrasekhar-mass white dwarf. This shell detonation drives a shock front into the carbon-oxygen white dwarf that triggers a secondary detonation in the core. The core detonation results in a complete disruption of the white dwarf. Earlier studies concluded that this scenario has difficulties in accounting for the observed properties of Type Ia supernovae since the explosion ejecta are surrounded by the products of explosive helium burning in the shell. Recently, however, it was proposed that detonations might be possible for much less massive helium shells than previously assumed (Bildsten et al.). Moreover, it was shown that even detonations of these minimum helium shell masses robustly trigger detonations of the carbon-oxygen core (Fink et al.). Therefore, it is possible that the impact of the helium layer on observables is less than previously thought. Here, we present time-dependent multi-wavelength radiative transfer calculations for models with minimum helium shell mass and derive synthetic observables for both the optical and γ-ray spectral regions. These differ strongly from those found in earlier simulations of sub-Chandrasekhar-mass explosions in which more massive helium shells were considered. Our models predict light curves that cover both the range of brightnesses and the rise and decline times of observed Type Ia supernovae. However, their colors and spectra do not match the observations. In particular, their B - V colors are generally too red. We show that this discrepancy is mainly due to the composition of the burning products of the helium shell of the Fink et al. models which contain significant amounts of titanium and chromium. Using a toy model, we also show that the burning products of the helium shell depend crucially on its initial composition. This leads us to conclude that good agreement between sub-Chandrasekhar-mass explosions and observed Type Ia supernovae may still be feasible but further study of the shell properties is required.

  20. AFIRM-Wake Forest/University of Pittsburgh Consortium

    DTIC Science & Technology

    2012-07-01

    therapy for infected burn wounds using Lactobacillu s was applied to a new m ouse model and is capable of rescuing the anim al from burn wound induced... Lactobacillus to reduce scar from burn wound infection. We have tested bacteriotherapy with Lactobacillus in a rabbit model of Pseudomonas-infected burn...probiotic therapy with Lactobacillus is sufficient to attenuate the length and severity of a Pseudo monal infection of the burn wound, and that this

  1. Topical Modulation of the Burn Wound Inflammatory Response to Improve Short and Long Term Outcomes

    DTIC Science & Technology

    2017-10-01

    casualty, treatment, organ failure, systemic inflammatory response syndrome , thermal injury, wound model, intervention 3. ACCOMPLISHMENTS:   What...thickness burns have a blister response. Using human eye or H&E studies, we did not observe any blisters in the pig model. However, the OCT...the deeper the partial thickness burn, the bigger the blister, until it gets close to full-thickness burns. The full-thickness burns are dry and

  2. Biomass burning CCN enhance the dynamics of a mesoscale convective system over the La Plata Basin: a numerical approach

    NASA Astrophysics Data System (ADS)

    Camponogara, Gláuber; Assunção Faus da Silva Dias, Maria; Carrió, Gustavo G.

    2018-02-01

    High aerosol loadings are discharged into the atmosphere every year by biomass burning in the Amazon and central Brazil during the dry season (July-December). These particles, suspended in the atmosphere, can be carried via a low-level jet toward the La Plata Basin, one of the largest hydrographic basins in the world. Once they reach this region, the aerosols can affect mesoscale convective systems (MCSs), whose frequency is higher during the spring and summer over the basin. The present study is one of the first that seeks to understand the microphysical effects of biomass burning aerosols from the Amazon Basin on mesoscale convective systems over the La Plata Basin. We performed numerical simulations initialized with idealized cloud condensation nuclei (CCN) profiles for an MCS case observed over the La Plata Basin on 21 September 2010. The experiments reveal an important link between CCN number concentration and MCS dynamics, where stronger downdrafts were observed under higher amounts of aerosols, generating more updraft cells in response. Moreover, the simulations show higher amounts of precipitation as the CCN concentration increases. Despite the model's uncertainties and limitations, these results represent an important step toward the understanding of possible impacts on the Amazon biomass burning aerosols over neighboring regions such as the La Plata Basin.

  3. In vitro burn model illustrating heat conduction patterns using compressed thermal papers.

    PubMed

    Lee, Jun Yong; Jung, Sung-No; Kwon, Ho

    2015-01-01

    To date, heat conduction from heat sources to tissue has been estimated by complex mathematical modeling. In the present study, we developed an intuitive in vitro skin burn model that illustrates heat conduction patterns inside the skin. This was composed of tightly compressed thermal papers with compression frames. Heat flow through the model left a trace by changing the color of thermal papers. These were digitized and three-dimensionally reconstituted to reproduce the heat conduction patterns in the skin. For standardization, we validated K91HG-CE thermal paper using a printout test and bivariate correlation analysis. We measured the papers' physical properties and calculated the estimated depth of heat conduction using Fourier's equation. Through contact burns of 5, 10, 15, 20, and 30 seconds on porcine skin and our burn model using a heated brass comb, and comparing the burn wound and heat conduction trace, we validated our model. The heat conduction pattern correlation analysis (intraclass correlation coefficient: 0.846, p < 0.001) and the heat conduction depth correlation analysis (intraclass correlation coefficient: 0.93, p < 0.001) showed statistically significant high correlations between the porcine burn wound and our model. Our model showed good correlation with porcine skin burn injury and replicated its heat conduction patterns. © 2014 by the Wound Healing Society.

  4. Role of burning season on initial understory vegetation response to prescribed fire in a mixed conifer forest

    USGS Publications Warehouse

    Knapp, E.E.; Schwilk, D.W.; Kane, J.M.; Keeley, J.E.

    2007-01-01

    Although the majority of fires in the western United States historically occurred during the late summer or early fall when fuels were dry and plants were dormant or nearly so, early-season prescribed burns are often ignited when fuels are still moist and plants are actively growing. The purpose of this study was to determine if burn season influences postfire vegetation recovery. Replicated early-season burn, late-season burn, and unburned control units were established in a mixed conifer forest, and understory vegetation was evaluated before and after treatment. Vegetation generally recovered rapidly after prescribed burning. However, late-season burns resulted in a temporary but significant drop in cover and a decline in species richness at the 1 m 2 scale in the following year. For two of the several taxa that were negatively affected by burning, the reduction in frequency was greater after late-season than early-season burns. Early-season burns may have moderated the effect of fire by consuming less fuel and lessening the amount of soil heating. Our results suggest that, when burned under high fuel loading conditions, many plant species respond more strongly to differences in fire intensity and severity than to timing of the burn relative to stage of plant growth. ?? 2007 NRC.

  5. [Enteral nutrition in burn patients].

    PubMed

    Pereira, J L; Garrido, M; Gómez-Cía, T; Serrera, J L; Franco, A; Pumar, A; Relimpio, F; Astorga, R; García-Luna, P P

    1992-01-01

    Nutritional support plays an important role in the treatment of patients with burns. Due to the severe hypercatabolism that develops in these patients, oral support is insufficient in most cases, and this makes it essential to initiate artificial nutritional support (either enteral or parenteral). Enteral nutrition is more physiological than parenteral, and data exist which show that in patients with burns, enteral nutrition exercises a protective effect on the intestine and may even reduce the hypermetabolic response in these patients. The purpose of the study was to evaluate the effectiveness and tolerance of enteral nutritional support with a hypercaloric, hyperproteic diet with a high content of branched amino acids in the nutritional support of patients suffering from burns. The study included 12 patients (8 males and 4 females), admitted to the Burns Unit. Average age was 35 +/- 17 years (range: 21-85 years). The percentage of body surface affected by the burns was 10% in two cases, between 10-30% in three cases, between 30-50% in five cases and over 50% in two cases. Initiation of the enteral nutrition was between twenty-four hours and seven days after the burn. The patients were kept in the unit until they were discharged, and the average time spent in the unit was 31.5 days (range: 17-63 days). Total energetic requirements were calculated based on Harris-Benedict, with a variable aggression factor depending on the body surface burned, which varied from 2,000 and 4,000 cal day. Nitrogenous balance was determined on a daily basis, and plasmatic levels of total proteins, albumin and prealbumin on a weekly basis. There was a significant difference between the prealbumin values at the initiation and finalization of the enteral nutrition (9.6 +/- 2.24 mg/dl compared with 19.75 +/- 5.48 mg/dl; p < 0.001). The nitrogenous balance improved, changing from -5.4 in the second week to positive values by the fourth and fifth weeks of treatment. Tolerance to the enteral diet was very good, and only mild complications such as diarrhoea developed in two patients. Enteral nutrition is a suitable nutritional support method for patients with burns, which maintains the nitrogenous balance positive and improves the visceral protein parameters in these patients at an early stage, with very few complications.

  6. Modeling prescribed burning experiments and assessing the fire impacts on local to regional air quality

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Baker, K. R.; Napelenok, S. L.; Elleman, R. A.; Urbanski, S. P.

    2016-12-01

    Biomass burning, including wildfires and prescribed burns, strongly impact the global carbon cycle and are of increasing concern due to the potential impacts on ambient air quality. This modelling study focuses on the evolution of carbonaceous compounds during a prescribed burning experiment and assesses the impacts of burning on local to regional air quality. The Community Multiscale Air Quality (CMAQ) model is used to conduct 4 and 2 km grid resolution simulations of prescribed burning experiments in southeast Washington state and western Idaho state in summer 2013. The ground and airborne measurements from the field experiment are used to evaluate the model performance in capturing surface and aloft impacts from the burning events. Phase partitioning of organic compounds in the plume are studied as it is a crucial step towards understanding the fate of carbonaceous compounds. The sensitivities of ambient concentrations and deposition to emissions are conducted for organic carbon, elemental carbon and ozone to estimate the impacts of fire on air quality.

  7. Shindand Airbase: Use of Open-Air Burn Pit Violated Department of Defense Requirements

    DTIC Science & Technology

    2014-07-01

    discontinue the use of the burn pit as soon 7 A refractory liner is made from a cement -like...initial combustion), asbestos, mercury, foam tent material, or any item containing any of the above items. The instruction allows for a small

  8. Human Mars Mission Performance Crew Taxi Profile. Part 1

    NASA Technical Reports Server (NTRS)

    Duaro, Vince A.

    1999-01-01

    This timeline was generated on the Integrated Mission Program (IMP). All burn events over 2 seconds are finite with IMP solving a two point boundary value setup for begin burn time, burn time and control angles. Perigee and apogee shown above are mean orbital values. Significant events are listed. Each finite thrust event has two lines. The first is the beginning time showing the initial conditions, thrust and ISP used. The second has the end burn conditions and the delta v and time of burn. This case is an abort from the 750 x 750 phasing abort, using the taxi's main engines. An abort using the Reaction Control System (RCS) was also investigated but required a large increase in RCS propellant and was abandoned.

  9. Our initial learning curve in the enzymatic debridement of severely burned hands-Management and pit falls of initial treatments and our development of a post debridement wound treatment algorithm.

    PubMed

    Schulz, A; Perbix, W; Shoham, Y; Daali, S; Charalampaki, C; Fuchs, P C; Schiefer, J

    2017-03-01

    Excisional surgical debridement (SD) is still the gold standard in the treatment of deeply burned hands, though the intricate anatomy is easily damaged. Previous studies demonstrated that enzymatic debridement with the bromelain debriding agent NexoBrid ® (EDNX) is more selective and thus can preserve viable tissue with excellent outcome results. So far no method paper has been published presenting different treatment algorithms in this new field. Therefore our aim was to close this gap by presenting our detailed learning curve in EDNX of deeply burned hands. We conducted a single-center prospective observational clinical trial treating 20 patients with deeply burned hands with EDNX. Different anaesthetic procedures, debridement and wound treatment algorithms were compared and main pitfalls described. EDNX was efficient in 90% of the treatments though correct wound bed evaluation was challenging and found unusual compared to SD. Post EDNX surprisingly the majority of the burn surface area was found overestimated (18 wounds). Finally we simplified our process and reduced treatment costs by following a modified treatment algorithm and treating under plexus anaesthesia bedside through a single nurse and one burn surgeon solely. Suprathel ® could be shown to be an appropriate dressing for wound treatment after EDNX. Complete healing (less 5% rest defect) was achieved at an average of day 28. EDNX in deep burned hands is promising regarding handling and duration of the treatment, efficiency and selectivity of debridement, healing potential and early rehabilitation. Following our treatment algorithm EDNX can be performed easily and even without special knowledge in burn wound depth evaluation. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  10. Combination of Landsat and Sentinel-2 MSI data for initial assessing of burn severity

    NASA Astrophysics Data System (ADS)

    Quintano, C.; Fernández-Manso, A.; Fernández-Manso, O.

    2018-02-01

    Nowadays Earth observation satellites, in particular Landsat, provide a valuable help to forest managers in post-fire operations; being the base of post-fire damage maps that enable to analyze fire impacts and to develop vegetation recovery plans. Sentinel-2A MultiSpectral Instrument (MSI) records data in similar spectral wavelengths that Landsat 8 Operational Land Imager (OLI), and has higher spatial and temporal resolutions. This work compares two types of satellite-based maps for evaluating fire damage in a large wildfire (around 8000 ha) located in Sierra de Gata (central-western Spain) on 6-11 August 2015. 1) burn severity maps based exclusively on Landsat data; specifically, on differenced Normalized Burn Ratio (dNBR) and on its relative versions (Relative dNBR, RdNBR, and Relativized Burn Ratio, RBR) and 2) burn severity maps based on the same indexes but combining pre-fire data from Landsat 8 OLI with post-fire data from Sentinel-2A MSI data. Combination of both Landsat and Sentinel-2 data might reduce the time elapsed since forest fire to the availability of an initial fire damage map. Interpretation of ortho-photograph Pléiades 1 B data (1:10,000) provided us the ground reference data to measure the accuracy of both burn severity maps. Results showed that Landsat based burn severity maps presented an adequate assessment of the damage grade (κ statistic = 0.80) and its spatial distribution in wildfire emergency response. Further using both Landsat and Sentinel-2 MSI data the accuracy of burn severity maps, though slightly lower (κ statistic = 0.70) showed an adequate level for be used by forest managers.

  11. Analysis of Electrocardiograms Associated with Pediatric Electrical Burns.

    PubMed

    McLeod, Jennifer S; Maringo, Alison E; Doyle, Patrick J; Vitale, Lisa; Klein, Justin D; Shanti, Christina M

    2017-05-26

    The purpose of this study was to examine the utility of electrocardiograms (EKGs) for low-risk, low-voltage pediatric electrical burn victims. A retrospective chart review was conducted on 86 pediatric patients who presented to the children's hospital between 2000 and 2015 after sustaining electrical burns. Variables included source and estimated voltage, extent of injuries, length of stay, high risk factors, and EKG results. High risk factors included estimated voltage > 1000 V, lightning, tetany, symptoms, loss of consciousness, or seizures. Statistical analyses were conducted. Average age was 5 years. Of those who sustained burns, 84.5% (n = 71/84) had second-degree burns ≤ 1% TBSA or less. Eleven patients had high risk factors, 12.9% (n = 11/85) and most had length of stay < 3 days (91.8%; n = 78/85). Majority sustained burns from low-voltage (< 300 V) household electrical outlets, cords, or light bulb sockets (90.4%; n = 75/83). Among patients with available EKGs, 12 had arrhythmias on initial EKG (i.e., low right atrial rhythm, t-wave inversions, sinus tachycardia, bundle branch block; 20.7%; n = 12/58). All were transient and nonfatal. The data suggest that low estimated voltage (< 300 V) electrical injuries were associated with negative EKGs; however, due to the low rate of arrhythmias, a Fisher's exact test did not show significance, P = 0.09 (P > 0.05). Preliminary data suggest that most pediatric electrical burns are due to low voltage (< 300 V) household sources. Few have high risk factors or arrhythmias that were transient and nonfatal. These data suggest that low-risk, asymptomatic, low-voltage pediatric electrical burns may not require an initial screening EKG.

  12. Fire spread in chaparral -"go or no-go?"

    Treesearch

    D.R. Weise; Xiangyang Zhou; Lulu Sun; Shankar Mahalingam

    2005-01-01

    Current fire models are designed to model the spread of a linear fire front in dead, small-diameter fuels. Fires in predominantly living vegetation account for a large proportion of annual burned area nationally. Prescribed burning is used to manage living fuels; however, prescribed burning is currently conducted under conditions that result in marginal burning. We do...

  13. Determining the Uncertainties in Prescribed Burn Emissions Through Comparison of Satellite Estimates to Ground-based Estimates and Air Quality Model Evaluations in Southeastern US

    NASA Astrophysics Data System (ADS)

    Odman, M. T.; Hu, Y.; Russell, A. G.

    2016-12-01

    Prescribed burning is practiced throughout the US, and most widely in the Southeast, for the purpose of maintaining and improving the ecosystem, and reducing the wildfire risk. However, prescribed burn emissions contribute significantly to the of trace gas and particulate matter loads in the atmosphere. In places where air quality is already stressed by other anthropogenic emissions, prescribed burns can lead to major health and environmental problems. Air quality modeling efforts are under way to assess the impacts of prescribed burn emissions. Operational forecasts of the impacts are also emerging for use in dynamic management of air quality as well as the burns. Unfortunately, large uncertainties exist in the process of estimating prescribed burn emissions and these uncertainties limit the accuracy of the burn impact predictions. Prescribed burn emissions are estimated by using either ground-based information or satellite observations. When there is sufficient local information about the burn area, the types of fuels, their consumption amounts, and the progression of the fire, ground-based estimates are more accurate. In the absence of such information satellites remain as the only reliable source for emission estimation. To determine the level of uncertainty in prescribed burn emissions, we compared estimates derived from a burn permit database and other ground-based information to the estimates by the Biomass Burning Emissions Product derived from a constellation of NOAA and NASA satellites. Using these emissions estimates we conducted simulations with the Community Multiscale Air Quality (CMAQ) model and predicted trace gas and particulate matter concentrations throughout the Southeast for two consecutive burn seasons (2015 and 2016). In this presentation, we will compare model predicted concentrations to measurements at monitoring stations and evaluate if the differences are commensurate with our emission uncertainty estimates. We will also investigate if spatial and temporal patterns in the differences reveal the sources of the uncertainty in the prescribed burn emission estimates.

  14. Pre-supernova models at low metallicities

    NASA Astrophysics Data System (ADS)

    Hirschi, Raphael

    ¢ A series of fast rotating models at very low metallicity (Z 10 8 ) was computed in order to¡ explain the surface abundances observed at the surface of CEMP stars, in particular for nitrogen. The main results are the following: - Strong mixing occurs during He-burning and leads to important primary nitrogen produc- tion. - Important mass loss takes place in the RSG stage for the most massive models. The 85 M£ model loses about three quarter of its initial mass, becomes a WO star and could produce a GRB. - The CNO elements of HE1327-2326 could have been produced in massive rotating stars and ejected by their stellar winds.

  15. Epidemiology and outcome of burns at the Saud Al Babtain Burns, Plastic Surgery and Reconstructive Center, Kuwait: our experience over five years (from 2006 to 2010)

    PubMed Central

    Khashaba, H.A.; Al-Fadhli, A.N.; Al-Tarrah, K.S.; Wilson, Y.T.; Moiemen, N.

    2012-01-01

    Summary Aim To determine the epidemiology and clinical presentation, and any contributing factors responsible for burns and outcome of care in Kuwait over the 5-yr period January 2006 to December 2010. Patients and methods. The study reviewed 1702 burn patients admitted over the study period to the Saud Al Babtain Burns, Plastic and Reconstructive Surgery Center, Kuwait. Patient characteristics, including age, sex, type of burn, nationality, total body surface area (TBSA) burn, hospital stay in days, and mortality were recorded. Results. Seventy-one per cent of the 1702 burn patients admitted were males; 540 were children. The majority of patients (64%) had less than 15% TBSA burns and only 14% had more than 50% TBSA burns. Flame burns were the most common cause of burn injuries (60%), followed by scalds (29%). Scalds were most common in children. The mortality rate was 5.75%. Flame burn was the leading cause of mortality. Lethal dose 50 (% TBSA at which a certain group has a 50% chance of survival) for adults (16-40 yr) and for the elderly (>65 yr) was 76.5% and 41.8% TBSA respectively. Conclusion. Burn injury is an important public health concern and is associated with high morbidity and mortality. Flame and scald burns are commonly a result of domestic and occupational accidents and they are preventable. Effective initial resuscitation, infection control, and adequate surgical treatment improve outcomes. PMID:23766750

  16. Accuracy of real time radiography burning rate measurement

    NASA Astrophysics Data System (ADS)

    Olaniyi, Bisola

    The design of a solid propellant rocket motor requires the determination of a propellant's burning-rate and its dependency upon environmental parameters. The requirement that the burning-rate be physically measured, establishes the need for methods and equipment to obtain such data. A literature review reveals that no measurement has provided the desired burning rate accuracy. In the current study, flash x-ray modeling and digitized film-density data were employed to predict motor-port area to length ratio. The pre-fired port-areas and base burning rate were within 2.5% and 1.2% of their known values, respectively. To verify the accuracy of the method, a continuous x-ray and a solid propellant rocket motor model (Plexiglas cylinder) were used. The solid propellant motor model was translated laterally through a real-time radiography system at different speeds simulating different burning rates. X-ray images were captured and the burning-rate was then determined. The measured burning rate was within 1.65% of the known values.

  17. Evidence of erosive burning in shuttle solid rocket motor

    NASA Technical Reports Server (NTRS)

    Martin, C. L.

    1983-01-01

    Known models of Shuttle Solid Rocket Motor (SRM) performance have failed to produce pressure-time traces which accurately matched actual motor performance, especially during the first 5 seconds after ignition and during the last quarter of web burn time. Efforts to compensate for these differences in model reconstruction and actual performance resulted in resorting to the use of a Burning Anomaly Rate Function (BARF). It was suspected that propellant erosive burning was primarily responsible for the variation of model from actual results. The three dimensional Hercules Grain Design and Internal Ballistics Evaluation Program was made operational and slightly modified and an extensive trial and error effort was begun to test the hypothesis of erosive burning as an explanation of the burning anomaly. It was found that introduction of erosive burning (using Green's erosive burning equation) over portions of the aft segment grain and above a threshold gas Mach number did, in fact, give excellent agreement with the actual motor trace.

  18. Risk factors for the development of heterotopic ossification in seriously burned adults: A National Institute on Disability, Independent Living and Rehabilitation Research burn model system database analysis.

    PubMed

    Levi, Benjamin; Jayakumar, Prakash; Giladi, Avi; Jupiter, Jesse B; Ring, David C; Kowalske, Karen; Gibran, Nicole S; Herndon, David; Schneider, Jeffrey C; Ryan, Colleen M

    2015-11-01

    Heterotopic ossification (HO) is a debilitating complication of burn injury; however, incidence and risk factors are poorly understood. In this study, we use a multicenter database of adults with burn injuries to identify and analyze clinical factors that predict HO formation. Data from six high-volume burn centers, in the Burn Injury Model System Database, were analyzed. Univariate logistic regression models were used for model selection. Cluster-adjusted multivariate logistic regression was then used to evaluate the relationship between clinical and demographic data and the development of HO. Of 2,979 patients in the database with information on HO that addressed risk factors for development of HO, 98 (3.5%) developed HO. Of these 98 patients, 97 had arm burns, and 96 had arm grafts. When controlling for age and sex in a multivariate model, patients with greater than 30% total body surface area burn had 11.5 times higher odds of developing HO (p < 0.001), and those with arm burns that required skin grafting had 96.4 times higher odds of developing HO (p = 0.04). For each additional time a patient went to the operating room, odds of HO increased by 30% (odds ratio, 1.32; p < 0.001), and each additional ventilator day increased odds by 3.5% (odds ratio, 1.035; p < 0.001). Joint contracture, inhalation injury, and bone exposure did not significantly increase odds of HO. Risk factors for HO development include greater than 30% total body surface area burn, arm burns, arm grafts, ventilator days, and number of trips to the operating room. Future studies can use these results to identify highest-risk patients to guide deployment of prophylactic and experimental treatments. Prognostic study, level III.

  19. Risk Factors for the Development of Heterotopic Ossification in Seriously Burned Adults: A NIDRR Burn Model System Database Analysis

    PubMed Central

    Levi, Benjamin; Jayakumar, Prakash; Giladi, Avi; Jupiter, Jesse B.; Ring, David C.; Kowalske, Karen; Gibran, Nicole S.; Herndon, David; Schneider, Jeffrey C.; Ryan, Colleen M.

    2015-01-01

    Purpose Heterotopic ossification (HO) is a debilitating complication of burn injury; however, incidence and risk factors are poorly understood. In this study we utilize a multicenter database of adults with burn injuries to identify and analyze clinical factors that predict HO formation. Methods Data from 6 high-volume burn centers, in the Burn Injury Model System Database, were analyzed. Univariate logistic regression models were used for model selection. Cluster-adjusted multivariate logistic regression was then used to evaluate the relationship between clinical and demographic data and the development of HO. Results Of 2,979 patients in the database with information on HO that addressed risk factors for development of HO, 98 (3.5%) developed HO. Of these 98 patients, 97 had arm burns, and 96 had arm grafts. Controlling for age and sex in a multivariate model, patients with >30% total body surface area (TBSA) burn had 11.5x higher odds of developing HO (p<0.001), and those with arm burns that required skin grafting had 96.4x higher odds of developing HO (p=0.04). For each additional time a patient went to the operating room, odds of HO increased 30% (OR 1.32, p<0.001), and each additional ventilator day increase odds 3.5% (OR 1.035, p<0.001). Joint contracture, inhalation injury, and bone exposure did not significantly increase odds of HO. Conclusion Risk factors for HO development include >30% TBSA burn, arm burns, arm grafts, ventilator days, and number of trips to the operating room. Future studies can use these results to identify highest-risk patients to guide deployment of prophylactic and experimental treatments. PMID:26496115

  20. Sensitivity of global terrestrial carbon cycle dynamics to variability in satellite-observed burned area

    NASA Astrophysics Data System (ADS)

    Poulter, Benjamin; Cadule, Patricia; Cheiney, Audrey; Ciais, Philippe; Hodson, Elke; Peylin, Philippe; Plummer, Stephen; Spessa, Allan; Saatchi, Sassan; Yue, Chao; Zimmermann, Niklaus E.

    2015-02-01

    Fire plays an important role in terrestrial ecosystems by regulating biogeochemistry, biogeography, and energy budgets, yet despite the importance of fire as an integral ecosystem process, significant advances remain to improve its prognostic representation in carbon cycle models. To recommend and to help prioritize model improvements, this study investigates the sensitivity of a coupled global biogeography and biogeochemistry model, LPJ, to observed burned area measured by three independent satellite-derived products, GFED v3.1, L3JRC, and GlobCarbon. Model variables are compared with benchmarks that include pantropical aboveground biomass, global tree cover, and CO2 and CO trace gas concentrations. Depending on prescribed burned area product, global aboveground carbon stocks varied by 300 Pg C, and woody cover ranged from 50 to 73 Mkm2. Tree cover and biomass were both reduced linearly with increasing burned area, i.e., at regional scales, a 10% reduction in tree cover per 1000 km2, and 0.04-to-0.40 Mg C reduction per 1000 km2. In boreal regions, satellite burned area improved simulated tree cover and biomass distributions, but in savanna regions, model-data correlations decreased. Global net biome production was relatively insensitive to burned area, and the long-term land carbon sink was robust, 2.5 Pg C yr-1, suggesting that feedbacks from ecosystem respiration compensated for reductions in fuel consumption via fire. CO2 transport provided further evidence that heterotrophic respiration compensated any emission reductions in the absence of fire, with minor differences in modeled CO2 fluxes among burned area products. CO was a more sensitive indicator for evaluating fire emissions, with MODIS-GFED burned area producing CO concentrations largely in agreement with independent observations in high latitudes. This study illustrates how ensembles of burned area data sets can be used to diagnose model structures and parameters for further improvement and also highlights the importance in considering uncertainties and variability in observed burned area data products for model applications.

  1. The importance of illumination in a non-contact photoplethysmography imaging system for burn wound assessment

    NASA Astrophysics Data System (ADS)

    Mo, Weirong; Mohan, Rachit; Li, Weizhi; Zhang, Xu; Sellke, Eric W.; Fan, Wensheng; DiMaio, J. Michael; Thatcher, Jeffery E.

    2015-02-01

    We present a non-contact, reflective photoplethysmogram (PPG) imaging method and a prototype system for identifying the presence of dermal burn wounds during a burn debridement surgery. This system aims to provide assistance to clinicians and surgeons in the process of dermal wound management and wound triage decisions. We examined the system variables of illumination uniformity and intensity and present our findings. An LED array, a tungsten light source, and eventually high-power LED emitters were studied as illumination methods for our PPG imaging device. These three different illumination sources were tested in a controlled tissue phantom model and an animal burn model. We found that the low heat and even illumination pattern using high power LED emitters provided a substantial improvement to the collected PPG signal in our animal burn model. These improvements allow the PPG signal from different pixels to be comparable in both time-domain and frequency-domain, simplify the illumination subsystem complexity, and remove the necessity of using high dynamic range cameras. Through the burn model output comparison, such as the blood volume in animal burn data and controlled tissue phantom model, our optical improvements have led to more clinically applicable images to aid in burn assessment.

  2. Forest ecology and management

    Treesearch

    William D. Boyer; James H. Miller

    1994-01-01

    Over a period of 16 years, unburned longleaf pine (Pinus palustris Mill.) pole stands grew an average of 27% more volume than similar stands regularly burned. Treatments included biennial burns in winter, spring, and summer plus an unburned check, each of which was combined with three supplemental treatments, namely, initial herbicide injection of...

  3. A steady-state technique for studying the properties of free-burning wood fires

    Treesearch

    Wallace L. Fons; H.D. Bruce; W.Y. Pong

    1961-01-01

    A laboratory study was set up by the U.S. Forest Service with the ultimate objective of determining model laws for properties of wood fires, including rate of spread. This is a report of the first phase of the work, the development of a suitable bed of solid fuel and the technique of study. The bed chosen for initial study is in the form of long cribs of wood sticks...

  4. The risk of burn injury during long-term oxygen therapy: a 17-year longitudinal national study in Sweden

    PubMed Central

    Tanash, Hanan A; Huss, Fredrik; Ekström, Magnus

    2015-01-01

    Background Long-term oxygen therapy (LTOT) improves the survival time in hypoxemic chronic obstructive pulmonary disease. Despite warnings about potential dangers, a considerable number of patients continue to smoke while on LTOT. The incidence of burn injuries related to LTOT is unknown. The aim of this study was to estimate the rate of burn injury requiring health care contact during LTOT. Methods Prospective, population-based, consecutive cohort study of people starting LTOT from any cause between January 1, 1992 and December 31, 2009 in the Swedish National Register of Respiratory Failure (Swedevox). Results In total, 12,497 patients (53% women) were included. The mean (standard deviation) age was 72±9 years. The main reasons for starting LTOT were chronic obstructive pulmonary disease (75%) and pulmonary fibrosis (15%). Only 269 (2%) were active smokers when LTOT was initiated. The median follow-up time to event was 1.5 years (interquartile range, 0.55–3.1). In total, 17 patients had a diagnosed burn injury during 27,890 person-years of LTOT. The rate of burn injury was 61 (95% confidence interval, 36–98) per 100,000 person-years. There was no statistically significant difference in the rate of burn injury between ever-smokers and never-smokers, or between men and women. Conclusion The rate of burn injuries in patients on LTOT seems to be low in Sweden. The strict requirements in Sweden for smoking cessation before LTOT initiation may contribute to this finding. PMID:26622175

  5. OH-initiated Aging of Biomass Burning Aerosol during FIREX

    NASA Astrophysics Data System (ADS)

    Lim, C. Y.; Hagan, D. H.; Cappa, C. D.; Kroll, J. H.; Coggon, M.; Koss, A.; Sekimoto, K.; De Gouw, J. A.; Warneke, C.

    2017-12-01

    Biomass burning emissions represent a major source of fine particulate matter to the atmosphere, and this source will likely become increasingly important in the future due to changes in the Earth's climate. Understanding the effects that increased fire emissions have on both air quality and climate requires understanding the composition of the particles emitted, since chemical and physical composition directly impact important particle properties such as absorptivity, toxicity, and cloud condensation nuclei activity. However, the composition of biomass burning particles in the atmosphere is dynamic, as the particles are subject to the condensation of low-volatility vapors and reaction with oxidants such as the hydroxyl radical (OH) during transport. Here we present a series of laboratory chamber experiments on the OH-initiated aging of biomass burning aerosol performed at the Fire Sciences Laboratory in Missoula, MT as part of the Fire Influences on Regional and Global Environments Experiment (FIREX) campaign. We describe the evolution of biomass burning aerosol produced from a variety of fuels operating the chamber in both particle-only and gas + particle mode, focusing on changes to the organic composition. In particle-only mode, gas-phase biomass burning emissions are removed before oxidation to focus on heterogeneous oxidation, while gas + particle mode includes both heterogeneous oxidation and condensation of oxidized volatile organic compounds onto the particles (secondary organic aerosol formation). Variability in fuels and burning conditions lead to differences in aerosol loading and secondary aerosol production, but in all cases aging results in a significant and rapid increases in the carbon oxidation state of the particles.

  6. A model of ponderosa pine growth response to prescribed burning

    Treesearch

    Elaine Kennedy Sutherland; W. Wallace Covington; Steve Andariese

    1991-01-01

    Our objective was to model the radial growth response of individual ponderosa pines to prescribed burning in northern Arizona. We sampled 188 trees from two study areas, which were burned in 1976. Within each study area, control and burned trees were of similar age, vigor, height, and competition index. At Chimney Spring, trees were older, less vigorous, and taller and...

  7. Carbon Transfers and Emissions Following Harvest and Pile Burning in Coastal Douglas-fir Forests Determined from Analysis of High-Resolution UAV Imagery and Point Clouds and from Field Surveys.

    NASA Astrophysics Data System (ADS)

    Trofymow, J. A.; Gougeon, F.; Kelley, J. W.

    2017-12-01

    Forest carbon (C) models require knowledge on C transfers due to intense disturbances such as fire, harvest, and slash burning. In such events, live trees die and C transferred to detritus or exported as round wood. With burning, live and detrital C is lost as emissions. Burning can be incomplete, leaving wood, charred and scattered or in unburnt rings and piles. For harvests, all round wood volume is routinely measured, while dispersed and piled residue volumes are typically assessed in field surveys, scaled to a block. Recently, geospatial methods have been used to determine, for an entire block, piled residues using LiDAR or image point clouds (PC) and dispersed residues by analysis of high-resolution imagery. Second-growth Douglas-fir forests on eastern Vancouver Island were examined, 4 blocks at Oyster River (OR) and 2 at Northwest Bay (NB). OR blocks were cut winter 2011, piled spring 2011, field survey, aerial RGB imagery and LiDAR PC acquired fall 2011, piles burned, burn residues surveyed, and post-burn aerial RGB imagery acquired 2012. NB blocks were cut fall 2014, piled spring 2015, field survey, UAV RGB imagery and image PC acquired summer 2015, piles burned and burn residues surveyed spring 2016, and post-burn UAV RGB imagery and PC acquired fall 2016. Volume to biomass conversion used survey species proportions and wood density. At OR, round wood was 261.7 SE 13.1, firewood 1.7 SE 0.3, and dispersed residue by survey, 13.8 SE 3.6 tonnes dry mass (t dm) ha-1. Piled residues were 8.2 SE 0.9 from pile surveys vs. 25.0 SE 5.9 t dm ha-1 from LiDAR PC bulk pile volumes and packing ratios. Post-burn, piles lost 5.8 SE 0.5 from survey of burn residues vs. 18.2 SE 4.7 t dm ha-1 from pile volume changes using 2011 LiDAR PC and 2012 imagery. The percentage of initial merchantable biomass exported as round & fire wood, remaining as dispersed & piled residue, and lost to burning was, respectively, 92.5%, 5.5% and 2% using only field methods vs. 87%, 7% and 6% from dispersed residues surveys and LIDAR PC pile volumes. At NB, preliminary analysis shows the post-burn difference in 2015 to 2016 UAV PC pile volumes, was similar to that using 2015 UAV PC pile volume and 2016 orthophoto pile area burned, suggesting the two geospatial methods are comparable. Comparisons will be made for transfers in all 6 blocks using only field survey or geospatial methods.

  8. Internal and surface phenomena in metal combustion

    NASA Technical Reports Server (NTRS)

    Dreizin, Edward L.; Molodetsky, Irina E.; Law, Chung K.

    1995-01-01

    Combustion of metals has been widely studied in the past, primarily because of their high oxidation enthalpies. A general understanding of metal combustion has been developed based on the recognition of the existence of both vapor-phase and surface reactions and involvement of the reaction products in the ensuing heterogeneous combustion. However, distinct features often observed in metal particle combustion, such as brightness oscillations and jumps (spearpoints), disruptive burning, and non-symmetric flames are not currently understood. Recent metal combustion experiments using uniform high-temperature metal droplets produced by a novel micro-arc technique have indicated that oxygen dissolves in the interior of burning particles of certain metals and that the subsequent transformations of the metal-oxygen solutions into stoichiometric oxides are accompanied with sufficient heat release to cause observed brightness and temperature jumps. Similar oxygen dissolution has been observed in recent experiments on bulk iron combustion but has not been associated with such dramatic effects. This research addresses heterogeneous metal droplet combustion, specifically focusing on oxygen penetration into the burning metal droplets, and its influence on the metal combustion rate, temperature history, and disruptive burning. A unique feature of the experimental approach is the combination of the microgravity environment with a novel micro-arc Generator of Monodispersed Metal Droplets (GEMMED), ensuring repeatable formation and ignition of uniform metal droplets with controllable initial temperature and velocity. The droplet initial temperatures can be adjusted within a wide range from just above the metal melting point, which provides means to ignite droplets instantly upon entering an oxygen containing environment. Initial droplet velocity will be set equal to zero allowing one to organize metal combustion microgravity experiments in a fashion similar to usual microgravity liquid fuel droplet combustion studies. In addition, the internal compositions of rapidly quenched metal particles will be analyzed using SEM technique. Such compositions are similar to those existing during the combustion and provide new insight on metal combustion processes. The results of this experimental work will be used to model the fundamental mechanisms of metal combustion. Preliminary experimental results on Al and Zr particle combustion at normal gravity are discussed here.

  9. Biomass Burning

    Atmospheric Science Data Center

    2015-07-27

    Projects:  Biomass Burning Definition/Description:  Biomass Burning: This data set represents the geographical and temporal distribution of total amount of biomass burned. These data may be used in general circulation models (GCMs) and ...

  10. A mobile app for measuring the surface area of a burn in three dimensions: comparison to the Lund and Browder assessment.

    PubMed

    Goldberg, Harry; Klaff, Justin; Spjut, Aaron; Milner, Stephen

    2014-01-01

    The aim of this study was to compare the ease and accuracy of measuring the surface area of a severe burn through the use of a mobile software application (BurnMed) to the traditional method of assessment, the Lund and Browder chart. BurnMed calculates the surface area of a burn by enabling the user to first manipulate a three-dimensional model on a mobile device and then by touching the model at the locations representing the patient's injury. The surface area of the burn is calculated in real time. Using a cohort of 18 first-year medical students with no experience in burn care, the surface area of a simulated burn on a mannequin was made using BurnMed and compared to estimates derived from the Lund and Browder chart. At the completion of this study, students were asked to complete a questionnaire designed to assess the ease of use of BurnMed. Users were able to easily and accurately measure the surface area of a simulated burn using the BurnMed application. In addition, there was less variability in surface area measurements with the application compared to the results obtained using the Lund and Browder chart. Users also reported that BurnMed was easier to use than the Lund and Browder chart. A software application, BurnMed, has been developed for a mobile device that easily and accurately determines the surface area of a burn. This system uses a three-dimensional model that can be rotated, enlarged, and transposed by the health care provider to easily determine the extent of a burn. Results show that the variability of measurements using BurnMed is lower than the measurements obtained using the Lund and Browder chart. BurnMed is available at no charge in the Apple™ Store.

  11. From Baghdad to Boston: International Transfer of Burned Children in Time of War

    DTIC Science & Technology

    2014-10-01

    369 Burns accounted for 13% of the large number of children admitted to U.S. combat support hospitals (CSHs) during recent conflicts in Iraq and...Afghani- stan.1 At the busiest CSH in Iraq, located at Ibn Sina Hospital in Baghdad, many of these burned children underwent wound care and discharge...initial care at the CSH, fol- lowed by transfer to one of the Shriners Hospitals for Children in Boston, Massachusetts. We conducted a review of the

  12. Free tissue transfer in acute burns.

    PubMed

    Oni, Georgette; Saint-Cyr, Michel; Mojallal, Ali

    2012-02-01

    Major burn injuries can be devastating for the patients and their carers both in terms of morbidity and mortality. Therefore, it is important to optimize the treatment of the injured patient. After initial resuscitation and physiological stabilization, thorough surgical débridement of the burn is necessary. Often resultant defects can be resurfaced with split skin grafting or local flaps. However, in a small percentage of cases free flap surgery is necessary. Free tissue transfer in burns surgery is rare, but is indicated in those patients in which there is loss of a vascularized surface suitable for grafting such as exposed tendon, or bone following surgical débridement, and in extreme cases for limb salvage. This review article discusses the rationale for free flap surgery in terms of types of burn injuries, perioperative considerations, and summarizes the literature in free tissue transfer in acute burns. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  13. Integrating satellite imagery with simulation modeling to improve burn severity mapping

    Treesearch

    Eva C. Karau; Pamela G. Sikkink; Robert E. Keane; Gregory K. Dillon

    2014-01-01

    Both satellite imagery and spatial fire effects models are valuable tools for generating burn severity maps that are useful to fire scientists and resource managers. The purpose of this study was to test a new mapping approach that integrates imagery and modeling to create more accurate burn severity maps. We developed and assessed a statistical model that combines the...

  14. The effect of a honey based gel and silver sulphadiazine on bacterial infections of in vitro burn wounds.

    PubMed

    Boekema, B K H L; Pool, L; Ulrich, M M W

    2013-06-01

    Bacterial contamination remains a constant threat in burn wound care. Topical treatments to combat contaminations have good bactericidal effects but can have detrimental effects for the healing process. Treatments with for example silver can increase healing times. Honey based products can be a good alternative as it is antibacterial and patient-friendly. We evaluated the bactericidal and cytotoxic effects of a honey based gel and silver sulphadiazine in a human burn wound model with Pseudomonas aeruginosa. After adding 10(5)colony forming units of P. aeruginosa, topical treatments were applied on the burn wound models. After 2, 12, 24, 28 and 70 h, bacteria were dislodged and counted by plating dilutions. Cytotoxic effects were evaluated histologically in samples of burn wound models treated topically for 3 weeks, without bacteria. L-Mesitran Soft significantly reduced the bacterial load (5-log reduction) up to 24h but did not completely eliminate bacteria from the burn wounds. After Flammazine(®) treatment, only a few colony forming units were observed at all time points. In contrast, re-epithelialization was significantly reduced after application of Flammazine(®) compared to L-Mesitran Soft or control. This in vitro model of burn wound infection can be used to evaluate topical treatments. L-Mesitran Soft is a good alternative for treating burn wounds but the slightly lower bactericidal activity in the burn wound model warrants a higher frequency of application. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  15. A Semi-analytic Criterion for the Spontaneous Initiation of Carbon Detonations in White Dwarfs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Garg, Uma; Chang, Philip, E-mail: umagarg@uwm.edu, E-mail: chang65@uwm.edu

    Despite over 40 years of active research, the nature of the white dwarf progenitors of SNe Ia remains unclear. However, in the last decade, various progenitor scenarios have highlighted the need for detonations to be the primary mechanism by which these white dwarfs are consumed, but it is unclear how these detonations are triggered. In this paper we study how detonations are spontaneously initiated due to temperature inhomogeneities, e.g., hotspots, in burning nuclear fuel in a simplified physical scenario. Following the earlier work by Zel’Dovich, we describe the physics of detonation initiation in terms of the comparison between the spontaneousmore » wave speed and the Chapman–Jouguet speed. We develop an analytic expression for the spontaneous wave speed and utilize it to determine a semi-analytic criterion for the minimum size of a hotspot with a linear temperature gradient between a peak and base temperature for which detonations in burning carbon–oxygen material can occur. Our results suggest that spontaneous detonations may easily form under a diverse range of conditions, likely allowing a number of progenitor scenarios to initiate detonations that burn up the star.« less

  16. A Semi-analytic Criterion for the Spontaneous Initiation of Carbon Detonations in White Dwarfs

    NASA Astrophysics Data System (ADS)

    Garg, Uma; Chang, Philip

    2017-02-01

    Despite over 40 years of active research, the nature of the white dwarf progenitors of SNe Ia remains unclear. However, in the last decade, various progenitor scenarios have highlighted the need for detonations to be the primary mechanism by which these white dwarfs are consumed, but it is unclear how these detonations are triggered. In this paper we study how detonations are spontaneously initiated due to temperature inhomogeneities, e.g., hotspots, in burning nuclear fuel in a simplified physical scenario. Following the earlier work by Zel’Dovich, we describe the physics of detonation initiation in terms of the comparison between the spontaneous wave speed and the Chapman-Jouguet speed. We develop an analytic expression for the spontaneous wave speed and utilize it to determine a semi-analytic criterion for the minimum size of a hotspot with a linear temperature gradient between a peak and base temperature for which detonations in burning carbon-oxygen material can occur. Our results suggest that spontaneous detonations may easily form under a diverse range of conditions, likely allowing a number of progenitor scenarios to initiate detonations that burn up the star.

  17. Modeling Emissions and Vertical Plume Transport of Crop Residue Burning Experiments in the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Baker, K. R.; Napelenok, S. L.; Pouliot, G.; Elleman, R. A.; ONeill, S. M.; Urbanski, S. P.; Wong, D. C.

    2017-12-01

    Crop residue burning has long been a common practice in agriculture with the smoke emissions from the burning linked to negative health impacts. A field study in eastern Washington and northern Idaho in August 2013 consisted of multiple burns of well characterized fuels with nearby surface and aerial measurements including trace species concentrations, plume rise height and boundary layer structure. The chemical transport model CMAQ (Community Multiscale Air Quality Model) was used to assess the fire emissions and subsequent vertical plume transport. The study first compared assumptions made by the 2014 National Emission Inventory approach for crop residue burning with the fuel and emissions information obtained from the field study and then investigated the sensitivity of modeled carbon monoxide (CO) and PM2.5 concentrations to these different emission estimates and plume rise treatment with CMAQ. The study suggests that improvements to the current parameterizations are needed in order for CMAQ to reliably reproduce smoke plumes from burning. In addition, there is enough variability in the smoke emissions, stemming from variable field-specific information such as field size, that attempts to model crop residue burning should use field-specific information whenever possible.

  18. Assessing the Efficacy of Restricting Access to Barbecue Charcoal for Suicide Prevention in Taiwan: A Community-Based Intervention Trial

    PubMed Central

    Chen, Ying-Yeh; Chen, Feng; Chang, Shu-Sen; Wong, Jacky; Yip, Paul S F

    2015-01-01

    Objective Charcoal-burning suicide has recently been spreading to many Asian countries. There have also been several cases involving this new method of suicide in Western countries. Restricting access to suicide means is one of the few suicide-prevention measures that have been supported by empirical evidence. The current study aims to assess the effectiveness of a community intervention program that restricts access to charcoal to prevent suicide in Taiwan. Methods and Findings A quasi-experimental design is used to compare method-specific (charcoal-burning suicide, non-charcoal-burning suicide) and overall suicide rates in New Taipei City (the intervention site, with a population of 3.9 million) with two other cities (Taipei City and Kaohsiung City, the control sites, each with 2.7 million residents) before (Jan 1st 2009- April 30th 2012) and after (May 1st 2012-Dec. 31st 2013) the initiation of a charcoal-restriction program on May 1st 2012. The program mandates the removal of barbecue charcoal from open shelves to locked storage in major retail stores in New Taipei City. No such restriction measure was implemented in the two control sites. Generalized linear regression models incorporating secular trends were used to compare the changes in method-specific and overall suicide rates before and after the initiation of the restriction measure. A simulation approach was used to estimate the number of lives saved by the intervention. Compared with the pre-intervention period, the estimated rate reduction of charcoal-burning suicide in New Taipei City was 37% (95% CI: 17%, 50%) after the intervention. Taking secular trends into account, the reduction was 30% (95% CI: 14%, 44%). No compensatory rise in non-charcoal-burning suicide was observed in New Taipei City. No significant reduction in charcoal-burning suicide was observed in the other two control sites. The simulation approach estimated that 91 (95%CI [55, 128]) lives in New Taipei City were saved during the 20 months of the intervention. Conclusion Our results demonstrate that the charcoal-restriction program reduced method-specific and overall suicides. This study provides strong empirical evidence that restricting the accessibility of common lethal methods of suicide can effectively reduce suicide rates. PMID:26305374

  19. Constraining the relative importance of raindrop- and flow-driven sediment transport mechanisms in postwildfire environments and implications for recovery time scales

    USGS Publications Warehouse

    McGuire, Luke; Kean, Jason W.; Staley, Dennis M.; Rengers, Francis K.; Wasklewicz, Thad A.

    2016-01-01

    Mountain watersheds recently burned by wildfire often experience greater amounts of runoff and increased rates of sediment transport relative to similar unburned areas. Given the sedimentation and debris flow threats caused by increases in erosion, more work is needed to better understand the physical mechanisms responsible for the observed increase in sediment transport in burned environments and the time scale over which a heightened geomorphic response can be expected. In this study, we quantified the relative importance of different hillslope erosion mechanisms during two postwildfire rainstorms at a drainage basin in Southern California by combining terrestrial laser scanner-derived maps of topographic change, field measurements, and numerical modeling of overland flow and sediment transport. Numerous debris flows were initiated by runoff at our study area during a long-duration storm of relatively modest intensity. Despite the presence of a well-developed rill network, numerical model results suggest that the majority of eroded hillslope sediment during this long-duration rainstorm was transported by raindrop-induced sediment transport processes, highlighting the importance of raindrop-driven processes in supplying channels with potential debris flow material. We also used the numerical model to explore relationships between postwildfire storm characteristics, vegetation cover, soil infiltration capacity, and the total volume of eroded sediment from a synthetic hillslope for different end-member erosion regimes. This study adds to our understanding of sediment transport in steep, postwildfire landscapes and shows how data from field monitoring can be combined with numerical modeling of sediment transport to isolate the processes leading to increased erosion in burned areas.

  20. Efficacy of enzymatic debridement of deeply burned hands.

    PubMed

    Krieger, Yuval; Bogdanov-Berezovsky, Alexander; Gurfinkel, Reuven; Silberstein, Eldad; Sagi, Amiram; Rosenberg, Lior

    2012-02-01

    The burned hand is a common and difficult to care-for entity in the field of burns. Due to the anatomy of the hand (important and delicate structures crowded in a small limited space without sub-dermal soft tissue), surgical debridement of the burned tissue is technically difficult and may cause considerable complications and, therefore, should be performed judiciously. Selective enzymatic debridement of the burn wound can preserve the spontaneous epithelialisation potential and reduce the added injury to the traumatised tissue added by a surgical debridement. The aim of the study was to assess the implication of a selective enzymatic compound (Debrase(®) - Ds) in the special field of deep hand burns, by comparing the actual burn area that required surgical coverage after enzymatic debridement to the burn area clinically judged to require skin grafting prior to debridement. This was a retrospective data collection and analysis from 154 complete files of prospective, open-label study in 275 hospitalised, Ds-treated burn patients. A total of 69 hand burns diagnosed as 'deep' was analysed; 36% of the wounds required surgical intervention after enzymatic debridement; 28.6% of the total burned area estimated initially as deep was covered by skin graft (statistically significant p<0.001). Debridement of deep-hand burns with a selective enzymatic agent decreased the perceived full-thickness wound area and skin-graft use. Copyright © 2011 Elsevier Ltd and ISBI. All rights reserved.

  1. Estimating the usage of allograft in the treatment of major burns.

    PubMed

    Horner, C W M; Atkins, J; Simpson, L; Philp, B; Shelley, O; Dziewulski, P

    2011-06-01

    To assess the amount of allograft used in the past treatment of major burns and calculate a figure to guide estimation of the quantity of allograft required to treat future patients and aid resource planning. A retrospective observational study. Records of 143 patients treated with major burns at a regional centre, from January 2004 to November 2008 were accessed with biometric data and quantity of allograft used being recorded. This data was used to calculate an allograft index (cm² allograft used/burn surface area (cm²)) (AI) for each patient. 112 of the 143 patients had complete sets of data, of the 112, 89 patients survived the initial stay in hospital. For all data average AI=1.077 ± 0.090. AI varied according to burn % area with burns < 40% requiring 0.490 cm² allo/cm²burn, increasing in a logarithmic fashion (R²=0.995) for burn areas > 40%. The ability to estimate deceased donor skin requirements based on % body surface area affected is important in the care planning for patients with major burns. Our findings of 0.5 cm² allograft/cm² burn for injuries less than 40% TBSA, increasing to 1.82 cm² allograft/cm² burn for injuries up to 80% TBSA can be used for planning purposes for individual services and for burn disaster planning. Copyright © 2010 Elsevier Ltd and ISBI. All rights reserved.

  2. Modeling crop residue burning experiments to evaluate smoke emissions and plume transport.

    PubMed

    Zhou, Luxi; Baker, Kirk R; Napelenok, Sergey L; Pouliot, George; Elleman, Robert; O'Neill, Susan M; Urbanski, Shawn P; Wong, David C

    2018-06-15

    Crop residue burning is a common land management practice that results in emissions of a variety of pollutants with negative health impacts. Modeling systems are used to estimate air quality impacts of crop residue burning to support retrospective regulatory assessments and also for forecasting purposes. Ground and airborne measurements from a recent field experiment in the Pacific Northwest focused on cropland residue burning was used to evaluate model performance in capturing surface and aloft impacts from the burning events. The Community Multiscale Air Quality (CMAQ) model was used to simulate multiple crop residue burns with 2 km grid spacing using field-specific information and also more general assumptions traditionally used to support National Emission Inventory based assessments. Field study specific information, which includes area burned, fuel consumption, and combustion completeness, resulted in increased biomass consumption by 123 tons (60% increase) on average compared to consumption estimated with default methods in the National Emission Inventory (NEI) process. Buoyancy heat flux, a key parameter for model predicted fire plume rise, estimated from fuel loading obtained from field measurements can be 30% to 200% more than when estimated using default field information. The increased buoyancy heat flux resulted in higher plume rise by 30% to 80%. This evaluation indicates that the regulatory air quality modeling system can replicate intensity and transport (horizontal and vertical) features for crop residue burning in this region when region-specific information is used to inform emissions and plume rise calculations. Further, previous vertical emissions allocation treatment of putting all cropland residue burning in the surface layer does not compare well with measured plume structure and these types of burns should be modeled more similarly to prescribed fires such that plume rise is based on an estimate of buoyancy. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Assessment of biomass burning emissions and their impacts on urban and regional PM2.5: a Georgia case study.

    PubMed

    Tian, Di; Hu, Yongtao; Wang, Yuhang; Boylan, James W; Zheng, Mei; Russell, Armistead G

    2009-01-15

    Biomass burning is a major and growing contributor to particulate matter with an aerodynamic diameter less than 2.5 microm (PM2.5). Such impacts (especially individual impacts from each burning source) are quantified using the Community Multiscale Air Quality (CMAQ) Model, a chemical transport model (CTM). Given the sensitivity of CTM results to uncertain emission inputs, simulations were conducted using three biomass burning inventories. Shortcomings in the burning emissions were also evaluated by comparing simulations with observations and results from a receptor model. Model performance improved significantly with the updated emissions and speciation profiles based on recent measurements for biomass burning: mean fractional bias is reduced from 22% to 4% for elemental carbon and from 18% to 12% for organic matter; mean fractional error is reduced from 59% to 50% for elemental carbon and from 55% to 49% for organic matter. Quantified impacts of biomass burning on PM2.5 during January, March, May, and July 2002 are 3.0, 5.1, 0.8, and 0.3 microg m(-3) domainwide on average, with more than 80% of such impacts being from primary emissions. Impacts of prescribed burning dominate biomass burning impacts, contributing about 55% and 80% of PM2.5 in January and March, respectively, followed by land clearing and agriculture field burning. Significant impacts of wildfires in May and residential wood combustion in fireplaces and woodstoves in January are also found.

  4. Towards more efficient burn care: Identifying factors associated with good quality of life post-burn.

    PubMed

    Finlay, V; Phillips, M; Allison, G T; Wood, F M; Ching, D; Wicaksono, D; Plowman, S; Hendrie, D; Edgar, D W

    2015-11-01

    As minor burn patients constitute the vast majority of a developed nation case-mix, streamlining care for this group can promote efficiency from a service-wide perspective. This study tested the hypothesis that a predictive nomogram model that estimates likelihood of good long-term quality of life (QoL) post-burn is a valid way to optimise patient selection and risk management when applying a streamlined model of care. A sample of 224 burn patients managed by the Burn Service of Western Australia who provided both short and long-term outcomes was used to estimate the probability of achieving a good QoL defined as 150 out of a possible 160 points on the Burn Specific Health Scale-Brief (BSHS-B) at least six months from injury. A multivariate logistic regression analysis produced a predictive model provisioned as a nomogram for clinical application. A second, independent cohort of consecutive patients (n=106) was used to validate the predictive merit of the nomogram. Male gender (p=0.02), conservative management (p=0.03), upper limb burn (p=0.04) and high BSHS-B score within one month of burn (p<0.001) were significant predictors of good outcome at six months and beyond. A Receiver Operating Curve (ROC) analysis demonstrated excellent (90%) accuracy overall. At 80% probability of good outcome, the false positive risk was 14%. The nomogram was validated by running a second ROC analysis of the model in an independent cohort. The analysis confirmed high (86%) overall accuracy of the model, the risk of false positive was reduced to 10% at a lower (70%) probability. This affirms the stability of the nomogram model in different patient groups over time. An investigation of the effect of missing data on sample selection determined that a greater proportion of younger patients with smaller TBSA burns were excluded due to loss to follow up. For clinicians managing comparable burn populations, the BSWA burns nomogram is an effective tool to assist the selection of patients to a streamlined care pathway with the aim of improving efficiency of service delivery. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  5. Relationships between human population density and burned area at continental and global scales.

    PubMed

    Bistinas, Ioannis; Oom, Duarte; Sá, Ana C L; Harrison, Sandy P; Prentice, I Colin; Pereira, José M C

    2013-01-01

    We explore the large spatial variation in the relationship between population density and burned area, using continental-scale Geographically Weighted Regression (GWR) based on 13 years of satellite-derived burned area maps from the global fire emissions database (GFED) and the human population density from the gridded population of the world (GPW 2005). Significant relationships are observed over 51.5% of the global land area, and the area affected varies from continent to continent: population density has a significant impact on fire over most of Asia and Africa but is important in explaining fire over < 22% of Europe and Australia. Increasing population density is associated with both increased and decreased in fire. The nature of the relationship depends on land-use: increasing population density is associated with increased burned are in rangelands but with decreased burned area in croplands. Overall, the relationship between population density and burned area is non-monotonic: burned area initially increases with population density and then decreases when population density exceeds a threshold. These thresholds vary regionally. Our study contributes to improved understanding of how human activities relate to burned area, and should contribute to a better estimate of atmospheric emissions from biomass burning.

  6. Relationships between Human Population Density and Burned Area at Continental and Global Scales

    PubMed Central

    Bistinas, Ioannis; Oom, Duarte; Sá, Ana C. L.; Harrison, Sandy P.; Prentice, I. Colin; Pereira, José M. C.

    2013-01-01

    We explore the large spatial variation in the relationship between population density and burned area, using continental-scale Geographically Weighted Regression (GWR) based on 13 years of satellite-derived burned area maps from the global fire emissions database (GFED) and the human population density from the gridded population of the world (GPW 2005). Significant relationships are observed over 51.5% of the global land area, and the area affected varies from continent to continent: population density has a significant impact on fire over most of Asia and Africa but is important in explaining fire over < 22% of Europe and Australia. Increasing population density is associated with both increased and decreased in fire. The nature of the relationship depends on land-use: increasing population density is associated with increased burned are in rangelands but with decreased burned area in croplands. Overall, the relationship between population density and burned area is non-monotonic: burned area initially increases with population density and then decreases when population density exceeds a threshold. These thresholds vary regionally. Our study contributes to improved understanding of how human activities relate to burned area, and should contribute to a better estimate of atmospheric emissions from biomass burning. PMID:24358108

  7. High-Fidelity Aerostructural Design Optimization of Transport Aircraft with Continuous Morphing Trailing Edge Technology

    NASA Astrophysics Data System (ADS)

    Burdette, David A., Jr.

    Adaptive morphing trailing edge technology offers the potential to decrease the fuel burn of transonic commercial transport aircraft by allowing wings to dynamically adjust to changing flight conditions. Current configurations allow flap and aileron droop; however, this approach provides limited degrees of freedom and increased drag produced by gaps in the wing's surface. Leading members in the aeronautics community including NASA, AFRL, Boeing, and a number of academic institutions have extensively researched morphing technology for its potential to improve aircraft efficiency. With modern computational tools it is possible to accurately and efficiently model aircraft configurations in order to quantify the efficiency improvements offered by mor- phing technology. Coupled high-fidelity aerodynamic and structural solvers provide the capability to model and thoroughly understand the nuanced trade-offs involved in aircraft design. This capability is important for a detailed study of the capabilities of morphing trailing edge technology. Gradient-based multidisciplinary design opti- mization provides the ability to efficiently traverse design spaces and optimize the trade-offs associated with the design. This thesis presents a number of optimization studies comparing optimized config- urations with and without morphing trailing edge devices. The baseline configuration used throughout this work is the NASA Common Research Model. The first opti- mization comparison considers the optimal fuel burn predicted by the Breguet range equation at a single cruise point. This initial singlepoint optimization comparison demonstrated a limited fuel burn savings of less than 1%. Given the effectiveness of the passive aeroelastic tailoring in the optimized non-morphing wing, the singlepoint optimization offered limited potential for morphing technology to provide any bene- fit. To provide a more appropriate comparison, a number of multipoint optimizations were performed. With a 3-point stencil, the morphing wing burned 2.53% less fuel than its optimized non-morphing counterpart. Expanding further to a 7-point stencil, the morphing wing used 5.04% less fuel. Additional studies demonstrate that the size of the morphing device can be reduced without sizable performance reductions, and that as aircraft wings' aspect ratios increase, the effectiveness of morphing trailing edge devices increases. The final set of studies in this thesis consider mission analy- sis, including climb, multi-altitude cruise, and descent. These mission analyses were performed with a number of surrogate models, trained with O(100) optimizations. These optimizations demonstrated fuel burn reductions as large as 5% at off-design conditions. The fuel burn predicted by the mission analysis was up to 2.7% lower for the morphing wing compared to the conventional configuration.

  8. Therapeutic effects of transdermal systems containing zinc-related materials on thermal burn rats.

    PubMed

    Otsuka, Makoto; Hatakeyama, Haruna; Shikamura, Masayuki; Otsuka, Kuniko; Ito, Atsuo

    2015-01-01

    The aim of the present study is to evaluate the efficacy of slow zinc (Zn) release from β-tricalcium phosphate powder (ZnTCP) containing 10 mol% Zn on rats with thermal burns. The first-aid tapes were contained zinc sulfate (ZnSO4) solution, ZnTCP suspensions or zinc oxide ointment. After thermal burn treatments were performed on Zn-deficient rats, the groups D1, D2 and D3 were treated with tapes containing ZnTCP, ZnSO4 and zinc oxide ointment. The effects of the tapes on wound area, plasma Zn levels and alkaline phosphatase activity (Alp) were investigated. The wound area profiles of all rat groups could be separated into before and after the scab formation at around day 6. The area under the curve (Aw-AUC) for wound area profiles, therefore, was evaluated as an index of therapeutic scores for the thermal wound. The order of Aw-AUC was D3>C>D2>D1. The degree of expansion at the initial stage by thermal burns of group D1 was the lowest and that of group D2 was the highest, and the order was D1

  9. Photoacoustic diagnosis of burns in rats: two-dimensional photo-acoustic imaging of burned tissue

    NASA Astrophysics Data System (ADS)

    Yamazaki, Mutsuo; Sato, Shunichi; Saito, Daizo; Okada, Yoshiaki; Kurita, Akira; Kikuchi, Makoto; Ashida, Hiroshi; Obara, Minoru

    2003-06-01

    We previously reported that for rat burn models, deep dermal burns and deep burns can be well differentiated by measuring the propagation time of the photoacoustic signals originated from the blood in the healthy skin tissue under the damaged tissue layer. However, the diagnosis was based on point measurement in the wound, and therefore site-dependent information on the injuries was not obtained; such information is very important for diagnosis of extended burns. In the present study, we scanned a photoacoustic detector on the wound and constructed two-dimensional (2-D) images of the blood-originated photoacoustic signals for superficial dermal burns (SDB), deep dermal burns (DDB), deep burns (DB), and healthy skins (control) in rats. For each burn model, site-dependent variation of the signal was observed; the variation probably reflects the distribution of blood vessels in the skin tissue. In spite of the variation, clear differentiation was obtained between SDB, DDB, and DB from the 2D images. The images were constructed as a function of post burn time. Temporal signal variation will be also presented.

  10. Waterfowl populations are resilient to immediate and lagged impacts of wildfires in the boreal forest

    USGS Publications Warehouse

    Lewis, Tyler; Schmutz, Joel A.; Amundson, Courtney L.; Lindberg, Mark S.

    2016-01-01

    Summary 1. Wildfires are the principal disturbance in the boreal forest, and their size and frequency are increasing as the climate warms. Impacts of fires on boreal wildlife are largely unknown, especially for the tens of millions of waterfowl that breed in the region. This knowledge gap creates significant barriers to the integrative management of fires and waterfowl, leading to fire policies that largely disregard waterfowl. 2. Waterfowl populations across the western boreal forest of North America have been monitored annually since 1955 by the Waterfowl Breeding Population and Habitat Survey (BPOP), widely considered the most extensive wildlife survey in the world. Using these data, we examined impacts of forest fires on abundance of two waterfowl guilds – dabblers and divers. We modelled waterfowl abundance in relation to fire extent (i.e. amount of survey transect burned) and time since fire, examining both immediate and lagged fire impacts. 3. From 1955 to 2014, >1100 fires in the western boreal forest intersected BPOP survey transects, and many transects burned multiple times. Nonetheless, fires had no detectable impact on waterfowl abundance; annual transect counts of dabbler and diver pairs remained stable from the pre- to post-fire period. 4. The absence of fire impacts on waterfowl abundance extended from the years immediately following the fire to those more than a decade afterwards. Likewise, the amount of transect burned did not influence waterfowl abundance, with similar pair counts from the pre- to post-fire period for small (1–20% burned), medium (21–60%) and large (>60%) burns. 5. Policy implications. Waterfowl populations appear largely resilient to forest fires, providing initial evidence that current policies of limited fire suppression, which predominate throughout much of the boreal forest, have not been detrimental to waterfowl populations. Likewise, fire-related management actions, such as prescribed burning or targeted suppression, seem to have limited impacts on waterfowl abundance and productivity. For waterfowl managers, our results suggest that adaptive models of waterfowl harvest, which annually guide hunting quotas, do not need to emphasize fires when integrating climate change effects.

  11. Quantifying the influence of boreal biomass burning emissions on tropospheric oxidant chemistry over the North Atlantic using BORTAS measurements

    NASA Astrophysics Data System (ADS)

    Parrington, Mark; Palmer, Paul I.; Rickard, Andrew; Young, Jennifer; Lewis, Ally; Lee, James; Henze, Daven; Tarasick, David; Hyer, Edward; Yantosca, Robert; Bowman, Kevin; Worden, John; Griffin, Debora; Franklin, Jonathan; Helmig, Detlev

    2013-04-01

    We use the GEOS-Chem chemistry transport model to quantify the impact of boreal biomass burning on tropospheric oxidant chemistry over the North Atlantic region during summer of 2011. The GEOS-Chem model is used at a spatial resolution of 1/2 degree latitude by 2/3 degree longitude for a domain covering eastern North America, the North Atlantic Ocean and western Europe. We initialise the model with biomass burning emissions from the Fire Locating and Monitoring of Burning Emissions (FLAMBE) inventory and use a modified chemical mechanism providing a detailed description of ozone photochemistry in boreal biomass burning outflow derived from the Master Chemical Mechanism (MCM). We evaluate the 3-D model distribution of ozone and tracers associated with biomass burning against measurements made by the UK FAAM BAe-146 research aircraft, ozonesondes, ground-based and satellite instruments as part of the BORTAS experiment between 12 July and 3 August 2011. We also use the GEOS-Chem model adjoint to fit the model to BORTAS measurements to analyse the sensitivity of the model chemical mechanism and ozone distribution to wildfire emissions in central Canada.

  12. Large Scale Flame Spread Environmental Characterization Testing

    NASA Technical Reports Server (NTRS)

    Clayman, Lauren K.; Olson, Sandra L.; Gokoghi, Suleyman A.; Brooker, John E.; Ferkul, Paul V.; Kacher, Henry F.

    2013-01-01

    Under the Advanced Exploration Systems (AES) Spacecraft Fire Safety Demonstration Project (SFSDP), as a risk mitigation activity in support of the development of a large-scale fire demonstration experiment in microgravity, flame-spread tests were conducted in normal gravity on thin, cellulose-based fuels in a sealed chamber. The primary objective of the tests was to measure pressure rise in a chamber as sample material, burning direction (upward/downward), total heat release, heat release rate, and heat loss mechanisms were varied between tests. A Design of Experiments (DOE) method was imposed to produce an array of tests from a fixed set of constraints and a coupled response model was developed. Supplementary tests were run without experimental design to additionally vary select parameters such as initial chamber pressure. The starting chamber pressure for each test was set below atmospheric to prevent chamber overpressure. Bottom ignition, or upward propagating burns, produced rapid acceleratory turbulent flame spread. Pressure rise in the chamber increases as the amount of fuel burned increases mainly because of the larger amount of heat generation and, to a much smaller extent, due to the increase in gaseous number of moles. Top ignition, or downward propagating burns, produced a steady flame spread with a very small flat flame across the burning edge. Steady-state pressure is achieved during downward flame spread as the pressure rises and plateaus. This indicates that the heat generation by the flame matches the heat loss to surroundings during the longer, slower downward burns. One heat loss mechanism included mounting a heat exchanger directly above the burning sample in the path of the plume to act as a heat sink and more efficiently dissipate the heat due to the combustion event. This proved an effective means for chamber overpressure mitigation for those tests producing the most total heat release and thusly was determined to be a feasible mitigation strategy to incorporate into the microgravity experiment.

  13. Measuring short-term post-fire forest recovery across a burn severity gradient in a mixed pine-oak forest using multi-sensor remote sensing techniques

    DOE PAGES

    Meng, Ran; Wu, Jin; Zhao, Feng; ...

    2018-06-01

    Understanding post-fire forest recovery is pivotal to the study of forest dynamics and global carbon cycle. Field-based studies indicated a convex response of forest recovery rate to burn severity at the individual tree level, related with fire-induced tree mortality; however, these findings were constrained in spatial/temporal extents, while not detectable by traditional optical remote sensing studies, largely attributing to the contaminated effect from understory recovery. For this work, we examined whether the combined use of multi-sensor remote sensing techniques (i.e., 1m simultaneous airborne imaging spectroscopy and LiDAR and 2m satellite multi-spectral imagery) to separate canopy recovery from understory recovery wouldmore » enable to quantify post-fire forest recovery rate spanning a large gradient in burn severity over large-scales. Our study was conducted in a mixed pine-oak forest in Long Island, NY, three years after a top-killing fire. Our studies remotely detected an initial increase and then decline of forest recovery rate to burn severity across the burned area, with a maximum canopy area-based recovery rate of 10% per year at moderate forest burn severity class. More intriguingly, such remotely detected convex relationships also held at species level, with pine trees being more resilient to high burn severity and having a higher maximum recovery rate (12% per year) than oak trees (4% per year). These results are one of the first quantitative evidences showing the effects of fire adaptive strategies on post-fire forest recovery, derived from relatively large spatial-temporal domains. Our study thus provides the methodological advance to link multi-sensor remote sensing techniques to monitor forest dynamics in a spatially explicit manner over large-scales, with important implications for fire-related forest management, and for constraining/benchmarking fire effect schemes in ecological process models.« less

  14. Measuring short-term post-fire forest recovery across a burn severity gradient in a mixed pine-oak forest using multi-sensor remote sensing techniques

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Meng, Ran; Wu, Jin; Zhao, Feng

    Understanding post-fire forest recovery is pivotal to the study of forest dynamics and global carbon cycle. Field-based studies indicated a convex response of forest recovery rate to burn severity at the individual tree level, related with fire-induced tree mortality; however, these findings were constrained in spatial/temporal extents, while not detectable by traditional optical remote sensing studies, largely attributing to the contaminated effect from understory recovery. For this work, we examined whether the combined use of multi-sensor remote sensing techniques (i.e., 1m simultaneous airborne imaging spectroscopy and LiDAR and 2m satellite multi-spectral imagery) to separate canopy recovery from understory recovery wouldmore » enable to quantify post-fire forest recovery rate spanning a large gradient in burn severity over large-scales. Our study was conducted in a mixed pine-oak forest in Long Island, NY, three years after a top-killing fire. Our studies remotely detected an initial increase and then decline of forest recovery rate to burn severity across the burned area, with a maximum canopy area-based recovery rate of 10% per year at moderate forest burn severity class. More intriguingly, such remotely detected convex relationships also held at species level, with pine trees being more resilient to high burn severity and having a higher maximum recovery rate (12% per year) than oak trees (4% per year). These results are one of the first quantitative evidences showing the effects of fire adaptive strategies on post-fire forest recovery, derived from relatively large spatial-temporal domains. Our study thus provides the methodological advance to link multi-sensor remote sensing techniques to monitor forest dynamics in a spatially explicit manner over large-scales, with important implications for fire-related forest management, and for constraining/benchmarking fire effect schemes in ecological process models.« less

  15. Variable carbon losses from recurrent fires in drained tropical peatlands.

    PubMed

    Konecny, Kristina; Ballhorn, Uwe; Navratil, Peter; Jubanski, Juilson; Page, Susan E; Tansey, Kevin; Hooijer, Aljosja; Vernimmen, Ronald; Siegert, Florian

    2016-04-01

    Tropical peatland fires play a significant role in the context of global warming through emissions of substantial amounts of greenhouse gases. However, the state of knowledge on carbon loss from these fires is still poorly developed with few studies reporting the associated mass of peat consumed. Furthermore, spatial and temporal variations in burn depth have not been previously quantified. This study presents the first spatially explicit investigation of fire-driven tropical peat loss and its variability. An extensive airborne Light Detection and Ranging data set was used to develop a prefire peat surface modelling methodology, enabling the spatially differentiated quantification of burned area depth over the entire burned area. We observe a strong interdependence between burned area depth, fire frequency and distance to drainage canals. For the first time, we show that relative burned area depth decreases over the first four fire events and is constant thereafter. Based on our results, we revise existing peat and carbon loss estimates for recurrent fires in drained tropical peatlands. We suggest values for the dry mass of peat fuel consumed that are 206 t ha(-1) for initial fires, reducing to 115 t ha(-1) for second, 69 t ha(-1) for third and 23 t ha(-1) for successive fires, which are 58-7% of the current IPCC Tier 1 default value for all fires. In our study area, this results in carbon losses of 114, 64, 38 and 13 t C ha(-1) for first to fourth fires, respectively. Furthermore, we show that with increasing proximity to drainage canals both burned area depth and the probability of recurrent fires increase and present equations explaining burned area depth as a function of distance to drainage canal. This improved knowledge enables a more accurate approach to emissions accounting and will support IPCC Tier 2 reporting of fire emissions. © 2015 John Wiley & Sons Ltd.

  16. Root Disease, Longleaf Pine Mortality, and Prescribed Burning

    Treesearch

    William J. Otrosina; Charles H. Walkinshaw; Stanley J. Zarnoch; Shi-Jean S. Sung; Brian T. Sullivan

    2002-01-01

    Abstract - A study was initiated at the Savannah River Site, New Ellenton, SC, to determine factors involved in decline of longleaf pine associated with prescribed burning. Pretreatment and post-treatment surveys were conducted on all treatment plots. Symptomatic trees were recorded by means of a crown rating system based upon symptom severity. Three...

  17. "First aid" for burned watersheds

    Treesearch

    J. S. Krammes; L. W. Hill

    1963-01-01

    Most of the vegetative cover on the San Dimas Experimental Forest was destroyed by a wildfire in 1960. Following the fire an emergency research program was initiated to test several "first -aid" treatments aimed at reducing flood and erosion damage from burned watersheds. This paper summarizes first - and second-year results of the research program.

  18. No correlation between initial arterial carboxyhemoglobin level and degree of lung injury following ovine burn and smoke inhalation.

    PubMed

    Lange, Matthias; Cox, Robert A; Traber, Daniel L; Hamahata, Atsumori; Nakano, Yoshimitsu; Traber, Lillian D; Enkhbaatar, Perenlei

    2014-04-01

    Fire victims often suffer from burn injury and concomitant inhalation trauma, the latter significantly contributing to the morbidity and mortality in these patients. Measurement of blood carboxyhemoglobin levels has been proposed as a diagnostic marker to verify and, perhaps, quantify the degree of lung injury following inhalation trauma. However, this correlation has not yet been sufficiently validated. A total of 77 chronically instrumented sheep received sham injury, smoke inhalation injury, or combined burn and inhalation trauma following an established protocol. Arterial carboxyhemoglobin concentrations were determined directly after injury and correlated to several clinical and histopathological determinants of lung injury that were detected 48 hours post-injury. The injury induced severe impairment of pulmonary gas exchange and increases in transvascular fluid flux, lung water content, and airway obstruction scores. No significant correlations were detected between initial carboxyhemoglobin levels and all measured clinical and histopathological determinants of lung injury. In conclusion, the amount of arterial carboxyhemoglobin concentration cannot predict the degree of lung injury at 48 hours after ovine burn and smoke inhalation trauma.

  19. Strain-Rate-Free Diffusion Flames: Initiation, Properties, and Quenching

    NASA Technical Reports Server (NTRS)

    Fendell, Francis; Rungaldier, Harald; Gokoglu, Suleyman; Schultz, Donald

    1997-01-01

    For about a half century, the stabilization of a steady planar deflagration on a heat-sink-type flat-flame burner has been of extraordinary service for the theoretical modeling and diagnostic probing of combusting gaseous mixtures. However, most engineering devices and most unwanted fire involve the burning of initially unmixed reactants. The most vigorous burning of initially separated gaseous fuel and oxidizer is the diffusion flame. In this useful idealization (limiting case), the reactants are converted to product at a mathematically thin interface, so no interpenetration of fuel and oxidizer occurs. This limit is of practical importance because it often characterizes the condition of optimal performance (and sometimes environmentally objectionable operation) of a combustor. A steady planar diffusion flame is most closely approached in the laboratory in the counterflow apparatus. The utility of this simple-strain-rate flow for the modeling and probing of diffusion flames was noted by Pandya and Weinberg 35 years ago, though only in the last decade or so has its use become internationally common place. However, typically, as the strain rate a is reduced below about 20 cm(exp -1), and the diffusion-flame limit (reaction rate much faster than the flow rate) is approached, the burning is observed to become unstable in earth gravity. The advantageous steady planar flow is not available in the diffusion-flame limit in earth gravity. This is unfortunate because the typical spatial scale in a counterflow is (k/a)(sup 1/2), where k denotes a characteristic diffusion coefficient; thus, the length scale becomes large, and the reacting flow is particularly amenable to diagnostic probing, as the diffusion-flame limit is approached. The disruption of planar symmetry is owing the fact that, as the strain rate a decreases, the residence time (l/a) of the throughput in the counterflow burner increases. Observationally, when the residence time exceeds about 50 msec, the inevitably present convective (Rayleigh-Benard) instabilities, associated with hot-under-cold (flame-under-fresh-reactant) stratification of fluid in a gravitational field, have time to grow to finite amplitude during transit of the burner.

  20. A One-Dimensional Global-Scaling Erosive Burning Model Informed by Blowing Wall Turbulence

    NASA Technical Reports Server (NTRS)

    Kibbey, Timothy P.

    2014-01-01

    A derivation of turbulent flow parameters, combined with data from erosive burning test motors and blowing wall tests results in erosive burning model candidates useful in one-dimensional internal ballistics analysis capable of scaling across wide ranges of motor size. The real-time burn rate data comes from three test campaigns of subscale segmented solid rocket motors tested at two facilities. The flow theory admits the important effect of the blowing wall on the turbulent friction coefficient by using blowing wall data to determine the blowing wall friction coefficient. The erosive burning behavior of full-scale motors is now predicted more closely than with other recent models.

  1. The conductive propagation of nuclear flames. 2: Convectively bounded flames in C + O and O + Ne + Mg cores

    NASA Technical Reports Server (NTRS)

    Timmes, F. X.; Woosley, S. E.; Taam, Ronald E.

    1994-01-01

    We determine the speeds, and many other physical properties, of flame fronts that propagate inward into degenerate and semidegenerate cores of carbon and oxygen (CO) and neon and oxygen (NeOMg) white dwarfs when such flames are bounded on their exterior by a convective region. Combustion in such fronts, per se, is incomplete, with only a small part of the initial mass function burned. A condition of balanced power is set up in the star where the rate of energy emitted as neutrinos from the convective region equals the power available from the unburned fuel that crosses the burning front. The propagation of the burning front itself is in turn limited by the temperature at the base of the convective shell, while cannot greatly exceed the adiabatic value. Solving for consistency between these two conditions gives a unique speed for the flame. Typical values for CO white dwarfs are a few hundredths of a centimeter per second. Flames in NeOMg mixtures are slower. Tables are presented in a form that can easily be implemented in stellar evolution codes and yield the rate at which the convective shell advances into the interior. Combining these velocities with the local equations for stellar structure, we find a minimum density for each gravitational potential below with the local equations for stellar structure, we find a minimum density for each gravitational potential below which the flame cannot propagate, and must die. Although detailed stellar models will have to be constructed to reslove some issues conclusively, our results that a CO white dwarf inginted at its edge will not burn carbon all the way to its center unless the mass of the white dwarf exceeds 0.8 solar mass. On the other hand, it is difficult to ignite carbon burning by compression alone anywhere in a white dwarf whose mass does not exceed 1.0 solar mass. Thus, compressionally ignited shell carbon burning in an accerting CO dwarf almost certainly propagates all the way to the center of the star. Implications for neutron star formation, and Type Ia supernova models, are briefly discussed. These are also applicable to massive stars in the about 10-12 solar mass range which ignite neon burning off center.

  2. Application of a MODIS Soil Moisture-Evapotranspiration (MOD-SMET) Model to Evaluate Landscape and Hydrologic Recovery after the High Park Fire in Colorado, USA

    NASA Astrophysics Data System (ADS)

    Blount, W. K.; Hogue, T. S.; Franz, K.; Knipper, K. R.

    2017-12-01

    Accurate estimation of evapotranspiration (ET) is critical for the management of water resources, especially in water-stressed regions. ET accounts for approximately 60% of terrestrial precipitation globally and approaches 100% of annual rainfall in arid ecosystems, where transpiration becomes the dominant term. ET is difficult to measure due to its spatiotemporal variation, which requires adequate data coverage. While new remote sensing-based ET products are available at a 1 km spatial resolution, including the Operational Simplified Surface Energy Balance model (SSEBop) and the MODIS Global Evapotranspiration Project (MOD16), these products are available at monthly and 8-day temporal resolutions, respectively. To better understand the changing dynamics of hydrologic fluxes and the partitioning of water after land cover disturbances and to identify statically significant trends, more frequent observations are necessary. Utilizing the recently developed MODIS Soil Moisture-Evapotranspiration (MOD-SMET) model, daily temporal resolution is achieved. This presentation outlines the methodology of the MOD-SMET model and compares SSEBop, MOD16, and MOD-SMET ET estimates over the High Park Fire burn scar in Colorado, USA. MOD-SMET estimates are used to identify changes in fluxes and partitioning of the water cycle after a wildfire and during recovery in the High Park Fire near Fort Collins, Colorado. Initial results indicate greenness and ET from all three models decrease post-fire, with higher statistical confidence in high burn areas and spatial patterns that closely align with burn severity. MOD-SMET improves the ability to resolve statistically significant changes in ET following wildfires and better understand changes in the post-fire water budget. Utilizing this knowledge, water resource managers can better plan for, and mitigate, the short- and long-term impacts of wildfire on regional water supplies.

  3. Vegetation management with fire modifies peatland soil thermal regime.

    PubMed

    Brown, Lee E; Palmer, Sheila M; Johnston, Kerrylyn; Holden, Joseph

    2015-05-01

    Vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. In the UK, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (Lagopus lagopus scotica) by rotational burning of shrub vegetation. To date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of the soil mass in the years after fire. In this study thermal regime was monitored across 12 burned peatland soil plots over an 18-month period, with the aim of (i) quantifying thermal dynamics between burned plots of different ages (from <2 to 15 + years post burning), and (ii) developing statistical models to determine the magnitude of thermal change caused by vegetation management. Compared to plots burned 15 + years previously, plots recently burned (<2-4 years) showed higher mean, maximum and range of soil temperatures, and lower minima. Statistical models (generalised least square regression) were developed to predict daily mean and maximum soil temperature in plots burned 15 + years prior to the study. These models were then applied to predict temperatures of plots burned 2, 4 and 7 years previously, with significant deviations from predicted temperatures illustrating the magnitude of burn management effects. Temperatures measured in soil plots burned <2 years previously showed significant statistical disturbances from model predictions, reaching +6.2 °C for daily mean temperatures and +19.6 °C for daily maxima. Soil temperatures in plots burnt 7 years previously were most similar to plots burned 15 + years ago indicating the potential for soil temperatures to recover as vegetation regrows. Our findings that prescribed peatland vegetation burning alters soil thermal regime should provide an impetus for further research to understand the consequences of thermal regime change for carbon processing and release, and hydrological processes, in these peatlands. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Accuracy of Currently Used Paper Burn Diagram vs a Three-Dimensional Computerized Model.

    PubMed

    Benjamin, Nicole C; Lee, Jong O; Norbury, William B; Branski, Ludwik K; Wurzer, Paul; Jimenez, Carlos J; Benjamin, Debra A; Herndon, David N

    Burn units have historically used paper diagrams to estimate percent burn; however, unintentional errors can occur. The use of a computer program that incorporates wound mapping from photographs onto a three-dimensional (3D) human diagram could decrease subjectivity in preparing burn diagrams and subsequent calculations of TBSA burned. Analyses were done on 19 burned patients who had an estimated TBSA burned of ≥20%. The patients were admitted to Shriners Hospitals for Children or the University of Texas Medical Branch in Galveston, Texas, from July 2012 to September 2013 for treatment. Digital photographs were collected before the patient's first surgery. Using BurnCase 3D (RISC Software GmbH, Hagenberg, Austria), a burn mapping software, the user traced partial- and full-thickness burns from photographs. The program then superimposed tracings onto a 3D model and calculated percent burned. The results were compared with the Lund and Browder diagrams completed after the first operation. A two-tailed t-test was used to calculate statistical differences. For partial-thickness burns, burn sizes calculated using Lund and Browder diagrams were significantly larger than those calculated using BurnCase 3D (15% difference, P < .01). The opposite was found for full-thickness burns, with burn sizes being smaller when calculated using Lund and Browder diagrams (11% difference, P < .05). In conclusion, substantial differences exist in percent burn estimations derived from BurnCase 3D and paper diagrams. In our studied cohort, paper diagrams were associated with overestimation of partial-thickness burn size and underestimation of full-thickness burn size. Additional studies comparing BurnCase 3D with other commonly used methods are warranted.

  5. Development of clinical process measures for pediatric burn care: Understanding variation in practice patterns.

    PubMed

    Kazis, Lewis E; Sheridan, Robert L; Shapiro, Gabriel D; Lee, Austin F; Liang, Matthew H; Ryan, Colleen M; Schneider, Jeffrey C; Lydon, Martha; Soley-Bori, Marina; Sonis, Lily A; Dore, Emily C; Palmieri, Tina; Herndon, David; Meyer, Walter; Warner, Petra; Kagan, Richard; Stoddard, Frederick J; Murphy, Michael; Tompkins, Ronald G

    2018-04-01

    There has been little systematic examination of variation in pediatric burn care clinical practices and its effect on outcomes. As a first step, current clinical care processes need to be operationally defined. The highly specialized burn care units of the Shriners Hospitals for Children system present an opportunity to describe the processes of care. The aim of this study was to develop a set of process-based measures for pediatric burn care and examine adherence to them by providers in a cohort of pediatric burn patients. We conducted a systematic literature review to compile a set of process-based indicators. These measures were refined by an expert panel of burn care providers, yielding 36 process-based indicators in four clinical areas: initial evaluation and resuscitation, acute excisional surgery and critical care, psychosocial and pain control, and reconstruction and aftercare. We assessed variability in adherence to the indicators in a cohort of 1,076 children with burns at four regional pediatric burn programs in the Shriners Hospital system. The percentages of the cohort at each of the four sites were as follows: Boston, 20.8%; Cincinnati, 21.1%; Galveston, 36.0%; and Sacramento, 22.1%. The cohort included children who received care between 2006 and 2010. Adherence to the process indicators varied both across sites and by clinical area. Adherence was lowest for the clinical areas of acute excisional surgery and critical care, with a range of 35% to 48% across sites, followed by initial evaluation and resuscitation (range, 34%-60%). In contrast, the clinical areas of psychosocial and pain control and reconstruction and aftercare had relatively high adherence across sites, with ranges of 62% to 93% and 71% to 87%, respectively. Of the 36 process indicators, 89% differed significantly in adherence between clinical sites (p < 0.05). Acute excisional surgery and critical care exhibited the most variability. The development of this set of process-based measures represents an important step in the assessment of clinical practice in pediatric burn care. Substantial variation was observed in practices of pediatric burn care. However, further research is needed to link these process-based measures to clinical outcomes. Therapeutic/care management, level IV.

  6. Using multilevel spatial models to understand salamander site occupancy patterns after wildfire

    USGS Publications Warehouse

    Chelgren, Nathan; Adams, Michael J.; Bailey, Larissa L.; Bury, R. Bruce

    2011-01-01

    Studies of the distribution of elusive forest wildlife have suffered from the confounding of true presence with the uncertainty of detection. Occupancy modeling, which incorporates probabilities of species detection conditional on presence, is an emerging approach for reducing observation bias. However, the current likelihood modeling framework is restrictive for handling unexplained sources of variation in the response that may occur when there are dependence structures such as smaller sampling units that are nested within larger sampling units. We used multilevel Bayesian occupancy modeling to handle dependence structures and to partition sources of variation in occupancy of sites by terrestrial salamanders (family Plethodontidae) within and surrounding an earlier wildfire in western Oregon, USA. Comparison of model fit favored a spatial N-mixture model that accounted for variation in salamander abundance over models that were based on binary detection/non-detection data. Though catch per unit effort was higher in burned areas than unburned, there was strong support that this pattern was due to a higher probability of capture for individuals in burned plots. Within the burn, the odds of capturing an individual given it was present were 2.06 times the odds outside the burn, reflecting reduced complexity of ground cover in the burn. There was weak support that true occupancy was lower within the burned area. While the odds of occupancy in the burn were 0.49 times the odds outside the burn among the five species, the magnitude of variation attributed to the burn was small in comparison to variation attributed to other landscape variables and to unexplained, spatially autocorrelated random variation. While ordinary occupancy models may separate the biological pattern of interest from variation in detection probability when all sources of variation are known, the addition of random effects structures for unexplained sources of variation in occupancy and detection probability may often more appropriately represent levels of uncertainty. ?? 2011 by the Ecological Society of America.

  7. 40 CFR Table 8 to Subpart Dddd of... - Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Apply to Waste-Burning Kilns After May 20, 2011 8 Table 8 to Subpart DDDD of Part 60 Protection of..., Table 8 Table 8 to Subpart DDDD of Part 60—Model Rule—Emission Limitations That Apply to Waste-Burning... to Waste-Burning Kilns After May 20, 2011 For the air pollutant You must meet this emissionlimitation...

  8. NASA's East and Southeast Asia Initiatives: BASE-ASIA and EAST-AIRE

    NASA Technical Reports Server (NTRS)

    Tsay, S.; Maring, H.

    2005-01-01

    Airborne dust from northern China influences air quality and regional climate in Asia during springtime. However, with the economic growth in China, increased emission of particulate air pollutants from industrial and vehicular sources will not only impact the earth's radiation balance, but also adversely affect human health year round. In addition, both of dust and aerosol pollutants can be transported swiftly across the Pacific affecting North America within a few days. Asian dust and pollutant aerosols can be detected by their colored appearance using current Earth observing satellites (e.g., MODIS, SeaWiFS, TOMS, etc.) and by sunphotometers deployed on the surface of the earth. Biomass burning has been a regular practice for land clearing and conversion in many countries, especially those in Africa, South America, and Southeast Asia. However, the climatology of Southeast Asia is very different than that of Africa and South America, such that large-scale biomass burning causes smoke to interact extensively with clouds during the peak-burning season of March to April. Globally significant sources of greenhouse gases (eg., CO2, CH4), chemically active gases (e.g., NO, CO, HC, CH3Br), and atmospheric aerosols are produced by biomass burning. These gases influence the Earth-atmosphere system, impacting both global climate and tropospheric chemistry. Some aerosols can serve as cloud condensation nuclei, which play a role in determining cloud lifetime and precipitation, altering the earth's radiation and water budgets. Biomass burning also affects the biogeochemical cycling of nitrogen and carbon compounds; the hydrological cycle; land surface reflectivity and emissivity; and ecosystem biodiversity and stability. Two NASA initiatives, EAST-AIRE (East Asian Study of Tropospheric Aerosols: an International Regional Experiment) and BASE-ASIA (Biomass-burning Aerosols in South East-Asia: Smoke Impact Assessment) will be presented. The objectives of these initiatives is to develop a better understanding of the impacts of aerosols on regional-to-global climate, hydrological and carbon cycles, and tropospheric chemistry.

  9. Rehabilitation and social adjustment of people with burns in society.

    PubMed

    Din, Sirajud; Shah, Mussawar; Asadullah; Jamal, Humera; Bilal, Muhammad

    2015-02-01

    The present study was conducted on rehabilitation and social adjustment of people with burns in society with the main objective to determine the relationship between social adjustment of people with burns and their psychosocial rehabilitation. The study was limited to the Burn Unit, Khyber Teaching Hospital, Peshawar, Pakistan. At bi-variate level, the following were observed: the relationship of psychosocial rehabilitation was highly significant (P=0.000) considering that people with burns feel shame in the society, a highly significant relation (P=0.000) was found between psychosocial rehabilitation and burn as the hurdle to contact other members of the society, a highly significant (P=0.000) relation was found between psychosocial rehabilitation and perception that society provides social support to people with burns, a highly significant (P=0.000) relationship between psychosocial rehabilitation and people with burns feel alienated from the society, a significant association (P=0.024) was found between psychosocial rehabilitation and loss of social network, and a significant (P=0.002) association between psychosocial rehabilitation and society insult toward people with burns. Regular provision of treatment, quota in job allocation for people with burns, initiation of stipend through Benazir Income Support Program, and keeping and updating record of burns at the district level in census centers were suggested as recommendations in light of the study. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  10. Initial Development and Testing of a State-of-the-Art Method to Quantify Hydrologic Model Uncertainty

    DTIC Science & Technology

    2013-09-01

    H. Teller , and E. Teller . 1953. Equation of state calculations by fast computing machines . J Chem Phys, 21: 1087-1092. Skahill, B. E. 2012. Practice...of DE-MC sampler burn-in, a hybrid semi- automated approach was implemented, consistent with available guidance regarding practical application of...treatment of jump proposal dimensions that are out of bounds, and a hybrid, heuristic, semi- automated approach for assessing convergence of the DE-MC

  11. Photoacoustic signal measurement for burned skins in the spectral range of 500-650 nm: experiment with rat burn models

    NASA Astrophysics Data System (ADS)

    Yamazaki, Mutsuo; Sato, Shunichi; Saito, Daizo; Fujita, Masanori; Okada, Yoshiaki; Kikuchi, Makoto; Ashida, Hiroshi; Obara, Minoru

    2002-06-01

    This paper reports the burn diagnosis that is based on the measurement of photoacoustic waves from skin, where the acoustic waves originate from the absorption of light by blood. For this purpose, a transducer composed of a ring-shaped piezoelectric film and a quartz fiber was made. An optical parametric oscillator (500 - 650 nm) was used as a light source and its output pulses were coupled to the quartz fiber. To investigate the optimum light wavelength, we conducted experiments using rat burn models. We demonstrated that the superficial dermal burn (SDB), deep dermal burn (DDB), deep burn (DB), and control (healthy skin) could be clearly differentiated based on the photoacoustic signals induced by the light of 532 - 580nm.

  12. A Minimum Delta V Orbit Maintenance Strategy for Low-Altitude Missions Using Burn Parameter Optimization

    NASA Technical Reports Server (NTRS)

    Brown, Aaron J.

    2011-01-01

    Orbit maintenance is the series of burns performed during a mission to ensure the orbit satisfies mission constraints. Low-altitude missions often require non-trivial orbit maintenance Delta V due to sizable orbital perturbations and minimum altitude thresholds. A strategy is presented for minimizing this Delta V using impulsive burn parameter optimization. An initial estimate for the burn parameters is generated by considering a feasible solution to the orbit maintenance problem. An low-lunar orbit example demonstrates the Delta V savings from the feasible solution to the optimal solution. The strategy s extensibility to more complex missions is discussed, as well as the limitations of its use.

  13. Climate vs. carbon dioxide controls on biomass burning: a model analysis of the glacial-interglacial contrast

    NASA Astrophysics Data System (ADS)

    Calvo, M. Martin; Prentice, I. C.; Harrison, S. P.

    2014-02-01

    Climate controls fire regimes through its influence on the amount and types of fuel present and their dryness; CO2 availability, in turn, constrains primary production by limiting photosynthetic activity in plants. However, although fuel accumulation depends on biomass production, and hence CO2 availability, the links between atmospheric CO2 and biomass burning are not well known. Here a fire-enabled dynamic global vegetation model (the Land surface Processes and eXchanges model, LPX) is used to attribute glacial-interglacial changes in biomass burning to CO2 increase, which would be expected to increase primary production and therefore fuel loads even in the absence of climate change, vs. climate change effects. Four general circulation models provided Last Glacial Maximum (LGM) climate anomalies - that is, differences from the pre-industrial (PI) control climate - from the Palaeoclimate Modelling Intercomparison Project Phase 2, allowing the construction of four scenarios for LGM climate. Modelled carbon fluxes in biomass burning were corrected for the model's observed biases in contemporary biome-average values. With LGM climate and low CO2 (185 ppm) effects included, the modelled global flux was 70 to 80% lower at the LGM than in PI time. LGM climate with pre-industrial CO2 (280 ppm) however yielded unrealistic results, with global and Northern Hemisphere biomass burning fluxes greater than in the pre-industrial climate. Using the PI CO2 concentration increased the modelled LGM biomass burning fluxes for all climate models and latitudinal bands to between four and ten times their values under LGM CO2 concentration. It is inferred that a substantial part of the increase in biomass burning after the LGM must be attributed to the effect of increasing CO2 concentration on productivity and fuel load. Today, by analogy, both rising CO2 and global warming must be considered as risk factors for increasing biomass burning. Both effects need to be included in models to project future fire risks.

  14. The Protective Effects of Epigallocatechin Gallate Against Distant Organ Damage After Severe Skin Burns--Experimental Study Using a Rat Model of Thermal Trauma.

    PubMed

    Hosnuter, Mubin; Melikoglu, Cenk; Aslan, Cem; Saglam, Gulcan; Sutcu, Recep

    2015-01-01

    Epigallocatechin gallate (EGCG), a green tea polyphenol, has potent antioxidant properties. The purpose of the present study was to examine the possible preventative effects of EGCG against internal organ injury due to large-surface skin burns in a rat model. The study design involved three groups of rats: a sham group and two groups with 25-30% full-thickness burns: (a) the sham group without burns or treatment (n=18); (b) the control burn group (burns+sterile saline, n=18); and (c) the burn treatment group (burns+treatment with EGCG, n=18). EGCG was administered intraperitoneally immediately after the thermal injury, and daily in 100 μmol/kg doses. Kidney and lung tissue samples were taken to determine the levels of malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), and glutathione peroxidase (GPX) after the first, third and seventh post-burn days. In the EGCG-treated burn group, SOD and GPX activity were significantly higher than in the burn control group. Additionally, MDA and TNF-α levels were significantly lower in the EGCG-treated burn group. Based on this study, it might be anticipated that EGCG treatment may be beneficial in burn injury cases.

  15. Restoring forest structure and process stabilizes forest carbon in wildfire-prone southwestern ponderosa pine forests.

    PubMed

    Hurteau, Matthew D; Liang, Shuang; Martin, Katherine L; North, Malcolm P; Koch, George W; Hungate, Bruce A

    2016-03-01

    Changing climate and a legacy of fire-exclusion have increased the probability of high-severity wildfire, leading to an increased risk of forest carbon loss in ponderosa pine forests in the southwestern USA. Efforts to reduce high-severity fire risk through forest thinning and prescribed burning require both the removal and emission of carbon from these forests, and any potential carbon benefits from treatment may depend on the occurrence of wildfire. We sought to determine how forest treatments alter the effects of stochastic wildfire events on the forest carbon balance. We modeled three treatments (control, thin-only, and thin and burn) with and without the occurrence of wildfire. We evaluated how two different probabilities of wildfire occurrence, 1% and 2% per year, might alter the carbon balance of treatments. In the absence of wildfire, we found that thinning and burning treatments initially reduced total ecosystem carbon (TEC) and increased net ecosystem carbon balance (NECB). In the presence of wildfire, the thin and burn treatment TEC surpassed that of the control in year 40 at 2%/yr wildfire probability, and in year 51 at 1%/yr wildfire probability. NECB in the presence of wildfire showed a similar response to the no-wildfire scenarios: both thin-only and thin and burn treatments increased the C sink. Treatments increased TEC by reducing both mean wildfire severity and its variability. While the carbon balance of treatments may differ in more productive forest types, the carbon balance benefits from restoring forest structure and fire in southwestern ponderosa pine forests are clear.

  16. Numerical simulation of the hydrodynamical combustion to strange quark matter in the trapped neutrino regime

    NASA Astrophysics Data System (ADS)

    Ouyed, Amir; Ouyed, Rachid; Jaikumar, Prashanth

    2018-02-01

    We simulate and study the microphysics of combustion (flame burning) of two flavored quark matter (u,d) to three flavored quark matter (u,d,s) in a trapped neutrino regime applicable to conditions prevailing in a hot proto-neutron star. The reaction-diffusion-advection equations for (u,d) to (u,d,s) combustion are coupled with neutrino transport, which is modeled through a flux-limited diffusion scheme. The flame speed is proportional to initial lepton fraction because of the release of electron chemical potential as heat, and reaches a steady-state burning speed of (0.001-0.008)c. We find that the burning speed is ultimately driven by the neutrino pressure gradient, given that the pressure gradient induced by quarks is opposed by the pressure gradients induced by electrons. This suggests, somewhat counter-intuitively, that the pressure gradients that drive the interface are controlled primarily by leptonic weak decays rather than by the quark Equation of State (EOS). In other words, the effects of the leptonic weak interaction, including the corresponding weak decay rates and the EOS of electrons and neutrinos, are at least as important as the uncertainties related to the EOS of high density matter. We find that for baryon number densities nB ≤ 0.35 fm-3, strong pressure gradients induced by leptonic weak decays drastically slow down the burning speed, which is thereafter controlled by the much slower burning process driven by backflowing downstream matter. We discuss the implications of our findings to proto-neutron stars.

  17. Alternative erythropoietin-mediated signaling prevents secondary microvascular thrombosis and inflammation within cutaneous burns

    PubMed Central

    Bohr, Stefan; Patel, Suraj J.; Shen, Keyue; Vitalo, Antonia G.; Brines, Michael; Cerami, Anthony; Berthiaume, Francois; Yarmush, Martin L.

    2013-01-01

    Alternate erythropoietin (EPO)–mediated signaling via the heteromeric receptor composed of the EPO receptor and the β-common receptor (CD131) exerts the tissue-protective actions of EPO in various types of injuries. Herein we investigated the effects of the EPO derivative helix beta surface peptide (synonym: ARA290), which specifically triggers alternate EPO-mediated signaling, but does not bind the erythropoietic EPO receptor homodimer, on the progression of secondary tissue damage following cutaneous burns. For this purpose, a deep partial thickness cutaneous burn injury was applied on the back of mice, followed by systemic administration of vehicle or ARA290 at 1, 12, and 24 h postburn. With vehicle-only treatment, wounds exhibited secondary microvascular thrombosis within 24 h postburn, and subsequent necrosis of the surrounding tissue, thus converting to a full-thickness injury within 48 h. On the other hand, when ARA290 was systemically administered, patency of the microvasculature was maintained. Furthermore, ARA290 mitigated the innate inflammatory response, most notably tumor necrosis factor-alpha–mediated signaling. These findings correlated with long-term recovery of initially injured yet viable tissue components. In conclusion, ARA290 may be a promising therapeutic approach to prevent the conversion of partial- to full-thickness burn injuries. In a clinical setting, the decrease in burn depth and area would likely reduce the necessity for extensive surgical debridement as well as secondary wound closure by means of skin grafting. This use of ARA290 is consistent with its tissue-protective properties previously reported in other models of injury, such as myocardial infarction and hemorrhagic shock. PMID:23401545

  18. Modeling post-wildfire hydrological processes with ParFlow

    NASA Astrophysics Data System (ADS)

    Escobar, I. S.; Lopez, S. R.; Kinoshita, A. M.

    2017-12-01

    Wildfires alter the natural processes within a watershed, such as surface runoff, evapotranspiration rates, and subsurface water storage. Post-fire hydrologic models are typically one-dimensional, empirically-based models or two-dimensional, conceptually-based models with lumped parameter distributions. These models are useful for modeling and predictions at the watershed outlet; however, do not provide detailed, distributed hydrologic processes at the point scale within the watershed. This research uses ParFlow, a three-dimensional, distributed hydrologic model to simulate post-fire hydrologic processes by representing the spatial and temporal variability of soil burn severity (via hydrophobicity) and vegetation recovery. Using this approach, we are able to evaluate the change in post-fire water components (surface flow, lateral flow, baseflow, and evapotranspiration). This work builds upon previous field and remote sensing analysis conducted for the 2003 Old Fire Burn in Devil Canyon, located in southern California (USA). This model is initially developed for a hillslope defined by a 500 m by 1000 m lateral extent. The subsurface reaches 12.4 m and is assigned a variable cell thickness to explicitly consider soil burn severity throughout the stages of recovery and vegetation regrowth. We consider four slope and eight hydrophobic layer configurations. Evapotranspiration is used as a proxy for vegetation regrowth and is represented by the satellite-based Simplified Surface Energy Balance (SSEBOP) product. The pre- and post-fire surface runoff, subsurface storage, and surface storage interactions are evaluated at the point scale. Results will be used as a basis for developing and fine-tuning a watershed-scale model. Long-term simulations will advance our understanding of post-fire hydrological partitioning between water balance components and the spatial variability of watershed processes, providing improved guidance for post-fire watershed management. In reference to the presenter, Isabel Escobar: Research is funded by the NASA-DIRECT STEM Program. Travel expenses for this presentation is funded by CSU-LSAMP. CSU-LSAMP is supported by the National Science Foundation under Grant # HRD-1302873 and the CSU Office of Chancellor.

  19. Magnetohydrodynamical Effects on Nuclear Deflagration Fronts in Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Hristov, Boyan; Collins, David C.; Hoeflich, Peter; Weatherford, Charles A.; Diamond, Tiara R.

    2018-05-01

    This article presents a study of the effects of magnetic fields on non-distributed nuclear burning fronts as a possible solution to a fundamental problem for the thermonuclear explosion of a Chandrasekhar mass ({M}Ch}) white dwarf (WD), the currently favored scenario for the majority of Type Ia SNe. All existing 3D hydrodynamical simulations predict strong global mixing of the burning products due to Rayleigh–Taylor (RT) instabilities, which contradicts observations. As a first step toward studying the flame physics, we present a set of computational magnet-hydrodynamic models in rectangular flux tubes, resembling a small inner region of a WD. We consider initial magnetic fields up to {10}12 {{G}} of various orientations. We find an increasing suppression of RT instabilities starting at about {10}9 {{G}}. The front speed tends to decrease with increasing magnitude up to about {10}11 {{G}}. For even higher fields new small-scale, finger-like structures develop, which increase the burning speed by a factor of 3 to 4 above the field-free RT-dominated regime. We suggest that the new instability may provide sufficiently accelerated energy production during the distributed burning regime to go over the Chapman–Jougey limit and trigger a detonation. Finally, we discuss the possible origins of high magnetic fields during the final stage of the progenitor evolution or the explosion.

  20. Combustion-transition interaction in a jet flame

    NASA Astrophysics Data System (ADS)

    Yule, A. J.; Chigier, N. A.; Ralph, S.; Boulderstone, R.; Ventura, J.

    1980-01-01

    The transition between laminar and turbulent flow in a round jet flame is studied experimentally. Comparison is made between transition in non-burning and burning jets and between jet flames with systematic variation in initial Reynolds number and equivalence ratio. Measurements are made using laser anemometry, miniature thermocouples, ionization probes, laser-schlieren and high speed cine films. Compared with the cold jet, the jet flame has a longer potential core, undergoes a slower transition to turbulence, has lower values of fluctuating velocity near the burner but higher values further downstream, contains higher velocity gradients in the mixing layer region although the total jet width does not alter greatly in the first twenty diameters. As in the cold jet, transitional flow in the flame contains waves and vortices and these convolute and stretch the initially laminar interface burning region. Unlike the cold jet, which has Kelvin-Helmholtz instabilities, the jet flame can contain at least two initial instabilities; an inner high frequency combustion driven instability and an outer low frequency instability which may be influenced by buoyancy forces.

  1. What determines area burned in large landscapes? Insights from a decade of comparative landscape-fire modelling

    Treesearch

    Geoffrey J. Cary; Robert E. Keane; Mike D. Flannigan; Ian D. Davies; Russ A. Parsons

    2015-01-01

    Understanding what determines area burned in large landscapes is critical for informing wildland fire management in fire-prone environments and for representing fire activity in Dynamic Global Vegetation Models. For the past ten years, a group of landscape-fire modellers have been exploring the relative influence of key determinants of area burned in temperate and...

  2. Fire modeling in the Brazilian arc of deforestation through nested coupling of atmosphere, dynamic vegetation, LUCC and fire spread models

    NASA Astrophysics Data System (ADS)

    Tourigny, E.; Nobre, C.; Cardoso, M. F.

    2012-12-01

    Deforestation of tropical forests for logging and agriculture, associated to slash-and-burn practices, is a major source of CO2 emissions, both immediate due to biomass burning and future due to the elimination of a potential CO2 sink. Feedbacks between climate change and LUCC (Land-Use and Land-Cover Change) can potentially increase the loss of tropical forests and increase the rate of CO2 emissions, through mechanisms such as land and soil degradation and the increase in wildfire occurrence and severity. However, current understanding of the processes of fires (including ignition, spread and consequences) in tropical forests and climatic feedbacks are poorly understood and need further research. As the processes of LUCC and associated fires occur at local scales, linking them to large-scale atmospheric processes requires a means of up-scaling higher resolutions processes to lower resolutions. Our approach is to couple models which operate at various spatial and temporal scales: a Global Climate Model (GCM), Dynamic Global Vegetation Model (DGVM) and local-scale LUCC and fire spread model. The climate model resolves large scale atmospheric processes and forcings, which are imposed on the surface DGVM and fed-back to climate. Higher-resolution processes such as deforestation, land use management and associated (as well as natural) fires are resolved at the local level. A dynamic tiling scheme allows to represent local-scale heterogeneity while maintaining computational efficiency of the land surface model, compared to traditional landscape models. Fire behavior is modeled at the regional scale (~500m) to represent the detailed landscape using a semi-empirical fire spread model. The relatively coarse scale (as compared to other fire spread models) is necessary due to the paucity of detailed land-cover information and fire history (particularly in the tropics and developing countries). This work presents initial results of a spatially-explicit fire spread model coupled to the IBIS DGVM model. Our area of study comprises selected regions in and near the Brazilian "arc of deforestation". For model training and evaluation, several areas have been mapped using high-resolution imagery from the Landsat TM/ETM+ sensors (Figure 1). This high resolution reference data is used for local-scale simulations and also to evaluate the accuracy of the global MCD45 burned area product, which will be used in future studies covering the entire "arc of deforestation".; Area of study along the arc of deforestation and cerrado: landsat scenes used and burned area (2010) from MCD45 product.

  3. Modeling crop residue burning experiments to evaluate smoke emissions and plume transport

    EPA Science Inventory

    Crop residue burning is a common land management practice that results in emissions of a variety of pollutants with negative health impacts. Modeling systems are used to estimate air quality impacts of crop residue burning to support retrospective regulatory assessments and also ...

  4. Treatments for Common Psychiatric Conditions Among Children and Adolescents During Acute Rehabilitation and Reintegration Phases of Burn Injury

    PubMed Central

    Arceneaux, Lisa L.; Meyer, Walter J.

    2016-01-01

    Advances in critical care and surgical management during the last 20 years have decreased mortality rates among children with severe burn injuries. This improved survival rate has prompted researchers to study the psychological aspects of recovering from a burn injury. Initially, research focused primarily on epidemiology, prevention and descriptions of the psychological phenomenon experienced by the children and adolescents. Whereas, previously, interventions were often utilized during the acute phases of burn injury without knowledge of the long-term effects, more recently, priorities have shifted to include long-term treatment outcome studies. The purpose of this paper is to review and discuss the current evidenced-based techniques and their efficacy in the treatment of common psychological and psychiatric conditions among children and adolescents during the 3 major phases of burn injury. PMID:19919208

  5. Evolution and nucleosynthesis of extremely metal-poor and metal-free low- and intermediate-mass stars. II. s-process nucleosynthesis during the core He flash

    NASA Astrophysics Data System (ADS)

    Campbell, S. W.; Lugaro, M.; Karakas, A. I.

    2010-11-01

    Context. Models of primordial and hyper-metal-poor stars that have masses similar to the Sun are known to experience an ingestion of protons into the hot core during the core helium flash phase at the end of their red giant branch evolution. This produces a concurrent secondary flash powered by hydrogen burning that gives rise to further nucleosynthesis in the core. Aims: We aim to model the nucleosynthesis occurring during the proton ingestion event to ascertain if any significant neutron-capture nucleosynthesis occurs. Methods: We perform post-process nucleosynthesis calculations on a one-dimensional stellar evolution calculation of a star with mass 1 M_⊙ and a metallicity of [Fe/H] = -6.5 that suffers a proton ingestion episode. Our network includes 320 nuclear species and 2366 reactions and treats mixing and burning simultaneously. Results: We find that the mixing and burning of protons into the hot convective core leads to the production of 13C, which then burns via the 13C(α, n)16O reaction, releasing a large number of free neutrons. During the first two years of neutron production the neutron poison 14N abundance is low, allowing the prodigious production of heavy elements such as strontium, barium, and lead via slow neutron captures (the s process). These nucleosynthetic products are later carried to the stellar surface and ejected via stellar winds. We compare our results with observations of the hyper-metal-poor halo star HE 1327-2326, which shows a strong Sr overabundance. Conclusions: Our model provides the possibility of self-consistently explaining the Sr overabundance in HE 1327-2326 together with its C, N, and O overabundances (all within a factor of ˜ ~4) if the material were heavily diluted, for example, via mass transfer in a wide binary system. The model produces at least 18 times too much Ba than observed, but this may be within the large modelling uncertainties. In this scenario, binary systems of low mass must have formed in the early Universe. If this is true, it puts constraints on the primordial initial mass function.

  6. Extinguishment of a Diffusion Flame Over a PMMA Cylinder by Depressurization in Reduced-Gravity

    NASA Technical Reports Server (NTRS)

    Goldmeer, Jeffrey Scott

    1996-01-01

    Extinction of a diffusion flame burning over horizontal PMMA (Polymethyl methacrylate) cylinders in low-gravity was examined experimentally and via numerical simulations. Low-gravity conditions were obtained using the NASA Lewis Research Center's reduced-gravity aircraft. The effects of velocity and pressure on the visible flame were examined. The flammability of the burning solid was examined as a function of pressure and the solid-phase centerline temperature. As the solid temperature increased, the extinction pressure decreased, and with a centerline temperature of 525 K, the flame was sustained to 0.1 atmospheres before extinguishing. The numerical simulation iteratively coupled a two-dimensional quasi-steady, gas-phase model with a transient solid-phase model which included conductive heat transfer and surface regression. This model employed an energy balance at the gas/solid interface that included the energy conducted by the gas-phase to the gas/solid interface, Arrhenius pyrolysis kinetics, surface radiation, and the energy conducted into the solid. The ratio of the solid and gas-phase conductive fluxes Phi was a boundary condition for the gas-phase model at the solid-surface. Initial simulations modeled conditions similar to the low-gravity experiments and predicted low-pressure extinction limits consistent with the experimental limits. Other simulations examined the effects of velocity, depressurization rate and Phi on extinction.

  7. A Modeling Approach for Burn Scar Assessment Using Natural Features and Elastic Property

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tsap, L V; Zhang, Y; Goldgof, D B

    2004-04-02

    A modeling approach is presented for quantitative burn scar assessment. Emphases are given to: (1) constructing a finite element model from natural image features with an adaptive mesh, and (2) quantifying the Young's modulus of scars using the finite element model and the regularization method. A set of natural point features is extracted from the images of burn patients. A Delaunay triangle mesh is then generated that adapts to the point features. A 3D finite element model is built on top of the mesh with the aid of range images providing the depth information. The Young's modulus of scars ismore » quantified with a simplified regularization functional, assuming that the knowledge of scar's geometry is available. The consistency between the Relative Elasticity Index and the physician's rating based on the Vancouver Scale (a relative scale used to rate burn scars) indicates that the proposed modeling approach has high potentials for image-based quantitative burn scar assessment.« less

  8. Growth rate predicts mortality of Abies concolor in both burned and unburned stands

    USGS Publications Warehouse

    van Mantgem, Phillip J.; Stephenson, Nathan L.; Mutch, Linda S.; Johnson, Veronica G.; Esperanza, Annie M.; Parsons, David J.

    2003-01-01

    Tree mortality is often the result of both long-term and short-term stress. Growth rate, an indicator of long-term stress, is often used to estimate probability of death in unburned stands. In contrast, probability of death in burned stands is modeled as a function of short-term disturbance severity. We sought to narrow this conceptual gap by determining (i) whether growth rate, in addition to crown scorch, is a predictor of mortality in burned stands and (ii) whether a single, simple model could predict tree death in both burned and unburned stands. Observations of 2622 unburned and 688 burned Abies concolor (Gord. & Glend.) Lindl. (white fir) in the Sierra Nevada of California, U.S.A., indicated that growth rate was a significant predictor of mortality in the unburned stands, while both crown scorch and radial growth were significant predictors of mortality in the burned stands. Applying the burned stand model to unburned stands resulted in an overestimation of the unburned stand mortality rate. While failing to create a general model of tree death for A. concolor, our findings underscore the idea that similar processes may affect mortality in disturbed and undisturbed stands.

  9. Empirical models to predict the volumes of debris flows generated by recently burned basins in the western U.S.

    USGS Publications Warehouse

    Gartner, J.E.; Cannon, S.H.; Santi, P.M.; deWolfe, V.G.

    2008-01-01

    Recently burned basins frequently produce debris flows in response to moderate-to-severe rainfall. Post-fire hazard assessments of debris flows are most useful when they predict the volume of material that may flow out of a burned basin. This study develops a set of empirically-based models that predict potential volumes of wildfire-related debris flows in different regions and geologic settings. The models were developed using data from 53 recently burned basins in Colorado, Utah and California. The volumes of debris flows in these basins were determined by either measuring the volume of material eroded from the channels, or by estimating the amount of material removed from debris retention basins. For each basin, independent variables thought to affect the volume of the debris flow were determined. These variables include measures of basin morphology, basin areas burned at different severities, soil material properties, rock type, and rainfall amounts and intensities for storms triggering debris flows. Using these data, multiple regression analyses were used to create separate predictive models for volumes of debris flows generated by burned basins in six separate regions or settings, including the western U.S., southern California, the Rocky Mountain region, and basins underlain by sedimentary, metamorphic and granitic rocks. An evaluation of these models indicated that the best model (the Western U.S. model) explains 83% of the variability in the volumes of the debris flows, and includes variables that describe the basin area with slopes greater than or equal to 30%, the basin area burned at moderate and high severity, and total storm rainfall. This model was independently validated by comparing volumes of debris flows reported in the literature, to volumes estimated using the model. Eighty-seven percent of the reported volumes were within two residual standard errors of the volumes predicted using the model. This model is an improvement over previous models in that it includes a measure of burn severity and an estimate of modeling errors. The application of this model, in conjunction with models for the probability of debris flows, will enable more complete and rapid assessments of debris flow hazards following wildfire.

  10. Cooling of burns: Mechanisms and models.

    PubMed

    Wright, E H; Harris, A L; Furniss, D

    2015-08-01

    The role of cooling in the acute management of burns is widely accepted in clinical practice, and is a cornerstone of basic first aid in burns. This has been underlined in a number of animal models. The mechanism by which it delivers its benefit is poorly understood, but there is a reduction in burns progression over the first 48 h, reduced healing time, and some subjective improvements in scarring when cooling is administered after burning. Intradermal temperature normalises within a matter of seconds to a few minutes, yet the benefits of even delayed cooling persist, implying it is not simply the removal of thermal energy from the damaged tissues. Animal models have used oedema formation, preservation of dermal perfusion, healing time and hair retention as indicators of burns severity, and have shown cooling to improve these indices, but pharmacological or immunological blockade of humoural and cellular mediators of inflammation did not reproduce the benefit of cooling. More recently, some studies of tissue from human and animal burns have shown consistent, reproducible, temporal changes in gene expression in burned tissues. Here, we review the experimental evidence of the role and mechanism of cooling in burns management, and suggest future research directions that may eventually lead to improved treatment outcomes. Copyright © 2015. Published by Elsevier Ltd.

  11. Comparison of mortality prediction models in burns ICU patients in Pinderfields Hospital over 3 years.

    PubMed

    Douglas, Helen E; Ratcliffe, Andrew; Sandhu, Rajdeep; Anwar, Umair

    2015-02-01

    Many different burns mortality prediction models exist; however most agree that important factors that can be weighted include the age of the patient, the total percentage of body surface area burned and the presence or absence of smoke inhalation. A retrospective review of all burns primarily admitted to Pinderfields Burns ICU under joint care of burns surgeons and intensivists for the past 3 years was completed. Predicted mortality was calculated using the revised Baux score (2010), the Belgian Outcome in Burn Injury score (2009) and the Boston group score by Ryan et al. (1998). Additionally 28 of the 48 patients had APACHE II scores recorded on admission and the predicted and actual mortality of this group were compared. The Belgian score had the highest sensitivity and negative predictive value (72%/85%); followed by the Boston score (66%/78%) and then the revised Baux score (53%/70%). APACHE II scores had higher sensitivity (81%) and NPV (92%) than any of the burns scores. In our group of burns ICU patients the Belgian model was the most sensitive and specific predictor of mortality. In our subgroup of patients with APACHE II data, this score more accurately predicted survival and mortality. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  12. Imaging Techniques for Clinical Burn Assessment with a Focus on Multispectral Imaging

    PubMed Central

    Thatcher, Jeffrey E.; Squiers, John J.; Kanick, Stephen C.; King, Darlene R.; Lu, Yang; Wang, Yulin; Mohan, Rachit; Sellke, Eric W.; DiMaio, J. Michael

    2016-01-01

    Significance: Burn assessments, including extent and severity, are some of the most critical diagnoses in burn care, and many recently developed imaging techniques may have the potential to improve the accuracy of these evaluations. Recent Advances: Optical devices, telemedicine, and high-frequency ultrasound are among the highlights in recent burn imaging advancements. We present another promising technology, multispectral imaging (MSI), which also has the potential to impact current medical practice in burn care, among a variety of other specialties. Critical Issues: At this time, it is still a matter of debate as to why there is no consensus on the use of technology to assist burn assessments in the United States. Fortunately, the availability of techniques does not appear to be a limitation. However, the selection of appropriate imaging technology to augment the provision of burn care can be difficult for clinicians to navigate. There are many technologies available, but a comprehensive review summarizing the tissue characteristics measured by each technology in light of aiding clinicians in selecting the proper device is missing. This would be especially valuable for the nonburn specialists who encounter burn injuries. Future Directions: The questions of when burn assessment devices are useful to the burn team, how the various imaging devices work, and where the various burn imaging technologies fit into the spectrum of burn care will continue to be addressed. Technologies that can image a large surface area quickly, such as thermography or laser speckle imaging, may be suitable for initial burn assessment and triage. In the setting of presurgical planning, ultrasound or optical microscopy techniques, including optical coherence tomography, may prove useful. MSI, which actually has origins in burn care, may ultimately meet a high number of requirements for burn assessment in routine clinical use. PMID:27602255

  13. Use and efficacy of a nutrition protocol for patients with burns in intensive care.

    PubMed

    Lown, D

    1991-01-01

    The University of Michigan Burn Center uses a protocol to standardize the assessment, initiation, and monitoring of nutritional support for patients with burns of greater than 30% total body surface area (TBSA). Six patients with 20% to 80% TBSA burns were followed for 3 weeks to determine the effect of the protocol on the assessment, initiation, monitoring, and adequacy of nutritional support. The protocol calls for resting energy expenditure (REE) measurement within 24 hours of injury, to be repeated 3 times per week, for assessment of caloric requirements. Patients experienced an average delay before first REE measurement of 3 days after burn injury because measurements were unavailable on weekends and surgical days. REE measurements were used to determine caloric requirements and to tailor nutritional support to fluctuating metabolic needs. In four of the six patients a Dobhoff feeding tube (Biosearch Medical Products, Inc., Somerville, N.J.) was placed in the small bowel and enteral nutrition was initiated within 24 hours of admission, as outlined in the protocol. Two patients received concurrent parenteral nutrition because of difficulty in placing the Dobhoff feeding tube when fluoroscopy was not available. The three patients receiving nutrition solely through enteral feeding had achieved 100% of their caloric requirements by day 2, 4, and greater than 7 days after injury, respectively. Overall, the six patients received enterally an average of 75% of their caloric requirements. The major reason for inadequate enteral support was interruption of tube feedings because of tube dislodgment or multiple surgical procedures. The protocol used weekly measurements of total iron-binding capacity and prealbumin level s parameters of nutritional support.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Debris-flow generation from recently burned watersheds

    USGS Publications Warehouse

    Cannon, S.H.

    2001-01-01

    Evaluation of the erosional response of 95 recently burned drainage basins in Colorado, New Mexico and southern California to storm rainfall provides information on the conditions that result in fire-related debris flows. Debris flows were produced from only 37 of 95 (~40 percent) basins examined; the remaining basins produced either sediment-laden streamflow or no discernable response. Debris flows were thus not the prevalent response of the burned basins. The debris flows that did occur were most frequently the initial response to significant rainfall events. Although some hillslopes continued to erode and supply material to channels in response to subsequent rainfall events, debris flows were produced from only one burned basin following the initial erosive event. Within individual basins, debris flows initiated through both runoff and infiltration-triggered processes. The fact that not all burned basins produced debris flows suggests that specific geologic and geomorphic conditions may control the generation of fire-related debris flows. The factors that best distinguish between debris-flow producing drainages and those that produced sediment-laden streamflow are drainage-basin morphology and lithology, and the presence or absence of water-repellent soils. Basins underlain by sedimentary rocks were most likely to produce debris flows that contain large material, and sand- and gravel-dominated flows were generated primarily from terrain underlain by decomposed granite. Basin-area and relief thresholds define the morphologic conditions under which both types of debris flows occur. Debris flows containing large material are more likely to be produced from basins without water-repellent soils than from basins with water repellency. The occurrence of sand-and gravel-dominated debris flows depends on the presence of water-repellent soils.

  15. Lessons from the fires of 2000: Post-fire heterogeneity in ponderosa pine forests

    USGS Publications Warehouse

    Kotliar, Natasha B.; Haire, Sandra L.; Key, Carl H.; Omni, Phillip N.; Joyce, Linda A.

    2003-01-01

    We evaluate burn-severity patterns for six burns that occurred in the southern Rocky Mountains and the Colorado Plateau in 2000. We compare the results of two data sources: Burned Area Rehabilitations Teams (BAER) and a spatial burnseverity model derived from satellite imagery (the Normalized Burn Ratio; NBR). BAER maps tended to overestimate area of severe burns and underestimate area of moderate-severity burns relative to NBR maps. Low elevation and more southern ponderosa pine burns were predominantly understory burns, whereas burns at higher elevations and farther north had a greater component of high-severity burns. Thus, much, if not most, of the area covered by these burns appears to be consistent with historic burns and contributes to healthy functioning ecosystems.

  16. Glue Guns: Aiming for Safety

    ERIC Educational Resources Information Center

    Roy, Ken

    2010-01-01

    While glue guns are very useful, there are safety issues. Regardless of the temperature setting, glue guns can burn skin. The teacher should demonstrate and supervise the use of glue guns and have a plan should a student get burned. There should be an initial first aid protocol in place, followed by a visit to the school nurse. An accident report…

  17. Emissions from biomass burning in the Yucatan

    Treesearch

    R. J. Yokelson; J. D. Crounse; P. F. DeCarlo; T. Karl; S. Urbanski; E. Atlas; T. Campos; Y. Shinozuka; V. Kapustin; A. D. Clarke; A. Weinheimer; D. J. Knapp; D. D. Montzka; J. Holloway; P. Weibring; F. Flocke; W. Zheng; D. Toohey; P. O. Wennberg; C. Wiedinmyer; L. Mauldin; A. Fried; D. Richter; J. Walega; J. L. Jimenez; K. Adachi; P. R. Buseck; S. R. Hall; R. Shetter

    2009-01-01

    In March 2006 two instrumented aircraft made the first detailed field measurements of biomass burning (BB) emissions in the Northern Hemisphere tropics as part of the MILAGRO project. The aircraft were the National Center for Atmospheric Research C-130 and a University of Montana/ US Forest Service Twin Otter. The initial emissions of up to 49 trace gas or particle...

  18. Soil reaction and germination of Douglas-fir seed.

    Treesearch

    Robert F. Tarrant

    1954-01-01

    Wood ash and its accompanying alkalinity have sometimes been cited as being harmful to germination of tree seed on slash-burned forest land. Unasylva, the United Nations forestry publication, recently carried a report of research in British Columbia on the effect of slash burning on germination and initial survival of lodgepole pine and Douglas-fir. One finding was...

  19. 40 CFR 63.11211 - How do I demonstrate initial compliance with the emission limits?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Table 4 to this subpart, conducting a fuel analysis for each type of fuel burned in your boiler... single type of fuel, you are exempted from the compliance requirements of conducting a fuel analysis for each type of fuel burned in your boiler. For purposes of this subpart, boilers that use a supplemental...

  20. 40 CFR 63.11211 - How do I demonstrate initial compliance with the emission limits?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Table 4 to this subpart, conducting a fuel analysis for each type of fuel burned in your boiler... single type of fuel, you are exempted from the compliance requirements of conducting a fuel analysis for each type of fuel burned in your boiler. For purposes of this subpart, boilers that use a supplemental...

  1. Nosocomial infections due to Acinetobacter calcoaceticus.

    PubMed

    Zaer, F; Deodhar, L

    1989-01-01

    Fifty four isolates of Acinetobacter calcoaceticus were studied in a period of 6 months. Maximum isolates were from burns cases and environmental sampling from burns ward also grew the same organism, indicating their role as nosocomial pathogen. Acinetobacter may initially be mistaken for Neisseria species. As the organisms show multidrug resistance to commonly used antibiotics their correct identification is important.

  2. Tree mortality 6 years after burning a thinned Quercus chrysolepis stand

    Treesearch

    T.E. Paysen; M.G. Narog

    1993-01-01

    Managers do not currently use prescribed fire in stands of canyon live oak (Quercus chrysolepis Liebm.) because it is highly susceptible to fire injury. A preliminary study investigating the effects of  prescribed burning on this species was initiated on the San Bernardino National Forest in southern California. The purpose was to assess the...

  3. AmeriFlux US-An1 Anaktuvuk River Severe Burn

    DOE Data Explorer

    Hobbie, John [Marine Biological Laboratory; Rocha, Adrian [Marine Biological Laboratory; Shaver, Gaius [Marine Biological Laboratory

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-An1 Anaktuvuk River Severe Burn. Site Description - The Anaktuvuk River fire on the North Slope of Alaska started on July 16, 2007 by lightning. It continued until the end of September when nearby lakes had already frozen over and burned >256,000 acres, creating a mosaic of patches that differed in burn severity. The Anaktuvuk River Severe Burn, Moderate Burn, and Unburned sites are 40 km to the west of the nearest road and were selected in late May 2008 to determine the effects of the fire on carbon, water, and energy exchanges during the growing season. Because the fire had burned through September of the previous year, initial deployment of flux towers occurred prior to any significant vegetative regrowth, and our sampling campaign captured the full growing season in 2008. The Severe Burn site consisted of a large area in which all of the green vegetation were consumed in the fire and some of the organic matter had burnt to the mineral soil in many places. A bear damaged the tower during the last week of August 2008, and it was repaired shortly after.

  4. 40 CFR 60.2195 - What information must I submit prior to initial startup?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... initial startup? 60.2195 Section 60.2195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... What information must I submit prior to initial startup? You must submit the information specified in paragraphs (a) through (e) of this section prior to initial startup. (a) The type(s) of waste to be burned...

  5. 40 CFR 60.2195 - What information must I submit prior to initial startup?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... initial startup? 60.2195 Section 60.2195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... What information must I submit prior to initial startup? You must submit the information specified in paragraphs (a) through (e) of this section prior to initial startup. (a) The type(s) of waste to be burned...

  6. Initial evaluation and management of the critical burn patient.

    PubMed

    Vivó, C; Galeiras, R; del Caz, Ma D P

    2016-01-01

    The major improvement in burn therapy is likely to focus on the early management of hemodynamic and respiratory failures in combination with an aggressive and early surgical excision and skin grafting for full-thickness burns. Immediate burn care by first care providers is important and can vastly alter outcomes, and it can significantly limit burn progression and depth. The goal of prehospital care should be to cease the burning process as well as prevent future complications and secondary injuries for burn shock. Identifying burn patients appropriate for immediate or subacute transfer is an important step in reducing morbidity and mortality. Delays in transport to Burn Unit should be minimized. The emergency management follows the principles of the Advanced Trauma Life Support Guidelines for assessment and stabilization of airway, breathing, circulation, disability, exposure and environment control. All patients with suspected inhalation injury must be removed from the enclosure as soon as possible, and immediately administer high-flow oxygen. Any patient with stridor, shortness of breath, facial burns, singed nasal hairs, cough, soot in the oral cavity, and history of being in a fire in an enclosed space should be strongly considered for early intubation. Fibroscopy may also be useful if airway damage is suspected and to assess known lung damage. Secondary evaluation following admission to the Burn Unit of a burned patient suffering a severe thermal injury includes continuation of respiratory support and management and treatment of inhalation injury, fluid resuscitation and cardiovascular stabilization, pain control and management of burn wound. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

  7. Microstructural Characterization of High Burn-up Mixed Oxide Fast Reactor Fuel

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Melissa C. Teague; Brian P. Gorman; Steven L. Hayes

    2013-10-01

    High burn-up mixed oxide fuel with local burn-ups of 3.4–23.7% FIMA (fissions per initial metal atom) were destructively examined as part of a research project to understand the performance of oxide fuel at extreme burn-ups. Optical metallography of fuel cross-sections measured the fuel-to-cladding gap, clad thickness, and central void evolution in the samples. The fuel-to-cladding gap closed significantly in samples with burn-ups below 7–9% FIMA. Samples with burn-ups in excess of 7–9% FIMA had a reopening of the fuel-to-cladding gap and evidence of joint oxide-gain (JOG) formation. Signs of axial fuel migration to the top of the fuel column weremore » observed in the fuel pin with a peak burn-up of 23.7% FIMA. Additionally, high burn-up structure (HBS) was observed in the two highest burn-up samples (23.7% and 21.3% FIMA). The HBS layers were found to be 3–5 times thicker than the layers found in typical LWR fuel. The results of the study indicate that formation of JOG and or HBS prevents any significant fuel-cladding mechanical interaction from occurring, thereby extending the potential life of the fuel elements.« less

  8. Relative importance of fuel management, ignition management and weather for area burned: Evidence from five landscape-fire-succession models

    Treesearch

    Geoffrey J. Cary; Mike D. Flannigan; Robert E. Keane; Ross A. Bradstock; Ian D. Davies; James M. Lenihan; Chao Li; Kimberley A. Logan; Russell A. Parsons

    2009-01-01

    The behaviour of five landscape fire models (CAFE, FIRESCAPE, LAMOS(HS), LANDSUM and SEMLAND) was compared in a standardised modelling experiment. The importance of fuel management approach, fuel management effort, ignition management effort and weather in determining variation in area burned and number of edge pixels burned (a measure of potential impact on assets...

  9. Burns in Baghdad from 2003 to 2014: Results of a randomized household cluster survey.

    PubMed

    Stewart, Barclay T; Lafta, Riyadh; Esa Al Shatari, Sahar A; Cherewick, Megan; Burnham, Gilbert; Hagopian, Amy; Galway, Lindsay P; Kushner, Adam L

    2016-02-01

    Civilians living amid conflict are at high-risk of burns. However, the epidemiology of burns among this vulnerable group is poorly understood, yet vital for health policy and relief planning. To address this gap, we aimed to determine the death and disability, healthcare needs and household financial consequences of burns in post-invasion Baghdad. A two-stage, cluster randomized, community-based household survey was performed in May 2014 to determine the civilian burden of injury from 2003 to 2014 in Baghdad. In addition to questions about cause of household member death, households were interviewed regarding burn specifics, healthcare required, disability, relationship to conflict and resultant financial hardship. Nine-hundred households, totaling 5148 individuals, were interviewed. There were 55 burns, which were 10% of all injuries reported. There were an estimated 2340 serious burns (39 per 100,000 persons) in Baghdad in 2003. The frequency of serious burns generally increased post-invasion to 8780 burns in 2013 (117 per 100,000 persons). Eight burns (15%) were the direct result of conflict. Individuals aged over 45 years had more than twice the odds of burn than children aged less than 13 years (aOR 2.42; 95%CI 1.08-5.44). Nineteen burns (35%) involved ≥ 20% body surface area. Death (16% of burns), disability (40%), household financial hardship (48%) and food insecurity (50%) were common after burn. Civilian burn in Baghdad is epidemic, increasing in frequency and associated with household financial hardship. Challenges of healthcare provision during prolonged conflict were evidenced by a high mortality rate and likelihood of disability after burn. Ongoing conflict will directly and indirectly generates more burns, which mandates planning for burn prevention and care within local capacity development initiatives, as well as humanitarian assistance. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  10. Burns in Baghdad from 2003–2014: results of a randomized household cluster survey

    PubMed Central

    Stewart, Barclay T; Lafta, Riyadh; Shatari, Sahar A Esa Al; Cherewick, Megan; Burnham, Gilbert; Hagopian, Amy; Galway, Lindsay P; Kushner, Adam L

    2015-01-01

    Purpose Civilians living amid conflict are at high-risk of burns. However, the epidemiology of burns among this vulnerable group is poorly understood, yet vital for health policy and relief planning. To address this gap, we aimed to determine the death and disability, healthcare needs and household financial consequences of burns in post-invasion Baghdad. Methods A two-stage, cluster randomized, community-based household survey was performed in May of 2014 to determine the civilian burden of injury from 2003 to 2014 in Baghdad. In addition to questions about cause of household member death, households were interviewed regarding burn specifics, healthcare required, disability, relationship to conflict and resultant financial hardship. Results Nine-hundred households, totaling 5,148 individuals, were interviewed. There were 55 burns, which were 10% of all injuries reported. There were an estimated 2,340 serious burn injures (39 per 100,000 persons) in Baghdad in 2003. The frequency of serious burn injuries generally increased post-invasion to 8,780 burns in 2013 (117 per 100,000 persons). Eight burns (15%) were the direct result of conflict. Individuals aged over 45 years had more than twice the odds of burn injury than children aged less than 13 years (aOR 2.42; 95%CI 1.08 – 5.44). Nineteen burns (35%) involved ≥20% body surface area. Death (16% of burn injuries), disability (40%), household financial hardship (48%) and food insecurity (50%) were common after burn injury. Conclusion Civilian burn injury in Baghdad is epidemic, increasing in frequency and associated with household financial hardship. Challenges of healthcare provision during prolonged conflict were evidenced by a high mortality rate and likelihood of disability after burn injury. Ongoing conflict will directly and indirectly generate more burns, which mandates planning for burn prevention and care within local capacity development initiatives, as well as humanitarian assistance. PMID:26526376

  11. Heat Effects of Promoters and Determination of Burn Criterion in Promoted Combustion Testing

    NASA Technical Reports Server (NTRS)

    Sparks, Kyle M.; Stoltzfus, Joel M.; Steinberg, Theodore A.; Lynn, David

    2010-01-01

    Promoted ignition testing (NASA Test 17) [1] is used to determine the relative flammability of metal rods in oxygen-enriched atmospheres. A promoter is used to ignite a metal sample rod, initiating sample burning. If a predetermined length of the sample burns, beyond the promoter, the material is considered flammable at the condition tested. Historically, this burn length has been somewhat arbitrary. Experiments were performed to better understand this test by obtaining insight into the effect a burning promoter has on the preheating of a test sample. Test samples of several metallic materials were prepared and coupled to fast-responding thermocouples along their length. Thermocouple measurements and test video were synchronized to determine temperature increase with respect to time and length along each test sample. A recommended flammability burn length, based on a sample preheat of 500 F, was determined based on the preheated zone measured from these tests. This length was determined to be 30 mm (1.18 in.). Validation of this length and its rationale are presented.

  12. 77 FR 13582 - Disability and Rehabilitation Research Project; Burn Model Systems Centers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    .... (2008). A clarion to recommit and reaffirm burn rehabilitation. Journal of Burn Care & Research, 29(3... injury. Journal of Burn Care & Research, 30(2), 294-300. Schneider, J.C., Holavanahalli, R., Helm, P... for the year of 2009. Journal of Burn Care & Research, 31(6), 836-848. Ullrich, P.M., Askay, SW...

  13. A comparative analysis of potential impact area of common sugar cane burning methods

    NASA Astrophysics Data System (ADS)

    Hiscox, A. L.; Flecher, S.; Wang, J. J.; Viator, H. P.

    2015-04-01

    The negative effects of agricultural burning are well-known, although the actual impact area of different activities has not previously been quantified. An elastic backscatter lidar system was used to examine the impact-area size and dispersion of smoke generated from different types of sugarcane burning activities; pre-harvest (standing) burning and post-harvest (ground) burning. Experiments were conducted in the sugarcane harvest season of 2010 and 2011 at two locations in Louisiana, USA. Current dispersion theory would suggest that the primary difference between burn types would be primarily in the initial plume rise, but that the overall plume shape would remain the same. However, remotely sensed lidar data with the capability to measure plume dispersion and the short time dynamics of plume location showed pre-harvest (standing) burning produced a larger plume with greater rise and more spread within the 300 m of the plume, but a decrease in dispersion, but not concentration further downwind. Post-harvest (ground) burning produced a more traditional plume shape, but still exceeded impact area predictions near the source. Moreover, large changes in plume size can occur with small increases in wind speed. These are the first instrumented measurements of the meteorological effects of the different types of sugarcane burning. These results indicate that ground burning is preferable, but should be avoided in lower wind speed conditions.

  14. Stratospheric emissions effects database development

    NASA Technical Reports Server (NTRS)

    Baughcum, Steven L.; Henderson, Stephen C.; Hertel, Peter S.; Maggiora, Debra R.; Oncina, Carlos A.

    1994-01-01

    This report describes the development of a stratospheric emissions effects database (SEED) of aircraft fuel burn and emissions from projected Year 2015 subsonic aircraft fleets and from projected fleets of high-speed civil transports (HSCT's). This report also describes the development of a similar database of emissions from Year 1990 scheduled commercial passenger airline and air cargo traffic. The objective of this work was to initiate, develop, and maintain an engineering database for use by atmospheric scientists conducting the Atmospheric Effects of Stratospheric Aircraft (AESA) modeling studies. Fuel burn and emissions of nitrogen oxides (NO(x) as NO2), carbon monoxide, and hydrocarbons (as CH4) have been calculated on a 1-degree latitude x 1-degree longitude x 1-kilometer altitude grid and delivered to NASA as electronic files. This report describes the assumptions and methodology for the calculations and summarizes the results of these calculations.

  15. Prevention of Over-Pressurization During Combustion in a Sealed Chamber

    NASA Technical Reports Server (NTRS)

    Gokoglu, Suleyman A.; Niehaus, Justin E.; Olson, Sandra L.; Dietrich, Daniel L.; Ruff, Gary A.; Johnston, Michael C.

    2012-01-01

    The combustion of flammable material in a sealed chamber invariably leads to an initial pressure rise in the volume. The pressure rise is due to the increase in the total number of gaseous moles (condensed fuel plus chamber oxygen combining to form gaseous carbon dioxide and water vapor) and, most importantly, the temperature rise of the gas in the chamber. Though the rise in temperature and pressure would reduce with time after flame extinguishment due to the absorption of heat by the walls and contents of the sealed spacecraft, the initial pressure rise from a fire, if large enough, could lead to a vehicle over-pressure and the release of gas through the pressure relief valve. This paper presents a simple lumped-parameter model of the pressure rise in a sealed chamber resulting from the heat release during combustion. The transient model considers the increase in gaseous moles due to combustion, and heat transfer to the chamber walls by convection and radiation and to the fuel-sample holder by conduction, as a function of the burning rate of the material. The results of the model are compared to the pressure rise in an experimental chamber during flame spread tests as well as to the pressure falloff after flame extinguishment. The experiments involve flame spread over thin solid fuel samples. Estimates of the heat release rate profiles for input to the model come from the assumed stoichiometric burning of the fuel along with the observed flame spread behavior. The sensitivity of the model to predict maximum chamber pressure is determined with respect to the uncertainties in input parameters. Model predictions are also presented for the pressure profile anticipated in the Fire Safety-1 experiment, a material flammability and fire safety experiment proposed for the European Space Agency (ESA) Automated Transfer Vehicle (ATV). Computations are done for a range of scenarios including various initial pressures and sample sizes. Based on these results, various mitigation approaches are suggested to prevent vehicle over-pressurization and help guide the definition of the space experiment.

  16. EDIN design study alternate space shuttle booster replacement concepts. Volume 1: Engineering analysis

    NASA Technical Reports Server (NTRS)

    Demakes, P. T.; Hirsch, G. N.; Stewart, W. A.; Glatt, C. R.

    1976-01-01

    The use of a recoverable liquid rocket booster (LRB) system to replace the existing solid rocket booster (SRB) system for the shuttle was studied. Historical weight estimating relationships were developed for the LRB using Saturn technology and modified as required. Mission performance was computed using February 1975 shuttle configuration groundrules to allow reasonable comparison of the existing shuttle with the study designs. The launch trajectory was constrained to pass through both the RTLS/AOA and main engine cut off points of the shuttle reference mission 1. Performance analysis is based on a point design trajectory model which optimizes initial tilt rate and exoatmospheric pitch profile. A gravity turn was employed during the boost phase in place of the shuttle angle of attack profile. Engine throttling add/or shutdown was used to constrain dynamic pressure and/or longitudinal acceleration where necessary. Four basic configurations were investigated: a parallel burn vehicle with an F-1 engine powered LRB; a parallel burn vehicle with a high pressure engine powered LRB; a series burn vehicle with a high pressure engine powered LRB. The relative sizes of the LRB and the ET are optimized to minimize GLOW in most cases.

  17. Use of Standardized, Quantitative Digital Photography in a Multicenter Web-based Study

    PubMed Central

    Molnar, Joseph A.; Lew, Wesley K.; Rapp, Derek A.; Gordon, E. Stanley; Voignier, Denise; Rushing, Scott; Willner, William

    2009-01-01

    Objective: We developed a Web-based, blinded, prospective, randomized, multicenter trial, using standardized digital photography to clinically evaluate hand burn depth and accurately determine wound area with digital planimetry. Methods: Photos in each center were taken with identical digital cameras with standardized settings on a custom backdrop developed at Wake Forest University containing a gray, white, black, and centimeter scale. The images were downloaded, transferred via the Web, and stored on servers at the principal investigator's home institution. Color adjustments to each photo were made using Adobe Photoshop 6.0 (Adobe, San Jose, Calif). In an initial pilot study, model hands marked with circles of known areas were used to determine the accuracy of the planimetry technique. Two-dimensional digital planimetry using SigmaScan Pro 5.0 (SPSS Science, Chicago, Ill) was used to calculate wound area from the digital images. Results: Digital photography is a simple and cost-effective method for quantifying wound size when used in conjunction with digital planimetry (SigmaScan) and photo enhancement (Adobe Photoshop) programs. The accuracy of the SigmaScan program in calculating predetermined areas was within 4.7% (95% CI, 3.4%–5.9%). Dorsal hand burns of the initial 20 patients in a national study involving several centers were evaluated with this technique. Images obtained by individuals denying experience in photography proved reliable and useful for clinical evaluation and quantification of wound area. Conclusion: Standardized digital photography may be used quantitatively in a Web-based, multicenter trial of burn care. This technique could be modified for other medical studies with visual endpoints. PMID:19212431

  18. Use of standardized, quantitative digital photography in a multicenter Web-based study.

    PubMed

    Molnar, Joseph A; Lew, Wesley K; Rapp, Derek A; Gordon, E Stanley; Voignier, Denise; Rushing, Scott; Willner, William

    2009-01-01

    We developed a Web-based, blinded, prospective, randomized, multicenter trial, using standardized digital photography to clinically evaluate hand burn depth and accurately determine wound area with digital planimetry. Photos in each center were taken with identical digital cameras with standardized settings on a custom backdrop developed at Wake Forest University containing a gray, white, black, and centimeter scale. The images were downloaded, transferred via the Web, and stored on servers at the principal investigator's home institution. Color adjustments to each photo were made using Adobe Photoshop 6.0 (Adobe, San Jose, Calif). In an initial pilot study, model hands marked with circles of known areas were used to determine the accuracy of the planimetry technique. Two-dimensional digital planimetry using SigmaScan Pro 5.0 (SPSS Science, Chicago, Ill) was used to calculate wound area from the digital images. Digital photography is a simple and cost-effective method for quantifying wound size when used in conjunction with digital planimetry (SigmaScan) and photo enhancement (Adobe Photoshop) programs. The accuracy of the SigmaScan program in calculating predetermined areas was within 4.7% (95% CI, 3.4%-5.9%). Dorsal hand burns of the initial 20 patients in a national study involving several centers were evaluated with this technique. Images obtained by individuals denying experience in photography proved reliable and useful for clinical evaluation and quantification of wound area. Standardized digital photography may be used quantitatively in a Web-based, multicenter trial of burn care. This technique could be modified for other medical studies with visual endpoints.

  19. The Effect of Prescribed Burns and Wildfire on Vegetation in Bastrop State Park, TX

    NASA Astrophysics Data System (ADS)

    Justice, C. J.

    2014-12-01

    In 2011, central Texas had its worst drought since the 1950's. This, in conjunction with the strong winds produced by Tropical Storm Lee created conditions that made possible the Bastrop County Complex Fire in September 2011. These record-breaking wildfires burned over 95% of the 6,565-acre Bastrop State Park (BSP). Since 2003, BSP had been using prescribed burns as a management practice to reduce fuel load and prevent high severity wildfires. Although these prescribed fires did not prevent the 2011 wildfires they may have mitigated their effects. This study considered the effect of prescribed burn history and wildfire burn severity on vegetation recovery in BSP since the 2011 wildfire. The hypotheses of this study are that prescribed burn history and wildfire burn severity separately and jointly have affected post wildfire vegetation. To test these hypotheses, data were collected in 2013 from 46 plots across BSP using the Fire Effects Monitoring and Inventory (FIREMON) protocol to determine herbaceous plant density, shrub density, overstory density, and midstory tree density. Data were analyzed using analyses of variance (ANOVA) to determine the effects of prescribed fire and wildfire severity on these vegetation measurements. It was found that more severely burned plots had more herbaceous plants, fewer midstory trees, and lower shrub densities than less severely burned plots. Contrary to an initial hypotheses, there were few relationships between prescribed burn history and wildfire effects. The only significant effect detected for prescribed burning was the positive effect of prescribed fire on midstory tree density, but only for plots that were not severely burned in the wildfire. In this system, burn severity had a greater effect on post-wildfire vegetation than prescribed burns.

  20. Initial experience with a composite autologous skin substitute.

    PubMed

    Sheridan, R L; Morgan, J R; Cusick, J L; Petras, L M; Lydon, M M; Tompkins, R G

    2001-08-01

    Patients with large burns are surviving in increasing numbers, but there remains no durable and reliable permanent skin replacement. After initial favorable small animal experiments, a pilot trial of a composite skin replacement was performed in patients with massive burns. A composite skin replacement (CSR) was developed by culturing autologous keratinocytes on acellular allogenic dermis. This material was engrafted in patients with massive burns and compared to a matched wound covered with split thickness autograft. With human studies committee approval, 12 wounds in 7 patients were grafted with CSR while a matched control wound was covered with split thickness autograft. These 7 children had an average age of 6.4+/-1.4 yr and burn size of 75.9+/-5.0% of the body surface. Nine wounds were acute burns and three were reconstructive releases. Successful vascularization at 14 days averaged 45.7+/-14.2% (range 0-100%) in the study wounds and 98+/-1% (range 90-100%) in the control sites (P<0.05). Reduced CSR take seemed to correlate with wound colonization. All children survived. While CSR did not engraft with the reliability of standard autograft, this pilot experience is encouraging in that successful wound closure with this material is possible, if not yet dependable. It is hoped that a more mature epidermal layer may facilitate engraftment, and trials to explore this possibility are in progress.

  1. Effect of Chamber Pressurization Rate on Combustion and Propagation of Solid Propellant Cracks

    NASA Astrophysics Data System (ADS)

    Yuan, Wei-Lan; Wei, Shen; Yuan, Shu-Shen

    2002-01-01

    area of the propellant grain satisfies the designed value. But cracks in propellant grain can be generated during manufacture, storage, handing and so on. The cracks can provide additional surface area for combustion. The additional combustion may significantly deviate the performance of the rocket motor from the designed conditions, even lead to explosive catastrophe. Therefore a thorough study on the combustion, propagation and fracture of solid propellant cracks must be conducted. This paper takes an isolated propellant crack as the object and studies the effect of chamber pressurization rate on the combustion, propagation and fracture of the crack by experiment and theoretical calculation. deformable, the burning inside a solid propellant crack is a coupling of solid mechanics and combustion dynamics. In this paper, a theoretical model describing the combustion, propagation and fracture of the crack was formulated and solved numerically. The interaction of structural deformation and combustion process was included in the theoretical model. The conservation equations for compressible fluid flow, the equation of state for perfect gas, the heat conducting equation for the solid-phase, constitutive equation for propellant, J-integral fracture criterion and so on are used in the model. The convective burning inside the crack and the propagation and fracture of the crack were numerically studied by solving the set of nonlinear, inhomogeneous gas-phase governing equations and solid-phase equations. On the other hand, the combustion experiments for propellant specimens with a precut crack were conducted by RTR system. Predicted results are in good agreement with experimental data, which validates the reasonableness of the theoretical model. Both theoretical and experimental results indicate that the chamber pressurization rate has strong effects on the convective burning in the crack, crack fracture initiation and fracture pattern.

  2. Contributions of Severe Burn and Disuse to Bone Structure and Strength in Rats

    PubMed Central

    Baer, L.A.; Wu, X.; Tou, J. C.; Johnson, E.; Wolf, S.E.; Wade, C.E.

    2012-01-01

    Burn and disuse results in metabolic and bone changes associated with substantial and sustained bone loss. Such loss can lead to an increased fracture incidence and osteopenia. We studied the independent effects of burn and disuse on bone morphology, composition and strength, and microstructure of the bone alterations 14 days after injury. Sprague-Dawley rats were randomized into four groups: Sham/Ambulatory (SA), Burn/Ambulatory (BA), Sham/Hindlimb Unloaded (SH) and Burn/Hindlimb Unloaded (BH). Burn groups received a 40% total body surface area full-thickness scald burn. Disuse by hindlimb unloading was initiated immediately following injury. Bone turnover was determined in plasma and urine. Femur biomechanical parameters were measured by three-point bending tests and bone microarchitecture was determined by microcomputed tomography (uCT). On day 14, a significant reduction in body mass was observed as a result of burn, disuse and a combination of both. In terms of bone health, disuse alone and in combination affected femur weight, length and bone mineral content. Bending failure energy, an index of femur strength, was significantly reduced in all groups and maximum bending stress was lower when burn and disuse were combined. Osteocalcin was reduced in BA compared to the other groups, indicating influence of burn. The reductions observed in femur weight, BMC, biomechanical parameters and indices of bone formation are primarily responses to the combination of burn and disuse. These results offer insight into bone degradation following severe injury and disuse. PMID:23142361

  3. Stellar models for a wide range of initial chemical compositions until helium burning IV. From X = 0.65 to X = 0.80, for Z = 0.004

    NASA Astrophysics Data System (ADS)

    Claret, A.; Gimenez, A.

    1998-11-01

    As a continuation of previous papers in a series devoted to the computation of stellar structure and evolution models we present a grid specifically obtained for detailed studies of the stellar content of the Small Magellanic Cloud. The initial metal content has thus been adopted to be Z = 0.004 while the hydrogen content varies from 0.65 to 0.80 leaving as an intermediate value that given by standard laws of enrichment, X = 0.744. Interpolation for different environment is therefore possible with these new models. Other input physics parameters, e.g. convective overshooting, mixing-length, opacities or nuclear reaction rates, have been adopted to be homogeneous with the previously published models in order to facilitate comparative studies. Tables 1-72 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html}

  4. Investigation of biomass burning and aerosol loading and transport in South America utilizing geostationary satellites

    NASA Technical Reports Server (NTRS)

    Menzel, Paul; Prins, Elaine

    1995-01-01

    This study attempts to assess the extent of burning and associated aerosol transport regimes in South America and the South Atlantic using geostationary satellite observations, in order to explore the possible roles of biomass burning in climate change and more directly in atmospheric chemistry and radiative transfer processes. Modeling and analysis efforts have suggested that the direct and indirect radiative effects of aerosols from biomass burning may play a major role in the radiative balance of the earth and are an important factor in climate change calculations. One of the most active regions of biomass burning is located in South America, associated with deforestation in the selva (forest), grassland management, and other agricultural practices. As part of the NASA Aerosol Interdisciplinary Program, we are utilizing GOES-7 (1988) and GOES-8 (1995) visible and multispectral infrared data (4, 11, and 12 microns) to document daily biomass burning activity in South America and to distinguish smoke/aerosols from other multi-level clouds and low-level moisture. This study catalogues the areal extent and transport of smoke/aerosols throughout the region and over the Atlantic Ocean for the 1988 (July-September) and 1995 (June-October) biomass burning seasons. The smoke/haze cover estimates are compared to the locations of fires to determine the source and verify the haze is actually associated with biomass burning activities. The temporal resolution of the GOES data (half-hourly in South America) makes it possible to determine the prevailing circulation and transport of aerosols by considering a series of visible and infrared images and tracking the motion of smoke, haze and adjacent clouds. The study area extends from 40 to 70 deg W and 0 to 40 deg S with aerosol coverage extending over the Atlantic Ocean when necessary. Fire activity is estimated with the GOES Automated Biomass Burning Algorithm (ABBA). To date, our efforts have focused on GOES-7 and GOES-8 ABBA development, algorithm development for aerosol monitoring, data acquisition and archiving, and participation in the SCAR-C and SCAR-B field programs which have provided valuable information for algorithm testing and validation. Implementation of the initial version of the GEOS-8 ABBA on case studies in North, Central, and South America has demonstrated the improved capability for monitoring diurnal fire activity and smoke/aerosol transport with the GOES-8 throughout the Western Hemisphere.

  5. Burn-center quality improvement: are burn outcomes dependent on admitting facilities and is there a volume-outcome "sweet-spot"?

    PubMed

    Hranjec, Tjasa; Turrentine, Florence E; Stukenborg, George; Young, Jeffrey S; Sawyer, Robert G; Calland, James F

    2012-05-01

    Risk factors of mortality in burn patients such as inhalation injury, patient age, and percent of total body surface area (%TBSA) burned have been identified in previous publications. However, little is known about the variability of mortality outcomes between burn centers and whether the admitting facilities or facility volumes can be recognized as predictors of mortality. De-identified data from 87,665 acute burn observations obtained from the National Burn Repository between 2003 and 2007 were used to estimate a multivariable logistic regression model that could predict patient mortality with reference to the admitting burn facility/facility volume, adjusted for differences in age, inhalation injury, %TBSA burned, and an additional factor, percent full thickness burn (%FTB). As previously reported, all three covariates (%TBSA burned, inhalation injury, and age) were found to be highly statistically significant risk factors of mortality in burn patients (P value < 0.0001). The additional variable, %FTB, was also found to be a statistically significant determinant, although it did not greatly improve the multivariable model. The treatment/admitting facility was found to be an independent mortality predictor, with certain hospitals having increased odds of death and others showing a protective effect (decreased odds ratio). Hospitals with high burn volumes had the highest risk of mortality. Mortality outcomes of patients with similar risk factors (%TBSA burned, inhalation injury, age, and %FTB) are significantly affected by the treating facility and their admission volumes.

  6. Quantification of the volatile organic compounds in the smoke from prescribed burning and comparison with the occupational exposure limits

    NASA Astrophysics Data System (ADS)

    Barboni, T.; Santoni, P.-A.

    2013-11-01

    Prescribed burning represents a serious threat to the personnel fighting fires because of smoke inhalation. This study aims to increase the knowledge about foresters exposure to the prescribed burning smoke by focusing on exposure to volatile organic compounds (VOCs). We initially assessed the methodology for smoke sampling. Then, we identified potentially dangerous molecules among the VOCs identified at 4 prescribed burning sites located around Corsica. The values measured were very high, exceeding the exposure limits, particularly for benzene, phenol, and furfural, whose concentrations were above short-term exposure limit (STEL) values. In conclusion, obvious but necessary recommendations were made for the protection of the personnel involved in fighting fires on a professional basis.

  7. Utilization of laser Doppler flowmetry and tissue spectrophotometry for burn depth assessment using a miniature swine model.

    PubMed

    Lotter, Oliver; Held, Manuel; Schiefer, Jennifer; Werner, Ole; Medved, Fabian; Schaller, Hans-Eberhard; Rahmanian-Schwarz, Afshin; Jaminet, Patrick; Rothenberger, Jens

    2015-01-01

    Currently, the diagnosis of burn depth is primarily based on a visual assessment and can be dependent on the surgeons' experience. The goal of this study was to determine the ability of laser Doppler flowmeter combined with a tissue spectrophotometer to discriminate burn depth in a miniature swine burn model. Burn injuries of varying depth, including superficial-partial, deep-partial, and full thickness, were created in seven Göttingen minipigs using an aluminium bar (100 °C), which was applied to the abdominal skin for periods of 1, 3, 6, 12, 30, and 60 seconds with gravity alone. The depth of injury was evaluated histologically using hematoxylin and eosin staining. All burns were assessed 3 hours after injury using a device that combines a laser light and a white light to determine blood flow, hemoglobin oxygenation, and relative amount of hemoglobin. The blood flow (41 vs. 124 arbitrary units [AU]) and relative amount of hemoglobin (32 vs. 52 AU) were significantly lower in full thickness compared with superficial-partial thickness burns. However, no significant differences in hemoglobin oxygenation were observed between these depths of burns (61 vs. 60%). These results show the ability of laser Doppler flowmeter and tissue spectrophotometer in combination to discriminate between various depths of injury in the minipig model, suggesting that this device may offer a valuable tool for burn depth assessment influencing burn management. © 2014 by the Wound Healing Society.

  8. Using the ``blue spike'' to characterize biomass-burning sites during Southern African Regional Science Initiative (SAFARI) 2000

    NASA Astrophysics Data System (ADS)

    McCourt, M. L.; McMillan, W. W.; Ackerman, S.; Holz, R.; Revercomb, H. E.; Tobin, D.

    2004-10-01

    During several flights of the ER-2 while participating in the Southern African Regional Science Initiative (SAFARI 2000), the University of Wisconsin-Madison's Scanning High Resolution Interferometer Sounder (S-HIS) obtained spectra containing isolated fires within its field of view (FOV). These fire-laden FOVs contain a spectral feature caused by rotational hot band transitions of CO2 near 2400 cm-1. Because of its location on the blue side of the 4.3 μm band of CO2, this feature is commonly referred to as the "blue spike." Using this feature, we detected fires on four flights: 24 and 27 August and 6 and 7 September 2000. Fire locations are further verified by the ER-2 pilot's flight logs and elevated brightness temperatures in the thermal detectors of the MODIS Airborne Simulator (MAS) also on board the ER-2. Using line-by-line radiative transfer calculations (Genln2) with corrections for a fire's extreme high temperatures (HiTemp), we model S-HIS spectra for various scenes: background (cool surface and cool atmosphere), smoldering (warm surface and cool atmosphere), hot gas layer (cool surface and warm atmosphere), and fire (hot surface and hot atmosphere) cases. Using the controlled burn in the Timbavati Game Reserve on 7 September 2000 as a test case, we spectrally modeled the blue spike feature seen in the spectra obtained by S-HIS while the ER-2 flew over the fire. For this case, we found that ˜4.12 ± 0.05% of the FOV contained the hot gas layer while ˜0.23 ± 0.05% was actively burning. Originally viewed as a straightforward task of using the blue spike to characterize the fire temperature and size (fraction of S-HIS FOV), our analysis shows that numerous variables, including amount of carbon dioxide, amount of water vapor, and the temperature near the fire, play significant roles in the blue spike's shape and spectral position.

  9. Development of an Animal Model for Burn-Blast Combined Injury and Cardiopulmonary System Changes in the Early Shock Stage.

    PubMed

    Hu, Quan; Chai, Jiake; Hu, Sen; Fan, Jun; Wang, Hong-Wei; Ma, Li; Duan, Hong-Jie; Liu, Lingying; Yang, Hongming; Li, Bai-Ling; Wang, Yi-He

    2015-12-01

    The purposes of this study were to establish an animal model for burn-blast combined injury research and elaborate cardiopulmonary system changes in the early shock stage. In this study, royal demolition explosive or RDX (hexagon, ring trimethylene nitramine) was used as an explosive source, and the injury conditions of the canine test subjects at various distances to the explosion (30, 50, and 70 cm) were observed by gross anatomy and pathology to determine a larger animal model of moderate blast injury. The canines were then subjected to a 35 % total body surface area (TBSA) full-thickness flame injury using napalm, which completed the development of a burn-blast combined injury model. Based on this model, the hemodynamic changes and arterial blood gas analysis after the burn-blast combined injury were measured to identify the cardiopulmonary system characteristics. In this research, RDX explosion and flame injury were used to develop a severe burn-blast injury animal model that was stable, close to reality, and easily controllable. The hemodynamic and arterial blood gas changes in the canine subjects after burn-blast injury changed distinctly from the burn and blast injuries. Blood pressure and cardiac output fluctuated, and the preload was significantly reduced, whereas the afterload significantly increased. Meanwhile, the oxygen saturation (SO2) decreased markedly with carbon dioxide partial pressure (PCO2), and lactic acid (Lac) rose, and oxygen partial pressure (PO2) reduced. These changes suggested that immediate clinical treatment is important during burn-blast injury both to stabilize cardiac function and supply blood volume and to reduce the vascular permeability, thereby preventing acute pneumonedema or other complications.

  10. Efect of an educative action on relatives' knowledge about childhood burns at home.

    PubMed

    Gimeniz-Paschoal, Sandra Regina; Pereira, Débora Morais; Nascimento, Edinalva Neves

    2009-01-01

    This article aimed to evaluate the effect of an educative action on the knowledge of children's relatives about burns at home. Participants were 40 relatives of children under four years of age, equally divided between an intervention and control group. An initial interview was held, the educative action involved a folder about burns and, after one week, another interview took place. The answers were compared using Fisher's statistical test. In the first interview, 60 answers on risk situations were registered in the control group and 62 in the intervention group; in the second, the results increased to 61 and 80, respectively. In the first interview, 90% of the control group and 80% of the intervention group expressed the belief that childhood burns can be avoided; in the second, this indication decreased to 84% and increased to 100%, respectively. This study showed the importance of the advisory folder on burns at home.

  11. Vagus nerve stimulation blocks vascular permeability following burn injury in both local and distal sites

    PubMed Central

    Ortiz-Pomales, Yan T; Krzyzaniak, Michael; Coimbra, Raul; Baird, Andrew; Eliceiri, Brian P.

    2012-01-01

    Recent studies have shown that vagus nerve stimulation (VNS) can block the burn injury-induced systemic inflammatory response (SIRS). In this study we examined the potential for VNS to modulate vascular permeability (VP) in local sites (i.e. skin) and in secondary sites (i.e. lung) following burn injury. In a 30% total body surface area burn injury model, VP was measured using intravascular fluorescent dextran for quantification of the VP response in skin and lung. A peak in VP of the skin was observed 24 hours post-burn injury, that was blocked by VNS. Moreover, in the lung, VNS led to a reduction in burn-induced VP compared to sham-treated animals subjected to burn injury alone. The protective effects of VNS in this model were independent of the spleen, suggesting that the spleen was not a direct mediator of VNS. These studies identify a role for VNS in the regulation of VP in burns, with the translational potential of attenuating lung complications following burn injury. PMID:22694873

  12. Quantitative Assessment of Graded Burn Wounds in a Porcine Model using Spatial Frequency Domain Imaging (SFDI) and Laser Speckle Imaging (LSI)

    DTIC Science & Technology

    2014-09-08

    used SFDI and LSI to investigate controlled burn wounds of graded severity in a Yorkshire pig model. Burn wounds were imaged starting at one hour...10–15 (1992). 39. M. Chvapil, D. P. Speer, J. A. Owen, and T. A. Chvapil, “Identification of the depth of burn injury by collagen stainability... collagen denaturation (via scattering changes), hemodynamics and vascular damage each of which have the potential to provide clinicians with

  13. Experimental and Analytical Study of Erosive Burning of Solid Propellants

    DTIC Science & Technology

    1981-06-01

    Identity by block number) Experirnert~iI - d analytical, *bdeling studies of the erosive burning ,..solfd propel l;n!t; w’r(, ,conducted at Atlantic Research...is approved for public ’release IAVV AFR 190-12 (Tb). Distribuiiou is unlitited. A. D . HLOSE Z Tecuhtgal Ina’o ’nation Offo icer - 3. Conduct...roughness. 8. Extend the erosive burning model from flat-plate geometry to axisymmetric flow. 9. Validate the 2- D model of erosive burning by experimental

  14. Modeling biomass burning emissions for Amazon forest and pastures in Rondônia, Brazil.

    Treesearch

    Liane S. Guild; J. Boone Kauffman; Warren B. Cohen; Christine A. Hlavka; Darold E. Ward

    2004-01-01

    As a source of atmospheric carbon, biomass burning emissions associated with deforestation in the Amazon are globally significant. Once deforested, these lands continue to be sources of substantial burning emissions for many years due to frequent pasture burning. The objective of this research was to quantify biomass-burning emissions at a local scale. We estimated...

  15. Early and Late Acute Kidney Injury in Severely Burned Patients

    PubMed Central

    Witkowski, Wojciech; Kawecki, Marek; Surowiecka-Pastewka, Agnieszka; Klimm, Wojciech; Szamotulska, Katarzyna; Niemczyk, Stanisław

    2016-01-01

    Background This study evaluated factors influencing early and late occurrence of AKI in severely burned patients and assessed the relationship between time of occurrence of AKI and mortality of AKI patients. Material/Methods Renal function was evaluated at 3 time points: at admission, at the critical point or middle point of hospitalization, and at the endpoint for which death or a discharge from the center was considered. AKI criteria were: decrease in GFR of less than 60 ml/min at admission, decrease in GFR of more than 75% compared to baseline, and decrease in the daily diuresis of less than 500 ml/24 h. Results At admission, 15.1% of the patients had eGFR <60 ml/min. AKI occurred in 38.5% of cases. The occurrence of AKI was associated with: elderly age (p<0.001), female sex (p=0.017), overweight and obesity (p=0.055); extent and depth of burns, respiratory failure, low protein concentration (for all p<0.001), low blood pressure (p=0.014), and high WBC (p=0.010). Early AKI was detected in 28% of patients. Mortality was 100% with the initial GFR ≥60, 100% with the initial GFR <60 and early deterioration of renal function, 80% with the initial GFR <60 and late worsening, and 60% with the initial GFR <60 and no worsening. Late AKI was observed in 10% of patients and mortality in this group was 79.2%. Mortality in the entire group with AKI was 88.0% versus 24.5%. Conclusions The frequent occurrence of AKI, especially early, worsens the prognosis for survival. Assessment of renal function should be included in the prognostic scales for burned patients. PMID:27746455

  16. Analysis of Alaskan burn severity patterns using remotely sensed data

    USGS Publications Warehouse

    Duffy, P.A.; Epting, J.; Graham, J.M.; Rupp, T.S.; McGuire, A.D.

    2007-01-01

    Wildland fire is the dominant large-scale disturbance mechanism in the Alaskan boreal forest, and it strongly influences forest structure and function. In this research, patterns of burn severity in the Alaskan boreal forest are characterised using 24 fires. First, the relationship between burn severity and area burned is quantified using a linear regression. Second, the spatial correlation of burn severity as a function of topography is modelled using a variogram analysis. Finally, the relationship between vegetation type and spatial patterns of burn severity is quantified using linear models where variograms account for spatial correlation. These results show that: 1) average burn severity increases with the natural logarithm of the area of the wildfire, 2) burn severity is more variable in topographically complex landscapes than in flat landscapes, and 3) there is a significant relationship between burn severity and vegetation type in flat landscapes but not in topographically complex landscapes. These results strengthen the argument that differential flammability of vegetation exists in some boreal landscapes of Alaska. Additionally, these results suggest that through feedbacks between vegetation and burn severity, the distribution of forest vegetation through time is likely more stable in flat terrain than it is in areas with more complex topography. ?? IAWF 2007.

  17. Projecting climate-driven increases in North American fire activity

    NASA Astrophysics Data System (ADS)

    Wang, D.; Morton, D. C.; Collatz, G. J.

    2013-12-01

    Climate regulates fire activity through controls on vegetation productivity (fuels), lightning ignitions, and conditions governing fire spread. In many regions of the world, human management also influences the timing, duration, and extent of fire activity. These coupled interactions between human and natural systems make fire a complex component of the Earth system. Satellite data provide valuable information on the spatial and temporal dynamics of recent fire activity, as active fires, burned area, and land cover information can be combined to separate wildfires from intentional burning for agriculture and forestry. Here, we combined satellite-derived burned area data with land cover and climate data to assess fire-climate relationships in North America between 2000-2012. We used the latest versions of the Global Fire Emissions Database (GFED) burned area product and Modern-Era Retrospective Analysis for Research and Applications (MERRA) climate data to develop regional relationships between burned area and potential evaporation (PE), an integrated dryness metric. Logistic regression models were developed to link burned area with PE and individual climate variables during and preceding the fire season, and optimal models were selected based on Akaike Information Criterion (AIC). Overall, our model explained 85% of the variance in burned area since 2000 across North America. Fire-climate relationships from the era of satellite observations provide a blueprint for potential changes in fire activity under scenarios of climate change. We used that blueprint to evaluate potential changes in fire activity over the next 50 years based on twenty models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). All models suggest an increase of PE under low and high emissions scenarios (Representative Concentration Pathways (RCP) 4.5 and 8.5, respectively), with largest increases in projected burned area across the western US and central Canada. Overall, near-term climate projections point to pronounced changes in fire season length, total burned area, and the frequency of extreme events across North America by 2050.

  18. Acute pavement burns: a unique subset of burn injuries: a five-year review of resource use and cost impact.

    PubMed

    Silver, Andrew G; Dunford, Gerrit M; Zamboni, William A; Baynosa, Richard C

    2015-01-01

    This study focuses on the hospital care of a rare subset of burn injuries caused by contact with environmentally heated pavement, to further understand the required use of resources. This article aims to show that pavement burns are typically more severe than their flame/scald counterparts. A retrospective review of patients admitted to the burn center with injuries suffered from contact with hot pavement was performed. Patients were stratified on the presence or absence of altered mental status (AMS) and additional inciting factors. A representative sample of similarly sized flame and scald wounds treated in the same time period was compiled for comparison. Those with pavement burns had a significantly greater requirement for operative intervention, repetitive debridements, overall cost/percent burned, and lengthier hospital stays than those with flame/scald burns. Pavement burn victims with AMS were significantly more likely to require an operation, a greater cost/percent burned, and longer hospital stays than those without AMS. Pavement burns are significantly worse than similarly sized scald/flame burns with regards to length of stay and total hospital costs, and the necessity of initial and repetitive operative intervention. These discrepancies are even greater in patients with AMS as a concomitant inciting factor. It is apparent that these wounds often continue to deepen during a patient's stay, likely because of continued pressure on the wounds while recumbent. As such, this article highly recommends pressure off-loading beds and more aggressive debridement in the treatment of these unique injuries.

  19. Initial effects of prescribed fire on quality of soil solution and streamwater in the Southern Appalachian Mountains

    Treesearch

    Katherine J. Elliott; James M. Vose

    2005-01-01

    Prescribed burning is being used in the Conasauga River Watershed in southeastern Tennessee and northern Georgia by National Forest managers to restore degraded pine/oak communities. The purpose of these burns is to restore shortleaf pine (Pinus echinata Miller)/mixed-oak forests with more diverse understories, which include native bluestem grasses...

  20. Foliar nitrogen content and tree growth after prescribed fire in ponderosa pine.

    Treesearch

    J.D. Landsberg; P.H. Cochran; M.M. Finck; R.E. Martin

    1984-01-01

    This initial study of prescribed burning in ponderosa pine (Pinus ponderosa Doug. ex Laws.) stands in central Oregon showed that all periodic annual growth increments were reduced for trees alive four growing seasons later. Height growth was reduced 8 percent in areas burned by fires with moderate fuel consumption and 18 percent in areas with high...

  1. Emissions from biomass burning in the Yucatan [Discussions

    Treesearch

    R. Yokelson; J. D. Crounse; P. F. DeCarlo; T. Karl; S. Urbanski; E. Atlas; T. Campos; Y. Shinozuka; V. Kapustin; A. D. Clarke; A. Weinheimer; D. J. Knapp; D. D. Montzka; J. Holloway; P. Weibring; F. Flocke; W. Zheng; D. Toohey; P. O. Wennberg; C. Wiedinmyer; L. Mauldin; A. Fried; D. Richter; J. Walega; J. L. Jimenez; K. Adachi; P. R. Buseck; S. R. Hall; R. Shetter

    2009-01-01

    In March 2006 two instrumented aircraft made the first detailed field measurements of biomass burning (BB) emissions in the Northern Hemisphere tropics as part of the MILAGRO project. The aircraft were the National Center for Atmospheric Research C-130 and a University of Montana/US Forest Service Twin Otter. The initial emissions of up to 49 trace gas or particle...

  2. Effects of understory prescribed burning on shortleaf pine (Pinus echinata Mill.)/mixed-hardwood forests

    Treesearch

    Katherine J. Elliott; James M. Vose

    2005-01-01

    We examined the effects of a single dormant season fire on overstory and understory species diversity and composition and tree seedling regeneration patterns the first and second years following a prescribed burn in the Conasauga River Watershed of southeastern Tennessee and northern Georgia. We asked: Can a single dormant season fire initiate a trajectory of overstory...

  3. Prescribed burning in the Kings River Ecosystem Project Area: lessons learned

    Treesearch

    David S. McCandliss

    2002-01-01

    The prescribed fire program on the Sierra National Forest is in its infancy. Prescription burning was initiated in 1994 in two 32,000-acre watersheds in the Kings River District of the Sierra National Forest. Primary objectives are to return fire to a more historical role in forest ecosystems and to provide opportunities for scientists from the Pacific Southwest...

  4. The effects of fepeated prescribed burning on Pinus ponderosa growth

    Treesearch

    David L. Peterson; Stephen S. Sackett; Lindsay J. Robinson; Sally M. Haase

    1994-01-01

    The effect of repeated prescribed burning on long term growth of Pinus ponderosa in northern Arizona was examined. Fire treatments for hazard reduction were initiated in 1976,and growthwas evaluated in 1988 for fire rotations of 1, 2, 4, 6, 8, and 10 years. Dendroecological analysis shows that there were only small changes in treegrowth (compared tocontrols) in the...

  5. Effects of magnetization on fusion product trapping and secondary neutron spectraa)

    NASA Astrophysics Data System (ADS)

    Knapp, P. F.; Schmit, P. F.; Hansen, S. B.; Gomez, M. R.; Hahn, K. D.; Sinars, D. B.; Peterson, K. J.; Slutz, S. A.; Sefkow, A. B.; Awe, T. J.; Harding, E.; Jennings, C. A.; Desjarlais, M. P.; Chandler, G. A.; Cooper, G. W.; Cuneo, M. E.; Geissel, M.; Harvey-Thompson, A. J.; Porter, J. L.; Rochau, G. A.; Rovang, D. C.; Ruiz, C. L.; Savage, M. E.; Smith, I. C.; Stygar, W. A.; Herrmann, M. C.

    2015-05-01

    By magnetizing the fusion fuel in inertial confinement fusion (ICF) systems, the required stagnation pressure and density can be relaxed dramatically. This happens because the magnetic field insulates the hot fuel from the cold pusher and traps the charged fusion burn products. This trapping allows the burn products to deposit their energy in the fuel, facilitating plasma self-heating. Here, we report on a comprehensive theory of this trapping in a cylindrical DD plasma magnetized with a purely axial magnetic field. Using this theory, we are able to show that the secondary fusion reactions can be used to infer the magnetic field-radius product, BR, during fusion burn. This parameter, not ρR, is the primary confinement parameter in magnetized ICF. Using this method, we analyze data from recent Magnetized Liner Inertial Fusion experiments conducted on the Z machine at Sandia National Laboratories. We show that in these experiments BR ≈ 0.34(+0.14/-0.06) MG . cm, a ˜ 14× increase in BR from the initial value, and confirming that the DD-fusion tritons are magnetized at stagnation. This is the first experimental verification of charged burn product magnetization facilitated by compression of an initial seed magnetic flux.

  6. Development of the ClearSky smoke dispersion forecast system for agricultural field burning in the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Jain, Rahul; Vaughan, Joseph; Heitkamp, Kyle; Ramos, Charleston; Claiborn, Candis; Schreuder, Maarten; Schaaf, Mark; Lamb, Brian

    The post-harvest burning of agricultural fields is commonly used to dispose of crop residue and provide other desired services such as pest control. Despite careful regulation of burning, smoke plumes from field burning in the Pacific Northwest commonly degrade air quality, particularly for rural populations. In this paper, ClearSky, a numerical smoke dispersion forecast system for agricultural field burning that was developed to support smoke management in the Inland Pacific Northwest, is described. ClearSky began operation during the summer through fall burn season of 2002 and continues to the present. ClearSky utilizes Mesoscale Meteorological Model version 5 (MM5v3) forecasts from the University of Washington, data on agricultural fields, a web-based user interface for defining burn scenarios, the Lagrangian CALPUFF dispersion model and web-served animations of plume forecasts. The ClearSky system employs a unique hybrid source configuration, which treats the flaming portion of a field as a buoyant line source and the smoldering portion of the field as a buoyant area source. Limited field observations show that this hybrid approach yields reasonable plume rise estimates using source parameters derived from recent field burning emission field studies. The performance of this modeling system was evaluated for 2003 by comparing forecast meteorology against meteorological observations, and comparing model-predicted hourly averaged PM 2.5 concentrations against observations. Examples from this evaluation illustrate that while the ClearSky system can accurately predict PM 2.5 surface concentrations due to field burning, the overall model performance depends strongly on meteorological forecast error. Statistical evaluation of the meteorological forecast at seven surface stations indicates a strong relationship between topographical complexity near the station and absolute wind direction error with wind direction errors increasing from approximately 20° for sites in open areas to 70° or more for sites in very complex terrain. The analysis also showed some days with good forecast meteorology with absolute mean error in wind direction less than 30° when ClearSky correctly predicted PM 2.5 surface concentrations at receptors affected by field burns. On several other days with similar levels of wind direction error the model did not predict apparent plume impacts. In most of these cases, there were no reported burns in the vicinity of the monitor and, thus, it appeared that other, non-reported burns were responsible for the apparent plume impact at the monitoring site. These cases do not provide information on the performance of the model, but rather indicate that further work is needed to identify all burns and to improve burn reports in an accurate and timely manner. There were also a number of days with wind direction errors exceeding 70° when the forecast system did not correctly predict plume behavior.

  7. Burns to the genitalia, perineum, and buttocks increase the risk of death among U.S. service members sustaining combat-related burns in Iraq and Afghanistan.

    PubMed

    Clemens, Michael S; Janak, Judson C; Rizzo, Julie A; Graybill, John C; Buehner, Michelle F; Hudak, Steven J; Thompson, Charles K; Chung, Kevin K

    2017-08-01

    Among service members injured in Iraq and Afghanistan, to determine the risk of mortality associated with combat-related burns to the genitalia, perineum, and buttocks. The prospectively maintained burn registry from the United States Army Institute of Surgical Research was retrospectively reviewed to identify all service members with combat-related burns sustained in Iraq and Afghanistan from March 2003 to October 2013. The two primary risk factors of interest were (1) any burn to the genitals, perineum, and/or buttocks (PB) and (2) burns involving the entire perineal, genital, and buttock region (complete PB). Cox proportional hazard models were used to estimate the risk of mortality for both primary risk factors, and adjusted for severe non-burn-related trauma, percent of burn over total body surface area (TBSA), inhalational injury, time to urinary tract infection, and time to bacteremia. A post-hoc analysis was performed to explore the potential effect modification of TBSA burned on the relationship between PB and mortality. Among the 902 U.S. service members with combat-related burns sustained during the study period, 226 (25.0%) had involvement of the genitalia, perineum, and/or buttocks. Complete PB was associated with a crude risk of mortality (HR: 5.3; 2.9-9.7), but not an adjusted risk (HR=1.8; 0.8-4.0). However, TBSA burned was identified as a potential negative effect modifier. Among patients with burns <60% TBSA, sustaining a complete PB conferred an adjusted risk of death (HR=2.7; 1.1-6.8). Further, patients with a perineal burn had a five-fold increased incidence of bacteremia. In adjusted models, each event of bacteremia increased the risk of mortality by 92% (HR 1.92; 1.39-2.65). Perineal burns were associated with a two-fold increased incidence of severe non-burn related trauma that also doubled mortality risk in adjusted models (HR 2.29; 1.23-4.27). Among those with relatively survivable combat-related burns (<60% TBSA), genital/perineal/buttock involvement increases the risk of death. Bacteremia may account for part of this increased risk, but does not fully explain the independent risk associated with perineal burns. Published by Elsevier Ltd.

  8. 40 CFR Table 5 to Subpart Llll of... - Summary of Reporting Requirements for New Sewage Sludge Incineration Units a

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Documentation for siting requirements. 4. Anticipated date of initial startup. § 60.4915(a). Notification of initial startup Prior to initial startup 1. Maximum design dry sewage sludge burning capacity2.... 4. Anticipated date of initial startup. 5. Site-specific monitoring plan. 6. The site-specific...

  9. 40 CFR Table 5 to Subpart Llll of... - Summary of Reporting Requirements for New Sewage Sludge Incineration Units a

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Documentation for siting requirements. 4. Anticipated date of initial startup. § 60.4915(a). Notification of initial startup Prior to initial startup 1. Maximum design dry sewage sludge burning capacity2.... 4. Anticipated date of initial startup. 5. Site-specific monitoring plan. 6. The site-specific...

  10. Topical Modulation of the Burn Wound Inflammatory Response to Improve Short and Long Term Outcomes

    DTIC Science & Technology

    2015-10-15

    between p38MAPK signaling, wound inflammatory response, wound healing and long-term scar formation using a burn model in the female red Duroc pig ... pig model burn model as the appropriate wound healing model that resembles human response. At the end of the project, we will have a well-defined animal...scarring (period before the award of the current grant). Table 1 Study ID Wound Dates Treatment Pigs # Duration of study Pg001 Dermatome Feb

  11. Topical Modulation of the Burn Wound Inflammatory Response to Improve Short and Long Term Outcomes

    DTIC Science & Technology

    2015-10-01

    between p38MAPK signaling, wound inflammatory response, wound healing and long-term scar formation using a burn model in the female red Duroc pig ... pig model burn model as the appropriate wound healing model that resembles human response. At the end of the project, we will have a well-defined animal...scarring (period before the award of the current grant). Table 1 Study ID Wound Dates Treatment Pigs # Duration of study Pg001 Dermatome Feb

  12. Modelling fire frequency and area burned across phytoclimatic regions in Spain using reanalysis data and the Canadian Fire Weather Index System

    NASA Astrophysics Data System (ADS)

    Bedia, J.; Herrera, S.; Gutiérrez, J. M.

    2013-09-01

    We develop fire occurrence and burned area models in peninsular Spain, an area of high variability in climate and fuel types, for the period 1990-2008. We based the analysis on a phytoclimatic classification aiming to the stratification of the territory into homogeneous units in terms of climatic and fuel type characteristics, allowing to test model performance under different climatic and fuel conditions. We used generalized linear models (GLM) and multivariate adaptive regression splines (MARS) as modelling algorithms and temperature, relative humidity, precipitation and wind speed, taken from the ERA-Interim reanalysis, as well as the components of the Canadian Forest Fire Weather Index (FWI) System as predictors. We also computed the standardized precipitation-evapotranspiration index (SPEI) as an additional predictor for the models of burned area. We found two contrasting fire regimes in terms of area burned and number of fires: one characterized by a bimodal annual pattern, characterizing the Nemoral and Oro-boreal phytoclimatic types, and another one exhibiting an unimodal annual cycle, with the fire season concentrated in the summer months in the Mediterranean and Arid regions. The fire occurrence models attained good skill in most of the phytoclimatic zones considered, yielding in some zones notably high correlation coefficients between the observed and modelled inter-annual fire frequencies. Total area burned also exhibited a high dependence on the meteorological drivers, although their ability to reproduce the observed annual burned area time series was poor in most cases. We identified temperature and some FWI system components as the most important explanatory variables, and also SPEI in some of the burned area models, highlighting the adequacy of the FWI system for fire modelling applications and leaving the door opened to the development a more complex modelling framework based on these predictors. Furthermore, we demonstrate the potential usefulness of ERA-Interim reanalysis data for the reconstruction of historical fire-climate relationships at the scale of analysis. Fire frequency predictions may provide a preferable basis for past fire history reconstruction, long-term monitoring and the assessment of future climate impacts on fire regimes across regions, posing several advantages over burned area as response variable.

  13. The Status of Multi-Dimensional Core-Collapse Supernova Models

    NASA Astrophysics Data System (ADS)

    Müller, B.

    2016-09-01

    Models of neutrino-driven core-collapse supernova explosions have matured considerably in recent years. Explosions of low-mass progenitors can routinely be simulated in 1D, 2D, and 3D. Nucleosynthesis calculations indicate that these supernovae could be contributors of some lighter neutron-rich elements beyond iron. The explosion mechanism of more massive stars remains under investigation, although first 3D models of neutrino-driven explosions employing multi-group neutrino transport have become available. Together with earlier 2D models and more simplified 3D simulations, these have elucidated the interplay between neutrino heating and hydrodynamic instabilities in the post-shock region that is essential for shock revival. However, some physical ingredients may still need to be added/improved before simulations can robustly explain supernova explosions over a wide range of progenitors. Solutions recently suggested in the literature include uncertainties in the neutrino rates, rotation, and seed perturbations from convective shell burning. We review the implications of 3D simulations of shell burning in supernova progenitors for the `perturbations-aided neutrino-driven mechanism,' whose efficacy is illustrated by the first successful multi-group neutrino hydrodynamics simulation of an 18 solar mass progenitor with 3D initial conditions. We conclude with speculations about the impact of 3D effects on the structure of massive stars through convective boundary mixing.

  14. Cytokine expression profile over time in burned mice.

    PubMed

    Finnerty, Celeste C; Przkora, Rene; Herndon, David N; Jeschke, Marc G

    2009-01-01

    The persistent inflammatory response induced by a severe burn increases patient susceptibility to infections and sepsis, potentially leading to multi-organ failure and death. In order to use murine models to develop interventions that modulate the post-burn inflammatory response, the response in mice and the similarities to the human response must first be determined. Here, we present the temporal serum cytokine expression profiles in burned mice in comparison to sham mice and human burn patients. Male C57BL/6 mice were randomized to control (n=47) or subjected to a 35% TBSA scald burn (n=89). Mice were sacrificed 3, 6, 9, 12, 24, and 48 h and 7, 10, and 14 days post-burn; cytokines were measured by multi-plex array. Following the burn injury, IL-6, IL-1beta, KC, G-CSF, TNF, IL-17, MIP-1alpha, RANTES, and GM-CSF were increased, p<0.05. IL-2, IL-3, and IL-5 were decreased, p<0.05. IL-10, IFN-gamma, and IL-12p70 were expressed in a biphasic manner, p<0.05. This temporal cytokine expression pattern elucidates the pathogenesis of the inflammatory response in burned mice. Expression of 11 cytokines were similar in mice and children, returning to lowest levels by post-burn day 14, confirming the utility of the burned mouse model for development of therapeutic interventions to attenuate the post-burn inflammatory response.

  15. Convective transport of biomass burning emissions over Brazil during TRACE A

    NASA Astrophysics Data System (ADS)

    Pickering, Kenneth E.; Thompson, Anne M.; Wang, Yansen; Tao, Wei-Kuo; McNamara, Donna P.; Kirchhoff, Volker W. J. H.; Heikes, Brian G.; Sachse, Glen W.; Bradshaw, John D.; Gregory, Gerald L.; Blake, Donald R.

    1996-10-01

    A series of large mesoscale convective systems that occurred during the Brazilian phase of GTE/TRACE A (Transport and Atmospheric Chemistry near the Equator-Atlantic) provided an opportunity to observe deep convective transport of trace gases from biomass burning. This paper reports a detailed analysis of flight 6, on September 27, 1992, which sampled cloud- and biomass-burning-perturbed regions north of Brasilia. High-frequency sampling of cloud outflow at 9-12 km from the NASA DC-8 showed enhancement of CO mixing ratios typically a factor of 3 above background (200-300 parts per billion by volume (ppbv) versus 90 ppbv) and significant increases in NOx and hydrocarbons. Clear signals of lightning-generated NO were detected; we estimate that at least 40% of NOx at the 9.5-km level and 32% at 11.3 km originated from lightning. Four types of model studies have been performed to analyze the dynamical and photochemical characteristics of the series of convective events. (1) Regional simulations for the period have been performed with the NCAR/Penn State mesoscale model (MM5), including tracer transport of carbon monoxide, initialized with observations. Middle-upper tropospheric enhancements of a factor of 3 above background are reproduced. (2) A cloud-resolving model (the Goddard cumulus ensemble (GCE) model) has been run for one representative convective cell during the September 26-27 episode. (3) Photochemical calculations (the Goddard tropospheric chemical model), initialized with trace gas observations (e.g., CO, NOx, hydrocarbons, O3) observed in cloud outflow, show appreciable O3 formation postconvection, initially up to 7-8 ppbv O3/d. (4) Forward trajectories from cloud outflow levels (postconvective conditions) put the ozone-producing air masses in eastern Brazil and the tropical Atlantic within 2-4 days and over the Atlantic, Africa, and the Indian Ocean in 6-8 days. Indeed, 3-4 days after the convective episode (September 30, 1992), upper tropospheric levels in the Natal ozone sounding show an average increase of ˜30 ppbv (3 Dobson units (DU) integrated) compared to the September 28 sounding. Our simulated net O3 production rates in cloud outflow are a factor of 3 or more greater than those in air undisturbed by the storms. Integrated over the 8- to 16-km cloud outflow layer, the postconvection net O3 production (˜5-6 DU over 8 days) accounts for ˜25% of the excess O3 (15-25 DU) over the South Atlantic. Comparison of TRACE A Brazilian ozonesondes and the frequency of deep convection with climatology [Kirchhoff et al., this issue] suggests that the late September 1992 conditions represented an unusually active period for both convection and upper tropospheric ozone formation.

  16. Health-related quality of life (EQ-5D) early after injury predicts long-term pain after burn.

    PubMed

    Gauffin, Emelie; Öster, Caisa; Sjöberg, Folke; Gerdin, Bengt; Ekselius, Lisa

    2016-12-01

    Chronic pain after burn can have severe physical and psychological effects on former patients years after the initial injury. Although the issue of pain after burn has gained increased attention over the past years, prospective, longitudinal studies are scarce. Our aim was to prospectively investigate consecutive burn patients for pain severity over time and to evaluate the prevalence and characteristics of post-burn pain to 2-7 years after the burn. As an additional aim, the effects of burn and individual-related factors, especially health-related Quality of Life (HRQoL), were investigated. Sixty-seven consecutive burn patients were assessed during acute care at 3, 6, 12 and 24 months, as well as at 2-7 years post-burn. HRQoL, symptoms of post-traumatic stress disorder (PTSD) and other psychiatric disorders were investigated. During the interviews that took place 2-7 years after the injury (mean 4.6±1.9 years), current chronic post-burn pain was assessed using the Brief Pain Inventory-Short Form (BPI-SF). One-third of the patients still reported pain 2-7 years after the injury. Pain severity and interference with daily life were mainly mild to moderate though they were found to be associated with significantly lower HRQoL. Chronic pain after burn was associated with both burn- and individual-related factors. In logistic regression analysis HRQoL at 3 and 12 months and symptoms of PTSD at 12 months were independent factors in predicting chronic pain after burn. Pain after burn becomes a chronic burden for many former burn patients and decreases HRQoL. A novel finding in this study was that HRQoL assessed early after burn was a predictor for the development of chronic pain. This finding may help to predict future pain problems and serve as an indicator for pain preventive measures. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Toll-Like Receptor Signaling in Burn Wound Healing and Scarring

    PubMed Central

    D'Arpa, Peter; Leung, Kai P.

    2017-01-01

    Significance: Damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) emanate from burn-injured tissue and enter systemic circulation. Locally and systemically, they activate pattern-recognition receptors, including toll-like receptors (TLRs), to stimulate cytokine secretion, which in the severest burns typically results in extreme systemic cytokine levels, a dysfunctioning immune system, infection, impaired healing, and excessive scarring. This system-wide disruption of homeostasis can advance to life-threatening, multiorgan dysfunction syndrome. Knowledge of DAMP- and PAMP-TLR signaling may lead to treatments that ameliorate local and systemic inflammation and reduce scarring and other burn injury sequela. Recent Advances: Many PAMPs and DAMPs, the TLRs they activate, and their downstream signaling molecules have been shown to contribute to local and systemic inflammation and tissue damage following burn injury. Critical Issues: Whether TLR-pathway-targeting treatments applied at different times postburn injury might improve scarring remains an open question. The evaluation of this question requires the use of appropriate preclinical and clinical burn models carried out until after mature scar has formed. Future Directions: After TLR-pathway-targeting treatments are evaluated in porcine burn wound models and their safety is demonstrated, they can be tested in proof-of-concept clinical burn wound models. PMID:29062590

  18. [Estimating Biomass Burned Areas from Multispectral Dataset Detected by Multiple-Satellite].

    PubMed

    Yu, Chao; Chen, Liang-fu; Li, Shen-shen; Tao, Jin-hua; Su, Lin

    2015-03-01

    Biomass burning makes up an important part of both trace gases and particulate matter emissions, which can efficiently degrade air quality and reduce visibility, destabilize the global climate system at regional to global scales. Burned area is one of the primary parameters necessary to estimate emissions, and considered to be the largest source of error in the emission inventory. Satellite-based fire observations can offer a reliable source of fire occurrence data on regional and global scales, a variety of sensors have been used to detect and map fires in two general approaches: burn scar mapping and active fire detection. However, both of the two approaches have limitations. In this article, we explore the relationship between hotspot data and burned area for the Southeastern United States, where a significant amount of biomass burnings from both prescribed and wild fire took place. MODIS (Moderate resolution imaging spectrometer) data, which has high temporal-resolution, can be used to monitor ground biomass. burning in time and provided hot spot data in this study. However, pixel size of MODIS hot spot can't stand for the real ground burned area. Through analysis of the variation of vegetation band reflectance between pre- and post-burn, we extracted the burned area from Landsat-5 TM (Thematic Mapper) images by using the differential normalized burn ratio (dNBR) which is based on TM band4 (0.84 μm) and TM band 7(2.22 μm) data. We combined MODIS fire hot spot data and Landsat-5 TM burned scars data to build the burned area estimation model, results showed that the linear correlation coefficient is 0.63 and the relationships vary as a function of vegetation cover. Based on the National Land Cover Database (NLCD), we built burned area estimation model over different vegetation cover, and got effective burned area per fire pixel, values for forest, grassland, shrub, cropland and wetland are 0.69, 1.27, 0.86, 0.72 and 0.94 km2 respectively. We validated the burned area estimates by using the ground survey data from National interagency Fire Center (NIFC), our results are more close to the ground survey data than burned area from Global Fire Emissions Database (GFED) and MODIS burned area product (MCD45), which omitted many small prescribed fires. We concluded that our model can provide more accurate burned area parameters for developing fire emission inventory, and be better for estimating emissions from biomass burning.

  19. A polygon-based modeling approach to assess exposure of resources and assets to wildfire

    Treesearch

    Matthew P. Thompson; Joe Scott; Jeffrey D. Kaiden; Julie W. Gilbertson-Day

    2013-01-01

    Spatially explicit burn probability modeling is increasingly applied to assess wildfire risk and inform mitigation strategy development. Burn probabilities are typically expressed on a per-pixel basis, calculated as the number of times a pixel burns divided by the number of simulation iterations. Spatial intersection of highly valued resources and assets (HVRAs) with...

  20. Burn severity mapping using simulation modeling and satellite imagery

    Treesearch

    Eva C. Karau; Robert E. Keane

    2010-01-01

    Although burn severity maps derived from satellite imagery provide a landscape view of fire impacts, fire effects simulation models can provide spatial fire severity estimates and add a biotic context in which to interpret severity. In this project, we evaluated two methods of mapping burn severity in the context of rapid post-fire assessment for four wildfires in...

  1. Modeling crop residue burning experiments to evaluate smoke emissions and plume transport

    Treesearch

    Luxi Zhou; Kirk R. Baker; Sergey L. Napelenok; George Pouliot; Robert Elleman; Susan M. O' Neill; Shawn P. Urbanski; David C. Wong

    2018-01-01

    Crop residue burning is a common land management practice that results in emissions of a variety of pollutants with negative health impacts. Modeling systems are used to estimate air quality impacts of crop residue burning to support retrospective regulatory assessments and also for forecasting purposes. Ground and airborne measurements from a recent field experiment...

  2. An improved model for the combustion of AP composite propellants

    NASA Technical Reports Server (NTRS)

    Cohen, N. S.; Strand, L. D.

    1981-01-01

    This paper presents several improvements to the BDP model of steady-state burning of AP composite solid propellants. The Price-Boggs-Derr model of AP monopropellant burning is incorporated to represent the AP. A separate energy equation is written for the binder to permit a different surface temperature from the AP; this includes an analysis of the sharing of primary diffusion flame energy, and correction of a BDP model inconsistency in treating the binder regression rate. A method for assembling component contributions to calculate the burning rates of multimodal propellants is also presented. Results are shown in the form of representative burning rate curves, comparisons with data, and calculated internal details of interest. Ideas for future work are discussed in an Appendix.

  3. A Preliminary Assessment of the SURF Reactive Burn Model Implementation in FLAG

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Johnson, Carl Edward; McCombe, Ryan Patrick; Carver, Kyle

    Properly validated and calibrated reactive burn models (RBM) can be useful engineering tools for assessing high explosive performance and safety. Experiments with high explosives are expensive. Inexpensive RBM calculations are increasingly relied on for predictive analysis for performance and safety. This report discusses the validation of Menikoff and Shaw’s SURF reactive burn model, which has recently been implemented in the FLAG code. The LANL Gapstick experiment is discussed as is its’ utility in reactive burn model validation. Data obtained from pRad for the LT-63 series is also presented along with FLAG simulations using SURF for both PBX 9501 and PBXmore » 9502. Calibration parameters for both explosives are presented.« less

  4. Thyroid Function in Critical Illness and Burn Injury,

    DTIC Science & Technology

    1993-07-01

    measrent of tyida x hor-etioogyof hperhyridis, Oive Cop eta15 mones in burn patients and animal burn models etiology of hyperthyroidism , Oliver Cope et...post-burn hypermetabolic condition following major burns.’ ൡ In fact, the opposite is a function of transient hyperthyroidism . They question of...concluded that hyperthyroidism was not present protracted illness, whether medical, surgical, and was not the mediator of the hypermetabol- or

  5. A National Disturbance Modeling System to Support Ecological Carbon Sequestration Assessments

    NASA Astrophysics Data System (ADS)

    Hawbaker, T. J.; Rollins, M. G.; Volegmann, J. E.; Shi, H.; Sohl, T. L.

    2009-12-01

    The U.S. Geological Survey (USGS) is prototyping a methodology to fulfill requirements of Section 712 of the Energy Independence and Security Act (EISA) of 2007. At the core of the EISA requirements is the development of a methodology to complete a two-year assessment of current carbon stocks and other greenhouse gas (GHG) fluxes, and potential increases for ecological carbon sequestration under a range of future climate changes, land-use / land-cover configurations, and policy, economic and management scenarios. Disturbances, especially fire, affect vegetation dynamics and ecosystem processes, and can also introduce substantial uncertainty and risk to the efficacy of long-term carbon sequestration strategies. Thus, the potential impacts of disturbances need to be considered under different scenarios. As part of USGS efforts to meet EISA requirements, we developed the National Disturbance Modeling System (NDMS) using a series of statistical and process-based simulation models. NDMS produces spatially-explicit forecasts of future disturbance locations and severity, and the resulting effects on vegetation dynamics. NDMS is embedded within the Forecasting Scenarios of Future Land Cover (FORE-SCE) model and informs the General Ensemble Biogeochemical Modeling System (GEMS) for quantifying carbon stocks and GHG fluxes. For fires, NDMS relies on existing disturbance histories, such as the Landsat derived Monitoring Trends in Burn Severity (MTBS) and Vegetation Change Tracker (VCT) data being used to update LANDFIRE fuels data. The MTBS and VCT data are used to parameterize models predicting the number and size of fires in relation to climate, land-use/land-cover change, and socioeconomic variables. The locations of individual fire ignitions are determined by an ignition probability surface and then FARSITE is used to simulate fire spread in response to weather, fuels, and topography. Following the fire spread simulations, a burn severity model is used to determine annual changes in biomass pools. Vegetation succession among LANDFIRE vegetation types is initiated using burn perimeter and severity data at the end of each annual simulation. Results from NDMS are used to update land-use/land-cover layers used by FORE-SCE and also transferred to GEMS for quantifying and updating carbon stocks and greenhouse gas fluxes. In this presentation, we present: 1) an overview of NDMS and its role in USGS's national ecological carbon sequestration assessment; 2) validation of NDMS using historic data; and 3) initial forecasts of disturbances for the southeastern United States and their impacts on greenhouse gas emissions, and post-fire carbon stocks and fluxes.

  6. Modeling the Complex Photochemistry of Biomass Burning Plumes in Plume-Scale, Regional, and Global Air Quality Models

    NASA Astrophysics Data System (ADS)

    Alvarado, M. J.; Lonsdale, C. R.; Yokelson, R. J.; Travis, K.; Fischer, E. V.; Lin, J. C.

    2014-12-01

    Forecasting the impacts of biomass burning (BB) plumes on air quality is difficult due to the complex photochemistry that takes place in the concentrated young BB plumes. The spatial grid of global and regional scale Eulerian models is generally too large to resolve BB photochemistry, which can lead to errors in predicting the formation of secondary organic aerosol (SOA) and O3, as well as the partitioning of NOyspecies. AER's Aerosol Simulation Program (ASP v2.1) can be used within plume-scale Lagrangian models to simulate this complex photochemistry. We will present results of validation studies of the ASP model against aircraft observations of young BB smoke plumes. We will also present initial results from the coupling of ASP v2.1 into the Lagrangian particle dispersion model STILT-Chem in order to better examine the interactions between BB plume chemistry and dispersion. In addition, we have used ASP to develop a sub-grid scale parameterization of the near-source chemistry of BB plumes for use in regional and global air quality models. The parameterization takes inputs from the host model, such as solar zenith angle, temperature, and fire fuel type, and calculates enhancement ratios of O3, NOx, PAN, aerosol nitrate, and other NOy species, as well as organic aerosol (OA). We will present results from the ASP-based BB parameterization as well as its implementation into the global atmospheric composition model GEOS-Chem for the SEAC4RS campaign.

  7. Local Burn-Up Effects in the NBSR Fuel Element

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Brown N. R.; Hanson A.; Diamond, D.

    2013-01-31

    This study addresses the over-prediction of local power when the burn-up distribution in each half-element of the NBSR is assumed to be uniform. A single-element model was utilized to quantify the impact of axial and plate-wise burn-up on the power distribution within the NBSR fuel elements for both high-enriched uranium (HEU) and low-enriched uranium (LEU) fuel. To validate this approach, key parameters in the single-element model were compared to parameters from an equilibrium core model, including neutron energy spectrum, power distribution, and integral U-235 vector. The power distribution changes significantly when incorporating local burn-up effects and has lower power peakingmore » relative to the uniform burn-up case. In the uniform burn-up case, the axial relative power peaking is over-predicted by as much as 59% in the HEU single-element and 46% in the LEU single-element with uniform burn-up. In the uniform burn-up case, the plate-wise power peaking is over-predicted by as much as 23% in the HEU single-element and 18% in the LEU single-element. The degree of over-prediction increases as a function of burn-up cycle, with the greatest over-prediction at the end of Cycle 8. The thermal flux peak is always in the mid-plane gap; this causes the local cumulative burn-up near the mid-plane gap to be significantly higher than the fuel element average. Uniform burn-up distribution throughout a half-element also causes a bias in fuel element reactivity worth, due primarily to the neutronic importance of the fissile inventory in the mid-plane gap region.« less

  8. Biomass Burning and the Production of Greenhouse Gases. Chapter 9

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    1994-01-01

    Biomass burning is a source of greenhouse gases, carbon dioxide, methane, and nitrous oxide. In addition, biomass burning is a source of chemically active gases, including carbon monoxide, nonmethane hydrocarbons, and nitric oxide. These gases, along with methane, lead to the chemical production of tropospheric ozone (another greenhouse gas) as well as control the concentration of the hydroxyl radical, which regulates the lifetime of almost every atmospheric gas. Following biomass burning, biogenic emissions of nitrous oxide, nitric oxide, and methane are significantly enhanced. It is hypothesized that enhanced postburn biogenic emissions of these gases are related to fire-induced changes in soil chemistry and/or microbial ecology. Biomass burning, once believed to be a tropical phenomenon, has been demonstrated by satellite imagery to also be a regular feature of the world's boreal forests. One example of biomass burning is the extensive 1987 fire that destroyed more than 12 million acres of boreal forest in the People's Republic of China and across its border in the Soviet Union. Recent estimates indicate that almost all biomass burning is human-initiated and that it is increasing with time. With the formation of greenhouse and chemically active gases as direct combustion products and a longer-term enhancement of biogenic emissions of gases, biomass burning may be a significant driver for global change.

  9. Gut microbiota trajectory in patients with severe burn: A time series study.

    PubMed

    Wang, Xinying; Yang, Jianbo; Tian, Feng; Zhang, Li; Lei, Qiucheng; Jiang, Tingting; Zhou, Jihong; Yuan, Siming; Wang, Jun; Feng, Zhijian; Li, Jieshou

    2017-12-01

    This time series experiments aimed to investigate the dynamic change of gut microbiomes after severe burn and its association with enteral nutrition (EN). Seven severely burned patients who suffered from a severe metal dust explosion injury were recruited in this study. The dynamic changes of gut microbiome of fecal samples at six time points (1-3days, 2, 3, 4, 5 and 6weeks after severe burn) were detected using 16S ribosomal RNA pyrosequencing technology. Following the post-burn temporal order, gut microbiota dysbiosis was detected in the gut microbiome after severe burn, then it was gradually resolved. The bio-diversity of gut bacteria was initially decreased, and then returned to normal level. In addition, at the early stage (from 2 to 4weeks), the majority of those patients' gut microbiome were opportunistic pathogen genus, Enterococcus and Escherichia; while at the end of this study, the majority was a beneficial genus, Bacteroides. EN can promote the recovery of gut microbiota, especially in EN well-tolerated patients. Severe burn injury can cause a dramatic dysbiosis of gut microbiota. A trend of enriched beneficial bacteria and diminished opportunistic pathogen bacteria may serve as prognosis microbiome biomarkers of severe burn patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Estrogen treatment of acetic acid burns to the vagina, cervix, and perineum: a case report and review of the literature.

    PubMed

    Ching, Jessica A; Kuykendall, Lauren V; Troy, Jared S; Smith, David J

    2014-01-01

    In colposcopic evaluation of the cervix, acetic acid of 3 to 5% is commonly used for identification of preneoplastic and neoplastic cells. Acetic acid is a known caustic substance and has the potential to cause irritation and chemical burns when there is sufficient concentration or duration of contact. The authors present a unique case of a woman who inadvertently received undiluted acetic acid during a routine colposcopy, resulting in significant chemical burns of the vagina, cervix, and perineum. Her burns were treated with topical estrogen cream of 1 g twice daily applied directly to the wounds. The burn wounds were fully healed within 8 weeks without complication or additional treatment. At 6 months after the injury, the patient was allowed to engage in sexual activity, and vaginal dilation and pelvic floor therapy were initiated. At 12 months postinjury, her only symptomatic scarring at the left vaginal wall continues to improve. Thus, topical estrogen treatment of 1 g applied twice daily should be continued until burn scar maturation is complete and treatment improvement plateaus in cases of burns to the vagina, cervix, and perineum. This case is further clinical evidence of estrogen's positive effect on wound healing and its potential role in burn treatment.

  11. Applications of virtual reality for pain management in burn-injured patients

    PubMed Central

    Miller, William; Teeley, Aubriana; Soltani, Maryam; Hoffman, Hunter G; Jensen, Mark P; Patterson, David R

    2009-01-01

    The pain associated with burn injuries is intense, unremitting and often exacerbated by anxiety, depression and other complicating patient factors. On top of this, modern burn care involves the repetitive performance – often on a daily basis for weeks to months – of painful and anxiety-provoking procedures that create additional treatment-related pain, such as wound care, dressing changes and rehabilitation activities. Pain management in burn patients is primarily achieved by potent pharmacologic analgesics (e.g., opioids), but is necessarily complemented by nonpharmacologic techniques, including distraction or hypnosis. Immersive virtual reality provides a particularly intense form of cognitive distraction during such brief, painful procedures, and has undergone preliminary study by several research groups treating burn patients over the past decade. Initial reports from these groups are consistent in suggesting that immersive virtual reality is logistically feasible, safe and effective in ameliorating the pain and anxiety experienced in various settings of post-burn pain. Furthermore, the technique appears applicable to a wide age range of patients and may be particularly well-adapted for use in children, one of the most challenging populations of burn victims to treat. However, confirmation and extension of these results in larger numbers of patients in various types of burn-related pain is necessary to more clearly define the specific benefits and limitations of virtual reality analgesia in the burn care setting. PMID:18986237

  12. A prospective observational study investigating all children presenting to a specialty paediatric burns centre.

    PubMed

    Stockton, K A; Harvey, J; Kimble, R M

    2015-05-01

    The aim of this study was to describe the mechanism of injury and outcome of all children who presented to The Stuart Pegg Paediatric Burns Centre (SPPBC) with a burn injury in the year 2013. A detailed proforma was completed prospectively at time of presentation to hospital. During the one year period, 758 children with a median age of 2 years 3 months presented with a burn injury. Overall, 12.7% of patients (n=96) were initially treated as inpatients. Similarities existed between in and outpatients. Over half the children admitted had a scald injury (53.1%). Whilst slightly higher than the outpatient scald rate of 43.1% there was no statistical significant difference. However, there was a significant difference between inpatients and outpatients with respect to other mechanisms of injury. Contact burns were under represented in inpatients (27.1%) compared to outpatients (44.5%), p<0.05. In contrast, flame burns were over represented in inpatients, 11.5% compared to outpatients, 2.9% (p<0.05). Paediatric burns are a common cause of childhood injury. The majority of children present with small to medium sized partial thickness injuries and are managed as outpatients. In order to understand the true impact of paediatric burn injury and to develop appropriate targeted injury prevention campaigns, data repositories must include detailed information regarding outpatient paediatric burns. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  13. Black Saturday: the immediate impact of the February 2009 bushfires in Victoria, Australia.

    PubMed

    Cameron, Peter A; Mitra, Biswadev; Fitzgerald, Mark; Scheinkestel, Carlos D; Stripp, Andrew; Batey, Chris; Niggemeyer, Louise; Truesdale, Melinda; Holman, Paul; Mehra, Rishi; Wasiak, Jason; Cleland, Heather

    2009-07-06

    To examine the response of the Victorian State Trauma System to the February 2009 bushfires. A retrospective review of the strategic response required to treat patients with bushfire-related injury in the first 72 hours of the Victorian bushfires that began on 7 February 2009. Emergency department (ED) presentations and initial management of patients presenting to the state's adult burns centre (The Alfred Hospital [The Alfred]) were analysed, as well as injuries and deaths associated with the fires. There were 414 patients who presented to hospital EDs as a result of the bushfires. Patients were triaged at the emergency scene, at treatment centres and in hospital. National and statewide burns disaster plans were activated. Twenty-two patients with burns presented to the state's burns referral centres, of whom 18 were adults. Adult burns patients at The Alfred spent 48.7 hours in theatre in the first 72 hours. There were a further 390 bushfire-related ED presentations across the state in the first 72 hours. Most patients with serious burns were triaged to and managed at burns referral centres. Throughout the disaster, burns referral centres continued to have substantial surge capacity. Most bushfire victims either died, or survived with minor injuries. As a result of good prehospital triage and planning, the small number of patients with serious burns did not overload the acute health care system.

  14. Results of Propellant Mixing Variable Study Using Precise Pressure-Based Burn Rate Calculations

    NASA Technical Reports Server (NTRS)

    Stefanski, Philip L.

    2014-01-01

    A designed experiment was conducted in which three mix processing variables (pre-curative addition mix temperature, pre-curative addition mixing time, and mixer speed) were varied to estimate their effects on within-mix propellant burn rate variability. The chosen discriminator for the experiment was the 2-inch diameter by 4-inch long (2x4) Center-Perforated (CP) ballistic evaluation motor. Motor nozzle throat diameters were sized to produce a common targeted chamber pressure. Initial data analysis did not show a statistically significant effect. Because propellant burn rate must be directly related to chamber pressure, a method was developed that showed statistically significant effects on chamber pressure (either maximum or average) by adjustments to the process settings. Burn rates were calculated from chamber pressures and these were then normalized to a common pressure for comparative purposes. The pressure-based method of burn rate determination showed significant reduction in error when compared to results obtained from the Brooks' modification of the propellant web-bisector burn rate determination method. Analysis of effects using burn rates calculated by the pressure-based method showed a significant correlation of within-mix burn rate dispersion to mixing duration and the quadratic of mixing duration. The findings were confirmed in a series of mixes that examined the effects of mixing time on burn rate variation, which yielded the same results.

  15. Scald burns in children aged 14 and younger in Australia and New Zealand—an analysis based on the Burn Registry of Australia and New Zealand (BRANZ).

    PubMed

    Riedlinger, Dorothee I; Jennings, Paul A; Edgar, Dale W; Harvey, John G; Cleland, Ms Heather J; Wood, Fiona M; Cameron, Peter A

    2015-05-01

    Scalds are a common injury in children and a frequent reason for hospitalisation despite being a preventable injury. This retrospective two year study reports data from 730 children aged 14 years or younger who sustained a scald between 2009 and 2010 and were admitted to a burns centre in Australia or New Zealand. Data were extracted from the Burn Registry of Australia and New Zealand (BRANZ), which included data from 13 burns centres in Australia and New Zealand. Scald injury contributed 56% (95% CI 53-59%) of all pediatric burns. There were two high risk groups; male toddlers age one to two, contributing 34% (95% CI 31-38%) of all scalds, and indigenous children who were over 3 times more likely to experience a scald requiring admission to a burns unit than their non-indigenous peers. First aid cooling by non-professionals was initiated in 89% (95% CI 86-91%) of cases but only 20% (95% CI 16-23%) performed it as recommended. This study highlights that effective burn first aid reduces hospital stay and reinforces the need to encourage, carers and bystanders to deliver effective first aid and the importance of targeted prevention campaigns that reduce the burden of pediatric scald burns in Australia and New Zealand. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  16. Ground Penetrating Radar, a Method for Exploration and Monitoring of Coal Fires in China

    NASA Astrophysics Data System (ADS)

    Gundelach, Volker

    2010-05-01

    Due to the climate change it is a global task to fight against gas emission of coal fires. In China exists many burning coal seams which should be extinguished. A Chinese-German initiative tries to find new technologies and solutions to control these fires. Most of the fires are close to the surface in arid areas. In that case GPR is a possible geophysical method to get detailed information about the structure of the soil. Mining activities and the burning coal are leaving voids which collapse or still exist as dangerous areas. With GPR it is possible to detect voids and clefts. Crevices are potential paths for oxygen transport from the surface to the fire. The knowledge of these structures would help to extinguish the fire. The heat of the burning coal changes the permittivity and the conductivity of the rock. This affects the radar signal and makes it possible to separate burning zones from intact zones. Monitoring of the burning zones helps to find optimal solutions for fire extinguishing strategies. Several field campaigns were made in China. One campaign was in the province Xinjiang with a 50 MHz system from Mala on a steep dipping coal seam. Other campaigns were in the Inner Mongolia with 40 MHz to 200 MHz antennae from GSSI on shallow dipping coal seams. The experiences from these measurements will be shown. The surveys were collected in rough terrain. The data from the unshielded antennae contained a lot of effects coming through the air. The limits of detecting crevices with GPR will be demonstrated. Some parts of the measurements over burning coal were influenced by strong anomalies of the magnetization. Modeling of the radar signal helps at the interpretation. Parts of the interpretation from the surveys can be validated by the outcrop of the investigated structures. A spatial visualization of the results is the basis for discussions.

  17. Using Logistic Regression To Predict the Probability of Debris Flows Occurring in Areas Recently Burned By Wildland Fires

    USGS Publications Warehouse

    Rupert, Michael G.; Cannon, Susan H.; Gartner, Joseph E.

    2003-01-01

    Logistic regression was used to predict the probability of debris flows occurring in areas recently burned by wildland fires. Multiple logistic regression is conceptually similar to multiple linear regression because statistical relations between one dependent variable and several independent variables are evaluated. In logistic regression, however, the dependent variable is transformed to a binary variable (debris flow did or did not occur), and the actual probability of the debris flow occurring is statistically modeled. Data from 399 basins located within 15 wildland fires that burned during 2000-2002 in Colorado, Idaho, Montana, and New Mexico were evaluated. More than 35 independent variables describing the burn severity, geology, land surface gradient, rainfall, and soil properties were evaluated. The models were developed as follows: (1) Basins that did and did not produce debris flows were delineated from National Elevation Data using a Geographic Information System (GIS). (2) Data describing the burn severity, geology, land surface gradient, rainfall, and soil properties were determined for each basin. These data were then downloaded to a statistics software package for analysis using logistic regression. (3) Relations between the occurrence/non-occurrence of debris flows and burn severity, geology, land surface gradient, rainfall, and soil properties were evaluated and several preliminary multivariate logistic regression models were constructed. All possible combinations of independent variables were evaluated to determine which combination produced the most effective model. The multivariate model that best predicted the occurrence of debris flows was selected. (4) The multivariate logistic regression model was entered into a GIS, and a map showing the probability of debris flows was constructed. The most effective model incorporates the percentage of each basin with slope greater than 30 percent, percentage of land burned at medium and high burn severity in each basin, particle size sorting, average storm intensity (millimeters per hour), soil organic matter content, soil permeability, and soil drainage. The results of this study demonstrate that logistic regression is a valuable tool for predicting the probability of debris flows occurring in recently-burned landscapes.

  18. Caring for burn patients at the United States Institute of Surgical Research: the nurses' multifaceted roles.

    PubMed

    Serio-Melvin, Maria; Yoder, Linda H; Gaylord, Kathryn M

    2010-06-01

    Nursing plays a critical role in the comprehensive burn care delivered at the US Army Institute of Surgical Research, otherwise known as the US Army's Burn Center serving the Department of Defense. This center serves as a model for burn units nationally and internationally. It also provides a challenging and innovative work environment for military and civilian nurses. Nurses in the Burn Center contribute to innovations in acute, rehabilitative, and psychological care for patients with burns. This article provides an overview of the complex nursing care provided to burn patients treated at the Burn Center. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  19. Inhibition of Na+/H+ exchanger 1 by cariporide reduces burn-induced intestinal barrier breakdown.

    PubMed

    Yang, Xuekang; Chen, Ji; Bai, Hua; Tao, Ke; Zhou, Qin; Hou, Hongyi; Hu, Dahai

    2013-12-01

    Severe burns initiate an inflammatory cascade within the gut, which leads to intestinal mucosal injury. Although Na(+)/H(+) exchanger 1 (NHE1) is recognised as a pivotal player in several inflammatory processes, its role in burn-induced intestinal injury is relatively unknown. We hypothesised that NHE1 might be involved in the increased intestinal permeability and barrier breakdown after severe burns. Thus, we here investigate whether the inhibition of NHE1 has a protective effect on burn-induced intestinal injury. Mice were subjected to a 30% total body surface area (TBSA) full-thickness steam burn. Cariporide was used to assess the function of NHE1 in mice with burn-induced intestinal injury by fluorescence spectrophotometry, Western blotting and enzyme linked immunosorbent assay (ELISA). We found that severe burn increased intestinal permeability, associated with the up-regulation of NHE1 and raised inflammatory cytokine levels. Mice treated with the NHE1 inhibitor cariporide had significantly attenuated burn-induced intestinal permeability and a reduced inflammatory response. NHE1 inhibition also reduced nuclear factor-κB (NF-κB) activation and attenuated p38 mitogen-activated protein kinase (MAPK) phosphorylation. Our study suggests that NHE1 plays an important role in burn-induced intestinal permeability through the regulation of the inflammatory response. Inhibition of NHE1 may be adopted as a potential therapeutic strategy for attenuating intestinal barrier breakdown. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  20. The use of an atmospheric dispersion model to determine influence regions in the Prince George, B.C. airshed from the burning of open wood waste piles.

    PubMed

    Ainslie, B; Jackson, P L

    2009-06-01

    A means of determining air emission source regions adversely influencing the city of Prince George, British Columbia, Canada from potential burning of isolated piles of mountain pine beetle-killed lodge pole pine is presented. The analysis uses the CALPUFF atmospheric dispersion model to identify safe burning regions based on atmospheric stability and wind direction. Model results show that the location and extent of influence regions is sensitive to wind speed, wind direction, atmospheric stability and a threshold used to quantify excessive concentrations. A concentration threshold based on the Canada Wide PM(2.5) Standard is used to delineate the influence regions while Environment Canada's (EC) daily ventilation index (VI) is used to quantify local atmospheric stability. Results from the analysis, to be used by air quality meteorologists in assessing daily requests for burning permits, are presented as a series of maps delineating acceptable burning locations for sources placed at various distances from the city center and under different ventilation conditions. The results show that no burning should be allowed within 10 km of the city center; under poor ventilation conditions, no burning should be allowed within 20 km of the city center; under good ventilation conditions, burning can be allowed within 10-15 km of the city center; under good to fair ventilation conditions, burning can be allowed beyond 15 km of the city center; and if the wind direction can be reliably forecast, burning can be allowed between 5 and 10 km downwind of the city center under good ventilation conditions.

  1. Sensitivity of burned area in Europe to climate change, atmospheric CO2 levels, and demography: A comparison of two fire-vegetation models

    NASA Astrophysics Data System (ADS)

    Wu, Minchao; Knorr, Wolfgang; Thonicke, Kirsten; Schurgers, Guy; Camia, Andrea; Arneth, Almut

    2015-11-01

    Global environmental changes and human activity influence wildland fires worldwide, but the relative importance of the individual factors varies regionally and their interplay can be difficult to disentangle. Here we evaluate projected future changes in burned area at the European and sub-European scale, and we investigate uncertainties in the relative importance of the determining factors. We simulated future burned area with LPJ-GUESS-SIMFIRE, a patch-dynamic global vegetation model with a semiempirical fire model, and LPJmL-SPITFIRE, a dynamic global vegetation model with a process-based fire model. Applying a range of future projections that combine different scenarios for climate changes, enhanced CO2 concentrations, and population growth, we investigated the individual and combined effects of these drivers on the total area and regions affected by fire in the 21st century. The two models differed notably with respect to the dominating drivers and underlying processes. Fire-vegetation interactions and socioeconomic effects emerged as important uncertainties for future burned area in some European regions. Burned area of eastern Europe increased in both models, pointing at an emerging new fire-prone region that should gain further attention for future fire management.

  2. In vivo terahertz imaging of rat skin burns

    NASA Astrophysics Data System (ADS)

    Tewari, Priyamvada; Kealey, Colin P.; Bennett, David B.; Bajwa, Neha; Barnett, Kelli S.; Singh, Rahul S.; Culjat, Martin O.; Stojadinovic, Alexander; Grundfest, Warren S.; Taylor, Zachary D.

    2012-04-01

    A reflective, pulsed terahertz (THz) imaging system was used to acquire high-resolution (d10-90/ λ~1.925) images of deep, partial thickness burns in a live rat. The rat's abdomen was burned with a brass brand heated to ~220°C and pressed against the skin with contact pressure for ~10 sec. The burn injury was imaged beneath a Mylar window every 15 to 30 min for up to 7 h. Initial images display an increase in local water concentration of the burned skin as evidenced by a marked increase in THz reflectivity, and this likely correlates to the post-injury inflammatory response. After ~1 h the area of increased reflectivity consolidated to the region of skin that had direct contact with the brand. Additionally, a low reflecting ring of tissue could be observed surrounding the highly reflective burned tissue. We hypothesize that these regions of increased and decreased reflectivity correlate to the zones of coagulation and stasis that are the classic foundation of burn wound histopathology. While further investigations are necessary to confirm this hypothesis, if true, it likely represents the first in vivo THz images of these pathologic zones and may represent a significant step forward in clinical application of THz technology.

  3. Rice cooker steam hand burn in the pediatric patient.

    PubMed

    Roh, T S; Kim, Y S; Burm, J S; Chung, C H; Kim, J B; Oh, S J

    2000-07-01

    Burn injuries often lead to significant cosmetic and functional deformity. In the Orient, household electric rice cookers have caused a significant number of steam burns to infant hands. The clinical course and treatment outcome of these burns have been studied retrospectively in a review of the medical records of 79 pediatric patients treated for acute hand steam burns and of 38 other patients who underwent correction for postburn contracture. Electric rice cookers caused all of the acute pediatric steam burns treated at our institute. Of the 81 hands treated between 1995 and 1998, 38.3 percent healed with conservative treatment and 61.7 percent required skin grafting. The volar aspects of the index and middle fingers were those most frequently involved. Eighteen of 36 hands (50 percent) grafted with split-thickness skin developed late contractures requiring additional procedures. Among the 38 patients who underwent correction for postburn deformity, initial treatment was split-thickness grafting for 60.5 percent, full-thickness skin grafting for 7.9 percent, and spontaneous healing for 31.6 percent. Awareness among medical personnel and continued public education should be promoted to help prevent this unique type of pediatric steam burn from occurring.

  4. [The Nutrition Care of Severe Burn Patients].

    PubMed

    Hsieh, Yu-Hsiu

    2016-02-01

    In addition to recent advances in burn patient care techniques such as maintaining warm circumambient temperature, the early excision of wounds, and the use of closed dressing, providing nutrition support through early feeding has proven instrumental in greatly increasing the survival rate of burn patients. Severe burns complicated by many factors initiate tremendous physiological stress that leads to postburn hypermetabolism that includes enhanced tissue catabolism, the loss of muscle mass, and decreases in the body's reservoirs of protein and energy. These problems have become the focus of burn therapy. Treating severe burns aims not only to enhance survival rates but also to restore normal bodily functions as completely as possible. Recent research evaluating the application of anabolic agents and immune-enhance formula for severe burns therapy has generated significant controversy. Inadequate caloric intake is one of the main differences among the related studies, with the effect of many special nutrients such as bran acid amides not taken into consideration. Therefore, considering the sufficiency of caloric and protein intake is critical in assessing effectiveness. Only after patients receive adequate calories and protein may the effect of special nutrients such as glutamine and supplements be evaluated effectively.

  5. The effect of azeotropism on combustion characteristics of blended fuel pool fire.

    PubMed

    Ding, Yanming; Wang, Changjian; Lu, Shouxiang

    2014-04-30

    The effect of azeotropism on combustion characteristics of blended fuel pool fire was experimentally studied in an open fire test space of State Key Laboratory of Fire Science. A 30 cm × 30 cm square pool filled with n-heptane and ethanol blended fuel was employed. Flame images, burning rate and temperature distribution were collected and recorded in the whole combustion process. Results show that azeotropism obviously dominates the combustion behavior of n-heptane/ethanol blended fuel pool fire. The combustion process after ignition exhibits four typical stages: initial development, azeotropic burning, single-component burning and decay stage. Azeotropism appears when temperature of fuel surface reaches azeotropic point and blended fuel burns at azeotropic ratio. Compared with individual pure fuel, the effect of azeotropism on main fire parameters, such as flame height, burning rate, flame puffing frequency and centerline temperature were analyzed. Burning rate and centerline temperature of blended fuel are higher than that of individual pure fuel respectively at azeotropic burning stage, and flame puffing frequency follows the empirical formula between Strouhal and Froude number for pure fuel. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. The effect of a rehabilitation nursing intervention model on improving the comprehensive health status of patients with hand burns.

    PubMed

    Li, Lin; Dai, Jia-Xi; Xu, Le; Huang, Zhen-Xia; Pan, Qiong; Zhang, Xi; Jiang, Mei-Yun; Chen, Zhao-Hong

    2017-06-01

    To observe the effect of a rehabilitation intervention on the comprehensive health status of patients with hand burns. Most studies of hand-burn patients have focused on functional recovery. There have been no studies involving a biological-psychological-social rehabilitation model of hand-burn patients. A randomized controlled design was used. Patients with hand burns were recruited to the study, and sixty patients participated. Participants were separated into two groups: (1) The rehabilitation intervention model group (n=30) completed the rehabilitation intervention model, which included the following measures: enhanced social support, intensive health education, comprehensive psychological intervention, and graded exercise. (2) The control group (n=30) completed routine treatment. Intervention lasted 5 weeks. Analysis of variance (ANOVA) and Student's t test were conducted. The rehabilitation intervention group had significantly better scores than the control group for comprehensive health, physical function, psychological function, social function, and general health. The differences between the index scores of the two groups were statistically significant. The rehabilitation intervention improved the comprehensive health status of patients with hand burns and has favorable clinical application. The comprehensive rehabilitation intervention model used here provides scientific guidance for medical staff aiming to improve the integrated health status of hand-burn patients and accelerate their recovery. What does this paper contribute to the wider global clinical community? Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Global emissions of trace gases, particulate matter, and hazardous air pollutants from open burning of domestic waste.

    PubMed

    Wiedinmyer, Christine; Yokelson, Robert J; Gullett, Brian K

    2014-08-19

    The open burning of waste, whether at individual residences, businesses, or dump sites, is a large source of air pollutants. These emissions, however, are not included in many current emission inventories used for chemistry and climate modeling applications. This paper presents the first comprehensive and consistent estimates of the global emissions of greenhouse gases, particulate matter, reactive trace gases, and toxic compounds from open waste burning. Global emissions of CO2 from open waste burning are relatively small compared to total anthropogenic CO2; however, regional CO2 emissions, particularly in many developing countries in Asia and Africa, are substantial. Further, emissions of reactive trace gases and particulate matter from open waste burning are more significant on regional scales. For example, the emissions of PM10 from open domestic waste burning in China is equivalent to 22% of China's total reported anthropogenic PM10 emissions. The results of the emissions model presented here suggest that emissions of many air pollutants are significantly underestimated in current inventories because open waste burning is not included, consistent with studies that compare model results with available observations.

  8. Valproic acid treatment attenuates caspase-3 activation and improves survival after lethal burn injury in a rodent model.

    PubMed

    Luo, Hong-Min; Hu, Sen; Bai, Hui-Ying; Wang, Hai-Bin; Du, Ming-Hua; Lin, Zhi-Long; Ma, Li; Wang, Huan; Lv, Yi; Sheng, Zhi-Yong

    2014-01-01

    Burn injury may result in multiple organ dysfunction partially because of apoptotic cell death. The authors have previously shown that valproic acid (VPA) improves survival in a dog burn model. The aim of this study is to examine whether a VPA improves survival in a rodent burn model and whether this was because of inhibition of cell apoptosis. Rats were subjected to third-degree 55% TBSA burns and randomized to treatment with a VPA (300 mg/kg) or normal saline. One group of animals was monitored for 12 hours for survival analysis; another group was killed at 6 hours after injury, and brains, hearts, and blood samples were harvested for examination. Plasma creatine kinase (CK)-MB activities and neuron-specific enolase (NSE) levels were measured to evaluate the cardiac and brain damages. The effects of a VPA on acetylation of histone H3 and caspase-3 activation were also evaluated. Major burn injury resulted in a significant decrease in the acetylation of histone H3, and there was an increase in plasma CK-MB activities, NSE concentrations, and tissue levels of activated caspase-3. A VPA treatment significantly increased the acetylation of histone H3 and survival of the animals after major burn injury. In addition, a VPA treatment significantly attenuated the plasma CK-MB activities, an NSE concentrations, and inhibited caspase-3 activation after major burn injury. These results indicate that a VPA can attenuate cardiac and brain injury, and can improve survival in a rodent model of lethal burn injury. These protective effects may be mediated in part through the inhibition of caspase-3 activation.

  9. The primordial and evolutionary abundance variations in globular-cluster stars: a problem with two unknowns

    NASA Astrophysics Data System (ADS)

    Denissenkov, P. A.; VandenBerg, D. A.; Hartwick, F. D. A.; Herwig, F.; Weiss, A.; Paxton, B.

    2015-04-01

    We demonstrate that among the potential sources of the primordial abundance variations of the proton-capture elements in globular-cluster stars proposed so far, such as the hot-bottom burning in massive asymptotic giant branch stars and H burning in the convective cores of supermassive and fast-rotating massive main-sequence (MS) stars, only the supermassive MS stars with M > 104 M⊙ can explain all the observed abundance correlations without any fine-tuning of model parameters. We use our assumed chemical composition for the pristine gas in M13 (NGC 6205) and its mixtures with 50 and 90 per cent of the material partially processed in H burning in the 6 × 104 M⊙ MS model star as the initial compositions for the normal, intermediate, and extreme populations of low-mass stars in this globular cluster, as suggested by its O-Na anticorrelation. We evolve these stars from the zero-age MS to the red giant branch (RGB) tip with the thermohaline and parametric prescriptions for the RGB extra mixing. We find that the 3He-driven thermohaline convection cannot explain the evolutionary decline of [C/Fe] in M13 RGB stars, which, on the other hand, is well reproduced with the universal values for the mixing depth and rate calibrated using the observed decrease of [C/Fe] with MV in the globular cluster NGC5466 that does not have the primordial abundance variations.

  10. Evolution and fate of very massive stars

    NASA Astrophysics Data System (ADS)

    Yusof, Norhasliza; Hirschi, Raphael; Meynet, Georges; Crowther, Paul A.; Ekström, Sylvia; Frischknecht, Urs; Georgy, Cyril; Abu Kassim, Hasan; Schnurr, Olivier

    2013-08-01

    There is observational evidence that supports the existence of very massive stars (VMS) in the local universe. First, VMS (Mini ≲ 320 M⊙) have been observed in the Large Magellanic Clouds (LMC). Secondly, there are observed supernovae (SNe) that bear the characteristics of pair creation supernovae (PCSNe, also referred to as pair instability SN) which have VMS as progenitors. The most promising candidate to date is SN 2007bi. In order to investigate the evolution and fate of nearby VMS, we calculated a new grid of models for such objects, for solar, LMC and Small Magellanic Clouds (SMC) metallicities, which covers the initial mass range from 120 to 500 M⊙. Both rotating and non-rotating models were calculated using the GENEVA stellar evolution code and evolved until at least the end of helium burning and for most models until oxygen burning. Since VMS have very large convective cores during the main-sequence phase, their evolution is not so much affected by rotational mixing, but more by mass loss through stellar winds. Their evolution is never far from a homogeneous evolution even without rotational mixing. All the VMS, at all the metallicities studied here, end their life as WC(WO)-type Wolf-Rayet stars. Because of very important mass losses through stellar winds, these stars may have luminosities during the advanced phases of their evolution similar to stars with initial masses between 60 and 120 M⊙. A distinctive feature which may be used to disentangle Wolf-Rayet stars originating from VMS from those originating from lower initial masses would be the enhanced abundances of Ne and Mg at the surface of WC stars. This feature is however not always apparent depending on the history of mass loss. At solar metallicity, none of our models is expected to explode as a PCSN. At the metallicity of the LMC, only stars more massive than 300 M⊙ are expected to explode as PCSNe. At the SMC metallicity, the mass range for the PCSN progenitors is much larger and comprises stars with initial masses between about 100 and 290 M⊙. All VMS in the metallicity range studied here produce either a Type Ib SN or a Type Ic SN but not a Type II SN. We estimate that the progenitor of SN 2007bi, assuming a SMC metallicity, had an initial mass between 160 and 175 M⊙. None of models presented in this grid produces gamma-ray bursts or magnetars. They lose too much angular momentum by mass loss or avoid the formation of a black hole by producing a completely disruptive PCSN.

  11. Monitoring the recovery of Juncus roemerianus marsh burns with the normalized difference vegetation index and Landsat Thematic Mapper data

    USGS Publications Warehouse

    Ramsey, Elijah W.; Sapkota, S.K.; Barnes, F.G.; Nelson, G.A.

    2002-01-01

    Nine atmospherically corrected Landsat Thematic Mapper images were used to generate mean normalized difference vegetation indices (NDVI) at 11 burn sites throughout a coastal Juncus roemerianus marsh in St. Marks National Wildlife Refuge, Florida. Time-since-burn, the time lapse from the date of burn to the date of image collection, was related to variation in mean NDVI over time. Regression analysis showed that NDVI increased for about 300 to 400 days immediately after the burn, overshooting the typical mean NDVI of a nonburned marsh. For about another 500 to 600 days NDVI decreased until reaching a nearly constant NDVI of about 0.40. During the phase of increasing NDVI the ability to predict time-since-burn was within about ??60 days. Within the decreasing phase this dropped to about ??88 days. Examination of each burn site revealed some nonburn related influences on NDVI (e.g., seasonality). Normalization of burn NDVI by site-specific nonburn control NDVI eliminated most influences. However, differential responses at the site-specific level remained related to either storm impacts or secondary burning. At these sites, collateral data helped clarify the abnormal changes in NDVI. Accounting for these abnormalities, site-specific burn recovery trends could be broadly standardized into four general phases: Phase 1-preburn, Phase 2-initial recovery (increasing NDVI), Phase 3-late recovery (decreasing NDVI), and Phase 4-final coalescence (unchanging NDVI). Phase 2 tended to last about 300 to 500 days, Phase 3 an additional 500 to 600 days, and finally reaching Phase 4, 900 to 1,000 days after burn.

  12. Medieval warming initiated exceptionally large wildfire outbreaks in the Rocky Mountains

    PubMed Central

    Calder, W. John; Parker, Dusty; Stopka, Cody J.; Jiménez-Moreno, Gonzalo; Shuman, Bryan N.

    2015-01-01

    Many of the largest wildfires in US history burned in recent decades, and climate change explains much of the increase in area burned. The frequency of extreme wildfire weather will increase with continued warming, but many uncertainties still exist about future fire regimes, including how the risk of large fires will persist as vegetation changes. Past fire-climate relationships provide an opportunity to constrain the related uncertainties, and reveal widespread burning across large regions of western North America during past warm intervals. Whether such episodes also burned large portions of individual landscapes has been difficult to determine, however, because uncertainties with the ages of past fires and limited spatial resolution often prohibit specific estimates of past area burned. Accounting for these challenges in a subalpine landscape in Colorado, we estimated century-scale fire synchroneity across 12 lake-sediment charcoal records spanning the past 2,000 y. The percentage of sites burned only deviated from the historic range of variability during the Medieval Climate Anomaly (MCA) between 1,200 and 850 y B.P., when temperatures were similar to recent decades. Between 1,130 and 1,030 y B.P., 83% (median estimate) of our sites burned when temperatures increased ∼0.5 °C relative to the preceding centuries. Lake-based fire rotation during the MCA decreased to an estimated 120 y, representing a 260% higher rate of burning than during the period of dendroecological sampling (360 to −60 y B.P.). Increased burning, however, did not persist throughout the MCA. Burning declined abruptly before temperatures cooled, indicating possible fuel limitations to continued burning. PMID:26438834

  13. Developing ecological criteria for prescribed fire in South Florida pine rockland ecosystems

    USGS Publications Warehouse

    Snyder, James R.; Ross, Michael S.; Koptur, Suzanne; Sah, Jay P.

    2005-01-01

    The pine rocklands of South Florida, characterized by a rich herbaceous flora with many narrowly endemic taxa beneath an overstory of south Florida slash pine (Pinus elliottii var. densa), are found in three areas: the Miami Rock Ridge of southeastern peninsular Florida, the Lower Florida Keys, and slightly elevated portions of the southern Big Cypress National Preserve. Fire is an important element in these ecosystems, since in its absence the pine canopy is likely to be replaced by dense hardwoods, resulting in loss of the characteristic pineland herb flora. Prescribed fire has been used in Florida Keys pine forests since the creation of the National Key Deer Refuge (NKDR), with the primary aim of reducing fuels. Because fire can also be an effective tool in shaping ecological communities, we conducted a 4-year research study which explored a range of fire management options in NKDR. The intent of the study was to provide the Fish and Wildlife Service and other land managers with information regarding when and where to burn in order to perpetuate these unique forests. In 1998 we initiated a burning experiment in a randomized complete block design. Three treatments were to be carried out in a single well-defined block in each of two characteristic understory types during each year from 1998 through 2000. One understory type was characterized by a relatively sparse shrub layer and a well-developed herb layer ('open'), and the second had a dense shrub layer and poorly developed herb layer ('shrubby'). The three burn treatments were: (a) summer burn, (b) winter burn, and (c) no burn, or control. Three 1- ha plots were established in each block, and randomly assigned to the three treatments. Though the first year experimental burns were carried out without incident, constraints posed by external factors, including nationwide and statewide prohibitions on prescribed burning due to wildfires in other regions, delayed the experimental burns and precluded collection of postburn data on one third of the burns. Ultimately we burned only eleven plots, three in winter and eight in summer, over a four-year period from 1998 to 2001. Vegetation was sampled in a stratified, nested design within 18 plots. Trees were sampled in a 1.0-ha plot, shrubs in twenty 50-m2 circular (radius 4 m) subplots within the tree plot, and the herb layer in four circular 1-m2 quadrats (radius 0.57 m) within each subplot. The amount of fuel in the shrub layer was estimated by applying regression models to plant dimensional data, and ground layer fuel was estimated by a harvest method. The effects of Key deer herbivory on regeneration of the understory pine rockland plant community after fire was studied by monitoring inside and outside exclosures established within two of the six blocks. Pine trees constituted more than half (53.3%) of the biomass, but understory fine fuels comprised a surprisingly high proportion of total aboveground biomass. In the three blocks in which paired summer and winter burns were successfully conducted, the summer burns were more intense than the winter burns as judged by our indicators of fire intensity. Because of the differences in fire intensity between seasons, it was not possible to say whether observed differences in vegetation response between summer and winter burns were due to season or to fire intensity. The mortality of South Florida slash pine trees was greater after the summer burn than the winter burn in each block, but other vegetation responses were rarely as consistent. For instance, Metopium showed less recovery after summer burns in two blocks and after the winter burn in the third block. Moreover, there were instances in which alternative growth stages of the same species responded differently. Adult palms succumbed more frequently to summer than winter burns, and mortality of Coccothrinax exceeded that of Thrinax. In contrast, small palms recovered more readily after summer burns than winter burns. High in

  14. Effects of Fuel Reduction Treatments on Incidence of Phytophthora Species in Soil of a Southern Appalachian Mountain Forest

    Treesearch

    I.M. Meadows; D.C. Zwart; S.N. Jeffers; T.A. Waldrop; W.C. Bridges

    2011-01-01

    The National Fire and Fire Surrogate Study was initiated to study the effects of fuel reduction treatments on forest ecosystems. Four fuel reduction treatments were applied to three sites in a southern Appalachian Mountain forest in western North Carolina: prescribed burning, mechanical fuel reduction, mechanical fuel reduction followed by prescribed burning, and a non...

  15. Response of overstory and understory vegetation 37 years after prescribed burning in an aspen-dominated forest in northern Minnesota, USA – a case study

    Treesearch

    A. Dhar; C.D. Baker; H.B. Massicotte; Brian J. Palik; C.D.B. Hawkins

    2016-01-01

    Many studies have examined short-term changes in understory vegetation following prescribed burning. However, knowledge concerning longer term effects on both forest understory and overstory vegetation is lacking. This investigation was initiated to examine changes in understory (herbaceous and shrub) and overstory species composition almost four decades after logging...

  16. Effects of Different Large-Scale Prescribed Burning Regimes of Advance Reproduction in the Missouri Ozarks

    Treesearch

    Daniel C. Dey; George Hartman

    2004-01-01

    In 1997, The Nature Conservancy initiated a large-scale prescribed fire management study on approximately 2,500 acres of their Chilton Creek property located in Shannon and Carter counties, Missouri. Since the spring of 1998, five management units, of roughly 500 acres each, have been burned in the dormant season to simulate a range of fire regimes that vary from...

  17. Treatment Strategies for Hypopigmentation in the Context of Burn Hypertrophic Scars

    PubMed Central

    Carney, Bonnie C.; McKesey, Jacqueline P.; Rosenthal, Dean S.

    2018-01-01

    Dyspigmentation in burn scars can contribute to the development of psychosocial complications after injury and can be detrimental to social reintegration and quality of life for burn survivors. Although treatments for skin lightening to treat hyperpigmentation have been well reviewed in the literature, skin-darkening strategies to treat hypopigmentation have not. The following potential treatment options in the context of burn hypertrophic scar will be discussed: use of the melanocyte-keratinocyte transplantation procedure, use of ectopic synthetic analogues of alpha-melanocyte stimulating hormone to initiate melanogenesis, and use of FK506 to induce melanogenesis. A proposed future direction of research in laser-assisted drug delivery of inducers of local melanin production, with the hope of developing a targeted, effective approach to dyspigmentation in hypertrophic scar is also discussed. PMID:29464168

  18. Surgical treatment and management of the severely burn patient: Review and update.

    PubMed

    Gacto-Sanchez, P

    Since one of the main challenges in treating acute burn injuries is preventing infection, early excising of the eschar and covering of the wound becomes critical. Non-viable tissue is removed by initial aggressive surgical debridement. Many surgical options for covering the wound bed have been described, although split-thickness skin grafts remain the standard for the rapid and permanent closure of full-thickness burns. Significant advances made in the past decades have greatly improved burns patient care, as such that major future improvements in survival rates seem to be more difficult. Research into stem cells, grafting, biomarkers, inflammation control, and rehabilitation will continue to improve individualized care and create new treatment options for these patients. Copyright © 2017 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  19. Theory and Observations of Plasma Waves Excited Space Shuttle OMS Burns in the Ionosphere

    NASA Astrophysics Data System (ADS)

    Bernhardt, P. A.; Pfaff, R. F.; Schuck, P. W.; Hunton, D. E.; Hairston, M. R.

    2010-12-01

    Measurements of artificial plasma turbulence were obtained during two Shuttle Exhaust Ionospheric Turbulence Experiments (SEITE) conducted during the flights of the Space Shuttle (STS-127 and STS-129). Based on computer modeling at the NRL PPD and Laboratory for Computational Physics & Fluid Dynamics (LCP), two dedicated burns of the Space Shuttle Orbital Maneuver Subsystem (OMS) engines were scheduled to produce 200 to 240 kg exhaust clouds that passed over the Air Force Research Laboratory (AFRL) Communications, Navigation, and Outage Forecast System (C/NOFS) satellite. This operation required the coordination by the DoD Space Test Program (STP), the NASA Flight Dynamics Officer (FDO), the C/NOFS payload operations, and the C/NOFS instrument principal investigators. The first SEITE mission used exhaust from a 12 Second OMS burn to deposit 1 Giga-Joules of energy into the upper atmosphere at a range of 230 km from C/NOFS. The burn was timed so C/NOFS could fly though the center of the exhaust cloud at a range of 87 km above the orbit of the Space Shuttle. The first SEITE experiment is important because is provided plume detection by ionospheric plasma and electric field probes for direct sampling of irregularities that can scatter radar signals. Three types of waves were detected by C/NOFS during and after the first SEITE burn. With the ignition and termination of the pair of OMS engines, whistler mode signals were recorded at C/NOFS. Six seconds after ignition, a large amplitude electromagnetic pulse reached the satellite. This has been identified as a fast magnetosonic wave propagating across magnetic field lines to reach the electric field (VEFI) sensors on the satellite. Thirty seconds after the burn, the exhaust cloud reach C/NOFS and engulfed the satellite providing very strong electric field turbulence along with enhancements in electron and ion densities. Kinetic modeling has been used to track the electric field turbulence to an unstable velocity distribution produced after the supersonic exhaust molecules charge exchanged with ambient oxygen ions. Based on the success of the first SEITE mission, a second dedicated burn of the OMS engine was scheduled to intercept the C/NOFS satellite, this time at an initial range of 430 km. The trajectory of this exhaust cloud was not centered on the satellite so the turbulent edge was sampled by the C/NOFS instruments. The electromagnetic pulse and the in situ plasma turbulence was recorded during the second SEITE experiment. A comparison of the data from the two OMS burns shows that a wide range of plasma waves are consistently produced with rocket engines are fired in the ionosphere.

  20. Implementation and outcomes of an evidence-based precepting program for burn nurses.

    PubMed

    Robbins, Johnnie R; Valdez-Delgado, Krystal K; Caldwell, Nicole W; Yoder, Linda H; Hayes, Elizabeth J; Barba, Michaèl G; Greeley, Hope L; Mitchell, Colleen; Mann-Salinas, Elizabeth A

    2017-11-01

    There is significant nationwide interest in transitioning new and new-to-specialty nurses into practice, especially in burn care. Lack of a structured transition program in our Burn Center was recognized as a contributing factor for nursing dissatisfaction and increased turnover compared to other hospital units. Employee evaluations exposed a need for more didactic instruction, hands-on learning, and preceptor support. The goal of this project was to implement an evidence-based transition to practice program specific to the burn specialty. The Iowa Model of Evidence-based Practice served as the model for this project. A working group was formed consisting of nurse scientists, clinical nurse leaders, clinical nurse specialists, lead preceptors, staff nurse preceptors and wound care coordinators. A systematic review of the literature was conducted focusing on nurse transition; preceptor development and transitioning nurse training programs with competency assessment, ongoing multifaceted evaluation and retention strategies were created. The evidence-based Vermont Nurses in Partnership (VNIP) Clinical Transition Framework was selected and subsequent education was provided to all Burn Center leaders and staff. Benchmarks for basic knowledge assessment (BKAT) and burn wound care were established among current staff by work site and education level to help evaluate transitioning nurses. Policies were modified to count each preceptor/transitioning nurse dyad as half an employee on the schedule. Multiple high-fidelity simulation scenarios were created to expand hands-on opportunities. From September 2012-December 2013, 110 (57% acute care nursing) Burn Center staff attended the VNIP Clinical Coaching Course, to include 34 interdisciplinary staff (rehabilitation, education, respiratory therapy, and outpatient clinic staff) and 100% of identified preceptors (n=33). A total of 30 new nurses participated in the transition program: 26 (87%) completed, 3 (10%) did not complete, and 1 (3%) received exception (no patient care). Transitioning nurses achieved passing BKAT scores (n=22; 76%) and WC scores (n=24; 93%); individual remediation was provided for those failing to achieve unit benchmarks and transition training was modified to improve areas of weakness. Transitioning nurses' weekly competency progression average initial ratings on a 10 point scale (10 most competent) were 5±2; final ratings averaged 9±1 (n=25) (p<0.0001). An evidence-based team practice approach toward preceptorship created a standardized, comprehensive and flexible precepting program to assist and support transition to specialty burn practice for experienced nurses. Use of objective metrics enabled ongoing assessment and made training adaptable, individualized, and cost effective. Application of this standardized approach across our organization may improve consistency for all transitions in practice specialty. Copyright © 2017. Published by Elsevier Ltd.

  1. Burning rates of wood cribs with implications for wildland fires

    Treesearch

    Sara McAllister; Mark Finney

    2016-01-01

    Wood cribs are often used as ignition sources for room fire tests and the well characterized burning rates may also have applications to wildland fires. The burning rate of wildland fuel structures, whether the needle layer on the ground or trees and shrubs themselves, is not addressed in any operational fire model and no simple model exists. Several relations...

  2. Challenges of assessing fire and burn severity using field measures, remote sensing and modelling

    Treesearch

    Penelope Morgan; Robert E. Keane; Gregory K. Dillon; Theresa B. Jain; Andrew T. Hudak; Eva C. Karau; Pamela G. Sikkink; Zachery A. Holden; Eva K. Strand

    2014-01-01

    Comprehensive assessment of ecological change after fires have burned forests and rangelands is important if we are to understand, predict and measure fire effects. We highlight the challenges in effective assessment of fire and burn severity in the field and using both remote sensing and simulation models. We draw on diverse recent research for guidance on assessing...

  3. Dynamics of an Overdriven Nitromethane Initiation System

    NASA Astrophysics Data System (ADS)

    Hároz, E. H.; Rae, P. J.; Armstrong, C. L.; Baca, E. V.; Campbell, C.; Gunderson, J. A.; Holmes, M.; Lopez-Pulliam, I.; Vaughan, L. D.; Dickson, P. M.

    2017-06-01

    For upcoming large-scale HE experiments, an initiation system is needed to ensure uniform and simultaneous burn. To that end, we developed an initiation system based on nitromethane. Initial, small-scale tests characterized the response of the nitromethane in the proposed cylindrical initiator geometry, indicating robust detonation under a variety of conditions such as a plane wave lenses & cylinders of PBX 9501 into a flyer plate or direct-drive. Detonation velocity, as measured by piezoelectric pin time-of-arrival measurements along the length and at bottom of vessel, shows an overdriven response. All cases show a detonation velocity faster than the literature value of 7.3 km s-1 for nitromethane, with the fastest velocity occurring for the 8-detonator, 8'' cylinder case with a velocity = 7.7 km s-1. Streak camera imaging characterized the curvature of the shock front as it arrived at the bottom of the vessel via spark gap. A final test of the initiator system looked at the expansion of the initiator vessel walls via PDV, showing velocities up to 3.5 km s-1. Finally, our initiator was placed inside a secondary vessel containing 1000 lbs of nitromethane. High-speed photography & pin data indicate complete symmetrical burn of the secondary nitromethane.

  4. Climate versus carbon dioxide controls on biomass burning: a model analysis of the glacial-interglacial contrast

    NASA Astrophysics Data System (ADS)

    Calvo, M. Martin; Prentice, I. C.; Harrison, S. P.

    2014-11-01

    Climate controls fire regimes through its influence on the amount and types of fuel present and their dryness. CO2 concentration constrains primary production by limiting photosynthetic activity in plants. However, although fuel accumulation depends on biomass production, and hence on CO2 concentration, the quantitative relationship between atmospheric CO2 concentration and biomass burning is not well understood. Here a fire-enabled dynamic global vegetation model (the Land surface Processes and eXchanges model, LPX) is used to attribute glacial-interglacial changes in biomass burning to an increase in CO2, which would be expected to increase primary production and therefore fuel loads even in the absence of climate change, vs. climate change effects. Four general circulation models provided last glacial maximum (LGM) climate anomalies - that is, differences from the pre-industrial (PI) control climate - from the Palaeoclimate Modelling Intercomparison Project Phase~2, allowing the construction of four scenarios for LGM climate. Modelled carbon fluxes from biomass burning were corrected for the model's observed prediction biases in contemporary regional average values for biomes. With LGM climate and low CO2 (185 ppm) effects included, the modelled global flux at the LGM was in the range of 1.0-1.4 Pg C year-1, about a third less than that modelled for PI time. LGM climate with pre-industrial CO2 (280 ppm) yielded unrealistic results, with global biomass burning fluxes similar to or even greater than in the pre-industrial climate. It is inferred that a substantial part of the increase in biomass burning after the LGM must be attributed to the effect of increasing CO2 concentration on primary production and fuel load. Today, by analogy, both rising CO2 and global warming must be considered as risk factors for increasing biomass burning. Both effects need to be included in models to project future fire risks.

  5. Long term mortality in critically ill burn survivors.

    PubMed

    Nitzschke, Stephanie; Offodile, Anaeze C; Cauley, Ryan P; Frankel, Jason E; Beam, Andrew; Elias, Kevin M; Gibbons, Fiona K; Salim, Ali; Christopher, Kenneth B

    2017-09-01

    Little is known about long term survival risk factors in critically ill burn patients who survive hospitalization. We hypothesized that patients with major burns who survive hospitalization would have favorable long term outcomes. We performed a two center observational cohort study in 365 critically ill adult burn patients who survived to hospital discharge. The exposure of interest was major burn defined a priori as >20% total body surface area burned [TBSA]. The modified Baux score was determined by age + %TBSA+ 17(inhalational injury). The primary outcome was all-cause 5year mortality based on the US Social Security Administration Death Master File. Adjusted associations were estimated through fitting of multivariable logistic regression models. Our final model included adjustment for inhalational injury, presence of 3rd degree burn, gender and the acute organ failure score, a validated ICU risk-prediction score derived from age, ethnicity, surgery vs. medical patient type, comorbidity, sepsis and acute organ failure covariates. Time-to-event analysis was performed using Cox proportional hazard regression. Of the cohort patients studied, 76% were male, 29% were non white, 14% were over 65, 32% had TBSA >20%, and 45% had inhalational injury. The mean age was 45, 92% had 2nd degree burns, 60% had 3rd degree burns, 21% received vasopressors, and 26% had sepsis. The mean TBSA was 20.1%. The mean modified Baux score was 72.8. Post hospital discharge 5year mortality rate was 9.0%. The 30day hospital readmission rate was 4%. Patients with major burns were significantly younger (41 vs. 47 years) had a significantly higher modified Baux score (89 vs. 62), and had significantly higher comorbidity, acute organ failure, inhalational injury and sepsis (all P<0.05). There were no differences in gender and the acute organ failure score between major and non-major burns. In the multivariable logistic regression model, major burn was associated with a 3 fold decreased odds of 5year post-discharge mortality compared to patients with TBSA<20% [OR=0.29 (95%CI 0.11-0.78; P=0.014)]. The adjusted model showed good discrimination [AUC 0.81 (95%CI 0.74-0.89)] and calibration (Hosmer-Lemeshow χ 2 P=0.67). Cox proportional hazard multivariable regression modeling, adjusting for inhalational injury, presence of 3rd degree burn, gender and the acute organ failure score, showed that major burn was predictive of lower mortality following hospital admission [HR=0.34 (95% CI 0.15-0.76; P=0.009)]. The modified Baux score was not predictive for mortality following hospital discharge [OR 5year post-discharge mortality=1.00 (95%CI 0.99-1.02; P=0.74); HR for post-discharge mortality=1.00 (95% CI 0.99-1.02; P=0.55)]. Critically ill patients with major burns who survive to hospital discharge have decreased 5year mortality compared to those with less severe burns. ICU Burn unit patients who survive to hospital discharge are younger with less comorbidities. The observed relationship is likely due to the relatively higher physiological reserve present in those who survive a Burn ICU course which may provide for a survival advantage during recovery after major burn. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

  6. Effects of slash-and-burn land management on soil spectral properties estimated with VIS-NIR-SWIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Rosero-Vlasova, Olga Alexandra; Vlassova, Lidia; Rosero Tufiño, Pedro; Pérez-Cabello, Fernando; Montorio Llovería, Raquel

    2017-04-01

    Slash-and-burn land management is typical for low-income tropical countries, such as Ecuador. It involves conversion of forest into areas used for agriculture. At first trees are cut and the wood debris is burnt. After initial clearing, biomass burning is performed after each production cycle. Usually, cultivation cycles are followed by the fallow period. In the medium and long term, these practices have negative effect on soil fertility and there is the need for clearing more forest for agricultural use. This is one of the reasons for continuing deforestation with the consequent loss of biodiversity. Changes in physico-chemical properties due to periodic burning are accompanied by changes in soil spectral properties and can be determined using VIS-NIR-SWIR spectroscopy, which can be a cost-effective alternative for traditional methods of soil analysis. The purpose of the study is to assess the viability of VIS-NIR-SWIR spectroscopy for characterization of soils from land areas under slash-and-burn management system. Eighteen samples from soil surface layer were collected from two corn fields in the province of Los Rios, Ecuador, in September 2015. One of the areas has experienced six slash-and-burn cycles, while in the other the samples were collected at the end of the first corn cultivation cycle. Spectral measurements of sieved and air-dried samples were performed in the laboratory of the University of Zaragoza using ASD Fieldspec®4 spectroradiometer (350-2500nm spectral range) and ASD Illuminator Lamp as a light source. Statistically significant differences were observed between soil spectra of the samples from two soil groups. Reflectance of repeatedly burnt soils was 20% higher (mean value for the entire spectrum) for 65% of the samples, being especially important in VIS (>45%) and NIR ( 35%), probably due to the lower organic matter (OM) content. OM models built using Partial least Squares Regression demonstrated high predictive capacity (R2>0.8). Thus, the study confirms VIS-NIR-SWIR soil spectroscopy can be used as a tool for monitoring changes in soils in areas of slash-and-burn land management systems.

  7. Combustion of Metals in Carbon Dioxide and Reduced-Gravity Environments

    NASA Technical Reports Server (NTRS)

    Branch, M. C.; Abbud-Madrid, A.; Modak, A.; Dreyer, C. B.; Daily, J. W.

    2001-01-01

    Ongoing exploration and future mission2001110444 s to Mars have given impetus to research on the use of natural resources of the planet. Since carbon dioxide (CO2) constitutes approximately 95% of the Mars atmosphere and since it reacts directly and vigorously with several metals, this investigation focuses on metal-CO2 reactions as a possible combination for rocket-propellant production and energy generation. Magnesium (Mg) has been initially selected as the metal fuel owing to its low ignition temperature and high specific impulse and burning rate in CO2. Our studies in this field started with low gravity (g) combustion tests of Mg in O2, CO2, and CO. Reduced gravity provided a clear picture of the burning phenomena by eliminating the intrusive buoyant flows in high-temperature metal reactions and by removing the destructive effect of gravity on the shape of molten metal samples. Suspended cylindrical metal samples of 2, 3, and 4-mm in diameter and length were radiatively ignited in low-g to generate free-floating samples exhibiting a spherically symmetric flame with increasing metal-oxide accumulation in an outer shell. For the Mg-CO2 combination, burning times twice as long as in normal-g and five times longer than in Mg-O2 flames were observed, revealing a diffusion-controlled reaction. The burning time is proportional to the square of the sample diameter. In tests conducted with pure CO, combustion was not possible without constant heating of the sample due to the formation of a thick carbon-containing coating around the Mg sample generated by surface reactions. The following work presents two new studies that attempt to explain some of the low-g experimental observations. First, a simplified one-dimensional, quasi-steady numerical model is developed to obtain temperature, species concentrations, and burning rates of the spherically symmetric diffusion flame around the Mg sample burning in O2 and CO2. Second, a Planar Laser Induced Fluorescence (PLIF) technique is implemented to provide spatially resolved measurements of magnesium oxide (MgO) in the reaction zone of Mg samples burning in O2 and CO2. These experiments reveal fundamental differences between the two combustion systems.

  8. Fast and Luminous Transients from the Explosions of Long-lived Massive White Dwarf Merger Remnants

    NASA Astrophysics Data System (ADS)

    Brooks, Jared; Schwab, Josiah; Bildsten, Lars; Quataert, Eliot; Paxton, Bill; Blinnikov, Sergei; Sorokina, Elena

    2017-12-01

    We study the evolution and final outcome of long-lived (≈ {10}5 years) remnants from the merger of an He white dwarf (WD) with a more massive C/O or O/Ne WD. Using Modules for Experiments in Stellar Astrophysics ({\\mathtt{MESA}}), we show that these remnants have a red giant configuration supported by steady helium burning, adding mass to the WD core until it reaches {M}{core}≈ 1.12{--}1.20 {M}⊙ . At that point, the base of the surface convection zone extends into the burning layer, mixing the helium-burning products (primarily carbon and magnesium) throughout the convective envelope. Further evolution depletes the convective envelope of helium and dramatically slows the mass increase of the underlying WD core. The WD core mass growth re-initiates after helium depletion, as then an uncoupled carbon-burning shell is ignited and proceeds to burn the fuel from the remaining metal-rich extended envelope. For large enough initial total merger masses, O/Ne WD cores would experience electron-capture triggered collapse to neutron stars (NSs) after growing to near Chandrasekhar mass ({M}{Ch}). Massive C/O WD cores could suffer the same fate after a carbon-burning flame converts them to ONe. The NS formation would release ≈ {10}50 erg into the remaining extended low mass envelope. Using the STELLA radiative transfer code, we predict the resulting optical light curves from these exploded envelopes. Reaching absolute magnitudes of {M}V≈ -17, these transients are bright for about one week and have many features of the class of luminous, rapidly evolving transients studied by Drout and collaborators.

  9. Spatially-varied erosion modeling using WEPP for timber harvested and burned hillslopes

    Treesearch

    Peter R. Robichaud; T. M. Monroe

    1997-01-01

    Spatially-varied hydrologic surface conditions exist on steep hillslopes after timber harvest operation and site preparation burning treatments. Site preparation burning creates low- and high-severity burn surface conditions or disturbances. In this study, a hillslope was divided into multiple combinations of surface conditions to determine how their spatial...

  10. Prior stress exposure increases pain behaviors in a rat model of full thickness thermal injury.

    PubMed

    Nyland, Jennifer E; McLean, Samuel A; Averitt, Dayna L

    2015-12-01

    Thermal burns among individuals working in highly stressful environments, such as firefighters and military Service Members, are common. Evidence suggests that pre-injury stress may exaggerate pain following thermal injury; however current animal models of burn have not evaluated the potential influence of pre-burn stress. This sham-controlled study evaluated the influence of prior stress exposure on post-burn thermal and mechanical sensitivity in male Sprague-Dawley rats. Rats were exposed to 20 min of inescapable swim stress or sham stress once per day for three days. Exposure to inescapable swim stress (1) increased the intensity and duration of thermal hyperalgesia after subsequent burn and (2) accelerated the onset of thermal hyperalgesia and mechanical allodynia after subsequent burn. This stress-induced exacerbation of pain sensitivity was reversed by pretreatment and concurrent treatment with the serotonin-norepinephrine reuptake inhibitor (SNRI) duloxetine. These data suggest a better understanding of mechanisms by which prior stress augments pain after thermal burn may lead to improved pain treatments for burn survivors. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  11. The American Burn Association/Shriners Hospitals for Children Burn Outcomes Program: a progress report at 15 years.

    PubMed

    Tompkins, Ronald G; Liang, Matthew H; Lee, Austin F; Kazis, Lewis E

    2012-09-01

    The American Burn Association and the Shriners Hospitals for Children Outcomes Program has been in development for more than 15 years. Many of the tools and important findings are described in this special issue of The Journal of Trauma. This unique program in outcomes research introduces a model for outcome assessments from the patient-centered perspective with a cohort of 1,140 children with burn injury after hospitalization for up to 4 years. The findings represent a fundamental contribution to the field of burn care for monitoring outcomes from the perspective of the parent or child/adolescent. The Multi-Center Benchmarking Study of four burn centers serve as a model for collecting empiric scientific data on the variation and the expected trajectories of recovery in the most important domains of patient outcomes and can inform clinical decisions and the conduct of health service research. The dramatic progress in survival of children with severe burn injury and other advances in burn management can now move into a new phase of understanding the most cost-effective components of this care.

  12. Ponderosa pine snag densities following multiple fires in the Gila Wilderness, New Mexico

    USGS Publications Warehouse

    Holden, Z.A.; Morgan, P.; Rollins, M.G.; Wright, R.G.

    2006-01-01

    Fires create and consume snags (standing dead trees), an important structural and ecological component of ponderosa pine forests. The effects of repeated fires on snag densities in ponderosa pine forests of the southwestern USA have not been studied. Line intercept sampling was used to estimate snag densities in areas of the Gila Wilderness that had burned one to three times under Wildland Fire Use for Resource Benefit (WFU), a fire management policy implemented since 1974 aimed at restoring natural fire regimes. Twenty randomly located transects were measured in areas burned since 1946; six in once-burned areas, six in twice-burned areas and eight in thrice-burned areas. The mean density ?? standard errors of large (>47.5 cm dbh) snags for areas that burned once, twice and thrice was 7.0 ?? 2.7, 4.4 ?? 1.1 and 4.1 ?? 1.3 snags/ha, respectively. Differences in snag densities between once- and multiple-burned areas were significant (F-test; p < 0.05). There was no significant difference in density of large snags between twice- and thrice-burned areas. Proportions of type 1 snags (recently created) were higher in once- and twice-burned areas than in areas that burned three times, likely reflecting high tree mortality and snag recruitment resulting from an initial entry fire. Type 3 snags (charred by previous fire) were more abundant in areas that burned multiple times. The lack of differences in snag densities between areas that burned two and three times suggests that repeated fires leave many snags standing. The increasing proportion of type 3 snags with repeated fires supports this conclusion. ?? 2005 Elsevier B.V. All rights reserved.

  13. Burn Wound Infections and Antibiotic Susceptibility Patterns at Pakistan Institute of Medical Sciences, Islamabad, Pakistan

    PubMed Central

    Saaiq, Muhammad; Ahmad, Shehzad; Zaib, Muhammad Salman

    2015-01-01

    BACKGROND Burn wound infections carry considerable mortality and morbidity amongst burn injury victims who have been successfully rescued through the initial resuscitation. This study assessed the prevalent microrganisms causing burn wound infections among hospitalized patients; their susceptibility pattern to commonly used antibiotics; and the frequency of infections with respect to the duration of the burn wounds. METHODS This study was carried out at Burn Care Centre, Pakistan Institute of Medical Sciences (PIMS), Islamabad, Pakistan over a period of two years (i.e. from June 2010 to May 2012). The study included all wound-culture-positive patients of either gender and all ages, who had sustained deep burns and underwent definitive management with wound excisions and skin auto-grafting. Patients with negative cultures of the wounds were excluded. Tissue specimens for culture and sensitivity were collected from burn wounds using standard collection techniques and analyzed at microbiological laboratory. RESULTS Out of a total of 95 positive microbial growths, 36 were Pseudomonas aeruginosa (35.29%) as the most frequent isolate found, followed by 21 Klebsiella pneumoniae (20.58%), 19 Staphylococcus aureaus (18.62%), 10 Proteus (9.80%), 7 E. coli (6.86%), 7 Acinetobacter (6.86%), and 4 Candida (3.92%). A variable antibiotic susceptibility pattern was observed among the grown microbes. Positive cultures were significantly more frequent among patients with over two weeks duration of burn wounds. CONCLUSION P. aeruginosa, K. pneumoniae and S. aureus constituted the most common bacterial microbes of burn wounds in our in-patients cases. Positive cultures were more frequent among patients with over two weeks duration of burn wounds. Early excision and skin grafting of deep burns and adherence to infection control measures can help to effectively reduce the burden of these infections. PMID:25606471

  14. Perceptions of prescribed burning in a local forest community in Victoria, Australia.

    PubMed

    Bell, Tina; Oliveras, Immaculada

    2006-11-01

    The general perceptions of prescribed burning were elicited from forest users for an area that has been subject to this form of land management for at least 20 years. The largest group consisted of local residents living in and around the Wombat State Forest with two smaller groups of students from a nearby university campus and local professional land managers. A questionnaire was given to each participant in order to explore how the forest was used, to determine the level of knowledge of burning in the targeted forest and Victoria and the perception of the appearance, effectiveness of protection, and accessibility to the forest after prescribed burning. Generally all groups had similar responses with community members having stronger views on the effectiveness and practicalities of prescribed burning, whereas students were more neutral in their opinions. All participants claimed knowledge of prescribed burning activities within Victoria, but fewer had experience of planned fires in the Wombat State Forest. All groups agreed that areas that had not been recently burned had a better appearance than those that had, but this result may have included a range of value judgments. Land managers had a greater understanding of the ecological importance of season and timing of burning; however, some students and community members were equally knowledgeable. Prescribed burning did not impede access to the forest, nor did smoke from prescribed burns pose any great problem. The majority of the participants felt that the amount of prescribed burning done in the forest was adequate for engendering a feeling of protection to life and property, yet many were still suspicious of this management practice. These initial findings indicate several areas in which further research would be useful including the efficacy of education programs for community members and improved communication of burn plans by land managers.

  15. Thermal characteristics of amphibian microhabitats in a fire-disturbed landscape

    USGS Publications Warehouse

    Hossack, B.R.; Eby, L.A.; Guscio, C.G.; Corn, P.S.

    2009-01-01

    Disturbance has long been a central issue in amphibian conservation, often regarding negative effects of logging or other forest management activities, but some amphibians seem to prefer disturbed habitats. After documenting increased use of recently burned forests by boreal toads (Bufo boreas), we hypothesized that burned habitats provided improved thermal opportunities in terrestrial habitats. We tested this hypothesis by conducting a radio telemetry study of habitat use (reported previously) and by using physical models that simulated the temperature of adult toads. We deployed 108 physical models in and adjacent to a 1-year old burn using a fully-replicated design with three burn severities (unburned, partial, high severity) and four microhabitats (open surface, under vegetation, under log, in burrow). Model temperatures were compared to a range of preferred temperatures in published studies. We found 70% more observations within the preferred temperature range of B. boreas in forests burned with high severity than in unburned areas. Burned forest was warmer than unburned forest across all microhabitats, but the largest relative difference was in burrows, which averaged 3 ??C warmer in high-severity burn areas and remained warmer though the night. More than twice as many observations were within the preferred temperature range in high-severity burrows than in unburned burrows. Areas burned with high severity were still warmer than unburned forest 3 years after the fire. Habitat use of toads during the concurrent radio telemetry study matched that predicted by the physical models. These results suggest there are fitness-linked benefits to toads using burned habitats, such as increased growth, fertility, and possibly disease resistance. However, increased soil temperatures that result from wildfire may be detrimental to other amphibian species that prefer cooler temperatures and stable environments. More broadly, our data illustrate the use of physical models to measure and interpret changes that amphibians may experience from disturbance, and highlight the need for research linking vital rates such as growth and survival to disturbance.

  16. EVALUATION OF EFFECTIVENESS IN A NOVEL WOUND HEALING OINTMENT-CROCODILE OIL BURN OINTMENT

    PubMed Central

    Li, Hua-Liang; Deng, Yi-Tao; Zhang, Zi-Ran; Fu, Qi-Rui; Zheng, Ya-Hui; Cao, Xing-Mei; Nie, Jing; Fu, Li-Wen; Chen, Li-Ping; Xiong, You-Xiong; Shen, Dong-Yan; Chen, Qing-Xi

    2017-01-01

    Background: Crocodile oil and its products are used as ointments for burns and scalds in traditional medicines. A new ointment formulation - crocodile oil burn ointment (COBO) was developed to provide more efficient wound healing activity. The purpose of the study was to evaluate the burn healing efficacy of this new formulation by employing deep second-degree burns in a Wistar rat model. The analgesic and anti-inflammatory activities of COBO were also studied to provide some evidences for its further use. Materials and methods: The wound healing potential of this formulation was evaluated by employing a deep second-degree burn rat model and the efficiency was comparatively assessed against a reference ointment - (1% wt/wt) silver sulfadiazine (SSD). After 28 days, the animals were euthanized and the wounds were removed for transversal and longitudinal histological studies. Acetic acid-induced writhing in mice was used to evaluate the analgesic activity and its anti-inflammatory activity was observed in xylene -induced edema in mice. Results: COBO enhanced the burn wound healing (20.5±1.3 d) as indicated by significant decrease in wound closure time compared with the burn control (25.0±2.16 d) (P<0.01). Hair follicles played an importance role in the physiological functions of the skin, and their growth in the wound could be revealed for the skin regeneration situation. Histological results showed that the hair follicles were well-distributed in the post-burn skin of COBO treatment group, and the amounts of total, active, primary and secondary hair follicles in post-burn 28-day skin of COBO treatment groups were more than those in burn control and SSD groups. On the other hand, the analgesic and anti-inflammatory activity of COBO were much better than those of control group, while they were very close to those of moist exposed burn ointment (MEBO). Conclusions: COBO accelerated wound closure, reduced inflammation, and had analgesic effects compared with SSD in deep second degree rat burn model. These findings suggest that COBO would be a potential therapy for treating human burns. Abbreviations: COBO, crocodile oil burn ointment; SSD, silver sulfadiazine; MEBO, moist exposed burn ointment; TCM, traditional Chinese medicine; CHM, Chinese herbal medicine; GC-MS, gas chromatography-mass spectrometry. PMID:28480384

  17. EVALUATION OF EFFECTIVENESS IN A NOVEL WOUND HEALING OINTMENT-CROCODILE OIL BURN OINTMENT.

    PubMed

    Li, Hua-Liang; Deng, Yi-Tao; Zhang, Zi-Ran; Fu, Qi-Rui; Zheng, Ya-Hui; Cao, Xing-Mei; Nie, Jing; Fu, Li-Wen; Chen, Li-Ping; Xiong, You-Xiong; Shen, Dong-Yan; Chen, Qing-Xi

    2017-01-01

    Crocodile oil and its products are used as ointments for burns and scalds in traditional medicines. A new ointment formulation - crocodile oil burn ointment (COBO) was developed to provide more efficient wound healing activity. The purpose of the study was to evaluate the burn healing efficacy of this new formulation by employing deep second-degree burns in a Wistar rat model. The analgesic and anti-inflammatory activities of COBO were also studied to provide some evidences for its further use. The wound healing potential of this formulation was evaluated by employing a deep second-degree burn rat model and the efficiency was comparatively assessed against a reference ointment - (1% wt/wt) silver sulfadiazine (SSD). After 28 days, the animals were euthanized and the wounds were removed for transversal and longitudinal histological studies. Acetic acid-induced writhing in mice was used to evaluate the analgesic activity and its anti-inflammatory activity was observed in xylene -induced edema in mice. COBO enhanced the burn wound healing (20.5±1.3 d) as indicated by significant decrease in wound closure time compared with the burn control (25.0±2.16 d) ( P <0.01). Hair follicles played an importance role in the physiological functions of the skin, and their growth in the wound could be revealed for the skin regeneration situation. Histological results showed that the hair follicles were well-distributed in the post-burn skin of COBO treatment group, and the amounts of total, active, primary and secondary hair follicles in post-burn 28-day skin of COBO treatment groups were more than those in burn control and SSD groups. On the other hand, the analgesic and anti-inflammatory activity of COBO were much better than those of control group, while they were very close to those of moist exposed burn ointment (MEBO). COBO accelerated wound closure, reduced inflammation, and had analgesic effects compared with SSD in deep second degree rat burn model. These findings suggest that COBO would be a potential therapy for treating human burns. Abbreviations: COBO, crocodile oil burn ointment; SSD, silver sulfadiazine; MEBO, moist exposed burn ointment; TCM, traditional Chinese medicine; CHM, Chinese herbal medicine; GC-MS, gas chromatography-mass spectrometry.

  18. Effect of nano-silver hydrogel coating film on deep partial thickness scald model of rabbit.

    PubMed

    Xi, Peng; Li, Yan; Ge, Xiaojin; Liu, Dandan; Miao, Mingsan

    2018-05-01

    Observing the effect of nano-silver hydrogel coating film on deep partial thickness scald model of rabbit. We prepared boiling water scalded rabbits with deep II degree scald models and applied high, medium and low doses of nano-silver hydrogel coating film for different time and area. Then we compared the difference of burned paper weight before administration and after administration model burns, burn local skin irritation points infection, skin crusting and scabs from the time, and the impact of local skin tissue morphology. Rabbits deep II degree burn model successful modeling; on day 12, 18, high, medium and low doses of nano-silver hydrogel coating film significantly reduced skin irritation of rabbits infected with the integral value ( P  < 0.01, P  < 0.05); high, medium and low doses of nano-silver hydrogel coating film group significantly decreased skin irritation, infection integral value ( P  < 0.01, P  < 0.05); high, medium and low doses of nano-silver hydrogel coating film significantly reduced film rabbits' scalded skin crusting time ( P  < 0.01), significantly shortened the rabbit skin burns from the scab time ( P  < 0.01), and significantly improved the treatment of skin diseases in rabbits scald model change ( P  < 0.01, P  < 0.05). The nano-silver hydrogel coating film on the deep partial thickness burns has a significant therapeutic effect; external use has a significant role in wound healing.

  19. A systematic review of advance practice providers in acute care: options for a new model in a burn intensive care unit.

    PubMed

    Edkins, Renee E; Cairns, Bruce A; Hultman, C Scott

    2014-03-01

    Accreditation Council for Graduate Medical Education mandated work-hour restrictions have negatively impacted many areas of clinical care, including management of burn patients, who require intensive monitoring, resuscitation, and procedural interventions. As surgery residents become less available to meet service needs, new models integrating advanced practice providers (APPs) into the burn team must emerge. We performed a systematic review of APPs in critical care questioning, how best to use all providers to solve these workforce challenges? We performed a systematic review of PubMed, CINAHL, Ovid, and Google Scholar, from 2002 to 2012, using the key words: nurse practitioner, physician assistant, critical care, and burn care. After applying inclusion/exclusion criteria, 18 relevant articles were selected for review. In addition, throughput and financial models were developed to examine provider staffing patterns. Advanced practice providers in critical care settings function in various models, both with and without residents, reporting to either an intensivist or an attending physician. When APPs participated, patient outcomes were similar or improved compared across provider models. Several studies reported considerable cost-savings due to decrease length of stay, decreased ventilator days, and fewer urinary tract infections when nurse practitioners were included in the provider mix. Restrictions in resident work-hours and changing health care environments require that new provider models be created for acute burn care. This article reviews current utilization of APPs in critical care units and proposes a new provider model for burn centers.

  20. Multispectral imaging burn wound tissue classification system: a comparison of test accuracies between several common machine learning algorithms

    NASA Astrophysics Data System (ADS)

    Squiers, John J.; Li, Weizhi; King, Darlene R.; Mo, Weirong; Zhang, Xu; Lu, Yang; Sellke, Eric W.; Fan, Wensheng; DiMaio, J. Michael; Thatcher, Jeffrey E.

    2016-03-01

    The clinical judgment of expert burn surgeons is currently the standard on which diagnostic and therapeutic decisionmaking regarding burn injuries is based. Multispectral imaging (MSI) has the potential to increase the accuracy of burn depth assessment and the intraoperative identification of viable wound bed during surgical debridement of burn injuries. A highly accurate classification model must be developed using machine-learning techniques in order to translate MSI data into clinically-relevant information. An animal burn model was developed to build an MSI training database and to study the burn tissue classification ability of several models trained via common machine-learning algorithms. The algorithms tested, from least to most complex, were: K-nearest neighbors (KNN), decision tree (DT), linear discriminant analysis (LDA), weighted linear discriminant analysis (W-LDA), quadratic discriminant analysis (QDA), ensemble linear discriminant analysis (EN-LDA), ensemble K-nearest neighbors (EN-KNN), and ensemble decision tree (EN-DT). After the ground-truth database of six tissue types (healthy skin, wound bed, blood, hyperemia, partial injury, full injury) was generated by histopathological analysis, we used 10-fold cross validation to compare the algorithms' performances based on their accuracies in classifying data against the ground truth, and each algorithm was tested 100 times. The mean test accuracy of the algorithms were KNN 68.3%, DT 61.5%, LDA 70.5%, W-LDA 68.1%, QDA 68.9%, EN-LDA 56.8%, EN-KNN 49.7%, and EN-DT 36.5%. LDA had the highest test accuracy, reflecting the bias-variance tradeoff over the range of complexities inherent to the algorithms tested. Several algorithms were able to match the current standard in burn tissue classification, the clinical judgment of expert burn surgeons. These results will guide further development of an MSI burn tissue classification system. Given that there are few surgeons and facilities specializing in burn care, this technology may improve the standard of burn care for patients without access to specialized facilities.

  1. Propulsion System Models for Rotorcraft Conceptual Design

    NASA Technical Reports Server (NTRS)

    Johnson, Wayne

    2014-01-01

    The conceptual design code NDARC (NASA Design and Analysis of Rotorcraft) was initially implemented to model conventional rotorcraft propulsion systems, consisting of turboshaft engines burning jet fuel, connected to one or more rotors through a mechanical transmission. The NDARC propulsion system representation has been extended to cover additional propulsion concepts, including electric motors and generators, rotor reaction drive, turbojet and turbofan engines, fuel cells and solar cells, batteries, and fuel (energy) used without weight change. The paper describes these propulsion system components, the architecture of their implementation in NDARC, and the form of the models for performance and weight. Requirements are defined for improved performance and weight models of the new propulsion system components. With these new propulsion models, NDARC can be used to develop environmentally-friendly rotorcraft designs.

  2. A Model to Improve Detection of Nonaccidental Pediatric Burns.

    PubMed

    Nigro, Lauren C; Feldman, Michael J; Foster, Robin L; Pozez, Andrea L

    2018-06-01

    Pediatric burn patients warrant thorough evaluation because a sizeable proportion of pediatric burns are nonaccidental. A multidisciplinary method involving an internal child protection team (CPT) was developed and used to identify suspected nonaccidental pediatric burns in all pediatric burn patients 5 years of age or younger who were evaluated by the CPT and social workers at our institution over a 55-month period. We identified 343 cases for review that fit our age criteria, 6 of which we identified as cases of suspected abuse or neglect. On average, these patients were younger, suffered greater total body surface area burns (TBSA), and required a longer length of stay in the hospital than the total population. We have not had readmissions for repeat nonaccidental pediatric burn injuries in this group of patients since this model was implemented. Our multidisciplinary method might provide a more consistent and reliable method for identifying cases of suspected abuse. © 2018 American Medical Association. All Rights Reserved.

  3. X-Ray Fluorescence to Estimate the Maximum Temperature Reached at Soil Surface during Experimental Slash-and-Burn Fires.

    PubMed

    Melquiades, Fábio L; Thomaz, Edivaldo L

    2016-05-01

    An important aspect for the evaluation of fire effects in slash-and-burn agricultural system, as well as in wildfire, is the soil burn severity. The objective of this study is to estimate the maximum temperature reached in real soil burn events using energy dispersive X-ray fluorescence (EDXRF) as an analytical tool, combined with partial least square (PLS) regression. Muffle-heated soil samples were used for PLS regression model calibration and two real slash-and-burn soils were tested as external samples in the model. It was possible to associate EDXRF spectra alterations to the maximum temperature reached in the heat affected soils with about 17% relative standard deviation. The results are promising since the analysis is fast, nondestructive, and conducted after the burn event, although local calibration for each type of burned soil is necessary. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  4. Assessing the response of area burned to changing climate in western boreal North America using a Multivariate Adaptive Regression Splines (MARS) approach

    USGS Publications Warehouse

    Balshi, M. S.; McGuire, A.D.; Duffy, P.; Flannigan, M.; Walsh, J.; Melillo, J.

    2009-01-01

    Fire is a common disturbance in the North American boreal forest that influences ecosystem structure and function. The temporal and spatial dynamics of fire are likely to be altered as climate continues to change. In this study, we ask the question: how will area burned in boreal North America by wildfire respond to future changes in climate? To evaluate this question, we developed temporally and spatially explicit relationships between air temperature and fuel moisture codes derived from the Canadian Fire Weather Index System to estimate annual area burned at 2.5?? (latitude ?? longitude) resolution using a Multivariate Adaptive Regression Spline (MARS) approach across Alaska and Canada. Burned area was substantially more predictable in the western portion of boreal North America than in eastern Canada. Burned area was also not very predictable in areas of substantial topographic relief and in areas along the transition between boreal forest and tundra. At the scale of Alaska and western Canada, the empirical fire models explain on the order of 82% of the variation in annual area burned for the period 1960-2002. July temperature was the most frequently occurring predictor across all models, but the fuel moisture codes for the months June through August (as a group) entered the models as the most important predictors of annual area burned. To predict changes in the temporal and spatial dynamics of fire under future climate, the empirical fire models used output from the Canadian Climate Center CGCM2 global climate model to predict annual area burned through the year 2100 across Alaska and western Canada. Relative to 1991-2000, the results suggest that average area burned per decade will double by 2041-2050 and will increase on the order of 3.5-5.5 times by the last decade of the 21st century. To improve the ability to better predict wildfire across Alaska and Canada, future research should focus on incorporating additional effects of long-term and successional vegetation changes on area burned to account more fully for interactions among fire, climate, and vegetation dynamics. ?? 2009 The Authors Journal compilation ?? 2009 Blackwell Publishing Ltd.

  5. The conductive propagation of nuclear flames. I - Degenerate C + O and O + Ne + Mg white dwarfs

    NASA Technical Reports Server (NTRS)

    Timmes, F. X.; Woosley, S. E.

    1992-01-01

    The paper determines the physical properties - speed, width, and density structure - of conductive burning fronts in degenerate carbon-oxygen (C + O) and oxygen-neon-magnesium (O + Ne + Mg) compositions for a grid of initial densities and compositions. The dependence of the physical properties of the flame on the assumed values of nuclear reaction rates, the nuclear reaction network employed, the thermal conductivity, and the choice of coordinate system are investigated. The occurrence of accretion-induced collapse of a white dwarf is found to be critically dependent on the velocity of the nuclear conductive burning front and the growth rate of hydrodynamic instabilities. Treating the expanding area of the turbulent burning region as a fractal whose tile size is identical to the minimum unstable Rayleigh-Taylor wavelength, it is found, for all reasonable values of the fractal dimension, that for initial C + O or O + Ne + Mg densities above about 9 x 10 exp 9 g/cu cm the white dwarf should collapse to a neutron star.

  6. Burnet Project

    PubMed Central

    Masellis, A.; Atiyeh, B.

    2009-01-01

    Summary The BurNet project, a pilot project of the Eumedis initiative, has become true. The Eumedis (EUro MEDiterranean Information Society) initiative is part of the MEDA programme of the EU to develop the Information Society in the Mediterranean area. In the health care sector, the objective of Eumedis is: the deployment of network-based solutions to interconnect - using userfriendly and affordable solutions - the actors at all levels of the "health care system" of the Euro-Mediterranean region. The Bur Net project interconnects 17 Burn Centres (BC) in the Mediterranean Area through an information network both to standardize courses of action in the field of prevention, treatment, and functional and psychological rehabilitation of burn patients and to coordinate interactions between BC and emergency rooms in peripheral hospitals using training/information activities and telemedicine to optimize first aid provided to burn patients before referral to a BC. Shared procedure protocols for prevention and the care and rehabilitation of patients, both at individual and mass level, will help to create an international specialized database and a Webbased teleconsultation system. PMID:21991176

  7. Lightning Forcing in Global Fire Models: The Importance of Temporal Resolution

    NASA Astrophysics Data System (ADS)

    Felsberg, A.; Kloster, S.; Wilkenskjeld, S.; Krause, A.; Lasslop, G.

    2018-01-01

    In global fire models, lightning is typically prescribed from observational data with monthly mean temporal resolution while meteorological forcings, such as precipitation or temperature, are prescribed in a daily resolution. In this study, we investigate the importance of the temporal resolution of the lightning forcing for the simulation of burned area by varying from daily to monthly and annual mean forcing. For this, we utilize the vegetation fire model JSBACH-SPITFIRE to simulate burned area, forced with meteorological and lightning data derived from the general circulation model ECHAM6. On a global scale, differences in burned area caused by lightning forcing applied in coarser temporal resolution stay below 0.55% compared to the use of daily mean forcing. Regionally, however, differences reach up to 100%, depending on the region and season. Monthly averaged lightning forcing as well as the monthly lightning climatology cause differences through an interaction between lightning ignitions and fire prone weather conditions, accounted for by the fire danger index. This interaction leads to decreased burned area in the boreal zone and increased burned area in the Tropics and Subtropics under the coarser temporal resolution. The exclusion of interannual variability, when forced with the lightning climatology, has only a minor impact on the simulated burned area. Annually averaged lightning forcing causes differences as a direct result of the eliminated seasonal characteristics of lightning. Burned area is decreased in summer and increased in winter where fuel is available. Regions with little seasonality, such as the Tropics and Subtropics, experience an increase in burned area.

  8. Reactive Nitrogen Multiphase Chemistry and Chlorine Activation on Authentic Biomass Burning Aerosol

    NASA Astrophysics Data System (ADS)

    Goldberger, Lexie

    Biomass burning is both a major source of particulate matter and reactive nitrogen oxide radicals, yet the rate and products of the multiphase chemistry between the two has not been well studied. Nitryl chloride (ClNO2), formed by the multiphase reaction of dinitrogen pentoxide (N2O 5) on chloride-containing particles, is known to occur in polluted marine environments where it contributes significantly to the oxidant budget. Since the observation of ClNO2 levels in a moderately polluted region far from the coast, there has been motivation to determine the source of particulate chloride, postulated as the limiting ingredient to ClNO2 formation. Using a smog chamber reactor at Carnegie Mellon University coupled to a biomass combustion chamber with controlled particle and gas injection, we simulated the nocturnal evolution of N2O5 in biomass burning plumes mixed with ozone. A range of authentic fuel types, including saw grass, cut grass, and white European birch were burned in the combustion chamber and a portion of the smoke plume was then mixed into the 12 m3 chamber, where it was exposed to 70-150 ppb of ozone and relative humidity ranging from 0-60% in the dark. Gaseous N 2O5, nitric acid (HNO3), ClNO 2, Cl2, and HCl were monitored using a high resolution time of flight iodide adduct chemical ionization mass spectrometer, and particle size distributions and composition were monitored continuously with an SMPS and a Soot-Particle Aerosol Mass Spectrometer among other instruments. With chemical mechanism modeling I attempt to abstract N2O 5 uptake coefficients as well as molar yields of ClNO2 and report correlated changes in Cl2 and HCl. I analyze dependences on combustion fuel type. These results suggest a potentially important impact of chlorine atom initiated oxidation in biomass burning plumes. The uptake of N2O5 and yields of ClNO2, Cl2, and HCl determined from this study will allow for more robust parameterizations of these compounds in atmospheric models.

  9. Analytic model to estimate thermonuclear neutron yield in z-pinches using the magnetic Noh problem

    NASA Astrophysics Data System (ADS)

    Allen, Robert C.

    The objective was to build a model which could be used to estimate neutron yield in pulsed z-pinch experiments, benchmark future z-pinch simulation tools and to assist scaling for breakeven systems. To accomplish this, a recent solution to the magnetic Noh problem was utilized which incorporates a self-similar solution with cylindrical symmetry and azimuthal magnetic field (Velikovich, 2012). The self-similar solution provides the conditions needed to calculate the time dependent implosion dynamics from which batch burn is assumed and used to calculate neutron yield. The solution to the model is presented. The ion densities and time scales fix the initial mass and implosion velocity, providing estimates of the experimental results given specific initial conditions. Agreement is shown with experimental data (Coverdale, 2007). A parameter sweep was done to find the neutron yield, implosion velocity and gain for a range of densities and time scales for DD reactions and a curve fit was done to predict the scaling as a function of preshock conditions.

  10. A New Mass Criterium for Electron Capture Supernovae

    NASA Astrophysics Data System (ADS)

    Poelarends, Arend

    2016-06-01

    Electron capture supernovae (ECSN) are thought to populate the mass range between massive white dwarf progenitors and core collapse supernovae. It is generally believed that the initial stellar mass range for ECSN from single stars is about 0.5-1.0 M⊙ wide and centered around a value of 8.5 or 9 M⊙, depending on the specifics of the physics of convection and mass loss one applies. Since mass loss in a binary system is able to delay or cancel the second dredge-up, it is also believed that the initial mass range for ECSN in binary systems is wider than in single stars, but an initial mass range has not been defined yet.The last phase of stars in this particular mass range, however, is challenging to compute, either due to recurring Helium shell flashes, or due to convectively bound flames in the degenerate interior of the star. It would be helpful, nevertheless, to know before we enter these computationally intensive phases whether a star will explode as an ECSN or not. The mass of the helium core after helium core burning is one such criterium (Nomoto, 1984), which predicts that ECSN will occur if the helium core mass is between 2.0 M⊙ and 2.5 M⊙. However, since helium cores can be subject to erosion due to mass loss — even during helium core burning, this criterium will not yield accurate predictions for stars in binary systems.We present a dense grid of stellar evolution models that allow us to put constraints on the final fate of their cores, based on a combination of Carbon/Oxygen core mass, the mass of the surrounding Helium layer and C/O abundance. We find that CO cores with masses between 1.365 and 1.420 M⊙ at the end of Carbon burning will result in ECSN, with some minor adjustments of these ranges due to the mass of the Helium layer and the C/O ratio. While detailed models of stars within the ECSN mass range remain necessary to understand the details of pre-ECSN evolution, our research refines the Helium core criterion and provides a useful way to determine the final fate of stars in this complicated mass range early on.

  11. 1984–2010 trends in fire burn severity and area for the conterminous US

    USGS Publications Warehouse

    Picotte, Joshua J.; Peterson, Birgit E.; Meier, Gretchen; Howard, Stephen M.

    2016-01-01

    Burn severity products created by the Monitoring Trends in Burn Severity (MTBS) project were used to analyse historical trends in burn severity. Using a severity metric calculated by modelling the cumulative distribution of differenced Normalized Burn Ratio (dNBR) and Relativized dNBR (RdNBR) data, we examined burn area and burn severity of 4893 historical fires (1984–2010) distributed across the conterminous US (CONUS) and mapped by MTBS. Yearly mean burn severity values (weighted by area), maximum burn severity metric values, mean area of burn, maximum burn area and total burn area were evaluated within 27 US National Vegetation Classification macrogroups. Time series assessments of burned area and severity were performed using Mann–Kendall tests. Burned area and severity varied by vegetation classification, but most vegetation groups showed no detectable change during the 1984–2010 period. Of the 27 analysed vegetation groups, trend analysis revealed burned area increased in eight, and burn severity has increased in seven. This study suggests that burned area and severity, as measured by the severity metric based on dNBR or RdNBR, have not changed substantially for most vegetation groups evaluated within CONUS.

  12. Aerosol Microphysics and Radiation Integration

    DTIC Science & Technology

    2003-09-30

    656-4769 email: reidj@nrlmry.navy.mil Award Number: N0001403WX20570 http://www.nrlmry.navy.mil/aerosol/ http://www.nrlmry.navy.mil/ flambe ...Fire Locating and Modeling of Burning Emissions ( FLAMBE ) project, which also provides NAAPS with a real-time biomass burning source function. In...Locating and Modeling of Burning Emissions ( FLAMBE ) project are currently being utilized by internet community, Air quality/human health research

  13. The impact of diverse types of biomass burning in a tropical country

    Treesearch

    R. J. Yokelson; I. R. Burling; Shawn Urbanski; T. J. Christian; E. L. Atlas; C. Wiedinmyer; S. K. Akagi; G. Engling

    2010-01-01

    We couple laboratory work, airborne and ground-based field measurements, remote sensing of fires, and modeling to assess the impact of diverse types of biomass burning (BB) in Mexico as a model tropical country. About 70-80% of open BB occurs in the tropics along with large amounts of biofuel use and garbage burning (GB); both in rural and urban areas. During the...

  14. Fine scale vegetation classification and fuel load mapping for prescribed burning

    Treesearch

    Andrew D. Bailey; Robert Mickler

    2007-01-01

    Fire managers in the Coastal Plain of the Southeastern United States use prescribed burning as a tool to reduce fuel loads in a variety of vegetation types, many of which have elevated fuel loads due to a history of fire suppression. While standardized fuel models are useful in prescribed burn planning, those models do not quantify site-specific fuel loads that reflect...

  15. The development of an erosive burning model for solid rocket motors using direct numerical simulation

    NASA Astrophysics Data System (ADS)

    McDonald, Brian A.

    A method for developing an erosive burning model for use in solid propellant design-and-analysis interior ballistics codes is described and evaluated. Using Direct Numerical Simulation, the primary mechanisms controlling erosive burning (turbulent heat transfer, and finite rate reactions) have been studied independently through the development of models using finite rate chemistry, and infinite rate chemistry. Both approaches are calibrated to strand burn rate data by modeling the propellant burning in an environment with no cross-flow, and adjusting thermophysical properties until the predicted regression rate matches test data. Subsequent runs are conducted where the cross-flow is increased from M = 0.0 up to M = 0.8. The resulting relationship of burn rate increase versus Mach Number is used in an interior ballistics analysis to compute the chamber pressure of an existing solid rocket motor. The resulting predictions are compared to static test data. Both the infinite rate model and the finite rate model show good agreement when compared to test data. The propellant considered is an AP/HTPB with an average AP particle size of 37 microns. The finite rate model shows that as the cross-flow increases, near wall vorticity increases due to the lifting of the boundary caused by the side injection of gases from the burning propellant surface. The point of maximum vorticity corresponds to the outer edge of the APd-binder flame. As the cross-flow increases, the APd-binder flame thickness becomes thinner; however, the point of highest reaction rate moves only slightly closer to the propellant surface. As such, the net increase of heat transfer to the propellant surface due to finite rate chemistry affects is small. This leads to the conclusion that augmentation of thermal transport properties and the resulting heat transfer increase due to turbulence dominates over combustion chemistry in the erosive burning problem. This conclusion is advantageous in the development of future models that can be calibrated to heat transfer conditions without the necessity for finite rate chemistry. These results are considered applicable for propellants with small, evenly distributed AP particles where the assumption of premixed APd-binder gases is reasonable.

  16. 40 CFR 60.3068 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3068 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only wood...

  17. 40 CFR 60.3068 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3068 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only wood...

  18. 40 CFR 60.3068 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3068 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only wood...

  19. 40 CFR 60.3068 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3068 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only wood...

  20. 40 CFR 60.3068 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3068 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only wood...

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