Science.gov

Sample records for firing rate oil

  1. VARIABLE FIRING RATE OIL BURNER USING PULSE FUEL FLOW CONTROL.

    SciTech Connect

    KRISHNA,C.R.; BUTCHER,T.A.; KAMATH,B.R.

    2004-10-01

    The residential oil burner market is currently dominated by the pressure-atomized retention head burner, which has an excellent reputation for reliability and efficiency. In this burner, oil is delivered to a fuel nozzle at pressures from 100 to 150 psi. In addition, to atomizing the fuel, the small, carefully controlled size of the nozzle exit orifice serves to control the burner firing rate. Burners of this type are currently available at firing rates of more than 0.5 gallons-per-hour (70,000 Btu/hr). Nozzles have been made for lower firing rates, but experience has shown that such nozzles suffer rapid fouling of the necessarily small passages, leading to bad spray patterns and poor combustion performance. Also, traditionally burners and the nozzles are oversized to exceed the maximum demand. Typically, this is figured as follows. The heating load of the house on the coldest day for the location is considered to define the maximum heat load. The contractor or installer adds to this to provide a safety margin and for future expansion of the house. If the unit is a boiler that provides domestic hot water through the use of a tankless heating coil, the burner capacity is further increased. On the contrary, for a majority of the time, the heating system is satisfying a much smaller load, as only rarely do all these demands add up. Consequently, the average output of the heating system has to be much less than the design capacity and this is accomplished by start and stop cycling operation of the system so that the time-averaged output equals the demand. However, this has been demonstrated to lead to overall efficiencies lower than the steady-state efficiency. Therefore, the two main reasons for the current practice of using oil burners much larger than necessary for space heating are the unavailability of reliable low firing rate oil burners and the desire to assure adequate input rate for short duration, high draw domestic hot water loads. One approach to solve this

  2. Flame quality monitor system for fixed firing rate oil burners

    SciTech Connect

    Butcher, T.A.; Cerniglia, P.

    1990-10-23

    A method and apparatus for determining and indicating the flame quality, or efficiency of the air-fuel ratio, in a fixed firing rate heating unit, such as an oil burning furnace, is provided. When the flame brightness falls outside a preset range, the flame quality, or excess air, has changed to the point that the unit should be serviced. The flame quality indicator output is in the form of lights mounted on the front of the unit. A green light indicates that the flame is about in the same condition as when the burner was last serviced. A red light indicates a flame which is either too rich or too lean, and that servicing of the burner is required. At the end of each firing cycle, the flame quality indicator goes into a hold mode which is in effect during the period that the burner remains off. A yellow or amber light indicates that the burner is in the hold mode. In this mode, the flame quality lights indicate the flame condition immediately before the burner turned off. Thus the unit can be viewed when it is off, and the flame condition at the end of the previous firing cycle can be observed.

  3. Flame quality monitor system for fixed firing rate oil burners

    DOEpatents

    Butcher, Thomas A.; Cerniglia, Philip

    1992-01-01

    A method and apparatus for determining and indicating the flame quality, or efficiency of the air-fuel ratio, in a fixed firing rate heating unit, such as an oil burning furnace, is provided. When the flame brightness falls outside a preset range, the flame quality, or excess air, has changed to the point that the unit should be serviced. The flame quality indicator output is in the form of lights mounted on the front of the unit. A green light indicates that the flame is about in the same condition as when the burner was last serviced. A red light indicates a flame which is either too rich or too lean, and that servicing of the burner is required. At the end of each firing cycle, the flame quality indicator goes into a hold mode which is in effect during the period that the burner remains off. A yellow or amber light indicates that the burner is in the hold mode. In this mode, the flame quality lights indicate the flame condition immediately before the burner turned off. Thus the unit can be viewed when it is off, and the flame condition at the end of the previous firing cycle can be observed.

  4. Fire and explosion hazards of oil shale

    SciTech Connect

    Not Available

    1989-01-01

    The US Bureau of Mines publication presents the results of investigations into the fire and explosion hazards of oil shale rocks and dust. Three areas have been examined: the explosibility and ignitability of oil shale dust clouds, the fire hazards of oil shale dust layers on hot surfaces, and the ignitability and extinguishment of oil shale rubble piles. 10 refs., 54 figs., 29 tabs.

  5. SO/sub 2/(g)-to-sulfate conversion rate in an oil-fired-power-plant plume in a fog bank

    SciTech Connect

    Eatough, D.J.; Arthur, R.J.; Eatough, N.L.; Hill, M.W.; Mangelson, N.F.; Richter, B.E.; Hansen, L.D.; Cooper, J.A.

    1983-01-01

    High acidity in rainfall, cloud droplets and fog droplets in areas influenced by anthropogenic sources of SO/sub 2/(g) and NO/sub x/(g) has been attributed to the formation of both H/sub 2/SO/sub 4/ and HNO/sub 3/. It has been suggested, based on the analysis of field data, that rapid conversion of SO/sub 2/(g) to sulfate must occur in cloud or fog droplets. Direct measurements of the rate of SO/sub 2/(g) to sulfate conversion in an oil-fired power plant plume as it passes through a fog bank are reported here. A conversion rate of 30+-4% SO/sub 2/(g) h/sup -1/ was found in the fog bank.

  6. DURABILITY OF VERY LOW CAPACITY PRESSURE ATOMIZED FUEL NOZZLES USED WITH LOW FIRING RATE RESIDENTIAL OIL BURNERS.

    SciTech Connect

    MCDONALD,R.J.

    2007-05-01

    Brookhaven National Laboratory (BNL), working for the United States Department of Energy (DOE), has conducted a preliminary evaluation of the potential of very low fuel input capacity Simplex type pressure atomizing nozzles for use with oil burners designed for residential boilers, furnaces and water heaters. These nozzles under suitable conditions can be sufficiently reliable to enable new heating system designs. This would allow for the design of heating appliances that match the smaller load demands of energy efficient homes built with modern components and architectural systems designed to minimize energy use. When heating systems are installed with excessive capacity, oversized by three to four times the load, the result is a loss of up to ten percent as compared to the rated appliance efficiency. The use of low capacity nozzles in systems designed to closely match the load can thereby result in significant energy savings. BNL investigated the limitations of low flow rate nozzles and designed long-term experiments to see if ways could be determined that would be beneficial to long-term operation at low input capacities without failures. In order to maximize the potential for success the best possible industry practices available were employed. Low flow rate nozzles primarily fail by blockage or partial blockage of internal fuel flow passages inside the nozzle. To prevent any contaminants from entering the nozzle BNL investigated the geometry and critical dimensions and the current sate of the art of fuel filter design. Based on this investigation it was concluded that the best available filters should be more than capable of filtering contaminants from the fuel prior to entering the oil burner itself. This position was indeed validated based on the long-term trials conducted under this study no evidence resulted to change our position. It is highly recommended that these filters rated at 10 microns and with large filter capacity (surface area), should be used

  7. Oil-And-Gas-Fire Snubber

    NASA Technical Reports Server (NTRS)

    Weinstein, Leonard M.

    1994-01-01

    Flame diverted and extinguished without explosives. Oil-and-gas-fire snubber consists of pipe with two exit branches and large selector valve, positioned over well, on path of escaping fuel. Flame moved to one side; then flow of fuel moved to other side, away from flame. Two versions of snubber have different uses. First used only to extinguish fire. Exit branch only long enough to keep fuel away to prevent reignition. Second needed if well not capped after fire at well extinguished and oil and gas remained present in problem quantities. Exit branch long enough to extend to oil-storage tank, and gas separated from oil and vented or burned at convenient location.

  8. Oil Fire Plumes Over Baghdad

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Dark smoke from oil fires extend for about 60 kilometers south of Iraq's capital city of Baghdad in these images acquired by the Multi-angle Imaging SpectroRadiometer (MISR) on April 2, 2003. The thick, almost black smoke is apparent near image center and contains chemical and particulate components hazardous to human health and the environment.

    The top panel is from MISR's vertical-viewing (nadir) camera. Vegetated areas appear red here because this display is constructed using near-infrared, red and blue band data, displayed as red, green and blue, respectively, to produce a false-color image. The bottom panel is a combination of two camera views of the same area and is a 3-D stereo anaglyph in which red band nadir camera data are displayed as red, and red band data from the 60-degree backward-viewing camera are displayed as green and blue. Both panels are oriented with north to the left in order to facilitate stereo viewing. Viewing the 3-D anaglyph with red/blue glasses (with the red filter placed over the left eye and the blue filter over the right) makes it possible to see the rising smoke against the surface terrain. This technique helps to distinguish features in the atmosphere from those on the surface. In addition to the smoke, several high, thin cirrus clouds (barely visible in the nadir view) are readily observed using the stereo image.

    The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbit 17489. The panels cover an area of about 187 kilometers x 123 kilometers, and use data from blocks 63 to 65 within World Reference System-2 path 168.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory,Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight

  9. Kuwaiti oil fires: Composition of source smoke

    SciTech Connect

    Cofer, W.R. III; Cahoon, D.R.; Stevens, R.K.; Pinto, J.P.; Winstead, E.L.; Sebacher, D.I.; Abdulraheem, M.Y.; Al-Sahafi, M.; Mazurek, M.A.; Rasmussen, R.A.

    1992-09-20

    While the Kuwaiti oil-fire smoke plumes manifested a pronounced impact on solar radiation in the Gulf region (visibility, surface temperatures, etc.), smoke plume concentrations of combustion-generated pollutants suggest that the overall chemical impact on the atmosphere of the smoke from these fires was probably much less than anticipated. Combustion in the Kuwaiti oil fires was surprisingly efficient, releasing on average more than 93% of the combusted hydrocarbon fuels as carbon dioxide (CO{sub 2}). Correspondingly, combustion-produced quantities of carbon monoxide (CO) and carbonaceous particles were low, each {approximately} 2% by weight. The fraction of methane (CH{sub 4}) produced by the fires was also relatively low ({approximately} 0.2%), but source emissions of nonmethane hydrocarbons were high ({approximately} 2%). Processes other than combustion (e.g., volatilization) probably contributed significantly to the measured in-plume hydrocarbon concentrations. Substantially, different elemental to organic carbon ratios were obtained for aerosol particles from several different types of fires/smokes. Sulfur emissions (particulate and gaseous) measured at the source fires were lower ({approximately} 0.5%) than predicted based on average sulfur contents in the crude. Sulfur dioxide measurements (SO{sub 2}) reported herein, however, were both limited in actual number and in the number of well fires sampled. Nitrous oxide (N{sub 2}O) emissions from the Kuwaiti oil fires were very low and often could not be distinguished from background concentrations. About 25-30% of the fires produced white smoke plumes that were found to be highly enriched in sodium and calcium chlorides. 18 refs., 1 fig., 4 tabs.

  10. Kuwait oil fires - Compositions of source smoke

    NASA Technical Reports Server (NTRS)

    Cofer, Wesley R., III; Stevens, Robert K.; Winstead, Edward L.; Pinto, Joseph P.; Sebacher, Daniel I.; Abdulraheem, Mahmood Y.; Al-Sahafi, Mohammed; Mazurek, Monica A.; Rasmussen, Rei A.; Cahoon, Donald R.

    1992-01-01

    While the Kuwait oil-fire smoke plumes manifested a pronounced impact on solar radiation in the Gulf region (such as visibility and surface temperatures), smoke plume concentrations of combustion-generated pollutants suggest that the overall chemical impact on the atmosphere of the smoke from these fires was probably much less than anticipated. Combustion in the Kuwaiti oil fires was surprisingly efficient, releasing on average more than 93 percent of the combusted hydrocarbon fuels as CO2. Correspondingly, combustion-produced quantities of carbon monoxide (CO) and carbonaceous particles were low, each about 2 percent by weight. The fraction of CH4 produced by the fires was also relatively low (about 0.2 percent), but source emissions of nonmethane hydrocarbons were high (about 2 percent). Processes other than combustion (e.g., volatilization) probably contributed significantly to the measured in-plume hydrocarbon concentrations. Sulfur emissions (particulate and gaseous) measured at the source fires were lower (about 0.5 percent) than predicted based on average sulfur contents in the crude. N2O emissions from the Kuwaiti oil fires were very low and often could not be distinguished from background concentrations.

  11. Residential oil burners with low input and two stages firing

    SciTech Connect

    Butcher, T.; Krajewski, R.; Leigh, R.

    1997-12-31

    The residential oil burner market is currently dominated by the pressure-atomized, retention head burner. At low firing rates pressure atomizing nozzles suffer rapid fouling of the small internal passages, leading to bad spray patterns and poor combustion performance. To overcome the low input limitations of conventional burners, a low pressure air-atomized burner has been developed watch can operate at fining rates as low as 0.25 gallons of oil per hour (10 kW). In addition, the burner can be operated in a high/low fining rate mode. Field tests with this burner have been conducted at a fixed input rate of 0.35 gph (14 kW) with a side-wall vented boiler/water storage tank combination. At the test home, instrumentation was installed to measure fuel and energy flows and record trends in system temperatures. Laboratory efficiency testing with water heaters and boilers has been completed using standard single purpose and combined appliance test procedures. The tests quantify benefits due to low firing rates and other burner features. A two stage oil burner gains a strong advantage in rated efficiency while maintaining capacity for high domestic hot water and space heating loads.

  12. Civilian residential fire fatality rates: Six high-rate states versus six low-rate states

    NASA Astrophysics Data System (ADS)

    Hall, J. R., Jr.; Helzer, S. G.

    1983-08-01

    Results of an analysis of 1,600 fire fatalities occurring in six states with high fire-death rates and six states with low fire-death rates are presented. Reasons for the differences in rates are explored, with special attention to victim age, sex, race, and condition at time of ignition. Fire cause patterns are touched on only lightly but are addressed more extensively in the companion piece to this report, "Rural and Non-Rural Civilian Residential Fire Fatalities in Twelve States', NBSIR 82-2519.

  13. Practical aspects of analyzing vegetable oils in fire debris.

    PubMed

    Schwenk, Lisa M; Reardon, Michelle R

    2009-07-01

    Vegetable oils undergo burning, self-heating, and spontaneous ignition, resulting in their presence in fire debris. As these processes can affect the fatty acid content of vegetable oils, it is important that debris be properly handled in order to obtain reliable and informative data. This research investigated changes in vegetable oil content as a result of storage conditions and different types of burning. Material spiked with vegetable oils and burned was stored under various long-term conditions, and debris was tested by heating overnight using passive headspace concentration. Results indicated that refrigeration is ideal for fire debris samples suspected of containing vegetable oils and that including passive headspace concentration in the analytical scheme would not affect oils. Spontaneous ignition experiments were conducted to compare the effects of various burning processes on vegetable oil content. Vegetable oils that experienced nonpiloted ignition, self-heating, and spontaneous ignition produced noticeably different chromatograms from those that underwent piloted ignition.

  14. Firing rate of noisy integrate-and-fire neurons with synaptic current dynamics

    SciTech Connect

    Andrieux, David; Monnai, Takaaki

    2009-08-15

    We derive analytical formulas for the firing rate of integrate-and-fire neurons endowed with realistic synaptic dynamics. In particular, we include the possibility of multiple synaptic inputs as well as the effect of an absolute refractory period into the description. The latter affects the firing rate through its interaction with the synaptic dynamics.

  15. Performance of electrostatic precipitators and fabric filter particulate controls on oil-fired electric utility boilers. Final report

    SciTech Connect

    McRanie, R.D.; Baker, S.S. Jr.

    1995-09-01

    Of the 189 hazardous air pollutants (HAPs) listed in Title III of the 1990 Clean Air Act Amendments, 11 are metals commonly found in particulate emissions from oil-fired boilers. In light of the potential future need for additional control of particulate emissions from oil-fired units, a white paper was prepared documenting the extent of particulate and HAPs emissions and the state-of-the-art in the use of electrostatic precipitator (ESP) and fabric filter (FF) technologies to control their emissions from oil-fired boilers. The white paper is based on EPRI research on particulate emissions from oil-fired boilers and a survey of ESP and FF manufacturers. The EPRI ESPM{trademark} performance model was used to estimate the particulate control effectiveness of oil-fired ESPs. The white paper describes the characteristics of oil ash, summarizes particulate and HAPs emission rates for oil-fired boilers, and projects the particulate and HAPs removal effectiveness for baghouses and different sized ESPs. Information on oil-fired ESP operation and maintenance requirements and overall costs is included.

  16. How to reduce your fire insurance rates

    NASA Technical Reports Server (NTRS)

    Dubain, M.

    1971-01-01

    Construction procedures and utilization of materials to reduce the cost of insuring large buildings against losses from fire are discussed. Examples of good and bad techniques in building construction and fire safety management are provided. The inadequacies of building codes and the hazards resulting from improper construction are examined.

  17. Canadian R&D on oil-fired integrated systems

    SciTech Connect

    Hayden, A.C.S.; Entchev, E.

    1995-04-01

    This presentation will describe research and development presently being conducted on oil-fired space and water heating systems at the Combustion & Carbonization Research Laboratory (CCRL) in Ottawa, Canada. It will focus on R& D activities at CCRL in support of the Canadian Oil Heat Association (COHA); in particular, progress will be reported on activities to develop suitable oil-fired integrated systems to satisfy the low energy demands of new homes and to define outstanding issues and recommend solutions relating to sidewall venting, particularly in cold climates. Additional activities to be discussed relate to the development of appropriate seasonal efficiency standards for oil-fired combustion systems, in support of Canadian federal and provincial policy initiatives. The first activity in this standards area is a determination of the most appropriate measure of seasonal efficiency of complex integrated space/water heating systems. Performance of a range of existing and prototype integrated systems will be examined and their overall performances defined, using heat loss, heat balance and combined methods, for a wide range of cyclic operations and demands. The draft standard may be either a (slight or detailed) modification of the existing ASHRAE standard, or may be a new more appropriate test and analysis procedure, for the range of present and future systems suitable for Canadian applications in both new, low energy housing and in existing housing. The second standards activity is the development of an appropriate measure for the seasonal efficiency of sidewall vented oil-fired appliances.

  18. Residential oil burners with low input and two-stage firing

    SciTech Connect

    Butcher, T.A.; Leigh, R.; Krajewski, R.; Celebi, Y.; Fisher, L.; Kamath, B.

    1997-12-31

    The residential oil burner market is currently dominated by the pressure-atomized retention head burner. At low firing rates, pressure-atomizing nozzles suffer rapid fouling of the small internal passages, leading to bad spray patterns and poor combustion performance. To overcome the low input limitations of conventional burners, a low-pressure air-atomized burner has been developed that can operate at firing rates, as low as 0.25 gallons of oil per hour (10 kW). In addition, the burner can be operated in a high/low firing rate mode. Field tests with this burner have been conducted at a fixed input rate of 0.35 gph (14 kW) with a sidewall vented boiler/water storage tank combination. At the test home, instrumentation was installed to measure fuel and energy flows and record trends in system temperatures. Laboratory efficiency testing with water heaters and boilers has been completed using standard single-purpose and combined appliance test procedures. The tests quantify benefits due to low firing rates and other burner features. A two-stage oil burner gains a strong advantage in rated efficiency while maintaining capacity for high domestic hot water and space-heating loads.

  19. Striatal firing rate reflects head movement velocity.

    PubMed

    Kim, Namsoo; Barter, Joseph W; Sukharnikova, Tatyana; Yin, Henry H

    2014-11-01

    Although the basal ganglia have long been implicated in the initiation of actions, their contribution to movement remains a matter of dispute. Using wireless multi-electrode recording and motion tracking, we examined the relationship between single-unit activity in the sensorimotor striatum and movement kinematics. We recorded single-unit activity from medium spiny projection neurons and fast-spiking interneurons while monitoring the movements of mice using motion tracking. In Experiment 1, we trained mice to generate movements reliably by water-depriving them and giving them periodic cued sucrose rewards. We found high correlations between single-unit activity and movement velocity in particular directions. This correlation was found in both putative medium spiny projection neurons and fast-spiking interneurons. In Experiment 2, to rule out the possibility that the observed correlations were due to reward expectancy, we repeated the same procedure but added trials in which sucrose delivery was replaced by an aversive air puff stimulus. The air puff generated avoidance movements that were clearly different from movements on rewarded trials, but the same neurons that showed velocity correlation on reward trials exhibited a similar correlation on air puff trials. These experiments show for the first time that the firing rate of striatal neurons reflects movement velocity for different types of movements, whether to seek rewards or to avoid harm. PMID:25209171

  20. A simple model for neural computation with firing rates and firing correlations.

    PubMed

    Maass, W

    1998-08-01

    A simple extension of standard neural network models is introduced which provides a model for neural computations that involve both firing rates and firing correlations. Such an extension appears to be useful since it has been shown that firing correlations play a significant computational role in many biological neural systems. Standard neural network models are only suitable for describing neural computations in terms of firing rates. The resulting extended neural network models are still relatively simple, so that their computational power can be analysed theoretically. We prove rigorous separation results, which show that the use of firing correlations in addition to firing rates can drastically increase the computational power of a neural network. Furthermore, one of our separation results also throws new light on a question that involves just standard neural network models: we prove that the gap between the computational power of high-order and first-order neural nets is substantially larger than shown previously.

  1. Mutagenicity in emissions from coal- and oil-fired boilers.

    PubMed Central

    Alfheim, I; Bergström, J G; Jenssen, D; Møller, M

    1983-01-01

    The mutagenicity of emission samples from three oil-fired and four coal-fired boilers have been compared by using the Salmonella/microsome assay. Very little or no mutagenic activity was observed in samples from five of these boilers. The sample from one oil-fired boiler showed mutagenic activity of about 500 revertants/MJ, and the sample from a coal-fired fluidized bed combustor had an activity of 58,000 revertants/MJ measured with strain TA 98 in the absence of metabolic activation. All samples contained substances that were cytotoxic to the test bacteria, thus making it difficult to obtain linear dose-response curves. Mutagenic activity at low levels may remain undetected due to this toxicity of the samples. Samples with mutagenic activity below the detection limit in the Salmonella test have also been tested for forward mutations at the HGPRT locus in V79 hamster cells. Weak mutagenic effects were detected in two of the samples, whereas the sample from one oil-fired boiler remained negative. In this test, as well as in the Salmonella test, a strong cytotoxic effect could be observed with all samples. PMID:6825617

  2. Forecasting method of nationak-level forest fire risk rating

    NASA Astrophysics Data System (ADS)

    Qin, Xian-lin; Zhang, Zi-hui; Li, Zeng-yuan; Yi, Hao-ruo

    2008-11-01

    The risk level of forest fire not only depends on weather, topography, human activities, socio-economic conditions, but is also closely related to the types, growth, moisture content, and quantity of forest fuel on the ground. How to timely acquire information about the growth and moisture content of forest fuel and climate for the whole country is critical to national-level forest fire risk forecasting. The development and application of remote sensing (RS), geographic information system (GIS), databases, internet, and other modern information technologies has provided important technical means for macro-regional forest fire risk forecasting. In this paper, quantified forecasting of national-level forest fire risk was studied using Fuel State Index (FSI) and Background Composite Index (BCI). The FSI was estimated using Moderate Resolution Imaging Spectroradiaometer (MODIS) data. National meteorological data and other basic data on distribution of fuel types and forest fire risk rating were standardized in ArcGIS platform to calculate BCI. The FSI and the BCI were used to calculate the Forest Fire Danger Index (FFDI), which is regarded as a quantitative indicator for national forest fire risk forecasting and forest fire risk rating, shifting from qualitative description to quantitative estimation. The major forest fires occurred in recent years were taken as examples to validate the above method, and results indicated that the method can be used for quantitative forecasting of national-level forest fire risks.

  3. Canadian R&D on oil-fired combustion systems

    SciTech Connect

    Hayden, A.C.S.; Entchev, E.

    1996-07-01

    This paper describes research and development presently being conducted on oil-fired space and tap water heating systems by the Advanced Combustion Technology Group, CCRL/ERL/CANMET, in Ottawa, Canada. The presentation will focus on R&D activities at CCRL in support of the Canadian Oil Heat Association (COHA) and of the energy policy initiatives of Natural Resources Canada. Progress will be reported on activities to develop suitable oil-fired integrated systems to satisfy the low energy demands of new homes. The utilization of fuzzy logic-based control heating systems including fan coils for a complete range of old and new North American housing will be discussed. Additional activities to be discussed in the presentation will relate to the development of appropriate seasonal efficiency standards for complex integrated space/water heating systems, as well as an evaluation of alternative sidewall venting technologies and their implications for seasonal energy efficiency.

  4. NICKEL SPECIES EMISSION INVENTORY FOR OIL-FIRED BOILERS

    SciTech Connect

    Kevin C. Galbreath; Richard L. Schulz; Donald L. Toman; Carolyn M. Nyberg

    2004-01-01

    Representative duplicate fly ash samples were obtained from the stacks of 400-MW and 385-MW utility boilers (Unit A and Unit B, respectively) using a modified U.S. Environmental Protection Agency (EPA) Method 17 sampling train assembly as they burned .0.9 and 0.3 wt% S residual oils, respectively, during routine power plant operations. Residual oil fly ash (ROFA) samples were analyzed for nickel (Ni) concentrations and speciation using inductively coupled plasma-atomic emission spectroscopy, x-ray absorption fine structure (XAFS) spectroscopy, x-ray diffraction (XRD), and a water-soluble Ni extraction method. ROFA water extraction residues were also analyzed for Ni speciation using XAFS and XRD. Total Ni concentrations in the ROFAs were similar, ranging from 1.3 to 1.5 wt%; however, stack gas Ni concentrations in the Unit A were {approx}990 {micro}g/Nm{sup 3} compared to {approx}620 {micro}g/Nm{sup 3} for Unit B because of the greater residual oil feed rates employed at Unit A to attain higher load (i.e., MW) conditions with a lower heating value oil. Ni speciation analysis results indicate that ROFAs from Unit A contain about 3 wt% NiSO{sub 4} {center_dot} xH{sub 2}O (where x is assumed to be 6 for calculation purposes) and a Ni-containing spinel compound, similar in composition to (Mg,Ni)(Al,Fe){sub 2}O{sub 4}. ROFAs from Unit B contain on average 2.0 wt% NiSO{sub 4} {center_dot} 6H{sub 2}O and 1.1 wt% NiO. XAFS and XRD analyses did not detect any nickel sulfide compounds, including nickel subsulfide (Ni{sub 3}S{sub 2}) (XAFS detection limit is 5% of the total Ni concentration). In addition, XAFS measurements indicated that inorganic sulfate and organic thiophene species account for >97% of the total sulfur in the ROFAs. The presence of NiSO{sub 4} {center_dot} xH{sub 2}O and nickel oxide compound mixtures and lack of carcinogenic Ni{sub 3}S{sub 2} or nickel sulfide compounds (e.g., NiS, NiS{sub 2}) in ROFAs stack-sampled from 400- and 385-MW boilers are contrary

  5. Flash-Fire Propensity and Heat-Release Rate Studies of Improved Fire Resistant Materials

    NASA Technical Reports Server (NTRS)

    Fewell, L. L.

    1978-01-01

    Twenty-six improved fire resistant materials were tested for flash-fire propensity and heat release rate properties. The tests were conducted to obtain a descriptive index based on the production of ignitable gases during the thermal degradation process and on the response of the materials under a specific heat load.

  6. The Kuwait oil fires as seen by Landsat

    NASA Technical Reports Server (NTRS)

    Cahalan, Robert F.

    1992-01-01

    A mosaic of two Landsat thematic mapper images acquired May 30, 1991, reveals a dark smoke plume 30-60 km wide extending hundreds of kilometers south of Kuwait City along the Persian Gulf. Smoke coming from the Raudhatain and Sabriyah oil fields blew across the Gulf of Kuwait and over Kuwait City, joined with smoke from the Greater Burgan and Minagish fields, and continued southward over smaller villages and regions of desert agriculture consisting of hundreds of axially irrigated fields in both Kuwait and Saudi Arabia. One agricultural region in Kuwait was completely obscured by the smoke. The light colored limestone gravel and sand surface was darkened by oil lakes near the wells, and by oil drizzling out of the plume downwind of the wells. Most fires produced either a light or dark plume, and the separate plumes mixed to form a combined plume much darker than the land surface, but slightly more reflective than the Gulf waters. A few of the hottest fires had no visible plume, and are presumably associated with methane combustion. The last of the Kuwait fires was reportedly extinguished in November of 1991. Continued monitoring is needed to assess the impact of emissions from both burning and nonburning oil wells on the region's climate, as well as on the agriculture, fishing, and other activities essential to life in the region.

  7. Thermal Effects by Firing Oil Shale Fuel in CFB Boilers

    NASA Astrophysics Data System (ADS)

    Neshumayev, D.; Ots, A.; Parve, T.; Pihu, T.; Plamus, K.; Prikk, A.

    It is well known that during firing of oil shale fuel the amount of heat released during its combustion per kg of fuel is significantly affected by the endothermic and exothermic processes taking place in mineral matter. These thermal effects are calcite and dolomite decomposing, marcasite FeS2 oxidising, CaO sulphation and formation of the new minerals. The given paper deals with the experimental study of the influence of these thermal effects of oil shale fuel having different heating value on total amount of heat released during combustion in calorimetric bomb, circulating fluidized bed (CFB) and pulverized-firing boiler (PFB). The large-scale (250 MWth) experiments were performed in the K11-1 CFB boiler of the Balti Power Plant. During experiments low heating value of a fuel varied within the range 8.5-11 MJ/kg. At the end some conclusions were drawn.

  8. Material and methods for oil spill control and cleanup and extinguishing petroleum fires

    SciTech Connect

    States, J. B.

    1981-02-03

    A dispersal medium is described for cleaning of oil spills and the like and extinguishing petroleum fires. Its major quantitative part consists of a household liquid detergent and also contains eucalyptus oil, bovine urine, alfalfa and vitamin b-6. Methods of oil spill clean-up and fire extinguishing are also described.

  9. Technical assessment of an oil-fired residential cogeneration system

    SciTech Connect

    McDonald, R.J.

    1993-01-01

    The definition of cogeneration, within the context of this project, is the simultaneous production of electricity and heat energy from a single machine. This report will present the results of an engineering analysis of the efficiency and energy-conservation potential associated with a unique residential oil-fired cogeneration system that provides both heat and electric power. The system operates whenever a thermostat signals a call for heat in the home, just as a conventional heating system. However, this system has the added benefit of cogenerating electricity whenever it is running to provide space heating comfort. The system is designed to burn No. 2 heating oil, which is consumed in an 11-horsepower, two cylinder, 56.75-cubic-inch, 1850-RPM diesel engine. This unit is the only pre-production prototype residential No. 2 oil-fired cogeneration system known to exist in the world. As such, it is considered a landmark development in the field of oil-heat technology.

  10. Firing rate of the noisy quadratic integrate-and-fire neuron.

    PubMed

    Brunel, Nicolas; Latham, Peter E

    2003-10-01

    We calculate the firing rate of the quadratic integrate-and-fire neuron in response to a colored noise input current. Such an input current is a good approximation to the noise due to the random bombardment of spikes, with the correlation time of the noise corresponding to the decay time of the synapses. The key parameter that determines the firing rate is the ratio of the correlation time of the colored noise, tau(s), to the neuronal time constant, tau(m). We calculate the firing rate exactly in two limits: when the ratio, tau(s)/tau(m), goes to zero (white noise) and when it goes to infinity. The correction to the short correlation time limit is O(tau(s)/tau(m)), which is qualita tively different from that of the leaky integrate-and-fire neuron, where the correction is O( radical tau(s)/tau(m)). The difference is due to the different boundary conditions of the probability density function of the membrane potential of the neuron at firing threshold. The correction to the long correlation time limit is O(tau(m)/tau(s)). By combining the short and long correlation time limits, we derive an expression that provides a good approximation to the firing rate over the whole range of tau(s)/tau(m) in the suprathreshold regime-that is, in a regime in which the average current is sufficient to make the cell fire. In the subthreshold regime, the expression breaks down somewhat when tau(s) becomes large compared to tau(m).

  11. Combustion performance of pyrolysis oil/ethanol blends in a residential-scale oil-fired boiler

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 40 kWth oil-fired commercial boiler was fueled with blends of biomass pyrolysis oil (py-oil) and ethanol to determine the feasibility of using these blends as a replacement for fuel oil in home heating applications. An optimal set of test parameters was determined for the combustion of these blend...

  12. Superclean coal-water slurry combustion testing in an oil-fired boiler

    SciTech Connect

    Miller, B.G.; Poe, R.L.; Morrison, J.L.; Xie, Jianyang; Walsh, P.M.; Schobert, H.H.; Scaroni, A.W.

    1992-05-29

    The Pennsylvania State University is conducting a superclean coal-water slurry (SCCWS) program for the United States Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of determining the capability of effectively firing SCCWS in an industrial boiler designed for oil. Penn State has entered into a cooperative agreement with DOE to determine if SCCWS (a fuel containing coal with less than 3.0 wt.% ash and 0.9 wt.% sulfur) can effectively be burned in an oil-designed industrial boiler without adverse impact on boiler rating, maintainability, reliability, and availability. The project will provide information on the design of new systems specifically configured to fire these clean coal-based fuels.

  13. Environmental effects of the Kuwaiti oil field fires

    SciTech Connect

    Hahn, J. )

    1991-09-01

    Theory suggests that the rates of smoke emission and heat generation and, consequently, the atmospheric injection height and residence time of the smoke are crucial in determining whether the environmental effects are of global or only regional importance. Confirming the results of model calculations, observations have shown that, up to now, the smoke did not rise higher than to the top of the planetary boundary layer (PBL), about 3,300 m at a maximum. The photochemistry within the smoke cloud very likely is significantly different from that of the smoke-free troposphere. Also, because there is very little precipitation in the greater Gulf region from May through October, it is difficult to predict how and where NO{sub x}, SO{sub 2}, and their oxidation products HNO{sub 3} and H{sub 2}SO{sub 4} will be deposited. Photochemical oxidation should be largely suppressed in the denser parts of the smoke cloud, so major acid deposition is likely to occur at some distance from the source area, probably as far away as 2,000 km. Results of model calculations suggest that the effect of the smoke emission in Kuwait on the Asian summer monsoon is small. In summary, one should expect severe environmental consequences of the Kuwaiti oil field fires for the territory of Kuwait and for parts of Iraq, Jordan, and Saudi Arabia. Serious effects also may be felt in Iran and the other Gulf states, and perhaps even as far away as Turkey and Afghanistan. The surface waters of the Gulf also may be severely affected by smoke deposition. Significant environmental effects on a global or even hemispheric scale, however, are not likely to occur.

  14. Burning phylogenies: fire, molecular evolutionary rates, and diversification.

    PubMed

    Verdú, Miguel; Pausas, Juli G; Segarra-Moragues, José Gabriel; Ojeda, Fernando

    2007-09-01

    Mediterranean-type ecosystems are among the most remarkable plant biodiversity "hot spots" on the earth, and fire has traditionally been invoked as one of the evolutionary forces explaining this exceptional diversity. In these ecosystems, adult plants of some species are able to survive after fire (resprouters), whereas in other species fire kills the adults and populations are only maintained by an effective post-fire recruitment (seeders). Seeders tend to have shorter generation times than resprouters, particularly under short fire return intervals, thus potentially increasing their molecular evolutionary rates and, ultimately, their diversification. We explored whether seeder lineages actually have higher rates of molecular evolution and diversification than resprouters. Molecular evolutionary rates in different DNA regions were compared in 45 phylogenetically paired congeneric taxa from fire-prone Mediterranean-type ecosystems with contrasting seeder and resprouter life histories. Differential diversification was analyzed with both topological and chronological approaches in five genera (Banksia, Daviesia, Lachnaea, Leucadendron, and Thamnochortus) from two fire-prone regions (Australia and South Africa). We found that seeders had neither higher molecular rates nor higher diversification than resprouters. Such lack of differences in molecular rates between seeders and resprouters-which did not agree with theoretical predictions-may occur if (1) the timing of the switch from seeding to resprouting (or vice versa) occurs near the branch tip, so that most of the branch length evolves under the opposite life-history form; (2) resprouters suffer more somatic mutations and therefore counterbalancing the replication-induced mutations of seeders; and (3) the rate of mutations is not related to shorter generation times because plants do not undergo determinate germ-line replication. The absence of differential diversification is to be expected if seeders and resprouters

  15. Panel sees oil hikes trailing inflation rate

    SciTech Connect

    Slaff, J.; Duffy, J.

    1983-01-24

    The oil-price declines or increases no higher than the 5.5% inflation rate projected by 73 price survey panelists reflect the oil glut and lower prices for OPEC and non-OPEC oil. Only natural-gas price forecasts show a nationwide increase as high as 20%. Competition for industrial load has softened both gas and oil prices as suppliers use discounting and other incentives to encourage sales. Electricity prices should be steady nationwide, but with a 14% increase in western states. (DCK)

  16. Coding Efficiency of Fly Motion Processing Is Set by Firing Rate, Not Firing Precision

    PubMed Central

    Spavieri, Deusdedit Lineu; Eichner, Hubert; Borst, Alexander

    2010-01-01

    To comprehend the principles underlying sensory information processing, it is important to understand how the nervous system deals with various sources of perturbation. Here, we analyze how the representation of motion information in the fly's nervous system changes with temperature and luminance. Although these two environmental variables have a considerable impact on the fly's nervous system, they do not impede the fly to behave suitably over a wide range of conditions. We recorded responses from a motion-sensitive neuron, the H1-cell, to a time-varying stimulus at many different combinations of temperature and luminance. We found that the mean firing rate, but not firing precision, changes with temperature, while both were affected by mean luminance. Because we also found that information rate and coding efficiency are mainly set by the mean firing rate, our results suggest that, in the face of environmental perturbations, the coding efficiency is improved by an increase in the mean firing rate, rather than by an increased firing precision. PMID:20661305

  17. Prevention of residential roof fires by use of a class "A" fire rated roof system.

    PubMed

    Edlich, Richard F; Winters, Kathryne L; Long, William B; Britt, L D

    2004-01-01

    Because residential roof fires remain a life-threatening danger to residential homeowners in the United States, we describe in detail a national fire prevention program for reducing residential roof fires by use of an Underwriters Laboratories Inc. (UL) and National Fire Protection Association Class A fire rated roof system. This Class A system should comply with the test requirements for fire resistance of roof coverings, as outlined in UL 790 or in ASTM International (ASTM) E-108. Both the Asphalt Roofing Manufacturer's Association (ARMA) and the National Roofing Contractors Association (NRCA) have set up guidelines for selecting a new roof for the homeowner. Class A, fiber-glass-based asphalt roofing shingles represent an overwhelming share of the United States residential roofing market, and, as such, the Class A rated roofing system remains an excellent alternative to wood shingles and shakes. Fortunately, the Class A fire rating is available for certain wood shingle products that incorporate a factory-applied, fire resistant treatment. However, in this circumstance, wood products labeled as Class B shakes or shingles must be installed over spaced or solid sheathing that have been covered either with one layer of 1/4 in. (6.4 mm) thick noncombustible roof board, or with one layer of minimum 72-lb. fiber-glass-based mineral surfaced cap sheet, or with another specialty roofing sheet to obtain the Class A fire rating. Clay, tile, slate, and metal have been assigned Class A fire ratings in the codes (but often without testing). These alternative roofing materials are often considerably more expensive. Proper application, ventilation, and insulation of roofing systems are required to prevent heat and moisture buildup in the attic, which can damage the roofing system, making it more susceptible to water leakage as well as ignition in the event of a fire. The NRCA has devised excellent recommendations for the homeowner to prequalify the contractor. In addition, a

  18. Prevention of residential roof fires by use of a class "A" fire rated roof system.

    PubMed

    Edlich, Richard F; Winters, Kathryne L; Long, William B; Britt, L D

    2004-01-01

    Because residential roof fires remain a life-threatening danger to residential homeowners in the United States, we describe in detail a national fire prevention program for reducing residential roof fires by use of an Underwriters Laboratories Inc. (UL) and National Fire Protection Association Class A fire rated roof system. This Class A system should comply with the test requirements for fire resistance of roof coverings, as outlined in UL 790 or in ASTM International (ASTM) E-108. Both the Asphalt Roofing Manufacturer's Association (ARMA) and the National Roofing Contractors Association (NRCA) have set up guidelines for selecting a new roof for the homeowner. Class A, fiber-glass-based asphalt roofing shingles represent an overwhelming share of the United States residential roofing market, and, as such, the Class A rated roofing system remains an excellent alternative to wood shingles and shakes. Fortunately, the Class A fire rating is available for certain wood shingle products that incorporate a factory-applied, fire resistant treatment. However, in this circumstance, wood products labeled as Class B shakes or shingles must be installed over spaced or solid sheathing that have been covered either with one layer of 1/4 in. (6.4 mm) thick noncombustible roof board, or with one layer of minimum 72-lb. fiber-glass-based mineral surfaced cap sheet, or with another specialty roofing sheet to obtain the Class A fire rating. Clay, tile, slate, and metal have been assigned Class A fire ratings in the codes (but often without testing). These alternative roofing materials are often considerably more expensive. Proper application, ventilation, and insulation of roofing systems are required to prevent heat and moisture buildup in the attic, which can damage the roofing system, making it more susceptible to water leakage as well as ignition in the event of a fire. The NRCA has devised excellent recommendations for the homeowner to prequalify the contractor. In addition, a

  19. Satellite observations of smoke from oil fires in kuwait.

    PubMed

    Limaye, S S; Suomi, V E; Velden, C; Tripoli, G

    1991-06-14

    Extensive dark smoke clouds associated with burning oil wells in Kuwait have been seen in data from weather satellites since early February 1991. The smoke is dispersed over a wide area. Variable and strong low level winds have held most of the smoke plume below 3 to 5 kilometers within a few hundred kilometers of the source. Thin veils of smoke have been detected in METEOSAT data as far away as 2000 kilometers east of Kuwait, over southwestern Pakistan at heights between 6 and 7 kilometers. The occasional presence of convective clouds over the fires indicates that some scavenging of the smoke is taking place.

  20. Performance control strategies for oil-fired residential heating systems

    SciTech Connect

    Butcher, T.

    1990-07-01

    Results are reported of a study of control system options which can be used to improve the combustion performance of residential, oil-fired heating equipment. Two basic control modes were considered in this program. The first is service required'' signals in which an indication is provided when the flame quality or heat exchanger cleanliness have degraded to the point that a service call is required. The second control mode is excess-air trim'' in which the burner would essentially tune itself continuously for maximum efficiency. 35 refs., 67 figs., 2 tabs.

  1. 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.

  2. Superclean coal-water slurry combustion testing in an oil-fired boiler

    SciTech Connect

    Miller, B.G.; Pisupati, S.V.; Poe, R.L.; Morrison, J.L.; Xie, J.; Walsh, P.M.; Wincek, R.T.; Clark, D.A.; Scaroni, A.W.

    1993-04-21

    The Pennsylvania State University is conducting a superclean coal-water slurry (SCCWS) program for the United States Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of determining the capability of effectively firing SCCWS in an industrial boiler designed for heavy fuel oil. Penn State has entered into a cooperative agreement with DOE to determine if SCCWS (a fuel containing coal with 3.0 wt.% ash and 0.9 wt.% sulfur) can effectively be burned in a heavy fuel oil-designed industrial boiler without adverse impact on boiler rating, maintainability, reliability, and availability. The project will provide information on the design of new systems specifically configured to fire these clean coal-based fuels. The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) program expansion (additional 1,000 hours of testing). The boiler testing wig determine if the SCCWS combustion characteristics, heat release rate, fouling and slagging behavior, corrosion and erosion limits, and fuel transport, storage, and handling characteristics can be accommodated in an oil-designed boiler system. In addition, the proof-of-concept demonstration will generate data to determine how the properties of SCCWS and its parent coal affect boiler performance. Economic factors associated with retrofitting boilers will be identified

  3. Detection rates of the MODIS active fire product in the United States

    USGS Publications Warehouse

    Hawbaker, T.J.; Radeloff, V.C.; Syphard, A.D.; Zhu, Z.; Stewart, S.I.

    2008-01-01

    MODIS active fire data offer new information about global fire patterns. However, uncertainties in detection rates can render satellite-derived fire statistics difficult to interpret. We evaluated the MODIS 1??km daily active fire product to quantify detection rates for both Terra and Aqua MODIS sensors, examined how cloud cover and fire size affected detection rates, and estimated how detection rates varied across the United States. MODIS active fire detections were compared to 361 reference fires (??? 18??ha) that had been delineated using pre- and post-fire Landsat imagery. Reference fires were considered detected if at least one MODIS active fire pixel occurred within 1??km of the edge of the fire. When active fire data from both Aqua and Terra were combined, 82% of all reference fires were found, but detection rates were less for Aqua and Terra individually (73% and 66% respectively). Fires not detected generally had more cloudy days, but not when the Aqua data were considered exclusively. MODIS detection rates decreased with fire size, and the size at which 50% of all fires were detected was 105??ha when combining Aqua and Terra (195??ha for Aqua and 334??ha for Terra alone). Across the United States, detection rates were greatest in the West, lower in the Great Plains, and lowest in the East. The MODIS active fire product captures large fires in the U.S. well, but may under-represent fires in areas with frequent cloud cover or rapidly burning, small, and low-intensity fires. We recommend that users of the MODIS active fire data perform individual validations to ensure that all relevant fires are included. ?? 2008 Elsevier Inc. All rights reserved.

  4. Comparison of hypothetical LNG and fuel oil fires on water.

    PubMed

    Lehr, William; Simecek-Beatty, Debra

    2004-02-27

    Large spills of refined petroleum products have been an occasional occurrence over the past few decades. This has not been true for large spills of liquefied natural gas (LNG). This paper compares the likely similarities and differences between accidental releases from a ship of sizable quantities of these different hydrocarbon fuels, their subsequent spreading, and possible pool-fire behavior. Quantitative estimates are made of the spread rate and maximum slick size, burn rate, and duration; effective thermal radiation; and subsequent soot generation. PMID:15036638

  5. The Kuwait Oil Fire Health Risk Assessment Biological Surveillance Initiative.

    PubMed

    Deeter, David P

    2011-07-01

    An important environmental concern during the first Gulf War (Operation Desert Storm) was assessing exposures and potential health effects in U.S. forces exposed to the Kuwait oil fires. With only 3 weeks for planning, a Biological Surveillance Initiative (BSI) was developed and implemented for a U.S. Army unit. The BSI included blood and urine collections, questionnaire administration, and other elements during the predeployment, deployment, and post-deployment phases. Many BSI objectives were accomplished. Difficulties encountered included planning failures, loss of data and information, and difficulty in interpreting laboratory results. In order for biological surveillance initiatives to provide useful information for future deployments where environmental exposures may be a concern, meaningful, detailed, and realistic planning and preparation must occur long before the deployment is initiated. PMID:21916331

  6. Oil glut forcing NE gas rate cuts

    SciTech Connect

    Cohn, L.

    1982-03-15

    Industrial users with dual-fuel capability may soon find natural gas cheaper as gas utilities try to adjust their rates in anticipation of cuts in surplus No. 6 oil. The price advantage of gas over oil has dropped from about $3 per million Btu to about $1 per million Btu on a national average, and the gap has closed in some areas of New England. Natural-gas utilities are applying to state regulators for rate relief in order to remain competitive. Gas companies already offer interruptible rates to customers who agree to switch to their alternative fuel upon request. They are now looking to year-long contract with limited interruption and other rate schemes. A table presents DOE industrial price projections by region for six fuels for 1979, 1985, 1990, and 1995. (DCK)

  7. Space View of the 1991 Gulf War Kuwaiti Oil Fires

    NASA Astrophysics Data System (ADS)

    Torres, O.; Bhartia, P. K.; Larko, D.

    2014-12-01

    During the 1991 Persian Gulf War, over 700 oil wells in Kuwait were set ablaze by the withdrawing Iraqi army with the apparent intent of hindering satellite reconnaissance and intelligence gathering activities by the coalition of forces repelling Iraq from occupied Kuwait. The oil fires that burned for an estimated 10 months, created a huge smoke plume whose spatial extent went at times beyond the Persian Gulf region, mobilized across the Saharan Desert reaching as far west as the North Atlantic Ocean. The Nimbus-7 TOMS Total Ozone Mapping Spectrometer, in operation from October 1978 to May 1993, measured the near UV radiances that in the mid-1990's became the input in the calculation of the well know Absorbing Aerosol Index that represented a major breakthrough in satellite-based aerosol remote sensing. Thus, unknowingly to the world, the N7-TOMS sensor was collecting in 1991 an unprecedented daily record of what can be considered the worst environmental catastrophe affecting the atmosphere since the beginning of the era of space-based remote sensing in the 1970's. An overview of the temporal and spatial extent of the synoptic scale 1991 Gulf War smoke plume as seen by the Nimbus-7 TOMS Absorbing Aerosol Index will be presented.

  8. Effects of fire intensity on vital rates of an endemic herb of the Florida keys, USA

    USGS Publications Warehouse

    Liu, H.; Menges, E.S.; Snyder, J.R.; Koptur, S.; Ross, M.S.

    2005-01-01

    Fire intensity is one of the important components of a fire regime. However, relatively few studies have linked fire intensity with post-fire population vital rates. In this study, we explored the effects of fire intensity on population vital rates of Chamaecrista keyensis Pennell (Fabaceae) up to two years post-fire. C. keyensis is an endemic understory plant of pine rockland, a fire-dependent ecosystem of the Lower Florida Keys. We measured one fire intensity indicator, fire temperature reached by steel plates on the ground, during three prescribed fires at different sites. We followed marked individuals up to two years post-fire to derive annual survival, annual growth rate, percentage of fruiting plants, mean number of fruits per reproductive plant, and number of seedlings per census plot (1 m2) of C. keyensis. We found fire intensity had significant effects on reproduction in the first year post-fire only. More specifically, mean number of fruits and percentage of fruiting plants increased as fire intensity increased. Results from this study suggest that extremely low fire intensity caused by very short fire return intervals (e.g., less than three years) may not provide sufficient stimulation to reproduction to achieve the best post-fire recovery for C. keyensis.

  9. DEVELOPMENT OF FINE PARTICULATE EMISSION FACTORS AND SPECIATION PROFILES FOR OIL AND GAS FIRED COMBUSTION SYSTEMS

    SciTech Connect

    Glenn England; Oliver Chang; Stephanie Wien

    2002-02-14

    This report provides results from the second year of this three-year project to develop dilution measurement technology for characterizing PM2.5 (particles with aerodynamic diameter smaller than 2.5 micrometers) and precursor emissions from stationary combustion sources used in oil, gas and power generation operation. Detailed emission rate and chemical speciation tests results for a gas turbine, a process heater, and a commercial oil/gas fired boiler are presented. Tests were performed using a research dilution sampling apparatus and traditional EPA methods. A series of pilot tests were conducted to identify the constraints to reduce the size of current research dilution sampler for future stack emission tests. Based on the test results, a bench prototype compact dilution sampler developed and characterized in GE EER in August 2002.

  10. Economic considerations in coverting from oil/gas firing to coal

    NASA Technical Reports Server (NTRS)

    Rau, J. G.

    1978-01-01

    Economic considerations involved in fuel conversion such as from oil and/or gas firing to coal are discussed including investments costs for new facilities and equipment (including air pollution control equipment), operation and maintenance costs, and purchased fuel costs. An analytical approach to assessing the cost effectiveness of fuel conversion in terms of the annual net cost of conversion, the equivalent annual number of barrels of oil saved, and the integral rate of return of the conversion investment is presented. Illustrative numerical examples are presented for typical utility boilers and industrial boiler facilities. A further consideration addressed deals with the impacts of these costs on the overall financial structure of the firm and the ability of the firm to raise the necessary investment captial.

  11. Invariance of Firing Rate and Field Potential Dynamics to Stimulus Modulation Rate in Human Auditory Cortex

    PubMed Central

    Mukamel, Roy; Nir, Yuval; Harel, Michal; Arieli, Amos; Malach, Rafael; Fried, Itzhak

    2011-01-01

    The effect of stimulus modulation rate on the underlying neural activity in human auditory cortex is not clear. Human studies (using both invasive and noninvasive techniques) have demonstrated that at the population level, auditory cortex follows stimulus envelope. Here we examined the effect of stimulus modulation rate by using a rare opportunity to record both spiking activity and local field potentials (LFP) in auditory cortex of patients during repeated presentations of an audio-visual movie clip presented at normal, double, and quadruple speeds. Mean firing rate during evoked activity remained the same across speeds and the temporal response profile of firing rate modulations at increased stimulus speeds was a linearly scaled version of the response during slower speeds. Additionally, stimulus induced power modulation of local field potentials in the high gamma band (64–128 Hz) exhibited similar temporal scaling as the neuronal firing rate modulations. Our data confirm and extend previous studies in humans and anesthetized animals, supporting a model in which both firing rate, and high-gamma LFP power modulations in auditory cortex follow the temporal envelope of the stimulus across different modulation rates. PMID:20665720

  12. Fire hose gripping device and process for fighting fires in oil refineries and the like

    SciTech Connect

    Lancaster, D.R.; Everding, R.J.

    1989-08-15

    This patent describes a firefighting process. It comprises the steps of: attaching one end of a fire hose to a fire hydrant when the end of the fire hose is in a generally collapsed flattened position; uncoiling the fire hose; attaching a manually grippable spray nozzle to the other end of the fire hose; inflating and substantially filling the fire hose with water from the water supply means to expand the hose to a semirigid expanded position; grasping, lifting, and carrying the filled fire hose with one hand; gripping a vertical elastomeric handle of a hose clamp with the other hand. The hose clamp having a generally U-shaped hose-engaging member. The U-shaped hose-engaging member having an open end defining an access opening for receiving the hose. The access opening being larger than the maximum diameter and transverse span of the uncoiled filled fire hose: inserting the hose-engaging member on the fire hose such that there is sufficient clearance between the hose-engaging member and the fire hose to side hose clamp to another position; moving the hose clamp at an acute angle of inclination relative to the hose to detachable secure and inter-lockingly engage the hose-engaging member to the filled fire hose; manually lifting the vertical elastomeric handle of the hose clamp to elevate the fire hose; pointing the nozzle towards the fire; and spraying water from the nozzle on the fire.

  13. Radiatively driven dynamics of the plume from 1991 Kuwait oil fires

    NASA Astrophysics Data System (ADS)

    Herring, John A.; Hobbs, Peter V.

    1994-09-01

    Optical properties of the aerosol from the 1991 Kuwait oil fires are calculated using measured aerosol size distributions and a spectral refractive index based on the measured chemical composition of the particulate matter. At a wavelength of 538 nm the calculated light-scattering coefficient agrees well with measurements, but the calculated single-scattering albedo is systematically higher by about 18% than the measured value. Radiative transfer calculations indicate maximum net daytime heating rates of 94 and 56 K d-1 for smoke 1 and 3 hours downwind of the fires, respectively. In the upper regions of the plume, where the calculated heating rates decrease with height, a radiauve-convective mixed layer developed. There was no significant temperature inversion at the top of this layer, which allowed rapid entrainment of air into the top of the plume, causing it to thicken at an observed rate of ˜0.1 m s-1. In addition, radiative heating of the plume as a whole caused it to lift as a unit at a measured rate of ˜0.1 m s-1 during the first few hours of plume evolution. A theory, based on mixed layer modeling and a scale analysis of the equations of motion, is presented that successfully reproduces the two rates of vertical transport. This model of the dynamics of a radiatively heated plume can be used to predict the evolution and lofting of large composite smoke plumes, such as those from forest fires; it also has implications for the transport, lifetime, and climatic importance of smoke generated on continental scales.

  14. Separating Spike Count Correlation from Firing Rate Correlation.

    PubMed

    Vinci, Giuseppe; Ventura, Valérie; Smith, Matthew A; Kass, Robert E

    2016-05-01

    Populations of cortical neurons exhibit shared fluctuations in spiking activity over time. When measured for a pair of neurons over multiple repetitions of an identical stimulus, this phenomenon emerges as correlated trial-to-trial response variability via spike count correlation (SCC). However, spike counts can be viewed as noisy versions of firing rates, which can vary from trial to trial. From this perspective, the SCC for a pair of neurons becomes a noisy version of the corresponding firing rate correlation (FRC). Furthermore, the magnitude of the SCC is generally smaller than that of the FRC and is likely to be less sensitive to experimental manipulation. We provide statistical methods for disambiguating time-averaged drive from within-trial noise, thereby separating FRC from SCC. We study these methods to document their reliability, and we apply them to neurons recorded in vivo from area V4 in an alert animal. We show how the various effects we describe are reflected in the data: within-trial effects are largely negligible, while attenuation due to trial-to-trial variation dominates and frequently produces comparisons in SCC that, because of noise, do not accurately reflect those based on the underlying FRC.

  15. Fire emissions and regional air quality impacts from fires in oil palm, timber, and logging concessions in Indonesia

    NASA Astrophysics Data System (ADS)

    Marlier, Miriam E.; DeFries, Ruth S.; Kim, Patrick S.; Koplitz, Shannon N.; Jacob, Daniel J.; Mickley, Loretta J.; Myers, Samuel S.

    2015-08-01

    Fires associated with agricultural and plantation development in Indonesia impact ecosystem services and release emissions into the atmosphere that degrade regional air quality and contribute to greenhouse gas concentrations. In this study, we estimate the relative contributions of the oil palm, timber (for wood pulp and paper), and logging industries in Sumatra and Kalimantan to land cover change, fire activity, and regional population exposure to smoke concentrations. Concessions for these three industries cover 21% and 49% of the land area in Sumatra and Kalimantan respectively, with the highest overall area in lowlands on mineral soils instead of more carbon-rich peatlands. In 2012, most remaining forest area was located in logging concessions for both islands, and for all combined concessions, there was higher remaining lowland and peatland forest area in Kalimantan (45% and 46%, respectively) versus Sumatra (20% and 27%, respectively). Emissions from all combined concessions comprised 41% of total fire emissions (within and outside of concession boundaries) in Sumatra and 27% in Kalimantan for the 2006 burning season, which had high fire activity relative to decadal emissions. Most fire emissions were observed in concessions located on peatlands and non-forested lowlands, the latter of which could include concessions that are currently under production, cleared in preparation for production, or abandoned lands. For the 2006 burning season, timber concessions from Sumatra (47% of area and 88% of emissions) and oil palm concessions from Kalimantan (33% of area and 67% of emissions) contributed the most to concession-related fire emissions from each island. Although fire emissions from concessions were higher in Kalimantan, emissions from Sumatra contributed 63% of concession-related smoke concentrations for the population-weighted region because fire sources were located closer to population centers. In order to protect regional public health, our results

  16. Portable sprinkler and process for fighting fires in oil refineries and the like

    SciTech Connect

    Owens, D.W.; Propp, J.E.

    1989-06-06

    This patent describes a process for fighting fires in oil refineries, petrochemical plants, and the like, comprising the steps of: attaching a hose to a sprinkler; coiling the hose about the sprinkler; attaching the other end of the hose to a water supply source; rolling the coiled hose toward a fire while concurrently filling the hose with water from the water supply source to uncoil the hose and remotely move the sprinkler attached to the hose near a fire; and spraying a mist of water from the sprinkler onto the fire.

  17. Reductions of NO{sub x} emissions on oil and gas firing at Bowline Unit 1

    SciTech Connect

    Paschedag, A.E.; Martinsen, R.A.; O`Sullivan, R.C.; Schmidt, D.W.

    1996-01-01

    In response to the NYSDEC, Part 227 regulations for the emissions of nitrogen oxides (NO{sub x}), Orange and Rockland Utilities, Inc. (ORU) and Burns & Roe Company (BRC) evaluated the options available to reduce the NO{sub x} emissions at two oil and gas fired units at Bowline Point Generating Station. Replacement of all of the existing burners with new low NO{sub x} burners and possibly overfire air ports presents the most costly method of achieving this goal. Therefore, other methods of NO{sub x} reduction were considered including utilizing some form of off-stoichiometric, burners out of service (BOOS), firing. It was determined that the stringent emission limits could be met utilizing off-stoichiometric firing techniques. New oil gun atomizer tips allowing off-stoichiometric firing with mechanical atomization and swirlers of a new design are replacing the existing atomizers. The new hardware eliminates the problems of opacity while operating with off-stoichiometric firing.

  18. Physical and chemical characterization of residual oil-fired power plant emissions

    EPA Science Inventory

    Although the toxicity of oil combustion emissions is a significant public health concern, few studies characterize the emissions from plant-scale utility boilers firing residual oil. This study remedies that deficiency by sampling and monitoring stack emissions from a 432 Giga Jo...

  19. Bioremediation of oil-contaminated soil -- A rate model

    SciTech Connect

    Li, K.Y.; Zhang, Y.; Xu, T.

    1995-12-31

    Three rate equations, a modified Monod equation and two mass transfer rate equations, were used to calculate the biodegradation rate, oxygen transfer rate and oil transfer rate during a bioremediation process of oil-contaminated soil. Based on experimental rate constants, these three rates were calculated and compared. It was found the bioremediation rate of oil-contaminated soil could be controlled by the mass transfer process of oil into aqueous solution (0.12 mg BOD/(1-h)). When the oil transfer rate is enhanced by at least 10 times, the oxygen transfer process (0.1--1.0 mg BOD/(1-h)) becomes the rate-controlling step. For most of the cases, the biodegradation of oil in aqueous solution is not the limiting step unless the microbial population in the aqueous solution is less than 100 mg VSS/1.

  20. Fall rates of prescribed fire-killed ponderosa pine. Forest Service research paper

    SciTech Connect

    Harrington, M.G.

    1996-05-01

    Fall rates of prescribed fire-killed ponderosa pine were evaluated relative to tree and fire damage characteristics. High crown scorch and short survival time after fire injury were factors leading to a high probability of early tree fall. The role of chemical defense mechanisms is discussed. Results apply to prescribed-fire injured, second-growth ponderosa pine less than 16 inches diameter at breast height.

  1. Measurement of polynuclear aromatic hydrocarbon concentrations in the plume of Kuwait oil well fires

    SciTech Connect

    Olsen, K.B.; Wright, C.W.; Veverka, C.; Ball, J.C.; Stevens, R.

    1995-03-01

    Following their retreat from Kuwait during February and March of 1991, the Iraqi Army set fire to over 500 oil wells dispersed throughout the Kuwait oil fields. During the period of sampling from July to August 1991, it was estimated that between 3.29 {times} 10{sup 6} barrels per day of crude oil were combusted. The resulting fires produced several plumes of black and white smoke that coalesced to form a composite ``super`` plume. Because these fires were uncontrolled, significant quantities of organic materials were dispersed into the atmosphere and drifted throughout the Middle East. The organic particulants associated with the plume of the oil well fires had a potential to be rich in polynuclear aromatic hydrocarbon (PAH) compounds. Based on the extreme mutagenic and carcinogenic activities of PAHs found in laboratory testing, a serious health threat to the population of that region potentially existed. Furthermore, the Kuwait oil fire plumes represented a unique opportunity to study the atmospheric chemistry associated with PAHs in the plume. If samples were collected near the plume source and from the plume many kilometers downwind from the source, comparisons could be made to better understand atmospheric reactions associated with particle-bound and gas-phase PAHs. To help answer health-related concerns and to better understand the fate and transport of PAHs in an atmospheric environment, a sampling and analysis program was developed.

  2. A Complex-Valued Firing-Rate Model That Approximates the Dynamics of Spiking Networks

    PubMed Central

    Schaffer, Evan S.; Ostojic, Srdjan; Abbott, L. F.

    2013-01-01

    Firing-rate models provide an attractive approach for studying large neural networks because they can be simulated rapidly and are amenable to mathematical analysis. Traditional firing-rate models assume a simple form in which the dynamics are governed by a single time constant. These models fail to replicate certain dynamic features of populations of spiking neurons, especially those involving synchronization. We present a complex-valued firing-rate model derived from an eigenfunction expansion of the Fokker-Planck equation and apply it to the linear, quadratic and exponential integrate-and-fire models. Despite being almost as simple as a traditional firing-rate description, this model can reproduce firing-rate dynamics due to partial synchronization of the action potentials in a spiking model, and it successfully predicts the transition to spike synchronization in networks of coupled excitatory and inhibitory neurons. PMID:24204236

  3. Feasibility of burning refuse derived fuel in institutional size oil-fired boilers. Final report

    SciTech Connect

    1980-10-01

    This study investigates the feasibility of retrofitting existing oil-fired boilers of institutional size, approximately 3.63 to 36.3 Mg steam/h (8000 to 80,000 lbs steam/h) for co-firing with refuse-derived fuel (RDF). Relevant quantities describing mixtures of oil and RDF and combustion products for various levels of excess air are computed. Savings to be realized from the use of RDF are derived under several assumptions and allowable costs for a retrofit are estimated. An extensive survey of manufacturers of burners, boilers, and combustion systems showed that no hardware or proven design is yet available for such retrofit. Approaches with significant promises are outlined: the slagging burner, and a dry ash double vortex burner for low heat input from RDF. These two systems, and an evaluation of a small separate RDF dedicated combustor in support of the oil-fired boiler, are recommended as topics for future study.

  4. Reduction of NOx emissions on oil firing at Bowline Point Unit No. 2

    SciTech Connect

    Conti, A.V.; Lucente, J.; O`Sullivan, R.C.; Schmidt, D.W.

    1995-12-31

    Improved combustion technology, based upon optimization of oil atomizer and flame stabilizer design, has been retrofitted to oil and oil/gas fired boilers to reduce NOx emissions, particulate matter emissions, opacity, and to provide operational and performance benefits. This technology, known as REACH, can be applied to wall and tangential-fired boilers at a fraction of the cost of installing new burners. The technology is also compatible with conventional NOx controls such as overfire air, flue gas recirculation, low-NOx burners, and can be combined with these controls to further reduce NOx Emissions. This paper describes the results achieved when this technology was applied to Orange and Rockland Utilities` Bowline Point Unit No. 2 to meet NYSDEC part 227 regulations for the emissions of nitrogen oxides (0.25 lbs/MBtu). Bowline Point No. 2 is a 600 MW opposed-wall fired boiler with overfire air and flue gas recirculation capability.

  5. A feasibility study of oil shale fired pulse combustors with applications to oil shale retorting

    SciTech Connect

    Morris, G.J.; Johnson, E.K.; Zhang, G.Q.; Roach, R.A.

    1992-07-01

    The results of the experimental investigation performed to determine the feasibility of using pulverized Colorado oil shale to fuel a bench scale pulse combustor reveal that oil shale cannot sustain pulsations when used alone as fuel. Trace amounts of propane mixed with the oil shale enabled the pulsations, however. Up to 80% of the organic material in the oil shale was consumed when it was mixed with propane in the combustor. Beyond the feasibility objectives, the operating conditions of the combustor fuel with propane and mixtures of oil shale and propane were characterized with respect to pulsation amplitude and frequency and the internal combustor wall temperature over fuel lean and fuel rich stoichiometries. Maximum pressure excursions of 12.5 kPa were experienced in the combustor. Pulsation frequencies ranged from 50 to nearly 80 Hz. Cycle resolved laser Doppler anemometry velocities were measured at the tail pipe exit plane. Injecting inert mineral matter (limestone) into the pulse combustor while using propane fuel had only a slight effect on the pulsation frequency for the feed rates tested.

  6. 76 FR 23768 - National Emission Standards for Hazardous Air Pollutants From Coal- and Oil-Fired Electric...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-28

    ... Coal- and Oil-Fired Electric Utility Steam Generating Units and Standards of Performance for Fossil... Utility Steam Generating Units and Standards of Performance for Fossil-Fuel-Fired Electric Utility... Performance for Fossil-Fuel-Fired Electric Utility, Industrial- Commercial-Institutional, and Small...

  7. A memristive spiking neuron with firing rate coding

    PubMed Central

    Ignatov, Marina; Ziegler, Martin; Hansen, Mirko; Petraru, Adrian; Kohlstedt, Hermann

    2015-01-01

    Perception, decisions, and sensations are all encoded into trains of action potentials in the brain. The relation between stimulus strength and all-or-nothing spiking of neurons is widely believed to be the basis of this coding. This initiated the development of spiking neuron models; one of today's most powerful conceptual tool for the analysis and emulation of neural dynamics. The success of electronic circuit models and their physical realization within silicon field-effect transistor circuits lead to elegant technical approaches. Recently, the spectrum of electronic devices for neural computing has been extended by memristive devices, mainly used to emulate static synaptic functionality. Their capabilities for emulations of neural activity were recently demonstrated using a memristive neuristor circuit, while a memristive neuron circuit has so far been elusive. Here, a spiking neuron model is experimentally realized in a compact circuit comprising memristive and memcapacitive devices based on the strongly correlated electron material vanadium dioxide (VO2) and on the chemical electromigration cell Ag/TiO2−x/Al. The circuit can emulate dynamical spiking patterns in response to an external stimulus including adaptation, which is at the heart of firing rate coding as first observed by E.D. Adrian in 1926. PMID:26539074

  8. A memristive spiking neuron with firing rate coding.

    PubMed

    Ignatov, Marina; Ziegler, Martin; Hansen, Mirko; Petraru, Adrian; Kohlstedt, Hermann

    2015-01-01

    Perception, decisions, and sensations are all encoded into trains of action potentials in the brain. The relation between stimulus strength and all-or-nothing spiking of neurons is widely believed to be the basis of this coding. This initiated the development of spiking neuron models; one of today's most powerful conceptual tool for the analysis and emulation of neural dynamics. The success of electronic circuit models and their physical realization within silicon field-effect transistor circuits lead to elegant technical approaches. Recently, the spectrum of electronic devices for neural computing has been extended by memristive devices, mainly used to emulate static synaptic functionality. Their capabilities for emulations of neural activity were recently demonstrated using a memristive neuristor circuit, while a memristive neuron circuit has so far been elusive. Here, a spiking neuron model is experimentally realized in a compact circuit comprising memristive and memcapacitive devices based on the strongly correlated electron material vanadium dioxide (VO2) and on the chemical electromigration cell Ag/TiO2-x /Al. The circuit can emulate dynamical spiking patterns in response to an external stimulus including adaptation, which is at the heart of firing rate coding as first observed by E.D. Adrian in 1926. PMID:26539074

  9. 40 CFR Appendix E to Part 75 - Optional NOX Emissions Estimation Protocol for Gas-Fired Peaking Units and Oil-Fired Peaking Units

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Optional NOX Emissions Estimation... MONITORING Pt. 75, App. E Appendix E to Part 75—Optional NOX Emissions Estimation Protocol for Gas-Fired Peaking Units and Oil-Fired Peaking Units 1. Applicability 1.1 Unit Operation Requirements This...

  10. 40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units D Appendix D to Part 75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. D Appendix D to Part 75—Optional SO2 Emissions...

  11. 40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units D Appendix D to Part 75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. D Appendix D to Part 75—Optional SO2 Emissions...

  12. 40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units D Appendix D to Part 75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. D Appendix D to Part 75—Optional SO2 Emissions...

  13. 40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Peaking Units

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Peaking Units D Appendix D to Part 75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. D Appendix D to Part 75—Optional SO2...

  14. 40 CFR Appendix D to Part 75 - Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Optional SO2 Emissions Data Protocol for Gas-Fired and Oil-Fired Units D Appendix D to Part 75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. D Appendix D to Part 75—Optional SO2 Emissions...

  15. 40 CFR Appendix E to Part 75 - Optional NOX Emissions Estimation Protocol for Gas-Fired Peaking Units and Oil-Fired Peaking Units

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Optional NOX Emissions Estimation Protocol for Gas-Fired Peaking Units and Oil-Fired Peaking Units E Appendix E to Part 75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS...

  16. [Acute paraffin oil pneumopathies. Apropos of a case in a fire-eater].

    PubMed

    Dominique, S; Lerebours Pigeonnière, G; Thiberville, L; Stain, J P; Genevois, A; Nouvet, G

    1988-01-01

    A case of acute paraffin oil-induced pneumonia due to accidental inhalation by a fire-eater of kerdane, a petroleum derivative is reported. The symptoms and course of respiratory manifestations of acute paraffin oil poisoning are reviewed. The physical properties of the petroleum derivative inhaled account for the pathogenesis of the pneumonia. Pulmonary lesions, usually fully reversible, result from the joint effects of an inflammatory phase with exudate and a proliferative phase. PMID:3406615

  17. Successful transmission of Solenopsis invicta virus 3 to Solenopsis invicta fire ant colonies in oil, sugar, and cricket bait formulations.

    PubMed

    Valles, Steven M; Porter, Sanford D; Choi, Man-Yeon; Oi, David H

    2013-07-01

    Tests were conducted to evaluate whether Solenopsis invicta virus 3 (SINV-3) could be delivered in various bait formulations to fire ant colonies and measure the corresponding colony health changes associated with virus infection in Solenopsis invicta. Three bait formulations (10% sugar solution, cricket paste, and soybean oil adsorbed to defatted corn grit) effectively transmitted SINV-3 infections to S. invicta colonies. Correspondingly, viral infection was shown to be detrimental to colony health and productivity. By day 32, all ant colonies exposed to a single 24h pulse treatment of SINV-3 became infected with the virus regardless of the bait formulation. However, the SINV-3 sugar and cricket bait-treated colonies became infected more rapidly than the oil-treated colonies. Sugar and cricket-treated colonies exhibited significant declines in their brood ratings compared with the untreated control and oil bait-treated colonies. Measures of colony health and productivity evaluated at the end of the study (day 47) showed a number of differences among the bait treatments and the control group. Statistically significant and similar patterns were exhibited among treatments for the quantity of live workers (lower), live brood (lower), total colony weight (lower), worker mortality (higher), proportion larvae (lower), and queen weight (lower). Significant changes were also observed in the number of eggs laid by queens (lower) and the corresponding ovary rating in SINV-3-treated colonies. The study provides the first successful demonstration of SINV-3 as a potential biopesticide against fire ants.

  18. Fire flood method for recovering petroleum from oil reservoirs of low permeability and temperature

    DOEpatents

    Kamath, Krishna

    1984-08-14

    The present invention is directed to a method of enhanced oil recovery by fire flooding petroleum reservoirs characterized by a temperature of less than the critical temperature of carbon dioxide, a pore pressure greater than the saturated vapor pressure of carbon dioxide at said temperature (87.7.degree. F. at 1070 psia), and a permeability in the range of about 20 to 100 millidarcies. The in situ combustion of petroleum in the reservoir is provided by injecting into the reservoir a combustion supporting medium consisting essentially of oxygen, ozone, or a combination thereof. The heat of combustion and the products of this combustion which consist essentially of gaseous carbon dioxide and water vapor sufficiently decrease the viscosity of oil adjacent to fire front to form an oil bank which moves through the reservoir towards a recovery well ahead of the fire front. The gaseous carbon dioxide and the water vapor are driven into the reservoir ahead of the fire front by pressure at the injection well. As the gaseous carbon dioxide cools to less than about 88.degree. F. it is converted to liquid which is dissolved in the oil bank for further increasing the mobility thereof. By using essentially pure oxygen, ozone, or a combination thereof as the combustion supporting medium in these reservoirs the permeability requirements of the reservoirs are significantly decreased since the liquid carbon dioxide requires substantially less voidage volume than that required for gaseous combustion products.

  19. 14 CFR 125.135 - Oil lines and fittings in designated fire zones.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Oil lines and fittings in designated fire... CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Special...

  20. 14 CFR 125.135 - Oil lines and fittings in designated fire zones.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Oil lines and fittings in designated fire... CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Special...

  1. 14 CFR 125.135 - Oil lines and fittings in designated fire zones.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Oil lines and fittings in designated fire... CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Special...

  2. 14 CFR 125.135 - Oil lines and fittings in designated fire zones.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Oil lines and fittings in designated fire... CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Special...

  3. 14 CFR 125.135 - Oil lines and fittings in designated fire zones.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Oil lines and fittings in designated fire... CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD CAPACITY OF 6,000 POUNDS OR MORE; AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Special...

  4. 46 CFR 62.35-20 - Oil-fired main boilers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... Automatic feedwater control subsystems must sense, at a minimum, boiler water level and steam flow. (c... conditions; and (2) Stable boiler steam pressure and outlet temperatures under steady state and transient... 46 Shipping 2 2011-10-01 2011-10-01 false Oil-fired main boilers. 62.35-20 Section...

  5. 46 CFR 62.35-20 - Oil-fired main boilers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... Automatic feedwater control subsystems must sense, at a minimum, boiler water level and steam flow. (c... conditions; and (2) Stable boiler steam pressure and outlet temperatures under steady state and transient... 46 Shipping 2 2014-10-01 2014-10-01 false Oil-fired main boilers. 62.35-20 Section...

  6. 46 CFR 62.35-20 - Oil-fired main boilers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... Automatic feedwater control subsystems must sense, at a minimum, boiler water level and steam flow. (c... conditions; and (2) Stable boiler steam pressure and outlet temperatures under steady state and transient... 46 Shipping 2 2013-10-01 2013-10-01 false Oil-fired main boilers. 62.35-20 Section...

  7. 46 CFR 62.35-20 - Oil-fired main boilers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... Automatic feedwater control subsystems must sense, at a minimum, boiler water level and steam flow. (c... conditions; and (2) Stable boiler steam pressure and outlet temperatures under steady state and transient... 46 Shipping 2 2012-10-01 2012-10-01 false Oil-fired main boilers. 62.35-20 Section...

  8. 46 CFR 62.35-20 - Oil-fired main boilers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... Automatic feedwater control subsystems must sense, at a minimum, boiler water level and steam flow. (c... conditions; and (2) Stable boiler steam pressure and outlet temperatures under steady state and transient... 46 Shipping 2 2010-10-01 2010-10-01 false Oil-fired main boilers. 62.35-20 Section...

  9. New insights into halocarbon emissions in boreal regions: Forest fires and Alberta oil sands

    NASA Astrophysics Data System (ADS)

    Simpson, I. J.; Barletta, B.; Meinardi, S.; Marrero, J.; Rowland, F. S.; Akagi, S. K.; Yokelson, R. J.; Blake, D. R.

    2011-12-01

    Boreal forest fires and Alberta oil sands represent two major co-located trace gas emission sources within the boreal ecosystem. During the airborne ARCTAS mission in summer 2008, UC-Irvine performed the most comprehensive characterization of halocarbon emissions from boreal forest fires to date. In summer 2008 and 2010 we also performed the first independent characterizations of halocarbon emissions from Alberta's oil sands industry. In both cases the measurements were made using whole air sampling followed by gas chromatography analysis using electron capture detection and mass spectrometer detection. In the case of boreal forest fires, of 26 speciated halocarbons that were measured, only the simplest halocarbons were emitted from the fires (CH3Cl, CH3Br, CH3I, 1,2-C2H4Cl2, C2H5Cl and CH2Br2) (Simpson et al., 2011). These compounds were released in relatively small quantities and together they represented <0.3% of the total carbon released from boreal forest fires in the form of non-methane volatile organic compounds (NMVOCs). Even though CH3Cl was the most abundantly emitted halocarbon, its average global emission from boreal forest fires (0.011 ± 0.003 Tg yr-1) was very small compared to its global source budget. The poly-chlorinated compounds CH2Cl2, CHCl3 and CH3CCl3 were not released from the fires. In the case of the Alberta oil sands, based on airborne measurements during the ARCTAS mission, 15 of 26 measured halocarbons were statistically enhanced over the oil sands compared to local background values (Simpson et al., 2010). The short-lived solvents C2HCl3, C2Cl4, C2H5Cl and CHCl3 were the most strongly enhanced halocarbons, with maximum values that were 1.5-34× the local background. A subsequent ground-based study in 2010 detected even stronger halocarbon enhancements downwind of upgraders and tailings sand at the oil sands surface mining sites. For example C2HCl3 and CHBrCl2 mixing ratios were up to 60-85× the local background values. Long

  10. Neuronal Firing Rate Homeostasis Is Inhibited by Sleep and Promoted by Wake.

    PubMed

    Hengen, Keith B; Torrado Pacheco, Alejandro; McGregor, James N; Van Hooser, Stephen D; Turrigiano, Gina G

    2016-03-24

    Homeostatic mechanisms stabilize neural circuit function by keeping firing rates within a set-point range, but whether this process is gated by brain state is unknown. Here, we monitored firing rate homeostasis in individual visual cortical neurons in freely behaving rats as they cycled between sleep and wake states. When neuronal firing rates were perturbed by visual deprivation, they gradually returned to a precise, cell-autonomous set point during periods of active wake, with lengthening of the wake period enhancing firing rate rebound. Unexpectedly, this resetting of neuronal firing was suppressed during sleep. This raises the possibility that memory consolidation or other sleep-dependent processes are vulnerable to interference from homeostatic plasticity mechanisms. PAPERCLIP. PMID:26997481

  11. Neuronal Firing Rate Homeostasis Is Inhibited by Sleep and Promoted by Wake.

    PubMed

    Hengen, Keith B; Torrado Pacheco, Alejandro; McGregor, James N; Van Hooser, Stephen D; Turrigiano, Gina G

    2016-03-24

    Homeostatic mechanisms stabilize neural circuit function by keeping firing rates within a set-point range, but whether this process is gated by brain state is unknown. Here, we monitored firing rate homeostasis in individual visual cortical neurons in freely behaving rats as they cycled between sleep and wake states. When neuronal firing rates were perturbed by visual deprivation, they gradually returned to a precise, cell-autonomous set point during periods of active wake, with lengthening of the wake period enhancing firing rate rebound. Unexpectedly, this resetting of neuronal firing was suppressed during sleep. This raises the possibility that memory consolidation or other sleep-dependent processes are vulnerable to interference from homeostatic plasticity mechanisms. PAPERCLIP.

  12. A review of the analysis of vegetable oil residues from fire debris samples: spontaneous ignition, vegetable oils, and the forensic approach.

    PubMed

    Stauffer, Eric

    2005-09-01

    This paper reviews the literature on the analysis of vegetable (and animal) oil residues from fire debris samples. The process of self-heating and spontaneous ignition is well-known by fire investigators and causes many fires. Vegetable oils are often the chemicals that originate such phenomenon. Vegetable oils are composed of lipids, which contain fatty acids. The autooxidation of the double bonds present in unsaturated fatty acids is the exothermic reaction at the origin of the self-heating process. The degree of unsaturation of fatty acids directly influences the propensity of an oil to undergo self-heating and, eventually, spontaneous ignition. When fire debris samples are collected, it is possible to examine them at the laboratory to extract and identify vegetable oil residues. This is typically performed by solvent extraction, followed by gas chromatographic(-mass spectrometric) analysis of the extract. Such analyses differ from ignitable liquid residue analyses, so a different forensic approach is necessary.

  13. Alternative to heavy fuel oil firing - emulsified hydrocarbon fuel conversion considerations

    SciTech Connect

    Cirillo, A.J.; Wiggins, D.S.

    1995-12-31

    With numerous emulsified hydrocarbon fuel-based conversion projects completed in the past five years and an even greater number being considered in the near future, this bitumen-based fuel is gaining world-wide popularity. The emergence of this fuel in the international market place holds promise for restoring heavy fuel oil-based boiler units to economic service. This paper will discuss the design modifications and considerations necessary to convert heavy fuel oil fired/co-fired boiler units to emulsified hydrocarbon fuel. Included will be a discussion on the boiler, fuels handling and emission/environmental control systems. An overview of the current use/application of emulsified fuel will be provided along with a comparative listing of the emulsified hydrocarbon fuel`s chemical and physical characteristics relative to that of heavy fuel oil.

  14. Fires

    MedlinePlus

    Whether a fire happens in your home or in the wild, it can be very dangerous. Fire spreads quickly. There is no time to gather ... a phone call. In just two minutes, a fire can become life-threatening. In five minutes, a ...

  15. Burning rate of merged pool fire on the hollow square tray.

    PubMed

    Wang, Changjian; Guo, Jin; Ding, Yanming; Wen, Jennifer; Lu, Shouxiang

    2015-06-15

    In order to characterize fire merging, pool fires on hollow trays with varying side lengths were burned under quasi-quiescent condition and in a wind tunnel with the wind speed ranging from 0m/s to 7.5m/s. Burning rate and flame images were recorded in the whole combustion process. The results show that even though the pool surface area was kept identical for hollow trays of different sizes, the measured burning rates and fire evolutions were found to be significantly different. Besides the five stages identified by previous studies, an extra stage, fire merging, was observed. Fire merging appeared possibly at any of the first four stages and moreover resulted in 50-100% increases of the fire burning rates and heights in the present tests. The tests in wind tunnel suggested that, as the wind speed ranges from 0 m/s to 2 m/s, the burning rates decrease. However with further increase of the wind speed from 2 m/s to 7.5 m/s, the burning rate was found to increase for smaller hollow trays while it remains almost constant for larger hollow trays. Two empirical correlations are presented to predict critical burning rate of fire merging on the hollow tray. The predictions were found to be in reasonably good agreement with the measurements.

  16. Burning rate of merged pool fire on the hollow square tray.

    PubMed

    Wang, Changjian; Guo, Jin; Ding, Yanming; Wen, Jennifer; Lu, Shouxiang

    2015-06-15

    In order to characterize fire merging, pool fires on hollow trays with varying side lengths were burned under quasi-quiescent condition and in a wind tunnel with the wind speed ranging from 0m/s to 7.5m/s. Burning rate and flame images were recorded in the whole combustion process. The results show that even though the pool surface area was kept identical for hollow trays of different sizes, the measured burning rates and fire evolutions were found to be significantly different. Besides the five stages identified by previous studies, an extra stage, fire merging, was observed. Fire merging appeared possibly at any of the first four stages and moreover resulted in 50-100% increases of the fire burning rates and heights in the present tests. The tests in wind tunnel suggested that, as the wind speed ranges from 0 m/s to 2 m/s, the burning rates decrease. However with further increase of the wind speed from 2 m/s to 7.5 m/s, the burning rate was found to increase for smaller hollow trays while it remains almost constant for larger hollow trays. Two empirical correlations are presented to predict critical burning rate of fire merging on the hollow tray. The predictions were found to be in reasonably good agreement with the measurements. PMID:25746567

  17. Chemical and biological characterization of emissions from coal- and oil-fired power plants.

    PubMed

    Ahlberg, M; Berghem, L; Nordberg, G; Persson, S A; Rudling, L; Steen, B

    1983-01-01

    Emission samples were obtained from two medium-sized power plants, one fired with oil and the other with pulverized coal. Particles obtained by a miniscale plume stack gas sampler (MIPSGAS), simulating the dilution process in the plume, were subjected to detailed physical, chemical and biological characterization. Studies by scanning electron microscopy and by Coulter counter demonstrated that the particles from the oil-fired boiler were considerably larger than the particles from the coal-fired boiler. Chemical analyses revealed more organic substances and more S, Ni, V, in the oil than in the coal particles. The latter contained a larger proportion of Al, Si, Cl, K, Ca, Ti, Mn, Fe, Se, Rb, Y, Zr, Ba and Pb. Biological testing revealed a greater acute and subacute toxicity by the intratracheal route in the hamster, a greater toxicity to alveolar macrophages and a greater lung retention of BaP coated on the particles from oil combustion than on those from coal combustion. In another sampling line, employed simultaneously with the MIPSGAS-particulate sampler, the total emissions were collected, i.e., both particle and gas phase. These samples were used for chemical analyses and Ames mutagenicity test. Analyses of specific PAHs in emissions from both plants demonstrated that concentrations were below the detection limit (less than 4 ng/m3 of benzo(a)pyrene), which is in accord with an efficient combustion of the fuel. The mutagenicity of the samples were below the detection limit of the mutagenicity assay.

  18. The application of masonry chimney venting tables for oil-fired appliances

    SciTech Connect

    Krajewski, R.F.; Strasser, J.

    1995-04-01

    This paper presents an overview of the results of work in developing a set of rational guidelines for the venting of modern oil-fired appliances. The activities included the continued development and completion of the Oil-Heat Vent Analysis Program (OHVAP), Version 1.0 and the interpretation of nearly 2,000 runs in preparing recommendations for presentation in table form. These results are presented in the form of venting tables for the installation of chimney vent systems for mid- and high-efficiency oil-fired heating appliances using masonry chimneys. A brief description of OHVAP is given as well as a discussion of what the program does. Recommendations based on the results of OHVAP are presented in the form of five tables spanning oil-fired appliance Steady state Efficiencies (Eff{sub ss}) of 80% to 88%. The assumptions used in the calculations and examples of the computed results are presented as well as a discussion of the rationale for masonry chimney system treatment. Working examples are given with suggested diagnostic approaches for application of the table recommendations.

  19. Changes of firing rate induced by changes of phase response curve in bifurcation transitions.

    PubMed

    Sato, Yasuomi D; Aihara, Kazuyuki

    2014-11-01

    We study dynamical mechanisms responsible for changes of the firing rate during four different bifurcation transitions in the two-dimensional Hindmarsh-Rose (2DHR) neuron model: the saddle node on an invariant circle (SNIC) bifurcation to the supercritical Andronov-Hopf (AH) one, the SNIC bifurcation to the saddle-separatrix loop (SSL) one, the AH bifurcation to the subcritical AH (SAH) one, and the SSL bifurcation to the AH one. For this purpose, we study slopes of the firing rate curve with respect to not only an external input current but also temperature that can be interpreted as a timescale in the 2DHR neuron model. These slopes are mathematically formulated with phase response curves (PRCs), expanding the firing rate with perturbations of the temperature and external input current on the one-dimensional space of the phase [Formula: see text] in the 2DHR oscillator. By analyzing the two different slopes of the firing rate curve with respect to the temperature and external input current, we find that during changes of the firing rate in all of the bifurcation transitions, the calculated slope with respect to the temperature also changes. This is largely dependent on changes in the PRC size that is also related to the slope with respect to the external input current. Furthermore, we find phase transition-like switches of the firing rate with a possible increase of the temperature during the SSL-to-AH bifurcation transition.

  20. Genotoxicity to human cells induced by air particulates isolated during the Kuwait oil fires.

    PubMed

    Kelsey, K T; Xia, F; Bodell, W J; Spengler, J D; Christiani, D C; Dockery, D W; Liber, H L

    1994-01-01

    In an effort to examine the potential of exposure to soot from the 1991 oil fires in the Kuwait desert for inducing genetic effects we studied the in vitro genotoxicity of this material. Air particulates isolated near the Kuwait oil fires were studied using three assays. Dose-dependent increases were observed for both sister chromatid exchanges in human peripheral blood lymphocytes and mutation at the hprt locus in the metabolically competent human lymphoblast cell line AHH-1. Similar magnitudes of response were seen using these two assays when testing a standard air particulate sample which had been isolated from the Washington, DC, area. Using the 32P-postlabeling assay, no increase in DNA adduct formation was observed in AHH-1 cells treated with particulates isolated from sampling in Kuwait.

  1. Rare earths: atmospheric signatures for oil-fired power plants and refineries.

    PubMed

    Olmez, I; Gordon, G E

    1985-09-01

    The concentration pattern of rare earth elements on fine airborne particles (less than 2.5 micrometers in diameter) is distorted from the crustal abundance pattern in areas influenced by emissions from oil-fired plants and refineries. For example, the ratio of lanthanum to samarium is often greater than 20 compared to a crustal ratio less than 6. The unusual pattern apparently results from the distribution of rare earths in zeolite catalysts used in refining oil. Oil industry emissions perturb the rare earth pattern even at remote locations such as the Mauna Loa Observatory in Hawaii. Rare earth ratios are probably better for long-range tracing of oil emissions than vanadium and nickel concentrations because the ratios of rare earths on fine particles are probably not influenced by deposition and other fractionating processes. Emissions from oil-fired plants can be differentiated from those of refineries on an urban scale by the much smaller amounts of vanadium in the latter. PMID:17782528

  2. Oil well fires of Operation Desert Storm--defining troop exposures and determining health risks.

    PubMed

    Heller, Jack M

    2011-07-01

    During Operation Desert Storm, in February 1991, Iraqi troops began burning Kuwaiti oil wells. Almost immediately there was concern about possible adverse health effects in U.S. personnel exposed to crude oil combustion products. Combustions products were predicted from the known composition of Kuwaiti crude oil. Monitoring sites were established in Saudi Arabia and Kuwait; about 5,000 environmental samples were studied. Data collected were used to develop health risk assessments for the geographic areas sampled. This initial approach to assessing risk had to be greatly expanded when Congress passed Public Law 102-190, requiring development of means to calculate environmental exposures for individual U.S. service members. To estimate daily exposure levels for the entire area over 10 months for all U.S. troops, air dispersion modeling was used in conjunction with satellite imagery and geographic information system technology. This methodology made it possible to separate the risk caused by oil fire smoke from the total risk from all sources for each service member. The U.S. military responses to health concerns related to the oil well fires and to Public Law 102-190 were reviewed. Consideration was given to changes in technology, practices, and policies over the last two decades that might impact a similar contemporary response.

  3. Experimental evaluation of the effectiveness of water mist automated fire extinguishing systems for oil transportation

    NASA Astrophysics Data System (ADS)

    Glushkov, D. O.; Nyashina, G. S.; Strizhak, P. A.; Volkov, R. S.

    2015-11-01

    Experimental investigation of regularities of carryover of water mist droplets (radius of 50 - 500 μm) by high temperature (500 - 1800 K) products of combustion of typical petroleum products (oil, gasoline, kerosene, etc.) was carried out. The panoramic optical methods and high-speed hardware and software systems were used. Speeds of droplets after mixing with oncoming high temperature gases were determined. Conditions of continuation of droplets movement through combustion products with preservation of initial trajectory in spite of intensive evaporation and braking were found. The predictive evaluation of effectiveness of water mist use for extinguishing of fires involving oil and typical petroleum products.

  4. Enclosure fire hazard analysis using relative energy release criteria. [burning rate and combustion control

    NASA Technical Reports Server (NTRS)

    Coulbert, C. D.

    1978-01-01

    A method for predicting the probable course of fire development in an enclosure is presented. This fire modeling approach uses a graphic plot of five fire development constraints, the relative energy release criteria (RERC), to bound the heat release rates in an enclosure as a function of time. The five RERC are flame spread rate, fuel surface area, ventilation, enclosure volume, and total fuel load. They may be calculated versus time based on the specified or empirical conditions describing the specific enclosure, the fuel type and load, and the ventilation. The calculation of these five criteria, using the common basis of energy release rates versus time, provides a unifying framework for the utilization of available experimental data from all phases of fire development. The plot of these criteria reveals the probable fire development envelope and indicates which fire constraint will be controlling during a criteria time period. Examples of RERC application to fire characterization and control and to hazard analysis are presented along with recommendations for the further development of the concept.

  5. Dynamics of the instantaneous firing rate in response to changes in input statistics.

    PubMed

    Fourcaud-Trocmé, Nicolas; Brunel, Nicolas

    2005-06-01

    We review and extend recent results on the instantaneous firing rate dynamics of simplified models of spiking neurons in response to noisy current inputs. It has been shown recently that the response of the instantaneous firing rate to small amplitude oscillations in the mean inputs depends in the large frequency limit f on the spike initiation dynamics. A particular simplified model, the exponential integrate-and-fire (EIF) model, has a response that decays as 1/f in the large frequency limit and describes very well the response of conductance-based models with a Hodgkin-Huxley type fast sodium current. Here, we show that the response of the EIF instantaneous firing rate also decays as 1/f in the case of an oscillation in the variance of the inputs for both white and colored noise. We then compute the initial transient response of the firing rate of the EIF model to a step change in its mean inputs and/or in the variance of its inputs. We show that in both cases the response speed is proportional to the neuron stationary firing rate and inversely proportional to a 'spike slope factor' Delta(T) that controls the sharpness of spike initiation: as 1/Delta(T) for a step change in mean inputs, and as 1/Delta(T) (2) for a step change in the variance in the inputs.

  6. Ultra-Low Carbon Emissions from Coal-Fired Power Plants through Bio-Oil Co-Firing and Biochar Sequestration.

    PubMed

    Dang, Qi; Mba Wright, Mark; Brown, Robert C

    2015-12-15

    This study investigates a novel strategy of reducing carbon emissions from coal-fired power plants through co-firing bio-oil and sequestering biochar in agricultural lands. The heavy end fraction of bio-oil recovered from corn stover fast pyrolysis is blended and co-fired with bituminous coal to form a bio-oil co-firing fuel (BCF). Life-cycle greenhouse gas (GHG) emissions per kWh electricity produced vary from 1.02 to 0.26 kg CO2-eq among different cases, with BCF heavy end fractions ranging from 10% to 60%, which corresponds to a GHG emissions reduction of 2.9% to 74.9% compared with that from traditional bituminous coal power plants. We found a heavy end fraction between 34.8% and 37.3% is required to meet the Clean Power Plan's emission regulation for new coal-fired power plants. The minimum electricity selling prices are predicted to increase from 8.8 to 14.9 cents/kWh, with heavy end fractions ranging from 30% to 60%. A minimum carbon price of $67.4 ± 13 per metric ton of CO2-eq was estimated to make BCF power commercially viable for the base case. These results suggest that BCF co-firing is an attractive pathway for clean power generation in existing power plants with a potential for significant reductions in carbon emissions. PMID:26545153

  7. Ultra-Low Carbon Emissions from Coal-Fired Power Plants through Bio-Oil Co-Firing and Biochar Sequestration.

    PubMed

    Dang, Qi; Mba Wright, Mark; Brown, Robert C

    2015-12-15

    This study investigates a novel strategy of reducing carbon emissions from coal-fired power plants through co-firing bio-oil and sequestering biochar in agricultural lands. The heavy end fraction of bio-oil recovered from corn stover fast pyrolysis is blended and co-fired with bituminous coal to form a bio-oil co-firing fuel (BCF). Life-cycle greenhouse gas (GHG) emissions per kWh electricity produced vary from 1.02 to 0.26 kg CO2-eq among different cases, with BCF heavy end fractions ranging from 10% to 60%, which corresponds to a GHG emissions reduction of 2.9% to 74.9% compared with that from traditional bituminous coal power plants. We found a heavy end fraction between 34.8% and 37.3% is required to meet the Clean Power Plan's emission regulation for new coal-fired power plants. The minimum electricity selling prices are predicted to increase from 8.8 to 14.9 cents/kWh, with heavy end fractions ranging from 30% to 60%. A minimum carbon price of $67.4 ± 13 per metric ton of CO2-eq was estimated to make BCF power commercially viable for the base case. These results suggest that BCF co-firing is an attractive pathway for clean power generation in existing power plants with a potential for significant reductions in carbon emissions.

  8. Firing rate dynamics in recurrent spiking neural networks with intrinsic and network heterogeneity.

    PubMed

    Ly, Cheng

    2015-12-01

    Heterogeneity of neural attributes has recently gained a lot of attention and is increasing recognized as a crucial feature in neural processing. Despite its importance, this physiological feature has traditionally been neglected in theoretical studies of cortical neural networks. Thus, there is still a lot unknown about the consequences of cellular and circuit heterogeneity in spiking neural networks. In particular, combining network or synaptic heterogeneity and intrinsic heterogeneity has yet to be considered systematically despite the fact that both are known to exist and likely have significant roles in neural network dynamics. In a canonical recurrent spiking neural network model, we study how these two forms of heterogeneity lead to different distributions of excitatory firing rates. To analytically characterize how these types of heterogeneities affect the network, we employ a dimension reduction method that relies on a combination of Monte Carlo simulations and probability density function equations. We find that the relationship between intrinsic and network heterogeneity has a strong effect on the overall level of heterogeneity of the firing rates. Specifically, this relationship can lead to amplification or attenuation of firing rate heterogeneity, and these effects depend on whether the recurrent network is firing asynchronously or rhythmically firing. These observations are captured with the aforementioned reduction method, and furthermore simpler analytic descriptions based on this dimension reduction method are developed. The final analytic descriptions provide compact and descriptive formulas for how the relationship between intrinsic and network heterogeneity determines the firing rate heterogeneity dynamics in various settings.

  9. Effect of oil and oil dispersant mixtures on the basal metabolic rate of ducks

    SciTech Connect

    Lambert, G.; Peakall, D.B.; Philogene, B.J.R.; Engelhardt, F.R.

    1982-11-01

    Wild strain adult mallards (Anas platrhynchos) were exposed to either Prudhoe Bay crude oil, Corexit 9527 dispersant or the crude oil + dispersant. Results show that the degree of oiling to which the ducks were exposed caused a modest but significant increase in the metabolic rate. Under the experimental conditions (one-hour exposure, small volume swimming tanks, measuring of metabolism after the removal of the bird from the water), the dispersant (at 30:1 ratio) does not appreciably increase the effects caused by the crude oil on the metabolic rate, although it seems to increase the damage to plumage which leads to progressive waterlogging. (JMT)

  10. On the Firing Rate Dependency of the Phase Response Curve of Rat Purkinje Neurons In Vitro

    PubMed Central

    Couto, João; Linaro, Daniele; De Schutter, E; Giugliano, Michele

    2015-01-01

    Synchronous spiking during cerebellar tasks has been observed across Purkinje cells: however, little is known about the intrinsic cellular mechanisms responsible for its initiation, cessation and stability. The Phase Response Curve (PRC), a simple input-output characterization of single cells, can provide insights into individual and collective properties of neurons and networks, by quantifying the impact of an infinitesimal depolarizing current pulse on the time of occurrence of subsequent action potentials, while a neuron is firing tonically. Recently, the PRC theory applied to cerebellar Purkinje cells revealed that these behave as phase-independent integrators at low firing rates, and switch to a phase-dependent mode at high rates. Given the implications for computation and information processing in the cerebellum and the possible role of synchrony in the communication with its post-synaptic targets, we further explored the firing rate dependency of the PRC in Purkinje cells. We isolated key factors for the experimental estimation of the PRC and developed a closed-loop approach to reliably compute the PRC across diverse firing rates in the same cell. Our results show unambiguously that the PRC of individual Purkinje cells is firing rate dependent and that it smoothly transitions from phase independent integrator to a phase dependent mode. Using computational models we show that neither channel noise nor a realistic cell morphology are responsible for the rate dependent shift in the phase response curve. PMID:25775448

  11. 46 CFR 167.45-40 - Fire-fighting equipment on nautical school ships using oil as fuel.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Requirements § 167.45-40 Fire-fighting equipment on nautical school ships using oil as fuel. Steam-propelled... school ship propelled by steam, in which a part of the fuel-oil installation is situated, 2 or more... steam propelled nautical school ship of over 1,000 gross tons having one boiler room there shall...

  12. 46 CFR 167.45-40 - Fire-fighting equipment on nautical school ships using oil as fuel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Requirements § 167.45-40 Fire-fighting equipment on nautical school ships using oil as fuel. Steam-propelled... school ship propelled by steam, in which a part of the fuel-oil installation is situated, 2 or more... steam propelled nautical school ship of over 1,000 gross tons having one boiler room there shall...

  13. The enrichment behavior of natural radionuclides in pulverized oil shale-fired power plants.

    PubMed

    Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

    2014-12-01

    The oil shale industry is the largest producer of NORM (Naturally Occurring Radioactive Material) waste in Estonia. Approximately 11-12 million tons of oil shale containing various amounts of natural radionuclides is burned annually in the Narva oil shale-fired power plants, which accounts for approximately 90% of Estonian electricity production. The radionuclide behavior characteristics change during the fuel combustion process, which redistributes the radionuclides between different ash fractions. Out of 24 operational boilers in the power plants, four use circulating fluidized bed (CFB) technology and twenty use pulverized fuel (PF) technology. Over the past decade, the PF boilers have been renovated, with the main objective to increase the efficiency of the filter systems. Between 2009 and 2012, electrostatic precipitators (ESP) in four PF energy blocks were replaced with novel integrated desulphurization technology (NID) for the efficient removal of fly ash and SO2 from flue gases. Using gamma spectrometry, activity concentrations and enrichment factors for the (238)U ((238)U, (226)Ra, (210)Pb) and (232)Th ((232)Th, (228)Ra) family radionuclides as well as (40)K were measured and analyzed in different PF boiler ash fractions. The radionuclide activity concentrations in the ash samples increased from the furnace toward the back end of the flue gas duct. The highest values in different PF boiler ash fractions were in the last field of the ESP and in the NID ash, where radionuclide enrichment factors were up to 4.2 and 3.3, respectively. The acquired and analyzed data on radionuclide activity concentrations in different PF boiler ashes (operating with an ESP and a NID system) compared to CFB boiler ashes provides an indication that changes in the fuel (oil shale) composition and boiler working parameters, as well as technological enhancements in Estonian oil shale fired power plants, have had a combined effect on the distribution patterns of natural radionuclides

  14. The enrichment behavior of natural radionuclides in pulverized oil shale-fired power plants.

    PubMed

    Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

    2014-12-01

    The oil shale industry is the largest producer of NORM (Naturally Occurring Radioactive Material) waste in Estonia. Approximately 11-12 million tons of oil shale containing various amounts of natural radionuclides is burned annually in the Narva oil shale-fired power plants, which accounts for approximately 90% of Estonian electricity production. The radionuclide behavior characteristics change during the fuel combustion process, which redistributes the radionuclides between different ash fractions. Out of 24 operational boilers in the power plants, four use circulating fluidized bed (CFB) technology and twenty use pulverized fuel (PF) technology. Over the past decade, the PF boilers have been renovated, with the main objective to increase the efficiency of the filter systems. Between 2009 and 2012, electrostatic precipitators (ESP) in four PF energy blocks were replaced with novel integrated desulphurization technology (NID) for the efficient removal of fly ash and SO2 from flue gases. Using gamma spectrometry, activity concentrations and enrichment factors for the (238)U ((238)U, (226)Ra, (210)Pb) and (232)Th ((232)Th, (228)Ra) family radionuclides as well as (40)K were measured and analyzed in different PF boiler ash fractions. The radionuclide activity concentrations in the ash samples increased from the furnace toward the back end of the flue gas duct. The highest values in different PF boiler ash fractions were in the last field of the ESP and in the NID ash, where radionuclide enrichment factors were up to 4.2 and 3.3, respectively. The acquired and analyzed data on radionuclide activity concentrations in different PF boiler ashes (operating with an ESP and a NID system) compared to CFB boiler ashes provides an indication that changes in the fuel (oil shale) composition and boiler working parameters, as well as technological enhancements in Estonian oil shale fired power plants, have had a combined effect on the distribution patterns of natural radionuclides

  15. Dynamics of excitatory synaptic components in sustained firing at low rates.

    PubMed

    Wyart, Claire; Cocco, Simona; Bourdieu, Laurent; Léger, Jean-Francois; Herr, Catherine; Chatenay, Didier

    2005-06-01

    Sustained firing is necessary for the persistent activity associated with working memory. The relative contributions of the reverberation of excitation and of the temporal dynamics of the excitatory postsynaptic potential (EPSP) to the maintenance of activity are difficult to evaluate in classical preparations. We used simplified models of synchronous excitatory networks, hippocampal autapses and pairs, to study the synaptic mechanisms underlying firing at low rates. Calcium imaging and cell attached recordings showed that these neurons spontaneously fired bursts of action potentials that lasted for seconds over a wide range of frequencies. In 2-wk-old cells, the median firing frequency was low (11 +/- 8.8 Hz), whereas in 3- to 4-wk-old cells, it decreased to a very low value (2 +/- 1.3 Hz). In both cases, we have shown that the slowest synaptic component supported firing. In 2-wk-old autapses, antagonists of N-methyl-d-aspartate receptors (NMDARs) induced rare isolated spikes showing that the NMDA component of the EPSP was essential for bursts at low frequency. In 3- to 4-wk-old neurons, the very low frequency firing was maintained without the NMDAR activation. However EGTA-AM or alpha-methyl-4-carboxyphenylglycine (MCPG) removed the very slow depolarizing component of the EPSP and prevented the sustained firing at very low rate. A metabotropic glutamate receptor (mGluR)-activated calcium sensitive conductance is therefore responsible for a very slow synaptic component associated with firing at very low rate. In addition, our observations suggested that the asynchronous release of glutamate might participate also in the recurring bursting.

  16. Chemical and biological characterization of emissions from coal- and oil-fired power plants.

    PubMed Central

    Ahlberg, M; Berghem, L; Nordberg, G; Persson, S A; Rudling, L; Steen, B

    1983-01-01

    Emission samples were obtained from two medium-sized power plants, one fired with oil and the other with pulverized coal. Particles obtained by a miniscale plume stack gas sampler (MIPSGAS), simulating the dilution process in the plume, were subjected to detailed physical, chemical and biological characterization. Studies by scanning electron microscopy and by Coulter counter demonstrated that the particles from the oil-fired boiler were considerably larger than the particles from the coal-fired boiler. Chemical analyses revealed more organic substances and more S, Ni, V, in the oil than in the coal particles. The latter contained a larger proportion of Al, Si, Cl, K, Ca, Ti, Mn, Fe, Se, Rb, Y, Zr, Ba and Pb. Biological testing revealed a greater acute and subacute toxicity by the intratracheal route in the hamster, a greater toxicity to alveolar macrophages and a greater lung retention of BaP coated on the particles from oil combustion than on those from coal combustion. In another sampling line, employed simultaneously with the MIPSGAS-particulate sampler, the total emissions were collected, i.e., both particle and gas phase. These samples were used for chemical analyses and Ames mutagenicity test. Analyses of specific PAHs in emissions from both plants demonstrated that concentrations were below the detection limit (less than 4 ng/m3 of benzo(a)pyrene), which is in accord with an efficient combustion of the fuel. The mutagenicity of the samples were below the detection limit of the mutagenicity assay. Images FIGURE 4. FIGURE 5. PMID:6825622

  17. Microfine coal firing results from a retrofit gas/oil-designed industrial boiler

    SciTech Connect

    Patel, R.; Borio, R.W.; Liljedahl, G.; Miller, B.G.; Scaroni, A.W.; McGowan, J.G.

    1995-12-31

    The development of a High Efficiency Advanced Coal Combustor (HEACC) has been in progress since 1987 and the ABB Power Plant Laboratories. The initial work on this concept produced an advanced coal firing system that was capable of firing both water-based and dry pulverized coal in an industrial boiler environment. Economics may one day dictate that it makes sense to replace oil or natural gas with coal in boilers that were originally designed to burn these fuels. The objective of the current program is to demonstrate the technical and economic feasibility of retrofitting a gas/oil designed boiler to burn micronized coal. In support of this overall objective, the following specific areas were targeted: A coal handling/preparation system that can meet the technical requirements for retrofitting microfine coal on a boiler designed for burning oil or natural gas; Maintaining boiler thermal performance in accordance with specifications when burning oil or natural gas; Maintaining NOx emissions at or below 0.6 lb/MBtu; Achieving combustion efficiencies of 98% or higher; and Calculating economic payback periods as a function of key variables. The overall program has consisted of five major tasks: (1) A review of current state-of-the-art coal firing system components; (2) Design and experimental testing of a prototype HEACC burner; (3) Installation and testing of a HEACC system in a commercial retrofit application; (4) Economic evaluation of the HEACC concept for retrofit applications; and (5) Long term demonstration under commercial user demand conditions. This paper will summarize the latest key experimental results (Task 3) and the economic evaluation (Task 4) of the HEACC concept for retrofit applications. 28 figs., 6 tabs.

  18. NORM emissions from heavy oil and natural gas fired power plants in Syria.

    PubMed

    Al-Masri, M S; Haddad, Kh

    2012-02-01

    Naturally occurring radioactive materials (NORM) have been determined in fly and bottom ash collected from four major Syrian power plants fired by heavy oil and natural gas. (210)Pb and (210)Po were the main NORM radionuclides detected in the fly and bottom ash. (210)Pb activity concentrations have reached 3393±10 Bq kg(-1) and 4023±7 Bq kg(-1) in fly ash and bottom ash, respectively; lower values of (210)Po were observed due to its high volatility. In addition, (210)Po and (210)Pb annual emissions in bottom ash from mixed (heavy oil and natural gas) fired power plants varied between 2.7×10(9)-7.95×10(9) Bq and 3.5×10(9)-10(10) Bq, respectively; higher emissions of (210)Po and (210)Pb from gas power plants being observed. However, the present study showed that (210)Po and (210)Pb emissions from thermal power plants fired by natural gas are much higher than the coal power plants operated in the World.

  19. Influence of proprioceptive feedback on the firing rate and recruitment of motoneurons

    NASA Astrophysics Data System (ADS)

    De Luca, C. J.; Kline, J. C.

    2012-02-01

    We investigated the relationships of the firing rate and maximal recruitment threshold of motoneurons recorded during isometric contraction with the number of spindles in individual muscles. At force levels above 10% of maximal voluntary contraction, the firing rate was inversely related to the number of spindles in a muscle, with the slope of the relationship increasing with force. The maximal recruitment threshold of motor units increased linearly with the number of spindles in the muscle. Thus, muscles with a greater number of spindles had lower firing rates and a greater maximal recruitment threshold. These findings may be explained by a mechanical interaction between muscle fibres and adjacent spindles. During low-level (0% to 10%) voluntary contractions, muscle fibres of recruited motor units produce force twitches that activate nearby spindles to respond with an immediate excitatory feedback that reaches maximal level. As the force increases further, the twitches overlap and tend towards tetanization, the muscle fibres shorten, the spindles slacken, their excitatory firings decrease, and the net excitation to the homonymous motoneurons decreases. Motoneurons of muscles with greater number of spindles receive a greater decrease in excitation which reduces their firing rates, increases their maximal recruitment threshold, and changes the motoneuron recruitment distribution.

  20. Superclean coal-water slurry combustion testing in an oil-fired boiler. Semiannual technical progress report, August 15, 1991--February 15, 1992

    SciTech Connect

    Miller, B.G.; Poe, R.L.; Morrison, J.L.; Xie, Jianyang; Walsh, P.M.; Schobert, H.H.; Scaroni, A.W.

    1992-05-29

    The Pennsylvania State University is conducting a superclean coal-water slurry (SCCWS) program for the United States Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of determining the capability of effectively firing SCCWS in an industrial boiler designed for oil. Penn State has entered into a cooperative agreement with DOE to determine if SCCWS (a fuel containing coal with less than 3.0 wt.% ash and 0.9 wt.% sulfur) can effectively be burned in an oil-designed industrial boiler without adverse impact on boiler rating, maintainability, reliability, and availability. The project will provide information on the design of new systems specifically configured to fire these clean coal-based fuels.

  1. Coal-water slurry fuel combustion testing in an oil-fired industrial boiler. Semiannual technical progress report, February 15--August 15, 1996

    SciTech Connect

    Miller, B.G.; Scaroni, A.W.

    1997-06-03

    The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) expanded demonstration and evaluation (installing a CWSF preparation circuit, performing baseline tests firing No. 6 fuel oil, and conducting additional CWSF testing). The boiler testing and evaluation will determine if the CWSF combustion characteristics, heat release rate, fouling and slagging behavior, corrosion and erosion tendencies, and fuel transport, storage, and handling characteristics can be accommodated in a boiler system designed to fire heavy fuel oil. In addition, the proof-of-concept demonstration will generate data to determine how the properties of a CWSF and its parent coal affect boiler performance. The economic factors associated with retrofitting boilers is also evaluated. The first three phases have been completed and the combustion performance of the burner that was provided with the boiler did not meet performance goals. A maximum coal combustion efficiency of 95% (compared to a target of 98%) was achieved and natural gas cofiring (15% of the total thermal input) was necessary to maintain a stable flame. Consequently, the first demonstration was terminated after 500 hours. The second CWSF demonstration (Phase 4) was conducted with a proven coal-designed burner. Prior to starting the second demonstration, a CWSF preparation circuit was constructed to provide flexibility in CWSF production. The circuit initially installed involved single-stage grinding. A regrind circuit was recently installed and was evaluated. A burner was installed from ABB Combustion Engineering (ABB/CE) and was used to generate baseline data firing No. 6 fuel oil and fire CWSF. A temporary storage system for No. 6 fuel oil was installed and modifications to the existing CWSF handling and preheating system were made to accommodate No. 6 oil.

  2. Comparison of fluence rate distributions made be side-firing fibers in an optical phantom

    NASA Astrophysics Data System (ADS)

    Royston, David; Richards, Philip Q.

    1999-07-01

    Side-firing fibers are used to provide coagulative therapy to the urologic tract. These fibers use different optical technologies to deflect the beam transverse to the fibers' optical axis. This produces emitted beams which differ in both beam direction and divergence angles. The relative optical performance of 13 fibers was studied in an optical phantom suspension. The fluence rate distribution created by each side-firing fiber was determined. The fluence rate distribution accounts for both the direct and spurious beams emitted from side-firing fibers as well as the light scattering produced by the target tissue. Based upon limited clinical dosimetry studies, the relative fluence rate distribution appears to indicate general exposure conditions for the evaluated fibers.

  3. Millimeter waves thermally alter the firing rate of the Lymnaea pacemaker neuron

    SciTech Connect

    Alekseev, S.I.; Kochetkova, N.V.; Ziskin, M.C.; Bolshakov, M.A.

    1997-05-01

    The effects of millimeter waves (mm-waves, 75 GHz) and temperature elevation on the firing rate of the BP-4 pacemaker neuron of the pond snail Lymnaea stagnalis were studied by using microelectrode techniques. The open end of a rectangular waveguide covered with a thin Teflon film served as a radiator. Specific absorption rates (SARs), measured in physiological solution at the radiator outlet, ranged from 600 to 4,200 W/kg, causing temperature rises from 0.3 to 2.2 C, respectively. Irradiation at an SAR of 4,200 W/kg caused a biphasic change in the firing rate, i.e., a transient decrease in the firing rate followed by a gradual increase to a new level that was 68 {+-} 21% above control. The biphasic changes in the firing rate were reproduced by heating under the condition that the magnitude (2 C) and the rate of temperature rise were equal to those produced by the irradiation. The addition of 0.05 mM of ouabain caused the disappearance of transient responses of the neuron to the irradiation. It was shown that the rate of temperature rise played an important role in the development of a transient neuronal response. The threshold stimulus for a transient response of the BP-4 neutron found in warming experiments was a temperature rise of 0.0025 C/s.

  4. Estimating carbon emissions in Russia using the Canadian Forest Fire Danger Rating System

    NASA Astrophysics Data System (ADS)

    McRae, D. J.; Jin, J.; Yang, Y.; Conard, S. G.; Sukhinin, A.; Stocks, B. J.

    2009-12-01

    The Russian boreal forest zone contains about 28 percent of the global terrestrial carbon. Wildfires in Russia burn an estimated 12-15 million ha annually. In a warming climate, fires in the boreal zone are expected to increase in area and severity, with the potential for increasing global fire emissions and decreasing carbon stored in soils and biomass. Current fire data for these forests generally do not account for the large spatial and temporal variations in fuel loads and consumption for differing forest types and weather patterns. As a result, it has been difficult to obtain good estimates of annual carbon emissions. While methods are being developed to estimate carbon emission remotely, there is an immediate need for more accurate estimates. Our previous work has indicated that the Canadian Forest Fire Danger Rating System (CFFDRS) is suitable for use in Russia. CFFDRS fuel consumption models can be used to estimate carbon emissions. The Canadian Forest Fire Weather Indexes (FWI) System, part of the CFFDRS, estimates the moisture content of various fuel classes and uses these estimates to generate a set of relative fire behavior indicators. As part of the Russian FIRE BEAR (Fire Effects in the Boreal Eurasia Region) Project, we conducted 14 experimental surface fires on Scots pine (Pinus sylvestris) forest sites in Siberia under a range of weather and fuel conditions. Detailed measurements of fuel consumption on each fire provided a basis for modeling carbon emissions using the FWI System. Carbon released by these experimental surface fires ranged from 4.8 to 15.4 t C ha-1 depending on burning conditions and fuel conditions. Provided burn areas and burn dates are known, and forest type and antecedent weather data are available, these models can be used to estimate the total annual carbon emissions for forest fires in Russia. Weather data was obtained for all Russian weather stations over a 55-year period (1953-2008) from the National Climate Data Center

  5. Model cerebellar granule cells can faithfully transmit modulated firing rate signals

    PubMed Central

    Rössert, Christian; Solinas, Sergio; D'Angelo, Egidio; Dean, Paul; Porrill, John

    2014-01-01

    A crucial assumption of many high-level system models of the cerebellum is that information in the granular layer is encoded in a linear manner. However, granule cells are known for their non-linear and resonant synaptic and intrinsic properties that could potentially impede linear signal transmission. In this modeling study we analyse how electrophysiological granule cell properties and spike sampling influence information coded by firing rate modulation, assuming no signal-related, i.e., uncorrelated inhibitory feedback (open-loop mode). A detailed one-compartment granule cell model was excited in simulation by either direct current or mossy-fiber synaptic inputs. Vestibular signals were represented as tonic inputs to the flocculus modulated at frequencies up to 20 Hz (approximate upper frequency limit of vestibular-ocular reflex, VOR). Model outputs were assessed using estimates of both the transfer function, and the fidelity of input-signal reconstruction measured as variance-accounted-for. The detailed granule cell model with realistic mossy-fiber synaptic inputs could transmit information faithfully and linearly in the frequency range of the vestibular-ocular reflex. This was achieved most simply if the model neurons had a firing rate at least twice the highest required frequency of modulation, but lower rates were also adequate provided a population of neurons was utilized, especially in combination with push-pull coding. The exact number of neurons required for faithful transmission depended on the precise values of firing rate and noise. The model neurons were also able to combine excitatory and inhibitory signals linearly, and could be replaced by a simpler (modified) integrate-and-fire neuron in the case of high tonic firing rates. These findings suggest that granule cells can in principle code modulated firing-rate inputs in a linear manner, and are thus consistent with the high-level adaptive-filter model of the cerebellar microcircuit. PMID:25352777

  6. Properties of human motor units after prolonged activity at a constant firing rate.

    PubMed

    Johnson, K V B; Edwards, S C; Van Tongeren, C; Bawa, P

    2004-02-01

    The primary purpose of this study was to examine if there are changes in the intrinsic properties of spinal motoneurons after prolonged submaximal contractions. To do this, we assessed whether or not the synaptic drive to motoneurons needs to increase in order to maintain a constant firing rate of a motor unit. Recruitment of new units and an increase in total electromyographic (EMG) activity of the muscle of interest were taken as estimates of an increase in synaptic drive. Subjects were asked to maintain a constant firing rate of a clearly identifiable (targeted) motor unit from the first dorsal interosseous muscle for approximately 10 min, while surface EMG and force were recorded simultaneously. For the 60 units studied, the duration of the constant-firing-rate period ranged from 73 to 1,140 s (448 +/- 227 s; mean +/- SD). There was a significant increase ( t-test, p<0.001) in the magnitude of mean surface EMG, and DC force while the targeted motoneuron maintained a constant rate suggesting an increase in the net excitatory input to the motoneuron pool. Changes occurring simultaneously in other parameters, namely, variability in interspike interval, magnitude of force fluctuations, the duration of motor unit action potentials, and the median power frequency of surface EMG were also computed. The firing rates of 16 concurrently firing motoneurons, not controlled by the subject, remained constant. The key finding of this study is that after prolonged activity, a motoneuron requires a stronger excitatory input to maintain its firing rate. Additional results are indicative of significant changes in the characteristics of the synaptic inputs, changes at the neuromuscular junction (both pre- and postsynaptic regions) and the sarcolemma.

  7. Global simulations of smoke from Kuwaiti oil fires and possible effects on climate

    SciTech Connect

    Glatzmaier, G.A.; Malone, R.C.; Kao, C.Y.J.

    1991-12-31

    The Los Alamos Global Climate Model has bee used to simulate the global evolution of the Kuwaiti oil fire smoke and its potential effects on the climate. The initial simulations were done shortly before the fires were lit in January 1991. They indicated that such an event would not result in a ``Mini Nuclear Winter`` as some people were suggesting. Further simulations during the year suggested that the smoke could be responsible for subtle regional climate changes in the spring such as a 5 degree centigrade decrease in the surface temperature in Kuwait, a 10% decrease in precipitation in Saudi Arabia and a 10% increase in precipitation in the Tibetan Plateau region. These results are in qualitative agreement with the observations this year.

  8. Estimating firing rates from calcium signals in locust projection neurons in vivo.

    PubMed

    Moreaux, Laurent; Laurent, Gilles

    2007-01-01

    Combining intracellular electrophysiology and multi-photon calcium imaging in vivo, we studied the relationship between calcium signals (sampled at 500-750 Hz) and spike output in principal neurons in the locust antennal lobe. Our goal was to determine whether the firing rate of individual neurons can be estimated in vivo with calcium imaging and, if so, to measure directly the accuracy and resolution of our estimates. Using the calcium indicator Oregon Green BAPTA-1, we describe a simple method to reconstruct firing rates from dendritic calcium signals with 80-90% accuracy and 50 ms temporal resolution.

  9. Current injection and receptor-mediated excitation produce similar maximal firing rates in hypoglossal motoneurons.

    PubMed

    Wakefield, Hilary E; Fregosi, Ralph F; Fuglevand, Andrew J

    2016-03-01

    The maximum firing rates of motoneurons (MNs), activated in response to synaptic drive, appear to be much lower than that elicited by current injection. It could be that the decrease in input resistance associated with increased synaptic activity (but not current injection) might blunt overall changes in membrane depolarization and thereby limit spike-frequency output. To test this idea, we recorded, in the same cells, maximal firing responses to current injection and to synaptic activation. We prepared 300 μm medullary slices in neonatal rats that contained hypoglossal MNs and used whole-cell patch-clamp electrophysiology to record their maximum firing rates in response to triangular-ramp current injections and to glutamate receptor-mediated excitation. Brief pressure pulses of high-concentration glutamate led to significant depolarization, high firing rates, and temporary cessation of spiking due to spike inactivation. In the same cells, we applied current clamp protocols that approximated the time course of membrane potential change associated with glutamate application and with peak current levels large enough to cause spike inactivation. Means (SD) of maximum firing rates obtained in response to glutamate application were nearly identical to those obtained in response to ramp current injection [glutamate 47.1 ± 12.0 impulses (imp)/s, current injection 47.5 ± 11.2 imp/s], even though input resistance was 40% less during glutamate application compared with current injection. Therefore, these data suggest that the reduction in input resistance associated with receptor-mediated excitation does not, by itself, limit the maximal firing rate responses in MNs.

  10. DEVELOPMENT OF FINE PARTICULATE EMISSION FACTORS AND SPECIATION PROFILES FOR OIL AND GAS-FIRED COMBUSTION SYSTEMS

    SciTech Connect

    Glenn C. England; Stephanie Wien; Mingchih O. Chang

    2002-08-01

    This report provides results from the first year of this three-year project to develop dilution measurement technology for characterizing PM2.5 (particles with aerodynamic diameter smaller than 2.5 micrometers) and precursor emissions from stationary combustion sources used in oil, gas and power generation operations. Detailed emission rate and chemical speciation test results for a refinery gas-fired process heater and plans for cogeneration gas turbine tests and pilot-scale tests are presented. Tests were performed using a research dilution sampling apparatus and traditional EPA methods to compare PM2.5 mass and chemical speciation. Test plans are presented for a gas turbine facility that will be tested in the fourth quarter of 2002. A preliminary approach for pilot-scale tests is presented that will help define design constraints for a new dilution sampler design that is smaller, lighter, and less costly to use.

  11. Association between Residential Proximity to Fuel-Fired Power Plants and Hospitalization Rate for Respiratory Diseases

    PubMed Central

    Liu, Xiaopeng; Lessner, Lawrence

    2012-01-01

    Background: Air pollution is known to cause respiratory disease. Unlike motor vehicle sources, fuel-fired power plants are stationary. Objective: Using hospitalization data, we examined whether living near a fuel-fired power plant increases the likelihood of hospitalization for respiratory disease. Methods: Rates of hospitalization for asthma, acute respiratory infection (ARI), and chronic obstructive pulmonary disease (COPD) were estimated using hospitalization data for 1993–2008 from New York State in relation to data for residences near fuel-fired power plants. We also explored data for residential proximity to hazardous waste sites. Results: After adjusting for age, sex, race, median household income, and rural/urban residence, there were significant 11%, 15%, and 17% increases in estimated rates of hospitalization for asthma, ARI, and COPD, respectively, among individuals > 10 years of age living in a ZIP code containing a fuel-fired power plant compared with one that had no power plant. Living in a ZIP code with a fuel-fired power plant was not significantly associated with hospitalization for asthma or ARI among children < 10 years of age. Living in a ZIP code with a hazardous waste site was associated with hospitalization for all outcomes in both age groups, and joint effect estimates were approximately additive for living in a ZIP code that contained a fuel-fired power plant and a hazardous waste site. Conclusions: Our results are consistent with the hypothesis that exposure to air pollution from fuel-fired power plants and volatile compounds coming from hazardous waste sites increases the risk of hospitalization for respiratory diseases. PMID:22370087

  12. Motor unit firing rates during spasms in thenar muscles of spinal cord injured subjects

    PubMed Central

    Zijdewind, Inge; Bakels, Rob; Thomas, Christine K.

    2014-01-01

    Involuntary contractions of paralyzed muscles (spasms) commonly disrupt daily activities and rehabilitation after human spinal cord injury (SCI). Our aim was to examine the recruitment, firing rate modulation, and derecruitment of motor units that underlie spasms of thenar muscles after cervical SCI. Intramuscular electromyographic activity (EMG), surface EMG, and force were recorded during thenar muscle spasms that occurred spontaneously or that were triggered by movement of a shoulder or leg. Most spasms were submaximal (mean: 39%, SD: 33 of the force evoked by median nerve stimulation at 50 Hz) with strong relationships between EMG and force (R2 > 0.69). Unit recruitment occurred over a wide force range (0.2–103% of 50 Hz force). Significant unit rate modulation occurred during spasms (frequency at 25% maximal force: 8.8 Hz, 3.3 SD; at maximal force: 16.1 Hz, 4.1 SD). Mean recruitment frequency (7.1 Hz, 3.2 SD) was significantly higher than derecruitment frequency (5.4 Hz, 2.4 SD). Coactive unit pairs that fired for more than 4 s showed high (R2 > 0.7, n = 4) or low (R2:0.3–0.7, n = 12) rate-rate correlations, and derecruitment reversals (21 pairs, 29%). Later recruited units had higher or lower maximal firing rates than lower threshold units. These discrepant data show that coactive motoneurons are drive both by common inputs and by synaptic inputs from different sources during muscle spasms. Further, thenar motoneurons can still fire at high rates in response to various peripheral inputs after SCI, supporting the idea that low maximal voluntary firing rates and forces in thenar muscles result from reduced descending drive. PMID:25452723

  13. Superclean coal-water slurry combustion testing in an oil-fired boiler. Quarterly technical progress report, August 15--November 15, 1989

    SciTech Connect

    Miller, B.G.; Scaroni, A.W.

    1990-04-06

    The Pennsylvania State University is conducting a superclean coal-water slurry (SCCWS) program for the US Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of demonstrating the capability of effectively firing SCCWS in industrial boilers designed for oil. Penn State has entered into a cooperative agreement with DOE to show that SCCWS (a fuel containing coal with less than 3% ash and 0.9% sulfur) can effectively be burned in oil-designed industrial boilers without adverse impact on boiler rating, maintainability, reliability, and availability. The project will provide information on the design of new systems specifically configured to fire these clean coal-based fuels. The project consists of three phases: (1) design, permitting, and test planning, (2) construction and start up, and (3) operations and disposition. The boiler testing will determine if the SCCWS combustion characteristics, heat release rate, slagging and fouling factors, erosion and corrosion limits, and fuel transport, storage, and handling can be accommodated in an oil-designed boiler. In addition, the proof-of-concept demonstration will generate data to determine how the properties of SCCWS and its parent coal affect boiler performance. Economic factors associated with retrofitting and operating boilers will be identified to assess the viability of future oil-to-coal retrofit. The status of all three phases and the individual tasks under each phase are described.

  14. Pseudacteon decapitating fly parasitism rates in fire ant colonies around Gainesville, Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to assess the impacts of phorid flies on fire ants in the Gainesville area, we collected 3 g of worker ants from 36 colonies. A total of 672 parasitized workers were recovered from the 36 colony samples. Confirmed parasitism rates ranged from 0-5% with an average of about 0.5%. Including c...

  15. Detection, mapping and estimation of rate of spread of grass fires from southern African ERTS-1 imagery

    NASA Technical Reports Server (NTRS)

    Wightman, J. M.

    1973-01-01

    Sequential band-6 imagery of the Zambesi Basin of southern Africa recorded substantial changes in burn patterns resulting from late dry season grass fires. One example from northern Botswana, indicates that a fire consumed approximately 70 square miles of grassland over a 24-hour period. Another example from western Zambia indicates increased fire activity over a 19-day period. Other examples clearly define the area of widespread grass fires in Angola, Botswana, Rhodesia and Zambia. From the fire patterns visible on the sequential portions of the imagery, and the time intervals involved, the rates of spread of the fires are estimated and compared with estimates derived from experimental burning plots in Zambia and Canada. It is concluded that sequential ERTS-1 imagery, of the quality studied, clearly provides the information needed to detect and map grass fires and to monitor their rates of spread in this region during the late dry season.

  16. Savanna fires increase rates and distances of seed dispersal by ants.

    PubMed

    Parr, C L; Andersen, A N; Chastagnol, C; Duffaud, C

    2007-02-01

    Myrmecochory (seed dispersal by ants) is a prominent dispersal mechanism in many environments, and can play a key role in local vegetation dynamics. Here we investigate its interaction with another key process in vegetation dynamics-fire. We examine ant dispersal of seeds immediately before and after experimental burning in an Australian tropical savanna, one of the world's most fire-prone ecosystems. Specifically, our study addressed the effects of burning on: (1) the composition of ants removing seeds, (2) number of seed removals, and (3) distance of seed dispersal. Fire led to higher rates of seed removal post-fire when compared with unburnt habitat, and markedly altered dispersal distance, with mean dispersal distance increasing more than twofold (from 1.6 to 3.8 m), and many distance dispersal events greater than the pre-fire maximum (7.55 m) being recorded. These changes were due primarily to longer foraging ranges of species of Iridomyrmex, most likely in response to the simplification of their foraging landscape. The significance of enhanced seed-removal rates and distance dispersal for seedling establishment is unclear because the benefits to plants in having their seeds dispersed by ants in northern Australia are poorly known. However, an enhanced removal rate would enhance any benefit of reduced predation by rodents. Similarly, the broader range of dispersal distances would appear to benefit plants in terms of reduced parent-offspring conflict and sibling competition, and the location of favourable seedling microsites. Given the high frequency of fire in Australian tropical savannas, enhanced benefits of seed dispersal by ants would apply for much of the year. PMID:17033801

  17. Evaporation rate and vapor pressure of selected polymeric lubricating oils.

    NASA Technical Reports Server (NTRS)

    Gardos, M. N.

    1973-01-01

    A recently developed ultrahigh-vacuum quartz spring mass sorption microbalance has been utilized to measure the evaporation rates of several low-volatility polymeric lubricating oils at various temperatures. The evaporation rates are used to calculate the vapor pressures by the Langmuir equation. A method is presented to accurately estimate extended temperature range evaporation rate and vapor pressure data for polymeric oils, incorporating appropriate corrections for the increases in molecular weight and the change in volatility of the progressively evaporating polymer fractions. The logarithms of the calculated data appear to follow linear relationships within the test temperature ranges, when plotted versus 1000/T. These functions and the observed effusion characteristics of the fluids on progressive volatilization are useful in estimating evaporation rate and vapor pressure changes on evaporative depletion.

  18. Observation of Oil Flow Characteristics in Rolling Piston Rotary Compressor for Reducing Oil Circulation Rate

    NASA Astrophysics Data System (ADS)

    Song, S. j.; Noh, K. Y.; Min, B. C.; Yang, J. S.; Choi, G. M.; Kim, D. J.

    2015-08-01

    The oil circulation rate (OCR) of the rolling piston rotary compressor is a significant factor which affects the performance of refrigeration system. The increase of oil discharge causes decreasing of the heat transfer efficiency in the heat exchanger, pressure drop and lack of oil in lubricate part in compressor. In this study, the internal flow of compressor was visualized to figure out the oil droplet flow characteristics. The experiments and Computational Fluid Dynamics (CFD) simulations were conducted in various frequency of compressor to observe the effect of operation frequency on oil droplet flow characteristics for reducing OCR. In situ, measurement of oil droplet diameter and velocity were conducted by using high speed image visualization and Particle Image Velocimetry (PIV). The flow paths were dominated by copper wire parts driving the motor which was inserted in compressor. In order to verify the reliability of CFD simulation, the tendency of oil flow characteristics in each flow path and the compressor operating conditions were applied in CFD simulation. For reducing OCR, the structure such as vane, disk and ring is installed in the compressor to restrict the main flow path of oil particle. The effect of additional structure for reducing OCR was evaluated using CFD simulation and the results were discussed in detail.

  19. Pre- and Post-Fire Infiltration Rates in a Montane Mixed Conifer Ecosystem

    NASA Astrophysics Data System (ADS)

    Kopp, E. S.; Pohlmann, M. A.; Jones, C. A.; Chorover, J.; Schaap, M. G.

    2013-12-01

    The NSF-funded Catalina-Jemez Critical Zone Observatory (CZO) studies couplings among hydrologic, lithologic, ecological, and geochemical dynamics in the Southwest U.S. The motivation to study this region is to understand and to develop predictive models of how slow changes and abrupt disturbances affect landscape evolution and water resources for growing urban populations. One of the prevalent disturbances in Southwestern forested ecosystems is fire, which can dramatically alter near surface hydraulic properties and cause large changes in hydrological response in catchments. This poster will present a unique data set of pre- and post-fire infiltration and subsurface data collected before and shortly after the June 2013 Thompson Ridge Fire near Redondo Peak in the Valles Caldera 10 miles north of Jemez Springs, NM. Single ring pre-fire infiltration measurements were taken in July 2011 at 22 different locations with high-precision GPS tags. Similar post-fire infiltration measurements were taken within 1 meter of spatial accuracy of the pre-fire measurements in July 2013. The near-surface soil was analyzed for texture and organic matter content at 53 GPS-referenced locations in 2011, and a more detailed soil analysis is currently being analyzed in the laboratory for the 22 infiltration sites (5 depth increments down to about 50 cm). Because of the recent nature of the burn and subsequent sampling, complete results from data analysis are not yet available, however, the poster will provide a statistical analysis among pre- and post fire infiltration rates, established burn intensity classes, and subsurface changes such as soil texture and organic matter content.

  20. Holocene fire regimes and treeline migration rates in sub-arctic Canada

    NASA Astrophysics Data System (ADS)

    Sulphur, Kyle C.; Goldsmith, Shantal A.; Galloway, Jennifer M.; Macumber, Andrew; Griffith, Fritz; Swindles, Graeme T.; Patterson, R. Timothy; Falck, Hendrik; Clark, Ian D.

    2016-10-01

    Holocene climate change resulted in major vegetation reorganization in sub-arctic Canada near modern treeline. However, little is known of the effects of long-term climate change on boreal forest composition and fire regimes below treeline in this region. We present a high-resolution vegetation and fire history from two sites within the modern boreal forest in the central Northwest Territories, Canada, to provide new insight on sub-arctic vegetation response to Holocene climate dynamics and the role of fire in boreal ecosystems. Palynological analysis of sediments retrieved from Waite and Danny's lakes (informal) is used to reconstruct regional vegetation dynamics and boreal fire regimes. The longer Danny's Lake record documents treeline expansion beginning at ca. 7430-7220 cal yr BP. Integration of our new data with previous work shows that treeline expanded between ca. 4050 cal. yr BP and ca. 3840 cal yr BP at a rate of ca. 50 m/yr in response to the 1-2 °C increase in temperature estimated for the Holocene Thermal Maximum. Forest fires were relatively frequent during the early Holocene, before declining in frequency in response to development of cooler and wetter climate conditions associated with the Neoglacial (beginning after ca. 2200-2320 cal yr BP). We document a trend of increasing fire frequency in the 20th century that is correlated with warming at this time. These dynamics south of modern treeline provide insight into factors creating heterogeneity in plant community responses to large-scale climate events in high northern latitudes and suggest that large scale reorganization of boreal vegetation and fire regimes can be expected over the coming decades.

  1. Exposure to fuel-oil ash and welding emissions during the overhaul of an oil-fired boiler.

    PubMed

    Liu, Youcheng; Woodin, Mark A; Smith, Thomas J; Herrick, Robert F; Williams, Paige L; Hauser, Russ; Christiani, David C

    2005-09-01

    The health effects of exposure to vanadium in fuel-oil ash are not well described at levels ranging from 10 to 500 microg/m(3). As part of a larger occupational epidemiologic study that assessed these effects during the overhaul of a large oil-fired boiler, this study was designed to quantify boilermakers' exposures to fuel-oil ash particles, metals, and welding gases, and to identify determinants of these exposures. Personal exposure measurements were conducted on 18 boilermakers and 11 utility workers (referents) before and during a 3-week overhaul. Ash particles < 10 microm in diameter (PM(10), mg/m(3)) were sampled over full work shifts using a one-stage personal size selective sampler containing a polytetrafluoroethylene filter. Filters were digested using the Parr bomb method and analyzed for the metals vanadium (V), nickel (Ni), iron (Fe), chromium (Cr), cadmium (Cd), lead (Pb), manganese (Mn), and arsenic (As) by inductively coupled plasma mass spectrometry. Nitrogen dioxide (NO(2)) was measured with an Ogawa passive badge-type sampler and ozone (O(3)) with a personal active pump sampler.Time-weighted average (TWA) exposures were significantly higher (p < 0.05) for boilermakers than for utility workers for PM(10) (geometric mean: 0.47 vs. 0.13 mg/m(3)), V (8.9 vs. 1.4 microg/m(3)), Ni (7.4 vs. 1.8 microg/m(3)) and Fe (56.2 vs. 11.2 microg/m(3)). Exposures were affected by overhaul time periods, tasks, and work locations. No significant increases were found for O(3) or NO(2) for boilermakers or utility workers regardless of overhaul period or task group. Fuel-oil ash was a major contributor to boilermakers' exposure to PM(10) and metals. Vanadium concentrations sometimes exceeded the 2003 American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value.

  2. Vanadium contamination of lichens and tree foliage in the vicinity of three oil-fired power plants in Eastern Canada

    SciTech Connect

    Juichang, R.; Freedman, B.; Coles, C.; Zwicker, B.; Holzbecker, J.; Chatt, A.

    1995-06-01

    Vanadium concentrations were determined by neutron activation analysis in samples of epiphytic lichens and tree foliage collected at sites along 10 transects in the vicinity of three oil-fired power plants in eastern Canada. The vanadium concentrations in plants decreased exponentially with increasing distance from the power plants. Substantially larger concentrations of vanadium occurred in lichen tissues than in tree foliage. Lichens clearly are more suitable for biomonitoring environmental contamination with vanadium near oil-fired power plants. 2 refs., 1 fig., 2 tabs.

  3. Inferring learning rules from distributions of firing rates in cortical neurons.

    PubMed

    Lim, Sukbin; McKee, Jillian L; Woloszyn, Luke; Amit, Yali; Freedman, David J; Sheinberg, David L; Brunel, Nicolas

    2015-12-01

    Information about external stimuli is thought to be stored in cortical circuits through experience-dependent modifications of synaptic connectivity. These modifications of network connectivity should lead to changes in neuronal activity as a particular stimulus is repeatedly encountered. Here we ask what plasticity rules are consistent with the differences in the statistics of the visual response to novel and familiar stimuli in inferior temporal cortex, an area underlying visual object recognition. We introduce a method that allows one to infer the dependence of the presumptive learning rule on postsynaptic firing rate, and we show that the inferred learning rule exhibits depression for low postsynaptic rates and potentiation for high rates. The threshold separating depression from potentiation is strongly correlated with both mean and s.d. of the firing rate distribution. Finally, we show that network models implementing a rule extracted from data show stable learning dynamics and lead to sparser representations of stimuli. PMID:26523643

  4. Influence of the contractile properties of muscle on motor unit firing rates during a moderate-intensity contraction in vivo.

    PubMed

    Trevino, Michael A; Herda, Trent J; Fry, Andrew C; Gallagher, Philip M; Vardiman, John P; Mosier, Eric M; Miller, Jonathan D

    2016-08-01

    It is suggested that firing rate characteristics of motor units (MUs) are influenced by the physical properties of the muscle. However, no study has correlated MU firing rates at recruitment, targeted force, or derecruitment with the contractile properties of the muscle in vivo. Twelve participants (age = 20.67 ± 2.35 yr) performed a 40% isometric maximal voluntary contraction of the leg extensors that included linearly increasing, steady force, and decreasing segments. Muscle biopsies were collected with myosin heavy chain (MHC) content quantified, and surface electromyography (EMG) was recorded from the vastus lateralis. The EMG signal was decomposed into the firing events of single MUs. Slopes and y-intercepts were calculated for 1) firing rates at recruitment vs. recruitment threshold, 2) mean firing rates at steady force vs. recruitment threshold, and 3) firing rates at derecruitment vs. derecruitment threshold relationships for each subject. Correlations among type I %MHC isoform content and the slopes and y-intercepts from the three relationships were examined. Type I %MHC isoform content was correlated with MU firing rates at recruitment (y-intercepts: r = -0.577; slopes: r = 0.741) and targeted force (slopes: r = 0.853) vs. recruitment threshold and MU firing rates at derecruitment (y-intercept: r = -0.597; slopes: r = 0.701) vs. derecruitment threshold relationships. However, the majority of the individual MU firing rates vs. recruitment and derecruitment relationships were not significant (P > 0.05) and, thus, revealed no systematic pattern. In contrast, MU firing rates during the steady force demonstrated a systematic pattern with higher firing rates for the lower- than higher-threshold MUs and were correlated with the physical properties of MUs in vivo. PMID:27146989

  5. Reconstruction of firing rate changes across neuronal populations by temporally deconvolved Ca2+ imaging.

    PubMed

    Yaksi, Emre; Friedrich, Rainer W

    2006-05-01

    Methods to record action potential (AP) firing in many individual neurons are essential to unravel the function of complex neuronal circuits in the brain. A promising approach is bolus loading of Ca(2+) indicators combined with multiphoton microscopy. Currently, however, this technique lacks cell-type specificity, has low temporal resolution and cannot resolve complex temporal firing patterns. Here we present simple solutions to these problems. We identified neuron types by colocalizing Ca(2+) signals of a red-fluorescing indicator with genetically encoded markers. We reconstructed firing rate changes from Ca(2+) signals by temporal deconvolution. This technique is efficient, dramatically enhances temporal resolution, facilitates data interpretation and permits analysis of odor-response patterns across thousands of neurons in the zebrafish olfactory bulb. Hence, temporally deconvolved Ca(2+) imaging (TDCa imaging) resolves limitations of current optical recording techniques and is likely to be widely applicable because of its simplicity, robustness and generic principle.

  6. Coexistence of reward and unsupervised learning during the operant conditioning of neural firing rates.

    PubMed

    Kerr, Robert R; Grayden, David B; Thomas, Doreen A; Gilson, Matthieu; Burkitt, Anthony N

    2014-01-01

    A fundamental goal of neuroscience is to understand how cognitive processes, such as operant conditioning, are performed by the brain. Typical and well studied examples of operant conditioning, in which the firing rates of individual cortical neurons in monkeys are increased using rewards, provide an opportunity for insight into this. Studies of reward-modulated spike-timing-dependent plasticity (RSTDP), and of other models such as R-max, have reproduced this learning behavior, but they have assumed that no unsupervised learning is present (i.e., no learning occurs without, or independent of, rewards). We show that these models cannot elicit firing rate reinforcement while exhibiting both reward learning and ongoing, stable unsupervised learning. To fix this issue, we propose a new RSTDP model of synaptic plasticity based upon the observed effects that dopamine has on long-term potentiation and depression (LTP and LTD). We show, both analytically and through simulations, that our new model can exhibit unsupervised learning and lead to firing rate reinforcement. This requires that the strengthening of LTP by the reward signal is greater than the strengthening of LTD and that the reinforced neuron exhibits irregular firing. We show the robustness of our findings to spike-timing correlations, to the synaptic weight dependence that is assumed, and to changes in the mean reward. We also consider our model in the differential reinforcement of two nearby neurons. Our model aligns more strongly with experimental studies than previous models and makes testable predictions for future experiments. PMID:24475240

  7. Coexistence of reward and unsupervised learning during the operant conditioning of neural firing rates.

    PubMed

    Kerr, Robert R; Grayden, David B; Thomas, Doreen A; Gilson, Matthieu; Burkitt, Anthony N

    2014-01-01

    A fundamental goal of neuroscience is to understand how cognitive processes, such as operant conditioning, are performed by the brain. Typical and well studied examples of operant conditioning, in which the firing rates of individual cortical neurons in monkeys are increased using rewards, provide an opportunity for insight into this. Studies of reward-modulated spike-timing-dependent plasticity (RSTDP), and of other models such as R-max, have reproduced this learning behavior, but they have assumed that no unsupervised learning is present (i.e., no learning occurs without, or independent of, rewards). We show that these models cannot elicit firing rate reinforcement while exhibiting both reward learning and ongoing, stable unsupervised learning. To fix this issue, we propose a new RSTDP model of synaptic plasticity based upon the observed effects that dopamine has on long-term potentiation and depression (LTP and LTD). We show, both analytically and through simulations, that our new model can exhibit unsupervised learning and lead to firing rate reinforcement. This requires that the strengthening of LTP by the reward signal is greater than the strengthening of LTD and that the reinforced neuron exhibits irregular firing. We show the robustness of our findings to spike-timing correlations, to the synaptic weight dependence that is assumed, and to changes in the mean reward. We also consider our model in the differential reinforcement of two nearby neurons. Our model aligns more strongly with experimental studies than previous models and makes testable predictions for future experiments.

  8. CO2 and CO emission rates from three forest fire controlled experiments in Western Amazonia

    NASA Astrophysics Data System (ADS)

    Carvalho, J. A., Jr.; Amaral, S. S.; Costa, M. A. M.; Soares Neto, T. G.; Veras, C. A. G.; Costa, F. S.; van Leeuwen, T. T.; Krieger Filho, G. C.; Tourigny, E.; Forti, M. C.; Fostier, A. H.; Siqueira, M. B.; Santos, J. C.; Lima, B. A.; Cascão, P.; Ortega, G.; Frade, E. F., Jr.

    2016-06-01

    Forests represent an important role in the control of atmospheric emissions through carbon capture. However, in forest fires, the carbon stored during photosynthesis is released into the atmosphere. The carbon quantification, in forest burning, is important for the development of measures for its control. The aim of this study was to quantify CO2 and CO emissions of forest fires in Western Amazonia. In this paper, results are described of forest fire experiments conducted in Cruzeiro do Sul and Rio Branco, state of Acre, and Candeias do Jamari, state of Rondônia, Brazil. These cities are located in the Western portion of the Brazilian Amazon region. The biomass content per hectare, in the virgin forest, was measured by indirect methods using formulas with parameters of forest inventories in the central hectare of the test site. The combustion completeness was estimated by randomly selecting 10% of the total logs and twelve 2 × 2 m2 areas along three transects and examining their consumption rates by the fire. The logs were used to determine the combustion completeness of the larger materials (characteristic diameters larger than 10 cm) and the 2 × 2 m2 areas to determine the combustion completeness of small-size materials (those with characteristic diameters lower than 10 cm) and the. The overall biomass consumption by fire was estimated to be 40.0%, 41.2% and 26.2%, in Cruzeiro do Sul, Rio Branco and Candeias do Jamari, respectively. Considering that the combustion gases of carbon in open fires contain approximately 90.0% of CO2 and 10.0% of CO in volumetric basis, the average emission rates of these gases by the burning process, in the three sites, were estimated as 191 ± 46.7 t ha-1 and 13.5 ± 3.3 t ha-1, respectively.

  9. Oil Prices and Interest Rates: Do They Determine the Exchange Rate?

    ERIC Educational Resources Information Center

    Law, I. A.; Old, J. L.

    1986-01-01

    Argues that the relationship between the British pound sterling, interest rates, and oil prices has been overemphasized by economic commentators because they ignored a basic economic theory about the determination of the exchange rate. Provides an example and suggestions for follow up instruction. (Author/JDH)

  10. Cortical Network Models of Firing Rates in the Resting and Active States Predict BOLD Responses.

    PubMed

    Bennett, Maxwell R; Farnell, Les; Gibson, William G; Lagopoulos, Jim

    2015-01-01

    Measurements of blood oxygenation level dependent (BOLD) signals have produced some surprising observations. One is that their amplitude is proportional to the entire activity in a region of interest and not just the fluctuations in this activity. Another is that during sleep and anesthesia the average BOLD correlations between regions of interest decline as the activity declines. Mechanistic explanations of these phenomena are described here using a cortical network model consisting of modules with excitatory and inhibitory neurons, taken as regions of cortical interest, each receiving excitatory inputs from outside the network, taken as subcortical driving inputs in addition to extrinsic (intermodular) connections, such as provided by associational fibers. The model shows that the standard deviation of the firing rate is proportional to the mean frequency of the firing when the extrinsic connections are decreased, so that the mean BOLD signal is proportional to both as is observed experimentally. The model also shows that if these extrinsic connections are decreased or the frequency of firing reaching the network from the subcortical driving inputs is decreased, or both decline, there is a decrease in the mean firing rate in the modules accompanied by decreases in the mean BOLD correlations between the modules, consistent with the observed changes during NREM sleep and under anesthesia. Finally, the model explains why a transient increase in the BOLD signal in a cortical area, due to a transient subcortical input, gives rises to responses throughout the cortex as observed, with these responses mediated by the extrinsic (intermodular) connections.

  11. Fire and Grazing Influences on Rates of Riparian Woody Plant Expansion along Grassland Streams

    PubMed Central

    Veach, Allison M.; Dodds, Walter K.; Skibbe, Adam

    2014-01-01

    Grasslands are threatened globally due to the expansion of woody plants. The few remaining headwater streams within tallgrass prairies are becoming more like typical forested streams due to rapid conversion of riparian zones from grassy to wooded. Forestation can alter stream hydrology and biogeochemistry. We estimated the rate of riparian woody plant expansion within a 30 m buffer zone surrounding the stream bed across whole watersheds at Konza Prairie Biological Station over 25 years from aerial photographs. Watersheds varied with respect to experimentally-controlled fire and bison grazing. Fire frequency, presence or absence of grazing bison, and the historical presence of woody vegetation prior to the study time period (a proxy for proximity of propagule sources) were used as independent variables to predict the rate of riparian woody plant expansion between 1985 and 2010. Water yield was estimated across these years for a subset of watersheds. Riparian woody encroachment rates increased as burning became less frequent than every two years. However, a higher fire frequency (1–2 years) did not reverse riparian woody encroachment regardless of whether woody vegetation was present or not before burning regimes were initiated. Although riparian woody vegetation cover increased over time, annual total precipitation and average annual temperature were variable. So, water yield over 4 watersheds under differing burn frequencies was quite variable and with no statistically significant detected temporal trends. Overall, burning regimes with a frequency of every 1–2 years will slow the conversion of tallgrass prairie stream ecosystems to forested ones, yet over long time periods, riparian woody plant encroachment may not be prevented by fire alone, regardless of fire frequency. PMID:25192194

  12. Fire and grazing influences on rates of riparian woody plant expansion along grassland streams.

    PubMed

    Veach, Allison M; Dodds, Walter K; Skibbe, Adam

    2014-01-01

    Grasslands are threatened globally due to the expansion of woody plants. The few remaining headwater streams within tallgrass prairies are becoming more like typical forested streams due to rapid conversion of riparian zones from grassy to wooded. Forestation can alter stream hydrology and biogeochemistry. We estimated the rate of riparian woody plant expansion within a 30 m buffer zone surrounding the stream bed across whole watersheds at Konza Prairie Biological Station over 25 years from aerial photographs. Watersheds varied with respect to experimentally-controlled fire and bison grazing. Fire frequency, presence or absence of grazing bison, and the historical presence of woody vegetation prior to the study time period (a proxy for proximity of propagule sources) were used as independent variables to predict the rate of riparian woody plant expansion between 1985 and 2010. Water yield was estimated across these years for a subset of watersheds. Riparian woody encroachment rates increased as burning became less frequent than every two years. However, a higher fire frequency (1-2 years) did not reverse riparian woody encroachment regardless of whether woody vegetation was present or not before burning regimes were initiated. Although riparian woody vegetation cover increased over time, annual total precipitation and average annual temperature were variable. So, water yield over 4 watersheds under differing burn frequencies was quite variable and with no statistically significant detected temporal trends. Overall, burning regimes with a frequency of every 1-2 years will slow the conversion of tallgrass prairie stream ecosystems to forested ones, yet over long time periods, riparian woody plant encroachment may not be prevented by fire alone, regardless of fire frequency.

  13. A feasibility study of oil shale fired pulse combustors with applications to oil shale retorting. Final report

    SciTech Connect

    Morris, G.J.; Johnson, E.K.; Zhang, G.Q.; Roach, R.A.

    1992-07-01

    The results of the experimental investigation performed to determine the feasibility of using pulverized Colorado oil shale to fuel a bench scale pulse combustor reveal that oil shale cannot sustain pulsations when used alone as fuel. Trace amounts of propane mixed with the oil shale enabled the pulsations, however. Up to 80% of the organic material in the oil shale was consumed when it was mixed with propane in the combustor. Beyond the feasibility objectives, the operating conditions of the combustor fuel with propane and mixtures of oil shale and propane were characterized with respect to pulsation amplitude and frequency and the internal combustor wall temperature over fuel lean and fuel rich stoichiometries. Maximum pressure excursions of 12.5 kPa were experienced in the combustor. Pulsation frequencies ranged from 50 to nearly 80 Hz. Cycle resolved laser Doppler anemometry velocities were measured at the tail pipe exit plane. Injecting inert mineral matter (limestone) into the pulse combustor while using propane fuel had only a slight effect on the pulsation frequency for the feed rates tested.

  14. Superclean coal-water slurry combustion testing in an oil-fired boiler. Semiannual technical progress report, August 15, 1992--February 15, 1993

    SciTech Connect

    Miller, B.G.; Pisupati, S.V.; Poe, R.L.; Morrison, J.L.; Xie, J.; Walsh, P.M.; Wincek, R.T.; Clark, D.A.; Scaroni, A.W.

    1993-04-21

    The Pennsylvania State University is conducting a superclean coal-water slurry (SCCWS) program for the United States Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of determining the capability of effectively firing SCCWS in an industrial boiler designed for heavy fuel oil. Penn State has entered into a cooperative agreement with DOE to determine if SCCWS (a fuel containing coal with 3.0 wt.% ash and 0.9 wt.% sulfur) can effectively be burned in a heavy fuel oil-designed industrial boiler without adverse impact on boiler rating, maintainability, reliability, and availability. The project will provide information on the design of new systems specifically configured to fire these clean coal-based fuels. The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) program expansion (additional 1,000 hours of testing). The boiler testing wig determine if the SCCWS combustion characteristics, heat release rate, fouling and slagging behavior, corrosion and erosion limits, and fuel transport, storage, and handling characteristics can be accommodated in an oil-designed boiler system. In addition, the proof-of-concept demonstration will generate data to determine how the properties of SCCWS and its parent coal affect boiler performance. Economic factors associated with retrofitting boilers will be identified

  15. Strategic Petroleum Reserve, West Hackberry oil storage cavern fire and spill of September 21, 1978: an environmental assessment. Final report

    SciTech Connect

    Taylor, A

    1980-02-29

    This report summarizes an environmental assessment of the fire and oil spill at the Strategic Petroleum Reserve site, West Hackberry, Louisiana. Subjective identification of oil contaminated habitats was supported by a more rigorous classification of samples utilizing discriminant analysis. Fourteen contaminated stations were identified along the shore of Black Lake just north and west of Wellpad 6, encompassing approximately 9 hectares. Seasonal variation in the structures of marsh and lake bottom communities in this contaminated area were not generally distinguishable from that of similar communities in uncontaminated habitats along the southern and southeastern shores of Black Lake. The major impact of spilled oil on the marsh vegetation was to accelerate the natural marsh deterioration which will eventually impact animals dependent on marsh vegetation for habitat structure. Vanadium, the predominate trace metal in the oil, and pyrogenic products due to the fire were found at the most distant sampling site (5 km) from Cavern 6 during Phase I, but were not detected downwind of the fire in excess of background levels in the later phases. Remote sensing evaluation of vegetation under the plume also indicated that stress existed immediately after the fire, but had disappeared by the end of the 1-year survey.

  16. 46 CFR 167.45-40 - Fire-fighting equipment on nautical school ships using oil as fuel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... steam propelled nautical school ship of over 1,000 gross tons having one boiler room there shall be..., an extinguisher of the above type shall be provided in each boiler room. On every steam propelled... Requirements § 167.45-40 Fire-fighting equipment on nautical school ships using oil as fuel....

  17. 46 CFR 167.45-40 - Fire-fighting equipment on nautical school ships using oil as fuel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... steam propelled nautical school ship of over 1,000 gross tons having one boiler room there shall be..., an extinguisher of the above type shall be provided in each boiler room. On every steam propelled... Requirements § 167.45-40 Fire-fighting equipment on nautical school ships using oil as fuel....

  18. 46 CFR 167.45-40 - Fire-fighting equipment on nautical school ships using oil as fuel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... steam propelled nautical school ship of over 1,000 gross tons having one boiler room there shall be..., an extinguisher of the above type shall be provided in each boiler room. On every steam propelled... Requirements § 167.45-40 Fire-fighting equipment on nautical school ships using oil as fuel....

  19. A simple method to reconstruct firing rates from dendritic calcium signals.

    PubMed

    Moreaux, Laurent; Laurent, Gilles

    2008-12-01

    Calcium imaging using fluorescent reporters is the most widely used optical approach to investigate activity in intact neuronal circuits with single-cell resolution. Calcium signals, however, are often difficult to interpret, especially if the desired output quantity is membrane voltage or instantaneous firing rates. Combining dendritic intracellular electrophysiology and multi-photon calcium imaging in vivo, we recently investigated the relationship between optical signals recorded with the fluorescent calcium indicator Oregon Green BAPTA-1 (OGB-1) and spike output in principal neurons in the locust antennal lobe. We derived from these experiments a simple, empirical and easily adaptable method requiring minimal calibration to reconstruct firing rates from calcium signals with good accuracy and 50-ms temporal resolution.

  20. Neuronal response impedance mechanism implementing cooperative networks with low firing rates and μs precision.

    PubMed

    Vardi, Roni; Goldental, Amir; Marmari, Hagar; Brama, Haya; Stern, Edward A; Sardi, Shira; Sabo, Pinhas; Kanter, Ido

    2015-01-01

    Realizations of low firing rates in neural networks usually require globally balanced distributions among excitatory and inhibitory links, while feasibility of temporal coding is limited by neuronal millisecond precision. We show that cooperation, governing global network features, emerges through nodal properties, as opposed to link distributions. Using in vitro and in vivo experiments we demonstrate microsecond precision of neuronal response timings under low stimulation frequencies, whereas moderate frequencies result in a chaotic neuronal phase characterized by degraded precision. Above a critical stimulation frequency, which varies among neurons, response failures were found to emerge stochastically such that the neuron functions as a low pass filter, saturating the average inter-spike-interval. This intrinsic neuronal response impedance mechanism leads to cooperation on a network level, such that firing rates are suppressed toward the lowest neuronal critical frequency simultaneously with neuronal microsecond precision. Our findings open up opportunities of controlling global features of network dynamics through few nodes with extreme properties.

  1. Neuronal response impedance mechanism implementing cooperative networks with low firing rates and μs precision

    PubMed Central

    Vardi, Roni; Goldental, Amir; Marmari, Hagar; Brama, Haya; Stern, Edward A.; Sardi, Shira; Sabo, Pinhas; Kanter, Ido

    2015-01-01

    Realizations of low firing rates in neural networks usually require globally balanced distributions among excitatory and inhibitory links, while feasibility of temporal coding is limited by neuronal millisecond precision. We show that cooperation, governing global network features, emerges through nodal properties, as opposed to link distributions. Using in vitro and in vivo experiments we demonstrate microsecond precision of neuronal response timings under low stimulation frequencies, whereas moderate frequencies result in a chaotic neuronal phase characterized by degraded precision. Above a critical stimulation frequency, which varies among neurons, response failures were found to emerge stochastically such that the neuron functions as a low pass filter, saturating the average inter-spike-interval. This intrinsic neuronal response impedance mechanism leads to cooperation on a network level, such that firing rates are suppressed toward the lowest neuronal critical frequency simultaneously with neuronal microsecond precision. Our findings open up opportunities of controlling global features of network dynamics through few nodes with extreme properties. PMID:26124707

  2. Information Transmission and Anderson Localization in two-dimensional networks of firing-rate neurons

    NASA Astrophysics Data System (ADS)

    Natale, Joseph; Hentschel, George

    Firing-rate networks offer a coarse model of signal propagation in the brain. Here we analyze sparse, 2D planar firing-rate networks with no synapses beyond a certain cutoff distance. Additionally, we impose Dale's Principle to ensure that each neuron makes only or inhibitory outgoing connections. Using spectral methods, we find that the number of neurons participating in excitations of the network becomes insignificant whenever the connectivity cutoff is tuned to a value near or below the average interneuron separation. Further, neural activations exceeding a certain threshold stay confined to a small region of space. This behavior is an instance of Anderson localization, a disorder-induced phase transition by which an information channel is rendered unable to transmit signals. We discuss several potential implications of localization for both local and long-range computation in the brain. This work was supported in part by Grants JSMF/ 220020321 and NSF/IOS/1208126.

  3. Firing rate analysis using decompostion-enhanced spike triggered averaging in the quadriceps femoris.

    PubMed

    Conwit, R A; Tracy, B; Cowl, A; McHugh, M; Stashuk, D; Brown, W F; Metter, E J

    1998-10-01

    Electromyographic signals detected from the quadriceps femoris during various constant force contractions were decomposed to identify individual motor unit discharges and mean firing rates (FRs). Subject and group mean FRs were calculated for each force level. Mean FR values and FR variability increased with force. Individual, subject, and group mean FRs showed slight increases until 30% of maximum voluntary contraction and larger increases thereafter. Findings are discussed in relation to motor unit recruitment, frequency modulation, and fatigue. PMID:9736067

  4. Conversion of an 800 MW oil fired generating unit to burn Orimulsion

    SciTech Connect

    Blum, J.; Halpin, M.; Morgan, D.; Alcantara, J.

    1998-07-01

    Florida Power and Light Company (FPL) is proposing to convert the two existing 800 megawatt (MW) residual oil fired generating units at its Manatee Plant located in Parrish, Florida, to burn Ormulsion. Ormulsion is the registered trademark name for a mixture of water and a naturally occurring heavy hydrocarbon known as bitumen. Orimulsion, which originates in Venezuela, will be shipped to Port Manatee in double-hulled vessels, stored at FPL's existing Port Manatee Terminal, and transported via FPL's existing fuel pipeline to the Manatee Plant. The proposed conversion involves modifications of the existing fuel handling facilities, enhancements of the boiler heat transfer surfaces and soot blowing system, and addition of new pollution control equipment. The Manatee Orimulsion conversion will result in overall environmental benefits and significant savings to FPL's customers. This paper summarizes the overall objectives of the project and briefly describes these modifications.

  5. Conversion of an 800 MW oil fired generating unit to burn Orimulsion

    SciTech Connect

    Blum, J.; Halpin, M.; Morgan, D.; Alcantara, J.

    1998-04-01

    Florida Power & Light Company (FPL) is proposing to convert the two existing 800 megawatt (MW) residual oil fired generating units at its Manatee Plant located in Parrish, Florida, to burn Orimulsion. Orimulsion is the registered trademark name for a mixture of water and a naturally occurring heavy hydrocarbon known as bitumen. Orimulsion, which originates in Venezuela, will be shipped to Port Manatee in double-hulled vessels, stored at FPL`s existing Port Manatee Terminal, and transported via FPL`s existing fuel pipeline to the Manatee Plant. The proposed conversion involves modifications of the existing fuel handling facilities, enhancements of the boiler heat transfer surfaces and soot blowing system, and addition of new pollution control equipment. The Manatee Orimulsion conversion will result in overall environmental benefits and significant savings to FPL`s customers. This paper summarizes the overall objectives of the project and briefly describes these modifications.

  6. Calibration and evaluation of the Canadian Forest Fire Weather Index (FWI) System for improved wildland fire danger rating in the United Kingdom

    NASA Astrophysics Data System (ADS)

    de Jong, Mark C.; Wooster, Martin J.; Kitchen, Karl; Manley, Cathy; Gazzard, Rob; McCall, Frank F.

    2016-05-01

    Wildfires in the United Kingdom (UK) pose a threat to people, infrastructure and the natural environment. During periods of particularly fire-prone weather, wildfires can occur simultaneously across large areas, placing considerable stress upon the resources of fire and rescue services. Fire danger rating systems (FDRSs) attempt to anticipate periods of heightened fire risk, primarily for early-warning and preparedness purposes. The UK FDRS, termed the Met Office Fire Severity Index (MOFSI), is based on the Fire Weather Index (FWI) component of the Canadian Forest FWI System. The MOFSI currently provides daily operational mapping of landscape fire danger across England and Wales using a simple thresholding of the final FWI component of the Canadian FWI System. However, it is known that the system has scope for improvement. Here we explore a climatology of the six FWI System components across the UK (i.e. extending to Scotland and Northern Ireland), calculated from daily 2km × 2km gridded numerical weather prediction data and supplemented by long-term meteorological station observations. We used this climatology to develop a percentile-based calibration of the FWI System, optimised for UK conditions. We find this approach to be well justified, as the values of the "raw" uncalibrated FWI components corresponding to a very "extreme" (99th percentile) fire danger situation vary by more than an order of magnitude across the country. Therefore, a simple thresholding of the uncalibrated component values (as is currently applied in the MOFSI) may incur large errors of omission and commission with respect to the identification of periods of significantly elevated fire danger. We evaluate our approach to enhancing UK fire danger rating using records of wildfire occurrence and find that the Fine Fuel Moisture Code (FFMC), Initial Spread Index (ISI) and FWI components of the FWI System

  7. Rate of heat release measurements with the Swedish box test (Nordtest NT fire 004)

    NASA Astrophysics Data System (ADS)

    Holmstedt, G. S.

    A method in which tendency to fire spread and smoke development is determined by gas temperature and smoke intensity measurements in relation to time was examined. The conventional measurement of exhaust gas temperature was tested against a measurement of the rate of heat release, using oxygen consumption calorimetry. Fourteen wall surfaces, including noncombustible materials of different thermal properties, wall linings and wood were used. Slow burning material shows good correlation between temperature measurement and rate of heat release. Fast burning material, however, consumes all the available oxygen and the temperature measurement becomes a measure of the thermal properties of the material.

  8. Shifted encoding strategy in retinal luminance adaptation: from firing rate to neural correlation.

    PubMed

    Xiao, Lei; Zhang, Mingsha; Xing, Dajun; Liang, Pei-Ji; Wu, Si

    2013-10-01

    Neuronal responses to prolonged stimulation attenuate over time. Here, we ask a fundamental question: is adaptation a simple process for the neural system during which sustained input is ignored, or is it actually part of a strategy for the neural system to adjust its encoding properties dynamically? After simultaneously recording the activities of a group of bullfrog's retinal ganglion cells (dimming detectors) in response to sustained dimming stimulation, we applied a combination of information analysis approaches to explore the time-dependent nature of information encoding during the adaptation. We found that at the early stage of the adaptation, the stimulus information was mainly encoded in firing rates, whereas at the late stage of the adaptation, it was more encoded in neural correlations. Such a transition in encoding properties is not a simple consequence of the attenuation of neuronal firing rates, but rather involves an active change in the neural correlation strengths, suggesting that it is a strategy adopted by the neural system for functional purposes. Our results reveal that in encoding a prolonged stimulation, the neural system may utilize concerted, but less active, firings of neurons to encode information.

  9. Calibration and evaluation of the Canadian Forest Fire Weather Index (FWI) System for improved wildland fire danger rating in the UK

    NASA Astrophysics Data System (ADS)

    De Jong, M. C.; Wooster, M. J.; Kitchen, K.; Manley, C.; Gazzard, R.

    2015-11-01

    Wildfires in the United Kingdom (UK) can pose a threat to people, infrastructure and the natural environment (e.g. to the carbon in peat soils), and their simultaneous occurrence within and across UK regions can periodically place considerable stress upon the resources of Fire and Rescue Services. "Fire danger" rating systems (FDRS) attempt to anticipate periods of heightened fire risk, primarily for early-warning purposes. The UK FDRS, termed the Met Office Fire Severity Index (MOFSI) is based on the Fire Weather Index (FWI) component of the Canadian Forest FWI System. MOFSI currently provides operational mapping of landscape fire danger across England and Wales using a simple thresholding of the final FWI component of the Canadian System. Here we explore a climatology of the full set of FWI System components across the entire UK (i.e. extending to Scotland and Northern Ireland), calculated from daily 2 km gridded numerical weather prediction data, supplemented by meteorological station observations. We used this to develop a percentile-based calibration of the FWI System optimised for UK conditions. We find the calibration to be well justified, since for example the values of the "raw" uncalibrated FWI components corresponding to a very "extreme" (99th percentile) fire danger situation can vary by up to an order of magnitude across UK regions. Therefore, simple thresholding of the uncalibrated component values (as is currently applied) may be prone to large errors of omission and commission with respect to identifying periods of significantly elevated fire danger compared to "routine" variability. We evaluate our calibrated approach to UK fire danger rating against records of wildfire occurrence, and find that the Fine Fuel Moisture Code (FFMC), Initial Spread Index (ISI) and final FWI component of the FWI system generally have the greatest predictive skill for landscape fires in Great Britain, with performance varying seasonally and by land cover type. At the

  10. BK channels regulate sinoatrial node firing rate and cardiac pacing in vivo.

    PubMed

    Lai, Michael H; Wu, Yuejin; Gao, Zhan; Anderson, Mark E; Dalziel, Julie E; Meredith, Andrea L

    2014-11-01

    Large-conductance Ca(2+)- and voltage-activated K(+) (BK) channels play prominent roles in shaping muscle and neuronal excitability. In the cardiovascular system, BK channels promote vascular relaxation and protect against ischemic injury. Recently, inhibition of BK channels has been shown to lower heart rate in intact rodents and isolated hearts, suggesting a novel role in heart function. However, the underlying mechanism is unclear. In the present study, we recorded ECGs from mice injected with paxilline (PAX), a membrane-permeable BK channel antagonist, and examined changes in cardiac conduction. ECGs revealed a 19 ± 4% PAX-induced reduction in heart rate in wild-type but not BK channel knockout (Kcnma1(-/-)) mice. The heart rate decrease was associated with slowed cardiac pacing due to elongation of the sinus interval. Action potential firing recorded from isolated sinoatrial node cells (SANCs) was reduced by 55 ± 15% and 28 ± 9% by application of PAX (3 μM) and iberiotoxin (230 nM), respectively. Furthermore, baseline firing rates from Kcnma1(-/-) SANCs were 33% lower than wild-type SANCs. The slowed firing upon BK current inhibition or genetic deletion was due to lengthening of the diastolic depolarization phase of the SANC action potential. Finally, BK channel immunoreactivity and PAX-sensitive currents were identified in SANCs with HCN4 expression and pacemaker current, respectively, and BK channels cloned from SANCs recapitulated similar activation as the PAX-sensitive current. Together, these data localize BK channels to SANCs and demonstrate that loss of BK current decreases SANC automaticity, consistent with slowed sinus pacing after PAX injection in vivo. Furthermore, these findings suggest BK channels are potential therapeutic targets for disorders of heart rate.

  11. 25 CFR 213.23 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Royalty rates for minerals other than oil and gas. 213.23... Royalty rates for minerals other than oil and gas. Unless otherwise authorized by the Commissioner of Indian Affairs, the minimum rates for minerals other than oil and gas shall be as follows: (a)...

  12. Experimental Evaluation the Effectiveness of Water Mist Fire Extinguishing Systems at Oil and Gas Industry

    NASA Astrophysics Data System (ADS)

    Nyashina, G. S.; Medvedev, V. V.; Shevyrev, S. A.; Vysokomornaya, O. V.

    2016-02-01

    Currently mist water is one of the most promising areas of fire protection. We performed an experimental study of phase transformations drops of water mist (range 50 - 500 microns) in motion in a high-temperature (500 - 2000 K) typical products of combustion of petroleum products (gasoline, kerosene, acetone, alcohol). We used high speed (the speed of shooting at least 105 frames per second) and optical methods of recording streams of liquid and gas medium. We determined the effect of the parameters of the test process (the initial temperature and the initial droplet size) at the rate of evaporation of atomized water under these conditions.

  13. Assessment of the histopathological lesions and chemical analysis of feral cats to the smoke from the Kuwait oil fires.

    PubMed

    Moeller, R B; Kalasinsky, V F; Razzaque, M; Centeno, J A; Dick, E J; Abdal, M; Petrov, I I; DeWitt, T W; al-Attar, M; Pletcher, J M

    1994-01-01

    Twenty-six adult or subadult feral cats were collected from Kuwait approximately 8 months after the ignition of the Kuwait oil wells. These animals were obtained from two sources: 12 animals from Kuwait City, a relatively smoke-free area, and 14 from the city of Ahmadi, an area with heavy smoke. Animals were euthanized and a complete set of tissues consisting of all major organs was taken for histopathology. Samples of lung, liver, kidney, urine, and blood were also taken for toxicology. Histopathological lesions observed in the lung were mild accumulations of anthracotic pigment in the lungs of 17 cats. Hyperplasia of the bronchial and bronchiolar gland in 8 cats, and smooth muscle hyperplasia of bronchioles in 14 cats. Tracheal gland hyperplasia was observed in 7 cats, and minimal squamous metaplasia of the tracheal mucosa in 17 cats, Laryngeal lesions consisted of submucosal gland hyperplasia in 2 cats and squamous metaplasia of the mucosa in 5 cats. Hyperplasia of the nasal submucosal glands was observed in 6 animals. The pharyngeal mucosa as well as other organs and organ systems were normal in all cats. Atomic absorption analysis for 11 metals was performed; vanadium and nickel levels (two metals that were present in the smoke from the oil fires) are not indicative of substantial exposure to the oil fires. Based on the histopathological findings and toxicological analysis, it is felt that inhalation of air contaminated with smoke from the oil fires had little or no long-term effect on the animals examined.

  14. Studies of images of short-lived events using ERTS data. [forest fires, oil spills, vegetation damage, volcanoes, storm ridges, earthquakes, and floods

    NASA Technical Reports Server (NTRS)

    Deutschman, W. A. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Detection of short-lived events has continued. Forest fires, oil spills, vegetation damage, volcanoes, storm ridges, earthquakes, and floods have been detected and analyzed.

  15. Forest Fires, Oil Spills, and Fractal Geometry: An Investigation in Two Parts. Part 2: Using Fractal Complexity to Analyze Mathematical Models.

    ERIC Educational Resources Information Center

    Biehl, L. Charles

    1999-01-01

    Presents an activity that utilizes the mathematical models of forest fires and oil spills that were generated (in the first part of this activity, published in the November 1998 issue) by students using probability and cellular automata. (ASK)

  16. Observations of the smoke plume from the December 2005 explosions and prolonged oil fire at Buncefield oil depot, southern UK and associated atmospheric changes

    NASA Astrophysics Data System (ADS)

    Mather, T. A.; Harrison, R. G.; Tsanev, V. I.; Pyle, D. M.; Karumudi, M. L.; Bennett, A. J.; Sawyer, G. M.; Highwood, E. J.

    2006-12-01

    The explosions and subsequent fire at the Buncefield oil depot in December 2005 afforded a rare opportunity to study the atmospheric consequences of a major oil fire at close range, using ground-based remote sensing instruments. The fire burned 5.6 × 107kg of refined fuel (unleaded petrol, aviation fuel and diesel) over 3 days and produced a plume of smoke that extended over much of southern England. Near-source measurements suggest that plume particles were ~50% black carbon (BC) with refractive index 1.73-0.42i, effective radius (Reff) 0.45-0.85μm and mass loading ~2000μg.m-3. About 50km downwind, particles were ~60-75% BC with refractive index between 1.80-0.52i and 1.89-0.69i, Reff ~1.0μm and mass loadings 320-780μg.m-3. Number distributions were almost all monomodal with peak at r<0.1μm. Near-source UV spectroscopy revealed elevated trace gas concentrations of SO2 (70ppb), NO2 (140ppb), HONO (20ppb), HCHO (160ppb) and CS2 (40ppb). We estimate that the Buncefield event emitted totals of ~6.3, 7.2 and 5.5Mg of SO2, HCHO and CS2 respectively; along with ~5500Mg of BC. Our measurements are consistent with others of the Buncefield plume, and with studies of the 1991 Kuwaiti oil-fire plumes; differences from the latter reflecting in part a contrast in source composition (refined fuels vs. crude oils) leading to important potential differences in atmospheric impacts. Measurements made as the plume passed overhead ~50km downwind showed a reduced solar flux reaching the surface but little effect on the atmospheric potential gradient. The wind speed data from the day of the explosion hints at a possible explosion signature.

  17. Oscillatory dynamics in an attractor neural network with firing rate adaptation

    NASA Astrophysics Data System (ADS)

    Rathore, S.; Bush, D.; Latham, P.; Burgess, N.

    2013-01-01

    We develop a framework for generating oscillations in ring attractor networks with firing rate adaptation. We show the relationship between the frequency of rotation around the ring of the shifting bump of activity, the adaptation variable and other model parameters using perturbation theory. The analytic solutions are validated against simulations of such networks. Further preliminary findings indicate that the frequency of these networks can be simply controlled using an external stimulus. The mechanism developed here could potentially be used for temporal coding of position through interference of oscillators of different frequencies.

  18. Modelling study of NOx removal in oil-fired waste off-gases under electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Zwolińska, Ewa; Sun, Yongxia; Chmielewski, A. G.; Nichipor, H.; Bulka, S.

    2015-08-01

    Computer simulations for high concentration of NOx removal from oil-fired waste off-gases under electron beam irradiation were carried out by using the Computer code "Kinetic" and GEAR method. 293 reactions involving 64 species were used for the modelling calculations. The composition of simulated oil-fired off-gas was the same as the experimental conditions. The calculations were made for following system: (75.78% N2+11.5% CO2+8.62% H2O+4.1% O2), NOx concentration varies from 200 ppm to 1500 ppm. Calculation results qualitatively agree with the experimental results. Furthermore the influence of temperature, SO2 concentration and ammonia addition is discussed.

  19. Firing microfine coal with a low NOx, RSFC burner in an industrial boiler designed for oil and gas

    SciTech Connect

    Thornhock, D.E.; Patel, R.; Borio, R.W.; Miller, B.G.; Scaroni, A.W.

    1996-12-31

    ABB Power Plant Laboratories (ABB-PPL) working under a US Department of Energy-Pittsburgh Energy Technology Center (DOE-PETC) contract has carried out tests with the Radially Stratified Flame Core (RSFC) burner which was licensed from the Massachusetts Institute of Technology who developed and patented the RSFC burner. Tests were carried out in a small industrial boiler, designed for oil and natural gas, located at the Energy and Fuels Research Center of Penn State University who was working as a subcontractor to ABB-PPL. The paper presents results from the long-term testing task in the DOE-PETC program with particular attention being paid to the challenges faced in maintaining high combustion efficiencies while achieving low NOx in a small industrial boiler designed for firing oil or natural gas. The paper will also address the issue of ash management when firing coal in a boiler designed for fuels having essentially no ash.

  20. Hardening by cooling rate control and post-firing heat treatment in Pd-Ag-Sn alloy for bonding porcelain.

    PubMed

    Yu, Young-Jun; Seol, Hyo-Joung; Cho, Mi-Hyang; Kim, Hyung-Il; Kwon, Yong Hoon

    2016-01-01

    The aim of this study was to determine the hardening effect by controlling the cooling rate during the porcelain firing process and performing an additional post-firing heat treatment in a Pd-Ag-Sn alloy. The most effective cooling rate for alloy hardening was determined by cooling the specimens at various cooling rates after oxidation treatment. A subsequent porcelain firing simulation followed by cooling at the selected cooling rate was performed. A post-firing heat treatment was then done at 600°C in a porcelain furnace. The hardening mechanism was characterized by a hardness test, X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Alloy softening occurred during the porcelain firing process followed by cooling at a controlled cooling rate. A post-firing heat treatment allowed apparent precipitation hardening. It is advisable to perform a postfiring heat treatment at 600°C in a porcelain furnace by annealing metal substructure after porcelain fusing.

  1. Hardening by cooling rate control and post-firing heat treatment in Pd-Ag-Sn alloy for bonding porcelain.

    PubMed

    Yu, Young-Jun; Seol, Hyo-Joung; Cho, Mi-Hyang; Kim, Hyung-Il; Kwon, Yong Hoon

    2016-01-01

    The aim of this study was to determine the hardening effect by controlling the cooling rate during the porcelain firing process and performing an additional post-firing heat treatment in a Pd-Ag-Sn alloy. The most effective cooling rate for alloy hardening was determined by cooling the specimens at various cooling rates after oxidation treatment. A subsequent porcelain firing simulation followed by cooling at the selected cooling rate was performed. A post-firing heat treatment was then done at 600°C in a porcelain furnace. The hardening mechanism was characterized by a hardness test, X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Alloy softening occurred during the porcelain firing process followed by cooling at a controlled cooling rate. A post-firing heat treatment allowed apparent precipitation hardening. It is advisable to perform a postfiring heat treatment at 600°C in a porcelain furnace by annealing metal substructure after porcelain fusing. PMID:27041022

  2. Declines in oil-rates of stranded birds in the North Sea highlight spatial patterns in reductions of chronic oil pollution.

    PubMed

    Camphuysen, Kees C J

    2010-08-01

    Strandings of oiled seabirds are used to signal the problem of chronic oil pollution. Species-specific oil rates reflect the risk for marine birds to become oiled at sea. High oil rates were characteristic for seabirds common in areas with frequent oil spills; low oil rates for birds wintering away from the busiest shipping lanes. Declining trends in oil-rates were found, reflecting a reduction in the amount of oil intentionally discharged over the past 50years. Spatial patterns in the risk to become oiled could be identified, when the winter distribution patterns of the affected birds were incorporated in the analysis. Declines in oil rates were most pronounced in coastal birds. These trends were consistent with tendencies to police nearshore waters more effectively than offshore waters. While levels of chronic oil pollution are much reduced, future emphasis should be to reduce chronic oiling more effectively in offshore waters.

  3. Chimney related energy losses in oil-fired heating systems: Configuration effects and venting alternatives

    SciTech Connect

    Butcher, T.; McDonald, R.; Krajewski, R.; Batey, J.

    1990-12-01

    Conventional venting systems for oil-fired residential heating equipment include the flue connector, a barometric damper, and the chimney. This venting arrangement is directly responsible for some of the annual energy losses associated with these heating installations. In the work described in this report a study of the relevant characteristics of burners and dampers was done to permit these energy losses to be estimated as a function of the installation details. The purpose of this work is to determine the potential energy savings which might be realized from alternative venting methods in a wide range of situations. The basic draft/flow characteristics of barometric dampers were measured using a flow tunnel arrangement under cold (no combustion) conditions. A range of damper diameters and draft settings were used. Off-cycle draft/flow relations for several burners and heating units with the burner ports sealed were also measured over a range of conditions. Recently, oil burners have become available which have significantly higher static pressure fans. The excess air level provided by these burners is much less sensitive to variations in draft and burners of this type might be operated without a barometric damper. Burner fan performance curves for both high and low static pressure units have been measured. Flows through the heating unit and barometric damper flows have been calculated during the on- and off-cycle for a range of configurations as a function of outdoor temperature. The annual energy losses due to the venting system were calculated using a bin method. The calculated flows were compared with available field data. To supplement the available data some additional field measurements were taken during this project and are described in this report. 19 refs., 42 figs., 7 tabs.

  4. The empirical relationship between satellite-derived tropospheric NO2 and fire radiative power and possible implications for fire emission rates of NOx

    NASA Astrophysics Data System (ADS)

    Schreier, Stefan F.; Richter, Andreas; Kaiser, Johannes W.; Schepaschenko, Dmitry; Shvidenko, Anatoly; Hilboll, Andreas; Burrows, John P.

    2014-05-01

    Vegetation fires across the globe have various impacts on Earth systems such as the atmosphere and biosphere. Every year, large quantities of biomass in different ecosystems are burned, either started by lightning strikes or caused by humans. Consequently, a considerable amount of trace gases (e.g. NOx) and aerosols is released into the atmosphere. As nitrogen oxides (NOx) affect atmospheric chemistry, air quality, and climate, a quantification of the total emissions is needed. Although several approaches have been developed for the estimation of NOx emissions from fires, they still suffer from large uncertainties. We present a simple statistical approach to estimate fire emission rates (FERs) of NOx based on the linear relationship between satellite-observed tropospheric NO2 vertical columns (TVC NO2) and fire radiative power (FRP). While the great advantage of the method is the spatial coverage of FERs and the application to various biomes and regions, the uncertainties in the two retrieved parameters can lead to uncertainties in the FERs. In general, the approach performs well for the tropical and subtropical regions where both the number and the spatial extent of vegetation fires are rather large throughout the fire season. However, due to the smaller number of fires and the patchy spatial occurrence, the estimation of FERs is more complicated in the boreal regions. Nevertheless, it is possible to derive FERs for some characteristic regions in the North American and Eurasian part of the boreal forest biome. The estimated FERs of NOx for the dominating types of vegetation burned are lowest for open shrublands, savannas, and boreal forest (0.28-1.03 g NOx s-1 MW-1) and highest for croplands and woody savannas (0.82-1.56 g NOx s-1 MW-1). Interestingly, there are large regional discrepancies of up to 40 % observed for evergreen broadleaf forest and boreal forest. Possible explanations for these regional discrepancies are discussed.

  5. The compatibility of metal electrodes in the oil fired MHD environment

    SciTech Connect

    Kusaka, Y.; Masuda, T.

    1986-06-01

    An important item in the development of the MHD generator is the development of a durable electrode. This paper investigates the compatibility of metal electrodes to the oil fired MHD environment by examining the degradation mechanism of type 304 steel and SHOMAC steel anodes and W-Cu and WC-Ag cathodes. For purpose of clarification, the authors wish to state that the cathode is the electrode that is bombarded by positive ions from the MHD plasma; the anode is bombarded by negative ions. It is shown that type 304 steel anode loss is due to both corrosion by current and abrasion/sup */ by combustion gas flow, and can be predicted by using empirical equations, if only the surface temperature is given. Abrasion appears if the surface temperature is over about 700 K. General corrosion also occurs on both type 304 steel and SHOMAC steel anodes and is accompanied by the formation of solid oxide scales. On the other hand, W-Cu cathode loss is mostly by abrasion in the current region below about 0.3 A/cm/sup 2/. However, above that current value, corrosion by current increases rapidly due to the generation of intensive arc spots.

  6. Chimney-related energy losses in residential oil-fired heating systems

    SciTech Connect

    Butcher, T.; Celebi, Y.; Krajewski, R. ); Batey, J. )

    1990-01-01

    Conventional venting systems for oil-fired residential heating equipment include the flue connector, a barometric damper, and the chimney. This arrangement is directly responsible for some of the system energy losses, including a part of the off-cycle heat loss and infiltration losses. The magnitude of these losses depends upon the location of the unit, the chimney constuction, and the characteristics of the barometric damper and the burner. In the work described in this paper, a study of the characteristics of burners and dampers was done to permit these energy losses to be estimated as a function of the installation details. The purpose is to determine the energy savings that might be realized from alternative venting methods. Flows through the heating unit and barometric damper flows have been calculated during the on- and off-cycle for a range of configurations as a function of outdoor temperature. Based on these flows, an example of the annual energy losses due to the venting system was calculated using a bin method for a boiler. Generally, the benefits of reducing barometric damper flows are to a great degree offset by increased off-cycle losses in the case of boilers.

  7. Firing-rate resonances in the peripheral auditory system of the cricket, Gryllus bimaculatus.

    PubMed

    Rau, Florian; Clemens, Jan; Naumov, Victor; Hennig, R Matthias; Schreiber, Susanne

    2015-11-01

    In many communication systems, information is encoded in the temporal pattern of signals. For rhythmic signals that carry information in specific frequency bands, a neuronal system may profit from tuning its inherent filtering properties towards a peak sensitivity in the respective frequency range. The cricket Gryllus bimaculatus evaluates acoustic communication signals of both conspecifics and predators. The song signals of conspecifics exhibit a characteristic pulse pattern that contains only a narrow range of modulation frequencies. We examined individual neurons (AN1, AN2, ON1) in the peripheral auditory system of the cricket for tuning towards specific modulation frequencies by assessing their firing-rate resonance. Acoustic stimuli with a swept-frequency envelope allowed an efficient characterization of the cells' modulation transfer functions. Some of the examined cells exhibited tuned band-pass properties. Using simple computational models, we demonstrate how different, cell-intrinsic or network-based mechanisms such as subthreshold resonances, spike-triggered adaptation, as well as an interplay of excitation and inhibition can account for the experimentally observed firing-rate resonances. Therefore, basic neuronal mechanisms that share negative feedback as a common theme may contribute to selectivity in the peripheral auditory pathway of crickets that is designed towards mate recognition and predator avoidance.

  8. Simulation of the interaction between muscle fiber conduction velocity and instantaneous firing rate.

    PubMed

    Fortune, Emma; Lowery, Madeleine M

    2011-01-01

    In this study, the relationships between the early and late afterpotentials and velocity and amplitude recovery functions (VRF and ARF) in skeletal muscle were examined using model simulation. A mathematical model of the muscle fiber action potential, that incorporated a tubular slow potassium conductance, was developed and used to simulate muscle fiber action potentials at a range of interpulse intervals. The slow potassium conductance produced an afterhyperpolarization which resulted in supernormal action potential conduction velocity and amplitude for interpulse intervals>7 ms. Increasing the number of conditioning stimuli caused a further increase in conduction velocity and amplitude, and an additional phase of supernormality, with a peak at approximately 100 ms. Positive correlations between instantaneous firing rate and both conduction velocity and amplitude were also observed during simulation of repetitive stimulation of the muscle fiber. The relationships were eliminated when the slow potassium conductance channel was removed from the model. The results suggest that an afterhyperpolarization, possibly due to a slow tubular potassium conductance, could cause the VRF and ARF observed in muscle. They additionally suggest that the positive correlations between instantaneous firing rate, conduction velocity, and amplitude are directly related to the VRF and ARF. PMID:20848314

  9. Analytical approximations of the firing rate of an adaptive exponential integrate-and-fire neuron in the presence of synaptic noise

    PubMed Central

    Hertäg, Loreen; Durstewitz, Daniel; Brunel, Nicolas

    2014-01-01

    Computational models offer a unique tool for understanding the network-dynamical mechanisms which mediate between physiological and biophysical properties, and behavioral function. A traditional challenge in computational neuroscience is, however, that simple neuronal models which can be studied analytically fail to reproduce the diversity of electrophysiological behaviors seen in real neurons, while detailed neuronal models which do reproduce such diversity are intractable analytically and computationally expensive. A number of intermediate models have been proposed whose aim is to capture the diversity of firing behaviors and spike times of real neurons while entailing the simplest possible mathematical description. One such model is the exponential integrate-and-fire neuron with spike rate adaptation (aEIF) which consists of two differential equations for the membrane potential (V) and an adaptation current (w). Despite its simplicity, it can reproduce a wide variety of physiologically observed spiking patterns, can be fit to physiological recordings quantitatively, and, once done so, is able to predict spike times on traces not used for model fitting. Here we compute the steady-state firing rate of aEIF in the presence of Gaussian synaptic noise, using two approaches. The first approach is based on the 2-dimensional Fokker-Planck equation that describes the (V,w)-probability distribution, which is solved using an expansion in the ratio between the time constants of the two variables. The second is based on the firing rate of the EIF model, which is averaged over the distribution of the w variable. These analytically derived closed-form expressions were tested on simulations from a large variety of model cells quantitatively fitted to in vitro electrophysiological recordings from pyramidal cells and interneurons. Theoretical predictions closely agreed with the firing rate of the simulated cells fed with in-vivo-like synaptic noise. PMID:25278872

  10. Urine vanadium concentrations in workers overhauling an oil-fired boiler.

    PubMed

    Hauser, R; Elreedy, S; Ryan, P B; Christiani, D C

    1998-01-01

    Since fuel oil ash contains vanadium (V), the measurement of urinary levels of V may provide a biological marker in workers exposed to fuel oil ash. The usefulness of urine V samples as a biological monitoring tool ultimately depends on determining the appropriate time of sampling relative to when exposure occurs. Twenty boilermakers were studied during the overhaul of a large oil-fired boiler. A total of 117 urine samples were collected, 65 start-of-shift (S-O-S) and 52 end-of-shift (E-O-S) samples. Air V exposures were estimated with personal sampling devices and work history diaries. Air V concentrations ranged from 0.36 to 32.19 micrograms V/m3, with a mean +/- SD of 19.1 +/- 10.7, and a median of 18.5. On the first day of work on the overhaul, the V urine levels at the E-O-S (mean +/- SD were 1.53 +/- 0.53, median was 1.52 mg V/g creatinine) were significantly higher than those at the S-O-S (0.87 +/- 0.32, median was 0.83), P = 0.004. However, the V concentrations of the S-O-S urine samples on the last Monday of the study were not significantly different from the S-O-S urine levels on the previous Saturday, a time interval of about 38 hr between the end of exposure and sample collection. The Spearman correlation coefficient (r) between the S-O-S urine V and the workplace concentration of V dust during the previous day was r = 0.35. In summary, the results suggest a rapid initial clearance of V (elevating the E-O-S V concentration on the first day of work relative to the S-O-S concentration), followed by a slow clearance that is not complete 38 hr after the end of exposure, as evidenced by the Monday morning urine V concentrations. The Spearman correlations suggest that the S-O-S urine is preferred to the E-O-S urine for across-shift biological monitoring of V exposure.

  11. Aircraft Engine Sump Fire Mitigation

    NASA Technical Reports Server (NTRS)

    Rosenlieb, J. W.

    1973-01-01

    An investigation was performed of the conditions in which fires can result and be controlled within the bearing sump simulating that of a gas turbine engine; Esso 4040 Turbo Oil, Mobil Jet 2, and Monsanto MCS-2931 lubricants were used. Control variables include the oil inlet temperature, bearing temperature, oil inlet and scavenge rates, hot air inlet temperature and flow rate, and internal sump baffling. In addition to attempting spontaneous combustion, an electric spark and a rub (friction) mechanism were employed to ignite fires. Spontaneous combustion was not obtained; however, fires were readily ignited with the electric spark while using each of the three test lubricants. Fires were also ignited using the rub mechanism with the only test lubricant evaluated, Esso 4040. Major parameters controlling ignitions were: Sump configuration; Bearing and oil temperatures, hot air temperature and flow and bearing speed. Rubbing between stationary parts and rotating parts (eg. labyrinth seal and mating rub strip) is a very potent fire source suggesting that observed accidental fires in gas turbine sumps may well arise from this cause.

  12. The empirical relationship between satellite-derived tropospheric NO2 and fire radiative power and possible implications for fire emission rates of NOx

    NASA Astrophysics Data System (ADS)

    Schreier, S. F.; Richter, A.; Kaiser, J. W.; Burrows, J. P.

    2014-03-01

    Nitrogen oxides (NOx) play key roles in atmospheric chemistry, air pollution, and climate. While the largest fraction of these reactive gases is released by anthropogenic emission sources, a significant amount can be attributed to vegetation fires. In this study, NO2 from GOME-2 on board EUMETSAT's MetOp-A and OMI on board NASA's Aura as well as fire radiative power (FRP) from the measurements of MODIS on board NASA's Terra and Aqua satellites are used to derive fire emission rates (FERs) of NOx for different types of vegetation using a simple statistical approach. Monthly means of tropospheric NO2 vertical columns (TVC NO2) have been analyzed for their temporal correlation with the monthly means of FRP for five consecutive years from 2007 to 2011 on a horizontal 1° × 1° grid. The strongest correlation is found to be largely confined to tropical and subtropical regions, which account for more than 80% of yearly burned area, on average, globally. In these regions, the seasonal variation of fire intensity, expressed by the FRP data, is similar to the pattern of TVC NO2. As chemical models typically require values for the amount of NOx being released as a function of time, we have converted the retrieved TVC NO2 into production rates of NOx from fire (Pf) by assuming a constant lifetime of NOx. The comparison between Pf and NOx emissions from the Global Fire Emissions Database (GFEDv3.1) over 5 characteristic biomass burning regions in the tropics and subtropics shows good agreement. By separating the monthly means of Pf and FRP according to land cover type, FERs of NOx could be derived for different biomes. The estimated FERs for the dominating types of vegetation burned are lowest for open shrublands and savannas (0.28-1.03 g NOx s-1 MW-1) and highest for croplands and woody savannas (0.82-1.56 g NOx s-1 MW-1). This analysis demonstrates that the strong empirical relationship between TVC NO2 and FRP and the following simplified assumptions are a useful tool for

  13. Chaos-induced modulation of reliability boosts output firing rate in downstream cortical areas

    NASA Astrophysics Data System (ADS)

    Tiesinga, P. H.

    2004-03-01

    The reproducibility of neural spike train responses to an identical stimulus across different presentations (trials) has been studied extensively. Reliability, the degree of reproducibility of spike trains, was found to depend in part on the amplitude and frequency content of the stimulus [J. Hunter and J. Milton, J. Neurophysiol. 90, 387 (2003)]. The responses across different trials can sometimes be interpreted as the response of an ensemble of similar neurons to a single stimulus presentation. How does the reliability of the activity of neural ensembles affect information transmission between different cortical areas? We studied a model neural system consisting of two ensembles of neurons with Hodgkin-Huxley-type channels. The first ensemble was driven by an injected sinusoidal current that oscillated in the gamma-frequency range (40 Hz) and its output spike trains in turn drove the second ensemble by fast excitatory synaptic potentials with short term depression. We determined the relationship between the reliability of the first ensemble and the response of the second ensemble. In our paradigm the neurons in the first ensemble were initially in a chaotic state with unreliable and imprecise spike trains. The neurons became entrained to the oscillation and responded reliably when the stimulus power was increased by less than 10%. The firing rate of the first ensemble increased by 30%, whereas that of the second ensemble could increase by an order of magnitude. We also determined the response of the second ensemble when its input spike trains, which had non-Poisson statistics, were replaced by an equivalent ensemble of Poisson spike trains. The resulting output spike trains were significantly different from the original response, as assessed by the metric introduced by Victor and Purpura [J. Neurophysiol. 76, 1310 (1996)]. These results are a proof of principle that weak temporal modulations in the power of gamma-frequency oscillations in a given cortical area

  14. Nitrogen-rich and fire-resistant carbon aerogels for the removal of oil contaminants from water.

    PubMed

    Yang, Yu; Tong, Zhen; Ngai, To; Wang, Chaoyang

    2014-05-14

    Effective removal of crude oils, petroleum products, organic solvents, and dyes from water is of significance in oceanography, environmental protection, and industrial production. Various techniques including physical and chemical absorption have been developed, but they suffer from problems such as low separation selectivity, a complicated and lengthy process, as well as high costs for reagents and devices. We present here a new material, termed nitrogen-rich carbon aerogels (NRC aerogels,) with highly porous structure and nitrogen-rich surfaces, exhibiting highly efficient separation of specific substances such as oils and organic pollutants. More importantly, we demonstrate that the fabricated NRC aerogels can also collect micrometer-sized oil droplets from an oil-water mixture with high efficiency that is well beyond what can be achieved by most existing separation methods, but is extremely important in practical marine oil-spill recovery because a certain amount of oils often shears into many micrometer-sized oil droplets by the sea wave, resulting in enormous potential destruction to marine ecosystem if not properly collected. Furthermore, our fabricated material can be used like a recyclable container for oils and chemicals cleanup because the oil/chemical-absorbed NRC aerogels can be readily cleaned for reuse by direct combustion in air because of their excellent hydrophobicity and fire-resistant property. We demonstrate that they keep 61.2% absorption capacity even after 100 absorption/combustion cycles, which thus has the highest recyclability of the reported carbon aerogels. All these features make these fabricated NRC aerogels suitable for a wide range of applications in water purification and treatment.

  15. Assessment of the histopathological lesions and chemical analysis of feral cats to the smoke from Kuwait oil fires

    SciTech Connect

    Moeller, R.B.; Kalasinsky, V.F.; Razzaque, M.; Centeno, J.A.; Dick, E.J.

    1994-12-31

    Twenty-six adult or subadult feral cats were collected from Kuwait approximately 8 months after the ignition of the Kuwait oil wells. These animals were obtained from two sources: 12 animals from Kuwait City, a relatively Co smoke-free area, and 14 from the city of Alimadi, an area with heavy smoke. Animals were euthanized and a complete set of tissues consisting of all 0 major organs was taken for histopathology. Samples of lung, liver, kidney, urine, and blood were also taken for toxicology. Histopathological lesions observed in the lung were mild accumulations of anthracotic pigment in the lungs of 17 cats. Hyperplasia of the bronchial and bronchiolar gland in 8 cats, and smooth muscle hyperplasia of bronchioles in 14 cats. Iracheal gland hyperplasia was observed in 7 cats, and minimal squamous metaplasia of the tracheal mucosa in 17 cats, Laryngeal lesions consisted of submucosal gland hyperplasia in 2 cats and squamous metaplasia of the mucosa in 5 cats. Hyperplasia of the nasal submucosal glands was observed in 6 animals. The pharyngeal mucosa as well as other organs and organ systems (a) were normal in all cats. Atomic absorption analysis for 11 metals was performed; vanadium and nickel levels (two metals that were present in the smoke from the oil fires) are not indicative of substantial exposure to the oil fires. Based on the histopathological findings and toxicological analysis, it is felt that inhalation of air contaminated with smoke from the oil fires had little or no long-term effect on the animals examined.

  16. Assessment of the histopathological lesions and chemical analysis of feral cats to the smoke from the Kuwait oil fires

    SciTech Connect

    Moeller, R.B. Jr.; Dick, E.J.; Pletcher, J.M.

    1994-12-31

    Twenty-six adult or subadult feral cats were collected from Kuwait approximately 8 months after the ignition of the Kuwait oil wells. These animals were obtained from two sources: 12 animals from Kuwait City, a relatively smoke-free area, and 14 from the city of Ahmadi, an area with heavy smoke. Animals were euthanized and a complete set of tissues consisting of all major organs was taken for histopathology. Samples of lung, liver, kidney, urine, and blood were also taken for toxicology. Histopathological lesions observed in the lung were mild accumulations of anthracotic pigment in the lungs of 17 cats. Hyperplasia of the bronchial and bronchiolar gland in 8 cats, and smooth muscle hyperplasia of bronchioles in 14 cats. Tracheal gland hyperplasia was observed in 7 cats, and minimal squamous metaplasia of the tracheal mucosa in 17 cats, Laryngeal lesions consisted of submucosal gland hyperplasia in 2 cats and squamous metaplasia of the mucosa in 5 cats. Hyperplasia of the nasal submucosal glands was observed in 6 animals. The pharyngeal mucosa as well as other organs and organ systems were normal in all cats. Atomic absorption analysis for 11 metals was performed; vanadium and nickel levels (two metals that were present in the smoke from the oil fires) are not indicative of substantial exposure to the oil fires. Based on the histopathological findings and toxicological analysis, it is felt that inhalation of air contaminated with smoke from the oil fires had little or no long-term effect on the animals examined. 36 refs., 3 figs., 7 tabs.

  17. Electron beam technology for multipollutant emissions control from heavy fuel oil-fired boiler.

    PubMed

    Chmielewski, Andrzej G; Ostapczuk, Anna; Licki, Janusz

    2010-08-01

    The electron beam treatment technology for purification of exhaust gases from the burning of heavy fuel oil (HFO) mazout with sulfur content approximately 3 wt % was tested at the Institute of Nuclear Chemistry and Technology laboratory plant. The parametric study was conducted to determine the sulfur dioxide (SO2), oxides of nitrogen (NO(x)), and polycyclic aromatic hydrocarbon (PAH) removal efficiency as a function of temperature and humidity of irradiated gases, absorbed irradiation dose, and ammonia stoichiometry process parameters. In the test performed under optimal conditions with an irradiation dose of 12.4 kGy, simultaneous removal efficiencies of approximately 98% for SO2, and 80% for NO(x) were recorded. The simultaneous decrease of PAH and one-ringed aromatic hydrocarbon (benzene, toluene, and xylenes [BTX]) concentrations was observed in the irradiated flue gas. Overall removal efficiencies of approximately 42% for PAHs and 86% for BTXs were achieved with an irradiation dose 5.3 kGy. The decomposition ratio of these compounds increased with an increase of absorbed dose. The decrease of PAH and BTX concentrations was followed by the increase of oxygen-containing aromatic hydrocarbon concentrations. The PAH and BTX decomposition process was initialized through the reaction with hydroxyl radicals that formed in the electron beam irradiated flue gas. Their decomposition process is based on similar principles as the primary reaction concerning SO2 and NO(x) removal; that is, free radicals attack organic compound chains or rings, causing volatile organic compound decomposition. Thus, the electron beam flue gas treatment (EBFGT) technology ensures simultaneous removal of acid (SO2 and NO(x)) and organic (PAH and BTX) pollutants from flue gas emitted from burning of HFO. This technology is a multipollutant emission control technology that can be applied for treatment of flue gas emitted from coal-, lignite-, and HFO-fired boilers. Other thermal processes such

  18. Effects of oblique air flow on burning rates of square ethanol pool fires.

    PubMed

    Tao, Changfa; He, Yaping; Li, Yuan; Wang, Xishi

    2013-09-15

    The effects of downward airflow on the burning rate and/or burning intensity of square alcohol pool fires for different airflow speeds and directions have been studied experimentally in an inclined wind tunnel. An interesting flame-wrapping phenomenon, caused by impingement of air flow, was observed. The mass burning intensity was found to increase with the airflow speed and the impinging angle. The fuel pan rim temperatures were also measured to study the effect of wind direction and speed on heat transfer from the flame to the fuel source. A model based on heat transfer analysis was developed to correlate the burning intensity with the pan rim characteristic temperature. A good correlation was established between the model results and the experimental results.

  19. Asymmetrical long-run dependence between oil price and US dollar exchange rate-Based on structural oil shocks

    NASA Astrophysics Data System (ADS)

    Jiang, Jiaqi; Gu, Rongbao

    2016-08-01

    The multifractal behavior in cross-correlation between oil prices and exchange rates is examined in this paper. We use the multifractal detrended cross-correlation analysis to investigate the general cross-correlations, and further show that these cross-correlations are asymmetric by multifractal asymmetric cross-correlation analysis. We recover the structural oil shocks and then use these indicators to characterize the asymmetries along with oil price trend itself. Our empirical results show that their asymmetric degrees vary significantly. The sign of oil supply shock leads to the most significant asymmetry among them.

  20. On how correlations between excitatory and inhibitory synaptic inputs maximize the information rate of neuronal firing

    PubMed Central

    Puzerey, Pavel A.; Galán, Roberto F.

    2014-01-01

    Cortical neurons receive barrages of excitatory and inhibitory inputs which are not independent, as network structure and synaptic kinetics impose statistical correlations. Experiments in vitro and in vivo have demonstrated correlations between inhibitory and excitatory synaptic inputs in which inhibition lags behind excitation in cortical neurons. This delay arises in feed-forward inhibition (FFI) circuits and ensures that coincident excitation and inhibition do not preclude neuronal firing. Conversely, inhibition that is too delayed broadens neuronal integration times, thereby diminishing spike-time precision and increasing the firing frequency. This led us to hypothesize that the correlation between excitatory and inhibitory synaptic inputs modulates the encoding of information of neural spike trains. We tested this hypothesis by investigating the effect of such correlations on the information rate (IR) of spike trains using the Hodgkin-Huxley model in which both synaptic and membrane conductances are stochastic. We investigated two different synaptic input regimes: balanced synaptic conductances and balanced currents. Our results show that correlations arising from the synaptic kinetics, τ, and millisecond lags, δ, of inhibition relative to excitation strongly affect the IR of spike trains. In the regime of balanced synaptic currents, for short time lags (δ ~ 1 ms) there is an optimal τ that maximizes the IR of the postsynaptic spike train. Given the short time scales for monosynaptic inhibitory lags and synaptic decay kinetics reported in cortical neurons under physiological contexts, we propose that FFI in cortical circuits is poised to maximize the rate of information transfer between cortical neurons. Our results also provide a possible explanation for how certain drugs and genetic mutations affecting the synaptic kinetics can deteriorate information processing in the brain. PMID:24936182

  1. Closed-loop firing rate regulation of two interacting excitatory and inhibitory neural populations of the basal ganglia.

    PubMed

    Haidar, Ihab; Pasillas-Lépine, William; Chaillet, Antoine; Panteley, Elena; Palfi, Stéphane; Senova, Suhan

    2016-02-01

    This paper develops a new closed-loop firing rate regulation strategy for a population of neurons in the subthalamic nucleus, derived using a model-based analysis of the basal ganglia. The system is described using a firing rate model, in order to analyse the generation of beta-band oscillations. On this system, a proportional regulation of the firing rate reduces the gain of the subthalamo-pallidal loop in the parkinsonian case, thus impeding pathological oscillation generation. A filter with a well-chosen frequency is added to this proportional scheme, in order to avoid a potential instability of the feedback loop due to actuation and measurement delays. Our main result is a set of conditions on the parameters of the stimulation strategy that guarantee both its stability and a prescribed delay margin. A discussion on the applicability of the proposed method and a complete set of mathematical proofs is included.

  2. Effects of barbell deadlift training on submaximal motor unit firing rates for the vastus lateralis and rectus femoris.

    PubMed

    Stock, Matt S; Thompson, Brennan J

    2014-01-01

    Previous investigations that have studied motor unit firing rates following strength training have been limited to small muscles, isometric training, or interventions involving exercise machines. We examined the effects of ten weeks of supervised barbell deadlift training on motor unit firing rates for the vastus lateralis and rectus femoris during a 50% maximum voluntary contraction (MVC) assessment. Twenty-four previously untrained men (mean age  = 24 years) were randomly assigned to training (n = 15) or control (n = 9) groups. Before and following the intervention, the subjects performed isometric testing of the right knee extensors while bipolar surface electromyographic signals were detected from the two muscles. The signals were decomposed into their constituent motor unit action potential trains, and motor units that demonstrated accuracy levels less than 92.0% were not considered for analysis. One thousand eight hundred ninety-two and 2,013 motor units were examined for the vastus lateralis and rectus femoris, respectively. Regression analyses were used to determine the linear slope coefficients (pulses per second [pps]/% MVC) and y-intercepts (pps) of the mean firing rate and firing rate at recruitment versus recruitment threshold relationships. Deadlift training significantly improved knee extensor MVC force (Cohen's d = .70), but did not influence force steadiness. Training had no influence on the slopes and y-intercepts for the mean firing rate and firing rate at recruitment versus recruitment threshold relationships. In agreement with previous cross-sectional comparisons and randomized control trials, our findings do not support the notion that strength training affects the submaximal control of motor units. PMID:25531294

  3. Effects of Barbell Deadlift Training on Submaximal Motor Unit Firing Rates for the Vastus Lateralis and Rectus Femoris

    PubMed Central

    Stock, Matt S.; Thompson, Brennan J.

    2014-01-01

    Previous investigations that have studied motor unit firing rates following strength training have been limited to small muscles, isometric training, or interventions involving exercise machines. We examined the effects of ten weeks of supervised barbell deadlift training on motor unit firing rates for the vastus lateralis and rectus femoris during a 50% maximum voluntary contraction (MVC) assessment. Twenty-four previously untrained men (mean age  = 24 years) were randomly assigned to training (n = 15) or control (n = 9) groups. Before and following the intervention, the subjects performed isometric testing of the right knee extensors while bipolar surface electromyographic signals were detected from the two muscles. The signals were decomposed into their constituent motor unit action potential trains, and motor units that demonstrated accuracy levels less than 92.0% were not considered for analysis. One thousand eight hundred ninety-two and 2,013 motor units were examined for the vastus lateralis and rectus femoris, respectively. Regression analyses were used to determine the linear slope coefficients (pulses per second [pps]/% MVC) and y-intercepts (pps) of the mean firing rate and firing rate at recruitment versus recruitment threshold relationships. Deadlift training significantly improved knee extensor MVC force (Cohen's d = .70), but did not influence force steadiness. Training had no influence on the slopes and y-intercepts for the mean firing rate and firing rate at recruitment versus recruitment threshold relationships. In agreement with previous cross-sectional comparisons and randomized control trials, our findings do not support the notion that strength training affects the submaximal control of motor units. PMID:25531294

  4. Controlling fine particulate and acid mist emissions from a residual oil fired utility boiler with an EDV{trademark} system

    SciTech Connect

    Olen, K.R.; Vincent, H.B.; Jones, G.

    1995-06-01

    Florida Power & Light Company (FPL), in cooperation with the Electric Power Research Institute (EPRI) and Belco Technologies Corporation, evaluated the performance of an EDV system to remove fine particulate and acid mist from untreated flue gas from a residual oil-fired utility boiler. The cosponsored project was carried out using a full-scale EDV module in a slip stream from one of the 400 MW wall-fired boilers at FPL`s Sanford Plant. Particulate, acid gas and chemical analytical data are presented, and used to illustrate the effects of operating variables on EDV performance. EDV system efficiencies of 90% were achieved, which resulted in controlled particulate and SO{sub 3} emissions of less than 10 mg/Nm{sup 3} (0.0065 lbs/10{sup 6}Btu) and 1 ppmv, respectively.

  5. Insecticidal, fumigant, and repellent activities of sweet wormwood oil and its individual components against red imported fire ant workers (Hymenoptera: Formicidae).

    PubMed

    Zhang, Ning; Tang, Liang; Hu, Wei; Wang, Kun; Zhou, You; Li, Hong; Huang, Congling; Chun, Jiong; Zhang, Zhixiang

    2014-01-01

    In total, 29 compounds from sweet wormwood (Artemisia annua L.) oil were identified using gas chromatography-mass spectrometry. The five active components were D-camphor, linalool, cineole, α-terpineol, and L(-)-borneol. The effectiveness of A. annua oil, as well as d-camphor, linalool, cineole, α-terpineol, and L(-)-borneol, as fumigants, contact insecticides, and repellents, were tested on the red imported fire ant Solenopsis invicta Buren. The results indicated that A. annua oil has no significant topical toxicity; however, the spray contact test revealed that it has strong insecticidal activity and the inhibitory effect is stronger during closed exposure than during open exposure. In the fumigant test, cineole and D-camphor exhibited strong fumigant toxicity on minor and major S. invicta workers. They also caused 100% mortality at 5, 3, 2, and 1 mg/centrifuge tube but not at 0.5 mg/centrifuge tube. The mortality rates of linalool, α-terpineol, and L(-)-borneol exceeded 80% at 5, 3, and 2 mg/centrifuge tube. In the repellent test, cineole and d-camphor showed significant repellency at 100, 10, and 1 mg/kg. However, linalool, α-terpineol, and L(-)-borneol significantly facilitated digging at 10 and 1 mg/kg.

  6. Insecticidal, fumigant, and repellent activities of sweet wormwood oil and its individual components against red imported fire ant workers (Hymenoptera: Formicidae).

    PubMed

    Zhang, Ning; Tang, Liang; Hu, Wei; Wang, Kun; Zhou, You; Li, Hong; Huang, Congling; Chun, Jiong; Zhang, Zhixiang

    2014-01-01

    In total, 29 compounds from sweet wormwood (Artemisia annua L.) oil were identified using gas chromatography-mass spectrometry. The five active components were D-camphor, linalool, cineole, α-terpineol, and L(-)-borneol. The effectiveness of A. annua oil, as well as d-camphor, linalool, cineole, α-terpineol, and L(-)-borneol, as fumigants, contact insecticides, and repellents, were tested on the red imported fire ant Solenopsis invicta Buren. The results indicated that A. annua oil has no significant topical toxicity; however, the spray contact test revealed that it has strong insecticidal activity and the inhibitory effect is stronger during closed exposure than during open exposure. In the fumigant test, cineole and D-camphor exhibited strong fumigant toxicity on minor and major S. invicta workers. They also caused 100% mortality at 5, 3, 2, and 1 mg/centrifuge tube but not at 0.5 mg/centrifuge tube. The mortality rates of linalool, α-terpineol, and L(-)-borneol exceeded 80% at 5, 3, and 2 mg/centrifuge tube. In the repellent test, cineole and d-camphor showed significant repellency at 100, 10, and 1 mg/kg. However, linalool, α-terpineol, and L(-)-borneol significantly facilitated digging at 10 and 1 mg/kg. PMID:25525106

  7. Microfine coal firing results from a retrofit gas/oil-designed industrial boiler

    SciTech Connect

    Patel, R.; Borio, R.W.; Liljedahl, G.

    1995-11-01

    Under US Department of Energy, Pittsburgh Energy Technology Center (PETC) support, the development of a High Efficiency Advanced Coal Combustor (HEACC) has been in progress since 1987 at the ABB Power Plant Laboratories. The initial work on this concept produced an advanced coal firing system that was capable of firing both water-based and dry pulverized coal in an industrial boiler environment.

  8. Pacific Northwest Laboratory Gulfstream I measurements of the Kuwait oil-fire plume, July--August 1991

    SciTech Connect

    Busness, K M; Hales, J M; Hannigan, R V; Thorp, J M; Tomich, S D; Warren, M J; Al-Sunaid, A A; Daum, P H; Mazurek, M

    1992-11-01

    In 1991, the Pacific Northwest Laboratory conducted a series of aircraft measurements to determine pollutant and radiative properties of the smoke plume from oil fires in Kuwait. This work was sponsored by the US Department emanating of Energy, in cooperation with several other agencies as part of an extensive effort coordinated by the World Meteorological Organization, to obtain a comprehensive data set to assess the characteristics of the plume and its environmental impact. This report describes field measurement activities and introduces the various data collected, but provides only limited analyses of these data. Results of further data analyses will be presented in subsequent open-literature publications.

  9. Population density methods for stochastic neurons with realistic synaptic kinetics: firing rate dynamics and fast computational methods.

    PubMed

    Apfaltrer, Felix; Ly, Cheng; Tranchina, Daniel

    2006-12-01

    An outstanding problem in computational neuroscience is how to use population density function (PDF) methods to model neural networks with realistic synaptic kinetics in a computationally efficient manner. We explore an application of two-dimensional (2-D) PDF methods to simulating electrical activity in networks of excitatory integrate-and-fire neurons. We formulate a pair of coupled partial differential-integral equations describing the evolution of PDFs for neurons in non-refractory and refractory pools. The population firing rate is given by the total flux of probability across the threshold voltage. We use an operator-splitting method to reduce computation time. We report on speed and accuracy of PDF results and compare them to those from direct, Monte-Carlo simulations. We compute temporal frequency response functions for the transduction from the rate of postsynaptic input to population firing rate, and examine its dependence on background synaptic input rate. The behaviors in the1-D and 2-D cases--corresponding to instantaneous and non-instantaneous synaptic kinetics, respectively--differ markedly from those for a somewhat different transduction: from injected current input to population firing rate output (Brunel et al. 2001; Fourcaud & Brunel 2002). We extend our method by adding inhibitory input, consider a 3-D to 2-D dimension reduction method, demonstrate its limitations, and suggest directions for future study. PMID:17162461

  10. A database on post-fire erosion rates and debris flows in Mediterranean-Basin watersheds

    NASA Astrophysics Data System (ADS)

    Parise, M.; Cannon, S. H.

    2009-04-01

    proceedings. The database derives from critical analysis of the existing literature, integrated by case studies directly studied by the authors. Studies on recently burned areas in the Mediterranean basin are most frequently carried out on small experimental plots, often with simulated rainfall A problem of scale therefore exists when trying to extrapolate the erosion rates (also reported as sediment yields or as sediment losses) from these studies to a watershed scale. Very few articles, on the other hand, were found that document the watershed-scale response of basins to rainfall-induced erosion and debris flows following wildfires. The few reported cases of debris flows in the Mediterranean Basin describe erosion of sediment from the hillslopes and the channels (sometimes down to bedrock), and, for a limited number of sites, failure of discrete landslides. This information indicates that debris-flow generation from recently burned areas in the Mediterranean basin appears to occur primarily through sediment bulking processes. Nevertheless, the database so far compiled shows a distribution of post-fire erosion and debris flows in the western Mediterranean basin (Spain, essentially, but also Portugal), followed by the eastern Mediterranean area (Israel), and then by France, Italy and Greece. Even though still in a preliminary version, that needs to be integrated and updated from further sources, our data compilation allows for the unique opportunity to examine issues related to the generation of post-wildfire debris flows across a variety of environments and under a variety of conditions, and to move from a qualitative conception of the controls on post-fire debris-flow generation to the definition of specific conditions that result in their occurrence. Future activities of the project will include: i) updating and integration of the preliminary version of the database; ii) development of models that can be used to identify the probability of debris-flow occurrence and the

  11. Effects of oil on the rate and trajectory of Louisiana marsh shoreline erosion

    NASA Astrophysics Data System (ADS)

    McClenachan, Giovanna; Turner, R. Eugene; Tweel, Andrew W.

    2013-12-01

    Oil can have long-term detrimental effects on marsh plant health, both above- and belowground. However, there are few data available that quantify the accelerated rate of erosion that oil may cause to marshes and the trajectory of change. Between November 2010 and August 2012, we collected data on shoreline erosion, soil strength, per cent cover of Spartina alterniflora, and marsh edge overhang at 30 closely spaced low oil and high oil sites in Bay Batiste, Louisiana. Surface oil samples were taken one meter into the marsh in February 2011. All high oiled sites in Bay Batiste were contaminated with Macondo 252 oil (oil from the Deepwater Horizon oil spill, 20 April-15 July 2010). The results suggest that there is a threshold where soil parameters change dramatically with a relatively small increase in oil concentration in the soil. Heavy oiling weakens the soil, creating a deeper undercut of the upper 50 cm of the marsh edge, and causing an accelerated rate of erosion that cascades along the shoreline. Our results demonstrate that it could take at least 2 yr to document the effects heavy oiling has had on the marsh shoreline. The presence of aboveground vegetation alone may not be an appropriate indicator of recovery.

  12. 25 CFR 213.23 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Royalty rates for minerals other than oil and gas. 213.23 Section 213.23 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF... Royalty rates for minerals other than oil and gas. Unless otherwise authorized by the Commissioner...

  13. 25 CFR 213.23 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Royalty rates for minerals other than oil and gas. 213.23 Section 213.23 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF... Royalty rates for minerals other than oil and gas. Unless otherwise authorized by the Commissioner...

  14. Motor unit firing rates of the gastrocnemii during maximal brief steady-state contractions in humans.

    PubMed

    Graham, Mitchell T; Rice, Charles L; Dalton, Brian H

    2016-02-01

    The human triceps surae (soleus, medial (MG) and lateral (LG) gastrocnemii) is complex and important for posture and gait. The soleus exhibits markedly lower motor unit firing rates (MUFRs; ∼16Hz) during maximal voluntary isometric contraction (MVC) than other limb muscles, but this information is unknown for the MG and LG. During multiple visits, subjects performed a series of 5-7, ∼7-s plantar flexor MVCs with tungsten microelectrodes inserted into the MG and LG. During a separate testing session, another group of subjects performed submaximal isometric contractions at 25%, 50%, and 75% MVC with inserted fine-wires in the MG, LG and soleus. Maximum steady-state MUFRs for MG and LG (∼23Hz) were not different, but faster than prior reports for the soleus. No differences between the three triceps surae components were detected for 25% or 50% MVC, but at 75% MVC, the MG MUFRs were 31% greater than soleus. The triceps surae exhibit similar torque modulation strategies at <75% MVC, but to achieve higher contraction intensities (>75% MVC) the gastrocnemii rely on faster rates to generate maximal torque than the soleus. Therefore, the MG and LG exhibit a larger range of MUFR capacities.

  15. Modelling a historic oil-tank fire allows an estimation of the sensitivity of the infrared receptors in pyrophilous Melanophila beetles.

    PubMed

    Schmitz, Helmut; Bousack, Herbert

    2012-01-01

    Pyrophilous jewel beetles of the genus Melanophila approach forest fires and there is considerable evidence that these beetles can detect fires from great distances of more than 60 km. Because Melanophila beetles are equipped with infrared receptors and are also attracted by hot surfaces it can be concluded that these infrared receptors are used for fire detection.The sensitivity of the IR receptors is still unknown. The lowest threshold published so far is 0.6 W/m(2) which, however, cannot explain the detection of forest fires by IR radiation from distances larger than approximately 10 km. To investigate the possible sensitivity of the IR receptors we assumed that beetles use IR radiation for remote fire detection and we made use of a historic report about a big oil-tank fire in Coalinga, California, in 1924. IR emission of an oil-tank fire can be calculated by "pool fire" simulations which now are used for fire safety and risk analysis. Assuming that beetles were lured to the fire from the nearest forests 25 and 130 km away, our results show that detection from a distance of 25 km requires a threshold of the IR receptors of at least 3×10(-2) W/m(2). According to our investigations most beetles became aware of the fire from a distance of 130 km. In this case the threshold has to be 1.3×10(-4) W/m(2). Because such low IR intensities are buried in thermal noise we suggest that the infrared sensory system of Melanophila beetles utilizes stochastic resonance for the detection of weak IR radiation. Our simulations also suggest that the biological IR receptors might be even more sensitive than uncooled technical IR sensors. Thus a closer look into the mode of operation of the Melanophila IR receptors seems promising for the development of novel IR sensors.

  16. Heterogeneous effects of oil shocks on exchange rates: evidence from a quantile regression approach.

    PubMed

    Su, Xianfang; Zhu, Huiming; You, Wanhai; Ren, Yinghua

    2016-01-01

    The determinants of exchange rates have attracted considerable attention among researchers over the past several decades. Most studies, however, ignore the possibility that the impact of oil shocks on exchange rates could vary across the exchange rate returns distribution. We employ a quantile regression approach to address this issue. Our results indicate that the effect of oil shocks on exchange rates is heterogeneous across quantiles. A large US depreciation or appreciation tends to heighten the effects of oil shocks on exchange rate returns. Positive oil demand shocks lead to appreciation pressures in oil-exporting countries and this result is robust across lower and upper return distributions. These results offer rich and useful information for investors and decision-makers. PMID:27516925

  17. Heterogeneous effects of oil shocks on exchange rates: evidence from a quantile regression approach.

    PubMed

    Su, Xianfang; Zhu, Huiming; You, Wanhai; Ren, Yinghua

    2016-01-01

    The determinants of exchange rates have attracted considerable attention among researchers over the past several decades. Most studies, however, ignore the possibility that the impact of oil shocks on exchange rates could vary across the exchange rate returns distribution. We employ a quantile regression approach to address this issue. Our results indicate that the effect of oil shocks on exchange rates is heterogeneous across quantiles. A large US depreciation or appreciation tends to heighten the effects of oil shocks on exchange rate returns. Positive oil demand shocks lead to appreciation pressures in oil-exporting countries and this result is robust across lower and upper return distributions. These results offer rich and useful information for investors and decision-makers.

  18. Lognormal distribution of firing time and rate from a single neuron?

    PubMed

    Kish, Eszter A; Granqvist, Claes-Göran; Dér, András; Kish, Laszlo B

    2015-08-01

    Even a single neuron may be able to produce significant lognormal features in its firing statistics due to noise in the charging ion current. A mathematical scheme introduced in advanced nanotechnology is relevant for the analysis of this mechanism in the simplest case, the integrate-and-fire model with white noise in the charging ion current.

  19. Recovery rates, enhanced oil recovery and technological limits.

    PubMed

    Muggeridge, Ann; Cockin, Andrew; Webb, Kevin; Frampton, Harry; Collins, Ian; Moulds, Tim; Salino, Peter

    2014-01-13

    Enhanced oil recovery (EOR) techniques can significantly extend global oil reserves once oil prices are high enough to make these techniques economic. Given a broad consensus that we have entered a period of supply constraints, operators can at last plan on the assumption that the oil price is likely to remain relatively high. This, coupled with the realization that new giant fields are becoming increasingly difficult to find, is creating the conditions for extensive deployment of EOR. This paper provides a comprehensive overview of the nature, status and prospects for EOR technologies. It explains why the average oil recovery factor worldwide is only between 20% and 40%, describes the factors that contribute to these low recoveries and indicates which of those factors EOR techniques can affect. The paper then summarizes the breadth of EOR processes, the history of their application and their current status. It introduces two new EOR technologies that are beginning to be deployed and which look set to enter mainstream application. Examples of existing EOR projects in the mature oil province of the North Sea are discussed. It concludes by summarizing the future opportunities for the development and deployment of EOR.

  20. Recovery rates, enhanced oil recovery and technological limits.

    PubMed

    Muggeridge, Ann; Cockin, Andrew; Webb, Kevin; Frampton, Harry; Collins, Ian; Moulds, Tim; Salino, Peter

    2014-01-13

    Enhanced oil recovery (EOR) techniques can significantly extend global oil reserves once oil prices are high enough to make these techniques economic. Given a broad consensus that we have entered a period of supply constraints, operators can at last plan on the assumption that the oil price is likely to remain relatively high. This, coupled with the realization that new giant fields are becoming increasingly difficult to find, is creating the conditions for extensive deployment of EOR. This paper provides a comprehensive overview of the nature, status and prospects for EOR technologies. It explains why the average oil recovery factor worldwide is only between 20% and 40%, describes the factors that contribute to these low recoveries and indicates which of those factors EOR techniques can affect. The paper then summarizes the breadth of EOR processes, the history of their application and their current status. It introduces two new EOR technologies that are beginning to be deployed and which look set to enter mainstream application. Examples of existing EOR projects in the mature oil province of the North Sea are discussed. It concludes by summarizing the future opportunities for the development and deployment of EOR. PMID:24298076

  1. Recovery rates, enhanced oil recovery and technological limits

    PubMed Central

    Muggeridge, Ann; Cockin, Andrew; Webb, Kevin; Frampton, Harry; Collins, Ian; Moulds, Tim; Salino, Peter

    2014-01-01

    Enhanced oil recovery (EOR) techniques can significantly extend global oil reserves once oil prices are high enough to make these techniques economic. Given a broad consensus that we have entered a period of supply constraints, operators can at last plan on the assumption that the oil price is likely to remain relatively high. This, coupled with the realization that new giant fields are becoming increasingly difficult to find, is creating the conditions for extensive deployment of EOR. This paper provides a comprehensive overview of the nature, status and prospects for EOR technologies. It explains why the average oil recovery factor worldwide is only between 20% and 40%, describes the factors that contribute to these low recoveries and indicates which of those factors EOR techniques can affect. The paper then summarizes the breadth of EOR processes, the history of their application and their current status. It introduces two new EOR technologies that are beginning to be deployed and which look set to enter mainstream application. Examples of existing EOR projects in the mature oil province of the North Sea are discussed. It concludes by summarizing the future opportunities for the development and deployment of EOR. PMID:24298076

  2. 40 CFR 75.12 - Specific provisions for monitoring NOX emission rate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Specific provisions for monitoring NOX... provisions for monitoring NOX emission rate. (a) Coal-fired units, gas-fired nonpeaking units or oil-fired... for a NOX continuous emission monitoring system (CEMS) for each affected coal-fired unit,...

  3. 40 CFR 75.12 - Specific provisions for monitoring NOX emission rate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Specific provisions for monitoring NOX... provisions for monitoring NOX emission rate. (a) Coal-fired units, gas-fired nonpeaking units or oil-fired... for a NOX continuous emission monitoring system (CEMS) for each affected coal-fired unit,...

  4. 40 CFR 75.12 - Specific provisions for monitoring NOX emission rate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Specific provisions for monitoring NOX... provisions for monitoring NOX emission rate. (a) Coal-fired units, gas-fired nonpeaking units or oil-fired... for a NOX continuous emission monitoring system (CEMS) for each affected coal-fired unit,...

  5. Effects of remote stimulation on the mean firing rate of cat retinal ganglion cells.

    PubMed

    Passaglia, C L; Enroth-Cugell, C; Troy, J B

    2001-08-01

    Visual stimulation outside the classical receptive field can have pronounced effects on cat retinal ganglion cells. We characterized the effects of such stimulation by varying the contrast, spatial frequency, temporal frequency, and spatial extent of remote drifting sinusoidal gratings. We found that the mean firing rate of some X-cells and most Y-cells increased to remote gratings of low spatial frequency and high temporal frequency and decreased to ones of high spatial frequency and low temporal frequency. At least 10-20% contrast was required to see either effect, which quickly saturated at higher contrasts. Both effects were substantial, raising or lowering the mean rate of some cells by over 40 impulses/sec. Classical receptive field mechanisms were not involved because the remote gratings caused little or no response modulation. We conclude that, in addition to a mean-increasing mechanism known from previous work, a mean-decreasing one operates in the cat retina. This mechanism prefers slower motion and resolves finer patterns than the mean-increasing one. We incorporate these findings into a model consisting of pools of small and large rectifying subunits of opposite polarity. Model estimates of subunit radius were primarily independent of eccentricity and averaged approximately 0.15 and approximately 0.60 degrees for the mean-decreasing and mean-increasing mechanisms, respectively. This makes the subunits approximately the center size of central X- and Y-cells. Because smooth movements of the eyes, head, or body should engage these mechanisms under natural conditions, we propose that the mean rate changes that would ensue are functionally relevant to cat vision. PMID:11466451

  6. An Investigation of Size-Dependent Concentration of Trace Elements in Aerosols Emitted from the Oil-Fired Heating Plants

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; Sentell, R. J.; Khandelwal, G. S.

    1976-01-01

    Aerosols emitted from two oil-fired heating plants were aerodynamically separated into eight size groups and were analyzed using the photon-induced X-ray emission (PIXE) technique. It was found that Zn, Mo, Ag, and Pb, and (to a lesser extent) Cd, have a tendency to concentrate preferentially on the smaller aerosols. All of these elements, in certain chemical forms, are known to be toxic. Zinc and molybdenum, although present in low concentrations in the parent fuels, show the strongest tendencies to be concentrated in finer aerosols. Selenium, previously reported to show a very strong tendency to concentration in finer fly ash from coal-fired power plants shows little preference for surface residence. Vanadium, which occurs in significant concentration in the oil fuels for both plants, also shows little preference for surface concentration. Even though the absolute concentrations of the toxic elements involved are well below the safety levels established by the National Institute for Occupational Safety and Health (NIOSH), it would be advisable to raise the heights of the heating-plant exhaust chimneys well above the neighborhood buildings to insure more efficient aerosol dispersal.

  7. Fire emission rates of NOx based on the empirical relationship between satellite-derived tropospheric NO2 and fire radiative power

    NASA Astrophysics Data System (ADS)

    Schreier, S. F.; Richter, A.; Kaiser, J. W.; Burrows, J. P.

    2013-11-01

    Nitrogen oxides (NOx) play key roles in atmospheric chemistry, air pollution, and climate. While the largest fraction of these reactive gases is released by anthropogenic emission sources, a significant amount can be attributed to vegetation fires. In this study, NO2 from GOME-2 on board EUMETSAT's MetOp-A and OMI on board NASA's Aura as well as fire radiative power (FRP) from the measurements of MODIS on board NASA's Terra and Aqua are used to derive fire emission rates (FERs) of NOx for different types of vegetation using a simple statistical approach. Monthly means of tropospheric NO2 vertical columns (TVC NO2) have been analyzed for their temporal correlation with the monthly means of FRP for five consecutive years from 2007 to 2011 on a horizontal 1° × 1° grid. The strongest correlation is found to be largely confined to tropical and subtropical regions, which account for more than 80% of yearly burned area on average globally. In these regions, the seasonal variation of fire intensity, expressed by the FRP data, is similar to the pattern of TVC NO2. As chemical models typically require values for the amount of NOx being released as a function of time, we have converted the retrieved TVC NO2 into production rates of NOx from fire (Pf) by assuming a constant lifetime of NOx. The comparison between Pf and NOx emissions from GFEDv3.1 over 5 characteristic biomass burning regions in the tropics and subtropics indicated good agreement. By separating the monthly means of Pf and FRP according to land cover type, FERs of NOx could be derived for different biomes. The estimated FERs for the dominating types of vegetation burned are lowest for open shrublands and savannas (0.28-1.03 g NOx s-1 MW-1) and highest for croplands and woody savannas (0.82-1.56 g NOx s-1 MW-1). This analysis demonstrates clearly that there are biome-specific, diurnal, and regional differences in FERs for the dominating types of vegetation burned in the tropics and subtropics. Possible

  8. Impacts, recovery rates, and treatment options for spilled oil in marshes.

    PubMed

    Michel, Jacqueline; Rutherford, Nicolle

    2014-05-15

    In a review of the literature on impacts of spilled oil on marshes, 32 oil spills and field experiments were identified with sufficient data to generate recovery curves and identify influencing factors controlling the rate of recovery. For many spills, recovery occurred within 1-2 growing seasons, even in the absence of any treatment. Recovery was longest for spills with the following conditions: Cold climate; sheltered settings; thick oil on the marsh surface; light refined products with heavy loading; oils that formed persistent thick residues; and intensive treatment. Recovery was shortest for spills with the following conditions: Warm climate; light to heavy oiling of the vegetation only; medium crude oils; and less-intensive treatment. Recommendations are made for treatment based on the following oiling conditions: Free-floating oil on the water in the marsh; thicker oil (>0.5 cm) on marsh surface; thinner oil (<0.5 cm) on marsh surface; heavy oil loading on vegetation; and light to moderate oil loading on vegetation.

  9. Action potential energetics at the organismal level reveal a trade-off in efficiency at high firing rates.

    PubMed

    Lewis, John E; Gilmour, Kathleen M; Moorhead, Mayron J; Perry, Steve F; Markham, Michael R

    2014-01-01

    The energetic costs of action potential (AP) production constrain the evolution of neural codes and brain networks. Cellular-level estimates of AP-related costs are typically based on voltage-dependent Na(+) currents that drive active transport by the Na(+)/K(+) ATPase to maintain the Na(+) and K(+) ion concentration gradients necessary for AP production. However, these estimates of AP cost have not been verified at the organismal level. Electric signaling in the weakly electric fish Eigenmannia virescens requires that specialized cells in an electric organ generate APs with large Na(+) currents at high rates (200-600 Hz). We measured these currents using a voltage-clamp protocol and then estimated the energetic cost at the cellular level using standard methods. We then used this energy-intensive signaling behavior to measure changes in whole-animal energetics for small changes in electric discharge rate. At low rates, the whole-animal measure of AP cost was similar to our cellular-level estimates. However, AP cost increased nonlinearly with increasing firing rates. We show, with a biophysical model, that this nonlinearity can arise from the increasing cost of maintaining AP amplitude at high rates. Our results confirm that estimates of energetic costs based on Na(+) influx are appropriate for low baseline firing rates, but that extrapolating to high firing rates may underestimate true costs in cases in which AP amplitude does not decrease. Moreover, the trade-off between energetic cost and firing rate suggests an additional constraint on the evolution of high-frequency signaling in neuronal systems. PMID:24381281

  10. Modelling Odor Decoding in the Antennal Lobe by Combining Sequential Firing Rate Models with Bayesian Inference

    PubMed Central

    Cuevas Rivera, Dario; Bitzer, Sebastian; Kiebel, Stefan J.

    2015-01-01

    The olfactory information that is received by the insect brain is encoded in the form of spatiotemporal patterns in the projection neurons of the antennal lobe. These dense and overlapping patterns are transformed into a sparse code in Kenyon cells in the mushroom body. Although it is clear that this sparse code is the basis for rapid categorization of odors, it is yet unclear how the sparse code in Kenyon cells is computed and what information it represents. Here we show that this computation can be modeled by sequential firing rate patterns using Lotka-Volterra equations and Bayesian online inference. This new model can be understood as an ‘intelligent coincidence detector’, which robustly and dynamically encodes the presence of specific odor features. We found that the model is able to qualitatively reproduce experimentally observed activity in both the projection neurons and the Kenyon cells. In particular, the model explains mechanistically how sparse activity in the Kenyon cells arises from the dense code in the projection neurons. The odor classification performance of the model proved to be robust against noise and time jitter in the observed input sequences. As in recent experimental results, we found that recognition of an odor happened very early during stimulus presentation in the model. Critically, by using the model, we found surprising but simple computational explanations for several experimental phenomena. PMID:26451888

  11. Modelling Odor Decoding in the Antennal Lobe by Combining Sequential Firing Rate Models with Bayesian Inference.

    PubMed

    Cuevas Rivera, Dario; Bitzer, Sebastian; Kiebel, Stefan J

    2015-10-01

    The olfactory information that is received by the insect brain is encoded in the form of spatiotemporal patterns in the projection neurons of the antennal lobe. These dense and overlapping patterns are transformed into a sparse code in Kenyon cells in the mushroom body. Although it is clear that this sparse code is the basis for rapid categorization of odors, it is yet unclear how the sparse code in Kenyon cells is computed and what information it represents. Here we show that this computation can be modeled by sequential firing rate patterns using Lotka-Volterra equations and Bayesian online inference. This new model can be understood as an 'intelligent coincidence detector', which robustly and dynamically encodes the presence of specific odor features. We found that the model is able to qualitatively reproduce experimentally observed activity in both the projection neurons and the Kenyon cells. In particular, the model explains mechanistically how sparse activity in the Kenyon cells arises from the dense code in the projection neurons. The odor classification performance of the model proved to be robust against noise and time jitter in the observed input sequences. As in recent experimental results, we found that recognition of an odor happened very early during stimulus presentation in the model. Critically, by using the model, we found surprising but simple computational explanations for several experimental phenomena. PMID:26451888

  12. Modelling a Historic Oil-Tank Fire Allows an Estimation of the Sensitivity of the Infrared Receptors in Pyrophilous Melanophila Beetles

    PubMed Central

    Schmitz, Helmut; Bousack, Herbert

    2012-01-01

    Pyrophilous jewel beetles of the genus Melanophila approach forest fires and there is considerable evidence that these beetles can detect fires from great distances of more than 60 km. Because Melanophila beetles are equipped with infrared receptors and are also attracted by hot surfaces it can be concluded that these infrared receptors are used for fire detection. The sensitivity of the IR receptors is still unknown. The lowest threshold published so far is 0.6 W/m2 which, however, cannot explain the detection of forest fires by IR radiation from distances larger than approximately 10 km. To investigate the possible sensitivity of the IR receptors we assumed that beetles use IR radiation for remote fire detection and we made use of a historic report about a big oil-tank fire in Coalinga, California, in 1924. IR emission of an oil-tank fire can be calculated by “pool fire” simulations which now are used for fire safety and risk analysis. Assuming that beetles were lured to the fire from the nearest forests 25 and 130 km away, our results show that detection from a distance of 25 km requires a threshold of the IR receptors of at least 3×10−2 W/m2. According to our investigations most beetles became aware of the fire from a distance of 130 km. In this case the threshold has to be 1.3×10−4 W/m2. Because such low IR intensities are buried in thermal noise we suggest that the infrared sensory system of Melanophila beetles utilizes stochastic resonance for the detection of weak IR radiation. Our simulations also suggest that the biological IR receptors might be even more sensitive than uncooled technical IR sensors. Thus a closer look into the mode of operation of the Melanophila IR receptors seems promising for the development of novel IR sensors. PMID:22629433

  13. Differences in globus pallidus neuronal firing rates and patterns relate to different disease biology in children with dystonia

    PubMed Central

    McClelland, V M; Valentin, A; Rey, H G; Lumsden, D E; Elze, M C; Selway, R; Alarcon, G; Lin, J-P

    2016-01-01

    Background The pathophysiology underlying different types of dystonia is not yet understood. We report microelectrode data from the globus pallidus interna (GPi) and globus pallidus externa (GPe) in children undergoing deep brain stimulation (DBS) for dystonia and investigate whether GPi and GPe firing rates differ between dystonia types. Methods Single pass microelectrode data were obtained to guide electrode position in 44 children (3.3–18.1 years, median 10.7) with the following dystonia types: 14 primary, 22 secondary Static and 8 progressive secondary to neuronal brain iron accumulation (NBIA). Preoperative stereotactic MRI determined coordinates for the GPi target. Digitised spike trains were analysed offline, blind to clinical data. Electrode placement was confirmed by a postoperative stereotactic CT scan. Findings We identified 263 GPi and 87 GPe cells. Both GPi and GPe firing frequencies differed significantly with dystonia aetiology. The median GPi firing frequency was higher in the primary group than in the secondary static group (13.5 Hz vs 9.6 Hz; p=0.002) and higher in the NBIA group than in either the primary (25 Hz vs 13.5 Hz; p=0.006) or the secondary static group (25 Hz vs 9.6 Hz; p=0.00004). The median GPe firing frequency was higher in the NBIA group than in the secondary static group (15.9 Hz vs 7 Hz; p=0.013). The NBIA group also showed a higher proportion of regularly firing GPi cells compared with the other groups (p<0.001). A higher proportion of regular GPi cells was also seen in patients with fixed/tonic dystonia compared with a phasic/dynamic dystonia phenotype (p<0.001). The GPi firing frequency showed a positive correlation with 1-year outcome from DBS measured by improvement in the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS-m) score (p=0.030). This association was stronger for the non-progressive patients (p=0.006). Interpretation Pallidal firing rates and patterns differ significantly with dystonia aetiology

  14. Fresh and weathered crude oil effects on potential denitrification rates of coastal marsh soil.

    PubMed

    Pietroski, Jason P; White, John R; DeLaune, Ronald D; Wang, Jim J; Dodla, Syam K

    2015-09-01

    On April 20, 2010, the Deepwater Horizon oil platform experienced an explosion which triggered the largest marine oil spill in US history, resulting in the release of ∼795 million L of crude oil into the Gulf of Mexico. Once oil reached the surface, changes in overall chemical composition occurred due to volatilization of the smaller carbon chain compounds as the oil was transported onshore by winds and currents. In this study, the toxic effects of both fresh and weathered crude oil on denitrification rates of coastal marsh soil were determined using soil samples collected from an unimpacted coastal marsh site proximal to areas that were oiled in Barataria Bay, LA. The 1:10 ratio of crude oil:field moist soil fully coated the soil surface mimicking a heavy oiling scenario. Potential denitrification rates at the 1:10 ratio, for weathered crude oil, were 46 ± 18.4% of the control immediately after exposure and 62 ± 8.0% of the control following a two week incubation period, suggesting some adaptation of the denitrifying microbial consortium over time. Denitrification rates of soil exposed to fresh crude oil were 51.5 ± 5.3% of the control after immediate exposure and significantly lower at 10.9 ± 1.1% after a 2 week exposure period. Results suggest that fresh crude oil has the potential to more severely impact the important marsh soil process of denitrification following longer term exposure. Future studies should focus on longer-term denitrification as well as changes in the microbial consortia in response to oil exposure. PMID:25929872

  15. 25 CFR 213.24 - Rate of rents and royalties on oil and gas leases.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Rate of rents and royalties on oil and gas leases. 213.24... of rents and royalties on oil and gas leases. The lessee shall pay, beginning with the date of approval of oil and gas leases by the Secretary of the Interior, a rental of $1.25 per acre per annum...

  16. Evaluation of Oil Sands Projects and Their Expansion Rate Using Real Options

    NASA Astrophysics Data System (ADS)

    Kobari, Laleh

    The rapidly expanding oil sands of western Canada, the third largest reserves in the world, are creating serious challenges, such as ecological harm, labour shortages, and extensive natural gas consumption. This thesis develops three practical real options models to evaluate the feasibility of oil sands projects and to estimate the optimal rate of oil sands expansion, while accounting for the stated concerns. (Abstract shortened by UMI.).

  17. Aircraft Engine Sump Fire Mitigation, Phase 2

    NASA Technical Reports Server (NTRS)

    Rosenlieb, J. W.

    1978-01-01

    The effect of changes in the input parameters (air leakage flow rate and temperature and lubricating oil inlet flow rate and temperature) over a specified range on the flammability conditions within an aircraft engine bearing sump was investigated. An analytical study was performed to determine the effect of various parameters on the generation rate of oil vapor from oil droplets in a hot air stream flowing in a cylindrical tube. The ignition of the vapor-air mixture by an ignition source was considered. The experimental investigation demonstrated that fires would be ignited by a spark ignitor over the full range of air and oil flow rates and air temperatures evaluated. However, no fires could be ignited when the oil inlet temperature was maintained below 41.7 K (290 F). The severity of the fires ignited were found to be directly proportional to the hot air flow rate. Reasonably good correlation was found between the mixture temperature in the sump at the ignitor location and the flammability limits as defined by flammability theory; thus a fairly reliable experimental method of determining flammable conditions within a sump was demonstrated. The computerized mathematical model shows that oil droplet size and air temperature have the greatest influence on the generation rate of oil vapor.

  18. Varying relative degradation rates of oil in different forms and environments revealed by ramped pyrolysis.

    PubMed

    Pendergraft, Matthew A; Rosenheim, Brad E

    2014-09-16

    Degradation of oil contamination yields stabilized products by removing and transforming reactive and volatile compounds. In contaminated coastal environments, the processes of degradation are influenced by shoreline energy, which increases the surface area of the oil as well as exchange between oil, water, sediments, microbes, oxygen, and nutrients. Here, a ramped pyrolysis carbon isotope technique is employed to investigate thermochemical and isotopic changes in organic material from coastal environments contaminated with oil from the 2010 BP Deepwater Horizon oil spill. Oiled beach sediment, tar ball, and marsh samples were collected from a barrier island and a brackish marsh in southeast Louisiana over a period of 881 days. Stable carbon ((13)C) and radiocarbon ((14)C) isotopic data demonstrate a predominance of oil-derived carbon in the organic material. Ramped pyrolysis profiles indicate that the organic material was transformed into more stable forms. Our data indicate relative rates of stabilization in the following order, from fastest to slowest: high energy beach sediments > low energy beach sediments > marsh > tar balls. Oil was transformed most rapidly where shoreline energy and the rates of oil dispersion and exchange with water, sediments, microbes, oxygen, and nutrients were greatest. Still, isotope data reveal persistence of oil. PMID:25105342

  19. Varying relative degradation rates of oil in different forms and environments revealed by ramped pyrolysis.

    PubMed

    Pendergraft, Matthew A; Rosenheim, Brad E

    2014-09-16

    Degradation of oil contamination yields stabilized products by removing and transforming reactive and volatile compounds. In contaminated coastal environments, the processes of degradation are influenced by shoreline energy, which increases the surface area of the oil as well as exchange between oil, water, sediments, microbes, oxygen, and nutrients. Here, a ramped pyrolysis carbon isotope technique is employed to investigate thermochemical and isotopic changes in organic material from coastal environments contaminated with oil from the 2010 BP Deepwater Horizon oil spill. Oiled beach sediment, tar ball, and marsh samples were collected from a barrier island and a brackish marsh in southeast Louisiana over a period of 881 days. Stable carbon ((13)C) and radiocarbon ((14)C) isotopic data demonstrate a predominance of oil-derived carbon in the organic material. Ramped pyrolysis profiles indicate that the organic material was transformed into more stable forms. Our data indicate relative rates of stabilization in the following order, from fastest to slowest: high energy beach sediments > low energy beach sediments > marsh > tar balls. Oil was transformed most rapidly where shoreline energy and the rates of oil dispersion and exchange with water, sediments, microbes, oxygen, and nutrients were greatest. Still, isotope data reveal persistence of oil.

  20. CFD analysis of turboprop engine oil cooler duct for best rate of climb condition

    NASA Astrophysics Data System (ADS)

    Kalia, Saurabh; CA, Vinay; Hegde, Suresh M.

    2016-09-01

    Turboprop engines are widely used in commuter category airplanes. Aircraft Design bureaus routinely conduct the flight tests to confirm the performance of the system. The lubrication system of the engine is designed to provide a constant supply of clean lubrication oil to the engine bearings, the reduction gears, the torque-meter, the propeller and the accessory gearbox. The oil lubricates, cools and also conducts foreign material to the oil filter where it is removed from further circulation. Thus a means of cooling the engine oil must be provided and a suitable oil cooler (OC) and ducting system was selected and designed for this purpose. In this context, it is relevant to study and analyse behaviour of the engine oil cooler system before commencing actual flight tests. In this paper, the performance of the oil cooler duct with twin flush NACA inlet housed inside the nacelle has been studied for aircraft best rate of climb (ROC) condition using RANS based SST K-omega model by commercial software ANSYS Fluent 13.0. From the CFD analysis results, it is found that the mass flow rate captured and pressure drop across the oil cooler for the best ROC condition is meeting the oil cooler manufacturer requirements thus, the engine oil temperature is maintained within prescribed limits.

  1. Oil in the Water, Fire in the Sky: Responding to Technological/Environmental Disasters

    ERIC Educational Resources Information Center

    Lazarus, Philip J.; Sulkowski, Michael L.

    2010-01-01

    On April 20, 2010, a massive explosion killed 11 workers on the Deepwater Horizon oil rig. Survivors of this explosion recounted terrifying near-death experiences and mourned the loss of coworkers and friends who had perished. Shock and grief spread through small coastal communities composed mostly of fishers and oil workers. However, this was…

  2. Literature Survey of Crude Oil Properties Relevant to Handling and Fire Safety in Transport.

    SciTech Connect

    Lord, David; Luketa, Anay; Wocken, Chad; Schlasner, Steve; Aulich, Ted; Allen, Ray; Rudeen, David Keith

    2015-03-01

    Several fiery rail accidents in 2013-2015 in the U.S. and Canada carrying crude oil produced from the Bakken region of North Dakota have raised questions at many levels on the safety of transporting this, and other types of crude oil, by rail. Sandia National Laboratories was commissioned by the U.S. Department of Energy to investigate the material properties of crude oils, and in particular the so-called "tight oils" like Bakken that comprise the majority of crude oil rail shipments in the U.S. at the current time. The current report is a literature survey of public sources of information on crude oil properties that have some bearing on the likelihood or severity of combustion events that may occur around spills associated with rail transport. The report also contains background information including a review of the notional "tight oil" field operating environment, as well a basic description of crude oils and potential combustion events in rail transport. This page intentionally blank

  3. Air injection project breathes fire into aging West Hackberry oil field

    SciTech Connect

    Duey, R.

    1996-02-01

    Amoco, the DOE and LSU seek more oil from Gulf Coast salt dome fields with air injection technique. The West Hackberry Field in Louisiana is a water-driven reservoir. By injecting air into the high-pressure, high-temperature reservoir rock, the water is backed down, allowing the oil to drain off the steeply dipped rock.

  4. CHARACTERIZATION OF AIR TOXICS FROM AN OIL-FIRED FIRETUBE BOILER

    EPA Science Inventory

    Tests were conducted on a commercially available firetube package boiler running on #2 through #6 oils to determine the emissions levels of hazardous air pollutants (HAPs) from the combustion of four fuel oils. Flue gas was sampled to determine levels of volatile and semivolatile...

  5. Co-Firing Oil Shale with Coal and Other Fuels for Improved Efficiency and Multi-Pollutant Control

    SciTech Connect

    Robert A. Carrington; William C. Hecker; Reed Clayson

    2008-06-01

    Oil shale is an abundant, undeveloped natural resource which has natural sorbent properties, and its ash has natural cementitious properties. Oil shale may be blended with coal, biomass, municipal wastes, waste tires, or other waste feedstock materials to provide the joint benefit of adding energy content while adsorbing and removing sulfur, halides, and volatile metal pollutants, and while also reducing nitrogen oxide pollutants. Oil shale depolymerization-pyrolysis-devolatilization and sorption scoping studies indicate oil shale particle sorption rates and sorption capacity can be comparable to limestone sorbents for capture of SO2 and SO3. Additionally, kerogen released from the shale was shown to have the potential to reduce NOx emissions through the well established “reburning” chemistry similar to natural gas, fuel oil, and micronized coal. Productive mercury adsorption is also possible by the oil shale particles as a result of residual fixed-carbon and other observed mercury capture sorbent properties. Sorption properties were found to be a function particle heating rate, peak particle temperature, residence time, and gas-phase stoichmetry. High surface area sorbents with high calcium reactivity and with some adsorbent fixed/activated carbon can be produced in the corresponding reaction zones that exist in a standard pulverized-coal or in a fluidized-bed combustor.

  6. Jaipur Indian Oil Fire of 29 September 2009 and Associated Atmospheric and Meteorological Changes Using Multi Sensor Data

    NASA Astrophysics Data System (ADS)

    Chauhan, Akshansha; Sharma, Manish; Mehdi, Waseem; Singh, Rachita; Mishra, Sunil K.; Singh, Ramesh

    An intense fire occurred at Indian Oil Corporation (IOC) located at Sitapur near Jaipur city on 29 October 2009 around 6.00 pm. High flames up to 70 ft were seen and emission of black plumes were observed over few days. The huge fire killed few and injured a dozen of people. Soon after this huge fire, people living in the adjoining areas escaped and a spurt of patients complaining respiratory problems were reported and taken to the nearest hospital for medical care. The people living in the surrounding villages suffered eye irritation, rashes and were also rushed to the nearest hospital for emergency care. Huge amount of carbon soot was seen in the atmosphere which was deposited in the field and houses. Huge emission of toxic gases like CO, CO2, SO2, NOx were due to burning of oil, although the routine observed data by the Central Pollution Control Board was not made available so it was difficult to comment on the exact amount of these toxic gases. These gases modify the atmospheric composition initially over the IOC region and with time dispersed in the direction of wind towards south-eastern parts affecting major cities Kota, Gwalior, etc. Soon after the fire, cloudy conditions were observed over Delhi which is north-east of IOC, with a thick smog which interrupted road and air traffic for a couple of days. An analysis of multi satellite sensor data (MODIS, AIRS, OMI AURA, AMSER) were carried out. Terra MODIS Image (1 km and 250 m resolution) clearly shows the dispersion of plume. The plume shows south-east direction due to dominance of north-westerly wind in the region. Numerous atmospheric (aerosol optical depth, angstrom coefficient, water vapor and CO mixing ratio, total ozone column) and meteorological parameters (air temperature, relative humidity) are found change. AIRS data show the enhancement of carbon monoxide and changes in atmospheric parameters at around 500 hPa pressure level in the nearby cities due to dispersion in the direction of wind towards

  7. Complete Firing-Rate Response of Neurons with Complex Intrinsic Dynamics.

    PubMed

    Puelma Touzel, Maximilian; Wolf, Fred

    2015-12-01

    The response of a neuronal population over a space of inputs depends on the intrinsic properties of its constituent neurons. Two main modes of single neuron dynamics-integration and resonance-have been distinguished. While resonator cell types exist in a variety of brain areas, few models incorporate this feature and fewer have investigated its effects. To understand better how a resonator's frequency preference emerges from its intrinsic dynamics and contributes to its local area's population firing rate dynamics, we analyze the dynamic gain of an analytically solvable two-degree of freedom neuron model. In the Fokker-Planck approach, the dynamic gain is intractable. The alternative Gauss-Rice approach lifts the resetting of the voltage after a spike. This allows us to derive a complete expression for the dynamic gain of a resonator neuron model in terms of a cascade of filters on the input. We find six distinct response types and use them to fully characterize the routes to resonance across all values of the relevant timescales. We find that resonance arises primarily due to slow adaptation with an intrinsic frequency acting to sharpen and adjust the location of the resonant peak. We determine the parameter regions for the existence of an intrinsic frequency and for subthreshold and spiking resonance, finding all possible intersections of the three. The expressions and analysis presented here provide an account of how intrinsic neuron dynamics shape dynamic population response properties and can facilitate the construction of an exact theory of correlations and stability of population activity in networks containing populations of resonator neurons. PMID:26720924

  8. Complete Firing-Rate Response of Neurons with Complex Intrinsic Dynamics

    PubMed Central

    Puelma Touzel, Maximilian; Wolf, Fred

    2015-01-01

    The response of a neuronal population over a space of inputs depends on the intrinsic properties of its constituent neurons. Two main modes of single neuron dynamics–integration and resonance–have been distinguished. While resonator cell types exist in a variety of brain areas, few models incorporate this feature and fewer have investigated its effects. To understand better how a resonator’s frequency preference emerges from its intrinsic dynamics and contributes to its local area’s population firing rate dynamics, we analyze the dynamic gain of an analytically solvable two-degree of freedom neuron model. In the Fokker-Planck approach, the dynamic gain is intractable. The alternative Gauss-Rice approach lifts the resetting of the voltage after a spike. This allows us to derive a complete expression for the dynamic gain of a resonator neuron model in terms of a cascade of filters on the input. We find six distinct response types and use them to fully characterize the routes to resonance across all values of the relevant timescales. We find that resonance arises primarily due to slow adaptation with an intrinsic frequency acting to sharpen and adjust the location of the resonant peak. We determine the parameter regions for the existence of an intrinsic frequency and for subthreshold and spiking resonance, finding all possible intersections of the three. The expressions and analysis presented here provide an account of how intrinsic neuron dynamics shape dynamic population response properties and can facilitate the construction of an exact theory of correlations and stability of population activity in networks containing populations of resonator neurons. PMID:26720924

  9. Physical properties and oxidation rates of unrefined menhaden oil (Brevoortia patronus).

    PubMed

    Yin, Huaixia; Sathivel, Subramaniam

    2010-04-01

    Unrefined menhaden oil was evaluated for thermal and rheological properties and its temperature-dependent viscosity and lipid oxidation rate were determined. Peroxide value, free fatty acids, density, specific gravity, water activity, moisture content, and enthalpy of the unrefined menhaden oil were 5.70 meq/kg, 3.80%, 0.93 g/mL, 0.93%, 0.52%, 0.15%, and 20.2 kJ/kg, respectively. The melting point range of unrefined menhaden oil was found to be -69.5 to 27.21 degrees C. The menhaden oil exhibited non-Newtonian fluid behavior at lower temperatures (5 to 25 degrees C), while it behaved like a Newtonian fluid at 30 degrees C. The oil apparent viscosity at 5 degrees C (0.22 Pa.s) was significantly higher (P < 0.05) than that at 30 degrees C (0.033 Pa.s). The average magnitude of activation energy for viscosity of the unrefined menhaden oil was 50.37 kJ/mol. The predicted apparent viscosity agreed (R(2)= 0.9837) satisfactorily with the experimental apparent viscosity. The minimal lipid oxidation rate of the oil was found at 25 and 35 degrees C for 6 h, higher lipid oxidation rates were observed when the oil was heated for 6 h at 45 to 85 degrees C. The rate of lipid oxidation for unrefined menhaden oil was temperature dependent (R(2)= 0.9425). This study showed that the magnitude of the apparent viscosity and oxidation rate of the unrefined menhaden oil was greatly influenced by temperature. PMID:20492290

  10. A model to predict rate of dissolution of toxic compounds into seawater from an oil spill.

    PubMed

    Riazi, M R; Roomi, Y A

    2008-01-01

    In this paper a semianalytical model has been proposed to predict the rate at which oil components dissolve in water when an oil spill occurs in a marine environment. The model breaks the oil into a number of pseudocomponents proportional to the number of compounds originally present in the oil and calculates the rate of dissolution for each component. In addition, the components are divided into paraffinic, naphthenic, and aromatic hydrocarbon types and the amount of dissolution of each pseudocomponent is calculated versus time. In this method the concentration of most toxic components of oil (mainly monoaromatics) is determined. The model considers variable surface area and slick thickness and requires oil specifications (i.e., American Petroleum Institute [API] gravity and boiling point) in addition to air and water temperatures and speeds. The model has been applied to a Kuwaiti crude oil and its products naphtha and kerosene samples at 20 degrees C and 40 degrees C. The results could be useful in selection of an appropriate method for oil spill clean up as well as simulation of environmental impact of oil spill from toxicity points of view. PMID:19037808

  11. Changes in cat medullary neurone firing rates and synchrony following induction of respiratory long-term facilitation

    PubMed Central

    Morris, K F; Shannon, R; Lindsey, B G

    2001-01-01

    Long-term facilitation is a respiratory memory expressed as an increase in motor output lasting more than an hour. This change is induced by repeated hypoxia, stimulation of carotid chemoreceptors, or electrical stimulation of the carotid sinus nerve or brainstem mid-line. The present work addressed the hypothesis that persistent changes in medullary respiratory neural networks contribute to long-term facilitation. Carotid chemoreceptors were stimulated by close arterial injection of CO2-saturated saline solution. Phrenic nerve efferent activity and up to 30 single medullary neurones were recorded simultaneously in nucleus tractus solitarii (NTS) including the dorsal respiratory group (DRG), Bötzinger-ventral respiratory group (Böt-VRG), and nucleus raphe obscurus of nine adult cats, anaesthetized, injected with a neuromuscular blocking agent, vagotomized and artificially ventilated. The firing rates of 87 of 105 neurones (83 %) changed following induction of long-term facilitation. Nine of eleven DRG and Böt-VRG putative premotor inspiratory neurones had increased firing rates with long-term facilitation. Fourteen of twenty-one raphe obscurus neurones with control firing rates less than 4 Hz had significant long-term increases in activity. Cross-correlogram analysis suggested that there were changes in effective connectivity of neuron pairs with long-term facilitation. Joint peristimulus time histograms and pattern detection methods used with ‘gravity’ analysis also detected changes in short time scale correlations associated with long-term facilitation. The results suggest that changes in firing rates and synchrony of VRG and DRG premotor neurones and altered effective connectivity among other functionally antecedent elements of the medullary respiratory network contribute to the expression of long-term facilitation. PMID:11306666

  12. Why the poor pay with their lives: oil pipeline vandalisation, fires and human security in Nigeria.

    PubMed

    Onuoha, Freedom C

    2009-07-01

    Since its discovery in Nigeria in 1956 crude oil has been a source of mixed blessing to the country. It is believed to have generated enormous wealth, but it has also claimed a great many lives. Scholarly attention on the impact of oil on security in Nigeria has largely focused on internal conflicts rather than on how disasters associated with oil pipeline vandalisation have impacted on human security in terms of causing bodily injuries and death, destroying livelihoods and fracturing families. This paper examines how pipeline vandalisation affects human security in these ways. It identifies women and children as those who are hardest hit and questions why the poor are the most vulnerable in oil pipeline disasters in this country. It recommends the adoption of a comprehensive and integrated framework of disaster management that will ensure prompt response to key early warning signs, risk-reduction and appropriate mitigation and management strategies.

  13. Investigation of Biomass Combustion Rate of Fire Radiative Energy Using Multiple-Satellite-observed Active Fires and Landsat TM Burn Severities across the Continental United States

    NASA Astrophysics Data System (ADS)

    Li, F.; Zhang, X.; Kondragunta, S.

    2015-12-01

    Biomass burning is a major source of atmospheric aerosol and greenhouse gases that substantially influence climate and regional air quality. However, the accuracy of biomass burning emissions estimated using traditional method is limited by large uncertainties in burned area and fuel loading. Alternatively, fire radiative energy (FRE) has recently been demonstrated to be linearly related to biomass combustion, which potentially improves the estimation of biomass burning emissions. The FRE-based combustion rate is 0.368-0.453 kg/MJ according to field controlled experiments while it varies from 1.37-4.5 kg/MJ derived from satellite-based bottom-up and top-down aerosol optical thickness estimates. Here we investigate the FRE combustion rate in over 1000 burn scars from 2011 to 2012 across the Continental United States (CONUS). Specifically, FRE was calculated by combining the high spatial observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the high temporal observations from the Geostationary Operational Environmental Satellite (GOES). Biomass consumption in burn scars was modeled using Landsat TM 30m burn severities, 30m fuel loading from Fuel Characteristic Classification System, and combustion completeness compiled from recent literatures. The combustion rate was then investigated by correlating FRE to biomass consumption across CONUS and Bailey's ecoregions. Our results show that the combustion rate can be extracted from the linear relationship between biomass consumption and FRE. The combustion rate is 0.415±10% kg/MJ across CONUS, which is similar to the rate derived from field experiments. However, it varies from 0.18-1.9 kg/MJ among ecoregions. This implies that a single combustion rate could produce large uncertainty in the estimation of biomass consumption at large scales. We suggest that ecoregion specified combustion rates should help to improve the accuracy of quantifying biomass burning emissions regionally and globally.

  14. [Study on effect of oil-bearing solution environment of Caryophylli Flos and other traditional Chinese medicines on system flux and oil recovery rate].

    PubMed

    Fan, Wen-Ling; Guo, Li-Wei; Lin, Ying; Shen, Jie; Cao, Gui-Ping; Zhu, Yun; Xu, Min; Yang, Lei

    2013-10-01

    The membrane enrichment process of traditional Chinese medicine volatile oil is environmental friendly and practical, with a good application prospect. In this article, oil-bearing solutions of eight traditional Chinese medicines, namely Caryophylli Flos, Schizonepetae Herba, Eupatorii Herb, Acori Talarinowii Rhizoma, Magnoliae Flos, Chrysanthemum indicum, Cyperi Rhizoma and Citri Reticulatae Pericarpium Viride, were taken as the experimental system. Under unified conditions (membrane: PVDF-14W, temperature: 40 degreeC, pressure: 0. 1 MPa, membrane surface speed: 150 r min- 1), trans-membrane was conducted for above eight oil-bearing solutions to explore the effect of their oil-bearing solution environment on system flux and oil recovery rate. The results showed that systems with smaller pH had a lower flux, without significant effect on oil recovery rate. Greater differences between the surface tension of solutions and that of pure water contributed to a lower oil recovery rate. The conductivity had no notable effect on membrane enrichment process. Systems with high turbidity had a lower flux, without remarkable effect on oil recovery rat. Heavy oils showed lower flux than light ones, but with a slightly higher oil recovery rat. Systems with higher viscosity had a lower flux than those with lower viscosity. Except for Magnoliae Flos volatile oil, all of the remaining volatile oils showed a much higher oil recovery rat than systems with high viscosity. The above results could provide data support and theoretical basis for the industrialization of membrane enrichment volatile oil technology. PMID:24422391

  15. Rates of post-fire vegetation recovery and fuel accumulation as a function of burn severity and time-since-burn in four western U.S. ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation recovery and fuel accumulation rates following wildfire are useful measures of ecosystem resilience, yet few studies have quantified these variables over 10 years post-fire. Conventional wisdom is that recovery time to pre-fire condition will be slower as a function of burn severity, as i...

  16. Identifying key climate and environmental factors affecting rates of post-fire big sagebrush (Artemisia tridentata) recovery in the northern Columbia Basin, USA

    USGS Publications Warehouse

    Shinneman, Douglas; McIlroy, Susan

    2016-01-01

    Sagebrush steppe of North America is considered highly imperilled, in part owing to increased fire frequency. Sagebrush ecosystems support numerous species, and it is important to understand those factors that affect rates of post-fire sagebrush recovery. We explored recovery of Wyoming big sagebrush (Artemisia tridentata ssp.wyomingensis) and basin big sagebrush (A. tridentata ssp. tridentata) communities following fire in the northern Columbia Basin (Washington, USA). We sampled plots across 16 fires that burned in big sagebrush communities from 5 to 28 years ago, and also sampled nearby unburned locations. Mixed-effects models demonstrated that density of large–mature big sagebrush plants and percentage cover of big sagebrush were higher with time since fire and in plots with more precipitation during the winter immediately following fire, but were lower when precipitation the next winter was higher than average, especially on soils with higher available water supply, and with greater post-fire mortality of mature big sagebrush plants. Bunchgrass cover 5 to 28 years after fire was predicted to be lower with higher cover of both shrubs and non-native herbaceous species, and only slightly higher with time. Post-fire recovery of big sagebrush in the northern Columbia Basin is a slow process that may require several decades on average, but faster recovery rates may occur under specific site and climate conditions.

  17. Mean-field modeling of the basal ganglia-thalamocortical system. I Firing rates in healthy and parkinsonian states.

    PubMed

    van Albada, S J; Robinson, P A

    2009-04-21

    Parkinsonism leads to various electrophysiological changes in the basal ganglia-thalamocortical system (BGTCS), often including elevated discharge rates of the subthalamic nucleus (STN) and the output nuclei, and reduced activity of the globus pallidus external (GPe) segment. These rate changes have been explained qualitatively in terms of the direct/indirect pathway model, involving projections of distinct striatal populations to the output nuclei and GPe. Although these populations partly overlap, evidence suggests dopamine depletion differentially affects cortico-striato-pallidal connection strengths to the two pallidal segments. Dopamine loss may also decrease the striatal signal-to-noise ratio, reducing both corticostriatal coupling and striatal firing thresholds. Additionally, nigrostriatal degeneration may cause secondary changes including weakened lateral inhibition in the GPe, and mesocortical dopamine loss may decrease intracortical excitation and especially inhibition. Here a mean-field model of the BGTCS is presented with structure and parameter estimates closely based on physiology and anatomy. Changes in model rates due to the possible effects of dopamine loss listed above are compared with experiment. Our results suggest that a stronger indirect pathway, possibly combined with a weakened direct pathway, is compatible with empirical evidence. However, altered corticostriatal connection strengths are probably not solely responsible for substantially increased STN activity often found. A lower STN firing threshold, weaker intracortical inhibition, and stronger striato-GPe inhibition help explain the relatively large increase in STN rate. Reduced GPe-GPe inhibition and a lower GPe firing threshold can account for the comparatively small decrease in GPe rate frequently observed. Changes in cortex, GPe, and STN help normalize the cortical rate, also in accord with experiments. The model integrates the basal ganglia into a unified framework along with an

  18. Amniotic Fluid or Its Fatty Acids Produce Actions Similar to Diazepam on Lateral Septal Neurons Firing Rate

    PubMed Central

    Gutiérrez-García, Ana G.; Vásquez-Hernández, Diana Idania

    2013-01-01

    Human amniotic fluid (AF) contains eight fatty acids (FATs), and both produce anxiolytic-like effects in adult rats and appetitive responses in human newborns. The medial amygdala and lateral septal nucleus function are related to social behavior, but the action of AF or its FATs in this circuit is known. We obtained 267 single-unit extracellular recordings in Wistar rats treated with vehicle (1 mL, s.c.; n = 12), human AF (1 mL, s.c.; n = 12), a FAT mixture (1 mL, s.c.; n = 13), diazepam (1 mg/kg, i.p.; n = 11), and fluoxetine (1 mg/kg, p.o.; n = 12). Compared with the vehicle group, the spontaneous septal firing rate in the AF, FAT mixture, and diazepam groups was the lowest and in the fluoxetine group the highest. Cumulative peristimulus histograms indicated that the significant change in septal firing occurred only in the AF and FAT mixture groups and exclusively in those neurons that increased their firing rate during amygdala stimulation. We conclude that human AF and its FATs produce actions comparable to anxiolytic drugs and are able to modify the responsivity of a circuit involved in social behavior, suggesting facilitation of social recognition processes by maternal-fetal fluids. PMID:23864826

  19. Low NO{sub x} burner retrofits to 240 MW, 300 MW and 400 MW oil/gas fired utility boilers; Final performance results and lessons learned

    SciTech Connect

    Kuretski, J.J. Jr.; Price, J.V.; Schindler, E.S.; Guarco, J.P.

    1996-12-31

    Low NO{sub x} burners (LNBs) and new windbox baffles were retrofitted to eight residual oil/gas fired boilers totaling 2,680 MW of generating capacity in the Florida Power and Light Co. (FPL) system. These TODD Combustion designed LNBs were installed, from 1992 to 1995, to comply with a NO{sub x} Reasonably Available Control Technology (R.A.C.T.) determination associated with a moderate ozone non-attainment area in south Florida. LNBs were the primary means of NO{sub x} emission rate reduction, with an objective to achieve the maximum NO{sub x} reduction possible through burner hardware changes. Accordingly, the full focus of the project was on the capabilities of state-of-the-art LNB technology. These LNB retrofits were deemed successful based on the significant NO{sub x} reductions that were achieved. FPL`s contract requirements included consideration of unit performance and boiler component life impacts in addition to the traditional emission parameter guarantees. In striving to simultaneously meet all contract requirements, various burner design adjustments were implemented. As the project progressed, much was learned about LNBs and their effects on utility boilers as well as the effects of boiler equipment design and boiler conditions on NO{sub x} emission rates.

  20. Determination of Nickel Species in Stack Emissions from Eight Residual Oil-Fired Utility Steam-Generating Units

    SciTech Connect

    F Huggins; K Galbreath; K Eylands; L Van Loon; J Olson; E Zillioux; S Ward; P Lynch; P Chu

    2011-12-31

    XAFS spectroscopy has been used to determine the Ni species in particulate matter collected on quartz thimble filters in the stacks of eight residual (No. 6 fuel) oil-burning electric utility steam-generating units. Proper speciation of nickel in emitted particulate matter is necessary to correctly anticipate potential health risks. Analysis of the spectroscopic data using least-squares linear combination methods and a newly developed method specific for small quantities of Ni sulfide compounds in such emissions show that potentially carcinogenic Ni sulfide compounds are absent within the detection limits of the method ({le}3% of the total Ni) in the particulate matter samples investigated. In addition to the major nickel sulfate phase (NiSO{sub 4} {center_dot} 6H{sub 2}O), lesser amounts of (Ni,Mg)O and/or NiFe{sub 2}O{sub 4} were also identified in most emission samples. On the basis of the results from these emission characterization studies, the appropriateness of the U.S. Environmental Protection Agency's assumption that the Ni compound mixture emitted from residual oil-fired power plants is 50% as carcinogenic as nickel subsulfide (Ni{sub 3}S{sub 2}) should be re-evaluated.

  1. Fuzzy fault tree assessment based on improved AHP for fire and explosion accidents for steel oil storage tanks.

    PubMed

    Shi, Lei; Shuai, Jian; Xu, Kui

    2014-08-15

    Fire and explosion accidents of steel oil storage tanks (FEASOST) occur occasionally during the petroleum and chemical industry production and storage processes and often have devastating impact on lives, the environment and property. To contribute towards the development of a quantitative approach for assessing the occurrence probability of FEASOST, a fault tree of FEASOST is constructed that identifies various potential causes. Traditional fault tree analysis (FTA) can achieve quantitative evaluation if the failure data of all of the basic events (BEs) are available, which is almost impossible due to the lack of detailed data, as well as other uncertainties. This paper makes an attempt to perform FTA of FEASOST by a hybrid application between an expert elicitation based improved analysis hierarchy process (AHP) and fuzzy set theory, and the occurrence possibility of FEASOST is estimated for an oil depot in China. A comparison between statistical data and calculated data using fuzzy fault tree analysis (FFTA) based on traditional and improved AHP is also made. Sensitivity and importance analysis has been performed to identify the most crucial BEs leading to FEASOST that will provide insights into how managers should focus effective mitigation.

  2. Are High-Severity Fires Burning at Much Higher Rates Recently than Historically in Dry-Forest Landscapes of the Western USA?

    PubMed

    Baker, William L

    2015-01-01

    Dry forests at low elevations in temperate-zone mountains are commonly hypothesized to be at risk of exceptional rates of severe fire from climatic change and land-use effects. Their setting is fire-prone, they have been altered by land-uses, and fire severity may be increasing. However, where fires were excluded, increased fire could also be hypothesized as restorative of historical fire. These competing hypotheses are not well tested, as reference data prior to widespread land-use expansion were insufficient. Moreover, fire-climate projections were lacking for these forests. Here, I used new reference data and records of high-severity fire from 1984-2012 across all dry forests (25.5 million ha) of the western USA to test these hypotheses. I also approximated projected effects of climatic change on high-severity fire in dry forests by applying existing projections. This analysis showed the rate of recent high-severity fire in dry forests is within the range of historical rates, or is too low, overall across dry forests and individually in 42 of 43 analysis regions. Significant upward trends were lacking overall from 1984-2012 for area burned and fraction burned at high severity. Upward trends in area burned at high severity were found in only 4 of 43 analysis regions. Projections for A.D. 2046-2065 showed high-severity fire would generally be still operating at, or have been restored to historical rates, although high projections suggest high-severity fire rotations that are too short could ensue in 6 of 43 regions. Programs to generally reduce fire severity in dry forests are not supported and have significant adverse ecological impacts, including reducing habitat for native species dependent on early-successional burned patches and decreasing landscape heterogeneity that confers resilience to climatic change. Some adverse ecological effects of high-severity fires are concerns. Managers and communities can improve our ability to live with high-severity fire in

  3. Are High-Severity Fires Burning at Much Higher Rates Recently than Historically in Dry-Forest Landscapes of the Western USA?

    PubMed Central

    Baker, William L.

    2015-01-01

    Dry forests at low elevations in temperate-zone mountains are commonly hypothesized to be at risk of exceptional rates of severe fire from climatic change and land-use effects. Their setting is fire-prone, they have been altered by land-uses, and fire severity may be increasing. However, where fires were excluded, increased fire could also be hypothesized as restorative of historical fire. These competing hypotheses are not well tested, as reference data prior to widespread land-use expansion were insufficient. Moreover, fire-climate projections were lacking for these forests. Here, I used new reference data and records of high-severity fire from 1984–2012 across all dry forests (25.5 million ha) of the western USA to test these hypotheses. I also approximated projected effects of climatic change on high-severity fire in dry forests by applying existing projections. This analysis showed the rate of recent high-severity fire in dry forests is within the range of historical rates, or is too low, overall across dry forests and individually in 42 of 43 analysis regions. Significant upward trends were lacking overall from 1984–2012 for area burned and fraction burned at high severity. Upward trends in area burned at high severity were found in only 4 of 43 analysis regions. Projections for A.D. 2046–2065 showed high-severity fire would generally be still operating at, or have been restored to historical rates, although high projections suggest high-severity fire rotations that are too short could ensue in 6 of 43 regions. Programs to generally reduce fire severity in dry forests are not supported and have significant adverse ecological impacts, including reducing habitat for native species dependent on early-successional burned patches and decreasing landscape heterogeneity that confers resilience to climatic change. Some adverse ecological effects of high-severity fires are concerns. Managers and communities can improve our ability to live with high-severity fire

  4. Are High-Severity Fires Burning at Much Higher Rates Recently than Historically in Dry-Forest Landscapes of the Western USA?

    PubMed

    Baker, William L

    2015-01-01

    Dry forests at low elevations in temperate-zone mountains are commonly hypothesized to be at risk of exceptional rates of severe fire from climatic change and land-use effects. Their setting is fire-prone, they have been altered by land-uses, and fire severity may be increasing. However, where fires were excluded, increased fire could also be hypothesized as restorative of historical fire. These competing hypotheses are not well tested, as reference data prior to widespread land-use expansion were insufficient. Moreover, fire-climate projections were lacking for these forests. Here, I used new reference data and records of high-severity fire from 1984-2012 across all dry forests (25.5 million ha) of the western USA to test these hypotheses. I also approximated projected effects of climatic change on high-severity fire in dry forests by applying existing projections. This analysis showed the rate of recent high-severity fire in dry forests is within the range of historical rates, or is too low, overall across dry forests and individually in 42 of 43 analysis regions. Significant upward trends were lacking overall from 1984-2012 for area burned and fraction burned at high severity. Upward trends in area burned at high severity were found in only 4 of 43 analysis regions. Projections for A.D. 2046-2065 showed high-severity fire would generally be still operating at, or have been restored to historical rates, although high projections suggest high-severity fire rotations that are too short could ensue in 6 of 43 regions. Programs to generally reduce fire severity in dry forests are not supported and have significant adverse ecological impacts, including reducing habitat for native species dependent on early-successional burned patches and decreasing landscape heterogeneity that confers resilience to climatic change. Some adverse ecological effects of high-severity fires are concerns. Managers and communities can improve our ability to live with high-severity fire in

  5. Two-component mixture model: Application to palm oil and exchange rate

    NASA Astrophysics Data System (ADS)

    Phoong, Seuk-Yen; Ismail, Mohd Tahir; Hamzah, Firdaus Mohamad

    2014-12-01

    Palm oil is a seed crop which is widely adopt for food and non-food products such as cookie, vegetable oil, cosmetics, household products and others. Palm oil is majority growth in Malaysia and Indonesia. However, the demand for palm oil is getting growth and rapidly running out over the years. This phenomenal cause illegal logging of trees and destroy the natural habitat. Hence, the present paper investigates the relationship between exchange rate and palm oil price in Malaysia by using Maximum Likelihood Estimation via Newton-Raphson algorithm to fit a two components mixture model. Besides, this paper proposes a mixture of normal distribution to accommodate with asymmetry characteristics and platykurtic time series data.

  6. Body size, but not cooling rate, affects supercooling points in the red imported fire ant, Solenopsis invicta.

    PubMed

    Hahn, Daniel A; Martin, Adam R; Porter, Sanford D

    2008-10-01

    The level of an animal's stress resistance is set by multiple intrinsic physiological and extrinsic environmental parameters. Body size is a critical intrinsic parameter that affects numerous fitness-related organismal traits including fecundity, survival, mating success, and stress resistance. The rate of cooling is a critical extrinsic environmental factor that can affect thermal stress resistance. Workers of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), display considerable variation in adult body size. Therefore, developing ecologically realistic models of thermotolerance in this species requires a consideration of body size. We tested the hypothesis that body size and cooling rate would interact to set the supercooling point in fire ant workers by exposing workers of a range of body sizes to three different cooling regimens: a very fast ramp of -10 degrees C/min, an intermediate ramp of -1 degrees C/min, and an ecologically relevant slow ramp of -0.1 degrees C/min. Specifically, we asked whether large workers were more susceptible to differences in cooling rate than smaller workers. We found that body size had a considerable effect on supercooling point with the largest workers freezing at a temperature approximately 3 degrees C higher than the smallest workers. Cooling rate had a very small effect on supercooling point, and there was no interaction between the two factors. Therefore, the allometry of supercooling points across the range of worker body sizes does not change with cooling rate.

  7. Valorisation of wastewater from two-phase olive oil extraction in fired clay brick production.

    PubMed

    de la Casa, José A; Lorite, Miguel; Jiménez, Juan; Castro, Eulogio

    2009-09-30

    Wastewater issued from oil-washing stage (OWW) in the two-phase olive oil extraction method was used to replace fresh water in clay brick manufacture. The extrusion trials were performed with one of the ceramic bodies currently being used in a local brick factory for red facing bricks (RB) production. Fresh water or OWW was added to a final consistency of 2.4 kg/cm(2), the same value as used at industrial scale for this kind of clay mixture. Comparative results of technological properties of facing bricks are presented. Results show that the products obtained with olive oil wastewater are comparable to traditional ones in terms of extrusion performance and technological properties of end products. Even dry-bending strength of the body formed by wastewater improves by 33% compared to fresh water body. In addition, heating requirements can be reduced in the range 2.4-7.3% depending on the final product. This application can alleviate environmental impacts from the olive oil extraction industry and, at the same time, result in economic savings for the brick manufacturing industry.

  8. Review of flow rate estimates of the Deepwater Horizon oil spill

    USGS Publications Warehouse

    McNutt, Marcia K.; Camilli, Rich; Crone, Timothy J.; Guthrie, George D.; Hsieh, Paul A.; Ryerson, Thomas B.; Savas, Omer; Shaffer, Frank

    2012-01-01

    The unprecedented nature of the Deepwater Horizon oil spill required the application of research methods to estimate the rate at which oil was escaping from the well in the deep sea, its disposition after it entered the ocean, and total reservoir depletion. Here, we review what advances were made in scientific understanding of quantification of flow rates during deep sea oil well blowouts. We assess the degree to which a consensus was reached on the flow rate of the well by comparing in situ observations of the leaking well with a time-dependent flow rate model derived from pressure readings taken after the Macondo well was shut in for the well integrity test. Model simulations also proved valuable for predicting the effect of partial deployment of the blowout preventer rams on flow rate. Taken together, the scientific analyses support flow rates in the range of ~50,000–70,000 barrels/d, perhaps modestly decreasing over the duration of the oil spill, for a total release of ~5.0 million barrels of oil, not accounting for BP's collection effort. By quantifying the amount of oil at different locations (wellhead, ocean surface, and atmosphere), we conclude that just over 2 million barrels of oil (after accounting for containment) and all of the released methane remained in the deep sea. By better understanding the fate of the hydrocarbons, the total discharge can be partitioned into separate components that pose threats to deep sea vs. coastal ecosystems, allowing responders in future events to scale their actions accordingly.

  9. Review of flow rate estimates of the Deepwater Horizon oil spill

    PubMed Central

    McNutt, Marcia K.; Camilli, Rich; Crone, Timothy J.; Guthrie, George D.; Hsieh, Paul A.; Ryerson, Thomas B.; Savas, Omer; Shaffer, Frank

    2012-01-01

    The unprecedented nature of the Deepwater Horizon oil spill required the application of research methods to estimate the rate at which oil was escaping from the well in the deep sea, its disposition after it entered the ocean, and total reservoir depletion. Here, we review what advances were made in scientific understanding of quantification of flow rates during deep sea oil well blowouts. We assess the degree to which a consensus was reached on the flow rate of the well by comparing in situ observations of the leaking well with a time-dependent flow rate model derived from pressure readings taken after the Macondo well was shut in for the well integrity test. Model simulations also proved valuable for predicting the effect of partial deployment of the blowout preventer rams on flow rate. Taken together, the scientific analyses support flow rates in the range of ∼50,000–70,000 barrels/d, perhaps modestly decreasing over the duration of the oil spill, for a total release of ∼5.0 million barrels of oil, not accounting for BP's collection effort. By quantifying the amount of oil at different locations (wellhead, ocean surface, and atmosphere), we conclude that just over 2 million barrels of oil (after accounting for containment) and all of the released methane remained in the deep sea. By better understanding the fate of the hydrocarbons, the total discharge can be partitioned into separate components that pose threats to deep sea vs. coastal ecosystems, allowing responders in future events to scale their actions accordingly. PMID:22187459

  10. Do monkey F5 mirror neurons show changes in firing rate during repeated observation of natural actions?

    PubMed Central

    Kraskov, A.; Lemon, R. N.

    2013-01-01

    Mirror neurons were first discovered in area F5 of macaque monkeys. In humans, noninvasive studies have demonstrated an increased blood oxygen level-dependent (BOLD) signal in homologous motor areas during action observation. One approach to demonstrating that this indicates the existence of mirror neurons in humans has been to employ functional (f)MRI adaptation to test whether the same population of neurons is active during both observation and execution conditions. Although a number of human studies have reported fMRI adaptation in these areas, a recent study has shown that macaque mirror neurons do not attenuate their firing rate with two repetitions. Here we investigated whether mirror neurons modulate their firing rate when monkeys observed the same repeated natural action multiple times. We recorded from 67 mirror neurons in area F5 of two macaque monkeys while they observed an experimenter perform a reach-to-grasp action on a small food reward using a precision grip. Although no changes were detectable for the first two repetitions, we show that both the firing rate and the latency at which mirror neurons discharged during observation were subtly modulated by the repetition of the observed action over 7–10 trials. Significant adaption was mostly found in the period immediately before the grasp was performed. We also found that the local field potential activity in F5 (beta-frequency range, 16–23 Hz), which is attenuated during action observation, also showed systematic changes with repeated observation. These LFP changes occurred well in advance of the mirror neuron adaptation. We conclude that macaque mirror neurons can show intra-modal adaptation, but whether this is related to fMRI adaptation of the BOLD signal requires further investigation. PMID:24371289

  11. Do monkey F5 mirror neurons show changes in firing rate during repeated observation of natural actions?

    PubMed

    Kilner, J M; Kraskov, A; Lemon, R N

    2014-03-01

    Mirror neurons were first discovered in area F5 of macaque monkeys. In humans, noninvasive studies have demonstrated an increased blood oxygen level-dependent (BOLD) signal in homologous motor areas during action observation. One approach to demonstrating that this indicates the existence of mirror neurons in humans has been to employ functional (f)MRI adaptation to test whether the same population of neurons is active during both observation and execution conditions. Although a number of human studies have reported fMRI adaptation in these areas, a recent study has shown that macaque mirror neurons do not attenuate their firing rate with two repetitions. Here we investigated whether mirror neurons modulate their firing rate when monkeys observed the same repeated natural action multiple times. We recorded from 67 mirror neurons in area F5 of two macaque monkeys while they observed an experimenter perform a reach-to-grasp action on a small food reward using a precision grip. Although no changes were detectable for the first two repetitions, we show that both the firing rate and the latency at which mirror neurons discharged during observation were subtly modulated by the repetition of the observed action over 7-10 trials. Significant adaption was mostly found in the period immediately before the grasp was performed. We also found that the local field potential activity in F5 (beta-frequency range, 16-23 Hz), which is attenuated during action observation, also showed systematic changes with repeated observation. These LFP changes occurred well in advance of the mirror neuron adaptation. We conclude that macaque mirror neurons can show intra-modal adaptation, but whether this is related to fMRI adaptation of the BOLD signal requires further investigation.

  12. Simple Learned Weighted Sums of Inferior Temporal Neuronal Firing Rates Accurately Predict Human Core Object Recognition Performance.

    PubMed

    Majaj, Najib J; Hong, Ha; Solomon, Ethan A; DiCarlo, James J

    2015-09-30

    To go beyond qualitative models of the biological substrate of object recognition, we ask: can a single ventral stream neuronal linking hypothesis quantitatively account for core object recognition performance over a broad range of tasks? We measured human performance in 64 object recognition tests using thousands of challenging images that explore shape similarity and identity preserving object variation. We then used multielectrode arrays to measure neuronal population responses to those same images in visual areas V4 and inferior temporal (IT) cortex of monkeys and simulated V1 population responses. We tested leading candidate linking hypotheses and control hypotheses, each postulating how ventral stream neuronal responses underlie object recognition behavior. Specifically, for each hypothesis, we computed the predicted performance on the 64 tests and compared it with the measured pattern of human performance. All tested hypotheses based on low- and mid-level visually evoked activity (pixels, V1, and V4) were very poor predictors of the human behavioral pattern. However, simple learned weighted sums of distributed average IT firing rates exactly predicted the behavioral pattern. More elaborate linking hypotheses relying on IT trial-by-trial correlational structure, finer IT temporal codes, or ones that strictly respect the known spatial substructures of IT ("face patches") did not improve predictive power. Although these results do not reject those more elaborate hypotheses, they suggest a simple, sufficient quantitative model: each object recognition task is learned from the spatially distributed mean firing rates (100 ms) of ∼60,000 IT neurons and is executed as a simple weighted sum of those firing rates. Significance statement: We sought to go beyond qualitative models of visual object recognition and determine whether a single neuronal linking hypothesis can quantitatively account for core object recognition behavior. To achieve this, we designed a

  13. Simple Learned Weighted Sums of Inferior Temporal Neuronal Firing Rates Accurately Predict Human Core Object Recognition Performance

    PubMed Central

    Hong, Ha; Solomon, Ethan A.; DiCarlo, James J.

    2015-01-01

    To go beyond qualitative models of the biological substrate of object recognition, we ask: can a single ventral stream neuronal linking hypothesis quantitatively account for core object recognition performance over a broad range of tasks? We measured human performance in 64 object recognition tests using thousands of challenging images that explore shape similarity and identity preserving object variation. We then used multielectrode arrays to measure neuronal population responses to those same images in visual areas V4 and inferior temporal (IT) cortex of monkeys and simulated V1 population responses. We tested leading candidate linking hypotheses and control hypotheses, each postulating how ventral stream neuronal responses underlie object recognition behavior. Specifically, for each hypothesis, we computed the predicted performance on the 64 tests and compared it with the measured pattern of human performance. All tested hypotheses based on low- and mid-level visually evoked activity (pixels, V1, and V4) were very poor predictors of the human behavioral pattern. However, simple learned weighted sums of distributed average IT firing rates exactly predicted the behavioral pattern. More elaborate linking hypotheses relying on IT trial-by-trial correlational structure, finer IT temporal codes, or ones that strictly respect the known spatial substructures of IT (“face patches”) did not improve predictive power. Although these results do not reject those more elaborate hypotheses, they suggest a simple, sufficient quantitative model: each object recognition task is learned from the spatially distributed mean firing rates (100 ms) of ∼60,000 IT neurons and is executed as a simple weighted sum of those firing rates. SIGNIFICANCE STATEMENT We sought to go beyond qualitative models of visual object recognition and determine whether a single neuronal linking hypothesis can quantitatively account for core object recognition behavior. To achieve this, we designed a

  14. Simple Learned Weighted Sums of Inferior Temporal Neuronal Firing Rates Accurately Predict Human Core Object Recognition Performance.

    PubMed

    Majaj, Najib J; Hong, Ha; Solomon, Ethan A; DiCarlo, James J

    2015-09-30

    To go beyond qualitative models of the biological substrate of object recognition, we ask: can a single ventral stream neuronal linking hypothesis quantitatively account for core object recognition performance over a broad range of tasks? We measured human performance in 64 object recognition tests using thousands of challenging images that explore shape similarity and identity preserving object variation. We then used multielectrode arrays to measure neuronal population responses to those same images in visual areas V4 and inferior temporal (IT) cortex of monkeys and simulated V1 population responses. We tested leading candidate linking hypotheses and control hypotheses, each postulating how ventral stream neuronal responses underlie object recognition behavior. Specifically, for each hypothesis, we computed the predicted performance on the 64 tests and compared it with the measured pattern of human performance. All tested hypotheses based on low- and mid-level visually evoked activity (pixels, V1, and V4) were very poor predictors of the human behavioral pattern. However, simple learned weighted sums of distributed average IT firing rates exactly predicted the behavioral pattern. More elaborate linking hypotheses relying on IT trial-by-trial correlational structure, finer IT temporal codes, or ones that strictly respect the known spatial substructures of IT ("face patches") did not improve predictive power. Although these results do not reject those more elaborate hypotheses, they suggest a simple, sufficient quantitative model: each object recognition task is learned from the spatially distributed mean firing rates (100 ms) of ∼60,000 IT neurons and is executed as a simple weighted sum of those firing rates. Significance statement: We sought to go beyond qualitative models of visual object recognition and determine whether a single neuronal linking hypothesis can quantitatively account for core object recognition behavior. To achieve this, we designed a

  15. Report on the costs of domestic and international emergencies and on the threats posed by the Kuwaiti oil fires as required by P. L. 102-55

    SciTech Connect

    Not Available

    1991-06-01

    The report fulfills the requirements of Public Law 12-55, the FY 1992 dire emergency supplemental appropriations bill, signed by the President on June 13, 1991. This law required the Director of the Office of Management and Budget to prepare and submit to the appropriate committees of Congress a report on: unfunded costs of dire emergencies because of floods, droughts, tornadoes, unemployment, and other disasters in the United States; unfunded costs, including food assistance, of international disaster emergencies existing because of floods, droughts, tornadoes, and other disasters; and the threats to oil supply, human health, and the environment that the Kuwaiti oil fires might pose.

  16. The short-term temperature response to smoke from oil fires

    NASA Technical Reports Server (NTRS)

    Westphal, Douglas L.; Toon, Owen B.

    1991-01-01

    The short-term effect of smoke, similar to that being emitted from the Kuwaiti oil fields, on the ground temperature of the afffected region was investigated using a numerical model of atmospheric dynamics, aerosol microphysics, and radiative transfer similar to that used previosly by Westphal and Toon (1991). Results show that, after one diurnal cycle beneath smoke plumes of moderate visible absorption, ground cooling and ground warming were both possible; the response of the ground temperature and the boundary layer dynamics depended on the surface characteristics, with desert exhibiting the strongest cooling of all the land types used.

  17. Effect of Shear Rate and Temperature on Rheological Properties of Vegetable Based Oil

    NASA Astrophysics Data System (ADS)

    Nik, W. B. Wan; Giap, S. G. Eng; Senin, H. B.; Bulat, K. H. Ku

    2007-05-01

    Petroleum oil has been the raw material for over 90% of hydraulic fluid. Limitations of this base material in the aspect of non-renewable, not environmental friendly and its sustainability in the future have prompted a search for more stable and environmentally friendly alternatives. This article presents rheological aspects of hydraulic fluid derived from bio-based material when used as hydraulic fluid. Palm oil with F10 additive is found to be most shearstable. Various empirical models such as modified Power Law, Herschel-Bulkley and Arrhenius-type-relationship are used to evaluate the rheological data. The influence of shear rate and temperature on the variation of viscosity is clearly observed but temperature has more significant influence. Interpretations of rheological models indicate that crop oils belong to pseudo-plastic category. The effect of oil degradation in the aspect of physical property on viscosity is also evaluated.

  18. Research, development, and testing of a prototype two-stage low-input rate oil burner for variable output heating system applications

    SciTech Connect

    Krajewski, R.F.; Butcher, T.A.

    1997-09-01

    The use of a Two-Stage Fan Atomized Oil Burner (TSFAB) in space and water heating applications will have dramatic advantages in terms of it`s potential for a high Annual Fuel Utilization Efficiency (AFUE) and/or Energy Factor (EF) rating for the equipment. While demonstrations of a single rate burner in an actual application have already yielded sufficient confidence that space and domestic heating loads can be met at a single low firing rate, this represents only a narrow solution to the diverse nature of building space heating and domestic water loads that the industry must address. The mechanical development, proposed control, and testing of the Two-Stage burner is discussed in terms of near term and long term goals.

  19. Comparison of GPU- and CPU-implementations of mean-firing rate neural networks on parallel hardware.

    PubMed

    Dinkelbach, Helge Ülo; Vitay, Julien; Beuth, Frederik; Hamker, Fred H

    2012-01-01

    Modern parallel hardware such as multi-core processors (CPUs) and graphics processing units (GPUs) have a high computational power which can be greatly beneficial to the simulation of large-scale neural networks. Over the past years, a number of efforts have focused on developing parallel algorithms and simulators best suited for the simulation of spiking neural models. In this article, we aim at investigating the advantages and drawbacks of the CPU and GPU parallelization of mean-firing rate neurons, widely used in systems-level computational neuroscience. By comparing OpenMP, CUDA and OpenCL implementations towards a serial CPU implementation, we show that GPUs are better suited than CPUs for the simulation of very large networks, but that smaller networks would benefit more from an OpenMP implementation. As this performance strongly depends on data organization, we analyze the impact of various factors such as data structure, memory alignment and floating precision. We then discuss the suitability of the different hardware depending on the networks' size and connectivity, as random or sparse connectivities in mean-firing rate networks tend to break parallel performance on GPUs due to the violation of coalescence.

  20. Anterior olfactory organ removal produces anxiety-like behavior and increases spontaneous neuronal firing rate in basal amygdala.

    PubMed

    Contreras, Carlos M; Gutiérrez-García, Ana G; Molina-Jiménez, Tania

    2013-09-01

    Some chemical cues may produce signs of anxiety and fear mediated by amygdala nuclei, but unknown is the role of two anterior olfactory epithelial organs, the septal and vomeronasal organs (SO-VNOs). The effects of SO-VNO removal were explored in different groups of Wistar rats using two complementary approaches: (i) the assessment of neuronal firing rate in basal and medial amygdala nuclei and (ii) behavioral testing. Fourteen days after SO-VNO removal, spontaneous activity in basal and medial amygdala nuclei in one group was determined using single-unit extracellular recordings. A separate group of rats was tested in the elevated plus maze, social interaction test, and open field test. Compared with sham-operated and intact control rats, SO-VNO removal produced a higher neuronal firing rate in the basal amygdala but not medial amygdala. In the behavioral tests, SO-VNO removal increased signs of anxiety in the elevated plus maze, did not alter locomotion, and increased self-directed behavior, reflecting anxiety-like behavior. Histological analysis showed neuronal destruction in the accessory olfactory bulb but not anterior olfactory nucleus in the SO-VNO group. The present results suggest the participation of SO-VNO/accessory olfactory bulb/basal amygdala relationships in the regulation of anxiety through a process of disinhibition.

  1. Experimental study on burning rates of square/rectangular gasoline and methanol pool fires under longitudinal air flow in a wind tunnel.

    PubMed

    Hu, L H; Liu, S; Peng, W; Huo, R

    2009-09-30

    Square pool fires with length of 5, 7.5, 10, 15, 20, 25 and 30 cm and rectangular pool fires with dimensions of 10 cm x 20 cm and 10 cm x 40 cm were burned in a wind tunnel, under a longitudinal air flow ranged from 0 to 3m/s with incremental change of about 0.5m/s. Methanol and gasoline were burned and compared, with results indicated that their burning rates showed different response to the longitudinal air flow. With the increase of the longitudinal air flow speed, the burning rates of methanol pool fires, except the 5 cm square one, first decreased and then increased, but those of the 5 cm methanol square one and the gasoline pool fires increased monotonously. The burning rate of smaller square pool fires increased more significantly than that of the larger ones, as well as the enlargement of their flame attachment length along the ground. The burning rate of a rectangular pool fire with longer rim parallel to the longitudinal flow increased faster, but the flame attachment length seemed to increase more gradually, with the increase of the longitudinal air flow speed than that perpendicular to.

  2. CRYPTOCHROME is a blue-light sensor that regulates neuronal firing rate.

    PubMed

    Fogle, Keri J; Parson, Kelly G; Dahm, Nicole A; Holmes, Todd C

    2011-03-18

    Light-responsive neural activity in central brain neurons is generally conveyed through opsin-based signaling from external photoreceptors. Large lateral ventral arousal neurons (lLNvs) in Drosophila melanogaster increase action potential firing within seconds in response to light in the absence of all opsin-based photoreceptors. Light-evoked changes in membrane resting potential occur in about 100 milliseconds. The light response is selective for blue wavelengths corresponding to the spectral sensitivity of CRYPTOCHROME (CRY). cry-null lines are light-unresponsive, but restored CRY expression in the lLNv rescues responsiveness. Furthermore, expression of CRY in neurons that are normally unresponsive to light confers responsiveness. The CRY-mediated light response requires a flavin redox-based mechanism and depends on potassium channel conductance, but is independent of the classical circadian CRY-TIMELESS interaction.

  3. Fire Safety Technician

    ERIC Educational Resources Information Center

    Moore, Pam

    2007-01-01

    Fire protection is one of the most important considerations in the construction and operation of industrial plants and commercial buildings. Fire insurance rates are determined by fire probability factors, such as the type of construction, ease of transporting personnel, and the quality and quantity of fire protection equipment available. Because…

  4. 25 CFR 212.43 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Royalty rates for minerals other than oil and gas. 212.43 Section 212.43 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS FOR MINERAL DEVELOPMENT Rents, Royalties, Cancellations, and Appeals § 212.43 Royalty...

  5. 25 CFR 212.43 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Royalty rates for minerals other than oil and gas. 212.43 Section 212.43 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING OF ALLOTTED LANDS FOR MINERAL DEVELOPMENT Rents, Royalties, Cancellations, and Appeals § 212.43 Royalty...

  6. Estimating oil concentration and flow rate with calibrated vessel-mounted acoustic echo sounders

    PubMed Central

    Weber, Thomas C.; De Robertis, Alex; Greenaway, Samuel F.; Smith, Shep; Mayer, Larry; Rice, Glen

    2012-01-01

    As part of a larger program aimed at evaluating acoustic techniques for mapping the distribution of subsurface oil and gas associated with the Deepwater Horizon-Macondo oil spill, observations were made on June 24 and 25, 2010 using vessel-mounted calibrated single-beam echo sounders on the National Oceanic and Atmospheric Administration ship Thomas Jefferson. Coincident with visual observations of oil at the sea surface, the 200-kHz echo sounder showed anomalously high-volume scattering strength in the upper 200 m on the western side of the wellhead, more than 100 times higher than the surrounding waters at 1,800-m distance from the wellhead, and weakening with increasing distance out to 5,000 m. Similar high-volume scattering anomalies were not observed at 12 or 38 kHz, although observations of anomalously low-volume scattering strength were made in the deep scattering layer at these frequencies at approximately the same locations. Together with observations of ocean currents, the acoustic observations are consistent with a rising plume of small (< 1-mm radius) oil droplets. Using simplistic but reasonable assumptions about the properties of the oil droplets, an estimate of the flow rate was made that is remarkably consistent with those made at the wellhead by other means. The uncertainty in this acoustically derived estimate is high due to lack of knowledge of the size distribution and rise speed of the oil droplets. If properly constrained, these types of acoustic measurements can be used to rapidly estimate the flow rate of oil reaching the surface over large temporal and spatial scales. PMID:22167799

  7. Estimating oil concentration and flow rate with calibrated vessel-mounted acoustic echo sounders.

    PubMed

    Weber, Thomas C; De Robertis, Alex; Greenaway, Samuel F; Smith, Shep; Mayer, Larry; Rice, Glen

    2012-12-11

    As part of a larger program aimed at evaluating acoustic techniques for mapping the distribution of subsurface oil and gas associated with the Deepwater Horizon-Macondo oil spill, observations were made on June 24 and 25, 2010 using vessel-mounted calibrated single-beam echo sounders on the National Oceanic and Atmospheric Administration ship Thomas Jefferson. Coincident with visual observations of oil at the sea surface, the 200-kHz echo sounder showed anomalously high-volume scattering strength in the upper 200 m on the western side of the wellhead, more than 100 times higher than the surrounding waters at 1,800-m distance from the wellhead, and weakening with increasing distance out to 5,000 m. Similar high-volume scattering anomalies were not observed at 12 or 38 kHz, although observations of anomalously low-volume scattering strength were made in the deep scattering layer at these frequencies at approximately the same locations. Together with observations of ocean currents, the acoustic observations are consistent with a rising plume of small (< 1-mm radius) oil droplets. Using simplistic but reasonable assumptions about the properties of the oil droplets, an estimate of the flow rate was made that is remarkably consistent with those made at the wellhead by other means. The uncertainty in this acoustically derived estimate is high due to lack of knowledge of the size distribution and rise speed of the oil droplets. If properly constrained, these types of acoustic measurements can be used to rapidly estimate the flow rate of oil reaching the surface over large temporal and spatial scales. PMID:22167799

  8. Transcontinental and translational high-tech acupuncture research using computer-based heart rate and "Fire of Life" heart rate variability analysis.

    PubMed

    Litscher, Gerhard

    2010-09-01

    A variable heartbeat was considered a sign of good health by ancient Asian physicians. Today, new computer-based methods (e.g., "Fire of Life" analysis) allow quantification of heart rate and heart rate variability during acupuncture. The objective of this article is to compare different acupuncture methods to evaluate the influence of acupuncture on heart rhythm in short-term and long-term measurements. There were four main sections in this study: (A) a randomized controlled study using needle acupuncture and acupressure at Yintang (Ex1); (B) an innovative blue (violet) laser acupuncture randomized controlled study in Asian volunteers; (C) a comparative study using moxibustion methods; and (D) teleacupuncture. A total of 72 patients (mean age ± SD: 27.9 ± 8.6 years) were monitored over periods of 20 minutes to 24 hours in Asia and Austria. Acupuncture was performed with metal needles (in sections A, C and D) or blue laser (in section B) on Yintang, Neiguan, Guanyuan or a special acupuncture regimen for stress disorders (in sections A, B, C and D, respectively). Significant decreases in heart rate after verum intervention at Yintang, Neiguan and Guanyuan were found. Improvements in state of health following teleacupuncture were also noted. Computer-based heart rate and heart rate variability analysis was demonstrated to be effective in evaluating the status of health during acupuncture.

  9. A Feedback Model of Attention Explains the Diverse Effects of Attention on Neural Firing Rates and Receptive Field Structure.

    PubMed

    Miconi, Thomas; VanRullen, Rufin

    2016-02-01

    Visual attention has many effects on neural responses, producing complex changes in firing rates, as well as modifying the structure and size of receptive fields, both in topological and feature space. Several existing models of attention suggest that these effects arise from selective modulation of neural inputs. However, anatomical and physiological observations suggest that attentional modulation targets higher levels of the visual system (such as V4 or MT) rather than input areas (such as V1). Here we propose a simple mechanism that explains how a top-down attentional modulation, falling on higher visual areas, can produce the observed effects of attention on neural responses. Our model requires only the existence of modulatory feedback connections between areas, and short-range lateral inhibition within each area. Feedback connections redistribute the top-down modulation to lower areas, which in turn alters the inputs of other higher-area cells, including those that did not receive the initial modulation. This produces firing rate modulations and receptive field shifts. Simultaneously, short-range lateral inhibition between neighboring cells produce competitive effects that are automatically scaled to receptive field size in any given area. Our model reproduces the observed attentional effects on response rates (response gain, input gain, biased competition automatically scaled to receptive field size) and receptive field structure (shifts and resizing of receptive fields both spatially and in complex feature space), without modifying model parameters. Our model also makes the novel prediction that attentional effects on response curves should shift from response gain to contrast gain as the spatial focus of attention drifts away from the studied cell. PMID:26890584

  10. Determination of PCDD/F, dioxin-like PCB and PAH levels in olive and olive oil samples from areas affected by the fires in summer 2007 in Greece.

    PubMed

    Costopoulou, Danae; Vassiliadou, Irene; Chrysafidis, Dimitrios; Bergele, Kyriaki; Tzavara, Eleni; Tzamtzis, Vassilios; Leondiadis, Leondios

    2010-04-01

    During the summer of 2007, a series of massive forest fires broke out in several areas across Greece. The main sources of PCDD/Fs and dioxin-like PCBs in Greece are considered to be the uncontrolled combustion of municipal solid waste in open landfills and accidental fires in forest, rural and industrial areas. Combustion may also lead to the formation of PAHs, which are fat soluble substances of considerable toxicity. The objective of this study was to investigate PCDD/F, dioxin-like PCB and PAH contamination of olive oil produced in fire-affected areas. Olive oil is a very significant agricultural product of Greece. Samples for this study were collected from all affected oil producing areas after the fire and 1year later. PCDD/Fs, dioxin-like PCBs and PAHs were at normal levels in all samples analysed. PMID:20153015

  11. [Polycyclic aromatic hidrocarbons deposition in the Milazzo-Valle del Mela (Sicily Region, Southern Italy) high-risk area following an oil refinery fire].

    PubMed

    Grechi, Daniele; Biggeri, Annibale

    2016-01-01

    On September 2014, a fire began within an oil refinery involving a storage tank containing several hundreds of thousands cubic meters of virgin naphtha. Mayors of neighbouring municipalities asked the Epidemiology and Prevention Society "Giulio A. Maccacaro" to carry out an environmental survey in order to evaluate what was the nature and how dangerous was suspended dust deposited by the fumes. In the following days, after fire had been extinguished we conducted a sample survey on the presence of polycyclic aromatic hydrocarbons (PAH) and metals in particulate deposited on the soil on a radius of five kilometres from the refinery and we engaged the exposed population. The Milazzo-Valle del Mela (Sicily Region, Southern Italy) high-risk area includes several industrial plants; among them, an oil refinery and a fuel powered energy plant. As reference area we selected the Sarroch municipality (Sardinia Region, Southern Italy), in the coast of the Tyrrhenian Sea, which is geographically comparable, where a large oil refinery is located and where an environmental campaign with measurement of PAH and metals in particulate matter was ongoing. Qualitatively, metal composition of particulate matter resulted similar in the Sarroch and Milazzo samples. Instead, a large excess of PAH was documented in the Milazzo samples as compared to the Sarroch ones. In conclusion, the results of the analysis of the samples of particulate matter deposited in the Milazzo area in the days immediately following the oil refinery fire showed a high quantity of PAH, carcinogenic substances which pose major hazard to population health. The greater fall-out was registered in the proximity of the burnt storage tank and the West neighbourhood, and at lesser extent in the Southern neighbourhood. As a consequence, there was a population exposure to carcinogenic substances which could have reached the food chain. PMID:26951697

  12. Persistence rates and detection probabilities of oiled king eider carcasses on St Paul Island, Alaska

    USGS Publications Warehouse

    Fowler, A.C.; Flint, P.L.

    1997-01-01

    Following an oil spill off St Paul Island, Alaska in February 1996, persistence rates and detection probabilities of oiled king eider (Somateria spectabilis) carcasses were estimated using the Cormack-Jolly-Seber model. Carcass persistence rates varied by day, beach type and sex, while detection probabilities varied by day and beach type. Scavenging, wave action and weather influenced carcass persistence. The patterns of persistence differed on rock and sand beaches and female carcasses had a different persistence function than males. Weather, primarily snow storms, and degree of carcass scavenging, diminished carcass detectability. Detection probabilities on rock beaches were lower and more variable than on sand beaches. The combination of persistence rates and detection probabilities can be used to improve techniques of estimating total mortality.

  13. Effects of Post-Fire Salvage Logging on Erosion Rates at Multiple Scales

    NASA Astrophysics Data System (ADS)

    Wagenbrenner, J. W.; Robichaud, P. R.; MacDonald, L. H.; Brown, R. E.

    2014-12-01

    Forest managers sometimes harvest burned trees after wildfires to realize economic value, reduce fuel loads, or achieve other operational goals. This logging can be controversial because some ecosystem effects are negative, yet the potential impacts on erosion rates have not been clearly identified. Our objectives were to quantify hillslope-scale erosion rates and compare the hillslope erosion rates to rates from larger (swale) and smaller (rill) scales. Soil characteristics, vegetative regrowth, and erosion rates were measured in logged areas and unlogged controls at seven severely burned sites in the western US. One site had replicated measurements at all three scales, five sites had only hillslope or swale scale measurements, and one site had only rill measurements. Erosion rates from hillslopes (70-170 m2) and swales (0.1-2.6 ha) were measured with sediment fences. Rill erosion rates were measured with rill experiments, where water was applied to a hillslope at five flow rates for 12 min each; water samples were collected at a point 9 m downslope. At the hillslope scale the passage of heavy logging equipment reduced soil water repellency, compacted the soil, reduced vegetative regrowth rates, and generally increased erosion rates by one or two orders of magnitude relative to the controls. The rill experiments also showed greater rates of rill incision and erosion from the areas disturbed by heavy logging equipment relative to the controls. At the swale scale erosion rates were higher in the logged areas than the controls when measurements were replicated and simultaneous but there was no detectable change in the other study areas. Overall, the absolute erosion rates from both logged and unlogged areas tended to decline over time while the relative difference in erosion tended to increase due to the slower vegetative recovery in the more heavily disturbed areas. The potential adverse effects of salvage logging can be minimized by reducing compaction and

  14. Reaction rate kinetics for in situ combustion retorting of Michigan Antrim oil shale

    USGS Publications Warehouse

    Rostam-Abadi, M.; Mickelson, R.W.

    1984-01-01

    The intrinsic reaction rate kinetics for the pyrolysis of Michigan Antrim oil shale and the oxidation of the carbonaceous residue of this shale have been determined using a thermogravimetric analysis method. The kinetics of the pyrolysis reaction were evaluated from both isothermal and nonisothermal rate data. The reaction was found to be second-order with an activation energy of 252.2 kJ/mole, and with a frequency factor of 9.25 ?? 1015 sec-1. Pyrolysis kinetics were not affected by heating rates between 0.01 to 0.67??K/s. No evidence of any reactions among the oil shale mineral constituents was observed at temperatures below 1173??K. However, it was found that the presence of pyrite in oil shale reduces the primary devolatilization rate of kerogen and increases the amount of residual char in the spent shale. Carbonaceous residues which were prepared by heating the oil shale at a rate of 0.166??K/s to temperatures between 923??K and 1073??K, had the highest reactivities when oxidized at 0.166??K/s in a gas having 21 volume percent oxygen. Oxygen chemisorption was found to be the initial precursor to the oxidation process. The kinetics governing oxygen chemisorption is (Equation Presented) where X is the fractional coverage. The oxidation of the carbonaceous residue was found also to be second-order. The activation energy and the frequency factor determined from isothermal experiments were 147 kJ/mole and 9.18??107 sec-1 respectively, while the values of these parameters obtained from a nonisothermal experiment were 212 kJ/mole and 1.5??1013 sec-1. The variation in the rate constants is attributed to the fact that isothermal and nonisothermal analyses represent two different aspects of the combustion process.

  15. Estimation of the synaptic input firing rates and characterization of the stimulation effects in an auditory neuron

    PubMed Central

    Kobayashi, Ryota; He, Jufang; Lansky, Petr

    2015-01-01

    To understand information processing in neuronal circuits, it is important to infer how a sensory stimulus impacts on the synaptic input to a neuron. An increase in neuronal firing during the stimulation results from pure excitation or from a combination of excitation and inhibition. Here, we develop a method for estimating the rates of the excitatory and inhibitory synaptic inputs from a membrane voltage trace of a neuron. The method is based on a modified Ornstein-Uhlenbeck neuronal model, which aims to describe the stimulation effects on the synaptic input. The method is tested using a single-compartment neuron model with a realistic description of synaptic inputs, and it is applied to an intracellular voltage trace recorded from an auditory neuron in vivo. We find that the excitatory and inhibitory inputs increase during stimulation, suggesting that the acoustic stimuli are encoded by a combination of excitation and inhibition. PMID:26042025

  16. Evaporation rates of water from concentrated oil-in-water emulsions.

    PubMed

    Aranberri, I; Binks, B P; Clint, J H; Fletcher, P D I

    2004-03-16

    We have investigated the rate of water evaporation from concentrated oil-in-water (o/w) emulsions containing an involatile oil. Evaporation of the water continuous phase causes compression of the emulsion with progressive distortion of the oil drops and thinning of the water films separating them. Theoretically, the vapor pressure of water is sensitive to the interdroplet interactions, which are a function of the film thickness. Three main possible situations are considered. First, under conditions when the evaporation rate is controlled by mass transfer across the stagnant vapor phase, model calculations show that evaporation can, in principle, be slowed by repulsive interdroplet interactions. However, significant retardation requires very strong repulsive forces acting over large separations for typical emulsion drop sizes. Second, water evaporation may be limited by diffusion in the network of water films within the emulsion. In this situation, water loss by evaporation from the emulsion surface leads to a gradient in the water concentration (and in the water film thickness). Third, compression of the drops may lead to coalescence of the emulsion drops and the formation of a macroscopic oil film at the emulsion surface, which serves to prevent further water evaporation. Water mass-loss curves have been measured for silicone o/w emulsions stabilized by the anionic surfactant SDS as a function of the water content, the thickness of the stagnant vapor-phase layer, and the concentration of electrolyte in the aqueous phase, and the results are discussed in terms of the three possible scenarios just described. In systems with added salt, water evaporation virtually ceases before all the water present is lost, probably as a result of oil-drop coalescence resulting in the formation of a water-impermeable oil film at the emulsion surface. PMID:15835653

  17. Evaporation rates of water from concentrated oil-in-water emulsions.

    PubMed

    Aranberri, I; Binks, B P; Clint, J H; Fletcher, P D I

    2004-03-16

    We have investigated the rate of water evaporation from concentrated oil-in-water (o/w) emulsions containing an involatile oil. Evaporation of the water continuous phase causes compression of the emulsion with progressive distortion of the oil drops and thinning of the water films separating them. Theoretically, the vapor pressure of water is sensitive to the interdroplet interactions, which are a function of the film thickness. Three main possible situations are considered. First, under conditions when the evaporation rate is controlled by mass transfer across the stagnant vapor phase, model calculations show that evaporation can, in principle, be slowed by repulsive interdroplet interactions. However, significant retardation requires very strong repulsive forces acting over large separations for typical emulsion drop sizes. Second, water evaporation may be limited by diffusion in the network of water films within the emulsion. In this situation, water loss by evaporation from the emulsion surface leads to a gradient in the water concentration (and in the water film thickness). Third, compression of the drops may lead to coalescence of the emulsion drops and the formation of a macroscopic oil film at the emulsion surface, which serves to prevent further water evaporation. Water mass-loss curves have been measured for silicone o/w emulsions stabilized by the anionic surfactant SDS as a function of the water content, the thickness of the stagnant vapor-phase layer, and the concentration of electrolyte in the aqueous phase, and the results are discussed in terms of the three possible scenarios just described. In systems with added salt, water evaporation virtually ceases before all the water present is lost, probably as a result of oil-drop coalescence resulting in the formation of a water-impermeable oil film at the emulsion surface.

  18. Airborne spectral measurements of surface-atmosphere anisotropy during the SCAR-A, Kuwait oil fire, and TARFOX experiments

    NASA Astrophysics Data System (ADS)

    Soulen, Peter F.; King, Michael D.; Tsay, Si-Chee; Arnold, G. Thomas; Li, Jason Y.

    2000-04-01

    During the SCAR-A, Kuwait Oil Fire Smoke Experiment, and TARFOX deployments, angular distributions of spectral reflectance for various surfaces were measured using the scanning Cloud Absorption Radiometer (CAR) mounted on the nose of the University of Washington C-131A research aircraft. The CAR contains 13 narrowband spectral channels between 0.47 and 2.3 μm with a 190° scan aperture (5° before zenith to 5° past nadir) and 1° instantaneous field of view. The bidirectional reflectance is obtained by flying a clockwise circular orbit above the surface, resulting in a ground track approximately 3 km in diameter within about 2 min. Spectral bidirectional reflectances of four surfaces are presented: the Great Dismal Swamp in Virginia with overlying haze layer, the Saudi Arabian Desert and the Persian Gulf in the Middle East, and the Atlantic Ocean measured east of Richmond, Virginia. Although the CAR measurements are contaminated by atmospheric effects, results show distinct spectral characteristics for various types of surface-atmosphere systems, including hot spots, limb brightening and darkening, and Sun glint. In addition, the hemispherical albedo of each surface-atmosphere system is calculated directly by integrating over all high angular-resolution CAR measurements for each spectral channel. Comparing the nadir reflectance with the overall hemispherical albedo of each surface, we find that using nadir reflectances as a surrogate for hemispherical albedo can cause albedos to be underestimated by as much as 95% and overestimated by up to 160%, depending on the type of surface and solar zenith angle.

  19. Brain activity modeling in general anesthesia: Enhancing local mean-field models using a slow adaptive firing rate

    NASA Astrophysics Data System (ADS)

    Molaee-Ardekani, B.; Senhadji, L.; Shamsollahi, M. B.; Vosoughi-Vahdat, B.; Wodey, E.

    2007-10-01

    In this paper, an enhanced local mean-field model that is suitable for simulating the electroencephalogram (EEG) in different depths of anesthesia is presented. The main building elements of the model (e.g., excitatory and inhibitory populations) are taken from Steyn-Ross [M. L. Steyn-Ross , Phys. Rev. E 64, 011917 (2001), D. A. Steyn-Ross , Phys. Rev. E 64, 011918 (2001)] and Bojak and Liley [I. Bojak and D. T. Liley, Phys. Rev. E 71, 041902 (2005)] mean-field models and a new slow ionic mechanism is included in the main model. Generally, in mean-field models, some sigmoid-shape functions determine firing rates of neural populations according to their mean membrane potentials. In the enhanced model, the sigmoid function corresponding to excitatory population is redefined to be also a function of the slow ionic mechanism. This modification adapts the firing rate of neural populations to slow ionic activities of the brain. When an anesthetic drug is administered, the slow mechanism may induce neural cells to alternate between two levels of activity referred to as up and down states. Basically, the frequency of up-down switching is in the delta band (0-4Hz) and this is the main reason behind high amplitude, low frequency fluctuations of EEG signals in anesthesia. Our analyses show that the enhanced model may have different working states driven by anesthetic drug concentration. The model is settled in the up state in the waking period, it may switch to up and down states in moderate anesthesia while in deep anesthesia it remains in the down state.

  20. Effect of OPEC oil pricing on output, prices, and exchange rates in the United States and other industrialized countries

    SciTech Connect

    Fleisig, H.

    1981-01-01

    Following each major oil price increase, real gross national product (GNP) has fallen, unemployment and inflation have risen, and exchange rates have moved erratically. But how do oil price increases produce these effects. This paper discusses some of the macroeconomic consequences of too high and rising oil prices, and some of the policy options that might control these effects. It finds that the high and rising price of oil imports from the Organization of Petroleum Exporting Countries (OPEC) burdens the industrial oil-importing countries in two ways. First, because total expenditures on oil rise relative to income, the potential real standard of living in oil-importing countries falls. Together, the countries of the Organization for Economic Cooperation and Development (OECD), for example, may have paid as much as $150 billion more for oil in 1979 than they would have paid in a competitive oil market. Second, the rising oil price increases unemployment and inflation in ways that are difficult for policymakers in oil-importing countries to manage; on the one hand, the rising oil price produces general inflation, and on the other hand, it depresses domestic demand and employment. Policymakers attempt to control part of the inflation, at the cost of increasing unemployment. The total loss in output from the 1974 to 1975 recession, though part of it may have followed from factors unrelated to oil, was about $350 billion.

  1. Allopregnanolone reduces immobility in the forced swimming test and increases the firing rate of lateral septal neurons through actions on the GABAA receptor in the rat.

    PubMed

    Rodrìguez-Landa, Juan Francisco; Contreras, Carlos M; Bernal-Morales, Blandina; Gutièrrez-Garcìa, Ana G; Saavedra, Margarita

    2007-01-01

    Since allopregnanolone reduces the total time of immobility in rats submitted to the forced swimming test, we decided to explore whether this neuroactive steroid shares other antidepressant-like actions, such as increasing the neuronal firing rate in the lateral septal nucleus (LSN). In order to discard the influence of the oestrous cycle on immobility and on the firing rate of LSN neurons, all Wistar rats used in the study underwent ovariectomy before treatments. A group of rats received different doses of allopregnanolone (0.5, 1.0, 2.0 and 3.0 mg/kg, i.p.) 1 hour before being forced to swim in order to identify the minimum effective dose diminishing immobility. None of the tested doses of allopregnanolone produced significant changes in motor activity in the open-field test. The minimum dose of allopregnanolone producing a significant reduction in the total time of immobility (p<0.05) against the vehicle was 1.0 mg/kg, while 2.0 mg/kg and above also increased the latency to the first period of immobility (p<0.05). The minimum effective dose of allopregnanolone reducing immobility in the forced swimming test (1.0 mg/kg) significantly (p <0.05) produced a higher (twofold) neuronal firing rate in LSN neurons, but did not produce any change in septofimbrial nucleus neurons, which fired at a rate similar to that of vehicle-treated rats. The pretreatment with the non-competitive GABAA receptor antagonist, picrotoxin (1.0 mg/kg), blocked the aforementioned actions of allopregnanolone on both immobility and LSN firing rate. In conclusion, allopregnanolone produces an antidepressant-like effect in the forced swimming test, associated with an increase in the LSN neuronal firing rate, seemingly mediated by the GABAA receptor.

  2. Using Chain Extenders to Modify Release Rates of Orange Oil from Poly(Urea-Urethane) Microcapsules.

    PubMed

    Pušlar, Jurij; Štefanec, Dejan; Vrhunec, Aljoša

    2015-01-01

    Poly(urea-urethane) and polyurea microcapsules were prepared by an interfacial polymerisation using orange oil as a core material and a mixture of polymeric 4,4'-methylene diphenyl diisocyanate and toluene diisocyanate in a molar ratio of 1:0.2 as oil-soluble monomers. The membrane composition, thickness, and other properties were varied by changing the type and amount of oil-soluble monomers and water-soluble chain extenders, such as ethylenediamine and diethylenetriamine based on amine groups and 1,4-butanediol and polyethylene glycol 400 based on hydroxyl groups. Studies of the morphology and release behaviour show high dependency on the reaction conditions and reactants' properties. The release rate of the orange oil from microcapsules is highest when using a polymeric linear chain extender, polyethylene glycol with a molecular mass of 400. Microcapsules with improved mechanical stability and a slower release rate were obtained by a thicker membrane and by using the branched multi-functional chain extender diethylenetriamine. PMID:26454605

  3. Quantifying the flow rate of the Deepwater Horizon Macondo Well oil spill

    NASA Astrophysics Data System (ADS)

    Camilli, R.; Bowen, A.; Yoerger, D. R.; Whitcomb, L. L.; Techet, A. H.; Reddy, C. M.; Sylva, S.; Seewald, J.; di Iorio, D.; Whoi Flow Rate Measurement Group

    2010-12-01

    The Deepwater Horizon blowout in the Mississippi Canyon block 252 of the Gulf of Mexico created the largest recorded offshore oil spill. The well outflow’s multiple leak sources, turbulent multiphase flow, tendency for hydrate formation, and extreme source depth of 1500 m below the sea surface complicated the quantitative estimation of oil and gas leakage rates. We present methods and results from a U.S. Coast Guard sponsored flow assessment study of the Deepwater Horizon’s damaged blow out preventer and riser. This study utilized a remotely operated vehicle equipped with in-situ acoustic sensors (a Doppler sonar and an imaging multibeam sonar) and isobaric gas-tight fluid samplers to measure directly outflow from the damaged well. Findings from this study indicate oil release rates and total release volume estimates that corroborate estimates made by the federal government’s Flow Rate Technical Group using non-acoustic techniques. The acoustic survey methods reported here provides a means for estimating fluid flow rates in subsurface environments, and are potentially useful for a diverse range of oceanographic applications. Photograph of the Discoverer Enterprise burning natural gas collected from the Macondo well blowout preventer during flow measurement operations. Copyright Wood Hole Oceanographic Institution.

  4. Dependence and risk assessment for oil prices and exchange rate portfolios: A wavelet based approach

    NASA Astrophysics Data System (ADS)

    Aloui, Chaker; Jammazi, Rania

    2015-10-01

    In this article, we propose a wavelet-based approach to accommodate the stylized facts and complex structure of financial data, caused by frequent and abrupt changes of markets and noises. Specifically, we show how the combination of both continuous and discrete wavelet transforms with traditional financial models helps improve portfolio's market risk assessment. In the empirical stage, three wavelet-based models (wavelet-EGARCH with dynamic conditional correlations, wavelet-copula, and wavelet-extreme value) are considered and applied to crude oil price and US dollar exchange rate data. Our findings show that the wavelet-based approach provides an effective and powerful tool for detecting extreme moments and improving the accuracy of VaR and Expected Shortfall estimates of oil-exchange rate portfolios after noise is removed from the original data.

  5. 76 FR 38590 - Proposed National Emission Standards for Hazardous Air Pollutants From Coal- and Oil-Fired...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... comment period for the proposed rule published May 3, 2011 (76 FR 24976) is being extended for 30 days to... Fossil-Fuel-Fired Electric Utility, Industrial-Commercial-Institutional, and Small Industrial-Commercial... Performance for Fossil-Fuel- Fired Electric Utility, Industrial-Commercial-Institutional, and Small...

  6. Long-term evolution of biodegradation and volatilization rates in a crude oil-contaminated aquifer

    USGS Publications Warehouse

    Chaplin, B.P.; Delin, G.N.; Baker, R.J.; Lahvis, M.A.

    2002-01-01

    Volatilization and subsequent biodegradation near the water Table make up a coupled natural attenuation pathway that results in significant mass loss of hydrocarbons. Rates of biodegradation and volatilization were documented twice 12 years apart at a crude-oil spill site near Bemidji, Minnesota. Biodegradation rates were determined by calibrating a gas transport model to O2, CO2, and CH4 gas-concentration data in the unsaturated zone. Reaction stoichiometry was assumed in converting O2 and CO2 gas-flux estimates to rates of aerobic biodegradation and CH4 gas-flux estimates to rates of methanogenesis. Model results indicate that the coupled pathway has resulted in significant hydrocarbon mass loss at the site, and it was estimated that approximately 10.52 kg/day were lost in 1985 and 1.99 kg/day in 1997. In 1985 3% of total volatile hydrocarbons diffusing from the floating oil were biodegraded in the lower 1 m of the unsaturated zone and increased to 52% by 1997. Rates of hydrocarbon biodegradation above the center of the floating oil were relatively stable from 1985 to 1997, as the primary metabolic pathway shifted from aerobic to methanogenic biodegradation. Model results indicate that in 1997 biodegradation under methanogenenic conditions represented approximately one-half of total hydrocarbon biodegradation in the lower 1 m of the unsaturated zone. Further downgradient, where substrate concentrations have greatly increased, total biodegradation rates increased by greater than an order of magnitude from 0.04 to 0.43 g/m2-day. It appears that volatilization is the primary mechanism for attenuation in early stages of plume evolution, while biodegradation dominates in later stages.

  7. 40 CFR Appendix E to Part 75 - Optional NOX Emissions Estimation Protocol for Gas-Fired Peaking Units and Oil-Fired Peaking Units

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....1Initial Performance Testing Use the following procedures for: measuring NOX emission rates at heat input rate levels corresponding to different load levels; measuring heat input rate; and plotting the correlation between heat input rate and NOX emission rate, in order to determine the emission rate of the...

  8. Fossil-Fired Boilers

    1993-09-23

    Boiler Performance Model (BPM 3.0S) is a set of computer programs developed to analyze the performance of fossil-fired utility boilers. The programs can model a wide variety of boiler designs, and can model coal, oil, or natural gas firing. The programs are intended for use by engineers performing analyses of alternative fuels, alternative operating modes, or boiler modifications.

  9. Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata.

    PubMed

    Segev, Ori; Polevikove, Antonina; Blank, Lior; Goedbloed, Daniel; Küpfer, Eliane; Gershberg, Anna; Koplovich, Avi; Blaustein, Leon

    2015-01-01

    Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping--i.e., bites inflicted by predators including conspecifics--on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail) on Near Eastern fire salamander (Salamandra infraimmaculata) larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length) at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample. PMID:26065683

  10. Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata

    PubMed Central

    Segev, Ori; Polevikove, Antonina; Blank, Lior; Goedbloed, Daniel; Küpfer, Eliane; Gershberg, Anna; Koplovich, Avi; Blaustein, Leon

    2015-01-01

    Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping – i.e., bites inflicted by predators including conspecifics - on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail) on Near Eastern fire salamander (Salamandra infraimmaculata) larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length) at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample. PMID:26065683

  11. Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata.

    PubMed

    Segev, Ori; Polevikove, Antonina; Blank, Lior; Goedbloed, Daniel; Küpfer, Eliane; Gershberg, Anna; Koplovich, Avi; Blaustein, Leon

    2015-01-01

    Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping--i.e., bites inflicted by predators including conspecifics--on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail) on Near Eastern fire salamander (Salamandra infraimmaculata) larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length) at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample.

  12. Smog O3 Production Rate in California Air: Marker Compounds Allow Checks on Source Attribution to Fire and Other Sources

    NASA Astrophysics Data System (ADS)

    Chatfield, R. B.; Esswein, R. F.; Cai, C.; Kaduwela, A.; Kulkarni, S.; Blake, D. R.; Weinheimer, A. J.; Fried, A.; Huey, L. G.

    2012-12-01

    We are able to attribute sources of both radical reactivity and NO that determined the smog-chemical production rate of ozone, P(O3), for NASA's wide-ranging sampling of California air in June, 2008, part of the ARCTAS intensive. We relate formaldehyde, HCHO, and reactive nitrogen oxides, NOx, to a variety of distinct "marker" species that identify origins. We have labeled the sources and markers as (i) Fire emissions (CH3CN), (ii) Biogenic emissions (Isoprene), (iii) Urban/business emissions (CHCl3), (iv) Transport-related fuel consumption, (SO2), and (v) Refining/Port emissions ("residual" toluene). We use multiple linear regression with some appropriate restrictions. We achieve R-squared or explained variance of 88% for HCHO (VOC's) and 60% for NOx. HCHO and NOx are slowly evolving measures of potential ozone generation. The two related but radiation-influenced measures j (HCHO->H+HCO) x [HCHO] and [NO] quantitatively, but non-linearly, relate to instantaneous ozone production in California air, with R-squared of 86-93%, just as in New York City (Chatfield et al., Atmos. Environ., 2010). Maps of attribution for 650 samples from the Port of San Diego to the Northern Sierra foothills, and offshore -— all show huge variability in source attributions for VOCs and NOx. They indicate a widespread fire-emission influence on VOCs as they produce peroxy radicals, but show no positive influence on NOx, in fact consuming NOx from other sources. Comparisons with simulations help to refine our attribution classes and also to check balances of VOC emissions in available inventories. The use of the P(O3) measures is directly translatable to a method for estimate smog-ozone production rate from space, as data from another intensive, DISCOVER-AQ, show. (Left) A rare example where all sources contribute significantly, with markers and tentative attributions marked. (Right) Three different situations describing the control of smog ozone production, all from the same geographic

  13. SENSOR FOR INDIVIDUAL BURNER CONTROL OF FIRING RATE, FUEL-AIR RATIO, AND COAL FINENESS CORRELATION

    SciTech Connect

    Wayne Hill; Roger Demler; Robert G. Mudry

    2005-01-01

    Additional calibration data were collected in the Coal Flow Test Facility early in this reporting period. These data comprised a total of 181 tests for stud and magnetic accelerometer mounts, with two mounting locations relative to two different pipe elbows, and including some tests with out-of-plane elbows upstream of the test section to produce coal ''roping''. The results found in analyzing these new data were somewhat disappointing: correlations for coal flow rate for a given mount type and mounting location were less accurate than desired, and degraded badly when data from other locations were included in the same analysis. Reviewing all of the data files (from both the earlier testing and recent calibration testing) disclosed a significant fraction of cases with several forms of noise. Eliminating these cases improved the correlations somewhat, but the number of cases that remained did not permit general conclusions to be drawn. It was finally learned that yet another type of noise is present in some data files, producing a strong effect on the correlation accuracy. The cases not subject to this noise correlated very well. It would be desirable to collect additional data in the Coal Flow Test Facility prior to moving on to field data collection, a change in program direction that would require a no-cost time extension.

  14. SENSOR FOR INDIVIDUAL BURNER CONTROL OF FIRING RATE, FUEL-AIR RATIO, AND COAL FINENESS CORRELATION

    SciTech Connect

    Wayne Hill; Roger Demler; Robert G. Mudry

    2005-04-01

    A no-cost time extension was requested, to permit additional laboratory testing prior to undertaking field data collection. This was received in this reporting period. To minimize program cost, this additional testing is planned to be performed in concert with EPRI-funded testing at the Coal Flow Test Facility. Since the EPRI schedule was undecided, a hiatus occurred in the test effort. Instead, a significant effort was exerted to analyze the available laboratory test data to see whether the source and nature of noise behaviors could be identified, or whether the key flow information could be extracted even in the presence of the noise. One analysis approach involved filtering the data numerically to reject dynamics outside of various frequency bands. By varying the center frequency and width of the band, the effect of signal frequency on flow dynamics could be examined. Essentially equivalent results were obtained for all frequency bands that excluded a neighborhood of the transducer resonance, indicating that there is little advantage to be gained by limiting the experimental frequency window. Another approach examined the variation of the dynamics over a series of 1-second windows of data, producing an improvement in the prediction of coal flow rate. Yet another approach compared the dynamics of a series of 1-second windows to those of a series of 5-second windows, producing still better results. These results will be developed further in the next reporting period, which should also include further laboratory testing at the Coal Flow Test Facility.

  15. Effects of beach sand properties, temperature and rainfall on the degradation rates of oil in buried oil/beach sand mixtures.

    PubMed

    Rowland, A P; Lindley, D K; Hall, G H; Rossall, M J; Wilson, D R; Benham, D G; Harrison, A F; Daniels, R E

    2000-07-01

    Lysimeters located outdoors have been used to evaluate the decomposition of buried oily beach sand waste (OBS) prepared using Forties light crude oil and sand from different locations around the British coast. The OBS (5% oil by weight) was buried as a 12-cm layer over dune pasture sub-sand and overlain by 20 cm of dune pasture topsoil. Decomposition rates of oil residues averaged 2300 kg ha(-1) in the first year and the pattern of oil decomposition may be represented by a power curve. Oil decomposition was strongly related to the temperature in the OBS layer, but was also significantly affected by rainfall in the previous 12 h. The CO(2) flux at the surface of the treatment lysimeters followed the relationship [log(10) CO(2) (mg C m(-2) h(-1))=0.93+0.058x OBS temp. (degrees C)-0.042x12 h rain (mm)]. There was considerable variation in the rate of oil decomposition in sands collected from different sites. Sand from Askernish supported most microbial activity whilst sand from Tain was relatively inactive. The decomposition process appeared to cease when the sand became saturated with water, i.e. temporarily anaerobic. However, decomposition recommenced when the soil dried out. The fastest rate of decomposition occurred in sand from one of the two sites predicted to have high populations of hydrocarbon-degrading bacteria. Larger particle size and higher Ca content may also be significant factors governing the rate of decomposition. PMID:15092918

  16. Mean-field equations for stochastic firing-rate neural fields with delays: Derivation and noise-induced transitions

    NASA Astrophysics Data System (ADS)

    Touboul, Jonathan

    2012-08-01

    In this manuscript we analyze the collective behavior of mean-field limits of large-scale, spatially extended stochastic neuronal networks with delays. Rigorously, the asymptotic regime of such systems is characterized by a very intricate stochastic delayed integro-differential McKean-Vlasov equation that remain impenetrable, leaving the stochastic collective dynamics of such networks poorly understood. In order to study these macroscopic dynamics, we analyze networks of firing-rate neurons, i.e. with linear intrinsic dynamics and sigmoidal interactions. In that case, we prove that the solution of the mean-field equation is Gaussian, hence characterized by its two first moments, and that these two quantities satisfy a set of coupled delayed integro-differential equations. These equations are similar to usual neural field equations, and incorporate noise levels as a parameter, allowing analysis of noise-induced transitions. We identify through bifurcation analysis several qualitative transitions due to noise in the mean-field limit. In particular, stabilization of spatially homogeneous solutions, synchronized oscillations, bumps, chaotic dynamics, wave or bump splitting are exhibited and arise from static or dynamic Turing-Hopf bifurcations. These surprising phenomena allow further exploring the role of noise in the nervous system.

  17. Multifaceted effects of oligodendroglial exosomes on neurons: impact on neuronal firing rate, signal transduction and gene regulation

    PubMed Central

    Fröhlich, Dominik; Kuo, Wen Ping; Frühbeis, Carsten; Sun, Jyh-Jang; Zehendner, Christoph M.; Luhmann, Heiko J.; Pinto, Sheena; Toedling, Joern; Trotter, Jacqueline; Krämer-Albers, Eva-Maria

    2014-01-01

    Exosomes are small membranous vesicles of endocytic origin that are released by almost every cell type. They exert versatile functions in intercellular communication important for many physiological and pathological processes. Recently, exosomes attracted interest with regard to their role in cell–cell communication in the nervous system. We have shown that exosomes released from oligodendrocytes upon stimulation with the neurotransmitter glutamate are internalized by neurons and enhance the neuronal stress tolerance. Here, we demonstrate that oligodendroglial exosomes also promote neuronal survival during oxygen–glucose deprivation, a model of cerebral ischaemia. We show the transfer from oligodendrocytes to neurons of superoxide dismutase and catalase, enzymes which are known to help cells to resist oxidative stress. Additionally, we identify various effects of oligodendroglial exosomes on neuronal physiology. Electrophysiological analysis using in vitro multi-electrode arrays revealed an increased firing rate of neurons exposed to oligodendroglial exosomes. Moreover, gene expression analysis and phosphorylation arrays uncovered differentially expressed genes and altered signal transduction pathways in neurons after exosome treatment. Our study thus provides new insight into the broad spectrum of action of oligodendroglial exosomes and their effects on neuronal physiology. The exchange of extracellular vesicles between neural cells may exhibit remarkable potential to impact brain performance. PMID:25135971

  18. Low rate of replication fork progression lengthens the replication timing of a locus containing an early firing origin

    PubMed Central

    Bénard, Marianne; Maric, Chrystelle; Pierron, Gérard

    2007-01-01

    Invariance of temporal order of genome replication in eukaryotic cells and its correlation with gene activity has been well-documented. However, recent data suggest a relax control of replication timing. To evaluate replication schedule accuracy, we detailed the replicational organization of the developmentally regulated php locus that we previously found to be lately replicated, even though php gene is highly transcribed in naturally synchronous plasmodia of Physarum. Unexpectedly, bi-dimensional agarose gel electrophoreses of DNA samples prepared at specific time points of S phase showed that replication of the locus actually begins at the onset of S phase but it proceeds through the first half of S phase, so that complete replication of php-containing DNA fragments occurs in late S phase. Origin mapping located replication initiation upstream php coding region. This proximity and rapid fork progression through the coding region result in an early replication of php gene. We demonstrated that afterwards an unusually low fork rate and unidirectional fork pausing prolong complete replication of php locus, and we excluded random replication timing. Importantly, we evidenced that the origin linked to php gene in plasmodium is not fired in amoebae when php expression dramatically reduced, further illustrating replication-transcription coupling in Physarum. PMID:17717000

  19. Low rate of replication fork progression lengthens the replication timing of a locus containing an early firing origin.

    PubMed

    Bénard, Marianne; Maric, Chrystelle; Pierron, Gérard

    2007-01-01

    Invariance of temporal order of genome replication in eukaryotic cells and its correlation with gene activity has been well-documented. However, recent data suggest a relax control of replication timing. To evaluate replication schedule accuracy, we detailed the replicational organization of the developmentally regulated php locus that we previously found to be lately replicated, even though php gene is highly transcribed in naturally synchronous plasmodia of Physarum. Unexpectedly, bi-dimensional agarose gel electrophoreses of DNA samples prepared at specific time points of S phase showed that replication of the locus actually begins at the onset of S phase but it proceeds through the first half of S phase, so that complete replication of php-containing DNA fragments occurs in late S phase. Origin mapping located replication initiation upstream php coding region. This proximity and rapid fork progression through the coding region result in an early replication of php gene. We demonstrated that afterwards an unusually low fork rate and unidirectional fork pausing prolong complete replication of php locus, and we excluded random replication timing. Importantly, we evidenced that the origin linked to php gene in plasmodium is not fired in amoebae when php expression dramatically reduced, further illustrating replication-transcription coupling in Physarum.

  20. Interfacial film formation: influence on oil spreading rates in lab basin tests and dispersant effectiveness testing in a wave tank.

    PubMed

    King, Thomas L; Clyburne, Jason A C; Lee, Kenneth; Robinson, Brian J

    2013-06-15

    Test facilities such as lab basins and wave tanks are essential when evaluating the use of chemical dispersants to treat oil spills at sea. However, these test facilities have boundaries (walls) that provide an ideal environment for surface (interfacial) film formation on seawater. Surface films may form from surfactants naturally present in crude oil as well as dispersant drift/overspray when applied to an oil spill. The objective of this study was to examine the impact of surface film formation on oil spreading rates in a small scale lab basin and on dispersant effectiveness conducted in a large scale wave tank. The process of crude oil spreading on the surface of the basin seawater was influenced in the presence of a surface film as shown using a 1st order kinetic model. In addition, interfacial film formation can greatly influence chemically dispersed crude oil in a large scale dynamic wave tank. PMID:23623652

  1. Technological study on reducing blast-hole rate during laser cutting oil pipe

    NASA Astrophysics Data System (ADS)

    Deng, Qiansong; Yang, Weihong; Tang, Xiahui; Peng, Hao; Qin, Yingxiong

    2012-03-01

    In this paper, a laser cutting technology for the oil pipes with the thickness of 10mm, the diameter of 142mm and the material of N80 has been developed, in order to reduce the high hole-blast rate in processing. Experiments are taken on the Rofin DC025 slab CO2 laser cutting system and a set of flexible fixtures. The reasons of forming blast-hole have been analyzed, and the influences of technique parameters on blast-hole rate have been studied, such as laser power, pulse frequency, laser delay, focus position and oxygen pressure. The results show that the blast-hole rate can be controlled lower than 5% at the conditions of laser power 1500W, laser delay 5s, pulse frequency 180Hz, the oxygen pressure 0.6 kg/cm2, focus length 190mm, nozzle diameter 1.5mm.

  2. Technological study on reducing blast-hole rate during laser cutting oil pipe

    NASA Astrophysics Data System (ADS)

    Deng, Qiansong; Yang, Weihong; Tang, Xiahui; Peng, Hao; Qin, Yingxiong

    2011-11-01

    In this paper, a laser cutting technology for the oil pipes with the thickness of 10mm, the diameter of 142mm and the material of N80 has been developed, in order to reduce the high hole-blast rate in processing. Experiments are taken on the Rofin DC025 slab CO2 laser cutting system and a set of flexible fixtures. The reasons of forming blast-hole have been analyzed, and the influences of technique parameters on blast-hole rate have been studied, such as laser power, pulse frequency, laser delay, focus position and oxygen pressure. The results show that the blast-hole rate can be controlled lower than 5% at the conditions of laser power 1500W, laser delay 5s, pulse frequency 180Hz, the oxygen pressure 0.6 kg/cm2, focus length 190mm, nozzle diameter 1.5mm.

  3. Plastic surgery and burns disasters. What impact do major civilian disasters have upon medicine? Bradford City Football Club stadium fire, 1985, King's Cross Underground fire, 1987, Piper Alpha offshore oil rig disaster, 1988.

    PubMed

    Vaghela, Kalpesh R

    2009-06-01

    Major disasters involving multiple casualties are neither new nor infrequent. Such events have important implications for medicine and can provide crucial lessons for the future. However, while the medical aspects of war have received considerable attention, rather less is known about civilian disasters. To redress this imbalance, this article reviews three major British disasters of the 1980s where serious burns injury was a significant feature of the human casualty: the Bradford City Football Club fire of 1985, the King's Cross Underground fire of 1987 and the Piper Alpha oil rig disaster of 1988. Four related themes are used to examine in detail the ways in which these events impacted on medicine: plastics and reconstructive surgery, clinical psychology, disaster management and long-term structural change. Drawing on articles in specialist burns and psychiatric journals, together with the personal communications and recollections of surgeons and psychiatrists involved, it is revealed that while ground-breaking advances are a relative rarity in medicine, numerous small but significant lessons did emerge from these events, although often in subtle and highly specialised fields of medicine.

  4. Refining Field Measurements of Methane Flux Rates from Abandoned Oil and Gas Wells

    NASA Astrophysics Data System (ADS)

    Lagron, C. S.; Kang, M.; Riqueros, N. S.; Jackson, R. B.

    2015-12-01

    Recent studies in Pennsylvania demonstrate the potential for significant methane emissions from abandoned oil and gas wells. A subset of tested wells was high emitting, with methane flux rates up to seven orders of magnitude greater than natural fluxes (up to 105 mg CH4/hour, or about 2.5LPM). These wells contribute disproportionately to the total methane emissions from abandoned oil and gas wells. The principles guiding the chamber design have been developed for lower flux rates, typically found in natural environments, and chamber design modifications may reduce uncertainty in flux rates associated with high-emitting wells. Kang et al. estimate errors of a factor of two in measured values based on previous studies. We conduct controlled releases of methane to refine error estimates and improve chamber design with a focus on high-emitters. Controlled releases of methane are conducted at 0.05 LPM, 0.50 LPM, 1.0 LPM, 2.0 LPM, 3.0 LPM, and 5.0 LPM, and at two chamber dimensions typically used in field measurements studies of abandoned wells. As most sources of error tabulated by Kang et al. tend to bias the results toward underreporting of methane emissions, a flux-targeted chamber design modification can reduce error margins and/or provide grounds for a potential upward revision of emission estimates.

  5. Rates and Mechanisms of Oil Shale Pyrolysis: A Chemical Structure Approach

    SciTech Connect

    Fletcher, Thomas; Pugmire, Ronald

    2015-01-01

    Three pristine Utah Green River oil shale samples were obtained and used for analysis by the combined research groups at the University of Utah and Brigham Young University. Oil shale samples were first demineralized and the separated kerogen and extracted bitumen samples were then studied by a host of techniques including high resolution liquid-state carbon-13 NMR, solid-state magic angle sample spinning 13C NMR, GC/MS, FTIR, and pyrolysis. Bitumen was extracted from the shale using methanol/dichloromethane and analyzed using high resolution 13C NMR liquid state spectroscopy, showing carbon aromaticities of 7 to 11%. The three parent shales and the demineralized kerogens were each analyzed with solid-state 13C NMR spectroscopy. Carbon aromaticity of the kerogen was 23-24%, with 10-12 aromatic carbons per cluster. Crushed samples of Green River oil shale and its kerogen extract were pyrolyzed at heating rates from 1 to 10 K/min at pressures of 1 and 40 bar and temperatures up to 1000°C. The transient pyrolysis data were fit with a first-order model and a Distributed Activation Energy Model (DAEM). The demineralized kerogen was pyrolyzed at 10 K/min in nitrogen at atmospheric pressure at temperatures up to 525°C, and the pyrolysis products (light gas, tar, and char) were analyzed using 13C NMR, GC/MS, and FTIR. Details of the kerogen pyrolysis have been modeled by a modified version of the chemical percolation devolatilization (CPD) model that has been widely used to model coal combustion/pyrolysis. This refined CPD model has been successful in predicting the char, tar, and gas yields of the three shale samples during pyrolysis. This set of experiments and associated modeling represents the most sophisticated and complete analysis available for a given set of oil shale samples.

  6. Fast synchronous oscillations of firing rate in cultured rat suprachiasmatic nucleus neurons: possible role in circadian synchronization in the intact nucleus.

    PubMed

    Kononenko, Nikolai I; Honma, Sato; Honma, Ken-Ichi

    2013-03-01

    The coherent circadian rhythm of the brain's master circadian pacemaker, the suprachiasmatic nucleus (SCN), is a result of synchronization of electrical activity of many SCN neurons possessing their own circadian oscillators. However, how the activity of these neurons is synchronized is not precisely known. By plotting the electrical firing rates of dispersed rat SCN neurons in multi-electrode array dishes with 20-s averaging of action-potential activity, we have investigated a novel phenomenon: fast (relative to the circadian cycle) oscillations of firing rate (FOFR) with duration of bursts ∼10min and interburst interval varying in a range from 20 to 60min in different cells, remaining nevertheless rather regular in individual cells. In many cases, separate neurons in distant parts of the 1mm recording area of an array exhibited correlated FOFR. FOFR of individual cells were positively or negatively correlated with those of other cells in a functioning neural network. Intriguingly, in occasional neuron pairs, transformation of their irregular firing to circadian peaks was accompanied by appearance of FOFR and an increase in the magnitude of firing correlation. We hypothesize that this FOFR observed in cultured SCN neurons contribute to synchronization of the circadian rhythm in the intact SCN.

  7. Response of Argentine ants and red imported fire ants to permethrin-impregnated plastic strips: foraging rates, colonization of potted soil, and differential mortality.

    PubMed

    Costa, Heather S; Greenberg, Les; Klotz, John; Rust, Michael K

    2005-12-01

    This study investigated the effects of the permethrin-impregnated plastic on ant mortality and foraging rates, and tested its potential for preventing ants from colonizing potted soil. Direct exposure to the plastic for as short as 1 min caused significant mortality of both red imported fire ants, Solenopsis invicta Buren, and Argentine ants, Linepithema humile (Mayr); however, red imported fire ants were more susceptible than Argentine ants. Knockdown of virtually all ants initially occurred within 15 min after exposure. However, some moribund ants recovered from the effects within 24 h. For example, after 1 min of direct exposure to the permethrin-impregnated plastic, 70% of Argentine ants and 5% of red imported fire ants recovered from the treatment. In established colonies of Argentine ants, significantly fewer ants foraged for food up posts treated with the plastic compared with untreated posts. In addition, colonies responded to introduction of the treatment by significantly reducing their overall foraging rates, even on untreated posts. When pots filled with moistened soil were introduced into established ant colonies, 82% of Argentine ants and 99% of red imported fire ants moved into the soil. In contrast, when a 1-cm-wide coil of the plastic was placed under the pot, no ants moved into the soil. The potential for use of these materials in nursery production is discussed. PMID:16539136

  8. 14 CFR 125.173 - Fire detectors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Fire detectors. 125.173 Section 125.173....173 Fire detectors. Fire detectors must be made and installed in a manner that assures their ability... subjected. Fire detectors must be unaffected by exposure to fumes, oil, water, or other fluids that may...

  9. 14 CFR 125.173 - Fire detectors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Fire detectors. 125.173 Section 125.173....173 Fire detectors. Fire detectors must be made and installed in a manner that assures their ability... subjected. Fire detectors must be unaffected by exposure to fumes, oil, water, or other fluids that may...

  10. 14 CFR 125.173 - Fire detectors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fire detectors. 125.173 Section 125.173....173 Fire detectors. Fire detectors must be made and installed in a manner that assures their ability... subjected. Fire detectors must be unaffected by exposure to fumes, oil, water, or other fluids that may...

  11. 14 CFR 125.173 - Fire detectors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Fire detectors. 125.173 Section 125.173....173 Fire detectors. Fire detectors must be made and installed in a manner that assures their ability... subjected. Fire detectors must be unaffected by exposure to fumes, oil, water, or other fluids that may...

  12. 14 CFR 125.173 - Fire detectors.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Fire detectors. 125.173 Section 125.173....173 Fire detectors. Fire detectors must be made and installed in a manner that assures their ability... subjected. Fire detectors must be unaffected by exposure to fumes, oil, water, or other fluids that may...

  13. Genotoxic potential and heart rate disorders in the Mediterranean mussel Mytilus galloprovincialis exposed to Superdispersant-25 and dispersed diesel oil.

    PubMed

    Martinović, Rajko; Kolarević, Stoimir; Kračun-Kolarević, Margareta; Kostić, Jovana; Marković, Sandra; Gačić, Zoran; Kljajić, Zoran; Vuković-Gačić, Branka

    2015-07-01

    The effects of ex situ exposure of Mytilus galloprovincialis to Superdispersant-25 (S-25), diesel oil and dispersed diesel oil mixtures were studied by the impact on level of DNA damage in haemocytes (comet assay) and the cardiac activity patterns of mussels. Specimens were exposed for 72 h in a static system to diesel oil (100 μL/L and 1 mL/L), S-25 (5 and 50 μL/L), and dispersed diesel oil mixtures M1 (diesel oil 100 μL/L + S-25 5 μL/L) and M2 (diesel oil 1 mL/L + S-25 50 μL/L). For positive control 40 μM CdCl2 was used. The comet assay results indicated genotoxic potential of S-25 while the effects of diesel oil alone were not observed. The highest response was detected for M1 while the effects of M2 were not detected. The heart rate disorders were recorded for the diesel oil (1 mL/L), S-25 (50 μL/L) and both dispersed diesel oil mixtures.

  14. View southeast of west and north sides of Fire Warehouse ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View southeast of west and north sides of Fire Warehouse and attached "fire cache" (firewood shed on far left, gas-and-oil house in far right) - Fire Warehouse, 730 Laurel Street, Butte Falls, Jackson County, OR

  15. Multifractal analysis of spot rates in tanker markets and their comparisons with crude oil markets

    NASA Astrophysics Data System (ADS)

    Zheng, Shiyuan; Lan, Xiangang

    2016-02-01

    This paper investigates the dynamic features of the spot rates for VLCC/ULCC, Suezmax, Aframax, Panamax and Handysize tanker markets by means of multifractal detrended fluctuation analysis (MF-DFA). The Hurst exponents, especially the time-dependent Hurst exponents, of the daily rate returns are calculated to capture the fractal properties of these different tanker markets. The origins of multifractility in these markets are identified by comparing their multifractal scaling exponents based on the original data, the shuffled data and the surrogate data. Furthermore, the non-periodic cycles for these markets are detected by the V-statistic. Finally, the comparisons of the fractal properties between the tanker markets and the crude oil commodity markets suggest that the tanker markets are more fractal than their upstream counterparts.

  16. 40 CFR Appendix E to Part 75 - Optional NOX Emissions Estimation Protocol for Gas-Fired Peaking Units and Oil-Fired Peaking Units

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... following procedures. 2.1.6.1Plot the heat input rate (mmBtu/hr) as the independent (or x) variable and the NOX emission rates (lb/mmBtu) as the dependent (or y) variable for each load point. Construct...

  17. Examination of event magnitude, contributing drainage basin area, channel gradient, and rainfall influences on channel yield rates of post-fire debris flows

    NASA Astrophysics Data System (ADS)

    Gartner, J. E.; Cannon, S. H.; Santi, P.

    2011-12-01

    Development of methods for estimating volumes of post-fire debris-flow material along drainage networks requires a better understanding of the factors that control channel erosion and deposition within recently-burned drainage basins. The amount of material eroded and deposited by debris flows at locations along a channel can be quantified using the channel yield rate; the change in debris-flow volume per unit length of channel caused by passage of a debris flow. Here, we use channel yield rates measured in basins recently burned the 2009 Station fire in the San Gabriel Mountains of southern California to examine relationships between these rates and event magnitude, contributing drainage basin area, channel gradient, and rainfall characteristics. Following the Station fire and prior to any significant rainstorms, two to nine cross section surveys were established along the entire lengths of the main channels of three steep, rugged drainage basins. Surveys of the channel cross sections were made both before and after two distinct debris-flow triggering storms. These data were used to calculate post-fire debris-flow channel yield rates at 40 locations. Tipping-bucket rain gages installed near the surveyed channels provide rainfall amounts and intensities. Measurements of the amount of material removed from debris-retention basins located at the drainage basin outlets provide information on debris-flow volumes deposited at drainage basin outlets. High-resolution LiDAR data (1 meter) provide accurate elevation data for defining contributing drainage basin areas and channel gradients. The measured channel yield rates varied from 1 to 19 m3/m, with a mean of 4 m3/m and standard deviation of 5 m3/m. The greatest yield rates coincide with locations immediately downstream of field-mapped bedrock steps or channel junctions. The coincidence with bedrock steps suggests that in-channel "fire-hose" entrainment is a major contributor to debris-flow volume. High channel yield

  18. The correlated blanching of synaptic bodies and reduction in afferent firing rates caused by transmitter-depleting agents in the frog semicircular canal

    NASA Technical Reports Server (NTRS)

    Guth, P.; Norris, C.; Fermin, C. D.; Pantoja, M.

    1993-01-01

    Synaptic bodies (SBs) associated with rings of synaptic vesicles and well-defined, pre- and post-synaptic membrane structures are indicators of maturity in most hair cell-afferent nerve junctions. The role of the SBs remains elusive despite several experiments showing that they may be involved in storage of neurotransmitter. Our results demonstrate that SBs of the adult posterior semicircular canal (SCC) cristae hair cells become less electron dense following incubation of the SCC with the transmitter-depleting drug tetrabenazine (TBZ). Objective quantification and comparison of the densities of the SBs in untreated and TBZ-treated frog SCC demonstrated that TBZ significantly decreased the electron density of SBs. This reduction in electron density was accompanied by a reduction in firing rates of afferent fibers innervating the posterior SCC. A second transmitter-depleting drug, guanethidine, previously shown to reduce the electron density of hair cell SBs, also reduced the firing rates of afferent fibers innervating the posterior SCC. In contrast, the electron density of dense granules (DG), similar in size and shape to synaptic bodies (SB) in hair cells, did not change after incubation in TBZ, thus indicating that granules and SBs are not similar in regard to their electron density. The role of SBs in synaptic transmission and the transmitter, if any, stored in the SBs remain unknown. Nonetheless, the association of the lessening of electron density with a reduction in afferent firing rate provides impetus for the further investigation of the SB's role in neurotransmission.

  19. Unconventional Gas and Oil Drilling Is Associated with Increased Hospital Utilization Rates.

    PubMed

    Jemielita, Thomas; Gerton, George L; Neidell, Matthew; Chillrud, Steven; Yan, Beizhan; Stute, Martin; Howarth, Marilyn; Saberi, Pouné; Fausti, Nicholas; Penning, Trevor M; Roy, Jason; Propert, Kathleen J; Panettieri, Reynold A

    2015-01-01

    Over the past ten years, unconventional gas and oil drilling (UGOD) has markedly expanded in the United States. Despite substantial increases in well drilling, the health consequences of UGOD toxicant exposure remain unclear. This study examines an association between wells and healthcare use by zip code from 2007 to 2011 in Pennsylvania. Inpatient discharge databases from the Pennsylvania Healthcare Cost Containment Council were correlated with active wells by zip code in three counties in Pennsylvania. For overall inpatient prevalence rates and 25 specific medical categories, the association of inpatient prevalence rates with number of wells per zip code and, separately, with wells per km2 (separated into quantiles and defined as well density) were estimated using fixed-effects Poisson models. To account for multiple comparisons, a Bonferroni correction with associations of p<0.00096 was considered statistically significant. Cardiology inpatient prevalence rates were significantly associated with number of wells per zip code (p<0.00096) and wells per km2 (p<0.00096) while neurology inpatient prevalence rates were significantly associated with wells per km2 (p<0.00096). Furthermore, evidence also supported an association between well density and inpatient prevalence rates for the medical categories of dermatology, neurology, oncology, and urology. These data suggest that UGOD wells, which dramatically increased in the past decade, were associated with increased inpatient prevalence rates within specific medical categories in Pennsylvania. Further studies are necessary to address healthcare costs of UGOD and determine whether specific toxicants or combinations are associated with organ-specific responses.

  20. Unconventional Gas and Oil Drilling Is Associated with Increased Hospital Utilization Rates

    PubMed Central

    Neidell, Matthew; Chillrud, Steven; Yan, Beizhan; Stute, Martin; Howarth, Marilyn; Saberi, Pouné; Fausti, Nicholas; Penning, Trevor M.; Roy, Jason; Propert, Kathleen J.; Panettieri, Reynold A.

    2015-01-01

    Over the past ten years, unconventional gas and oil drilling (UGOD) has markedly expanded in the United States. Despite substantial increases in well drilling, the health consequences of UGOD toxicant exposure remain unclear. This study examines an association between wells and healthcare use by zip code from 2007 to 2011 in Pennsylvania. Inpatient discharge databases from the Pennsylvania Healthcare Cost Containment Council were correlated with active wells by zip code in three counties in Pennsylvania. For overall inpatient prevalence rates and 25 specific medical categories, the association of inpatient prevalence rates with number of wells per zip code and, separately, with wells per km2 (separated into quantiles and defined as well density) were estimated using fixed-effects Poisson models. To account for multiple comparisons, a Bonferroni correction with associations of p<0.00096 was considered statistically significant. Cardiology inpatient prevalence rates were significantly associated with number of wells per zip code (p<0.00096) and wells per km2 (p<0.00096) while neurology inpatient prevalence rates were significantly associated with wells per km2 (p<0.00096). Furthermore, evidence also supported an association between well density and inpatient prevalence rates for the medical categories of dermatology, neurology, oncology, and urology. These data suggest that UGOD wells, which dramatically increased in the past decade, were associated with increased inpatient prevalence rates within specific medical categories in Pennsylvania. Further studies are necessary to address healthcare costs of UGOD and determine whether specific toxicants or combinations are associated with organ-specific responses. PMID:26176544

  1. Unconventional Gas and Oil Drilling Is Associated with Increased Hospital Utilization Rates.

    PubMed

    Jemielita, Thomas; Gerton, George L; Neidell, Matthew; Chillrud, Steven; Yan, Beizhan; Stute, Martin; Howarth, Marilyn; Saberi, Pouné; Fausti, Nicholas; Penning, Trevor M; Roy, Jason; Propert, Kathleen J; Panettieri, Reynold A

    2015-01-01

    Over the past ten years, unconventional gas and oil drilling (UGOD) has markedly expanded in the United States. Despite substantial increases in well drilling, the health consequences of UGOD toxicant exposure remain unclear. This study examines an association between wells and healthcare use by zip code from 2007 to 2011 in Pennsylvania. Inpatient discharge databases from the Pennsylvania Healthcare Cost Containment Council were correlated with active wells by zip code in three counties in Pennsylvania. For overall inpatient prevalence rates and 25 specific medical categories, the association of inpatient prevalence rates with number of wells per zip code and, separately, with wells per km2 (separated into quantiles and defined as well density) were estimated using fixed-effects Poisson models. To account for multiple comparisons, a Bonferroni correction with associations of p<0.00096 was considered statistically significant. Cardiology inpatient prevalence rates were significantly associated with number of wells per zip code (p<0.00096) and wells per km2 (p<0.00096) while neurology inpatient prevalence rates were significantly associated with wells per km2 (p<0.00096). Furthermore, evidence also supported an association between well density and inpatient prevalence rates for the medical categories of dermatology, neurology, oncology, and urology. These data suggest that UGOD wells, which dramatically increased in the past decade, were associated with increased inpatient prevalence rates within specific medical categories in Pennsylvania. Further studies are necessary to address healthcare costs of UGOD and determine whether specific toxicants or combinations are associated with organ-specific responses. PMID:26176544

  2. Activity patterns and parasitism rates of fire ant decapitating flies (Diptera:Phoridae:Pseudacteon spp.) in their native Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract: This work describes the annual and daily activity patterns of two parasitoid fly communities of the fire ant S. invicta (Hymenoptera: Formicidae) in their native Argentina. Pseudacteon (Diptera: Phoridae) flies were censused monthly for one year at two sites in northwestern Corr...

  3. DEVELOPMENT OF FINE PARTICULATE EMISSION FACTORS AND SPECIATION PROFILES FOR OIL AND GAS-FIRED COMBUSTION SYSTEMS

    SciTech Connect

    Glenn C. England

    2004-10-20

    In 1997, the United States Environmental Protection Agency (EPA) promulgated new National Ambient Air Quality Standards (NAAQS) for particulate matter, including for the first time particles with aerodynamic diameter smaller than 2.5 micrometers ({micro}m) referred to as PM2.5. PM2.5 in the atmosphere also contributes to reduced atmospheric visibility, which is the subject of existing rules for siting emission sources near Class 1 areas and new Regional Haze rules. There are few existing data regarding emissions and characteristics of fine aerosols from oil, gas and power generation industry combustion sources, and the information that is available is generally outdated and incomplete. Traditional stationary source air emission sampling methods tend to underestimate or overestimate the contribution of the source to ambient aerosols because they do not properly account for primary aerosol formation, which occurs after the gases leave the stack. Primary aerosol includes both filterable particles that are solid or liquid aerosols at stack temperature plus those that form as the stack gases cool through mixing and dilution processes in the plume downwind of the source. These deficiencies in the current methods can have significant impacts on regulatory decision-making. PM2.5 measurement issues were extensively reviewed by the American Petroleum Institute (API) (England et al., 1998), and it was concluded that dilution sampling techniques are more appropriate for obtaining a representative particulate matter sample from combustion systems for determining PM2.5 emission rate and chemical speciation. Dilution sampling is intended to collect aerosols including those that condense and/or react to form solid or liquid aerosols as the exhaust plume mixes and cools to near-ambient temperature immediately after the stack discharge. These techniques have been widely used in recent research studies. For example, Hildemann et al. (1994) and McDonald et al. (1998) used filtered

  4. Long-term carcinogenicity study in Syrian golden hamster of particulate emissions from coal- and oil-fired power plants

    SciTech Connect

    Persson, S.A.; Ahlberg, M.; Berghem, L.; Koenberg, E.N.; Nordberg, G.F.; Bergman, F.

    1988-04-01

    Male Syrian golden hamsters were given 15 weekly intratracheal instillations with suspensions of coal fly ash or oil fly ash. Controls were instilled with saline containing gelatine (0.5 g/100 mL) or to check particle effects with suspensions of hematite (Fe/sub 2/O/sub 3/). The common weekly dose was 4.5 mg/hamster. In addition, one subgroup of hamsters was treated with oil fly ash at a weekly dose of 3.0 mg/hamster and another with coal fly ash at a weekly dose of 6.0 mg/hamster. Other groups of hamsters were treated with suspensions of benzo(a)pyrene (BaP) or with suspensions on coal fly ash, oil fly ash, or Fe/sub 2/O/sub 3/ coated with BaP. The mass median aerodynamic diameters of the coal and oil fly ashes were 4.4 microns and 28 microns, respectively. Hamsters treated with oil fly ash showed a higher frequency of bronchiolar-alveolar hyperplasia than hamsters in the other treatment groups. Squamous dysplasia and squamous metaplasia were most frequent in animals treated with suspensions of BaP or BaP-coated particles. The earliest appearance of a tumor, the highest incidence of tumors, and the highest incidence of malignant tumors were observed in hamsters treated with oil fly ash coated with BaP. Squamous cell carcinoma and adenosquamous carcinoma were the most frequent malignant tumors. No malignant tumors and only few benign tumors were observed in hamsters instilled with suspensions of fly ash not coated with BaP. The present study gives no indication that coal fly ash could create more serious health problems than oil fly ash.

  5. Oil and drug control the release rate from lyotropic liquid crystals.

    PubMed

    Martiel, Isabelle; Baumann, Nicole; Vallooran, Jijo J; Bergfreund, Jotam; Sagalowicz, Laurent; Mezzenga, Raffaele

    2015-04-28

    The control of the diffusion coefficient by the dimensionality d of the structure appears as a most promising lever to efficiently tune the release rate from lyotropic liquid crystalline (LLC) phases and dispersed particles towards sustained, controlled and targeted release. By using phosphatidylcholine (PC)- and monolinoleine (MLO)-based mesophases with various apolar structural modifiers and water-soluble drugs, we present a comprehensive study of the dimensional structural control of hydrophilic drug release, including 3-d bicontinuous cubic, 2-d lamellar, 1-d hexagonal and 0-d micellar cubic phases in excess water. We investigate how the surfactant, the oil properties and the drug hydrophilicity mitigate or even cancel the effect of structure variation on the drug release rate. Unexpectedly, the observed behavior cannot be fully explained by the thermodynamic partition of the drug into the lipid matrix, which points out to previously overlooked kinetic effects. We therefore interpret our results by discussing the mechanism of structural control of the diffusion rate in terms of drug permeation through the lipid membrane, which includes exchange kinetics. A wide range of implications follow regarding formulation and future developments, both for dispersed LLC delivery systems and topical applications in bulk phase.

  6. Bare Shear Viscosity and Anomalous Fall Rate of Oil Droplets in Nitrogen

    NASA Astrophysics Data System (ADS)

    Varley, Rodney

    2011-11-01

    Experimental evidence of Kim and Fedele (1982) indicates a breakdown of the Millikan Law for the fall rate of oil droplets in Nitrogen gas over a pressure range of 1-15 atm. The discrepancy is most pronounced for smallest, 0.1 micron radius droplets for which the fall rate increases with pressure. The opposite behavior was observed by Millikan with larger drops in air of pressure at most one atm. We explain these results by arguing that the particle's motion, in particular Stokes' drag formula, is determined by the so-called bare shear viscosity which applies to micro fluid flows. This is in contrast with the usual theory which uses a renormalized shear viscosity and which is well approximated by the Enskog value. A mode coupling formula for the bare shear viscosity is discussed and a graphical comparison is made with the experimental results. Basically an increase in gas pressure produces a decrease in the bare shear viscosity and thus the fall rate increases. The idea that the shear viscosity is smaller for micro flows is consistent with the intuitive belief that on small enough spatial and time scales, fluid flows are conservative without dissipation.

  7. Oil and drug control the release rate from lyotropic liquid crystals.

    PubMed

    Martiel, Isabelle; Baumann, Nicole; Vallooran, Jijo J; Bergfreund, Jotam; Sagalowicz, Laurent; Mezzenga, Raffaele

    2015-04-28

    The control of the diffusion coefficient by the dimensionality d of the structure appears as a most promising lever to efficiently tune the release rate from lyotropic liquid crystalline (LLC) phases and dispersed particles towards sustained, controlled and targeted release. By using phosphatidylcholine (PC)- and monolinoleine (MLO)-based mesophases with various apolar structural modifiers and water-soluble drugs, we present a comprehensive study of the dimensional structural control of hydrophilic drug release, including 3-d bicontinuous cubic, 2-d lamellar, 1-d hexagonal and 0-d micellar cubic phases in excess water. We investigate how the surfactant, the oil properties and the drug hydrophilicity mitigate or even cancel the effect of structure variation on the drug release rate. Unexpectedly, the observed behavior cannot be fully explained by the thermodynamic partition of the drug into the lipid matrix, which points out to previously overlooked kinetic effects. We therefore interpret our results by discussing the mechanism of structural control of the diffusion rate in terms of drug permeation through the lipid membrane, which includes exchange kinetics. A wide range of implications follow regarding formulation and future developments, both for dispersed LLC delivery systems and topical applications in bulk phase. PMID:25744826

  8. Exposure to the water soluble fraction of crude oil or to naphthalenes alters breathing rates in Gulf killifish, Fundulus grandis

    SciTech Connect

    Russell, L.C.; Fingerman, M.

    1984-03-01

    Alteration in breathing rate has been used to monitor the effects of pollutants on fishes. Particularly pertinent to the study described herein are the observations that the water soluble fractions (WSF) from Cook Inlet crude oil, Prudhoe Bay crude oil and No. 2 fuel oil increased the breathing rate of pink salmon, Oncorhynchus gorbuscha, fry. However, possible underlying neurological mechanisms for this response have not been identified. Pollutant-induced changes in a fish's breathing rate may indicate neurochemical imbalances in the brain. Exposure of the longnose killifish, Fundulus similis, to the WSF of petroleum resulted in accumulation of naphthalenes from this WSF in high levels in the brain. Various organic compounds have been found to ultimately produce reductions in the whole brain concentration of dopamine in fishes. In view of these effects of various pollutants on breathing rate and the brain dopamine level in fishes, experiments were performed to determine the effects of (a) the WSF of South Louisiana crude oil, (b) two of its most toxic components (naphthalene and 2,6-dimethylnaphthalene) and (c) the dopamine precursor, L-DOPA, on the breathing rate of Fundulus grandis. These experiments would not only reveal whether the WSF and naphthalenes affect the breathing rate but also whether it might be affected by the dopamine concentration in the fish.

  9. Evaluation of surfactants as steam diverters/mobility control agents in light oil steamfloods: Effect of oil composition, rates and experimental conditions

    SciTech Connect

    Mahmood, S.M.; Olsen, D.K.; Ramzel, E.B.

    1991-12-01

    A series of experiments was performed to evaluate the effectiveness of commercially available surfactants for steam-foam EOR applications in light oil reservoirs. The experiments were performed in a 3-ft long, 1-1/2 in.-diameter cylindrical sandpack of about 1 darcy permeability. The sandpack and injected fluids were preheated to 430{degree}F at 155 psi. The main objective of these tests was to investigate the effectiveness of several surfactants in providing mobility control under a variety of conditions expected in light-oil steamfloods. Thus, maximum pressure-rise and foam-bank buildup/decay were noted as operating conditions were changed in a test or in various tests. Tests were performed with various oil types, sacrificial salts, injection rates, injection strategies, vapor-to-liquid fractions (VLF), and steam/N{sub 2} ratios (SNR).

  10. Subsidence rate monitoring of Aghajari oil field based on Differential SAR Interferometry

    NASA Astrophysics Data System (ADS)

    Moghaddam, N. Fouladi; Sahebi, M. R.; Matkan, A. A.; Roostaei, M.

    2013-06-01

    Land subsidence, due to natural or anthropogenic processes, causes significant costs in both economic and structural aspects. That part of subsidence observed most is the result of human activities, which relates to underground exploitation. Since the gradual surface deformation is a consequence of hydrocarbon reservoirs extraction, the process of displacement monitoring is amongst the petroleum industry priorities. Nowadays, Differential SAR Interferometry, in which satellite images are utilized for elevation change detection and analysis - in a millimetre scale, has proved to be a more real-time and cost-effective technology in contrast to the traditional surveying method. In this study, surface displacements in Aghajari oil field, i.e. one of the most industrious Iranian hydrocarbon sites, are being examined using radar observations. As in a number of interferograms, the production wells inspection reveals that surface deformation signals develop likely due to extraction in a period of several months. In other words, different subsidence or uplift rates and deformation styles occur locally depending on the geological conditions and excavation rates in place.

  11. Contribution of peat fires to the 2015 Indonesian fires

    NASA Astrophysics Data System (ADS)

    Kaiser, Johannes W.; Heil, Angelika; Wooster, Martin J.; van der Werf, Guido R.

    2016-04-01

    Indonesia experienced widespread fires and severe air quality degradation due to smoke during September and October 2015. The fires are thought to have originated from the combination of El-Niño-induced drought and human activities. Fires ignited for land clearing escaped into drained peatlands and burned until the onset of the monsoonal rain. In addition to the health impact, these fires are thought to have emitted large amounts of greenhouse gases, e.g. more than Japan over the entire year. The Copernicus Atmosphere Monitoring Service (CAMS) has detected and quantified the fires with the Global Fire Assimilation System (GFAS) and the smoke dispersion with the Chemistry-Integrated Forecasting System (C-IFS) in near real time. GFAS and C-IFS are constrained by satellite-based observations of fire and smoke constituents, respectively. The distinction between peat and above-ground fires is a crucial and difficult step in fire emission estimation as it introduces errors of up to one order of magnitude. Here, we quantify the contribution of peat fires to the total emission flux of the 2015 Indonesian fires by (1) using an improved peat map in GFAS and (2) analysing the observed diurnal cycle of the fire activity as represented in a new development for GFAS. Furthermore, we link the fires occurrence to economic activity by analysing the coincidence with concessions for palm oil plantations and other industrial forest uses.

  12. Impacts of the post-fire erosion processes compared with the agricultural erosion rates for a mountain catchment in NW Iberia

    NASA Astrophysics Data System (ADS)

    Marisa Santos, Juliana; Nunes, João Pedro; Bernard-Jannin, Léonard; Gonzalez Pelayo, Oscar; Keizer, Jan Jacob

    2014-05-01

    after forest fires. The last forest fire in August 2011 burned 10% of the total area in the north-west part of the catchment. Post-fire management operations 9 month after the fire (clear-cutting and deep plowing operations) and after plantation of "Quercus robur" left the soil exposed, and relatively mild rainstorms led to large amounts of soil loss, including a large amount of rills and other erosion features. This constituted an opportunity to compare these erosion rates with the ones observed in agricultural fields for similar edapho-climatic conditions, and also observe distinct timing of erosion occurrence which was linked with different periods when soils are exposed. This communication presents the assessment of the impact of this fire on soil erosion rates, where results indicate that soil losses after soil preparation for forest replanting might be equivalent, in long-term, to soil losses in agricultural fields.

  13. Well blowout rates in California Oil and Gas District 4--Update and Trends

    SciTech Connect

    Jordan, Preston D.; Benson, Sally M.

    2009-10-01

    Well blowouts are one type of event in hydrocarbon exploration and production that generates health, safety, environmental and financial risk. Well blowouts are variously defined as 'uncontrolled flow of well fluids and/or formation fluids from the wellbore' or 'uncontrolled flow of reservoir fluids into the wellbore'. Theoretically this is irrespective of flux rate and so would include low fluxes, often termed 'leakage'. In practice, such low-flux events are not considered well blowouts. Rather, the term well blowout applies to higher fluxes that rise to attention more acutely, typically in the order of seconds to days after the event commences. It is not unusual for insurance claims for well blowouts to exceed US$10 million. This does not imply that all blowouts are this costly, as it is likely claims are filed only for the most catastrophic events. Still, insuring against the risk of loss of well control is the costliest in the industry. The risk of well blowouts was recently quantified from an assembled database of 102 events occurring in California Oil and Gas District 4 during the period 1991 to 2005, inclusive. This article reviews those findings, updates them to a certain extent and compares them with other well blowout risk study results. It also provides an improved perspective on some of the findings. In short, this update finds that blowout rates have remained constant from 2005 to 2008 within the limits of resolution and that the decline in blowout rates from 1991 to 2005 was likely due to improved industry practice.

  14. Basal level of FANCD2 monoubiquitination is required for the maintenance of a sufficient number of licensed-replication origins to fire at a normal rate.

    PubMed

    Panneerselvam, Jayabal; Pickering, Anna; Han, Bing; Li, Liantao; Zheng, Junnian; Zhang, Jun; Zhang, Yanbin; Fei, Peiwen

    2014-03-15

    Normal DNA replication starts following the stepwise recruitment of replication initiators to assemble Mini-chromosome Maintenance (MCM) 2-7 protein complexes at an adequate amount of DNA replication origins. Under normal conditions, the monoubiquitination of Fanconi Anemia (FA) group D2 protein (FANCD2) occurs in each S-phase of cell cycle, which is the basal level of FANCD2 monoubiquitination. However, little is known regarding the roles of this basal level of monoubiquitinated FANCD2. Here we show that monoubiquitinated FANCD2 in each S-phase of normal cell cycle is essential for replication origins to fire at a normal rate. We found that the basal level of the monoubiquitinated FANCD2 can interact with replication origins as well as mini-chromosome maintenance protein 3 (MCM3) in an S-phase specific manner to secure an enough number of the licensed-origins to fire. Non-monoubiquitinated FANCD2 or mutant MCM3 lacking AA 477-480 responsible for interacting with FANCD2 can lead to an insufficient amount of licensed origins to fire and, thereby, enlarged intervals between the fired origins. Our results demonstrate that the monoubiquitinated FANCD2 in each S-phase of normal cell cycle is required to maintain an enough number of licensed origins to initiate the normal DNA replication. This finding is the first to provide insights into how FANCD2 functions under normal condition of cell cycle to maintain genome stability, as well as resulting implications in the strategic improvement for the fight against human cancer.

  15. Assessment of opportunities to increase the recovery and recycling rates of waste oils

    SciTech Connect

    Graziano, D.J.; Daniels, E.J.

    1995-08-01

    Waste oil represents an important energy resource that, if properly managed and reused, would reduce US dependence on imported fuels. Literature and current practice regarding waste oil generation, regulations, collection, and reuse were reviewed to identify research needs and approaches to increase the recovery and recycling of this resource. The review revealed the need for research to address the following three waste oil challenges: (1) recover and recycle waste oil that is currently disposed of or misused; (2) identify and implement lubricating oil source and loss reduction opportunities; and (3) develop and foster an effective waste oil recycling infrastructure that is based on energy savings, reduced environment at impacts, and competitive economics. The United States could save an estimated 140 {times} 1012 Btu/yr in energy by meeting these challenges.

  16. Tremor-related activity of neurons in the 'motor' thalamus: changes in firing rate and pattern in the MPTP vervet model of parkinsonism.

    PubMed

    Guehl, D; Pessiglione, M; François, C; Yelnik, J; Hirsch, E C; Féger, J; Tremblay, L

    2003-06-01

    The pathophysiology of parkinsonian tremor remains a matter of debate with two opposing hypotheses proposing a peripheral and a central origin, respectively. A central origin of tremor could arise either from a rhythmic activity of the internal segment of the globus pallidus (GPi) or from a structure such as the thalamus, outside the basal ganglia. In this study, single-unit recordings were performed in three 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated monkeys within the GPi and within three territories of the motor thalamus (delimited by their afferent inputs from the GPi, the substantia nigra and the cerebellum, respectively). For each recorded neuron, we compared the variations in firing rate and pattern in tremor and no tremor periods. Tremor either occurred spontaneously or was induced by external stimulation. When the animals entered into a tremor period we observed: (i) an increase in the mean firing rate in about half of the recorded neurons of the motor thalamus; and (ii), a change from an irregular to a rhythmic discharge within the range of tremor frequency (5-7 Hz) in about 10% of the recorded neurons of the motor thalamus (pallidal and cerebellar territories) and the GPi. Most of the thalamic neurons that exhibited a rhythmic discharge during tremor were found to be sensitive to external stimulation. Because the changes in firing rate occurred predominantly in the motor thalamus and not in the GPi, and because a fast rhythmic discharge of 10-15 Hz was frequently observed in the GPi and not in the motor thalamus, we conclude that thalamic activity is not a simple reproduction of basal ganglia output. Moreover, we suggest that thalamic processing of basal ganglia outputs could participate in the genesis of tremor, and that this thalamic processing could be influenced by sensory inputs and/or changes in attentional level elicited by external stimulation. PMID:12814370

  17. Development and technology transfer of the BNL flame quality indicator for oil-fired applications: Project report

    SciTech Connect

    Butcher, T.A.; Litzke, Wai Lin; McDonald, R.J.

    1994-09-01

    The purpose of a flame quality indicator is to continuously and closely monitor the quality of the flame to determine a heating system`s operating performance. The most efficient operation of a system is achieved under clean burning conditions at low excess air level. By adjusting a burner to function in such a manner, monitoring the unit to maintain these conditions can be accomplished with a simple, cheap and reliable device. This report details the development of the Flame Quality Indicator (FQI) at Brookhaven National Laboratory for residential oil-heating equipment. It includes information on the initial testing of the original design, field testing with other cooperating organizations, changes and improvements to the design, and finally technology transfer and commercialization activities geared towards the development of commercially available products designed for the oil heat marketplace. As a result of this work, a patent for the technology was obtained by the U.S. Department of Energy (DOE). Efforts to commercialize the technology have resulted in a high level of interest amongst industry members including boiler manufacturers, controls manufacturers, oil dealers, and service organizations. To date DOE has issued licenses to three different manufacturers, on a non-exclusive basis, to design, build, and sell FQIs.

  18. 43 CFR 3162.7-4 - Royalty rates on oil; sliding and step-scale leases (public land only).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... during the month, and disregard wells that produced less than 15 days during the month. (b) Wells...-scale leases (public land only). 3162.7-4 Section 3162.7-4 Public Lands: Interior Regulations Relating... Royalty rates on oil; sliding and step-scale leases (public land only). Sliding- and step-scale...

  19. 43 CFR 3162.7-4 - Royalty rates on oil; sliding and step-scale leases (public land only).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... during the month, and disregard wells that produced less than 15 days during the month. (b) Wells...-scale leases (public land only). 3162.7-4 Section 3162.7-4 Public Lands: Interior Regulations Relating... Royalty rates on oil; sliding and step-scale leases (public land only). Sliding- and step-scale...

  20. 43 CFR 3162.7-4 - Royalty rates on oil; sliding and step-scale leases (public land only).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... during the month, and disregard wells that produced less than 15 days during the month. (b) Wells...-scale leases (public land only). 3162.7-4 Section 3162.7-4 Public Lands: Interior Regulations Relating... Royalty rates on oil; sliding and step-scale leases (public land only). Sliding- and step-scale...

  1. Estimation of Soil Erosion Rates in Oil Palm Plantation with Different Land Cover

    NASA Astrophysics Data System (ADS)

    Sahat, S.; Yusop, Z.; Askari, M.; Ziegler, A. D.

    2016-07-01

    Soil losses from hill slopes in oil palm plantation in Sedenak Estate, Johor were measured using runoff plot and rainfall simulator. The plot was designed to be removable but the size was fixed at 8 x 3.75m. Four types of surface covers were investigated for the plots, i.e. half bare soil and half grass cover (HGC), half bare soil and half dry frond (HDF), fully grass cover (FG), and fully bare soil (BS). The influence of initial soil moisture, saturated hydraulics conductivity, Ks, bulk density and slope on rates of soil loss were also evaluated. The rainfall simulator produced rainfall intensities between 90 and 160 mm/hr with durations from 45 to 60 min per run. BS plot exhibited the highest Ks value among all plots but the percentage of initial soil moisture on this surface was low. BS plot recorded the highest runoff coefficient (C) and soil loss values of 73.6 ± 4 percent and 5.26 ± 3.2 t/ha respectively, while the lowest was from plot FG with 41.7 ± 5.7 percent and soil loss of 2.85 ± 2.1 t/ha. Meanwhile, the results suggested that the ground cover had the ability to reduce soil loss by 67% and 17%, respectively for plots BS-HGC and BS-HDF. Overall, soil erosion control such as surface is effective measures in reducing level of runoff and soil erosion.

  2. Moderate Image Spectrometer (MODIS) Fire Radiative Energy: Physics and Applications

    NASA Technical Reports Server (NTRS)

    Kaufman, Y.

    2004-01-01

    MODIS fire channel does not saturate in the presence of fires. The fire channel therefore is used to estimate the fire radiative energy, a measure of the rate of biomass consumption in the fire. We found correlation between the fire radiative energy, the rate of formation of burn scars and the rate of emission of aerosol from the fires. Others found correlations between the fire radiative energy and the rate of biomass consumption. This relationships can be used to estimates the emissions from the fires and to estimate the fire hazards.

  3. Growth rates and ages of deep-sea corals impacted by the Deepwater Horizon oil spill

    USGS Publications Warehouse

    Prouty, Nancy G.; Fisher, Charles R.; Demopoulos, Amanda W. J.; Druffel, Ellen R. M.

    2016-01-01

    The impact of the April 2010 Deepwater Horizon (DWH) spill on deep-sea coral communities in the Gulf of Mexico (GoM) is still under investigation, as is the potential for these communities to recover. Impacts from the spill include observation of corals covered with flocculent material, with bare skeleton, excessive mucous production, sloughing tissue, and subsequent colonization of damaged areas by hydrozoans. Information on growth rates and life spans of deep-sea corals is important for understanding the vulnerability of these ecosystems to both natural and anthropogenic perturbations, as well as the likely duration of any observed adverse impacts. We report radiocarbon ages and radial and linear growth rates based on octocorals (Paramuricea spp. and Chrysogorgia sp.) collected in 2010 and 2011 from areas of the DWH impact. The oldest coral radiocarbon ages were measured on specimens collected 11 km to the SW of the oil spill from the Mississippi Canyon (MC) 344 site: 599 and 55 cal yr BP, suggesting continuous life spans of over 600 years for Paramuricea biscaya, the dominant coral species in the region. Calculated radial growth rates, between 0.34 μm yr−1 and 14.20 μm yr−1, are consistent with previously reported proteinaceous corals from the GoM. Anomalously low radiocarbon (Δ14C) values for soft tissue from some corals indicate that these corals were feeding on particulate organic carbon derived from an admixture of modern surface carbon and a low 14C carbon source. Results from this work indicate fossil carbon could contribute 5–10% to the coral soft tissue Δ14C signal within the area of the spill impact. The influence of a low 14C carbon source (e.g., petro-carbon) on the particulate organic carbon pool was observed at all sites within 30 km of the spill site, with the exception of MC118, which may have been outside of the dominant northeast-southwest zone of impact. The quantitatively assessed extreme longevity and slow growth rates documented

  4. Fight Fire Without Fire Fighters!

    ERIC Educational Resources Information Center

    Peacock, Richard D.

    1977-01-01

    There is a role for the classroom teacher in teaching fire safety. Discusses the inadequacies of present fire prevention programs and provides ten specific steps teachers can take to avoid suffering and death from fire. (Author/RK)

  5. Vegetation dynamics in response to water inflow rates and fire in a brackish Typha domingensis Pers. marsh in the delta of the Colorado River, Mexico

    USGS Publications Warehouse

    Mexicano, Lourdes; Nagler, Pamela L.; Zamora-Arroyo, Francisco; Glenn, Edward P.

    2012-01-01

    The Cienega de Santa Clara is a 5600 ha, anthropogenic wetland in the delta of the Colorado River in Mexico. It is the inadvertent creation of the disposal of brackish agricultural waste water from the U.S. into the intertidal zone of the river delta in Mexico, but has become an internationally important wetland for resident and migratory water birds. We used high resolution Quickbird and WorldView-2 images to produce seasonal vegetation maps of the Cienega before, during and after a test run of the Yuma Desalting Plant, which will remove water from the inflow stream and replace it with brine. We also used moderate resolution, 16-day composite NDVI imagery from the Moderate Resolution Imaging Spectrometer (MODIS) sensors on the Terra satellite to determine the main factors controlling green vegetation density over the years 2000–2011. The marsh is dominated by Typha domingensis Pers. with Phragmites australis (Cav.) Trin. Ex Steud. as a sub-dominant species in shallower marsh areas. The most important factor controlling vegetation density was fire. Spring fires in 2006 and 2011 were followed by much more rapid green-up of T. domingensis in late spring and 30% higher peak summer NDVI values compared to non-fire years (P < 0.001). Fires removed thatch and returned nutrients to the water, resulting in more vigorous vegetation growth compared to non-fire years. The second significant (P < 0.01) factor controlling NDVI was flow rate of agricultural drain water from the U.S. into the marsh. Reduced summer flows in 2001 due to canal repairs, and in 2010 during the YDP test run, produced the two lowest NDVI values of the time series from 2000 to 2011 (P < 0.05). Salinity is a further determinant of vegetation dynamics as determined by greenhouse experiments, but was nearly constant over the period 2000–2011, so it was not a significant variable in regression analyses. It is concluded that any reduction in inflow volumes will result in a linear decrease in green foliage

  6. Fire prevention on aircraft

    NASA Technical Reports Server (NTRS)

    Kuhn, Fritz

    1931-01-01

    The following discussion is at first restricted to the light-oil engines now in use. We shall consider how far it is possible to reduce fire hazards by changes in the design of the engines and carburetors and in the arrangement of the fuel pipes.

  7. Assessment of soil contamination by (210)Po and (210)Pb around heavy oil and natural gas fired power plants.

    PubMed

    Al-Masri, M S; Haddad, Kh; Doubal, A W; Awad, I; Al-Khatib, Y

    2014-06-01

    Soil contamination by (210)Pb and (210)Po around heavy oil and natural gas power plants has been investigated; fly and bottom ash containing enhanced levels of (210)Pb and (210)Po were found to be the main source of surface soil contamination. The results showed that (210)Pb and (210)Po in fly-ash (economizer, superheater) is highly enriched with (210)Pb and (210)Po, while bottom-ash (boiler) is depleted. The highest (210)Pb and (210)Po activity concentrations were found to be in economizer ash, whereas the lowest activity concentration was in the recirculator ash. On the other hand, (210)Pb and (210)Po activity concentrations in soil samples were found to be higher inside the plant site area than those samples collected from surrounding areas. The highest levels were found in the vicinity of Mhardeh and Tishreen power plants; both plants are operated by heavy oil and natural fuels, while the lowest values were found to be in those samples collected from Nasrieh power plant, which is only operated by one type of fuel, viz. natural gas. In addition, the levels of surface soil contamination have decreased as the distance from the power plant site center increased.

  8. Assessment of soil contamination by (210)Po and (210)Pb around heavy oil and natural gas fired power plants.

    PubMed

    Al-Masri, M S; Haddad, Kh; Doubal, A W; Awad, I; Al-Khatib, Y

    2014-06-01

    Soil contamination by (210)Pb and (210)Po around heavy oil and natural gas power plants has been investigated; fly and bottom ash containing enhanced levels of (210)Pb and (210)Po were found to be the main source of surface soil contamination. The results showed that (210)Pb and (210)Po in fly-ash (economizer, superheater) is highly enriched with (210)Pb and (210)Po, while bottom-ash (boiler) is depleted. The highest (210)Pb and (210)Po activity concentrations were found to be in economizer ash, whereas the lowest activity concentration was in the recirculator ash. On the other hand, (210)Pb and (210)Po activity concentrations in soil samples were found to be higher inside the plant site area than those samples collected from surrounding areas. The highest levels were found in the vicinity of Mhardeh and Tishreen power plants; both plants are operated by heavy oil and natural fuels, while the lowest values were found to be in those samples collected from Nasrieh power plant, which is only operated by one type of fuel, viz. natural gas. In addition, the levels of surface soil contamination have decreased as the distance from the power plant site center increased. PMID:24602817

  9. Hypertonicity increases NO production to modulate the firing rate of magnocellular neurons of the supraoptic nucleus of rats.

    PubMed

    da Silva, M P; Ventura, R R; Varanda, W A

    2013-10-10

    Increases in plasma osmolality enhance nitric oxide (NO) levels in magnocellular neurosecretory cells (MNCs) of the supraoptic nucleus (SON) and modulate the secretion of both vasopressin (VP) and oxytocin (OT). In this paper, we describe the effects of hypertonicity on the electrical properties of MNCs by focusing on the nitrergic modulation of their activity in this condition. Membrane potentials were measured using the patch clamp technique, in the presence of both glutamatergic and GABAergic neurotransmission blockers, in coronal brain slices of male Wistar rats. The recordings were first made under a control condition (295 mosm/kg H2O), then in the presence of a hypertonic stimulus (330 mosm/kg H2O) and, finally, with a hypertonic stimulus plus 500 μM L-Arginine or 100 μM N-nitro-L-Arginine methyl ester hydrochloride (L-NAME). Hypertonicity per se increased the firing frequency of the neurons. L-Arginine prevented the increase in fire frequency induced by hypertonic stimulus, and L-NAME (inhibitor of nitric oxide synthase) induced an additional increase in frequency when applied together with the hypertonic solution. Moreover, L-Arginine hyperpolarizes the resting potential and decreases the peak value of the after-hyperpolarization; both effects were blocked by L-NAME and hypertonicity and/or L-NAME reduced the time constant of the rising phase of the after-depolarization. These results demonstrate that an intrinsic nitrergic system is part of the mechanisms controlling the excitability of MNCs of the SON when the internal fluid homeostasis is disturbed. PMID:23850590

  10. In Situ Burning of Oil Spills.

    PubMed

    Evans, D D; Mulholland, G W; Baum, H R; Walton, W D; McGrattan, K B

    2001-01-01

    For more than a decade NIST conducted research to understand, measure and predict the important features of burning oil on water. Results of that research have been included in nationally recognized guidelines for approval of intentional burning. NIST measurements and predictions have played a major role in establishing in situ burning as a primary oil spill response method. Data are given for pool fire burning rates, smoke yield, smoke particulate size distribution, smoke aging, and polycyclic aromatic hydrocarbon content of the smoke for crude and fuel oil fires with effective diameters up to 17.2 m. New user-friendly software, ALOFT, was developed to quantify the large-scale features and trajectory of wind blown smoke plumes in the atmosphere and estimate the ground level smoke particulate concentrations. Predictions using the model were tested successfully against data from large-scale tests. ALOFT software is being used by oil spill response teams to help assess the potential impact of intentional burning.

  11. 25 CFR 213.23 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... substances other than gold, silver, copper, lead, zinc, tungsten, coal, asphaltum and allied substances, oil... deducting forwarding charges to the point of sale; and for copper, lead, zinc, and tungsten, a royalty...

  12. 25 CFR 213.23 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... substances other than gold, silver, copper, lead, zinc, tungsten, coal, asphaltum and allied substances, oil... deducting forwarding charges to the point of sale; and for copper, lead, zinc, and tungsten, a royalty...

  13. Fighting Fire with Fire.

    ERIC Educational Resources Information Center

    Spoor, Dana L.

    1996-01-01

    School districts are integrating security and life-safety systems into school buildings to protect students and property. This proactive approach includes sprinkler systems, fire alarms, and security systems that monitor door movement. Some school districts that are incorporating the latest life-safety technology are in Missouri, Ohio, California,…

  14. Improving growth rate of microalgae in a 1191m(2) raceway pond to fix CO2 from flue gas in a coal-fired power plant.

    PubMed

    Cheng, Jun; Yang, Zongbo; Huang, Yun; Huang, Lei; Hu, Lizuo; Xu, Donghua; Zhou, Junhu; Cen, Kefa

    2015-08-01

    CO2 fixation between microalgal biomass and culture solution and the weight ratio of biomass consumption at nighttime to biomass growth at daytime were compared in an open raceway pond aerated with flue gas from a coal-fired power plant. Average daytime sunlight intensity and solution temperature were optimized to improve microalgal growth rate and to enhance the efficiency of CO2 fixation. When the average daytime solution temperature increased from 12 to 26°C, the rate of biomass consumption due to microalgal respiration at nighttime increased from 6.0 to 7.9g/m(2)/d, which was approximately 25% of the biomass growth rate at daytime. Furthermore, when the average daytime sunlight intensity increased from 39,900 to 88,300lux, CO2 fixation rate in the microalgal biomass increased from 18.4 to 40.7g/m(2)/d, which was approximately 1/3 of CO2 removal rate from flue gas by the microalgal culture system. PMID:25958147

  15. Croton megalocarpus oil-fired micro-trigeneration prototype for remote and self-contained applications: experimental assessment of its performance and gaseous and particulate emissions

    PubMed Central

    Wu, Dawei; Roskilly, Anthony P.; Yu, Hongdong

    2013-01-01

    According to the International Energy Agency's World Energy Outlook 2011, 60 per cent of the population in Africa, some 587 million people, mostly in sub-Saharan Africa, lacked access to electricity in 2009. We developed a 6.5 kWe micro-trigeneration prototype, on the basis of internal combustion engine with pure Croton megalocarpus oil (CMO) fuelling, which configures a distributed energy system to generate power, heating and cooling from a single sustainable fuel source for remote users. Croton megalocarpus is an indigenous tree in East and South Africa which has recently attracted lots of interests as a biofuel source because of its high oil-yield rate. The direct and local use of CMO, instead of CMO biodiesel converted by the transesterification process, minimizes the carbon footprints left behind because of the simple fuel production of CMO. The experimental assessment proves that the prototype fuelled with CMO achieves similar efficiency as with diesel. Also, with the elevation of the oil injection temperature, the gaseous and particulate emissions of CMO could be ameliorated to some extent as improvement of the atomization in the spray and the combustion in the engine cylinder. PMID:24427514

  16. Croton megalocarpus oil-fired micro-trigeneration prototype for remote and self-contained applications: experimental assessment of its performance and gaseous and particulate emissions.

    PubMed

    Wu, Dawei; Roskilly, Anthony P; Yu, Hongdong

    2013-02-01

    According to the International Energy Agency's World Energy Outlook 2011, 60 per cent of the population in Africa, some 587 million people, mostly in sub-Saharan Africa, lacked access to electricity in 2009. We developed a 6.5 kWe micro-trigeneration prototype, on the basis of internal combustion engine with pure Croton megalocarpus oil (CMO) fuelling, which configures a distributed energy system to generate power, heating and cooling from a single sustainable fuel source for remote users. Croton megalocarpus is an indigenous tree in East and South Africa which has recently attracted lots of interests as a biofuel source because of its high oil-yield rate. The direct and local use of CMO, instead of CMO biodiesel converted by the transesterification process, minimizes the carbon footprints left behind because of the simple fuel production of CMO. The experimental assessment proves that the prototype fuelled with CMO achieves similar efficiency as with diesel. Also, with the elevation of the oil injection temperature, the gaseous and particulate emissions of CMO could be ameliorated to some extent as improvement of the atomization in the spray and the combustion in the engine cylinder. PMID:24427514

  17. Croton megalocarpus oil-fired micro-trigeneration prototype for remote and self-contained applications: experimental assessment of its performance and gaseous and particulate emissions.

    PubMed

    Wu, Dawei; Roskilly, Anthony P; Yu, Hongdong

    2013-02-01

    According to the International Energy Agency's World Energy Outlook 2011, 60 per cent of the population in Africa, some 587 million people, mostly in sub-Saharan Africa, lacked access to electricity in 2009. We developed a 6.5 kWe micro-trigeneration prototype, on the basis of internal combustion engine with pure Croton megalocarpus oil (CMO) fuelling, which configures a distributed energy system to generate power, heating and cooling from a single sustainable fuel source for remote users. Croton megalocarpus is an indigenous tree in East and South Africa which has recently attracted lots of interests as a biofuel source because of its high oil-yield rate. The direct and local use of CMO, instead of CMO biodiesel converted by the transesterification process, minimizes the carbon footprints left behind because of the simple fuel production of CMO. The experimental assessment proves that the prototype fuelled with CMO achieves similar efficiency as with diesel. Also, with the elevation of the oil injection temperature, the gaseous and particulate emissions of CMO could be ameliorated to some extent as improvement of the atomization in the spray and the combustion in the engine cylinder.

  18. Size distribution and concentration of soot generated in oil and gas-fired residential boilers under different combustion conditions

    NASA Astrophysics Data System (ADS)

    Jiménez, Santiago; Barroso, Jorge; Pina, Antonio; Ballester, Javier

    2016-05-01

    In spite of the relevance of residential heating burners in the global emission of soot particles to the atmosphere, relatively little information on their properties (concentration, size distribution) is available in the literature, and even less regarding the dependence of those properties on the operating conditions. Instead, the usual procedure to characterize those emissions is to measure the smoke opacity by several methods, among which the blackening of a paper after filtering a fixed amount of gas (Bacharach test) is predominant. In this work, the size distributions of the particles generated in the combustion of a variety of gaseous and liquid fuels in a laboratory facility equipped with commercial burners have been measured with a size classifier coupled to a particle counter in a broad range of operating conditions (air excesses), with simultaneous determination of the Bacharach index. The shape and evolution of the distribution with progressively smaller oxygen concentrations depends essentially on the state of the fuel: whereas the combustion of the gases results in monomodal distributions that 'shift' towards larger diameters, in the case of the gas-oils an ultrafine mode is always observed, and a secondary mode of coarse particle grows in relevance. In both cases, there is a strong, exponential correlation between the total mass concentration and the Bacharach opacity index, quite similar for both groups of fuels. The empirical expressions proposed may allow other researchers to at least estimate the emissions of numerous combustion facilities routinely characterized by their smoke opacities.

  19. Designing fire safe interiors.

    PubMed

    Belles, D W

    1992-01-01

    Any product that causes a fire to grow large is deficient in fire safety performance. A large fire in any building represents a serious hazard. Multiple-death fires almost always are linked to fires that grow quickly to a large size. Interior finishes have large, continuous surfaces over which fire can spread. They are regulated to slow initial fire growth, and must be qualified for use on the basis of fire tests. To obtain meaningful results, specimens must be representative of actual installation. Variables--such as the substrate, the adhesive, and product thickness and density--can affect product performance. The tunnel test may not adequately evaluate some products, such as foam plastics or textile wall coverings, thermoplastic materials, or materials of minimal mass. Where questions exist, products should be evaluated on a full-scale basis. Curtains and draperies are examples of products that ignite easily and spread flames readily. The present method for testing curtains and draperies evaluates one fabric at a time. Although a fabric tested alone may perform well, fabrics that meet test standards individually sometimes perform poorly when tested in combination. Contents and furnishings constitute the major fuels in many fires. Contents may involve paper products and other lightweight materials that are easily ignited and capable of fast fire growth. Similarly, a small source may ignite many items of furniture that are capable of sustained fire growth. Upholstered furniture can reach peak burning rates in less than 5 minutes. Furnishings have been associated with many multiple-death fires.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Riparian reserves within oil palm plantations conserve logged forest leaf litter ant communities and maintain associated scavenging rates

    PubMed Central

    Gray, Claudia L; Lewis, Owen T; Chung, Arthur Y C; Fayle, Tom M

    2015-01-01

    The expansion of oil palm plantations at the expense of tropical forests is causing declines in many species and altering ecosystem functions. Maintaining forest-dependent species and processes in these landscapes may therefore limit the negative impacts of this economically important industry. Protecting riparian vegetation may be one such opportunity; forest buffer strips are commonly protected for hydrological reasons, but can also conserve functionally important taxa and the processes they support. We surveyed leaf litter ant communities within oil palm-dominated landscapes in Sabah, Malaysia, using protein baits. As the scavenging activity of ants influences important ecological characteristics such as nutrient cycling and soil structure, we quantified species-specific rates of bait removal to examine how this process may change across land uses and establish which changes in community structure underlie observed shifts in activity. Riparian reserves had similar ant species richness, community composition and scavenging rates to nearby continuous logged forest. Reserve width and vegetation structure did not affect ant species richness significantly. However, the number of foraging individuals decreased with increasing reserve width, and scavenging rate increased with vegetation complexity. Oil palm ant communities were characterized by significantly lower species richness than logged forest and riparian reserves and also by altered community composition and reduced scavenging rates. Reduced scavenging activity in oil palm was not explained by a reduction in ant species richness, nor by replacement of forest ant species by those with lower per species scavenging rates. There was also no significant effect of land use on the scavenging activity of the forest species that persisted in oil palm. Rather, changes in scavenging activity were best explained by a reduction in the mean rate of bait removal per individual ant across all species in the community

  1. Fire investigation

    NASA Astrophysics Data System (ADS)

    Gomberg, A.

    There was considerable progress made on several fronts of fire investigation in the United States in recent years. Progress was made in increasing the quantity of fire investigation and reporting, through efforts to develop the National Fire Incident Reporting System. Improving overall quality of fire investigation is the objective of efforts such as the Fire Investigation Handbook, which was developed and published by the National Bureau of Standards, and the upgrading and expanding of the ""dictionary'' of fire investigation and reporting, the NFPA 901, Uniform Coding for Fire Protection, system. The science of fire investigation as furthered also by new approaches to post fire interviews being developed at the University of Washington, and by in-depth research into factors involved in several large loss fires, including the MGM Grand Hotel in Las Vegas. Finally, the use of special study fire investigations - in-depth investigations concentrating on specific fire problems - is producing new glimpses into the nature of the national fire problem. A brief description of the status of efforts in each of these areas is discussed.

  2. Fire Protection Jacket

    NASA Technical Reports Server (NTRS)

    1991-01-01

    NERAC, Inc., Tolland, CT, aided Paul Monroe Engineering, Orange, CA, in the development of their PC1200 Series Fire Protection Jacket that protects the oil conduit system on an offshore drilling platform from the intense hydrocarbon fires that cause buckling and could cause structural failure of the platform. The flame-proof jacketing, which can withstand temperatures of 2000 degrees Fahrenheit for four hours or more, was developed from a combination of ceramic cloth (similar to the ceramic in Space Shuttle tiles), and laminates used in space suits.

  3. 25 CFR 213.24 - Rate of rents and royalties on oil and gas leases.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... advance during the continuance thereof, together with a royalty of 121/2 percent of the value or amount of... gas leases. During the period of supervision, “value” for the purposes of the lease may, in the... of the oil of the same gravity, and gas, and/or natural gasoline, and/or all other...

  4. Understory Fires

    NASA Video Gallery

    The flames of understory fires in the southern Amazon reach on average only a few feet tall, but the fire type can claim anywhere from 10 to 50 percent of a burn area's trees. Credit: NASA/Doug Morton

  5. Oregon Fires

    Atmospheric Science Data Center

    2014-05-15

    ... a distinct plume rises from the location of the Bear Butte Fire (just northwest of the larger Booth Fire), the fire-lines had merged ... clouds or other factors precluded a retrieval the map is colored black. The  animation  depicts a "multi-angle fly-over" of the ...

  6. Simultaneous treatment of raw palm oil mill effluent and biodegradation of palm fiber in a high-rate CSTR.

    PubMed

    Khemkhao, Maneerat; Techkarnjanaruk, Somkiet; Phalakornkule, Chantaraporn

    2015-02-01

    A high-rate continuous stirred tank reactor (CSTR) was used to produce biogas from raw palm oil mill effluent (POME) at 55°C at a highest organic loading rate (OLR) of 19 g COD/ld. Physical and chemical pretreatments were not performed on the raw POME. In order to promote retention of suspended solids, the CSTR was installed with a deflector at its upper section. The average methane yield was 0.27 l/g COD, and the biogas production rate per reactor volume was 6.23 l/l d, and the tCOD removal efficiency was 82%. The hydrolysis rate of cellulose, hemicelluloses and lignin was 6.7, 3.0 and 1.9 g/d, respectively. The results of denaturing gradient gel electrophoresis (DGGE) suggested that the dominant hydrolytic bacteria responsible for the biodegradation of the palm fiber and residual oil were Clostridium sp., while the dominant methanogens were Methanothermobacter sp.

  7. Onversion rates in power plant plumes based on filter pack data: The coal-fired cumberland plume

    NASA Astrophysics Data System (ADS)

    Forrest, Joseph; Garber, Robert W.; Newman, Leonard

    The TVA Cumberland Steam Plant plume was monitored during the August 1978 Tennessee Plume Study of Project STATE. Samples were obtained by employing a triple screen high-volume assembly which contained (1) a quartz filter for collecting particulate SO 42-, NO 3- and NH 4+, (2) two NaCl-impregnated cellulose filters for collecting gaseous nitrate and (3) two K 2CO 3-impregnated cellulose filters for collecting SO 2. Formation rates of sulfate and nitrate in the atmosphere were calculated by using total sulfur as a conservative tracer. Conversion of SO 2 to SO 42- varied from ~0.-0.8%h -1 during night and early morning hours; late morning and afternoon rates ranged from ~1-4% h -1'. Plumes were tracked to distances of 200 km and 9 h duration. Rate of formation of NO 3-from NO was ~0.1-3%h -1 and ~3-12%h -1 for similar time periods. Particulate NH 4+ concentrations generally increased with plume age, but rates of formation varied widely. Mole ratios of NH 4+/SO 42- fell within 1-3.

  8. Conversion rates in power plant plumes based on filter pack data. Part I. Coal-fired Cumberland plume

    SciTech Connect

    Forrest, J; Garber, R W; Newman, L

    1980-01-01

    The TVA Cumberland Steam Plant plume was monitored during the August 1978 Tennessee Plume Study of Project STATE. Samples were obtained by employing a triple screen high-volume assembly which contained: (1) a quartz filter for collecting particulate SO/sub 4//sup 2 -/, NO/sub 3//sup -/ and NH/sub 4//sup +/, (2) two NaCl-impregnated cellulose filters for collecting gaseous nitrate, and (3) two K/sub 2/CO/sub 3/-impregnated cellulose filters for collecting SO/sub 2/. Formation rates of sulfate and nitrate in the atmosphere were calculated by using total sulfur as a conservative tracer. Conversion of SO/sub 2/ to SO/sub 4//sup 2 -/ varied from approx. 0.1 to 0.8% h/sup -1/ during night and early morning hours; late morning and afternoon rates ranged from approx. 1 to 4% h/sup -1/. Rate of formation of NO/sub 3//sup -/ from NO was approx. 0.1 to 3% h/sup -1/ and approx. 3 to 12% h/sup -1/ for similar time periods. Particulate NH/sub 4//sup +/ concentrations generally increased with plume age, but rates of formation varied widely. Mole ratios of NH/sub 4//sup +//SO/sub 4//sup 2 -/ fell within 1 to 3.

  9. A Model for the Fast Synchronous Oscillations of Firing Rate in Rat Suprachiasmatic Nucleus Neurons Cultured in a Multielectrode Array Dish

    PubMed Central

    Stepanyuk, Andrey R.; Belan, Pavel V.; Kononenko, Nikolai I.

    2014-01-01

    When dispersed and cultured in a multielectrode dish (MED), suprachiasmatic nucleus (SCN) neurons express fast oscillations of firing rate (FOFR; fast relative to the circadian cycle), with burst duration ∼10 min, and interburst interval varying from 20 to 60 min in different cells but remaining nevertheless rather regular in individual cells. In many cases, separate neurons in distant parts of the 1 mm recording area of a MED exhibited correlated FOFR. Neither the mechanism of FOFR nor the mechanism of their synchronization among neurons is known. Based on recent data implicating vasoactive intestinal polypeptide (VIP) as a key intercellular synchronizing agent, we built a model in which VIP acts as both a feedback regulator to generate FOFR in individual neurons, and a diffusible synchronizing agent to produce coherent electrical output of a neuronal network. In our model, VIP binding to its (VPAC2) receptors acts through Gs G-proteins to activate adenylyl cyclase (AC), increase intracellular cAMP, and open cyclic-nucleotide-gated (CNG) cation channels, thus depolarizing the cell and generating neuronal firing to release VIP. In parallel, slowly developing homologous desensitization and internalization of VPAC2 receptors terminates elevation of cAMP and thereby provides an interpulse silent interval. Through mathematical modeling, we show that this VIP/VPAC2/AC/cAMP/CNG-channel mechanism is sufficient for generating reliable FOFR in single neurons. When our model for FOFR is combined with a published model of synchronization of circadian rhythms based on VIP/VPAC2 and Per gene regulation synchronization of circadian rhythms is significantly accelerated. These results suggest that (a) auto/paracrine regulation by VIP/VPAC2 and intracellular AC/cAMP/CNG-channels are sufficient to provide robust FOFR and synchrony among neurons in a heterogeneous network, and (b) this system may also participate in synchronization of circadian rhythms. PMID:25192180

  10. Effects of aeration rate on degradation process of oil palm empty fruit bunch with kinetic-dynamic modeling.

    PubMed

    Talib, Ahmad Tarmezee; Mokhtar, Mohd Noriznan; Baharuddin, Azhari Samsu; Sulaiman, Alawi

    2014-10-01

    The effect of different aeration rates on the organic matter (OM) degradation during the active phase of oil palm empty fruit bunch (EFB)-rabbit manure co-composting process under constant forced-aeration system has been studied. Four different aeration rates, 0.13 L min(-1) kg(DM)(-1),0.26 L min(-1) kg(DM)(-1),0.49 L min(-1) kg(DM)(-1) and 0.74 L min(-1) kg(DM)(-1) were applied. 0.26 L min(-1) kg(DM)(-1) provided enough oxygen level (10%) for the rest of composting period, showing 40.5% of OM reduction that is better than other aeration rates. A dynamic mathematical model describing OM degradation, based on the ratio between OM content and initial OM content with correction functions of moisture content, free air space, oxygen and temperature has been proposed.

  11. Effects of aeration rate on degradation process of oil palm empty fruit bunch with kinetic-dynamic modeling.

    PubMed

    Talib, Ahmad Tarmezee; Mokhtar, Mohd Noriznan; Baharuddin, Azhari Samsu; Sulaiman, Alawi

    2014-10-01

    The effect of different aeration rates on the organic matter (OM) degradation during the active phase of oil palm empty fruit bunch (EFB)-rabbit manure co-composting process under constant forced-aeration system has been studied. Four different aeration rates, 0.13 L min(-1) kg(DM)(-1),0.26 L min(-1) kg(DM)(-1),0.49 L min(-1) kg(DM)(-1) and 0.74 L min(-1) kg(DM)(-1) were applied. 0.26 L min(-1) kg(DM)(-1) provided enough oxygen level (10%) for the rest of composting period, showing 40.5% of OM reduction that is better than other aeration rates. A dynamic mathematical model describing OM degradation, based on the ratio between OM content and initial OM content with correction functions of moisture content, free air space, oxygen and temperature has been proposed. PMID:25079208

  12. Forest fires

    SciTech Connect

    Fuller, M.

    1991-01-01

    This book examines the many complex and sensitive issues relating to wildland fires. Beginning with an overview of the fires of 1980s, the book discusses the implications of continued drought and considers the behavior of wildland fires, from ignition and spread to spotting and firestorms. Topics include the effects of weather, forest fuels, fire ecology, and the effects of fire on plants and animals. In addition, the book examines firefighting methods and equipment, including new minimum impact techniques and compressed air foam; prescribed burning; and steps that can be taken to protect individuals and human structures. A history of forest fire policies in the U.S. and a discussion of solutions to fire problems around the world completes the coverage. With one percent of the earth's surface burning every year in the last decade, this is a penetrating book on a subject of undeniable importance.

  13. Sensor for Individual Burner Control of Coal Firing Rate, Fuel-Air Ratio and Coal Fineness Correlation

    SciTech Connect

    Wayne Hill; Roger Demler

    2004-06-01

    The project's overall objective is to develop a commercially viable dynamic signature based sensing system that is used to infer the flow rate and fineness of pulverized coal. This eighteen month effort will focus on developments required to transfer the measurement system from the laboratory to a field ready prototype system. This objective will be achieved through the completion of the laboratory development of the sensor and data algorithm followed by full scale field tests of a portable measurement system. The sensing system utilizes accelerometers attached externally to coal feeder pipes. Raw data is collected from the impingement of the coal particles as well as the acoustic noise generated from the flow and is transformed into characteristic signatures through proper calibration that are meaningful to the operator. The laboratory testing will use a portable version of the sensing system to collect signature data from a variety of flow conditions including coal flow rates, flow orientations, and coal particle characteristics. This work will be conducted at the Coal Flow Measurement Laboratory that is sponsored by EPRI and operated by Airflow Sciences. The data will be used to enhance the algorithm and neural network required to perform real time analysis of the nonspecific signature data. The system will be installed at two full scale power plants to collect data in a real time operating scenario. These short term duration tests will evaluate the ability of the algorithm to accurately infer coal flow rates and determine if the measurement system can be used effectively in an active control loop for combustion diagnostics and burner balancing. At the completion of this project, prototype versions of both a portable system and a permanent installation will be available for final packaging and commercialization by one of the team members. Both types of systems will be marketed for conducting combustion diagnostics and balancing of individual flows to pulverized

  14. SENSOR FOR INDIVIDUAL BURNER CONTROL OF COAL FIRING RATE, FUEL-AIR RATIO AND COAL FINENESS CORRELATION

    SciTech Connect

    Wayne Hill

    2004-02-01

    The project's overall objective is to development a commercially viable dynamic signature based sensing system that is used to infer the flow rate and fineness of pulverized coal. This eighteen month effort will focus on developments required to transfer the measurement system from the laboratory to a field ready prototype system. This objective will be achieved through the completion of the laboratory development of the sensor and data algorithm followed by full scale field tests of a portable measurement system. The sensing system utilizes accelerometers attached externally to coal feeder pipes. Raw data is collected from the impingement of the coal particles as well as the acoustic noise generated from the flow and is transformed into characteristic signatures through proper calibration that are meaningful to the operator. The laboratory testing will use a portable version of the sensing system to collect signature data from a variety of flow conditions including coal flow rates, flow orientations, and coal particle characteristics. This work will be conducted at the Coal Flow Measurement Laboratory that is sponsored by EPRI and operated by Airflow Sciences. The data will be used to enhance the algorithm and neural network required to perform real time analysis of the non-specific signature data. The system will be installed at two full scale power plants to collect data in a real time operating scenario. These short term duration tests will evaluate the ability of the algorithm to accurately infer coal flow rates and determine if the measurement system can be used effectively in an active control loop for combustion diagnostics and burner balancing. At the completion of this project, prototype versions of both a portable system and a permanent installation will be available for final packaging and commercialization by one of the team members. Both types of systems will be marketed for conducting combustion diagnostics and balancing of individual flows to

  15. Deoxyxylulose 5-phosphate reductoisomerase is not a rate-determining enzyme for essential oil production in spike lavender.

    PubMed

    Mendoza-Poudereux, Isabel; Muñoz-Bertomeu, Jesús; Arrillaga, Isabel; Segura, Juan

    2014-11-01

    Spike lavender (Lavandula latifolia) is an economically important aromatic plant producing essential oils, whose components (mostly monoterpenes) are mainly synthesized through the plastidial methylerythritol 4-phosphate (MEP) pathway. 1-Deoxy-D-xylulose-5-phosphate (DXP) synthase (DXS), that catalyzes the first step of the MEP pathway, plays a crucial role in monoterpene precursors biosynthesis in spike lavender. To date, however, it is not known whether the DXP reductoisomerase (DXR), that catalyzes the conversion of DXP into MEP, is also a rate-limiting enzyme for the biosynthesis of monoterpenes in spike lavender. To investigate it, we generated transgenic spike lavender plants constitutively expressing the Arabidopsis thaliana DXR gene. Although two out of the seven transgenic T0 plants analyzed accumulated more essential oils than the controls, this is hardly imputable to the DXR transgene effect since a clear correlation between transcript accumulation and monoterpene production could not be established. Furthermore, these increased essential oil phenotypes were not maintained in their respective T1 progenies. Similar results were obtained when total chlorophyll and carotenoid content in both T0 transgenic plants and their progenies were analyzed. Our results then demonstrate that DXR enzyme does not play a crucial role in the synthesis of plastidial monoterpene precursors, suggesting that the control flux of the MEP pathway in spike lavender is primarily exerted by the DXS enzyme. PMID:25151124

  16. Calculation of Fire Severity Factors and Fire Non-Suppression Probabilities For A DOE Facility Fire PRA

    SciTech Connect

    Tom Elicson; Bentley Harwood; Jim Bouchard; Heather Lucek

    2011-03-01

    Over a 12 month period, a fire PRA was developed for a DOE facility using the NUREG/CR-6850 EPRI/NRC fire PRA methodology. The fire PRA modeling included calculation of fire severity factors (SFs) and fire non-suppression probabilities (PNS) for each safe shutdown (SSD) component considered in the fire PRA model. The SFs were developed by performing detailed fire modeling through a combination of CFAST fire zone model calculations and Latin Hypercube Sampling (LHS). Component damage times and automatic fire suppression system actuation times calculated in the CFAST LHS analyses were then input to a time-dependent model of fire non-suppression probability. The fire non-suppression probability model is based on the modeling approach outlined in NUREG/CR-6850 and is supplemented with plant specific data. This paper presents the methodology used in the DOE facility fire PRA for modeling fire-induced SSD component failures and includes discussions of modeling techniques for: • Development of time-dependent fire heat release rate profiles (required as input to CFAST), • Calculation of fire severity factors based on CFAST detailed fire modeling, and • Calculation of fire non-suppression probabilities.

  17. Injury Rates on New and Old Technology Oil and Gas Rigs Operated by the Largest United States Onshore Drilling Contractor

    PubMed Central

    Blackley, David J.; Retzer, Kyla D.; Hubler, Warren G.; Hill, Ryan D.; Laney, A. Scott

    2015-01-01

    Background Occupational fatality rates among oil and gas extraction industry and specifically among drilling contractor workers are high compared to the U.S. all-industry average. There is scant literature focused on non-fatal injuries among drilling contractors, some of which have introduced engineering controls to improve rig efficiency and reduce injury risk. Methods We compared injury rates on new and old technology rigs operated by the largest U.S. drilling contractor during 2003–2012, stratifying by job type and grouping outcomes by injury severity and body part affected. Results Six hundred seventy-one injuries were recorded over 77.4 million person-hours. The rate on new rigs was 66% of that on old rigs. Roughnecks had lower injury rates on new rigs, largely through reduced limb injury rates. New rigs had lower rates in each non-fatal injury severity category. Conclusions For this company, new technology rigs appear to provide a safer environment for roughnecks. Future studies could include data from additional companies. PMID:25164118

  18. Differential oil flowmeter

    NASA Technical Reports Server (NTRS)

    Powers, W. T.

    1979-01-01

    Difference in oil flow volume through two mechanical flowmeters is converted to analog signal by simple inexpensive circuit. Circuit can be implemented with only minor changes to conventional oil flowmeters and used to measure fuel consumed by oil fired furnace or water heater.

  19. Dispersant Corexit 9500A and chemically dispersed crude oil decreases the growth rates of meroplanktonic barnacle nauplii (Amphibalanus improvisus) and tornaria larvae (Schizocardium sp.).

    PubMed

    Almeda, Rodrigo; Bona, Shawn; Foster, Charles R; Buskey, Edward J

    2014-08-01

    Our knowledge of the lethal and sublethal effects of dispersants and dispersed crude oil on meroplanktonic larvae is limited despite the importance of planktonic larval stages in the life cycle of benthic invertebrates. We determined the effects of Light Louisiana Sweet crude oil, dispersant Corexit 9500A, and dispersant-treated crude oil on the survival and growth rates of nauplii of the barnacle Amphibalanus improvisus and tornaria larvae of the enteropneust Schizocardium sp. Growth rates of barnacle nauplii and tornaria larvae were significantly reduced after exposure to chemically dispersed crude oil and dispersant Corexit 9500A at concentrations commonly found in the water column after dispersant application in crude oil spills. We also found that barnacle nauplii ingested dispersed crude oil, which may have important consequences for the biotransfer of petroleum hydrocarbons through coastal pelagic food webs after a crude oil spill. Therefore, application of chemical dispersants increases the impact of crude oil spills on meroplanktonic larvae, which may affect recruitment and population dynamics of marine benthic invertebrates.

  20. Dispersant Corexit 9500A and chemically dispersed crude oil decreases the growth rates of meroplanktonic barnacle nauplii (Amphibalanus improvisus) and tornaria larvae (Schizocardium sp.).

    PubMed

    Almeda, Rodrigo; Bona, Shawn; Foster, Charles R; Buskey, Edward J

    2014-08-01

    Our knowledge of the lethal and sublethal effects of dispersants and dispersed crude oil on meroplanktonic larvae is limited despite the importance of planktonic larval stages in the life cycle of benthic invertebrates. We determined the effects of Light Louisiana Sweet crude oil, dispersant Corexit 9500A, and dispersant-treated crude oil on the survival and growth rates of nauplii of the barnacle Amphibalanus improvisus and tornaria larvae of the enteropneust Schizocardium sp. Growth rates of barnacle nauplii and tornaria larvae were significantly reduced after exposure to chemically dispersed crude oil and dispersant Corexit 9500A at concentrations commonly found in the water column after dispersant application in crude oil spills. We also found that barnacle nauplii ingested dispersed crude oil, which may have important consequences for the biotransfer of petroleum hydrocarbons through coastal pelagic food webs after a crude oil spill. Therefore, application of chemical dispersants increases the impact of crude oil spills on meroplanktonic larvae, which may affect recruitment and population dynamics of marine benthic invertebrates. PMID:25028258

  1. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses..., fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length must...) Fire main, hydrants, hoses and nozzles. (1) A vessel required to have a fixed fire main system...

  2. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses..., fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length must...) Fire main, hydrants, hoses and nozzles. (1) A vessel required to have a fixed fire main system...

  3. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses..., fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length must...) Fire main, hydrants, hoses and nozzles. (1) A vessel required to have a fixed fire main system...

  4. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses..., fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length must...) Fire main, hydrants, hoses and nozzles. (1) A vessel required to have a fixed fire main system...

  5. 46 CFR 28.315 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses..., fire mains, fire hydrants, and fire hoses. (a) Each vessel 36 feet (11.8 meters) or more in length must...) Fire main, hydrants, hoses and nozzles. (1) A vessel required to have a fixed fire main system...

  6. Determining air pollutant emission rates based on mass balance using airborne measurement data over the Alberta oil sands operations

    NASA Astrophysics Data System (ADS)

    Gordon, M.; Li, S.-M.; Staebler, R.; Darlington, A.; Hayden, K.; O'Brien, J.; Wolde, M.

    2015-09-01

    Top-down approaches to measure total integrated emissions provide verification of bottom-up, temporally resolved, inventory-based estimations. Aircraft-based measurements of air pollutants from sources in the Canadian oil sands were made in support of the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring during a summer intensive field campaign between 13 August and 7 September 2013. The measurements contribute to knowledge needed in support of the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring. This paper describes the top-down emission rate retrieval algorithm (TERRA) to determine facility emissions of pollutants, using SO2 and CH4 as examples, based on the aircraft measurements. In this algorithm, the flight path around a facility at multiple heights is mapped to a two-dimensional vertical screen surrounding the facility. The total transport of SO2 and CH4 through this screen is calculated using aircraft wind measurements, and facility emissions are then calculated based on the divergence theorem with estimations of box-top losses, horizontal and vertical turbulent fluxes, surface deposition, and apparent losses due to air densification and chemical reaction. Example calculations for two separate flights are presented. During an upset condition of SO2 emissions on one day, these calculations are within 5 % of the industry-reported, bottom-up measurements. During a return to normal operating conditions, the SO2 emissions are within 11 % of industry-reported, bottom-up measurements. CH4 emissions calculated with the algorithm are relatively constant within the range of uncertainties. Uncertainty of the emission rates is estimated as less than 30 %, which is primarily due to the unknown SO2 and CH4 mixing ratios near the surface below the lowest flight level.

  7. Estimates of future regional heavy oil production at three production rates--background information for assessing effects in the US refining industry

    SciTech Connect

    Olsen, D.K.

    1993-07-01

    This report is one of a series of publications from a project considering the feasibility of increasing domestic heavy oil (10{degree} to 20{degree} API gravity inclusive) production being conducted for the US Department of Energy. The report includes projections of future heavy oil production at three production levels: 900,000; 500,000; and 300,000 BOPD above the current 1992 heavy oil production level of 750,000 BOPD. These free market scenario projections include time frames and locations. Production projections through a second scenario were developed to examine which heavy oil areas would be developed if significant changes in the US petroleum industry occurred. The production data helps to define the possible constraints (impact) of increased heavy oil production on the US refining industry (the subject of a future report). Constraints include a low oil price and low rate of return. Heavy oil has high production, transportation, and refining cost per barrel as compared to light oil. The resource is known, but the right mix of technology and investment is required to bring about significant expansion of heavy oil production in the US.

  8. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2011-01-01

    The article discusses the latest developments in the fire clay industry, particularly in the U.S., as of June 2011. It claims that the leading fire clay producer in the U.S. is the state of Missouri. The other major producers include California, Texas and Washington. It reports that the use of heavy clay products made of fire clay like brick, cement and lightweight aggregate has increased slightly in 2010.

  9. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2013-01-01

    Four companies mined fire clay in three states in 2012. Production, based on a preliminary survey of the fire clay industry, was estimated to be 230 kt (254,000 st) valued at $6.98 million, an increase from 215 kt (237,000 st) valued at $6.15 million in 2011. Missouri was the leading producing state, followed by Colorado and Texas, in decreasing order by quantity. The number of companies mining fire clay declined in 2012 because several common clay producers that occasionally mine fire clay indicated that they did not do so in 2012.

  10. The demonstration of an advanced cyclone coal combustor, with internal sulfur, nitrogen, and ash control for the conversion of a 23 MMBtu/hour oil fired boiler to pulverized coal

    SciTech Connect

    Zauderer, B.; Fleming, E.S.

    1991-08-30

    The project objective was to demonstrate a technology which can be used to retrofit oil/gas designed boilers, and conventional pulverized coal fired boilers to direct coal firing, by using a patented sir cooled coal combustor that is attached in place of oil/gas/coal burners. A significant part of the test effort was devoted to resolving operational issues related to uniform coal feeding, efficient combustion under very fuel rich conditions, maintenance of continuous slag flow and removal from the combustor, development of proper air cooling operating procedures, and determining component materials durability. The second major focus of the test effort was on environmental control, especially control of SO{sub 2} emissions. By using staged combustion, the NO{sub x} emissions were reduced by around 3/4 to 184 ppmv, with further reductions to 160 ppmv in the stack particulate scrubber. By injection of calcium based sorbents into the combustor, stack SO{sub 2} emissions were reduced by a maximum of of 58%. (VC)

  11. Estimation of the Thickness and Emulsion Rate of Oil Spilled at Sea Using Hyperspectral Remote Sensing Imagery in the SWIR Domain

    NASA Astrophysics Data System (ADS)

    Sicot, G.; Lennon, M.; Miegebielle, V.; Dubucq, D.

    2015-08-01

    The thickness and the emulsion rate of an oil spill are two key parameters allowing to design a tailored response to an oil discharge. If estimated on per pixel basis at a high spatial resolution, the estimation of the oil thickness allows the volume of pollutant to be estimated, and that volume is needed in order to evaluate the magnitude of the pollution, and to determine the most adapted recovering means to use. The estimation of the spatial distribution of the thicknesses also allows the guidance of the recovering means at sea. The emulsion rate can guide the strategy to adopt in order to deal with an offshore oil spill: efficiency of dispersants is for example not identical on a pure oil or on an emulsion. Moreover, the thickness and emulsion rate allow the amount of the oil that has been discharged to be estimated. It appears that the shape of the reflectance spectrum of oil in the SWIR range (1000-2500nm) varies according to the emulsion rate and to the layer thickness. That shape still varies when the oil layer reaches a few millimetres, which is not the case in the visible range (400-700nm), where the spectral variation saturates around 200 μm (the upper limit of the Bonn agreement oil appearance code). In that context, hyperspectral imagery in the SWIR range shows a high potential to describe and characterize oil spills. Previous methods which intend to estimate those two parameters are based on the use of a spectral library. In that paper, we will present a method based on the inversion of a simple radiative transfer model in the oil layer. We will show that the proposed method is robust against another parameter that affects the reflectance spectrum: the size of water droplets in the emulsion. The method shows relevant results using measurements made in laboratory, equivalent to the ones obtained using methods based on the use of a spectral library. The method has the advantage to release the need of a spectral library, and to provide maps of thickness

  12. Detection and Characterization of Low Temperature Peat Fires during the 2015 Fire Catastrophe in Indonesia Using a New High-Sensitivity Fire Monitoring Satellite Sensor (FireBird).

    PubMed

    Atwood, Elizabeth C; Englhart, Sandra; Lorenz, Eckehard; Halle, Winfried; Wiedemann, Werner; Siegert, Florian

    2016-01-01

    Vast and disastrous fires occurred on Borneo during the 2015 dry season, pushing Indonesia into the top five carbon emitting countries. The region was affected by a very strong El Niño-Southern Oscillation (ENSO) climate phenomenon, on par with the last severe event in 1997/98. Fire dynamics in Central Kalimantan were investigated using an innovative sensor offering higher sensitivity to a wider range of fire intensities at a finer spatial resolution (160 m) than heretofore available. The sensor is onboard the TET-1 satellite, part of the German Aerospace Center (DLR) FireBird mission. TET-1 images (acquired every 2-3 days) from the middle infrared were used to detect fires continuously burning for almost three weeks in the protected peatlands of Sebangau National Park as well as surrounding areas with active logging and oil palm concessions. TET-1 detection capabilities were compared with MODIS active fire detection and Landsat burned area algorithms. Fire dynamics, including fire front propagation speed and area burned, were investigated. We show that TET-1 has improved detection capabilities over MODIS in monitoring low-intensity peatland fire fronts through thick smoke and haze. Analysis of fire dynamics revealed that the largest burned areas resulted from fire front lines started from multiple locations, and the highest propagation speeds were in excess of 500 m/day (all over peat > 2m deep). Fires were found to occur most often in concessions that contained drainage infrastructure but were not cleared prior to the fire season. Benefits of implementing this sensor system to improve current fire management techniques are discussed. Near real-time fire detection together with enhanced fire behavior monitoring capabilities would not only improve firefighting efforts, but also benefit analysis of fire impact on tropical peatlands, greenhouse gas emission estimations as well as mitigation measures to reduce severe fire events in the future.

  13. Detection and Characterization of Low Temperature Peat Fires during the 2015 Fire Catastrophe in Indonesia Using a New High-Sensitivity Fire Monitoring Satellite Sensor (FireBird)

    PubMed Central

    Atwood, Elizabeth C.; Englhart, Sandra; Lorenz, Eckehard; Halle, Winfried; Wiedemann, Werner; Siegert, Florian

    2016-01-01

    Vast and disastrous fires occurred on Borneo during the 2015 dry season, pushing Indonesia into the top five carbon emitting countries. The region was affected by a very strong El Niño-Southern Oscillation (ENSO) climate phenomenon, on par with the last severe event in 1997/98. Fire dynamics in Central Kalimantan were investigated using an innovative sensor offering higher sensitivity to a wider range of fire intensities at a finer spatial resolution (160 m) than heretofore available. The sensor is onboard the TET-1 satellite, part of the German Aerospace Center (DLR) FireBird mission. TET-1 images (acquired every 2–3 days) from the middle infrared were used to detect fires continuously burning for almost three weeks in the protected peatlands of Sebangau National Park as well as surrounding areas with active logging and oil palm concessions. TET-1 detection capabilities were compared with MODIS active fire detection and Landsat burned area algorithms. Fire dynamics, including fire front propagation speed and area burned, were investigated. We show that TET-1 has improved detection capabilities over MODIS in monitoring low-intensity peatland fire fronts through thick smoke and haze. Analysis of fire dynamics revealed that the largest burned areas resulted from fire front lines started from multiple locations, and the highest propagation speeds were in excess of 500 m/day (all over peat > 2m deep). Fires were found to occur most often in concessions that contained drainage infrastructure but were not cleared prior to the fire season. Benefits of implementing this sensor system to improve current fire management techniques are discussed. Near real-time fire detection together with enhanced fire behavior monitoring capabilities would not only improve firefighting efforts, but also benefit analysis of fire impact on tropical peatlands, greenhouse gas emission estimations as well as mitigation measures to reduce severe fire events in the future. PMID:27486664

  14. Detection and Characterization of Low Temperature Peat Fires during the 2015 Fire Catastrophe in Indonesia Using a New High-Sensitivity Fire Monitoring Satellite Sensor (FireBird).

    PubMed

    Atwood, Elizabeth C; Englhart, Sandra; Lorenz, Eckehard; Halle, Winfried; Wiedemann, Werner; Siegert, Florian

    2016-01-01

    Vast and disastrous fires occurred on Borneo during the 2015 dry season, pushing Indonesia into the top five carbon emitting countries. The region was affected by a very strong El Niño-Southern Oscillation (ENSO) climate phenomenon, on par with the last severe event in 1997/98. Fire dynamics in Central Kalimantan were investigated using an innovative sensor offering higher sensitivity to a wider range of fire intensities at a finer spatial resolution (160 m) than heretofore available. The sensor is onboard the TET-1 satellite, part of the German Aerospace Center (DLR) FireBird mission. TET-1 images (acquired every 2-3 days) from the middle infrared were used to detect fires continuously burning for almost three weeks in the protected peatlands of Sebangau National Park as well as surrounding areas with active logging and oil palm concessions. TET-1 detection capabilities were compared with MODIS active fire detection and Landsat burned area algorithms. Fire dynamics, including fire front propagation speed and area burned, were investigated. We show that TET-1 has improved detection capabilities over MODIS in monitoring low-intensity peatland fire fronts through thick smoke and haze. Analysis of fire dynamics revealed that the largest burned areas resulted from fire front lines started from multiple locations, and the highest propagation speeds were in excess of 500 m/day (all over peat > 2m deep). Fires were found to occur most often in concessions that contained drainage infrastructure but were not cleared prior to the fire season. Benefits of implementing this sensor system to improve current fire management techniques are discussed. Near real-time fire detection together with enhanced fire behavior monitoring capabilities would not only improve firefighting efforts, but also benefit analysis of fire impact on tropical peatlands, greenhouse gas emission estimations as well as mitigation measures to reduce severe fire events in the future. PMID:27486664

  15. Characterization of potential fire regimes: applying landscape ecology to fire management in Mexico

    NASA Astrophysics Data System (ADS)

    Jardel, E.; Alvarado, E.; Perez-Salicrup, D.; Morfín-Rios, J.

    2013-05-01

    Knowledge and understanding of fire regimes is fundamental to design sound fire management practices. The high ecosystem diversity of Mexico offers a great challenge to characterize the fire regime variation at the landscape level. A conceptual model was developed considering the main factors controlling fire regimes: climate and vegetation cover. We classified landscape units combining bioclimatic zones from the Holdridge life-zone system and actual vegetation cover. Since bioclimatic conditions control primary productivity and biomass accumulation (potential fuel), each landscape unit was considered as a fuel bed with a particular fire intensity and behavior potential. Climate is also a determinant factor of post-fire recovery rates of fuel beds, and climate seasonality (length of the dry and wet seasons) influences fire probability (available fuel and ignition efficiency). These two factors influence potential fire frequency. Potential fire severity can be inferred from fire frequency, fire intensity and behavior, and vegetation composition and structure. Based in the conceptual model, an exhaustive literature review and expert opinion, we developed rules to assign a potential fire regime (PFR) defined by frequency, intensity and severity (i.e. fire regime) to each bioclimatic-vegetation landscape unit. Three groups and eight types of potential fire regimes were identified. In Group A are fire-prone ecosystems with frequent low severity surface fires in grasslands (PFR type I) or forests with long dry season (II) and infrequent high-severity fires in chaparral (III), wet temperate forests (IV, fire restricted by humidity), and dry temperate forests (V, fire restricted by fuel recovery rate). Group B includes fire-reluctant ecosystems with very infrequent or occasional mixed severity surface fires limited by moisture in tropical rain forests (VI) or fuel availability in seasonally dry tropical forests (VII). Group C and PFR VIII include fire-free environments

  16. A FIRE-ACE/SHEBA Case Study of Mixed-Phase Arctic Boundary Layer Clouds: Entrainment Rate Limitations on Rapid Primary Ice Nucleation Processes

    NASA Technical Reports Server (NTRS)

    Fridlin, Ann; vanDiedenhoven, Bastiaan; Ackerman, Andrew S.; Avramov, Alexander; Mrowiec, Agnieszka; Morrison, Hugh; Zuidema, Paquita; Shupe, Matthew D.

    2012-01-01

    Observations of long-lived mixed-phase Arctic boundary layer clouds on 7 May 1998 during the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE)Arctic Cloud Experiment (ACE)Surface Heat Budget of the Arctic Ocean (SHEBA) campaign provide a unique opportunity to test understanding of cloud ice formation. Under the microphysically simple conditions observed (apparently negligible ice aggregation, sublimation, and multiplication), the only expected source of new ice crystals is activation of heterogeneous ice nuclei (IN) and the only sink is sedimentation. Large-eddy simulations with size-resolved microphysics are initialized with IN number concentration N(sub IN) measured above cloud top, but details of IN activation behavior are unknown. If activated rapidly (in deposition, condensation, or immersion modes), as commonly assumed, IN are depleted from the well-mixed boundary layer within minutes. Quasi-equilibrium ice number concentration N(sub i) is then limited to a small fraction of overlying N(sub IN) that is determined by the cloud-top entrainment rate w(sub e) divided by the number-weighted ice fall speed at the surface v(sub f). Because w(sub c)< 1 cm/s and v(sub f)> 10 cm/s, N(sub i)/N(sub IN)<< 1. Such conditions may be common for this cloud type, which has implications for modeling IN diagnostically, interpreting measurements, and quantifying sensitivity to increasing N(sub IN) (when w(sub e)/v(sub f)< 1, entrainment rate limitations serve to buffer cloud system response). To reproduce observed ice crystal size distributions and cloud radar reflectivities with rapidly consumed IN in this case, the measured above-cloud N(sub IN) must be multiplied by approximately 30. However, results are sensitive to assumed ice crystal properties not constrained by measurements. In addition, simulations do not reproduce the pronounced mesoscale heterogeneity in radar reflectivity that is observed.

  17. Seasonal Variations in CO2 Efflux, Vadose Zone Gas Concentrations, and Natural Attenuation Rates at a Crude Oil Spill Site

    NASA Astrophysics Data System (ADS)

    Trost, J.; Sihota, N.; Delin, G. N.; Warren, E.

    2014-12-01

    Accurate estimates of hydrocarbon source zone natural attenuation (SZNA) rates are important for managing contaminated sites but are difficult to measure. Moreover, SZNA rates may vary seasonally in response to climatic conditions. Previous research at a crude oil spill site near Bemidji, Minnesota, USA showed that SZNA rates in the summer can be estimated by subtracting background soil CO2 efflux from the total soil CO2 efflux above the contaminated source. In this study, seasonal variations in surficial CO2 efflux were evaluated with measurements of gas concentrations (including 14CO2), temperature, and volumetric water content in the vadose zone at the site during a 2-year period. Soil CO2 effluxes in the source zone were consistently greater than background CO2 effluxes, and the magnitude and areal extent of the increased efflux varied seasonally. In the source zone, the 14CO2 and the CO2 efflux data showed a larger proportion of soil CO2 was derived from SZNA in fall and winter (October - February) compared to the summer (June - August). Surficial CO2 effluxes and vadose zone CO2 and CH4 concentrations in the source (2 - 7 meters below land surface) were positively correlated with soil temperature, indicating seasonal variability in SZNA rates. However, peak surficial CO2 effluxes did not correspond with periods of highest CO2 or CH4 concentrations at the 2 - 7 meter depth, demonstrating the effects of physical attributes (such as soil depth, frost, and volumetric water content) on gas transport. Overall, results showed that SZNA rates, background soil respiration rates, and gas transport varied seasonally, and that biological and physical factors are important to consider for accurately estimating SZNA rates.

  18. How Fire History, Fire Suppression Practices and Climate Change Affect Wildfire Regimes in Mediterranean Landscapes

    PubMed Central

    Brotons, Lluís; Aquilué, Núria; de Cáceres, Miquel; Fortin, Marie-Josée; Fall, Andrew

    2013-01-01

    Available data show that future changes in global change drivers may lead to an increasing impact of fires on terrestrial ecosystems worldwide. Yet, fire regime changes in highly humanised fire-prone regions are difficult to predict because fire effects may be heavily mediated by human activities We investigated the role of fire suppression strategies in synergy with climate change on the resulting fire regimes in Catalonia (north-eastern Spain). We used a spatially-explicit fire-succession model at the landscape level to test whether the use of different firefighting opportunities related to observed reductions in fire spread rates and effective fire sizes, and hence changes in the fire regime. We calibrated this model with data from a period with weak firefighting and later assess the potential for suppression strategies to modify fire regimes expected under different levels of climate change. When comparing simulations with observed fire statistics from an eleven-year period with firefighting strategies in place, our results showed that, at least in two of the three sub-regions analysed, the observed fire regime could not be reproduced unless taking into account the effects of fire suppression. Fire regime descriptors were highly dependent on climate change scenarios, with a general trend, under baseline scenarios without fire suppression, to large-scale increases in area burnt. Fire suppression strategies had a strong capacity to compensate for climate change effects. However, strong active fire suppression was necessary to accomplish such compensation, while more opportunistic fire suppression strategies derived from recent fire history only had a variable, but generally weak, potential for compensation of enhanced fire impacts under climate change. The concept of fire regime in the Mediterranean is probably better interpreted as a highly dynamic process in which the main determinants of fire are rapidly modified by changes in landscape, climate and

  19. Influence of Volume Deformation Rate on the Intensity of Oil-Bearing Crop Pressing-out in Relation to Rape Extrudate

    NASA Astrophysics Data System (ADS)

    Slavnov, E. V.; Petrov, I. A.

    2015-07-01

    The influence of the volume deformation rate on the intensity of piston pressing-out of oil has been investigated. The results of pressing by a piston moving with different speeds are presented. Mathematical simulation is carried out for the stage of pressing-out after the termination of sample loading, when oil release occurs due to the accumulated deformations of the skeleton. It has been assumed that in mechanical pressing there remains the least residual content of oil. A dimensionless complex representing the ratio of the characteristic times of loading to the material response (the process of pressing) has been obtained. The dependence of the rate of oil pressing-out at the stage of pressure relaxation on the dimensionless complex has been determined.

  20. Fire Power

    ERIC Educational Resources Information Center

    Denker, Deb; West, Lee

    2009-01-01

    For education administrators, campus fires are not only a distressing loss, but also a stark reminder that a campus faces risks that require special vigilance. In many ways, campuses resemble small communities, with areas for living, working and relaxing. A residence hall fire may raise the specter of careless youth, often with the complication of…

  1. Siberian Fires

    Atmospheric Science Data Center

    2013-04-16

    ... of fires across Siberia and the Russian Far East, northeast China and northern Mongolia. Fires in Eastern Siberia have been increasing in ... spatial contrast. The heights correspond to elevations above sea level. Taking into account the surface elevation, the smoke plumes range ...

  2. Returning Fire

    ERIC Educational Resources Information Center

    Gould, Jon B.

    2007-01-01

    Last December saw another predictable report from the Foundation for Individual Rights in Education (FIRE), a self-described watchdog group, highlighting how higher education is supposedly under siege from a politically correct plague of so-called hate-speech codes. In that report, FIRE declared that as many as 96 percent of top-ranked colleges…

  3. Utilization of coal-water fuels in fire-tube boilers. Final report, October 1990--August 1994

    SciTech Connect

    Sommer, T.; Melick, T.; Morrison, D.

    1994-12-31

    The objective of this DOE sponsored project was to successfully fire coal-water slurry in a fire-tube boiler that was designed for oil/gas firing and establish a data base that will be relevant to a large number of existing installations. Firing slurry in a fire-tube configuration is a very demanding application because of the extremely high heat release rates and the correspondingly low furnace volume where combustion can be completed. Recognizing that combustion efficiency is the major obstacle when firing slurry in a fire-tube boiler, the program was focused on innovative approaches for improving carbon burnout without major modifications to the boiler. The boiler system was successfully designed and operated to fire coal-water slurry for extended periods of time with few slurry related operational problems. The host facility was a 3.8 million Btu/hr Cleaver-Brooks fire-tube boiler located on the University of Alabama Campus. A slurry atomizer was designed that provided outstanding atomization and was not susceptible to pluggage. The boiler was operated for over 1000 hours and 12 shipments of slurry were delivered. The new equipment engineered for the coal-water slurry system consisted of the following: combustion air and slurry heaters; cyclone; baghouse; fly ash reinjection system; new control system; air compressor; CWS/gas burner and gas valve train; and storage tank and slurry handling system.

  4. Toxicity and repellency of compounds from clove (Syzygium aromaticum) to red imported fire ants Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Kafle, Lekhnath; Shih, Cheng Jen

    2013-02-01

    The toxicity and repellency of the bioactive chemicals of clove (Syzygium aromaticum) powder, eugenol, eugenol acetate, and beta-caryophyllene were evaluated against workers of the red imported fire ant, Solenopsis invicta Buren. Clove powder applied at 3 and 12 mg/cm2 provided 100% ant mortality within 6 h, and repelled 99% within 3 h. Eugenol was the fastest acting compound against red imported fire ant compared with eugenol acetate, beta-caryophyllene, and clove oil. The LT50 values inclined exponentially with the increase in the application rate of the chemical compounds tested. However, repellency did not increase with the increase in the application rate of the chemical compounds tested, but did with the increase in exposure time. Eugenol, eugenol acetate, as well as beta-caryophyllene and clove oil may provide another tool for red imported fire ant integrated pest management, particularly in situations where conventional insecticides are inappropriate.

  5. Toxicity and repellency of compounds from clove (Syzygium aromaticum) to red imported fire ants Solenopsis invicta (Hymenoptera: Formicidae).

    PubMed

    Kafle, Lekhnath; Shih, Cheng Jen

    2013-02-01

    The toxicity and repellency of the bioactive chemicals of clove (Syzygium aromaticum) powder, eugenol, eugenol acetate, and beta-caryophyllene were evaluated against workers of the red imported fire ant, Solenopsis invicta Buren. Clove powder applied at 3 and 12 mg/cm2 provided 100% ant mortality within 6 h, and repelled 99% within 3 h. Eugenol was the fastest acting compound against red imported fire ant compared with eugenol acetate, beta-caryophyllene, and clove oil. The LT50 values inclined exponentially with the increase in the application rate of the chemical compounds tested. However, repellency did not increase with the increase in the application rate of the chemical compounds tested, but did with the increase in exposure time. Eugenol, eugenol acetate, as well as beta-caryophyllene and clove oil may provide another tool for red imported fire ant integrated pest management, particularly in situations where conventional insecticides are inappropriate. PMID:23448024

  6. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses..., fire hydrants, and fire hoses. (a) Each vessel must be equipped with a self-priming, power driven fire... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall...

  7. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses..., fire hydrants, and fire hoses. (a) Each vessel must be equipped with a self-priming, power driven fire... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall...

  8. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses..., fire hydrants, and fire hoses. (a) Each vessel must be equipped with a self-priming, power driven fire... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall...

  9. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses..., fire hydrants, and fire hoses. (a) Each vessel must be equipped with a self-priming, power driven fire... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall...

  10. 46 CFR 28.820 - Fire pumps, fire mains, fire hydrants, and fire hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Fire pumps, fire mains, fire hydrants, and fire hoses..., fire hydrants, and fire hoses. (a) Each vessel must be equipped with a self-priming, power driven fire... water from a hose connected to the highest outlet. The minimum capacity of the power fire pump shall...

  11. 25 CFR 211.43 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sold from the lease. (3) For geothermal resources, the royalty rate shall be 10 percent of the amount or value of steam, or any other form of heat or energy derived from production of geothermal... Section 211.43 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING...

  12. 25 CFR 211.43 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... sold from the lease. (3) For geothermal resources, the royalty rate shall be 10 percent of the amount or value of steam, or any other form of heat or energy derived from production of geothermal... Section 211.43 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING...

  13. 25 CFR 211.43 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sold from the lease. (3) For geothermal resources, the royalty rate shall be 10 percent of the amount or value of steam, or any other form of heat or energy derived from production of geothermal... Section 211.43 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING...

  14. 25 CFR 211.43 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... sold from the lease. (3) For geothermal resources, the royalty rate shall be 10 percent of the amount or value of steam, or any other form of heat or energy derived from production of geothermal... Section 211.43 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING...

  15. 25 CFR 211.43 - Royalty rates for minerals other than oil and gas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... sold from the lease. (3) For geothermal resources, the royalty rate shall be 10 percent of the amount or value of steam, or any other form of heat or energy derived from production of geothermal... Section 211.43 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEASING...

  16. Effect of Colloidal Interactions on the Rate of Interdroplet Heterogeneous Nucleation in Oil-in-Water Emulsions

    PubMed

    McClements; Dungan

    1997-02-01

    Pulsed nuclear magnetic resonance was used to monitor the crystallization of supercooled liquid droplets in 30 wt% n-hexadecane oil-in-water emulsions at 6°C. Crystallization was induced in the liquid droplets when solid droplets of the same material were present. The rate of induced crystallization increased as the concentration of free non-ionic surfactant (polyoxyethylene sorbitan monolaurate) in the aqueous phase increased from 0 to 14 wt%. Differential scanning calorimetry measurements indicated that free surfactant had no effect on crystal nucleation of individual droplets. These results indicate that the surfactant enhances induced crystallization by altering colloidal interactions between droplets. Creaming measurements showed that flocculation was enhanced in emulsions when the free surfactant concentration was increased. We propose that the presence of free surfactant micelles increases the attraction between droplets because of an osmotic effect, and this attraction facilitates the ability of solid crystals from one droplet to induce crystallization in an adjacent liquid droplet.

  17. Spacecraft Fire Safety

    NASA Technical Reports Server (NTRS)

    Margle, Janice M. (Editor)

    1987-01-01

    Fire detection, fire standards and testing, fire extinguishment, inerting and atmospheres, fire-related medical science, aircraft fire safety, Space Station safety concerns, microgravity combustion, spacecraft material flammability testing, and metal combustion are among the topics considered.

  18. 46 CFR 189.25-45 - Fire hazards.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Fire hazards. 189.25-45 Section 189.25-45 Shipping COAST... CERTIFICATION Inspection for Certification § 189.25-45 Fire hazards. At each inspection for certification and... that there is no accumulation of oil which might create a fire hazard....

  19. 46 CFR 91.25-45 - Fire hazards.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Fire hazards. 91.25-45 Section 91.25-45 Shipping COAST... CERTIFICATION Inspection for Certification § 91.25-45 Fire hazards. (a) At each inspection for certification and... that there is no accumulation of oil which might create a fire hazard....

  20. 46 CFR 91.25-45 - Fire hazards.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Fire hazards. 91.25-45 Section 91.25-45 Shipping COAST... CERTIFICATION Inspection for Certification § 91.25-45 Fire hazards. (a) At each inspection for certification and... that there is no accumulation of oil which might create a fire hazard....

  1. 46 CFR 91.25-45 - Fire hazards.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Fire hazards. 91.25-45 Section 91.25-45 Shipping COAST... CERTIFICATION Inspection for Certification § 91.25-45 Fire hazards. (a) At each inspection for certification and... that there is no accumulation of oil which might create a fire hazard....

  2. 46 CFR 91.25-45 - Fire hazards.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Fire hazards. 91.25-45 Section 91.25-45 Shipping COAST... CERTIFICATION Inspection for Certification § 91.25-45 Fire hazards. (a) At each inspection for certification and... that there is no accumulation of oil which might create a fire hazard....

  3. 46 CFR 91.25-45 - Fire hazards.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Fire hazards. 91.25-45 Section 91.25-45 Shipping COAST... CERTIFICATION Inspection for Certification § 91.25-45 Fire hazards. (a) At each inspection for certification and... that there is no accumulation of oil which might create a fire hazard....

  4. 46 CFR 189.25-45 - Fire hazards.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Fire hazards. 189.25-45 Section 189.25-45 Shipping COAST... CERTIFICATION Inspection for Certification § 189.25-45 Fire hazards. At each inspection for certification and... that there is no accumulation of oil which might create a fire hazard....

  5. 46 CFR 189.25-45 - Fire hazards.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Fire hazards. 189.25-45 Section 189.25-45 Shipping COAST... CERTIFICATION Inspection for Certification § 189.25-45 Fire hazards. At each inspection for certification and... that there is no accumulation of oil which might create a fire hazard....

  6. 46 CFR 189.25-45 - Fire hazards.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Fire hazards. 189.25-45 Section 189.25-45 Shipping COAST... CERTIFICATION Inspection for Certification § 189.25-45 Fire hazards. At each inspection for certification and... that there is no accumulation of oil which might create a fire hazard....

  7. Effect of natural fiber types and sodium silicate coated on natural fiber mat/PLA composites: Tensile properties and rate of fire propagation

    NASA Astrophysics Data System (ADS)

    Thongpin, C.; Srimuk, J.; hipkam, N.; Wachirapong, P.

    2015-07-01

    In this study, 3 types of natural fibres, i.e. jute, sisal and abaca, were plain weaved to fibre mat. Before weaving, the fibres were treated with 5% NaOH to remove hemi cellulose and lignin. The weaving was performed by hand using square wooden block fit with nails for weaving using one and two types of natural fibres as weft and warp fibre to produce natural fibre mat. The fibre mat was also impregnated in sodium silicate solution extracted from rich husk ash. The pH of the solution was adjusted to pH 7 using H2SO4 before impregnation. After predetermined time, sodium silicate was gelled and deposited on the mat. The fabric mat and sodium silicate coated mat were then impregnated with PLA solution to produce prepreg. Dried pepreg was laminated with PLA sheet using compressing moulding machine to obtain natural fibre mat/PLA composite. The composite containing abaca aligned in longitudinal direction with respect to tension force enhanced Young's modulus more than 300%. Fibre mat composites with abaca aligned in longitudinal direction also showed tensile strength enhancement nearly 400% higher than neat PLA. After coating with sodium silicate, the tensile modulus of the composites was found slightly increased. The silicate coating was disadvantage on tensile strength of the composite due to the effect of sodium hydroxide solution that was used as solvent for silicate extraction from rice husk ash. However, sodium silicate could retard rate of fire propagation about 50%compare to neat PLA and about 10% reduction compared to fibre mat composites without sodium silicate coated fibre mat.

  8. Hazards of conveyor belt fires

    SciTech Connect

    Perzak, F.J.; Litton, C.D.; Mura, K.E.; Lazzara, C.P.

    1995-12-31

    This report describes a US Bureau of Mines study on the hazards of large-scale conveyor belt fires in underground coal mines, as a function of both air velocity and distance from belt surface to gallery roof. The fire hazards considered were smoke obscuration, toxic effects of carbon monoxide (CO), and elevated air temperatures downstream of the fire. All of these hazards scale with the ratio of fire intensity to ventilation airflow. These hazards were all found to be greater at the lower belt-to-roof distance, owing to the greater fire intensities that resulted. The hazards of smoke obscuration and elevated CO levels were greater at lower air velocities. Smoke obscuration was found to be the earliest hazard, reaching critical levels before the stages of flame spread. Fire growth rates during rapid flame spread were much greater than rates measured during the early stages of flame spread. Fire growth rates during rapid flame spread were much greater than rates measured during the early stages of belt burning. Data were analyzed to determine the early-warning capability of fire sensors. Smoke sensors provided the earliest warning, followed closely by CO sensors. Thermal sensors did not exhibit any early warning capability.

  9. Analysis of Multiengine Transport Airplane Fire Records

    NASA Technical Reports Server (NTRS)

    Pesman, Gerard J.

    1950-01-01

    An analysis has been made of Civil Aeronautics Administration and Civil Aeronautics Board commercial airplane fire records collected during the 10-year period ending July 1, 1948. The results of the analysis show that: 1. Gasoline was most frequently the initial combustible ignited in flight and ground fires and is considered to be the most hazardous of the combustibles carried. 2. Although electrical-ignition sources are the most frequent flight-fire ignition source by a small margin, the exhaust system is concluded to be the most hazardous ignition source because it is necessarily located near the lubricating-oil and gasoline-plumbing systems and the resulting fires are relatively severe. The electrical-ignition sources usually involve only the electrical insulation and result in small-volume fires. The exhaust system was found to be the most frequent ground-fire ignition source. 3. Engine failures were the most frequent cause of the union of combustible and ignition source that resulted in flight fires. 4. Fuel-plumbing-system failures were the most frequent cause of fires occurring during ground operation. 5. The evidence concerning crash fires was not sufficiently extensive to provide information concerning the factors that affect the start and the spread of fire. In order that future records may be more useful, all crash accidents should be studied to determine why fire does or does not occur and to establish data that relate the occurrence and the spread of fire to airplane design and operation.

  10. Fire extinguishers for manned spacecraft

    NASA Astrophysics Data System (ADS)

    Kopylov, S.; Smirnov, N. V.; Tanklevsky, L. T.

    2015-04-01

    Based on an analysis of fires in the oxygen-enriched atmosphere conditions in spacecraft and other sealed chambers of various purposes, the most dangerous groups of fires are identified. For this purpose, groups were compiled to analyze dependences that describe the increase of fire hazard to a critical value. A criterion for determining timely and effective fire extinguishing was offered. Fire experiments in oxygen-enriched atmosphere conditions were conducted, and an array of experimental data on the mass burning rate of materials and their extinguishing by water mist was obtained. Relationships colligating an array of experimental data were offered. Experimental and analytical studies were taken as a basis for hand fire extinguisher implementation for manned spacecraft.

  11. Fire-related medical science

    NASA Technical Reports Server (NTRS)

    Knight, Douglas R.

    1987-01-01

    Spacecraft fire safety may be improved by the use of a fire-retardant atmosphere in occupied spaces. Low concentrations of oxygen can protect humans from fire damage by reducing the rate and spread of combustion, but care must be taken to avoid the hypoxic effects of oxygen-lean atmospheres. Crews can live and work in 11 percent oxygen if barometric pressure were adjusted to maintain the partial pressure of oxygen above 16 kPa. Eleven percent oxygen should prevent most types of fires, since 15 percent oxygen retards the combustion of paper and 13 percent oxygen extinguishes pentane flames. Test results indicate that seated humans can perform mental tasks in atmospheres containing 11.5 percent oxygen. Although this strategy of fire safety is under consideration for submarines, it could be adapted to spacecraft once operational procedures define a maximum hyperbaric pressure and fire research defines the effects of reduced oxygen concentrations on combustion in low gravity environments.

  12. California Fires

    Atmospheric Science Data Center

    2014-05-15

    article title:  Smoke from Station Fire Blankets Southern California     ... 105,000 acres (164 square miles) of the Angeles National Forest by mid-day August 31, destroying at least 21 homes and threatening more ...

  13. Can Charcoal Provide Information About Fire Effects and Fire Severity?

    NASA Astrophysics Data System (ADS)

    Belcher, Claire; Hudpsith, Victoria; Doerr, Stefan; Santin, Cristina

    2016-04-01

    Building an understanding of the impact of a wildfire is critical to the management of ecosystems. Aspects of fire severity such as the amount of soil heating, can relate to post-fire ecosystem recovery. Yet, there is no quantitative measure of this in current post-burn fire severity assessments, which are mostly qualitative ground-based visual assessments of organic matter loss, and as such can be subjective and variable between ecosystems. In order to develop a unifying fire severity assessment we explore the use of charcoal produced during a wildfire, as a tool. Charcoal has been suggested to retain some information about the nature of the fire in which it was created and one such physical property of charcoal that can be measured post-fire is its ability to reflect light when studied under oil using reflectance microscopy. The amount of light reflected varies between charcoals and is thought to be explained by the differential ordering of graphite-like phases within the char however, to what aspects of a fire's nature this alteration pertains is unknown. We have explored the formation of charcoal reflectance in 1) laboratory-based experiments using an iCone calorimeter and in 2) experimental forest scale and natural wildland fires occurring in Canada in spring 2015. In our laboratory experiments we assessed the formation and evolution of charcoal reflectance during pre-ignition heating, peak fire intensity through to the end of flaming and the transition to oxidative/smoldering heating regimes. In the prescribed and natural wildland fires we positioned the same woods used in our laboratory experiments, rigged with thermocouples in the path of oncoming fires in order to assess the resulting charcoal reflectance in response to the heating regime imposed by the fire on the samples. In this presentation we will outline our approach, findings and discuss the potential for charcoal reflectance to provide a tool in post-fire assessments seeking to determine levels of

  14. Fire clay

    USGS Publications Warehouse

    Virta, R.L.

    2012-01-01

    Five companies mined fire clay in four states in 2011. Production, based on a preliminary survey of the fire clay industry, was estimated to be 240 kt (265,000 st), valued at $7.68 million, an increase from 216 kt (238,000 st), valued at $6.12 million in 2010. Missouri was the leading producing state, followed by Texas, Washington and Ohio, in decreasing order by quantity.

  15. Risk Factors for Rural Residential Fires

    ERIC Educational Resources Information Center

    Allareddy, Veerasathpurush; Peek-Asa, Corinne; Yang, Jingzhen; Zwerling, Craig

    2007-01-01

    Context and Purpose: Rural households report high fire-related mortality and injury rates, but few studies have examined the risk factors for fires. This study aims to identify occupant and household characteristics that are associated with residential fires in a rural cohort. Methods: Of 1,005 households contacted in a single rural county, 691…

  16. Insect repellent activity of medicinal plant oils against Aedes aegypti (Linn.), Anopheles minimus (Theobald) and Culex quinquefasciatus Say based on protection time and biting rate.

    PubMed

    Phasomkusolsil, Siriporn; Soonwera, Mayura

    2010-07-01

    This study investigated insect bite protection and length of the protection with 30 repellents which were divided into 3 categories: plant oil, essential oil and essential oil with ethyl alcohol, tested against three mosquito species, Aedes aegypti, Anopheles minimus and Culex quinquefasciatus, under laboratory conditions. The plant oil group was comprised of Phlai (Zingiber cassumunar) and Sweet basil (Ocimum basilicum). Both substances were effective as repellents and feeding deterrents against An. minimus (205 minutes protection time and a biting rate of 0.9%), Cx. quinquefasciatus (165 minutes protection time and 0.9% biting rate) and Ae. aegypti (90 minutes protection time and 0.8% biting rate). Essential oil from citronella grass (Cymbopogon nardus) exhibited protection against biting from all 3 mosquito species: for An. minimus, Cx. quinquefasciatus and Ae. aegypti, the results were 130 minutes and 0.9%, 140 minutes and 0.8%, and 115 minutes and 0.8%, respectively. The period of protection time against Ae. aegypti for all repellent candidates tested was lower than the Thai Industrial Standards Institute (TISI) determined time of greater than 2 hours. PMID:21073057

  17. Solenopsis invicta virus-1 tissue tropism and intracolony infection rate in the red imported fire ant: A quantitative PCR-based study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantitative real-time PCR was employed to measure the Solenopsis invicta virus 1 (SINV-1) load in tissues, individuals, and among colonies of the red imported fire ant, Solenopsis invicta Buren. Among tissues examined from SINV-1-infected adults and larvae, the alimentary canal (specifically the mi...

  18. Towards Ideal NOx and CO2 Emission Control Technology for Bio-Oils Combustion Energy System Using a Plasma-Chemical Hybrid Process

    NASA Astrophysics Data System (ADS)

    Okubo, M.; Fujishima, H.; Yamato, Y.; Kuroki, T.; Tanaka, A.; Otsuka, K.

    2013-03-01

    A pilot-scale low-emission boiler system consisting of a bio-fuel boiler and plasma-chemical hybrid NOx removal system is investigated. This system can achieve carbon neutrality because the bio-fuel boiler uses waste vegetable oil as one of the fuels. The plasma-chemical hybrid NOx removal system has two processes: NO oxidation by ozone produced from plasma ozonizers and NO2 removal using a Na2SO3 chemical scrubber. Test demonstrations of the system are carried out for mixed oils (mixture of A-heavy oil and waste vegetable oil). Stable combustion is achieved for the mixed oil (20 - 50% waste vegetable oil). Properties of flue gas—e.g., O2, CO2 and NOx—when firing mixed oils are nearly the same as those when firing heavy oil for an average flue gas flow rate of 1000 Nm3/h. NOx concentrations at the boiler outlet are 90 - 95 ppm. Furthermore, during a 300-min continuous operation when firing 20% mixed oil, NOx removal efficiency of more than 90% (less than 10 ppm NOx emission) is confirmed. In addition, the CO2 reduction when heavy oil is replaced with waste vegetable oil is estimated. The system comparison is described between the plasma-chemical hybrid NOx removal and the conventional technology.

  19. Soybean seed protein oil fatty acids sugars and minerals as affected by seeding rates and row spacing in the Midsouth USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research on the effects of seeding rates (SDR) and row spacing (RS) on soybean seed composition is almost non-existent. The objective of this research was to investigate the effect of SDR and RS on soybean seed protein, oil, fatty acids, sugars, and minerals using two soybean cultivars, P 93M90 (ear...

  20. Development and testing of commercial-scale, coal-fired combustion systems: Phase III. Final report

    SciTech Connect

    1996-03-01

    Based on studies that indicated a large potential for significantly increased coal-firing in the commercial sector, the U.S. Department of Energy`s Pittsburgh Energy Technology Center (PETC) sponsored a multi-phase development effort for advanced coal combustion systems. This Final Report presents the results of the last phase (Phase III) of a project for the development of an advanced coal-fired system for the commercial sector of the economy. The project performance goals for the system included dual-fuel capability (i.e., coal as primary fuel and natural gas as secondary fuel), combustion efficiency exceeding 99 percent, thermal efficiency greater than 80 percent, turndown of at least 3:1, dust-free and semi-automatic dry ash removal, fully automatic start-up with system purge and ignition verification, emissions performance exceeding New Source Performance Standards (NSPS) and approaching those produced by oil-fired, Commercial-sized units, and reliability, safety, operability, maintainability, and service life comparable to oil-fired units. The program also involved a site demonstration at a large facility owned by Striegel Supply Company, a portion of which was leased to MTCI. The site, mostly warehouse space, was completely unheated and the advanced coal-fired combustion system was designed and sized to heat this space. Three different coals were used in the project, one low and one high sulfur pulverized Pittsburgh No. 8 coal, and a micronized low volatile, bituminous coal. The sorbents used were Pfizer dolomitic limestone and an Anvil lime. More than 100 hours of screening test`s were performed to characterize the system. The parameters examined included coal firing rate, excess air level, ash recycle rate, coal type, dolomitic limestone feed rate, and steam injection rate. These tests indicated that some additional modifications for coal burning in the system were required.

  1. FINE PARTICLE EMISSIONS FROM RESIDUAL FUEL OIL COMBUSTION: CHARACTERIZATION AND MECHANISMS OF FORMATION

    EPA Science Inventory

    The paper gives results of a comparison of the characteristics of particulate matter (PM) emitted from residual fuel oil combustion in two types of combustion equipment. A small commercial 732-kW-rated fire-tube boiler yielded a weakly bimodal PM size distribution (PSD) with over...

  2. Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 1. Degradation rates using tropical marine microbes.

    PubMed

    Mercurio, Philip; Burns, Kathryn A; Negri, Andrew

    2004-05-01

    Vegetable-derived lubricants (VDL) might be more biodegradable than mineral-derived lubricants (MDL) due to the absence of high molecular weight aromatics, but this remains largely untested in tropical conditions. In this laboratory study, the degradation rates of 2-stroke, 4-stroke and hydraulic VDLs were compared with their MDL counterparts in the presence of mangrove and coral reef microbial communities. While MDLs were comprised largely of unresolved saturated and some aromatic hydrocarbons, their VDL counterparts contained, potentially more degradable, fatty acid methyl esters. Degradation of some VDL was observed by day 7, with the 2-stroke VDL markedly consumed by mangrove microorganisms and the hydraulic VDL degraded by both microorganism communities after this short period. All of the VDL groups were significantly more degraded than the comparable MDLs mineral oil lubricants over 14 days in the presence of either mangrove or coral reef microbial communities. In general the mangrove-sourced microorganisms more efficiently degraded the lubricants than reef-sourced microorganisms.

  3. 75 FR 61624 - Promotion of Development, Reduction of Royalty Rates for Stripper Well and Heavy Oil Properties

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-06

    ... that Federal lessees would have incentives to keep economically marginal oil wells in production. This... 35973 (Aug. 11, 1992); 61 FR 4750 (Feb. 8, 1996)). A stripper well property, within the meaning of... property with an average daily production of less than 15 barrels of oil per well, or less than...

  4. Combustion of Coal/Oil/Water Slurries

    NASA Technical Reports Server (NTRS)

    Kushida, R. O.

    1982-01-01

    Proposed test setup would measure combustion performance of new fuels by rapidly heating a droplet of coal/oil/water mixture and recording resulting explosion. Such mixtures are being considered as petroleum substitutes in oil-fired furnaces.

  5. Active Fire Mapping Program

    MedlinePlus

    ... Incidents (Home) New Large Incidents Fire Detection Maps MODIS Satellite Imagery VIIRS Satellite Imagery Fire Detection GIS ... Data Web Services Latest Detected Fire Activity Other MODIS Products Frequently Asked Questions About Active Fire Maps ...

  6. The velocity field of laboratory fire whirls

    NASA Astrophysics Data System (ADS)

    Hartl, Katherine; Guo, Stacy; Smits, Alexander

    2012-11-01

    Fire whirls increase the intensity of wild fires, and they enhance the spreading rate of fire by ejecting flaming debris, often rendering prepared fire fighting plans useless. Fire whirls are produced by buoyancy, ambient vorticity, and the titling of regions of intense horizontal negative shear at the fire front. They can shed from a smoke plume, form in the turbulent wake of a hill, or arise due to concentrated heat sources. To understand and model fire whirls in greater detail, an experimental study is conducted to generate a fire whirl in the laboratory, and examine the velocity fields outside and inside the vortex core. We use flow visualization and PIV to obtain qualitative and quantitative data, and discuss the scaling behavior.

  7. Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults

    PubMed Central

    2010-01-01

    Background To determine the effects of supplemental fish oil (FO) on resting metabolic rate (RMR), body composition, and cortisol production in healthy adults. Methods A total of 44 men and women (34 ± 13y, mean+SD) participated in the study. All testing was performed first thing in the morning following an overnight fast. Baseline measurements of RMR were measured using indirect calorimetry using a facemask, and body composition was measured using air displacement plethysmography. Saliva was collected via passive drool and analyzed for cortisol concentration using ELISA. Following baseline testing, subjects were randomly assigned in a double blind manner to one of two groups: 4 g/d of Safflower Oil (SO); or 4 g/d of FO supplying 1,600 mg/d eicosapentaenoic acid (EPA) and 800 mg/d docosahexaenoic acid (DHA). All tests were repeated following 6 wk of treatment. Pre to post differences were analyzed using a treatment X time repeated measures ANOVA, and correlations were analyzed using Pearson's r. Results Compared to the SO group, there was a significant increase in fat free mass following treatment with FO (FO = +0.5 ± 0.5 kg, SO = -0.1 ± 1.2 kg, p = 0.03), a significant reduction in fat mass (FO = -0.5 ± 1.3 kg, SO = +0.2 ± 1.2 kg, p = 0.04), and a tendency for a decrease in body fat percentage (FO = -0.4 ± 1.3% body fat, SO = +0. 3 ± 1.5% body fat, p = 0.08). No significant differences were observed for body mass (FO = 0.0 ± 0.9 kg, SO = +0.2 ± 0.8 kg), RMR (FO = +17 ± 260 kcal, SO = -62 ± 184 kcal) or respiratory exchange ratio (FO = -0.02 ± 0.09, SO = +0.02 ± 0.05). There was a tendency for salivary cortisol to decrease in the FO group (FO = -0.064 ± 0.142 μg/dL, SO = +0.016 ± 0.272 μg/dL, p = 0.11). There was a significant correlation in the FO group between change in cortisol and change in fat free mass (r = -0.504, p = 0.02) and fat mass (r = 0.661, p = 0.001). Conclusion 6 wk of supplementation with FO significantly increased lean mass and

  8. Well blowout rates and consequences in California Oil and Gas District 4 from 1991 to 2005: Implications for geological storage of carbon dioxide

    SciTech Connect

    Jordan, Preston; Jordan, Preston D.; Benson, Sally M.

    2008-05-15

    Well blowout rates in oil fields undergoing thermally enhanced recovery (via steam injection) in California Oil and Gas District 4 from 1991 to 2005 were on the order of 1 per 1,000 well construction operations, 1 per 10,000 active wells per year, and 1 per 100,000 shut-in/idle and plugged/abandoned wells per year. This allows some initial inferences about leakage of CO2 via wells, which is considered perhaps the greatest leakage risk for geological storage of CO2. During the study period, 9% of the oil produced in the United States was from District 4, and 59% of this production was via thermally enhanced recovery. There was only one possible blowout from an unknown or poorly located well, despite over a century of well drilling and production activities in the district. The blowout rate declined dramatically during the study period, most likely as a result of increasing experience, improved technology, and/or changes in safety culture. If so, this decline indicates the blowout rate in CO2-storage fields can be significantly minimized both initially and with increasing experience over time. Comparable studies should be conducted in other areas. These studies would be particularly valuable in regions with CO2-enhanced oil recovery (EOR) and natural gas storage.

  9. Application of MODIS-Derived Active Fire Radiative Energy to Fire Disaster and Smoke Pollution Monitoring

    NASA Technical Reports Server (NTRS)

    Ichoku, Charles; Kaufman, Yoram J.; Hao, Wei Min; Habib, Shahid

    2004-01-01

    The radiative energy emitted by large fires and the corresponding smoke aerosol loading are simultaneously measured from the MODIS sensor from both the Terra and Aqua satellites. Quantitative relationships between the rates of emission of fire radiative energy and smoke are being developed for different fire-prone regions of the globe. Preliminary results are presented. When fully developed, the system will enable the use of MODIS direct broadcast fire data for near real-time monitoring of fire strength and smoke emission as well as forecasting of fire progression and smoke dispersion, several hours to a few days in advance.

  10. Effects of alternate fuels report No. 8: analysis of degradiation of magnesia-based refractory bricks from a residual oil-fired rotary cement kiln

    SciTech Connect

    Federer, J.I.; Tennery, V.J.

    1980-05-01

    Residual oil was used as an alternate fuel to natural gas to supply heat in a rotary cement kiln. Principal impurities in the residual oil were Ca, Fe, Mg, Na, Ni, P.S. and V. the kiln operators were concerned about the effects of these oil impurities on observed degradation of the magnesia-based bricks used as a liner in the burning zone of the kiln. Two degraded bricks, which had been in service for six to nine months, were analyzed to determine the role of fuel impurities on the observed degradation. The maximum hot-face temperature of the refractory during service was about 1500/sup 0/C. One brick had decreased in thickness about 45%, the about 15%. Various analytical measurements on these samples failed to reveal the presence of fuel impurities at or near the hot face of the bricks, and therefore it is concluded that the relatively short service life of these refractories was not due to use of residual oil as the fuel in the kiln. The observed degradation, therefore, was attributed to other reactions and to thermal mechanical conditions in the kiln, which inevitably resulted in extensive erosion of the bricks.

  11. Fire regimes, fire ecology, and fire management in Mexico.

    PubMed

    Rodríguez Trejo, Dante Arturo

    2008-12-01

    I propose several broad fire regimes and provide an analysis of fire ecology for the principal vegetation types in Mexico. Forty percent of Mexican ecosystems are fire-dependent (pine forests, several oak forests, grasslands, several shrublands, savannas, palm lands, wet prairies, "popal" and "tular" swamps), 50% are fire-sensitive (tropical rain forests and tropical seasonal forests, tropical cloud forests, mangrove, fir forests, several oak forests, and several shrublands), and the remaining 10% fall into fire-influenced (such as several gallery forests) and fire-independent categories (shrublands in most xeric environments, very high-altitude prairies). I also present an analysis of current fire-management trends, highlighting the trend toward integral fire management, which merges prevention and control, community-based fire management, and ecological fire management.

  12. Dalhousie Fire

    ERIC Educational Resources Information Center

    Matthews, Fred W.

    1986-01-01

    Describes steps taken by the Weldon Law Library at Dalhousie University in salvaging books damaged in a major fire, including procedures and processes used in packing, sorting, drying, and cleaning the books. The need for a disaster plan for specific libraries is emphasized, and some suggestions are made. (CDD)

  13. 33 CFR 145.10 - Locations and number of fire extinguishers required.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... vicinity of exits, either inside or outside of spaces. machinery spaces Gas-fired boilers B-II (CO2 or dry chemical) 2 required. Gas-fired boilers B-V 1 required. 1 Oil-fired boilers B-II 2 required. Oil-fired boilers B-V 2 required. 1 Internal combustion or gas turbine engines B-II 1 for each engine. 2...

  14. Design and analysis of the federal aviation administration next generation fire test burner

    NASA Astrophysics Data System (ADS)

    Ochs, Robert Ian

    The United States Federal Aviation Administration makes use of threat-based fire test methods for the certification of aircraft cabin materials to enhance the level of safety in the event of an in-flight or post-crash fire on a transport airplane. The global nature of the aviation industry results in these test methods being performed at hundreds of laboratories around the world; in some cases testing identical materials at multiple labs but yielding different results. Maintenance of this standard for an elevated level of safety requires that the test methods be as well defined as possible, necessitating a comprehensive understanding of critical test method parameters. The tests have evolved from simple Bunsen burner material tests to larger, more complicated apparatuses, requiring greater understanding of the device for proper application. The FAA specifies a modified home heating oil burner to simulate the effects of large, intense fires for testing of aircraft seat cushions, cargo compartment liners, power plant components, and thermal acoustic insulation. Recently, the FAA has developed a Next Generation (NexGen) Fire Test burner to replace the original oil burner that has become commercially unavailable. The NexGen burner design is based on the original oil burner but with more precise control of the air and fuel flow rates with the addition of a sonic nozzle and a pressurized fuel system. Knowledge of the fundamental flow properties created by various burner configurations is desired to develop an updated and standardized burner configuration for use around the world for aircraft materials fire testing and airplane certification. To that end, the NexGen fire test burner was analyzed with Particle Image Velocimetry (PIV) to resolve the non-reacting exit flow field and determine the influence of the configuration of burner components. The correlation between the measured flow fields and the standard burner performance metrics of flame temperature and

  15. Forest fire scenario and challenges of mitigation during fire season in North East India

    NASA Astrophysics Data System (ADS)

    Chakraborty, K.; Mondal, P. P.; Chabukdhara, M.; Sudhakar, S.

    2014-11-01

    Forest fires are a major environmental problem in North East Region (NER) with large tracts of forest areas being affected in every season. Forest fires have become a major threat to the forest ecosystems in the region, leading to loss of timber, biodiversity, wildlife habitat and loss to other natural resources. Studies on forest fire have reported that about 50% of forest fire in the country takes place in NE region. The forest fire in NER is anthropogenic in nature. The forest fire hazard map generated based on appropriate weightage given to the factors affecting fire behavior like topography, fuel characteristic and proximity to roads, settlements and also historical fire locations helped to demarcate the fire prone zones. Whereas, during fire season the weather pattern also governs the fire spread in the given area. Therefore, various data on fuel characteristics (land use/land cover, forest type map, forest density map), topography (DEM, slope, aspect) proximity to settlement, road, waterbodies, meteorological data from AWS on wind speed, wind direction, dew point have been used for each fire point to rank its possible hazard level. Near real time fire location data obtained from MODIS/FIRMSwere used to generate the fire alerts. This work demonstrates dissemination of information in the form of maps and tables containing information of latitude and longitude of fire location, fire occurrence date, state and district name, LULC, road connectivity, slope and aspect, settlements/water bodies and meteorological data and the corresponding rating of possibility of fire spread to the respective fire control authorities during fire season.

  16. Fire Detection Organizing Questions

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Verified models of fire precursor transport in low and partial gravity: a. Development of models for large-scale transport in reduced gravity. b. Validated CFD simulations of transport of fire precursors. c. Evaluation of the effect of scale on transport and reduced gravity fires. Advanced fire detection system for gaseous and particulate pre-fire and fire signaturesa: a. Quantification of pre-fire pyrolysis products in microgravity. b. Suite of gas and particulate sensors. c. Reduced gravity evaluation of candidate detector technologies. d. Reduced gravity verification of advanced fire detection system. e. Validated database of fire and pre-fire signatures in low and partial gravity.

  17. Fire flame detection based on GICA and target tracking

    NASA Astrophysics Data System (ADS)

    Rong, Jianzhong; Zhou, Dechuang; Yao, Wei; Gao, Wei; Chen, Juan; Wang, Jian

    2013-04-01

    To improve the video fire detection rate, a robust fire detection algorithm based on the color, motion and pattern characteristics of fire targets was proposed, which proved a satisfactory fire detection rate for different fire scenes. In this fire detection algorithm: (a) a rule-based generic color model was developed based on analysis on a large quantity of flame pixels; (b) from the traditional GICA (Geometrical Independent Component Analysis) model, a Cumulative Geometrical Independent Component Analysis (C-GICA) model was developed for motion detection without static background and (c) a BP neural network fire recognition model based on multi-features of the fire pattern was developed. Fire detection tests on benchmark fire video clips of different scenes have shown the robustness, accuracy and fast-response of the algorithm.

  18. Investigation of the Potential for Biofuel Blends in Residual Oil-Fired Power Generation Units as an Emissions Reduction Strategy for New York State

    SciTech Connect

    Krishna, C.R.; McDonald, R.

    2009-05-01

    There is a significant amount of oil, about 12.6 million barrels per year, used for power generation in New York State. The majority of it is residual oil. The primary reason for using residual oil probably is economic, as these fuels are cheaper than distillates. However, the stack emissions from the use of such fuels, especially in densely populated urban areas, can be a cause for concern. The emissions of concern include sulfur and nitrogen oxides and particulates, particularly PM 2.5. Blending with distillate (ASTM No.2) fuels may not reduce some or all of these emissions. Hence, a case can be made for blending with biofuels, such as biodiesel, as they tend to have very little fuel bound sulfur and nitrogen and have been shown in prior work at Brookhaven National Laboratory (BNL) to reduce NOx emissions as well in small boilers. Some of the research carried out at CANMET in Canada has shown potential reductions in PM with blending of biodiesel in distillate oil. There is also the benefit obtaining from the renewable nature of biofuels in reducing the net carbon dioxide emitted thus contributing to the reduction of green house gases that would otherwise be emitted to the atmosphere. The present project was conceived to examine the potential for such benefits of blending biofuels with residual oil. A collaboration was developed with personnel at the New York City Poletti Power Plant of the New York Power Authority. Their interest arose from an 800 MW power plant that was using residual oil and which was mandated to be shut down in 2010 because of environmental concerns. A blend of 20% biodiesel in residual oil had also been tested for a short period of about two days in that boiler a couple of years back. In this project, emission measurements including particulate measurements of PM2.5 were made in the commercial boiler test facility at BNL described below. Baseline tests were done using biodiesel as the blending biofuel. Biodiesel is currently and probably in

  19. 29 CFR 1926.150 - Fire protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... firefighting equipment—(1) Fire extinguishers and small hose lines. (i) A fire extinguisher, rated not less... extinguisher having a 2A rating. (iii) A 1/2-inch diameter garden-type hose line, not to exceed 100 feet in... capable of discharging a minimum of 5 gallons per minute with a minimum hose stream range of 30...

  20. Dispersants have limited effects on exposure rates of oil spills on fish eggs and larvae in shelf seas.

    PubMed

    Vikebø, Frode B; Rønningen, Petter; Meier, Sonnich; Grøsvik, Bjørn Einar; Lien, Vidar S

    2015-05-19

    Early life stages of fish are particularly vulnerable to oil spills. Simulations of overlap of fish eggs and larvae with oil from different oil-spill scenarios, both without and with the dispersant Corexit 9500, enable quantitative comparisons of dispersants as a mitigation alternative. We have used model simulations of a blow out of 4500 m(3) of crude oil per day (Statfjord light crude) for 30 days at three locations along the Norwegian coast. Eggs were released from nine different known spawning grounds, in the period from March 1st until the end of April, and all spawning products were followed for 90 days from the spill start at April first independent of time for spawning. We have modeled overlap between spawning products and oil concentrations giving a total polycyclic hydrocarbon (TPAH) concentration of more than 1.0 or 0.1 ppb (μg/l). At these orders of magnitude, we expect acute mortality or sublethal effects, respectively. In general, adding dispersants results in higher concentrations of TPAHs in a reduced volume of water compared to not adding dispersants. Also, the TPAHs are displaced deeper in the water column. Model simulations of the spill scenarios showed that addition of chemical dispersant in general moderately decreased the fraction of eggs and larvae that were exposed above the selected threshold values. PMID:25875213

  1. Dispersants have limited effects on exposure rates of oil spills on fish eggs and larvae in shelf seas.

    PubMed

    Vikebø, Frode B; Rønningen, Petter; Meier, Sonnich; Grøsvik, Bjørn Einar; Lien, Vidar S

    2015-05-19

    Early life stages of fish are particularly vulnerable to oil spills. Simulations of overlap of fish eggs and larvae with oil from different oil-spill scenarios, both without and with the dispersant Corexit 9500, enable quantitative comparisons of dispersants as a mitigation alternative. We have used model simulations of a blow out of 4500 m(3) of crude oil per day (Statfjord light crude) for 30 days at three locations along the Norwegian coast. Eggs were released from nine different known spawning grounds, in the period from March 1st until the end of April, and all spawning products were followed for 90 days from the spill start at April first independent of time for spawning. We have modeled overlap between spawning products and oil concentrations giving a total polycyclic hydrocarbon (TPAH) concentration of more than 1.0 or 0.1 ppb (μg/l). At these orders of magnitude, we expect acute mortality or sublethal effects, respectively. In general, adding dispersants results in higher concentrations of TPAHs in a reduced volume of water compared to not adding dispersants. Also, the TPAHs are displaced deeper in the water column. Model simulations of the spill scenarios showed that addition of chemical dispersant in general moderately decreased the fraction of eggs and larvae that were exposed above the selected threshold values.

  2. Zaca Fire

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On August 7, 2007, the Zaca fire continued to burn in the Los Padres National Forest near Santa Barbara, California. The fire started more than a month ago, on July 4, and has burned 69,800 acres. The fire remains in steep, rocky terrain with poor access. The continued poor access makes containment difficult in the wilderness area on the eastern flank. So far only one outbuilding has been destroyed; but over 450 homes are currently threatened. Over 2300 fire personnel, aided by four air tankers and 15 helicopters, are working to contain this massive fire. Full containment is expected on September 1.

    The image covers 45.2 x 46.1 km, and is centered near 34.6 degrees north latitude, 119.7 degrees west longitude.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra spacecraft. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission

  3. Estimation of spreading fire geometrical characteristics using near infrared stereovision

    NASA Astrophysics Data System (ADS)

    Rossi, L.; Toulouse, T.; Akhloufi, M.; Pieri, A.; Tison, Y.

    2013-03-01

    In fire research and forest firefighting, there is a need of robust metrological systems able to estimate the geometrical characteristics of outdoor spreading fires. In recent years, we assist to an increased interest in wildfire research to develop non destructive techniques based on computer vision. This paper presents a new approach for the estimation of fire geometrical characteristics using near infrared stereovision. Spreading fire information like position, rate of spread, height and surface, are estimated from the computed 3D fire points. The proposed system permits to track fire spreading on a ground area of 5mx10m. Keywords: near infrared, stereovision, spreading fire, geometrical characteristics

  4. The enrichment of natural radionuclides in oil shale-fired power plants in Estonia--the impact of new circulating fluidized bed technology.

    PubMed

    Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

    2014-03-01

    Burning oil shale to produce electricity has a dominant position in Estonia's energy sector. Around 90% of the overall electric energy production originates from the Narva Power Plants. The technology in use has been significantly renovated - two older types of pulverized fuel burning (PF) energy production units were replaced with new circulating fluidized bed (CFB) technology. Additional filter systems have been added to PF boilers to reduce emissions. Oil shale contains various amounts of natural radionuclides. These radionuclides concentrate and become enriched in different boiler ash fractions. More volatile isotopes will be partially emitted to the atmosphere via flue gases and fly ash. To our knowledge, there has been no previous study for CFB boiler systems on natural radionuclide enrichment and their atmospheric emissions. Ash samples were collected from Eesti Power Plant's CFB boiler. These samples were processed and analyzed with gamma spectrometry. Activity concentrations (Bq/kg) and enrichment factors were calculated for the (238)U ((238)U, (226)Ra, (210)Pb) and (232)Th ((232)Th, (228)Ra) family radionuclides and for (40)K in different CFB boiler ash fractions. Results from the CFB boiler ash sample analysis showed an increase in the activity concentrations and enrichment factors (up to 4.5) from the furnace toward the electrostatic precipitator block. The volatile radionuclide ((210)Pb and (40)K) activity concentrations in CFB boilers were evenly distributed in finer ash fractions. Activity balance calculations showed discrepancies between input (via oil shale) and output (via ash fractions) activities for some radionuclides ((238)U, (226)Ra, (210)Pb). This refers to a situation where the missing part of the activity (around 20% for these radionuclides) is emitted to the atmosphere. Also different behavior patterns were detected for the two Ra isotopes, (226)Ra and (228)Ra. A part of (226)Ra input activity, unlike (228)Ra, was undetectable in the

  5. Construction poses highest power plant fire threat

    SciTech Connect

    Not Available

    1980-03-01

    Power plants are more vulnerable to fire during the construction period than at any other time. Data gathered from fires at plant construction sites show that 65% result from cutting and welding activities and that the Control of combustible materials and work processes is the key factor. Contractors need to cooperate on cleanup and to upgrade the quality of temporary buildings on the site. Among the steps which could reduce fire risks are the early installation of water for fire hydrants and automatic sprinklers, testing of tarpaulins for flame retardency, the use of metal or fire retardant scaffolding and forms, approved temporary heating equipment, flushing turbine oil systems before startup, and the use of non-flammable water pipe tubing. Seven safety rules are outlined for welding and cutting procedures. (DCK)

  6. Material Analysis for a Fire Assessment.

    SciTech Connect

    Brown, Alexander; Nemer, Martin B.

    2014-08-01

    This report consolidates technical information on several materials and material classes for a fire assessment. The materials include three polymeric materials, wood, and hydraulic oil. The polymers are polystyrene, polyurethane, and melamine- formaldehyde foams. Samples of two of the specific materials were tested for their behavior in a fire - like environment. Test data and the methods used to test the materials are presented. Much of the remaining data are taken from a literature survey. This report serves as a reference source of properties necessary to predict the behavior of these materials in a fire.

  7. Fire suppressing apparatus. [sodium fires

    DOEpatents

    Buttrey, K.E.

    1980-12-19

    Apparatus for smothering a liquid sodium fire comprises a pan, a perforated cover on the pan, and tubed depending from the cover and providing communication between the interior of the pan and the ambient atmosphere through the perforations in the cover. Liquid caught in the pan rises above the lower ends of the tubes and thus serves as a barrier which limits the amount of air entering the pan.

  8. A fishery-dependent based study of fish species composition and associated catch rates around oil and gas structures off Louisiana

    SciTech Connect

    Stanley, D.R.; Wilson, C.A. )

    1990-01-01

    The impact of oil and gas development on fish populations off Louisiana is presumed significant but poorly understood. This study was undertaken to determine the applicability of a logbook program in developing a long-term database of species composition and relative abundance of fish associated with oil and gas structures. A pilot logbook program involving 120 private vessel owners and 25 charterboat operators was conducted between March 1987 and December 1988. Participants recorded date, fishing time, fishing method, number of anglers, and catch composition at each structure fished. Logbooks from a total of 55 private vessel owners and 10 charterboat operators were used in the analysis. Data collected included 15,780 angler hours of fishing effort and 61,227 fish caught over the study period. A total of 1,719 trips were made to 589 different oil and gas structures with at least 46 different species of fish caught. Red snapper and spotted seatrout were the most commonly caught species and had the highest catch rates. Results differed from past logbook programs and creel surveys, possibly indicating a change in the community of fish associated with oil and gas structures.

  9. FIRE ALARM SYSTEM OUTDATED.

    ERIC Educational Resources Information Center

    CHANDLER, L.T.

    AN EFFICIENT FIRE ALARM SYSTEM SHOULD--(1) PROVIDE WARNING OF FIRES THAT START IN HIDDEN OR UNOCCUPIED LOCATIONS, (2) INDICATE WHERE THE FIRE IS, (3) GIVE ADVANCE WARNING TO FACULTY AND ADMINISTRATION SO THAT PANIC AND CONFUSION CAN BE AVOIDED AND ORDERLY EVACUATION OCCUR, (4) AUTOMATICALLY NOTIFY CITY FIRE HEADQUARTERS OF THE FIRE, (5) OPERATE BY…

  10. Fire Safety Training Handbook.

    ERIC Educational Resources Information Center

    Montgomery County Dept. of Fire and Rescue Services, Rockville, MD. Div. of Fire Prevention.

    Designed for a community fire education effort, particularly in which local volunteers present general information on fire safety to their fellow citizens, this workbook contains nine lessons. Included are an overview of the household fire problem; instruction in basic chemistry and physics of fire, flammable liquids, portable fire extinguishers,…

  11. Fire Protection for Buildings

    ERIC Educational Resources Information Center

    Edmunds, Jane

    1972-01-01

    Reviews attack on fire safety in high rise buildings made by a group of experts representing the iron and steel industry at a recent conference. According to one expert, fire problems are people oriented, which calls for emphasis on fire prevention rather than reliance on fire suppression and for fire pretection to be built into a structure.…

  12. Evaluation of the fire simulation processes of the National Fire Management System's Initial Attack Analysis processor.

    PubMed

    Dimitrakopoulos, A P; Omi, P N

    2003-01-01

    The fire simulation processes of the National Fire Management System's (NFMAS) Initial Attack Analysis (IAA) processor were evaluated by conducting two types of sensitivity analysis: one based on a hypothetical set of data to assess IAA's outputs under a wide range of fire input values, and the other using an actual Stanislaus National Forest database to test IAA's validity with a real set of data. The results revealed that IAA's outputs (projected annual number of fires and area burned) were most sensitive, in descending order, to the input values of the fire spread rate, the productivity rates of the suppression forces, and the initial attack time, for all fuel models tested. In contrast, IAA's outputs were extremely insensitive to variations in the fire size at discovery. Changes are necessary in the ways IAA incorporates the fire size at discovery to facilitate the comparison among various fire detection options. The program's "escaped fire situation" analysis was found inadequate, because the projected annual frequencies and final sizes of the simulated escaped fire events produced unacceptable results with the Stanislaus National Forest database. Assigning final sizes to simulated escaped fires according to the fire intensity level in which they are historically expected to occur provides a consistent way of calculation of the projected annual area burned and the consequent cost plus net value change (C + NVC).

  13. Future fire emissions associated with projected land use change in Indonesia

    NASA Astrophysics Data System (ADS)

    Marlier, M. E.; DeFries, R. S.; Pennington, D.; Ordway, E.; Nelson, E.; Mickley, L.; Koplitz, S.

    2013-12-01

    Indonesia has experienced rapid land use change in past decades as forests and peatlands are cleared for agricultural development, including oil palm and timber plantations1. Fires are the predominant method of clearing and the subsequent emissions can have important public health impacts by contributing to regional particulate matter and ozone concentrations2. This regional haze was dramatically seen in Singapore during June 2013 due to the transport of emissions from fires in Sumatra. Our study is part of a larger project that will quantify the public health impact of various land use development scenarios for Sumatra over the coming decades. Here, we describe how we translate economic projections of land use change into future fire emissions inventories for GEOS-Chem atmospheric transport simulations. We relate past GFED3 fire emissions3 to detailed 1-km land use change data and MODIS fire radiative power observations, and apply these relationships to future estimates of land use change. The goal of this interdisciplinary project is to use modeling results to interact with policy makers and influence development strategies in ways that protect public health. 1Miettinen et al. 2011. Deforestation rates in insular Southeast Asia between 2000 and 2010. Glob. Change Biol.,17 (7), 2261-2270. 2Marlier et al. 2013. El Niño and health risks from landscape fire emissions in southeast Asia. Nature Clim. Change, 3, 131-136. 3van der Werf et al. 2010. Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997-2009). Atmos. Chem. Physics, 10 (23), 11707-11735.

  14. In Situ Burning of Oil Spills

    PubMed Central

    Evans, David D.; Mulholland, George W.; Baum, Howard R.; Walton, William D.; McGrattan, Kevin B.

    2001-01-01

    For more than a decade NIST conducted research to understand, measure and predict the important features of burning oil on water. Results of that research have been included in nationally recognized guidelines for approval of intentional burning. NIST measurements and predictions have played a major role in establishing in situ burning as a primary oil spill response method. Data are given for pool fire burning rates, smoke yield, smoke particulate size distribution, smoke aging, and polycyclic aromatic hydrocarbon content of the smoke for crude and fuel oil fires with effective diameters up to 17.2 m. New user-friendly software, ALOFT, was developed to quantify the large-scale features and trajectory of wind blown smoke plumes in the atmosphere and estimate the ground level smoke particulate concentrations. Predictions using the model were tested successfully against data from large-scale tests. ALOFT software is being used by oil spill response teams to help assess the potential impact of intentional burning. PMID:27500022

  15. In Situ Burning of Oil Spills.

    PubMed

    Evans, D D; Mulholland, G W; Baum, H R; Walton, W D; McGrattan, K B

    2001-01-01

    For more than a decade NIST conducted research to understand, measure and predict the important features of burning oil on water. Results of that research have been included in nationally recognized guidelines for approval of intentional burning. NIST measurements and predictions have played a major role in establishing in situ burning as a primary oil spill response method. Data are given for pool fire burning rates, smoke yield, smoke particulate size distribution, smoke aging, and polycyclic aromatic hydrocarbon content of the smoke for crude and fuel oil fires with effective diameters up to 17.2 m. New user-friendly software, ALOFT, was developed to quantify the large-scale features and trajectory of wind blown smoke plumes in the atmosphere and estimate the ground level smoke particulate concentrations. Predictions using the model were tested successfully against data from large-scale tests. ALOFT software is being used by oil spill response teams to help assess the potential impact of intentional burning. PMID:27500022

  16. 14 CFR 29.1203 - Fire detector systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... than 900 cubic inches displacement, there must be approved, quick-acting fire detectors in designated... affected by any oil, water, other fluids, or fumes that might be present. (d) There must be means to...

  17. 14 CFR 29.1203 - Fire detector systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... than 900 cubic inches displacement, there must be approved, quick-acting fire detectors in designated... affected by any oil, water, other fluids, or fumes that might be present. (d) There must be means to...

  18. Comparison of the Hazard Mapping System (HMS) fire product to ground-based fire records in Georgia, USA

    NASA Astrophysics Data System (ADS)

    Hu, Xuefei; Yu, Chao; Tian, Di; Ruminski, Mark; Robertson, Kevin; Waller, Lance A.; Liu, Yang

    2016-03-01

    Biomass burning has a significant and adverse impact on air quality, climate change, and various ecosystems. The Hazard Mapping System (HMS) detects fires using data from multiple satellite sensors in order to maximize its fire detection rate. However, to date, the detection rate of the HMS fire product for small fires has not been well studied, especially using ground-based fire records. This paper utilizes the 2011 fire information compiled from ground observations and burn authorizations in Georgia to assess the comprehensiveness of the HMS active fire product. The results show that detection rates of the hybrid HMS increase substantially by integrating multiple satellite instruments. The detection rate increases dramatically from 3% to 80% with an increase in fire size from less than 0.02 km2 to larger than 2 km2, resulting in detection of approximately 12% of all recorded fires which represent approximately 57% of the total area burned. The spatial pattern of detection rates reveals that grid cells with high detection rates are generally located in areas where large fires occur frequently. The seasonal analysis shows that overall detection rates in winter and spring (12% and 13%, respectively) are higher than those in summer and fall (3% and 6%, respectively), mainly because of higher percentages of large fires (>0.19 km2) that occurred in winter and spring. The land cover analysis shows that detection rates are 2-7 percentage points higher in land cover types that are prone to large fires such as forestland and shrub land.

  19. Keynote address: Reinventing fire: Physics + markets = energy solutions

    SciTech Connect

    Lovins, Amory B.

    2015-03-30

    Rocky Mountain Institute's multi-year, 61-author, peer-reviewed Reinventing Fire synthesis showed how the U.S. can realistically run a 2.6× bigger U.S. economy in 2050 with no oil, coal, or nuclear energy, one-third less natural gas, tripled efficiency, and 74% renewable supplies (80% for electricity). This transition, at historically reasonable rates, could be led by business for profit, applying normal rates of return, with some innovative subnational and administrative policies but no Acts of Congress. Excluding carbon emissions and all other externalities, the net present value would be $5 trillion more favorable than business-as-usual, averaging a 14% Internal Rate of Return.

  20. Keynote address: Reinventing fire: Physics + markets = energy solutions

    NASA Astrophysics Data System (ADS)

    Lovins, Amory B.

    2015-03-01

    Rocky Mountain Institute's multi-year, 61-author, peer-reviewed Reinventing Fire synthesis showed how the U.S. can realistically run a 2.6× bigger U.S. economy in 2050 with no oil, coal, or nuclear energy, one-third less natural gas, tripled efficiency, and 74% renewable supplies (80% for electricity). This transition, at historically reasonable rates, could be led by business for profit, applying normal rates of return, with some innovative subnational and administrative policies but no Acts of Congress. Excluding carbon emissions and all other externalities, the net present value would be 5 trillion more favorable than business-as-usual, averaging a 14% Internal Rate of Return.