Science.gov

Sample records for aerial pyrotechnic flare

  1. Optically thick line widths in pyrotechnic flares

    NASA Technical Reports Server (NTRS)

    Douda, B. E.; Exton, R. J.

    1975-01-01

    Experimentally determined sodium line widths for pyrotechnic flares are compared with simple analytical, optically-thick-line-shape calculations. Three ambient pressure levels are considered (760, 150 and 30 torr) for three different flare compositions. The measured line widths range from 1.3 to 481 A. The analytic procedure emphasizes the Lorentz line shape as observed under optically-thick conditions. Calculated widths are in good agreement with the measured values over the entire range.

  2. Unusual pattern of injury caused by a pyrotechnic hand held signal flare.

    PubMed

    Oliver, D W; Ragbir, M; Saxby, P J

    1997-07-01

    The case is reported of a man shot with a distress flare from a range of about 3 m. The flare caused a large cavity deep in the pectoral muscles. There should be a high index of suspicion about the extent of the injury in all types of penetrating trauma. PMID:9248919

  3. Unusual pattern of injury caused by a pyrotechnic hand held signal flare.

    PubMed Central

    Oliver, D W; Ragbir, M; Saxby, P J

    1997-01-01

    The case is reported of a man shot with a distress flare from a range of about 3 m. The flare caused a large cavity deep in the pectoral muscles. There should be a high index of suspicion about the extent of the injury in all types of penetrating trauma. Images Figure 1 Figure 2 Figure 3 PMID:9248919

  4. Piezoelectrically Initiated Pyrotechnic Igniter

    NASA Technical Reports Server (NTRS)

    Quince, Asia; Dutton, Maureen; Hicks, Robert; Burnham, Karen

    2013-01-01

    This innovation consists of a pyrotechnic initiator and piezoelectric initiation system. The device will be capable of being initiated mechanically; resisting initiation by EMF, RF, and EMI (electromagnetic field, radio frequency, and electromagnetic interference, respectively); and initiating in water environments and space environments. Current devices of this nature are initiated by the mechanical action of a firing pin against a primer. Primers historically are prone to failure. These failures are commonly known as misfires or hang-fires. In many cases, the primer shows the dent where the firing pin struck the primer, but the primer failed to fire. In devices such as "T" handles, which are commonly used to initiate the blowout of canopies, loss of function of the device may result in loss of crew. In devices such as flares or smoke generators, failure can result in failure to spot a downed pilot. The piezoelectrically initiated ignition system consists of a pyrotechnic device that plugs into a mechanical system (activator), which on activation, generates a high-voltage spark. The activator, when released, will strike a stack of electrically linked piezo crystals, generating a high-voltage, low-amperage current that is then conducted to the pyro-initiator. Within the initiator, an electrode releases a spark that passes through a pyrotechnic first-fire mixture, causing it to combust. The combustion of the first-fire initiates a primary pyrotechnic or explosive powder. If used in a "T" handle, the primary would ramp the speed of burn up to the speed of sound, generating a shock wave that would cause a high explosive to go "high order." In a flare or smoke generator, the secondary would produce the heat necessary to ignite the pyrotechnic mixture. The piezo activator subsystem is redundant in that a second stack of crystals would be struck at the same time with the same activation force, doubling the probability of a first strike spark generation. If the first

  5. Pyrotechnic filled molding powder

    DOEpatents

    Hartzel, Lawrence W.; Kettling, George E.

    1978-01-01

    The disclosure relates to thermosetting molding compounds and more particularly to a pyrotechnic filled thermosetting compound comprising a blend of unfilled diallyl phthalate molding powder and a pyrotechnic mixture.

  6. Pyrotechnic device technology

    SciTech Connect

    Wilcox, P.D.

    1989-01-01

    This talk was given at the 14th International Pyrotechnic Seminar on September 21, 1989, in Jersey, United Kingdom, as one of two plenary lectures. It briefly surveys the current technology of pyrotechnic devices and examines trends for the future. The pyrotechnic'' can have several meanings. In this talk, pyrotechnic devices'' are devices in which porous materials undergo reduction-oxidation reactions and produce useful products. The pyrotechnic materials are generally fuel-oxidizer systems without binders, in contrast to primary or secondary explosives or propellants. The word pyrotechnic'' is often used to include explosive, squib, propellant, or other ordnance type devices, especially in the European community. The major need for pyrotechnic devices has always been military and defense; however, as technology advances, the civilian uses of pyrotechnics will continue to grow. If every automobile had a pyrotechnic device to trigger its air or crash bag, that application alone would mean millions of devices per year. Applications in safety, fire fighting, law enforcement, and other commercial applications are likely to increase due to the increased capability of pyrotechnic devices and the integration of such devices in system designs. 2 refs., 56 figs.

  7. Low-Shock Pyrotechnic Actuator

    NASA Technical Reports Server (NTRS)

    Lucy, M. H.

    1984-01-01

    Miniature 1-ampere, 1-watt pyrotechnic actuator enclosed in flexible metal bellows. Bellows confines outgassing products, and pyrotechnic shock reduction achieved by action of bellows, gas cushion within device, and minimum use of pyrotechnic material. Actuator inexpensive, compact, and lightweight.

  8. Ultimately Reliable Pyrotechnic Systems

    NASA Technical Reports Server (NTRS)

    Scott, John H.; Hinkel, Todd

    2015-01-01

    This paper presents the methods by which NASA has designed, built, tested, and certified pyrotechnic devices for high reliability operation in extreme environments and illustrates the potential applications in the oil and gas industry. NASA's extremely successful application of pyrotechnics is built upon documented procedures and test methods that have been maintained and developed since the Apollo Program. Standards are managed and rigorously enforced for performance margins, redundancy, lot sampling, and personnel safety. The pyrotechnics utilized in spacecraft include such devices as small initiators and detonators with the power of a shotgun shell, detonating cord systems for explosive energy transfer across many feet, precision linear shaped charges for breaking structural membranes, and booster charges to actuate valves and pistons. NASA's pyrotechnics program is one of the more successful in the history of Human Spaceflight. No pyrotechnic device developed in accordance with NASA's Human Spaceflight standards has ever failed in flight use. NASA's pyrotechnic initiators work reliably in temperatures as low as -420 F. Each of the 135 Space Shuttle flights fired 102 of these initiators, some setting off multiple pyrotechnic devices, with never a failure. The recent landing on Mars of the Opportunity rover fired 174 of NASA's pyrotechnic initiators to complete the famous '7 minutes of terror.' Even after traveling through extreme radiation and thermal environments on the way to Mars, every one of them worked. These initiators have fired on the surface of Titan. NASA's design controls, procedures, and processes produce the most reliable pyrotechnics in the world. Application of pyrotechnics designed and procured in this manner could enable the energy industry's emergency equipment, such as shutoff valves and deep-sea blowout preventers, to be left in place for years in extreme environments and still be relied upon to function when needed, thus greatly enhancing

  9. Do pyrotechnics contain radium?

    NASA Astrophysics Data System (ADS)

    Steinhauser, Georg; Musilek, Andreas

    2009-07-01

    Many pyrotechnic devices contain barium nitrate which is used as an oxidizer and colouring agent primarily for green-coloured fireworks. Similarly, strontium nitrate is used for red-coloured pyrotechnic effects. Due to their chemical similarities to radium, barium and strontium ores can accumulate radium, causing a remarkable activity in these minerals. Radium in such contaminated raw materials can be processed together with the barium or strontium, unless extensive purification of the ores was undertaken. For example, the utilization of 'radiobarite' for the production of pyrotechnic ingredients can therefore cause atmospheric pollution with radium aerosols when the firework is displayed, resulting in negative health effects upon inhalation of these aerosols. In this study, we investigated the occurrence of gamma-photon-emitting radionuclides in several pyrotechnic devices. The highest specific activities were due to K-40 (up to 20 Bq g-1, average value 14 Bq g-1). Radium-226 activities were in the range of 16-260 mBq g-1 (average value 81 mBq g-1). Since no uranium was found in any of the samples, indeed, a slight enrichment of Ra-226 in coloured pyrotechnics can be observed. Radioactive impurities stemming from the Th-232 decay chain were found in many samples as well. In the course of novel developments aiming at the 'greening' of pyrotechnics, the potential radioactive hazard should be considered as well.

  10. "Green" pyrotechnics: a chemists' challenge.

    PubMed

    Steinhauser, Georg; Klapötke, Thomas M

    2008-01-01

    Fireworks are probably the application of chemistry which resonates best with the general public. However, fireworks and (civil and military) pyrotechnic applications cause environmental pollution and thus have given rise to the development of new, environmentally friendly pyrotechnic compounds and formulations. Nitrogen-rich energetic materials, such as the derivatives of tetrazoles and tetrazines, are about to revolutionize traditional pyrotechnic compositions. This Review summarizes the sources of pollution in current formulations and recent efforts toward "green" pyrotechnics. PMID:18311738

  11. Pyrotechnic Tubing Connector

    NASA Technical Reports Server (NTRS)

    Graves, Thomas J.; Yang, Robert A.

    1988-01-01

    Tool forms mechanical seal at joint without levers or hydraulic apparatus. Proposed tool intended for use in outer space used on Earth by heavily garbed workers to join tubing in difficult environments. Called Pyrotool, used with Lokring (or equivalent) fittings. Piston slides in cylinder when pushed by gas from detonating pyrotechnic charge. Impulse of piston compresses fittings, sealing around butting ends of tubes.

  12. Space shuttles: A pyrotechnic overview

    NASA Technical Reports Server (NTRS)

    Graves, T. J.

    1980-01-01

    Pyrotechnic components specified in Shuttle system designs to accomplish varied tasks during all mission phases are described. The function of these pyrotechnics in the operation of the space shuttle vehicle is discussed. Designs are presented for pyrotechnics with innovative features of those meeting unique shuttle requirements for safety and reliability. A rationale for the qualification and certification of these devices is developed. Maintenance of this qualified system in production hardware is explained through a description of shuttle flight certification review process.

  13. NASA pyrotechnically actuated systems program

    NASA Technical Reports Server (NTRS)

    Schulze, Norman R.

    1993-01-01

    The Office of Safety and Mission Quality initiated a Pyrotechnically Actuated Systems (PAS) Program in FY-92 to address problems experienced with pyrotechnically actuated systems and devices used both on the ground and in flight. The PAS Program will provide the technical basis for NASA's projects to incorporate new technological developments in operational systems. The program will accomplish that objective by developing/testing current and new hardware designs for flight applications and by providing a pyrotechnic data base. This marks the first applied pyrotechnic technology program funded by NASA to address pyrotechnic issues. The PAS Program has been structured to address the results of a survey of pyrotechnic device and system problems with the goal of alleviating or minimizing their risks. Major program initiatives include the development of a Laser Initiated Ordnance System, a pyrotechnic systems data base, NASA Standard Initiator model, a NASA Standard Linear Separation System and a NASA Standard Gas Generator. The PAS Program sponsors annual aerospace pyrotechnic systems workshops.

  14. Integration of pyrotechnics into aerospace systems

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1993-01-01

    The application of pyrotechnics to aerospace systems has been resisted because normal engineering methods cannot be used in design and evaluation. Commonly used approaches for energy sources, such as electrical, hydraulic and pneumatic, do not apply to explosive and pyrotechnic devices. This paper introduces the unique characteristics of pyrotechnic devices, describes how functional evaluations can be conducted, and demonstrates an engineering approach for pyrotechnic integration. Logic is presented that allows evaluation of two basic types of pyrotechnic systems to demonstrate functional margin.

  15. Effects Of Pyrotechnically Generated Shocks

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Evans, Maria J.; Neubert, Vernon H.

    1989-01-01

    Research program provides better understanding of pyrotechnic phenomenon for design purposes. Evaluating potential for damage to spacecraft by activation of pyrotechnic mechanisms, pyrotechnic-shock tests conducted on three configurations: pin pullers on orthogonal double Hopkinson bar arrangement; pin pullers on mockup of Halogen Occultation Experiment (HALOE) structure; and section of separation joint on single Hopkinson bar. Strains and accelerations measured. Strains converted to output stresses, forces, and moments. Acceleration shock-response spectra obtained for both acceleration and force signals. Results of research useful to designers in making comparison and evaluation tests before committing to costly spacecraft hardware.

  16. Determination of pyrotechnic functional margin

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1993-01-01

    Following the failure of a previously qualified pyrotechnically actuated pin puller design, an investigation led to a redesign and requalification. The emphasis of the second qualification was placed on determining the functional margin of the pin puller by comparing the energy deliverable by the pyrotechnic cartridge to the energy required to accomplish the function. Also determined were the effects of functional variables. This paper describes the failure investigation, the test methods employed and the results of the evaluation, and provides a recommended approach to assure the successful functioning of pyrotechnic devices.

  17. Determination of pyrotechnic functional margin

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1992-01-01

    Following the failure of a previously qualified pyrotechnically actuated pin puller design, an investigation led to a redesign and requalification. The emphasis of the second qualification was placed on determining the functional margin of the pin puller by comparing the energy deliverable by the pyrotechnic cartridge to the energy required to accomplish the function. Also determined were the effects of functional variables. This paper describes the failure investigation, the test methods employed and the results of the evaluation, and provides a recommended approach to assure the successful functioning of pyrotechnic devices.

  18. Hazard-Free Pyrotechnic Simulator

    NASA Technical Reports Server (NTRS)

    Mcalister, William B., Jr.

    1988-01-01

    Simulator evaluates performance of firing circuits for electroexplosive devices (EED's) safely and inexpensively. Tests circuits realistically when pyrotechnic squibs not connected and eliminates risks of explosions. Used to test such devices as batteries where test conditions might otherwise degrade them.

  19. 46 CFR 160.066-11 - Approval procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-11 Approval procedures. (a) Red aerial pyrotechnic flare distress signals are approved under...

  20. 46 CFR 160.066-11 - Approval procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-11 Approval procedures. (a) Red aerial pyrotechnic flare distress signals are approved under...

  1. 46 CFR 160.066-11 - Approval procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-11 Approval procedures. (a) Red aerial pyrotechnic flare distress signals are approved under...

  2. 46 CFR 160.066-11 - Approval procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-11 Approval procedures. (a) Red aerial pyrotechnic flare distress signals are approved under...

  3. 46 CFR 160.066-11 - Approval procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-11 Approval procedures. (a) Red aerial pyrotechnic flare distress signals are approved under...

  4. Pyrotechnic reaction residue particle analysis.

    PubMed

    Kosanke, Kenneth L; Dujay, Richard C; Kosanke, Bonnie J

    2006-03-01

    Pyrotechnic reaction residue particle (PRRP) production, sampling and analysis are all very similar to that for primer gunshot residue. In both cases, the preferred method of analysis uses scanning electron microscopy to locate suspect particles and then uses energy dispersive x-ray spectroscopy to characterize the particle's constituent chemical elements. There are relatively few times when standard micro-analytical chemistry performed on pyrotechnic residues may not provide sufficient information for forensic investigators. However, on those occasions, PRRP analysis provides a greatly improved ability to discriminate between materials of pyrotechnic origin and other unrelated substances also present. The greater specificity of PRRP analysis is the result of its analyzing a large number of individual micron-sized particles, rather than producing only a single integrated result such as produced using standard micro-analytical chemistry. For example, PRRP analyses are used to demonstrate its ability to successfully (1) discriminate between pyrotechnic residues and unrelated background contamination, (2) identify that two different pyrotechnic compositions had previously been exploded within the same device, and (3) establish the chronology of an incident involving two separate and closely occurring explosions. PMID:16566762

  5. 16 CFR 1507.5 - Pyrotechnic leakage.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be...

  6. 16 CFR 1507.5 - Pyrotechnic leakage.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be...

  7. 16 CFR 1507.5 - Pyrotechnic leakage.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be...

  8. 16 CFR 1507.5 - Pyrotechnic leakage.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be...

  9. 16 CFR 1507.5 - Pyrotechnic leakage.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be...

  10. Burst-Disk Device Simulates Effect Of Pyrotechnic Device

    NASA Technical Reports Server (NTRS)

    Rogers, James P.; Sexton, James H.

    1995-01-01

    Expendable disks substituted for costly pyrotechnic devices for testing actuators. Burst-disk device produces rush of pressurized gas similar to pyrotechnic device. Designed to reduce cost of testing pyrotechnically driven emergency actuators (parachute-deploying mechanisms in original application).

  11. Equipment limitations in pyrotechnic shock testing

    NASA Astrophysics Data System (ADS)

    Rehard, John W.; Czajkowski, John

    1990-01-01

    Limitations on the equipment used to measure, analyze, and record ordnance-indced pyrotechnic shocks are discussed. The focus is on the four primary components of the data acquisition and analysis system: accelerometers, tape recorders, filters, and analyzers. It is argued that a large percentage of pyrotechnic shock test data that are being generated today are inaccurate in that higher shock levels are indicated than the hardware is actually experiencing. It is suggested that a standard for pyrotechnic shock testing be established.

  12. NASA aerospace pyrotechnically actuated systems: Program plan

    NASA Technical Reports Server (NTRS)

    Schulze, Norman R.

    1992-01-01

    The NASA Aerospace Pyrotechnically Actuated Systems (PAS) Program, a focused technology program, is being initiated to enhance the reliability, safety, and performance of pyrotechnically actuated systems. In broad terms, this Program Plan presents the approach that helps to resolve concerns raised by the NASA/DOD/DOE Aerospace Pyrotechnic Steering Committee. This Plan reflects key efforts needed in PAS technology. The resources committed to implement the Program will be identified in the Program Implementation Plan (PIP). A top level schedule is included along with major Program milestones and products. Responsibilities are defined in the PIP. The Plan identifies the goals and detailed objectives which define how those goals are to be accomplished. The Program will improve NASA's capabilities to design, develop, manufacture, and test pyrotechnically actuated systems for NASA's programs. Program benefits include the following: advanced pyrotechnic systems technology developed for NASA programs; hands-on pyrotechnic systems expertise; quick response capability to investigate and resolve pyrotechnic problems; enhanced communications and intercenter support among the technical staff; and government-industry PAS technical interchange. The PAS Program produces useful products that are of a broad-based technology nature rather than activities intended to meet specific technology objectives for individual programs. Serious problems have occurred with pyrotechnic devices although near perfect performance is demanded by users. The lack of a program to address those problems in the past is considered a serious omission. The nature of problems experienced as revealed by a survey are discussed and the origin of the program is explained.

  13. Update: NASA Pyrotechnically Actuated Systems Program

    NASA Technical Reports Server (NTRS)

    Schulze, Norman R.

    1994-01-01

    This technical report discusses the NASA Pyrotechnically Actuated Systems (PAS) Program. It contains the following three sections: program origin, program description, and summary. The first section, program origin, contains an introduction to pyrotechnic systems and devices and discusses some examples. Section two focuses on the PAS program goals, program flow, and PAS programs organization. And section three gives a overall summary of the program.

  14. Apollo experience report: Spacecraft pyrotechnic systems

    NASA Technical Reports Server (NTRS)

    Falbo, M. J.; Robinson, R. L.

    1973-01-01

    Pyrotechnic devices were used successfully in many systems of the Apollo spacecraft. The physical and functional characteristics of each device are described. The development, qualification, and performance tests of the devices and the ground-support equipment are discussed briefly. Recommendations for pyrotechnic devices on future space vehicles are given.

  15. 46 CFR 160.066-1 - Type.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-1 Type. (a) Red aerial pyrotechnic distress signals specified by this subpart must be either self-contained...

  16. 46 CFR 160.066-1 - Type.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-1 Type. (a) Red aerial pyrotechnic distress signals specified by this subpart must be either self-contained...

  17. 46 CFR 160.066-1 - Type.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-1 Type. (a) Red aerial pyrotechnic distress signals specified by this subpart must be either self-contained...

  18. 46 CFR 160.066-1 - Type.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-1 Type. (a) Red aerial pyrotechnic distress signals specified by this subpart must be either self-contained...

  19. 46 CFR 160.066-1 - Type.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-1 Type. (a) Red aerial pyrotechnic distress signals specified by this subpart must be either self-contained...

  20. 46 CFR 160.066-12 - Operational tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160... the pyrotechnic candle; (2) Color; (3) Whether the pyrotechnic candle burns out above, at, or below... pyrotechnic candle fails to ignite, (3) The pyrotechnic candle continues to burn after it falls back to...

  1. 46 CFR 160.066-12 - Operational tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160... the pyrotechnic candle; (2) Color; (3) Whether the pyrotechnic candle burns out above, at, or below... pyrotechnic candle fails to ignite, (3) The pyrotechnic candle continues to burn after it falls back to...

  2. 46 CFR 160.066-12 - Operational tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160... the pyrotechnic candle; (2) Color; (3) Whether the pyrotechnic candle burns out above, at, or below... pyrotechnic candle fails to ignite, (3) The pyrotechnic candle continues to burn after it falls back to...

  3. 27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles... Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles pyrotechnic. (a) Display fireworks, pyrotechnic compositions, and explosive...

  4. 27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles... Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles pyrotechnic. (a) Display fireworks, pyrotechnic compositions, and explosive...

  5. 27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles... Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles pyrotechnic. (a) Display fireworks, pyrotechnic compositions, and explosive...

  6. 27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles... Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles pyrotechnic. (a) Display fireworks, pyrotechnic compositions, and explosive...

  7. 27 CFR 555.221 - Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles... Requirements for display fireworks, pyrotechnic compositions, and explosive materials used in assembling fireworks or articles pyrotechnic. (a) Display fireworks, pyrotechnic compositions, and explosive...

  8. The First NASA Aerospace Pyrotechnic Systems Workshop

    NASA Technical Reports Server (NTRS)

    St.cyr, William W. (Compiler)

    1993-01-01

    Papers from the conference proceedings are presented, and they are grouped by the following sessions: pyrotechnically actuated systems, laser initiation, and modeling and analysis. A fourth session, a panel discussion and open forum, concluded the workshop.

  9. Flare Hybrids

    NASA Astrophysics Data System (ADS)

    Tomczak, M.; Dubieniecki, P.

    2015-12-01

    On the basis of the Solar Maximum Mission observations, Švestka ( Solar Phys. 121, 399, 1989) introduced a new class of flares, the so-called flare hybrids. When they start, they look like typical compact flares (phase 1), but later on, they look like flares with arcades of magnetic loops (phase 2). We summarize the characteristic features of flare hybrids in soft and hard X-rays as well as in the extreme ultraviolet; these features allow us to distinguish flare hybrids from other flares. In this article, additional energy release or long plasma cooling timescales are suggested as possible causes of phase 2. We estimate the frequency of flare hybrids, and study the magnetic configurations favorable for flare hybrid occurrence. Flare hybrids appear to be quite frequent, and the difference between the lengths of magnetic loops in the two interacting loop systems seem to be a crucial parameter for determining their characteristics.

  10. 3. EAST FACE OF PYROTECHNIC SHED (BLDG. 757); DOORS FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. EAST FACE OF PYROTECHNIC SHED (BLDG. 757); DOORS FOR STORAGE ROOMS. SECURITY FENCE ON RIGHT SIDE OF PHOTOGRAPH. - Vandenberg Air Force Base, Space Launch Complex 3, Pyrotechnic Shed, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  11. 5. PERSONNEL ROOM ON WEST SIDE OF PYROTECHNIC SHED (BLDG. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. PERSONNEL ROOM ON WEST SIDE OF PYROTECHNIC SHED (BLDG. 757) STORAGE LOCKER ON EAST WALL; PADDED TABLE ON SOUTH WALL. - Vandenberg Air Force Base, Space Launch Complex 3, Pyrotechnic Shed, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  12. Explosive and pyrotechnic aging demonstration

    NASA Technical Reports Server (NTRS)

    Rouch, L. L., Jr.; Maycock, J. N.

    1976-01-01

    The survivability was experimentally verified of fine selected explosive and pyrotechnic propellant materials when subjected to sterilization, and prolonged exposure to space environments. This verification included thermal characterization, sterilization heat cycling, sublimation measurements, isothermal decomposition measurements, and accelerated aging at a preselected elevated temperature. Temperatures chosen for sublimation and isothermal decomposition measurements were those in which the decomposition processess occurring would be the same as those taking place in real-time aging. The elevated temperature selected (84 C) for accelerated aging was based upon the parameters calculated from the kinetic data obtained in the isothermal measurement tests and was such that one month of accelerated aging in the laboratory approximated one year of real-time aging at 66 C. Results indicate that HNS-IIA, pure PbN6, KDNBF, and Zr/KC10 are capable of withstanding sterilization. The accelerated aging tests indicated that unsterilized HNS-IIA and Zr/KC104 can withstand the 10 year, elevated temperature exposure, pure PbN6 and KDNBF exhibit small weight losses (less than 2 percent) and B/KC104 exhibits significant changes in its thermal characteristics. Accelerated aging tests after sterilization indicated that only HNS-IIA exhibited high stability.

  13. Investigation of pyrotechnic shock. [for spacecraft structural tests

    NASA Technical Reports Server (NTRS)

    Prescott, S. N.

    1974-01-01

    Review of comparative pyrotechnic shock outputs of various electro-explosive release devices that have been obtained in tests of an instrumented spacecraft structure. This research uses pyrotechnic shock spectra levels as an indicator of shock environment severity in support of a program of pyrotechnic device analysis and redesign intended to reduce shock generation.

  14. 2. SOUTH FACE OF PYROTECHNIC SHED (BLDG. 757) SHOWING SIGN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. SOUTH FACE OF PYROTECHNIC SHED (BLDG. 757) SHOWING SIGN HOLDER ON LEFT AND ENTRANCE TO TEST CELL. METEOROLOGICAL TOWER AND METEOROLOGICAL SHED (BLDG. 756) IN BACKGROUND ON LEFT; SOUTHEAST CORNER OF GPS AZIMUTH STATION (BLDG. 775) IN BACKGROUND BEHIND AND RIGHT OF PYROTECHNIC SHED. - Vandenberg Air Force Base, Space Launch Complex 3, Pyrotechnic Shed, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  15. 46 CFR 169.553 - Pyrotechnic distress signals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Pyrotechnic distress signals. 169.553 Section 169.553... Lifesaving and Firefighting Equipment Additional Lifesaving Equipment § 169.553 Pyrotechnic distress signals. (a) All pyrotechnic distress signals must be of an approved type. (b) Replacement must be made...

  16. 46 CFR 169.553 - Pyrotechnic distress signals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Pyrotechnic distress signals. 169.553 Section 169.553... Lifesaving and Firefighting Equipment Additional Lifesaving Equipment § 169.553 Pyrotechnic distress signals. (a) All pyrotechnic distress signals must be of an approved type. (b) Replacement must be made...

  17. 46 CFR 169.553 - Pyrotechnic distress signals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Pyrotechnic distress signals. 169.553 Section 169.553... Lifesaving and Firefighting Equipment Additional Lifesaving Equipment § 169.553 Pyrotechnic distress signals. (a) All pyrotechnic distress signals must be of an approved type. (b) Replacement must be made...

  18. 46 CFR 169.553 - Pyrotechnic distress signals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Pyrotechnic distress signals. 169.553 Section 169.553... Lifesaving and Firefighting Equipment Additional Lifesaving Equipment § 169.553 Pyrotechnic distress signals. (a) All pyrotechnic distress signals must be of an approved type. (b) Replacement must be made...

  19. 46 CFR 169.553 - Pyrotechnic distress signals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Pyrotechnic distress signals. 169.553 Section 169.553... Lifesaving and Firefighting Equipment Additional Lifesaving Equipment § 169.553 Pyrotechnic distress signals. (a) All pyrotechnic distress signals must be of an approved type. (b) Replacement must be made...

  20. Pyrotechnic hazards classification and evaluation program test report. Heat flux study of deflagrating pyrotechnic munitions

    NASA Technical Reports Server (NTRS)

    Fassnacht, P. O.

    1971-01-01

    A heat flux study of deflagrating pyrotechnic munitions is presented. Three tests were authorized to investigate whether heat flux measurements may be used as effective hazards evaluation criteria to determine safe quantity distances for pyrotechnics. A passive sensor study was conducted simultaneously to investigate their usefulness in recording events and conditions. It was concluded that heat flux measurements can effectively be used to evaluate hazards criteria and that passive sensors are an inexpensive tool to record certain events in the vicinity of deflagrating pyrotechnic stacks.

  1. Solar flares

    NASA Technical Reports Server (NTRS)

    Zirin, H.

    1974-01-01

    A review of the knowledge about solar flares which has been obtained through observations from the earth and from space by various methods. High-resolution cinematography is best carried out at H-alpha wavelengths to reveal the structure, time history, and location of flares. The classification flares in H alpha according to either physical or morphological criteria is discussed. The study of flare morphology, which shows where, when, and how flares occur, is important for evaluating theories of flares. Consideration is given to studies of flares by optical spectroscopy, radio emissions, and at X-ray and XUV wavelengths. Research has shown where and possibly why flares occur, but the physics of the instability involved, of the particle acceleration, and of the heating are still not understood.

  2. Pyrotechnic shock measurement and data analysis requirements

    NASA Technical Reports Server (NTRS)

    Albers, L.

    1975-01-01

    An investigation is described into the laboratory measurement and analysis of pyrotechnic shock which was prompted at JPL when two separate facilities generated discrepant pyrotechnic shock data while testing Mariner Jupiter/Saturn 1977 spacecraft hardware. Both of the testing facilities were surveyed. The only difference noted was in the FM tape recorders used to record the data. One facility used a tape recorder operating at 60 in./sec with a frequency response of 20 kHz; the other used a tape recorder operating at 120 in./sec with a frequency response of 80 kHz. The accelerometers, cables, charge amplifiers, and mechanical setups were identical.

  3. Pyrotechnic hazards classification and evaluation program. Run-up reaction testing in pyrotechnic dust suspensions

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A preliminary investigation of the parameters included in run-up dust reactions is presented. Two types of tests were conducted: (1) ignition criteria of large bulk pyrotechnic dusts, and (2) optimal run-up conditions of large bulk pyrotechnic dusts. These tests were used to evaluate the order of magnitude and gross scale requirements needed to induce run-up reactions in pyrotechnic dusts and to simulate at reduced scale an accident that occurred in a manufacturing installation. Test results showed that propagation of pyrotechnic dust clouds resulted in a fireball of relatively long duration and large size. In addition, a plane wave front was observed to travel down the length of the gallery.

  4. Pyrotechnic system failures: Causes and prevention

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.

    1988-01-01

    Although pyrotechnics have successfully accomplished many critical mechanical spacecraft functions, such as ignition, severance, jettisoning and valving (excluding propulsion), failures continue to occur. Provided is a listing of 84 failures of pyrotechnic hardware with completed design over a 23-year period, compiled informally by experts from every NASA Center, as well as the Air Force Space Division and the Naval Surface Warfare Center. Analyses are presented as to when and where these failures occurred, their technical source or cause, followed by the reasons why and how these kinds of failures persist. The major contributor is a fundamental lack of understanding of the functional mechanisms of pyrotechnic devices and systems, followed by not recognizing pyrotechnics as an engineering technology, insufficient manpower with hands-on experience, too few test facilities, and inadequate guidelines and specifications for design, development, qualification and acceptance. Recommendations are made on both a managerial and technical basis to prevent failures, increase reliability, improve existing and future designs, and develop the technology to meet future requirements.

  5. Advances in laser diodes for pyrotechnic applications

    NASA Technical Reports Server (NTRS)

    Craig, Richard R.

    1993-01-01

    Background information concerning the use of laser diodes in pyrotechnic applications is provided in viewgraph form. The following topics are discussed: damage limits, temperature stability, fiber coupling issues, and small (100 micron) and large (400 micron) fiber results. The discussions concerning fiber results concentrate on the areas of package geometry and electro-optical properties.

  6. Pyrotechnic whistle technology enhancements to law enforcement applications

    NASA Astrophysics Data System (ADS)

    Domanico, Joseph A.; Thomas, Terry E.

    1998-12-01

    In the past several years, there has been increasing interest in acoustic technology for less-than-lethal applications. Pyrotechnic whistles have been under study at the Edgewood Research, Development and engineering Center for several years for similar applications. Improvements in safety and handling, combined with increased levels of acoustic output, make the properly designed pyrotechnic whistle a valuable addition (read augmentation) to some current device designs. Either alone or in combination with other distraction effects, such as multiple concussion, strobing pyrotechnic, or microstarts, the pyrotechnic whistle family of devices provide a high level of target reaction with a minimum of collateral damage. This paper will summarize the recent research and development efforts in pyrotechnic whistle compositions, and the capabilities for the application of pyrotechnic whistles for typical law enforcement applications.

  7. SBASI: Actuated pyrotechnic time delay initiator

    NASA Technical Reports Server (NTRS)

    Salter, S. J.; Lundberg, R. E.; Mcdougal, G. L.

    1975-01-01

    A precision pyrotechnic time delay initiator for missile staging was developed and tested. Incorporated in the assembly is a single bridgewire Apollo standard initiator (SBASI) for initiation, a through-bulkhead-initiator to provide isolation of the SBASI output from the delay, the pyrotechnic delay, and an output charge. An attempt was made to control both primary and secondary variables affecting functional performance of the delay initiator. Design and functional limit exploration was performed to establish tolerance levels on manufacturing and assembling operations. The test results demonstrate a 2% coefficient of variation at any one temperature and an overall 2.7% coefficient of variation throughout the temperature range of 30 to 120 F. Tests were conducted at simulated operational altitude from sea level to 200,000 feet.

  8. Pyrotechnic shock measurement and data analysis requirements

    NASA Technical Reports Server (NTRS)

    Albers, L.

    1975-01-01

    A study of laboratory measurement and analysis of pyrotechnic shock prompted by a discrepancy in preliminary Mariner Jupiter/Saturn shock test data is reported. It is shown that before generating shock response plots from any recorded pyrotechnic event, a complete review of each instrumentation and analysis system must be made. In addition, the frequency response capability of the tape recorder used should be as high as possible; the discrepancies in the above data were due to inadequate frequency response in the FM tape recorders. The slew rate of all conditioning amplifiers and input converters must be high enough to prevent signal distortion at maximum input voltage; amplifier ranges should be selected so that the input pulse is approximately 50% of full scale; the Bessel response type should be chosen for digital shock analysis if antialiasing filters are employed; and transducer selection must consider maximum acceleration limit, mounted resonance frequency, flat clean mounting surfaces, base bending sensitivity, and proper torque.

  9. Ignition of THKP and TKP pyrotechnic powders :

    SciTech Connect

    Maharrey, Sean P.; Erikson, William W; Highley, Aaron M.; Wiese-Smith, Deneille; Kay, Jeffrey J

    2014-03-01

    We have conducted Simultaneous Thermogravimetric Modulated Beam Mass Spectrometry (STMBMS) experiments on igniter/actuator pyrotechnic powders to characterize the reactive processes controlling the ignition and combustion behavior of these materials. The experiments showed a complex, interactive reaction manifold involving over ten reaction pathways. A reduced dimensionality reaction manifold was developed from the detailed 10-step manifold and is being incorporated into existing predictive modeling codes to simulate the performance of pyrotechnic powders for NW component development. The results from development of the detailed reaction manifold and reduced manifold are presented. The reduced reaction manifold has been successfully used by SNL/NM modelers to predict thermal ignition events in small-scale testing, validating our approach and improving the capability of predictive models.

  10. Mechanism of failure of two pyrotechnic components

    SciTech Connect

    Munger, A.C.; Woods, C.M.

    1985-01-01

    An investigation of two unrelated pyrotechnic test device misfires revealed an ignition phenomenon that helps to explain the well-known necessity of maintaining good integrity between bridgewire and powder in hot-wire devices that use insensitive pyrotechnic powders. The factor common to both devices was the TiH/sub 1.65/:KC10/sub 4/ in a 33:67 weight percent ratio. This material is being used because of its high static insensitivity, a characteristic that makes good bridgewire contact mandatory for reliable ignition. Extensive work with a scanning electron microscope revealed that not only does the bridgewire require entrapment, but the initiation reaction gases must be contained within the immediate vicinity of the bridgewire or the initiation will not be sustained. Evidence is presented to document the phenomenon that caused the misfire of both components that were investigated. 9 refs., 17 figs.

  11. Chlorine-Free Red-Burning Pyrotechnics.

    PubMed

    Sabatini, Jesse J; Koch, Ernst-Christian; Poret, Jay C; Moretti, Jared D; Harbol, Seth M

    2015-09-01

    The development of a red, chlorine-free pyrotechnic illuminant of high luminosity and spectral purity was investigated. Red-light emission based solely on transient SrOH(g) has been achieved by using either 5-amino-1H-tetrazole or hexamine to deoxidize the combustion flame of a Mg/Sr(NO3 )2 /Epon-binder composition and reduce the amount of both condensed and gaseous SrO, which emits undesirable orange-red light. The new formulations were found to possess high thermal onset temperatures. Avoiding chlorine in these formulations eliminates the risk of the formation of PCBs, PCDDs, and PCDFs. This finding, hence, will have a great impact on both military pyrotechnics and commercial firework sectors. PMID:26333055

  12. Pyrotechnic study and test. Final report

    SciTech Connect

    Smith, R.D.; Fronabarger, J.W.

    1992-01-14

    Unidynamics/Phoenix entered into LANL contract {number_sign}9-X51-D9928-1 on March 11, 1991. The contract was to perform chemical analysis and provide analytical data, provide test data from functioning units, build and test pyrotechnic devices and fabricate and test approximately 100 pyrotechnic devices to approximate the chemical and functioning characteristics of the devices from the Army inventory. Because of government regulations, it became nearly impossible to ship the units from White Sands to Unidynamics. Consequently a series of functional tests were conducted at White Sands Missile Range. Comments on the functional tests are included herein. In addition, small scale tests were conducted at Unidynamics. These tests were to demonstrate a so called {open_quotes}line{close_quotes} charge and a {open_quotes}walking{close_quotes} charge. A discussion of these two charges is presented. The program was put on hold on November 6, 1991 and subsequently reopened to prepare and submit this report.

  13. Solar Flares

    NASA Technical Reports Server (NTRS)

    Savage, Sabrina

    2013-01-01

    Because the Earth resides in the atmosphere of our nearest stellar neighbor, events occurring on the Sun's surface directly affect us by interfering with satellite operations and communications, astronaut safety, and, in extreme circumstances, power grid stability. Solar flares, the most energetic events in our solar system, are a substantial source of hazardous space weather affecting our increasingly technology-dependent society. While flares have been observed using ground-based telescopes for over 150 years, modern space-bourne observatories have provided nearly continuous multi-wavelength flare coverage that cannot be obtained from the ground. We can now probe the origins and evolution of flares by tracking particle acceleration, changes in ionized plasma, and the reorganization of magnetic fields. I will walk through our current understanding of why flares occur and how they affect the Earth and also show several examples of these fantastic explosions.

  14. Solar Flares

    NASA Technical Reports Server (NTRS)

    Shih, Albert

    2011-01-01

    Solar flares accelerate both ions and electrons to high energies, and their X-ray and gamma-ray signatures not only probe the relationship between their respective acceleration, but also allow for the measurement of accelerated and ambient abundances. RHESSI observations have shown a striking close linear correlation of gamma-ray line fluence from accelerated ions > approx.20 MeV and bremsstrahlung emission from relativistic accelerated electrons >300 keV, when integrated over complete flares, suggesting a common acceleration mechanism. SMM/GRS observations, however, show a weaker correlation, and this discrepancy might be associated with previously observed electron-rich episodes within flares and/or temporal variability of gamma-ray line fluxes over the course of flares. We use the latest RHESSI gamma-ray analysis techniques to study the temporal behavior of the RHESSI flares, and determine what changes can be attributed to an evolving acceleration mechanism or to evolving abundances.

  15. Determining Functional Reliability of Pyrotechnic Mechanical Devices

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Multhaup, Herbert A.

    1997-01-01

    This paper describes a new approach for evaluating mechanical performance and predicting the mechanical functional reliability of pyrotechnic devices. Not included are other possible failure modes, such as the initiation of the pyrotechnic energy source. The requirement of hundreds or thousands of consecutive, successful tests on identical components for reliability predictions, using the generally accepted go/no-go statistical approach routinely ignores physics of failure. The approach described in this paper begins with measuring, understanding and controlling mechanical performance variables. Then, the energy required to accomplish the function is compared to that delivered by the pyrotechnic energy source to determine mechanical functional margin. Finally, the data collected in establishing functional margin is analyzed to predict mechanical functional reliability, using small-sample statistics. A careful application of this approach can provide considerable cost improvements and understanding over that of go/no-go statistics. Performance and the effects of variables can be defined, and reliability predictions can be made by evaluating 20 or fewer units. The application of this approach to a pin puller used on a successful NASA mission is provided as an example.

  16. Shock compaction of a porous pyrotechnic material

    SciTech Connect

    Lee, L. M.; Schwarz, A. C.

    1980-01-01

    The results of an experimental program to generate Hugoniot data for an unreacted pyrotechnic material are discussed and the data presented. The program included both sample fabrication and experimental determination of stress-particle velocity Hugoniot data for the pyrotechnic, titanium hydride-potassium perchlorate (TiH/sub 2/-KClO/sub 4/), at two densities. The TiH/sub 2/-KClO/sub 4/, which was supplied as a powder mixture, was pressed to the desired bulk sample density and size using a ram and die technique. Samples were produced with nominal 2.02 or 2.27 g/cm/sup 3/ densities. Hugoniot data were generated on the porous pyrotechnic samples using standard flat plate impact techniques. The experimental program provided information defining the shock compaction behavior of porous TiH/sub 2/-KClO/sub 4/ up to 70 kbar. The Hugoniot data for both sample densities indicated full compaction was achieved in the 15 to 20 kbar stress range.

  17. Miniature pyrotechnic shock simulator. [for testing on spacecraft

    NASA Technical Reports Server (NTRS)

    Milder, G.; Albers, L.

    1975-01-01

    The development of pyrotechnic shock testing is prompted by requirements created by pyrotechnic devices. At the present time there are no standard techniques for the production of a given pulse. At the Jet Propulsion Laboratory a device has been developed which appears to be promising as a general-purpose laboratory tool. This paper concerns the development of that device.

  18. 1. VIEW OF WEST AND SOUTH FACES OF PYROTECHNIC SHED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW OF WEST AND SOUTH FACES OF PYROTECHNIC SHED (BLDG. 757). ENTRANCE TO TEST CELL ON SOUTH SIDE; ENTRANCE TO PERSONNEL ROOM ON WEST SIDE. SECURITY FENCE BETWEEN SLC-3E AND SLC-3W IN BACKGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Pyrotechnic Shed, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  19. Comparison of seismic sources for shallow seismic: sledgehammer and pyrotechnics

    NASA Astrophysics Data System (ADS)

    Brom, Aleksander; Stan-Kłeczek, Iwona

    2015-10-01

    The pyrotechnic materials are one of the types of the explosives materials which produce thermal, luminous or sound effects, gas, smoke and their combination as a result of a self-sustaining chemical reaction. Therefore, pyrotechnics can be used as a seismic source that is designed to release accumulated energy in a form of seismic wave recorded by tremor sensors (geophones) after its passage through the rock mass. The aim of this paper was to determine the utility of pyrotechnics for shallow seismic engineering. The work presented comparing the conventional method of seismic wave excitation for seismic refraction method like plate and hammer and activating of firecrackers on the surface. The energy released by various sources and frequency spectra was compared for the two types of sources. The obtained results did not determine which sources gave the better results but showed very interesting aspects of using pyrotechnics in seismic measurements for example the use of pyrotechnic materials in MASW.

  20. Aerial Explorers

    NASA Technical Reports Server (NTRS)

    Young, Larry A.; Pisanich, Greg; Ippolito, Corey

    2005-01-01

    This paper presents recent results from a mission architecture study of planetary aerial explorers. In this study, several mission scenarios were developed in simulation and evaluated on success in meeting mission goals. This aerial explorer mission architecture study is unique in comparison with previous Mars airplane research activities. The study examines how aerial vehicles can find and gain access to otherwise inaccessible terrain features of interest. The aerial explorer also engages in a high-level of (indirect) surface interaction, despite not typically being able to takeoff and land or to engage in multiple flights/sorties. To achieve this goal, a new mission paradigm is proposed: aerial explorers should be considered as an additional element in the overall Entry, Descent, Landing System (EDLS) process. Further, aerial vehicles should be considered primarily as carrier/utility platforms whose purpose is to deliver air-deployed sensors and robotic devices, or symbiotes, to those high-value terrain features of interest.

  1. Compatibility of header materials with pyrotechnic powder

    SciTech Connect

    Weirick, L.J.

    1982-12-01

    The intent of this research program is to qualify several stainless steels, nickel-base alloys and a titanium alloy as candidates for explosive component applications. This report focuses on the compatibility of these materials with pyrotechnic powder. The powder is a combined titanium subhydride-potassium perchlorate mixture, used both wet and dry. Hollow tensile bars were utilized to discern interactions between the metal and powder which underwent accelerated aging. Metallography was employed along with the mechanical property results to characterize the extent of interaction. No degradation in mechanical properties was noted. 6 figures, 6 tables.

  2. Supercritical water oxidation of colored smoke, dye, and pyrotechnic compositions. Phase 1, Final report

    SciTech Connect

    Rice, S.F.; LaJeunesse, C.A.; Hanush, R.G.; Aiken, J.D.; Johnston, S.C.

    1994-01-01

    The US military stockpile has large quantities of obsolete munitions awaiting disposal. Although suitable means for the safe dismantlement of much of this stockpile have been identified, there are still considerable quantities of specialty materials for which existing methods have been deemed inappropriate from an environmental standpoint. Among these munitions are colored spotting dyes and a wide assortment of pyrotechnics, including colored smokes and flares. In open bum or incineration treatment processes these materials produce large quantities of toxic, and possibly carcinogenic, gases and particulate matter. The U.S Army Armament Research, Development and Engineering Center at Picatinny Arsenal, NJ is interested in developing a method of treatment that will dispose of these munitions without the difficulties identified above. This report examines the feasibility of supercritical water oxidation, an emerging waste treatment technology, to process these materials. Four colored dyes and one pyrotechnic smoke composition were processed in a flow reactor, and the effluent was analyzed to determine the effectiveness of the processing. The tests showed that all of these materials could by oxidized to much less hazardous compounds in less than 10 seconds with a destruction and removal efficiency (DRE) typically > 99.5%. Two technical issues were identified as needing more attention in Phase II of this project: formation of sulfate and chloride salt deposits within the flow reactor and corrosion of the materials of construction.

  3. Solar Flares

    NASA Astrophysics Data System (ADS)

    Rust, David

    1998-01-01

    The Sun is constantly changing. Not an hour goes by without a rise or fall in solar x-radiation or radio emission. Not a day goes by without a solar flare. Our active star, this inconsistent Sun, this gaseous cloud that blows in all directions, warms the air we breathe and nourishes the food we eat. From Earth, it seems the very model of stability, but in space it often creates havoc. Over the past century, solar physicists have learned how to detect even the weakest of solar outbursts or flares. We know that flares must surely trace their origins to the magnetic strands stretched and tangled by the rolling plasma of the solar interior. Although a century of astrophysical research has produced widely accepted, fundamental understanding about the Sun, we have yet to predict successfully the emergence of any magnetic fields from inside the Sun or the ignition of any flare. As in any physical experiment, the ability to predict events not only validates the scientific ideas, it also has practical value. In astrophysics, a demonstrated understanding of sunspots, flares, and ejections of plasma would allow us to approach many other mysteries, such as stellar X-ray bursters, with tested theories.

  4. Characterization of pyrotechnic reaction residue particles by SEM/EDS.

    PubMed

    Kosanke, Ken L; Dujay, Richard C; Kosanke, Bonnie

    2003-05-01

    Today the method commonly used for detecting gunshot residue is through the combined use of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). In recent years, this same methodology began to find use in detecting and characterizing pyrotechnic reaction residue (PRR) particles whether produced by explosion or burning. This is accomplished by collecting particulate samples from a surface in the immediate area of the pyrotechnic reaction. Suspect PRR particles are identified by their morphology (typically 1 to 20 microm spheroidal particles) using an SEM; then they are analyzed for the elements they contain using X-ray EDS. This can help to identify the general type of pyrotechnic composition involved. PMID:12762523

  5. Ignition Temperature of Magnesium Powder and Pyrotechnic Composition

    NASA Astrophysics Data System (ADS)

    Zhu, Chen-Guang; Wang, Hai-Zhen; Min, Li

    2014-07-01

    Using potassium nitrate, strontium nitrate, and potassium perchlorate as the oxidizing agents, the ignition and combustion behaviors of magnesium powders with different specific surface area were studied. The ignition temperature (Te) was extrapolated using a differential thermal analyzer, and the pyrotechnic spontaneous reaction temperature (Ts) was inferred from the temperature curve by inflection point analysis. The results showed that Ts has much better reproducibility than the extrapolated Te in characterizing the ignition of the pyrotechnic formulations. Increasing the specific surface area of the magnesium powder resulted in decreased Ts of the pyrotechnics.

  6. Characterizing pyrotechnic igniter output with high-speed schlieren imaging

    NASA Astrophysics Data System (ADS)

    Skaggs, M. N.; Hargather, M. J.; Cooper, M. A.

    2016-03-01

    Small-scale pyrotechnic igniter output has been characterized using a high-speed schlieren imaging system for observing critical features of the post-combustion flow. The diagnostic, with laser illumination, was successfully applied towards the quantitative characterization of the output from Ti/KClO_4 and TiH_{1.65}/KClO_4 pyrotechnic igniters. The high-speed image sequences showed shock motion, burned gas expansion, and particle motion. A statistical-based analysis methodology for tracking the full-field shock motion enabled straightforward comparisons across the experimental parameters of pyrotechnic material and initial density. This characterization of the mechanical energy of the shock front within the post-combustion environment is a necessary addition to the large body of literature focused on pyrotechnic combustion behavior within the powder bed. Ultimately, understanding the role that the combustion behavior has on the resulting multiphase environment is required for tailored igniter development and comparative performance assessments.

  7. Pyrotechnic modeling for the NSI and pin puller

    NASA Technical Reports Server (NTRS)

    Powers, Joseph M.; Gonthier, Keith A.

    1993-01-01

    A discussion concerning the modeling of pyrotechnically driven actuators is presented in viewgraph format. The following topics are discussed: literature search, constitutive data for full-scale model, simple deterministic model, observed phenomena, and results from simple model.

  8. Improved system measures output energy of pyrotechnic devices

    NASA Technical Reports Server (NTRS)

    Shortly, E. M.

    1966-01-01

    System for measuring the output energy of pyrotechnic devices discharges the reaction products into a test chamber. It measures the radiant heat output from a pinhole aperture as well as internal pressure changes on a common time base.

  9. The role of thermal contact resistance in pyrotechnic ignition

    NASA Technical Reports Server (NTRS)

    Sernas, V.; Murphy, A. J.

    1974-01-01

    This paper describes a pyrotechnic ignition model based on transient heat conduction from a heated bridgewire to a pyrotechnic that is placed in contact with it. The boundary condition used at the interface was a thermal contact conductance estimated at 31,200 W per sq m-K between the wire and the pyrotechnic. Ignition was assumed to occur when a 2.5-micron layer of pyrotechnic next to the bridgewire reached a critical ignition temperature. The times to ignition predicted by this model for constant current firings were in good agreement with experimentally observed times to fire at 3.5- and 5-ampere current levels and ambient temperatures from 144 K to 366 K.

  10. Role of surface chemistry in the ignition of pyrotechnic materials

    SciTech Connect

    Moddeman, W.E.; Collins, L.W.; Wang, P.S.; Wittberg, T.N.

    1980-01-01

    The surface chemistry of fuels has been shown to play a key role in the ignition of pyrotechnic materials. Since these fuels are usually easily oxidized, the surface must provide protection from undesirable oxidation processes such as pyrophoricity while permitting the desirable pyrotechnic reactions. For both titanium and aluminum, these criteria are met by metal oxide coatings which control the accessibility of the fuel to the oxidizer. However, we have shown that the mechanisms through which this control is exerted are substantially different. The ignition of titanium based pyrotechnics seems to be kinetically controlled by the dissolution of the titanium oxide coating to generate a reactive surface for the pyrotechnic reaction. Reactions of aluminum seem to depend on diffusion of aluminum (or oxygen at higher temperatures) through its oxide coating. It was also shown that the accessibility of aluminum can be improved by alloying.

  11. Pyrotechnic component development at Sandia National Laboratory

    SciTech Connect

    Wilcox, P.D.

    1987-01-01

    Pyrotechnic and explosive devices are designed at Sandia National Laboratories, SNL, which must satisfy high reliability requirements for reliable function and storage life. Since only a small number of devices may be built, high standards of quality of both the explosive and structural materials are necessary. We have developed special alloys and glass-ceramic seals for headers and structural parts of these devices to satisfy requirements for minimum size and weight but with increased ruggedness and safety. Hermetic sealing is used extensively to aid in the control of corrosion and aging effects. There is an increasing demand for the integration of these devices with safer (less sensitive) materials, better handling methods, and the use of electrical or fiber optic logic input elements. This paper addresses the trends in active materials, structural materials and a new method of ignition which enhances device designs compatible with low voltage and digital electronics.

  12. Measurement of pyrotechnic ignition energy by thermography

    SciTech Connect

    Mohler, J.H.; Abney, L.D.; Chow, T.S.

    1985-01-01

    Measuring the laser energy required to ignite pyrotechnic pellets is complicated by several factors that are difficult to control or predict. These include reflection of part of the incident laser energy, reemission from the heated sample, and heat conduction away from the ignition site. In addition to these factors, it is often difficult to control and/or measure the incident laser power. High-speed thermographic recording of the temperature distribution in the test sample makes it possible to calculate the heat content of the test pellet at any instant. Thus, one can actually observe the laser heating and on-set of reaction in the pellet and avoid having to make measurements or assumptions to account for possible energy losses.

  13. A numerical model of combustion in gasless pyrotechnic systems

    SciTech Connect

    Boddington, T.; Cottrell, A.; Laye, P.G.

    1989-04-01

    A simple numerical model has been developed for the propagation of a combustion wave through a gasless pyrotechnic mixture. A pseudo one-dimensional approach has been adopted in which an allowance for heat loss has been made by the inclusion of a simple Newtonian heat transfer term. Implementation requires a knowledge of the thermal and kinetic properties of the pyrotechnic mixture. The model reproduces the observed trends in burning velocity and predicts conditions leading to combustion failure.

  14. Thermal ignition of pyrotechnics with lasers

    SciTech Connect

    Chow, C.T.S.; Mohler, J.H.

    1987-01-01

    We are studying the transient phenomena of thermal ignition using laser energy. Present-day infrared scanning and recording techniques enable us to determine the heat content based on the thermal profiles, during ignition, with spatial and temporal resolution. Thus, we can actually observe the laser heating and onset of self-sustained combustion in the sample pellet, and we can use the data obtained with existing theory to characterize pyrotechnic materials and to develop more-precise kinetic models of the ignition process. The results demonstrate the viability of our methods for studying the pyrotechnic ignition process. The whole ignition process consists of two stages. In the first stage, a laser acts as an external heat source that heats the surface of a pellet, an inert body. When the temperature reaches a certain level, a second-stage chemical reaction occurs. The two stages are separated by the inflection point of the temperature-vs-time trace. We present a formula derived from the thermal-explosion theory that allows one to determine the kinetic constants, with the surface-heat flux and the inflection temperature as the only parameters. In addition, we also report the ignition delay time as a function of the heat flux and describe the experimental apparatus used. We investigated three reactions: Fe/sub 3/O/sub 4//Al, Fe/sub 2/O/sub 3//Al, and Ti/2B. For our test samples, we used several kinds of powders, including spherical and flaked aluminum powders and medium and fine iron-oxide powders, with various compact densities. 7 refs., 7 figs., 2 tabs.

  15. Flare models: Chapter 9 of solar flares

    NASA Technical Reports Server (NTRS)

    Sturrock, P. A. (Editor)

    1979-01-01

    By reviewing the properties of solar flares analyzed by each of the seven teams of the Skylab workshop, a set of primary and secondary requirements of flare models are derived. A number of flare models are described briefly and their properties compared with the primary requirements. It appears that, at this time, each flare model has some strong points and some weak points. It has not yet been demonstrated that any one flare model meets all the proposed requirements.

  16. Making nanostructured pyrotechnics in a beaker

    SciTech Connect

    Gash, A E; Simpson, R L; Tillotson, T M; Satcher, J H; Hrubesh, L W

    2000-04-10

    Controlling composition at the nanometer scale is well known to alter material properties in sometimes highly desirable and dramatic ways. In the field of energetic materials component distributions, particle size, and morphology, effect both sensitivity and reactivity performance. To date nanostructured energetic materials are largely unknowns with the exception of nanometer-sized reactive powders now being produced at a number of laboratories. We have invented a new method of making nanostructured energetic materials, specifically explosives, propellants, and pyrotechnics, using sol-gel chemistry. The ease of this synthetic approach along with the inexpensive, stable, and benign nature of the metal precursors and solvents permit large-scale syntheses to be carried out. This approach can be accomplished using low cost processing methods. We will describe here, for the first time, this new synthetic route for producing metal-oxide-based pyrotechnics. The procedure employs the use of stable and inexpensive hydrated-metal inorganic salts and environmentally friendly solvents such as water and ethanol. The synthesis is straightforward and involves the dissolution the metal salt in a solvent followed by the addition of an epoxide, which induces gel formation in a timely manner. Experimental evidence suggests that the epoxide acts as an irreversible proton scavenger that induces the hydrated-metal species to undergo hydrolysis and condensation to form a sol that undergoes. further condensation to form a metal-oxide nanostructured gel. Both critical point and atmospheric drying have been employed to produce monolithic aerogels and xerogels, respectively. Using this method we have synthesized metal-oxide nanostructured materials using Fe{sup 3+}, Cr{sup 3+}, Al{sup 3+}, Ga{sup 3+}, In{sup 3+}, Hf{sup 4+}, Sn{sup 4+} and Zr{sup 4+} inorganic salts. Using related methods we have made nanostructured oxides of Mo, Ti, V, Co, Ni, Cu, Y , Ta, W, Pb, B, Pr, Er, Nd and Si. These

  17. A manual for pyrotechnic design, development and qualification

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1995-01-01

    Although pyrotechnic devices have been singularly responsible for the success of many of the critical mechanical functions in aerospace programs for over 30 years, ground and in-flight failures continue to occur. Subsequent investigations reveal that little or no quantitative information is available on measuring the effects on performance of system variables or on determining functional margins. Pyrotechnics are considered to be readily available and, therefore, can be managed by any subsystem in which they are applied, such as structure, propulsion, electric power, or life support. The primary purpose of this manual is to alter the concept that the use of pyrotechnics is an art and refute 'justifications' that applications do not need to be understood by providing information on pyrotechnic design, development, and qualification on an engineering basis. Included are approaches to demonstrate functional reliability with less than 10 units, how to manage pyrotechnic-unique requirements, and methods to assure that the system is properly assembled and will perform the required tasks.

  18. A manual for pyrotechnic design, development and qualification

    NASA Astrophysics Data System (ADS)

    Bement, Laurence J.; Schimmel, Morry L.

    1995-06-01

    Although pyrotechnic devices have been singularly responsible for the success of many of the critical mechanical functions in aerospace programs for over 30 years, ground and in-flight failures continue to occur. Subsequent investigations reveal that little or no quantitative information is available on measuring the effects on performance of system variables or on determining functional margins. Pyrotechnics are considered to be readily available and, therefore, can be managed by any subsystem in which they are applied, such as structure, propulsion, electric power, or life support. The primary purpose of this manual is to alter the concept that the use of pyrotechnics is an art and refute 'justifications' that applications do not need to be understood by providing information on pyrotechnic design, development, and qualification on an engineering basis. Included are approaches to demonstrate functional reliability with less than 10 units, how to manage pyrotechnic-unique requirements, and methods to assure that the system is properly assembled and will perform the required tasks.

  19. Potassium perchlorate reaction with pyrotechnic fuels

    SciTech Connect

    Wang, P.S.; Moddeman, W.E.; Bowling, W.C.

    1983-01-01

    Surface sensitive x-ray photoelectron spectroscopy (XPS) and x-ray induced Auger electron spectroscopy (XAES) were used to analyze surface changes in Fe/KC10/sub 4/, TiH/sub 0.65//KC10/sub 4/ and Al foils in KC10/sub 4/ during accelerated aging at 60 and 120/sup 0/C. The result shows a 0.02% Cl/sup -/ formation per day in Fe/KC10/sub 4/ and TiH/sub 0.65//KC10/sub 4/ powders aged at 120/sup 0/C for less than or equal to 145 days. No KC10/sub 4/ decomposition was observed under the similar aging conditions in KC10/sub 4/ samples without pyrotechnic fuels. Titanium oxide to KC10/sub 4/ signal ratio in a pressed disk of TiH/sub 0.65//KC10/sub 4/ was found to be lower than that of the powdered samples. Carbon impurities were noted in all powders, especially strong in metal (or subhydride) containing specimens; carbon impurities were slightly removed from the subhydride during aging.

  20. SCB ignition of pyrotechnics, thermites and intermetallics

    SciTech Connect

    Bickes, R.W. Jr.; Grubelich, M.C.

    1996-09-01

    We investigated ignition of pyrotechnics, metal-fuel/metal-oxide compositions (thermites), and exothermic alloy compositions (intermetallics) using a semiconductor bridge (SCB). It was shown that these materials could be ignited at low energy levels with an appropriately designed SCB, proper loading density, and good thermal isolation. Materials tested included Al/CuO, B/BaCrO{sub 4}, TiH{sub 1.65}/KClO{sub 4}, Ti/KClO{sub 4}, Zr/BaCrO{sub 4}, Zr/CuO, Zr/Fe{sub 2}O{sub 3}, Zr/KClO{sub 4}, and 100-mesh Al/Pd. Firing set was a capacitor discharge unit with charge capacitors ranging from 3 to 20,000 {mu}F at charge voltages 5-50 V. Devices functioned a few miliseconds after onset of current pulse at input energies as low as 3 mJ. We also report on a thermite torch design.

  1. Detonation and deflagration properties of pyrotechnic mixtures

    SciTech Connect

    Tanaka, Katsumi

    1996-07-01

    Theoretical calculation of detonation and deflagration properties of pyrotechnic mixtures have been performed including report charges and display charges. Calculation were performed with the KHT (Kihara-Hikta-Tanaka) code. KHT results are compared with a modified version of the TIGER code which allows calculation with 900 gaseous and 600 condensed product species at high pressure. Detonation properties computed by KHT and BKWS (Becker-Kistiakowskii-Wilson) give favorable agreement with experimental results of detonation velocity measurements. Hydrodynamic computation by one dimensional Lagrangian hydrodynamic code using the isentrope given by KHT constant volume explosion, indicated that experimental results for blast wave measurement for 30kg and 50kg of report charge were an incomplete reaction. Underwater detonation experiments with explosive charge of 25g, however, indicates a more energetic nature than the KHT prediction. This scale effect indicates complicated slow reactions and a number of condensed phase deflagration products of powder mixtures such as aluminum or titanium with oxidizers such as potassium perchlorate or nitrate salts as suggested by Hobbs et al.

  2. Periodate salts as pyrotechnic oxidizers: development of barium- and perchlorate-free incendiary formulations.

    PubMed

    Moretti, Jared D; Sabatini, Jesse J; Chen, Gary

    2012-07-01

    In a flash: pyrotechnic incendiary formulations with good stabilities toward various ignition stimuli have been developed without the need for barium or perchlorate oxidizers. KIO(4) and NaIO(4) were introduced as pyrotechnic oxidizers and exhibited excellent pyrotechnic performance. The periodate salts may garner widespread use in military and civilian fireworks because of their low hygroscopicities and high chemical reactivities. PMID:22639415

  3. Solar flare nomenclature

    NASA Astrophysics Data System (ADS)

    Cliver, E. W.

    1995-03-01

    The evolution of solar flare nomenclature is reviewed in the context of the paradigm shift, in progress, from flares to coronal mass ejections (CMEs) in solar-terrestrial physics. Emphasis is placed on: the distinction between eruptive (Class II) flares and confined (Class I) flares; and the underlying similarity of eruptive flares inside (two-ribbon flares) and outside (flare-like brightenings accompanying disappearing filaments) of active regions. A list of reserach questions/ problems raised, or brought into focus, by the new paradigm is suggested; in general, these questions bear on the inter- relationships and associations of the two classes (or phases) or flares. Terms such as 'eruptive flare' and 'eruption' (defined to encompass both the CME and its associated eruptive flare) may be useful as nominal links between opposing viewpoints in the 'flares vs CMEs' controversy.

  4. COMBUSTION EFFICIENCY OF FLARES

    EPA Science Inventory

    The paper gives results of a study to provide data on industrial flare emissions. (Emissions of incompletely burned hydrocarbons from industrial flares may contribute to air pollution. Available data on flare emissions are sparse, and methods to sample operating flares are unavai...

  5. Independent Orbiter Assessment (IOA): Assessment of the pyrotechnics subsystem

    NASA Technical Reports Server (NTRS)

    Robinson, W. M.

    1988-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Pyrotechnics (PYRO) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. This report documents the results of that comparison for the Orbiter Pyrotechnics hardware.

  6. WSTF Propulsion and Pyrotechnics Corrective Action Test Program Status-2000

    NASA Technical Reports Server (NTRS)

    Saulsberry, R.; Ramirez, J.; Julien, H. L.; Hart, M.; Smith, W.; Bement, L.; Meagher, N. E.

    2000-01-01

    Extensive propulsion and pyrotechnic testing has been in progress at the NASA Johnson Space Center White Sands Test Facility (WSTF) since 1995. This started with the Mars Observer Propulsion and Pyrotechnics Corrective Action Test Program (MOCATP). The MOCATP has concluded, but extensive pyrovalve testing and research and development has continued at WSTF. The capability to accurately analyze and measure pyrovalve combustion product blow-by, evaluate propellant explosions initiated by blow-by, and characterize pyrovalve operation continues to be used and improved. This paper contains an overview of testing since MOCATP inception, but focuses on accomplishments since the status was last reported at the 35th Joint Propulsion Conference, June, 1999. This new activity includes evaluation of 3/8 inch Conax pyrovalves; development and testing of advanced pyrovalve technologies; investigation of nondestructive evaluation techniques to inspect pyrotechnically induced hydrazine explosions both through testing and modeling. Data from this collection of projects are now being formatted into a pyrovalve applications and testing handbook and consensus standard to benefit pyrovalve users and spacecraft designers. The handbook is briefly described here and in more detail in a separate paper. To increase project benefit, pyrovalve manufacturers are encouraged to provide additional valves for testing and consideration, and feedback is encouraged in all aspects of the pyrotechnic projects.

  7. Tethered Pyrotechnic Apparatus for Acquiring a Ground Sample

    NASA Technical Reports Server (NTRS)

    Jones, Jack; Zimmerman, Wayne; Wu, Jiunn Jenq; Badescu, Mircea; Sherrit, Stewart

    2009-01-01

    A proposed alternative design for the balloon-borne ground-sampling system described in the immediately preceding article would not rely on free fall to drive a harpoonlike sample-collecting device into the ground. Instead, the harpoon-like sample-collecting device would be a pyrotechnically driven, tethered projectile. The apparatus would include a tripod that would be tethered to the gondola. A gun for shooting the projectile into the ground would be mounted at the apex of the tripod. The gun would include an electronic trigger circuit, a chamber at the breech end containing a pyrotechnic charge, and a barrel. A sabot would be placed in the barrel just below the pyrotechnic charge, and the tethered projectile would be placed in the barrel just below the sabot. The tripod feet would be equipped with contact sensors connected to the trigger circuit. In operation, the tripod would be lowered to the ground on its tether. Once contact with the ground was detected by the sensors on all three tripod feet, the trigger circuit would fire the pyrotechnic charge to drive the projectile into the ground. (Requiring contact among all three tripod feet and the ground would ensure that the projectile would be fired into the ground, rather than up toward the gondola or the balloon.) The tethered projectile would then be reeled back up to the gondola for analysis of the sample.

  8. Pyrotechnical timing devices for objects of space technology

    NASA Astrophysics Data System (ADS)

    Dem'yanenko, D. B.; Dudyrev, A. S.; Efanov, V. V.; Strakhov, I. G.; Tsinbal, M. N.

    2013-12-01

    The article presents results of developments of pyrotechnical timing devices charged with quick- and slow-burning low-gas compositions of the new generation. The devices provide a wide range of time intervals from milliseconds up to tens of minutes and are highly resistant to conditions of the launch and space flight.

  9. Pyrotechnic device provides one-shot heat source

    NASA Technical Reports Server (NTRS)

    Haller, H. C.; Lalli, V. R.

    1968-01-01

    Pyrotechnic heater provides a one-shot heat source capable of creating a predetermined temperature around sealed packages. It is composed of a blend of an active chemical element and another compound which reacts exothermically when ignited and produces fixed quantities of heat.

  10. Transient burning analysis of pyrotechnic materials in a closed bomb

    SciTech Connect

    Razani, A.; Shahinpoor, M.

    1988-01-01

    The transient mass burning rate of energetic materials in a conductive mode can be calculated from the single pressure-time record of a closed bomb experiment. Assuming negligible heat loss and no initial gas in the bomb, the mass burning rate of pyrotechnic materials in the conductive heat mode can be related to the pressure-time record p(t), its derivative par. deltap/par. deltat(t), and the thermodynamic properties of gaseous combustion products. These thermodynamic parameters are the isochoric flame temperature, the molecular weight and the co-volume of the combustion product gases. The mass burning rate of pyrotechnic materials in the conductive mode can also be determined directly from equilibrium thermodynamic analysis without having to find the intermediate thermodynamic properties. The calculations based on two methods are performed and the results for a typical pressure-time record are compared. Convective burning of pyrotechnic materials can be theoretically analyzed by either a complicated porous flow and heat transfer analysis or by using a very simple homogeneous model. The former is not suitable for parametric study and the latter is too simple to simulate the underlying physical phenomena. In this work a model based on two measurements of pressure-time records is proposed and discussed. The model is simple enough for parametric study while addressing important physical phenomena associated with convective burning of pyrotechnic materials in closed systems. 12 refs., 3 figs., 2 tabs.

  11. Understanding Solar Flare Statistics

    NASA Astrophysics Data System (ADS)

    Wheatland, M. S.

    2005-12-01

    A review is presented of work aimed at understanding solar flare statistics, with emphasis on the well known flare power-law size distribution. Although avalanche models are perhaps the favoured model to describe flare statistics, their physical basis is unclear, and they are divorced from developing ideas in large-scale reconnection theory. An alternative model, aimed at reconciling large-scale reconnection models with solar flare statistics, is revisited. The solar flare waiting-time distribution has also attracted recent attention. Observed waiting-time distributions are described, together with what they might tell us about the flare phenomenon. Finally, a practical application of flare statistics to flare prediction is described in detail, including the results of a year of automated (web-based) predictions from the method.

  12. Emission factors and exposures from ground-level pyrotechnics

    NASA Astrophysics Data System (ADS)

    Croteau, Gerry; Dills, Russell; Beaudreau, Marc; Davis, Mac

    Potential exposures from ground-level pyrotechnics were assessed by air monitoring and developing emission factors. Total particulate matter, copper and SO 2 exposures exceeded occupational health guidelines at two outdoor performances using consumer pyrotechnics. Al, Ba, B, Bi, Mg, Sr, Zn, and aldehyde levels were elevated, but did not pose a health hazard based on occupational standards. Emission factors for total particulate matter, metals, inorganic ions, aldehydes, and polyaromatic hydrocarbons (PAHs) were determined for seven ground-supported pyrotechnics through air sampling in an airtight room after combustion. Particle generation ranged from 5 to 13% of the combusted mass. Emission factors (g Kg -1) for metals common to pyrotechnics were also high: K, 23-45; Mg, 1-7; Cu, 0.05-7; and Ba, 0.03-6. Pb emission rates of 1.6 and 2.7% of the combusted mass for two devices were noteworthy. A high correlation ( r2 ≥ 0.89) between metal concentrations in pyrotechnic compositions and emission factors were noted for Pb, Cr, Mg, Sb, and Bi, whereas low correlations ( r2 ≤ 0.1) were observed for Ba, Sr, Fe, and Zn. This may be due to the inherent heterogeneity of multi-effect pyrotechnics. The generation of inorganic nitrogen in both the particulate (NO 2-, NO 3-) and gaseous (NO, NO 2) forms varied widely (<0.1-1000 mg Kg -1). Aldehyde emission factors varied by two orders of magnitude even though the carbon source was carbohydrates and charcoal for all devices: formaldehyde (<7.0-82 mg Kg -1), acetaldehyde (43-210 mg Kg -1), and acrolein (1.9-12 mg Kg -1). Formation of lower molecular weight PAHs such as naphthalene and acenaphthylene were favored, with their emission factors being comparable to that from the combustion of household refuse and agricultural debris. Ba, Sr, Cu, and Pb had emission factors that could produce exposures exceeding occupational exposure guidelines. Sb and unalloyed Mg, which are banned from consumer fireworks in the US, were present in

  13. Time evolution of atmospheric particle number concentration during high-intensity pyrotechnic events

    NASA Astrophysics Data System (ADS)

    Crespo, Javier; Yubero, Eduardo; Nicolás, Jose F.; Caballero, Sandra; Galindo, Nuria

    2014-10-01

    The Mascletàs are high-intensity pyrotechnic events, typical of eastern Spanish festivals, in which thousands of firecrackers are burnt at ground level in an intense, short-time (<8 min) deafening spectacle that generates short-lived, thick aerosol clouds. In this study, the impact of such events on air quality has been evaluated by means of particle number concentration measurements performed close to the venue during the June festival in Alicante (southeastern Spain). Peak concentrations and dilution times observed throughout the Mascletàs have been compared to those measured when conventional aerial fireworks were launched 2 km away from the monitoring site. The impact of the Mascletàs on the total number concentration of particles larger than 0.3 μm was higher (maximum ˜2·104 cm-3) than that of fireworks (maximum ˜2·103 cm-3). The effect of fireworks depended on whether the dominant meteorological conditions favoured the transport of the plume to the measurement location. However, the time required for particle concentrations to return to background levels is longer and more variable for firework displays (minutes to hours) than for the Mascletàs (<25 min).

  14. Demonstration of a Pyrotechnic Bolt-Retractor System

    NASA Technical Reports Server (NTRS)

    Johnston, Nick; Ahmed, Rafiq; Garrison, Craig; Gaines, Joseph; Waggoner, Jason

    2004-01-01

    A paper describes a demonstration of the X-38 bolt-retractor system (BRS) on a spacecraft-simulating apparatus, called the Large Mobility Base, in NASA's Flight Robotics Laboratory (FRL). The BRS design was proven safe by testing in NASA's Pyrotechnic Shock Facility (PSF) before being demonstrated in the FRL. The paper describes the BRS, FRL, PSF, and interface hardware. Information on the bolt-retraction time and spacecraft-simulator acceleration, and an analysis of forces, are presented. The purpose of the demonstration was to show the capability of the FRL for testing of the use of pyrotechnics to separate stages of a spacecraft. Although a formal test was not performed because of schedule and budget constraints, the data in the report show that the BRS is a successful design concept and the FRL is suitable for future separation tests.

  15. Salvaging pyrotechnic data with minor overloads and offsets

    SciTech Connect

    Smallwood, D.O.; Cap, J.S.

    1998-01-27

    The authors are sometimes presented with data with serious flaws, like saturation, over-range, zero shifts, and impulsive noise, including much of the available pyrotechnic data. Obviously, these data should not be used if at all possible. However, they are sometimes forced to use these data as the only data available. A method to salvage these data using wavelets is discussed. The results must be accepted with the understanding that the answers are credible, not necessarily correct. None of the methods will recover information lost due to saturation and over-range with the subsequent nonlinear behavior of the data acquisition system. The results are illustrated using analytical examples and flawed pyrotechnic data.

  16. Lightning tests of the orbiter pyrotechnic escape system

    NASA Technical Reports Server (NTRS)

    Cohen, R.; Schulte, E. H.

    1977-01-01

    An experimental test program was undertaken to demonstrate that the Space Shuttle Orbiter Vehicle pyrotechnics actuated Crew Escape System was not subject to failure resulting from a lightning strike in the vicinity of the cockpit. A test sample representing a full-scale portion of the Orbiter Outer Panel was preheated to 325 F and struck with three different current waveforms to simulate the various effects of lightning: (1) 2 micro sec risetime, to 180 kA pulse to evaluate fast current rise shock effects; (2) a 205 kA, 100 micro sec wide pulse to evaluate full energy shock effects; and (3) a 490 ampere, 370 msec continuing current to evaluate the thermal effects of a lightning strike. These tests show that the Orbiter outer panel pyrotechnics are adequately protected against damage resulting from a lightning strike.

  17. Optical system for measurement of pyrotechnic test accelerations

    NASA Astrophysics Data System (ADS)

    Lieberman, Paul; Czajkowski, John; Rehard, John

    1992-12-01

    This effort was directed at comparing the response of several different accelerometer and amplifier combinations to the pyrotechnic pulse simulating the ordnance separation of stages of multistage missiles. These pyrotechnic events can contain peak accelerations in excess of 100,000 G and a frequency content exceeding 100,000 Hz. The main thrust of this work was to compare the several accelerometer systems with each other and with a very accurate laser Doppler displacement meter in order to establish the frequency bands and acceleration amplitudes where the accelerometer systems are in error. The comparisons were made in simple sine-wave and low-acceleration amplitude environments, as well as in very severe pyroshock environments. An optical laser Doppler displacement meter (LDDM) was used to obtain the displacement velocity and acceleration histories, as well as the corresponding shock spectrum.

  18. Independent Orbiter Assessment (IOA): Analysis of the pyrotechnics subsystem

    NASA Technical Reports Server (NTRS)

    Robinson, W. W.

    1988-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Pyrotechnics hardware. The IOA analysis process utilized available pyrotechnics hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode.

  19. A Method for Sizing Booster Charges in Pyrotechnic Mechanisms

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.

    1998-01-01

    Since no generally accepted guidelines exist on sizing booster charges to assure functional margins in pyrotechnically actuated devices, a study was conducted to provide an approach to meet this need. An existing pyrovalve was modified from a single cartridge input to a dual-cartridge input with a booster charge. The objectives of this effort were to demonstrate an energy-based functional margin approach for sizing booster charges, and to determine booster charge energy delivery characteristics in this valve. Functional margin was demonstrated by determining the energy required to actuate the valve through weight drop tests for comparison to the energy delivered by the cartridge and booster charge in firings in the modified valve. The results of this study indicated that this energy-based approach fully met the study objectives, showing its usefulness for this and possibly other pyrotechnic devices.

  20. A study of the role of pyrotechnic systems on the space shuttle program

    NASA Technical Reports Server (NTRS)

    Lake, E. R.; Thompson, S. J.; Drexelius, V. W.

    1973-01-01

    Pyrotechnic systems, high burn rate propellant and explosive-actuated mechanisms, have been used extensively in aerospace vehicles to perform a variety of work functions, including crew escape, staging, deployment and destruction. Pyrotechnic system principles are described in this report along with their applications on typical military fighter aircraft, Mercury, Gemini, Apollo, and a representative unmanned spacecraft. To consider the possible pyrotechnic applications on the space shuttle the mechanical functions on a large commercial aircraft, similar in scale to the shuttle orbiter, were reviewed. Many potential applications exist for pyrotechnic system on the space shuttle, both in conventional short-duration functions and in longer duration and/or repetitive type gas generators.

  1. The 2nd NASA Aerospace Pyrotechnic Systems Workshop

    NASA Technical Reports Server (NTRS)

    St.Cyr, William W. (Compiler)

    1994-01-01

    This NASA Conference Publication contains the proceedings of the Second NASA Aerospace Pyrotechnics Systems Workshop held at Sandia National Laboratories, Albuquerque, New Mexico, February 8-9, 1994. The papers are grouped by sessions: (1) Session 1 - Laser Initiation and Laser Systems; (2) Session 2 - Electric Initiation; (3) Session 3 - Mechanisms & Explosively Actuated Devices; (4) Session 4 - Analytical Methods and Studies; and (5) Session 5 - Miscellaneous. A sixth session, a panel discussion and open forum, concluded the workshop.

  2. Pyrotechnic shock at the orbiter/external tank forward attachment

    NASA Technical Reports Server (NTRS)

    Rogers, W. F.; Grissom, D. S.; Rhodes, L. R.

    1980-01-01

    During the initial certification test of the forward structural attachment of the space shuttle orbiter to the external tank, pyrotechnic shock from actuation of the separation device resulted in structural failure of the thermal protection tiles surrounding the attachment. Because of the high shock associated with the separation bolt, the development of alternative low shock separation designs was initiated. Two concepts that incorporate a 5.08 centimeter frangible nut as the release device were developed and tested.

  3. Emission spectra of pyrotechnic mixtures of heat flux simulators

    NASA Astrophysics Data System (ADS)

    Azharonok, V. V.; Kratsko, L. E.; Chubryk, N. I.; Goncharik, S. V.; Miatselskaya, N. S.; Yakshonak, P. P.; Hamayunau, V. I.

    2012-01-01

    Comprehensive optical spectroscopic studies of the combustion process of solid-state pyrotechnic mixtures based on Mg and Sr(NO3)2 have been carried out. Emission spectra of the mixtures in the ultraviolet, visible, and infrared wavelength regions have been studied under various atmospheric conditions taking into account radiation transfer in air along an optical path of observation up to 5 km long.

  4. Design and evaluation of progressively burning pyrotechnic formulations

    SciTech Connect

    Austing, J. L.; Cooper, P. W.

    1980-01-01

    The design and evaluation of a pyrotechnic that burns for 2 ms and generates gas cubically with time is described. The charge is a mixture of two aluminum-plated pyrotechnics, viz., aluminum-potassium perchlorate (Al-KCl0/sub 4/) and aluminum-vanadium pentoxide (Al-V/sub 2/O/sub 5/). The Al-KCl0/sub 4/ is a gas generator, each gram of which produces 320 cc of gas (STP); the Al-V/sub 2/O/sub 5/, on the other hand, is a gasless pyrotechnic. Progressive generation of gas is achieved by utilizing mixtures of two pyrotechncs in increments that are progressively richer in gas generant, over a range of 14.6% to 100% Al-KCl0/sub 4/ by weight. The deflagration rate of the system is a function of the Al-KCl0/sub 4/ content, and ranges from 16.2 in./msec for a mixture with 14.6% Al-KCl0/sub 4/ by weight to 30.0 in./msec for pure Al-KCl0/sub 4/. An evaluation of the pyrotechnic charge fired in air showed that the design goals were adequately achieved. The growth of the gas cloud was monitored by high speed Fastax photography. Two criteria were utilized to verify the performance: (a) a plot of gas cloud volume as a function of time on logarithmic coordinates approached and maintained the required slope of 3, and (b) a plot of cloud diameter versus time on these coordinates achieved a slope of 1. In addition, the gas specific volume maintained a consistent value of about 27,000 cc/g of reacted Al-KCl0/sub 4/ throughout the 2.0-ms burning time.

  5. Test component attachment effects on resonant plate pyrotechnic shock simulation

    SciTech Connect

    Bell, G.R.; Zimmerman, R.M.

    1989-01-01

    An accepted technique for simulating pyrotechnic shock inputs has been the resonant plate test. The plate is designed so that its predominant modes generate the desired frequency content of a given shock test specification. The success of the test is dependent on the engineer's ability to effectively design and control the response of the resonant plate. In designing a test to simulated a pyrotechnic environment, the location and mass of the test item become very important considerations since they have a profound impact on the dynamic response of the resonant plate. A relatively massive test item can change the plates's resonant frequency. Differences in the relative frequencies of the test item's fixture and the resonant plate may also effect the input to the test items. In this study, a simple mock test assembly is used to study test item and resonant plate interactions during a test. The implications of this interaction regarding the deviations of the shock test specification are also discussed. Data from shock tests performed with the test assembly mounted to a rigid mounting surface and a flexible resonant plate are compared. Frequency response functions and shock response spectra are generated from the test data and compared to show the significance of: (1) the relative stiffness of the mounting surface; and (2) the location of the input control point during a resonant plate test. These factors are shown to be particularly important in using resonant plate testing to simulate pyrotechnic shock environments. 5 refs., 7 figs.

  6. Quasi-static compaction studies of a porous pyrotechnic powder

    NASA Astrophysics Data System (ADS)

    Atwood, A. I.; Curran, P. O.; Price, C. F.; Wiknich, J.

    1996-05-01

    The compaction and relaxation properties of a live and an inert pyrotechnic powder simulant mixture have been evaluated under quasi-static loading conditions. The pyrotechnic powder consisted of a mixture of potassium perchlorate, magnesium-aluminum alloy, and inert binder. Potassium chloride replaced the potassium perchlorate in the inert mixture. Porous beds of powder were compacted using a double acting piston arrangement, operating at a constant loading rate of 0.11 in/min. Applied and transmitted forces were measured using either 7,500 or 20,000 lbf capacity strain gage load cells. The intragranular stress as a function of percent TMD was determined from the compaction data. The experimental intragranular stress data were further analyzed using a modified Carroll-Holt model to describe the compaction process and to allow extrapolation to a density range not achievable by experiment. The porous bed of pyrotechnic powder was much more rigid than homogeneous crystalline powders such as ammonium perchlorate (AP). Microscopic examination of the compacted material showed only light damage to the crystalline particles with little fracture. Bed relaxation resulted in a 2.8 to 4.5 percent change in bed height after compaction. These data demonstrate the presence of elastic deformation properties in a porous bed of non-viscoelastic material.

  7. Autoignition Chamber for Remote Testing of Pyrotechnic Devices

    NASA Technical Reports Server (NTRS)

    Harrington, Maureen L.; Steward, Gerald R.; Dartez, Toby W.

    2009-01-01

    The autoignition chamber (AIC) performs by remotely heating pyrotechnic devices that can fit the inner diameter of the tube furnace. Two methods, a cold start or a hot start, can be used with this device in autoignition testing of pyrotechnics. A cold start means extending a pyrotechnic device into the cold autoignition chamber and then heating the device until autoignition occurs. A hot start means heating the autoignition chamber to a specified temperature, and then extending the device into a hot autoignition chamber until autoignition occurs. Personnel are remote from the chamber during the extension into the hot chamber. The autoignition chamber, a commercially produced tubular furnace, has a 230-V, single-phase, 60-Hz electrical supply, with a total power output of 2,400 W. It has a 6-in. (15.2-cm) inner diameter, a 12-in. (30.4-cm) outer diameter and a 12-in.- long (30.4-cm), single-zone, solid tubular furnace (element) capable of heating to temperatures up to 2,012 F (1,100 C) in air.

  8. State study of pyrotechnics-related injuries and property damage.

    PubMed

    Grant, E; Fuller, C; Birckmayer, J; Marshall, S; Peterson, H D

    1998-01-01

    In December 1993, the State of North Carolina legalized the sale of certain types of fireworks. To date, no study has examined the impact of legalization of fireworks on health care and public safety. The purpose of this study was to examine the impact of legalized pyrotechnics specific to our state with regard to injury, property damage, and suppression costs. The population groups surveyed were the state fire departments, county fire marshals, hospital emergency departments, and county forest rangers. Each group was asked to complete a questionnaire on all incidents involving pyrotechnics devices, both legal and illegal, used during the study period. A total of 233 responses were received from the 1644 agencies surveyed. Forty-one injuries and 129 fireworks-related fires were reported. Total property loss was $185,570. Property loss, injury costs, and fire suppression costs totaled $799,450. This study provides a very conservative estimate of the problem within our state. Stronger legislation to restrict access to pyrotechnics may reduce the damage and costs they cause. PMID:9622474

  9. Heavy metals from pyrotechnics in New Years Eve snow

    NASA Astrophysics Data System (ADS)

    Steinhauser, Georg; Sterba, Johannes H.; Foster, Michaela; Grass, Friedrich; Bichler, Max

    Pyrotechnics and fireworks cause pollution with barium aerosols, which is a result of the utilization of barium nitrate as a combined pyrotechnic oxidizer and coloring agent. In this study, the washing-out of barium-rich aerosols by snowflakes during the New Years Eve celebrations in an Austrian village in the Alps has been investigated. It could be shown that the fireworks caused an increase in the barium concentration in snow of up to a factor of 580 compared to the blank value. An increase of the concentrations of strontium and occasionally arsenic in snow was also observed. The geographic distribution of the pyrotechnic combustion products on this snowy evening was restricted to a relatively small area and even in a very local scale, the variations in the concentrations were remarkable. Post-firework snow from the summits of nearby located mountains was found to be as clean as pre-firework snow. However, snow that was visibly contaminated with smoke residues contained exorbitant concentrations of Ba, K, Sr, and Fe.

  10. Pyrotechnic hazards classification and evaluation program. Phase 2, segment 3: Test plan for determining hazards associated with pyrotechnic manufacturing processes

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A comprehensive test plan for determining the hazards associated with pyrotechnic manufacturing processes is presented. The rationale for each test is based on a systematic analysis of historical accounts of accidents and a detailed study of the characteristics of each manufacturing process. The most hazardous manufacturing operations have been determined to be pressing, mixing, reaming, and filling. The hazard potential of a given situation is evaluated in terms of the probabilities of initiation, communication, and transition to detonation (ICT). The characteristics which affect the ICT probabilities include the ignition mechanisms which are present either in normal or abnormal operation, the condition and properties of the pyrotechnic material, and the configuration of the processing equipment. Analytic expressions are derived which describe the physical conditions of the system, thus permitting a variety of processes to be evaluated in terms of a small number of experiments.

  11. Towards Predicting Solar Flares

    NASA Astrophysics Data System (ADS)

    Winter, Lisa; Balasubramaniam, Karatholuvu S.

    2015-04-01

    We present a statistical study of solar X-ray flares observed using GOES X-ray observations of the ~50,000 fares that occurred from 1986 - mid-2014. Observed X-ray parameters are computed for each of the flares, including the 24-hour non-flare X-ray background in the 1-8 A band and the maximum ratio of the short (0.5 - 4 A) to long band (1-8 A) during flares. These parameters, which are linked to the amount of active coronal heating and maximum flare temperature, reveal a separation between the X-, M-, C-, and B- class fares. The separation was quantified and verified through machine-learning algorithms (k nearest neighbor; nearest centroid). Using the solar flare parameters learned from solar cycles 22-23, we apply the models to predict flare categories of solar cycle 24. Skill scores are then used to assess the success of our models, yielding correct predictions for ~80% of M-, C-, and B-class flares and 100% correct predictions for X-flares. We present details of the analysis along with the potential uses of our model in flare forecasting.

  12. Deflagration-induced flash of solid pyrotechnics as pumps for high-energy solid state lasers

    NASA Astrophysics Data System (ADS)

    Kang, Xiaoli; Liu, Liming; Tang, Yongjian

    2013-09-01

    Using the flash produced by deflagration of solid pyrotechnics to pump the laser gain medium is a potentially effective way to develop portable high power lasers. The purpose of this work is to examine the effect of some optimization or modifications in terms of compositions and distribution of the pyrotechnic pumping sources on the laser output. The optimization means the transmittance of the output couple. Modifications include: (1) pyrotechnic compositions are improved by adding small amounts of nano Al powders; (2) distribution of pumping light around the laser rod is changed through changing the discrete pyrotechnic tablets into continuous pyrotechnic bars. Results showed that laser output energy reached the maximum of 656 mJ when the transmittance of output mirror raised to10%; after adding nano Al powders into pyrotechnic compositions, laser energy increased by 80% at addition of 2% in the case of discrete distribution, while in the case of continuous distribution, even the mass of pyrotechnics was halved, laser energy still increased to the maximum of 442 mJ with 1% nano Al added. Besides, typical temporal waveform and spot of the laser as well as the light radiation performance of the pyrotechnic tablet are measured to help analyze the laser output performance. It is suggested that the mechanisms of the three modifications we employed are different though they all lead to increase in laser output.

  13. Solar Flares: Magnetohydrodynamic Processes

    NASA Astrophysics Data System (ADS)

    Shibata, Kazunari; Magara, Tetsuya

    2011-12-01

    This paper outlines the current understanding of solar flares, mainly focused on magnetohydrodynamic (MHD) processes responsible for producing a flare. Observations show that flares are one of the most explosive phenomena in the atmosphere of the Sun, releasing a huge amount of energy up to about 10^32 erg on the timescale of hours. Flares involve the heating of plasma, mass ejection, and particle acceleration that generates high-energy particles. The key physical processes for producing a flare are: the emergence of magnetic field from the solar interior to the solar atmosphere (flux emergence), local enhancement of electric current in the corona (formation of a current sheet), and rapid dissipation of electric current (magnetic reconnection) that causes shock heating, mass ejection, and particle acceleration. The evolution toward the onset of a flare is rather quasi-static when free energy is accumulated in the form of coronal electric current (field-aligned current, more precisely), while the dissipation of coronal current proceeds rapidly, producing various dynamic events that affect lower atmospheres such as the chromosphere and photosphere. Flares manifest such rapid dissipation of coronal current, and their theoretical modeling has been developed in accordance with observations, in which numerical simulations proved to be a strong tool reproducing the time-dependent, nonlinear evolution of a flare. We review the models proposed to explain the physical mechanism of flares, giving an comprehensive explanation of the key processes mentioned above. We start with basic properties of flares, then go into the details of energy build-up, release and transport in flares where magnetic reconnection works as the central engine to produce a flare.

  14. Emergency flare tip repair

    SciTech Connect

    Harrison, G.A.

    1982-07-01

    Two damaged propane storage tank flares serving a large LPG storage facility near the Arabian Gulf were given emergency service. A diagram of over-all layout and spatial relationships between tanks and piping, and tables with general information relevant to selecting an acceptable radiant heat load factor and flare line flow characteristics were presented. The general equation for predicting radiant heat flux from a point source was used. The ignition of the temporary flare was discussed.

  15. Solar flares. [plasma physics

    NASA Technical Reports Server (NTRS)

    Rust, D. M.

    1979-01-01

    The present paper deals with explosions in a magnetized solar plasma, known as flares, whose effects are seen throughout the electromagnetic spectrum, from gamma-rays through the visible and to the radio band. The diverse phenomena associated with flares are discussed, along with the physical mechanisms that have been advanced to explain them. The impact of solar flare research on the development of plasma physics and magnetohydrodynamics is noted. The rapid development of solar flare research during the past 20 years, owing to the availability of high-resolution images, detailed magnetic field measurements, and improved spectral data, is illustrated.

  16. Particle acceleration in flares

    NASA Technical Reports Server (NTRS)

    Benz, Arnold O.; Kosugi, Takeo; Aschwanden, Markus J.; Benka, Steve G.; Chupp, Edward L.; Enome, Shinzo; Garcia, Howard; Holman, Gordon D.; Kurt, Victoria G.; Sakao, Taro

    1994-01-01

    Particle acceleration is intrinsic to the primary energy release in the impulsive phase of solar flares, and we cannot understand flares without understanding acceleration. New observations in soft and hard X-rays, gamma-rays and coherent radio emissions are presented, suggesting flare fragmentation in time and space. X-ray and radio measurements exhibit at least five different time scales in flares. In addition, some new observations of delayed acceleration signatures are also presented. The theory of acceleration by parallel electric fields is used to model the spectral shape and evolution of hard X-rays. The possibility of the appearance of double layers is further investigated.

  17. Flared tube attachment fitting

    NASA Technical Reports Server (NTRS)

    Alkire, I. D.; King, J. P., Jr.

    1980-01-01

    Tubes can be flared first, then attached to valves and other flow line components, with new fitting that can be disassembled and reused. Installed fitting can be disassembled so parts can be inspected. It can be salvaged and reused without damaging flared tube; tube can be coated, tempered, or otherwise treated after it has been flared, rather than before, as was previously required. Fitting consists of threaded male portion with conical seating surface, hexagonal nut with hole larger than other diameter of flared end of tube, and split ferrule.

  18. Pyrotechnic hazards classification and evaluation program. Phase 3, segments 1-4: Investigation of sensitivity test methods and procedures for pyrotechnic hazards evaluation and classification, part A

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The findings, conclusions, and recommendations relative to the investigations conducted to evaluate tests for classifying pyrotechnic materials and end items as to their hazard potential are presented. Information required to establish an applicable means of determining the potential hazards of pyrotechnics is described. Hazard evaluations are based on the peak overpressure or impulse resulting from the explosion as a function of distance from the source. Other hazard classification tests include dust ignition sensitivity, impact ignition sensitivity, spark ignition sensitivity, and differential thermal analysis.

  19. Smart drug delivery injector microsystem based on pyrotechnical actuation

    NASA Astrophysics Data System (ADS)

    Puig-Vidal, Manel; Lopez, Jaime; Miribel, Pere; Samitier-Marti, Josep; Rossi, Carole; Berthold, Axel

    2003-04-01

    A smart drug delivery injector microsystem is presented based on small pyrotechnics to impulse drugs to be injected to a human being. The proposal refers to a feasibility demonstration of the technology for pharmaceutical chips. These chips would be around some cm2 in section and will be able to inject a drug into de subject skin responding to an electrical signal. The product derived from this activity will be useful for astronaut's health, being able to administrate emergency doses of products (for instance cardio-tonic or hypoallegic drugs) enough to survive an emergency situation (as it can be a heart attack during EVA). The system can also be used for easy administration of drugs needed for physiological research. The usefulness of the device in terrestrial applications has no doubt, allowing remote administration of drugs to patients whose biomedical parameters are remotely monitored. The concept proposed here is new in combining the idea of pharmaceutical chip with the ultrasonic droplet technology and the use of pyrotechnics to provide energy to the drug to be injected. The proposed Drug Injector Microsystem is based on 2 main blocks:- Micropyrotechnic system: defines the ignition part based on pyrotechnic.- Microfluidic system: defines the drug injection part. This part is also divided in different critical parts: Expansion chamber, membrane or piston, drug reservoir and a needle. Different sensors are placed on the expansion chamber of microfluidic system and on the micropyrotechnic system. A complete electronic module is implemented with a PC interface to define flexible and user friendly experiences showing the smart drug delivery injector microsystem principle.

  20. Report on Alternative Devices to Pyrotechnics on Spacecraft

    NASA Technical Reports Server (NTRS)

    Lucy, M. H.; Hardy, R. C.; Kist, E. H., Jr.; Watson, J. J.; Wise, S. A.

    1996-01-01

    Pyrotechnics accomplish many functions on today's spacecraft, possessing minimum volume/weight, providing instantaneous operation on demand, and requiring little input energy. However, functional shock, safety, and overall system cost issues, combined with emergence and availability of new technologies question their continued use on space missions. Upon request from the National Aeronautics and Space Administration's (NASA) Program Management Council (PMC), Langley Research Center (LaRC) conducted a survey to identify and evaluate state-of-the-art non-explosively actuated (NEA) alternatives to pyrotechnics, identify NEA devices planned for NASA use, and investigate potential interagency cooperative efforts. In this study, over 135 organizations were contacted, including NASA field centers, Department of Defense (DOD) and other government laboratories, universities, and American and European industrial sources resulting in further detailed discussions with over half, and 18 face-to-face briefings. Unlike their single use pyrotechnic predecessors, NEA mechanisms are typically reusable or refurbishable, allowing flight of actual tested units. NEAs surveyed include spool-based devices, thermal knife, Fast Acting Shockless Separation Nut (FASSN), paraffin actuators, and shape memory alloy (SMA) devices (e.g., Frangibolt). The electro-mechanical spool, paraffin actuator and thermal knife are mature, flight proven technologies, while SMA devices have a limited flight history. There is a relationship between shock, input energy requirements, and mechanism functioning rate. Some devices (e.g., Frangibolt and spool based mechanisms) produce significant levels of functional shock. Paraffin, thermal knife, and SMA devices can provide gentle, shock-free release but cannot perform critically timed, simultaneous functions. The FASSN flywheel-nut release device possesses significant potential for reducing functional shock while activating nearly instantaneously. Specific study

  1. Applications catalog of pyrotechnically actuated devices/systems

    NASA Technical Reports Server (NTRS)

    Seeholzer, Thomas L.; Smith, Floyd Z.; Eastwood, Charles W.; Steffes, Paul R.

    1995-01-01

    A compilation of basic information on pyrotechnically actuated devices/systems used in NASA aerospace and aeronautic applications was formatted into a catalog. The intent is to provide (1) a quick reference digest of the types of operational pyro mechanisms and (2) a source of contacts for further details. Data on these items was furnished by the NASA Centers that developed and/or utilized such devices to perform specific functions on spacecraft, launch vehicles, aircraft, and ground support equipment. Information entries include an item title, user center name, commercial contractor/vendor, identifying part number(s), a basic figure, briefly described purpose and operation, previous usage, and operational limits/requirements.

  2. Strobes: pyrotechnic compositions that show a curious oscillatory combustion.

    PubMed

    Corbel, Justine M L; van Lingen, Joost N J; Zevenbergen, John F; Gijzeman, Onno L J; Meijerink, Andries

    2013-01-01

    Strobes are pyrotechnic compositions which show an oscillatory combustion; a dark phase and a flash phase alternate periodically. The strobe effect has applications in various fields, most notably in the fireworks industry and in the military area. All strobe compositions mentioned in the literature were discovered by trial and error methods and the mechanisms involved remain unclear. Many oscillatory systems such as Belousov-Zhabotinsky reactions, cool flames, self-propagating high-temperature synthesis have been observed and theories developed to elucidate their unstable behavior based on chemical interactions or based on physical processes. These systems are compared to experimental observations made on strobe mixtures. PMID:23255499

  3. Numerical routines for predicting ignition in pyrotechnic devices

    SciTech Connect

    Pierce, K.G.

    1986-06-01

    Two numerical models of the thermal processes leading to ignition in a pyrotechnic device have been developed. These models are based on finite difference approximations to the heat diffusion equation, with temperature-dependent thermal properties, in a single spatial coordinate. The derivation of the finite difference equations is discussed and the methods employed at boundaries and interfaces are given. The sources of the thermal-properties data are identified and how these data are used is explained. The program structure is explained and example runs of the programs are given.

  4. Flares in childhood eczema.

    PubMed

    Langan, S M

    2009-01-01

    Eczema is a major public health problem affecting children worldwide. Few studies have directly assessed triggers for disease flares. This paper presents evidence from a published systematic review and a prospective cohort study looking at flare factors in eczema. This systematic review suggested that foodstuffs in selected groups, dust exposure, unfamiliar pets, seasonal variation, stress, and irritants may be important in eczema flares. We performed a prospective cohort study that focused on environmental factors and identified associations between exposure to nylon clothing, dust, unfamiliar pets, sweating, shampoo, and eczema flares. Results from this study also demonstrated some new key findings. First, the effect of shampoo was found to increase in cold weather, and second, combinations of environmental factors were associated with disease exacerbation, supporting a multiple component disease model. This information is likely to be useful to families and may lead to the ability to reduce disease flares in the future. PMID:20054505

  5. Aerial radiation surveys

    SciTech Connect

    Jobst, J.

    1980-01-01

    A recent aerial radiation survey of the surroundings of the Vitro mill in Salt Lake City shows that uranium mill tailings have been removed to many locations outside their original boundary. To date, 52 remote sites have been discovered within a 100 square kilometer aerial survey perimeter surrounding the mill; 9 of these were discovered with the recent aerial survey map. Five additional sites, also discovered by aerial survey, contained uranium ore, milling equipment, or radioactive slag. Because of the success of this survey, plans are being made to extend the aerial survey program to other parts of the Salt Lake valley where diversions of Vitro tailings are also known to exist.

  6. Flare build-up study - Homologous flares group. I

    NASA Technical Reports Server (NTRS)

    Martres, M.-J.; Mein, N.; Mouradian, Z.; Rayrole, J.; Schmieder, B.; Simon, G.; Soru-Escaut, I.; Woodgate, B. E.

    1984-01-01

    Solar Maximum Mission observations have been used to study the origin and amount of energy, mechanism of storage and release, and conditions for the occurrence of solar flares, and some results of these studies as they pertain to homologous flares are briefly discussed. It was found that every set of flares produced 'rafales' of homologous flares, i.e., two, three, four, or more flares separated in time by an hour or less. No great changes in macroscopic photospheric patterns were observed during these flaring periods. A quantitative brightness parameter of the relation between homologous flares is defined. Scale changes detected in the dynamic spectrum of flare sites are in good agreement with a theoretical suggestion by Sturrock. Statistical results for different homologous flare active regions show the existence in homologous flaring areas of a 'pivot' of previous filaments interpreted as a signature of an anomaly in the solar rotation.

  7. Test component attachment effects on resonant plate pyrotechnic shock simulation

    NASA Astrophysics Data System (ADS)

    Bell, R. Glenn; Zimmerman, Roger M.

    An accepted technique for simulating pyrotechnic shock inputs has been the resonant plate test. The plate is designed so that its predominant modes generate the desired frequency content of a given shock test specification. The success of the test is dependent on the engineer's ability to effectively design and control the response of the resonant plate. In designing a test to simulate a pyrotechnic environment, the location and mass of the test item become very important considerations since they have a profound impact on the dynamic response of the resonant plate. A relatively massive test item can change the plates's resonant frequency. Differences in the relative frequencies of the test item's fixture and the resonant plate may also effect the input to the test items. In this study, a simple mock test assembly is used to study test item and resonant plate interactions during a test. The implications of this interaction regarding the deviations of the shock test specification are also discussed. Data from shock tests performed with the test assembly mounted to a rigid mounting surface and a flexible resonant plate are compared. Frequency response functions and shock response spectra are generated from the test data and compared to show the significance of: (1) the relative stiffness of the mounting surface; and (2) the location of the input control point during a resonant plate test.

  8. Pollution prevention opportunity assessment for propellants, explosives, and pyrotechnics

    SciTech Connect

    Phillips, N.M.; Torres, H.M.

    1996-04-01

    In 1991, a DOE ``Tiger Team`` audited the SNL/California Explosives Program and cited Sandia for not being in compliance with the DOE Explosives Safety Manual requirements for having an explosives storage review program. At that time, SNL/California did not have a site-wide inventory record of explosives, and no storage review as in place. Sandia corporately owns approximately 1,800,000 lb energetic material, which is located at various sites throughout the country. In 1992, in response to the Tiger Team findings, Sandia formed the Propellants, Explosives, and Pyrotechnics Evaluation and Reapplication Task Force (PEPER) to develop the tools to implement life-cycle management of energetic materials at Sandia. PEPER met the following objectives: (1) create an accurate inventory of all energetic materials owned by Sandia; (2) evaluate the stability of the inventory, and thereby identify and destroy all imminent hazards; (3) draw down the inventory to be consistent with post-Cold War business needs; (4) create a cradle-to-grave ownership process. This pollution prevention opportunity assessment was conducted to document the activities at SNL/California that have involved propellants, explosives, and pyrotechnics; and to outline options for minimizing energetic materials and waste at SNL/California.

  9. Development of diode laser-ignited pyrotechnic and explosive components

    SciTech Connect

    Jungst, R.G.; Salas, F.J.; Watkins, R.D.; Kovacic, L.

    1990-01-01

    Studies are described which have led to the development of prototype diode laser-ignited pyrotechnic and explosive devices. These are of interest because they eliminate some concerns associated with ignition from hot wires such as conductance after firing, sensitivity to electromagnetic radiation and electrostatic discharge, and bridgewire corrosion. The availability of high power diode lasers is a key feature for the success of this concept. A pyrotechnic, Ti/KClO{sub 4}, and the deflagration-to-detonation transition (DDT) explosive CP have been evaluated and found suitable for use in LDI components. Doping with materials such as carbon black to increase light absorption near 800 nm is a major factor in reducing the laser power required to ignite CP, but does not strongly affect the ignition of Ti/KClO{sub 4}. Other material and laser input parameters were also studied to determine their influence on ignition thresholds. Even though they contain different energetic materials, the energy-power relationship of these optical igniters was generally similar in shape to those of other thermal ignition devices such as stable and electric igniters. Prototype, hermetically sealed, optical headers have been fabricated, loaded, and test fired with CP and Ti/KClO{sub 4}. Glass to metal sealing technology has been developed to insert sapphire windows or optical fiber segments in these fixtures. Devices containing fiber segments demonstrated superior performance in threshold tests. 8 refs., 12 figs., 3 tabs.

  10. Comparison of numerical models of a pyrotechnic device

    SciTech Connect

    Pierce, K.G.

    1986-01-01

    The predictions of two numerical models of a hot-wire initiated pyrotechnic device are compared to each other and to experimental results. Both models employ finite difference approximations to the heat diffusion equation in cylindrical coordinates. The temperature dependence of the thermal properties of the pyrotechnic materials and of the bridgewire are modeled. An Arrhenius' model is used to describe the exothermic reaction in the powder. One model employs a single radial coordinate and predicts the radial temperature distribution in the bridgewire and surrounding powder mass. In addition to the radial coordinate, the other model also employs a longitudinal coordinate to predict the temperature distribution parallel to the axis of the bridgewire. The predictions of the two-dimensional model concerning the energy requirements for ignition and the energy losses from the ends of the bridgewire are presented. A comparison of the predictions of the two models and the development of thermal gradients are employed to define the regime where the assumption, in the one-dimensional model, of negligible heat transfer axial to the bridgewire does not lead to significant error. The general problems associated with predicting ignition from a diffusion model are also discussed.

  11. COMPTEL solar flare observations

    NASA Technical Reports Server (NTRS)

    Ryan, J. M.; Aarts, H.; Bennett, K.; Debrunner, H.; Devries, C.; Denherder, J. W.; Eymann, G.; Forrest, D. J.; Diehl, R.; Hermsen, W.

    1992-01-01

    COMPTEL as part of a solar target of opportunity campaign observed the sun during the period of high solar activity from 7-15 Jun. 1991. Major flares were observed on 9 and 11 Jun. Although both flares were large GOES events (greater than or = X10), they were not extraordinary in terms of gamma-ray emission. Only the decay phase of the 15 Jun. flare was observed by COMPTEL. We report the preliminary analysis of data from these flares, including the first spectroscopic measurement of solar flare neutrons. The deuterium formation line at 2.223 MeV was present in both events and for at least the 9 Jun. event, was comparable to the flux in the nuclear line region of 4-8 MeV, consistent with Solar-Maximum Mission (SSM) Observations. A clear neutron signal was present in the flare of 9 Jun. with the spectrum extending up to 80 MeV and consistent in time with the emission of gamma-rays, confirming the utility of COMPTEL in measuring the solar neutron flux at low energies. The neutron flux below 100 MeV appears to be lower than that of the 3 Jun. 1982 flare by more than an order of magnitude. The neutron signal of the 11 Jun. event is under study. Severe dead time effects resulting from the intense thermal x-rays require significant corrections to the measured flux which increase the magnitude of the associated systematic uncertainties.

  12. Development of low-shock pyrotechnic separation nuts. [design performance of flight type nuts

    NASA Technical Reports Server (NTRS)

    Bement, L. J.; Neubert, V. H.

    1973-01-01

    Performance demonstrations and comparisons were made on six flight type pyrotechnic separation nut designs, two of which are standard designs in current use, and four of which were designed to produce low shock on actuation. Although the shock performances of the four low shock designs are considerably lower than the standard designs, some penalties may be incurred in increased volume, weight, or complexity. These nuts, and how they are installed, can significantly influence the pyrotechnic shock created in spacecraft structures. A high response monitoring system has been developed and demonstrated to provide accurate performance comparisons for pyrotechnic separation nuts.

  13. Copper(I) Bromide: An Alternative Emitter for Blue-Colored Flame Pyrotechnics.

    PubMed

    Juknelevicius, Dominykas; Karvinen, Eero; Klapötke, Thomas M; Kubilius, Rytis; Ramanavicius, Arunas; Rusan, Magdalena

    2015-10-19

    Copper(I) bromide was evaluated as an alternative emitter for blue flame pyrotechnic compositions. CuBr and CuCl emission spectra were recorded from a butane torch flame and compared. Cu(BrO3 )2 was synthesized and used in pyrotechnic compositions as an oxidizer and the source for the generation of CuBr species. Pyrotechnic compositions, which contained copper and potassium bromates as oxidizers, were optimized for the generation of blue flames. The experimental data, including emission spectra of the flames, chromaticity coordinates, burning rates, luminous intensities, and sensitivity tests, were analyzed and compared. PMID:26471445

  14. 46 CFR 160.066-9 - Labeling.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... boats as required by 33 CFR 175.110. For Emergency Use Only”. (b) If the signal is too small to contain...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160...: (1) The manufacturer's name, (2) The designed burning time of the pyrotechnic candle(s), (3)...

  15. 46 CFR 160.066-9 - Labeling.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... boats as required by 33 CFR 175.110. For Emergency Use Only”. (b) If the signal is too small to contain...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160...: (1) The manufacturer's name, (2) The designed burning time of the pyrotechnic candle(s), (3)...

  16. 46 CFR 160.066-9 - Labeling.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... boats as required by 33 CFR 175.110. For Emergency Use Only”. (b) If the signal is too small to contain...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160...: (1) The manufacturer's name, (2) The designed burning time of the pyrotechnic candle(s), (3)...

  17. 46 CFR 160.066-9 - Labeling.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... boats as required by 33 CFR 175.110. For Emergency Use Only”. (b) If the signal is too small to contain...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160...: (1) The manufacturer's name, (2) The designed burning time of the pyrotechnic candle(s), (3)...

  18. Flare Activity on Stars

    NASA Astrophysics Data System (ADS)

    Oskanian, V. S.

    A review of the existing flare data analyses indicates that most probably the flare phenomenon should be considered as one of the manifestation forms of solar-type chromospheric activity on stars and therefore has to be investigated in common with other phenomena specifying this activity. In order to estimate the reliability of such an approach different types of observational data are discussed. It could be shown that most of the phenomena specifying the solar chromospheric activity (BY Dra syndrome, indicating the spottedness of the stellar surface, long-term cyclic variations of emission line intensities, variable local magnetic fields, flares, coronal phenomena, etc.) are observable on a constantly growing number of stars of almost all spectral types and luminosity classes. This fact indicates that the proposed approach could be the right way to solve the problem of the flare phenomenon.

  19. Flare ignition system

    SciTech Connect

    Sorelle, R.R.

    1984-05-22

    A flare ignition system is claimed for oil well flaring of combustible gases. It includes a central control unit, low voltage interconnect line and plural remote igniter units which include alternate first and second spark gaps coordinated in fail-safe operation. Coordination is carried out by pulse counting and validating circuitry which assures that one of the spark gaps will always be ignitable or alarm condition will exist.

  20. Solar flare particle radiation

    NASA Technical Reports Server (NTRS)

    Lanzerotti, L. J.

    1972-01-01

    The characteristics of the solar particles accelerated by solar flares and subsequently observed near the orbit of the earth are studied. Considered are solar particle intensity-time profiles, the composition and spectra of solar flare events, and the propagation of solar particles in interplanetary space. The effects of solar particles at the earth, riometer observations of polar cap cosmic noise absorption events, and the production of solar cell damage at synchronous altitudes by solar protons are also discussed.

  1. Aerial Image Systems

    NASA Astrophysics Data System (ADS)

    Clapp, Robert E.

    1987-09-01

    Aerial images produce the best stereoscopic images of the viewed world. Despite the fact that every optic in existence produces an aerial image, few persons are aware of their existence and possible uses. Constant reference to the eye and other optical systems have produced a psychosis of design that only considers "focal planes" in the design and analysis of optical systems. All objects in the field of view of the optical device are imaged by the device as an aerial image. Use of aerial images in vision and visual display systems can provide a true stereoscopic representation of the viewed world. This paper discusses aerial image systems - their applications and designs and presents designs and design concepts that utilize aerial images to obtain superior visual displays, particularly with application to visual simulation.

  2. Aquarium test evaluation of a pyrotechnic's ability to perform work in microsecond time frames

    NASA Astrophysics Data System (ADS)

    Forbes, J. W.; Glancy, B. C.; Liddiard, T. P.; Wilson, W. H.

    1998-07-01

    Pyrotechnic materials can release tremendous thermal energy upon reaction. A pyrotechnic's ability to do work, when mixed with other materials to produce a working fluid at high pressure and temperature, is studied in this work. An experimental technique is used to measure underwater expansion of cylinders containing porous pyrotechnic materials shock compressed by a surrounding annular explosive charge. Expansion velocity enhancement due to reaction in the pyrotechnic core is detected as an increase in outer wall velocity over that obtained with a solid inert core. The outer wall expansion is measured for 180 μs after wall motion begins, so that relatively late-time energy release from the core may be detected.

  3. Strain gage selection and bonding techniques for application in a cryogenic-pyrotechnic environment

    NASA Astrophysics Data System (ADS)

    Law, William F.

    Strain gage tests were conducted in order to evaluate the performance of WK06-062AP-350 and weldable MG120-09-30155 gages and different combinations of bonding agent M600 and spot welding techniques in a cryogenic-pyrotechnic environment. The experimental conditions for the cryogenic-pyrotechnic shock, tension-cryogenic, and compression tests are described. The cryogenic-pyrotechnic shock test was performed to examine the strain gage bonding integrity of different installation methods; the tension-cryogenic tests evaluated strain gage ranges and temperature characteristics; and the compression tests provided data on the strain level of directly bonded and welded strain gages. The test data reveal that the WK06-062AP-350 gage and direct bonding are most applicable in a cryogenic-pyrotechnic environment.

  4. [Study on flame temperature measurement of pyrotechnics using multi-spectral thermometer].

    PubMed

    Li, Zhan-ying; Xi, Lan-xia; Chen, Jun; Guo, Chong-xing; Liu, Chun-jian; Liu, Huan-yang

    2010-08-01

    The radiation spectrum of pyrotechnics' burning flame was analyzed using transient spectrum radiometer. The working principle of multi-spectral thermometry was described. Combined with the radiation spectrum of pyrotechnics' burning flame, the multi-spectral thermometer system was designed which had twelve working channels. The tester can choose the right working channels to calculate according to the radiation spectrum of the flame to be tested. The system is composed by optics part, electronic part, data acquisition part and data processing part. In this paper, the emissive power of black powder's flame has been tested using the multi-spectral thermometer system. The burning flame temperature-time curve was showed after iteration calculation Experiments indicate that the multi-spectral thermometer system can be well used to measure the flame temperature of pyrotechnics based on analyzing the emissive power when choosing the right working channels. This method lays a foundation for the research of combustion output characteristics of pyrotechnics. PMID:20939307

  5. 115. PYROTECHNICS MAGAZINE (BUILDINGS 99100), PLAN AND ELEVATIONS, FULLER/SCOTT, MARCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    115. PYROTECHNICS MAGAZINE (BUILDINGS 99-100), PLAN AND ELEVATIONS, FULLER/SCOTT, MARCH 16, 1941. QP ACC 1793. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  6. Apollo Spacecraft and Saturn V Launch Vehicle Pyrotechnics/Explosive Devices

    NASA Technical Reports Server (NTRS)

    Interbartolo, Michael

    2009-01-01

    The Apollo Mission employs more than 210 pyrotechnic devices per mission.These devices are either automatic of commanded from the Apollo spacecraft systems. All devices require high reliability and safety and most are classified as either crew safety critical or mission critical. Pyrotechnic devices have a wide variety of applications including: launch escape tower separation, separation rocket ignition, parachute deployment and release and electrical circuit opening and closing. This viewgraph presentation identifies critical performance, design requirements and safety measures used to ensure quality, reliability and performance of Apollo pyrotechnic/explosive devices. The major components and functions of a typical Apollo pyrotechnic/explosive device are listed and described (initiators, cartridge assemblies, detonators, core charges). The presentation also identifies the major locations and uses for the devices on: the Command and Service Module, Lunar Module and all stages of the launch vehicle.

  7. Development and testing of the pyrotechnic subsystem to the Mariner Mars 1971 spacecraft

    NASA Technical Reports Server (NTRS)

    Alexander, P. (Compiler); Earnest, J.; Murphy, A.; Quinn, J.

    1971-01-01

    Design, fabrication, and testing of the Mariner Mars 1971 pyrotechnic subsystem are reviewed. Emphasis is placed on those changes from the Mariner Mars 1969 configuration. Major problems occurring in the developmental and testing phases are discussed.

  8. Experimental studies of silver iodide pyrotechnic aerosol ice forming efficiency dynamics

    NASA Astrophysics Data System (ADS)

    Shilin, A. G.; Drofa, A. S.; Ivanov, V. N.; Savchenko, A. V.; Shilin, V. A.

    2013-05-01

    The study concerns the problems connected with the temporal variability of aerosol ice forming activity at introduction into the sub-cloud layer and the comparison of aerosol efficiency of produced pyrotechnic mixtures with different silver contents.

  9. Flares on Mira stars?

    NASA Technical Reports Server (NTRS)

    Schaefer, Bradley E.

    1991-01-01

    Fourteen cases of flares reported on Mira type stars have been collected. These flares typically have an amplitude of over half a magnitude, a rise time of minutes, and a duration of tens of minutes. Nine of the 11 stars represent a normal cross section of the Mira population, while the remaining two are in symbiotic systems (CH Cyg and RX Pup). The flares were observed photographically (five cases), photometrically (three cases), visually (three cases), and with radio telescopes (two cases), while CH Cyg has had flares observed by many techniques. The evidence for the existence of flares on Miras is strong but not definitive. It is possible to hypothesize a variety of background or instrumental effects that could explain all 14 events; however, there is no evidence that suggests the data should be taken at other than face value, and there are good arguments for rejecting the possibility of artifacts. It is felt that the current data warrant systematic observational and theoretical investigation of the possibility of flares on Mira stars.

  10. The solar flare myth

    NASA Technical Reports Server (NTRS)

    Gosling, J. T.

    1993-01-01

    Many years of research have demonstrated that large, nonrecurrent geomagnetic storms, shock wave disturbances in the solar wind, and energetic particle events in interplanetary space often occur in close association with large solar flares. This result has led to a pradigm of cause and effect - that large solar flares are the fundamental cause of these events in the near-Earth space environmemt. This paradigm, which I call 'the solar flare myth,' dominates the popular perception of the relationship between solar activity and interplanetary and geomagnetic events and has provided much of the pragmatic rationale for the study of the solar flare phenomenon. Yet there is good evidence that this paradigm is wrong and that flares do not generally play a central role in producing major transient disturbances in the near-Earth space environment. In this paper I outline a different paradigm of cause and effect that removes solar flares from their central position in the chain of events leading from the Sun to near-Earth space. Instead, this central role is given to events known as coronal mass ejections.

  11. Alternate methods for high level pyrotechnic shock simulation

    NASA Astrophysics Data System (ADS)

    Gray, Phillip J., Sr.

    Two effective methods to recreate a realistic pyrotechnic shock are presented. The first method employs a resonant beam and is used for SRS levels of 12,000 G or more. The test unit is at one end of the beam and a hammer strikes the opposite end causing a shock to be transmitted to the other end of the fixture. The second method is based on a standard shaker system with a resonant beam to amplify the input signal. The engineer defines the duration of the shock signal induced to the vibration amplifier using the GenRad 2514 controller. The shock signal is then input via the shaker to the resonant beam, which amplifies the signal to produce the desired response at the end of the fixture. The shock response spectrum stays within a +/-6 dB tolerance with levels as high as 3000 G peak. These methods are repeatable, reliable, cost-effective, and consistent with a real pyroevent.

  12. Solar flares, flare particles and geomagnetic disturbances

    NASA Astrophysics Data System (ADS)

    Ogawa, T.

    1986-03-01

    Geomagnetic disturbances related to solar-terrestrial events during the period June-September 1982 are described. The cause of these activities is investigated using solar phenomena and solar flare particles observed by the geostationary satellite GMS-2/SEM (Space Environment Monitor). It is noted that the geomagnetic disturbances in June were weak, two big geomagnetic storms occurred in September, and the largest storm, caused by a large flare, occurred on July 13-14. The July 13-14, 1972 storm is compared to the February 11-12, 1958 storm observed by Hakura and Nagai (1964, 1965) and the August 4-5, 1972 storm data of Hakura (1976). The July storm was characterized by a deep depression of the H-component caused by an abnormal expansion of the substorm-associated current system in the auroral zone toward the Far East and was short-lived.

  13. Aerial photographic reproductions

    USGS Publications Warehouse

    U.S. Geological Survey

    1975-01-01

    The National Cartographic Information Center of the U.S. Geological Survey maintains records of aerial photographic coverage of the United States and its Territories, based on reports from other Federal agencies as well as State governmental agencies and commercial companies. From these records, the Center furnishes data to prospective purchasers on available photography and the agency holding the aerial film.

  14. Flare Plasma Iron Abundance

    NASA Technical Reports Server (NTRS)

    Dennis, Brian R.; Dan, Chau; Jain, Rajmal; Schwartz, Richard A.; Tolbert, Anne K.

    2008-01-01

    The equivalent width of the iron-line complex at 6.7 keV seen in flare X-ray spectra suggests that the iron abundance of the hottest plasma at temperatures >approx.10 MK may sometimes be significantly lower than the nominal coronal abundance of four times the photospheric value that is commonly assumed. This conclusion is based on X-ray spectral observations of several flares seen in common with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Solar X-ray Spectrometer (SOXS) on the second Indian geostationary satellite, GSAT-2. The implications of this will be discussed as it relates to the origin of the hot flare plasma - either plasma already in the corona that is directly heated during the flare energy release process or chromospheric plasma that is heated by flare-accelerated particles and driven up into the corona. Other possible explanations of lower-than-expected equivalent widths of the iron-line complex will also be discussed.

  15. Flares and habitability

    NASA Astrophysics Data System (ADS)

    Abrevaya, Ximena C.; Cortón, Eduardo; Mauas, Pablo J. D.

    2012-07-01

    At present, dwarf M stars are being considered as potential hosts for habitable planets. However, an important fraction of these stars are flare stars, which among other kind of radiation, emit large amounts of UV radiation during flares, and it is unknown how this events can affect life, since biological systems are particularly vulnerable to UV. In this work we evaluate a well known dMe star, EV Lacertae (GJ 873) as a potential host for the emergence and evolution of life, focusing on the effects of the UV emission associated with flare activity. Since UV-C is particularly harmful for living organisms, we studied the effect of UV-C radiation on halophile archaea cultures. The halophile archaea or haloarchaea are extremophile microorganisms, which inhabit in hypersaline environments and which show several mechanisms to cope with UV radiation since they are naturally exposed to intense solar UV radiation on Earth. To select the irradiance to be tested, we considered a moderate flare on this star. We obtained the mean value for the UV-C irradiance integrating the IUE spectrum in the impulsive phase, and considering a hypothetical planet in the center of the liquid water habitability zone. To select the irradiation times we took the most frequent duration of flares on this star which is from 9 to 27 minutes. Our results show that even after considerable UV damage, the haloarchaeal cells survive at the tested doses, showing that this kind of life could survive in a relatively hostile UV environment.

  16. Flare build-up study: Homologous flares group - Interim report

    NASA Technical Reports Server (NTRS)

    Woodgate, B. E.

    1982-01-01

    When homologous flares are broadly defined as having footpoint structures in common, it is found that a majority of flares fall into homologous sets. Filament eruptions and mass ejection in members of an homologous flare set show that maintainance of the magnetic structure is not a necessary condition for homology.

  17. AuNP flares-capped mesoporous silica nanoplatform for MTH1 detection and inhibition.

    PubMed

    Gao, Wen; Cao, Wenhua; Sun, Yuhui; Wei, Xueping; Xu, Kehua; Zhang, Huaibin; Tang, Bo

    2015-11-01

    The human mutT homologue MTH1, a nucleotide pool sanitizing enzyme, represents a vulnerability factor and an attractive target for anticancer therapy. However, there is currently a lack of selective and effective platforms for the detection and inhibition of MTH1 in cells. Here, we demonstrate for the first time a gold nanoparticle (AuNP) flares-capped mesoporous silica nanoparticle (MSN) nanoplatform that is capable of detecting MTH1 mRNA and simultaneously suppressing MTH1 activity. The AuNP flares are made from AuNPs that are functionalized with a dense shell of MTH1 recognition sequences hybridized to short cyanine (Cy5)-labeled reporter sequences and employed to seal the pores of MSN to prevent the premature MTH1 inhibitors (S-crizotinib) release. Just like the pyrotechnic flares that produce brilliant light when activated, the resulting AuNP flares@MSN (S-crizotinib) undergo a significant burst of red fluorescence enhancement upon MTH1 mRNA binding. This hybridization event subsequently induces the opening of the pores and the release of S-crizotinib in an mRNA-dependent manner, leading to significant cytotoxicity in cancer cells and improved therapeutic response in mouse xenograft models. We anticipate that this nanoplatform may be an important step toward the development of MTH1-targeting theranostics and also be a useful tool for cancer phenotypic lethal anticancer therapy. PMID:26298289

  18. Towards understanding solar flares

    NASA Technical Reports Server (NTRS)

    Acton, L. W.

    1982-01-01

    Instrumentation and spacecraft payloads developed at Lockheed for solar flare studies are reviewed, noting the significance of the observations for adding to a data base for eventual prediction of the occurrence of flares and subsequent radiation hazards to people in space. Developmental work on the two solar telescopes on board the Skylab pallet was performed at a Lockheed facility, as was the fabrication of very-large-area proportional counter for flights on the Aerobee rocket in 1967. The rocket work led to the fabrication of the Mapping X Ray Heliometer on the Orbiting Solar Observatory and the X Ray Polychromator for the Solar Maximum Mission. The Polychromator consists of a bent crystal spectrometer for high time resolution flare studies over a wide field of view, and a flat crystal spectrometer for simultaneous polychromatic imaging at 7 different X ray wavelengths.

  19. Fields, Flares, And Forecasts

    NASA Astrophysics Data System (ADS)

    Boucheron, L.; Al-Ghraibah, Amani; McAteer, J.; Cao, H.; Jackiewicz, J.; McNamara, B.; Voelz, D.; Calabro, B.; DeGrave, K.; Kirk, M.; Madadi, A.; Petsov, A.; Taylor, G.

    2011-05-01

    Solar active regions are the source of many energetic and geo-effective events such as solar flares and coronal mass ejections (CMEs). Understanding how these complex source regions evolve and produce these events is of fundamental importance, not only to solar physics, but also to the demands of space weather forecasting. We propose to investigate the physical properties of active region magnetic fields using fractal-, gradient-, neutral line-, emerging flux-, wavelet- and general image-based techniques, and to correlate them to solar activity. The combination of these projects with solarmonitor.org and the international Max Millenium Campaign presents an opportunity for accurate and timely flare predictions for the first time. Many studies have attempted to relate solar flares to their concomitant magnetic field distributions. However, a consistent, causal relationship between the magnetic field on the photosphere and the production of solar flares is unknown. Often the local properties of the active region magnetic field - critical in many theories of activity - are lost in the global definition of their diagnostics, in effect smoothing out variations that occur on small spatial scales. Mindful of this, our overall goal is to create measures that are sensitive to both the global and the small-scale nature of energy storage and release in the solar atmosphere in order to study solar flare prediction. This set of active region characteristics will be automatically explored for discriminating features through the use of feature selection methods. Such methods search a feature space while optimizing a criterion - the prediction of a flare in this case. The large size of the datasets used in this project make it well suited for an exploration of a large feature space. This work is funded through a New Mexico State University Interdisciplinary Research Grant.

  20. Solar flare model atmospheres

    NASA Technical Reports Server (NTRS)

    Hawley, Suzanne L.; Fisher, George H.

    1993-01-01

    Solar flare model atmospheres computed under the assumption of energetic equilibrium in the chromosphere are presented. The models use a static, one-dimensional plane parallel geometry and are designed within a physically self-consistent coronal loop. Assumed flare heating mechanisms include collisions from a flux of non-thermal electrons and x-ray heating of the chromosphere by the corona. The heating by energetic electrons accounts explicitly for variations of the ionized fraction with depth in the atmosphere. X-ray heating of the chromosphere by the corona incorporates a flare loop geometry by approximating distant portions of the loop with a series of point sources, while treating the loop leg closest to the chromospheric footpoint in the plane-parallel approximation. Coronal flare heating leads to increased heat conduction, chromospheric evaporation and subsequent changes in coronal pressure; these effects are included self-consistently in the models. Cooling in the chromosphere is computed in detail for the important optically thick HI, CaII and MgII transitions using the non-LTE prescription in the program MULTI. Hydrogen ionization rates from x-ray photo-ionization and collisional ionization by non-thermal electrons are included explicitly in the rate equations. The models are computed in the 'impulsive' and 'equilibrium' limits, and in a set of intermediate 'evolving' states. The impulsive atmospheres have the density distribution frozen in pre-flare configuration, while the equilibrium models assume the entire atmosphere is in hydrostatic and energetic equilibrium. The evolving atmospheres represent intermediate stages where hydrostatic equilibrium has been established in the chromosphere and corona, but the corona is not yet in energetic equilibrium with the flare heating source. Thus, for example, chromospheric evaporation is still in the process of occurring.

  1. Valentines Day X2 Flare

    NASA Video Gallery

    Active region 1158 let loose with an X2.2 flare at 0153 UT or 8:50 pm ET on February 15, 2011, the largest flare since Dec. 2006 and the biggest flare so far in Solar Cycle 24. This video was taken...

  2. Activation of solar flares

    SciTech Connect

    Cargill, P.J.; Migliuolo, S.; Hood, A.W.

    1984-11-01

    The physics of the activation of two-ribbon solar flares via the MHD instability of coronal arcades is presented. The destabilization of a preflare magnetic field is necessary for a rapid energy release, characteristic of the impulsive phase of the flare, to occur. The stability of a number of configurations are examined, and the physical consequences and relative importance of varying pressure profiles and different sets of boundary conditions (involving field-line tying) are discussed. Instability modes, driven unstable by pressure gradients, are candidates for instability. Shearless vs. sheared equilibria are also discussed. (ESA)

  3. GAMMA-RAY BURST FLARES: ULTRAVIOLET/OPTICAL FLARING. I

    SciTech Connect

    Swenson, C. A.; Roming, P. W. A.; De Pasquale, M.; Oates, S. R.

    2013-09-01

    We present a previously unused method for the detection of flares in gamma-ray burst (GRB) light curves and use this method to detect flares in the ultraviolet/optical. The algorithm makes use of the Bayesian Information Criterion to analyze the residuals of the fitted light curve, removing all major features, and to determine the statistically best fit to the data by iteratively adding additional ''breaks'' to the light curve. These additional breaks represent the individual components of the detected flares: T{sub start}, T{sub stop}, and T{sub peak}. We present the detection of 119 unique flaring periods detected by applying this algorithm to light curves taken from the Second Swift Ultraviolet/Optical Telescope (UVOT) GRB Afterglow Catalog. We analyzed 201 UVOT GRB light curves and found episodes of flaring in 68 of the light curves. For those light curves with flares, we find an average number of {approx}2 flares per GRB. Flaring is generally restricted to the first 1000 s of the afterglow, but can be observed and detected beyond 10{sup 5} s. More than 80% of the flares detected are short in duration with {Delta}t/t of <0.5. Flares were observed with flux ratios relative to the underlying light curve of between 0.04 and 55.42. Many of the strongest flares were also seen at greater than 1000 s after the burst.

  4. Gamma-Ray Burst Flares: Ultraviolet/Optical Flaring. I.

    NASA Astrophysics Data System (ADS)

    Swenson, C. A.; Roming, P. W. A.; De Pasquale, M.; Oates, S. R.

    2013-09-01

    We present a previously unused method for the detection of flares in gamma-ray burst (GRB) light curves and use this method to detect flares in the ultraviolet/optical. The algorithm makes use of the Bayesian Information Criterion to analyze the residuals of the fitted light curve, removing all major features, and to determine the statistically best fit to the data by iteratively adding additional "breaks" to the light curve. These additional breaks represent the individual components of the detected flares: T start, T stop, and T peak. We present the detection of 119 unique flaring periods detected by applying this algorithm to light curves taken from the Second Swift Ultraviolet/Optical Telescope (UVOT) GRB Afterglow Catalog. We analyzed 201 UVOT GRB light curves and found episodes of flaring in 68 of the light curves. For those light curves with flares, we find an average number of ~2 flares per GRB. Flaring is generally restricted to the first 1000 s of the afterglow, but can be observed and detected beyond 105 s. More than 80% of the flares detected are short in duration with Δt/t of <0.5. Flares were observed with flux ratios relative to the underlying light curve of between 0.04 and 55.42. Many of the strongest flares were also seen at greater than 1000 s after the burst.

  5. Statistical aspects of solar flares

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1987-01-01

    A survey of the statistical properties of 850 H alpha solar flares during 1975 is presented. Comparison of the results found here with those reported elsewhere for different epochs is accomplished. Distributions of rise time, decay time, and duration are given, as are the mean, mode, median, and 90th percentile values. Proportions by selected groupings are also determined. For flares in general, mean values for rise time, decay time, and duration are 5.2 + or - 0.4 min, and 18.1 + or 1.1 min, respectively. Subflares, accounting for nearly 90 percent of the flares, had mean values lower than those found for flares of H alpha importance greater than 1, and the differences are statistically significant. Likewise, flares of bright and normal relative brightness have mean values of decay time and duration that are significantly longer than those computed for faint flares, and mass-motion related flares are significantly longer than non-mass-motion related flares. Seventy-three percent of the mass-motion related flares are categorized as being a two-ribbon flare and/or being accompanied by a high-speed dark filament. Slow rise time flares (rise time greater than 5 min) have a mean value for duration that is significantly longer than that computed for fast rise time flares, and long-lived duration flares (duration greater than 18 min) have a mean value for rise time that is significantly longer than that computed for short-lived duration flares, suggesting a positive linear relationship between rise time and duration for flares. Monthly occurrence rates for flares in general and by group are found to be linearly related in a positive sense to monthly sunspot number. Statistical testing reveals the association between sunspot number and numbers of flares to be significant at the 95 percent level of confidence, and the t statistic for slope is significant at greater than 99 percent level of confidence. Dependent upon the specific fit, between 58 percent and 94 percent of

  6. FLARE EFFICIENCY STUDY

    EPA Science Inventory

    The report gives results of a full-scale experimental study to determine the efficiencies of flare burners for disposing of hydrocarbon (HC) emissions from refinery and petrochemical processes. With primary objectives of determining the combustion efficiency and HC destruction ef...

  7. Metal-organic fireworks: MOFs as integrated structural scaffolds for pyrotechnic materials.

    PubMed

    Blair, L H; Colakel, A; Vrcelj, R M; Sinclair, I; Coles, S J

    2015-08-01

    A new approach to formulating pyrotechnic materials is presented whereby constituent ingredients are bound together in a solid-state lattice. This reduces the batch inconsistencies arising from the traditional approach of combining powders by ensuring the key ingredients are 'mixed' in appropriate quantities and are in intimate contact. Further benefits of these types of material are increased safety levels as well as simpler logistics, storage and manufacture. A systematic series of new frameworks comprising fuel and oxidiser agents (group 1 and 2 metal nodes & terephthalic acid derivatives as linkers) has been synthesised and structurally characterised. These new materials have been assessed for pyrotechnic effect by calorimetry and burn tests. Results indicate that these materials exhibit the desired pyrotechnic material properties and the effect can be correlated to the dimensionality of the structure. A new approach to formulating pyrotechnic materials is proposed whereby constituent ingredients are bound together in a solid-state lattice. A series of Metal-organic framework frameworks comprising fuel and oxidiser agents exhibits the desired properties of a pyrotechnic material and this effect is correlated to the dimensionality of the structure. PMID:26138789

  8. Study of the Spatial Distribution of Burning Particles in a Pyrotechnic Flame Based on Particle Velocity

    NASA Astrophysics Data System (ADS)

    Zhu, Chen-Guang; Xu, Chungen; Xue, Rui

    2014-10-01

    The burning particles in the pyrotechnic flame play an important role in the ignition and spectral radiance of the pyrotechnic. We used particle image velocimetry (PIV) and high-speed camera (HSC) photography to investigate the 3D spatial pattern and velocity of the burning particles in the flame of pyrotechnics. The original images captured by the HSC were preprocessed through threshold selection, image bivalency, edge detection, and contour extraction and segmentation to obtain the particle coordinates and velocity. Consequently, the particle tracking model was established and the velocity and spatial distribution of the burning particles were obtained. A comparison of the flame flow field with particle image velocimetry demonstrated the typical characteristics of the two-phase flow of the pyrotechnic flame between burning particles and gas. Compared with the convergent gas flow field, the higher velocity burning particles had a discrete distribution in the "comet tail" shape region and showed the same direction of motion as the flame flow field, whereas the lower velocity burning particles had larger outlying regions and showed inconsistent directions of motion. The flow field of the burning particles was more chaotic than the flame flow field of the burning pyrotechnics.

  9. Chemical and toxicological evaluation of pyrotechnically disseminated terephthalic acid smoke.

    PubMed

    Muse, W T; Anthony, J S; Bergmann, J D; Burnett, D C; Crouse, C L; Gaviola, B P; Thomson, S A

    1997-11-01

    The terephthalic acid (TPA) smoke obscurants (M-83 grenade and M-8 smoke pot) were developed by the U.S. Army for training purposes to replace the more toxic hexachloroethane (HC) smoke. Inhalation toxicity testing and chemical characterization of pyrotechnically generated TPA was conducted to assess the health hazard potential of TPA and its combustion products. Fisher 344 rats were subjected to acute and repeated exposures to TPA smoke generated from the M-83 grenade. Acute exposure levels ranged from 150-1,900 mg/m3 for 30 minutes and repeated dose exposures ranged from 128-1,965 mg/m3 for 30 min/day for 5 days. Exposed and control rats were evaluated for toxic signs, and histopathologic changes. During exposure, the rats exhibited slight to moderate lacrimation, rhinorrhea, lethargy and dyspnea, which reversed within 1-hr post-exposure. No deaths occurred, even at the highest smoke concentrations. Histopathological changes were confined to exposure related nasal necrosis and inflammation in both the acute and repeated dose exposures at levels above 900 mg/m3. Chemical characterization of the M-83 grenade and the M-8 smoke pot showed that formaldehyde, benzene and carbon monoxide were the major organic vapor by-products formed. These by-products were above their respective ACGIH threshold limit values at various concentrations, but should not pose a hazard if the smoke is deployed in an open area. Overall, TPA is a safer training smoke to replace the HC smoke. PMID:9433658

  10. Surface compatibility studies of potassium perchlorate reaction with pyrotechnic fuels

    SciTech Connect

    Wang, P.S.; Moddeman, W.E.; Bowling, W.C.

    1983-01-01

    Surface sensitive x-ray photoelectron spectroscopy (XPS) and x-ray induced Auger electron spectroscopy (XAES) were used to analyze surface changes in Fe/KClO/sub 4/, TiH/sub 0/ /sub 65//KClO/sub 4/ and Al foils in KClO/sub 4/ during accelerated aging at 60 and 120/sup 0/C. The result shows a 0.02% Cl/sup -/ formation per day in Fe/KClO/sub 4/ and TiH/sub 0/ /sub 65//KC 1O/sub 4/ powders aged at 120/sup 0/C for less than or equal to 145 days. No KClO/sub 4/ decomposition was observed under the similar aging conditions in KClO/sub 4/ samples without pyrotechnic fuels. Titanium oxide to KClO/sub 4/ signal ratio in a pressed disk of TiH/sub 0/ /sub 65//KClO/sub 4/ was found to be lower than that of the powdered samples. Carbon impurities were noted in all powders, especially strong in metal (or subhydride) containing specimens; carbon impurities were slightly removed from the subhydride during aging.

  11. Modeling low energy laser ignition of explosive and pyrotechnic powders

    SciTech Connect

    Glass, M.W.; Merson, J.A.; Salas, F.J.

    1992-01-01

    Laser diode ignition (LDI) of explosives and pyrotechnics is being developed at Sandia National Laboratories as a replacement for low energy hotwire devices. This technology offers significant improvements in device safety due to the insensitivity to electrostatic discharge (ESD) and electromagnetic radiation (EMR). The LDI system incorporates a laser diode source, a fiber optic cable to transmit the laser energy, and the energetic component. The laser energy is volumetrically absorbed by the explosive component causing its temperature to rise to its auto-ignition temperature. Substantial experimental work characterizing the optical ignition mechanism has been undertaken in support of the LDI development work. This work has primarily been focused on the explosive component, CP, 2-(5-cyanotetrazolato) pentaamminecobalt(III) perchlorate, doped with a small amount of carbon black to enhance the laser energy absorptance at the 850 nm wavelength of the laser diode. To support the experimental efforts, numerical modeling of the thermal response of CP to a low energy laser input has been undertaken.

  12. Modeling low energy laser ignition of explosive and pyrotechnic powders

    SciTech Connect

    Glass, M.W.; Merson, J.A.; Salas, F.J.

    1992-07-01

    Laser diode ignition (LDI) of explosives and pyrotechnics is being developed at Sandia National Laboratories as a replacement for low energy hotwire devices. This technology offers significant improvements in device safety due to the insensitivity to electrostatic discharge (ESD) and electromagnetic radiation (EMR). The LDI system incorporates a laser diode source, a fiber optic cable to transmit the laser energy, and the energetic component. The laser energy is volumetrically absorbed by the explosive component causing its temperature to rise to its auto-ignition temperature. Substantial experimental work characterizing the optical ignition mechanism has been undertaken in support of the LDI development work. This work has primarily been focused on the explosive component, CP, 2-(5-cyanotetrazolato) pentaamminecobalt(III) perchlorate, doped with a small amount of carbon black to enhance the laser energy absorptance at the 850 nm wavelength of the laser diode. To support the experimental efforts, numerical modeling of the thermal response of CP to a low energy laser input has been undertaken.

  13. Safety analysis of optically ignited explosive and pyrotechnic devices

    SciTech Connect

    Merson, J.A.; Salas, F.J.; Holswade, S.

    1994-05-01

    The future of optical ordnance depends on the acceptance, validation and verification of the stated safety enhancement claims of optical ordnance over existing electrical explosive devices (EED`s). Sandia has been pursuing the development of optical ordnance, with the primary motivation of this effort being the enhancement of explosive safety by specifically reducing the potential of premature detonation that can occur with low energy electrically ignited explosive devices. By using semiconductor laser diodes for igniting these devices, safety improvements can be made without being detrimental to current system concerns since the inputs required for these devices are similar to electrical systems. Laser Diode Ignition (LDI) of the energetic material provides the opportunity to remove the bridgewire and electrically conductive pins from the charge cavity, creating a Faraday cage and thus isolating the explosive or pyrotechnic materials from stray electrical ignition sources. Recent results from our continued study of safety enhancements are presented. The areas of investigation which are presented include: (1) unintended optical source analysis, specifically lightning insensitivity, (2) electromagnetic radiation (EMR) and electrostatic discharge (ESD) insensitivity analysis, and (3) powder safety.

  14. Diode laser ignition of explosive and pyrotechnic components

    SciTech Connect

    Jungst, R.G.; Salas, F.J.

    1990-01-01

    The Laser Diode Ignition (LDI) program at Sandia Laboratories has as its objective the development of optically ignited analogs to the presently used low energy, hot wire igniters, DDT detonators, and actuators. In our concept, optical energy would be transmitted from a diode laser to the explosive or pyrotechnic power via a fiber optic. The laser energy is coupled to the energetic powder through a hermetically sealed optical feedthrough in the charge cavity. Optical ignition has many advantages, most of which are related to the removal of electrical leads to the powder interface. This eliminates concerns such as sensitivity to electrostatic discharge and electromagnetic radiation, conductance after fire, and isolation resistance. The optical interface would also not have the corrosion tendency that has occasionally been a problem with bridgewires. Another convenient property of diode laser sources is that the current and voltage needed to drive them are quite similar to those now applied to bridgewires for hot wire ignition. Therefore LDI devices would have an overall electrical requirement which is nearly identical to that of the hot wire components they are replacing.

  15. Gamma-ray burst flares: X-ray flaring. II

    SciTech Connect

    Swenson, C. A.; Roming, P. W. A.

    2014-06-10

    We present a catalog of 498 flaring periods found in gamma-ray burst (GRB) light curves taken from the online Swift X-Ray Telescope GRB Catalogue. We analyzed 680 individual light curves using a flare detection method developed and used on our UV/optical GRB Flare Catalog. This method makes use of the Bayesian Information Criterion to analyze the residuals of fitted GRB light curves and statistically determines the optimal fit to the light curve residuals in an attempt to identify any additional features. These features, which we classify as flares, are identified by iteratively adding additional 'breaks' to the light curve. We find evidence of flaring in 326 of the analyzed light curves. For those light curves with flares, we find an average number of ∼1.5 flares per GRB. As with the UV/optical, flaring in our sample is generally confined to the first 1000 s of the afterglow, but can be detected to beyond 10{sup 5} s. Only ∼50% of the detected flares follow the 'classical' definition of Δt/t ≤ 0.5, with many of the largest flares exceeding this value.

  16. Effect of equations of state on transient burning analysis of pyrotechnic materials in a closed system

    SciTech Connect

    Razani, A.; Shahinpoor, M. . Dept. of Mechanical Engineering); Hingorani, S.L. )

    1990-01-01

    The effect of equations of state on transient burning of pyrotechnic materials burning in a closed system is discussed. The effect of condensed species and appropriate equations of state parameters as generated from chemical equilibrium codes such as the BLAKE and the TIGER are presented. It is shown that defining a co-volume for use in transient burning analysis in the presence of condensed species requires careful considerations. A variable co-volume is defined for use in simplified transient burning analysis. Furthermore, its effect on pressure-time history of pyrotechnic materials burning in a closed system is presented. A pressure dependent co-volume for the analysis of a particular pyrotechnic material greatly simplifies its transient burning analysis under zero-volume firing conditions. The formulation of transient burning in a closed system is developed using the NBS equation of state. 9 refs., 3 figs.

  17. Pyrotechnic shock: A literature survey of the Linear Shaped Charge (LSC)

    NASA Technical Reports Server (NTRS)

    Smith, J. L.

    1984-01-01

    Linear shaped charge (LSC) literature for the past 20 years is reviewed. The following topics are discussed: (1) LSC configuration; (2) LSC usage; (3) LSC induced pyroshock; (4) simulated pyrotechnic testing; (5) actual pyrotechnic testing; (6) data collection methods; (7) data analysis techniques; (8) shock reduction methods; and (9) design criteria. Although no new discoveries have been made in LSC research, charge shapes are improved to allow better cutting performance, testing instrumentation is refined, and some new explosives, for use in LSC, are formulated.

  18. Numerical model of the thermal processes leading to ignition in a pyrotechnic device

    SciTech Connect

    Pierce, K.G.; Leith, J.R.

    1986-01-01

    The predicted ignition behavior of a hot-wire initiated pyrotechnic device, as obtained from simple numerical models, is presented. The models are based on the heat diffusion equation with temperature dependent properties. The predictions of the model for the short-term responses of a specific pyrotechnic device are consistent with experimental results. The predictions of the long-term response differ significantly from experimental data. The causes of this difference are discussed, and a parametric study of the variables which have an effect on the ignition process is presented.

  19. Morphology and composition of pyrotechnic residues formed at different levels of confinement.

    PubMed

    Vermeij, Erwin; Duvalois, Willem; Webb, Rutger; Koeberg, Mattijs

    2009-04-15

    Post explosion residues (PER) are residues from pyrotechnic compositions or explosives that are generated during an explosion. In the recent past SEM/EDX was used several times to analyze PER from pyrotechnic compositions. The results from these studies suggest that there might be a difference in morphology and composition of pyrotechnic residues formed at different levels of confinement. Also because of general thermodynamic principles it is believed that at higher levels of confinement the final pressure and temperature during the explosion is probably (but not necessarily) higher, eventually resulting in smaller and more spherical particles and a more homogeneous elemental composition. If there is a relation between morphology and composition of pyrotechnic residues and the level of confinement at which these are formed, it would be possible to draw conclusions about the conditions at which pyrotechnic residues were formed and the kind and construction of the device used. This may aid forensic scientists not only in the determination of the original explosive composition, but also of the explosive device. To perform controlled experiments with pyrotechnic charges at, at least, two pre-set levels of confinement a test vessel was built by TNO Defence, Security and Safety. For this study, three different flash powder compositions and black powder were selected. The generated residues were sampled on collecting plates and Nucleopore filters connected to a pump system in the immediate vicinity of the venting area for further analyses by SEM/EDX and XRD. From the results it follows that in the pressure range studied, the level of confinement seems to have a minor effect on the features of the generated residue particles. Because passive sampling by means of collector plates seemed doubtful and because the number of experiments had to be limited it is impossible to draw definitive conclusions. In addition to the level of confinement several other variables may affect

  20. Preheating slow-burning pyrotechnic compositions to aid ignition and combustion

    SciTech Connect

    Rao, V.K.; Bardon, M.F.; Twardawa, P.

    1987-01-01

    Proposal is made to preheat the unburned mixture ahead of the reaction front in slow-burning pyrotechnic compositions by incorporating heat-conducting rods parallel to the direction of flame propagation. The objective is to enhance the reliability of ignition transfer and prevent flame quenching in marginally combustible mixtures. A Bruceton analysis of the results of a gap test on a slow-burning pyrotechnic composition, with and without heat-conducting rods, indicates that the mean gap for successful ignition transfer can be increased by almost an order of magnitude by incorporating the heat-conducting rods. 5 references.

  1. Failure Mode Analysis of V-Shaped Pyrotechnically Actuated Valves

    NASA Technical Reports Server (NTRS)

    Sachdev, Jai S.; Hosangadi, A.; Chenoweth, James D.; Saulsberry, Regor L.; McDougle, Stephen H.

    2012-01-01

    Current V-shaped stainless steel pyrovalve initiators have rectified many of the deficiencies of the heritage Y-shaped aluminum design. However, a credible failure mode still exists for dual simultaneous initiator (NSI) firings in which low temperatures were detected at the booster cap and less consistent ignition was observed than when a single initiator was fired. In order to asses this issue, a numerical framework has been developed for predicting the flow through pyrotechnically actuated valves. This framework includes a fully coupled solution of the gas-phase equation with a non-equilibrium dispersed phase for solid particles as well as the capability to model conjugate gradient heat transfer to the booster cap. Through a hierarchy of increasingly complex simulations, a hypothesis for the failure mode of the nearly simultaneous dual NSI firings has been proven. The simulations indicate that the failure mode for simultaneous dual NSI firings may be caused by flow interactions between the flame channels. The shock waves from each initiator interact in the booster cavity resulting in a high pressure that prevents the gas and particulate velocity from rising in the booster cap region. This impedes the bulk of the particulate phase from impacting the booster cap and reduces the heat transfer to the booster cap since the particles do not impact it. Heat transfer calculations to the solid metal indicate that gas-phase convective heat transfer may not be adequate by itself and that energy transfer from the particulate phase may be crucial for the booster cap burn through.

  2. Solar Flare Physics

    NASA Technical Reports Server (NTRS)

    Schmahl, Edward J.; Kundu, Mukul R.

    2000-01-01

    During the past year we have been working with the HESSI (High Energy Solar Spectroscopic Imager) team in preparation for launch in early 2001. HESSI has as its primary scientific goal photometric imaging and spectroscopy of solar flares in hard X-rays and gamma-rays with an approx. 2 sec angular resolution, approx. keV energy resolution and approx. 2 s time resolution over the 6 keV to 15 MeV energy range. We have performed tests of the imager using a specially designed experiment which exploits the second-harmonic response of HESSI's sub-collimators to an artificial X-ray source at a distance of 1550 cm from its front grids. Figures show the response to X-rays at energies in the range where HESSI is expected to image solar flares. To prepare the team and the solar user community for imaging flares with HESSI, we have written a description of the major imaging concepts. This paper will be submitted for publication in a referred journal.

  3. Aerial Photography Summary Record System

    USGS Publications Warehouse

    U.S. Geological Survey

    1998-01-01

    The Aerial Photography Summary Record System (APSRS) describes aerial photography projects that meet specified criteria over a given geographic area of the United States and its territories. Aerial photographs are an important tool in cartography and a number of other professions. Land use planners, real estate developers, lawyers, environmental specialists, and many other professionals rely on detailed and timely aerial photographs. Until 1975, there was no systematic approach to locate an aerial photograph, or series of photographs, quickly and easily. In that year, the U.S. Geological Survey (USGS) inaugurated the APSRS, which has become a standard reference for users of aerial photographs.

  4. Energy release in solar flares

    NASA Technical Reports Server (NTRS)

    Brown, John C.; Correia, Emilia; Farnik, Frantisek; Garcia, Howard; Henoux, Jean-Claude; La Rosa, Ted N.; Machado, Marcos E. (Compiler); Nakajima, Hiroshi; Priest, Eric R.

    1994-01-01

    Team 2 of the Ottawa Flares 22 Workshop dealt with observational and theoretical aspects of the characteristics and processes of energy release in flares. Main results summarized in this article stress the global character of the flaring phenomenon in active regions, the importance of discontinuities in magnetic connectivity, the role of field-aligned currents in free energy storage, and the fragmentation of energy release in time and space.

  5. Evaporative cooling of flare plasma

    NASA Technical Reports Server (NTRS)

    Antiochos, S. K.; Sturrock, P. A.

    1978-01-01

    We investigate a one-dimensional loop model for the evaporative cooling of the coronal flare plasma. The important assumptions are that conductive losses dominate radiative cooling and that the evaporative velocities are small compared with the sound speed. We calculate the profile and evolution of the temperature and verify the accuracy of our assumptions for plasma parameters typical of flare regions. The model is in agreement with soft X-ray observations on the evolution of flare temperatures and emission measures. The effect of evaporation is to greatly reduce the conductive heat flux into the chromosphere and to enhance the EUV emission from the coronal flare plasma.

  6. The flares of August 1972. [solar flare characteristics and spectra

    NASA Technical Reports Server (NTRS)

    Zirin, H.; Tanaka, K.

    1973-01-01

    Observations of the August, 1972 flares at Big Bear and Tel Aviv, involving monochromatic movies, magnetograms, and spectra, are analyzed. The region (McMath 11976) showed inverted polarity from its inception on July 11; the great activity was due to extremely high shear and gradients in the magnetic field, as well as a constant invasion of one polarity into the opposite; observations in lambda 3835 show remarkable fast flashes in the impulsive flare of 18:38 UT on Aug. 2 with lifetimes of 5 sec, which may be due to dumping of particles in the lower chromosphere. Flare loops show evolutionary increases of their tilts to the neutral line in the flares of Aug. 4 and 7. Spectroscopic observations show red asymmetry and red shift of the H alpha emission in the flash phase of the Aug. 7 flare, as well as substantial velocity shear in the photosphere during the flare, somewhat like earthquake movement along a fault. Finally the total H alpha emission of the Aug. 7 flare could be measured accurately as about 2.5 x 10 to the 30th power erg, considerably less than coarser previous estimates for great flares.

  7. 78 FR 27304 - Safety Zone; Melrose Pyrotechnics Fireworks Display; Chicago Harbor, Chicago, IL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-10

    ...-9826. SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Melrose Pyrotechnics Fireworks Display... safety zone is intended to restrict vessels from a portion of Chicago Harbor due to a Fireworks...

  8. State-of-the-art accelerometer characteristics for pyrotechnic shock measurement

    NASA Astrophysics Data System (ADS)

    Wilson, Jon

    1986-08-01

    A brief history, a brief summary of a user survey, and a brief summary of a manufacturer's survey that was conducted to find the state-of-the-art for pyrotechnic shock measurements are presented. It provides a chart summarizing the characteristics of several different accelerometers.

  9. A survey of combustible metals, thermites, and intermetallics for pyrotechnic applications

    SciTech Connect

    Fischer, S.H.; Grubelich, M.C.

    1996-08-01

    Thermite mixtures, intermetallic reactants, and metal fuels have long been used in pyrotechnics. Advantages include high energy density, impact insensitivity, high combustion temperature, and a wide range of gas production. They generally exhibit high temperature stability and possess insensitive ignition properties. This paper reviews the applications, benefits, and characteristics of thermite mixtures, intermetallic reactants, and metal fuels. 50 refs, tables.

  10. 78 FR 39057 - Hours of Service of Drivers; Renewal and Expansion of American Pyrotechnics Association Exemption...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-28

    ...FMCSA announces the granting of an exemption of 55 member- companies of the American Pyrotechnics Association (APA) from FMCSA's regulation prohibiting drivers of commercial motor vehicles (CMVs) from driving after the 14th hour after coming on duty. The FMCSA renews the exemption for 45 APA member-companies and grants 10 additional carriers coverage by the exemption, which is applicable......

  11. Aerial Explorers and Robotic Ecosystems

    NASA Technical Reports Server (NTRS)

    Young, Larry A.; Pisanich, Greg

    2004-01-01

    A unique bio-inspired approach to autonomous aerial vehicle, a.k.a. aerial explorer technology is discussed. The work is focused on defining and studying aerial explorer mission concepts, both as an individual robotic system and as a member of a small robotic "ecosystem." Members of this robotic ecosystem include the aerial explorer, air-deployed sensors and robotic symbiotes, and other assets such as rovers, landers, and orbiters.

  12. Supplier's Status for Critical Solid Propellants, Explosive, and Pyrotechnic Ingredients

    NASA Technical Reports Server (NTRS)

    Sims, B. L.; Painter, C. R.; Nauflett, G. W.; Cramer, R. J.; Mulder, E. J.

    2000-01-01

    In the early 1970's a program was initiated at the Naval Surface Warfare Center/Indian Head Division (NSWC/IHDIV) to address the well-known problems associated with availability and suppliers of critical ingredients. These critical ingredients are necessary for preparation of solid propellants and explosives manufactured by the Navy. The objective of the program was to identify primary and secondary (or back-up) vendor information for these critical ingredients, and to develop suitable alternative materials if an ingredient is unavailable. In 1992 NSWC/IHDIV funded Chemical Propulsion Information Agency (CPIA) under a Technical Area Task (TAT) to expedite the task of creating a database listing critical ingredients used to manufacture Navy propellant and explosives based on known formulation quantities. Under this task CPIA provided employees that were 100 percent dedicated to the task of obtaining critical ingredient suppliers information, selecting the software and designing the interface between the computer program and the database users. TAT objectives included creating the Explosive Ingredients Source Database (EISD) for Propellant, Explosive and Pyrotechnic (PEP) critical elements. The goal was to create a readily accessible database, to provide users a quick-view summary of critical ingredient supplier's information and create a centralized archive that CPIA would update and distribute. EISD funding ended in 1996. At that time, the database entries included 53 formulations and 108 critical used to manufacture Navy propellant and explosives. CPIA turned the database tasking back over to NSWC/IHDIV to maintain and distribute at their discretion. Due to significant interest in propellant/explosives critical ingredients suppliers' status, the Propellant Development and Characterization Subcommittee (PDCS) approached the JANNAF Executive committee (EC) for authorization to continue the critical ingredient database work. In 1999, JANNAF EC approved the PDCS panel

  13. Aerial photographic reproductions

    USGS Publications Warehouse

    U.S. Geological Survey

    1971-01-01

    Geological Survey vertical aerial photography is obtained primarily for topographic and geologic mapping. Reproductions from this photography are usually satisfactory for general use. Because reproductions are not stocked, but are custom processed for each order, they cannot be returned for credit or refund.

  14. Aerial of the VAB

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Even in this aerial view at KSC, the Vehicle Assembly Building is imposing. In front of it is the Launch Control Center. In the background is the Rotation/Processing Facility, next to the Banana Creek. In the foreground is the Saturn Causeway that leads to Launch Pads 39A and 39B.

  15. Aerial Perspective Artistry

    ERIC Educational Resources Information Center

    Wolfe, Linda

    2010-01-01

    This article presents a lesson centering on aerial perspective artistry of students and offers suggestions on how art teachers should carry this project out. This project serves to develop students' visual perception by studying reproductions by famous artists. This lesson allows one to imagine being lured into a landscape capable of captivating…

  16. Nuclear processes in solar flares

    NASA Technical Reports Server (NTRS)

    Ramaty, R.

    1982-01-01

    The theory of solar gamma-ray line production is reviewed and new calculations of line production yields are presented. Observations, carried out with gamma-ray spectrometers on OSO-7, HEAO-1, HEAO-3 and SMM are reviewed and compared with theory. These observations provide direct evidence for nuclear reactions in flares and furnish unique information on particle acceleration and flare mechanisms.

  17. Solar flare discovery

    NASA Technical Reports Server (NTRS)

    Hudson, Hugh S.

    1987-01-01

    This paper considers the discoveries that have appreciably changed our understanding of the physics of solar flares. A total of 42 discoveries from all disciplines, ranging from Galileo's initial observation of faculae to the recent discovery of strong limb brightening in 10-MeV gamma-radiation, are identified. The rate of discovery increased dramatically over the past four decades as new observational tools became available. The assessment of significance suggests that recent discoveries -though more numerous - are individually less significant; perhaps this is because the minor early discoveries tend to be taken for granted.

  18. Fine Structure in Solar Flares.

    PubMed

    Warren

    2000-06-20

    We present observations of several large two-ribbon flares observed with both the Transition Region and Coronal Explorer (TRACE) and the soft X-ray telescope on Yohkoh. The high spatial resolution TRACE observations show that solar flare plasma is generally not confined to a single loop or even a few isolated loops but to a multitude of fine coronal structures. These observations also suggest that the high-temperature flare plasma generally appears diffuse while the cooler ( less, similar2 MK) postflare plasma is looplike. We conjecture that the diffuse appearance of the high-temperature flare emission seen with TRACE is due to a combination of the emission measure structure of these flares and the instrumental temperature response and does not reflect fundamental differences in plasma morphology at the different temperatures. PMID:10859129

  19. Parameterization of solar flare dose

    SciTech Connect

    Lamarche, A.H.; Poston, J.W.

    1996-12-31

    A critical aspect of missions to the moon or Mars will be the safety and health of the crew. Radiation in space is a hazard for astronauts, especially high-energy radiation following certain types of solar flares. A solar flare event can be very dangerous if astronauts are not adequately shielded because flares can deliver a very high dose in a short period of time. The goal of this research was to parameterize solar flare dose as a function of time to see if it was possible to predict solar flare occurrence, thus providing a warning time. This would allow astronauts to take corrective action and avoid receiving a dose greater than the recommended limit set by the National Council on Radiation Protection and Measurements (NCRP).

  20. Study of flow field of burning particles in a pyrotechnic flame based on particle image and particle velocity

    NASA Astrophysics Data System (ADS)

    Xue, R.; Xu, H. Q.; Li, Y.; Zhu, C. G.

    2014-11-01

    Studying the burning particles in the pyrotechnic flame is important to acquire the decomposition mechanism and spectral radiance of pyrotechnics. The high speed video (HSV) and particle image velocimetry (PIV) were used in this paper to analyze the flow field and velocity of burning particles in the flame of pyrotechnics. The binary image was obtained through gray scale treatment and adaptive threshold segmentation from HSV and PIV data, by which the coordinate of each particle was marked. On the basis, the movement trajectory of each particle during combustion was pursued by the most recent guidelines algorithm of cancroids matching. Through the method proposed in this study, the velocity variation of each particle was obtained, the approximate distribution of particle quantity at each zone was visualized and the mathematical model of pyrotechnic particle velocity flow field was established.

  1. Gage tests tube flares quickly and accurately

    NASA Technical Reports Server (NTRS)

    Griffin, F. D.

    1966-01-01

    Flared tube gage with a test cone that is precisely made with a tapering surface to complement the tube flare is capable of determining the accuracy of a tube flare efficiently and economically. This device should improve the speed, efficiency, and accuracy of tube flare inspections.

  2. The Shock and Vibration Bulletin. Part 1: Welcome, Keynote Address, Invited Papers, Nondevelopment Items Workshop and Pyrotechnic Shock Workshop

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The proceedings of the 57th Shock and Vibration Symposium are presented. In part 1 is presented the welcoming and the keynote address along with invited papers such as, Dynamic Testing - Seven Years Later. Papers from the Nondevelopment Items workshop such as, Guidelines for Qualifying Nondevelopment Equipment to Shock and Vibration, are presented. And from the Pyrotechnic Shock Workshop the paper entitled, Designing Electronics for Pyrotechnic Shock, is presented.

  3. Ultraviolet flare on Lambda Andromedae

    NASA Technical Reports Server (NTRS)

    Baliunas, S. L.; Guinan, E. F.; Dupree, A. K.

    1984-01-01

    On November 5, 6, 1982, a luminous, flarelike brightening of the ultraviolet emissions was observed with IUE from the active RS CVn type star Lambda And during the phase of rotation period corresponding to maximum area coverage of the visible hemisphere by starspots and active regions. Enhancements during the flare in the ultraviolet emission lines as large as factors of several and in the ultraviolet continuum up to 80 percent persisted for over 5 hours. The bulk of the radiative output of the flare occurred in Mg II h and k and H I Ly-alpha. Because of the long duration and extreme luminosity of the event, the energy radiated by the flare alone is in excess of 10 to the 35th ergs just in the ultraviolet region. This is the most energetic stellar flare ever recorded in the ultraviolet. In addition, it is the first ultraviolet flare observed from a giant star. In comparison to the largest solar flares, the flare on Lambda And is at least three orders of magnitude more energetic in similar emission lines.

  4. SCATTERING POLARIZATION IN SOLAR FLARES

    SciTech Connect

    Štěpán, Jiří; Heinzel, Petr

    2013-11-20

    There is ongoing debate about the origin and even the very existence of a high degree of linear polarization of some chromospheric spectral lines observed in solar flares. The standard explanation of these measurements is in terms of the impact polarization caused by non-thermal proton and/or electron beams. In this work, we study the possible role of resonance line polarization due to radiation anisotropy in the inhomogeneous medium of the flare ribbons. We consider a simple two-dimensional model of the flaring chromosphere and we self-consistently solve the non-LTE problem taking into account the role of resonant scattering polarization and of the Hanle effect. Our calculations show that the horizontal plasma inhomogeneities at the boundary of the flare ribbons can lead to a significant radiation anisotropy in the line formation region and, consequently, to a fractional linear polarization of the emergent radiation of the order of several percent. Neglecting the effects of impact polarization, our model can provide a clue for resolving some of the common observational findings, namely: (1) why a high degree of polarization appears mainly at the edges of the flare ribbons; (2) why polarization can also be observed during the gradual phase of a flare; and (3) why polarization is mostly radial or tangential. We conclude that radiation transfer in realistic multi-dimensional models of solar flares needs to be considered as an essential ingredient for understanding the observed spectral line polarization.

  5. AERIAL RADIOLOGICAL SURVEYS

    SciTech Connect

    Proctor, A.E.

    1997-06-09

    Measuring terrestrial gamma radiation from airborne platforms has proved to be a useful method for characterizing radiation levels over large areas. Over 300 aerial radiological surveys have been carried out over the past 25 years including U.S. Department of Energy (DOE) sites, commercial nuclear power plants, Formerly Utilized Sites Remedial Action Program/Uranium Mine Tailing Remedial Action Program (FUSRAP/UMTRAP) sites, nuclear weapons test sites, contaminated industrial areas, and nuclear accident sites. This paper describes the aerial measurement technology currently in use by the Remote Sensing Laboratory (RSL) for routine environmental surveys and emergency response activities. Equipment, data-collection and -analysis methods, and examples of survey results are described.

  6. Evaporative cooling of flare plasma

    NASA Technical Reports Server (NTRS)

    Antiochos, S. K.; Sturrock, P. A.

    1976-01-01

    A one-dimensional loop model for the evaporative cooling of the coronal flare plasma was investigated. Conductive losses dominated radiative cooling, and the evaporative velocities were small compared to the sound speed. The profile and evolution of the temperature were calculated. The model was in agreement with soft X-ray observations on the evolution of flare temperatures and emission measures. The effect of evaporation was to greatly reduce the conductive heat flux into the chromosphere and to enhance the EUV emission from the coronal flare plasma.

  7. Flare physics at high energies

    NASA Technical Reports Server (NTRS)

    Ramaty, R.

    1990-01-01

    High-energy processes, involving a rich variety of accelerated particle phenomena, lie at the core of the solar flare problem. The most direct manifestation of these processes are high-energy radiations, gamma rays, hard X-rays and neutrons, as well as the accelerated particles themselves, which can be detected in interplanetary space. In the study of astrophysics from the moon, the understanding of these processes should have great importance. The inner solar system environment is strongly influenced by activity on the sun; the physics of solar flares is of great intrinsic interest; and much high-energy astrophysics can be learned from investigations of flare physics at high energies.

  8. Solar Flare Physics

    NASA Technical Reports Server (NTRS)

    Schmahl, Edward J.; Kundu, Mukul R.

    1998-01-01

    We have continued our previous efforts in studies of fourier imaging methods applied to hard X-ray flares. We have performed physical and theoretical analysis of rotating collimator grids submitted to GSFC(Goddard Space Flight Center) for the High Energy Solar Spectroscopic Imager (HESSI). We have produced simulation algorithms which are currently being used to test imaging software and hardware for HESSI. We have developed Maximum-Entropy, Maximum-Likelihood, and "CLEAN" methods for reconstructing HESSI images from count-rate profiles. This work is expected to continue through the launch of HESSI in July, 2000. Section 1 shows a poster presentation "Image Reconstruction from HESSI Photon Lists" at the Solar Physics Division Meeting, June 1998; Section 2 shows the text and viewgraphs prepared for "Imaging Simulations" at HESSI's Preliminary Design Review on July 30, 1998.

  9. Building Big Flares: Constraining Generating Processes of Solar Flare Distributions

    NASA Astrophysics Data System (ADS)

    Wyse Jackson, T.; Kashyap, V.; McKillop, S.

    2015-12-01

    We address mechanisms which seek to explain the observed solar flare distribution, dN/dE ~ E1.8. We have compiled a comprehensive database, from GOES, NOAA, XRT, and AIA data, of solar flares and their characteristics, covering the year 2013. These datasets allow us to probe how stored magnetic energy is released over the course of an active region's evolution. We fit power-laws to flare distributions over various attribute groupings. For instance, we compare flares that occur before and after an active region reaches its maximum area, and show that the corresponding flare distributions are indistinguishable; thus, the processes that lead to magnetic reconnection are similar in both cases. A turnover in the distribution is not detectable at the energies accessible to our study, suggesting that a self-organized critical (SOC) process is a valid mechanism. However, we find changes in the distributions that suggest that the simple picture of an SOC where flares draw energy from an inexhaustible reservoir of stored magnetic energy is incomplete. Following the evolution of the flare distribution over the lifetimes of active regions, we find that the distribution flattens with time, and for larger active regions, and that a single power-law model is insufficient. This implies that flares that occur later in the lifetime of the active region tend towards higher energies. We conclude that the SOC process must have an upper bound. Increasing the scope of the study to include data from other years and more instruments will increase the robustness of these results. This work was supported by the NSF-REU Solar Physics Program at SAO, grant number AGS 1263241, NASA Contract NAS8-03060 to the Chandra X-ray Center and by NASA Hinode/XRT contract NNM07AB07C to SAO

  10. Multichannel spectrophotometry of stellar flares

    NASA Technical Reports Server (NTRS)

    Mochnacki, S. W.; Zirin, H.

    1980-01-01

    Stellar flares have been observed using the 32 channel spectrophotometer on the 5 m telescope. Net flare fluxes in the region 3200-7000 A are presented. A simple model of blackbody radiation and hydrogen recombination emission appears to fit the continuum points well. Owing to vignetting problems, only the region between 4200 and 7000 A was used for a detailed fit to the Planck function to obtain apparent temperatures and effective areas. The rise of each flare was associated with an increase of the area, while the initial steep decline of the light was associated with a similar decrease of the blackbody temperature. The maximum temperatures, coincident with maximum light, were 7500-9500 K, similar to values for solar flares. The hydrogen line emission rose simultaneously with the continuum but declined more slowly. The ratio of H sub gamma to H sub alpha was about 1.5 at the peak, declining to about 1.0 after the peak.

  11. Chandra Monitors the Flaring Crab

    NASA Video Gallery

    Scientists hoped that NASA's Chandra X-ray Observatory would locate X-ray sources correlated to the gamma-ray flares seen by Fermi and Italy's AGILE satellites. Two observations were made during th...

  12. Radiation hydrodynamics in solar flares

    SciTech Connect

    Fisher, G.H.

    1985-10-18

    Solar flares are rather violent and extremely complicated phenomena, and it should be made clear at the outset that a physically complete picture describing all aspects of flares does not exist. From the wealth of data which is available, it is apparent that many different types of physical processes are involved during flares: energetic particle acceleration, rapid magnetohydrodynamic motion of complex field structures, magnetic reconnection, violent mass motion along magnetic field lines, and the heating of plasma to tens of millions of degrees, to name a few. The goal of this paper is to explore just one aspect of solar flares, namely, the interaction of hydrodynamics and radiation processes in fluid being rapidly heated along closed magnetic field lines. The models discussed are therefore necessarily restrictive, and will address only a few of the observed or observable phenomena. 46 refs., 6 figs.

  13. The processing, properties and use of the pyrotechnic mixture titanium subhydride/potassium perchlorate

    SciTech Connect

    Massis, T.M.

    1996-07-01

    Development of this pyrotechnic occurred because of the need for a static insensitive material to meet personnel safety requirements and related system safety issues in nuclear weapon energetic material component designs. Ti subhydride materials are made by the thermal dehydrding of commercial Ti hydride powder to the desired equivalent hydrogen composition in the Ti lattice. These Ti subhydrides, when blended with K perchlorate, meet the static insensitivity requirement of not being initiated from an equivalent human body electrostatic discharge. Individual material and blend qualification requirements provide a reproducible material from lot to lot. These pyrotechnic formulations meet the high reliability requirements (0.9995) for initiation and performance parameters and have the necessary stability and compatibility to meet long lived requirements of more than 25 years. Various experiences and problems are also discussed that have led to a mature technology for Ti subhydride/K perchlorate during its use in energetic material component designs.

  14. Measurement, data analysis and prediction of pyrotechnic shock from pin-pullers and separation joints

    NASA Technical Reports Server (NTRS)

    Evans, Maria J.; Neubert, Vernon H.; Bement, Laurence J.

    1987-01-01

    To evaluate the potential for spacecraft damage caused by activation of pyrotechnic mechanisms, pyrotechnic shock tests were conducted on three configurations: pin-pullers on an orthogonal double Hopkinson bar arrangement, pin-pullers on a mock-up of the HALOE (Halogen Occultation Experiment) structure, and a section of separation joint on a single Hopkinson bar. Strains and accelerations were measured. The strains were converted to output stresses, forces and moments. Acceleration shock response spectra are presented for both acceleration- and force-time signals. The devices were attached to the Hopkinson bars with adaptors, which are typical of attachments used in practice. In order to predict the effect of the adaptors, finite element models of the adaptor-bar combinations were analyzed and results are presented with regard to grid size, time interval, and frequency range required to predict the response to pulses of 10 and 100 microsecond duration.

  15. Experimental approach on the pyrotechnical shock reduction of Ariane-5 upper stage

    NASA Astrophysics Data System (ADS)

    Uribarri, I.; Tejero, P.; Rivaillon, B.; Laviron, B.

    1991-10-01

    The separation of the upper stage of the Ariane 5 launcher is to be achieved by means of a Pyrotechnical Expansive Tube (PET) installed in the Vehicle Equipment Bay (VEB) structure. When the pyrotechnical device is activated, severe shock levels are transmitted to the structural components and electronic equipment located near the separation section. These shock inputs could affect the operational performances of the above mentioned components during and after separation. An experimental research project to verify that VEB equipment will not be damaged, to achieve a deeper knowledge of the nature and consequences of the event, and to improve existing theoretical models, was undertaken. A specification was identified for the equipment platform, and a campaign of technological tests were started in order to select a damping material and its layout to obtain the highest shock reduction without compromising the VEB structural integrity and stiffness.

  16. Pyrotechnic shock measurement and data analysis requirements. [for Mariner Jupiter-Saturn 1977 hardware

    NASA Technical Reports Server (NTRS)

    Albers, L.

    1975-01-01

    An investigation of laboratory measurement and analysis of pyrotechnic shock is described which was prompted when two separate facilities produced discrepant pyrotechnic-shock data while testing Mariner Jupiter/Saturn 1977 spacecraft hardware. Both testing facilities are thoroughly examined to find a possible cause for the discrepancies, and it is noted that one facility incorporated an FM tape recorder operating at 60 in./sec with a frequency response of 20 kHz while the other incorporated a tape recorder operating at 120 in./sec with a frequency response of 80 kHz. It is found that the discrepancies were a direct result of the inadequate recording frequency response of the tape recorders. Other factors involved in obtaining more accurate data are discussed.

  17. Pyrotechnic shock simulation using the controlled response of a resonating bar fixture

    NASA Astrophysics Data System (ADS)

    Davie, N. T.

    Test laboratories frequently simulate pyrotechnic shock by mounting test items on various bar or plate fixtures which are excited into resonance by mechanical impact. A method for controlling the longitudinal response of a bar fixture is described. Masses clamped along the bar allow one to select which of the bar's natural frequencies will dominate its response upon impact. A test item mounted on one end of the bar thus experiences a controlled shock environment. This method ultimately provides a predictive means for controlling the shock spectrum shape produced by the simulated pyrotechnic shock. Control of the shock spectrum shape eliminates much of the trial and error usually required to tailor a shock test to satisfy the test requirement. A simple analytical model is described which derives the propagation and reflection of strain waves in the bar fixture. Bar responses predicted by this model agree with actual measurements.

  18. A study of shock-induced reactivity in a porous pyrotechnic powder mixture

    NASA Astrophysics Data System (ADS)

    Lindfors, A. J.; Finnegan, S. A.; Boteler, J. M.

    1996-05-01

    Shock and reactive properties of a pressed pyrotechnic powder mixture were examined using gun-launched planar impact techniques. The pyrotechnic powder consisted of a mixture of potassium perchlorate, magnesium-aluminum alloy, and inert binder pressed to approximately 84% theoretical maximum density (TMD). Polyvinylidene fluoride (PVDF) piezoelectric polymer film shock-pressure gages were used to track the progress of the shock wave through the mixture and establish the shock Hugoniot and pressure-time trends. A comparison of experimental pressure-time trends with those obtained using a one-dimensional hydrocode shows good agreement for input pressures below 2 GPa, but increasing differences for pressures above 2.6 GPa. These differences, in the form of rising pressure levels in the region immediately behind the shock front for the experimental data, are tentatively attributed to shock-induced chemical reaction.

  19. Pyrotechnic shock simulation using the controlled response of a resonating bar fixture

    NASA Astrophysics Data System (ADS)

    Davis, N. T.

    Test laboratories frequently simulate pyrotechnic shock by mounting test items on various bar or plate fixtures which are excited into resonance by mechanical impact. A method for controlling the longitudinal response of a bar fixture is described. Masses clamped along the bar allow one to select which of the bar's natural frequencies will dominate its response upon impact. A test item mounted on one end of the bar thus experiences a controlled shock environment. This method ultimately provides a predictive means for controlling the shock spectrum shape produced by the simulated pyrotechnic shock. Control of the shock spectrum shape eliminates much of the trial and error usually required to tailor a shock test to satisfy the test requirement. A simple analytical model which describes the propagation and reflection of strain waves in the bar fixture is also derived. Bar responses predicted by this model agree with actual measurements.

  20. Pyrotechnic shock simulation using the controlled response of a resonating bar fixture

    SciTech Connect

    Davie, N.T.

    1985-01-01

    Test laboratories frequently simulate pyrotechnic shock by mounting test items on various bar or plate fixtures which are excited into resonance by mechanical impact. The author describes a method for controlling the longitudinal response of a bar fixture. Masses clamped along the bar allow one to select which of the bar's natural frequencies will dominate its response upon impact. A test item mounted on one end of the bar thus experiences a controlled shock environment. This method ultimately provides a predictive means for controlling the shock spectrum shape produced by the simulated pyrotechnic shock. Control of the shock spectrum shape eliminates much of the trial and error usually required to tailor a shock test to satisfy the test requirement. The author also derives a simple analytical model which describes the propagation and reflection of strain waves in the bar fixture. Bar responses predicted by this model agree with actual measurements.

  1. [Hand injuries by pyrotechnic articles--case report and reconstructive experimental investigations].

    PubMed

    Schröder, Ann Sophie; Jahnke, Philipp; Hessler, Christian; Lockemann, Ute

    2014-01-01

    Injuries caused by explosions of fireworks often involve people's hands. The case of a young man who suffered severe hand injuries as well as damage to both eardrums and one eye is described. Reconstructive experimental investigations of the explosive effect of six different pyrotechnic articles were carried out using human hands from body donors. With the most powerful firecrackers that used to be legally available in Germany ("Super-Böller A", "Kanonenschlag") and a self-made one with 36 g gunpowder only blackening of the skin occurred. Three pyrotechnic articles not allowed in Germany ("La Bomba", "Color salute" and "Vogelschreck") caused serious injury to the hand's soft tissue and bones. PMID:25122993

  2. A High-efficiency, Small, Solid-state Laser for Pyrotechnic Ignition

    NASA Technical Reports Server (NTRS)

    Yang, L. C.; Menichelli, V. J.

    1973-01-01

    A completely self-contained, small, neodymium laser has been designed and demonstrated for use in a pyrotechnic ignition system. A nominal 16 J of laser energy (1.06 micron wavelength, 1-ms duration) was achieved in a rectangular 10.5-X 15.1-X 25.4-cm package weighting 5.14 kg. This high energy-to-weight ratio is encouraging for laser applications in which specific energy efficiency (energy per unit weight or volume) is important. The laser design concepts are described, and some results on pyrotechnic ignition are given. Some details on a laser currently under construction, which will be 1/8 the size of the above laser, are included.

  3. Formulation, predictions, and sensitivity analysis of a pyrotechnically actuated pin puller model

    SciTech Connect

    Gonthier, K.A.; Powers, J.M.

    1994-07-01

    This article presents an analysis for pyrotechnic combustion and pin motion in the NASA Standard Initiator (NSI) actuated pin puller. The conservation principles and constitutive relations for a multiphase system are posed and reduced to a set of five ordinary differential equations which are solved to predict the system`s performance. The model tracks the interactions of the unreacted, incompressible solid pyrotechnic, incompressible condensed phase combustion products, and gas phase combustion products. Predicted pressure histories for the firing of an NSI into (1) the pin puller device, (2) a 10 cm(sup 3) closed vessel, and (3) an apparatus known as the Dynamic Test Device compare well with experimental results. A sensitivity analysis reveals large regions in parameter space where system performance is insensitive to particular parametric values; smaller regions of high sensitivity are also found. 15 refs.

  4. Simulating VIIRS Observed Gas Flare

    NASA Astrophysics Data System (ADS)

    Hsu, F. C.

    2015-12-01

    VIIRS Nightfire (VNF) had been proved being able to effectively detect gas flares at night, and characterize their temperature and source size. [1] However, limited access to generally confidential gas flare operation measurements made it difficult to verify the output. Although flared gas volume is occasionally available, it is not common to log the temperature and flames size which directly links to VNF output. To understand the mechanism of gas flare and how VIIRS perceives the event, a platform is proposed to simulate the gas flare being observed by VIIRS. The methodology can be described in three steps. (1) Use CFD simulation software ISIS-3D to simulate a simple gas flare. [2] Scalar fields of temperature and species concentration related to combustion are extracted from the simulation. The instantaneous scalar can be determined from time-averaging or guess by stochastic time and space series (TASS) from single-point statistics [3]. (2) Model spectral radiance intensity of simulated gas flare using RADCAL. [4] RADCAL developed by NIST can accurately model the spectral radiance emitted on the direction of lineof-sight given the spatial profile of temperature and concentration of species. (3) Use radiative transfer modeling to calculate the energy propagated to VIIRS. The modeled radiation will then be weighted by the MODTRAN [5] modeled transmissivity over predefined atmosphere to the satellite, with geometrical effects considered. Such platform can help understanding how exactly VNF is measuring gas flares, and thus lead to more precise characterization of combustion events. [1] C. D. Elvidge et al, Remote Sensing, 2013[2] IRSN ISIS-3D[3] M. E. Kounalakis et al, ASME J. Heat Transfer, 1991 [4] W. L. Grosshandler, NIST Technical Note 1402, 1993 [5] A. Berk et al, MODTRAN 5.2.0.0 User's Manual

  5. Particle acceleration in solar flares

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Forman, M. A.

    1987-01-01

    The most direct signatures of particle acceleration in flares are energetic particles detected in interplanetary space and in the Earth atmosphere, and gamma rays, neutrons, hard X-rays, and radio emissions produced by the energetic particles in the solar atmosphere. The stochastic and shock acceleration theories in flares are reviewed and the implications of observations on particle energy spectra, particle confinement and escape, multiple acceleration phases, particle anistropies, and solar atmospheric abundances are discussed.

  6. Shock ignition of pyrotechnic heat powders. [Aluminium/ferric oxide mixture

    SciTech Connect

    Hornig, H.C.; Kury, J.W.; Simpson, R.L.; Helm, F.H.; Von Holle, W.G.

    1986-05-14

    Over a dozen pyrotechnic mixtures of alloy forming elements or solid oxidizers and fuels were subjected to shock pressures of from 2 to 35 GPa. More than half of these formulations were ignited by the shock. Visible and ir time resolved radiometry experiments using one of these mixtures, aluminum/ferric oxide, showed that this shock induced ignition occurred in less than 0.1 usec. 9 refs., 15 figs., 3 tabs.

  7. Chlorine-free pyrotechnics: copper(I) iodide as a "green" blue-light emitter.

    PubMed

    Klapötke, Thomas M; Rusan, Magdalena; Sabatini, Jesse J

    2014-09-01

    The generation of blue-light-emitting pyrotechnic formulations without the use of chlorine-containing compounds is reported. Suitable blue-light emission has been achieved through the generation of molecular emitting copper(I) iodide. The most optimal copper(I) iodide based blue-light-emitting formulation was found to have performances exceeding those of chlorine-containing compositions, and was found to be insensitive to various ignition stimuli. PMID:25044436

  8. Low temperature pyrotechnic smokes: A potential low cost alternative to nonpyrotechnic smoke for access delay applications

    SciTech Connect

    Greenholt, C.J.

    1995-07-01

    Smokes are frequently used as visual obscurants in access delay applications. A new generation of low temperature pyrotechnic smokes is being developed. Terephthalic Acid (TPA) smoke was developed by the U.S. Army and Sebacic Acid (SA) smoke is being developed by Thiokol Corp. The advantages these smokes offer over traditional pyrotechnic smokes include; low generation temperature (approximately 450{degree}C), lower toxicity, and lower corrosivity. The low generation temperature reduces smoke layering effects and allows the addition of sensory irritants, such as o-Chlorobenzylidene Malononitrile (CS), to the formulation. Some advantages low temperature pyrotechnic smokes offer over nonpyrotechnic smokes include; low cost, simplicity, compactness, light weight, long storage life, and orientation insensitive operation. Low cost permits distribution of multiple units for reduced vulnerability and refill flexibility. Some disadvantages may include the combustibility of the smoke particulate; however, the published lower explosive limit of the mentioned materials is approximately ten times greater than the concentration required for effective obscuration. The TPA smoke cloud contains small quantities of benzene, formaldehyde, and carbon monoxide; no benzene or formaldehyde was identified during preliminary SA smoke analyses performed by Thiokol Corp. Sandia performed tests and analyses on TPA smoke to determine the smoke cloud composition, the quantity of particulate produced per canister, and the relationship between airborne particulate concentration and measured optical density values. Current activities include characterization of SA smoke.

  9. A simplified model of TiH1.65/KClO4 pyrotechnic ignition.

    SciTech Connect

    Chen, Ken Shuang

    2009-04-01

    A simplified model was developed and is presented in this report for simulating thermal transport coupled with chemical reactions that lead to the pyrotechnic ignition of TiH1.65/KClO4 powder. The model takes into account Joule heating via a bridgewire, thermal contact resistance at the wire/powder interface, convective heat loss to the surroundings, and heat released from the TiH1.65- and KClO4-decomposition and TiO2-oxidation reactions. Chemical kinetic sub-models were put forth to describe the chemical reaction rate(s) and quantify the resultant heat release. The simplified model predicts pyrotechnic ignition when heat from the pyrotechnic reactions is accounted for. Effects of six key parameters on ignition were examined. It was found that the two reaction-rate parameters and the thermal contact resistance significantly affect the dynamic ignition process whereas the convective heat transfer coefficient essentially has no effect on the ignition time. Effects of the initial/ambient temperature and electrical current load through the wire are as expected. Ignition time increases as the initial/ambient temperature is lowered or the wire current load is reduced. Lastly, critical needs such as experiments to determine reaction-rate and other model-input parameters and to measure temperature profiles, time to ignition and burn-rate data for model validation as well as efforts in incorporating reaction-rate dependency on pressure are pointed out.

  10. Harnessing modified manganin technique to study processes of explosive transformation in pyrotechnic compositions

    NASA Astrophysics Data System (ADS)

    Batalov, Sergei

    2005-07-01

    The paper reviews results of the experimental study of explosive transformation in pyrotechnic compositions with modified manganin technique. In particular, experimental data on pressure profiles recorded with tiny manganin sensors are cited to characterize the effect of parameters of the loading pulse, dispersion and density on peculiarities of explosive transformation in studied pyrotechnic pieces under shock-wave initiation. In the paper are shown the experimental pressure profiles, characteristic for processes of explosive transformation of extended delay. The experimental results prove the effect of density variation of the specimens under study on the process of the explosive transformation. It is felt that for given range of pressures of the incoming shock wave the difference of the explosive transformation history, at equal parameters of loading pulse, is caused also by different dispersion of the initial powder and final porosity of studied specimens. The experimental results provide support for possibility of use of tiny manganin and constantan sensors in studying processes of explosive transformation of pyrotechnic compositions under initiation by divergent shock waves of large curve front and slumping pressure profile.

  11. Thermal and electrostatic initiation of TiH/sub x/ based pyrotechnics

    SciTech Connect

    Collins, L.W.

    1980-01-01

    The thermal and electrostatic initiations of TiH/sub x/ based pyrotechnics have been investigated to determne the material properties which influence these processes. Controlled electrostatic sensitivity experiments showed that the initiation reaction for TiH/sub x/KC10/sub 4/ pyrotechnic involved a reaction of the fuel with oxygen gas an that the KC10/sub 4/ chemically interacts with the titanium to desensitize the material to electrostatic ignition. Other factors which influence the initiation process were also identified. As a result to these experiments, a new theory for the electrostatic initiation of TiH/sub x/ based pyrotechnics has emerged which relates the sensitivity to ignition to the chemistry of the titanium oxides which coat the metal particles. Thermal ignition of the TiH/sub x/KC10/sub 4/ was whown to be controlled by chemical processes associated with the titanium fuel. DTA experiments were correlated with Auger spectroscopic measurements to demonstrate the role of the dissolution of the oxide coating in the thermal ignition of titanium.

  12. High pressure aspects of TiH/sub x//KClO/sub 4/ pyrotechnics

    SciTech Connect

    Munger, A.C.; Reed, J.W.

    1986-01-01

    Actuators containing pyrotechnic materials are considered safe if, when actuated under normal conditions, no shrapnel is thrown about. There are, however, some abnormal and unlikely conditions under which these devices may not remain self-contained when installed in the next assembly. A condition can be envisioned that would require the actuator to fire and remain contained in its own volume. Such a condition has been called ''zero volume'' firing. Previous test data under different conditions had been construed to indicate that the maximum pressure reached in a zero volume case would be approx.100,000 psi (690 MPa). When the hardware was actually tested, pressures approaching the predicted values were obtained. In response to that finding, new hardware and test techniques were developed. overall, the results of these calculations and actual tests done from them were in reasonable agreement, and the pressures were much higher than anticipated. Numerical methods were then employed to predict PVT properties of the pyrotechnic systems in the zero volume situations, where the pyrotechnic material completely fills the available volume at the prevailing packing density. Two major computational problems arise: first, the handling of nonideal gas and condensed phase conditions; and second, heat loss and its estimation. Only the nonideal problem is considered in this work. 4 refs., 12 figs.

  13. Aerial Video Imaging

    NASA Technical Reports Server (NTRS)

    1991-01-01

    When Michael Henry wanted to start an aerial video service, he turned to Johnson Space Center for assistance. Two NASA engineers - one had designed and developed TV systems in Apollo, Skylab, Apollo- Soyuz and Space Shuttle programs - designed a wing-mounted fiberglass camera pod. Camera head and angles are adjustable, and the pod is shaped to reduce vibration. The controls are located so a solo pilot can operate the system. A microprocessor displays latitude, longitude, and bearing, and a GPS receiver provides position data for possible legal references. The service has been successfully utilized by railroads, oil companies, real estate companies, etc.

  14. Starspots on flare stars

    NASA Technical Reports Server (NTRS)

    Mullan, D. J.

    1974-01-01

    Sizes of starspots on flare stars can be derived from the author's convection-cell hypothesis. The sizes are in fair agreement with those observed on YY Gem, CC Eri, and BY Dra by Bopp and Evans (1973). The hypothesis predicts that periodic brightness variations due to starspots are restricted to stars brighter than a critical absolute visual magnitude. A convective model of a starspot on YY Gem has been computed, assuming that the missing flux is in the form of Alfven waves. It is found that the surface field must exceed 10,000 G, and is probably less than about 30,000 G. With a surface field of 20,000 G, the effective temperature of the spot is in the range from 1590 to 1890 K, depending on the field gradient. These figures are to be compared with an effective temperature of 2000 K estimated from observations by Bopp and Evans. Efficient dynamo action is shown to be a possible mechanism for generating such large surface fields. There is a possibility that tidal effects may influence starspot formation.

  15. Infrared film for aerial photography

    USGS Publications Warehouse

    Anderson, William H.

    1979-01-01

    Considerable interest has developed recently in the use of aerial photographs for agricultural management. Even the simplest hand-held aerial photographs, especially those taken with color infrared film, often provide information not ordinarily available through routine ground observation. When fields are viewed from above, patterns and variations become more apparent, often allowing problems to be spotted which otherwise may go undetected.

  16. AERIAL PHOTOGRAPHY AND LEGAL APPLICATIONS

    EPA Science Inventory

    Aerial photographic interpretation is the process of examining objects on aerial photographs and determining their significance. t is often defined as both art and science because the process, and the quality of the derived information, is often a qualitative nature and much depe...

  17. THE SOLAR FLARE IRON ABUNDANCE

    SciTech Connect

    Phillips, K. J. H.; Dennis, B. R. E-mail: Brian.R.Dennis@nasa.gov

    2012-03-20

    The abundance of iron is measured from emission line complexes at 6.65 keV (Fe line) and 8 keV (Fe/Ni line) in RHESSI X-ray spectra during solar flares. Spectra during long-duration flares with steady declines were selected, with an isothermal assumption and improved data analysis methods over previous work. Two spectral fitting models give comparable results, viz., an iron abundance that is lower than previous coronal values but higher than photospheric values. In the preferred method, the estimated Fe abundance is A(Fe) = 7.91 {+-} 0.10 (on a logarithmic scale, with A(H) = 12) or 2.6 {+-} 0.6 times the photospheric Fe abundance. Our estimate is based on a detailed analysis of 1898 spectra taken during 20 flares. No variation from flare to flare is indicated. This argues for a fractionation mechanism similar to quiet-Sun plasma. The new value of A(Fe) has important implications for radiation loss curves, which are estimated.

  18. Largest Solar Flare on Record

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The largest solar flare ever recorded occurred at 4:51 p.m. EDT, on Monday, April 2, 2001. as Observed by the Solar and Heliospheric Observatory (SOHO) satellite. Solar flares, among the solar systems mightiest eruptions, are tremendous explosions in the atmosphere of the Sun capable of releasing as much energy as a billion megatons of TNT. Caused by the sudden release of magnetic energy, in just a few seconds, solar flares can accelerate solar particles to very high velocities, almost to the speed of light, and heat solar material to tens of millions of degrees. The recent explosion from the active region near the sun's northwest limb hurled a coronal mass ejection into space at a whopping speed of roughly 7.2 million kilometers per hour. Luckily, the flare was not aimed directly towards Earth. Second to the most severe R5 classification of radio blackout, this flare produced an R4 blackout as rated by the NOAA SEC. This classification measures the disruption in radio communications. Launched December 2, 1995 atop an ATLAS-IIAS expendable launch vehicle, the SOHO is a cooperative effort involving NASA and the European Space Agency (ESA). (Image courtesy NASA Goddard SOHO Project office)

  19. Magnetic reconnection in solar flares

    NASA Technical Reports Server (NTRS)

    Forbes, T. G.

    1991-01-01

    The magnetic energy stored in the corona is the only plausible source for the energy released during large solar flares. During the last 20 years most theoretical work has concentrated on models which store magnetic energy in the corona in the form of electrical currents, and a major goal of present day research is to understand how these currents are created, and then later dissipated during a flare. Another important goal is to find a flare model which can eject magnetic flux into interplanetary space. Although many flares do not eject magnetic flux, those which do are of special importance for solar-terrestrial relations since the ejected flux can have dramatic effects if it hits the Earth's magnetosphere. Three flare models which have been extensively investigated are the emerging-flux model, the sheared-arcade model, and the magnetic-flux-rope model. All of these models can store and release magnetic energy efficiently provided that rapid magnetic reconnection occurs. However, only the magnetic-flux-rope model appears to provide a plausible mechanism for ejecting magnetic flux into interplanetary space.

  20. Anvil for Flaring PCB Guide Pins

    NASA Technical Reports Server (NTRS)

    Winn, E.; Turner, R.

    1985-01-01

    Spring-loaded anvil results in fewer fractured pins. New anvil for flaring guide pins in printed-circuit boards absorbs approximately 80 percent of press force. As result fewer pins damaged, and work output of flaring press greatly increased.

  1. What's an Asthma Flare-Up?

    MedlinePlus

    ... Things to Know About Zika & Pregnancy What's an Asthma Flare-Up? KidsHealth > For Parents > What's an Asthma ... of a straw that's being pinched. Causes of Asthma Flare-Ups People with asthma have airways that ...

  2. The Flare Genesis Experiment

    NASA Technical Reports Server (NTRS)

    Rust, D. M.

    2002-01-01

    Using the Flare Genesis Experiment (FGE), a balloon-borne observatory with an 80-cm solar telescope we observed the active region NOAA 8844 on January 25, 2000 for several hours. FGE was equipped with a vector polarimeter and a tunable Fabry-Perot narrow-band filter. It recorded time series of filtergrams, vector magnetograms, and Dopplergrams at the Ca(I) 6122.2 angstrom line, and H-alpha filtergrams with a cadence between 2.5 and 7.5 minutes. At the time of the observations, NOAA 8844 was located at approximately 5 N 30 W. The region was rapidly growing during the observations; new magnetic flux was constantly emerging in three supergranules near its center. We describe in detail how the FGE data were analyzed and report on the structure and behavior of peculiar moving dipolar features (MDFs) observed in the active region. In longitudinal magnetograms, the MDFs appeared to be small dipoles in the emerging fields. The east-west orientation of their polarities was opposite that of the sunspots. The dipoles were oriented parallel to their direction of motion, which was in most cases towards the sunspots. Previously, dipolar moving magnetic features have only been observed flowing out from sunspots. Vector magnetograms show that the magnetic field of each MDF negative part was less inclined to the local horizontal than the ones of the positive part. We identify the MDFs as undulations, or stitches, where the emerging flux ropes are still tied to the photosphere. We present a U-loop model that can account for their unusual structure and behavior, and it shows how emerging flux can shed its entrained mass.

  3. Model of slowly evolving flare.

    NASA Astrophysics Data System (ADS)

    Chiuderi Drago, F.; Landini, M.; Monsignori Fossi, B. C.

    A gradual rise and fall flare with a duration of about one hour was observed on June 10, 1980 in the radio (Toyokawa and VLA), optical (Bing Bear) and XUV (SMM satellite) ranges of wavelengths. The flare developed as a large loop connecting two regions of opposite polarity in a pre-existing active region. A model of the differential emission measure of the loop observed at three different stages of the flare is deduced from the analysis of the XUV images in C IV (1549 Å), O VIII (18.97 Å), Ne IX (13.45 Å), Mg XI (9.17 Å) and Si XIII (6.65 Å) emission lines. The differential emission measure as a function of temperature is controlled by the conductive flux via the temperature gradient; the evaluation of the divergence of the conductive flux is used in the energy balance to have information on the power deposition function.

  4. Chasing White-Light Flares

    NASA Astrophysics Data System (ADS)

    Hudson, H. S.

    2016-05-01

    In this memoir I describe my life in research, mostly in the area of solar physics. The recurring theme is "white-light flares," and several sections of this paper deal with this and related phenomena; I wind up describing how I see the state of the art in this still-interesting and crucially important (as it has been since 1859) area of flare research. I also describe my participation in two long-lived satellite programs dedicated to solar observations ( Yohkoh and RHESSI) and elaborate on their discoveries. These have both helped with white-light flares both directly and also with closely related X-ray and γ-ray emissions), with the result that this article leans heavily in that direction.

  5. Chasing White-Light Flares

    NASA Astrophysics Data System (ADS)

    Hudson, H. S.

    2016-06-01

    In this memoir I describe my life in research, mostly in the area of solar physics. The recurring theme is "white-light flares," and several sections of this paper deal with this and related phenomena; I wind up describing how I see the state of the art in this still-interesting and crucially important (as it has been since 1859) area of flare research. I also describe my participation in two long-lived satellite programs dedicated to solar observations (Yohkoh and RHESSI) and elaborate on their discoveries. These have both helped with white-light flares both directly and also with closely related X-ray and γ-ray emissions), with the result that this article leans heavily in that direction.

  6. 6Li from Solar Flares.

    PubMed

    Ramaty; Tatischeff; Thibaud; Kozlovsky; Mandzhavidze

    2000-05-10

    By introducing a hitherto ignored 6Li producing process, due to accelerated 3He reactions with 4He, we show that accelerated particle interactions in solar flares produce much more 6Li than 7Li. By normalizing our calculations to gamma-ray data, we demonstrate that the 6Li produced in solar flares, combined with photospheric 7Li, can account for the recently determined solar wind lithium isotopic ratio, obtained from measurements in lunar soil, provided that the bulk of the flare-produced lithium is evacuated by the solar wind. Further research in this area could provide unique information on a variety of problems, including solar atmospheric transport and mixing, solar convection and the lithium depletion issue, and solar wind and solar particle acceleration. PMID:10813684

  7. Magnetic reconnection models of flares

    NASA Technical Reports Server (NTRS)

    Forbes, T. G.

    1988-01-01

    The most feasible energy source for solar and stellar flares is the energy stored in coronal magnetic fields. To convert a significant fraction of this energy into heat and kinetic energy in a short time requires rapid change in the topology of the magnetic fields, and hence, rapid reconnection of field lines. Recent numerical and analytical models of solar flares suggest that the magnetic energy released by reconnection drives chromospheric ablation in the flare ribbons. Simple theoretical arguments based on compressible reconnection theory predict that the temperature of the ablated plasma should be about 1.03 x 10 to the 6th B exp 0.62 K where B is the coronal magnetic field strength in Gauss.

  8. Solar flare emissions and geophysical disturbances

    NASA Technical Reports Server (NTRS)

    Sakurai, K.

    1973-01-01

    Various geophysical phenomena are produced by both wave and particle emissions from solar flares. Using the observed data for these emissions, a review is given on the nature of solar flares and their development. Geophysical phenomena are discussed by referring to the results for solar flare phenomena.

  9. The smallest hard X-ray flare?

    NASA Astrophysics Data System (ADS)

    Glesener, Lindsay; Krucker, Sam; Hannah, Iain; Smith, David M.; Grefenstette, Brian; Marsh, Andrew; Hudson, Hugh S.; White, Stephen M.; Chen, Bin

    2016-05-01

    We report a NuSTAR observation of a small solar flare on 2015 September 1, estimated to be on the order of a GOES class A.05 flare in brightness. This flare is fainter than any hard X-ray (HXR) flares in the existing literature, and with a peak rate of only ∼5 counts s‑1 detector‑1 observed by RHESSI, is effectively the smallest that can just barely be detected by the current standard (indirectly imaging) solar HXR instrumentation, though we expect that smaller flares will continue to be discovered as instrumental and observational techniques progress. The flare occurred during a solar observation by the highly sensitive NuSTAR astrophysical HXR spacecraft, which used its direct focusing optics to produce detailed flare spectra and images. The flare exhibits properties commonly observed in larger flares, including a fast rise and more gradual decay, and similar spatial dimensions to the RHESSI microflares. We will discuss the presence of non-thermal (flare-accelerated) electrons during the impulsive phase. The flare is small in emission measure, temperature, and energy, though not in physical dimensions. Its presence is an indication that flares do indeed scale down to smaller energies and retain what we customarily think of as “flarelike” properties.

  10. Forming tool improves quality of tubing flares

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Punch and die set improves the quality of tubing flares for use with standard flared-tube fittings in high-pressure systems. It forges a dimensionally accurate flare in the tubing and forces more tubing material into the high-stress areas to improve the strength and tightness of the tubing connection.

  11. Relativistic electrons associated with solar flares.

    NASA Technical Reports Server (NTRS)

    Sakurai, K.

    1972-01-01

    Solar flares which produce relativistic electrons generally occur within sunspot groups which are active in the emission of meter type I noise storms. It is suggested that relativistic electrons in solar flares are accelerated from the keV-energy electrons responsible for the type I noise storms. The relationship between flare developments and the ejection of keV-electrons is briefly considered.

  12. AERIAL MEASURING SYSTEM IN JAPAN

    SciTech Connect

    Lyons, Craig; Colton, David

    2012-01-01

    The U.S. Department of Energy National Nuclear Security Agency’s Aerial Measuring System deployed personnel and equipment to partner with the U.S. Air Force in Japan to conduct multiple aerial radiological surveys. These were the first and most comprehensive sources of actionable information for U.S. interests in Japan and provided early confirmation to the government of Japan as to the extent of the release from the Fukushima Daiichi Nuclear Power Generation Station. Many challenges were overcome quickly during the first 48 hours; including installation and operation of Aerial Measuring System equipment on multiple U.S. Air Force Japan aircraft, flying over difficult terrain, and flying with talented pilots who were unfamiliar with the Aerial Measuring System flight patterns. These all combined to make for a dynamic and non-textbook situation. In addition, the data challenges of the multiple and on-going releases, and integration with the Japanese government to provide valid aerial radiological survey products that both military and civilian customers could use to make informed decisions, was extremely complicated. The Aerial Measuring System Fukushima response provided insight in addressing these challenges and gave way to an opportunity for the expansion of the Aerial Measuring System’s mission beyond the borders of the US.

  13. FNAS/solar flare energetics

    NASA Technical Reports Server (NTRS)

    Machado, M. E.

    1992-01-01

    We have performed an extensive study of solar flare energy buildup and release, concentrating in two aspects: (1) relationship with 3D field topology and measured electric currents; and (2) flare onset characteristics as determined from combined x ray and ultraviolet observations. We extended our previous studies on the characteristic topology of flaring regions, by following the evolution of an active region over three consecutive days. From comparison with flare observations in x rays and h alpha, we found further support for the hypothesis that flares were triggered by taking place at the separators (3D generalization of and x-type neutral point). Furthermore, we found that emerging in flux at a site within the active regions where no (or little) activity was previously observed, caused the appearance of a secondary separator and thereon continuous triggering of activity at such site. Our topology arguments were then applied to a study of sympathetic activity between two regions within an active complex. Here again we found that interacting field structures along separators and separatrices, which act as pathways for recurrent flaring to spread between the regions, could be used to understand how activity spread to potentially explosive sites with the complex. We also finished our study of flare onset characteristics as determined from combined x ray and ultraviolet observations. Using a quasi-static modeling approach, we find that this phase is characterized by a relatively low level of energy release, 10 exp 26-27 erg/s, which is sufficient to produce 'gentle' evaporation, a shift in the location of the transition zone as compared to pre-flare conditions, and an increase in the temperature and density of coronal loops. All these changes have profound implications on the observed signatures of impulsive phase phenomena, which had been neglected in the past. As a follow-up of this investigation, we now plan to apply our results to the interpretation of high

  14. Delta spots and great flares

    NASA Technical Reports Server (NTRS)

    Zirin, Harold; Liggett, Margaret A.

    1987-01-01

    The development of delta spots and the great flares they produce are reviewed based on 18 years of observations. Delta groups are found to develop in three ways: (1) by the eruption of a single complex active region formed below the surface; (2) by the eruption of large satellite spots near a large older spot; and (3) by the collision of spots of opposite polarity from different dipoles. It is shown that the present sample of 21 delta spots never separate once they lock together, and that the driving force for the shear is spot motion. Indicators for the prediction of the occurrence of great flares are identified.

  15. Characterization of total flare energy

    NASA Technical Reports Server (NTRS)

    Hudson, H. S.

    1986-01-01

    It is concluded that the estimates of total energy in the prime flares lie well below the Active Cavity Radiometer Irradiance Monitor upper limits. This is consistent with our knowledge of the energy distribution in solar flares. Insufficient data exist for us to be very firm about this conclusion, however, and major energetic components could exist undetected, especially in the EUV-XUV and optical bands. In addition, the radiant energy cannot quantitatively be compared at this time with non-radiant terms because of even larger uncertainties in the latter.

  16. Tuning laser output characteristics of a pyrotechnically pumped free-running Nd:YAG laser in terms of pumping kinetics

    NASA Astrophysics Data System (ADS)

    Kang, Xiaoli; Yang, Fan; Luo, Jiangshan; Tang, Yongjian

    2015-02-01

    Using light radiation directly produced by combustion of some pyrotechnics as pumping sources of solid state lasers is a potentially effective way to obtain compact and high energy lasers. Kinetics of this kind of pumping is studied in terms of pulse energy and pulse time characteristics as well as laser output energy. Pumping kinetics is turned through changing fabrication methods of the pumping modules. It was found that the useful light energy and pulse time for the pyrotechnic pumping light showed opposite changing trend. Compressing pulse duration from 45 ms to about 10 ms would simultaneously cause 20%~ 50% decreases in useful light radiation energy. However, the laser output energy produced by these pumping sources only had a variation 9%, ranging from 427 mJ to 468 mJ. Reasons were related to the decrease in fluorescence loss in pumping energy below the threshold for the pyrotechnic modules having shorter pulse duration but higher radiation power.

  17. Aerial thermography for energy conservation

    NASA Technical Reports Server (NTRS)

    Jack, J. R.

    1978-01-01

    Thermal infrared scanning from an aircraft is a convenient and commercially available means for determining relative rates of energy loss from building roofs. The need to conserve energy as fuel costs makes the mass survey capability of aerial thermography an attractive adjunct to community energy awareness programs. Background information on principles of aerial thermography is presented. Thermal infrared scanning systems, flight and environmental requirements for data acquisition, preparation of thermographs for display, major users and suppliers of thermography, and suggested specifications for obtaining aerial scanning services were reviewed.

  18. Biggest Solar Flare on Record

    NASA Technical Reports Server (NTRS)

    2002-01-01

    View an animation from the Extreme ultraviolet Imaging Telescope (EIT). At 4:51 p.m. EDT, on Monday, April 2, 2001, the sun unleashed the biggest solar flare ever recorded, as observed by the Solar and Heliospheric Observatory (SOHO) satellite. The flare was definitely more powerful than the famous solar flare on March 6, 1989, which was related to the disruption of power grids in Canada. This recent explosion from the active region near the sun's northwest limb hurled a coronal mass ejection into space at a whopping speed of roughly 7.2 million kilometers per hour. Luckily, the flare was not aimed directly towards Earth. Solar flares, among the solar system's mightiest eruptions, are tremendous explosions in the atmosphere of the Sun capable of releasing as much energy as a billion megatons of TNT. Caused by the sudden release of magnetic energy, in just a few seconds flares can accelerate solar particles to very high velocities, almost to the speed of light, and heat solar material to tens of millions of degrees. Solar ejections are often associated with flares and sometimes occur shortly after the flare explosion. Coronal mass ejections are clouds of electrified, magnetic gas weighing billions of tons ejected from the Sun and hurled into space with speeds ranging from 12 to 1,250 miles per second. Depending on the orientation of the magnetic fields carried by the ejection cloud, Earth-directed coronal mass ejections cause magnetic storms by interacting with the Earth's magnetic field, distorting its shape, and accelerating electrically charged particles (electrons and atomic nuclei) trapped within. Severe solar weather is often heralded by dramatic auroral displays, northern and southern lights, and magnetic storms that occasionally affect satellites, radio communications and power systems. The flare and solar ejection has also generated a storm of high-velocity particles, and the number of particles with ten million electron-volts of energy in the space near

  19. Optimization of a pyrotechnic igniter with the release of reactive particles

    NASA Astrophysics Data System (ADS)

    Saurel, R.; Loraud, J. C.; Larini, M.

    1991-06-01

    This paper deals with the effects of reactive particles on the performance of a pyrotechnic igniter. These particles are placed on the inner surface of a “flash tube”, released into the main flow of the gas and ignited by the passage of one of the two discontinuities (the shock wave or the contact surface). Two particle sizes have been studied (3 μm and 10 μm). It is shown that the best performance is achieved with small particles released into the flow by the shock wave. Another focal point of this study is the combining of two fundamentally different methods to calculate the two phase flow.

  20. Shock response spectra variational analysis for pyrotechnic qualification testing of flight hardware

    NASA Technical Reports Server (NTRS)

    Smith, J. L.

    1984-01-01

    Shock response spectra data from flight certification tests were analyzed to determine envelope variation with respect to mean values in each axis. An overall variation of + or - 8.61 dB or 169 percent exists for the data. This large variation may be attributed to one or more of the following: (1) Instrumentation problems may exist. (2) Variations in the source charge (blasting caps) such as shape or explosive load may exist. (3) Two blasting caps were used to excite the pyrotechnic plate tester. Delay time between charge firings may have varied. The cause or causes of the variations need to be identified and researched to prevent future pyroshock problems.

  1. Experimental and Numerical Investigation of a Pyrotechnic Mixture Under a Cylindrically Converging Shock Condition

    NASA Astrophysics Data System (ADS)

    Jenkins, Charles M.; Horie, Yasuyuki; Lindsay, C. Michael; Lambert, David E.; Welle, Eric J.; Butler, George C.

    2011-06-01

    This research builds on Forbes et al. (1997) study of inducing a rapid solid state reaction in a highly porous core using a converging cylindrical shock driven by a high explosive in the annular space. Using high speed photography and photon doppler velocimetry (PDV), the expansion velocity of the cylinder outer wall provides a comparison to the baseline high explosive core and the pyrotechnic cores. The CTH hydrocode model analysis of the case expansion and fluid velocities indicated that the outer case expansion velocity differs according to the formulation in the core and that the core materials are responding similarly to the baseline high explosive core.

  2. High G pyrotechnic shock simulation using metal-to-metal impact

    NASA Technical Reports Server (NTRS)

    Bai, M.; Thatcher, W.

    1979-01-01

    A technique for simulating high g level pyrotechnic shocks is described and the results of applying the technique to obtain the MIL-STD-1540A shock spectrum with a maximum acceleration of 18,000g at 2,000 Hz are presented. Designing the resonant beam and plate on which the test unit is mounted, and generating a proper impulsive load on them, were the essentials of the technique. One dimensional stress wave and Euler equations were employed in the design. A metal pendulum hammer was used to generate the impulsive load.

  3. Comparison of Barium and Amorphous Boron Pyrotechnics for Green Light Emission

    NASA Astrophysics Data System (ADS)

    Poret, Jay C.; Sabatini, Jesse J.

    2013-01-01

    A comparison of green light emission from both barium- and amorphous boron-based pyrotechnics is described. Emission spectra are shown for both the U.S. Army in-service M125A1 green star cluster formulation and an amorphous boron-potassium nitrate-binder formulation. The main peaks of the emission spectra, average dominant wavelength, and average spectral purity of both formulations are given. The role that combustion products play in determining flame temperature and continuum radiation is also discussed.

  4. Mars Observer Propulsion and Pyrotechnics Corrective Actions Test Program Blanket Release

    NASA Technical Reports Server (NTRS)

    Saulsberry, Regor L.; Fries, Joseph (Technical Monitor)

    1999-01-01

    The Mars Observer Propulsion and Pyrotechnic Corrective Actions Test Program has been in progress at the NASA White Sands Test Facility since 1995. This program has developed capabilities to accurately characterize pyrovalve hazards and has established corrective actions that arc helping to preclude loss of spacecraft due to pyrovalve and propellant interaction. Rather than wait for conclusion of the test program, significant rest results, findings, and safety recommendations have been and will continue to be released soon after they became available to meet needs of near-term NASA and commercial space programs. This release will cover approximately three to five papers per year until program end.

  5. Four-terminal connector for measuring resistance of a pyrotechnic initiator

    NASA Technical Reports Server (NTRS)

    Robinson, Robert L. (Inventor); Graves, Thomas J. (Inventor); Hoffman, III, William C. (Inventor)

    1989-01-01

    A four-terminal electrical connector device (40) for testing and measuring unknown resistances of initiators (11) used for starting pyrotechnic events aboard a Space Transportation System. The testing device minimizes contact resistance degradation effects and so improves the reliability of resistance measurement taken with the device. Separate and independent voltage sensing (19) and current supply (20) circuits each includes a pair of socket contacts (13-16) for mating engagement with the pins (17,18) of the initiator. The unknown resistance that is measured by the device is the resistance of the bridgewire (23) of the initiator which is required to be between 0.95 and 1.15 ohms.

  6. Pulsed acceleration in solar flares

    NASA Technical Reports Server (NTRS)

    Aschwanden, Markus J.; Benz, Arnold O.; Dennis, Brian R.; Kundu, Mukul R.

    1994-01-01

    We study the nonlinear dynamics of particle acceleration in solar flares by analyzing the time series of various quasi-periodic radio signatures during flares. In particular we present the radio and hard X-ray data of three flares which suppport the following tentative conclusions: (1) Particle acceleration and injection into magnetic structures occurs intrinsically in a pulsed mode (with a typical period of 1-2 s), produced by a single, spatially coherent, nonlinear system, rather than by a stochastic system with many spatially independent components ('statistical flare' produced by a fragmented primary energy release). (2) The nonlinear (quasi-periodic) mode of pulsed particle acceleration and injection into a coronal loop can be stabilized by phase locking with an MHD wave (oscillation) mode, if both periods are close to each other. (3) Pulsed injection of electron beams into a coronal loop may trigger nonlinear relaxational oscillations of wave-particle interactions. This is particularly likely when the limit cycles of both systems are similar.

  7. Collective acceleration in solar flares

    SciTech Connect

    Barletta, W.; Sessler, A.M.; Xie, M.; Gershtein, S.S.; Krishan, V.; Reiser, M.

    1993-11-01

    Solar flare data are examined with an eye to seeing if they suggest collective acceleration of ions. That, in fact, seems to be the case. The collective acceleration mechanism of Gershtein is reviewed and the possibilities of the mechanism are discussed.

  8. Magnetic Reconnection in Solar Flares

    NASA Astrophysics Data System (ADS)

    Forbes, Terry G.

    2016-05-01

    Reconnection has at least three possible roles in solar flares: First, it may contribute to the build-up of magnetic energy in the solar corona prior to flare onset; second, it may directly trigger the onset of the flare; and third, it may allow the release of magnetic energy by relaxing the magnetic field configuration to a lower energy state. Although observational support for the first two roles is somewhat limited, there is now ample support for the third. Within the last few years EUV and X-ray instruments have directly observed the kind of plasma flows and heating indicative of reconnection. Continued improvements in instrumentation will greatly help to determine the detailed physics of the reconnection process in the solar atmosphere. Careful measurement of the reconnection outflows will be especially helpful in this regard. Current observations suggest that in some flares the jet outflows are accelerated within a short diffusion region that is more characteristic of Petschek-type reconnection than Sweet-Parker reconnection. Recent resistive MHD theoretical and numerical analyses predict that the length of the diffusion region should be just within the resolution range of current X-ray and EUV telescopes if the resistivity is uniform. On the other hand, if the resistivity is not uniform, the length of the diffusion region could be too short for the outflow acceleration region to be observable.

  9. Sunspot 1504 is Spitting Flares

    NASA Video Gallery

    This movie from the Solar Dynamics Observatory (SDO) shows the M class flare on June 14, 2012 from 9:15 AM to 2:00 PM EDT. The sun is shown here in teal as this is the color typically used to repre...

  10. Solar Flare Aimed at Earth

    NASA Technical Reports Server (NTRS)

    2002-01-01

    At the height of the solar cycle, the Sun is finally displaying some fireworks. This image from the Solar and Heliospheric Observatory (SOHO) shows a large solar flare from June 6, 2000 at 1424 Universal Time (10:24 AM Eastern Daylight Savings Time). Associated with the flare was a coronal mass ejection that sent a wave of fast moving charged particles straight towards Earth. (The image was acquired by the Extreme ultaviolet Imaging Telescope (EIT), one of 12 instruments aboard SOHO) Solar activity affects the Earth in several ways. The particles generated by flares can disrupt satellite communications and interfere with power transmission on the Earth's surface. Earth's climate is tied to the total energy emitted by the sun, cooling when the sun radiates less energy and warming when solar output increases. Solar radiation also produces ozone in the stratosphere, so total ozone levels tend to increase during the solar maximum. For more information about these solar flares and the SOHO mission, see NASA Science News or the SOHO home page. For more about the links between the sun and climate change, see Sunspots and the Solar Max. Image courtesy SOHO Extreme ultaviolet Imaging Telescope, ESA/NASA

  11. Ion Acceleration in Solar Flares

    NASA Technical Reports Server (NTRS)

    Miller, James A.; Weir, Sue B.

    1996-01-01

    Solar flares are among the most energetic and interesting phenomena in the Solar system, releasing up to 1032 ergs of energy on timescales of several tens of seconds to several tens of minutes. Much of this energy is in the form of suprathermal electrons and ions, which remain trapped at the Sun and produce a wide variety of radiations, as well as escape into interplanetary space, where they can be directly observed. The radiation from trapped particles consists in general of (1) continuum emission; (2) narrow gamma-ray nuclear deexcitation lines; and (3) high-energy neutrons observed in space or by ground-based neutron monitors. The particles that escape into space consist of both electrons and ions, which often have compositions quite different than that of the ambient solar atmosphere. Flares thus present many diagnostics of the particle acceleration mechanism(s), the identification of which is the ultimate goal of flare research. Moreover, flares in fact offer the only opportunity in astrophysics to study the simultaneous energization of both electrons and ions. Hopefully, an understanding of flares with their wealth of diagnostic data will lead to a better understanding of particle acceleration at other sites in the Universe. It is now generally accepted that flares are roughly divided into two classes: impulsive and gradual. Gradual events are large, occur high in the corona, have long-duration soft and hard X-rays and gamma rays, are electron poor, are associated with Type II radio emission and coronal mass ejections (CMEs), and produce energetic ions with coronal abundance ratios. Impulsive events are more compact, occur lower in the corona, produce short-duration radiation, and exhibit dramatic abundance enhancements in the energetic ions. Their He-3/He-4 ratio is - 1, which is a huge increase over the coronal value of about 5 x 10(exp -4), and they also posses smaller but still significant enhancements of Ne, Mg, Si, and Fe relative to He-4, C, N, and O

  12. Modeling aerial refueling operations

    NASA Astrophysics Data System (ADS)

    McCoy, Allen B., III

    Aerial Refueling (AR) is the act of offloading fuel from one aircraft (the tanker) to another aircraft (the receiver) in mid flight. Meetings between tanker and receiver aircraft are referred to as AR events and are scheduled to: escort one or more receivers across a large body of water; refuel one or more receivers; or train receiver pilots, tanker pilots, and boom operators. In order to efficiently execute the Aerial Refueling Mission, the Air Mobility Command (AMC) of the United States Air Force (USAF) depends on computer models to help it make tanker basing decisions, plan tanker sorties, schedule aircraft, develop new organizational doctrines, and influence policy. We have worked on three projects that have helped AMC improve its modeling and decision making capabilities. Optimal Flight Planning. Currently Air Mobility simulation and optimization software packages depend on algorithms which iterate over three dimensional fuel flow tables to compute aircraft fuel consumption under changing flight conditions. When a high degree of fidelity is required, these algorithms use a large amount of memory and CPU time. We have modeled the rate of aircraft fuel consumption with respect to AC GrossWeight, Altitude and Airspeed. When implemented, this formula will decrease the amount of memory and CPU time needed to compute sortie fuel costs and cargo capacity values. We have also shown how this formula can be used in optimal control problems to find minimum costs flight plans. Tanker Basing Demand Mismatch Index. Since 1992, AMC has relied on a Tanker Basing/AR Demand Mismatch Index which aggregates tanker capacity and AR demand data into six regions. This index was criticized because there were large gradients along regional boundaries. Meanwhile tankers frequently cross regional boundaries to satisfy the demand for AR support. In response we developed continuous functions to score locations with respect to their proximity to demand for AR support as well as their

  13. Fast electrons in small solar flares

    NASA Technical Reports Server (NTRS)

    Lin, R. P.

    1975-01-01

    This review summarizes both the direct spacecraft observations of nonrelativistic solar electrons, and observations of the X-ray and radio emission generated by these particles at the sun and in the interplanetary medium. These observations bear on the basic astrophysical process of particle acceleration in tenuous plasmas. We find that in many small solar flares, the nearly 5-100 keV electrons accelerated during flash phase constitute the bulk of the total flare energy. Thus the basic flare mechanism in these flares essentially converts the available flare energy into fast electrons. These electrons may produce the other flare electromagnetic emissions through their interactions with the solar atmosphere. In large proton flares these electrons may provide the energy to eject material from the sun and to create a shock wave which could accelerate nuclei and electrons to much higher energies.

  14. Observations of small solar flares with BATSE

    NASA Astrophysics Data System (ADS)

    Biesecker, D. A.; Ryan, J. M.; Fishman, G. J.

    1994-12-01

    The Burst and Transient Source Experiment on board the Compton Gamma Ray Observatory is being used to observe solar flares. The Large Area Detectors are sensitive to small solar flares. We are searching the BATSE data for solar flares with an automated algorithm that allows for independent confirmation of the event origin. With this search method, we have detected solar flares almost an order of magnitude smaller than those found in a visual search of the BASTE data. We present results that are consistent with the differential distribution of peak flare rates observed by other researchers. These results show that the rate of occurrence of the smallest flares observed by BATSE can be predicted from the rate of occurrence of larger flares.

  15. KEPLER FLARES. II. THE TEMPORAL MORPHOLOGY OF WHITE-LIGHT FLARES ON GJ 1243

    SciTech Connect

    Davenport, James R. A.; Hawley, Suzanne L.; Johnson, Emily C.; Peraza, Jesus; Jansen, Tiffany C.; Larsen, Daniel M.; Hebb, Leslie; Wisniewski, John P.; Malatesta, Michael; Keil, Marcus; Silverberg, Steven M.; Scheffler, Matthew S.; Berdis, Jodi R.; Kowalski, Adam F.; Hilton, Eric J.

    2014-12-20

    We present the largest sample of flares ever compiled for a single M dwarf, the active M4 star GJ 1243. Over 6100 individual flare events, with energies ranging from 10{sup 29} to 10{sup 33} erg, are found in 11 months of 1 minute cadence data from Kepler. This sample is unique for its completeness and dynamic range. We have developed automated tools for finding flares in short-cadence Kepler light curves, and performed extensive validation and classification of the sample by eye. From this pristine sample of flares we generate a median flare template. This template shows that two exponential cooling phases are present during the white-light flare decay, providing fundamental constraints for models of flare physics. The template is also used as a basis function to decompose complex multi-peaked flares, allowing us to study the energy distribution of these events. Only a small number of flare events are not well fit by our template. We find that complex, multi-peaked flares occur in over 80% of flares with a duration of 50 minutes or greater. The underlying distribution of flare durations for events 10 minutes and longer appears to follow a broken power law. Our results support the idea that sympathetic flaring may be responsible for some complex flare events.

  16. Statistical study of spatio-temporal distribution of precursor solar flares associated with major flares

    NASA Astrophysics Data System (ADS)

    Gyenge, N.; Ballai, I.; Baranyi, T.

    2016-07-01

    The aim of the present investigation is to study the spatio-temporal distribution of precursor flares during the 24 h interval preceding M- and X-class major flares and the evolution of follower flares. Information on associated (precursor and follower) flares is provided by Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Flare list, while the major flares are observed by the Geostationary Operational Environmental Satellite (GOES) system satellites between 2002 and 2014. There are distinct evolutionary differences between the spatio-temporal distributions of associated flares in about one-day period depending on the type of the main flare. The spatial distribution was characterized by the normalized frequency distribution of the quantity δ (the distance between the major flare and its precursor flare normalized by the sunspot group diameter) in four 6 h time intervals before the major event. The precursors of X-class flares have a double-peaked spatial distribution for more than half a day prior to the major flare, but it changes to a lognormal-like distribution roughly 6 h prior to the event. The precursors of M-class flares show lognormal-like distribution in each 6 h subinterval. The most frequent sites of the precursors in the active region are within a distance of about 0.1 diameter of sunspot group from the site of the major flare in each case. Our investigation shows that the build-up of energy is more effective than the release of energy because of precursors.

  17. Statistical study of spatio-temporal distribution of precursor solar flares associated with major flares

    NASA Astrophysics Data System (ADS)

    Gyenge, N.; Ballai, I.; Baranyi, T.

    2016-04-01

    The aim of the present investigation is to study the spatio-temporal distribution of precursor flares during the 24-hour interval preceding M- and X-class major flares and the evolution of follower flares. Information on associated (precursor and follower) flares is provided by Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Flare List, while the major flares are observed by the Geostationary Operational Environmental Satellite (GOES) system satellites between 2002 and 2014. There are distinct evolutionary differences between the spatio-temporal distributions of associated flares in about one day period depending on the type of the main flare. The spatial distribution was characterised by the normalised frequency distribution of the quantity δ (the distance between the major flare and its precursor flare normalised by the sunspot group diameter) in four 6-hour time intervals before the major event. The precursors of X-class flares have a double-peaked spatial distribution for more than half a day prior to the major flare, but it changes to a lognormal-like distribution roughly 6 hours prior to the event. The precursors of M-class flares show lognormal-like distribution in each 6-hour subinterval. The most frequent sites of the precursors in the active region are within a distance of about 0.1 diameter of sunspot group from the site of the major flare in each case. Our investigation shows that the build-up of energy is more effective than the release of energy because of precursors.

  18. Statistical Analyses of White-Light Flares: Two Main Results about Flare Behaviour

    NASA Astrophysics Data System (ADS)

    Dal, Hasan Ali

    2012-08-01

    We present two main results, based on models and the statistical analyses of 1672 U-band flares. We also discuss the behaviour of white-light flares. In addition, the parameters of the flares detected from two years of observations on CR Dra are presented. By comparing with flare parameters obtained from other UV Ceti-type stars, we examine the behaviour of the optical flare processes along with the spectral types. Moreover, we aimed, using large white-light flare data, to analyse the flare time-scales with respect to some results obtained from X-ray observations. Using SPSS V17.0 and GraphPad Prism V5.02 software, the flares detected from CR Dra were modelled with the OPEA function, and analysed with the t-Test method to compare similar flare events in other stars. In addition, using some regression calculations in order to derive the best histograms, the time-scales of white-light flares were analysed. Firstly, CR Dra flares have revealed that white-light flares behave in a similar way as their counterparts observed in X-rays. As can be seen in X-ray observations, the electron density seems to be a dominant parameter in white-light flare process, too. Secondly, the distributions of the flare time-scales demonstrate that the number of observed flares reaches a maximum value in some particular ratios, which are 0.5, or its multiples, and especially positive integers. The thermal processes might be dominant for these white-light flares, while non-thermal processes might be dominant in the others. To obtain better results for the behaviour of the white-light flare process along with the spectral types, much more stars in a wide spectral range, from spectral type dK5e to dM6e, must be observed in white-light flare patrols.

  19. Flare-antenna unit for system in which flare is remotely activated by radio

    NASA Astrophysics Data System (ADS)

    Hiltz, Frederick F.; Wilson, Charles E.

    1995-06-01

    A flare-antenna assembly has flare material enclosed in a cylindrical antenna and forms part of a marker beacon. The flare aids in the search for the marker beacon by providing means for both visual and infrared detection. The flare is actuated in response to a specific remote radio signal being received by the antenna. The received signal is decoded by the electronic system within the marker beacon. If the received signal meets the necessary criteria the electronic system generates an electrical signal that detonates a squib embedded in the flare material. The detonation of the squib activates the flare.

  20. Effects of variables upon pyrotechnically induced shock response spectra, part 2

    NASA Technical Reports Server (NTRS)

    Smith, James Lee

    1988-01-01

    Throughout the aerospace industry, large variations of 50 percent (6 dB) or more in shock response spectra (SRS) derived from pyrotechnic separation events continue to be reported from actual spaceflight data and from laboratory tests. As a result of these variations, NASA funded a research program for 1984 through 1986. The purpose of the 1984 through 1986 project was to analyze variations in pyrotechnically induced SRS and to determine if and to what degree manufacturing and assembly variables and tolerances, distance from the shock source, data acquisition instrumentation, and shock energy propagation affect the SRS. Sixty-four free-free boundary plate tests were performed. NASA funded an additional study for 1987 through 1988. This paper is a summary of the additional study. The purpose was to evaluate shock dissipation through various spacecraft structural joint types, to evaluate shock variation for various manufacturing and assembly variables on clamped boundary test plates, and to verify data correction techniques. Five clamped boundary plate tests investigated manufacturing and assembly variables and mass loading effects. Six free-free boundary plate tests investigated shock dissipation across spacecraft joint structures.

  1. The development of laser ignited deflagration-to-detonation transition (DDT) detonators and pyrotechnic actuators

    SciTech Connect

    Merson, J.A.; Salas, F.J.; Harlan, J.G.

    1993-11-01

    The use of laser ignited explosive components has been recognized as a safety enhancement over existing electrical explosive devices (EEDs). Sandia has been pursuing the development of optical ordnance for many years with recent emphasis on developing optical deflagration-to-detonation (DDT) detonators and pyrotechnic actuators. These low energy optical ordnance devices can be ignited with either a semiconductor diode laser, laser diode arrays or a solid state rod laser. By using a semiconductor laser diode, the safety improvement can be made without sacrificing performance since the input energy required for the laser diode and the explosive output are similar to existing electrical systems. The use of higher powered laser diode arrays or rod lasers may have advantages in fast DDT applications or lossy optical environments such as long fiber applications and applications with numerous optical connectors. Recent results from our continued study of optical ignition of explosive and pyrotechnic materials are presented. These areas of investigation can be separated into three different margin categories: (1) the margin relative to intended inputs (i.e. powder performance as a function of laser input variation), (2) the margin relative to anticipated environments (i.e. powder performance as a function of thermal environment variation), and (3) the margin relative to unintended environments (i.e. responses to abnormal environments or safety).

  2. An extreme pressure attenuation in metals from a miniaturized pyrotechnic train configuration

    NASA Astrophysics Data System (ADS)

    Yoh, Jack; Kim, Bohoon; Yu, Hyeonju; Seoul National University Team

    A pyrotechnic device that consists of donor/acceptor pair separated by a bulkhead relies on shock attenuation in metal and shock sensitivity of the energetic materials. Despite of its common use, full-scale numerical simulation of such explosive train configuration is seldom reported because the proper modeling of the entire process requires precise capturing of extreme pressure waves from the donor charge during its attenuation in the metal before triggering of an acceptor charge and the accurate material modeling of high strain rate dynamics of both reactive and inert solids. The considered train consists of HMX as donor, STS 304 as the bulkhead, and RDX as acceptor. The simulation of such multi-material configuration reveals the critical bulkhead thickness for successful initiation of a pyrotechnic device. Furthermore, the miniaturization of such system is considered by obtaining the distance to shock front sharpening for building an analytical theory of pressure attenuation in STS sample of microscale thickness, and a new shock Hugoniot data is provided from the laser-based shock experiment using such samples. Hanwha Research Grant 2015.

  3. Laser-generated shock wave attenuation aimed at microscale pyrotechnic device design

    NASA Astrophysics Data System (ADS)

    Yu, Hyeonju; Yoh, Jack J.

    2016-05-01

    To meet the rising demand for miniaturizing the pyrotechnic device that consists of donor/acceptor pair separated by a bulkhead or a thin gap, the shock initiation sensitivity in the microscale gap test configuration is investigated. For understanding the shock attenuation within a gap sample (304 stainless steel) thickness of 10˜800 μm, the laser-generated shock wave in water confinement is adopted. The shock properties are obtained from the free surface velocity by making use of a velocity interferometer system for any reflector (VISAR). Analytical models for plasma generation in a confined geometry and for evolution and decay of shock waves during the propagation are considered. The shape and amplitude of the laser-driven initial pressure load and its attenuation pattern in the gap are effectively controlled for targeting the microscale propagation distance and subsequent triggering pressure for the acceptor charge. The reported results are important in the precise controlling of the shock strength during the laser initiation of microscale pyrotechnic devices.

  4. Supercritical water oxidation of colored smoke, dye, and pyrotechnic compositions. Final report: Pilot plant conceptual design

    SciTech Connect

    LaJeunesse, C.A.; Chan, Jennifer P.; Raber, T.N.; Macmillan, D.C.; Rice, S.F.; Tschritter, K.L.

    1993-11-01

    The existing demilitarization stockpile contains large quantities of colored smoke, spotting dye, and pyrotechnic munitions. For many years, these munitions have been stored in magazines at locations within the continental United States awaiting completion of the life-cycle. The open air burning of these munitions has been shown to produce toxic gases that are detrimental to human health and harmful to the environment. Prior efforts to incinerate these compositions have also produced toxic emissions and have been unsuccessful. Supercritical water oxidation (SCWO) is a rapidly developing hazardous waste treatment method that can be an alternative to incineration for many types of wastes. The primary advantage SCWO affords for the treatment of this selected set of obsolete munitions is that toxic gas and particulate emissions will not occur as part of the effluent stream. Sandia is currently designing a SCWO reactor for the US Army Armament Research, Development & Engineering Center (ARDEC) to destroy colored smoke, spotting dye, and pyrotechnic munitions. This report summarizes the design status of the ARDEC reactor. Process and equipment operation parameters, process flow equations or mass balances, and utility requirements for six wastes of interest are developed in this report. Two conceptual designs are also developed with all process and instrumentation detailed.

  5. Mars Observer Propulsion and Pyrotechnics Corrective Actions Test Program Status-1999

    NASA Technical Reports Server (NTRS)

    Saulsberry, Regor; Ramirez, Joseph; Julien, Howard L.; Hart, Matthew; Smith, William; Fries, Joseph (Technical Monitor)

    1999-01-01

    An extensive propulsion and pyrotechnic test program has been in progress at the NASA White Sands Test Facility since 1995. This program created the capabilities to: accurately measure and characterize pyrovalve combustion product blow-by into propellant systems; characterize valve operation using a Velocity Interferometer System for Any Reflector (VISAR); and evaluate hydrazine and monomethylhydrazine thermal decomposition initiated by blow-by. These capabilities were further utilized and refined this year. Low blow-by pyrovalves manufactured by Conax Florida Corporation continued to be evaluated as a potential corrective measure for blow-by induced propellant explosions. Development and testing of various advanced pyrovalves and investigation of explosion mechanisms also continued. Current and near-term testing includes: evaluation of 3/8 in. Conax pyrovalves and other commercially available valves; development and testing of advanced pyrovalve subcomponent technologies including a zero blow-by pyrovalve ram, composite overwrapped ram cylinder, and a zero particulate generating poppet; investigation of non-destructive evaluation techniques to evaluate pyrovalve ram seals; and testing and modeling of pyrotechnically induced explosive hydrazine decomposition. Evaluation of 3/8 in. Conax valves will include operational margin testing to be accomplished at NASA Langley Research Center. The test program also seeks to compile and format significant amounts of data from this and other pyrovalve test programs to generate a pyrovalve applications handbook. The handbook will facilitate formation of standards that ensure safe spacecraft applications. Current data and future plans are discussed, and community interaction is encouraged.

  6. High-time resolution and size-segregated elemental composition in high-intensity pyrotechnic exposures.

    PubMed

    Crespo, Javier; Yubero, Eduardo; Nicolás, Jose F; Lucarelli, Franco; Nava, Silvia; Chiari, Massimo; Calzolai, Giulia

    2012-11-30

    Typical of festivals in Eastern Spain, mascletàs are high-intensity pyrotechnic events where thousands of firecrackers are burnt in an intense, rapid episode that generates short-lived heavy aerosol clouds. High temporal resolution and size distribution characterisation of aerosol components were performed to evaluate the effects of the brief (<30 min) and acute exposure on the spectators present. Very high concentrations of firework specific elements, especially in the fine fraction, were reached during mascletàs, with values of about 500 μg/m(3) for K and 300 μg/m(3) for Cl. Sr, Al, Mg, Ba, Cu, Co, Zn, and Pb concentration increase factors of more than 100 (1000 for Sr and Ba) were observed in the fine fraction with respect to background levels. Crustal origin elements, like Ca, Fe, Si, Ti, also showed an important concentration rise (~10 times above background levels) but this is due to dust resuspension by pyrotechnic explosions. The crustal components are mainly in the coarse mode (>90% elemental mass), between 2 and 3 μm. Most firework related metals are concentrated in the submicrometric region (>80%) with a trimodal size distribution. This may be interesting to epidemiologists given the toxic effects that such fine, metal-rich particles can have on human health. PMID:23026448

  7. The development of laser ignited deflagration-to-detonation transition (DDT) detonators and pyrotechnic actuators

    SciTech Connect

    Merson, J.A.; Salas, F.J.

    1994-05-01

    The use of laser ignited explosive components has been recognized as a safety enhancement over existing electrical explosive devices (EEDs). Sandia has been pursuing the development of optical ordnance for many years with recent emphasis on developing optical deflagration-to-detonation (DDT) detonators and pyrotechnic actuators. These low energy optical ordnance devices can be ignited with either a semiconductor diode laser, laser diode arrays or a solid state rod laser. By using a semiconductor laser diode, the safety improvement can be made without sacrificing performance since the input energy required for the laser diode and the explosive output are similar to existing electrical systems. The use of higher powered laser diode arrays or rod lasers may have advantages in fast DDT applications or lossy optical environments such as long fiber applications and applications with numerous optical connectors. Recent results from our continued study of optical ignition of explosive and pyrotechnic materials are presented. These areas of investigation can be separated into three different margin categories: (1) the margin relative to intended inputs ( i.e. powder performance as a function of laser input variation), (2) the margin relative to anticipated environments (i.e. powder performance as a function of thermal environment variation), and (3) the margin relative to unintended environments (i.e. responses to abnormal environments or safety).

  8. Plasma arc technology development for application to demilitarization of pyrotechnic ordnance

    SciTech Connect

    Mescavage, G.; Filius, K. |

    1995-12-31

    An initial investigation into the use of a plasma arc furnace for demilitarization of completely assembled, small-caliber, hand-emplaced pyrotechnic, smoke, and dye ordnance was conducted at the Department of Energy`s Western Environmental Technology Office, located in Butte, Montana. This technology is being pursued as an alternative to open burning/open detonation (OB/OD), which is the method of demilitarization traditionally used for these items, as increasingly more stringent environmental regulations have discouraged and disallowed the use of OB/OD. Problems have been experienced with the use of existing incinerators for demilitarization of these items. Varying quantities of 19 different types of live, completely assembled, small pyrotechnic, smoke, and dye items were processed in a pilot-scale Retech, Inc., Plasma Arc Centrifugal Treatment System. This testing demonstrated that a plasma arc furnace equipped with pollution abatement equipment can safely demilitarize these items in compliance with applicable environmental regulations. In addition, the process encapsulates heavy metals and other hazardous constituents into a solid, low-leachable slag product that passes Federally established tests as a nonhazardous material. This provides an advantage over standard incineration which yields a hazardous ash. The process also is able to overcome problems reported with standard incinerators. In addition, gas flows are significantly lower than those in standard incinerators, allowing smaller pollution abatement equipment to be used. However, operational problems and inefficiencies were identified that need to be resolved before full-scale implementation.

  9. Thermal expansion coefficients of a 30% glass fiber filled PEEK pyrotechnic charge holder

    SciTech Connect

    Donnelly, M.W.; Walters, R.R.; Miller, G.D.

    1985-01-01

    Pyrotechnic actuators use hollow cylindrical ceramic or plastic charge holders to electrically isolate the pyrotechnic charge from the actuator case. In a newly developed actuator, 30% glass fiber filled polyetheretherketone (PEEK) was selected as the charge holder material both for its strength and its forming properties. Because the actuators are exposed to significant temperature variations during storage and flight, a determination of the coefficient of thermal expansion, ..cap alpha.., of the charge holders was required to assure success in this, the first electroexplosive device application of PEEK. Of special interest in this project were the questions of whether ..cap alpha.. depends on the direction (with respect to flow in the mold) or on injection pressure. From the test results, the conclusions are: (1) ..cap alpha.. does depend on direction. Its value in the thickness direction is approximately twice that in either the height or circumferential direction. This is probably because the wall thickness, 0.015'', is less than the average fiber length, 0.100'', and the PEEK is, therefore, not acting as a composite in the t direction. (2) Varying the injection pressure over the range of this study has no detectable effect on ..cap alpha... This charge holder is molded into an Inconel actuator case with ..cap alpha.. = 11.4 ..mu..m/m.C. This relatively close match of ..cap alpha..'s between adjacent materials has resulted in no dimensional problems during manufacturing and environmental testing. 1 fig., 1 tab.

  10. Semiconductor bridge (SCB) igniter studies: 1, Comparison of SCB and hot-wire pyrotechnic actuators

    SciTech Connect

    Bickes, R.W. Jr.; Schlobohm, S.L.; Ewick, D.W.

    1988-01-01

    Sandia National Laboratories has developed a means for igniting pyrotechnics, propellants and primary or secondary explosives using a semiconductor bridge (SCB) instead of the small metal bridgewires, called hot wires, conventionally used for explosive components. The SCB is a heavily n-doped silicon film, typically 100 ..mu..m long by 380 ..mu..m wide by 2 ..mu..m thick, which when driven with a short (20 ..mu..s), low-energy current pulse (less than 3 mJ), generates a hot plasma that ignites the explosives. We report in this paper a study of pyrotechnic actuators built with SCB igniters in which we obtained the Langlie All-Fire, Langlie No-Fire and Electrostatic Discharge (ESD) characteristics. Two SCB designs were tested. The first (designated as a type 3-2) was the rectangularly shaped bridge described above. The second (designated as a type 15) included a modification of the rectangular bridge consisting of a narrow waist region. We compare our data for these prototype SCB components with the same actuators built with conventional hot-wire igniters. The results obtained demonstrated the main characteristics of SCB devices: (1) the SCB actuators functioned at one-tenth the input energy of the hot-wire actuators, (2) had higher no-fire currents than the hot-wire devices, (3) passed ESD tests, and (4) functioned in a few tens of microseconds versus the millisecond response of the hot-wire components. 8 refs., 5 figs., 3 tabs.

  11. Development and testing of hermetic, laser-ignited pyrotechnic and explosive components

    NASA Technical Reports Server (NTRS)

    Kramer, Daniel P.; Beckman, Thomas M.; Spangler, Ed M.; Munger, Alan C.; Woods, C. M.

    1993-01-01

    During the last decade there has been increasing interest in the use of lasers in place of electrical systems to ignite various pyrotechnic and explosive materials. The principal driving force for this work was the requirement for safer energetic components which would be insensitive to electrostatic and electromagnetic radiation. In the last few years this research has accelerated since the basic concepts have proven viable. At the present time it is appropriate to shift the research emphasis in laser initiation from the scientific arena--whether it can be done--to the engineering realm--how it can be put into actual practice in the field. Laser initiation research and development at EG&G Mound was in three principal areas: (1) laser/energetic material interactions; (2) development of novel processing techniques for fabricating hermetic (helium leak rate of less than 1 x 10(exp -8) cu cm/s) laser components; and (3) evaluation and testing of laser-ignited components. Research in these three areas has resulted in the development of high quality, hermetic, laser initiated components. Examples are presented which demonstrate the practicality of fabricating hermetic, laser initiated explosive or pyrotechnic components that can be used in the next generation of ignitors, actuators, and detonators.

  12. The Effects of Flare Definitions on the Statistics of Derived Flare Distrubtions

    NASA Astrophysics Data System (ADS)

    Ryan, Daniel; Dominique, Marie; Seaton, Daniel B.; Stegen, Koen; White, Arthur

    2016-05-01

    The statistical examination of solar flares is crucial to revealing their global characteristics and behaviour. However, statistical flare studies are often performed using standard but basic flare detection algorithms relying on arbitrary thresholds which may affect the derived flare distributions. We explore the effect of the arbitrary thresholds used in the GOES event list and LYRA Flare Finder algorithms. We find that there is a small but significant relationship between the power law exponent of the GOES flare peak flux frequency distribution and the algorithms’ flare start thresholds. We also find that the power law exponents of these distributions are not stable but appear to steepen with increasing peak flux. This implies that the observed flare size distribution may not be a power law at all. We show that depending on the true value of the exponent of the flare size distribution, this deviation from a power law may be due to flares missed by the flare detection algorithms. However, it is not possible determine the true exponent from GOES/XRS observations. Additionally we find that the PROBA2/LYRA flare size distributions are clearly non-power law. We show that this is consistent with an insufficient degradation correction which causes LYRA absolute irradiance values to be unreliable. This means that they should not be used for flare statistics or energetics unless degradation is adequately accounted for. However they can be used to study time variations over shorter timescales and for space weather monitoring.

  13. Improved green-light-emitting pyrotechnic formulations based on tris(2,2,2-trinitroethyl)borate and boron carbide.

    PubMed

    Klapötke, Thomas M; Krumm, Burkhard; Rusan, Magdalena; Sabatini, Jesse J

    2014-08-28

    Green-light-emitting pyrotechnic compositions based on tris(2,2,2-trinitroethyl)borate (TNEB) and boron carbide have been investigated. The best performing formulations were found to be insensitive to various ignition stimuli, and exhibited very high spectral purities and luminosities compared to previously reported green-light-emitting formulations. PMID:25012058

  14. Using the Chemistry of Fireworks to Engage Students in Learning Basic Chemical Principles: A Lesson in Eco-Friendly Pyrotechnics

    ERIC Educational Resources Information Center

    Steinhauser, Georg; Klapotke, Thomas M.

    2010-01-01

    Fascination with fireworks and pyrotechnics can be used for educational purposes. Several aspects of pyrochemistry such as redox reactions, flame colors, or the theory of combustion can be incorporated in the curriculum to illustrate some basic chemical principles, guaranteeing a lesson that will be engaging and memorable. Beyond classic…

  15. The Flare-CME Connection

    NASA Astrophysics Data System (ADS)

    Raftery, Claire; Gallagher, P. T.; Lin, C.

    2009-05-01

    The connection between flares and CMEs has long been hypothesized and modelled. However, a full understanding of the processes at work remains ambiguous. A detailed study of the kinematical evolution of a CME was conducted using instruments on STEREO. Flare parameters, such as the motion of soft X-ray sources, imaged using RHESSI, and emission measure and plasma temperature measured from Mercury MESSENGER are presented in conjunction with the CME data to explain the evolution of the entire system. These results are then compared to a number of theoretical models to determine which of the many hypotheses are most probable for this event. CLR is supported by an SPD studentship and the ESA/Prodex grant administered by Enterprise Ireland.

  16. Helium (3) Rich Solar Flares

    DOE R&D Accomplishments Database

    Colgate, S. A.; Audouze, J.; Fowler, W. A.

    1977-05-03

    The extreme enrichment of {sup 3} He {sup 4} He greater than or equal to 1 in some solar flares as due to spallation and the subsequent confinement of the products in a high temperature, kT approx. = 200 keV, high density, n{sub e} approx. = 3 x 10{sup 15} cm {sup -3} plasma associated with the magnetic instability producing the flare is interpreted. The pinch or filament is a current of high energy protons that creates the spallation and maintains the temperature that produces the high energy x-ray spectrum and depletes other isotopes D, Li, Be, and B as observed. Finally the high temperature plasma is a uniquely efficient spallation target that is powered by the interaction of stellar convection and self generated magnetic field.

  17. Flare instability and driving mechanism

    NASA Astrophysics Data System (ADS)

    Raychaudhuri, Probhas

    A mechanism is described for the generation of solar flares in which a Buneman instability is produced by electrons moving faster than thermal speed. A trapped population of particles accelerates in the magnetic field of active solar regions causing a streaming of ions relative to electrons which moves and heats the electrons. The theoretical argument also concludes that instability at the inner solar core directly bears on solar activities at the outer heliosphere.

  18. Flare emission from Sagittarius A*

    NASA Astrophysics Data System (ADS)

    Eckart, A.; García-Marín, M.; Vogel, S. N.; Teuben, P.; Morris, M. R.; Baganoff, F.; Dexter, J.; Schödel, R.; Witzel, G.; Valencia-S, M.; Karas, V.; Kunneriath, D.; Bremer, M.; Straubmeier, C.; Moser, L.; Sabha, N.; Buchholz, R.; Zamaninasab, M.; Mužić, K.; Moultaka, J.; Zensus, J. A.

    2012-07-01

    Based on Bremer et al. (2011) and Eckart et al. (2012) we report on simultaneous observations and modeling of the millimeter, near-infrared, and X-ray flare emission of the source Sagittarius A* (SgrA*) associated with the super-massive (4×106 Modot) black hole at the Galactic Center. We study physical processes giving rise to the variable emission of SgrA* from the radio to the X-ray domain. To explain the statistics of the observed variability of the (sub-)mm spectrum of SgrA*, we use a sample of simultaneous NIR/X-ray flare peaks and model the flares using a synchrotron and SSC mechanism. The observations reveal flaring activity in all wavelength bands that can be modeled as the signal from adiabatically expanding synchrotron self-Compton (SSC) components. The model parameters suggest that either the adiabatically expanding source components have a bulk motion larger than vexp or the expanding material contributes to a corona or disk, confined to the immediate surroundings of SgrA*. For the bulk of the synchrotron and SSC models, we find synchrotron turnover frequencies in the range 300-400 GHz. For the pure synchrotron models this results in densities of relativistic particles of the order of 106.5 cm-3 and for the SSC models, the median densities are about one order of magnitude higher. However, to obtain a realistic description of the frequency-dependent variability amplitude of SgrA*, models with higher turnover frequencies and even higher densities are required. We discuss the results in the framework of possible deviations from equilibrium between particle and magnetic field energy. We also summarize alternative models to explain the broad-band variability of SgrA*.

  19. Characteristics of gamma-ray line flares

    NASA Technical Reports Server (NTRS)

    Bai, T.; Dennis, B.

    1983-01-01

    Observations of solar gamma rays by the Solar Maximum Mission (SMM) demonstrate that energetic protons and ions are rapidly accelerated during the impulsive phase. To understand the acceleration mechanisms for these particles, the characteristics of the gamma ray line flares observed by SMM were studied. Some very intense hard X-ray flares without detectable gamma ray lines were also investigated. Gamma ray line flares are distinguished from other flares by: (1) intense hard X-ray and microwave emissions; (2) delay of high energy hard X-rays; (3) emission of type 2 and/or type 4 radio bursts; and (4) flat hard X-ray spectra (average power law index: 3.1). The majority of the gamma ray line flares shared all these characteristics, and the remainder shared at least three of them. Positive correlations were found between durations of spike bursts and spatial sizes of flare loops as well as between delay times and durations of spike bursts.

  20. Solar flares controlled by helicity conservation

    NASA Technical Reports Server (NTRS)

    Gliner, Erast B.; Osherovich, Vladimir A.

    1995-01-01

    The energy release in a class of solar flares is studied on the assumption that during burst events in highly conducting plasma the magnetic helicity of plasma is approximately conserved. The available energy release under a solar flare controlled by the helicity conservation is shown to be defined by the magnetic structure of the associated prominence. The approach throws light on some solar flare enigmas: the role of the associated prominence. The approach throws light on some solar flare enigmas: the role of the associated prominences; the discontinuation of the reconnection of magnetic lines long before the complete reconnection of participated fields occurs; the existence of quiet prominences which, in spite of their usual optical appearance, do not initiate any flare events; the small energy release under a solar flare in comparison with the stockpile of magnetic energy in surrounding fields. The predicted scale of the energy release is in a fair agreement with observations.

  1. Pre-flare dynamics of sunspot groups

    SciTech Connect

    Korsós, M. B.; Baranyi, T.; Ludmány, A. E-mail: baranyi.tunde@csfk.mta.hu

    2014-07-10

    Several papers provide evidence that the most probable sites of flare onset are the regions of high horizontal magnetic field gradients in solar active regions. Besides the localization of flare-producing areas, this work intends to reveal the characteristic temporal variations in these regions prior to flares. This study uses sunspot data instead of magnetograms and follows the behavior of a suitable defined proxy measure representing the horizontal magnetic field gradient. The source of the data is the SDD (SOHO/MDI-Debrecen Data) sunspot catalog. The most promising pre-flare signatures are the following properties of gradient variation: (1) steep increase, (2) high maximum, (3) significant fluctuation, and (4) a gradual decrease between the maximum and the flare onset that can be related to the 'pull mode' of the current layer. These properties may yield a tool for the assessment of flare probability and intensity within the following 8-10 hr.

  2. Solar flares and energetic particles.

    PubMed

    Vilmer, Nicole

    2012-07-13

    Solar flares are now observed at all wavelengths from γ-rays to decametre radio waves. They are commonly associated with efficient production of energetic particles at all energies. These particles play a major role in the active Sun because they contain a large amount of the energy released during flares. Energetic electrons and ions interact with the solar atmosphere and produce high-energy X-rays and γ-rays. Energetic particles can also escape to the corona and interplanetary medium, produce radio emissions (electrons) and may eventually reach the Earth's orbit. I shall review here the available information on energetic particles provided by X-ray/γ-ray observations, with particular emphasis on the results obtained recently by the mission Reuven Ramaty High-Energy Solar Spectroscopic Imager. I shall also illustrate how radio observations contribute to our understanding of the electron acceleration sites and to our knowledge on the origin and propagation of energetic particles in the interplanetary medium. I shall finally briefly review some recent progress in the theories of particle acceleration in solar flares and comment on the still challenging issue of connecting particle acceleration processes to the topology of the complex magnetic structures present in the corona. PMID:22665901

  3. Modeling Repeatedly Flaring δ Sunspots.

    PubMed

    Chatterjee, Piyali; Hansteen, Viggo; Carlsson, Mats

    2016-03-11

    Active regions (ARs) appearing on the surface of the Sun are classified into α, β, γ, and δ by the rules of the Mount Wilson Observatory, California on the basis of their topological complexity. Amongst these, the δ sunspots are known to be superactive and produce the most x-ray flares. Here, we present results from a simulation of the Sun by mimicking the upper layers and the corona, but starting at a more primitive stage than any earlier treatment. We find that this initial state consisting of only a thin subphotospheric magnetic sheet breaks into multiple flux tubes which evolve into a colliding-merging system of spots of opposite polarity upon surface emergence, similar to those often seen on the Sun. The simulation goes on to produce many exotic δ sunspot associated phenomena: repeated flaring in the range of typical solar flare energy release and ejective helical flux ropes with embedded cool-dense plasma filaments resembling solar coronal mass ejections. PMID:27015469

  4. Observing white-light flares

    NASA Astrophysics Data System (ADS)

    Neidig, D. F.; Beckers, J. M.

    1983-03-01

    Observational techniques and instrumentation for tracking the occurrence of solar white light flares back to their origin are discussed. The rare events have been found to happen in the chromospheric and coronal regions over sunspots, and are thought to be the release of accumulated energy breaking free from the magnetic field lines and reforming into simpler structures. Use of an achromatic f/15 objective lens, together with a reimaging system for field magnification as a prelude to 35 mm photography, at the Sacramento Peak Observatory is described. A Wollaston prism is also used to split the image into two beams for detection of intensity variations due to polarization, which has thus far not been observed in the white light flares. Spectroscopic data indicate visual emission due to negatively-charged hydrogen ions in the upper photosphere, and shorter wavelength neutral hydrogen Balmer continuum features. A white light flare can be up to 300% as brilliant as the surrounding region, and involve several percent of the total spontaneous solar output.

  5. Interplanetary shock waves associated with solar flares

    NASA Technical Reports Server (NTRS)

    Chao, J. K.; Sakurai, K.

    1974-01-01

    The interaction of the earth's magnetic field with the solar wind is discussed with emphasis on the influence of solar flares. The geomagnetic storms are considerered to be the result of the arrival of shock wave generated by solar flares in interplanetary space. Basic processes in the solar atmosphere and interplanetary space, and hydromagnetic disturbances associated with the solar flares are discussed along with observational and theoretical problems of interplanetary shock waves. The origin of interplanetary shock waves is also discussed.

  6. 46 CFR 160.066-5 - Design, construction, and manufacturing requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Design, construction, and manufacturing requirements. 160.066-5 Section 160.066-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Boats, Red Aerial Pyrotechnic Flare § 160.066-5 Design, construction, and manufacturing requirements....

  7. 46 CFR 160.066-5 - Design, construction, and manufacturing requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 6 2012-10-01 2012-10-01 false Design, construction, and manufacturing requirements. 160.066-5 Section 160.066-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Boats, Red Aerial Pyrotechnic Flare § 160.066-5 Design, construction, and manufacturing requirements....

  8. 46 CFR 160.066-5 - Design, construction, and manufacturing requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Design, construction, and manufacturing requirements. 160.066-5 Section 160.066-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Boats, Red Aerial Pyrotechnic Flare § 160.066-5 Design, construction, and manufacturing requirements....

  9. 46 CFR 160.066-5 - Design, construction, and manufacturing requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 6 2014-10-01 2014-10-01 false Design, construction, and manufacturing requirements. 160.066-5 Section 160.066-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Boats, Red Aerial Pyrotechnic Flare § 160.066-5 Design, construction, and manufacturing requirements....

  10. 46 CFR 160.066-5 - Design, construction, and manufacturing requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 6 2013-10-01 2013-10-01 false Design, construction, and manufacturing requirements. 160.066-5 Section 160.066-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Boats, Red Aerial Pyrotechnic Flare § 160.066-5 Design, construction, and manufacturing requirements....

  11. 46 CFR 160.066-12 - Operational tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Operational tests. 160.066-12 Section 160.066-12 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare § 160.066-12 Operational tests. (a)...

  12. 46 CFR 160.066-7 - Performance requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 6 2012-10-01 2012-10-01 false Performance requirements. 160.066-7 Section 160.066-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare §...

  13. 46 CFR 160.066-15 - Production testing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 6 2014-10-01 2014-10-01 false Production testing. 160.066-15 Section 160.066-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare §...

  14. 46 CFR 160.066-15 - Production testing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 6 2013-10-01 2013-10-01 false Production testing. 160.066-15 Section 160.066-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare §...

  15. 46 CFR 160.066-7 - Performance requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 6 2013-10-01 2013-10-01 false Performance requirements. 160.066-7 Section 160.066-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare §...

  16. 46 CFR 160.066-15 - Production testing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 6 2012-10-01 2012-10-01 false Production testing. 160.066-15 Section 160.066-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare §...

  17. 46 CFR 160.066-7 - Performance requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 6 2011-10-01 2011-10-01 false Performance requirements. 160.066-7 Section 160.066-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Distress Signal for Boats, Red Aerial Pyrotechnic Flare §...

  18. Aerial camera auto focusing system

    NASA Astrophysics Data System (ADS)

    Wang, Xuan; Lan, Gongpu; Gao, Xiaodong; Liang, Wei

    2012-10-01

    Before the aerial photographic task, the cameras focusing work should be performed at first to compensate the defocus caused by the changes of the temperature, pressure etc. A new method of aerial camera auto focusing is proposed through traditional photoelectric self-collimation combined with image processing method. Firstly, the basic principles of optical self-collimation and image processing are introduced. Secondly, the limitations of the two are illustrated and the benefits of the new method are detailed. Then the basic principle, the system composition and the implementation of this new method are presented. Finally, the data collection platform is set up reasonably and the focus evaluation function curve is draw. The results showed that: the method can be used in the Aerial camera focusing field, adapt to the aviation equipment trends of miniaturization and lightweight .This paper is helpful to the further work of accurate and automatic focusing.

  19. Orbital tube flaring system produces tubing connectors with zero leakage

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1967-01-01

    An orbital tube flaring system produces tubing connectors with a zero-leak potential needed in high pressure hydraulic and pneumatic systems. The flaring system incorporates a rolling cone and rolling die to closely control flare characteristics.

  20. OBSERVATIONS OF CHROMOSPHERIC FLARE RE-BRIGHTENINGS

    SciTech Connect

    Miklenic, C. H.; Veronig, A. M.; Vrsnak, B.; Barta, M.

    2010-08-20

    We investigate an active region that produced three C-class flares and one M-class flare within 2.5 hr. The morphology and location of the C-flares indicate that these events constitute a set of homologous flares. Radio observations indicate the occurrence of a downward-moving plasmoid during the impulsive phase of the M flare. We use TRACE 1700 A filtergrams and SOHO Michelson Doppler Imager magnetograms to examine the character of the UV brightenings; i.e., we search for re-brightenings of former flare areas both across the series of events and within one and the same event. We find that essentially the same footpoints re-brighten in each C flare. Based on the progression of both the derived magnetic flux change rate and the observed Radio Solar Telescope Network microwave emission, we speculate about a further re-brightening during the decay phase of the M flare as a further member of the series of homologous flares. We conclude that the 'postflare' field is driven to repeated eruption by continuous, shear-increasing, horizontal, photospheric flows, as one end of the involved magnetic arcade is anchored in the penumbra of a large sunspot. The observed motion pattern of the UV kernels indicates that the arcade evolves during the series of events from a both highly sheared and heavily entangled state to a still sheared but more organized state.

  1. Coronal behavior before the large flare onset

    NASA Astrophysics Data System (ADS)

    Imada, Shinsuke; Bamba, Yumi; Kusano, Kanya

    2014-12-01

    Flares are a major explosive event in our solar system. They are often followed by a coronal mass ejection that has the potential to trigger geomagnetic storms. There are various studies aiming to predict when and where the flares are likely to occur. Most of these studies mainly discuss the photospheric and chromospheric activity before the flare onset. In this paper we study the coronal features before the famous large flare occurrence on 2006 December 13. Using the data from Hinode/Extreme ultraviolet Imaging Spectrometer (EIS), X-Ray Telescope (XRT), and Solar and Heliospheric Observatory (SOHO)/Extreme ultraviolet Imaging Telescope (EIT), we discuss the coronal features in the large scale (a few 100″) before the flare onset. Our findings are as follows. (1) The upflows in and around the active region start growing from ˜ 10 to 30 km s-1 a day before the flare. (2) The expanding coronal loops are clearly observed a few hours before the flare. (3) Soft X-ray and extreme ultraviolet intensity are gradually reduced. (4) The upflows are further enhanced after the flare. From these observed signatures, we conclude that the outer part of active region loops with low density was expanding a day before the flare onset, and the inner part with high density was expanding a few hours before the onset.

  2. Radiative backwarming in white-light flares

    NASA Technical Reports Server (NTRS)

    Machado, Marcos E.; Emslie, A. Gordon; Avrett, Eugene H.

    1989-01-01

    Consideration is given to empirical atmospheric structures that are consistent with enhanced white-light continuum emission in solar flares. Results are presented from calculations of radiative transfer in lines and continua in empirical white-light flare model atmospheres, showing that flares with strong emission in the Balmer lines and continuum must show increases at longer wavelengths due to H(-) emission from overheated photospheric levels, which the Paschen continuum contribution in the same wavelength range is neglible. Also, plausible heating mechanisms that can lead to white-light flare emission are examined.

  3. Dynamics of aerial target pursuit

    NASA Astrophysics Data System (ADS)

    Pal, S.

    2015-12-01

    During pursuit and predation, aerial species engage in multitasking behavior that involve simultaneous target detection, tracking, decision-making, approach and capture. The mobility of the pursuer and the target in a three dimensional environment during predation makes the capture task highly complex. Many researchers have studied and analyzed prey capture dynamics in different aerial species such as insects and bats. This article focuses on reviewing the capture strategies adopted by these species while relying on different sensory variables (vision and acoustics) for navigation. In conclusion, the neural basis of these capture strategies and some applications of these strategies in bio-inspired navigation and control of engineered systems are discussed.

  4. AERIAL OF VEHICLE ASSEMBLY BUILDING & SURROUNDING AREA

    NASA Technical Reports Server (NTRS)

    1977-01-01

    AERIAL OF VEHICLE ASSEMBLY BUILDING & SURROUNDING AREA KSC-377C-0082.41 116-KSC-377C-82.41, P-15877, ARCHIVE-04151 Aerial view - Shuttle construction progress - VAB and Orbiter Processing Facilities - direction northwest.

  5. A Rayleigh Scatter-Based Ocular Flare Analysis Meter for Flare Photometry of the Anterior Chamber

    PubMed Central

    Lam, Deborah L.; Axtelle, Jim; Rath, Susan; Dyer, Andrew; Harrison, Benjamin; Rogers, Claude; Menon, Naresh; Van Gelder, Russell N.

    2015-01-01

    Purpose Existing flare photometers are based on the Tyndall effect, which requires sophisticated laser photometry. The ocular flare analysis meter (OFAM) is a nonlaser photometer that uses quantitative Rayleigh scatter and absorption from visible light to compute a flare value. This study is designed to correlate OFAM measurements with qualitative measurements of flare in vitro and in vivo. Methods Following validation of the device on artificial anterior chambers containing known protein concentrations, flare readings were obtained from 90 subjects (46 with and 44 without uveitis) in one eye. Subjects were graded by the Standardization of Uveitis Nomenclature (SUN) working group flare scoring system and received the OFAM flare measurements. Results The OFAM showed linear response in vitro to protein concentrations ranging from 0 to 0.5 mg/ml. In clinical use in subjects ranging from SUN flare scores of 0+ to 2+, OFAM showed statistically significant measurement accuracy (P = 0.0008 of flare 0 versus flare 2; P = 0.031 of flare 0 versus flare 1). Distinction of SUN scores 1 and 2 was borderline significant (P = 0.057). Conclusion The OFAM photometry correlates with the standard SUN scoring system. This method may provide an objective method to diagnosis and monitor uveitis. Further longitudinal studies are warranted. Translational Relevance Currently, ocular flare is assessed qualitatively in most clinical settings. The existing methodology uses only Tyndall effect to measure flare. The OFAM uses an alternate, nonlaser means for measurement of anterior chamber flare by measure of Raleigh scatter. This pilot clinical study suggests that the OFAM device may be useful in measurement of uveitis activity. PMID:26688778

  6. Measurement and analysis of force-time outputs of pyrotechnic nuts

    NASA Technical Reports Server (NTRS)

    Neubert, V. H.

    1973-01-01

    The dynamic loadings produced by two standard pyrotechnic nuts were compared with loadings produced by four recently developed low-shock nuts. The nuts were manufactured by separate contractors. Each nut was given a number designation, the number having no special significance. The results show that the use of the Hopkinson bar to measure force-time outputs of the nuts at stud and housing sides aided greatly in understanding the events occurring in the nuts. Acceleration data appear to be dependable, for the most part, but of more limited value. The low-shock designs show considerable improvement over the standard designs above 4,000 Hz when the results are plotted in shock spectrum form. They involve some penalties with regard to weight and cost.

  7. Hot-spot model for calculating the threshold for shock initiation of pyrotechnic mixtures

    SciTech Connect

    Maiden, D.E.; Nutt, G.L.

    1986-05-14

    A model for predicting the pressure required to initiate a reaction in pyrotechnic mixtures is described. The pore temperature is determined by calculating the dynamics of pore collapse. An approximate solution for the motion of the pore radius is determined as a function of the pore size, viscosity, yield stress and pressure. The heating of the material surrounding the pore is given by an approximate solution of the heat conduction equation with a source term accounting for viscoplastic heating as a function of the pore motion. Ignition occurs when the surface temperature of the pore matches the hot-spot ignition criterion. The hot-spot ignition temperatures for 2Al/Fe/sub 2/O/sub 3/, Ti/2B, and Ti/C are determined. Predictions for the ignition pressure of 2Al/Fe/sub 2/O/sub 3/ (thermite) are in resonable agreement with experiment. 18 refs.

  8. Mathematical modelling of pyrotechnic shock in the Ariane 5 VEB structure

    NASA Astrophysics Data System (ADS)

    Huerta, M. C.; Alarcon, E.; Gomez-Lera, S.

    1991-10-01

    The theoretical improvements performed since the last spacecraft and mechanical testing conference on the study of the pyrotechnic shock phenomena produced during the separation of the lower stage of the Ariane 5 Vehicle Equipment Bay (VEB) structure are described. The first theoretical approach used was based on the wave propagation method, including axial and shear waves. The method was changed, in order to capture the bending effects, as well as the influence of the frequency dependent damping values. In addition to the development of the theoretical method, efforts were made to improve the criteria used to model the structure. Comparison of the theoretical predictions with the test results of a flat test sample 1 m width, as well as a preliminary test performed on a small sample, are presented.

  9. Explosives and pyrotechnic propellants for use in long term deep space missions

    NASA Technical Reports Server (NTRS)

    Gorzynski, C. S., Jr.; Maycock, J. N.

    1973-01-01

    Explosives and pyrotechnic propellant materials which will withstand heat sterilization cycling at 125 C and ten year deep space aging under 10 to the minus 6th power torr and 66 C have been selected. The selection was accomplished through a detailed literature survey and an analytical evaluation of the physicochemical properties of the materials. The chemical components of the electroexplosive devices used in U.S. missiles and spacecraft were categorized into primary explosives, secondary explosives, and propellant ingredients. Kinetic data on such parameters as thermal decomposition and sublimation were obtained for these materials and used as a basis for the ten year life prediction. From these experimental data and some analytical calculations, a listing of candidate materials for deep space missions was made.

  10. [Combustion temperature measurement of pyrotechnic composition using remote sensing Fourier transform infrared spectrometry].

    PubMed

    Zhou, Xin-li; Li, Yan; Liu, Zu-liang; Zhu, Chang-jiang; Wang, Jun-de; Lu, Chun-xu

    2002-10-01

    In this paper, combustion characterization of pyrotechnic composition is investigated using a remote sensing Fourier transform infrared spectrometry. The emission spectra have been recorded between 4,700 and 740 cm-1 with a spectral resolution of 4 cm-1. The combustion temperature can be determined remotely from spectral line intensity distribution of the fine structure of the emission fundamental band of gaseous products such as HF. The relationship between combustion temperature and combustion time has been given. Results show that there is a violent mutative temperature field with bigger temperature gradient near combustion surface. It reveals that the method of temperature measurement using remote sensing FTIR for flame temperature of unstable, violent and short time combustion on real time is a rapid, accurate and sensitive technique without interference the flame temperature field. Potential prospects of temperature measurement, gas product concentration measurement and combustion mechanism are also revealed. PMID:12938424

  11. Analysis of pyrotechnic devices by laser-illuminated high speed photography

    SciTech Connect

    Dosser, L.R.; Stark, M.A.

    1990-01-01

    Several types of pyrotechnic igniters have been evaluated using the technique of laser-illuminated high speed photography with a copper vapor laser. The accompanying video tape shows the results of high speed films recorded for two types of igniters (Type X1 and Type X2) fired in confinement in a lucite block and four types of igniters (Type X1, Type X2, Type X3, and Type X4) igniters fired at ambient. The films of the Type X1 and Type X2 igniters were recorded for both a coarse particle titanium potassium perchlorate (TiKP) output charge and a fine particle TiKP output charge. The results of these films are most informative, and the technique is shown to be useful as a design tool for studying the performance of igniters. 2 figs., 1 tab.

  12. Study of bridgewire size and pyrotechnic density relationships on all-fire levels

    SciTech Connect

    Hegedus, S.M.; Munger, A.C.

    1984-01-01

    The effects of bridgewire size and pyrotechnic density on the characteristics of a hot wire test device were evaluated. These characteristics were examined before and during initiation. Five bridgewire diameters and two loading densities were examined. Groups of hot wire devices of each bridgewire and density combination were fabricated. After final assembly, electrothermal response data were obtained on each test device, and a normalizing technique was introduced so that all groups of test devices could be compared. Then, each group of devices was subjected to a Langlie all-fire test to determine the threshold initiation current for each configuration. The results obtained reveal important boundary conditions and limiting factors related to the functioning characteristics of hot-wire devices. This information may be used to develop improved techniques of hot-wire device design such as computer modeling. Further study in this area would be valuable and is warranted.

  13. CIRCULAR RIBBON FLARES AND HOMOLOGOUS JETS

    SciTech Connect

    Wang Haimin; Liu Chang

    2012-12-01

    Solar flare emissions in the chromosphere often appear as elongated ribbons on both sides of the magnetic polarity inversion line (PIL), which has been regarded as evidence of a typical configuration of magnetic reconnection. However, flares having a circular ribbon have rarely been reported, although it is expected in the fan-spine magnetic topology involving reconnection at a three-dimensional (3D) coronal null point. We present five circular ribbon flares with associated surges, using high-resolution and high-cadence H{alpha} blue wing observations obtained from the recently digitized films of Big Bear Solar Observatory. In all the events, a central parasitic magnetic field is encompassed by the opposite polarity, forming a circular PIL traced by filament material. Consequently, a flare kernel at the center is surrounded by a circular flare ribbon. The four homologous jet-related flares on 1991 March 17 and 18 are of particular interest, as (1) the circular ribbons brighten sequentially, with cospatial surges, rather than simultaneously, (2) the central flare kernels show an intriguing 'round-trip' motion and become elongated, and (3) remote brightenings occur at a region with the same magnetic polarity as the central parasitic field and are co-temporal with a separate phase of flare emissions. In another flare on 1991 February 25, the circular flare emission and surge activity occur successively, and the event could be associated with magnetic flux cancellation across the circular PIL. We discuss the implications of these observations combining circular flare ribbons, homologous jets, and remote brightenings for understanding the dynamics of 3D magnetic restructuring.

  14. 29 CFR 1926.453 - Aerial lifts.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... lift, except in case of emergency. (x) Climbers shall not be worn while performing work from an aerial... 29 Labor 8 2010-07-01 2010-07-01 false Aerial lifts. 1926.453 Section 1926.453 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Scaffolds § 1926.453 Aerial lifts. (a)...

  15. Pyrotechnic shock response predictions combining statistical energy analysis and local random phase reconstruction.

    PubMed

    Bodin, E; Brévart, B; Wagstaff, P; Borello, G

    2002-07-01

    Numerous pyrotechnic devices are used on satellites to separate structural subsystems, deploy appendages, and activate on-board operating subsystems. The firing of these pyrotechnic mechanisms leads to severe impulsive loads which could sometimes lead to failures in electronic systems. The objective of the present investigation is to assess the relevance of a method combining deterministic calculations and statistical energy analysis to predict the time overall shock environment of electronic equipment components. The methods are applied to the low- and high-frequency ranges, respectively, which may be defined using a modal parameter based on the effective transmissibility. Initially, in order to address the problem of the low-frequency content of the mechanical shock pulse, the linear dynamic response of the equipment was calculated using direct time integration of a finite element model of the structure. The inputs in the form of the accelerations measured in all three directions at each of the four bolted interfaces were injected into the model. The high-frequency content of the shock response is taken into account by considering the intrinsic dynamic filtering of the equipment. This frequency filter magnitude is extrapolated from the transfer function given by statistical energy analysis between the different imposed accelerations and the response accelerations. Their associated phases are synthesized by considering pseudo-modal phase variations around the group velocity of the structural flexural waves. Combining the effects of the high-frequency filter outputs and the low-frequency finite element calculations yields good predictions of the equipment shock time response over the whole frequency range of interest. PMID:12141340

  16. Pyrotechnic shock response predictions combining statistical energy analysis and local random phase reconstruction

    NASA Astrophysics Data System (ADS)

    Bodin, E.; Brevart, B.; Wagstaff, P.; Borello, G.

    2002-07-01

    Numerous pyrotechnic devices are used on satellites to separate structural subsystems, deploy appendages, and activate on-board operating subsystems. The firing of these pyrotechnic mechanisms leads to severe impulsive loads which could sometimes lead to failures in electronic systems. The objective of the present investigation is to assess the relevance of a method combining deterministic calculations and statistical energy analysis to predict the time overall shock environment of electronic equipment components. The methods are applied to the low- and high-frequency ranges, respectively, which may be defined using a modal parameter based on the effective transmissibility. Initially, in order to address the problem of the low-frequency content of the mechanical shock pulse, the linear dynamic response of the equipment was calculated using direct time integration of a finite element model of the structure. The inputs in the form of the accelerations measured in all three directions at each of the four bolted interfaces were injected into the model. The high-frequency content of the shock response is taken into account by considering the intrinsic dynamic filtering of the equipment. This frequency filter magnitude is extrapolated from the transfer function given by statistical energy analysis between the different imposed accelerations and the response accelerations. Their associated phases are synthesized by considering pseudo-modal phase variations around the group velocity of the structural flexural waves. Combining the effects of the high-frequency filter outputs and the low-frequency finite element calculations yields good predictions of the equipment shock time response over the whole frequency range of interest. copyright 2002 Acoustical Society of America.

  17. Effect of oxide coated thickness on thermal ignition of titanium-based pyrotechnics

    SciTech Connect

    Erickson, K.L.

    1984-01-01

    The effect which variations in oxide coating thickness can have on thermal ignition of titanium-based pyrotechnics was examined theoretically. The analyses were developed using previously published experimental studies of ignition mechanisms. Those studies indicated that ignition is controlled by the rate at which an already existing oxide coating dissolves in the bulk metal. The specific case of hot-wire ignition at near minimum energy was considered. It was assumed that oxide dissolution occurs by molecular diffusion, and an approximate ignition model was developed to examine the relative variations in ignition times which result from variations in oxide coating thickness. The model consists of a heat conduction equation for the wire and pyrotechnic and a Fick's-law diffusion equation, with Arrhenius-type diffusion coefficient, for the oxygen in the titanium particles. Calculations showed that the ratio of ignition times t/sub i/sub 2///t/sub i/sub 1// could be estimated from t/sub i/sub 2///t/sub i/sub 1// approx. = (h/sub 2//h/sub 1/)/sup y/, where y = 2/(1 + Q/6 kcal mole/sup -1/); h/sub 2//h/sub 1/ is the respective ratio of oxide coating thicknesses, and Q is the oxygen-diffusion activation energy. Literature values for Q vary from 16 to 75 kcal/mole, while the exponent y varies from 0.6 to 0.2, respectively. At lower activation energies, moderate variations in oxide coating thickness could cause significant variations in ignition time.

  18. Implications of Dynamic Pressure Transducer Mounting Variations on Measurements in Pyrotechnic Test Apparatus

    NASA Technical Reports Server (NTRS)

    Dibbern, Andreas; Crisafulli, Jeffrey; Hagopia, Michael; McDougle, Stephen H.; Saulsberry, Regor L.

    2009-01-01

    Accurate dynamic pressure measurements are often difficult to make within small pyrotechnic devices, and transducer mounting difficulties can cause data anomalies that lead to erroneous conclusions. Delayed initial pressure response followed by data ringing has been observed when using miniaturized pressure transducer mounting adapters required to interface transducers to small test chambers. This delayed pressure response and ringing, combined with a high data acquisition rate, has complicated data analysis. This paper compares the output signal characteristics from different pressure transducer mounting options, where the passage distance from the transducer face to the pyrotechnic chamber is varied in length and diameter. By analyzing the data and understating the associated system dynamics, a more realistic understanding of the actual dynamic pressure variations is achieved. Three pressure transducer mounting configurations (elongated, standard, and face/flush mount) were simultaneously tested using NASA standard initiators in closed volume pressure bombs. This paper also presents results of these pressure transducer mounting configurations as a result of a larger NASA Engineering and Safety Center pyrovalve test project. Results from these tests indicate the improved performance of using face/flush mounted pressure transducers in this application. This type of mounting improved initial pressure measurement response time by approximately 19 s over standard adapter mounting, eliminating most of the lag time; provided a near step-function type initial pressure increase; and greatly reduced data ringing in high data acquisition rate systems. The paper goes on to discuss other issues associated with the firing and instrumentation that are important for the tester to understand.

  19. Cytokinetic pyrotechnics.

    PubMed

    Bement, William M

    2007-05-01

    Cytokinesis, the final step in cell division, is dependent on formation and closure of a ring of actin filaments (F-actin) and myosin-2 which is, in turn, dependent on activation of the small GTPase, RhoA, at the cell equator. Four new papers, including two in this issue of Developmental Cell (Petronczki et al., 2007; Birkenfeld et al., 2007), provide new insights into how RhoA activation at the equator is initiated and maintained. PMID:17488616

  20. Reconnaissance mapping from aerial photographs

    NASA Technical Reports Server (NTRS)

    Weeden, H. A.; Bolling, N. B. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. Engineering soil and geology maps were successfully made from Pennsylvania aerial photographs taken at scales from 1:4,800 to 1:60,000. The procedure involved a detailed study of a stereoscopic model while evaluating landform, drainage, erosion, color or gray tones, tone and texture patterns, vegetation, and cultural or land use patterns.

  1. The Queen's flare - Its structure and development; precursors, pre-flare brightenings, and aftermaths

    NASA Technical Reports Server (NTRS)

    De Jager, C.; Schadee, A.; Svestka, Z.; Van Tend, W.; Machado, M. E.; Strong, K. T.; Woodgate, B. E.

    1983-01-01

    A limb flare, which started at about 20:20 UT on April 30, 1980, was observed by several of the instruments on the Solar Maximum Mission (SMM) spacecraft. This flare has been the subject of a joint analysis of the SMM instruments. The present investigation represents a continuation of research reported in part by Woodgate et al. (1981) and Gabriel et al. (1981). Several questions are explored regarding the preflare activity, the evolution of the flare, and its decay. It is concluded that the X-ray brightenings observed before the flare were indicative only of the generally high level of activity from this region. They were not connected with the build-up of energy before the flare since similar brightenings were observed in the region after the flare. At least one brightening occurred at the site of the kernel before the flare. There is also some evidence of a tongue.

  2. Perimenstrual Flare of Adult Acne

    PubMed Central

    Geller, Lauren; Rosen, Jamie; Frankel, Amylynne; Goldenberg, Gary

    2014-01-01

    Background: Acne is typically regarded as an adolescent disease. A significant body of literature suggests a post-adolescent or adult form of acne. Female patients are known to experience perimenstrual acne flares, the exact prevalence of which is unknown. Objective: To establish a pattern of perimenstrual acne flare in adult women in order to better characterize the disorder. Methods: Subjects aged 18 and over were recruited during previously scheduled visits with their dermatologist at Mount Sinai Hospital in New York. An anonymous survey was distributed to women who reported their first menses at least six months earlier and had a complaint of acne within the last 30 days. Women <18 years of age and postmenopausal women were excluded from the study population. Results: Participants included women 18- to 29-years old (67%) and women 30- to 49-years old (33%). The ethnicity of respondents was Caucasian (50%), African American (20%), Latino (19%), Asian (5%), and Other (6%). The majority of participants with perimenstrual acne reported the onset of acne between the ages of 12 and 18 years. Sixty-five percent of participants reported that their acne symptoms were worse with their menses. Of those who reported perimenstrual acne symptoms, 56 percent reported worsening symptoms in the week preceding their menses, 17 percent reported worsening symptoms during their menses, three percent reported worsening symptoms after their menses, and 24 percent reported worsening symptoms throughout their cycle. Thirty-five percent of patients with perimenstrual acne reported oral contraceptive pill use. Conclusion: A significant number of adult women have perimenstrual acne symptoms. This study has proven to be useful in characterizing perimenstrual acne flare and is one of the first qualitative documentations of the presence and degree of this disorder. PMID:25161758

  3. Sun Releases X-class Solar Flare

    NASA Video Gallery

    This movie shows the July 6, 2012 X1.1 flare in the 171 Angstrom wavelength as captured by NASA’s Solar Dynamics Observatory (SDO). AR1515 was the source for this flare. AR1515 has been active ...

  4. AR 1121 Unleases X-ray Flare

    NASA Video Gallery

    Increasingly active sunspot 1121 has unleashed one of the brightest x-ray solar flares in years, an M5.4-class eruption at 15:36 UT on Nov. 6th. This close-up video shows the detail of the flare an...

  5. Excitation of XUV radiation in solar flares

    NASA Technical Reports Server (NTRS)

    Emslie, A. Gordon

    1992-01-01

    The goal of the proposed research was to understand the means by which XUV radiation in solar flares is excited, and to use this radiation as diagnostics of the energy release and transport processes occurring in the flare. Significant progress in both of these areas, as described, was made.

  6. FLARES AND THEIR UNDERLYING MAGNETIC COMPLEXITY

    SciTech Connect

    Engell, Alexander J.; Golub, Leon; Korreck, Kelly; Siarkowski, Marek; Gryciuk, Magda; Sylwester, Janusz; Sylwester, Barbara; Cirtain, Jonathan

    2011-01-01

    SphinX (Solar PHotometer IN X-rays), a full-disk-integrated spectrometer, observed 137 flare-like/transient events with active region (AR) 11024 being the only AR on disk. The Hinode X-Ray Telescope (XRT) and Solar Optical Telescope observe 67 of these events and identified their location from 12:00 UT on July 3 through 24:00 UT 2009 July 7. We find that the predominant mechanisms for flares observed by XRT are (1) flux cancellation and (2) the shearing of underlying magnetic elements. Point- and cusp-like flare morphologies seen by XRT all occur in a magnetic environment where one polarity is impeded by the opposite polarity and vice versa, forcing the flux cancellation process. The shearing is either caused by flux emergence at the center of the AR and separation of polarities along a neutral line or by individual magnetic elements having a rotational motion. Both mechanisms are observed to contribute to single- and multiple-loop flares. We observe that most loop flares occur along a large portion of a polarity inversion line. Point- and cusp-like flares become more infrequent as the AR becomes organized with separation of the positive and negative polarities. SphinX, which allows us to identify when these flares occur, provides us with a statistically significant temperature and emission scaling law for A and B class flares: EM = 6.1 x 10{sup 33} T{sup 1.9{+-}0.1}.

  7. Flares and Their Underlying Magnetic Complexity

    NASA Astrophysics Data System (ADS)

    Engell, Alexander J.; Siarkowski, Marek; Gryciuk, Magda; Sylwester, Janusz; Sylwester, Barbara; Golub, Leon; Korreck, Kelly; Cirtain, Jonathan

    2011-01-01

    SphinX (Solar PHotometer IN X-rays), a full-disk-integrated spectrometer, observed 137 flare-like/transient events with active region (AR) 11024 being the only AR on disk. The Hinode X-Ray Telescope (XRT) and Solar Optical Telescope observe 67 of these events and identified their location from 12:00 UT on July 3 through 24:00 UT 2009 July 7. We find that the predominant mechanisms for flares observed by XRT are (1) flux cancellation and (2) the shearing of underlying magnetic elements. Point- and cusp-like flare morphologies seen by XRT all occur in a magnetic environment where one polarity is impeded by the opposite polarity and vice versa, forcing the flux cancellation process. The shearing is either caused by flux emergence at the center of the AR and separation of polarities along a neutral line or by individual magnetic elements having a rotational motion. Both mechanisms are observed to contribute to single- and multiple-loop flares. We observe that most loop flares occur along a large portion of a polarity inversion line. Point- and cusp-like flares become more infrequent as the AR becomes organized with separation of the positive and negative polarities. SphinX, which allows us to identify when these flares occur, provides us with a statistically significant temperature and emission scaling law for A and B class flares: EM = 6.1 × 1033 T 1.9±0.1.

  8. Mechanisms for fast flare reconnection

    NASA Technical Reports Server (NTRS)

    Vanhoven, G.; Deeds, D.; Tachi, T.

    1988-01-01

    Normal collisional-resistivity mechanisms of magnetic reconnection have the drawback that they are too slow to explain the fast rise of solar flares. Two methods are examined which are proposed for the speed-up of the magnetic tearing instability: the anomalous enhancement of resistivity by the injection of MHD turbulence and the increase of Coulomb resistivity by radiative cooling. The results are described for nonlinear numerical simulations of these processes which show that the first does not provide the claimed effects, while the second yields impressive rates of reconnection, but low saturated energy outputs.

  9. Thermal Fronts in Solar Flares

    NASA Astrophysics Data System (ADS)

    Karlický, Marian

    2015-12-01

    We studied the formation of a thermal front during the expansion of hot plasma into colder plasma. We used a three-dimensional electromagnetic particle-in-cell model that includes inductive effects. In early phases, in the area of the expanding hot plasma, we found several thermal fronts, which are defined as a sudden decrease of the local electron kinetic energy. The fronts formed a cascade. Thermal fronts with higher temperature contrast were located near plasma density depressions, generated during the hot plasma expansion. The formation of the main thermal front was associated with the return-current process induced by hot electron expansion and electrons backscattered at the front. A part of the hot plasma was trapped by the thermal front while another part, mainly with the most energetic electrons, escaped and generated Langmuir and electromagnetic waves in front of the thermal front, as shown by the dispersion diagrams. Considering all of these processes and those described in the literature, we show that anomalous electric resistivity is produced at the location of the thermal front. Thus, the thermal front can contribute to energy dissipation in the current-carrying loops of solar flares. We estimated the values of such anomalous resistivity in the solar atmosphere together with collisional resistivity and electric fields. We propose that the slowly drifting reverse drift bursts, observed at the beginning of some solar flares, could be signatures of the thermal front.

  10. Symposium on Explosives and Pyrotechnics, 13th, Hilton Head Island, SC, Dec. 2-4, 1986, Proceedings

    SciTech Connect

    Not Available

    1987-01-01

    The present conference on explosive and pyrotechnic technologies discusses the shock-sensitivity of RDX, the thermodynamic properties of RDX, TNT, nitroglycerine, and HMX energetic molecules, the dynamic resistivity of exploding conductors, the decomposition of azides, the critical shock-initiation energy of emulsion explosives, actuator valve optimization, pyrotechnic aerosolization from novel imbibed liquid matrices, tetrazole initiators, and polymeric binders for red phosphorus pellets. Also discussed are channel-effect studies, the dynamic desensitization of coal mine explosives, the electromagnetic and electrostatic protection of explosives, the reliability of fuze explosive trains, the hazardous properties of explosive chemicals, the emulsification of an explosive with a chemical foaming agent, and low energy ignition of HMX using a foil bridge.

  11. High-performing red-light-emitting pyrotechnic illuminants through the use of perchlorate-free materials.

    PubMed

    Moretti, Jared D; Sabatini, Jesse J; Poret, Jay C

    2014-07-01

    The development of perchlorate-free M662 40 mm illuminating pyrotechnic compositions is described. On the bases of cost, performance, and sensitivity, potassium periodate was determined to be most effective potassium perchlorate replacement in the compositions tested. The optimal periodate-based composition exceeded the performance of the perchlorate-containing control, exhibited low sensitivity values to impact, friction, and electrostatic discharge, and had high thermal onset temperatures. PMID:24939042

  12. Heating and Cooling of Flare Loops in a C5.7 Two-ribbon Flare

    NASA Astrophysics Data System (ADS)

    Pearce, Sarah; Qiu, Jiong

    2016-05-01

    Heating and cooling of flare plasmas can be studied using models constrained by observations. In this work, we analyze and model thermal evolution of a C5.7 two-ribbon flare that occurred on December 26, 2011. The flare was observed by AIA. Two hundred flare loops are identified, which formed sequentially during one hour. Light curves of these flare loops in multiple EUV bands are analyzed to derive the duration and timing of flare emission in each bandpass. These timescales usually reflect cooling of flare plasmas from 10~MK to successively lower temperatures. We then use a zero-dimensional enthalpy-based thermal evolution of loops (EBTEL) model to study flare heating and cooling. Several variations on the EBTEL model are assessed. The first model uses an impulsive heating function inferred from the rapid rise of the foot-point UV emission. Synthetic emission from this model evolves and decays more quickly than the observations, as many models do. Two other variations on the model are analyzed, in an attempt to counter this. In one variation the heating function is a combination of an impulsive pulse followed by an extended tail (i.e., continuous heating). The other model uses reduced thermal conduction to slow the flares evolution. These models are compared with one another and the observations, to evaluate effects of different mechanisms governing the thermal evolution of flare plasmas.

  13. Investigations of turbulent motions and particle acceleration in solar flares

    NASA Technical Reports Server (NTRS)

    Jakimiec, J.; Fludra, A.; Lemen, J. R.; Dennis, B. R.; Sylwester, J.

    1986-01-01

    Investigations of X-raya spectra of solar flares show that intense random (turbulent) motions are present in hot flare plasma. Here it is argued that the turbulent motions are of great importance for flare development. They can efficiently enhance flare energy release and accelerate particles to high energies.

  14. Trends in quantitative aerial thermography

    SciTech Connect

    Schott, J.R.; Wilkinson, E.P.

    1983-06-01

    Recent improvements in aerial thermographic techniques, particularly in achievable spatial resolution and noise equivalent temperature variation, have enabled the use of thermography in a more objective fashion. Interpretation of the information contained in thermograms has also been improved through the use of certain techniques accounting for roof material type (emissivity), background effects, and atmospheric variables. With current methods, roof surface temperature from aerial imagery can be measured to within 1.8/sup 0/F (1.0/sup 0/C) of the actual temperature. These advances in thermogram analysis have opened the door for potential direct measurement of rooftop heat-loss levels from thermogram data. Ultimately, it is felt that this type of information would make it feasible to direct intensive energy-conservation efforts toward a smaller population, where the need and cost benefits will be the greatest.

  15. Aerial Photographs and Satellite Images

    USGS Publications Warehouse

    U.S. Geological Survey

    1997-01-01

    Photographs and other images of the Earth taken from the air and from space show a great deal about the planet's landforms, vegetation, and resources. Aerial and satellite images, known as remotely sensed images, permit accurate mapping of land cover and make landscape features understandable on regional, continental, and even global scales. Transient phenomena, such as seasonal vegetation vigor and contaminant discharges, can be studied by comparing images acquired at different times. The U.S. Geological Survey (USGS), which began using aerial photographs for mapping in the 1930's, archives photographs from its mapping projects and from those of some other Federal agencies. In addition, many images from such space programs as Landsat, begun in 1972, are held by the USGS. Most satellite scenes can be obtained only in digital form for use in computer-based image processing and geographic information systems, but in some cases are also available as photographic products.

  16. Solar flare leaves sun quaking

    NASA Astrophysics Data System (ADS)

    1998-05-01

    Dr. Alexander G. Kosovichev, a senior research scientist from Stanford University, and Dr. Valentina V. Zharkova from Glasgow (United Kingdom) University found the tell-tale seismic signature in data on the Sun's surface collected by the Michelson Doppler Imager onboard the Solar and Heliospheric Observatory (SOHO) spacecraft immediately following a moderate-sized flare on July 9, 1996. "Although the flare was a moderate one, it still released an immense amount of energy," said Dr. Craig Deforest, a researcher with the SOHO project. "The energy released is equal to completely covering the Earth's continents with a yard of dynamite and detonating it all at once." SOHO is a joint project of the European Space Agency and NASA. The finding is reported in the May 28 issue of the journal Nature, and is the subject of a press conference at the spring meeting of the American Geophysical Union in Boston, Mass., May 27. The solar quake that the science team recorded looks much like ripples spreading from a rock dropped into a pool of water. But over the course of an hour, the solar waves traveled for a distance equal to 10 Earth diameters before fading into the fiery background of the Sun's photosphere. Unlike water ripples that travel outward at a constant velocity, the solar waves accelerated from an initial speed of 22,000 miles per hour to a maximum of 250,000 miles per hour before disappearing. "People have looked for evidence of seismic waves from flares before, but they didn't have a theory so they didn't know where to look," says Kosovichev. Several years ago Kosovichev and Zharkova developed a theory that can explain how a flare, which explodes in space above the Sun's surface, can generate a major seismic wave in the Sun's interior. According to the currently accepted model of solar flares, the primary explosion creates high-energy electrons (electrically charged subatomic particles). These are funneled down into a magnetic flux tube, an invisible tube of magnetic

  17. Avalanches and the distribution of solar flares

    NASA Technical Reports Server (NTRS)

    Lu, Edward T.; Hamilton, Russell J.

    1991-01-01

    The solar coronal magnetic field is proposed to be in a self-organized critical state, thus explaining the observed power-law dependence of solar-flare-occurrence rate on flare size which extends over more than five orders of magnitude in peak flux. The physical picture that arises is that solar flares are avalanches of many small reconnection events, analogous to avalanches of sand in the models published by Bak and colleagues in 1987 and 1988. Flares of all sizes are manifestations of the same physical processes, where the size of a given flare is determined by the number of elementary reconnection events. The relation between small-scale processes and the statistics of global-flare properties which follows from the self-organized magnetic-field configuration provides a way to learn about the physics of the unobservable small-scale reconnection processes. A simple lattice-reconnection model is presented which is consistent with the observed flare statistics. The implications for coronal heating are discussed and some observational tests of this picture are given.

  18. Quantifying the Complexity of Flaring Active Regions

    NASA Astrophysics Data System (ADS)

    Stark, B.; Hagyard, M. J.

    1997-05-01

    While solar physicists have a better understanding of the importance magnetic fields play in the solar heating mechanism, it is still not possible to predict whether or when an active region will flare. In recent decades, qualitative studies of the changes in active region morphology have shown that there is generally an increase in the complexity of the spatial configuration of a solar active region leading up to a flare event. In this study, we quantify the spatial structure of the region using the Differential Box-Counting Method (DBC)of fractal analysis. We analyze data from NASA/Marshall Space Flight Center's vector magnetograph from two flaring active regions: AR 6089 from June 10, 1990, which produced one M1.7 flare, and AR 6659 from June 8, 9 and 10, 1991, this data set including one C5.7 and two M(6.4 and 3.2) flares. (AR 6659 produced several other flares). Several magnetic parameters are studied, including the transverse and longitudinal magnetic field components (Bt and Bl), the total field (Bmag), and the magnetic shear, which describes the non-potentiality of the field. Results are presented for the time series of magnetograms in relation to the timing of flare events.

  19. Quantifying the Complexity of Flaring Active Regions

    NASA Technical Reports Server (NTRS)

    Stark, B.; Hagyard, M. J.

    1997-01-01

    While solar physicists have a better understanding of the importance magnetic fields play in the solar heating mechanism, it is still not possible to predict whether or when an active region will flare. In recent decades, qualitative studies of the changes in active region morphology have shown that there is generally an increase in the complexity of the spatial configuration of a solar active region leading up to a flare event. In this study, we quantify the spatial structure of the region using the differential Box-Counting Method (DBC) of fractal analysis. We analyze data from NASA/Marshall Space Flight Centr's vector magnetograph from two flaring active regions: AR 6089 from June 10, 1990, which produced one M1.7 flare, and AR 6659 from June 8, 9 and 10, 1991, this data set including one C5.7 and two M(6.4 and 3.2) flare. (AR 6659 produced several other flares). Several magnetic parameters are studied, including the transverse and longitudinal magnetic field components (Bt and B1), the total field (Bmag), and the magnetic shear, which describes the non-potentiality of the field. Results are presented for the time series of magnetograms in relation to the timing of flare events.

  20. Aerial robotic data acquisition system

    SciTech Connect

    Hofstetter, K.J.; Hayes, D.W.; Pendergast, M.M.; Corban, J.E.

    1993-12-31

    A small, unmanned aerial vehicle (UAV), equipped with sensors for physical and chemical measurements of remote environments, is described. A miniature helicopter airframe is used as a platform for sensor testing and development. The sensor output is integrated with the flight control system for real-time, interactive, data acquisition and analysis. Pre-programmed flight missions will be flown with several sensors to demonstrate the cost-effective surveillance capabilities of this new technology.

  1. Telemetry of Aerial Radiological Measurements

    SciTech Connect

    H. W. Clark, Jr.

    2002-10-01

    Telemetry has been added to National Nuclear Security Administration's (NNSA's) Aerial Measuring System (AMS) Incident Response aircraft to accelerate availability of aerial radiological mapping data. Rapid aerial radiological mapping is promptly performed by AMS Incident Response aircraft in the event of a major radiological dispersal. The AMS airplane flies the entire potentially affected area, plus a generous margin, to provide a quick look at the extent and severity of the event. The primary result of the AMS Incident Response over flight is a map of estimated exposure rate on the ground along the flight path. Formerly, it was necessary to wait for the airplane to land before the map could be seen. Now, while the flight is still in progress, data are relayed via satellite directly from the aircraft to an operations center, where they are displayed and disseminated. This permits more timely utilization of results by decision makers and redirection of the mission to optimize its value. The current telemetry capability can cover all of North America. Extension to a global capability is under consideration.

  2. The flare kernel in the impulsive phase

    NASA Technical Reports Server (NTRS)

    Dejager, C.

    1986-01-01

    The impulsive phase of a flare is characterized by impulsive bursts of X-ray and microwave radiation, related to impulsive footpoint heating up to 50 or 60 MK, by upward gas velocities (150 to 400 km/sec) and by a gradual increase of the flare's thermal energy content. These phenomena, as well as non-thermal effects, are all related to the impulsive energy injection into the flare. The available observations are also quantitatively consistent with a model in which energy is injected into the flare by beams of energetic electrons, causing ablation of chromospheric gas, followed by convective rise of gas. Thus, a hole is burned into the chromosphere; at the end of impulsive phase of an average flare the lower part of that hole is situated about 1800 km above the photosphere. H alpha and other optical and UV line emission is radiated by a thin layer (approx. 20 km) at the bottom of the flare kernel. The upward rising and outward streaming gas cools down by conduction in about 45 s. The non-thermal effects in the initial phase are due to curtailing of the energy distribution function by escape of energetic electrons. The single flux tube model of a flare does not fit with these observations; instead we propose the spaghetti-bundle model. Microwave and gamma-ray observations suggest the occurrence of dense flare knots of approx. 800 km diameter, and of high temperature. Future observations should concentrate on locating the microwave/gamma-ray sources, and on determining the kernel's fine structure and the related multi-loop structure of the flaring area.

  3. The flare star EV Lac. II - Relations between the characteristics of the flares

    NASA Astrophysics Data System (ADS)

    Avgoloupis, S.

    1986-07-01

    Characteristics of the four types of flares observed during the 184 events that were observed on the flare star EV Lac in the period 1967-1980 are analyzed. The data include the duration and magnitude of each event, the mean rate of luminosity and apparent magnitude increases, the integrated flare intensity over the whole event, and time histograms of intensity levels of the events. The flares were distributed into 49 type IV events, 71 type III events, 38 type II events and 25 type I events. Intensities were highest in type II events, and the extremes of other distinguishing characteristics were distributed among the other events, with some having correlations exceeding the 95 percent level. The differences were sufficiently pronounced to conclude that the individual type of flare event must be considered in future analyses, rather than considering all flare events as a uniform database.

  4. Flare diagnostics from loop modeling of a stellar flare observed with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Reale, Fabio

    2006-01-01

    XMM-Newton data of an X-ray flare observed on Proxima Centauri provide detailed and challenging constraints for flare modeling. The comparison of the data with the results of time-dependent hydrodynamic loop modeling of this flare allows us to constrain not only the loop morphology, but also the details of the heating function. The results show that even a complex flare event like this can be described with a relatively few though constrained components: two loop systems, i.e., a single loop and an arcade, and two heat components, an intense pulse probably located at the loop footpoints followed by a low gradual decay distributed in the coronal part of the loop. The similarity to at least one solar event (the Bastille Day flare in 2000) indicates that this pattern may be common to solar and stellar flares.

  5. New flare diagnostics from loop modeling of a stellar flare observedwith XMM-Newton

    NASA Astrophysics Data System (ADS)

    Reale, F.

    XMM-Newton data of an X-ray flare observed on Proxima Centauri provide detailed and challenging constraints for flare modeling. The comparison of the data with the results of time-dependent hydrodynamic loop modeling of this flare allows us to constrain not only the loop morphology, but also the details of the heating function. The results show that even a complex flare event like this can be described with a relatively few - though constrained - components: two loop systems, i.e. a single loop and an arcade, and two heat components, an intense pulse probably located at the loop footpoints followed by a low gradual decay distributed in the coronal part of the loop. The similarity to at least one solar event (the Bastille Day flare in 2000) indicate that this pattern may be common to solar and stellar flares.

  6. Lithographic measurement of EUV flare in the 0.3-NA Micro ExposureTool optic at the Advanced Light Source

    SciTech Connect

    Cain, Jason P.; Naulleau, Patrick; Spanos, Costas J.

    2005-01-01

    The level of flare present in a 0.3-NA EUV optic (the MET optic) at the Advanced Light Source at Lawrence Berkeley National Laboratory is measured using a lithographic method. Photoresist behavior at high exposure doses makes analysis difficult. Flare measurement analysis under scanning electron microscopy (SEM) and optical microscopy is compared, and optical microscopy is found to be a more reliable technique. In addition, the measured results are compared with predictions based on surface roughness measurement of the MET optical elements. When the fields in the exposure matrix are spaced far enough apart to avoid influence from surrounding fields and the data is corrected for imperfect mask contrast and aerial image proximity effects, the results match predicted values quite well. The amount of flare present in this optic ranges from 4.7% for 2 {micro}m features to 6.8% for 500 nm features.

  7. Dwarf Star Erupts in Giant Flare

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This movie taken by NASA'S Galaxy Evolution Explorer shows one of the largest flares, or star eruptions, ever recorded at ultraviolet wavelengths. The star, called GJ 3685A, just happened to be in the Galaxy Evolution Explorer's field of view while the telescope was busy observing galaxies. As the movie demonstrates, the seemingly serene star suddenly exploded once, then even more intensely a second time, pouring out in total about one million times more energy than a typical flare from our Sun. The second blast of light constituted an increase in brightness by a factor of at least 10,000.

    Flares are huge explosions of energy stemming from a single location on a star's surface. They are caused by the brief destruction of a star's magnetic fields. Many types of stars experience them, though old, small, rapidly rotating 'red dwarfs' like GJ 3685A tend to flare more frequently and dramatically. These stars, called flare stars, can experience powerful eruptions as often as every few hours. Younger stars, in general, also erupt more often. One of the reasons astronomers study flare stars is to gain a better picture and history of flare events taking place on the Sun.

    A preliminary analysis of the GJ 3685A flare shows that the mechanisms underlying stellar eruptions may be more complex than previously believed. Evidence for the two most popular flare theories was found.

    Though this movie has been sped up (the actual flare lasted about 20 minutes), time-resolved data exist for each one-hundredth of a second. These observations were taken at 2 p.m. Pacific time, April 24, 2004. In the still image, the time sequence starts in the upper left panel, continues in the upper right, then moves to the lower left and ends in the lower right.

    The circular and linear features that appear below and to the right of GJ 3685A during the flare event are detector artifacts caused by the extreme brightness of the flare.

  8. Determining the Altitude of Iridium Flares

    NASA Technical Reports Server (NTRS)

    Foster, James; Owe, Manfred

    1999-01-01

    Iridium flares have nothing to do with the element iridium. Iridium is also the name of a telecommunications company that has been launching satellites into low orbits around the Earth. These satellites are being used for a new type of wireless phone and paging service. Flares have been observed coming from these satellites. These flares have the potential, especially when the full fleet of satellites is in orbit, to disrupt astronomical observations. The paper reviews using simple trigonometry how to calculate the altitude of one of these satellites.

  9. He-3-rich flares - A possible explanation

    NASA Technical Reports Server (NTRS)

    Fisk, L. A.

    1978-01-01

    A plasma mechanism is proposed to explain the dramatic enhancements in He-3 observed in He-3-rich flares. It is shown that a common current instability in the corona may heat ambient He-3(2+) over any other ion and thus may preferentially inject He-3 into the flare acceleration process. This mechanism operates when the abundance of He-4 and heavier elements is larger than normal in the coronal plasma. It may also preferentially heat and thus inject certain ions of iron. The mechanism thus provides a possible explanation for the observed correlation between He-3 and heavy enhancements in He-3-rich flares.

  10. The landing flare: An analysis and flight-test investigation

    NASA Technical Reports Server (NTRS)

    Seckel, E.

    1975-01-01

    Results are given of an extensive investigation of conventional landing flares in general aviation type airplanes. A wide range of parameters influencing flare behavior are simulated in experimental landings in a variable-stability Navion. The most important feature of the flare is found to be the airplane's deceleration in the flare. Various effects on this are correlated in terms of the average flare load factor. Piloting technique is extensively discussed. Design criteria are presented.

  11. Explosive evaporation in solar flares

    NASA Technical Reports Server (NTRS)

    Fisher, George H.

    1987-01-01

    This paper develops a simple analytical model for the phenomenon of 'explosive evaporation' driven by nonthermal electron heating in solar flares. The model relates the electron energy flux and spectrum, plus details of the preflare atmosphere, to the time scale for explosive evaporation to occur, the maximum pressure and temperature to be reached, rough estimates for the UV pulse emission flux and duration, and the evolution of the blueshifted component of the soft X-ray lines. An expression is given for the time scale for buildup to maximum pressures and the onset of rapid motion of the explosively evaporating plasma. This evaporation can excite a rapid response of UV line and continuum emission. The emission lines formed in the plasma approach a given emissivity-weighted blueshift speed.

  12. FLARING SOLAR HALE SECTOR BOUNDARIES

    SciTech Connect

    Svalgaard, L.; Hannah, I. G.; Hudson, H. S.

    2011-05-20

    The sector structure that organizes the magnetic field of the solar wind into large-scale domains has a clear pattern in the photospheric magnetic field as well. The rotation rate, 27-28.5 days, implies an effectively rigid rotation originating deeper in the solar interior than the sunspots. The photospheric magnetic field is known to be concentrated near that portion (the Hale boundary) in each solar hemisphere, where the change in magnetic sector polarity matches that between the leading and following sunspot polarities in active regions in the respective hemispheres. We report here that flares and microflares also concentrate at the Hale boundaries, implying that flux emergence and the creation of free magnetic energy in the corona also have a direct cause in the deep interior.

  13. Development of Daily Solar Maximum Flare Flux Forecast Models for Strong Flares

    NASA Astrophysics Data System (ADS)

    Shin, Seulki; Chu, Hyoungseok

    2015-08-01

    We have developed a set of daily solar maximum flare flux forecast models for strong flares using Multiple Linear Regression (MLR) and Artificial Neural Network (ANN) methods. We consider input parameters as solar activity data from January 1996 to December 2013 such as sunspot area, X-ray maximum flare flux and weighted total flux of the previous day, and mean flare rates of McIntosh sunspot group (Zpc) and Mount Wilson magnetic classification. For a training data set, we use the same number of 61 events for each C-, M-, and X-class from Jan. 1996 to Dec. 2004, while other previous models use all flares. For a testing data set, we use all flares from Jan. 2005 to Nov. 2013. The statistical parameters from contingency tables show that the ANN models are better for maximum flare flux forecasting than the MLR models. A comparison between our maximum flare flux models and the previous ones based on Heidke Skill Score (HSS) shows that our all models for X-class flare are much better than the other models. According to the Hitting Fraction (HF), which is defined as a fraction of events satisfying that the absolute differences of predicted and observed flare flux in logarithm scale are less than equal to 0.5, our models successfully forecast the maximum flare flux of about two-third events for strong flares. Since all input parameters for our models are easily available, the models can be operated steadily and automatically on daily basis for space weather service.

  14. Solar flare count periodicities in different X-ray flare classes

    NASA Astrophysics Data System (ADS)

    Gao, Peng-Xin; Xu, Jing-Chen

    2016-04-01

    Using the Morlet wavelet transform and the Hilbert-Huang transform (HHT), we investigate the periodic behaviours of C, M and X-class flare counts, respectively, recorded by the Geostationary Operational Environmental Satellites (GOES) from 1983 May to 2014 December, which cover the two complete solar cycles (SCs) 22 and 23 as well as the part of declining phase of SC 21 and rise and maximum phases of SC 24. Analyses show that the periodic behaviours of various class flare counts are different. (1) Not all periods of various class flare counts appear dominant during the cycle maxima. For C-class flares, during SC 23, periods appear dominant during the maximum phase, however, compared to those during SC 23, there are more periods during the declining phase of SC 22; for M-class flares, during SCs 22 and 23, periods appear dominant during the cycle maxima; for X-class flares, during SC 22, almost all periods appear during the maximum phase; however, during SC 23, there are more periods during the declining phase compared to those during SC 22. (2) For C-class flares, the appearance of periods do not follow the amplitude of C-class flare cycles; while, for M and X-class flares, the appearance of periods follows the amplitude of the investigated corresponding class flare cycles. (3) From the overall trends, the 10 yr and longer time-scale trends of the monthly numbers of M and X-class flares, we can infer that the maximum values of the monthly M and X-class flare numbers would increase during SC 25.

  15. The DAWN and FLARE Surveys

    NASA Astrophysics Data System (ADS)

    Rhoads, James E.; Malhotra, Sangeeta; Zheng, Zhenya; Monson, Andrew; Persson, S. Eric; Gonzalez, Alicia; Probst, Ronald G.; Swaters, Robert A.; Tilvi, Vithal; Finkelstein, Steven L.; Jiang, Tianxing; Mobasher, Bahram; Dickinson, Mark; Dressler, Alan; Lee, Janice C.; Ammons, S. Mark; Zabludoff, Ann I.; Emig, Kimberly; Hibon, Pascale; Joshi, Bhavin; Pharo, John; Smith, Mark David; Trahan, Jacob; Veilleux, Sylvain; Wang, JunXian; Wong, Kenneth C.; Yang, Huan; Zabl, Johannes; FLARE Team, the DAWN Team

    2016-01-01

    Lyman alpha galaxy populations at redshifts 8 and 9 offer a unique probe of cosmological reionization. Resonant scattering by neutral hydrogen should obscure such galaxies if the intergalactic medium is neutral, implying a steep decline in their observed counts at redshifts prior to the central phases of reionization. We are pursuing a pair of ambitious near-infrared narrow bandpass surveys to probe these populations: The Cosmic Deep and Wide Narrowband (DAWN) survey, using the NEWFIRM camera at the National Optical Astronomy Observatory's 4m Mayall telescope, and the First Light And Reionization Experiment (FLARE), using the FourStar camera at the 6.5m Magellan Telescopes. DAWN is an NOAO survey program, covering a total of five NEWFIRM fields (one square degree in all) to a limiting sensitivity around 9e-18 erg/cm2/s for emission lines at 1.06 micron wavelength, corresponding to redshift 7.7 for Lyman alpha. FLARE uses the larger aperture of the Magellan telescope to push to still higher redshift, with a limiting line flux near 5e-18 erg/cm2/s in the COSMOS field, and with additional coverage of a half dozen strongly lensed fields where we can probe still further down the Lyman alpha luminosity function. Imaging observations are largely complete for both surveys, and we are now pursuing spectroscopic followup at both near-IR and optical wavelengths. We will summarize initial results from both surveys in this meeting. With two nights of Keck+MOSFIRE observations complete already (and more scheduled in late 2015), we have numerous emission line confirmations-- both including many H alpha and Oxygen emitters in the foreground, and at least one Lyman alpha galaxy in the epoch of reionization.

  16. Xrt And Shinx Joint Flare Study: Ar 11024

    NASA Astrophysics Data System (ADS)

    Engell, Alexander; Sylwester, J.; Siarkowski, M.

    2010-05-01

    From 12:00 UT on July 3 through July 7, 2009 SphinX (Solar Photometer IN X-rays) observes 130 flares with active region (AR) 11024 being the only AR on disk. XRT (X-Ray Telescope) is able to observe 64 of these flare events. The combination of both instruments results in a flare study revealing (1) a relationship between flux emergence and flare rate, (2) that the presence of active region loops typically results in different flare morphologies (single and multiple loop flares) then when there is a lack of an active region loop environment where more cusp and point-like flares are observed, (3) cusp and point-like flares often originate from the same location, and (4) a distribution of flare temperatures corresponding to the different flare morphologies. The differences between the observed flare morphologies may occur as the result of the heated plasma through the flaring process being confined by the proximity of loop structures as for the single and multiple loop flares, while for cusp and point-like flares they occur in an early-phase environment that lack loop presence. The continuing flux emergence of AR 11024 likely provides different magnetic interactions and may be the source responsible for all of the flares.

  17. Development of Daily Maximum Flare-Flux Forecast Models for Strong Solar Flares

    NASA Astrophysics Data System (ADS)

    Shin, Seulki; Lee, Jin-Yi; Moon, Yong-Jae; Chu, Hyoungseok; Park, Jongyeob

    2016-03-01

    We have developed a set of daily maximum flare-flux forecast models for strong flares (M- and X-class) using multiple linear regression (MLR) and artificial neural network (ANN) methods. Our input parameters are solar-activity data from January 1996 to December 2013 such as sunspot area, X-ray maximum, and weighted total flare flux of the previous day, as well as mean flare rates of McIntosh sunspot group (Zpc) and Mount Wilson magnetic classifications. For a training dataset, we used 61 events each of C-, M-, and X-class from January 1996 to December 2004. For a testing dataset, we used all events from January 2005 to November 2013. A comparison between our maximum flare-flux models and NOAA model based on true skill statistics (TSS) shows that the MLR model for X-class and the average of all flares (M{+}X-class) are much better than the NOAA model. According to the hitting fraction (HF), which is defined as a fraction of events satisfying the condition that the absolute differences of predicted and observed flare flux on a logarithm scale are smaller than or equal to 0.5, our models successfully forecast the maximum flare flux of about two-thirds of the events for strong flares. Since all input parameters for our models are easily available, the models can be operated steadily and automatically on a daily basis for space-weather services.

  18. AR1429 Releases X1 Class Flare

    NASA Video Gallery

    The Solar Dynamics Observatory captured the X1 flare, shown here in the 171 Angstrom wavelength, a wavelength typically shown in the color gold. This movie runs from 10 PM ET March 4 to 3 AM March ...

  19. 2011 Valentines Day X-Class Flare

    NASA Video Gallery

    The video clip of the large X2 flare seen by Solar Dynamics Observatory (SDO) in extreme ultraviolet light on February 15, 2011, has been enlarged and superimposed on a video of SOHO's C2 coronagra...

  20. C3-class Solar Flare Eruption

    NASA Video Gallery

    Just as sunspot 1105 was turning away from Earth on Sept. 8, the active region erupted, producing a C3-class solar flare (peak @ 2330 UT) and a fantastic prominence. This is a three color closeup o...

  1. SDO Sees Late Phase in Solar Flares

    NASA Video Gallery

    On May 5, 2010, shortly after the Solar Dynamics Observatory (SDO) began normal operation, the sun erupted with numerous coronal loops and flares. Many of these showed a previously unseen "late pha...

  2. Solar Eruptions: Coronal Mass Ejections and Flares

    NASA Technical Reports Server (NTRS)

    Gopalswamy, Nat

    2012-01-01

    This lecture introduces the topic of Coronal mass ejections (CMEs) and solar flares, collectively known as solar eruptions. During solar eruptions, the released energy flows out from the Sun in the form of magnetized plasma and electromagnetic radiation. The electromagnetic radiation suddenly increases the ionization content of the ionosphere, thus impacting communication and navigation systems. Flares can be eruptive or confined. Eruptive flares accompany CMEs, while confined flares hav only electromagnetic signature. CMEs can drive MHD shocks that accelerate charged particles to very high energies in the interplanetary space, which pose radiation hazard to astronauts and space systems. CMEs heading in the direction of Earth arrive in about two days and impact Earth's magnetosphere, producing geomagnetic storms. The magnetic storms result in a number of effects including induced currnts that can disrupt power grids, railroads, and underground pipelines

  3. An Observational Overview of Solar Flares

    NASA Technical Reports Server (NTRS)

    Fletcher, Lyndsay; Battaglia, M.; Dennis, Brian R.; Liu, W.; Milligan, R. O.; Hudson, H. S.; Krucker, S.; Phillips, K.; Bone, L.; Veronig, A.; Caspi, A.; Temmer, M.

    2011-01-01

    We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.

  4. Positron annihilation radiation from solar flares

    NASA Technical Reports Server (NTRS)

    Share, G. H.; Chupp, E. L.; Forrest, D. J.; Rieger, E.

    1983-01-01

    Positron-annihilation radiation has been observed from the June 21, 1980 and June 3, 1982 flares by the gamma-ray spectrometer on the Solar Maximum Mission satellite. The observed 0.511-MeV line fluences from the flares were 14.6 + or - 3.3 gamma/sq cm and 103 + or - 8 gamma/sq cm, respectively. Measurement of the line width establishes an upper limit to the temperature in the annihilation region of 3 x 10 to the 6th K. The time dependence of the 0.511-MeV line during the 1980 flare is consistent with the calculations of Ramaty et al. (1983) for positrons created in the decay of radioactive nuclei. The time dependence of the 0.511-MeV line for the 1982 flare is more complex and requires more detailed study.

  5. Ion acceleration in impulsive solar flares

    NASA Technical Reports Server (NTRS)

    Steinacker, Jurgen; Jaekel, Uwe; Schlickeiser, Reinhard

    1993-01-01

    Nonrelativistic spectra of protons and ions accelerated in impulsive solar flares are derived using more realistic turbulence power spectra. The calculation is based on a particle transport equation extracted from a second step acceleration model containing stochastic acceleration. The turbulence model is generalized to waves with a small angle to the magnetic field vector and to turbulence power spectra with spectral indices s smaller than 2. Due to the occurrence of impulsive flares at low coronal heights, Coulomb losses at the dense coronal plasma and diffusive particle escape are taken into account. The ion spectra show deviations from long-duration spectra near the Coulomb barrier, where the losses become maximal. The Z-squared/A-dependence of the Coulomb losses leads to spectral variations for different ions. We present a method to estimate the turbulence parameters and injection conditions of the flare particles using ion ratios like Fe/O of impulsive flares.

  6. Observational aspects of stellar radio flares

    NASA Technical Reports Server (NTRS)

    Bookbinder, Jay A.

    1991-01-01

    The study of stellar flares in the radio regime provides a nearly unique observational perspective, as the emission generally arises from the particle acceleration region. Continuum and spectral studies of radio burst emission for several classes of stars are reviewed, and some preliminary connections with the quiescent radio emission from flare stars are made. Further, the radio observations are placed in a broader observational context provided by X-ray, UV, and optical observations.

  7. Composition of energetic particles from solar flares

    NASA Technical Reports Server (NTRS)

    Garrard, T. L.; Stone, E. C.

    1994-01-01

    We present a model for composition of heavy ions in the Solar Energetic Particles (SEP). The SEP composition in a typical large solar particle event reflects the composition of the Sun, with adjustments due to fractionation effects which depend on the First Ionization Potential (FIP) of the ion and on the ratio of ionic charge to mass (Q/M). Flare-to flare variations in composition are represented by parameters describing these fractionation effects and the distributions of these parameters are presented.

  8. The flare productivity of active regions

    NASA Astrophysics Data System (ADS)

    Kuroda, N.; Christe, S.

    2012-12-01

    Previous studies have shown that the flare frequency distribution is consistent with a power-law. Furthermore, studies have shown that regions of higher magnetic complexity produce more large flares. This may imply that the flare frequency distribution is harder for magnetically complex active regions. However, the relationship between source active regions' magnetic complexity and the flare size distribution has not been extensively studied. We present a new study of 25,000 microflares detected by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) from March 2002 to February 2007. For each flare, we have obtained the two classifications of magnetic complexity, the Mount Wilson Magnetic Classification and the Zurich/McIntosh Sunspot Classification, from the Solar Region Summary prepared by the National Oceanic and Atmospheric Administration (NOAA)/ Space Weather Prediction Center (SWPC), and compared them with the RHESSI flare size distribution as observed in the 12 to 25 keV energy range. We investigate the relationship between the slope of the microflare size distribution and the magnetic properties of source active regions. For each flare we obtain the relevant MDI magnetogram to determine properties such as the area of the source active region and total unsigned magnetic flux. These properties are then compared to properties of the associated microflares such as peak flux and microflare size distribution. We find that, for both the Mount Wilson Magnetic Classification and the Zurich/McIntosh Sunspot Classification, the slopes of the microflare size distribution tend to get harder as a function of magnetic complexity. For example, in Mount Wilson Magnetic Classification the slope for α regions was 1.66 and the slope for βγδ region was 1.51.This suggests that βγδ regions are 50 % more likely to produce X class flares than α regions.

  9. A very low shock alternative to conventional, pyrotechnically operated release devices

    NASA Technical Reports Server (NTRS)

    Robinson, Steven P.

    1994-01-01

    NiTiNOL is best known for its ability to remember a preset shape, even after being 'plastically' deformed. This is accomplished by heating the material to an elevated temperature up to 120 degrees C. However, NiTiNOL has other material and mechanical properties that provide a novel method of structural release. This combination of properties allows NiTiNOL to be used as a mechanical fuse between structural components. When electrical power is applied to the NiTiNOL fuse(s), the material is annealed reducing the mechanical strength to a small fraction of the as-wrought material. The preload then fractures the weakened NiTiNOL fuse(s) and releases the structure. This paper describes the mechanical characteristics of the NiTiNOL allow used in this invention, structural separation design concepts using the NiTiNOL material, and initial test data. Elimination of the safety hazard, high shock levels, and non-reusability inherent with pyrotechnic separation devices allows NiTiNOL actuated release devices to become a viable alternative for aerospace components and systems.

  10. Modeling laser ignition of explosives and pyrotechnics: Effects and characterization of radiative transfer

    SciTech Connect

    Skocypec, R.D.; Mahoney, A.R.; Glass, M.W.; Jungst, R.G.; Evans, N.A.; Erickson, K.L.

    1990-01-01

    The ignition of explosives and pyrotechnics using commercial diode lasers has been demonstrated and is of interest as a potential replacement for hot-wire ignition. Initial laser diode ignitor (LDI) test results using the detonation-to-deflagration transition(DDT) explosive CP (2-(5-cyanotetrazolato) pentaamminecobalt (III) perchlorate, C{sub 2}H{sub 15}N{sub 10}Co--Cl{sub 2}O{sub 8}) doped with carbon black and graphite have reinforced the need for a better understanding of the interaction of the radiant energy transfer within the pressed material. The present work is directed toward developing a model to predict the transfer of laser energy in the pressed particulate charges. It is shown here that scattering can have a major effect on the volumetric absorption of laser energy, significantly affecting the thermal response of the granular energetic material. This paper describes an effort to characterize the radiative properties of compacted granular beds of CP and CP doped with carbon black or graphite that were prepared using normal pressing techniques. Current estimates of the radiative properties are presented and indicate dramatic in absorption for CP when even a minute amount of carbon black or graphite is added. Initial data indicate pressed, undoped CP scatters radiative energy significantly. The radiative properties are dependent upon both wavelength and packing density; the less-densely packed samples exhibit more scattering. Doped samples exhibit essentially wavelength-independent characteristics. 14 refs., 7 figs., 1 tab.

  11. Age Life Evaluation of Space Shuttle Crew Escape System Pyrotechnic Components Loaded with Hexanitrostilbene (HNS)

    NASA Technical Reports Server (NTRS)

    Hoffman, William C., III

    1996-01-01

    Determining deterioration characteristics of the Space Shuttle crew escape system pyrotechnic components loaded with hexanitrostilbene would enable us to establish a hardware life-limit for these items, so we could better plan our equipment use and, possibly, extend the useful life of the hardware. We subjected components to accelerated-age environments to determine degradation characteristics and established a hardware life-limit based upon observed and calculated trends. We extracted samples using manufacturing lots currently installed in the Space Shuttle crew escape system and from other NASA programs. Hardware included in the study consisted of various forms and ages of mild detonating fuse, linear shaped charge, and flexible confined detonating cord. The hardware types were segregated into 5 groups. One was subjected to detonation velocity testing for a baseline. Two were first subjected to prolonged 155 F heat exposure, and the other two were first subjected to 255 F, before undergoing detonation velocity testing and/or chromatography analysis. Test results showed no measurable changes in performance to allow a prediction of an end of life given the storage and elevated temperature environments the hardware experiences. Given the lack of a definitive performance trend, coupled with previous tests on post-flight Space Shuttle hardware showing no significant changes in chemical purity or detonation velocity, we recommend a safe increase in the useful life of the hardware to 20 years, from the current maximum limits of 10 and 15 years, depending on the hardware.

  12. Dielectric structure pyrotechnic initiator realized by integrating Ti/CuO-based reactive multilayer films

    NASA Astrophysics Data System (ADS)

    Zhu, Peng; Shen, Ruiqi; Fiadosenka, N. N.; Ye, Yinghua; Hu, Yan

    2011-04-01

    A dielectric structure pyrotechnic initiator was proposed and the initiator samples were designed and realized by integrating Ti/CuO-based reactive multilayer films on ceramic substrate. The dielectric structure consists of essentially two titanium films separated by a copper oxide (CuO) film, which is just like as a capacitor guaranteeing the initiator will not be discharged until the external voltage has exceeded the breakdown strength of the CuO film. Results of the electrical explosion experiment show that the breakdown strength of 1-μm-thick CuO film is 60 V, and the initiator has "late time discharge" characteristics, which will improve the conversion ratio of the electricity greatly, and there is a nanoscale exothermic reaction in the electrical explosion process. A systematic temperature measurement model based on the "double-line atomic emission spectroscopy of copper element" was presented and used to test the explosion temperature and duration. The ejected explosion flame was seen clearly with a potential temperature exceeding 4500 K for 0.1 ms, 4250 K for 0.35 ms, and 4000 K for 0.5 ms. Besides, electric energy and exothermic reaction create high-temperature products, which discharge to a distance of 1 cm or more. The high temperature and ejected products may be able to ignite the attached energetic materials even if the initiator makes no physical contact. These characteristics of the initiator may open a door to the preparation of the highly efficient and insensitive initiating explosive device.

  13. Development report: ball milling of boron/calcium chromate pyrotechnic blends

    SciTech Connect

    Rogers, J.W. Jr.

    1986-07-01

    The development of an automated blending procedure for the production of 20/80 weight percent boron/calcium chromate (B/CaCrO/sub 4/) pyrotechnic is summarized chronologically in this report. The development included: (1) a blending study to assess the physical and chemical effects that various steps from previous and new blending procedures had on boron and CaCrO/sub 4/; (2) ball milling small quantities of older blends to improve firing performance and subsequent scale up to kilogram-size batches; (3) optimization of drying conditions; and, (4) blending B/CaCrO/sub 4/ from its individual constituents in a ball mill followed by drying in a Ross mixer. Extensive high and low current all-fire sensitivity testing along with electrostatic sensitivity testing indicate that compositions which are blended in a ball mill have equal or superior performance to compositions produced by previous methods; in addition, the blended compositions can be produced in a more reliable manner. These results have led to a new specification for B/CaCrO/sub 4/ production based upon the ball milling procedure. 28 refs., 9 tabs.

  14. Chromospheric Acoustic Oscillations in Active Flaring Regions

    NASA Astrophysics Data System (ADS)

    Monsue, T.; Hill, F.; Stassun, K.

    2014-12-01

    Chromospheric p-mode oscillations are studied in Hα to obtain helioseismic information regarding the local structural conditions around highly magnetic regions such as sunspots. Solar flares commonly occur in active regions where these sunspots exist therefore boosting the p-mode power. In our current study of analyzing p-modes in the chromosphere we study the time evolution of acoustic p-mode oscillation data taken from the Global Oscillation Network Group (GONG) Hα, and investigate the p-modes across the frequency band (1 < ν < 8.33 mHz). This study entails three active regions directly over sunspots, with accompanying flaring activity from two solar flares, occurring on June 13th and July 12th, 2012. Our analysis utilizes time series data to create Fourier power spectra of individual pixels spatially resolved around the flare region, to study the frequency bands. We then study how the frequency distribution evolves temporally by constructing a Power Map Movie (PMM) of the regions. From these PMMs we can take a survey of the chromospheric oscillations for each frequency band. We found that the intensity of the flare has an effect on the behavior of the p-modes within different frequency bands. The suppression of power was observed in dark anomalous structures within the PMMs and in other regions there was an observed boost in power due to flaring activity.

  15. New Results from the Flare Genesis Experiment

    NASA Astrophysics Data System (ADS)

    Rust, D. M.; Bernasconi, P. N.; Eaton, H. A.; Keller, C.; Murphy, G. A.; Schmieder, B.

    2000-05-01

    From January 10 to 27, 2000, the Flare Genesis solar telescope observed the Sun while suspended from a balloon in the stratosphere above Antarctica. The goal of the mission was to acquire long time series of high-resolution images and vector magnetograms of the solar photosphere and chromosphere. Images were obtained in the magnetically sensitive Ca I line at 6122 Angstroms and at H-alpha (6563 Angstroms). The FGE data were obtained in the context of Max Millennium Observing Campaign #004, the objective of which was to study the ``Genesis of Solar Flares and Active Filaments/Sigmoids." Flare Genesis obtained about 26,000 usable images on the 8 targeted active regions. A preliminary examination reveals a good sequence on an emerging flux region and data on the M1 flare on January 22, as well as a number of sequences on active filaments. We will present the results of our first analysis efforts. Flare Genesis was supported by NASA grants NAG5-4955, NAG5-5139, and NAG5-8331 and by NSF grant OPP-9615073. The Air Force Office of Scientific Research and the Ballistic Missile Defense Organization supported early development of the Flare Genesis Experiment.

  16. The energy spectra of solar flare electrons

    NASA Technical Reports Server (NTRS)

    Evenson, P. A.; Hovestadt, D.; Meyer, P.; Moses, D.

    1985-01-01

    A survey of 50 electron energy spectra from .1 to 100 MeV originating from solar flares was made by the combination of data from two spectrometers onboard the International Sun Earth Explorer-3 spacecraft. The observed spectral shapes of flare events can be divided into two classes through the criteria of fit to an acceleration model. This standard two step acceleration model, which fits the spectral shape of the first class of flares, involves an impulsive step that accelerates particles up to 100 keV and a second step that further accelerates these particles up to 100 MeV by a single shock. This fit fails for the second class of flares that can be characterized as having excessively hard spectra above 1 MeV relative to the predictions of the model. Correlations with soft X-ray and meter radio observations imply that the acceleration of the high energy particles in the second class of flares is dominated by the impulsive phase of the flares.

  17. Origins and effects of solar flares

    SciTech Connect

    Rust, D.M. ||

    1993-12-31

    During the 1989 - 1991 peak of solar activity, geomagnetic storms from interplanetary shocks caused a massive failure in the Canadian power grid, minor failures in other power eqipment, and many communications disruptions and satellite malfunctions. The proton storms would have been lethal for unshielded space travellers. Had the power managers been given a credible, timely forecast of the solar storm, they could have protected their generating equipment and the grid. They do not keep protective circuits in place full-time because that reduces efficiency and increases the cost of power distribution. Nor will astronauts on the moon or in deep space confine themselves full-time to thick-walled, radiation-resistant closets. To enable manned deep space exploration we have to find a way to determine what happens in solar flares. Only this will improve the forecasts. Expensive and restrictive protective measures would then have to be applied only when a major flare is clearly imminent. There is no generally accepted flare theory or description of the pre-flare state or of the instabilities. The Solar Maximum Mission (SMM) cleared up many questions about electromagnetic flare emissions and the structure of the flaring atmosphere, but the dynamic of the magnetic fields is still a mystery.

  18. Absolute Abundance Measurements in Solar Flares

    NASA Astrophysics Data System (ADS)

    Warren, Harry

    2014-06-01

    We present measurements of elemental abundances in solar flares with EVE/SDO and EIS/Hinode. EVE observes both high temperature Fe emission lines Fe XV-XXIV and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (F). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is F=1.17+-0.22. Furthermore, we have compared the EVE measurements with corresponding flare observations of intermediate temperature S, Ar, Ca, and Fe emission lines taken with EIS. Our initial calculations also indicate a photospheric composition for these observations. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation in the non-flaring corona occurs.

  19. Global ionospheric flare detection system (GIFDS)

    NASA Astrophysics Data System (ADS)

    Wenzel, Daniela; Jakowski, Norbert; Berdermann, Jens; Mayer, Christoph; Valladares, Cesar; Heber, Bernd

    2016-02-01

    The Global Ionospheric Flare Detection System (GIFDS) is currently under development at the German Aerospace Center as a ground based detector for continuous monitoring of the solar flare activity in order to provide real time warnings on solar X-ray events. GIFDS is using Very Low Frequency (VLF) radio transmissions in the northern hemisphere which respond to enhanced ionization in the bottomside ionosphere caused by X-ray flares. Since solar flares can only be detected during daytime, VLF receivers have to be installed around the globe to guarantee continuous records at the dayside sector. GIFDS consists of a network of Perseus SDR (Software Defined Radio) receivers equipped with a MiniWhip antenna each. Reliable detection of solar flares is ensured by recording multiple frequency channels ranging from 0 to 500 kHz. The applicability of the system is demonstrated in a first analysis by comparing VLF measurements with GOES's (Geostationary Operational Environmental Satellite) X-ray flux data. The high potential of GIFDS for a permanent monitoring of solar flares in near real time is discussed.

  20. Using Two-Ribbon Flare Observations and MHD Simulations to Constrain Flare Properties

    NASA Astrophysics Data System (ADS)

    Kazachenko, Maria D.; Lynch, Benjamin J.; Welsch, Brian

    2016-05-01

    Flare ribbons are emission structures that are frequently observed during flares in transition-region and chromospheric radiation. These typically straddle a polarity inversion line (PIL) of the radial magnetic field at the photosphere, and move apart as the flare progresses. The ribbon flux - the amount of unsigned photospheric magnetic flux swept out by flare ribbons - is thought to be related to the amount coronal magnetic reconnection, and hence provides a key diagnostic tool for understanding the physical processes at work in flares and CMEs. Previous measurements of the magnetic flux swept out by flare ribbons required time-consuming co-alignment between magnetograph and intensity data from different instruments, explaining why those studies only analyzed, at most, a few events. The launch of the Helioseismic and Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA), both aboard the Solar Dynamics Observatory (SDO), presented a rare opportunity to compile a much larger sample of flare-ribbon events than could readily be assembled before. We created a dataset of 363 events of both flare ribbon positions and fluxes, as a function of time, for all C9.-class and greater flares within 45 degrees of disk center observed by SDO from June 2010 till April 2015. For this purpose, we used vector magnetograms (2D magnetic field maps) from HMI and UV images from AIA. A critical problem with using unprocessed AIA data is the existence of spurious intensities in AIA data associated with strong flare emission, most notably "blooming" (spurious smearing of saturated signal into neighboring pixels, often in streaks). To overcome this difficulty, we have developed an algorithmic procedure that effectively excludes artifacts like blooming. We present our database and compare statistical properties of flare ribbons, e.g. evolutions of ribbon reconnection fluxes, reconnection flux rates and vertical currents with the properties from MHD simulations.

  1. Effects of flare definitions on the statistics of derived flare distributions

    NASA Astrophysics Data System (ADS)

    Ryan, D. F.; Dominique, M.; Seaton, D.; Stegen, K.; White, A.

    2016-08-01

    The statistical examination of solar flares is crucial to revealing their global characteristics and behaviour. Such examinations can tackle large-scale science questions or give context to detailed single-event studies. However, they are often performed using standard but basic flare detection algorithms relying on arbitrary thresholds. This arbitrariness may lead to important scientific conclusions being drawn from results caused by subjective choices in algorithms rather than the true nature of the Sun. In this paper, we explore the effect of the arbitrary thresholds used in the Geostationary Operational Environmental Satellite (GOES) event list and Large Yield RAdiometer (LYRA) Flare Finder algorithms. We find that there is a small but significant relationship between the power law exponent of the GOES flare peak flux frequency distribution and the flare start thresholds of the algorithms. We also find that the power law exponents of these distributions are not stable, but appear to steepen with increasing peak flux. This implies that the observed flare size distribution may not be a power law at all. We show that depending on the true value of the exponent of the flare size distribution, this deviation from a power law may be due to flares missed by the flare detection algorithms. However, it is not possible determine the true exponent from GOES/XRS observations. Additionally we find that the PROBA2/LYRA flare size distributions are artificially steep and clearly non-power law. We show that this is consistent with an insufficient degradation correction. This means that PROBA2/LYRA should not be used for flare statistics or energetics unless degradation is adequately accounted for. However, it can be used to study variations over shorter timescales and for space weather monitoring.

  2. A Spherical Aerial Terrestrial Robot

    NASA Astrophysics Data System (ADS)

    Dudley, Christopher J.

    This thesis focuses on the design of a novel, ultra-lightweight spherical aerial terrestrial robot (ATR). The ATR has the ability to fly through the air or roll on the ground, for applications that include search and rescue, mapping, surveillance, environmental sensing, and entertainment. The design centers around a micro-quadcopter encased in a lightweight spherical exoskeleton that can rotate about the quadcopter. The spherical exoskeleton offers agile ground locomotion while maintaining characteristics of a basic aerial robot in flying mode. A model of the system dynamics for both modes of locomotion is presented and utilized in simulations to generate potential trajectories for aerial and terrestrial locomotion. Details of the quadcopter and exoskeleton design and fabrication are discussed, including the robot's turning characteristic over ground and the spring-steel exoskeleton with carbon fiber axle. The capabilities of the ATR are experimentally tested and are in good agreement with model-simulated performance. An energy analysis is presented to validate the overall efficiency of the robot in both modes of locomotion. Experimentally-supported estimates show that the ATR can roll along the ground for over 12 minutes and cover the distance of 1.7 km, or it can fly for 4.82 minutes and travel 469 m, on a single 350 mAh battery. Compared to a traditional flying-only robot, the ATR traveling over the same distance in rolling mode is 2.63-times more efficient, and in flying mode the system is only 39 percent less efficient. Experimental results also demonstrate the ATR's transition from rolling to flying mode.

  3. Feasibility of flare gas reformation to practical energy in Farashband gas refinery: no gas flaring.

    PubMed

    Rahimpour, Mohammad Reaza; Jokar, Seyyed Mohammad

    2012-03-30

    A suggested method for controlling the level of hazardous materials in the atmosphere is prevention of combustion in flare. In this work, three methods are proposed to recover flare gas instead of conventional gas-burning in flare at the Farashband gas refinery. These methods aim to minimize environmental and economical disadvantages of burning flare gas. The proposed methods are: (1) gas to liquid (GTL) production, (2) electricity generation with a gas turbine and, (3) compression and injection into the refinery pipelines. To find the most suitable method, the refinery units that send gas to the flare as well as the required equipment for the three aforementioned methods are simulated. These simulations determine the amount of flare gas, the number of GTL barrels, the power generated by the gas turbine and the required compression horsepower. The results of simulation show that 563 barrels/day of valuable GTL products is produced by the first method. The second method provides 25 MW electricity and the third method provides a compressed natural gas with 129 bar pressure for injection to the refinery pipelines. In addition, the economics of flare gas recovery methods are studied and compared. The results show that for the 4.176MMSCFD of gas flared from the Farashband gas refinery, the electricity production gives the highest rate of return (ROR), the lowest payback period, the highest annual profit and mild capital investment. Therefore, the electricity production is the superior method economically. PMID:22305604

  4. EVALUATION OF THE EFFICIENCY OF INDUSTRIAL FLARES: FLARE HEAD DESIGN AND GAS COMPOSITION

    EPA Science Inventory

    The report gives continued Phase 4 results of a research program to quantify emissions from, and efficiencies of, industrial flares. Initial results were limited to tests conducted burning propane/nitrogen mixtures in pipe flares without pilot light stabilization. The work report...

  5. Properties of white light flares. I - Association with H-alpha flares and sudden frequency deviations.

    NASA Technical Reports Server (NTRS)

    Mcintosh, P. S.; Donnelly, R. F.

    1972-01-01

    All four large EUV bursts for which there were available concurrent white light observations of at least fair quality, were detected as white light flares. The rise times and maxima of the white light emissions coincided with rise times and maxima of the EUV bursts. The frequency of strong EUV bursts suggests that white light flares may occur at the rate of five or six per year near sunspot maximum. All of the white light flare areas coincided with intense bright areas of the H-alpha flares. These small areas appeared to be sources of high velocity ejecta in H-alpha. The white light flares occurred as several knots or patches of 2 to 15 arc-sec diameter, with bright cores perhaps less than 2 arc-sec diameter (1500 km). They preferred the outer penumbral borders of strong sunspots within 10 arc-sec of a longitudinal neutral line in the magnetic field.

  6. Astronomical Methods in Aerial Navigation

    NASA Technical Reports Server (NTRS)

    Beij, K Hilding

    1925-01-01

    The astronomical method of determining position is universally used in marine navigation and may also be of service in aerial navigation. The practical application of the method, however, must be modified and adapted to conform to the requirements of aviation. Much of this work of adaptation has already been accomplished, but being scattered through various technical journals in a number of languages, is not readily available. This report is for the purpose of collecting under one cover such previous work as appears to be of value to the aerial navigator, comparing instruments and methods, indicating the best practice, and suggesting future developments. The various methods of determining position and their application and value are outlined, and a brief resume of the theory of the astronomical method is given. Observation instruments are described in detail. A complete discussion of the reduction of observations follows, including a rapid method of finding position from the altitudes of two stars. Maps and map cases are briefly considered. A bibliography of the subject is appended.

  7. Enclosed ground-flare incinerator

    DOEpatents

    Wiseman, Thomas R.

    2000-01-01

    An improved ground flare is provided comprising a stack, two or more burner assemblies, and a servicing port so that some of the burner assemblies can be serviced while others remain in operation. The burner assemblies comprise a burner conduit and nozzles which are individually fitted to the stack's burner chamber and are each removably supported in the chamber. Each burner conduit is sealed to and sandwiched between a waste gas inlet port and a matching a closure port on the other side of the stack. The closure port can be opened for physically releasing the burner conduit and supplying sufficient axial movement room for extracting the conduit from the socket, thereby releasing the conduit for hand removal through a servicing port. Preferably, the lower end of the stack is formed of one or more axially displaced lower tubular shells which are concentrically spaced for forming annular inlets for admitting combustion air. An upper tubular exhaust stack, similarly formed, admits additional combustion air for increasing the efficiency of combustion, increasing the flow of exhausted for improved atmospheric dispersion and for cooling the upper stack.

  8. 29 CFR 1926.453 - Aerial lifts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Aerial lifts. 1926.453 Section 1926.453 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Scaffolds § 1926.453 Aerial lifts. (a) General requirements. (1) Unless otherwise provided...

  9. A Classroom Simulation of Aerial Photography.

    ERIC Educational Resources Information Center

    Baker, Simon

    1981-01-01

    Explains how a simulation of aerial photography can help students in a college level beginning course on interpretation of aerial photography understand the interrelationships of the airplane, the camera, and the earth's surface. Procedures, objectives, equipment, and scale are discussed. (DB)

  10. BOREAS Level-0 ER-2 Aerial Photography

    NASA Technical Reports Server (NTRS)

    Newcomer, Jeffrey A.; Dominquez, Roseanne; Hall, Forrest G. (Editor)

    2000-01-01

    For BOReal Ecosystem-Atmosphere Study (BOREAS), the ER-2 and other aerial photography was collected to provide finely detailed and spatially extensive documentation of the condition of the primary study sites. The ER-2 aerial photography consists of color-IR transparencies collected during flights in 1994 and 1996 over the study areas.

  11. Identifying flares in rheumatoid arthritis: reliability and construct validation of the OMERACT RA Flare Core Domain Set

    PubMed Central

    Bykerk, Vivian P; Bingham, Clifton O; Choy, Ernest H; Lin, Daming; Alten, Rieke; Christensen, Robin; Furst, Daniel E; Hewlett, Sarah; Leong, Amye; March, Lyn; Woodworth, Thasia; Boire, Gilles; Haraoui, Boulos; Hitchon, Carol; Jamal, Shahin; Keystone, Edward C; Pope, Janet; Tin, Diane; Thorne, J Carter

    2016-01-01

    Objective To evaluate the reliability of concurrent flare identification using 3 methods (patient, rheumatologist and Disease Activity Score (DAS)28 criteria), and construct validity of candidate items representing the Outcome Measures in Rheumatology Clinical Trials (OMERACT) RA Flare Core Domain Set. Methods Candidate flare questions and legacy measures were administered at consecutive visits to Canadian Early Arthritis Cohort (CATCH) patients between November 2011 and November 2014. The American College of Rheumatology (ACR) core set indicators were recorded. Concordance to identify flares was assessed using the agreement coefficient. Construct validity of flare questions was examined: convergent (Spearman's r); discriminant (mean differences between flaring/non-flaring patients); and consequential (proportions with prior treatment reductions and intended therapeutic change postflare). Results The 849 patients were 75% female, 81% white, 42% were in remission/low disease activity (R/LDA), and 16–32% were flaring at the second visit. Agreement of flare status was low–strong (κ's 0.17–0.88) and inversely related to RA disease activity level. Flare domains correlated highly (r's≥0.70) with each other, patient global (r's≥0.66) and corresponding measures (r's 0.49–0.92); and moderately highly with MD and patient-reported joint counts (r's 0.29–0.62). When MD/patients agreed the patient was flaring, mean flare domain between-group differences were 2.1–3.0; 36% had treatment reductions prior to flare, with escalation planned in 61%. Conclusions Flares are common in rheumatoid arthritis (RA) and are often preceded by treatment reductions. Patient/MD/DAS agreement of flare status is highest in patients worsening from R/LDA. OMERACT RA flare questions can discriminate between patients with/without flare and have strong evidence of construct and consequential validity. Ongoing work will identify optimal scoring and cut points to identify RA flares. PMID

  12. Energetics of RHESSI X-Class Flares

    NASA Technical Reports Server (NTRS)

    Dennis, Brian R.; Haga, Leah; Holman, Gordon D.; Hudson, Hugh

    2005-01-01

    The thermal and nonthermal energies of several X-class flares seen with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) will be presented. The same techniques described by Emslie et al. (JGR, 109, A10104, 2004) are used to take the RHESSI imaging spectroscopic observations and compute the energies in the thermal plasma and in the nonthermal electrons as a function of time throughout the flares. Radiative and conductive cooling rates are estimated and total thermal and nonthermal energies are computed for each flare. Typically, the energy in nonthermal electrons integrated up to the time of peak soft X-ray emission is equal to or exceeds the energy in the thermal plasma at that time. This suggests that energy must have been converted into a form not visible with RHESSI and that the total energy released by the flares may be significantly greater than the sum of energies calculated from the RHESSI observations alone. This conclusion is supported by the high radiative energy seen with SORCE during the impulsive phase of the 28 October 2003 flare. The peak increase in total solar irradiance of 270 mW per square meters measured with SORCE was over two orders of magnitude higher than the peak soft X-ray flux seen with GOES or RHESSI. The implications of this new observation as compared to the energetics derived from the X-ray observations of that flare will be discussed along with the energetics analysis of most of the other X- class flares in October/November 2003.

  13. A solar tornado triggered by flares?

    NASA Astrophysics Data System (ADS)

    Panesar, N. K.; Innes, D. E.; Tiwari, S. K.; Low, B. C.

    2013-01-01

    Context. Solar tornados are dynamical, conspicuously helical magnetic structures that are mainly observed as a prominence activity. Aims: We investigate and propose a triggering mechanism for the solar tornado observed in a prominence cavity by SDO/AIA on September 25, 2011. Methods: High-cadence EUV images from the SDO/AIA and the Ahead spacecraft of STEREO/EUVI are used to correlate three flares in the neighbouring active-region (NOAA 11303) and their EUV waves with the dynamical developments of the tornado. The timings of the flares and EUV waves observed on-disk in 195 Å are analysed in relation to the tornado activities observed at the limb in 171 Å. Results: Each of the three flares and its related EUV wave occurred within ten hours of the onset of the tornado. They have an observed causal relationship with the commencement of activity in the prominence where the tornado develops. Tornado-like rotations along the side of the prominence start after the second flare. The prominence cavity expands with the accelerating tornado motion after the third flare. Conclusions: Flares in the neighbouring active region may have affected the cavity prominence system and triggered the solar tornado. A plausible mechanism is that the active-region coronal field contracted by the "Hudson effect" through the loss of magnetic energy as flares. Subsequently, the cavity expanded by its magnetic pressure to fill the surrounding low corona. We suggest that the tornado is the dynamical response of the helical prominence field to the cavity expansion. Movies are available in electronic form at http://www.aanda.org

  14. SPECTROPOLARIMETRY OF C-CLASS FLARE FOOTPOINTS

    SciTech Connect

    Kleint, L.

    2012-04-01

    We investigate the decay phase of a C-class flare in full-Stokes imaging spectropolarimetry with quasi-simultaneous measurements in the photosphere (6302.5 A line) and in the chromosphere (8542 A line) with the IBIS instrument. We analyze data from two fields of view, each spanning about 40'' Multiplication-Sign 80'' and targeting the two footpoints of the flare. A region of interest is identified from V/I images: a patch of opposite polarity in the smaller sunspot's penumbra. We find unusual flows in this patch at photospheric levels: a Doppler shift of -4 km s{sup -1}, but also a possible radial inflow into the sunspot of 4 km s{sup -1}. Such patches seem to be common during flares, but only high-resolution observations allowed us to see the inflow, which may be related to future flares observed in this region. Chromospheric images show variable overlying emission and flows and unusual Stokes profiles. We also investigate the irregular penumbra, whose formation may be blocked by the opposite polarity patch and flux emergence. The 40 minute temporal evolution depicts the larger of the flare ribbons becoming fainter and changing its shape. Measurable photospheric magnetic fields remain constant and we do not detect flare energy transport down from the chromosphere. We find no clear indications of impact polarization in the 8542 A line. We cannot exclude the possibility of impact polarization, because weaker signals may be buried in the prominent Zeeman signatures or it may have been present earlier during the flare.

  15. FLARES PRODUCING WELL-ORGANIZED POST-FLARE ARCADES (SLINKIES) HAVE EARLY PRECURSORS

    SciTech Connect

    Ryutova, M. P.

    2011-06-01

    Exploding loop systems producing X-ray flares often, but not always, bifurcate into a long-living, well-organized system of multi-threaded loop arcades resembling solenoidal slinkies. The physical conditions that cause or prevent this process are not known. To address this problem, we examined most of the major (X-class) flares that occurred during the last decade and found that the flares that bifurcate into long-living slinky arcades have different signatures than those that do not 'produce' such structures. The most striking difference is that, in all cases of slinky formation, GOES high energy proton flux becomes significantly enhanced 10-24 hr before the flare occurs. No such effect was found prior to the 'non-slinky' flares. This fact may be associated with the difference between energy production by a given active region and the amount of energy required to bring the entire system into the form of well-organized, self-similar loop arcades. As an example illustrating the process of post-flare slinky formation, we present observations taken with the Hinode satellite, in several wavelengths, showing a time sequence of pre-flare and flare activity, followed by the formation of dynamically stable, well-organized structures. One of the important features revealed is that post-flare coronal slinky formation is preceded by scale invariant structure formation in the underlying chromosphere/transition region. We suggest that the observed regularities can be understood within the framework of self-organized critical dynamics characterized by scale invariant structure formation with critical parameters largely determined by energy saturation level. The observed regularities per se may serve as a long-term precursor of strong flares and may help to study predictability of system behavior.

  16. Adaptive planning of emergency aerial photogrammetric mission

    NASA Astrophysics Data System (ADS)

    Shen, Fuqiang; Zhu, Qing; Zhang, Junxiao; Miao, Shuangxi; Zhou, Xingxia; Cao, Zhenyu

    2015-12-01

    Aiming at the diversity of emergency aerial photogrammetric mission requirements, complex ground and air environmental constraints make the planning mission time-consuming. This paper presents a fast adaptation for the UAV aerial photogrammetric mission planning. First, Building emergency aerial UAVs mission the unified expression of UAVs model and mechanical model of performance parameters in the semantic space make the integrated expression of mission requirements and low altitude environment. Proposed match assessment method which based on resource and mission efficiency. Made the Adaptive match of UAV aerial resources and mission. According to the emergency aerial resource properties, considering complex air-ground environment and mission requirements constraints. Made accurate design of UAV route. Experimental results show, the method scientific and efficient, greatly enhanced the emergency response rate.

  17. High-nitrogen-based pyrotechnics: longer- and brighter-burning, perchlorate-free, red-light illuminants for military and civilian applications.

    PubMed

    Sabatini, Jesse J; Nagori, Amita V; Chen, Gary; Chu, Phillip; Damavarapu, Reddy; Klapötke, Thomas M

    2012-01-01

    The full-up prototype testing of perchlorate-free, hand-held, signal illuminants for the US Army's M126A1 red star parachute hand-held signal is described. Compared to the perchlorate-containing control, the disclosed illuminants yielded excellent stabilities toward various ignition stimuli while offering superior pyrotechnic performance. Militarily, the illuminants provided further evidence that development of smaller hand-held signal items in an environmentally conscious way is a realistic and obtainable goal. The results are also important from the perspective of civilian fireworks, as the development of brighter, longer-burning, and environmentally compatible red-light-emitting pyrotechnics is now possible. PMID:22161957

  18. The standard flare model in three dimensions. II. Upper limit on solar flare energy

    NASA Astrophysics Data System (ADS)

    Aulanier, G.; Démoulin, P.; Schrijver, C. J.; Janvier, M.; Pariat, E.; Schmieder, B.

    2013-01-01

    Context. Solar flares strongly affect the Sun's atmosphere as well as the Earth's environment. Quantifying the maximum possible energy of solar flares of the present-day Sun, if any, is thus a key question in heliophysics. Aims: The largest solar flares observed over the past few decades have reached energies of a few times 1032 erg, possibly up to 1033 erg. Flares in active Sun-like stars reach up to about 1036 erg. In the absence of direct observations of solar flares within this range, complementary methods of investigation are needed to assess the probability of solar flares beyond those in the observational record. Methods: Using historical reports for sunspot and solar active region properties in the photosphere, we scaled to observed solar values a realistic dimensionless 3D MHD simulation for eruptive flares, which originate from a highly sheared bipole. This enabled us to calculate the magnetic fluxes and flare energies in the model in a wide paramater space. Results: Firstly, commonly observed solar conditions lead to modeled magnetic fluxes and flare energies that are comparable to those estimated from observations. Secondly, we evaluate from observations that 30% of the area of sunspot groups are typically involved in flares. This is related to the strong fragmentation of these groups, which naturally results from sub-photospheric convection. When the model is scaled to 30% of the area of the largest sunspot group ever reported, with its peak magnetic field being set to the strongest value ever measured in a sunspot, it produces a flare with a maximum energy of ~6 × 1033 erg. Conclusions: The results of the model suggest that the Sun is able to produce flares up to about six times as energetic in total solar irradiance fluence as the strongest directly observed flare of Nov. 4, 2003. Sunspot groups larger than historically reported would yield superflares for spot pairs that would exceed tens of degrees in extent. We thus conjecture that superflare

  19. An MHD model for magnetar giant flares

    SciTech Connect

    Meng, Y.; Lin, J.; Zhang, Q. S.; Zhang, L.; Reeves, K. K.; Yuan, F. E-mail: jlin@ynao.ac.cn

    2014-04-10

    Giant flares on soft gamma-ray repeaters that are thought to take place on magnetars release enormous energy in a short time interval. Their power can be explained by catastrophic instabilities occurring in the magnetic field configuration and the subsequent magnetic reconnection. By analogy with the coronal mass ejection events on the Sun, we develop a theoretical model via an analytic approach for magnetar giant flares. In this model, the rotation and/or displacement of the crust causes the field to twist and deform, leading to flux rope formation in the magnetosphere and energy accumulation in the related configuration. When the energy and helicity stored in the configuration reach a threshold, the system loses its equilibrium, the flux rope is ejected outward in a catastrophic way, and magnetic reconnection helps the catastrophe develop to a plausible eruption. By taking SGR 1806–20 as an example, we calculate the free magnetic energy released in such an eruptive process and find that it is more than 10{sup 47} erg, which is enough to power a giant flare. The released free magnetic energy is converted into radiative energy, kinetic energy, and gravitational energy of the flux rope. We calculated the light curves of the eruptive processes for the giant flares of SGR 1806–20, SGR 0526–66, and SGR 1900+14, and compared them with the observational data. The calculated light curves are in good agreement with the observed light curves of giant flares.

  20. Solar Flare Impacts on Ionospheric Electrodynamics

    NASA Technical Reports Server (NTRS)

    Qian, Liying; Burns, Alan G.; Solomon, Stanley C.; Chamberlin, Phillip C.

    2012-01-01

    The sudden increase of X-ray and extreme ultra-violet irradiance during flares increases the density of the ionosphere through enhanced photoionization. In this paper, we use model simulations to investigate possible additional contributions from electrodynamics, finding that the vertical E X B drift in the magnetic equatorial region plays a significant role in the ionosphere response to solar flares. During the initial stage of flares, upward E X B drifts weaken in the magnetic equatorial region, causing a weakened equatorial fountain effect, which in turn causes lowering of the peak height of the F2 region and depletion of the peak electron density of the F2 region. In this initial stage, total electron content (TEC) enhancement is predominantly determined by solar zenith angle control of photoionization. As flares decay, upward E X B drifts are enhanced in the magnetic equatorial region, causing increases of the peak height and density of the F2 region. This process lasts for several hours, causing a prolonged F2-region disturbance and TEC enhancement in the magnetic equator region in the aftermath of flares. During this stage, the global morphology of the TEC enhancement becomes predominantly determined by these perturbations to the electrodynamics of the ionosphere.

  1. The great flare of 1982 June 6

    NASA Technical Reports Server (NTRS)

    Tanaka, K.; Zirin, H.

    1985-01-01

    The great soft X-ray (SXR) flare (X12) of the past solar maximum was observed by Hinotori and by Big Bear Solar Observatory (BBSO) on June 6, 1982. Hinotori data consist of hard X-ray (HXR) and SXR images in the rise and decay of the flare, high-resolution soft X-ray spectra throughout the flare, and HXR and gamma-ray data. The BBSO data include films of H-alpha, H-alpha blue wing, D3 and longitudinal magnetic field, as well as video tapes of continuum. Images in HXR, SXR, H-alpha, D3 and the continuum are compared and SXR spectra analyzed. The flare resulted from extended motion of a large spot shearing the magnetic field. D3 and white-light images exhibit a progression from fast flashes to two ribbons, while both HXR and SXR are centered on the optical kernels. The continuum emission shows the same temporal behavior as the HXR at 160 keV. In its early phases, the Fe XXV line was double-peaked, and a decreasing blueshifted (up to 400 km/sec) component was observed, from which the evaporation rate of chromospheric material was estimated. It is suggested that this upflow is adequate to supply the coronal cloud. Flare energetics are discussed in detail, and it is concluded that a significant amount of energy was deposited in the corona, and that nonthermal electrons are the major energy input.

  2. Flare model sensitivity of the Balmer spectrum

    NASA Technical Reports Server (NTRS)

    Falchi, A.; Falciani, R.; Smaldone, L. A.; Tozzi, G. P.

    1989-01-01

    Careful studies of various chromospheric spectral signatures are very important in order to explore their possible sensitivity to the modifications of the thermodynamic quantities produced by the flare occurrence. Pioneer work of Canfield and co-workers have shown how the H alpha behavior is able to indicate different changes in the atmospheric parameters structure associated to the flare event. It was decided to study the behavior of the highest Balmer lines and of the Balmer continuum in different solar flare model atmospheres. These spectral features, originating in the deep photosphere in a quiet area, may have a sensitivity different from H alpha to the modification of a flare atmosphere. The details of the method used to compute the Stark profile of the higher Balmer line (n is greater than or equal to 6) and their merging were extensively given elsewhere (Donati-Falchi et al., 1985; Falchi et al., 1989). The models used were developed by Ricchiazzi in his thesis (1982) evaluating the chromospheric response to both the nonthermal electron flux, for energy greater than 20 kev, (F sub 20) and to the thermal conduction, (F sub c). The effect of the coronal pressure values (P sub O) at the apex of the flare loop is also included.

  3. Radiative transfer simulations of magnetar flare beaming

    NASA Astrophysics Data System (ADS)

    van Putten, T.; Watts, A. L.; Baring, M. G.; Wijers, R. A. M. J.

    2016-05-01

    Magnetar giant flares show oscillatory modulations in the tails of their light curves, which can only be explained via some form of beaming. The fireball model for magnetar bursts has been used successfully to fit the phase-averaged light curves of the tails of giant flares, but so far no attempts have been made to fit the pulsations. We present a relatively simple numerical model to simulate beaming of magnetar flare emission. In our simulations, radiation escapes from the base of a fireball trapped in a dipolar magnetic field, and is scattered through the optically thick magnetosphere of the magnetar until it escapes. Beaming is provided by the presence of a relativistic outflow, as well as by the geometry of the system. We find that a simple picture for the relativistic outflow is enough to create the pulse fraction and sharp peaks observed in pulse profiles of magnetar flares, while without a relativistic outflow the beaming is insufficient to explain giant flare rotational modulations.

  4. Radiative transfer simulations of magnetar flare beaming

    NASA Astrophysics Data System (ADS)

    van Putten, T.; Watts, A. L.; Baring, M. G.; Wijers, R. A. M. J.

    2016-09-01

    Magnetar giant flares show oscillatory modulations in the tails of their light curves, which can only be explained via some form of beaming. The fireball model for magnetar bursts has been used successfully to fit the phase-averaged light curves of the tails of giant flares, but so far no attempts have been made to fit the pulsations. We present a relatively simple numerical model to simulate beaming of magnetar flare emission. In our simulations, radiation escapes from the base of a fireball trapped in a dipolar magnetic field, and is scattered through the optically thick magnetosphere of the magnetar until it escapes. Beaming is provided by the presence of a relativistic outflow, as well as by the geometry of the system. We find that a simple picture for the relativistic outflow is enough to create the pulse fraction and sharp peaks observed in pulse profiles of magnetar flares, while without a relativistic outflow the beaming is insufficient to explain giant flare rotational modulations.

  5. An MHD Model for Magnetar Giant Flares

    NASA Astrophysics Data System (ADS)

    Meng, Y.; Lin, J.; Zhang, L.; Reeves, K. K.; Zhang, Q. S.; Yuan, F.

    2014-04-01

    Giant flares on soft gamma-ray repeaters that are thought to take place on magnetars release enormous energy in a short time interval. Their power can be explained by catastrophic instabilities occurring in the magnetic field configuration and the subsequent magnetic reconnection. By analogy with the coronal mass ejection events on the Sun, we develop a theoretical model via an analytic approach for magnetar giant flares. In this model, the rotation and/or displacement of the crust causes the field to twist and deform, leading to flux rope formation in the magnetosphere and energy accumulation in the related configuration. When the energy and helicity stored in the configuration reach a threshold, the system loses its equilibrium, the flux rope is ejected outward in a catastrophic way, and magnetic reconnection helps the catastrophe develop to a plausible eruption. By taking SGR 1806-20 as an example, we calculate the free magnetic energy released in such an eruptive process and find that it is more than 1047 erg, which is enough to power a giant flare. The released free magnetic energy is converted into radiative energy, kinetic energy, and gravitational energy of the flux rope. We calculated the light curves of the eruptive processes for the giant flares of SGR 1806-20, SGR 0526-66, and SGR 1900+14, and compared them with the observational data. The calculated light curves are in good agreement with the observed light curves of giant flares.

  6. X-Class: A Guide to Solar Flares

    NASA Video Gallery

    Solar flares are classified according to their strength. The smallest ones are B-class, followed by C, M and X, the largest. A powerful X-class flare can create long lasting radiation storms, which...

  7. The Origin of the Solar Flare Waiting-Time Distribution.

    PubMed

    Wheatland

    2000-06-20

    It was recently pointed out that the distribution of times between solar flares (the flare waiting-time distribution) follows a power law for long waiting times. Based on 25 years of soft X-ray flares observed by Geostationary Operational Environmental Satellite instruments, it is shown that (1) the waiting-time distribution of flares is consistent with a time-dependent Poisson process and (2) the fraction of time the Sun spends with different flaring rates approximately follows an exponential distribution. The second result is a new phenomenological law for flares. It is shown analytically how the observed power-law behavior of the waiting times originates in the exponential distribution of flaring rates. These results are argued to be consistent with a nonstationary avalanche model for flares. PMID:10859130

  8. 46 CFR 117.68 - Distress flares and smoke signals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... (1) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of this chapter... section: (i) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of...

  9. 46 CFR 180.68 - Distress flares and smoke signals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Substitutions. (1) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of this... section: (i) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of...

  10. 46 CFR 180.68 - Distress flares and smoke signals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Substitutions. (1) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of this... section: (i) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of...

  11. 46 CFR 180.68 - Distress flares and smoke signals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Substitutions. (1) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of this... section: (i) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of...

  12. 46 CFR 180.68 - Distress flares and smoke signals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Substitutions. (1) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of this... section: (i) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of...

  13. 46 CFR 117.68 - Distress flares and smoke signals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... (1) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of this chapter... section: (i) A rocket parachute flare approved in accordance with § 160.036 in subchapter Q of...

  14. COCOA: tracking in aerial imagery

    NASA Astrophysics Data System (ADS)

    Ali, Saad; Shah, Mubarak

    2006-05-01

    Unmanned Aerial Vehicles (UAVs) are becoming a core intelligence asset for reconnaissance, surveillance and target tracking in urban and battlefield settings. In order to achieve the goal of automated tracking of objects in UAV videos we have developed a system called COCOA. It processes the video stream through number of stages. At first stage platform motion compensation is performed. Moving object detection is performed to detect the regions of interest from which object contours are extracted by performing a level set based segmentation. Finally blob based tracking is performed for each detected object. Global tracks are generated which are used for higher level processing. COCOA is customizable to different sensor resolutions and is capable of tracking targets as small as 100 pixels. It works seamlessly for both visible and thermal imaging modes. The system is implemented in Matlab and works in a batch mode.

  15. The DOE ARM Aerial Facility

    SciTech Connect

    Schmid, Beat; Tomlinson, Jason M.; Hubbe, John M.; Comstock, Jennifer M.; Mei, Fan; Chand, Duli; Pekour, Mikhail S.; Kluzek, Celine D.; Andrews, Elisabeth; Biraud, S.; McFarquhar, Greg

    2014-05-01

    The Department of Energy Atmospheric Radiation Measurement (ARM) Program is a climate research user facility operating stationary ground sites that provide long-term measurements of climate relevant properties, mobile ground- and ship-based facilities to conduct shorter field campaigns (6-12 months), and the ARM Aerial Facility (AAF). The airborne observations acquired by the AAF enhance the surface-based ARM measurements by providing high-resolution in-situ measurements for process understanding, retrieval-algorithm development, and model evaluation that are not possible using ground- or satellite-based techniques. Several ARM aerial efforts were consolidated into the AAF in 2006. With the exception of a small aircraft used for routine measurements of aerosols and carbon cycle gases, AAF at the time had no dedicated aircraft and only a small number of instruments at its disposal. In this "virtual hangar" mode, AAF successfully carried out several missions contracting with organizations and investigators who provided their research aircraft and instrumentation. In 2009, AAF started managing operations of the Battelle-owned Gulfstream I (G-1) large twin-turboprop research aircraft. Furthermore, the American Recovery and Reinvestment Act of 2009 provided funding for the procurement of over twenty new instruments to be used aboard the G-1 and other AAF virtual-hangar aircraft. AAF now executes missions in the virtual- and real-hangar mode producing freely available datasets for studying aerosol, cloud, and radiative processes in the atmosphere. AAF is also engaged in the maturation and testing of newly developed airborne sensors to help foster the next generation of airborne instruments.

  16. Unmanned aerial survey of elephants.

    PubMed

    Vermeulen, Cédric; Lejeune, Philippe; Lisein, Jonathan; Sawadogo, Prosper; Bouché, Philippe

    2013-01-01

    The use of a UAS (Unmanned Aircraft System) was tested to survey large mammals in the Nazinga Game Ranch in the south of Burkina Faso. The Gatewing ×100™ equipped with a Ricoh GR III camera was used to test animal reaction as the UAS passed, and visibility on the images. No reaction was recorded as the UAS passed at a height of 100 m. Observations, made on a set of more than 7000 images, revealed that only elephants (Loxodonta africana) were easily visible while medium and small sized mammals were not. The easy observation of elephants allows experts to enumerate them on images acquired at a height of 100 m. We, therefore, implemented an aerial strip sample count along transects used for the annual wildlife foot count. A total of 34 elephants were recorded on 4 transects, each overflown twice. The elephant density was estimated at 2.47 elephants/km(2) with a coefficient of variation (CV%) of 36.10%. The main drawback of our UAS was its low autonomy (45 min). Increased endurance of small UAS is required to replace manned aircraft survey of large areas (about 1000 km of transect per day vs 40 km for our UAS). The monitoring strategy should be adapted according to the sampling plan. Also, the UAS is as expensive as a second-hand light aircraft. However the logistic and flight implementation are easier, the running costs are lower and its use is safer. Technological evolution will make civil UAS more efficient, allowing them to compete with light aircraft for aerial wildlife surveys. PMID:23405088

  17. Unmanned Aerial Survey of Elephants

    PubMed Central

    Vermeulen, Cédric; Lejeune, Philippe; Lisein, Jonathan; Sawadogo, Prosper; Bouché, Philippe

    2013-01-01

    The use of a UAS (Unmanned Aircraft System) was tested to survey large mammals in the Nazinga Game Ranch in the south of Burkina Faso. The Gatewing ×100™ equipped with a Ricoh GR III camera was used to test animal reaction as the UAS passed, and visibility on the images. No reaction was recorded as the UAS passed at a height of 100 m. Observations, made on a set of more than 7000 images, revealed that only elephants (Loxodonta africana) were easily visible while medium and small sized mammals were not. The easy observation of elephants allows experts to enumerate them on images acquired at a height of 100 m. We, therefore, implemented an aerial strip sample count along transects used for the annual wildlife foot count. A total of 34 elephants were recorded on 4 transects, each overflown twice. The elephant density was estimated at 2.47 elephants/km2 with a coefficient of variation (CV%) of 36.10%. The main drawback of our UAS was its low autonomy (45 min). Increased endurance of small UAS is required to replace manned aircraft survey of large areas (about 1000 km of transect per day vs 40 km for our UAS). The monitoring strategy should be adapted according to the sampling plan. Also, the UAS is as expensive as a second-hand light aircraft. However the logistic and flight implementation are easier, the running costs are lower and its use is safer. Technological evolution will make civil UAS more efficient, allowing them to compete with light aircraft for aerial wildlife surveys. PMID:23405088

  18. Isotopic overabundances and the energetic particle model of solar flares

    NASA Technical Reports Server (NTRS)

    Perez-Enriquez, R.; Bravo, S.

    1985-01-01

    According to the energetic particle model of solar flares particles are efficiently accelerated in the magnetic field loop of an active region (AR) by hydromagnetic turbulence. It is demonstrated that the isotopic overabundances observed in some flares are not a consequence of the flare itself but are characteristic of the plasma in the AR. Only when a flare releases the plasma into the interplanetary space it is possible to observe this anomalous composition at spacecraft locations.

  19. KEPLER FLARES. I. ACTIVE AND INACTIVE M DWARFS

    SciTech Connect

    Hawley, Suzanne L.; Davenport, James R. A.; Kowalski, Adam F.; Wisniewski, John P.; Deitrick, Russell; Hilton, Eric J.; Hebb, Leslie

    2014-12-20

    We analyzed Kepler short-cadence M dwarf observations. Spectra from the Astrophysical Research Consortium 3.5 m telescope identify magnetically active (Hα in emission) stars. The active stars are of mid-M spectral type, have numerous flares, and have well-defined rotational modulation due to starspots. The inactive stars are of early M type, exhibit less starspot signature, and have fewer flares. A Kepler to U-band energy scaling allows comparison of the Kepler flare frequency distributions with previous ground-based data. M dwarfs span a large range of flare frequency and energy, blurring the distinction between active and inactive stars designated solely by the presence of Hα. We analyzed classical and complex (multiple peak) flares on GJ 1243, finding strong correlations between flare energy, amplitude, duration, and decay time, with only a weak dependence on rise time. Complex flares last longer and have higher energy at the same amplitude, and higher energy flares are more likely to be complex. A power law fits the energy distribution for flares with log E{sub K{sub p}}> 31 erg, but the predicted number of low-energy flares far exceeds the number observed, at energies where flares are still easily detectable, indicating that the power-law distribution may flatten at low energy. There is no correlation of flare occurrence or energy with starspot phase, the flare waiting time distribution is consistent with flares occurring randomly in time, and the energies of consecutive flares are uncorrelated. These observations support a scenario where many independent active regions on the stellar surface are contributing to the observed flare rate.

  20. A kinematic model of a solar flare.

    NASA Technical Reports Server (NTRS)

    Nakagawa, Y.; Wu, S. T.; Han, S. M.

    1973-01-01

    Hyder advocated the idea that the optical (H-alpha) flares can be identified with the response of the solar chromosphere to an infalling material stream resulting from the 'disparition brusque' of a prominence. Since some flares are observed without any apparent association with infalling streams, in this paper we examine the possibility of identifying the optical flare with the response of the chromosphere to a supersonic disturbance, i.e., a shock, propagating downward. The undisturbed chromosphere is represented by the Harvard-Smithsonian Reference Atmosphere and the evolution of the shock is evaluated with the use of the CCW (Chisnell, Chester, Whitham) approximation based on the theory of characteristics. It is shown that the chromosphere is heated by the shock, that radiation is enhanced, and that the enhanced radiation terminates the shock around the height of the temperature minimum.

  1. Observations of particle acceleration in solar flares

    NASA Technical Reports Server (NTRS)

    Hudson, H. S.

    1979-01-01

    Solar flares provide several examples of nonthermal particle acceleration. The paper reviews the information gained about these processes via X-ray and gamma-ray astronomy, which can presently distinguish among three separate particle-acceleration processes at the sun: an impulsive accelerator of more than 20 keV electrons, a gradual accelerator of more than 20 keV electrons, and a gradual accelerator of more than 10 MeV ions. The acceleration energy efficiency (total particle energy divided by total flare energy) of any of these mechanisms cannot be less than about 0.1%, although the gradual acceleration does not occur in every flare. The observational material suggests that both the impulsive and gradual accelerations take place preferentially in closed magnetic-field structures, but that the electrons decay in these traps before they can escape. The ions escape very efficiently.

  2. Aerial videotape mapping of coastal geomorphic changes

    USGS Publications Warehouse

    Debusschere, Karolien; Penland, Shea; Westphal, Karen A.; Reimer, P. Douglas; McBride, Randolph A.

    1991-01-01

    An aerial geomorphic mapping system was developed to examine the spatial and temporal variability in the coastal geomorphology of Louisiana. Between 1984 and 1990 eleven sequential annual and post-hurricane aerial videotape surveys were flown covering periods of prolonged fair weather, hurricane impacts and subsequent post-storm recoveries. A coastal geomorphic classification system was developed to map the spatial and temporal geomorphic changes between these surveys. The classification system is based on 10 years of shoreline monitoring, analysis of aerial photography for 1940-1989, and numerous field surveys. The classification system divides shorelines into two broad classes: natural and altered. Each class consists of several genetically linked categories of shorelines. Each category is further subdivided into morphologic types on the basis of landform relief, elevation, habitat type, vegetation density and type, and sediment characteristics. The classification is used with imagery from the low-altitude, high-resolution aerial videotape surveys to describe and quantify the longshore and cross-shore geomorphic, sedimentologic, and vegetative character of Louisiana's shoreline systems. The mapping system makes it possible to delineate and map detailed geomorphic habitat changes at a resolution higher than that of conventional vertical aerial photography. Morphologic units are mapped parallel to the regional shoreline from the aerial videotape imagery onto the base maps at a scale of 1:24,000. The base maps were constructed from vertical aerial photography concurrent with the data of the video imagery.

  3. Predicting large solar flares with data assimilation

    NASA Astrophysics Data System (ADS)

    Strugarek, Antoine; Charbonneau, Paul

    2015-08-01

    Solar and stellar flares are magnetically-driven, scale-invariant energy release events spanning over 8 orders of magnitude in energy. The prediction of the largest solar flares, of class X, is a particularly hard task due the scarcity of such events. The detailed 3D modelling of flaring active regions still requires today too much numerical resources to be routinely used for near real-time predictions. Alternative, empirical models hence have to be designed to perform such predictions. Among the models that adequately reproduce the power-law distribution in flare sizes, avalanche models have the advantage of being numerically cheap to operate. However, they usually rely on a stochastic driver, which can be expected to degrade their predictive capabilities. Building on the pioneering work of Lu and Hamilton, we develop a class of avalanche models which succeed in minimizing the built-in stochastic ingredients while retaining the solar flares power-law distribution. We show that the largest avalanches occurring in these models are robust with respect to the stochastic realization, which opens new perspectives for the prediction of the largest (and most dangerous) solar flares.We further combine data assimilation of the GOES X-ray flux with our avalanche models to carry out actual predictions. The GOES X-ray flux is transformed into a series of peaks that is fed to the model, which automatically finds an initial condition that is compatible with the observed series of events. We then test our prediction model against past GOES large events and discuss the possibility to use our data assimilation package in near real-time applications.

  4. Recurrent flares in active region NOAA 11283

    NASA Astrophysics Data System (ADS)

    Romano, P.; Zuccarello, F.; Guglielmino, S. L.; Berrilli, F.; Bruno, R.; Carbone, V.; Consolini, G.; de Lauretis, M.; Del Moro, D.; Elmhamdi, A.; Ermolli, I.; Fineschi, S.; Francia, P.; Kordi, A. S.; Landi Degl'Innocenti, E.; Laurenza, M.; Lepreti, F.; Marcucci, M. F.; Pallocchia, G.; Pietropaolo, E.; Romoli, M.; Vecchio, A.; Vellante, M.; Villante, U.

    2015-10-01

    Context. Flares and coronal mass ejections (CMEs) are solar phenomena that are not yet fully understood. Several investigations have been performed to single out their related physical parameters that can be used as indices of the magnetic complexity leading to their occurrence. Aims: In order to shed light on the occurrence of recurrent flares and subsequent associated CMEs, we studied the active region NOAA 11283 where recurrent M and X GOES-class flares and CMEs occurred. Methods: We use vector magnetograms taken by HMI/SDO to calculate the horizontal velocity fields of the photospheric magnetic structures, the shear and the dip angles of the magnetic field, the magnetic helicity flux distribution, and the Poynting fluxes across the photosphere due to the emergence and the shearing of the magnetic field. Results: Although we do not observe consistent emerging magnetic flux through the photosphere during the observation time interval, we detected a monotonic increase of the magnetic helicity accumulated in the corona. We found that both the shear and the dip angles have high values along the main polarity inversion line (PIL) before and after all the events. We also note that before the main flare of X2.1 GOES class, the shearing motions seem to inject a more significant energy than the energy injected by the emergence of the magnetic field. Conclusions: We conclude that the very long duration (about 4 days) of the horizontal displacement of the main photospheric magnetic structures along the PIL has a primary role in the energy release during the recurrent flares. This peculiar horizontal velocity field also contributes to the monotonic injection of magnetic helicity into the corona. This process, coupled with the high shear and dip angles along the main PIL, appears to be responsible for the consecutive events of loss of equilibrium leading to the recurrent flares and CMEs. A movie associated to Fig. 4 is available in electronic form at http://www.aanda.org

  5. Diagnostics of Solar Flare Energetic Particles

    NASA Astrophysics Data System (ADS)

    Mallik, Procheta; Brown, J. C.; MacKinnon, A. L.

    2009-05-01

    For work on my thesis dissertation, we have been studying some energetic processes in solar flares. On our work on Hard X-ray (HXR) emission from flares, we have shown that recombination emission can exceed the bremsstrahlung HXR flux for certain flare conditions. We will show some spectral features characteristic of non-thermal recombination HXR emission and will suggest how it plays a significant role in the flare HXR continuum, something that has been ignored in the past. It is important to note that these results could demand a reconsideration of the numbers of accelerated electrons since recombination can be much more efficient in producing HXR photons than bremsstrahlung. In related work on diagnosing particle acceleration in flares, we also have an interest in studying solar neutrons. To this end, we will present our work done with new-age neutron detectors developed by our colleagues at the University of New Hampshire. Using laboratory and simulated data from the detector to produce its response matrix, we then employ regularisation and deconvolution techniques to produce encouraging results for data inversion. As a corollary, we have also been reconsidering the role of inverse Compton (IC) scattering of photospheric photons. Gamma-ray observations clearly show the presence of 100 MeV electrons and positrons in the solar corona, by-products of GeV energy ions. Here we will present results of IC scattering of such photons taking proper account of radiation field geometry near the solar surface. If observed, such radiation would let us determine the number of secondary positrons produced in large flares, contributing to a full picture of ion acceleration and to predicting neutron fluxes to be encountered by future inner heliosphere space missions. This work is supported by a UK STFC Rolling Grant and a Dorothy Hodgkin's Scholarship (PM).

  6. Active Region Emergence and Remote Flares

    NASA Astrophysics Data System (ADS)

    Fu, Yixing; Welsch, Brian T.

    2016-02-01

    We study the effect of new emerging solar active regions on the large-scale magnetic environment of existing regions. We first present a theoretical approach to quantify the "interaction energy" between new and pre-existing regions as the difference between i) the summed magnetic energies of their individual potential fields and ii) the energy of their superposed potential fields. We expect that this interaction energy can, depending upon the relative arrangements of newly emerged and pre-existing magnetic flux, indicate the existence of "topological" free magnetic energy in the global coronal field that is independent of any "internal" free magnetic energy due to coronal electric currents flowing within the newly emerged and pre-existing flux systems. We then examine the interaction energy in two well-studied cases of flux emergence, but find that the predicted energetic perturbation is relatively small compared to energies released in large solar flares. Next, we present an observational study of the influence of the emergence of new active regions on flare statistics in pre-existing active regions, using NOAA's Solar Region Summary and GOES flare databases. As part of an effort to precisely determine the emergence time of active regions in a large event sample, we find that emergence in about half of these regions exhibits a two-stage behavior, with an initial gradual phase followed by a more rapid phase. Regarding flaring, we find that the emergence of new regions is associated with a significant increase in the occurrence rate of X- and M-class flares in pre-existing regions. This effect tends to be more significant when pre-existing and new emerging active regions are closer. Given the relative weakness of the interaction energy, this effect suggests that perturbations in the large-scale magnetic field, such as topology changes invoked in the "breakout" model of coronal mass ejections, might play a significant role in the occurrence of some flares.

  7. SECONDARY FLARE RIBBONS OBSERVED BY THE SOLAR DYNAMICS OBSERVATORY

    SciTech Connect

    Zhang, Jun; Li, Ting; Yang, Shuhong E-mail: liting@nao.cas.cn

    2014-02-20

    Using the observations from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, we statistically investigate the flare ribbons (FRs) of 19 X-class flares of the 24th solar cycle from 2010 June to 2013 August. Of these 19 flares, the source regions of 16 can be observed by AIA and the FRs of each flare are well detected, and 11 of the 16 display multiple ribbons. Based on the ribbon brightness and the relationship between the ribbons and post-flare loops, we divide the multiple ribbons into two types: normal FRs, which are connected by post-flare loops and have been extensively investigated, and secondary flare ribbons (SFRs), which are weaker than the FRs, not connected by post-flare loops, and always have a short lifetime. Of the 11 SFRs, 10 appear simultaneously with the FRs, and none of them have post-flare loops. The last one, on the other hand, appears 80 minutes later than the FR, lasts almost two hours, and also has no post-flare loops detected. We suggest that the magnetic reconnection associated with this SFR is triggered by the blast wave that results from the main flare. These observations imply that in some flare processes, more than two sets of magnetic loops or more than twice the number of magnetic reconnections are involved.

  8. Detection of Flare Stars in TAOS 2-year Data

    NASA Astrophysics Data System (ADS)

    Kim, D.-W.; Protopapas, P.; Alcock, C.; Byun, Y.-I.; Zhang, Z.-W.; Wang, J.-H.; King, S.-K.; Wen, C. Y.; Lehner, M. J.; Bianco, F. B.; Coehlo, N. K.; Mondal, S.; Axelrod, T.; Chen, W. P.; Cook, K. H.; Dave, R.; de Pater, I.; Porrata, R.; Lee, T.; Lin, H.-C.; Lissauer, J. J.; Marshall, S. L.; Rice, J. A.; Schwamb, M. E.; Wang, S. Y.

    2009-04-01

    We analyzed 2 years of data from the Taiwan-American Occultation Survey (TAOS, Lehner et al. 2009), accumulated during 2005 and 2006, and found 3 flare stars. All of them are known x-ray sources. Among the detected flare stars, 1RXS J044712.8+203809 shows three recurrences of flare events within a month.

  9. On the relationship between sunspots number and the flare index

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    1994-01-01

    During the years 1976-1991, sunspot number and the Kleczek flare index have displayed a strong linear correlation (r = 0.94), one that can be described by the equation y = -0.15 + 0.10 x, where x denotes annual sunspot number. While true, the temporal behaviors of the two parameters have differed, with sunspot number peaking first in 1979 and the flare index peaking much later in 1982 during cycle 21 and with more contemporaneous behavior in cycle 22 (both peaking in 1989, with a secondary peak in 1991). The difference appears to be directly attributable to the way in which the Kleczek flare index has been defined; namely, the annual flare index is the sum of the product of each flare's intensity (importance) times its duration (in minutes) divided by the total number of flares during the year. Because the number of 'major' flares (those of importance greater than or equal to 2) and flares of very long duration (duration greater than or equal to 100 min) both peaked after sunspot maximum (1982/81, respectively) in cycle 21, one should have expected the flare index to also peak (which it did). Likewise, because the number of major flares and flares of very long duration peaked simultaneously with sunspot number (1989) in cycle 22, one should have expected the flare index to also peak (which it did).

  10. When and where to look to observe major solar flares

    NASA Technical Reports Server (NTRS)

    Bai, T.

    1989-01-01

    When and where to look is an important issue to observers planning to observe major solar flares. Prediction of major flares is also important because they influence the Earth's environment. Techniques for utilizing recently discovered solar hot spots and a solar activity periodicity of about 154 days in determining when and where to look to catch major flares are discussed.

  11. Turbulence in the Flare Reconnection Region

    NASA Astrophysics Data System (ADS)

    Doschek, George A.; McKenzie, D. E.; Warren, H.

    2013-07-01

    The physical conditions such as temperature, density, and dynamical properties in the flare reconnection region, located above the bright soft X-ray loops, are basically not known although there have been measurements of non-thermal hard X-ray emission properties by RHESSI and earlier by HXT on Yohkoh. The advent of Hinode and the Solar Dynamics Observatory (SDO) spatially resolved observations, however, has changed this and it is now possible to measure in more detail some of the properties of the reconnection region. AIA imagery on SDO and the Extreme-ultraviolet Imaging Spectrometer (EIS) and X-ray Telescope (XRT) on Hinode allow values of non-thermal motions or turbulence in the reconnection region to be determined. Turbulence is predicted by theoretical models of magnetic reconnection in flares (e.g., see Liu et al. 2008, ApJ, 676, 704) and has long been inferred spectroscopically from non-thermal broadening of flare emission lines. Studies with Hinode/XRT and SDO/AIA demonstrate that two-dimensional investigations of flare velocity fields can be made, by imaging the plasma sheets above post-CME flare arcades. These measurements are made possible through the use of local correlation tracking (LCT), as shown by McKenzie (2013), ApJ, 766, 39, and reveal signatures of turbulence, including temporally and spatially varying vorticity. For some flares the AIA and XRT results can be combined with Doppler measurements of turbulence obtained with EIS. EIS data consist of raster scans that include the reconnection region for flares on the limb or near the limb. A set of spectral lines are observed that cover temperatures from 0.25 MK up to ~20 MK. A temperature in the reconnection region is calculated from the Fe XXIII/Fe XXIV line ratio and the thermal Doppler and instrumental widths are subtracted from the total line widths. The remainder is non-thermal motions or turbulence. We will present coordinated analyses of EIS and AIA observations of plasma sheets in post

  12. The solar-flare induced earth's environment

    NASA Technical Reports Server (NTRS)

    Wu, S. T.; Dryer, M.; Han, S. M.

    1985-01-01

    A composite numerical simulation model developed from a series of MHD models was used to compute the solar-flare-generated disturbances of physical parameters, such as density, temperature, velocity, and magnetic field from the solar surface (i.e., the photospheric level) to the earth's environment. It is shown that the disturbed earth's environment at high latitudes can be approximated by starting with the knowledge of the occurrence and the strength of a solar flare, then simulating the evolutionary consequences of the solar disturbance through interplanetary space up to and through the magnetosphere.

  13. Universality in solar flare and earthquake occurrence.

    PubMed

    de Arcangelis, L; Godano, C; Lippiello, E; Nicodemi, M

    2006-02-10

    Earthquakes and solar flares are phenomena involving huge and rapid releases of energy characterized by complex temporal occurrence. By analyzing available experimental catalogs, we show that the stochastic processes underlying these apparently different phenomena have universal properties. Namely, both problems exhibit the same distributions of sizes, interoccurrence times, and the same temporal clustering: We find after flare sequences with power law temporal correlations as the Omori law for seismic sequences. The observed universality suggests a common approach to the interpretation of both phenomena in terms of the same driving physical mechanism. PMID:16486917

  14. Universality in Solar Flare and Earthquake Occurrence

    SciTech Connect

    De Arcangelis, L.; Godano, C.; Lippiello, E.; Nicodemi, M.

    2006-02-10

    Earthquakes and solar flares are phenomena involving huge and rapid releases of energy characterized by complex temporal occurrence. By analyzing available experimental catalogs, we show that the stochastic processes underlying these apparently different phenomena have universal properties. Namely, both problems exhibit the same distributions of sizes, interoccurrence times, and the same temporal clustering: We find after flare sequences with power law temporal correlations as the Omori law for seismic sequences. The observed universality suggests a common approach to the interpretation of both phenomena in terms of the same driving physical mechanism.

  15. Carbon-poor solar flare events

    NASA Technical Reports Server (NTRS)

    Mason, G. M.; Gloeckler, G.; Hovestadt, D.

    1979-01-01

    Energetic particle flux enhancements over the period October 1973 - December 1977 were surveyed using ULET sensor on the IMP-8 spacecraft. During the four year period the most extreme periods of Fe enrichment compared to oxygen were during solar flare events in February 1974 and May 1974. In these same events, the carbon abundance with respect to oxygen was significantly depleted when compared with a value C:0 is approximately 0.45:1 for typical solar flares. These observations, taken together with previously reported He-3 enrichment in these events, give strong evidence for the importance of a wave-particle interaction in the pre-injection heating of the ambient matter.

  16. Aerial Terrain Mapping Using Unmanned Aerial Vehicle Approach

    NASA Astrophysics Data System (ADS)

    Tahar, K. N.

    2012-08-01

    This paper looks into the latest achievement in the low-cost Unmanned Aerial Vehicle (UAV) technology in their capacity to map the semi-development areas. The objectives of this study are to establish a new methodology or a new algorithm in image registration during interior orientation process and to determine the accuracy of the photogrammetric products by using UAV images. Recently, UAV technology has been used in several applications such as mapping, agriculture and surveillance. The aim of this study is to scrutinize the usage of UAV to map the semi-development areas. The performance of the low cost UAV mapping study was established on a study area with two image processing methods so that the results could be comparable. A non-metric camera was attached at the bottom of UAV and it was used to capture images at both sites after it went through several calibration steps. Calibration processes were carried out to determine focal length, principal distance, radial lens distortion, tangential lens distortion and affinity. A new method in image registration for a non-metric camera is discussed in this paper as a part of new methodology of this study. This method used the UAV Global Positioning System (GPS) onboard to register the UAV image for interior orientation process. Check points were established randomly at both sites using rapid static Global Positioning System. Ground control points are used for exterior orientation process, and check point is used for accuracy assessment of photogrammetric product. All acquired images were processed in a photogrammetric software. Two methods of image registration were applied in this study, namely, GPS onboard registration and ground control point registration. Both registrations were processed by using photogrammetric software and the result is discussed. Two results were produced in this study, which are the digital orthophoto and the digital terrain model. These results were analyzed by using the root mean square

  17. Verification of Potency of Aerial Digital Oblique Cameras for Aerial Photogrammetry in Japan

    NASA Astrophysics Data System (ADS)

    Nakada, Ryuji; Takigawa, Masanori; Ohga, Tomowo; Fujii, Noritsuna

    2016-06-01

    Digital oblique aerial camera (hereinafter called "oblique cameras") is an assembly of medium format digital cameras capable of shooting digital aerial photographs in five directions i.e. nadir view and oblique views (forward and backward, left and right views) simultaneously and it is used for shooting digital aerial photographs efficiently for generating 3D models in a wide area. For aerial photogrammetry of public survey in Japan, it is required to use large format cameras, like DMC and UltraCam series, to ensure aerial photogrammetric accuracy. Although oblique cameras are intended to generate 3D models, digital aerial photographs in 5 directions taken with them should not be limited to 3D model production but they may also be allowed for digital mapping and photomaps of required public survey accuracy in Japan. In order to verify the potency of using oblique cameras for aerial photogrammetry (simultaneous adjustment, digital mapping and photomaps), (1) a viewer was developed to interpret digital aerial photographs taken with oblique cameras, (2) digital aerial photographs were shot with an oblique camera owned by us, a Penta DigiCAM of IGI mbH, and (3) accuracy of 3D measurements was verified.

  18. Draper Laboratory small autonomous aerial vehicle

    NASA Astrophysics Data System (ADS)

    DeBitetto, Paul A.; Johnson, Eric N.; Bosse, Michael C.; Trott, Christian A.

    1997-06-01

    The Charles Stark Draper Laboratory, Inc. and students from Massachusetts Institute of Technology and Boston University have cooperated to develop an autonomous aerial vehicle that won the 1996 International Aerial Robotics Competition. This paper describes the approach, system architecture and subsystem designs for the entry. This entry represents a combination of many technology areas: navigation, guidance, control, vision processing, human factors, packaging, power, real-time software, and others. The aerial vehicle, an autonomous helicopter, performs navigation and control functions using multiple sensors: differential GPS, inertial measurement unit, sonar altimeter, and a flux compass. The aerial transmits video imagery to the ground. A ground based vision processor converts the image data into target position and classification estimates. The system was designed, built, and flown in less than one year and has provided many lessons about autonomous vehicle systems, several of which are discussed. In an appendix, our current research in augmenting the navigation system with vision- based estimates is presented.

  19. Officials: Aerial Spraying Working Against Miami Mosquitoes

    MedlinePlus

    ... Officials: Aerial Spraying Working Against Miami Mosquitoes The insects are to blame for first cases of Zika ... mosquitoes in a part of Miami where the insects have been linked to 16 cases of Zika ...

  20. Rangeland monitoring with unmanned aerial vehicles (UAVs)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unmanned aerial vehicles (UAVs) have great potential for rangeland management applications, such as monitoring vegetation change, developing grazing strategies, determining rangeland health, and assessing remediation treatment effectiveness. UAVs have several advantages: they can be deployed quickly...

  1. Outer Atmospheres of Low Mass Stars — Flare Characteristics.

    NASA Astrophysics Data System (ADS)

    Lalitha, S.; Schmitt, J. H. M. M.

    2013-04-01

    We compare the coronal properties during flares on active low mass stars CN Leonis, AB Doradus A and Proxima Centauri observed with XMM-Newton. From the X-ray data we analyze the temporal evolution of temperature, emission measure and coronal abundance. The nature of these flares are with secondary events following the first flare peak in the light curve, raising the question regarding the involved magnetic structure. We infer from the plasma properties and the geometry of the flaring structure that the flare originates from a compact arcade rather than in a single loop.

  2. The H-alpha/H-beta ratio in solar flares

    NASA Technical Reports Server (NTRS)

    Zirin, H.; Liggett, M.; Patterson, A.

    1982-01-01

    The present investigation involves the study of an extensive body of data accumulated of simultaneous H-alpha and H-beta cinematography of flares. The data were obtained with two telescopes simultaneously photographing flares in H-alpha and H-beta. The results of measurements in a number of flares are presented in a table. The flares were selected purely by optical quality of the data. That the measured ratios are not too different from those in stellar flares is suggested by the last two columns of the table. These columns show that a variety of possible line width ratios could give an integrated intensity ratio of less than unity.

  3. IUE spectra of a flare in HR 5110: A flaring RS CVn or Algol system?

    NASA Technical Reports Server (NTRS)

    Simon, T.; Linsky, J. L.; Schiffer, F. H., III

    1981-01-01

    Ultraviolet spectra of the RS CVn type binary system HR 5110 were obtained with IUE on May 31, 1979 during a period of intense radio flaring of this star. High temperature transition region lines are present, but are not enhanced above observed quiescent strengths. The similarities of HR 5110 to the Algol system, As Eri, suggest that the 1979 May to June flare may involve mass exchange rather than annihilation of coronal magnetic fields.

  4. Locating buildings in aerial photos

    NASA Technical Reports Server (NTRS)

    Green, James S.

    1994-01-01

    Algorithms and techniques for use in the identification and location of large buildings in digitized copies of aerial photographs are developed and tested. The building data would be used in the simulation of objects located in the vicinity of an airport that may be detected by aircraft radar. Two distinct approaches are considered. Most building footprints are rectangular in form. The first approach studied is to search for right-angled corners that characterize rectangular objects and then to connect these corners to complete the building. This problem is difficult because many nonbuilding objects, such as street corners, parking lots, and ballparks often have well defined corners which are often difficult to distinguish from rooftops. Furthermore, rooftops come in a number of shapes, sizes, shadings, and textures which also limit the discrimination task. The strategy used linear sequences of different samples to detect straight edge segments at multiple angles and to determine when these segments meet at approximately right-angles with respect to each other. This technique is effective in locating corners. The test image used has a fairly rectangular block pattern oriented about thirty degrees clockwise from a vertical alignment, and the overall measurement data reflect this. However, this technique does not discriminate between buildings and other objects at an operationally suitable rate. In addition, since multiple paths are tested for each image pixel, this is a time consuming task. The process can be speeded up by preprocessing the image to locate the more optimal sampling paths. The second approach is to rely on a human operator to identify and select the building objects and then to have the computer determine the outline and location of the selected structures. When presented with a copy of a digitized aerial photograph, the operator uses a mouse and cursor to select a target building. After a button on the mouse is pressed, with the cursor fully within

  5. Reliable aerial thermography for energy conservation

    NASA Technical Reports Server (NTRS)

    Jack, J. R.; Bowman, R. L.

    1981-01-01

    A method for energy conservation, the aerial thermography survey, is discussed. It locates sources of energy losses and wasteful energy management practices. An operational map is presented for clear sky conditions. The map outlines the key environmental conditions conductive to obtaining reliable aerial thermography. The map is developed from defined visual and heat loss discrimination criteria which are quantized based on flat roof heat transfer calculations.

  6. Aerial righting reflexes in flightless animals.

    PubMed

    Jusufi, Ardian; Zeng, Yu; Full, Robert J; Dudley, Robert

    2011-12-01

    Animals that fall upside down typically engage in an aerial righting response so as to reorient dorsoventrally. This behavior can be preparatory to gliding or other controlled aerial behaviors and is ultimately necessary for a successful landing. Aerial righting reflexes have been described historically in various mammals such as cats, guinea pigs, rabbits, rats, and primates. The mechanisms whereby such righting can be accomplished depend on the size of the animal and on anatomical features associated with motion of the limbs and body. Here we apply a comparative approach to the study of aerial righting to explore the diverse strategies used for reorientation in midair. We discuss data for two species of lizards, the gecko Hemidactylus platyurus and the anole Anolis carolinensis, as well as for the first instar of the stick insect Extatosoma tiaratum, to illustrate size-dependence of this phenomenon and its relevance to subsequent aerial performance in parachuting and gliding animals. Geckos can use rotation of their large tails to reorient their bodies via conservation of angular momentum. Lizards with tails well exceeding snout-vent length, and correspondingly large tail inertia to body inertia ratios, are more effective at creating midair reorientation maneuvers. Moreover, experiments with stick insects, weighing an order of magnitude less than the lizards, suggest that aerodynamic torques acting on the limbs and body may play a dominant role in the righting process for small invertebrates. Both inertial and aerodynamic effects, therefore, can play a role in the control of aerial righting. We propose that aerial righting reflexes are widespread among arboreal vertebrates and arthropods and that they represent an important initial adaptation in the evolution of controlled aerial behavior. PMID:21930662

  7. Dust Reprocessing of Stellar Tidal Disruption Flares

    NASA Astrophysics Data System (ADS)

    van Velzen, Sjoert; Gorjian, Varoujan; Krolik, Julian; Mendez, Alexander

    2015-10-01

    A stellar tidal disruption flare (TDF) occurs when a star gets too close to a supermassive black hole and is shredded into streams that are accreted. Traditionally, TDFs are observed at optical to soft X-ray wavelengths. We have recently made a discovery that opens a new (and unexpected) wavelength regime for the study of these flares: transient emission at 3.4 micron in WISE multi-epoch imaging. This dust reprocessing signal was not previously predicted, but will likely be of great importance to further our (limited) understanding the TDF emission mechanism. Since the radius of the IR-emitting shell is determined by the dust sublimation temperature, the break in the IR light curve can be used to measure the bolometric luminosity of the tidal flare. With the low-cadence WISE observations as a proof-of-concept, the time is ripe to use warm Spitzer observations to make a major breakthrough: we wish to obtain the first well-sampled light curve of dust reverberation by a stellar tidal flare. If successful, these observations will have lasting impact; near-future synoptic surveys (ZTF, LSST) will find thousands of TDFs per year, which can be followed-up by IR missions (JWST, WFIRST) to obtain a census of dust within the sphere of influence of quiescent supermassive black holes.

  8. Radio Frequency-Tomography of Solar Flares

    NASA Astrophysics Data System (ADS)

    Aschwanden, M. J.

    2002-05-01

    The Frequency-Agile Solar Radiotelescope (FASR) is designed to produce simultaneous images of solar phenomena at many frequencies. A data cube with a stack of multiple frequency images can be used for tomographic reconstruction of the 3D density and temperature distribution of flares, based on the free-free emission at cm and mm wavelengths. We simulate a set of multi-frequency images for the Bastille-Day flare of 2000-July-14, based on EUV observations from TRACE and soft X-ray observations from Yohkoh. The 3D model consists of some 200 postflare loops with observationally constrained densities and temperatures. The temporal evolution involves flare plasma heating, a phase of conductive cooling, followed by a phase of radiative cooling. The images simulated at different microwave frequencies reveal a sequence of optically-thick free-free emission layers, which can be "pealed off" like onion shells with increasing radio frequency. We envision a tomographic method that yields information on the density and temperature structure of flare systems and their evolution. Comparison with EUV and soft X-ray based 3D models will also allow to quantify wave scattering at radio frequencies and provide information on small-scale inhomogeneities and wave turbulence. Besides the thermal free-free emission, radio images contain also information on coherent emission processes, such as plasma emission from electron beams and loss-cone emission from gyroresonant trapped particles, conveying information on particle acceleration processes.

  9. White-light flares observed by Yohkoh

    NASA Technical Reports Server (NTRS)

    Hudson, Hugh S.; Acton, Loren W.; Hirayama, Tadashi; Uchida, Yutaka

    1992-01-01

    The Yohkoh observatory is producing a first sample of white-light flares observed from space. We present observations of four of them, all X-class events. The Yohkoh Soft X-ray Telescope white-light data typically have a 12-s cadence for images with 2.46 arcsec pixels over a field of view of 2.62 arcmin in one of two broad-band optical filters, and the November 15, 1991 flare produced a brightness increase of about 38 percent over the photospheric brightness in the 30 A passband filter centered at 4308 A. The white-light flare morphology in the best-observed flares displays a double 'footpoint' character, establishing a close relationship with the compact magnetic flux tubes involved with both hard and soft X-ray emissions. We describe the data in the context of the soft and hard X-ray observations simultaneously carried out on board the Yohkoh satellite, emphasizing energetics and timing.

  10. Energetic electrons generated during solar flares

    NASA Astrophysics Data System (ADS)

    Mann, Gottfried

    2015-12-01

    > electrons are accelerated up to energies beyond 30 keV is one of the open questions in solar physics. A flare is considered as the manifestation of magnetic reconnection in the solar corona. Which mechanisms lead to the production of energetic electrons in the magnetic reconnection region is discussed in this paper. Two of them are described in more detail.

  11. What's an Asthma Flare-Up?

    MedlinePlus

    ... Quizzes Kids' Dictionary of Medical Words En Español What Other Kids Are Reading Back-to-School Butterflies? ... Got Homework? Here's Help White House Lunch Recipes What's an Asthma Flare-Up? KidsHealth > For Kids > What's ...

  12. Measurements of Absolute Abundances in Solar Flares

    NASA Astrophysics Data System (ADS)

    Warren, Harry P.

    2014-05-01

    We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory. EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (f). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is f = 1.17 ± 0.22. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation occurs.

  13. MEASUREMENTS OF ABSOLUTE ABUNDANCES IN SOLAR FLARES

    SciTech Connect

    Warren, Harry P.

    2014-05-01

    We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory. EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (f). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is f = 1.17 ± 0.22. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation occurs.

  14. Dependence of Sunspot Properties on Flare Occurrence and Flare-CME Association

    NASA Astrophysics Data System (ADS)

    Yang, Ya-Hui

    2015-04-01

    Previous studies showed that the intense flares tend to erupt from the large sunspot region with complex magnetic configuration and strong magnetic field. However, note that not all the active regions (ARs) classified as βγδ would produce X-class flares. To clarify the significance of sunspot properties on solar explosive events, we reexamine the dependence of flare magnitude on sunspot size and magnetic type during 1996-2014 based on the report of NOAA Solar Region Summary and the measurements of GOES soft X-ray flux. In particular, we focus on the βγδ-type ARs to relate the flare productivity to the sunspot area and magnetic field strength by means of the line-of-sight magnetograms from SOHO/MDI and SDO/HMI. Two flare-productive ARs, 10486 and 12192, with βγδ magnetic configuration during most periods of their disk passages are further investigated to characterize the sunspots and flare-CME association.

  15. On Flare and CME Predictability Based on Sunspot Group Evolution

    NASA Astrophysics Data System (ADS)

    Korsós, M. B.; Ruderman, M. S.

    2016-04-01

    We propose to apply the weighted horizontal magnetic gradient (WGM), introduced in Korsós et al. (2015), for analysing the pre-flare and pre-CME behaviour and evolution of Active Regions (ARs) using the SDO/HMI-Debrecen Data catalogue. To demonstrate the power of investigative capabilities of the WGM method in terms of flare/CME eruptions, we show the results of studying three typical active regions, namely, AR11818, AR12017 and AR11495. The choice of ARs represent typical cases of flaring with a fast CME, flare eruption without a CME and non-flaring cases, respectively. AR11818 produced an M1.4 energetic flare with a fast "halo" CME (vlinear=1202 km/s) while in AR12017 occurred an X1.0 flare without a CME. The AR11495 is a good example for non-flaring ARs. The value and temporal variation of WGM is found to possess potentially important diagnostic information about the intensity of expected flares. However, this test turns out not only to provide information about the intensity of expected flares but may also show whether a flare will occur with/without a fast CME.

  16. Understanding flaring solar-type stars seen by Kepler

    NASA Astrophysics Data System (ADS)

    Soderblom, David

    2012-02-01

    The early Kepler data show unambiguous and dramatic evidence of large-scale, massive white-light stellar flares on G and early-K dwarfs. The energies released in these flares are at least 103?104 times that of the largest solar flares ever seen, meaning that they put substantial energy into their circumstellar environments, and much of that energy may be in hard x-rays. At the same time, it is not clear from the Kepler data alone why these particular stars flare because there are many other stars with no evident flares that have similar rotation periods and amplitudes of variation. Are bouts of massive flaring episodic? Do the flaring stars have other properties (activity, v sin i, lithium, inter alia) that distinguish them? Are the flaring stars in close binaries? Keck HIRES spectra can address all these questions and more, and help us to more fully understand this important phenomenon that has critical implications for the formation and evolution of planets and, e! specially, for chemistry and astrobiology in those regions. These stars are also of potential great importance for understanding the flaring behavior of the Sun because white-light flares have not been seen on G stars before, and it is crucial to understand if these flaring stars are unusually young, in close pairs, or if they represent a broader phenomenon that has not yet been appreciated.

  17. White-light Flares on Close Binaries Observed with Kepler

    NASA Astrophysics Data System (ADS)

    Gao, Qing; Xin, Yu; Liu, Ji-Feng; Zhang, Xiao-Bin; Gao, Shuang

    2016-06-01

    Based on Kepler data, we present the results of a search for white light flares on 1049 close binaries. We identify 234 flare binaries, of which 6818 flares are detected. We compare the flare-binary fraction in different binary morphologies (“detachedness”). The result shows that the fractions in over-contact and ellipsoidal binaries are approximately 10%–20% lower than those in detached and semi-detached systems. We calculate the binary flare activity level (AL) of all the flare binaries, and discuss its variations along the orbital period (P orb) and rotation period (P rot, calculated for only detached binaries). We find that the AL increases with decreasing P orb or P rot, up to the critical values at P orb ∼ 3 days or P rot ∼ 1.5 days, and thereafter the AL starts decreasing no matter how fast the stars rotate. We examine the flaring rate as a function of orbital phase in two eclipsing binaries on which a large number of flares are detected. It appears that there is no correlation between flaring rate and orbital phase in these two binaries. In contrast, when we examine the function with 203 flares on 20 non-eclipse ellipsoidal binaries, bimodal distribution of amplitude-weighted flare numbers shows up at orbital phases 0.25 and 0.75. Such variation could be larger than what is expected from the cross section modification.

  18. In-progress X-ray Flare Forecasting

    NASA Astrophysics Data System (ADS)

    Balasubramaniam, K. S.; Winter, L. M.

    2015-12-01

    Solar X-ray flares release intense amounts of radiation and can be associated with subsequent changes in the geomagnetic field as well as a large influx of solar energetic particles. From analyses of 50,000 flares detected with the NOAA GOES satellites over the past 40 years, Winter & Balasubramaniam (2015) introduced a flare phase diagram where X-ray observables indicating flare temperature and background solar activity levels can be used to separate flares of different peak flux. We present results from adapting this method into a real-time forecast tool. Real-time GOES X-ray observations are used to predict expected flare class, with updates made every 1-minute. KSB, in part by the Air Force Office of Scientific Research on "the Physics of Coupled Flares and CME Systems". LM was supported by AER, and in part by a contract supported by AFRL/RV

  19. X-ray flares in early GRB afterglows.

    PubMed

    Burrows, D N; Falcone, A; Chincarini, G; Morris, D; Romano, P; Hill, J E; Godet, O; Moretti, A; Krimm, H; Osborne, J P; Racusin, J; Mangano, V; Page, K; Perri, M; Stroh, M

    2007-05-15

    The Swift X-ray Telescope (XRT) has discovered that flares are quite common in early X-ray afterglows of gamma-ray bursts (GRBs), being observed in roughly 50% of afterglows with prompt follow-up observations. The flares range in fluence from a few per cent to approximately 100% of the fluence of the prompt emission (the GRB). Repetitive flares are seen, with more than four successive flares detected by the XRT in some afterglows. The rise and fall times of the flares are typically considerably smaller than the time since the burst. These characteristics suggest that the flares are related to the prompt emission mechanism, but at lower photon energies. We conclude that the most likely cause of these flares is late-time activity of the GRB central engine. PMID:17293338

  20. Using subsurface helicity measurements to predict flare occurrence

    NASA Astrophysics Data System (ADS)

    Reinard, A. A.; Henthorn, J.; Komm, R.; Hill, F.

    2009-12-01

    Solar flares are responsible for a number of hazardous effects including disabling high-frequency radio communications, interfering with GPS measurements, and disrupting satellites. Forecasting flare occurrence is very difficult, giving little advanced notice of these events. One possible means for predicting flare occurrence lies in helioseismology, i.e. analysis of the region below the active region for signs of an impending flare. Time series helioseismic data collected by the Global Oscillation Network Group (GONG) have been analyzed for a subset of active regions that produce large flares and a subset with very high magnetic field strength that produce no flares. A predictive parameter has been developed and analyzed using discriminant analysis as well as traditional forecasting tools such as the Heidke skill score. Preliminary results indicate this parameter predicts flare occurrence with a high success rate.