WorldWideScience

Sample records for two-frame flash x-radiography

  1. Food consumption and digestion time estimation of spotted scat, Scatophagus argus, using X-radiography technique

    Energy Technology Data Exchange (ETDEWEB)

    Hashim, Marina; Abidin, Diana Atiqah Zainal [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Das, Simon K. [Marine Ecosystem Research Centre, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi (Malaysia); Ghaffar, Mazlan Abd. [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia and Marine Ecosystem Research Centre, Faculty of Science and Technology, Universiti Kebangsaan M (Malaysia)

    2014-09-03

    The present study was conducted to investigate the food consumption pattern and gastric emptying time using x-radiography technique in scats fish, Scatophagus argus feeding to satiation in laboratory conditions. Prior to feeding experiment, fish of various sizes were examined their stomach volume, using freshly prepared stomachs ligatured at the tips of the burret, where the maximum amount of distilled water collected in the stomach were measured (ml). Stomach volume is correlated with maximum food intake (S{sub max}) and it can estimate the maximum stomach distension by allometric model i.e volume=0.0000089W{sup 2.93}. Gastric emptying time was estimated using a qualitative X-radiography technique, where the fish of various sizes were fed to satiation at different time since feeding. All the experimental fish was feed into satiation using radio-opaque barium sulphate (BaSO{sub 4}) paste injected in the wet shrimp in proportion to the body weight. The BaSO{sub 4} was found suitable to track the movement of feed/prey in the stomach over time and gastric emptying time of scats fish can be estimated. The results of qualitative X-Radiography observation of gastric motility, showed the fish (200 gm) that fed to maximum satiation meal (circa 11 gm) completely emptied their stomach within 30 - 36 hrs. The results of the present study will provide the first baseline information on the stomach volume, gastric emptying of scats fish in captivity.

  2. Food consumption and digestion time estimation of spotted scat, Scatophagus argus, using X-radiography technique

    Science.gov (United States)

    Hashim, Marina; Abidin, Diana Atiqah Zainal; Das, Simon K.; Ghaffar, Mazlan Abd.

    2014-09-01

    The present study was conducted to investigate the food consumption pattern and gastric emptying time using x-radiography technique in scats fish, Scatophagus argus feeding to satiation in laboratory conditions. Prior to feeding experiment, fish of various sizes were examined their stomach volume, using freshly prepared stomachs ligatured at the tips of the burret, where the maximum amount of distilled water collected in the stomach were measured (ml). Stomach volume is correlated with maximum food intake (Smax) and it can estimate the maximum stomach distension by allometric model i.e volume=0.0000089W2.93. Gastric emptying time was estimated using a qualitative X-radiography technique, where the fish of various sizes were fed to satiation at different time since feeding. All the experimental fish was feed into satiation using radio-opaque barium sulphate (BaSO4) paste injected in the wet shrimp in proportion to the body weight. The BaSO4 was found suitable to track the movement of feed/prey in the stomach over time and gastric emptying time of scats fish can be estimated. The results of qualitative X-Radiography observation of gastric motility, showed the fish (200 gm) that fed to maximum satiation meal (circa 11 gm) completely emptied their stomach within 30 - 36 hrs. The results of the present study will provide the first baseline information on the stomach volume, gastric emptying of scats fish in captivity.

  3. Estimation of gastric emptying time (GET) in clownfish (Amphiprion ocellaris) using X-radiography technique

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Khoo Mei; Ghaffar, Mazlan Abd. [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2014-09-03

    This study examines the movement of food item and the estimation of gastric emptying time using the X-radiography techniques, in the clownfish (Amphiprion ocellaris) fed in captivity. Fishes were voluntarily fed to satiation after being deprived of food for 72 hours, using pellets that were tampered with barium sulphate (BaSO{sub 4}). The movement of food item was monitored over different time of feeding. As a result, a total of 36 hours were needed for the food items to be evacuated completely from the stomach. Results on the modeling of meal satiation were also discussed. The size of satiation meal to body weight relationship was allometric, with the power value equal to 1.28.

  4. MEASUREMENT OF ROOT LENGTH DENSITY IN INTACT SAMPLES USING X-RADIOGRAPHY AND IMAGE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Alain Pierret

    2011-05-01

    Full Text Available Measurement of root system attributes is of critical importance to understand and model plant growth. Root length density, the length of roots per unit volume of soil, is one of the important parameters required to understand plant performance. Measuring techniques currently in use to assess this parameter, such as for example core washing, are notoriously imprecise and labour-intensive. Roots and soil being inextricably linked, it is virtually impossible to separate them without loosing a significant amount of the root sample to be measured. This noticeably compromises the accuracy of washing techniques. For this reason, non-invasive measurement approaches are highly desirable. Here, a method based on the combination of X-radiography and image analysis is proposed as a new alternative for the measurement of root length density from intact samples. The successive steps of the method, from sampling to image acquisition are briefly described. A specific measurement algorithm, designed to account for the complex spatial arrangement of the roots within the samples is then presented and discussed in detail.

  5. Zwei-Dreibein Gravity : A Two-Frame-Field Model of 3D Massive Gravity

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; de Haan, Sjoerd; Hohm, Olaf; Merbis, Wout; Townsend, Paul K.

    2013-01-01

    We present a generally covariant and parity-invariant two-frame field ("zwei-dreibein") action for gravity in three space-time dimensions that propagates two massive spin-2 modes, unitarily, and we use Hamiltonian methods to confirm the absence of unphysical degrees of freedom. We show how

  6. Zwei-Dreibein Gravity : A Two-Frame-Field Model of 3D Massive Gravity

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; de Haan, Sjoerd; Hohm, Olaf; Merbis, Wout; Townsend, Paul K.

    2013-01-01

    We present a generally covariant and parity-invariant two-frame field ("zwei-dreibein") action for gravity in three space-time dimensions that propagates two massive spin-2 modes, unitarily, and we use Hamiltonian methods to confirm the absence of unphysical degrees of freedom. We show how zwei-drei

  7. Two-frame phase-shifting interferometry for testing optical surfaces.

    Science.gov (United States)

    Tian, Chao; Liu, Shengchun

    2016-08-08

    Standard phase-shifting interferometry (PSI) generally requires collecting at least three phase-shifted interferograms to extract the physical quantity being measured. Here, we propose the application of a simple two-frame PSI for the testing of a range of optical surfaces, including flats, spheres, and aspheres. The two-frame PSI extracts modulated phase from two randomly phase-shifted interferograms using a Gram-Schmidt algorithm, and can work in either null testing or non-null testing modes. Since only two interferograms are used for phase demodulation and the phase shift amount can be random, requirements on environmental conditions and phase shifter calibration are greatly relaxed. Experimental results of three different mirrors suggest that the two-frame PSI can achieve comparable measurement precision with conventional multi-frame PSI, but has faster data acquisition speed and less stringent hardware requirements. The proposed two-frame PSI expands the flexibility of PSI and holds great potential in many applications.

  8. X-radiography, XRD and Ultrasonic Data Transfer Function Technique - Simultaneous Measurements Under Simulated Mantle Conditions in a Multi-Anvil Device

    Science.gov (United States)

    Mueller, H. J.; Schilling, F. R.; Lathe, C.

    2004-05-01

    The interpretation of seismic data from the Earth's deep interior requires measurements of the physical properties of Earth materials under experimental simulated mantle conditions. Elastic wave velocity measurement is an important tool for the determination of the elastic properties. Ultrasonic interferometry allows the highly precise travel time measurement at a sample enclosed in a high-pressure multi-anvil device. But the calculation of wave velocities requires the exact sample length under in situ conditions. There are two options - scanning the interfaces of the sample by XRD (Mueller et al., 2003) and X-radiography (Li et al., 2001). The multi-anvil apparatus MAX80 is equipped for both methods. Only the X-radiography is fast enough for transient measurements. Contrary to XRD measurements, imaging the sample by X-rays requires a beam diameter larger than the sample length. Therefore the fixed primary slits of Max80 were exchanged by 4-blade high precision slits of Advanced Design Consulting, Inc. A Ce-YAG-crystal converts the X-ray image to an optical one, redirected by a mirror and captured by a CCD-camera. To derive the sample length, the different brightness of sample, buffer rod and reflector at the electronic image is evaluated. Classical ultrasonic interferometry is very time consuming, because the ultrasonic waves of the frequency range under study are generated and detected one after another with a given step rate. A 60 MHz frequency sweep with 100 kHz steps lasts for more than 30 minutes. This is a serious limitation for all transient measurements, but also limits the data collection at elevated temperatures to prevent the pressure transmitting boron epoxy cubes and the anvils from overheating. The ultrasonic transfer function technique (UTF), first described by Li et al. (2002), generates all the frequencies simultaneously. Related to the results and experiences of Li the UTF-technique was developed independently at GFZ. This version allows to

  9. The effects of temperature on gastric emptying time of malabar blood snapper (Lutjanus malabaricus, Bloch & Schneider 1801) using X-radiography technique

    Energy Technology Data Exchange (ETDEWEB)

    Mazumder, Sabuj Kanti, E-mail: sabujsau@gmail.com [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Ghaffar, Mazlan Abd., E-mail: magfish05@yahoo.com [Marine Ecosystem Research Centre (EKOMAR), Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Institute of Tropical Aquaculture, University of Malaysia Terengganu, 21030 Kuala Terengganu (Malaysia); Das, Simon Kumar, E-mail: skdas-maa@yahoo.com [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Marine Ecosystem Research Centre (EKOMAR), Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-09-25

    Water temperature can influence the metabolic rate of ectothermal animal such as, fish. This study aims to investigate the gastric emptying time (GET) of malabar blood snapper (L. malabaricus) at different temperature (22, 26, 30, 34°C) fed with commercial diet pellet. The gastric emptying times at different temperatures were determined X-radiographically, using barium sulfate (BaSO{sub 4}) as a contrast medium food marker. The food marker and X-radiography showed that initial voidance of fecal matter began 4-8 h after feeding at all temperature. The fastest GET (18 h) was obsereved at 30°C, whereas the longest (28 h) GET was seen at 22°C. GET was increased with increasing temperature up to 30°C whereas decreased at extreme (34°C) and stress temperature (22°C). The findings of this study suggest to culture L. malabaricus at 26-30°C with commercial diet pellet as this temperature ranges escalate the faster digestion process which may contribute faster growth rate of this commercially important fish species. Overall, the data obtained from this study may have important consequences for optimization of commercial production of malabar blood snapper.

  10. Foundation Flash Catalyst

    CERN Document Server

    Goralski, Greg

    2010-01-01

    This book offers an introduction to Flash Catalyst for designers with intermediate to advanced skills. It discusses where Catalyst sits within the production process and how it communicates with other programs. It covers all of the features of the Flash Catalyst workspace, teaching you how to create designs from scratch, how to build application designs and add functionality, and how to master the Catalyst/Flex workflow. * Introduces Flash Catalyst * Focuses on production process * Covers the interrelation between Flash Catalyst and Photoshop/Illustrator/Flex/Flash What you'll learn Starting f

  11. EPI Nyquist ghost and geometric distortion correction by two-frame phase labeling.

    Science.gov (United States)

    Xie, Victor B; Lyu, Mengye; Wu, Ed X

    2017-05-01

    To develop a new Nyquist ghost and geometric distortion correction method in echo planar imaging (EPI) using parallel imaging. Two frames of EPI data are acquired with normal and phase-labeled sequence. The phase label is applied by modifying the PE prephase gradient to shift the central echo by one echo spacing. GRAPPA weights are trained from both frames and used to reconstruct images from positive or negative echoes in each frame to remove Nyquist ghost. Geometric distortion is then corrected by the B0 field map generated from the phase difference between positive and negative echo images. Phantom and in vivo experiments at 7 Tesla (T) and 3T were performed to evaluate the proposed method. Nyquist ghost was greatly reduced in all images even under oblique imaging and poor eddy current conditions, yielding significant improvements over the existing reference scan and image entropy minimization based methods. Image geometries were fully restored after distortion correction. Phantom results indicated that the signal-to-noise ratio efficiency was largely preserved while fMRI results showed no apparent degradation of temporal resolution. The proposed method provides robust correction of both Nyquist ghost and geometric distortion in EPI, and it is particularly suitable for dynamic EPI applications. Magn Reson Med 77:1749-1761, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  12. The Recognition Techniques of Single Moving Target from Two Frames of Sequence Images

    Institute of Scientific and Technical Information of China (English)

    LIJinzong; WEIXiangquan; LINingning; MAZimo

    2005-01-01

    The binary quadric model for piecewise grayvalue distribution of an image and the F-test model for change detection are successively established so as torecognize single moving target from two frames of a sequence image. Firstly, the optimal estimators of the coefficients of the binary quadric model which is the best approach to piecewise grayvalue distribution are deduced by using the least quadratic multiplication. Then, F-test model is ulteriorly deduced by the statistic hypothesis testing based on the quadratic model, whose degrees of free-dom is (n+3, 2n-12). The results of detecting change using only F-test generally include two kinds of errors, i.e., the false alarm and the target loss, therefore, the techniques of clustering analysis and filling holes are specially designed,which can make both errors to approach to zero. The experimental results made with the television- and infrared sequence images have fully proven the validity and compatibility of the technique scheme and the key techniques proposed in this paper.

  13. NAND flash memory technologies

    CERN Document Server

    Aritome, Seiichi

    2016-01-01

    This book discusses basic and advanced NAND flash memory technologies, including the principle of NAND flash, memory cell technologies, multi-bits cell technologies, scaling challenges of memory cell, reliability, and 3-dimensional cell as the future technology. Chapter 1 describes the background and early history of NAND flash. The basic device structures and operations are described in Chapter 2. Next, the author discusses the memory cell technologies focused on scaling in Chapter 3, and introduces the advanced operations for multi-level cells in Chapter 4. The physical limitations for scaling are examined in Chapter 5, and Chapter 6 describes the reliability of NAND flash memory. Chapter 7 examines 3-dimensional (3D) NAND flash memory cells and discusses the pros and cons in structure, process, operations, scalability, and performance. In Chapter 8, challenges of 3D NAND flash memory are dis ussed. Finally, in Chapter 9, the author summarizes and describes the prospect of technologies and market for the fu...

  14. Optical Flashes Preceding GRBs

    CERN Document Server

    Paczynski, B

    2001-01-01

    Only one optical flash associated with a gamma-ray burst has been detected so far by ROTSE. There are also upper limits obtained by several groups for several bursts. Recent model calculations indicate a possibility that optical flash may precede the GRB. Such flashes are undetectable in the currently popular observing mode, with optical instruments responding to GRB triggers. There is a need to develop all sky optical monitoring system capable of recognizing flashes in real time, and more powerful instruments that could respond robotically to optical triggers and carry out follow up observations.

  15. Pro Android Flash

    CERN Document Server

    Chin, Stephen; Campesato, Oswald

    2011-01-01

    Did you know you can take your Flash skills beyond the browser, allowing you to make apps for Android, iOS and the BlackBerry Tablet OS? Build dynamic apps today starting with the easy-to-use Android smartphones and tablets. Then, take your app to other platforms without writing native code. Pro Android Flash is the definitive guide to building Flash and other rich Internet applications (RIAs) on the Android platform. It covers the most popular RIA frameworks for Android developers - Flash and Flex - and shows how to build rich, immersive user experiences on both Android smartphones and tablet

  16. Flash-Type Discrimination

    Science.gov (United States)

    Koshak, William J.

    2010-01-01

    This viewgraph presentation describes the significant progress made in the flash-type discrimination algorithm development. The contents include: 1) Highlights of Progress for GLM-R3 Flash-Type discrimination Algorithm Development; 2) Maximum Group Area (MGA) Data; 3) Retrieval Errors from Simulations; and 4) Preliminary Global-scale Retrieval.

  17. Understanding Green Flashes

    Science.gov (United States)

    Young, Andrew T.

    1998-05-01

    Most astronomers learn about green flashes from either Minnaert's old book (Dover, 1954) or O'Connell's ``The Green Flash....'' Both have defects. Minnaert's account mostly represents what was known in the 1920s; it repeats Mulder's 3-fold classification, which omits Joule's second type of flash --- the one most commonly seen from mountain observatories. O'Connell searched only the astronomical literature, missing Dietze's crucially important paper (Z.f.Met. 9, 169 (1955)) showing that the ``textbook'' mechanism cannot produce flashes visible to the naked eye. He also erred in thinking that distortions of the setting Sun arise in the upper atmosphere (they are due to the marine boundary layer), and copied an error from Feenstra Kuiper's thesis that misidentified a common mirage-like phenomenon as Wegener's ``blank strip'' (Young et al., Appl. Opt. 36, 2689 (1997).) Most phenomena shown in O'Connell's book are caused by inversion layers below eye level, not above as in Wegener's phenomenon. The two commonest forms of green flash are associated with the inferior mirage and the mock mirage, corresponding to Fisher's Type A and Type B sunsets, respectively. Superrefraction, advocated by Wood and by Rayleigh as the cause of large flashes, actually suppress them: the airmass is proportional to the refraction (by Laplace's extinction theorem), so no green is transmitted when refraction is much larger than average. Although there is a physical green flash that can be photographed, the colors seen at sunset are strongly modified by bleaching of the L cones. Most ``green'' sunset flashes are actually yellow. Writers should stop representing Jules Verne's ``ancient legend'' as fact, as it was invented by Verne as a plot device for his novel ``Le Rayon Vert.'' Green-flash photos and simulations will be shown. This material is based upon work supported by the NSF under Award No. ATM-9714357.

  18. Floods and Flash Flooding

    Science.gov (United States)

    Floods and flash flooding Now is the time to determine your area’s flood risk. If you are not sure whether you ... If you are in a floodplain, consider buying flood insurance. Do not drive around barricades. If your ...

  19. Professional Flash Lite Mobile Development

    CERN Document Server

    Anderson, J G

    2010-01-01

    Discover how to create Flash Lite mobile apps from the ground up. Adobe Flash is an ideal choice for developing rich interactive content for "Flash-enabled" mobile devices; and with this book, you'll learn how to create unique applications with Flash Lite. Through a series of code samples and extensive example applications, you'll explore the core concepts, key features, and best practices of the Flash Lite player. Coverage reveals various ways to develop Flash mobile content, create applications with a cross-platform programming framework based on the Model, View and Controller conc

  20. Foundation Flash Cartoon Animation

    CERN Document Server

    Jones, Tim; Rosson, Allan S

    2008-01-01

    One of Flash s most common uses is still animation for cartoons, games, advertising etc, and this book takes a fresh look at the topic, breaking it down pre-production, production, and post production, and looking at each section in detail, and covering topics such as storyboarding, character libraries and camera mechanics like no Flash book has before. The book is written by members of the Emmy award winning ANIMAX team, who have created work for clients such as Disney, AOL, Fox, WWE, ESPN, and Sesame workshop. This book is an opportunity for them to share their secrets, and is written to sui

  1. Learning Flash CS4 Professional

    CERN Document Server

    Shupe, Rich

    2009-01-01

    Learning Flash CS4 Professional offers beginners and intermediate Flash developers a unique introduction to the latest version of Adobe's powerful multimedia application. This easy-to-read book is loaded with full-color examples and hands-on tasks to help you master Flash CS4's new motion editor, integrated 3D system, and character control using the new inverse kinematics bones animation system. No previous Flash experience is necessary.

  2. Flash Builder and Flash Catalyst The New Workflow

    CERN Document Server

    Peeters, Steven

    2010-01-01

    The Flash Platform is changing. Flash Builder and Flash Catalyst have brought a new separation of design and coding to web development that enables a much more efficient and streamlined workflow. For designers and developers used to the close confines of Flash, this is a hugely liberating but at first alien concept. This book teaches you the new workflow for the Flash platform. It gives an overview of the technologies involved and provides you with real-world project examples and best-practice guidelines to get from design to implementation with the tools at hand. * Includes many examples* Foc

  3. Jaan Toomik Flash Artis

    Index Scriptorium Estoniae

    1999-01-01

    1999. a. mai-juuni 'Flash Artis' on ajakirja Eesti korrespondendi Ando Keskküla artikkel Jaan Toomikust. Jaan Toomik on kutsutud esinema Londoni The Photographers' Gallery grupinäitusele, tema videot 'Father and Son' näidatakse Londonis avataval näitusel 'Near and Elsewhere' 11.-24. juunini

  4. Inessa Josing Flash Artis

    Index Scriptorium Estoniae

    1999-01-01

    'Flash Art'i' 1998. a. nov.-dets. numbris Rosa Martínezi artiklis suvisest Manifesta II näitusest Luxembourg'is on positiivselt mainitud ka Inessa Josingut. Illustratsiooniks toodud seitsmest fotost ühel on I. Josingu aknakujundus 'What Must I Do to be Saved?'

  5. Inessa Josing Flash Artis

    Index Scriptorium Estoniae

    1999-01-01

    'Flash Art'i' 1998. a. nov.-dets. numbris Rosa Martínezi artiklis suvisest Manifesta II näitusest Luxembourg'is on positiivselt mainitud ka Inessa Josingut. Illustratsiooniks toodud seitsmest fotost ühel on I. Josingu aknakujundus 'What Must I Do to be Saved?'

  6. Jaan Toomik Flash Artis

    Index Scriptorium Estoniae

    1999-01-01

    1999. a. mai-juuni 'Flash Artis' on ajakirja Eesti korrespondendi Ando Keskküla artikkel Jaan Toomikust. Jaan Toomik on kutsutud esinema Londoni The Photographers' Gallery grupinäitusele, tema videot 'Father and Son' näidatakse Londonis avataval näitusel 'Near and Elsewhere' 11.-24. juunini

  7. Phase-step calibration technique based on a two-run-times-two-frame phase-shift method.

    Science.gov (United States)

    Zhong, Xianghong

    2006-12-10

    A novel phase-step calibration technique is presented on the basis of a two-run-times-two-frame phase-shift method. First the symmetry factor M is defined to describe the distribution property of the distorted phase due to phase-shifter miscalibration; then the phase-step calibration technique, in which two sets of two interferograms with a straight fringe pattern are recorded and the phase step is obtained by calculating M of the wrapped phase map, is developed. With this technique, a good mirror is required, but no uniform illumination is needed and no complex mathematical operation is involved. This technique can be carried out in situ and is applicable to any phase shifter, whether linear or nonlinear.

  8. Document Flash Thermography

    OpenAIRE

    Larsen, Cory; Baker, Doran

    2011-01-01

    This paper presents an extension of flash thermography techniques to the analysis of documents. Motivation for this research is to develop the ability to reveal covered writings in archaeological artifacts such as the Codex Selden or Egyptian Cartonnage. An emphasis is placed on evaluating several common existing signal processing techniques for their effectiveness in enhancing subsurface writings found within a set of test documents. These processing techniques include: contrast stretching, ...

  9. The lightning flash

    CERN Document Server

    Cooray, Vernon

    2014-01-01

    With contributions from today's leading lightning engineers and researchers, this updated 2nd edition of Vernon Cooray's classic text, The Lightning Flash provides the reader with an essential introduction to lightning and its impact on electrical and electronic equipment. Providing the reader with a thorough background into almost every aspect of lightning and its impact on electrical and electronic equipment, this new edition is updated throughout and features eight new chapters that bring the science up to date.

  10. Flash Lidar Data Processing

    Science.gov (United States)

    Bergkoetter, M. D.; Ruppert, L.; Weimer, C. S.; Ramond, T.; Lefsky, M. A.; Burke, I. C.; Hu, Y.

    2009-12-01

    Late last year, a prototype Flash LIDAR instrument flew on a series of airborne tests to demonstrate its potential for improved vegetation measurements. The prototype is a precursor to the Electronically Steerable Flash LIDAR (ESFL) currently under development at Ball Aerospace and Technology Corp. with funding from the NASA Earth Science Technology Office. ESFL may soon significantly expand our ability to measure vegetation and forests and better understand the extent of their role in global climate change and the carbon cycle - all critical science questions relating to the upcoming NASA DESDynI and ESA BIOMASS missions. In order to more efficiently exploit data returned from the experimental Flash Lidar system and plan for data exploitation from future flights, Ball funded a graduate student project (through the Ball Summer Intern Program, summer 2009) to develop and implement algorithms for post-processing of the 3-Dimensional Flash Lidar data. This effort included developing autonomous algorithms to resample the data to a uniform rectangular grid, geolocation of the data, and visual display of large swaths of data. The resampling, geolocation, surface hit detection, and aggregation of frame data are implemented with new MATLAB code, and the efficient visual display is achieved with free commercial viewing software. These efforts directly support additional tests flights planned as early as October 2009, including possible flights over Niwot Ridge, CO, for which there is ICESat data, and a sea-level coastal area in California to test the effect of higher altitude (above ground level) on the divergence of the beams and the beam spot sizes.

  11. Physics Flash December 2016

    Energy Technology Data Exchange (ETDEWEB)

    Kippen, Karen Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). ADEPS Communications

    2016-12-01

    This is the December 2016 issue of Physics Flash, the newsletter of the Physics Division of Los Alamos National Laboratory (LANL). In this issue, the following topics are covered: Novel liquid helium technique to aid highly sensitive search for a neutron electrical dipole moment; Silverleaf: Prototype Red Sage experiments performed at Q-site; John L. Kline named 2016 APS Fellow; Physics students in the news; First Entropy Engine quantum random number generator hits the market; and celebrating service.

  12. Physics Flash August 2016

    Energy Technology Data Exchange (ETDEWEB)

    Kippen, Karen Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-25

    Physics Flash is the newsletter for the Physics Division at Los Alamos National Laboratory. This newsletter is for August 2016. The following topics are covered: "Accomplishments in the Trident Laser Facility", "David Meyerhofer elected as chair-elect APS Nominating Committee", "HAWC searches for gamma rays from dark matter", "Proton Radiography Facility commissions electromagnetic magnifier", and "Cosmic ray muon computed tomography of spent nuclear fuel in dry storage casks."

  13. Flash Point Performance Evaluation

    Science.gov (United States)

    2014-03-01

    7094 Grabner D3828B Seta Flash CL12-3453 42.5 43.8 43.8 47.7 44.3 47.3 42.0 42.5 43.8 43.8 47.7 45.3 47.2 42.0 CL12-3475 58.5 61.7 58.7 59.7 61.3...division of Petroleum Analyzers Company (PAC) Houston, TX 14. Herzog is division of PAC 15. Stanhope- Seta , London, UK 16. Grabner Instruments is a

  14. Methods of flash sintering

    Energy Technology Data Exchange (ETDEWEB)

    Raj, Rishi; Cologna, Marco; Francis, John S.

    2016-05-10

    This disclosure provides methods of flash sintering and compositions created by these methods. Methods for sintering multilayered bodies are provided in which a sintered body is produced in less than one minute. In one aspect, each layer is of a different composition, and may be constituted wholly from a ceramic or from a combination of ceramic and metallic particles. When the body includes a layer of an anode composition, a layer of an electrolyte composition and a layer of a cathode composition, the sintered body can be used to produce a solid oxide fuel cell.

  15. Geomorphological factors of flash floods

    Science.gov (United States)

    Kuznetsova, Yulia

    2016-04-01

    Growing anthropogenic load, rise of extreme meteorological events frequency and total precipitation depth often lead to increasing danger of catastrophic fluvial processes worldwide. Flash floods are one of the most dangerous and less understood types of them. Difficulties of their study are mainly related to short duration of single events, remoteness and hard access to origin areas. Most detailed researches of flash floods focus on hydrological parameters of the flow itself and its meteorological factors. At the same time, importance of the basin geological and geomorphological structure for flash floods generation and the role they play in global sediment redistribution is yet poorly understood. However, understanding and quantitative assessment of these features is a real basis for a complete concept of factors, characteristics and dynamics of flash floods. This work is a review of published data on flash floods, and focuses on the geomorphological factors of the phenomenon. We consider both individual roles and interactions between different geomorphological features (the whole basin parameters, characteristics of the single slopes and valley bottom). Special attention is paid to critical values of certain factors. This approach also highlights the gaps or less studied factors of flash floods. Finally, all data is organized into a complex diagram that may be used for flash floods modeling. This also may help to reach a new level of flash flood predictions and risk assessment.

  16. Flashing LEDs for Microalgal Production.

    Science.gov (United States)

    Schulze, Peter S C; Guerra, Rui; Pereira, Hugo; Schüler, Lisa M; Varela, João C S

    2017-08-30

    Flashing lights are next-generation tools to mitigate light attenuation and increase the photosynthetic efficiency of microalgal cultivation systems illuminated by light-emitting diodes (LEDs). Optimal flashing light conditions depend on the reaction kinetics and properties of the linear electron transfer chain, energy dissipation, and storage mechanisms of a phototroph. In particular, extremely short and intense light flashes potentially mitigate light attenuation in photobioreactors without impairing photosynthesis. Intelligently controlling flashing light units and selecting electronic components can maximize light emission and energy efficiency. We discuss the biological, physical, and technical properties of flashing lights for algal production. We combine recent findings about photosynthetic pathways, self-shading in photobioreactors, and developments in solid-state technology towards the biotechnological application of LEDs to microalgal production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Step & flash imprint lithography

    Directory of Open Access Journals (Sweden)

    Douglas J. Resnick

    2005-02-01

    Full Text Available The escalating cost of next generation lithography (NGL is driven in part by the need for complex sources and optics. The cost for a single NGL tool could soon exceed $50 million, a prohibitive amount for many companies. As a result, several research groups are looking at alternative, low-cost methods for printing sub-100 nm features. Many of these methods are limited in their ability to do precise overlay. In 1999, Willson and Sreenivasan developed step and flash imprint lithography (S-FIL™. The use of a quartz template opens up the potential for optical alignment of the wafer and template. This paper reviews several key aspects of the S-FIL process, including template, tool, ultraviolet (UV-curable monomer, and pattern transfer. Two applications are also presented: contact holes and surface acoustic wave (SAW filters.

  18. Flash sintering of ceramic materials

    OpenAIRE

    Dancer, C. E. J.

    2016-01-01

    During flash sintering, ceramic materials can sinter to high density in a matter of seconds while subjected to electric field and elevated temperature. This process, which occurs at lower furnace temperatures and in shorter times than both conventional ceramic sintering and field-assisted methods such as spark plasma sintering, has the potential to radically reduce the power consumption required for the densification of ceramic materials. This paper reviews the experimental work on flash sint...

  19. Digital X-Radiography Scanning Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Generates digital X-radiographic images of sediment cores that portray density variations, sediment stratigraphy, bioturbation, and inclusions.DESCRIPTION:...

  20. Flash Professional CS5 Digital Classroom

    CERN Document Server

    Gerantabee, Fred

    2011-01-01

    Learn Flash in a flash with this full-color book and video training package! Adobe Flash is used by designers, game programmers, and hobbyists to create interactive Web sites, digital experiences, and mobile content. The latest release of Flash promises exciting new capabilities and this book-and-video training package makes learning the new features of Flash less intimidating. Fifteen self-paced lessons encourage you to discover essential skills and explore new aspects of Flash. The tutorials featured in the videos are each approximately five minutes long and supplement the concepts and topic

  1. Flashing light in microalgae biotechnology.

    Science.gov (United States)

    Abu-Ghosh, Said; Fixler, Dror; Dubinsky, Zvy; Iluz, David

    2016-03-01

    Flashing light can enhance photosynthesis and improve the quality and quantity of microalgal biomass, as it can increase the products of interest by magnitudes. Therefore, the integration of flashing light effect into microalgal cultivation systems should be considered. However, microalgae require a balanced mix of the light/dark cycle for higher growth rates, and respond to light intensity differently according to the pigments acquired or lost during the growth. This review highlights recently published results on flashing light effect on microalgae and its applications in biotechnology, as well as the recently developed bioreactors designed to fulfill this effect. It also discusses how this knowledge can be applied in selecting the optimal light frequencies and intensities with specific technical properties for increasing biomass production and/or the yield of the chemicals of interest by microalgae belonging to different genera.

  2. Flash sintering of ceramic materials

    Science.gov (United States)

    Dancer, C. E. J.

    2016-10-01

    During flash sintering, ceramic materials can sinter to high density in a matter of seconds while subjected to electric field and elevated temperature. This process, which occurs at lower furnace temperatures and in shorter times than both conventional ceramic sintering and field-assisted methods such as spark plasma sintering, has the potential to radically reduce the power consumption required for the densification of ceramic materials. This paper reviews the experimental work on flash sintering methods carried out to date, and compares the properties of the materials obtained to those produced by conventional sintering. The flash sintering process is described for oxides of zirconium, yttrium, aluminium, tin, zinc, and titanium; silicon and boron carbide, zirconium diboride, materials for solid oxide fuel applications, ferroelectric materials, and composite materials. While experimental observations have been made on a wide range of materials, understanding of the underlying mechanisms responsible for the onset and latter stages of flash sintering is still elusive. Elements of the proposed theories to explain the observed behaviour include extensive Joule heating throughout the material causing thermal runaway, arrested by the current limitation in the power supply, and the formation of defect avalanches which rapidly and dramatically increase the sample conductivity. Undoubtedly, the flash sintering process is affected by the electric field strength, furnace temperature and current density limit, but also by microstructural features such as the presence of second phase particles or dopants and the particle size in the starting material. While further experimental work and modelling is still required to attain a full understanding capable of predicting the success of the flash sintering process in different materials, the technique non-etheless holds great potential for exceptional control of the ceramic sintering process.

  3. Flash Builder building user interaction

    CERN Document Server

    Rocchi, Cesare

    2010-01-01

    Develop a working understanding of events and components, and containers and states so you can build and deploy RIAs in Flex. Work through a demo implementation of a login panel that employs feedback from the server side, to hone your understanding. Use the validators and the debugger to inspect your code execution. Building User Interaction is the second of five articles that will be compiled in the book, Data Visualization with Flash Builder: Designing RIA and AIR Applications with Remote Data Sources. Each full-color article illustrates specific aspects of Flash Builder data visualization

  4. Quick Guide to Flash Catalyst

    CERN Document Server

    Elmansy, Rafiq

    2011-01-01

    How do you transform user interface designs created in Photoshop or Illustrator into interactive web pages? It's easier than you think. This guide shows you how to use Adobe Flash Catalyst to create interactive UIs and website wireframes for Rich Internet Applications-without writing a single line of code. Ideal for web designers, this book introduces Flash Catalyst basics with detailed step-by-step instructions and screenshots that illustrate every part of the process. You'll learn hands-on how to turn your static design or artwork into working user interfaces that can be implemented in Fla

  5. Flash Builder charting and multimedia

    CERN Document Server

    Rocchi, Cesare

    2010-01-01

    Charting and multimedia are two vital tools for data-driven applications. Learn about the main components of the chart library included in Flash Builder, and see how to build and customize widely used charts. Turning your attention to the multimedia capabilities of the Flex framework, you will review the multimedia components built into the Flex library, and learn how to use ActionScript to manipulate video and audio files. Charting and Multimedia is the third of five articles that will be compiled in the book, Data Visualization with Flash Builder: Designing RIA and AIR Applications with Rem

  6. 3D Flash LIDAR Space Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business that has developed 3D Flash LIDAR systems for space and terrestrial applications. 3D Flash LIDAR is...

  7. Flash CS4: The Missing Manual

    CERN Document Server

    Grover, Chris

    2008-01-01

    Unlock the power of Flash and bring gorgeous animations to life onscreen. Flash CS4: The Missing Manual includes a complete primer on animation, a guided tour of the program's tools and capabilities, lots of new illustrations, and more details on working with video. Beginners will learn to use the software in no time, and experienced Flash designers will improve their skills.

  8. Evaluation of Flash Bainite in 4130 Steel

    Science.gov (United States)

    2011-07-01

    Technical Report ARWSB-TR-11011 Evaluation of Flash Bainite in 4130 Steel G. Vigilante M. Hespos S. Bartolucci...4. TITLE AND SUBTITLE Evaluation of Flash Bainite in 4130 Steel 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...STATEMENT 13. SUPPLEMENTARY NOTES 14. ABSTRACT ARDEC independently evaluated a Flash Bainite process developed by Gary Cola, Jr., Sirius Protection

  9. Jaan Toomik ajakirjas Flash Art

    Index Scriptorium Estoniae

    1999-01-01

    Kunstiajakirja "Flash Art" maikuu numbris Ando Keskküla artikkel, mis annab ülevaate J. Toomiku loomingust ja peatub pikemalt tema olulisematel töödel. 10. juunist J. Toomiku isiknäitus Londoni fotograafide galeriis. Eksponeeritud video "Uisutaja"

  10. Ingmar Muusikuse foto Flash Artis

    Index Scriptorium Estoniae

    1999-01-01

    Flash Arti 1999. a. oktoobrinumbris virtuaalse näituse rubriigis Ando Keskküla artikkel radikaalsemast eesti kunstist ja kunstielust postsotsialistlikul ajastul. Illustratsiooniks Liina Siibi fotokompositsioonid, Ingmar Muusikuse foto Raoul Kurvitza, Ene-Liis Semperi ja Kiwa Eesti Panga performance'ist

  11. Ingmar Muusikuse foto Flash Artis

    Index Scriptorium Estoniae

    1999-01-01

    Flash Arti 1999. a. oktoobrinumbris virtuaalse näituse rubriigis Ando Keskküla artikkel radikaalsemast eesti kunstist ja kunstielust postsotsialistlikul ajastul. Illustratsiooniks Liina Siibi fotokompositsioonid, Ingmar Muusikuse foto Raoul Kurvitza, Ene-Liis Semperi ja Kiwa Eesti Panga performance'ist

  12. Jaan Toomik ajakirjas Flash Art

    Index Scriptorium Estoniae

    1999-01-01

    Kunstiajakirja "Flash Art" maikuu numbris Ando Keskküla artikkel, mis annab ülevaate J. Toomiku loomingust ja peatub pikemalt tema olulisematel töödel. 10. juunist J. Toomiku isiknäitus Londoni fotograafide galeriis. Eksponeeritud video "Uisutaja"

  13. Observers can reliably identify illusory flashes in the illusory flash paradigm.

    Science.gov (United States)

    van Erp, Jan B F; Philippi, Tom G; Werkhoven, Peter

    2013-04-01

    In the illusory flash paradigm, a single flash may be experienced as two flashes when accompanied by two beeps or taps, and two flashes may be experienced as a single flash when accompanied by one beep or tap. The classic paradigm restricts responses to '1' and '2' (2-AFC), ignoring possible qualitative differences between real and illusory flashes and implicitly assuming that illusory flashes are indistinguishable from real flashes. We added a third response category 'different from that of either 1 or 2 flashes' (3-AFC). Eight naïve and 6 experienced observers responded to 160 real and 160 illusory flash trials. Experienced observers were exposed to 1,200 trials before the experiment but without receiving feedback on their performance. The third response category was used for only 4 % of the real flash trials and for 44 % of the illusory flash trials. Experienced observers did so more often (78 %) than naïve observers (18 %). This shows that observers can reliably identify illusory flashes and indicates that mere exposure to illusory flash trials (without feedback) is enough to detect and classify potential qualitative differences between real and illusory flashes.

  14. On multiphase negative flash for ideal solutions

    DEFF Research Database (Denmark)

    Yan, Wei; Stenby, Erling Halfdan

    2012-01-01

    coefficients. It is shown that this inner loop, named here as multiphase negative flash for ideal solutions, can be solved either by Michelsen's algorithm for multiphase normal flash, or by its variation which uses F−1 phase amounts as independent variables. In either case, the resulting algorithm is actually...... simpler than the corresponding normal flash algorithm. Unlike normal flash, multiphase negative flash for ideal solutions can diverge if the feasible domain for phase amounts is not closed. This can be judged readily during the iteration process. The algorithm can also be extended to the partial negative...

  15. Foundation Flash CS4 for Designers

    CERN Document Server

    Green, Tom

    2008-01-01

    In this book, you'll learn:* How to create effective animations using the new Motion Editor and animation tools * How to use the new 3D features to animate objects in 3D space * Best-practice tips and techniques from some of the top Flash practitioners on the planet * How to create captioned video and full-screen video, and deploy HD video using Flash * Techniques for using the Flash UI components as well as XML documents to create stunning,interactive presentations If you're a Flash designer looking for a solid overview of Flash CS4, this book is for you. Through the use of solid and practica

  16. uFlip: Understanding Flash IO Patterns

    DEFF Research Database (Denmark)

    Bouganim, Luc; Jonsson, Bjørn; Bonnet, Philippe

    2009-01-01

    want to establish what kind of IOs should be favored (or avoided) when designing algorithms and architectures for flash-based systems. In this paper, we focus on flash IO patterns, that capture relevant distribution of IOs in time and space, and our goal is to quantify their performance. We define u......FLIP, a benchmark for measuring the response time of flash IO patterns. We also present a benchmarking methodology which takes into account the particular characteristics of flash devices. Finally, we present the results obtained by measuring eleven flash devices, and derive a set of design hints that should drive...

  17. From Sulfide Flash Smelting to a Novel Flash Ironmaking Technology

    Science.gov (United States)

    Sohn, Hong Yong

    A novel flash ironmaking technology is under development at the University of Utah under the support of U.S. Department of Energy (DOE) and American Iron and Steel Institute (AISI). The history of the development from the conception of the idea to the current status will be discussed. The flash ironmaking process produces iron directly from fine iron ore concentrates without requiring cokemaking and pelletization/sintering, which will enable the technology to significantly reduce energy consumption and carbon dioxide emissions compared with blast furnace ironmaking. Unlike other gas-based ironmaking processes, this technology will not suffer from the problems of solid sticking and fusion. Current work is focused on the method of supplying the energy required to maintain the necessary temperature, as an intermediate step to determine the scalability for larger, industrial-scale pilot trials.

  18. Spurious dispersion effects at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Prat, Eduard

    2009-07-15

    The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

  19. Multi-stage flash degaser

    Science.gov (United States)

    Rapier, Pascal M.

    1982-01-01

    A multi-stage flash degaser (18) is incorporated in an energy conversion system (10) having a direct-contact, binary-fluid heat exchanger to remove essentially all of the noncondensable gases from geothermal brine ahead of the direct-contact binary-fluid heat exchanger (22) in order that the heat exchanger (22) and a turbine (48) and condenser (32) of the system (10) can operate at optimal efficiency.

  20. Trajectory Codes for Flash Memory

    CERN Document Server

    Anxiao,; Langberg, Michael; Schwartz, Moshe; Bruck, Jehoshua

    2010-01-01

    Flash memory is well-known for its inherent asymmetry: the flash-cell charge levels are easy to increase but are hard to decrease. In a general rewriting model, the stored data changes its value with certain patterns. The patterns of data updates are determined by the data structure and the application, and are independent of the constraints imposed by the storage medium. Thus, an appropriate coding scheme is needed so that the data changes can be updated and stored efficiently under the storage-medium's constraints. In this paper, we define the general rewriting problem using a graph model. It extends many known rewriting models such as floating codes, WOM codes, buffer codes, etc. We present a new rewriting scheme for flash memories, called the trajectory code, for rewriting the stored data as many times as possible without block erasures. We prove that the trajectory code is asymptotically optimal in a wide range of scenarios. We also present randomized rewriting codes optimized for expected performance (g...

  1. FLASH2: Operation, beamlines, and photon diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Plönjes, Elke, E-mail: elke.ploenjes@desy.de; Faatz, Bart; Kuhlmann, Marion; Treusch, Rolf [Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg (Germany)

    2016-07-27

    FLASH2, a major extension of the soft X-ray free-electron laser FLASH at DESY, turns FLASH into a multi-user FEL facility. A new undulator line is located in a separate accelerator tunnel and driven additionally by the FLASH linear accelerator. First lasing of FLASH2 was achieved in August 2014 with simultaneous user operation at FLASH1. The new FLASH2 experimental hall offers space for up to six experimental end stations, some of which will be installed permanently. The wide wavelength range spans from 4-60 nm and 0.8 nm in the 5{sup th} harmonic and in the future deep into the water window in the fundamental. While this is of high interest to users, it is challenging from the beamline instrumentation point of view. Online diagnostics - which are mostly pulse resolved - for beam intensity, position, wavelength, wave front, and pulse length have been to a large extent developed at FLASH(1) and have now been optimized for FLASH2. Pump-probe facilities for XUV-XUV, XUV optical and XUV-THz experiments will complete the FLASH2 user facility.

  2. Flash Sintering of Alumina-based Ceramics

    OpenAIRE

    Biesuz, Mattia

    2017-01-01

    Flash sintering is an electrical field-assisted consolidation technology and represents a very novel technique for producing ceramic materials, which allows to decrease sensibly both processing temperature and time. Starting from 2010, when flash sintering was discovered, different ceramic materials with a wide range of electrical properties have been successfully densified. Up to date, the research on flash sintering has been mainly focused on ionic and electronic conductors and on semicondu...

  3. Search Engine Optimization for Flash Best Practices for Using Flash on the Web

    CERN Document Server

    Perkins, Todd

    2009-01-01

    Search Engine Optimization for Flash dispels the myth that Flash-based websites won't show up in a web search by demonstrating exactly what you can do to make your site fully searchable -- no matter how much Flash it contains. You'll learn best practices for using HTML, CSS and JavaScript, as well as SWFObject, for building sites with Flash that will stand tall in search rankings.

  4. Adobe Flash Professional CS6 digital classroom

    CERN Document Server

    Team, AGI Creative

    2012-01-01

    Full-color book and video package teaches you Flash in a flash! If you want to design and maintain dynamic websites with Adobe Flash, this full-color book-and-video training package from expert instructors is the perfect place to start. Fifteen self-paced, step-by-step lessons are accompanied by video tutorials, and this powerful combination helps you master the basics, acquire essential skills, and learn what's new. Making all aspects of Flash less intimidating, this superb training tool covers topics such as using layers to build animation sequences, creating interactive web

  5. Flash CS5 The Missing Manual

    CERN Document Server

    Grover, Chris

    2010-01-01

    Once you know how to use Flash, you can create everything from simple animations to high-end desktop applications, but it's a complex tool that can be difficult to master on your own-unless you have this Missing Manual. This book will help you learn all you need to know about Flash CS5 to create animations that bring your ideas to life. Learn animation basics. Find everything you need to know to get started with FlashMaster the Flash tools. Learn the animation and effects toolset, with clear explanations and hands-on examplesUse 3D effects. Rotate and put objects in motion in three dimensions

  6. GeckoFTL: Scalable Flash Translation Techniques For Very Large Flash Devices

    DEFF Research Database (Denmark)

    Dayan, Niv; Bonnet, Philippe; Idreos, Stratos

    2016-01-01

    The volume of metadata needed by a flash translation layer (FTL) is proportional to the storage capacity of a flash device. Ideally, this metadata should reside in the device's integrated RAM to enable fast access. However, as flash devices scale to terabytes, the necessary volume of metadata...

  7. Rh-flash acquisition card

    CERN Document Server

    Bourrion, O

    2003-01-01

    The rh-flash card main purpose is to convert and store the image of the analog data present at input into an output buffer, namely in a given timing window besides a stop signal (like a digital oscilloscope). It is conceived in VME format 1U wide with an additional connector. Novelty of this card is its ability to sample at a high frequency, due to flash coders, and this at a high repetition rate. To do that the card allows the storage of the data considered 'useful' and that is done by storing only the data exceeding a certain threshold. This can be useful for instance for viewing peaks in a spectrum, and obtaining their relative location. The goal is to stock and process the data sampled before and after the arrival of a stop signal (what entails a storage depth). A threshold is defined and any peak exceeding its level will really be stored in the output buffer which is readable through the VME bus. The peak values will be stored as well as m preceding and n subsequent values (both programmable). Obviously,...

  8. Flash Expansion Threshold in Whirligig Swarms.

    Directory of Open Access Journals (Sweden)

    William L Romey

    Full Text Available In the selfish herd hypothesis, prey animals move toward each other to avoid the likelihood of being selected by a predator. However, many grouped animals move away from each other the moment before a predator attacks. Very little is known about this phenomenon, called flash expansion, such as whether it is triggered by one individual or a threshold and how information is transferred between group members. We performed a controlled experiment with whirligig beetles in which the ratio of sighted to unsighted individuals was systematically varied and emergent flash expansion was measured. Specifically, we examined: the percentage of individuals in a group that startled, the resulting group area, and the longevity of the flash expansion. We found that one or two sighted beetles in a group of 24 was not enough to cause a flash expansion after a predator stimulus, but four sighted beetles usually initiated a flash expansion. Also, the more beetles that were sighted the larger the resulting group area and the longer duration of the flash expansion. We conclude that flash expansion is best described as a threshold event whose adaptive value is to prevent energetically costly false alarms while quickly mobilizing an emergent predator avoidance response. This is one of the first controlled experiments of flash expansion, an important emergent property that has applications to understanding collective motion in swarms, schools, flocks, and human crowds. Also, our study is a convincing demonstration of social contagion, how the actions of one individual can pass through a group.

  9. On Coding Efficiency for Flash Memories

    CERN Document Server

    Ma, Xudong

    2012-01-01

    Recently, flash memories have become a competitive solution for mass storage. The flash memories have rather different properties compared with the rotary hard drives. That is, the writing of flash memories is constrained, and flash memories can endure only limited numbers of erases. Therefore, the design goals for the flash memory systems are quite different from these for other memory systems. In this paper, we consider the problem of coding efficiency. We define the "coding-efficiency" as the amount of information that one flash memory cell can be used to record per cost. Because each flash memory cell can endure a roughly fixed number of erases, the cost of data recording can be well-defined. We define "payload" as the amount of information that one flash memory cell can represent at a particular moment. By using information-theoretic arguments, we prove a coding theorem for achievable coding rates. We prove an upper and lower bound for coding efficiency. We show in this paper that there exists a fundamen...

  10. Heat wave flash droughts in decline

    Science.gov (United States)

    Mo, Kingtse C.; Lettenmaier, Dennis P.

    2015-04-01

    Flash drought is a term that was popularized during rapidly evolving droughts in the Central U.S. in 2012 that were associated with heat waves. We posit that there are two kinds of flash droughts, and we will focus on heat wave flash droughts, of which the 2012 events were typical. We find, based on an analysis of temperature observations and model-reconstructed soil moisture (SM) and evapotranspiration from 1916 to 2013, that heat wave flash droughts in the conterminous U.S. (CONUS) are most likely to occur over the Midwest and the Pacific Northwest during the growing season. We also find that the number of such events across the CONUS has been decreasing over the last century but rebounded after 2011. The long-term downward trends appear to be associated with generally increasing trends in SM resulting from increasing trends in precipitation over the areas where heat wave flash droughts are most likely to occur.

  11. Statistical Evolution of the Lightning Flash

    Science.gov (United States)

    Zoghzoghy, F. G.; Cohen, M.; Said, R.; Inan, U. S.

    2012-12-01

    Natural lightning is one of the most fascinating and powerful electrical processes on Earth. To date, the physics behind this natural phenomenon are not fully understood, due primarily to the difficulty of obtaining measurements inside thunderstorms and to the wide range of timescales involved (from nanoseconds to seconds). Our aim is to use accurate lightning geo-location data from the National Lightning Detection Network (NLDN) to study statistical patterns in lightning, taking advantage of the fact that millions of lightning flashes occur around the globe every day. We present two sets of results, one involving the patterns of flashes in a storm, and a second involving the patterns of strokes in a flash. These patterns can provide a surrogate measure of the timescales and the spatial extents of the underlying physical processes. First, we study the timescales of charge buildup inside thunderstorms. We find that, following a lightning flash, the probability of another neighboring flash decreases and takes tens of seconds to recover. We find that this suppression effect is a function of flash type, stroke peak current, cloud-to-ground (CG) stroke multiplicity, and other lightning and geographical parameters. We find that the probabilities of subsequent flashes are more suppressed following oceanic lightning, or following flashes with higher peak currents and/or higher multiplicities (for CG flashes). Second, we use NLDN data to study the evolution of the strokes within a CG flash. A CG flash typically includes multiple return strokes, which can occur in the same channel or in multiple channels within a few kilometers. We cluster NLDN stroke data into flashes and produce the probability density function of subsequent strokes as a function of distance and time-delays relative to the previous stroke. Using this technique, we investigate processes which occur during the CG lightning flash with nanosecond to millisecond timescales. For instance, our results suggest

  12. Terrestrial gamma-ray flashes

    Energy Technology Data Exchange (ETDEWEB)

    Marisaldi, Martino, E-mail: marisaldi@iasfbo.inaf.it [INAF-IASF Bologna, Via Gobetti 101, I-40129 Bologna (Italy); Fuschino, Fabio; Labanti, Claudio [INAF-IASF Bologna, Via Gobetti 101, I-40129 Bologna (Italy); Tavani, Marco [INAF-IASF Roma, Via Fosso del Cavaliere 100, I-00133 Roma (Italy); Argan, Andrea [INAF, Viale del Parco Mellini 84, 00136 Roma (Italy); Del Monte, Ettore [INAF-IASF Roma, Via Fosso del Cavaliere 100, I-00133 Roma (Italy); Longo, Francesco; Barbiellini, Guido [Dipartimento di Fisica Università di Trieste and INFN Trieste, via A. Valerio 2, I-34127 Trieste (Italy); Giuliani, Andrea [INAF-IASF Milano, Via Bassini 15, I-20133 Milano (Italy); Trois, Alessio [INAF Osservatorio Astronomico di Cagliari, loc. Poggio dei Pini, strada 54, I-09012 Capoterra (Italy); Bulgarelli, Andrea; Gianotti, Fulvio; Trifoglio, Massimo [INAF-IASF Bologna, Via Gobetti 101, I-40129 Bologna (Italy)

    2013-08-21

    Lightning and thunderstorm systems in general have been recently recognized as powerful particle accelerators, capable of producing electrons, positrons, gamma-rays and neutrons with energies as high as several tens of MeV. In fact, these natural systems turn out to be the highest energy and most efficient natural particle accelerators on Earth. Terrestrial Gamma-ray Flashes (TGFs) are millisecond long, very intense bursts of gamma-rays and are one of the most intriguing manifestation of these natural accelerators. Only three currently operative missions are capable of detecting TGFs from space: the RHESSI, Fermi and AGILE satellites. In this paper we review the characteristics of TGFs, including energy spectrum, timing structure, beam geometry and correlation with lightning, and the basic principles of the associated production models. Then we focus on the recent AGILE discoveries concerning the high energy extension of the TGF spectrum up to 100 MeV, which is difficult to reconcile with current theoretical models.

  13. [Nikola Tesla: flashes of inspiration].

    Science.gov (United States)

    Villarejo-Galende, Albero; Herrero-San Martín, Alejandro

    2013-01-16

    Nikola Tesla (1856-1943) was one of the greatest inventors in history and a key player in the revolution that led to the large-scale use of electricity. He also made important contributions to such diverse fields as x-rays, remote control, radio, the theory of consciousness or electromagnetism. In his honour, the international unit of magnetic induction was named after him. Yet, his fame is scarce in comparison with that of other inventors of the time, such as Edison, with whom he had several heated arguments. He was a rather odd, reserved person who lived for his inventions, the ideas for which came to him in moments of inspiration. In his autobiography he relates these flashes with a number of neuropsychiatric manifestations, which can be seen to include migraine auras, synaesthesiae, obsessions and compulsions.

  14. Radiometry of flashing LED sources

    Science.gov (United States)

    Gregory, Don A.; Medley, Stephanie; Roberts, Adam

    2008-08-01

    A laboratory based technique has been devised for measuring the illumination characteristics of flashing light emitting diode (LED) sources. The difference between the photopic measurement of a continuous source and a flashing source is that some analytic method must be incorporated into the measurement to account for the response of the eye. Ohno et al have devised an analytic expression for the impulse response of the eye, which closely matches existing forms used for finding effective intensity1. These other forms are the Blondel-Rey equation, the Form Factor method, and the Allard method.4,5,6 Ohno's research suggests a modified Allard method, but offers no procedure for actually making the measurement. In this research, the modified Allard1 method approach has been updated using standard laboratory equipment such as a silicon detector in conjunction with a digital multi-meter and Labview® software to make this measurement. Labview® allows exact computation of the modified Allard method. However, an approximation scheme for the conversion from radiometric units to photopic units must be adopted. The LED spectral form is approximately a Gaussian line shape with full width at half maximum of about 15 to 30nm. The Gaussian curve makes converting from radiometric to photopic units difficult. To simplify, the technique presented here estimates the spectral form of the LEDs to be a Dirac delta function situated at the peak wavelength. This allows the conversion from watts to lumens to be a simple application of the luminous efficiency curve.2 For LEDs with a full width half maximum of 20nm, this scheme is found to be accurate to +/- 5%.

  15. Machine Learning Predictions of Flash Floods

    Science.gov (United States)

    Clark, R. A., III; Flamig, Z.; Gourley, J. J.; Hong, Y.

    2016-12-01

    This study concerns the development, assessment, and use of machine learning (ML) algorithms to automatically generate predictions of flash floods around the world from numerical weather prediction (NWP) output. Using an archive of NWP outputs from the Global Forecast System (GFS) model and a historical archive of reports of flash floods across the U.S. and Europe, we developed a set of ML models that output forecasts of the probability of a flash flood given a certain set of atmospheric conditions. Using these ML models, real-time global flash flood predictions from NWP data have been generated in research mode since February 2016. These ML models provide information about which atmospheric variables are most important in the flash flood prediction process. The raw ML predictions can be calibrated against historical events to generate reliable flash flood probabilities. The automatic system was tested in a research-to-operations testbed enviroment with National Weather Service forecasters. The ML models are quite successful at incorporating large amounts of information in a computationally-efficient manner and and result in reasonably skillful predictions. The system is largely successful at identifying flash floods resulting from synoptically-forced events, but struggles with isolated flash floods that arise as a result of weather systems largely unresolvable by the coarse resolution of a global NWP system. The results from this collection of studies suggest that automatic probabilistic predictions of flash floods are a plausible way forward in operational forecasting, but that future research could focus upon applying these methods to finer-scale NWP guidance, to NWP ensembles, and to forecast lead times beyond 24 hours.

  16. Flash memory in embedded Java programs

    DEFF Research Database (Denmark)

    Korsholm, Stephan Erbs

    2011-01-01

    This paper introduces a Java execution environment with the capability for storing constant heap data in Flash, thus saving valuable RAM. The extension is motivated by the structure of three industrial applications which demonstrate the need for storing constant data in Flash on small embedded...... devices. The paper introduces the concept of host initialization of constant data to prepare a Flash image of constant data that can be kept outside the heap during runtime. The concept is implemented in an interpreter based Java execution environment....

  17. The flash-lag effect and the flash-drag effect in the same display.

    Science.gov (United States)

    Murai, Yuki; Murakami, Ikuya

    2016-09-01

    Visual motion distorts the perceived position of a stimulus. In the flash-drag effect (FDE), the perceived position of a flash appears to be shifted in the direction of nearby motion. In the flash-lag effect (FLE), a flash adjacent to a moving stimulus appears to lag behind. The FLE has been explained by several models, including the differential latency hypothesis, that a moving stimulus has a shorter processing latency than a flash does. The FDE even occurs when the flash is presented earlier than the moving stimulus, and it has been discussed whether this temporal property can be explained by the differential latency model. In the present study, we simultaneously quantified the FDE and FLE using the random jump technique (Murakami, 2001b) and compared their temporal properties. While the positional offset between a randomly jumping stimulus and a flashed stimulus determined the FLE, a drifting grating appeared next to the flash at various stimulus-onset asynchronies to induce the FDE. The grating presented up to 200 ms after the flash onset induced the FDE, whose temporal tuning was explained by a simple convolution model incorporating stochastic fluctuations of differential latency estimated from the FLE data and a transient-sustained temporal profile of motion signals. Thus, a common temporal mechanism to compute the stimulus position in reference to surrounding stimuli governs both the FDE and the FLE.

  18. Flash Point: Evaluation, Experimentation and Estimation

    Science.gov (United States)

    Rowley, J. R.; Freeman, D. K.; Rowley, R. L.; Oscarson, J. L.; Giles, N. F.; Wilding, W. V.

    2010-05-01

    The flash point is an important indicator of the flammability of a chemical. For safety purposes, many data compilations report the lowest value and not the most likely. This practice, combined with improper documentation and poor data storage methods, has resulted in compilations filled with fire-hazard data that are inconsistent with related properties and between members of homologous chemical series. In this study, the flash points reported in the DIPPR® 801 database and more than 1,400 other literature values were critically reviewed based on measurement method, inter-property relations, and trends in chemical series. New measurements for seven compounds illustrate the differences between experimental flash points and data commonly found in fire-hazard compilations. With a critically reviewed set of experimental data, published predictive methods for the flash point were evaluated for accuracy.

  19. 3D Flash LIDAR Space Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc (ASC) is a small business, which has developed a compact, eye-safe 3D Flash LIDARTM Camera (FLC) well suited for real-time...

  20. Hot Flashes amd Night Sweats (PDQ)

    Science.gov (United States)

    ... Other Funding Find NCI funding for small business innovation, technology transfer, and contracts Training Cancer Training at ... remedies for hot flashes. These include dong quai , milk thistle , red clover , licorice root extract , and chaste ...

  1. Method for programming a flash memory

    Science.gov (United States)

    Brosky, Alexander R.; Locke, William N.; Maher, Conrado M.

    2016-08-23

    A method of programming a flash memory is described. The method includes partitioning a flash memory into a first group having a first level of write-protection, a second group having a second level of write-protection, and a third group having a third level of write-protection. The write-protection of the second and third groups is disabled using an installation adapter. The third group is programmed using a Software Installation Device.

  2. Hydrodynamic simulations of the core helium flash

    CERN Document Server

    Mocak, M; Weiss, A; Kifonidis, K; 10.1017/S1743921308022813

    2009-01-01

    We describe and discuss hydrodynamic simulations of the core helium flash using an initial model of a 1.25 M_sol star with a metallicity of 0.02 near at its peak. Past research concerned with the dynamics of the core helium flash is inconclusive. Its results range from a confirmation of the standard picture, where the star remains in hydrostatic equilibrium during the flash (Deupree 1996), to a disruption or a significant mass loss of the star (Edwards 1969; Cole & Deupree 1980). However, the most recent multidimensional hydrodynamic study (Dearborn 2006) suggests a quiescent behavior of the core helium flash and seems to rule out an explosive scenario. Here we present partial results of a new comprehensive study of the core helium flash, which seem to confirm this qualitative behavior and give a better insight into operation of the convection zone powered by helium burning during the flash. The hydrodynamic evolution is followed on a computational grid in spherical coordinates using our new version of th...

  3. The free-electron laser FLASH

    Institute of Scientific and Technical Information of China (English)

    Siegfried Schreiber; Bart Faatz

    2015-01-01

    FLASH at DESY, Hamburg, Germany is the first free-electron laser(FEL) operating in the extreme ultraviolet(EUV)and soft x-ray wavelength range. FLASH is a user facility providing femtosecond short pulses with an unprecedented peak and average brilliance, opening new scientific opportunities in many disciplines. The first call for user experiments has been launched in 2005. The FLASH linear accelerator is based on TESLA superconducting technology, providing several thousands of photon pulses per second to user experiments. Probing femtosecond-scale dynamics in atomic and molecular reactions using, for instance, a combination of x-ray and optical pulses in a pump and probe arrangement,as well as single-shot diffraction imaging of biological objects and molecules, are typical experiments performed at the facility. We give an overview of the FLASH facility, and describe the basic principles of the accelerator. Recently,FLASH has been extended by a second undulator beamline(FLASH2) operated in parallel to the first beamline, extending the capacity of the facility by a factor of two.

  4. FPGA Flash Memory High Speed Data Acquisition

    Science.gov (United States)

    Gonzalez, April

    2013-01-01

    The purpose of this research is to design and implement a VHDL ONFI Controller module for a Modular Instrumentation System. The goal of the Modular Instrumentation System will be to have a low power device that will store data and send the data at a low speed to a processor. The benefit of such a system will give an advantage over other purchased binary IP due to the capability of allowing NASA to re-use and modify the memory controller module. To accomplish the performance criteria of a low power system, an in house auxiliary board (Flash/ADC board), FPGA development kit, debug board, and modular instrumentation board will be jointly used for the data acquisition. The Flash/ADC board contains four, 1 MSPS, input channel signals and an Open NAND Flash memory module with an analog to digital converter. The ADC, data bits, and control line signals from the board are sent to an Microsemi/Actel FPGA development kit for VHDL programming of the flash memory WRITE, READ, READ STATUS, ERASE, and RESET operation waveforms using Libero software. The debug board will be used for verification of the analog input signal and be able to communicate via serial interface with the module instrumentation. The scope of the new controller module was to find and develop an ONFI controller with the debug board layout designed and completed for manufacture. Successful flash memory operation waveform test routines were completed, simulated, and tested to work on the FPGA board. Through connection of the Flash/ADC board with the FPGA, it was found that the device specifications were not being meet with Vdd reaching half of its voltage. Further testing showed that it was the manufactured Flash/ADC board that contained a misalignment with the ONFI memory module traces. The errors proved to be too great to fix in the time limit set for the project.

  5. Single Particle Difraction at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Bogan, M.; Boutet, S.; Starodub, Dmitri; Decorwin-Martin, Philippe; /SLAC; Chapman, H.; Bajt, S.; Schulz, J.; /DESY; Hajdu, Janos; Seibert, M.M.; Iwan, Bianca; Timneanu, Nicusor; /Uppsala U.; Marchesini, Stefano; /LBL, Berkeley; Barty, Anton; Benner, W.Henry; Frank, Matthias; Hau-Riege, Stefan P.; Woods, Bruce; /LLNL, Livermore; Rohner, Urs; /Tofwerk AG, Thun

    2010-06-11

    Single-pulse coherent diffraction patterns have been collected from randomly injected single particles with a soft X-ray free-electron laser (FEL). The intense focused FEL pulse gives a high-resolution low-noise coherent diffraction pattern of the object before that object turns into a plasma and explodes. A diffraction pattern of a single particle will only be recorded when the particle arrival into the FEL interaction region coincides with FEL pulse arrival and detector integration. The properties of the experimental apparatus coinciding with these three events set the data acquisition rate. For our single particle FLASH diffraction imaging experiments: (1) an aerodynamic lens stack prepared a particle beam that consisted of particles moving at 150-200 m/s positioned randomly in space and time, (2) the 10 fs long FEL pulses were delivered at a fixed rate, and (3) the detector was set to integrate and readout once every two seconds. The effect of these experimental parameters on the rate of data acquisition using randomly injected particles will be discussed. Overall, the ultrashort FEL pulses do not set the limit of the data acquisition, more important is the effective interaction time of the particle crossing the FEL focus, the pulse sequence structure and the detector readout rate. Example diffraction patterns of randomly injected ellipsoidal iron oxide nanoparticles in different orientations are presented. This is the first single particle diffraction data set of identical particles in different orientations collected on a shot-to-shot basis. This data set will be used to test algorithms for recovering 3D structure from single particle diffraction.

  6. Karst flash floods: an example from the Dinaric karst (Croatia

    Directory of Open Access Journals (Sweden)

    O. Bonacci

    2006-01-01

    Full Text Available Flash floods constitute one of the deadliest and costliest natural disasters worldwide. This paper explains the karst flash flood phenomenon, which represents a special kind of flash flood. As the majority of flash floods karst flash floods are caused by intensive short-term precipitation in an area whose surface rarely exceeds a few square kilometres. The characteristics of all flash floods are their short duration, small areal extent, high flood peaks and rapid flows, and heavy loss of life and property. Karst flash floods have specific characteristics due to special conditions for water circulation, which exist in karst terrains. During karst flash floods a sudden rise of groundwater levels occurs, which causes the appearance of numerous, unexpected, abundant and temporary karst springs. This paper presents in detail an example of a karst flash flood in the Marina bay (Dinaric karst region of Croatia, which occurred in December 2004.

  7. A Comparative Study of Reduced-Variables-Based Flash and Conventional Flash

    DEFF Research Database (Denmark)

    Yan, Wei; Stenby, Erling Halfdan; Michelsen, Michael Locht

    2013-01-01

    the advantages of the reduced-variables methods in their recent paper. A fair comparison between the reduced-variables-based flash and the conventional flash is not straightforward because it is difficult to formulate the former as unconstrained minimization problems, and the flash calculation time is also...... related to the implementation quality. With the recent formulations by Nichita and Graciaa (2011), it is possible to code the reduced-variables methods without extensive modifications of Michelsen's conventional flash algorithm. A minimization-based reduced-variables algorithm was coded and compared...... with the conventional minimization-based flash. A test with the use of the SPE 3 example (Kenyon and Behie 1987) showed that the best reduction in time was less than 20% for the extreme situation of 25 components and just one row/column with nonzero BIPs. A better performance can be achieved by a simpler implementation...

  8. General review of flashing jet studies.

    Science.gov (United States)

    Polanco, Geanette; Holdø, Arne Erik; Munday, George

    2010-01-15

    The major concern on the management of superheated liquids, in industrial environments, is the large potential hazards involved in cases of any accidental release. There is a possibility that a violent phase change could take place inside the fluid released generating a flashing jet. This violent phase change might produce catastrophic consequences, such as explosions, fires or toxic exposure, in the installations and in the surroundings. The knowledge and understanding of the mechanisms involved in those releases become an important issue in the prevention of these consequences and the minimization of their impact. This work presents a comprehensive review of information about flashing processes. The review begins with a description of the single phase jet followed by a description of the two-phase flashing jet. The concepts and implications of the thermodynamic and mechanical effects on the behaviour of the jets are considered at the beginning of the review. Following the review is devoted to the classification of the different study approaches used to understand flashing processes in the past, highlighting various critical parameters on the behaviour and the hazard consequences of flashing jets. The review also contains an extensive compilation of experimental, theoretical and numerical data relating to these phenomena, which includes information on the distinct characteristics of the jet, since type of jet, velocity distribution, expansion angle and mass phase change all require individual estimation.

  9. General review of flashing jet studies

    Energy Technology Data Exchange (ETDEWEB)

    Polanco, Geanette, E-mail: gpolanco@usb.ve [Simon Bolivar University, Caracas (Venezuela, Bolivarian Republic of); Holdo, Arne Erik, E-mail: Erik.Holdo@coventry.ac.uk [Narvik University College, Narvik (Norway); Munday, George, E-mail: G.Munday@isaaconsult.co.uk [Coventry University, Coventry (United Kingdom)

    2010-01-15

    The major concern on the management of superheated liquids, in industrial environments, is the large potential hazards involved in cases of any accidental release. There is a possibility that a violent phase change could take place inside the fluid released generating a flashing jet. This violent phase change might produce catastrophic consequences, such as explosions, fires or toxic exposure, in the installations and in the surroundings. The knowledge and understanding of the mechanisms involved in those releases become an important issue in the prevention of these consequences and the minimization of their impact. This work presents a comprehensive review of information about flashing processes. The review begins with a description of the single phase jet followed by a description of the two-phase flashing jet. The concepts and implications of the thermodynamic and mechanical effects on the behaviour of the jets are considered at the beginning of the review. Following the review is devoted to the classification of the different study approaches used to understand flashing processes in the past, highlighting various critical parameters on the behaviour and the hazard consequences of flashing jets. The review also contains an extensive compilation of experimental, theoretical and numerical data relating to these phenomena, which includes information on the distinct characteristics of the jet, since type of jet, velocity distribution, expansion angle and mass phase change all require individual estimation.

  10. Lightning flash multiplicity in eastern Mediterranean thunderstorms

    Science.gov (United States)

    Yair, Y.; Shalev, S.; Erlich, Z.; Agrachov, A.; Katz, E.; Saaroni, H.; Price, C.; Ziv, B.

    2014-02-01

    Cloud-to-ground lightning flashes usually consist of one or several strokes coming in very short temporal succession and close spatial proximity. A commonly used method for converting stroke data into flashes is using the National Lightning Detection Network (NLDN) thresholds of maximum temporal separation of 0.5 s and maximum lateral distance of 10 km radius between successive strokes. In the present study, we tested a location-based algorithm with several spatial and temporal ranges, and analyzed stroke data obtained by the Israel Lightning Location System (ILLS) during one year (1.8.2009-31.7.2010). We computed the multiplicity, the percentage of single stroke flashes and the geographical distribution of average multiplicity values for thunderstorms in the Eastern Mediterranean region. Results show that for the NLDN thresholds, the percentage of single stroke flashes in Israel was 37% and the average multiplicity was 1.7. We reanalyzed the data with a spatial range that equals twice the ILLS location error and shorter times. For the new thresholds of maximum distance of 2.5 km and maximum allowed temporal separation of 0.2 s we find that the mean multiplicity of negative CGs is lowered to 1.4 and find a percentage of 58% of single stroke flashes. A unique severe storm from 30 October 2009 is analyzed and compared with the annual average of 2009/2010, showing that large deviations from the mean values can occur in specific events.

  11. Reduced Comparator Flash ADC for ECG Applications

    Directory of Open Access Journals (Sweden)

    Saravanan. V. A

    2013-03-01

    Full Text Available A CMOS based low power 4-bit Flash Analog to Digital Converter (ADC design with reduced number of comparators than the conventional Flash Analog to Digital Converter and multiplexer based architecture is proposed. For improving the conversion rate, both the analog and digital parts of the ADC are fully modified and the architecture uses only 4 comparators instead of 15 as used in conventional flash ADC, thus saving considerable amount of power. The proposed 4-bit ADC is designed and simulated in TANNER tools with 1.2 V supply voltage using TSpice simulation. The proposed design consumes low power of 2.15mW and operates at a faster rate hence it is suitable for ECG applications.

  12. Mental models of flash floods and landslides.

    Science.gov (United States)

    Wagner, Klaus

    2007-06-01

    Perceptions of flash floods and landslides were analyzed in four communities of the Bavarian Alps using the mental model approach. Thirty-eight qualitative interviews, two telephone surveys with 600 respondents, and two onsite interviews (74/95 respondents) were conducted. Mental models concerning flash floods are much better developed than those for landslides because the key physical processes for flash floods are easier for the general public to recognize and understand. Mental models are influenced by the local conditions. People who have a better knowledge about the hazards are those who use many different sources to inform themselves, express fear about natural hazards, or have previous experience with hazards. Conclusions for how to improve information for the general public are discussed.

  13. Centrally active nonhormonal hot flash therapies.

    Science.gov (United States)

    Loprinzi, Charles L; Stearns, Vered; Barton, Debra

    2005-12-19

    Given the problems associated with hormonal therapy, and the prominent problem of hot flashes in menopausal women, there is a need for nonhormonal agents to alleviate hot flashes. Several compounds that appear to act on the central nervous system have been investigated. Potential mechanisms for their effects on hot flashes have been described. Bellergal (no longer available on the US market, where it was known as Bellergal-S), a combination preparation sedative that consists of low-dose phenobarbital, ergotamine tartrate, and levorotatory alkaloids of belladonna, is an old agent that was popular approximately 20 years ago; however, there is limited suggestion of efficacy for this agent. Clonidine, an older antihypertensive drug, is another centrally active agent that has been studied. Randomized trials have demonstrated that it clearly works for reducing hot flashes, but the magnitude of efficacy is somewhat limited. Toxicity from this agent limits its utility in the clinic. Methyldopa is another centrally active agent that has been studied but to a more limited degree. It appears to have minimal efficacy and too much toxicity to make it clinically useful. Anecdotal observations from a number of sources suggested that newer antidepressants can alleviate hot flashes. This led to pilot trials of venlafaxine and paroxetine, with results suggesting benefit from both drugs. Subsequently, randomized, placebo-controlled, double-blind clinical trials of venlafaxine, paroxetine, and fluoxetine were conducted. All 3 of these clinical trials demonstrated statistically significant reductions in hot flashes with these newer antidepressants compared with placebo. Pilot trials of citalopram and mirtazapine, 2 other newer antidepressants, have also suggested efficacy. Toxicity evaluations have suggested that these agents are, again, well tolerated by the majority of patients. A recent trial, however, was unable to demonstrate any benefit for fluoxetine or citalopram over a placebo

  14. Foundation Flash CS5 for Designers

    CERN Document Server

    Green, T

    2010-01-01

    Flash is one of the most engaging, innovative, and versatile technologies available - allowing the creation of anything from animated banners and simple cartoons to Rich Internet Applications, interactive videos, and dynamic user interfaces for web sites, kiosks, devices, or DVDs. The possibilities are endless, and now it just got better. Flash CS5 boasts a host of new features, including better support for mobile devices, a whole new animation engine enabling full manipulation of tweens and paths, custom easing, improved inverse kinematics, a revamped timeline, built-in 3D, and much more. Thi

  15. Cancer treatment: dealing with hot flashes and night sweats

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000826.htm Cancer treatment: dealing with hot flashes and night sweats To ... this page, please enable JavaScript. Certain types of cancer treatments can cause hot flashes and night sweats. Hot ...

  16. Flash3D EDL Sensor Technology Advancement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts Inc. (ASC) is a small business, which has developed a number of 3D flash LADAR systems. Flash Ladar sensors are 3D video systems that...

  17. 3D Flash LIDAR EDL Resolution Improvement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business that has developed 3D Flash LIDAR systems for space and terrestrial applications. 3D Flash LIDAR is...

  18. Sunset science. III. Visual adaptation and green flashes.

    Science.gov (United States)

    Young, A T

    2000-12-01

    Photographs of green flashes do not preclude a role for physiological effects in these phenomena. While green flashes are certainly not after-images, there is compelling evidence that adaptation in the visual system strongly affects the perceived color of most sunset green flashes. Furthermore, the retinal image of the setting Sun is usually bright enough to bleach most of the red-sensitive photopigment in a few seconds, making the yellow stage of a sunset flash appear green. Even in air so hazy that no green light reaches the eye, a yellow flash may occur and appear green. Many, but not all, visual observations of sunset green flashes are of this yellow flash. The yellow portion of sunset green flashes helps explain their reported durations, which exceed those expected for the appearance of green light alone.

  19. Mainostoimiston Flash-tuotantoprosessin kehittäminen

    OpenAIRE

    Heinonen, Toni

    2012-01-01

    Tämän opinnäytetyön tarkoituksena oli kehittää mainostoimiston Flash-tuotantoprosessia. Mainostoimiston Flash-tuotanto on pääosin display-mainonnan eli bannereiden sekä Flashmainoskampanjasivustojen luontia. Lisäksi tarkoituksena oli tutkia mahdollisuutta soveltaa ohjelmistokehityksessä toimiviksi havaittujen ketterien prosessimallien soveltamista mainostoimiston Flash-tuotantoprosessiin. Työ aloitettiin kuvaamalla mainostoimiston nykyinen Flash-tuotantoprosessi tarkoitukseen ...

  20. Ultrafast-Contactless Flash Sintering using Plasma Electrodes

    OpenAIRE

    Theo Saunders; Salvatore Grasso; Reece, Michael J.

    2016-01-01

    This paper presents a novel derivative of flash sintering, in which contactless flash sintering (CFS) is achieved using plasma electrodes. In this setup, electrical contact with the sample to be sintered is made by two arc plasma electrodes, one on either side, allowing current to pass through the sample. This opens up the possibility of continuous throughput flash sintering. Preheating, a usual precondition for flash sintering, is provided by the arc electrodes which heat the sample to 1400 ...

  1. Mathematical modeling of the flash converting process

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, H.Y.; Perez-Tello, M.; Riihilahti, K.M. [Utah Univ., Salt Lake City, UT (United States)

    1996-12-31

    An axisymmetric mathematical model for the Kennecott-Outokumpu flash converting process for converting solid copper matte to copper is presented. The model is an adaptation of the comprehensive mathematical model formerly developed at the University of Utah for the flash smelting of copper concentrates. The model incorporates the transport of momentum, heat, mass, and reaction kinetics between gas and particles in a particle-laden turbulent gas jet. The standard k-{epsilon} model is used to describe gas-phase turbulence in an Eulerian framework. The particle-phase is treated from a Lagrangian viewpoint which is coupled to the gas-phase via the source terms in the Eulerian gas-phase governing equations. Matte particles were represented as Cu{sub 2}S yFeS, and assumed to undergo homogeneous oxidation to Cu{sub 2}O, Fe{sub 3}O{sub 4}, and SO{sub 2}. A reaction kinetics mechanism involving both external mass transfer of oxygen gas to the particle surface and diffusion of oxygen through the porous oxide layer is proposed to estimate the particle oxidation rate Predictions of the mathematical model were compared with the experimental data collected in a bench-scale flash converting facility. Good agreement between the model predictions and the measurements was obtained. The model was used to study the effect of different gas-injection configurations on the overall fluid dynamics in a commercial size flash converting shaft. (author)

  2. In Situ Flash Pyrolysis of Straw

    DEFF Research Database (Denmark)

    Bech, Niels

    In-Situ Flash Pyrolysis of Straw Ph.D. dissertation by Niels Bech Submitted: April 2007. Supervisors: Professor Kim Dam-Johansen, Associate Professor Peter Arendt Jensen Erfaringerne med forbrænding af halm opnået gennem et årti har vist, at en proces der kan koncentrere energien på marken, fjerne...

  3. High-fidelity flash lidar model development

    Science.gov (United States)

    Hines, Glenn D.; Pierrottet, Diego F.; Amzajerdian, Farzin

    2014-06-01

    NASA's Autonomous Landing and Hazard Avoidance Technologies (ALHAT) project is currently developing the critical technologies to safely and precisely navigate and land crew, cargo and robotic spacecraft vehicles on and around planetary bodies. One key element of this project is a high-fidelity Flash Lidar sensor that can generate three-dimensional (3-D) images of the planetary surface. These images are processed with hazard detection and avoidance and hazard relative navigation algorithms, and then are subsequently used by the Guidance, Navigation and Control subsystem to generate an optimal navigation solution. A complex, high-fidelity model of the Flash Lidar was developed in order to evaluate the performance of the sensor and its interaction with the interfacing ALHAT components on vehicles with different configurations and under different flight trajectories. The model contains a parameterized, general approach to Flash Lidar detection and reflects physical attributes such as range and electronic noise sources, and laser pulse temporal and spatial profiles. It also provides the realistic interaction of the laser pulse with terrain features that include varying albedo, boulders, craters slopes and shadows. This paper gives a description of the Flash Lidar model and presents results from the Lidar operating under different scenarios.

  4. Flash-Aware Page Replacement Algorithm

    Directory of Open Access Journals (Sweden)

    Guangxia Xu

    2014-01-01

    Full Text Available Due to the limited main memory resource of consumer electronics equipped with NAND flash memory as storage device, an efficient page replacement algorithm called FAPRA is proposed for NAND flash memory in the light of its inherent characteristics. FAPRA introduces an efficient victim page selection scheme taking into account the benefit-to-cost ratio for evicting each victim page candidate and the combined recency and frequency value, as well as the erase count of the block to which each page belongs. Since the dirty victim page often contains clean data that exist in both the main memory and the NAND flash memory based storage device, FAPRA only writes the dirty data within the victim page back to the NAND flash memory based storage device in order to reduce the redundant write operations. We conduct a series of trace-driven simulations and experimental results show that our proposed FAPRA algorithm outperforms the state-of-the-art algorithms in terms of page hit ratio, the number of write operations, runtime, and the degree of wear leveling.

  5. RELATIONSHIP BETWEEN FLASH POINTS OF SOME BINARY ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    and BS-150 in the formulation of engine oils, the recent mineral oils were chosen for study. On the other .... blend. Upon analysis of the data due to Figure 1 (b) it can be shown that the flash point of every. SN-150: .... complex compositions.

  6. Initial electric field changes of lightning flashes in two thunderstorms

    Science.gov (United States)

    Chapman, Ryan; Marshall, Thomas; Karunarathne, Sumedhe; Stolzenburg, Maribeth

    2017-04-01

    The beginning of all 75 lightning flashes in two small thunderstorms was investigated using an array of electric field change (E-change) meters and an array of VHF sensors with the goal of determining if an initial E-change (IEC) preceded the initial breakdown (IB) pulses in each flash. IECs were found at the beginning of all 62 flashes in Storm 1 and all 13 flashes in Storm 2. Hence, it is concluded that an IEC is a fundamental part of most or all lightning initiations and that an IEC is needed prior to the first IB pulse in a flash. IEC durations averaged 0.23 ms for cloud-to-ground (CG) flashes (range 0.08-0.54 ms) and averaged 2.7 ms for normal intracloud (IC) flashes (range 0.04-9.8 ms). IEC point dipole moments averaged 26 C m for CG flashes (range 4-86 C m) and averaged -140 C m for normal IC flashes (range -8 to -650 C m). IEC current moments averaged 120 kA m for CG flashes (range 41-410 kA m) and averaged -91 kA m for normal IC flashes (range -2 to -630 kA m). E-change data support the suggestion that weak narrow bipolar event type events initiate some lightning flashes, but 41 of the 75 flashes had no detectable initiating pulse > 0.04 V m-1 range normalized to 100 km. Two flashes had two IECs; the second IEC of each flash initiated a new lightning channel that propagated in a new direction and at a higher altitude than the original development after the first IEC.

  7. Matter Flashed at Ultra Speed

    Science.gov (United States)

    2007-06-01

    "REM observations of GRB060418 and GRB060607A: the onset of the afterglow and the initial fireball Lorentz factor determination", by E. Molinari, S. D. Vergani, D. Malesani, S. Covino, et al. The paper is available at http://dx.doi.org/10.1051/0004-6361:20077388 (A&A, 469, L13-L16, 2007). The REM team is formed by G. Chincarini, E. Molinari, F.M. Zerbi, L.A. Antonelli, S. Covino, P. Conconi, L. Nicastro, E. Palazzi, M. Stefanon, V. Testa, G. Tosti, F. Vitali, A. Monfardini, F. D'Alessio, P. D'Avanzo, D. Fugazza, G. Malaspina, S. Piranomonte, S.D. Vergani, P.A. Ward, S. Campana, P. Goldoni, D. Guetta, D. Malesani, N. Masetti, E.J.A. Meurs, L. Norci, E. Pian, A. Fernandez-Soto, L. Stella, G. Tagliaferri, G. Ihle, L. Gonzalez, A. Pizarro, P. Sinclair, and J. Valenzuela. Notes Gamma-ray bursts (GRBs) are short flashes of energetic gamma-rays lasting from less than a second to several minutes. They release a tremendous quantity of energy in this short time making them the most powerful events since the Big Bang. They come in two different flavours, long and short ones. Over the past few years, international efforts have convincingly shown that long gamma-ray bursts are linked with the ultimate explosion of massive stars (hypernovae; see e.g. ESO PR 16/03) while the short ones most likely originate from the violent collision of neutron stars and/or black holes (see e.g. ESO PR 26/05 and 32/05). Irrespective of the original source of the GRB energy, the injection of so much energy into a confined volume will cause a fireball to form. Gamma-ray photons have nearly a million times more energy than the 'visual' photons the eye can see. Strictly speaking, the Lorentz factor is the ratio between the total and rest-mass energy of the fireball. REM (Rapid Eye Mount) is a small (60 cm mirror diameter) rapid reaction automatic telescope dedicated to monitor the prompt afterglow of Gamma Ray Burst events. It is located at the ESO La Silla Observatory in Chile. For more information, see

  8. Next High Performance and Low Power Flash Memory Package Structure

    Institute of Scientific and Technical Information of China (English)

    Jung-Hoon Lee

    2007-01-01

    In general, SAND flash memory has advantages in low power consumption, storage capacity, and fast erase/write performance in contrast to NOR flash. But, main drawback of the SAND flash memory is the slow access time for random read operations. Therefore, we proposed the new SAND flash memory package for overcoming this major drawback. We present a high performance and low power SAND flash memory system with a dual cache memory. The proposed SAND flash package consists of two parts, i.e., an SAND flash memory module, and a dual cache module. The new SAND flash memory system can achieve dramatically higher performance and lower power consumption compared with any conventional NAND-type flash memory module. Our results show that the proposed system can reduce about 78% of write operations into the flash memory cell and about 70% of read operations from the flash memory cell by using only additional 3KB cache space. This value represents high potential to achieve low power consumption and high performance gain.

  9. Using GHz Flash ADCs at STACEE

    Science.gov (United States)

    Zweerink, Jeffrey

    2002-04-01

    The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) detects 50-500 GeV gamma rays by sampling the Cherenkov light wavefront generated as the gamma rays interact with the atmosphere. Using steerable heliostat mirrors and stationary secondary optics at the National Solar Thermal Test Facility in New Mexico, the Cherenkov light is recorded using fast electronics with good timing. One significant improvement of the full 64 channel STACEE detector over earlier prototypes is the addition of GHz flash ADCs on each channel. We are developing analysis techniques to extract timing and other pulse information from the flash ADCs in order to 1.) discriminate against the abundant cosmic ray background, and 2.) understand how well the shower direction and energy can be reconstructed. We describe the techniques and present results from data taken during the 2001-2002 observing season.

  10. Electrical Safety and Arc Flash Protections

    Energy Technology Data Exchange (ETDEWEB)

    R. Camp

    2008-03-04

    Over the past four years, the Electrical Safety Program at PPPL has evolved in addressing changing regulatory requirements and lessons learned from accident events, particularly in regards to arc flash hazards and implementing NFPA 70E requirements. This presentation will discuss PPPL's approaches to the areas of electrical hazards evaluation, both shock and arc flash; engineered solutions for hazards mitigation such as remote racking of medium voltage breakers, operational changes for hazards avoidance, targeted personnel training and hazard appropriate personal protective equipment. Practical solutions for nominal voltage identification and zero voltage checks for lockout/tagout will also be covered. Finally, we will review the value of a comprehensive electrical drawing program, employee attitudes expressed as a personal safety work ethic, integrated safety management, and sustained management support for continuous safety improvement.

  11. Direct flash steam geothermal power plant assessment

    Science.gov (United States)

    Alt, T. E.

    1982-01-01

    The objective was to analyze the capacity and availability factors of an operating direct flash geothermal power plant. System and component specifications, operating procedures, maintenance history, malfunctions, and outage rate are discussed. The plant studied was the 75 MW(e) geothermal power plant at Cerro Prieto, Mexico, for the years 1973 to 1979. To describe and assess the plant, the project staff reviewed documents, visited the plant, and met with staff of the operating utility. The high reliability and availability of the plant was documented and actions responsible for the good performance were identified and reported. The results are useful as guidance to US utilities considering use of hot water geothermal resources for power generation through a direct flash conversion cycle.

  12. How to give a science flash talk

    DEFF Research Database (Denmark)

    Veldhuis, Djuke

    2015-01-01

    Whether you are applying for funding, telling a family member about your research or engaging the public, your success will depend on how well you communicate. Persuading people that your research should be prioritised and funded relies on being a solid negotiator and developing political nous; b......; but these skills are also rooted in communication. One way to do this is by challenging yourself to summarise your research in a short, sharp, three-minute elevator pitch, or ‘flash talk’....

  13. Flash CS3 The Missing Manual

    CERN Document Server

    Grover, Chris

    2008-01-01

    Flash CS3, the latest version of the premier tool for creating web animations and interactive web sites, can be intimidating to learn. This entertaining reference tutorial provides a reader-friendly animation primer and a guided tour of all the program's tools and capabilities. Beginners will learn to use the software in no time, and experienced users will quickly take their skills to the next level.

  14. Mechanisms of Flash Sintering in Cubic Zirconia

    OpenAIRE

    Downs, John Axel

    2013-01-01

    The recently discovered flash sintering technique has shown that the application of a sufficiently large dc electric field (E-field) to a ceramic during sintering can cause sintering at temperatures several hundred degrees below conventional temperatures with sintering rates that allow for sintering in seconds rather than hours. This technique has already been demonstrated in wide range of ceramic materials including ionic conductors, electronic conductors, semi-conductors and insulators. Th...

  15. Advances in flash flood monitoring using UAVs

    Science.gov (United States)

    Perks, Matthew; Russell, Andrew; Large, Andrew

    2016-04-01

    UAVs have the potential to capture information about the earth's surface in dangerous and previously inaccessible locations. Through image acquisition of flash flood events and subsequent object-based analysis, highly dynamic and oft-immeasurable hydraulic phenomenon may be quantified at previously unattainable spatial and temporal resolutions. The potential for this approach to provide valuable information about the hydraulic conditions present during dynamic, high-energy flash floods has until now not been explored. In this paper we adopt a novel approach, utilising the Kande-Lucas-Tomasi (KLT) algorithm to track features present on the water surface which are related to the free-surface velocity. Following the successful tracking of features, a method analogous to the vector correction method has enabled accurate geometric rectification of velocity vectors. Uncertainties associated with the rectification process induced by unsteady camera movements are subsequently explored. Geo-registration errors are relatively stable and occur as a result of persistent residual distortion effects following image correction. The apparent ground movement of immobile control points between measurement intervals ranges from 0.05 - 0.13m. The application of this approach to assess the hydraulic conditions present in Alyth Burn, Scotland during a 1:200 year flash flood resulted in the generation of an average 4.2 measurements/m2 at a rate of 508 measurements/s. Analysis of these vectors provide a rare insight into the complexity of channel-overbank interactions during flash floods. The uncertainty attached to the calculated velocities is relatively low with a spatial average across the area of ± 0.15m/s. Little difference is observed in the uncertainty attached to out-of-bank velocities (± 0.15m/s), and within-channel velocities (± 0.16m/s), illustrating the consistency of the approach.

  16. Membuat Game Kuis Menggunakan Macromedia Flash 8

    OpenAIRE

    Lumban Gaol, Cindi N

    2016-01-01

    In the final project , the author makes an application quiz games . This application is a medium of learning that helps students to study for a quiz pep contained in this application relate to the lessons in school . Methods and design a quiz game designed by using software Macromedia Flash 8 as the programming language , script editor program , and is also used to design this application . This study was made aiming to broaden how to create a quiz game simple one. Word Keys : Mac...

  17. Magnesia-Chrome Refractories for Flash Furnace

    Institute of Scientific and Technical Information of China (English)

    LI Yong; CHEN Kaixian; LU Xinghua; LIU Jianlong; SUN Jialin; HONG Yanruo

    2002-01-01

    The rapid development of our country's heavy nonferrous metallurgical technology and the revolution in new type of heavynon-ferrous metallurgical furnace have imposed more critical demand on the refractory materials ,i. e. high quality and long service life. This paper presents the domestic status of the refractories for flash furnace , briefly describes the wear of the refractory used , and it is considered that the domestic in refractories for flashfurnace can be surely realized.

  18. A Comparative Study of Reduced Variables Based Flash and Conventional Flash

    DEFF Research Database (Denmark)

    Michelsen, Michael Locht; Yan, Wei; Stenby, Erling Halfdan

    Speeding up flash calculation is a central issue in compositional reservoir simulations since phase equilibrium calculation is the most time-consuming part in those simulations. The reduced variables methods, or the reduction methods, reformulate the original phase equilibrium problem with a smal......Speeding up flash calculation is a central issue in compositional reservoir simulations since phase equilibrium calculation is the most time-consuming part in those simulations. The reduced variables methods, or the reduction methods, reformulate the original phase equilibrium problem....... Most of the studies in the last decade suggest that the reduced variables methods are much more efficient than the conventional flash method. However, Haugen and Beckner questioned the advantages of the reduced variables methods in their recent paper (SPE 141399). A fair comparison between the reduced...... variables based flash and the conventional flash is not straightforward since the former is difficult to be formulated as unconstrained minimization and involves more complicated composition derivatives. With the recent formulations by Nichita and Graciaa (2010), it is possible to code the reduced variables...

  19. Extreme flash floods in Barcelona County

    Directory of Open Access Journals (Sweden)

    A. Barrera

    2005-01-01

    Full Text Available In this paper the catastrophic and extraordinary floods occurring in Barcelona County (Catalonia, NE Spain are studied, in order to characterise the temporal evolution of extreme flash floods in that area and their main features. These events usually cause economical losses and major problems for undertaking daily activity in Barcelona city. This kind of floods is a very common feature in the North-east of Spain and they are recorded every year in some point of Catalonia. This contribution also shows the frequency of those events, within the framework of all the floods that have occurred in Barcelona since the 14th century, but also describes the flooded area, urban evolution, impacts and the weather conditions for any of most severe events. The evolution of flood occurrence shows the existence of oscillations in the earlier and later modern age periods that can be attributed to climatic variability, evolution of the perception threshold and changes in vulnerability. A great increase of vulnerability can be assumed for the period 1850-1900. The analysis of the time evolution for the Barcelona rainfall series (1854-2000 shows that no trend exists, although, due to the changes in urban planning, flash-floods impact has changed over this time. The number of catastrophic flash floods has diminished, although the extraordinary ones have increased.

  20. External validation of the New Orleans Criteria (NOC), the Canadian CT Head Rule (CCHR) and the National Emergency X-Radiography Utilization Study II (NEXUS II) for CT scanning in pediatric patients with minor head injury in a non-trauma center

    Energy Technology Data Exchange (ETDEWEB)

    Schachar, Jennifer L. [Albert Einstein College of Medicine, Department of Radiology, Bronx, NY (United States); Zampolin, Richard L.; Miller, Todd S.; Farinhas, Joaquim M.; Taragin, Benjamin H. [Albert Einstein College of Medicine and Montefiore Medical Center, Department of Radiology, Bronx, NY (United States); Freeman, Katherine [Albert Einstein College of Medicine and Montefiore Medical Center, Department of Biostatistics, Bronx, NY (United States)

    2011-08-15

    Head CT scans are considered the imaging modality of choice to screen patients with head trauma for neurocranial injuries; however, widespread CT imaging is not recommended and much research has been conducted to establish objective clinical predictors of intracranial injury (ICI) in order to optimize the use of neuroimaging in children with minor head trauma. To evaluate whether a strict application of the New Orleans Criteria (NOC), Canadian CT Head Rule (CCHR) and National Emergency X-Radiography Utilization Study II (NEXUS II) in pediatric patients with head trauma presenting to a non-trauma center (level II) could reduce the number of cranial CT scans performed without missing clinically significant ICI. We conducted an IRB-approved retrospective analysis of pediatric patients with head trauma who received a cranial CT scan between Jan. 1, 2001, and Sept. 1, 2008, and identified which patients would have required a scan based on the criteria of the above listed decision instruments. We then determined the sensitivities, specificities and negative predictive values of these aids. In our cohort of 2,101 patients, 92 (4.4%) had positive head CT findings. The sensitivities for the NOC, CCHR and NEXUS II were 96.7% (95%CI 93.1-100), 65.2% (95%CI 55.5-74.9) and 78.3% (95%CI 69.9-86.7), respectively, and their negative predictive values were 98.7%, 97.6% and 97.2%, respectively. In contrast, the specificities for these aids were 11.2% (95%CI 9.8-12.6), 64.2% (95%CI 62.1-66.3) and 34.2% (95%CI 32.1-36.3), respectively. Therefore, in our population it would have been possible to scan at least 10.9% fewer patients. The number of cranial CT scans conducted in our pediatric cohort with head trauma would have been reduced had any of the three clinical decision aids been applied. Therefore, we recommend that further validation and adoption of pediatric head CT decision aids in non-trauma centers be considered to ultimately increase patient safety while reducing medical

  1. Flash memories economic principles of performance, cost and reliability optimization

    CERN Document Server

    Richter, Detlev

    2014-01-01

    The subject of this book is to introduce a model-based quantitative performance indicator methodology applicable for performance, cost and reliability optimization of non-volatile memories. The complex example of flash memories is used to introduce and apply the methodology. It has been developed by the author based on an industrial 2-bit to 4-bit per cell flash development project. For the first time, design and cost aspects of 3D integration of flash memory are treated in this book. Cell, array, performance and reliability effects of flash memories are introduced and analyzed. Key performance parameters are derived to handle the flash complexity. A performance and array memory model is developed and a set of performance indicators characterizing architecture, cost and durability is defined.   Flash memories are selected to apply the Performance Indicator Methodology to quantify design and technology innovation. A graphical representation based on trend lines is introduced to support a requirement based pr...

  2. Modeling on Flash Flood Disaster Induced by Bed Load

    Institute of Scientific and Technical Information of China (English)

    CAO Shuyou; LIU Xingnian; HUANG Er; YANG Keiun

    2008-01-01

    Flash floods result from a complex interaction among hydro-meteorological, hydrologi-cal, and hydraulic processes across various spatial and temporal scales. Sichuan Province suffers flash floods frequently owing to mountain weather and topography. A flash flood and gravel bed load transport are two key relative problems in mountain river engineering. Bed materials are often encountered in alternate scouring and deposition in mountain fluvial processes during a flash flood.In this circumstance, CRS-1 bed load numerical model jointly with scale physical model is em-ployed to predict water level and gravel bed scour and deposition for design of flood control dykes and flash flood disaster mitigation. A case study on the mechanism of a flash flood disaster in-duced by bed load transport for a hydropower station in Sichuan Province is conducted. Finally,suggestions to protect the hydropower station are proposed.

  3. Onset conditions for flash sintering of UO2

    Science.gov (United States)

    Raftery, Alicia M.; Pereira da Silva, João Gustavo; Byler, Darrin D.; Andersson, David A.; Uberuaga, Blas P.; Stanek, Christopher R.; McClellan, Kenneth J.

    2017-09-01

    In this work, flash sintering was demonstrated on stoichiometric and non-stoichiometric uranium dioxide pellets at temperatures ranging from room temperature (26 °C) up to 600 °C . The onset conditions for flash sintering were determined for three stoichiometries (UO2.00, UO2.08, and UO2.16) and analyzed against an established thermal runaway model. The presence of excess oxygen was found to enhance the flash sintering onset behavior of uranium dioxide, lowering the field required to flash and shortening the time required for a flash to occur. The results from this study highlight the effect of stoichiometry on the flash sintering behavior of uranium dioxide and will serve as the foundation for future studies on this material.

  4. Multi-channel analyzer controlled by applet and flash

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Both java applet and flash were applied to emulate virtual panel of multi-channel pulse height analyzer (MCA), and Microsoft IE browser was used to control MCA through internet to measure the γ-ray energy spectrum of 137Cs. It Was shown that most of the work completed by applet can be done by flash too, and with flash, more beautiful panel of the remote controlled instruments can be easily designed.

  5. Multi—channel analyzer controlled by applet and flash

    Institute of Scientific and Technical Information of China (English)

    HUANGWen-Da

    2002-01-01

    Both java applet and flash were applied to emulate virtual panel of multi-channel pulse height analyzer(MCA),and Microsoft IE browser was used to control MCA through internet to measure the γ-ray energy spectrum of 137Cs.It was shown that most of the work completed by applet can be done by flash too,and with flash,more beautiful panel of the remote controlled instruments can be easily designed.

  6. The echo-enabled harmonic generation options for FLASH II

    CERN Document Server

    Deng, Haixiao; Faatz, Bart

    2011-01-01

    FLASH II is an upgrade to the existing free electron laser (FEL) FLASH. The echo-enabled harmonic generation (EEHG) scheme is proposed to be a potential seeding option of FLASH II. In this paper, the possibility of EEHG operation of FLASH II is investigated for the first time. With a combination of existing numerical codes, i.e. a laser-beam interaction code in an undulator (LBICU), a beam tracking code in a chicane (ELEGANT) and an universal FEL simulating code (GENESIS), the effects of beam energy chirp and coherent synchrotron radiation (CSR) on EEHG operation are studied as well. In addition, several interesting issues concerning EEHG simulation are discussed.

  7. Flash CS5.5 The Missing Manual

    CERN Document Server

    Grover, Chris

    2011-01-01

    You can build everything from simple animations to full-fledged iOS and Android apps with Flash CS5.5, but learning this complex program can be difficult-unless you have this fully updated, bestselling guide. Learn how to create gorgeous Flash effects even if you have no programming experience. With Flash CS5.5: The Missing Manual, you'll move from the basics to power-user tools with ease. Learn animation basics. Discover how to turn simple ideas into stunning animations.Master Flash's tools. Learn the animation and effects tools with clear explanations and hands-on examples.Use 3D effects. R

  8. Laser Flash Photolysis Studies on Gallic Acid

    Institute of Scientific and Technical Information of China (English)

    ZHU Hong-Ping; ZHAO Hong-Wei; ZHANG Zhao-Xia; WANG Wen-Feng; YAO Si-De

    2006-01-01

    The transient species of gallic acid (GA) have been studied by 266 nm nanosecond laser flash photolysis in aqueous solution and acetonitrile. The intermediate with absorption at 320 nm was identified as excited triplet state (3GA*), the decay rates of which were obtained in aqueous solution and acetonitrile respectively. Energy transfer from 3GA* to β-carotene was observed and the energy transfer rate constant kent was determined to be 2.2 × 109 mol-1·L·s-1. GA underwent photoionization during photolysis and the quantum yield of photoionization was determined to be 0.12 at room temperature with KI as a reference.

  9. Animación con Flash

    OpenAIRE

    Agelet Ordobàs, Ferran; Villar Posada, Feliciano

    2009-01-01

    Flash es una aplicación informática producida por la empresa de software norteamericana Macromedia, que se utiliza principalmente para la generación de páginas web animadas e interactivas. Este programa se está convirtiendo en un estándar para la creación de contenidos animados y altamente interactivos para ser distribuidos en la Red. Este tutorial pretende recorrer el camino necesario para llegar a conocer las posibilidades de la aplicación sin experiencia previa. El usuario interesado tiene...

  10. 3D flash lidar imager onboard UAV

    Science.gov (United States)

    Zhou, Guoqing; Liu, Yilong; Yang, Jiazhi; Zhang, Rongting; Su, Chengjie; Shi, Yujun; Zhou, Xiang

    2014-11-01

    A new generation of flash LiDAR sensor called GLidar-I is presented in this paper. The GLidar-I has been being developed by Guilin University of Technology in cooperating with the Guilin Institute of Optical Communications. The GLidar-I consists of control and process system, transmitting system and receiving system. Each of components has been designed and implemented. The test, experiments and validation for each component have been conducted. The experimental results demonstrate that the researched and developed GLiDAR-I can effectively measure the distance about 13 m at the accuracy level about 11cm in lab.

  11. Influence of Pressure in Flash Sintering Technique

    Science.gov (United States)

    Pcheliakov, D. A.; Yurlova, M. S.; Grigoryev, E. G.; Olevsky, E. A.

    An innovative pressure-assisted flash-sintering technique has been developed to investigate the effect of pressure applied on microstructure and the sintering behavior of titanium dioxide. There are numerous applications for titanium dioxide in ceramics including microeletronics, glass ceramics, refractive materials, structural ceramics and titanium-containing ceramic materials and chemical intermediates. The traditional sintering of titanium dioxide usually requires several hours at over 1200 °C. The conducted research indicates that titanium dioxide can be sintered to full density in only a few seconds at 800-1000 °C, when subjected to a DC electrical field at a certain temperature moment.

  12. Flash ADC data processing with correlation coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Blyth, D.; Gibson, M.; Mcfarland, D.; Comfort, J.R., E-mail: Joseph.Comfort@asu.edu

    2014-02-21

    The large growth of flash ADC techniques for processing signals, especially in applications of streaming data, raises issues such as data flow through an acquisition system, long-term storage, and greater complexity in data analysis. In addition, experiments that push the limits of sensitivity need to distinguish legitimate signals from noise. The use of correlation coefficients is examined to address these issues. They are found to be quite successful well into the noise region. The methods can also be extended to Field Programmable Gate Array modules for compressing the data flow and greatly enhancing the event rate capabilities.

  13. The attentional modulation of the flash-lag effect

    Directory of Open Access Journals (Sweden)

    M.V.C. Baldo

    2002-08-01

    Full Text Available If a dot is flashed in perfect alignment with a pair of dots rotating around the visual fixation point, most observers perceive the rotating dots as being ahead of the flashing dot (flash-lag effect. This perceptual effect has been interpreted to result from the perceptual extrapolation of the moving dots, the differential visual latencies between flashing and moving stimuli, as well as the modulation of attentional mechanisms. Here we attempted to uncouple the attentional effects brought about by the spatial predictability of the flashing dot from the sensory effects dependent on its visual eccentricity. The stimulus was a pair of dots rotating clockwise around the fixation point. Another dot was flashed at either the upper right or the lower left of the visual field according to three separate blocked situations: fixed, alternate and random positions. Twenty-four participants had to judge, in all three situations, the location of the rotating dots in relation to the imaginary line connecting the flashing dot and the fixation point at the moment the dot was flashed. The flash-lag effect was observed in all three situations, and a clear influence of the spatial predictability of the flashing dot on the magnitude of the perceptual phenomenon was revealed, independently of sensory effects related to the eccentricity of the stimulus in the visual field. These findings are consistent with our proposal that, in addition to sensory factors, the attentional set modulates the magnitude of the differential latencies that give rise to the flash-lag phenomenon.

  14. Flash Vacuum Pyrolysis - Techniques and Reactions.

    Science.gov (United States)

    Wentrup, Curt

    2017-07-04

    While pyrolysis reactions have been performed since ancient times and been crucial for the invention of several technologies, the methodology now commonly known as flash vacuum pyrolysis, FVP (or flash vacuum thermolysis, FVT) had its early beginnings in the 1940s and1950s, mainly through mass spectrometric detection of pyrolytically formed free radicals. In the 1960s many organic chemists started performing FVP experiments with the purpose of isolating new and interesting compounds and understanding pyrolysis processes. Meanwhile, many different types of apparatus and techniques have been developed, and it is the purpose of this review to present the most important methods as well as a survey of typical reactions and observations that can be achieved with the various techniques. This includes preparative FVP, chemical trapping reactions, matrix isolation and low temperature spectroscopy of reactive intermediates and unstable molecules, the use of online mass, photoelectron, microwave and millimeterwave spectroscopies, gas-phase laser pyrolysis, pulsed pyrolysis with supersonic jet expansion, very low pressure pyrolysis for kinetic investigations, solution-spray and falling-solid FVP for involatile compounds, and pyrolysis over solid supports and reagents. Moreover, the combination of FVP with matrix isolation and photochemistry is a powerful tool for investigations of reaction mechanism. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Flash pyrolysis fuel oil: BIO-POK

    Energy Technology Data Exchange (ETDEWEB)

    Gust, S. [Neste Oy, Porvoo (Finland)

    1995-12-31

    Flash pyrolysis oil from Ensyn Tech., Canada and Union Fenosa, Spain was combusted with simple pressure atomisation equipment commonly used with light fuel oils in intermediate size (0.1-1 MW) boilers. With a number of modifications to the combustion system, carbon monoxide (CO) and nitrous oxide (NO{sub x}) could be reduced to acceptable levels: CO < 30 ppm and NO{sub x} < 140 ppm. Particulate emissions which were initially very high (Bacharach 4-5) were reduced (Bach. 2-3) by system changes but are still higher than from light fuel oil (Bach. <1). The modifications to the combustion system were: acid resistant progressive cavity pump, higher oil preheat temperature and higher oil pressure than for light fuel oils, refractory section between burner and boiler warmed up to at least 800 deg C. In addition, it was necessary to store pyrolysis oil samples under inert conditions to prevent oxidation and to rinse nozzles with alcohol after shutdown to prevent coking. The complexity and cost of these system modifications are considered to be too great for current grades of flash pyrolysis oil to be sold as a light fuel oil replacement. Improvements to fuel quality will be necessary. The main improvements are lowering of viscosity and improving of stability

  16. Honeywell optical investigations on FLASH program

    Science.gov (United States)

    O'Rourke, Ken; Peterson, Eric; Yount, Larry

    1995-05-01

    The increasing performance and reduction of life cycle cost requirements placed on commercial and military transport aircraft are resulting in more complex, highly integrated aircraft control and management systems. The use of fiber optic data transmission media can make significant contributions in achieving these performance and cost goals. The Honeywell portion of Task 2A on the Fly-by-Light Advanced System Hardware (FLASH) program is evaluating a Primary Flight Control System (PFCS) using pilot and copilot inputs from Active Hand Controllers (AHC) which are optically linked to the primary flight Control Computers (PFCC). Customer involvement is an important element of the Task 2A activity. Establishing customer requirements and perspectives on productization of systems developed under FLASH are key to future product success. The Honeywell elements of the PFCS demonstrator provide a command path that is optically interfaced from crew inputs to commands of distributed, smart actuation subsystems commands. Optical communication architectures are implemented using several protocols including the new AS-1773A 20 Mbps data bus standard. The interconnecting fiber optic cable plant is provided by our Task 1A teammate McDonnell Douglas Aerospace (West). Fiber optic cable plant fabrication uses processed, tools and materials reflecting necessary advances in manufacturing required to make fly-by-light avionics systems marketable.

  17. Nanocrystalline magnetic materials obtained by flash annealing

    Directory of Open Access Journals (Sweden)

    R.K. Murakami

    1999-04-01

    Full Text Available The aim of the present work was to produce enhanced-remanence nanocrystalline magnetic material by crystallizing amorphous or partially amorphous Pr4.5Fe77B18.5 alloys by the flash annealing process, also known as the dc-Joule heating process, and to determine the optimal conditions for obtaining good magnetic coupling between the magnetic phases present in this material. Ribbons of Pr4.5Fe77B18.5 were produced by melt spinning and then annealed for 10-30 s at temperatures 500 - 640 °C by passing current through the sample to develop the enhanced-remanence nanocrystalline magnetic material. These materials were studied by X-ray diffraction, differential thermal analysis and magnetic measurements. Coercivity increases of up to 15% were systematically observed in relation to furnace-annealed material. Two different samples were carefully examined: (i a sample annealed at 600 °C which showed the highest coercive field Hc and remanence ratio Mr/Ms and (ii a sample annealed at 520 °C which showed phase separation in the second quadrant demagnetization curve. Our results are in agreement with other studies which show that flash annealing improves the magnetic properties of some amorphous ferromagnetic ribbons.

  18. Flash Infrared Thermography Contrast Data Analysis Technique

    Science.gov (United States)

    Koshti, Ajay

    2014-01-01

    This paper provides information on an IR Contrast technique that involves extracting normalized contrast versus time evolutions from the flash thermography inspection infrared video data. The analysis calculates thermal measurement features from the contrast evolution. In addition, simulation of the contrast evolution is achieved through calibration on measured contrast evolutions from many flat-bottom holes in the subject material. The measurement features and the contrast simulation are used to evaluate flash thermography data in order to characterize delamination-like anomalies. The thermal measurement features relate to the anomaly characteristics. The contrast evolution simulation is matched to the measured contrast evolution over an anomaly to provide an assessment of the anomaly depth and width which correspond to the depth and diameter of the equivalent flat-bottom hole (EFBH) similar to that used as input to the simulation. A similar analysis, in terms of diameter and depth of an equivalent uniform gap (EUG) providing a best match with the measured contrast evolution, is also provided. An edge detection technique called the half-max is used to measure width and length of the anomaly. Results of the half-max width and the EFBH/EUG diameter are compared to evaluate the anomaly. The information provided here is geared towards explaining the IR Contrast technique. Results from a limited amount of validation data on reinforced carbon-carbon (RCC) hardware are included in this paper.

  19. Initial Electric Field Changes of Lightning Flashes in Two Thunderstorms

    Science.gov (United States)

    Marshall, T. C.; Stolzenburg, M.; Karunarathne, S.; Chapman, R.

    2015-12-01

    In a study of lightning initiation, Marshall et al. [2014, JGR Atmospheres] found that an initial electric field change (IEC) occurred before the initial breakdown (IB) pulses in 18 cloud-to-ground (CG) flashes and in 18 intracloud (IC) flashes. Because the IECs were small in amplitude and slowly developing (i.e., primarily electrostatic events), they were only detected by sensors within the reversal distance of each flash. In this presentation we report on a search for IECs in two small Florida thunderstorms that occurred close to several E-change sensors. One storm had 57 flashes; the other had only 13 flashes. The key result is that 69 of the 70 flashes began with detectable IECs. For the one flash without a detectable IEC, the closest sensor was at the reversal distance, presumably masking the IEC. Three of the flashes analyzed seemed to begin twice, in the sense that they had two sets of IB pulses; each beginning was preceded by an IEC.

  20. Algorithms for Lunar Flash Video Search, Measurement, and Archiving

    Science.gov (United States)

    Swift, Wesley; Suggs, Robert; Cooke, Bill

    2007-01-01

    Lunar meteoroid impact flashes provide a method to estimate the flux of the large meteoroid flux and thus their hazard to spacecraft. Although meteoroid impacts on the Moon have been detected using video methods for over a decade, the difficulty of manually searching hours of video for the rare, extremely brief impact flashes has discouraged the technique's systematic implementation. A prototype has been developed for the purpose of automatically searching lunar video records for impact flashes, eliminating false detections, editing the returned possible flashes, Z and archiving and documenting the results. The theory and organization of the program is discussed with emphasis on the filtering out of several classes of false detections and retaining the brief portions of the raw video necessary for in depth analysis of the flashes detected. Several utilities for measurement, analysis, and location of the flashes on the moon included in the program are demonstrated. Application of the program to a year's worth of lunar observations is discussed along with examples of impact flashes as well as several classes of false impact flashes.

  1. Assessment of Vulnerability to Extreme Flash Floods in Design Storms

    Directory of Open Access Journals (Sweden)

    Hyun Il Choi

    2011-07-01

    Full Text Available There has been an increase in the occurrence of sudden local flooding of great volume and short duration caused by heavy or excessive rainfall intensity over a small area, which presents the greatest potential danger threat to the natural environment, human life, public health and property, etc. Such flash floods have rapid runoff and debris flow that rises quickly with little or no advance warning to prevent flood damage. This study develops a flash flood index through the average of the same scale relative severity factors quantifying characteristics of hydrographs generated from a rainfall-runoff model for the long-term observed rainfall data in a small ungauged study basin, and presents regression equations between rainfall characteristics and the flash flood index. The aim of this study is to develop flash flood index-duration-frequency relation curves by combining the rainfall intensity-duration-frequency relation and the flash flood index from probability rainfall data in order to evaluate vulnerability to extreme flash floods in design storms. This study is an initial effort to quantify the flash flood severity of design storms for both existing and planned flood control facilities to cope with residual flood risks due to extreme flash floods that have ocurred frequently in recent years.

  2. Sunshine Trading: Flashes of Trading Intent at the NASDAQ

    NARCIS (Netherlands)

    J.A. Skjeltorp (Johannes); E. Sojli (Elvira); W.W. Tham (Wing Wah)

    2012-01-01

    textabstractWe use the introduction and the subsequent removal of the flash order facility (an actionable indication of interest, IOI) from the NASDAQ as a natural experiment to investigate the impact of voluntary disclosure of trading intent on market quality. We find that flash orders significantl

  3. Assessment of vulnerability to extreme flash floods in design storms.

    Science.gov (United States)

    Kim, Eung Seok; Choi, Hyun Il

    2011-07-01

    There has been an increase in the occurrence of sudden local flooding of great volume and short duration caused by heavy or excessive rainfall intensity over a small area, which presents the greatest potential danger threat to the natural environment, human life, public health and property, etc. Such flash floods have rapid runoff and debris flow that rises quickly with little or no advance warning to prevent flood damage. This study develops a flash flood index through the average of the same scale relative severity factors quantifying characteristics of hydrographs generated from a rainfall-runoff model for the long-term observed rainfall data in a small ungauged study basin, and presents regression equations between rainfall characteristics and the flash flood index. The aim of this study is to develop flash flood index-duration-frequency relation curves by combining the rainfall intensity-duration-frequency relation and the flash flood index from probability rainfall data in order to evaluate vulnerability to extreme flash floods in design storms. This study is an initial effort to quantify the flash flood severity of design storms for both existing and planned flood control facilities to cope with residual flood risks due to extreme flash floods that have ocurred frequently in recent years.

  4. Microstructure of wood charcoal prepared by flash heating

    NARCIS (Netherlands)

    Kurosaki, F; Ishimaru, K; Hata, T; Bronsveld, P; Kobayashi, E; Imamura, Y

    2003-01-01

    Carbonized wood prepared by flash heating at 800 degreesC for I h shows a different microstructure and surface chemical structure than char formed after slow heating at 4 degreesC/min to 800 degreesC for I h. Flash heating produces pores that are surrounded by aggregates of carbon structures 25 to 1

  5. Flash ionisation signature in coherent cyclotron emission from Brown Dwarfs

    CERN Document Server

    Vorgul, Irena

    2016-01-01

    Brown dwarfs form mineral clouds in their atmospheres, where charged particles can produce large-scale discharges in form of lightning resulting in a substantial sudden increase of local ionisation. Brown dwarfs are observed to emit cyclotron radio emission. We show that signatures of strong transient atmospheric ionisation events (flash ionisation) can be imprinted on a pre-existing radiation. Detection of such flash ionisation events will open investigations into the ionisation state and atmospheric dynamics. Such ionisation events can also result from explosion shock waves, bursts or eruptions. We present an analytical model that describes the modulation of a pre-existing electromagnetic radiation by a time-dependent (flash) conductivity that is characteristic for flash ionisation events like lightning. Our conductivity model reproduces the conductivity function derived from observations of Terrestrial Gamma Ray Flashes, and is applicable to astrophysical objects with strong temporal variations in the loca...

  6. Lightning Mapping Array flash detection performance with variable receiver thresholds

    Science.gov (United States)

    Chmielewski, Vanna C.; Bruning, Eric C.

    2016-07-01

    This study characterizes Lightning Mapping Array performance for networks that participated in the Deep Convective Clouds and Chemistry field program using new Monte Carlo and curvature matrix model simulations. These open-source simulation tools are readily adapted to real-time operations or detailed studies of performance. Each simulation accounted for receiver threshold and location, as well as a reference distribution of source powers and flash sizes based on thunderstorm observations and the mechanics of station triggering. Source and flash detection efficiency were combined with solution bias and variability to predict flash area distortion at long ranges. Location errors and detection efficiency were highly dependent on the station configuration and thresholds, especially at longer ranges, such that performance varied more than expected across different networks and with azimuth within networks. Error characteristics matched prior studies, which led to an increase in flash distortion with range. Predicted flash detection efficiency exceeded 95% within 100 km of all networks.

  7. Features of positive ground flashes observed in Kathmandu Nepal

    Science.gov (United States)

    Adhikari, Pitri Bhakta; Sharma, Shriram; Baral, Kedarnath

    2016-07-01

    Lightning vertical electric fields pertinent to the subtropical thunderstorms occurring over the rugged terrain have been measured and recorded at a hilly station Kathmandu, Nepal. In the present work, waveforms of the positive ground flashes have been selected from all the records and were analyzed. To the best of our knowledge, this is the first time that fine structure of electric field signature pertinent to the positive return stroke; have been analyzed and presented from Nepal. One hundred and thirty three (133) of the total of four hundred twenty-five (425) flashes were selected from seven thunderstorm days and analyzed. Of the data recorded for seven days, 133 flashes (31.3%) were positive flashes and 276 flashes (64.9%) were cloud flashes. Majority of the positive ground flashes were found to be single stroke ones, whereas, the average number of strokes per flash is found to be 1.1 with a maximum value of 4. Majority of the positive ground flashes were found either lacking the initial breakdown process and the leader stage or these processes could not be detected. The return strokes are found to be succeeded by large in cloud activity in the continuing current portion of the flash. The average zero-crossing time of the positive return strokes was found to be 60.45 μs with a range of 447.81 μs and the average rise time was found to be 9.44 μs with a range of 42.56 μs.

  8. Mechanisms of cutaneous vasodilation during the postmenopausal hot flash

    Science.gov (United States)

    Low, David A.; Hubing, Kimberley A.; Del Coso, Juan; Crandall, Craig G.

    2010-01-01

    Objective Menopausal hot flashes can seriously disrupt the lives of symptomatic women. The physiological mechanisms of the hot flash efferent responses, particularly in the cutaneous circulation, are not completely understood. The aim of this study was to examine the mechanisms of increases in skin blood flow during the postmenopausal hot flash in symptomatic women. Methods Healthy postmenopausal women rested in a temperature controlled laboratory while responses prior to and during hot flashes were recorded for three unique protocols. Protocols 1 and 2: Women were locally pretreated with an intradermal injection of botulinum toxin A (BTX; blocks the release of neurotransmitters from sympathetic cholinergic nerves) in the forearm (protocol 1) and in the glabellar region (protocol 2). Protocol 3: Skin sympathetic nerve activity from the peroneal nerve was recorded, along with skin blood flow and sweating within the region innervated by that neural signal. Skin blood flow was indexed using laser-Doppler flowmetry at BTX-treated and adjacent untreated control sites. The onset of a hot flash was objectively identified as a transient and pronounced elevation of sternal sweat rate. Results The elevation in forearm (protocol 1) and glabellar skin blood flow (protocol 2) during hot flashes were attenuated at BTX sites relative to adjacent untreated sites (P<0.05 for both protocols). In protocol 3, skin sympathetic nerve activity significantly increased during hot flashes and returned to pre-flash levels following the hot flashes. Conclusion Elevations in skin blood flow during the postmenopausal hot flash are neurally mediated primarily through BTX sensitive nerves; presumably sympathetic cholinergic. PMID:21107299

  9. Looking for Similarities Between Lowland (Flash) Floods

    Science.gov (United States)

    Brauer, C.; Teuling, R.; Torfs, P.; Hobbelt, L.; Jansen, F.; Melsen, L.; Uijlenhoet, R.

    2012-12-01

    On 26 August 2010 the eastern part of The Netherlands and the bordering part of Germany were struck by a series of rainfall events. Over an area of 740 km2 more than 120 mm of rainfall were observed in 24 h. We investigated the unprecedented flash flood triggered by this exceptionally heavy rainfall event (return period > 1000 years) in the 6.5 km2 Hupsel Brook catchment, which has been the experimental watershed employed by Wageningen University since the 1960s. This study improved our understanding of the dynamics of such lowland flash floods (Brauer et al., 2011). These observations, however, only show how our experimental catchment behaved and the results cannot be extrapolated directly to different floods in other (neighboring) lowland catchments. Therefore, it is necessary to use the information collected in one well-monitored catchment in combination with data from other, less well monitored catchments to find common signatures which could describe the runoff response during a lowland flood as a function of catchment characteristics. Because of the large spatial extent of the rainfall event in August 2010, many brooks and rivers in the Netherlands and Germany flooded. With data from several catchments we investigated the influence of rainfall and catchment characteristics (such as slope, size and land use) on the reaction of discharge to rainfall. We also investigated the runoff response in these catchments during previous floods by analyzing the relation between storage and discharge and the recession curve. In addition to the flood in August 2010, two other floods occurred in The Netherlands in recently. The three floods occurred in different parts of the country, after different types of rainfall events and with different initial conditions. We selected several catchments during each flood to compare their response and find out if these cases are fundamentally different or that they were produced by the same underlying processes and can be treated in a

  10. 浅析OpenFlashChart的使用%Brief Introduction Usage of Open Flash Chart

    Institute of Scientific and Technical Information of China (English)

    周伟伟; 童敏娟

    2012-01-01

    Open Flash Chart是基于Web网络应用图表技术,用简单方便配置提供出绚丽动画效果,并且图表类型丰富多彩、数据文件结构清晰而明了.通过Open Flash Chart可以生成线图、饼状图、柱状图、雷达图、区域图以及组合图表等.设定颜色、字体、背景等CSS样式,为用户提供了大量可选择的数据图表显示方式.

  11. Article coated with flash bonded superhydrophobic particles

    Science.gov (United States)

    Simpson, John T [Clinton, TN; Blue, Craig A [Knoxville, TN; Kiggans, Jr., James O [Oak Ridge, TN

    2010-07-13

    A method of making article having a superhydrophobic surface includes: providing a solid body defining at least one surface; applying to the surface a plurality of diatomaceous earth particles and/or particles characterized by particle sizes ranging from at least 100 nm to about 10 .mu.m, the particles being further characterized by a plurality of nanopores, wherein at least some of the nanopores provide flow through porosity, the particles being further characterized by a plurality of spaced apart nanostructured features that include a contiguous, protrusive material; flash bonding the particles to the surface so that the particles are adherently bonded to the surface; and applying a hydrophobic coating layer to the surface and the particles so that the hydrophobic coating layer conforms to the nanostructured features.

  12. Flash photolysis-shock tube studies

    Energy Technology Data Exchange (ETDEWEB)

    Michael, J.V. [Argonne National Laboratory, IL (United States)

    1993-12-01

    Even though this project in the past has concentrated on the measurement of thermal bimolecular reactions of atomic species with stable molecules by the flash or laser photolysis-shock tube (FP- or LP-ST) method using atomic resonance absorption spectrometry (ARAS) as the diagnostic technique, during the past year the authors have concentrated on studies of the thermal decompositions of selected chlorocarbon molecules. These studies are necessary if the degradation of chlorine containing organic molecules by incineration are to be understood at the molecular level. Clearly, destruction of these molecules will not only involve abstraction reactions, when possible, but also thermal decomposition followed by secondary reactions of the initially formed atoms and radicals. Studies on the thermal decomposition of CH{sub 3}Cl are complete, and the curve-of-growth for Cl-atom atomic resonance absorption has been determined. The new thermal decomposition studies are similar to those already reported for CH{sub 3}Cl.

  13. A new French flash flood warning service

    Directory of Open Access Journals (Sweden)

    de Saint-Aubin Céline

    2016-01-01

    Full Text Available The French State services in charge of flood forecasting supervise about 22,000 km among the 120,000 km of the French rivers within a warning procedure called Vigilance Crues (http://www.vigicrues.gouv.fr. Some recent dramatic flood events on small watershed not covered by Vigilance Crues highlight the need for a new warning procedure to anticipate violent flash floods that regularly affect rapid river-basins. Thus the concept emerged of an automatic warning service specifically dedicated to local crisis managers. This service will be less elaborated than Vigilance Crues, probably with false alarms and missed events sometimes, but it will deliver a first information. The generation of the warning is based on a simple rainfall-runoff hydrological model developed by Irstea on all French rivers, fed with radar-gauge rainfall grids provided by Meteo-France. Every fifteen minutes, the hydrological model estimates the discharges on the rivers eligible to the service and determine if certain thresholds corresponding to a high or very high flood are likely to be exceeded. The last step of the real-time system is to determine which municipalities are concerned with flood risk and send them an automatic warning by voice call, optionally by sms or email. A specific web interface is available for users to monitor the evolution of the flood risk on maps that are updated every 15 minutes. This new flash flood warning service will be operational early 2017 as a free service for about 8,000 French municipalities.

  14. Storage Coding for Wear Leveling in Flash Memories

    CERN Document Server

    Anxiao,; Mateescu, Robert; Yaakobi, Eitan; Bruck, Jehoshua; Siegel, Paul H; Vardy, Alexander; Wolf, Jack K

    2009-01-01

    Flash memory is a non-volatile computer memory comprised of blocks of cells, wherein each cell is implemented as either NAND or NOR floating gate. NAND flash is currently the most widely used type of flash memory. In a NAND flash memory, every block of cells consists of numerous pages; rewriting even a single page requires the whole block to be erased and reprogrammed. Block erasures determine both the longevity and the efficiency of a flash memory. Therefore, when data in a NAND flash memory are reorganized, minimizing the total number of block erasures required to achieve the desired data movement is an important goal. This leads to the flash data movement problem studied in this paper. We show that coding can significantly reduce the number of block erasures required for data movement, and present several optimal or nearly optimal data-movement algorithms based upon ideas from coding theory and combinatorics. In particular, we show that the sorting-based (non-coding) schemes require at least O(nlogn) erasu...

  15. Simulated CONUS Flash Flood Climatologies from Distributed Hydrologic Models

    Science.gov (United States)

    Flamig, Z.; Gourley, J. J.; Vergara, H. J.; Kirstetter, P. E.; Hong, Y.

    2016-12-01

    This study will describe a CONUS flash flood climatology created over the period from 2002 through 2011. The MRMS reanalysis precipitation dataset was used as forcing into the Ensemble Framework For Flash Flood Forecasting (EF5). This high resolution 1-sq km 5-minute dataset is ideal for simulating flash floods with a distributed hydrologic model. EF5 features multiple water balance components including SAC-SMA, CREST, and a hydrophobic model all coupled with kinematic wave routing. The EF5/SAC-SMA and EF5/CREST water balance schemes were used for the creation of dual flash flood climatologies based on the differing water balance principles. For the period from 2002 through 2011 the daily maximum streamflow, unit streamflow, and time of peak streamflow was stored along with the minimum soil moisture. These variables are used to describe the states of the soils right before a flash flood event and the peak streamflow that was simulated during the flash flood event. The results will be shown, compared and contrasted. The resulting model simulations will be verified on basins less than 1,000-sq km with USGS gauges to ensure the distributed hydrologic models are reliable. The results will also be compared spatially to Storm Data flash flood event observations to judge the degree of agreement between the simulated climatologies and observations.

  16. Flash ionization signature in coherent cyclotron emission from brown dwarfs

    Science.gov (United States)

    Vorgul, I.; Helling, Ch.

    2016-05-01

    Brown dwarfs (BDs) form mineral clouds in their atmospheres, where charged particles can produce large-scale discharges in the form of lightning resulting in substantial sudden increase of local ionization. BDs are observed to emit cyclotron radio emission. We show that signatures of strong transient atmospheric ionization events (flash ionization) can be imprinted on a pre-existing radiation. Detection of such flash ionization events will open investigations into the ionization state and atmospheric dynamics. Such events can also result from explosion shock waves, material outbursts or (volcanic) eruptions. We present an analytical model that describes the modulation of a pre-existing electromagnetic radiation by a time-dependent (flash) conductivity that is characteristic for flash ionization events like lightning. Our conductivity model reproduces the conductivity function derived from observations of terrestrial gamma-ray flashes, and is applicable to astrophysical objects with strong temporal variations in the local ionization, as in planetary atmospheres and protoplanetary discs. We show that the field responds with a characteristic flash-shaped pulse to a conductivity flash of intermediate intensity. More powerful ionization events result in smaller variations of the initial radiation, or in its damping. We show that the characteristic damping of the response field for high-power initial radiation carries information about the ionization flash magnitude and duration. The duration of the pulse amplification or the damping is consistently shorter for larger conductivity variations and can be used to evaluate the intensity of the flash ionization. Our work suggests that cyclotron emission could be probe signals for electrification processes inside BD atmosphere.

  17. Weak positive cloud-to-ground flashes in Northeastern Colorado

    Science.gov (United States)

    Lopez, Raul E.; Maier, Michael W.; Garcia-Miguel, Juan A.; Holle, Ronald L.

    1991-01-01

    The frequency distributions of the peak magnetic field associated with the first detected return stroke of positive and negative cloud-to-ground (CG) flashes were studied using lightning data from northeastern Colorado. These data were obtained during 1985 with a medium-to-high gain network of three direction finders (DF's). The median signal strength of positive flashes was almost two times that of the negatives for flashes within 300 km of the DF's, which have an inherent detection-threshold bias that tends to discriminate against weak signals. This bias increases with range, and affects the detection of positive and negative flashes in different ways, because of the differing character of their distributions. Positive flashes appear to have a large percentage of signals clustered around very weak values that are lost to the medium-to-high gain Colorado Detection System very quickly with increasing range. The resulting median for positive signals could thus appear to be much larger than the median for negative signals, which are more clustered around intermediate values. When only flashes very close to the DF's are considered, however, the two distributions have almost identical medians. The large percentage of weak positive signals detected close to the DF's has not been explored previously. They have been suggested to come from intracloud discharges and thus are improperly classified as CG flashes. Evidence in hand, points to their being real positive, albeit weak CG flashes. Whether or not they are real positive ground flashes, it is important to be aware of their presence in data from magnetic DF networks.

  18. Gamma ray flashes add to mystery of upper atmosphere

    Science.gov (United States)

    Atmospheric electricity research has come a long way since Benjamin Franklin's kite-flying days. But what researchers have been learning lately about above-thunderstorm electricity has wrought a whole new era of mysteries.For a start, last summer a Colorado meteorologist sparked interest in a terrestrial phenomenon that the community first observed more than 100 years ago: optical flashes that occur above thunderstorms—at least 30 km above Earth. Walter Lyons with the Ft. Collins-based Mission Research Corporation, demonstrated that such flashes are not anomalies, as conventional scientific wisdom had held. He filmed hundreds of flashes during a 2-week period.

  19. FLASH is an essential component of Cajal bodies.

    Science.gov (United States)

    Barcaroli, D; Dinsdale, D; Neale, M H; Bongiorno-Borbone, L; Ranalli, M; Munarriz, E; Sayan, A E; McWilliam, J M; Smith, T M; Fava, E; Knight, R A; Melino, G; De Laurenzi, V

    2006-10-03

    Cajal bodies are small nuclear organelles with a number of nuclear functions. Here we show that FLICE-associated huge protein (FLASH), originally described as a component of the apoptosis signaling pathway, is mainly localized in Cajal bodies and is essential for their structure. Reduction in FLASH expression by short hairpin RNA results in disruption of the normal architecture of the Cajal body and relocalization of its components. Because the function of FLASH in the apoptosis receptor signaling pathway has been strongly questioned, we have now identified a clear function for this protein.

  20. FLASH-OFDM-通信业的新宠

    Institute of Scientific and Technical Information of China (English)

    李勇民

    2008-01-01

    OFDM技术是宽带无线接(BWA)领域内的一种重要技术,本文从介绍OFDM原理入手,突出了它抗干扰能力强、频谱利用率高等特点,而FLASH-OFDM则是OFDM技术中的一种.之后进一步介绍了FLASH-OFDM技术的协议模型,对物理层、MAC/路层和网络层进行了详细的介绍,从而得到了FLASH-OFDM技术的优越性.

  1. Heavy rainfall induced flash flood management

    Science.gov (United States)

    Weiler, Markus; Steinbrich, Andreas; Stölzle, Michael; Leistert, Hannes

    2016-04-01

    Heavy rain induced flash floods are still a serious hazard. In context of climate change even a rise of threat potential of flash flood must be suspected. To improve prediction of endangered areas hydraulic models was developed in the past that implement topography information in heigh resolution, gathered by laser scan applications. To run such models it is crucial to estimate the runoff input spatial distributed. However, this information is usually derived with relatively simple models lacking the process rigour that is required for prediction in engaged basins. Though available rain runoff models are able to model runoff response integral for measured catchments they do not indicate the spatial distribution of processes. Moreover they are commonly calibrated to measured runoff data and not applicable in other environments. Since runoff generation is commonly not measured, a calibration on it is hardly possible. In this study, we present a new approach for quantification of runoff generation in height spatial and temporal resolution. A suited model needs to work without calibration in every given environment under any given conditions. It is possible to develop such a model by combining spatial distributed input data of land surface properties (e.g. soil, geology, land use, …) with worldwide findings of runoff generation research. We developed such a model for the state of Baden-Württemberg, what has an extensive pool of spatial data. E.g. a digital elevation model of 1*1m² resolution, degree of sealing of the earth surface in 1*1m² resolution, soil properties (1:50.000) and geology (1:200.000). Within the state of Baden-Württemberg different regions are situated, with distinct environmental characteristics concerning as well climate, soil properties, land use, topography and geology. The model was tested and validated by modelling 36 observed flood events in 13 mesoscale catchments representing the different regions of Baden-Württemberg as well as by

  2. Robust Flash 3D-FPA Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business, which has developed a compact, eye-safe 3D Flash LIDARTM Camera (FLC) well suited for real-time...

  3. Flash3D EDL Sensor Technology Advancement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — 3D Flash LIDAR is ideal for determining real-time spacecraft trajectory, speed, orientation, and range to the planet surface, as well as evaluating potential hazards...

  4. Flash 3D Rendezvous and Docking Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — 3D Flash Ladar is a breakthrough technology for many emerging and existing 3D vision areas, and sensor improvements will have an impact on nearly all these fields....

  5. Space Qualified, Radiation Hardened, Dense Monolithic Flash Memory Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Micro proposes to build a radiation hardened by design (RHBD) flash memory, using a modified version of our RH-eDRAM Memory Controller to solve all the single...

  6. The Essential Guide to 3D in Flash

    CERN Document Server

    Olsson, Ronald A

    2010-01-01

    If you are an ActionScript developer or designer and you would like to work with 3D in Flash, this book is for you. You will learn the core Flash 3D concepts, using the open source Away3D engine as a primary tool. Once you have mastered these skills, you will be able to realize the possibilities that the available Flash 3D engines, languages, and technologies have to offer you with Flash and 3D.* Describes 3D concepts in theory and their implementation using Away3D* Dives right in to show readers how to quickly create an interactive, animated 3D scene, and builds on that experience throughout

  7. Photosynthetic efficiency of Chlamydomonas reinhardtii in flashing light

    NARCIS (Netherlands)

    Vejrazka, C.; Janssen, M.G.J.; Streefland, M.; Wijffels, R.H.

    2011-01-01

    Efficient light to biomass conversion in photobioreactors is crucial for economically feasible microalgae production processes. It has been suggested that photosynthesis is enhanced in short light path photobioreactors by mixing-induced flashing light regimes. In this study, photosynthetic efficienc

  8. Quantitative observation of light flash sensations experiment MA-106

    Science.gov (United States)

    Budinger, T. F.; Tobias, C. A.; Schopper, E.; Schott, J. U.; Huesman, R. H.; Upham, F. T.; Wieskamp, T. F.; Kucala, J. M.; Goulding, F. S.; Landis, D. A.

    1976-01-01

    Light flashes caused by the interaction of cosmic particles with the visual apparatus have been observed by astronauts on all space missions since Apollo 11. This Apollo Soyuz Test Project experiment compared measurements of the observer's visual sensitivity with measurements of the ambient radiation environment and with the frequency and character of the flashes observed. The data obtained reveal a latitude dependence of the frequency of observed flashes. This distribution of flashes is correlated with the distribution of cosmic particles with stopping power greater than 15 keV/ micrometers in the eye. The interaction of dark adaptation, specific ionization, and range of particles in the retina as factors in the visualization of particle passage is discussed.

  9. Flash Cracking Reactor for Waste Plastic Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design, model, build, and test a novel flash cracking reactor to convert plastic waste, and potentially other unconventional hydrocarbon feedstocks,...

  10. Impact of rainfall spatial variability on Flash Flood Forecasting

    Science.gov (United States)

    Douinot, Audrey; Roux, Hélène; Garambois, Pierre-André; Larnier, Kevin

    2014-05-01

    According to the United States National Hazard Statistics database, flooding and flash flooding have caused the largest number of deaths of any weather-related phenomenon over the last 30 years (Flash Flood Guidance Improvement Team, 2003). Like the storms that cause them, flash floods are very variable and non-linear phenomena in time and space, with the result that understanding and anticipating flash flood genesis is far from straightforward. In the U.S., the Flash Flood Guidance (FFG) estimates the average number of inches of rainfall for given durations required to produce flash flooding in the indicated county. In Europe, flash flood often occurred on small catchments (approximately 100 km2) and it has been shown that the spatial variability of rainfall has a great impact on the catchment response (Le Lay and Saulnier, 2007). Therefore, in this study, based on the Flash flood Guidance method, rainfall spatial variability information is introduced in the threshold estimation. As for FFG, the threshold is the number of millimeters of rainfall required to produce a discharge higher than the discharge corresponding to the first level (yellow) warning of the French flood warning service (SCHAPI: Service Central d'Hydrométéorologie et d'Appui à la Prévision des Inondations). The indexes δ1 and δ2 of Zoccatelli et al. (2010), based on the spatial moments of catchment rainfall, are used to characterize the rainfall spatial distribution. Rainfall spatial variability impacts on warning threshold and on hydrological processes are then studied. The spatially distributed hydrological model MARINE (Roux et al., 2011), dedicated to flash flood prediction is forced with synthetic rainfall patterns of different spatial distributions. This allows the determination of a warning threshold diagram: knowing the spatial distribution of the rainfall forecast and therefore the 2 indexes δ1 and δ2, the threshold value is read on the diagram. A warning threshold diagram is

  11. Photosynthetic efficiency of Chlamydomonas reinhardtii in flashing light

    NARCIS (Netherlands)

    Vejrazka, C.; Janssen, M.G.J.; Streefland, M.; Wijffels, R.H.

    2011-01-01

    Efficient light to biomass conversion in photobioreactors is crucial for economically feasible microalgae production processes. It has been suggested that photosynthesis is enhanced in short light path photobioreactors by mixing-induced flashing light regimes. In this study, photosynthetic

  12. Distributed query processing in flash-based sensor networks

    Institute of Scientific and Technical Information of China (English)

    Jianliang XU; Xueyan TANG; Wang-Chien LEE

    2008-01-01

    Wireless sensor networks are used in a large array of applications to capture,collect,and analyze physical environmental data.Many existing sensor systems instruct sensor nodes to report their measurements to central repositories outside the network,which is expensive in energy cost.Recent technological advances in flash memory have given rise to the development of storagecentric sensor networks,where sensor nodes are equipped with high-capacity flash memory storage such that sensor data can b.e stored and managed inside the network to reduce expensive communication.This novel architecture calls for new data management techniques to fully exploit distributed in-network data storage.This paper describes some of our research on distributed query processing in such flash-based sensor networks.Of particular interests are the issues that arise in the design of storage management and indexing structures combining sensor system workload and read/write/erase characteristics of flash memory.

  13. 3D Flash LIDAR EDL Resolution Improvement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business, which has developed a compact, eye-safe 3D Flash LIDARTM Camera (FLC) well suited for real-time...

  14. 3D Flash LIDAR Real-Time Embedded Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — 3D Flash LIDAR (3DFL) is ideal for determining real-time spacecraft trajectory, speed and orientation to the planet surface, as well as evaluating potential hazards...

  15. Interim report on flash floods, Area 5 - Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    French, R.H.

    1980-09-01

    Examination of the presently available data indicates that consideration must be given to the possibility of flash floods when siting waste management facilities in Area 5 of the Nevada Test Site. 6 figures, 7 tables.

  16. Percepciones sobre seguridad ciudadana en Lima. Encuesta Flash

    OpenAIRE

    Zavaleta Martínez Vargas, Alfonso; Chávez, Virgilio; Tapia, Luis; Vertiz, Rosa

    2016-01-01

    La investigación presenta un aporte relacionado con "consumo de drogas cocaínicas, alcohol y violencia". Resultados de la encuesta flash "Seguridad Ciudadana" realizada por CEDRO en diciembre de 2015.

  17. 3D Flash LIDAR Real-Time Embedded Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) is a small business, which has developed a compact, eye-safe 3D Flash LIDARTM Camera (FLC) well suited for real-time...

  18. Dynamic simulation of flash drums using rigorous physical property calculations

    Directory of Open Access Journals (Sweden)

    F. M. Gonçalves

    2007-06-01

    Full Text Available The dynamics of flash drums is simulated using a formulation adequate for phase modeling with equations of state (EOS. The energy and mass balances are written as differential equations for the internal energy and the number of moles of each species. The algebraic equations of the model, solved at each time step, are those of a flash with specified internal energy, volume and mole numbers (UVN flash. A new aspect of our dynamic simulations is the use of direct iterations in phase volumes (instead of pressure for solving the algebraic equations. It was also found that an iterative procedure previously suggested in the literature for UVN flashes becomes unreliable close to phase boundaries and a new alternative is proposed. Another unusual aspect of this work is that the model expressions, including the physical properties and their analytical derivatives, were quickly implemented using computer algebra.

  19. Modeling Flash Floods in Small Ungaged Watersheds using Embedded GIS

    OpenAIRE

    Knocke, Ethan William

    2006-01-01

    Effective prediction of localized flash flood regions for an approaching rainfall event requires an in-depth knowledge of the land surface and stream characteristics of the forecast area. Flash Flood Guidance (FFG) is currently formulated once or twice a day at the county level by River Forecast Centers (RFC) in the U.S. using modeling systems that contain coarse, generalized land and stream characteristics and hydrologic runoff techniques that often are not calibrated for the forecast regio...

  20. Tutorial Pengenalan Adobe Photoshop Menggunakan Adobe Flash CS3

    OpenAIRE

    Mayoka, Rio

    2011-01-01

    Kajian ini bertujuan untuk membangun sebuah aplikasi yang dapat menjadi alat bantu dalam pembelajaran Adobe Photoshop, dimana terdapat beberapa materi pengenalan dasar Adobe Photoshop. Aplikasi ini suatu gagasan dengan membuat tutorial beranimasi yang interatif. Aplikasi ini dibuat dengan menggunakan Adobe Flash CS3 dan dapat dijalankan dengan Flash player. Aplikasi ini dapat membantu para penggunanya dalam memahami pengenalan Adobe Photoshop, terutama pengenalan tool pada Adob...

  1. Neural Coding of Green Flash in Retinal Bipolar Pathways

    OpenAIRE

    Caiping Hu

    2012-01-01

    What visual information do the graded potentials among retinal bipolar pathways actually transmit from photoreceptors to ganglion cells? The answer does not exist. Even the graded electric signals have not been understood completely. Here, this paper tries to analyze the encoding mechanisms of graded signals among the parallel bipolar pathways in response to brief green flash. The typical ON, OFF and ON-OFF bipolar cells simultaneously abstracted vectors from green flash stimulus with sine-li...

  2. Flash (Ultra-Rapid) Spark-Plasma Sintering of Silicon Carbide

    OpenAIRE

    Eugene A. Olevsky; Stephen M. Rolfing; Maximenko, Andrey L.

    2016-01-01

    A new ultra-rapid process of flash spark plasma sintering is developed. The idea of flash spark plasma sintering (or flash hot pressing - FHP) stems from the conducted theoretical analysis of the role of thermal runaway phenomena for material processing by flash sintering. The major purpose of the present study is to theoretically analyze the thermal runaway nature of flash sintering and to experimentally address the challenge of uncontrollable thermal conditions by the stabilization of the f...

  3. Coherence measurements and coherent diffractive imaging at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Vartanyants, I A; Mancuso, A P; Singer, A; Yefanov, O M; Gulden, J, E-mail: ivan.vartaniants@desy.d [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany)

    2010-10-14

    We present an overview of recent experiments performed at the free-electron laser (FEL) FLASH at DESY in Hamburg. Experiments were focused on coherence measurements and coherent x-ray diffractive imaging (CXDI) of periodic and non-periodic biological samples. Young's double slit experiment was performed at FLASH to measure its coherence properties at a fundamental wavelength of 13.7 nm. Additionally, a uniformly redundant array was used to measure the coherence properties of the third harmonic (2.7 nm) of an 8 nm fundamental wavelength at FLASH. Coherent imaging of a two-dimensional (2D) finite crystal structure using a single pulse train of FLASH radiation was demonstrated. We show that the structure is reconstructed to the detector-limited resolution of 220 nm, given an adequate signal to noise ratio. We have also employed CXDI in a non-destructive regime to compare the images of a biological sample using single, femtosecond pulses of FLASH radiation. We have verified that images reconstructed using CXDI are similar for statistically different FEL pulses. We have also demonstrated Fourier transform holography of the same biological sample and present diffraction data measured at the third harmonic of FLASH, reaching into the water window.

  4. Flash floods in the Tatra Mountain streams: frequency and triggers.

    Science.gov (United States)

    Ballesteros-Cánovas, J A; Czajka, B; Janecka, K; Lempa, M; Kaczka, R J; Stoffel, M

    2015-04-01

    Flash floods represent a frequently recurring natural phenomenon in the Tatra Mountains. On the northern slopes of the mountain chain, located in Poland, ongoing and expected future changes in climate are thought to further increase the adverse impacts of flash floods. Despite the repeat occurrence of major floods in the densely populated foothills of the Polish Tatras, the headwaters have been characterized by a surprising lack of data, such that any analysis of process variability or hydrometeorological triggers has been largely hampered so far. In this study, dendrogeomorphic techniques have been employed in four poorly-gauged torrential streams of the northern slope of the Tatra Mountains to reconstruct temporal and spatial patterns of past events. Using more than 1100 increment cores of trees injured by past flash floods, we reconstruct 47 events covering the last 148 years and discuss synoptic situations leading to the triggering of flash floods with the existing meteorological and flow gauge data. Tree-ring analyses have allowed highlighting the seasonality of events, providing new insights about potential hydrometeorological triggers as well as a differentiating flash flood activity between catchments. Results of this study could be useful to design future strategies to deal with flash flood risks at the foothills of the Polish Tatras and in the Vistula River catchment.

  5. Establishment of the NIST flashing-light photometric unit

    Science.gov (United States)

    Ohno, Yoshihiro; Zong, Yuqin

    1997-09-01

    There is a need for accurate measurement of flashing lights for the proper maintenance of aircraft anticollision lights. A large variation in the measured intensities of anticollision lights has been a problem, and thus, NIST has undertaken the task to establish flashing-light photometric standards to provide calibration services in this area. A flashing-light photometric unit [lux second, (lx (DOT) s)] has been realized based on the NIST detector-based candela, using four standard photometers equipped with current integrators. Two different approaches have been taken to calibrate these standard photometers: one based on electrical calibration of the current integrator, and the other based on electronic pulsing of a steady-state photometric standard. The units realized using these two independent methods agreed to within 0.2%. The relative expanded uncertainty (k equals 2) of the standard photometers, in the measurement of the white xenon flash, is estimated to be 0.6%. The standard photometers are characterized for temporal response, linearity, and spectral responsivity, to be used for measurement of xenon flash sources of various waveforms and colors. Calibration services have been established at NIST for flashing-light photometers with white and red anticollision lights.

  6. Flash light sintering of nickel nanoparticles for printed electronics

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung-Hyeon [School of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Hak-Sung, E-mail: kima@hanyang.ac.kr [School of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul 133-79 (Korea, Republic of)

    2014-01-01

    In this paper, a sintering process for nickel nanoparticles using flash light irradiation was investigated for multilayer ceramic capacitors, magnetic devices and printed electronics. The existence of a small amount of 10 nm size nanoparticles in the ink significantly improved the flash light absorption and induced the melting and sintering of the nanoparticles. Due to this phenomenon, uniform diameter nickel nanoparticles (50 nm) could not be sintered, while the nickel nanoparticles with varying diameters (5–500 nm) were sintered by flash light irradiation. In order to acquire high electrical conductivity in the sintered nickel nanoparticles, several flash light sintering parameters such as light energy and pulsed light patterns were optimized. Also, the nickel nano-ink was optimized by changing the weight fractions of organic binder in the ink. - Highlights: • Nickel nanoparticle was sintered by flash light irradiation technique. • The existence of 10 nm size nanoparticles improved the flash light absorption. • The melting temperature of the 10 nm size nanoparticles is significantly decreased. • The only nickel nanoparticles with varying diameters (5–500 nm) were sintered. • Several sintering parameters were optimized for conductivity of nickel nanoparticle.

  7. Production of bio-oil with flash pyrolysis; Biooeljyn tuotanto flash-pyrolyysillae ja sen poltto

    Energy Technology Data Exchange (ETDEWEB)

    Nyroenen, T. [Vapo Oy, Jyvaeskylae (Finland)

    1997-12-01

    The target of the R and D work is to study the production of bio-oils using Flash-pyrolysis technology and utilisation of the bio-oil in oil-fuelled boilers. The PDU-unit was installed at VTT Energy in Otaniemi in April 1996. The first test were carried out in June. In the whole project Vapo Oy is responsible for: acquiring the 20 kg/h PDU-device for development; follow up of the engine tests; the investment of 5 MW demonstration plant; to carry on the boiler and engine tests with Finnish bio-oils. (orig.)

  8. Flash lidar performance testing: configuration and results

    Science.gov (United States)

    Poberezhskiy, Ilya; Johnson, Andrew; Chang, Daniel; Ek, Eric; Natzic, David; Spiers, Gary; Penniman, Steve; Short, Brad

    2012-06-01

    Future planetary and lunar landers can benefit from a hazard detection (HD) system that employs a lidar to create a highresolution 3D terrain map in the vicinity of the landing site and an onboard computer to process the lidar data and identify the safest landing site within the surveyed area. A divert maneuver would then be executed to land in this safe site. An HD system enables landing in regions with a relatively high hazard abundance that would otherwise be considered unacceptably risky, but are of high interest to the scientific community. A key component of a HD system is a lidar with the ability to generate a 3D terrain image with the required range precision in the prescribed time and fits within the project resource constraints. In this paper, we present the results obtained during performance testing of a prototype "GoldenEye" 3D flash lidar developed by ASC, Inc. The testing was performed at JPL with the lidar and the targets separated by 200 m. The analysis of the lidar performance obtained for different target types and albedos, pulse energies, and fields of view is presented and compared to key HD lidar requirements identified for the Mars 2018 lander.

  9. Studying white dwarf merger remnants with FLASH

    Science.gov (United States)

    Jenks, Malia

    2017-01-01

    There is still uncertainty as to the progenitor systems of type Ia supernova (SN Ia). Both single and double degenerate systems have been suggested as progenitors. In a double degenerate system a merger between the two white dwarfs, with total mass at or exceeding the Chandrasekhar mass, leads to the supernova. If the explosion occurs during the merging process it is a violent merger. If an explosion doesn't occur while the stars merge the system becomes a white dwarf of unstable mass. For mergers of this type with differing starting masses it has been shown that during the viscous evolution carbon burning starts far from the center and stably converts the star to oxygen and neon. In this case the star will eventually collapse to a neutron star and not produce an SN Ia. The case of similar mass mergers has been much less explored. Using the results of a smooth particle hydrodynamic merger we simulate the viscous evolution of models of different mass ratios with FLASH. These simulations test if a similar mass merger can lead to an SN Ia, and begin to probe where the transition from similar to dissimilar mass occurs.

  10. Flash pyrolysis fuel oil: bio-pok

    Energy Technology Data Exchange (ETDEWEB)

    Gust, S. [Neste Oy, Porvoo (Finland)

    1997-12-01

    Samples of flash pyrolysis liquid produced by Union Fenosa, Spain from pine and straw and samples produced by Ensyn of Canada from mixed hardwoods were combusted with simple pressure atomization equipment commonly used with light fuel oils in intermediate size (0.1-1 MW) boilers. With a number of modifications to the combustion system, carbon monoxide (CO) and nitrous oxide (NO{sub x}) could be reduced to acceptable levels: CO < 30 ppm and NO{sub x} < 140 ppm. Particulate emissions which were initially very high (Bacharach 4-5) were reduced (Bach. 2-3) by system improvements but are still higher than from light fuel oil (Bach. <1). The modifications to the combustion system were: refractory section between burner and boiler, acid resistant progressive cavity pump, higher liquid preheat temperature and higher pressure than for light fuel oils. The main problems with pyrolysis liquids concerns their instability or reactivity. At temperatures above 100 deg C they begin to coke, their viscosity increases during storage and oxygen from air causes skin formation. This requires that special handling procedures are developed for fuel storage, delivery and combustion systems. (orig.)

  11. "Know What to Do If You Encounter a Flash Flood": Mental Models Analysis for Improving Flash Flood Risk Communication and Public Decision Making.

    Science.gov (United States)

    Lazrus, Heather; Morss, Rebecca E; Demuth, Julie L; Lazo, Jeffrey K; Bostrom, Ann

    2016-02-01

    Understanding how people view flash flood risks can help improve risk communication, ultimately improving outcomes. This article analyzes data from 26 mental models interviews about flash floods with members of the public in Boulder, Colorado, to understand their perspectives on flash flood risks and mitigation. The analysis includes a comparison between public and professional perspectives by referencing a companion mental models study of Boulder-area professionals. A mental models approach can help to diagnose what people already know about flash flood risks and responses, as well as any critical gaps in their knowledge that might be addressed through improved risk communication. A few public interviewees mentioned most of the key concepts discussed by professionals as important for flash flood warning decision making. However, most interviewees exhibited some incomplete understandings and misconceptions about aspects of flash flood development and exposure, effects, or mitigation that may lead to ineffective warning decisions when a flash flood threatens. These include important misunderstandings about the rapid evolution of flash floods, the speed of water in flash floods, the locations and times that pose the greatest flash flood risk in Boulder, the value of situational awareness and environmental cues, and the most appropriate responses when a flash flood threatens. The findings point to recommendations for ways to improve risk communication, over the long term and when an event threatens, to help people quickly recognize and understand threats, obtain needed information, and make informed decisions in complex, rapidly evolving extreme weather events such as flash floods.

  12. Post-event analysis and flash flood hydrology in Slovakia

    Directory of Open Access Journals (Sweden)

    Hlavčová Kamila

    2016-12-01

    Full Text Available This work examines the main features of the flash flood regime in Central Europe as revealed by an analysis of flash floods that have occurred in Slovakia. The work is organized into the following two parts: The first part focuses on estimating the rainfall-runoff relationships for 3 major flash flood events, which were among the most severe events since 1998 and caused a loss of lives and a large amount of damage. The selected flash floods occurred on the 20th of July, 1998, in the Malá Svinka and Dubovický Creek basins; the 24th of July, 2001, at Štrbský Creek; and the 19th of June, 2004, at Turniansky Creek. The analysis aims to assess the flash flood peaks and rainfall-runoff properties by combining post-flood surveys and the application of hydrological and hydraulic post-event analyses. Next, a spatially-distributed hydrological model based on the availability of the raster information of the landscape’s topography, soil and vegetation properties, and rainfall data was used to simulate the runoff. The results from the application of the distributed hydrological model were used to analyse the consistency of the surveyed peak discharges with respect to the estimated rainfall properties and drainage basins. In the second part these data were combined with observations from flash flood events which were observed during the last 100 years and are focused on an analysis of the relationship between the flood peaks and the catchment area. The envelope curve was shown to exhibit a more pronounced decrease with the catchment size with respect to other flash flood relationships found in the Mediterranean region. The differences between the two relationships mainly reflect changes in the coverage of the storm sizes and hydrological characteristics between the two regions.

  13. Atmospheric Rivers, Floods, and Flash Floods in California

    Science.gov (United States)

    Skelly, Klint T.

    Atmospheric Rivers (ARs) are long (>2000 km), narrow (<1000 km) corridors of enhanced vertically integrated water vapor (IWV) and enhanced IWV transport (IVT). The landfall of ARs along the U.S. West Coast have been linked to extreme precipitation and flooding/flash flooding in regions of complex topography. The objective of this study is to investigate the relationship between a 10 water-year (2005-2014) climatology of floods, flash floods, and landfalling ARs. The ARs in this study are defined using IVT following the Rutz et al. (2013) methodology, whereas floods and flash floods are identified by the National Centers for Environmental Information (NCEI) Storm Events Database. The results of this study indicate that landfalling ARs are present on a majority of days that there are floods in northern California. Landfalling ARs are predominantly present on a majority of days that there are flash flood reports during the cold-season (November-March); however, the North American monsoon is present on days that there are flash flood reports during the warm-season (April-October). Two exemplary case studies are provided to illustrate the hydrologic impact of landfalling ARs. The first case study illustrated a flood event that occurred in associated with three landfalling ARs that produced 800 mm in regions over the Russian River watershed in northern California and the second case study illustrated a flash flood event that occurred in association with a landfalling AR that produced ˜225 mm of precipitation in regions over the Santa Ynez xii watershed in which produced a flash flood over the southern portions of Santa Barbara County in southern California.

  14. Central Flash Analysis of the 29 June 2015 Occultation

    Science.gov (United States)

    Person, Michael J.; Bosh, A. S.; Sickafoose, A. A.; Zuluaga, C. A.; Levine, S. E.; Pasachoff, J. M.; Babcock, B. A.; Dunham, E. W.; McLean, I.; Wolf, J.; Abe, F.; Becklin, E.; Bida, T. A.; Bright, L. P.; Brothers, T. C.; Christie, G.; Collins, P. L.; Durst, R. F.; Gilmore, A. C.; Hamilton, R.; Harris, H. C.; Johnson, C.; Kilmartin, P. M.; Kosiarek, M. R.; Leppik, K.; Logsdon, S. E.; Lucas, R.; Mathers, S.; Morley, C. J. K.; Natusch, T.; Nelson, P.; Ngan, H.; Pfueller, E.; Roeser, H.-P.; Sallum, S.; Savage, M.; Seeger, C. H.; Siu, H.; Stockdale, C.; Suzuki, D.; Thanathibodee, T.; Tilleman, T.; Tristram, P. J.; Van Cleeve, J.; Varughese, C.; Weisenbach, L. W.; Widen, E.; Wiedemann, M.

    2015-11-01

    After an extensive prediction effort, the 29 June 2015 occultation by Pluto was observed from both airborne (Stratospheric Observatory for Infrared Astronomy - SOFIA) and numerous ground-based telescopes (Bosh et al. - this meeting). Real-time prediction updates allowed placement of the SOFIA telescope with its four detectors deep within the central-flash region of the atmospheric occultation. Fortuitously, the Mount John University Observatory (Lake Tekapo, New Zealand) was also within the central-flash region (Pasachoff et al. - this meeting). This happenstance resulted in multiple central-flash detections in several colors from each facility allowing direct comparison of different areas of the central-flash evolute.Here we examine and discuss the central-flash signatures from the highest signal-to-noise light curves from each facility. The relative orientations and asymmetries in the central flashes allow us to use them to tightly constrain the lower atmospheric ellipticity and orientation of likely winds with respect to Pluto’s figure. The ratio of the two separate central flashes is also a strong constraint on the geometric solution for the full occultation data set, and the absolute height of the central flashes with respect to those expected for a clear isothermal atmosphere places constraints on haze densities and thermal gradients in Pluto’s lower atmosphere. We can also compare the central-flash signatures in several colors (similar to Sickafoose et. al - this meeting) to establish bounds on haze-particle sizes in the lower atmosphere.SOFIA is jointly operated by the Universities Space Research Association, Inc. (USRA), under NASA contract NAS2-97001, and the Deutsches SOFIA Institut (DSI) under DLR contract 50 OK 0901 to the University of Stuttgart. Support for this work was provided, in part, by NASA grants SSO NNX15AJ82G (Lowell Observatory), PA NNX10AB27G (MIT), and PA NNX12AJ29G (Williams College), as well as the National Research Foundation of

  15. Multi-Level Bitmap Indexes for Flash Memory Storage

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kesheng; Madduri, Kamesh; Canon, Shane

    2010-07-23

    Due to their low access latency, high read speed, and power-efficient operation, flash memory storage devices are rapidly emerging as an attractive alternative to traditional magnetic storage devices. However, tests show that the most efficient indexing methods are not able to take advantage of the flash memory storage devices. In this paper, we present a set of multi-level bitmap indexes that can effectively take advantage of flash storage devices. These indexing methods use coarsely binned indexes to answer queries approximately, and then use finely binned indexes to refine the answers. Our new methods read significantly lower volumes of data at the expense of an increased disk access count, thus taking full advantage of the improved read speed and low access latency of flash devices. To demonstrate the advantage of these new indexes, we measure their performance on a number of storage systems using a standard data warehousing benchmark called the Set Query Benchmark. We observe that multi-level strategies on flash drives are up to 3 times faster than traditional indexing strategies on magnetic disk drives.

  16. An Evaluation of Flash Cells Used in Critical Applications

    Science.gov (United States)

    Katz, Richard B.; Flowers, David; Bergevin, Keith

    2016-01-01

    Due to the common use of Flash technology in many commercial and industrial Programmable Logic Devices (PLDs) such as FPGAs and mixed-signal microcontrollers, flash technology is being utilized in fuzed munition applications. This presents a long-term reliability issue for both DoD and NASA safety- and mission-critical applications. A thorough understanding of the data retention failure modes and statistics associated with Flash data retention is of vital concern to the fuze safety community. A key retention parameter for a flash cell is the threshold voltage (VTH), which is an indirect indicator of the amount of charge stored on the cells floating gate. Initial test results based on a study of charge loss in flash cells in an FPGA device is presented. Statistical data taken from a small sample set indicates quantifiable charge loss for devices stored at both room temperature and 150 C. Initial evaluation of the distribution of threshold voltage in a large sample set (800 devices) is presented. The magnitude of charge loss from exposure to electrostatic discharge and electromagnetic fields is measured and presented. Simulated data (and measured data as available) resultant from harsh-environment testing (neutron, heavy ion, EMP) is presented.

  17. Venlafaxine and desvenlafaxine in the management of menopausal hot flashes

    Directory of Open Access Journals (Sweden)

    Johnson ED

    2011-09-01

    Full Text Available Vasomotor flushes are common complaints of women during and after menopause, affecting about 75 percent of this population. Estrogen therapy is the most effective treatment for hot flashes. However, there are a significant number of women who have contraindications or choose not to use estrogen due to potential risks such as breast cancer and thromboembolic disorders. These women need alternative options. The selective norepinephrine reuptake inhibitors, venlafaxine and desvenlafaxine, have shown efficacy in alleviating hot flashes.Objective: The purpose of this review is to assess the efficacy and tolerability of these two agents for treatment of hot flashes in healthy postmenopausal women.Methods: A literature search of the MEDLINE and Ovid databases from inception to June 2011 was conducted. Randomized controlled trials, published in English, with human participants were included. Studies included postmenopausal women, and trials with breast cancer only populations were excluded.Results: Venlafaxine reduced hot flashes by 37 to 61 percent and desvenlafaxine by 55 to 69 percent. Both agents were well tolerated. The most common adverse effects were headache, dry mouth, nausea, insomnia, somnolence, and dizziness.Conclusion: Based on the evidence, venlafaxine and desvenlafaxine are both viable options for reducing the frequency and severity of hot flashes.

  18. Multi-Level Bitmap Indexes for Flash Memory Storage

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kesheng; Madduri, Kamesh; Canon, Shane

    2010-07-23

    Due to their low access latency, high read speed, and power-efficient operation, flash memory storage devices are rapidly emerging as an attractive alternative to traditional magnetic storage devices. However, tests show that the most efficient indexing methods are not able to take advantage of the flash memory storage devices. In this paper, we present a set of multi-level bitmap indexes that can effectively take advantage of flash storage devices. These indexing methods use coarsely binned indexes to answer queries approximately, and then use finely binned indexes to refine the answers. Our new methods read significantly lower volumes of data at the expense of an increased disk access count, thus taking full advantage of the improved read speed and low access latency of flash devices. To demonstrate the advantage of these new indexes, we measure their performance on a number of storage systems using a standard data warehousing benchmark called the Set Query Benchmark. We observe that multi-level strategies on flash drives are up to 3 times faster than traditional indexing strategies on magnetic disk drives.

  19. X-ray flashes in ROSAT PSPC data

    Energy Technology Data Exchange (ETDEWEB)

    Sun, X.; Li, H.; Fenimore, E.E. [Los Alamos National Lab., NM (United States); Wang, Q.D. [Northwestern Univ., Evanston, IL (United States)

    1998-12-01

    The authors find 24 short (200--2,500s) X-ray flashes from all the ROSAT Position Sensitive Proportional Counter (PSPC) observations above galactic latitude 30 degrees ({approximately} 9.6 Msec) and some observations toward low latitudes ({approximately} 2.4 Msec). The brightest flash is quite extraordinary. Its flux rises from nondetection by a factor of > 200 in less than 100 sec. Its spectrum can be fitted either by a thermal plasma model with kT {ge} 2.4 keV, or by a single power-law with the photon number index of {approx} {minus}1.7. Photon statistics are not sufficient to obtain spectra for other flashes. The flash event fields can vary from optically crowded regions to blank fields. Although eight flashes are found from observations from nearby galaxies, and three of them are within the optical extent of their corresponding galaxies, they could not statistically establish that there are two different populations between nearby galaxies and control fields.

  20. Flash on disk for low-power multimedia computing

    Science.gov (United States)

    Singleton, Leo; Nathuji, Ripal; Schwan, Karsten

    2007-01-01

    Mobile multimedia computers require large amounts of data storage, yet must consume low power in order to prolong battery life. Solid-state storage offers low power consumption, but its capacity is an order of magnitude smaller than the hard disks needed for high-resolution photos and digital video. In order to create a device with the space of a hard drive, yet the low power consumption of solid-state storage, hardware manufacturers have proposed using flash memory as a write buffer on mobile systems. This paper evaluates the power savings of such an approach and also considers other possible flash allocation algorithms, using both hardware- and software-level flash management. Its contributions also include a set of typical multimedia-rich workloads for mobile systems and power models based upon current disk and flash technology. Based on these workloads, we demonstrate an average power savings of 267 mW (53% of disk power) using hardware-only approaches. Next, we propose another algorithm, termed Energy-efficient Virtual Storage using Application-Level Framing (EVS-ALF), which uses both hardware and software for power management. By collecting information from the applications and using this metadata to perform intelligent flash allocation and prefetching, EVS-ALF achieves an average power savings of 307 mW (61%), another 8% improvement over hardware-only techniques.

  1. Environmental Effects on Data Retention in Flash Cells

    Science.gov (United States)

    Katz, Rich; Flowers, David; Bergevin, Keith

    2017-01-01

    Flash technology is being utilized in fuzed munition applications and, based on the development of digital logic devices in the commercial world, usage of flash technology will increase. Antifuse technology, prevalent in non-volatile field programmable gate arrays (FPGAs), will eventually be phased out as new devices have not been developed for approximately a decade. The reliance on flash technology presents a long-term reliability issue for both DoD and NASA safety- and mission-critical applications. A thorough understanding of the data retention failure modes and statistics associated with Flash data retention is of vital concern to the fuze safety community. A key retention parameter for a flash cell is the threshold voltage (VTH), which is an indirect indicator of the amount of charge stored on the cells floating gate. This paper will present the results of our on-going tests: long-term storage at 150 C for a small population of devices, neutron radiation exposure, electrostatic discharge (ESD) testing, and the trends of large populations (over 300 devices for each condition) exposed to three difference temperatures: 25 C, 125 C, and 150 C.

  2. Venlafaxine and desvenlafaxine in the management of menopausal hot flashes

    Science.gov (United States)

    Johnson, Emily D; Carroll, Dana G

    Vasomotor flushes are common complaints of women during and after menopause, affecting about 75 percent of this population. Estrogen therapy is the most effective treatment for hot flashes. However, there are a significant number of women who have contraindications or choose not to use estrogen due to potential risks such as breast cancer and thromboembolic disorders. These women need alternative options. The selective norepinephrine reuptake inhibitors, venlafaxine and desvenlafaxine, have shown efficacy in alleviating hot flashes. Objective The purpose of this review is to assess the efficacy and tolerability of these two agents for treatment of hot flashes in healthy postmenopausal women. Methods A literature search of the MEDLINE and Ovid databases from inception to June 2011 was conducted. Randomized controlled trials, published in English, with human participants were included. Studies included postmenopausal women, and trials with breast cancer only populations were excluded. Results Venlafaxine reduced hot flashes by 37 to 61 percent and desvenlafaxine by 55 to 69 percent. Both agents were well tolerated. The most common adverse effects were headache, dry mouth, nausea, insomnia, somnolence, and dizziness. Conclusions Based on the evidence, venlafaxine and desvenlafaxine are both viable options for reducing the frequency and severity of hot flashes. PMID:24367464

  3. Theoretical investigation of flash vaporisation in a screw expander

    Science.gov (United States)

    Vasuthevan, Hanushan; Brümmer, Andreas

    2017-08-01

    In the present study flash vaporisation of liquid injection in a twin screw expander for a Trilateral Flash Cycle (TFC) is examined theoretically. The TFC process comprises a pressure increase in the working fluid, followed by heating the liquid close to boiling point. The hot liquid is injected into the working chamber of a screw expander. During this process the pressure of the liquid drops below the saturation pressure, while the temperature of the liquid remains virtually constant. Hence the liquid is superheated and in a metastable state. The liquid jet seeks to achieve a stable state in thermodynamic equilibrium and is therefore partially vaporised. This effect is referred to as flash vaporisation. Accordingly, a two-phase mixture, consisting of vapour and liquid, exists in the working chamber. Thermodynamic simulations were carried out using water as the working fluid for representative screw expander geometry. The simulations presented are performed from two different aspects during the filling process of a screw expander. The first case is the vaporisation of the injected liquid in a state of thermodynamic equilibrium, whereby the two-phase mixture is treated entirely as a compressible and homogeneous gas. The second case considers flashing efficiency. It describes the quantity of flashed vapour and consists of a liquid and vapour domain. Both models are compared and analysed with respect to the operational behaviour of a screw expander.

  4. Desorption of deuterium from beryllium codeposits using flash heating

    Science.gov (United States)

    Yu, J. H.; Baldwin, M. J.; Doerner, R. P.; Pitts, R. A.; Smirnov, R. D.; Xu, H. W.

    2013-07-01

    As a result of safety concerns, limits will be placed on the allowable tritium inventory retained inside the ITER vacuum vessel. The primary motivation for the present work is to test the proposed method of removing tritium from main chamber codeposits using radiative heat flashing from controlled ITER plasma shutdowns. Detritiation of Be codeposits is studied in the PISCES-B facility using flash-heating by a 10 ms laser with up to 2 MJ/m2 of absorbed energy density. Three types of codeposits are flash-heated with layer thickness ranging from 0.1 to 1.2 μm. Less than 25% of the D in the Be layer escapes at ITER-relevant flash energy densities and with peak surface temperature up to ˜900 °C. Repetitive flashing with peak surface temperature of 400-500 °C results in an increased population of higher energy trap sites, implying that transient heating which causes appropriate surface temperature excursion redistributes D among codeposit trap sites.

  5. Design of NAND FLASH File System Based on Loss of Balance Algorithm

    Directory of Open Access Journals (Sweden)

    Jinwu Ju

    2011-02-01

    Full Text Available NAND FLASH is a commonly large capacity memory, which used in embedded systems .It often used to store the operating system kernel and file system. NAND FLASH memory has a limited number of block erase feature. Built file system in NAND FLASH, loss of balance method should be adopted. A balanced system of block erase operation, can extend the life of NAND FLASH and improve overall system reliability. The paper analyzes the characteristics of NAND FLASH work .presents a loss of balance algorithm which used in NAND FLASH memory , and given out the implementation of the algorithm design method.

  6. The Essential Guide to Flash CS4 with ActionScript

    CERN Document Server

    Milbourne, P

    2009-01-01

    For any professional designer or developer working in the world of web technologies or multimedia, Flash is the must-have application, and knowing how to use it effectively is vital. Add in ActionScript 3.0, and Flash becomes an even more powerful tool for the development of high-performance web applications. The Essential Guide to Flash CS4 with ActionScript introduces and explores the possibilities available to you through using Flash CS4. You will learn the aspects basics of Flash's working environment and, using a step-by-step approach, work through the features of Flash and ActionScript n

  7. Modular, Microprocessor-Controlled Flash Lighting System

    Science.gov (United States)

    Kiefer, Dwayne; Gray, Elizabeth; Skupinski, Robert; Stachowicz, Arthur; Birchenough, William

    2006-01-01

    A microprocessor-controlled lighting system generates brief, precisely timed, high-intensity flashes of light for scientific imaging at frame rates up to about 1 kHz. The system includes an array of light-emitting diodes (LEDs) that are driven in synchronism with an externally generated timing signal (for example, a timing signal generated by a video camera). The light output can be varied in peak intensity, pulse duration, pulse delay, and pulse rate, all depending on the timing signal and associated externally generated control signals. The array of LEDs comprises as many as 16 LED panels that can be attached together. Each LED panel is a module consisting of a rectangular subarray of 10 by 20 LEDs of advanced design on a printed-circuit board in a mounting frame with a power/control connector. The LED panels are controlled by an LED control module that contains an AC-to-DC power supply, a control board, and 8 LED-panel driver boards. In prior LED panels, the LEDs are packaged at less than maximum areal densities in bulky metal housings that reduce effective active areas. In contrast, in the present LED panels, the LEDs are packed at maximum areal density so as to afford 100-percent active area and so that when panels are joined side by side to form the array, there are no visible seams between them and the proportion of active area is still 100 percent. Each panel produces an illuminance of .5 x 10( exp 4) lux at a distance of 5.8 in. (approx.1.6 cm). The LEDs are driven according to a pulse-width-modulation control scheme that makes it safe to drive the LEDs beyond their rated steady-state currents in order to generate additional light during short periods. The drive current and the pulse-width modulation for each LED panel can be controlled independently of those of the other 15 panels. The maximum allowable duration of each pulse of drive current is a function of the amount of overdrive, the total time to be spent in overdrive operation, and the limitations

  8. Model of UV flashes due to gigantic blue jets

    Energy Technology Data Exchange (ETDEWEB)

    Milikh, G M [University of Maryland, College Park, MD, 20742 (United States); Shneider, M N [Princeton University, Princeton, NJ (United States)], E-mail: milikh@astro.umd.edu, E-mail: shneyder@princeton.edu

    2008-12-07

    Analysis of UV flashes observed by the UV detector on board the 'Tatiana' microsatellite suggests, based on their location, pulse width and energy of the source of the photons, that the flashes were generated by gigantic blue jets (GBJs). Presented in this paper is a numerical model of UV flashes due to a bunch of long streamers which form a leader, a prong such as that observed in a GBJ. Using a previously developed model of upward propagation of a long streamer in the exponential atmosphere the paper describes temporal evolution of the UV flux generated by a bunch of long streamers, in the given spectral range 300-400 nm used by the UV detector on board 'Tatiana'. The model is in agreement with the observations.0.

  9. Post-irradiation flashes and continuous emission from solid deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Forrest, J.A.; Brooks, R.L. [Guelph-Waterloo Program for Graduate Work in Physics, University of Guelph, Guelph, Ontario, N1G2W1 (CANADA)

    1997-01-01

    Optical emission from proton-beam-irradiated solid deuterium near 800 nm has been studied after termination of the proton beam. The continuous red emission shows a residual intensity that persists over 30 min from termination of the beam. Optical flashes can also be thermally triggered over 10 min after termination of irradiation. Such triggered flashes are shown to quench the infrared absorption of Stark-shifted charge-induced features. Ultraviolet photons can stimulate this red emission after termination of irradiation with no measurable decrease in intensity for 40 min. The cause of this continuous emission and optical flashes is discussed in the light of these results. {copyright} {ital 1997} {ital The American Physical Society}

  10. DERIVING FLASH FLOODS IN THE CASE OF SIMULATED PRECIPITATIONS

    Directory of Open Access Journals (Sweden)

    GYŐRI MARIA-MIHAELA

    2013-01-01

    Full Text Available Deriving flash floods in the case of simulated precipitations. The present study sets to determine the historical flash-floods on the Petriș watershed making use of the implemented mathematical models in a Hydrological Modeling System. In order to simulate the 1%, 2% and 10% exceedance probability flash-floods, the Intensity-Frequency-Duration (IDF curves have been built on the basis of 22 years of precipitation records (1988-2009. They serve as input data together with the hydrological parameters identified by the means of a Geographic Information Systems. The results, computed mainly on the basis of the Soil Conservation Service (SCS method, consist of hyetographs and hydrographs at the outlet of the main watershed, as well as to that of the ungauged tributaries of the Petriș River.

  11. X-ray Flashes from Off-axis Nonuniform Jets

    Institute of Scientific and Technical Information of China (English)

    Zhi-Ping Jin; Da-Ming Wei

    2004-01-01

    It has been widely believed that the outflows in gamma-ray bursts are jetted and some jets may have structures like ∈(θ) ∝θ-κ. We check the possibility that X-ray flashes come from such jets. Both qualitative and quantitative analyses have shown that this model can reproduce most of the observational features of both X-ray flashes and gamma-ray bursts. Using the usual parameters of gamma-ray bursts, we have carried out numerical calculations for both uniform and nonuniform jets, of their fluxes, spectra and peak energies. It seems that nonuniform jets are more appropriate to these observational properties than uniform jets. We have also shown that in our model the observational ratio of gamma-ray bursts to X-ray flashes is about a few units.

  12. Storage Management Strategy of Flash-Based Platform

    Institute of Scientific and Technical Information of China (English)

    WANG Taiyong; ZHAO Li; HU Shiguang; WANG Tao

    2009-01-01

    Storage management strategy can be expressed by a file system. Commercial file system for embedded application is generally complicated and resource wasted. In this paper, a specified file system adapted to embedded system with flash-based memory is developed. To guarantee the average usage of flash storage sectors, the strategy of wear leveling and adaptive damage management is introduced, in which a dynamic storage space management mode and the strategy of first in first out (FIFO) are adopted. Moreover, the strategy of redundancy design and fast-calculation and tracing is also adopted to extend the life of kernel sector, which can guarantee the reliable ser-vice of system booting. The practical application in an embedded CNC (computerized numerical control) platform proves that the file system has effective performance. Furthermore, the flash file system can be transplanted to dif-ferent embedded platforms by changing a few bottom hardware parameters with universality.

  13. A simple experiment that demonstrates the ``green flash''

    Science.gov (United States)

    Courtial, Johannes

    2012-11-01

    The green flash occurs when, under certain atmospheric conditions, the top segment of the low sun is visibly green. It is surrounded—in at least a few minds—by an air of mystery. I describe a simple experiment that demonstrates different aspects of the green flash. The experiment uses an odd-shaped, water-filled, fish tank to simulate the refractive properties of the atmosphere; milk powder added to the water mimicks the atmosphere's scattering properties. A circular white-light source is viewed through the fish tank and the combination of refraction and scattering makes one end of the light source look green. The setup also allows experimentation with mirage effects, thereby drawing attention to their often neglected contribution to the green flash.

  14. FlashCam: A fully digital camera for CTA telescopes

    CERN Document Server

    Pühlhofer, G; Biland, A; Florin, D; Föhr, C; Gadola, A; Hermann, G; Kalkuhl, C; Kasperek, J; Kihm, T; Koziol, J; Manalaysay, A; Marszalek, A; Rajda, P J; Schanz, T; Steiner, S; Straumann, U; Tenzer, C; Vogler, P; Vollhardt, A; Weitzel, Q; Winiarski, K; Zietara, K

    2012-01-01

    The future Cherenkov Telescope Array (CTA) will consist of several tens of telescopes of different mirror sizes. CTA will provide next generation sensitivity to very high energy photons from few tens of GeV to >100 TeV. Several focal plane instrumentation options are currently being evaluated inside the CTA consortium. In this paper, the current status of the FlashCam prototyping project is described. FlashCam is based on a fully digital camera readout concept and features a clean separation between photon detector plane and signal digitization/triggering electronics.

  15. Space and terrestrial radiation effects in flash memories

    Science.gov (United States)

    Bagatin, Marta; Gerardin, Simone; Paccagnella, Alessandro

    2017-03-01

    We present a comprehensive review of the effects of ionizing radiation on advanced flash memories. The effects of ionizing radiation as well as the mechanisms underlying the observed phenomena are thoroughly discussed on both floating gate cells and the complex control circuitry. The covered effects are relevant for all floating-gate based flash memories that require very high levels of reliability, from critical applications at the terrestrial level to radiation-harsh environments, such as space, nuclear power plants, and high-energy physics experiments.

  16. Mitochondrial Flashes: Dump Superoxide and Dance with Protons Now.

    Science.gov (United States)

    Demaurex, Nicolas; Schwarzländer, Markus

    2016-09-20

    Transient changes in the physiology of individual mitochondria have recently drawn much interest. The use of a circular permuted yellow fluorescent protein (cpYFP) to monitor mitochondrial flashes and their interpretation as superoxide bursts has added confusion, however. Reviewing mitochondrial flashes in this Forum, Wang et al. again deem cpYFP to be a specific and reversible superoxide indicator, dismissing evidence that purified cpYFP is insensitive to superoxide. This interpretation lacks reproducible evidence and conflicts with the parsimony principle. We offer a constructive, transparent pathway to reach definitive clarification of contradictory reports. Antioxid. Redox Signal. 25, 550-551.

  17. INVESTIGATION OF DIFFERENT MODELS OF COMBINED PARALLEL FLASH BINARY CYCLES

    OpenAIRE

    A. Jafar Yazdi*

    2017-01-01

    The aim of this paper is a comparative study of the different geothermal power plant concepts, based on the energy and exergy analysis. The cycles studied in this paper are the combination of single and double flash power plants with two different ORC cycles as basic Organic Rankine Cycle (ORC), ORC with IHE, regenerative ORC and regenerative ORC with an IHE. The main gain due to using combined flash-binary power plants with various types of ORCs is to achieve optimum and efficient energy uti...

  18. Development of Full Automatic Flash Butt Welding with Digital Control

    Institute of Scientific and Technical Information of China (English)

    WANG Rui; SUN Hexu; WANG Hongwen

    2006-01-01

    The hardware and software design of two digital control systems based on 80C196KB MCU for flash butt welder is introduced in this paper. The welding power supply is made of six-phase half-wave rectifier. The welding outer characteristic of welding machine is realized by digital PI algorithm with the voltage close-loop feedback. The flashing curve is finished by electric-hydraulic servo valve .The process control system transfers datum with power supply system by a serial communication interface. The parameters of the control systems are collected by photoelectrical seclusion to avoid the disturbing of the electromagnetism in welding process.

  19. Flash 3D Planetary Entry, Descent and Landing Sensor Hardening Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts Inc. (ASC) is a small business that has developed a number of 3D flash LADAR systems. Flash Ladar Video Cameras are 3D video cameras...

  20. Flash 3D Enhancements for Autonomous Precision Landing and Hazard Detection and Avoidance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) has developed a 128 x 128 frame, 3D Flash LADAR video camera which produces 3-D point clouds at 30 Hz. Flash Ladar Video...

  1. Development of a 3D Flash LADAR Video Camera for Entry, Decent, and Landing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) has developed a 128 x 128 frame, 3D Flash LADAR video camera which produces 3-D point clouds at 30 Hz. Flash LADAR captures...

  2. Development of a 3D Flash LADAR Video Camera for Entry, Decent and Landing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) has developed a 128 x 128 frame, 3D Flash LADAR video camera capable of a 30 Hz frame rate. Because Flash LADAR captures an...

  3. 46 CFR 113.25-10 - Emergency red-flashing lights.

    Science.gov (United States)

    2010-10-01

    ... heard over the background noise, there must be a red-flashing light or rotating beacon, in addition to... system. (b) A red-flashing light or rotating beacon must be installed so that it is visible in the...

  4. Development of PIN Diode Detector Arrays for 3D Flash LIDAR Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) has developed a number of 3D Flash LIDAR systems. Flash LIDAR sensors are 3D video systems that return range and intensity...

  5. Flash 3D Planetary Entry, Descent and Landing Sensor Hardening Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Scientific Concepts, Inc. (ASC) has developed a 128 x 128 frame, 3D Flash LADAR video camera which produces 3-D point clouds at 30 Hz. Flash Ladar Video...

  6. Audition influences color processing in the sound-induced visual flash illusion

    OpenAIRE

    Mishra, Jyoti; Martinez, Antigona; Hillyard, Steven A.

    2013-01-01

    Multisensory interactions can lead to illusory percepts, as exemplified by the sound-induced extra flash illusion (SIFI: Shams et al., 2000, 2002). In this illusion, an audio-visual stimulus sequence consisting of two pulsed sounds and a light flash presented within a 100 ms time window generates the visual percept of two flashes. Here, we used colored visual stimuli to investigate whether concurrent auditory stimuli can affect the perceived features of the illusory flash. Zero, one or two pu...

  7. Two Applications of Flash Dynamic Technology Based on Flash-Website%基于Flash-Website的两个Flash动态技术的应用

    Institute of Scientific and Technical Information of China (English)

    虞智辉

    2010-01-01

    随着Flash-Website技术的发展,Flash与网页的联系越来越紧密.因此,如何合理运用Flash技术为网站服务,就成了摆在网页制作者面前的一道实践题.从制作的实践出发,介绍2种Flash与网页技术相结合的制作技巧.

  8. Hot Flashes and Panic Attacks: A Comparison of Symptomatology, Neurobiology, Treatment, and a Role for Cognition

    Science.gov (United States)

    Hanisch, Laura J.; Hantsoo, Liisa; Freeman, Ellen W.; Sullivan, Gregory M.; Coyne, James C.

    2008-01-01

    Despite decades of research, the causal mechanisms of hot flashes are not adequately understood, and a biopsychosocial perspective on hot flashes remains underdeveloped. This article explores overlooked parallels between hot flashes and panic attacks within 5 areas: course and symptomatology, physiological indicators, neurocircuitry and…

  9. Effect of Escitalopram on Hot Flash Interference: A Randomized, Controlled Trial

    Science.gov (United States)

    Carpenter, Janet S.; Guthrie, Katherine A.; Larson, Joseph C.; Freeman, Ellen W.; Joffe, Hadine; Reed, Susan D.; Ensrud, Kristine E.; LaCroix, Andrea Z.

    2012-01-01

    Objectives To estimate the effect of escitalopram 10–20 mg/day versus placebo for reducing hot flash interference in daily life and understand correlates and predictors of reductions in hot flash interference, a key measure of quality of life. Design Multi-site, randomized, double-blind, placebo-controlled clinical trial. Patients 205 midlife women (46% African-American) who met criteria participated. Setting MsFLASH clinical sites in Boston, Indianapolis, Oakland, and Philadelphia. Intervention After baseline, women were randomized to 1 pill of escitalopram 10 mg/day (n=104) or placebo (n=101) with follow-up at 4- and 8-weeks. At week 4, those not achieving 50% fewer hot flashes were increased to 2 pills daily (20 mg/day or 2 placebo pills). Main outcome measures The Hot Flash Related Daily Interference Scale; Correlates were variables from hot flash diaries; Predictors were baseline demographics, clinical variables, depression, anxiety, sleep quality, and hot flashes. Results Compared to placebo, escitalopram significantly reduced hot flash interference by 6.0 points at week 4 and 3.4 points at week 8 more than placebo (p=0.012). Reductions in hot flash interference correlated with changes in hot flash diary variables. However, baseline variables did not significantly predict reductions in hot flash interference. Conclusions Escitalopram 10–20mg/day for 8 weeks improves women’s quality of life and this benefit did not vary by demographic, clinical, mood, sleep, or hot flash variables. PMID:22480818

  10. The Status of the Ultra Fast Flash Observatory - Pathfinder

    DEFF Research Database (Denmark)

    Nam, J. W.; Ahmad, S.; Ahn, K. B.

    2014-01-01

    The Ultra Fast Flash Observatory (UFFO) is a project to study early optical emissions from Gamma Ray Bursts (GRBs). The primary scientific goal of UFFO is to see if GRBs can be calibrated with their rising times, so that they could be used as new standard candles. In order to minimize delay in op...

  11. Measuring and Estimating Normalized Contrast in Infrared Flash Thermography

    Science.gov (United States)

    Koshti, Ajay M.

    2013-01-01

    Infrared flash thermography (IRFT) is used to detect void-like flaws in a test object. The IRFT technique involves heating up the part surface using a flash of flash lamps. The post-flash evolution of the part surface temperature is sensed by an IR camera in terms of pixel intensity of image pixels. The IR technique involves recording of the IR video image data and analysis of the data using the normalized pixel intensity and temperature contrast analysis method for characterization of void-like flaws for depth and width. This work introduces a new definition of the normalized IR pixel intensity contrast and normalized surface temperature contrast. A procedure is provided to compute the pixel intensity contrast from the camera pixel intensity evolution data. The pixel intensity contrast and the corresponding surface temperature contrast differ but are related. This work provides a method to estimate the temperature evolution and the normalized temperature contrast from the measured pixel intensity evolution data and some additional measurements during data acquisition.

  12. A comparison of radiometric calibration techniques for lunar impact flashes

    Science.gov (United States)

    Suggs, R. M.; Ehlert, S. R.; Moser, D. E.

    2017-09-01

    Video observations of lunar impact flashes have been made by a number of researchers since the late 1990's and the problem of determination of the impact energies has been approached in different ways Bellot Rubio et al. (2000a, b), Yanagisawa et al. (2008), Bouley et al. (2012), Suggs et al. (2014), Rembold and Ryan (2015), Ortiz et al. (2015), Madiedo et al. (2015). The wide spectral response of the unfiltered video cameras in use for all published measurements necessitates color correction for the standard filter magnitudes available for the comparison stars but this is not typically considered. In our approach, the published color of the comparison star and an estimate of the color of the impact flash is used to correct it to the chosen filter bandpass. Magnitudes corrected to standard filters are then used to determine the luminous energy in the filter bandpass according to the stellar atmosphere calibrations of Bessell et al. (1998). In this paper we compare the various photometric calibration techniques and calculation of luminous energy (radiometry) of impact flashes. This issue has significant implications for determination of luminous efficiency, predictions of impact crater sizes for observed flashes, and the determination of the flux of meteoroids in the 10 s of grams to kilograms mass range.

  13. Searching for neutrino radio flashes from the Moon with LOFAR

    NARCIS (Netherlands)

    Buitink, Stijn; Corstanje, Arthur; Enriquez, Emilio; Falcke, Heino; Frieswijk, Wilfred; Hörandel, Jörg; Mevius, Maaijke; Nelles, Anna; Thoudam, Satyendra; Schellart, Pim; Scholten, Olaf; ter Veen, Sander; van den Akker, Martin; LOFAR Collaboration, [No Value

    2013-01-01

    Ultra-high-energy neutrinos and cosmic rays produce short radio flashes through the Askaryan effect when they impact on the Moon. Earthbound radio telescopes can search the Lunar surface for these signals. A new generation of lowfrequency, digital radio arrays, spearheaded by LOFAR, will allow for s

  14. FLASH assembly of TALENs for high-throughput genome editing.

    Science.gov (United States)

    Reyon, Deepak; Tsai, Shengdar Q; Khayter, Cyd; Foden, Jennifer A; Sander, Jeffry D; Joung, J Keith

    2012-05-01

    Engineered transcription activator–like effector nucleases (TALENs) have shown promise as facile and broadly applicable genome editing tools. However, no publicly available high-throughput method for constructing TALENs has been published, and large-scale assessments of the success rate and targeting range of the technology remain lacking. Here we describe the fast ligation-based automatable solid-phase high-throughput (FLASH) system, a rapid and cost-effective method for large-scale assembly of TALENs. We tested 48 FLASH-assembled TALEN pairs in a human cell–based EGFP reporter system and found that all 48 possessed efficient gene-modification activities. We also used FLASH to assemble TALENs for 96 endogenous human genes implicated in cancer and/or epigenetic regulation and found that 84 pairs were able to efficiently introduce targeted alterations. Our results establish the robustness of TALEN technology and demonstrate that FLASH facilitates high-throughput genome editing at a scale not currently possible with other genome modification technologies.

  15. Data Acquisition System of FlashADC on GTAF Facility

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Qi-wei; HE; Guo-zhu; HUANG; Xing; RUAN; Xi-chao; ZHOU; Zu-ying; ZHU; Xing-hua

    2013-01-01

    The data acquisition system of GTAF facility bases on the digitizer of FlashADC(DC271A,made by Acqiris Technologies Inc.),which can achieve the acquisition of experimental data and real-time monitoring of on-line measure by the capture of digital full pulse waveform from 40 BaF2 detectors.Fig.1

  16. Novel approach for low-cost muzzle flash detection system

    Science.gov (United States)

    Voskoboinik, Asher

    2008-04-01

    A low-cost muzzle flash detection based on CMOS sensor technology is proposed. This low-cost technology makes it possible to detect various transient events with characteristic times between dozens of microseconds up to dozens of milliseconds while sophisticated algorithms successfully separate them from false alarms by utilizing differences in geometrical characteristics and/or temporal signatures. The proposed system consists of off-the-shelf smart CMOS cameras with built-in signal and image processing capabilities for pre-processing together with allocated memory for storing a buffer of images for further post-processing. Such a sensor does not require sending giant amounts of raw data to a real-time processing unit but provides all calculations in-situ where processing results are the output of the sensor. This patented CMOS muzzle flash detection concept exhibits high-performance detection capability with very low false-alarm rates. It was found that most false-alarms due to sun glints are from sources at distances of 500-700 meters from the sensor and can be distinguished by time examination techniques from muzzle flash signals. This will enable to eliminate up to 80% of falsealarms due to sun specular reflections in the battle field. Additional effort to distinguish sun glints from suspected muzzle flash signal is made by optimization of the spectral band in Near-IR region. The proposed system can be used for muzzle detection of small arms, missiles and rockets and other military applications.

  17. DEVELOPMENT OF PRINCIPLES OF DCNET AND FLASH ENVIRONMENTS INTERACTION

    Directory of Open Access Journals (Sweden)

    A. V. Denisenko

    2016-08-01

    Full Text Available The question of implementation of the interface between the DCNET and Flash media is examined. Usage of the interface-based DCNET environment allows to reduce time and material costs for the development t and study of complicated technological system and to increase functional imaging capabilities compared to ActionScript.

  18. Grass Valley Venom FlashPak录像机

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Thomson新推出的Grass Valley Venom FIashPak录像机,可配合草谷VIPER Film Stream数字电影摄像机使用。Venom FlashPak是一款灵巧可靠的台式系统,可以记录VIPER摄影机输出的未压缩视频。

  19. High-frequency Trading, Algorithmic Finance, and the Flash Crash

    DEFF Research Database (Denmark)

    Borch, Christian

    2016-01-01

    The Flash Crash of 6 May 2010 has an interesting status in discussions of high-frequency trading, i.e. fully automated, superfast computerized trading: it is invoked both as an important illustration of how this field of algorithmic trading operates and, more often, as an example of how fully aut...

  20. Collecting response times using Amazon Mechanical Turk and Adobe Flash.

    Science.gov (United States)

    Simcox, Travis; Fiez, Julie A

    2014-03-01

    Crowdsourcing systems like Amazon's Mechanical Turk (AMT) allow data to be collected from a large sample of people in a short amount of time. This use has garnered considerable interest from behavioral scientists. So far, most experiments conducted on AMT have focused on survey-type instruments because of difficulties inherent in running many experimental paradigms over the Internet. This study investigated the viability of presenting stimuli and collecting response times using Adobe Flash to run ActionScript 3 code in conjunction with AMT. First, the timing properties of Adobe Flash were investigated using a phototransistor and two desktop computers running under several conditions mimicking those that may be present in research using AMT. This experiment revealed some strengths and weaknesses of the timing capabilities of this method. Next, a flanker task and a lexical decision task implemented in Adobe Flash were administered to participants recruited with AMT. The expected effects in these tasks were replicated. Power analyses were conducted to describe the number of participants needed to replicate these effects. A questionnaire was used to investigate previously undescribed computer use habits of 100 participants on AMT. We conclude that a Flash program in conjunction with AMT can be successfully used for running many experimental paradigms that rely on response times, although experimenters must understand the limitations of the method.

  1. Visual reinforcement audiometry: an Adobe Flash based approach.

    Science.gov (United States)

    Atherton, Steve

    2010-09-01

    Visual Reinforcement Audiometry (VRA) is a key behavioural test for young children. It is central to the diagnosis of hearing-impaired infants (1) . Habituation to the visual reinforcement can give misleading results. Medical Illustration ABM University Health Board has designed a collection of Flash animations to overcome this.

  2. Flash-lamp-pumped picosecond Nd:YAG regenerative amplifier

    Institute of Scientific and Technical Information of China (English)

    Bingyuan Zhang; Gang Li; Meng Chen; Guoju Wang; Yonggang Wang; Xiaoyu Ma

    2005-01-01

    @@ A flash-lamp-pumped Nd:YAG regenerative amplifier has been developed at 1.06 μm, seeded with 10-ps pulses from a diode-end-pumped and mode-locked Nd:YAG oscillator with homemade semiconductor saturable absorber mirror(SESAM).

  3. An empirical explanation of the flash-lag effect.

    Science.gov (United States)

    Wojtach, William T; Sung, Kyongje; Truong, Sandra; Purves, Dale

    2008-10-21

    When a flash of light is presented in physical alignment with a moving object, the flash is perceived to lag behind the position of the object. This phenomenon, known as the flash-lag effect, has been of particular interest to vision scientists because of the challenge it presents to understanding how the visual system generates perceptions of objects in motion. Although various explanations have been offered, the significance of this effect remains a matter of debate. Here, we show that: (i) contrary to previous reports based on limited data, the flash-lag effect is an increasing nonlinear function of image speed; and (ii) this function is accurately predicted by the frequency of occurrence of image speeds generated by the perspective transformation of moving objects. These results support the conclusion that perceptions of the relative position of a moving object are determined by accumulated experience with image speeds, in this way allowing for visual behavior in response to real-world sources whose speeds and positions cannot be perceived directly.

  4. FLASH FLOODS IN THE ILIŞUA BASIN

    Directory of Open Access Journals (Sweden)

    G. HOGNOGI

    2011-03-01

    Full Text Available Flash Floods in the Ilişua Basin. The Ilişua Valley is a right tributary of the Someşu Mare Valley and has its spring in the south-western part of the Tibleş Mountains. It is a perennial river, and its maximum flow sometimes exceeds the national multi-anual average. One manifestation of this high flow is represented by two types of flash floods: the ones caused by heavy rainfall and the ones caused by the both heavy precipitation and the melting of snow. These two types of flash floods have specific characteristics not only in terms of causes but also in the happening, the impact area and the scale or proportions of damage. These features are further explained in the analysis of two flash floods that have taken place on May 12-17, 1970 and June 20-21, 2006. The occurence of these extreme hydrological phenomena in the basin and their impact upon nature, people and infrastructure makes the need of more hydrological survey a fact.

  5. Flash floods, hydro-geomorphic response and risk management

    Science.gov (United States)

    Braud, Isabelle; Borga, Marco; Gourley, Jonathan; Hürlimann, Marcel; Zappa, Massimilano; Gallart, Francesc

    2016-10-01

    Each year, natural disasters are responsible for fatalities and economic losses worldwide with 101 billion USD in economic losses and 7000 fatalities reported for 2014 (SwissRE, 2015). Even if earthquakes are responsible for most of these fatalities, flash floods and landslides are recognized as a significant source of threat to human lives (SwissRE, 2015). Jonkman (2005), in a global assessment of flood-related casualties, showed that flash floods lead to the highest mortality (number of fatalities divided by the number of affected people). They are also often associated with shallow landslides and geomorphic processes that can increase threat to human lives. Analysis of a global data set of fatalities from non-seismically triggered landslides (Petley, 2012) shows that 2620 fatal landslides were recorded worldwide in the period 2004-2010, causing a total of 32,322 recorded fatalities. In addition, heavy precipitation events, at the origin of flash floods and shallow landsliding are expected to increase in the future (e.g. Scoccimarro et al., 2016 for a recent study in Europe). Progress in flash floods and landslides understanding, forecasting and warning is therefore still needed to disentangle the complex interactions between hazards, exposure and vulnerability and to increase resilience (Borga et al., 2014).

  6. Modelling (flash) floods in a Dutch lowland catchment

    NARCIS (Netherlands)

    Brauer, C.C.; Teuling, A.J.; Overeem, A.; Velde, Y. van der; Hazenberg, P.; Warmerdam, P.M.M.; Kloosterman, P.; Uijlenhoet, R.

    2012-01-01

    On 26 August 2010 the eastern part of The Netherlands and the bordering part of Germany were struck by a series of rainfall events.We investigated the unprecedented flash flood triggered by this exceptionally heavy rainfall event (return period > 1000 years) in the 6.5 km2 Hupsel Brook catchment, wh

  7. Ultrafast-Contactless Flash Sintering using Plasma Electrodes

    Science.gov (United States)

    Saunders, Theo; Grasso, Salvatore; Reece, Michael J.

    2016-06-01

    This paper presents a novel derivative of flash sintering, in which contactless flash sintering (CFS) is achieved using plasma electrodes. In this setup, electrical contact with the sample to be sintered is made by two arc plasma electrodes, one on either side, allowing current to pass through the sample. This opens up the possibility of continuous throughput flash sintering. Preheating, a usual precondition for flash sintering, is provided by the arc electrodes which heat the sample to 1400 °C. The best results were produced with pre-compacted samples (bars 1.8 mm thick) of pure B4C (discharge time 2s, current 4A) and SiC:B4C 50 wt% (3s at 6A), which were fully consolidated under a heating rate approaching 20000 °C/min. For the composite a cylindrical volume of 14 mm3 was sintered to full density with limited grain growth.

  8. Monitoring of flash visual evoked potentials during neurosurgical operations.

    Science.gov (United States)

    Cedzich, C; Schramm, J

    1990-01-01

    In summary, our results suggest that flash VEP monitoring is not specific for visual acuity and has not proved helpful as an intraoperative warning system. The future challenge will be to devise a method which activates only those fibers specific to visual acuity and which provides reproducible and reliable information quickly enough that adjustments in patient management can be made.

  9. Recovery of Flash Memories for Reliable Mobile Storages

    Directory of Open Access Journals (Sweden)

    Daesung Moon

    2010-01-01

    Full Text Available As the mobile appliance is applied to many ubiquitous services and the importance of the information stored in it is increased, the security issue to protect the information becomes one of the major concerns. However, most previous researches focused only on the communication security, not the storage security. Especially, a flash memory whose operational characteristics are different from those of HDD is used increasingly as a storage device for the mobile appliance because of its resistance to physical shock and lower power requirement. In this paper, we propose a flash memory management scheme targeted for guaranteeing the data integrity of the mobile storage. By maintaining the old data specified during the recovery window, we can recover the old data when the mobile appliance is attacked. Also, to reduce the storage requirement for the recovery, we restrict the number of versions to be copied, called Degree of Integrity (DoI. Especially, we consider both the reclaim efficiency and the wear leveling which is a unique characteristic of the flash memory. Based on the performance evaluation, we confirm that the proposed scheme can be acceptable to many applications as a flash memory management scheme for improving data integrity.

  10. Implementation of Power Efficient Flash Analogue-to-Digital Converter

    Directory of Open Access Journals (Sweden)

    Taninki Sai Lakshmi

    2014-01-01

    Full Text Available An efficient low power high speed 5-bit 5-GS/s flash analogue-to-digital converter (ADC is proposed in this paper. The designing of a thermometer code to binary code is one of the exacting issues of low power flash ADC. The embodiment consists of two main blocks, a comparator and a digital encoder. To reduce the metastability and the effect of bubble errors, the thermometer code is converted into the gray code and there after translated to binary code through encoder. The proposed encoder is thus implemented by using differential cascade voltage switch logic (DCVSL to maintain high speed and low power dissipation. The proposed 5-bit flash ADC is designed using Cadence 180 nm CMOS technology with a supply rail voltage typically ±0.85 V. The simulation results include a total power dissipation of 46.69 mW, integral nonlinearity (INL value of −0.30 LSB and differential nonlinearity (DNL value of −0.24 LSB, of the flash ADC.

  11. RAFFS: Model Checking a Robust Abstract Flash File Store

    NARCIS (Netherlands)

    Taverne, P.; Pronk, C.

    2009-01-01

    Accepted for publication in the Proceedings of the 11th International Conference on Formal Engineering Methods, ICFEM 2009. This paper presents a case study in modeling and verifying a POSIX-like file store for Flash memory. This work fits in the context of Hoare’s verification challenge and, in pa

  12. Lightning flash density in relation to aerosol over Nanjing (China)

    Science.gov (United States)

    Tan, Y. B.; Peng, L.; Shi, Z.; Chen, H. R.

    2016-06-01

    Time series data of lightning flash density, aerosol optical depth (AOD), surface temperature, convective available potential energy (CAPE) and thunderstorm days for 10 years (2002-2011), cloud-to-ground lightning (CG), and AOD of 5 years for summer season, i.e., June, July, and August over Nanjing, China, have been analyzed, to investigate the impact of aerosols on lightning. The results indicate that the radiative effect of aerosol may be one of the main reason for the decrease of the lightning flash density in a long period, while the aerosol microphysical effect may be a major role in the increase of the percent of + CG flashes (P+ CG). The dependence of surface temperature, CAPE, and thunderstorm days on AOD (R = - 0.748, - 0.741, - 0.744), and the negative correlation (R = - 0.634) between lightning flash density and AOD may lend support for the radiative effect of aerosol on lightning. In addition, elevated aerosols may change the charge distribution in thundercloud, hence enhancing the positive cloud-to-ground lightning (+ CG) activity, as P+ CG is positively correlated with AOD.

  13. Temporal uncertainty separates flashes from their background during saccades

    NARCIS (Netherlands)

    Maij, F.; Brenner, E.M.; Smeets, J.B.J.

    2011-01-01

    It is known that spatial localization of flashed objects fails around the time of rapid eye movements (saccades). This mislocalization is often interpreted in terms of a combination of shifts and deformations of the brain's representation of space to account for the eye movement. Such temporary

  14. Temporal uncertainty separates flashes from their background during saccades.

    NARCIS (Netherlands)

    Maij, F.; Brenner, E.; Smeets, J.B.J.

    2011-01-01

    It is known that spatial localization of flashed objects fails around the time of rapid eye movements (saccades). This mislocalization is often interpreted in terms of a combination of shifts and deformations of the brain’s representation of space to account for the eye movement. Such temporary

  15. Sub-seasonal forecasting of flash droughts in China

    Science.gov (United States)

    Yuan, Xing; Wang, Linying

    2016-04-01

    Short-term droughts during the crop growing seasons sometimes occur with abnormally high temperature, the decreasing soil moisture but increasing evapotranspiration (ET) often intensify the drought conditions. These droughts are recently termed as "flash droughts" due to their rapid development, unusual intensity and devastating impacts. For example, a flash drought that lasted for less than a month during the summer of 2013 affected 13 provinces in southern China and damaged over 2 million hectares of crops in two southern provinces alone. Currently, seasonal forecasting of flash droughts remains a grand challenge because they usually happened without persistent oceanic anomalies while mainly due to the short-term anomalies in the atmospheric circulations and the land surface conditions. Moreover, forecasting of a flash drought event is not only to predict a water deficit, but also to predict a heat extreme (i.e., abnormally high temperature) and the water-energy coupling anomaly between the land and atmosphere (e.g., ET anomaly). On the other hand, sub-seasonal to seasonal (S2S) forecasting that intends to bridge the weather and climate predictions for a seamless climate service is an emerging area and will also be essential for advancing the extended hydrological forecasting. Recently, a number of S2S projects including the second phase of the North American Multimodel Ensemble (NMME) project have been launched to understand the hydro-climate predictability from weeks to a season, and to explore its usefulness for the applications within the Global Framework for Climate Services. Therefore, the emerging S2S forecasting activities provide an unprecedent opportunity for improving the understanding of the predictability of flash drought, and sub-seasonal forecasting of flash drought will in turn be a good measure for assessing the phenomenological forecast skill of the S2S forecasting practices. In this presentation, a 29-year daily NCEP Climate Forecast System

  16. Machine protection for FLASH and the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Lars

    2009-05-15

    The Free-Electron Laser in Hamburg (FLASH) and the future European X-Ray Free-Electron Laser (XFEL) are sources of brilliant extremeultraviolet and X-ray radiation pulses. Both facilities are based on superconducting linear accelerators (linacs) that can produce and transport electron beams of high average power. With up to 90 kW or up to 600 kW of power, respectively, these beams hold a serious potential to damage accelerator components. This thesis discusses several passive and active machine protection measures needed to ensure safe operation. At FLASH, dark current from the rf gun electron source has activated several accelerator components to unacceptable radiation levels. Its transport through the linac is investigated with detailed tracking simulations using a parallelized and enhanced version of the tracking code Astra; possible remedies are evaluated. Beam losses can lead to the demagnetization of permanent magnet insertion devices. A number of beam loss scenarios typical for FLASH are investigated with shower simulations. A shielding setup is designed and its efficiency is evaluated. For the design parameters of FLASH, it is concluded that the average relative beam loss in the undulators must be controlled to a level of about 10{sup -8}. FLASH is equipped with an active machine protection system (MPS) comprising more than 80 photomultiplier-based beam loss monitors and several subsystems. The maximum response time to beam losses is less than 4 {mu}s. Setup procedures and calibration algorithms for MPS subsystems and components are introduced and operational problems are addressed. Finally, an architecture for a fully programmable machine protection system for the XFEL is presented. Several options for the topology of this system are reviewed, with the result that an availability goal of at least 0.999 for the MPS is achievable with moderate hardware requirements. (orig.)

  17. Upper limits of flash flood stream power in Europe

    Science.gov (United States)

    Marchi, Lorenzo; Cavalli, Marco; Amponsah, William; Borga, Marco; Crema, Stefano

    2016-11-01

    Flash floods are characterized by strong spatial gradients of rainfall inputs that hit different parts of a river basin with different intensity. Stream power values associated with flash floods therefore show spatial variations that depend on geological controls on channel geometry and sediment characteristics, as well as on the variations of flood intensity: this stresses the need for a field approach that takes into account the variability of the controlling factors. Post-flood assessment of peak discharge after major floods makes it possible to analyse stream power in fluvial systems affected by flash floods. This study analyses the stream power of seven intense (return period of rainfall > 100 years at least in some sectors of the river basin) flash floods that occurred in mountainous basins of central and southern Europe from 2007 to 2014. In most of the analysed cross sections, high values of unit stream power were observed; this is consistent with the high severity of the studied floods. The highest values of cross-sectional stream power and unit stream power usually occur in Mediterranean regions. This is mainly ascribed to the larger peak discharges that characterize flash floods in these regions. The variability of unit stream power with catchment area is clearly nonlinear and has been represented by log-quadratic relations. The values of catchment area at which maximum values of unit stream power occur show relevant differences among the studied floods and are linked to the spatial scale of the events. Values of stream power are generally consistent with observed geomorphic changes in the studied cross sections: bedrock channels show the highest values of unit stream power but no visible erosion, whereas major erosion has been observed in alluvial channels. Exceptions to this general pattern, which mostly occur in semi-alluvial cross sections, urge the recognition of local or event-specific conditions that increase the resistance of channel bed and

  18. Flash flood warning based on fully dynamic hydrology modelling

    Science.gov (United States)

    Pejanovic, Goran; Petkovic, Slavko; Cvetkovic, Bojan; Nickovic, Slobodan

    2016-04-01

    Numerical hydrologic modeling has achieved limited success in the past due to, inter alia, lack of adequate input data. Over the last decade, data availability has improved substantially. For modelling purposes, high-resolution data on topography, river routing, and land cover and soil features have meanwhile become available, as well as the observations such as radar precipitation information. In our study, we have implemented the HYPROM model (Hydrology Prognostic Model) to predict a flash flood event at a smaller-scale basin in Southern Serbia. HYPROM is based on the full set of governing equations for surface hydrological dynamics, in which momentum components, along with the equation of mass continuity, are used as full prognostic equations. HYPROM also includes a river routing module serving as a collector for the extra surface water. Such approach permits appropriate representation of different hydrology scales ranging from flash floods to flows of large and slow river basins. The use of full governing equations, if not appropriately parameterized, may lead to numerical instability systems when the surface water in a model is vanishing. To resolve these modelling problems, an unconditionally stable numerical scheme and a method for height redistribution avoiding shortwave height noise have been developed in HYPROM, which achieve numerical convergence of u, v and h when surface water disappears. We have applied HYPROM, driven by radar-estimated precipitation, to predict flash flooding occurred over smaller and medium-size river basins. Two torrential rainfall cases have been simulated to check the accuracy of the model: the exceptional flooding of May 2014 in Western Serbia, and the convective flash flood of January 2015 in Southern Serbia. The second episode has been successfully predicted by HYPROM in terms of timing and intensity six hours before the event occurred. Such flash flood warning system is in preparation to be operationally implemented in the

  19. Flash chemistry: fast chemical synthesis by using microreactors.

    Science.gov (United States)

    Yoshida, Jun-ichi; Nagaki, Aiichiro; Yamada, Takeshi

    2008-01-01

    This concept article provides a brief outline of the concept of flash chemistry for carrying out extremely fast reactions in organic synthesis by using microreactors. Generation of highly reactive species is one of the key elements of flash chemistry. Another important element of flash chemistry is the control of extremely fast reactions to obtain the desired products selectively. Fast reactions are usually highly exothermic, and heat removal is an important factor in controlling such reactions. Heat transfer occurs very rapidly in microreactors by virtue of a large surface area per unit volume, making precise temperature control possible. Fast reactions often involve highly unstable intermediates, which decompose very quickly, making reaction control difficult. The residence time can be greatly reduced in microreactors, and this feature is quite effective in controlling such reactions. For extremely fast reactions, kinetics often cannot be used because of the lack of homogeneity of the reaction environment when they are conducted in conventional reactors such as flasks. Fast mixing using micromixers solves such problems. The concept of flash chemistry has been successfully applied to various organic reactions including a) highly exothermic reactions that are difficult to control in conventional reactors, b) reactions in which a reactive intermediate easily decomposes in conventional reactors, c) reactions in which undesired byproducts are produced in the subsequent reactions in conventional reactors, and d) reactions whose products easily decompose in conventional reactors. The concept of flash chemistry can be also applied to polymer synthesis. Cationic polymerization can be conducted with an excellent level of molecular-weight control and molecular-weight distribution control.

  20. 因特网移动宽带接入解决方案FLASH-OFDM%FLASH-OFDM--Solution of Internet Mobile Broadband Access

    Institute of Scientific and Technical Information of China (English)

    张磊

    2004-01-01

    从介绍OFDM技术入手,分析了VOFDM、WOFDM和FLASH-OFDM技术的性能特点,接着详细介绍了FLASH-OFDM技术的协议模型及其物理层、数据链路层和网络层,最后展望了FLASH-OFDM技术在未来移动通信系统中的应用.

  1. Professional Flash Mobile Development Creating Android and iPhone Applications

    CERN Document Server

    Wagner, Richard

    2010-01-01

    Professional Flash Mobile Development: Creating Android and iPhone ApplicationsEverything Flash developers need to know to create native Android and iPhone appsThis Wrox guide shows Flash developers how to create native applications for Android and iPhone mobile devices using Flash. Packed with practical examples, it shows how to build a variety of apps and integrate them with core mobile services such as Accelerometer, GPS, Photo Library,and more.Offers Flash developers the tools to create apps for the Android and iPhone mobile devicesSho

  2. High-speed video and electric field observation of upward flashes in Brazil

    Science.gov (United States)

    Saba, Marcelo M. F.; Schumann, Carina; Ferro, Marco A. S.; Paiva, Amanda R.; Jaques, Robson; Warner, Tom A.

    2015-04-01

    Upward flashes from tall towers in Brazil have been observed since January 2012. They have been responsible for damages on equipment installed nearby tall structures that caused their initiation. Almost all upward flashes were observed with high-speed cameras and electric field sensors; a combination of measurements that provides a very accurate classification and characterization of their properties. Although present during all seasons, upward flashes are predominant during summer. They are almost always initiated by a preceding positive cloud-to-ground flash. This study is based on an up-to-date database of 86 upward flashes observed during the last three years. The main characteristics described in this work are: time interval between triggering event and the upward leader initiation, characteristics of the triggering +CG flashes, upward leader characteristics (polarity, presence of recoil leaders and branching), initial continuous current (duration, presence of pulses and recoil leaders), flash duration and presence of subsequence of return stroke.

  3. Adobe Flash as a medium for online experimentation: a test of reaction time measurement capabilities.

    Science.gov (United States)

    Reimers, Stian; Stewart, Neil

    2007-08-01

    Adobe Flash can be used to run complex psychological experiments over the Web. We examined the reliability of using Flash to measure reaction times (RTs) using a simple binary-choice task implemented both in Flash and in a Linux-based system known to record RTs with millisecond accuracy. Twenty-four participants were tested in the laboratory using both implementations; they also completed the Flash version on computers of their own choice outside the lab. RTs from the trials run on Flash outside the lab were approximately 20 msec slower than those from trials run on Flash in the lab, which in turn were approximately 10 msec slower than RTs from the trials run on the Linux-based system (baseline condition). RT SDs were similar in all conditions, suggesting that although Flash may overestimate RTs slightly, it does not appear to add significant noise to the data recorded.

  4. Flash Heating of Crustal Rocks at Seismic Slip Rates

    Science.gov (United States)

    Goldsby, D. L.; Spagnuolo, E.; Smith, S. A.; Beeler, N. M.; Tullis, T. E.; Di Toro, G.; Nielsen, S. B.

    2012-12-01

    Recent experiments have demonstrated that rocks undergo extreme frictional weakening at near-earthquake slip rates due to the thermal degradation of the strength, or even melting, of microscopic asperity contacts on their sliding surfaces (Goldsby and Tullis, 2012). These previous experiments, conducted at constant normal stress and slip rates of up to ~0.4 m/s, revealed a 1/V dependence of friction on slip rate above a characteristic weakening velocity, Vw, in accord with theories of flash heating (e.g., Rice, 2006). The weakening velocity obtains values of ~0.1 m/s for many crustal silicate rocks (Goldsby and Tullis, 2012). Here we test two further predictions of flash-heating theory - that the degree of weakening saturates at slip rates approaching 1 m/s, and that the weakening behavior due to flash heating is independent of normal stress - by testing samples at slip rates of up to 1 m/s at different normal stresses. Experiments were conducted in a 1-atm, high-velocity friction apparatus at the Istituto Nazionale di Geofisica e Vulcanologia in Rome. A sample consisted of a pair of hollow cylinders of Westerly granite or Frederick diabase subjected to a nominally constant normal stress of from 1 to 30 MPa and subjected to a variety of rate-stepping sequences. Data were acquired at rates of up to 1 MHz. As predicted, the experiments demonstrate that the degree of weakening due to flash heating saturates at slip rates approaching 1 m/s; in a few cases, friction even increases slightly with increasing slip rate near 1 m/s. The experiments also demonstrate that, within the scatter of the data, the value of Vw and the friction coefficient in the weakened state is independent of normal stress, the expected result if average contact sizes and contact stresses are independent of normal stress. The data thus further corroborate existing theories and experimental data for flash heating, allowing for a more reliable determination of the conditions under which flash heating

  5. Impact Flash Physics: Modeling and Comparisons With Experimental Results

    Science.gov (United States)

    Rainey, E.; Stickle, A. M.; Ernst, C. M.; Schultz, P. H.; Mehta, N. L.; Brown, R. C.; Swaminathan, P. K.; Michaelis, C. H.; Erlandson, R. E.

    2015-12-01

    Hypervelocity impacts frequently generate an observable "flash" of light with two components: a short-duration spike due to emissions from vaporized material, and a long-duration peak due to thermal emissions from expanding hot debris. The intensity and duration of these peaks depend on the impact velocity, angle, and the target and projectile mass and composition. Thus remote sensing measurements of planetary impact flashes have the potential to constrain the properties of impacting meteors and improve our understanding of impact flux and cratering processes. Interpreting impact flash measurements requires a thorough understanding of how flash characteristics correlate with impact conditions. Because planetary-scale impacts cannot be replicated in the laboratory, numerical simulations are needed to provide this insight for the solar system. Computational hydrocodes can produce detailed simulations of the impact process, but they lack the radiation physics required to model the optical flash. The Johns Hopkins University Applied Physics Laboratory (APL) developed a model to calculate the optical signature from the hot debris cloud produced by an impact. While the phenomenology of the optical signature is understood, the details required to accurately model it are complicated by uncertainties in material and optical properties and the simplifications required to numerically model radiation from large-scale impacts. Comparisons with laboratory impact experiments allow us to validate our approach and to draw insight regarding processes that occur at all scales in impact events, such as melt generation. We used Sandia National Lab's CTH shock physics hydrocode along with the optical signature model developed at APL to compare with a series of laboratory experiments conducted at the NASA Ames Vertical Gun Range. The experiments used Pyrex projectiles to impact pumice powder targets with velocities ranging from 1 to 6 km/s at angles of 30 and 90 degrees with respect to

  6. Audition influences color processing in the sound-induced visual flash illusion.

    Science.gov (United States)

    Mishra, Jyoti; Martinez, Antigona; Hillyard, Steven A

    2013-12-18

    Multisensory interactions can lead to illusory percepts, as exemplified by the sound-induced extra flash illusion (SIFI: Shams, Kamitani, & Shimojo, 2000, 2002). In this illusion, an audio-visual stimulus sequence consisting of two pulsed sounds and a light flash presented within a 100 ms time window generates the visual percept of two flashes. Here, we used colored visual stimuli to investigate whether concurrent auditory stimuli can affect the perceived features of the illusory flash. Zero, one or two pulsed sounds were presented concurrently with either a red or green flash or with two flashes of different colors (red followed by green) in rapid sequence. By querying both the number and color of the participants' visual percepts, we found that the double flash illusion is stimulus specific: i.e., two sounds paired with one red or one green flash generated the percept of two red or two green flashes, respectively. This implies that the illusory second flash is induced at a level of visual processing after perceived color has been encoded. In addition, we found that the presence of two sounds influenced the integration of color information from two successive flashes. In the absence of any sounds, a red and a green flash presented in rapid succession fused to form a single orange percept, but when accompanied by two sounds, this integrated orange percept was perceived to flash twice on a significant proportion of trials. In addition, the number of concurrent auditory stimuli modified the degree to which the successive flashes were integrated to an orange percept vs. maintained as separate red-green percepts. Overall, these findings show that concurrent auditory input can affect both the temporal and featural properties of visual percepts. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. A first look at global flash drought: long term change and short term predictability

    Science.gov (United States)

    Yuan, Xing; Wang, Linying; Ji, Peng

    2017-04-01

    "Flash drought" became popular after the unexpected 2012 central USA drought, mainly due to its rapid development, low predictability and devastating impacts on water resources and crop yields. A pilot study by Mo and Lettenmaier (2015) found that flash drought, based on a definition of concurrent heat extreme, soil moisture deficit and evapotranspiration (ET) enhancement at pentad scale, were in decline over USA during recent 100 years. Meanwhile, a recent work indicated that the occurrence of flash drought in China was doubled during the past 30 years, where a severe flash drought in the summer of 2013 ravaged 13 provinces in southern China. As global warming increases the frequency of heat waves and accelerates the hydrological cycle, the flash drought is expected to increase in general, but its trend might also be affected by interannual to decadal climate oscillations. To consolidate the hotspots of flash drought and the effects of climate change on flash drought, a global inventory is being conducted by using multi-source observations (in-situ, satellite and reanalysis), CMIP5 historical simulations and future projections under different forcing scenarios, as well as global land surface hydrological modeling for key variables including surface air temperature, soil moisture and ET. In particular, a global picture of the flash drought distribution, the contribution of naturalized and anthropogenic forcings to global flash drought change, and the risk of global flash drought in the future, will be presented. Besides investigating the long-term change of flash drought, providing reliable early warning is also essential to developing adaptation strategies. While regional drought early warning systems have been emerging in recent decade, forecasting of flash drought is still at an exploratory stage due to limited understanding of flash drought predictability. Here, a set of sub-seasonal to seasonal (S2S) hindcast datasets are being used to assess the short term

  8. Biodiesel Production by Reactive Flash: A Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Alejandro Regalado-Méndez

    2016-01-01

    Full Text Available Reactive flash (RF in biodiesel production has been studied in order to investigate steady-state multiplicities, singularities, and effect of biodiesel quality when the RF system approaches to bubble point. The RF was modeled by an index-2 system of differential algebraic equations, the vapor split (ϕ was computed by modified Rachford-Rice equation and modified Raoult’s law computed bubble point, and the continuation analysis was tracked on MATCONT. Results of this study show the existence of turning points, leading to a unique bubble point manifold, (xBiodiesel,T=(0.46,478.41 K, which is a globally stable flashing operation. Also, the results of the simulation in MATLAB® of the dynamic behavior of the RF show that conversion of triglycerides reaches 97% for a residence time of 5.8 minutes and a methanol to triglyceride molar flow ratio of 5 : 1.

  9. Flash pryolysis of biomass with reactive and nonreactive gases

    Science.gov (United States)

    Sundaram, M. S.; Steinberg, M.; Fallon, P. T.

    1982-10-01

    Studies were done on the flash pyrolysis of Douglas Fir wood in the presence of reactive and nonreactive gases including hydrogen, methane, and helium. Pyrolysis and gasification of the wood particles was done in one step, without catalysts. Almost complete (98%) gasification of the carbon in Douglas fir wood was achieved at 10000C and 500-psi hydrogen pressure. The reaction products were methane, ethane, ethylene, carbon monoxide, BTX, and water. Flash hydropyrolysis produced a large yield of hydrocarbon gases (up to 78% C) comprising methane and ethane. High yields of ethylene (up to 21% C) and BTX (up to 12% C) were obtained via methane pyrolysis of fir wood; a free radical mechanism is proposed to explain the enhanced yield of ethylene in a methane atmosphere.

  10. Measurement and analysis of coherent synchrotron radiation effects at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Beutner, B.

    2007-12-15

    The vacuum-ultra-violet Free Electron Laser in Hamburg (FLASH) is a linac driven SASE-FEL. High peak currents are produced using magnetic bunch compression chicanes. In these magnetic chicanes, the energy distribution along an electron bunch is changed by eff ects of Coherent Synchrotron Radiation (CSR). Energy changes in dispersive bunch compressor chicanes lead to transverse displacements along the bunch. These CSR induced displacements are studied using a transverse deflecting RF-structure. Experiments and simulations concerning the charge dependence of such transverse displacements are presented and analysed. In these experiments an over-compression scheme is used which reduces the peak current downstream the bunch compressor chicanes. Therefore other self interactions like space charge forces which might complicate the measurements are suppressed. Numerical simulations are used to analyse the beam dynamics under the influence of CSR forces. The results of these numerical simulations are compared with the data obtained in the over-compression experiments at FLASH. (orig.)

  11. Measuring x-ray spectra of flash radiographic sources

    Science.gov (United States)

    Gehring, Amanda E.; Espy, Michelle A.; Haines, Todd J.; Mendez, Jacob; Moir, David C.; Sedillo, Robert; Shurter, Roger P.; Volegov, Petr; Webb, Timothy J.

    2015-08-01

    A Compton spectrometer has been re-commissioned for measurements of flash radiographic sources. The determination of the energy spectrum of these sources is difficult due to the high count rates and short nature of the pulses (~50 ns). The spectrometer is a 300 kg neodymium-iron magnet which measures spectra in the <1 MeV to 20 MeV energy range. Incoming x-rays are collimated into a narrow beam incident on a converter foil. The ejected Compton electrons are collimated so that the forward-directed electrons enter the magnetic field region of the spectrometer. The position of the electrons at the magnet's focal plane is a function of their momentum, allowing the x-ray spectrum to be reconstructed. Recent measurements of flash sources are presented.

  12. Flash characteristics of plasma induced by hypervelocity impact

    Science.gov (United States)

    Zhang, Kai; Long, Renrong; Zhang, Qingming; Xue, Yijiang; Ju, Yuanyuan

    2016-08-01

    Using a two-stage light gas gun, a series of hypervelocity impact experiments was conducted in which 6.4-mm-diameter spherical 2024-aluminum projectiles impact 23-mm-thick targets made of the same material at velocities of 5.0, 5.6, and 6.3 km/s. Both an optical pyrometer composed of six photomultiplier tubes and a spectrograph were used to measure the flash of the plasma during hypervelocity impact. Experimental results show that, at a projectile velocity of 6.3 km/s, the strong flash lasted about 10 μs and reached a temperature of 4300 K. Based on the known emission lines of AL I, spectral methods can provide the plasma electron temperature. An electron-temperature comparison between experiment and theoretical calculation indicates that single ionization and secondary ionization are the two main ionizing modes at velocities 5.0-6.3 km/s.

  13. Visualizing Library Statistics using Open Flash Chart 2 and Drupal

    Directory of Open Access Journals (Sweden)

    Laura K. Wiegand

    2013-01-01

    Full Text Available Libraries continue to need to demonstrate their value to stakeholders, and while statistics alone do not represent value, they are an important element. We found ourselves, and our stakeholders, uninspired by our infrequently updated bulleted list of statistics on our website and so set out to create a more dynamic and visually appealing look at our statistics. This article outlines how we used our content management system, Drupal, Open Flash Chart and custom programming to convert library statistics into Flash charts, including how to populate the graphs with dynamic data from external sources. The end result is our Library Statistics Dashboard (http://library.uncw.edu/facts_planning/dashboard that visually demonstrates the use, activity and resources in the library via interactive and visually interesting graphs.

  14. Hartmann wavefront sensors and their application at FLASH.

    Science.gov (United States)

    Keitel, Barbara; Plönjes, Elke; Kreis, Svea; Kuhlmann, Marion; Tiedtke, Kai; Mey, Tobias; Schäfer, Bernd; Mann, Klaus

    2016-01-01

    Different types of Hartmann wavefront sensors are presented which are usable for a variety of applications in the soft X-ray spectral region at FLASH, the free-electron laser (FEL) in Hamburg. As a typical application, online measurements of photon beam parameters during mirror alignment are reported on. A compact Hartmann sensor, operating in the wavelength range from 4 to 38 nm, was used to determine the wavefront quality as well as aberrations of individual FEL pulses during the alignment procedure. Beam characterization and alignment of the focusing optics of the FLASH beamline BL3 were performed with λ(13.5 nm)/116 accuracy for wavefront r.m.s. (w(rms)) repeatability, resulting in a reduction of w(rms) by 33% during alignment.

  15. Flash Flooding - Ways That Science and Adaptation Reduce Losses

    Science.gov (United States)

    Gruntfest, E.

    2014-12-01

    Flash flood vulnerability is increasing. Predictability is more difficult as more flooding results after wildfires destroy hillside vegetation. Recent extreme events have occurred outside of seasonal norms with well beyond expected precipitation rates, and with unusual storm behavior where precipitation rates increase at the end of a storm. Engineers, social scientists, physical scientists, planners, emergency managers and others must collaborate in new ways to keep losses from rising. For example improved detection using cameras and gages must be complemented by understanding why people drive through flooded roads and what can be done to reduce the number of people on flooded roadways. Case studies of successful collaborations will be provided along with discussion of challenges and opportunities for expanding the innovative flash flood risk reduction strategies.

  16. uFLIP: Understanding the Energy Consumption of Flash Devices

    DEFF Research Database (Denmark)

    Bjørling, Matias; Bonnet, Philippe; Bouganim, Luc

    2010-01-01

    Understanding the energy consumption of flash devices is important for two reasons. First, energy is emerging as a key metric for data management systems. It is thus important to understand how we can reason about the energy consumption of flash devices beyond their approximate aggregate...... consumption (low power consumption in idle mode, average Watt consumption from the data sheets). Second, when measured at a sufficiently fine granularity, the energy consumption of a given device might complement the performance characteristics derived from its response time profile. Indeed, background work...... which is not directly observable with a response time profile appears clearly when energy is used as a metric. In this paper, we discuss the results from the {uFLIP} benchmark applied to four different {SSD} devices using both response time and energy as metric....

  17. Total Lightning Flash Activity Response to Aerosol over China Area

    Directory of Open Access Journals (Sweden)

    Pengguo Zhao

    2017-01-01

    Full Text Available Twelve years of measurements of aerosol optical depth (AOD, cloud fraction, cloud top height, ice cloud optical thickness and lightning flash density from 2001 to 2012 have been analyzed to investigate the effect of aerosols on electrical activity over an area of China. The results show that increasing aerosol loading inspires the convective intensity, and then increases the lightning flash density. The spatial distribution of the correlation between aerosol loading and electrical activity shows a remarkable regional difference over China. The high-correlation regions embody the positive aerosol microphysical effect on the intensity of the electrical activity, while the large-scale processes may play the main role in convection development and producing lightning in low-correlation regions.

  18. uFLIP: Understanding the Energy Consumption of Flash Devices

    DEFF Research Database (Denmark)

    Bjørling, Matias; Bonnet, Philippe; Bouganim, Luc

    2010-01-01

    Understanding the energy consumption of flash devices is important for two reasons. First, energy is emerging as a key metric for data management systems. It is thus important to understand how we can reason about the energy consumption of flash devices beyond their approximate aggregate...... consumption (low power consumption in idle mode, average Watt consumption from the data sheets). Second, when measured at a sufficiently fine granularity, the energy consumption of a given device might complement the performance characteristics derived from its response time profile. Indeed, background work...... which is not directly observable with a response time profile appears clearly when energy is used as a metric. In this paper, we discuss the results from the {uFLIP} benchmark applied to four different {SSD} devices using both response time and energy as metric....

  19. Measurement of thermophysical properties of ceramics by the flash method

    Directory of Open Access Journals (Sweden)

    Cláudio S. C. Pinto

    2006-01-01

    Full Text Available The flash method, proposed by Parker, Butler, Jenkins and Abbott from the U.S. Navy Radiological Defense Laboratory in 1961, is the most popular method for measuring the thermal diffusivity of solids. In this method, the front surface of a small sample is subjected to a very short burst of radiant thermal energy. The resulting temperature rise on the opposite surface of the sample is measured and the thermal diffusivity is computed from the temperature rise versus time data. Also, the specific heat can be computed from the measured data, thus allowing for the calculation of the thermal conductivity. Several theoretical models are available for the flash method, which include adiabatic boundary conditions, heat losses, surface coating effects, among other aspects. In this paper, tests were made for the identification of thermo-physical properties of a Ceramic block. The Netzsch Nanoflash LFA 447/1 of LTTC/COPPE/UFRJ was used for the measurements.

  20. Flash flood modeling with the MARINE hydrological distributed model

    Directory of Open Access Journals (Sweden)

    V. Estupina-Borrell

    2006-11-01

    Full Text Available Flash floods are characterized by their violence and the rapidity of their occurrence. Because these events are rare and unpredictable, but also fast and intense, their anticipation with sufficient lead time for warning and broadcasting is a primary subject of research. Because of the heterogeneities of the rain and of the behavior of the surface, spatially distributed hydrological models can lead to a better understanding of the processes and so on they can contribute to a better forecasting of flash flood. Our main goal here is to develop an operational and robust methodology for flash flood forecasting. This methodology should provide relevant data (information about flood evolution on short time scales, and should be applicable even in locations where direct observations are sparse (e.g. absence of historical and modern rainfalls and streamflows in small mountainous watersheds. The flash flood forecast is obtained by the physically based, space-time distributed hydrological model "MARINE'' (Model of Anticipation of Runoff and INondations for Extreme events. This model is presented and tested in this paper for a real flash flood event. The model consists in two steps, or two components: the first component is a "basin'' flood module which generates flood runoff in the upstream part of the watershed, and the second component is the "stream network'' module, which propagates the flood in the main river and its subsidiaries. The basin flash flood generation model is a rainfall-runoff model that can integrate remotely sensed data. Surface hydraulics equations are solved with enough simplifying hypotheses to allow real time exploitation. The minimum data required by the model are: (i the Digital Elevation Model, used to calculate slopes that generate runoff, it can be issued from satellite imagery (SPOT or from French Geographical Institute (IGN; (ii the rainfall data from meteorological radar, observed or

  1. FLASH Assembly of TALENs Enables High-Throughput Genome Editing

    OpenAIRE

    Reyon, Deepak; Tsai, Shengdar Q.; Khayter, Cyd; Foden, Jennifer A.; Sander, Jeffry D.; Joung, J. Keith

    2012-01-01

    Engineered transcription activator-like effector nucleases (TALENs) have shown promise as facile and broadly applicable genome editing tools. However, no publicly available high-throughput method for constructing TALENs has been published and large-scale assessments of the success rate and targeting range of the technology remain lacking. Here we describe the Fast Ligation-based Automatable Solid-phase High-throughput (FLASH) platform, a rapid and cost-effective method we developed to enable ...

  2. Temporal Parameter Optimization in Four-Dimensional Flash Trajectory Imaging

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-Wei; ZHOU Yan; FAN Song-Tao; LIU Yu-Liang

    2011-01-01

    In four-dimensional fiash trajectory imaging, temporal parameters include time delay, laser pulse width, gate time, pulse pair repetition frequency and the frame rate of CCD, which directly impact on the acquisition of target trajectories over time. We propose a method of optimizing the temporal parameters of flash trajectory imaging. All the temporal parameters can be estimated by the spatial parameters of the volumes of interest, target scale and velocity, and target sample number. The formulae for optimizing temporal parameters are derived, and the method is demonstrated in an experiment with a ball oscillating as a pendulum.%In four-dimensional flash trajectory imaging,temporal parameters include time delay,laser pulse width,gate time,pulse pair repetition frequency and the frame rate of CCD,which directly impact on the acquisition of target trajectories over time.We propose a method of optimizing the temporal parameters of flash trajectory imaging.All the temporal parameters can be estimated by the spatial parameters of the volumes of interest,target scale and velocity,and target sample number.The formulae for optimizing temporal parameters are derived,and the method is demonstrated in an experiment with a ball oscillating as a pendulum.Four-dimensional flash trajectory imaging (FTI)based on time-delay-modulated range-gated viewing can directly image the trajectories of moving objects with backgrounds filtered and deduce target 3D positions over time,[1] which has potentials in astronomy,remote sensing and biomedical applications.[2 4] Temporal parameters are crucial for FTI.An unreasonable setting of temporal parameters will lead to failure in obtaining target trajectories.However,in the previous work,[1] the optimization of temporal parameters has not been discussed in detail.Therefore,in this Letter we give a method of estimating the temporal parameters of FTI.

  3. Media Pengetahuan Metamorfosis Kupu-Kupu dengan Adobe Flash

    OpenAIRE

    Adjie, Fauzan

    2015-01-01

    Kajian ini bertujuan untuk membangun sebuah sistem aplikasi pengenalan. Aplikasi pengethauan metamorfosis kupu - kupu ini dibuat dengan menggunakan perangkat lunak macromedia flash 5. Manfaat dari sistem pengenalan ini adalah membantu para siswa sekolah dasar maupun sekolah menengah atas untuk mengetahui metamorfosis kupu - kupu, khususnya pengetahuan alam. Isi yang di sampaikan mulai dari teori pengetahuan metamorfosis kupu - kupu, yaitu siklus hidup dan metamorfosis yang dimulai dari telur ...

  4. Media Pengetahuan Metamorfosis Kupu-Kupu dengan Adobe Flash

    OpenAIRE

    Adjie, Fauzan

    2015-01-01

    Kajian ini bertujuan untuk membangun sebuah sistem aplikasi pengenalan. Aplikasi pengethauan metamorfosis kupu - kupu ini dibuat dengan menggunakan perangkat lunak macromedia flash 5. Manfaat dari sistem pengenalan ini adalah membantu para siswa sekolah dasar maupun sekolah menengah atas untuk mengetahui metamorfosis kupu - kupu, khususnya pengetahuan alam. Isi yang di sampaikan mulai dari teori pengetahuan metamorfosis kupu - kupu, yaitu siklus hidup dan metamorfosis yang dimulai dari telur ...

  5. Flash flood swift water rescues, Texas, 2005–2014

    Directory of Open Access Journals (Sweden)

    Vaidehi Shah

    2017-01-01

    Full Text Available Although rainfall patterns are complex and difficult to predict, climate models suggest precipitation in Texas will occur less frequently and with greater intensity in the future. In combination with rapid population growth and development, extreme rainfall events are likely to lead to flash floods and necessitate swift water rescues. Swift water rescues are used to retrieve person(s from swift water flowing at a rate of 1 knot or greater. Data were obtained from the Texas Fire Marshal’s Office and analyzed to describe spatial and temporal characteristics of rescues. Between 2005 and 2014, 3256 swift water rescues were reported from 136 of 254 (54% counties. Over half (54.6%, n = 1777 occurred in counties known as Flash Flood Alley, which includes Texas’ largest and fastest growing cities. Less than 1.0% (n = 18 were reported from 49 counties designated as completely rural, or with an urban population less than 2500. Increases in swift water rescues were seen between March and September and during major weather events such as tropical storms. Because county-level data was utilized and demographic data was missing in all but 2% (n = 47 of the incidents, our ability to identify populations at risk or target interventions in the future using this data is limited. Despite the frequency of flash flood events and swift water rescues in Texas, knowledge gaps persist that should be addressed through the conduct of interdisciplinary research by epidemiologists and climatologists and by disseminating evidence-based health education and safety programs, particularly in rapidly growing counties that make up Texas’ Flash Flood Alley.

  6. On the Mechanism of Microwave Flash Sintering of Ceramics

    Directory of Open Access Journals (Sweden)

    Yury V. Bykov

    2016-08-01

    Full Text Available The results of a study of ultra-rapid (flash sintering of oxide ceramic materials under microwave heating with high absorbed power per unit volume of material (10–500 W/cm3 are presented. Ceramic samples of various compositions—Al2O3; Y2O3; MgAl2O4; and Yb(LaO2O3—were sintered using a 24 GHz gyrotron system to a density above 0.98–0.99 of the theoretical value in 0.5–5 min without isothermal hold. An analysis of the experimental data (microwave power; heating and cooling rates along with microstructure characterization provided an insight into the mechanism of flash sintering. Flash sintering occurs when the processing conditions—including the temperature of the sample; the properties of thermal insulation; and the intensity of microwave radiation—facilitate the development of thermal runaway due to an Arrhenius-type dependency of the material’s effective conductivity on temperature. The proper control over the thermal runaway effect is provided by fast regulation of the microwave power. The elevated concentration of defects and impurities in the boundary regions of the grains leads to localized preferential absorption of microwave radiation and results in grain boundary softening/pre-melting. The rapid densification of the granular medium with a reduced viscosity of the grain boundary phase occurs via rotation and sliding of the grains which accommodate their shape due to fast diffusion mass transport through the (quasi-liquid phase. The same mechanism based on a thermal runaway under volumetric heating can be relevant for the effect of flash sintering of various oxide ceramics under a dc/ac voltage applied to the sample.

  7. Fabric Fashion Flash Autumn-Winter 2011-2012

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Italian Trade Commission (I.C.E) joined Ornella Bignami releasing the FABRIC FASHION FLASH AUTUMN-WINTER 2011-2012, in Intertex Shanghai, October.Enriched by an uninterrupted dialogue within the profession for over 25 years, through a fine tuned skill in deciphering major trends and social changes, Ornella Bignami has earned a wide credibility in the field of textile industry, fashion and home textile products.

  8. Fluctuation theorem for the flashing ratchet model of molecular motors

    Science.gov (United States)

    Lacoste, D.; Mallick, K.

    2009-08-01

    Molecular motors convert chemical energy derived from the hydrolysis of adenosine triphosphate (ATP) into mechanical energy. A well-studied model of a molecular motor is the flashing ratchet model. We show that this model exhibits a fluctuation relation known as the Gallavotti-Cohen symmetry. Our study highlights the fact that the symmetry is present only if the chemical and mechanical degrees of freedom are both included in the description.

  9. Spatial Frequency Modulates the Degree of Illusory Second Flash Perception.

    Science.gov (United States)

    Takeshima, Yasuhiro; Gyoba, Jiro

    2015-01-01

    When a brief single flash is presented simultaneously with two brief beeps, the number of presented flashes is often perceived as two. This phenomenon is referred to as the fission illusion. Several effects related to the fission illusion have been investigated using both psychophysical and neurophysiological methods. The present study examined the effects of spatial frequency on the fission illusion. At a low spatial frequency, transient channels respond preferably; conversely, sustained channels respond preferably at a high spatial frequency. Sustained channels differ in temporal properties from transient channels and are characterized by poor temporal resolution and slow-onset responses. In our previous study, visual stimuli presented at a slow processing speed were not conducive to the fission illusion. Therefore, we hypothesized that the fission illusion would not be difficult to observe when using high spatial frequencies. The results indicated that the degree of the perceived illusory second flash was reduced when spatial frequency was high as compared to when it was is low. Furthermore, according to signal detection theory, this difference between high and low spatial frequencies was not attributed to participants' response biases. Therefore, the fission illusion likely will not occur in conditions of slow processing speed and long response latencies in sustained channels, which respond preferably to high spatial frequency stimuli. Overall, the results indicated that the fission illusion was affected by temporal characteristics of lower-order sensory processing stages.

  10. Energetic and exergetic Improvement of geothermal single flash cycle

    Directory of Open Access Journals (Sweden)

    Navid Nazari

    2016-08-01

    Full Text Available This paper presents a detailed analysis of a new method for improving energetic and exergetic efficiencies of single flash cycle. The thermodynamic process of the new method consists of extracting a fraction of hot wellhead geothermal brine for the purpose of superheating saturated steam entering the turbine. Computer programming scripts were developed and optimized based on mathematical proposed models for the different components of the systems. The operating parameters such as separator temperature, geofluid wellhead enthalpy and geothermal source temperature are varied to investigate their effects on both net power output and turbine exhaust quality of the systems. Also, full exergy assessment was performed for the new design. The results of separator temperature optimization revealed that specific net power output of the new design can be boosted up to 8% and turbine exhaust quality can be diminished up to 50% as compared to common single flash cycle. In addition, for wells with higher discharge enthalpy, superheating process improve specific net power output even up to 10%. Finally, it was observed that the overall system exergy efficiency was approximately raised 3%. Article History: Received January 5th 2016; Received in revised form June 25th 2016; Accepted July 3rd 2016; Available online How to Cite This Article: Nazari, N. and Porkhial, S. (2016. Energetic and Exergetic Improvement of Geothermal Single Flash Cycle. Int. Journal of Renewable Energy Development, 5(2,129-138. http://dx.doi.org/10.14710/ijred.5.2.129-138 

  11. Detection and spectral measurements of coherent synchrotron radiation at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, Christopher

    2010-02-15

    The operation of high-gain free-electron laser (FEL) underlies tremendous demands on high quality electron beams with high peak currents. At the Free-Electron-Laser in Hamburg (FLASH), two magnetic bunch compressors are used to compress the electron bunches longitudinally. In the bunch compressor magnets, these short electron bunches generate coherent synchrotron radiation (CSR). This CSR contains information on the longitudinal bunch profile, which is relevant for driving an FEL. In order to investigate coherent synchrotron radiation at the second bunch compressor BC3 at FLASH, a new setup behind the last dipole was installed. For the detection of coherent synchrotron radiation, which is emitted in the infrared regime, pyroelectric detectors were used. These pyroelectric detectors have been calibrated at the free-electron laser FELIX in the wavelength range from 5 {mu}m to 110 {mu}m. For characterisation of the emitted radiation, a transverse scanning device was used to measure the transverse intensity distribution. Various transmission filters were used to obtain additional information about the spectral content. In order to get spectral information with high resolution over a wide wavelength range, a rotating mirror spectrometer using reflective blazed gratings was installed. Using this spectrometer, the first spectral measurements of coherent synchrotron radiation at FLASH in a wavelength range from 10 {mu}m to 160 {mu}m were done. (orig.)

  12. Nonequilibrium vapor-generation model for flashing flows

    Energy Technology Data Exchange (ETDEWEB)

    Saha, P.; Abuaf, N.; Wu, B. J.C.

    1981-01-01

    A nonequilibrium vapor generation model for flashing flows is presented. The model consists of a flashing inception point, a bubbly flow regime followed by a bubbly-slug regime, an annular or annular-mist regime, and finally a dispersed-droplet regime. Existence of superheated liquid at the inception point and beyond is recognized. The vapor generation rate in each flow regime is calculated from the estimates for interfacial area density and net interfacial heat flux. However, the bubble number density at the flashing inception point was varied to obtain optimum fits with the void fraction data taken in a vertical converging-diverging nozzle. The interfacial area density at the inception point, thus determined, showed a rapid increase with the decrease in the liquid superheat at that point. This trend is correct since in the limit of thermal equilibrium flow where the liquid superheat approaches zero, the interfacial area for heat and mass transfer should approach infinity. 32 refs., 7 figs., 1 tab.

  13. Modelling (flash) floods in a Dutch lowland catchment

    Science.gov (United States)

    Brauer, C. C.; Teuling, A. J.; Overeem, A.; van der Velde, Y.; Hazenberg, P.; Warmerdam, P. M. M.; Kloosterman, P.; Uijlenhoet, R.

    2012-04-01

    On 26 August 2010 the eastern part of The Netherlands and the bordering part of Germany were struck by a series of rainfall events. We investigated the unprecedented flash flood triggered by this exceptionally heavy rainfall event (return period > 1000 years) in the 6.5 km2 Hupsel Brook catchment, which has been the experimental watershed employed by Wageningen University since the 1960s. This study improved our understanding of the dynamics of such lowland flash floods and the results have been published in HESS (Brauer et al., 2011). During this extreme event some thresholds became apparent that do not play a role during average conditions and are not incorporated in rainfall-runoff models. We present a detailed analysis of this extreme event, focusing on (1) the measured soil moisture, groundwater and discharge response of the catchment, (2) the thresholds we found, (3) the manner in which these processes and thresholds are incorporated in some well-known conceptual hydrological models and (4) how well these models are able to simulate the rainfall-runoff processes during the 2010 flash flood.

  14. Flash co-pyrolysis of biomass with plastic waste

    Energy Technology Data Exchange (ETDEWEB)

    T. Cornelissen; S. Schreurs; G. Reggers; R. Carleer; J. Yperman [Hasselt University, Diepenbeek (Belgium). Lab of Applied Chemistry

    2007-07-01

    The Global Warming, the Kyoto Protocol and the emission of greenhouse gasses such as CO{sub 2} are the topics of environmental pleadings. The world's energy supply is limited due to the depletion of fossil fuels, which are still the most important energy sources consumed. The development of new and renewable energies is the key to change. The flash pyrolysis of biomass is a promising route for the production of solid, liquid and gaseous products. A high liquid production requires very low vapour residence time to minimise secondary reactions. Flash co-pyrolytic techniques, at low temperature, provide an alternative way to dispose and convert waste (like plastics) and biomass into high value feedstock. The specific benefits of this method potentially include: the reduction of the volume of the waste, the recovery of chemicals and the replacement of fossil fuels. Co-pyrolysing of PLA (although a biologically degradable polymer, polylactic acid), with biomass (such as willow) may be an alternative waste treatment option. This research indicates that during the flash co-pyrolysis of PLA and willow (even when contaminated with high amounts of heavy metals) a synergy is attained, resulting in a higher yield of bio-oil with a lower water content. 10 refs., 1 fig.

  15. Efficacy of desvenlafaxine succinate for menopausal hot flashes.

    Science.gov (United States)

    Tella, Sri Harsha; Gallagher, John Christopher

    2014-11-01

    The concern for the development of breast cancer, stroke, cardiovascular disease and deep venous thrombosis with the use of hormonal therapy has led to the development of alternative nonhormonal forms of therapy like desvenlafaxine for the management of hot flashes. This review is based upon a PubMed search and clinical trials. The pharmacokinetics and pharmacodynamics of desvenlafaxine are reviewed. This review outlines the effects of desvenlafaxine in management of severity and frequency of vasomotor symptoms, sleep quality and quality of life in postmenopausal women. The potential adverse effects of desvenlafaxine are summarized. Based on the evidence from randomized clinical trials, desvenlafaxine is an alternate viable option for reducing the frequency and severity of hot flashes when other treatments fail. In clinical trials, it has been shown that desvenlafaxine reduced the frequency of hot flashes by 55 - 69%. In the trials so far it appears to have good safety and tolerability profile when the drug is initiated in titrating doses. The optimum dose is 100 mg/day and is to be started at 50 mg/day for 3 days and titrated to 100 mg/day. The most common adverse events reported were nausea, dry mouth, fatigue, constipation, diarrhea and somnolence.

  16. Ignition of Nanoparticles by a Compact Camera Flash

    Science.gov (United States)

    2014-09-01

    output for different power settings of a Canon 580 XE II camera  flash  as seen by the  DET36A  fast  photodiode detector.  M1/1 and M1/128 represents the...lamp at and below M1/64 output setting of the Xe‐ flash .   The curves in Figure 2 are produced by the temporal response of the DET36A  fast  photodiode...photographic applications the timescale in Figure 2 is  fast   enough at any setting, but as we will describe later the pulse duration of the Xe‐ flash

  17. Infrared Contrast Analysis Technique for Flash Thermography Nondestructive Evaluation

    Science.gov (United States)

    Koshti, Ajay

    2014-01-01

    The paper deals with the infrared flash thermography inspection to detect and analyze delamination-like anomalies in nonmetallic materials. It provides information on an IR Contrast technique that involves extracting normalized contrast verses time evolutions from the flash thermography infrared video data. The paper provides the analytical model used in the simulation of infrared image contrast. The contrast evolution simulation is achieved through calibration on measured contrast evolutions from many flat bottom holes in the subject material. The paper also provides formulas to calculate values of the thermal measurement features from the measured contrast evolution curve. Many thermal measurement features of the contrast evolution that relate to the anomaly characteristics are calculated. The measurement features and the contrast simulation are used to evaluate flash thermography inspection data in order to characterize the delamination-like anomalies. In addition, the contrast evolution prediction is matched to the measured anomaly contrast evolution to provide an assessment of the anomaly depth and width in terms of depth and diameter of the corresponding equivalent flat-bottom hole (EFBH) or equivalent uniform gap (EUG). The paper provides anomaly edge detection technique called the half-max technique which is also used to estimate width of an indication. The EFBH/EUG and half-max width estimations are used to assess anomaly size. The paper also provides some information on the "IR Contrast" software application, half-max technique and IR Contrast feature imaging application, which are based on models provided in this paper.

  18. Flash pyrolysis, a process for utilizing contaminated wood; Flash-Pyrolyse - eine Moeglichkeit der stofflichen Verwertung von kontaminiertem Holz

    Energy Technology Data Exchange (ETDEWEB)

    Meier, D.; Wehlte, S.; Faix, O. [Bundesforschungsanstalt fuer Forst- und Holzwirtschaft, Hamburg (Germany). Inst. fuer Holzchemie und Chemische Technologie des Holzes

    1996-12-31

    Flash pyrolysis of wood treated with common pesticides poses no technical probelms. Product yields, with a maximum oil yield at 475 C, are similar to those of untreated wood. Most of the heavy metals are retained by the coal while a small part aheres to the coal layer of the sand bed. The resulting pyrolysis oil contains neither chromium nor copper. (orig) [Deutsch] Die Flash-Pyrolyse der mit den gaengigsten Schutzmitteln behandelten Hoelzer bereitet verfahrenstechnisch keine Probleme. Auch die Produktausbeuten, mit einem oelmaximum bei 475 C, aehneln denen von naturbelassenem Holz. Der groesste Teil der Schwermetalle wurde an die Kohle gebunden, ein geringer Teil blieb auf der Kohleschicht des Sandes haften. Im Hauptprodukt Pyrolyseoel konnten weder Chrom noch Kupfer nachgewiesen werden. (orig)

  19. Flow ensemble prediction for flash flood warnings at ungauged basins

    Science.gov (United States)

    Demargne, Julie; Javelle, Pierre; Organde, Didier; Caseri, Angelica; Ramos, Maria-Helena; de Saint Aubin, Céline; Jurdy, Nicolas

    2015-04-01

    Flash floods, which are typically triggered by severe rainfall events, are difficult to monitor and predict at the spatial and temporal scales of interest due to large meteorological and hydrologic uncertainties. In particular, uncertainties in quantitative precipitation forecasts (QPF) and quantitative precipitation estimates (QPE) need to be taken into account to provide skillful flash flood warnings with increased warning lead time. In France, the AIGA discharge-threshold flood warning system is currently being enhanced to ingest high-resolution ensemble QPFs from convection-permitting numerical weather prediction (NWP) models, as well as probabilistic QPEs, to improve flash flood warnings for small-to-medium (from 10 to 1000 km²) ungauged basins. The current deterministic AIGA system is operational in the South of France since 2005. It ingests the operational radar-gauge QPE grids from Météo-France to run a simplified hourly distributed hydrologic model at a 1-km² resolution every 15 minutes (Javelle et al. 2014). This produces real-time peak discharge estimates along the river network, which are subsequently compared to regionalized flood frequency estimates of given return periods. Warnings are then provided to the French national hydro-meteorological and flood forecasting centre (SCHAPI) and regional flood forecasting offices, based on the estimated severity of ongoing events. The calibration and regionalization of the hydrologic model has been recently enhanced to implement an operational flash flood warning system for the entire French territory. To quantify the QPF uncertainty, the COSMO-DE-EPS rainfall ensembles from the Deutscher Wetterdienst (20 members at a 2.8-km resolution for a lead time of 21 hours), which are available on the North-eastern part of France, were ingested in the hydrologic model of the AIGA system. Streamflow ensembles were produced and probabilistic flash flood warnings were derived for the Meuse and Moselle river basins and

  20. Flash sintering of dielectric nanoparticles as a percolation phenomenon through a softened film

    Science.gov (United States)

    Chaim, Rachman; Chevallier, Geoffroy; Weibel, Alicia; Estournès, Claude

    2017-04-01

    Recent work [Biesuz et al., J. Appl. Phys. 120, 145107 (2016)] showed analogies between the flash sintering and dielectric breakdown in α-aluminas pre-sintered to different densities. Here, we show that flash sintering of dielectric nanoparticles can be described as a universal behavior by the percolation model. The electrical system is composed of particles and their contact point resistances, the latter softened first due to preferred local Joule heating and thermal runaway during the flash. Local softening has a hierarchical and invasive nature and propagates between the electrodes. The flash event signals the percolation threshold by invasive nature of the softened layer at the particle surfaces. Rapid densification is associated with local particle rearrangements due to attractive capillary forces induced by the softened film at the particle contacts. Flash sintering is a critical phenomenon with a self-organizing character. The experimental electric conductivity results from flash sintering are in full agreement with those calculated from the percolation model.

  1. Circulating leptin and adiponectin are associated with insulin resistance in healthy postmenopausal women with hot flashes.

    Science.gov (United States)

    Huang, Wan-Yu; Chang, Chia-Chu; Chen, Dar-Ren; Kor, Chew-Teng; Chen, Ting-Yu; Wu, Hung-Ming

    2017-01-01

    Hot flashes have been postulated to be linked to the development of metabolic disorders. This study aimed to evaluate the relationship between hot flashes, adipocyte-derived hormones, and insulin resistance in healthy, non-obese postmenopausal women. In this cross-sectional study, a total of 151 women aged 45-60 years were stratified into one of three groups according to hot-flash status over the past three months: never experienced hot flashes (Group N), mild-to-moderate hot flashes (Group M), and severe hot flashes (Group S). Variables measured in this study included clinical parameters, hot flash experience, fasting levels of circulating glucose, lipid profiles, plasma insulin, and adipocyte-derived hormones. Multiple linear regression analysis was used to evaluate the associations of hot flashes with adipocyte-derived hormones, and with insulin resistance. The study was performed in a hospital medical center. The mean (standard deviation) of body-mass index was 22.8(2.7) for Group N, 22.6(2.6) for Group M, and 23.5(2.4) for Group S, respectively. Women in Group S displayed statistically significantly higher levels of leptin, fasting glucose, and insulin, and lower levels of adiponectin than those in Groups M and N. Multivariate linear regression analysis revealed that hot-flash severity was significantly associated with higher leptin levels, lower adiponectin levels, and higher leptin-to-adiponectin ratio. Univariate linear regression analysis revealed that hot-flash severity was strongly associated with a higher HOMA-IR index (% difference, 58.03%; 95% confidence interval, 31.00-90.64; p adiponectin and was no longer significant after simultaneously adjusting for leptin and adiponectin. The present study provides evidence that hot flashes are associated with insulin resistance in postmenopausal women. It further suggests that hot flash association with insulin resistance is dependent on the combination of leptin and adiponectin variables.

  2. ActionScript 30 Cookbook Solutions for Flash Platform and Flex Application Developers

    CERN Document Server

    Lott, Joey; Peters, Keith

    2008-01-01

    Well before Ajax and Windows Presentation Foundation, Macromedia Flash provided the first method for building rich" web pages. Now, Adobe is making Flash a full-fledged development environment, and learning ActionScript 3.0 is key. That's a challenge for even the most experienced Flash developer. This Cookbook offers more than 300 solutions to solve a wide range of coding dilemmas, so you can learn to work with the new version right away."

  3. Calculation of flash temperature for hybrid ceramic ball bearing lubricated with solid

    Institute of Scientific and Technical Information of China (English)

    李秀娟; 王黎钦; 古乐; 齐毓霖

    2002-01-01

    The scuffing behavior of hybrid ceramic bearing lubricated with solid is greatly affected by the contact flash temperature. Formulas are dedused using Lee' s asperity flash temperature method, to calculate the flash temperature of ball bearing lubricated with solid. The maximum flash temperature is calculated for hybrid ceramic ball bearings. The results show that under given conditions, the flash temperature of inner race is higher than that of outer race, the flash temperature of the hybrid ceramic bearing is sensitive to the load, rotational speed and race curvature. The flash temperature of inner race at 20 000 r/min is 66.9% more than that that at 11 000 r/min, and with the load changing from 1.1 kN to 2 kN, the flash temperature inner race goes up to 165.7%. Very common for high speed ball bearings, when curvature coefficients of both inner and outer race change from 0. 515 to 0.56, the inner race flash temperature decreases from 421. 446℃ to 56.2℃.

  4. Mechanism of red-luminescence flash in CdS single crystals irradiated by electrons

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanyuk, N.S.; Galushka, A.P.; Ostapenko, S.S.; Shejnkman, M.K. (AN Ukrainskoj SSR, Kiev. Inst. Poluprovodnikov)

    1984-02-01

    Results of investigations into ''red''-luminescence flash (lambdasub(x)=720 nm) in cadmium sulfide, irradiated by electrons at 77 K, are presented. Measurement of spectra of stationary photoluminescence and its excitation, as well as flash luminescence, its pumping and stimulation along with temperature flash dependences enabled to suggest a new mechanism of optical luminescence stimulation, based on the model of complex center of flash luminescense. The mechanism consists in modulation of probabilities of intercenter electron transitions, when charge state of one of components of the complex center changes.

  5. Cost-Effective Test Solutions for Smart Card and Other Integrated Flash Applications

    Institute of Scientific and Technical Information of China (English)

    Thomas M. Trexler

    2004-01-01

    @@ From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.

  6. A European precipitation index for extreme rain‐storm and flash flood early warning

    National Research Council Canada - National Science Library

    Alfieri, L; Thielen, J

    2015-01-01

    .... Despite recent notable advances in weather forecasting, most operational early warning systems for extreme rainstorms and flash floods are still based on rainfall measurements from rain gauges...

  7. THE FLASH FLOODS ANALYSIS, REPRESENTATIVE FOR NIRAJ RIVER BETWEEN 1970-2008

    Directory of Open Access Journals (Sweden)

    ROŞCA SANDA

    2011-03-01

    Full Text Available The flash floods analysis, representative for Niraj River between 1970-2008. The need to know the characteristics of the flash floods is derived from the number and the intensity of floods occurred in the drainage basin of the Niraj river. Therefore, there were analyzed only the flash floods representatives for the years: 1970, 1995, 1998, 2001, 2008.The classification of the floods was realized according to the genesis and the flash flood hydrograph shape for the period 1970-2008, before and after the completion of the drainage basin planning/management depending on climatic, morphometric and morphological factors.

  8. Hot flashes and midlife symptoms in relation to levels of salivary cortisol.

    Science.gov (United States)

    Gerber, Linda M; Sievert, Lynnette L; Schwartz, Joseph E

    2017-02-01

    This study examined the relationship between salivary cortisol levels and hot flashes during midlife. Previous studies have shown that cortisol levels increase with hot flashes in the laboratory, and higher cortisol levels have been associated with more severe hot flashes. Salivary cortisol levels were also examined in relation to total number of midlife symptoms. Women aged 40-60 years (n=109) reported the presence or absence of 23 symptoms, including hot flashes, during the previous 2 weeks. Salivary samples were collected at waking, 30min after waking, 1h before bedtime, and at bedtime. The cortisol awakening response (CAR), cortisol daily decline (CDD), log transformed salivary cortisol levels at each time point, and mean cortisol levels were compared by hot flash report using t-tests. Logistic regression analyses were performed to assess the association between each cortisol measure and the presence or absence of hot flashes, after controlling for potential covariates. Salivary cortisol levels were not significantly associated with hot flashes or sum of symptoms. Hot flash report did not differentiate women who had a positive CAR from those who did not, or women who showed strong CDD from those who did not. Symptomatic women - defined by hot flash report or symptom total - were not found to have higher salivary cortisol levels. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Effectiveness of Automatic Control over Flash Distillation Kettle for Liquid-Phase Bulk Polymerization of Propylene

    Institute of Scientific and Technical Information of China (English)

    Han Linge; Ma Jiantong

    2004-01-01

    Automatic control over flash distillation section at SINOPEC Cangzhou Refinery has been realized, resulting in saving of propylene feedstock and emission reduction to harvest significant economic benefits.

  10. Flash Flooding and Green Stormwater Infrastructure in Philadelphia: Areas for Further Improvement

    OpenAIRE

    DOĞANAY, Ela; MAGAZINER, Jamie

    2017-01-01

    Flash flooding is one of the most dangerous and the most common catastrophes among the other types of floods occure in USA. Flash flooding may occur in any area that may not even be located in floodplain zone. Since the flash flooding can take a few minutes or a few hours with out any warning and has high damaging potential, in this study, it is focused on identifying areas prone to flash flooding in the Philadelphia city, which has many natural streams and high development rates. In this stu...

  11. The properties of optical lightning flashes and the clouds they illuminate

    Science.gov (United States)

    Peterson, Michael; Deierling, Wiebke; Liu, Chuntao; Mach, Douglas; Kalb, Christina

    2017-01-01

    Optical lightning sensors like the Optical Transient Detector and Lightning Imaging Sensor (LIS) measure total lightning across large swaths of the globe with high detection efficiency. With two upcoming missions that employ these sensors - LIS on the International Space Station and the Geostationary Lightning Mapper on the GOES-R satellite - there has been increased interest in what these measurements can reveal about lightning and thunderstorms in addition to total flash activity. Optical lightning imagers are capable of observing the characteristics of individual flashes that include their sizes, durations, and radiative energies. However, it is important to exercise caution when interpreting trends in optical flash measurements because they can be affected by the scene. This study uses coincident measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite to examine the properties of LIS flashes and the surrounding cloud regions they illuminate. These combined measurements are used to assess to what extent optical flash characteristics can be used to make inferences about flash structure and energetics. Clouds illuminated by lightning over land and ocean regions that are otherwise similar based on TRMM measurements are identified. Even when LIS flashes occur in similar clouds and background radiances, oceanic flashes are still shown to be larger, brighter, longer lasting, more prone to horizontal propagation, and to contain more groups than their land-based counterparts. This suggests that the optical trends noted in literature are not entirely the result of radiative transfer effects but rather stem from physical differences in the flashes.

  12. Integrated flash flood vulnerability assessment: Insights from East Attica, Greece

    Science.gov (United States)

    Karagiorgos, Konstantinos; Thaler, Thomas; Heiser, Micha; Hübl, Johannes; Fuchs, Sven

    2016-10-01

    In the framework of flood risk assessment, vulnerability is a key concept to assess the susceptibility of elements at risk. Besides the increasing amount of studies on flash floods available, in-depth information on vulnerability in Mediterranean countries was missing so far. Moreover, current approaches in vulnerability research are driven by a divide between social scientists who tend to view vulnerability as representing a set of socio-economic factors, and natural scientists who view vulnerability in terms of the degree of loss to an element at risk. Further, vulnerability studies in response to flash flood processes are rarely answered in the literature. In order to close this gap, this paper implemented an integrated vulnerability approach focusing on residential buildings exposed to flash floods in Greece. In general, both physical and social vulnerability was comparable low, which is interpreted as a result from (a) specific building regulations in Greece as well as general design principles leading to less structural susceptibility of elements at risk exposed, and (b) relatively low economic losses leading to less social vulnerability of citizens exposed. The population show high risk awareness and coping capacity to response to natural hazards event and in the same time the impact of the events are quite low, because of the already high use of local protection measures. The low vulnerability score for East Attica can be attributed especially to the low physical vulnerability and the moderate socio-economic well-being of the area. The consequence is to focus risk management strategies mainly in the reduction of the social vulnerability. By analysing both physical and social vulnerability an attempt was made to bridge the gap between scholars from sciences and humanities, and to integrate the results of the analysis into the broader vulnerability context.

  13. The development of a flash flood severity index

    Science.gov (United States)

    Schroeder, Amanda J.; Gourley, Jonathan J.; Hardy, Jill; Henderson, Jen J.; Parhi, Pradipta; Rahmani, Vahid; Reed, Kimberly A.; Schumacher, Russ S.; Smith, Brianne K.; Taraldsen, Matthew J.

    2016-10-01

    Flash flooding is a high impact weather event that requires clear communication regarding severity and potential hazards among forecasters, researchers, emergency managers, and the general public. Current standards used to communicate these characteristics include return periods and the United States (U.S.) National Weather Service (NWS) 4-tiered river flooding severity scale. Return periods are largely misunderstood, and the NWS scale is limited to flooding on gauged streams and rivers, often leaving out heavily populated urban corridors. To address these shortcomings, a student-led group of interdisciplinary researchers came together in a collaborative effort to develop an impact-based Flash Flood Severity Index (FFSI). The index was proposed as a damage-based, post-event assessment tool, and preliminary work toward the creation of this index has been completed and presented here. Numerous case studies were analyzed to develop the preliminary outline for the FFSI, and three examples of such cases are included in this paper. The scale includes five impact-based categories ranging from Category 1 very minor flooding to Category 5 catastrophic flooding. Along with the numerous case studies used to develop the initial outline of the scale, empirical data in the form of semi-structured interviews were conducted with multiple NWS forecasters across the country and their responses were analyzed to gain more perspective on the complicated nature of flash flood definitions and which tools were found to be most useful. The feedback from these interviews suggests the potential for acceptance of such an index if it can account for specific challenges.

  14. The relativistic feedback discharge model of terrestrial gamma ray flashes

    Science.gov (United States)

    Dwyer, Joseph R.

    2012-02-01

    As thunderclouds charge, the large-scale fields may approach the relativistic feedback threshold, above which the production of relativistic runaway electron avalanches becomes self-sustaining through the generation of backward propagating runaway positrons and backscattered X-rays. Positive intracloud (IC) lightning may force the large-scale electric fields inside thunderclouds above the relativistic feedback threshold, causing the number of runaway electrons, and the resulting X-ray and gamma ray emission, to grow exponentially, producing very large fluxes of energetic radiation. As the flux of runaway electrons increases, ionization eventually causes the electric field to discharge, bringing the field below the relativistic feedback threshold again and reducing the flux of runaway electrons. These processes are investigated with a new model that includes the production, propagation, diffusion, and avalanche multiplication of runaway electrons; the production and propagation of X-rays and gamma rays; and the production, propagation, and annihilation of runaway positrons. In this model, referred to as the relativistic feedback discharge model, the large-scale electric fields are calculated self-consistently from the charge motion of the drifting low-energy electrons and ions, produced from the ionization of air by the runaway electrons, including two- and three-body attachment and recombination. Simulation results show that when relativistic feedback is considered, bright gamma ray flashes are a natural consequence of upward +IC lightning propagating in large-scale thundercloud fields. Furthermore, these flashes have the same time structures, including both single and multiple pulses, intensities, angular distributions, current moments, and energy spectra as terrestrial gamma ray flashes, and produce large current moments that should be observable in radio waves.

  15. Modeling of Pulses in Terrestrial Gamma-ray Flashes

    Science.gov (United States)

    Xu, Wei; Celestin, Sebastien; Pasko, Victor

    2015-04-01

    Terrestrial Gamma-ray Flashes (TGFs) are high-energy photon bursts originating from the Earth's atmosphere that are associated with lightning activities. After their discovery in 1994 by the Burst and Transient Source Experiment (BATSE) detector aboard the Compton Gamma-Ray Observatory [Fishman et al., Science, 264, 1313, 1994], this phenomenon has been further observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) [Smith et al., Science, 307, 1085, 2005], the Fermi Gamma-ray Space Telescope [Briggs et al., JGR, 115, A07323, 2010] and the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite [Marisaldi et al., JGR, 115, A00E13, 2010]. Photon spectra corresponding to the mechanism of relativistic runaway electron avalanches (RREAs) usually provide a very good agreement with satellite observations [Dwyer and Smith, GRL, 32, L22804, 2005]. On the other hand, Celestin and Pasko [JGR, 116, A03315, 2011] have shown theoretically that the large flux of thermal runaway electrons generated by streamers during the negative corona flash stage of stepping lightning leaders in intracloud lightning flashes could be responsible for TGFs. Recently, based on analysis of the temporal profiles of 278 TGF events observed by the Fermi Gamma-Ray Burst Monitor, Foley et al. [JGR, 119, 5931, 2014] have suggested that 67% of TGF pulses detected are asymmetric and these asymmetric pulses are consistent with the production mechanism of TGFs by relativistic feedback discharges. In the present work, we employ a Monte Carlo model to study the temporal distribution of photons at low-orbit satellite altitudes during TGF events. Using the pulse fitting method described in [Foley et al., 2014], we further investigate the characteristics of TGF pulses. We mainly focus on the effects of Compton scattering on the symmetry properties and the rise and fall times of TGF pulses.

  16. Assessing Patterns in the Surface Electric Field Prior to First CG Flashes and After Last CG Flashes in Air-Mass Thunderstorms

    Science.gov (United States)

    Williams, D. E.; Beasley, W. H.; Hyland, P. T.

    2007-12-01

    In an effort to elicit patterns in the temporal and spatial evolution of the contours of surface electric field relevant to the occurrence of cloud-to-ground (CG) lightning, we have analyzed data from the network of 31 electric-field mills jointly operated by the John F. Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). To identify cases of interest, we used lightning ground-strike data, maps of in-cloud lightning discharges, rainfall data, and radar data. In particular, we have focused on two critical problems: 1) estimation of when and where the first CG flash in a storm might occur and 2) assessment of the likelihood of CG flashes occurring late in a storm after a long period without a CG flash. Our long-term goal is to understand the evolution of surface contours of electric field for periods of 30 minutes or more before the first flash of any kind and 30 minutes or more before and after the last flash of any kind. For practical reasons, we are reporting here on analysis of data for periods of 30 minutes before the first CG flash and 30 minutes after the last CG flash in each storm of interest. We have analyzed electric-field data from isolated air-mass convective storms that developed over KSC/CCAFS from late May through early September, 2004-2006. To identify thunderstorms that fit the air-mass, or "pop-up" criteria, we started by examining rainfall and CG lightning data, then looked at radar data. Then, for the storms selected, we performed a two-pass Barnes objective analysis on the electric-field data. Each analysis cycle resulted in one contour plot of 20-second averaged data, yielding 90 plots for each 30 minute interval, which we then animated. This resulted in 58 animations of the field contours prior to first CG flashes and 62 animations of the field contours after last CG flashes. Preliminary impressions from examinations of these cases suggest that the electric-field contours before the first flash exhibit a smooth transition

  17. A Flashing Model for Transport of Brownian Motors

    Institute of Scientific and Technical Information of China (English)

    赵同军; 展永; 吴建海; 王永宏

    2002-01-01

    A flashing coloured noise model is proposed to describe the motion of a molecular motor. In this model,the overdamped Brownian particle moves in an asymmetric periodic potential with a tashing Ornstein-Ulenbeck coloured noise. The relationship between the current and the parameters-such as the intensity, the correlation time of coloured noise and the flip rate of the noise-is discussed using the Monte Carlo simulation method.Current reversal occurs with the change of the correlation time and the flip rate of coloured noise, which may be related to the directed motion and the current reversal of molecular motors.

  18. Coal flash pyrolysis. 5. Pyrolysis in an atmosphere of methane

    Energy Technology Data Exchange (ETDEWEB)

    Calkins, W.H.; Bonifaz, C.

    1984-12-01

    Flash pyrolysis of coal at temperatures above 700/sup 0/C and in the presence of methane produces substantially more ethylene and other low molecular weight hydrocarbons than are produced by pyrolysis of coal in the presence of nitrogen alone. Evidence is presented to show that the increase is due to pyrolysis of the methane quite independently of the coal, except with the possible catalysis by the coal, coke or mineral matter in the coal ash. This is contrary to recent reports in the literature.

  19. An Effective Approach to Flash Vacuum Thermolytic Studies

    DEFF Research Database (Denmark)

    Carlsen, Lars; Egsgaard, Helge

    1980-01-01

    Flash vacuum thermolysis in combination with field ionization mass spectrometry, supplementary with collision activated spectra of the single field ionized molecules, is shown to be a facile and highly informative method for studying even very complex mixtures of primarily formed products...... in the gas phase thermolysis of organic molecules. The method allows quantitative detection of substances with half lifes t1/2 > 10−3 sec. A detailed description of the apparatus, which offers the possibility of studying gas phase thermolyses over a wide range of temperatures (300—1400 K), and the method...

  20. STUDY ON MULTIMEDIA ANIMATION SYSTEM OF ACUPOINT ANATOMY WITH FLASH

    Institute of Scientific and Technical Information of China (English)

    WANG Bin; LUO Zhi-yong; PU Yu-feng; HONG Hong; ZUO Zhi-xiong

    2006-01-01

    Mastering anatomic structures of acupoints is of active significance for avoiding blindly needling and preventing accidents of acupuncture and moxibustion. This multimedia animation system of acupoint anatomy adopts Flash software as developing tool and can dynamically display anatomic layers of needle insertion, with objectivity, convenient operation and English-Chinese control, higher reliability, easy to study and master anatomic knowledge of acupoint anatomy, increase teaching efficiency, and richen teaching ways. This system can be used as a teaching tool of acupuncture and moxibustion, a software of studying anatomy of acupoints and an adjuvant tool of medical workers in studying anatomy.

  1. Frequency upshift via flash ionization phenomena using semiconductor plasma

    Directory of Open Access Journals (Sweden)

    Nishida A.

    2013-11-01

    Full Text Available We have demonstrated frequency upshift in the terahertz region by flash ionization. The magnitude of upshift frequency is tuned by the laser intensity. A proof of principle experiment has been performed with a plasma creation time scale much shorter than the period of the electromagnetic wave and a plasma length longer than its wavelength. Frequency upshifted from 0.35 to 3.5 THz by irradiating a ZnSe crystal with a ultra-short laser pulse has been observed.

  2. Temperature distribution study in flash-annealed amorphous ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Moron, C. E-mail: cmoron@eui.upm.es; Garcia, A.; Carracedo, M.T

    2003-01-01

    Negative magnetrostrictive amorphous ribbons have been locally current annealed with currents from 1 to 8 A and annealing times from 14 ms to 200 s. In order to obtain information about the sample temperature during flash or current annealing, a study of the temperature dispersion during annealing in amorphous ribbons was made. The local temperature variation was obtained by measuring the local intensity of the infrared emission of the sample with a CCD liquid nitrogen cooled camera. A distribution of local temperature has been found in spite of the small dimension of the sample.

  3. Sunset Times, El Niño and Green Flashes

    Science.gov (United States)

    Liller, William

    2010-01-01

    On 637 occasions since 1988, precise times of sunset over the Pacific Ocean have been observed from a coastal site in central Chile (lat. 32.9º S.) at an elevation of approximately 120 meters. The original intent was to find if there was a connection between these times and the presence of the El Niño Oscillation event owing to the variation in atmospheric refraction that would be expected with a change in sea surface temperature. While no such effect was found, other phenomena were noted including the occurence of the green flash.

  4. Temporal Binding Window of the Sound-Induced Flash Illusion in Amblyopia.

    Science.gov (United States)

    Narinesingh, Cindy; Goltz, Herbert C; Wong, Agnes M F

    2017-03-01

    Amblyopia is a neurodevelopmental visual disorder caused by abnormal visual experience in childhood. In addition to known visual deficits, there is evidence for changes in audiovisual integration in amblyopia using explicit tasks. We examined audiovisual integration in amblyopia using an implicit task that is more relevant in a real-world context. A total of 11 participants with amblyopia and 16 controls were tested binocularly and monocularly on the sound-induced flash illusion, in which flashes and beeps are presented concurrently and the perceived number of flashes is influenced by the number of beeps. The task used 1 to 2 rapid peripheral flashes presented with 0 to 2 beeps, at 5 stimulus onset asynchronies, that is, beep (-200 milliseconds, -100 milliseconds) or flash leading (100 milliseconds, 200 milliseconds) or simultaneous (0 milliseconds). Participants reported the number of perceived flashes. Susceptibility was indicated by a "2 flashes" response to "fission" (1 flash, 2 beeps) or "1 flash" to "fusion" (2 flashes, 1 beep). For fission with the beep leading during binocular viewing, controls showed an expected decrease in illusion strength as stimulus onset asynchronies increased, whereas the illusion strength remained constant in participants with amblyopia, indicating a wider temporal binding window in amblyopia (P = 0.007). For fusion, participants with amblyopia showed reduced illusion strength during amblyopic eye viewing (P = 0.044) with the flash leading. Amblyopia is associated with the widening of the temporal binding window, specifically for fission when viewing binocularly with the beep leading. This suggests a developmental adaptation to delayed amblyopic eye visual processing to optimize audiovisual integration.

  5. RURAL FLASH-FLOOD BEHAVIOR IN GOUYAVE WATERSHED, GRENADA, CARIBBEAN ISLAND

    Directory of Open Access Journals (Sweden)

    Rahmat Aris Pratomo

    2016-10-01

    Full Text Available Flash-flood is considered as one of the most common natural disasters in Grenada, a tropical small state island in Caribbean Island. Grenada has several areas which are susceptible to flooding. One of them is Gouyave town which is located in the north-west of Grenada. Its land-use types are highly dominated by green areas, especially in the upper-part of the region. The built-up areas can only be found in the lower-part of Gouyave watershed, near the coastal area. However, there were many land conversions from natural land-use types into built-up areas in the upper-part region. They affected the decrease of water infiltration and the increase of potential run-off, making these areas susceptible to flash-flood. In addition, it is also influenced by the phenomenon of climate change. Changes in extreme temperature increase higher potential of hurricanes or wind-storm, directly related to the potential escalation of flash-flood. To develop effective mitigation strategies, understanding the behavior of flash-flood is required. The purpose of this paper was to observe the behavior of flash-flood in Gouyave watershed in various return periods using OpenLISEM software. It was used to develop and analyse the flash-flood characteristics. The result showed that the climatic condition (rainfall intensity and land-use are influential to the flash-flood event. Flash-flood occurs in 35 and 100 years return period. Flash-flood inundates Gouyave’s area in long duration, with below 1 m flood depth. The flood propagation time is slow. This condition is also influenced by the narrower and longer of Gouyave basin shape. To develop flash-flood reduction strategies, the overall understanding of flash-flood behavior is important. If the mitigation strategy is adapted to their behavior, the implementation will be more optimum.

  6. Flash droughts in a typical humid and subtropical basin: A case study in the Gan River Basin, China

    Science.gov (United States)

    Zhang, Yuqing; You, Qinglong; Chen, Changchun; Li, Xin

    2017-08-01

    As opposed to traditional drought events, flash droughts evolve rapidly and are characterized by soil moisture deficits. The general lack of high resolution soil moisture and evapotranspiration data makes identifying flash droughts at short-term scales (pentads or weeks) nearly impossible, particularly at the basin scale. In this study, we investigated the spatial patterns, temporal characteristics, and related mechanisms of flash droughts in a humid and subtropical basin (Gan River Basin) in China. The variable infiltration capacity (VIC) model can accurately reflect hydrological processes in the Gan River Basin at daily and monthly time scales; here, flash droughts were determined based on VIC outputs (soil moisture and evapotranspiration) and meteorological observations (maximum temperature and precipitation) during the growing season (March-October) from 1961 to 2013. We classified flash droughts into two categories (heat wave and precipitation deficit flash droughts) based on the formation mechanisms. Heat wave flash droughts are high temperature driven events, high temperatures (heat waves) cause evapotranspiration to increase and soil moisture to decrease rapidly. The main driver of precipitation deficit flash droughts is precipitation deficits, which cause soil moisture to drop and in turn cause evapotranspiration anomalies to decrease and temperature to increase. The northern part of the basin is apparently vulnerable to heat wave flash droughts, whereas precipitation deficit flash droughts tend to occur across the central and southern parts of the basin. Precipitation deficit flash droughts are more common than heat wave flash droughts in general. Both types of flash droughts became significantly more frequent from 1997 to 2013. These increases in both types of flash droughts are likely attributable to climate-related variables such as temperature, precipitation, evapotranspiration, and soil moisture during 1997-2013. As evidenced by our investigation of

  7. Conditions for Production of Terrestral Gamma-Ray Flashes

    Science.gov (United States)

    Lehtinen, N. G.; Inan, U. S.

    2005-12-01

    Terrestrial gamma-ray flashes (TGFs) are the most energetic natural photon phenomena on Earth and have been a subject of keen interest since their accidental discovery by the Burst and Transient Source Experiment (BATSE) instrument on the Compton Gamma Ray Observatory (CGRO), which has observed a total of 76 flashes at an average rate of once per month. The new observations of hundreds of TGFs on the RHESSI spacecraft, with many tens of events observed per month, corresponding to a rate of >50 events per day globally, bring to the fore the need of theoretical studies of new TGF mechanisms. In this work, we study the TGF production by a combined action of the electromagnetic pulse (EMP) from a lightning return stroke and the post-discharge quasi-electrostatic (QES) field. We investigate various parameters necessary for the production of a detectable TGF, including the return stroke speed and maximum value, the charge removed by a continuing current in the positive cloud-to-ground (+CG) discharge, and the dependence on the pre-discharge atmosphere conductivity profile.

  8. Hydrodynamic simulations of He-shell flash convection

    CERN Document Server

    Herwig, F; Hückstädt, R M; Timmes, F X; Freytag, Bernd; Herwig, Falk; Hueckstaedt, Robert M.; Timmes, Francis X.

    2006-01-01

    We present the first hydrodynamic, multi-dimensional simulations of He-shell flash convection. Specifically, we investigate the properties of shell convection at a time immediately before the He- luminosity peak during the 15th thermal pulse of a stellar evolution track with initially two solar masses and metallicity Z=0.01. This choice is a representative example of a low-mass asymptotic giant branch thermal pulse. We construct the initial vertical stratification with a set of polytropes to resemble the stellar evolution structure. Convection is driven by a constant volume heating in a thin layer at the bottom of the unstable layer. We calculate a grid of 2D simulations with different resolutions and heating rates. Our set of simulations includes one low-resolution 3D run. The computational domain includes 11.4 pressure scale heights. He-shell flash convection is dominated by large convective cells that are centered in the lower half of the convection zone. Convective rolls have an almost circular appearance...

  9. The mutagenic potential of high flash aromatic naphtha.

    Science.gov (United States)

    Schreiner, C A; Edwards, D A; McKee, R H; Swanson, M; Wong, Z A; Schmitt, S; Beatty, P

    1989-06-01

    Catalytic reforming is a refining process that converts naphthenes to aromatics by dehydrogenation to make higher octane gasoline blending components. A portion of this wide boiling range hydrocarbon stream can be separated by distillation and used for other purposes. One such application is a mixture of predominantly 9-carbon aromatic molecules (C9 aromatics, primarily isomers of ethyltoluene and trimethylbenzene), which is removed and used as a solvent--high-flash aromatic naphtha. A program was initiated to assess the toxicological properties of high-flash aromatic naphtha since there may be human exposure through inhalation or external body contact. The current study was conducted partly to assess the potential for mutagenic activity and also to assist in an assessment of carcinogenic potential. The specific tests utilized included the Salmonella/mammalian microsome mutagenicity assay, the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) forward mutation assay in CHO cells, in vitro chromosome aberration and sister chromatid exchange (SCE) assays in CHO cells, and an in vivo chromosome aberration assay in rat bone marrow.

  10. Experimental Research on Flash Boiling Spray of Dimethyl Ether

    Institute of Scientific and Technical Information of China (English)

    Peng Zhang

    2014-01-01

    The high-speed digital imaging technique is applied to observe the developing process of flash boiling spray of dimethyl ether at low ambient pressure, and the effects of nozzle opening pressure and nozzle hole diameter on the spray shape, spray tip penetration and spray angle during the injection are investigated. The experimental results show that the time when the vortex ring structure of flash boiling spray forms and its developing process are determined by the combined action of the bubble growth and breakup in the spray and the air drag on the leading end of spray;with the enhancement of nozzle opening pressure, the spray tip penetration increases and the spray angle decreases. The influence of nozzle hole diameter on the spray tip penetration is relatively complicated, the spray tip penetration is longer with a smaller nozzle hole diameter at the early stage of injection, while the situation is just opposite at the later stage of injection. This paper establishes that the variation of spray angle is consistent with that of nozzle hole diameter.

  11. Helium shells and faint emission lines from slitless flash spectra.

    Science.gov (United States)

    Bazin, Cyril; Koutchmy, Serge

    2013-05-01

    At the time of the two last solar total eclipses of August 1st, 2008 in Siberia and July 11th, 2010 in French Polynesia, high frame rate CCD flash spectra were obtained. These eclipses occurred in quiet Sun period and after. The slitless flash spectra show two helium shells, in the weak Paschen α 4686 Å line of the ionized helium HeII and in the neutral helium HeI line at 4713 Å. The extensions of these helium shells are typically 3 Mm. In prominences, the extension of the interface with the corona is much more extended. The observations and analysis of these lines can properly be done only in eclipse conditions, when the intensity threshold reaches the coronal level, and the parasitic scattered light is virtually zero. Under the layers of 1 Mm above the limb, many faint low FIP lines were also seen in emission. These emission lines are superposed on the continuum containing absorption lines. The solar limb can be defined using the weak continuum appearing between the emission lines at the time of the second and third contact. The variations of the singly ionized iron line, the HeI and HeII lines and the continuum intensity are analyzed. The intensity ratio of ionized to neutral helium is studied for evaluating the ionization rate in low layers up to 2 Mm and also around a prominence.

  12. Helium shells and faint emission lines from slitless flash spectra

    Directory of Open Access Journals (Sweden)

    Cyril Bazin

    2013-05-01

    Full Text Available At the time of the two last solar total eclipses of August 1st, 2008 in Siberia and July 11th, 2010 in French Polynesia, high frame rate CCD flash spectra were obtained. These eclipses occurred in quiet Sun period and after. The slitless flash spectra show two helium shells, in the weak Paschen α 4686 Å line of the ionized helium HeII and in the neutral helium HeI line at 4713 Å. The extensions of these helium shells are typically 3 Mm. In prominences, the extension of the interface with the corona is much more extended. The observations and analysis of these lines can properly be done only in eclipse conditions, when the intensity threshold reaches the coronal level, and the parasitic scattered light is virtually zero. Under the layers of 1 Mm above the limb, many faint low FIP lines were also seen in emission. These emission lines are superposed on the continuum containing absorption lines. The solar limb can be defined using the weak continuum appearing between the emission lines at the time of the second and third contact. The variations of the singly ionized iron line, the HeI and HeII lines and the continuum intensity are analyzed. The intensity ratio of ionized to neutral helium is studied for evaluating the ionization rate in low layers up to 2 Mm and also around a prominence.

  13. Pengembangan Program Macromedia Flash 8 untuk Pembelajaran Fisika di SMA

    Directory of Open Access Journals (Sweden)

    Wiji Susilowati

    2007-12-01

    Full Text Available Tujuan penelitian adalah membuat dan mengevaluasi media pembelajaran fisika SMA menggunakan program Macromedia Flash 8. Subjek coba pada penelitian ini berjumlah 40 orang yang terdiri dari 10 siswa untuk uji coba instrumen penelitian, 10 siswa untuk ujicoba kelompok kecdl, dan 20 siswa untuk uji coba lapangan. Pengumpulan data dilakukan dengan mengguna­kan kuesioner dan tes fisika (pre-test dan post-test. Evaluasi terhadap program ditinjau dari aspek pembelajaran dan aspek media. Kritik dan saran digunakan untuk memperbaiki program. Hasil penelitian menunjukkan bahwa program Macromedia Flash 8 untuk pembelajaran fisika di SMA: (1 dirancang sesuai dengan prinsip-prinsip desain pembelajaran, (2 terbukti mampu menaikkan skor rerata tes fisika siswa sebesar 55,42%, (3 memiliki efisiensi waktu yang tinggi, (4 ditinjau dari aspek media Hinilai cukup bagus/menarik (dinilai/dikategorikan sedang oleh siswa, (5 ditinjau dari aspek pembelajaran secara keseluruhan program ini dinilai tinggi/jelas dimengerti oleh siswa, (6 ditinjau dari aspek media dinilai menarik (bagus/kategori tinggi oleh guru fisika, dan (7 ditinjau dari aspek pembelajaran juga dinilai menarik (bagus/kategori tinggi oleh guru fisika. Kata kunci: media pembelajaran fisika diSMA.

  14. The fracture energy of ruptures driven by flash heating

    Science.gov (United States)

    Brantut, Nicolas; Viesca, Robert C.

    2017-07-01

    We present a model for dynamic weakening of faults based on local flash heating at microscopic asperity contacts coupled to bulk heating at macroscopic scale. We estimate the fracture energy G associated with that rheology and find that for constant slip rate histories G scales with slip δ as G∝δ2 at small slip, while G∝δ1/2 at large slip. This prediction is quantitatively consistent with data from laboratory experiments conducted on dry rocks at constant slip rate. We also estimate G for crack-like ruptures propagating at constant speed and find that G∝δ2/3 in the large slip limit. Quantitative estimates of G in that regime tend to be several orders of magnitude lower than seismologically inferred values of G. We conclude that while flash heating provides a consistent explanation for the observed dynamic weakening in laboratory experiments with kinematically imposed slip, its contribution to the energy dissipation during earthquakes becomes negligible for large events when considering the elastodynamic coupling between strength and slip evolution.

  15. Experimental research on flash boiling spray of dimethyl ether

    Science.gov (United States)

    Zhang, Peng

    2014-12-01

    The high-speed digital imaging technique is applied to observe the developing process of flash boiling spray of dimethyl ether at low ambient pressure, and the effects of nozzle opening pressure and nozzle hole diameter on the spray shape, spray tip penetration and spray angle during the injection are investigated. The experimental results show that the time when the vortex ring structure of flash boiling spray forms and its developing process are determined by the combined action of the bubble growth and breakup in the spray and the air drag on the leading end of spray; with the enhancement of nozzle opening pressure, the spray tip penetration increases and the spray angle decreases. The influence of nozzle hole diameter on the spray tip penetration is relatively complicated, the spray tip penetration is longer with a smaller nozzle hole diameter at the early stage of injection, while the situation is just opposite at the later stage of injection. This paper establishes that the variation of spray angle is consistent with that of nozzle hole diameter.

  16. FLASH: A finite element computer code for variably saturated flow

    Energy Technology Data Exchange (ETDEWEB)

    Baca, R.G.; Magnuson, S.O.

    1992-05-01

    A numerical model was developed for use in performance assessment studies at the INEL. The numerical model, referred to as the FLASH computer code, is designed to simulate two-dimensional fluid flow in fractured-porous media. The code is specifically designed to model variably saturated flow in an arid site vadose zone and saturated flow in an unconfined aquifer. In addition, the code also has the capability to simulate heat conduction in the vadose zone. This report presents the following: description of the conceptual frame-work and mathematical theory; derivations of the finite element techniques and algorithms; computational examples that illustrate the capability of the code; and input instructions for the general use of the code. The FLASH computer code is aimed at providing environmental scientists at the INEL with a predictive tool for the subsurface water pathway. This numerical model is expected to be widely used in performance assessments for: (1) the Remedial Investigation/Feasibility Study process and (2) compliance studies required by the US Department of Energy Order 5820.2A.

  17. The rarity of terrestrial gamma-ray flashes

    Science.gov (United States)

    Smith, D. M.; Dwyer, J. R.; Hazelton, B. J.; Grefenstette, B. W.; Martinez-McKinney, G. F. M.; Zhang, Z. Y.; Lowell, A. W.; Kelley, N. A.; Splitt, M. E.; Lazarus, S. M.; Ulrich, W.; Schaal, M.; Saleh, Z. H.; Cramer, E.; Rassoul, H. K.; Cummer, S. A.; Lu, G.; Blakeslee, R. J.

    2011-04-01

    We report on the first search for Terrestrial Gamma-ray Flashes (TGFs) from altitudes where they are thought to be produced. The Airborne Detector for Energetic Lightning Emissions (ADELE), an array of gamma-ray detectors, was flown near the tops of Florida thunderstorms in August/September 2009. The plane passed within 10 km horizontal distance of 1213 lightning discharges and only once detected a TGF. If these discharges had produced TGFs of the same intensity as those seen from space, every one should have been seen by ADELE. Separate and significant nondetections are established for intracloud lightning, negative cloud-to-ground lightning, and narrow bipolar events. We conclude that TGFs are not a primary triggering mechanism for lightning. We estimate the TGF-to-flash ratio to be on the order of 10-2 to 10-3 and show that TGF intensities cannot follow the well-known power-law distribution seen in earthquakes and solar flares, due to our limits on the presence of faint events.

  18. Characterization and modeling of fast programming bits in flash EEPROM

    Science.gov (United States)

    Nkansah, F.; Hatalis, M.; Olasupo, K.

    2000-11-01

    The effects of flash EEPROM floating gate (FG) morphology on the generation and density of fast programming bits in a 2Mbit flash EEPROM array has been characterized. These fast programming bits exhibit identical subthreshold characteristics similar to that of a normal bit after UV erase, thus establishing that the initial charge stored on the FG of both fast and normal bit is the same. Experimental results clearly indicates that the fast programming phenomena result from an interaction of the programming process with the FG polysilicon microstructure. An in-depth experimentation previously reported, reveals that the FG poly deposition and doping processes are crucial for controlling the desired Fowler-Nordheim tunneling. A correlation is established between the fast bit density observed in the memory arrays, the FG polysilicon grain size and tunneling field enhancement factor μ( Rc). A compact model of the fast programming bit memory threshold voltage as a function of the effective FG polysilicon grain area factor Geff, and tunneling field enhancement factor μ( Rc) has been developed for the first time.

  19. Recent precipitation trends, flash floods and landslides in southern Brazil

    Science.gov (United States)

    Ávila, Alvaro; Justino, Flavio; Wilson, Aaron; Bromwich, David; Amorim, Marcelo

    2016-11-01

    In order to understand the rising number of flash floods and landslides in the densely populated region of southeastern Brazil, this study analyzes the spatial and temporal changes in precipitation from 1978 to 2014. We focus on the sensitivity of mountainous regions, specifically the Rio de Janeiro (RJMR) and Santa Catarina (SCMR) regions. Daily rainfall observations are aggregated into annual and seasonal indexes, and RClimdex is used to evaluate a suite of precipitation and extreme event indexes. Results show positive annual and seasonal precipitation trends during all seasons except for the winter season in the RJMR. Diverse change points in their time series, spatial differences in the trends at individual stations, and trends associated with elevation suggest that despite the close proximity of these two regions, climate impacts are not uniform across all of southeastern Brazil. The majority of precipitation-related indexes present positive trends, especially in the extreme precipitation indexes (PRCPTOT, RX1day, Rx5day and R30 mm). Statistically significant positive correlations are discovered between landslides/flash floods events and annual maximum 1-day and 5-day consecutive precipitation, and these indexes may be useful indicators of natural hazard events for this region.

  20. Relativistic outflow from two thermonuclear shell flashes on neutron stars

    CERN Document Server

    Zand, Jean in 't; Cavecchi, Yuri

    2014-01-01

    We study the exceptionally short (32-41 ms) precursors of two intermediate-duration thermonuclear X-ray bursts observed with RXTE from the neutron stars in 4U 0614+09 and 2S 0918-549. They exhibit photon fluxes that surpass those at the Eddington limit later in the burst by factors of 2.6 to 3.1. We are able to explain both the short duration and the super-Eddington flux by mildly relativistic outflow velocities of 0.1$c$ to 0.3$c$ subsequent to the thermonuclear shell flashes on the neutron stars. These are the highest velocities ever measured from any thermonuclear flash. The precursor rise times are also exceptionally short: about 1 ms. This is inconsistent with predictions for nuclear flames spreading laterally as deflagrations and suggests detonations instead. This is the first time that a detonation is suggested for such a shallow ignition column depth ($y_{\\rm ign}$ = 10$^{10}$ g cm$^{-2}$). The detonation would possibly require a faster nuclear reaction chain, such as bypassing the alpha-capture on $^...

  1. Nuclear fusion and carbon flashes on neutron stars

    Science.gov (United States)

    Taam, R. E.; Picklum, R. E.

    1978-01-01

    This paper reports on detailed calculations of the thermal evolution of the carbon-burning shells in the envelopes of accreting neutron stars for mass-accretion rates of 1 hundred-billionth to 2 billionths of a solar mass per yr and neutron-star masses of 0.56 and 1.41 solar masses. The work of Hansen and Van Horn (1975) is extended to higher densities, and a more detailed treatment of nuclear processing in the hydrogen- and helium-burning regions is included. Results of steady-state calculations are presented, and results of time-dependent computations are examined for accretion rates of 3 ten-billionths and 1 billionth of solar mass per yr. It is found that two evolutionary sequences lead to carbon flashes and that the carbon abundance at the base of the helium shell is a strong function of accretion rate. Upper limits are placed on the accretion rates at which carbon flashes will be important.

  2. Study on Predrying by Spin Flash Dryer for Granulation

    Institute of Scientific and Technical Information of China (English)

    王晓静; 叶鸣; 钱树德

    2004-01-01

    Spin flash dryer has the advantages of both fluidized bed dryer and pneumatic dryer.It has predominance in dealing with thermal sensitive materials.In this paper,the distribution of the air velocity in the spin flash dryer is discussed,which indicates that the rotating air in the dryer chamber can be divided into two areas,potential flow area and plane swirl area.Experiments show that air tangent velocity effects the process of granulation most remarkably.The radial distribution and moisture content of the particles have their intrinsic rules along either the diameter or height of the drying chamber.Besides,the operating parameters of predrying on bleaching powder are optimized.To meet the strict standard of the wet-pressing granulator on the moisture content of the feeder,a narrow lap is made at proper height in the wall of the drying chamber,where a chute and a rotating valve are installed in order to predry the filter cake and remove a part of water.Then the material is fed into the wet-pressing granulator.

  3. Formation of curcumin nanoparticles by flash nanoprecipitation from emulsions.

    Science.gov (United States)

    Margulis, Katherine; Magdassi, Shlomo; Lee, Han Seung; Macosko, Christopher W

    2014-11-15

    Nanometric particles of a model hydrophobic substance curcumin were prepared by a novel method, namely, flash nanoprecipitation from a coarse oil-in-water emulsion. The method employs turbulent co-mixing of water with curcumin-loaded emulsion using manually-operated confined impingement jets mixer. A clear and stable dispersion of nanoparticles was formed in this process, and could be converted to dry, easily water-dispersible powder by spray drying. The mean size of the particles was about 40 nm by DLS, confirmed by Cryo-TEM. The obtained particles contained 20.4 wt% curcumin, X-ray analysis showed it was amorphous. The significant advantages of the studied process are its feasibility, speed and low cost. It does not require any special high-energy input equipment to reduce the droplet size of the initial emulsion as required by the vast majority of other methods, and relies on rapid turbulent mixing and on flow-induced shear stress formed in the simple, manually-operated mixer. Control experiments clearly indicate that employing emulsion, instead of a plain solution and flash nanoprecipitation instead of a simple antisolvent precipitation are advantageous in terms of particle size and stability.

  4. Development of cable fed flash X-ray (FXR) system

    Science.gov (United States)

    Menon, Rakhee; Mitra, S.; Patel, A. S.; Kumar, R.; Singh, G.; Senthil, K.; Kumar, Ranjeet; Kolge, T. S.; Roy, Amitava; Acharya, S.; Biswas, D.; Sharma, Archana

    2017-08-01

    Flash X-ray sources driven by pulsed power find applications in industrial radiography, and a portable X-ray source is ideal where the radiography needs to be taken at the test site. A compact and portable flash X-ray (FXR) system based on a Marx generator has been developed with the high voltage fed to the FXR tube via a cable feed-through arrangement. Hard bremsstrahlung X-rays of few tens of nanosecond duration are generated by impinging intense electron beams on an anode target of high Z material. An industrial X-ray source is developed with source size as low as 1 mm. The system can be operated from 150 kV to 450 kV peak voltages and a dose of 10 mR has been measured at 1 m distance from the source window. The modeling of the FXR source has been carried out using particle-in-cell and Monte Carlo simulations for the electron beam dynamics and X-ray generation, respectively. The angular dose profile of X-ray has been measured and compared with the simulation.

  5. The Production of the Beautiful Star Based on Flash ActionScript%基于Flash ActionScript制作美丽的星空

    Institute of Scientific and Technical Information of China (English)

    周国福

    2009-01-01

    FLASH8是美国的MACROMEDIA公司推出的一款多媒体动画制作软件.它是一种交互式动画设计工具,用它可以将音乐,声效,动画方便地融合在一起,从而制作出高品质的动态效果.该文通过Flash 8动画编辑软件制作出美丽的星空效果.%FLASH8 by the United States MACROMEDIA company launched a multi-media animation software. It is an interactive ani-mation design tools, it not only easily take music, sound, animation to blend but also produce high-quality dynamic effects. This article manufactures the beautiful starry sky effect through the Flash 8 animation edition software.

  6. Improving the flash flood frequency analysis applying dendrogeomorphological evidences

    Science.gov (United States)

    Ruiz-Villanueva, V.; Ballesteros, J. A.; Bodoque, J. M.; Stoffel, M.; Bollschweiler, M.; Díez-Herrero, A.

    2009-09-01

    Flash floods are one of the natural hazards that cause major damages worldwide. Especially in Mediterranean areas they provoke high economic losses every year. In mountain areas with high stream gradients, floods events are characterized by extremely high flow and debris transport rates. Flash flood analysis in mountain areas presents specific scientific challenges. On one hand, there is a lack of information on precipitation and discharge due to a lack of spatially well distributed gauge stations with long records. On the other hand, gauge stations may not record correctly during extreme events when they are damaged or the discharge exceeds the recordable level. In this case, no systematic data allows improvement of the understanding of the spatial and temporal occurrence of the process. Since historic documentation is normally scarce or even completely missing in mountain areas, tree-ring analysis can provide an alternative approach. Flash floods may influence trees in different ways: (1) tilting of the stem through the unilateral pressure of the flowing mass or individual boulders; (2) root exposure through erosion of the banks; (3) injuries and scars caused by boulders and wood transported in the flow; (4) decapitation of the stem and resulting candelabra growth through the severe impact of boulders; (5) stem burial through deposition of material. The trees react to these disturbances with specific growth changes such as abrupt change of the yearly increment and anatomical changes like reaction wood or callus tissue. In this study, we sampled 90 cross sections and 265 increment cores of trees heavily affected by past flash floods in order to date past events and to reconstruct recurrence intervals in two torrent channels located in the Spanish Central System. The first study site is located along the Pelayo River, a torrent in natural conditions. Based on the external disturbances of trees and their geomorphological position, 114 Pinus pinaster (Ait

  7. A Bayesian Network approach for flash flood risk assessment

    Science.gov (United States)

    Boutkhamouine, Brahim; Roux, Hélène; Pérès, François

    2017-04-01

    Climate change is contributing to the increase of natural disasters such as extreme weather events. Sometimes, these events lead to sudden flash floods causing devastating effects on life and property. Most recently, many regions of the French Mediterranean perimeter have endured such catastrophic flood events; Var (October 2015), Ardèche (November 2014), Nîmes (October 2014), Hérault, Gard and Languedoc (September 2014), and Pyrenees mountains (Jun 2013). Altogether, it resulted in dozens of victims and property damages amounting to millions of euros. With this heavy loss in mind, development of hydrological forecasting and warning systems is becoming an essential element in regional and national strategies. Flash flood forecasting but also monitoring is a difficult task because small ungauged catchments ( 10 km2) are often the most destructive ones as for the extreme flash flood event of September 2002 in the Cévennes region (France) (Ruin et al., 2008). The problem of measurement/prediction uncertainty is particularly crucial when attempting to develop operational flash-flood forecasting methods. Taking into account the uncertainty related to the model structure itself, to the model parametrization or to the model forcing (spatio-temporal rainfall, initial conditions) is crucial in hydrological modelling. Quantifying these uncertainties is of primary importance for risk assessment and decision making. Although significant improvements have been made in computational power and distributed hydrologic modelling, the issue dealing with integration of uncertainties into flood forecasting remains up-to-date and challenging. In order to develop a framework which could handle these uncertainties and explain their propagation through the model, we propose to explore the potential of graphical models (GMs) and, more precisely, Bayesian Networks (BNs). These networks are Directed Acyclic Graphs (DAGs) in which knowledge of a certain phenomenon is represented by

  8. Motion-induced positional biases in the flash-lag configuration.

    Science.gov (United States)

    Shi, Zhuanghua; de'Sperati, Claudio

    2008-01-01

    When both stationary and moving objects are present in the visual field, localizing objects in space may become difficult, as shown by illusory phenomena such as the Fröhlich effect and the flash-lag effect. Despite the efforts to decipher how motion and position information are combined to form a coherent visual representation, a unitary picture is still lacking. In the flash-lag effect, a flash presented in alignment with a moving stimulus is perceived to lag behind it. We investigated whether this relative spatial localization (i.e., judging the position of the flash relative to that of the moving stimulus) is the result of a linear combination of two absolute localization mechanisms--that is, the coding of the flash position in space and the coding of the position of the moving stimulus in space. In three experiments we showed that (a) the flash is perceived to be shifted in the direction of motion; (b) the moving stimulus is perceived to be ahead of its physical position, the forward shift being larger than that of the flash; (c) the linear combination of these two shifts is quantitatively equivalent to the flash-lag effect, which was measured independently. The results are discussed in relation to perceptual and motor localization mechanisms.

  9. Differentiation of debris-flow and flash-flood deposits: implications for paleoflood investigations

    Science.gov (United States)

    Waythomas, Christopher F.; Jarrett, Robert D.; ,

    1993-01-01

    Debris flows and flash floods are common geomorphic processes in the Colorado Rocky Mountain Front Range and foothills. Usually, debris flows and flash floods are associated with excess summer rainfall or snowmelt, in areas were unconsolidated surficial deposits are relatively thick and slopes are steep. In the Front Range and foothills, flash flooding is limited to areas below about 2300m whereas, debris flow activity is common throughout the foothill and alpine zones and is not necessarily elevation limited. Because flash floods and debris flows transport large quantities of bouldery sediment, the resulting deposits appear somewhat similar even though such deposits were produced by different processes. Discharge estimates based on debris-flow deposits interpreted as flash-flood deposits have large errors because techniques for discharge retrodiction were developed for water floods with negligible sediment concentrations. Criteria for differentiating between debris-flow and flash-flood deposits are most useful for deposits that are fresh and well-exposed. However, with the passage of time, both debris-flow and flash-flood deposits become modified by the combined effects of weathering, colluviation, changes in surface morphology, and in some instances removal of interstitial sediment. As a result, some of the physical characteristics of the deposits become more alike. Criteria especially applicable to older deposits are needed. We differentiate flash-flood from debris-flow and other deposits using clast fabric measurements and other morphologic and sedimentologic techniques (e.g., deposit morphology, clast lithology, particle size and shape, geomorphic setting).

  10. Flash flood hazard mapping: a pilot case study in Xiapu River Basin, China

    Directory of Open Access Journals (Sweden)

    Da-wei Zhang

    2015-07-01

    Full Text Available Flash flood hazard mapping is a supporting component of non-structural measures for flash flood prevention. Pilot case studies are necessary to develop more practicable methods for the technical support systems of flash flood hazard mapping. In this study, the headwater catchment of the Xiapu River Basin in central China was selected as a pilot study area for flash flood hazard mapping. A conceptual distributed hydrological model was developed for flood calculation based on the framework of the Xinanjiang model, which is widely used in humid and semi-humid regions in China. The developed model employs the geomorphological unit hydrograph method, which is extremely valuable when simulating the overland flow process in ungauged catchments, as compared with the original Xinanjiang model. The model was tested in the pilot study area, and the results agree with the measured data on the whole. After calibration and validation, the model is shown to be a useful tool for flash flood calculation. A practicable method for flash flood hazard mapping using the calculated peak discharge and digital elevation model data was presented, and three levels of flood hazards were classified. The resulting flash flood hazard maps indicate that the method successfully predicts the spatial distribution of flash flood hazards, and it can meet the current requirements in China.

  11. A Modern Apparatus for Performing Flash Chromatography: An Experiment for the Organic Laboratory

    Science.gov (United States)

    Naumiec, Gregory R.; Del Padre, Angela N.; Hooper, Matthew M.; Germaine, Alison St.; DeBoef, Brenton

    2013-01-01

    A modern apparatus for performing flash chromatography using commercially available, prepacked silica cartridges has been developed. The key advantage of this system, when compared to traditional flash chromatography, is its use of commercially available silica cartridges, which obviates the need for students to handle silica gel. The apparatus…

  12. Animating an Equation: A Guide to Using FLASH in Mathematics Education

    Science.gov (United States)

    Bakhoum, Ezzat G.

    2008-01-01

    Macromedia's FLASH development system can be a great tool for mathematics education. This article presents detailed Flash tutorials that were developed and taught by the author to a group of mathematics professors in a summer course in 2005. The objective was to educate the teachers in the techniques of animating equations and mathematical…

  13. Flash (Ultra-Rapid) Spark-Plasma Sintering of Silicon Carbide

    Science.gov (United States)

    Olevsky, Eugene A.; Rolfing, Stephen M.; Maximenko, Andrey L.

    2016-09-01

    A new ultra-rapid process of flash spark plasma sintering is developed. The idea of flash spark plasma sintering (or flash hot pressing - FHP) stems from the conducted theoretical analysis of the role of thermal runaway phenomena for material processing by flash sintering. The major purpose of the present study is to theoretically analyze the thermal runaway nature of flash sintering and to experimentally address the challenge of uncontrollable thermal conditions by the stabilization of the flash sintering process through the application of the external pressure. The effectiveness of the developed FHP technique is demonstrated by the few seconds-long consolidation of SiC powder in an industrial spark plasma sintering device. Specially designed sacrificial dies heat the pre-compacted SiC powder specimens to a critical temperature before applying any voltage to the powder volume and allowing the electrode-punches of the SPS device setup to contact the specimens and pass electric current through them under elevated temperatures. The experimental results demonstrate that flash sintering phenomena can be realized using conventional SPS devices. The usage of hybrid heating SPS devices is pointed out as the mainstream direction for the future studies and utilization of the new flash hot pressing (ultra-rapid spark plasma sintering) technique.

  14. 49 CFR 234.253 - Flashing light units and lamp voltage.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Flashing light units and lamp voltage. 234.253... Maintenance, Inspection, and Testing Inspections and Tests § 234.253 Flashing light units and lamp voltage. (a... voltage shall be tested when installed and at least once every 12 months thereafter. (c) Each...

  15. Concepts and approaches to study disruption and change of everyday life during flash flood events.

    NARCIS (Netherlands)

    Jeuring, Jelmer

    2013-01-01

    Concepts and approaches to study disruption and change of everyday life during flash flood events. The dynamics of extreme precipitations and consequential flash-floods in Southern France lead to important variations in vulnerability of people and property across space and time. In turn, these event

  16. Flash Floods Simulation using a Physical-Based Hydrological Model at Different Hydroclimatic Regions

    Science.gov (United States)

    Saber, Mohamed; Kamil Yilmaz, Koray

    2016-04-01

    Currently, flash floods are seriously increasing and affecting many regions over the world. Therefore, this study will focus on two case studies; Wadi Abu Subeira, Egypt as arid environment, and Karpuz basin, Turkey as Mediterranean environment. The main objective of this work is to simulate flash floods at both catchments considering the hydrometeorological differences between them which in turn effect their flash flood behaviors. An integrated methodology incorporating Hydrological River Basin Environmental Assessment Model (Hydro-BEAM) and remote sensing observations was devised. Global Satellite Mapping of Precipitation (GSMAP) were compared with the rain gauge network at the target basins to estimate the bias in an effort to further use it effectively in simulation of flash floods. Based on the preliminary results of flash floods simulation on both basins, we found that runoff behaviors of flash floods are different due to the impacts of climatology, hydrological and topographical conditions. Also, the simulated surface runoff hydrographs are reasonably coincide with the simulated ones. Consequently, some mitigation strategies relying on this study could be introduced to help in reducing the flash floods disasters at different climate regions. This comparison of different climatic basins would be a reasonable implication for the potential impact of climate change on the flash floods frequencies and occurrences.

  17. All-season flash flood forecasting system for real-time operations

    Science.gov (United States)

    Flash floods can cause extensive damage to both life and property, especially because they are difficult to predict. Flash flood prediction requires high-resolution meteorologic observations and predictions, as well as calibrated hydrologic models in addition to extensive data handling. We have de...

  18. Ultra-fast flash observatory for detecting the early photons from gamma-ray bursts

    DEFF Research Database (Denmark)

    Lim, H.; Ahn, K.-B.; Barrillon, P.

    Gamma-ray bursts (GRBs) are the most luminous transient events with short intense flashes that have been detected in random directions in the sky once or twice per day. Their durations have been measured in seconds, especially short GRBs with duration of <2 sec. The Ultra-Fast Flash Observatory (...

  19. A Comparison of Two Flash-Card Methods for Improving Sight-Word Reading

    Science.gov (United States)

    Kupzyk, Sara; Daly, Edward J., III; Andersen, Melissa N.

    2011-01-01

    Flash cards have been shown to be useful for teaching sight-word reading. To date, the most effective flash-card instruction method is incremental rehearsal (IR). This method involves the instructor interspersing unknown stimulus items into the presentation of known stimulus items. In this study, we compared IR to a modified IR…

  20. Production of bio-oils from wood by flash pyrolysis; Herstellung von Bio-Oelen aus Holz in einer Flash-Pyrolyseanlage

    Energy Technology Data Exchange (ETDEWEB)

    Meier, D.; Ollesch, T. [Bundesforschungsanstalt fuer Forst- und Holzwirtschaft, Hamburg (Germany). Inst. fuer Holzchemie und Chemische Technologie des Holzes; Gerdes, C.; Kaminsky, W. [Hamburg Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie (ITMCh)

    1998-09-01

    Flash pyrolysis is a medium-temperature process (around 475 C) in which biomass is heated up rapidly in the absence of oxygen. The pyrolysis products are cooled down rapidly, condensing into a reddish-brown liquid with around half the calorific value of a conventional heating oil. In contrast to conventional charcoal production, flash pyrolysis is a modern process whose process parameters enure high liquid yields. Modern fluidized-bed reactors for flash pyrolysis of biomass tend to have high heating rates and short times of residue. In the `Hamburg process`, fluidized-bed reactors are used successfully for pyrolysis of plastics. A flash pyrolysis plant for biomass treatment was constructed in cooperation with Hamburg University with funds provided by the `Bundesstiftung Umwelt`. This contribution describes the first series of experiments, mass balances and oil analyses using beech wood as material to be pyrolyzed. (orig./SR) [Deutsch] Flash-Pyrolyse ist ein Mitteltemperatur-Prozess (ca. 475 C), in dem Biomasse unter Sauerstoffausschluss sehr schnell erhitzt wird. Die entstehenden Pyrolyseprodukte werden schnell abgekuehlt und kondensieren zu einer roetlich-braunen Fluessigkeit, die etwa die Haelfte des Heizwertes eines konventionellen Heizoeles besitzt. Flash-Pyrolyse ist, im Gegensatz zur konventionellen Holzverkohlung, ein modernes Verfahren, dessen spezielle Verfahrensparameter hohe Fluessigausbeuten ermoeglichen. Hohe Aufheizraten, verbunden mit kurzen Verweilzeiten, werden mit stationaeren Wirbelbettreaktoren erzielt die gegenwaertig vorwiegend fuer die Flash-Pyrolyse von Biomasse eingesetzt werden. Im `Hamburger Verfahren` haben sich Wirbelbettreaktoren im Bereich der Kunststoffpyrolyse bewaehrt. Daher wurde in Zusammenarbeit mit der Universitaet Hamburg und finanzieller Foerderung der Bundesstiftung Umwelt eine Flash-Pyrolyseanlage fuer Biomasse gebaut: In dieser Arbeit werden erste Versuchsreihen, Massenbilanzen und Oelanalysen aus der Pyrolyse von

  1. FlashPaper在E-Learning课程建设中的应用%FlashPaper Applied to E-Learning Curriculum Construction

    Institute of Scientific and Technical Information of China (English)

    董方旭; 周檬

    2011-01-01

    伴随E-learning信息化辅助教学在全国高校中普遍开展,如何快速的建设E-learning课程越来越被大家所关注.结合FlashPaper软件的工作原理,详细介绍在E-learning课程建设过程中应用FlashPaper的优越性.

  2. Menopausal hot flashes: a review of physiology and biosociocultural perspective on methods of assessment.

    Science.gov (United States)

    Kronenberg, Fredi

    2010-07-01

    Hot flashes continue to be a troublesome problem for menopausal women the world over. After >50 y of research, we still do not understand the etiology and mechanism of hot flashes, nor do we know how estrogen, the major pharmaceutical treatment, works to reduce hot flashes. We are gaining insight into sociocultural complexities that may affect how and whether women report hot flashes. And we are becoming more sophisticated in our research tools (be it questionnaires, physiological monitors, or brain imaging techniques). New aspects of hot flash research, including neuroimaging and the study of genetic polymorphisms, when combined with increasingly nuanced ways of asking questions of culturally distinct populations, provide challenges but rich complexity from which a better understanding will emerge.

  3. Effect of Speed Overestimation on Flash-Lag Effect at Low Luminance

    Directory of Open Access Journals (Sweden)

    Maryam Vaziri-Pashkam

    2011-12-01

    Full Text Available When a brief flash is presented at the same location as a moving object, the flash is perceived to lag behind the moving object to an extent that increases with the speed of the object. Previous studies showed that moving objects appear faster at low luminance as a result of their longer motion trace. Here we examine whether this faster perceived motion also affects the amount of the flash lag at low luminance. We first verified that speed was overestimated at low luminance with our stimulus. We then asked subjects to align a briefly flashed dot with the moving target. Results showed that the flash-lag effect increased with physical speed at both high and low luminance, but there was no additional increase due to the perceived increase of speed at low luminance. We suggest that although motion blur contributes to perceived speed, it does not contribute to the speed information that influences its perceived position.

  4. Design and Implementation for Multi-Level Cell Flash Memory Storage Systems

    Directory of Open Access Journals (Sweden)

    Amarnath Gaini

    2011-11-01

    Full Text Available The flash memory management functions of write coalescing, space management, logical-to-physical mapping, wear leveling, and garbage collection require significant on-going computation and data movement. MLC flash memory also introduces new challenges: (1 Pages in a block must be written sequentially. (2 Information to indicate a page being obsolete cannot be recorded in its spare area. This paper designs an MLC Flash Translation Layer (MFTL for flash-memory storage systems which takes new constraints of MLC flash memory and access behaviors of file system into consideration. A series of trace driven simulations is conducted to evaluate the performance of the proposed scheme. Our experiment results show that the proposed MFTL outperforms other related works in terms of the number of extra page writes, the number of total block erasures, and the memory requirement for the management.

  5. Continuous background light significantly increases flashing-light enhancement of photosynthesis and growth of microalgae.

    Science.gov (United States)

    Abu-Ghosh, Said; Fixler, Dror; Dubinsky, Zvy; Iluz, David

    2015-01-01

    Under specific conditions, flashing light enhances the photosynthesis rate in comparison to continuous illumination. Here we show that a combination of flashing light and continuous background light with the same integrated photon dose as continuous or flashing light alone can be used to significantly enhance photosynthesis and increase microalgae growth. To test this hypothesis, the green microalga Dunaliella salina was exposed to three different light regimes: continuous light, flashing light, and concomitant application of both. Algal growth was compared under three different integrated light quantities; low, intermediate, and moderately high. Under the combined light regime, there was a substantial increase in all algal growth parameters, with an enhanced photosynthesis rate, within 3days. Our strategy demonstrates a hitherto undescribed significant increase in photosynthesis and algal growth rates, which is beyond the increase by flashing light alone.

  6. 基于Flash的MV的制作%Flash-based Production of MV

    Institute of Scientific and Technical Information of China (English)

    杨萍

    2014-01-01

    Flash MV network applications is more, the more popular online video music, people can be accompanied by their own favorite songs with lyrics melody mood made into Flash animation. Flash MV unique technology and artistic expression to bring a unique visual experience.%Flash MV是目前网络应用较多、较为流行的网络视频音乐,人们可以将自己喜欢的伴随着词曲旋律意境的歌曲制作成Flash动画。Flash MV以独特的技术和艺术表现给人们带来了特殊的视觉感受。

  7. Design of 6-Bit Flash Analog to Digital Converter Using Variable Switching Voltage CMOS Comparator

    Directory of Open Access Journals (Sweden)

    Gulrej Ahmed

    2014-04-01

    Full Text Available This paper presents the design of 6-bit flash analog to digital Converter (ADC using the new variable switching voltage (VSV comparator. In general, Flash ADCs attain the highest conversion speed at the cost of high power consumption. By using the new VSV comparator, the designed 6-bit Flash ADC exhibits significant improvement in terms of power and speed of previously reported Flash ADCs. The simulation result shows that the converter consumes peak power 2.1 mW from a 1.2 V supply and achieves the speed of 1 GHz in a 65nm standard CMOS process. The measurement of maximum differential and integral nonlinearities (DNL and INL of the Flash ADC are 0.3 LSB and 0.6 LSB respectively.

  8. Negative Flash for Calculating the Intersecting Key Tie lines in Multicomponent Gas Injection

    DEFF Research Database (Denmark)

    Yan, Wei; Michelsen, Michael Locht; Stenby, Erling Halfdan

    2014-01-01

    to the initial oil where all the intersecting key tielines must be identified. Calculation of these intersecting tielines requires a series of special negative flashes, which allow not only phase fractions outside the physical interval [0,1] but also negative feed compositions. The phase compositions from one...... negative flash are used to recombine the feed for the next negative flash. Despite the apparent complexity due to multicomponent phase equilibrium and transport, for pure component gas injection, negative flash and elimination of components can be performed in an alternating manner. In particular, if K......-values are constant, there exists a simple feature that the vapor fraction roots (beta-roots) for the RachfordRice equation for the initial oil are the roots to be found in all the negative flashes involved. This leads to a simple and well-structured algorithm for the solution with constant K-values. A special...

  9. Methods of Real Time Image Enhancement of Flash LIDAR Data and Navigating a Vehicle Using Flash LIDAR Data

    Science.gov (United States)

    Vanek, Michael D. (Inventor)

    2014-01-01

    A method for creating a digital elevation map ("DEM") from frames of flash LIDAR data includes generating a first distance R(sub i) from a first detector i to a first point on a surface S(sub i). After defining a map with a mesh THETA having cells k, a first array S(k), a second array M(k), and a third array D(k) are initialized. The first array corresponds to the surface, the second array corresponds to the elevation map, and the third array D(k) receives an output for the DEM. The surface is projected onto the mesh THETA, so that a second distance R(sub k) from a second point on the mesh THETA to the detector can be found. From this, a height may be calculated, which permits the generation of a digital elevation map. Also, using sequential frames of flash LIDAR data, vehicle control is possible using an offset between successive frames.

  10. Mitochondrial Flash: Integrative Reactive Oxygen Species and pH Signals in Cell and Organelle Biology.

    Science.gov (United States)

    Wang, Wang; Gong, Guohua; Wang, Xianhua; Wei-LaPierre, Lan; Cheng, Heping; Dirksen, Robert; Sheu, Shey-Shing

    2016-09-20

    Recent breakthroughs in mitochondrial research have advanced, reshaped, and revolutionized our view of the role of mitochondria in health and disease. These discoveries include the development of novel tools to probe mitochondrial biology, the molecular identification of mitochondrial functional proteins, and the emergence of new concepts and mechanisms in mitochondrial function regulation. The discovery of "mitochondrial flash" activity has provided unique insights not only into real-time visualization of individual mitochondrial redox and pH dynamics in live cells but has also advanced understanding of the excitability, autonomy, and integration of mitochondrial function in vivo. The mitochondrial flash is a transient and stochastic event confined within an individual mitochondrion and is observed in a wide range of organisms from plants to Caenorhabditis elegans to mammals. As flash events involve multiple transient concurrent changes within the mitochondrion (e.g., superoxide, pH, and membrane potential), a number of different mitochondrial targeted fluorescent indicators can detect flash activity. Accumulating evidence indicates that flash events reflect integrated snapshots of an intermittent mitochondrial process arising from mitochondrial respiration chain activity associated with the transient opening of the mitochondrial permeability transition pore. We review the history of flash discovery, summarize current understanding of flash biology, highlight controversies regarding the relative roles of superoxide and pH signals during a flash event, and bring forth the integration of both signals in flash genesis. Investigations using flash as a biomarker and establishing its role in cell signaling pathway will move the field forward. Antioxid. Redox Signal. 25, 534-549.

  11. Ignition of Liquid Fuel Spray and Simulated Solid Rocket Fuel by Photoignition of Carbon Nanotube Utilizing a Camera Flash

    Science.gov (United States)

    2011-12-01

    Badakhshan A1 , Danczyk S. A.2, Wirth D.3 and Pilon L. 3 Abstract We have studied the ignition of fuel sprays and simulated solid rocket fuels (SRF...photoignition of solid oxidizer/CNT mixtures exposed to a flash of light. The flash source was a commercial studio flash lamp with a rated maximum

  12. Optical Emissions Associated with Terrestrial Gamma-ray Flashes

    Science.gov (United States)

    Xu, W.; Celestin, S. J.; Pasko, V. P.

    2013-12-01

    Terrestrial Gamma-ray Flashes (TGFs) are high-energy photon bursts originating from the Earth's atmosphere. After their discovery in 1994 by the Burst and Transient Source Experiment (BATSE) detector aboard the Compton Gamma-Ray Observatory [Fishman et al., Science, 264, 1313, 1994], this phenomenon has been further observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) [Smith et al., Science, 307, 1085, 2005], the Fermi Gamma-ray Space Telescope [Briggs et al., JGR, 115, A07323, 2010] and the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite [Marisaldi et al., JGR, 115, A00E13, 2010]. Measurements have correlated TGFs with initial development stages of normal polarity intracloud lightning that transports negative charge upward (+IC) [e.g., Lu et al., GRL, 37, L11806, 2010; JGR, 116, A03316, 2011]. Moreover, Østgaard et al. [GRL, 40, 2423, 2013] have recently reported, for the first time, space-based observations of optical emissions from TGF-associated IC lightning flashes. The purpose of the present work is to quantify the intensities of optical emissions resulting from the excitation of air molecules produced by conventional streamer discharges in negative corona flashes of stepping negative leaders and by the large amount of electrons involved in TGF events based on two production mechanisms: relativistic runaway electron avalanches (RREAs) [Dwyer and Smith, GRL, 32, L22804, 2005] and production of runaway electrons by high-potential +IC lightning leaders [e.g., Celestin and Pasko, JGR, 116, A03315, 2011; Xu et al., GRL, 39, L08801, 2012]. We employ a Monte Carlo model to simulate the acceleration of electrons in the energy range from sub-eV to GeV in either large-scale homogeneous electric field sustaining RREAs or highly inhomogeneous electric field produced around the lightning leader tip region. With the knowledge of the electron energy distribution function, a model similar to that described in [Liu and Pasko, JGR, 109, A

  13. Flash floods in Mediterranean ephemeral streams in Valencia Region (Spain)

    Science.gov (United States)

    Camarasa-Belmonte, Ana M.

    2016-10-01

    Ephemeral streams are typical Mediterranean fluvial systems with high risk of flash flooding, and few data are available about these systems in most locales. However, the SAIH network (Automatic Hydrological Information Systems) of the Jucar River Water Authority has been providing detailed information about ephemeral streams in Spain every 5 min since 1988. Using these data, we evaluated the processes of rainfall-runoff conversion and flood generation in five Mediterranean ephemeral streams ranging in size from 25 to 450 km2. To provide a general framework for hydrological analysis, the study included 142 flash flood events registered between 1989 and 2007. A more detailed analysis was conducted for the Carraixet Basin under the dry antecedent moisture condition (AMC I) to evaluate the influence of rainfall on the basin's response. A simple index called Momentum of Maximum Intensity (MMI) was developed to describe the influence of rainfall intensity on hydrograph. Correlations between the main indicators of precipitation and flow also were assessed. Results showed that flash floods were generally generated by average accumulated rainfall of around 100 mm at high intensities that could exceed 300 mm/h. Initial abstractions and average water losses during the rainfall-runoff conversion processes were very important (runoff coefficients of 6% and runoff thresholds of 62 mm). No correlation was found between initial abstractions (Ia) calculated from the basin characteristics and runoff thresholds (P0) empirically obtained, which create some doubts about the validity of Ia method for predicting floods in ephemeral streams. Accumulated rainfall was very important for flood volume, peak flow and water balance indicators, whereas intensity indicators were more related to the response times of the basins. Rainfall intensity variables influenced lag time. Accumulated rainfall, in combination with high reduced mean intensity and low persistence, were a good predictor for

  14. Enhanced detection of terrestrial gamma-ray flashes by AGILE

    CERN Document Server

    Marisaldi, M; Ursi, A; Gjesteland, T; Fuschino, F; Labanti, C; Galli, M; Tavani, M; Pittori, C; Verrecchia, F; D'Amico, F; Østgaard, N; Mereghetti, S; Campana, R; Cattaneo, P W; Bulgarelli, A; Colafrancesco, S; Dietrich, S; Longo, F; Gianotti, F; Giommi, P; Rappoldi, A; Trifoglio, M; Trois, A

    2016-01-01

    At the end of March 2015 the onboard software configuration of the AGILE satellite was modified in order to disable the veto signal of the anticoincidence shield for the minicalorimeter instrument. The motivation for such a change was the understanding that the dead time induced by the anticoincidence prevented the detection of a large fraction of Terrestrial Gamma-Ray Flashes (TGFs). The configuration change was highly successful resulting in an increase of one order of magnitude in TGF detection rate. As expected, the largest fraction of the new events has short duration ($< 100 \\mathrm {\\mu s}$), and part of them has simultaneous association with lightning sferics detected by the World Wide Lightning Location Network (WWLLN). The new configuration provides the largest TGF detection rate surface density (TGFs/$\\mathrm{km^2}$/year) to date, opening prospects for improved correlation studies with lightning and atmospheric parameters on short spatial and temporal scales along the equatorial region.

  15. The examination of berberine excited state by laser flash photolysis

    Science.gov (United States)

    Cheng, Lingli; Wang, Mei; Zhao, Ping; Zhu, Hui; Zhu, Rongrong; Sun, Xiaoyu; Yao, Side; Wang, Shilong

    2009-07-01

    The property of the excited triplet state of berberine (BBR) was investigated by using time-resolved laser flash photolysis of 355 nm in acetonitrile. The transient absorption spectra of the excited triplet BBR were obtained in acetonitrile, which have an absorption maximum at 420 nm. And the ratio of excitation to ionization of BBR in acetonitrile solvent was calculated. The self-decay and self-quenching rate constants, and the absorption coefficient of 3BBR* were investigated and the excited state quantum yield was determined. Furthermore utilizing the benzophenone (BEN) as a triplet sensitizer, and the β-carotene (Car) as an excited energy transfer acceptor, the assignment of 3BBR* was further confirmed and the related energy transfer rate constants were also determined.

  16. Gamma-Ray Localization of Terrestrial Gamma-Ray Flashes

    CERN Document Server

    Marisaldi, M; Trois, A; Giuliani, A; Tavani, M; Labanti, C; Fuschino, F; Bulgarelli, A; Longo, F; Barbiellini, G; Del Monte, E; Moretti, E; Trifoglio, M; Costa, E; Caraveo, P; Cattaneo, P W; Chen, A; D'Ammando, F; De Paris, G; Di Cocco, G; Di Persio, G; Donnarumma, I; Evangelista, Y; Feroci, M; Ferrari, A; Fiorini, M; Froysland, T; Galli, M; Gianotti, F; Lapshov, I; Lazzarotto, F; Lipari, P; Mereghetti, S; Morselli, A; Pacciani, L; Pellizzoni, A; Perotti, F; Picozza, P; Piano, G; Pilia, M; Prest, M; Pucella, G; Rapisarda, M; Rappoldi, A; Rubini, A; Sabatini, S; Soffitta, P; Striani, E; Vallazza, E; Vercellone, S; Vittorini, V; Zambra, A; Zanello, D; Antonelli, L A; Colafrancesco, S; Cutini, S; Giommi, P; Lucarelli, F; Pittori, C; Santolamazza, P; Verrecchia, F; Salotti, L; 10.1103/PhysRevLett.105.128501

    2010-01-01

    Terrestrial Gamma-Ray Flashes (TGFs) are very short bursts of high energy photons and electrons originating in Earth's atmosphere. We present here a localization study of TGFs carried out at gamma-ray energies above 20 MeV based on an innovative event selection method. We use the AGILE satellite Silicon Tracker data that for the first time have been correlated with TGFs detected by the AGILE Mini-Calorimeter. We detect 8 TGFs with gamma-ray photons of energies above 20 MeV localized by the AGILE gamma-ray imager with an accuracy of 5-10 degrees at 50 MeV. Remarkably, all TGF-associated gamma rays are compatible with a terrestrial production site closer to the sub-satellite point than 400 km. Considering that our gamma rays reach the AGILE satellite at 540 km altitude with limited scattering or attenuation, our measurements provide the first precise direct localization of TGFs from space.

  17. Thermal Conductivity Based on Modified Laser Flash Measurement

    Science.gov (United States)

    Lin, Bochuan; Ban, Heng; Li, Chao; Scripa, Rosalia N.; Su, Ching-Hua; Lehoczky, Sandor L.

    2005-01-01

    The laser flash method is a standard method for thermal diffusivity measurement. It employs single-pulse heating of one side of a thin specimen and measures the temperature response of the other side. The thermal diffusivity of the specimen can be obtained based on a one-dimensional transient heat transfer analysis. This paper reports the development of a theory that includes a transparent reference layer with known thermal property attached to the back of sample. With the inclusion of heat conduction from the sample to the reference layer in the theoretical analysis, the thermal conductivity and thermal diffusivity of sample can be extracted from the temperature response data. Furthermore, a procedure is established to select two points from the data to calculate these properties. The uncertainty analysis indicates that this method can be used with acceptable levels of uncertainty.

  18. Searching for Neutrino Radio Flashes from the Moon with LOFAR

    CERN Document Server

    Buitink, Stijn; Enriquez, Emilio; Falcke, Heino; Frieswijk, Wilfred; Hörandel, Jörg; Mevius, Maaijke; Nelles, Anna; Thoudam, Satyendra; Schellart, Pim; Scholten, Olaf; ter Veen, Sander; Akker, Martin van den

    2013-01-01

    Ultra-high-energy neutrinos and cosmic rays produce short radio flashes through the Askaryan effect when they impact on the Moon. Earthbound radio telescopes can search the Lunar surface for these signals. A new generation of low- frequency, digital radio arrays, spearheaded by LOFAR, will allow for searches with unprecedented sensitivity. In the first stage of the NuMoon project, low-frequency observations were carried out with the Westerbork Synthesis Radio Telescope, leading to the most stringent limit on the cosmic neutrino flux above 10$^{23}$ eV. With LOFAR we will be able to reach a sensitivity of over an order of magnitude better and to decrease the threshold energy.

  19. GRB 990123 Reverse and Internal Shock Flashes and Late Afterglow

    CERN Document Server

    Mészáros, P

    1999-01-01

    The prompt $(t \\siml 0.16$ days) light curve and initial 9-th magnitude optical flash from GRB 990123 can be attributed to a reverse external shock, or possibly to internal shocks. We discuss the time decay laws and spectral slopes expected under various dynamical regimes, and discuss the constraints imposed on the model by the observations, arguing that they provide strongly suggestive evidence for features beyond those in the simple standard model. The longer term afterglow behavior is discussed in the context of the forward shock, and it is argued that, if the steepening after three days is due to a jet geometry, this is likely to be due to jet-edge effects, rather than sideways expansion.

  20. Scattering Correction For Image Reconstruction In Flash Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Liangzhi; Wang, Mengqi; Wu, Hongchun; Liu, Zhouyu; Cheng, Yuxiong; Zhang, Hongbo [Xi' an Jiaotong Univ., Xi' an (China)

    2013-08-15

    Scattered photons cause blurring and distortions in flash radiography, reducing the accuracy of image reconstruction significantly. The effect of the scattered photons is taken into account and an iterative deduction of the scattered photons is proposed to amend the scattering effect for image restoration. In order to deduct the scattering contribution, the flux of scattered photons is estimated as the sum of two components. The single scattered component is calculated accurately together with the uncollided flux along the characteristic ray, while the multiple scattered component is evaluated using correction coefficients pre-obtained from Monte Carlo simulations.The arbitrary geometry pretreatment and ray tracing are carried out based on the customization of AutoCAD. With the above model, an Iterative Procedure for image restORation code, IPOR, is developed. Numerical results demonstrate that the IPOR code is much more accurate than the direct reconstruction solution without scattering correction and it has a very high computational efficiency.

  1. Bio-oil from Flash Pyrolysis of Agricultural Residues

    DEFF Research Database (Denmark)

    Ibrahim, Norazana

    -oil was around 525 °C to 550 °C for all straw moisture contents. It was investigated how differences in biomass composition influence pyrolysis products yields and the composition of char and bio-oils. Details about this investigation are explained in Paper II (Chapter 3). The used pine wood had a low ash...... at reactor temperatures ranging from 475 to 575 oC. It was observed that the formation of char and gas is affected by the biomass alkali content. Increasing biomass alkali content caused an increased feedstock conversion at low temperature, a lower maximum liquid organic yield temperature and a lower maximum......This thesis describes the production of bio-oils from flash pyrolysis of agricultural residues, using a pyrolysis centrifugal reactor (PCR). By thermal degradation of agricultural residues in the PCR, a liquid oil, char and non-condensable gases are produced. The yield of each fraction...

  2. Thermodynamic performance testing of the orbiter flash evaporator system

    Science.gov (United States)

    Jaax, J. R.; Melgares, M. A.; Frahm, J. P.

    1980-01-01

    System level testing of the space shuttle orbiter's development flash evaporator system (FES) was performed in a thermal vacuum chamber capable of simulating ambient ascent, orbital, and entry temperature and pressure profiles. The test article included the evaporator assembly, high load and topping exhaust duct and nozzle assemblies, and feedwater supply assembly. Steady state and transient heat load, water pressure/temperature and ambient pressure/temperature profiles were imposed by especially designed supporting test hardware. Testing in 1978 verified evaporator and duct heater thermal design, determined FES performance boundaries, and assessed topping evaporator plume characteristics. Testing in 1979 combined the FES with the other systems in the orbiter active thermal control subsystem (ATCS). The FES met or exceeded all nominal and contingency performance requirements during operation with the integrated ATCS. During both tests stability problems were encountered during steady state operations which resulted in subsequent design changes to the water spray nozzle and valve plate assemblies.

  3. Incoherent-light-flash annealing of phosphorus-implanted silicon

    Science.gov (United States)

    Correra, L.; Pedulli, L.

    1980-07-01

    Incoherent light pulses emitted from a xenon flash lamp were used to anneal radiation damage in (100) silicon implanted with 2×1015 31P+/cm2 at 100 keV. Electrical carrier concentration has been determined by means of differential sheet resistivity and Hall effect together with the anodic oxidation stripping technique; the surface photovoltage technique has been used to evaluate bulk lifetime and Rutherford backscattering and transmission electron microscopy for analysis of radiation damage. Damage recovery appears to take place via a solid phase epitaxial process. Electrical activity and carrier mobility values of samples annealed by incoherent light are similar to those obtained by laser, electron beam, and furnace annealing. The bulk lifetime of minority carriers is not degraded.

  4. Operational flash flood forecasting platform based on grid technology

    Science.gov (United States)

    Thierion, V.; Ayral, P.-A.; Angelini, V.; Sauvagnargues-Lesage, S.; Nativi, S.; Payrastre, O.

    2009-04-01

    Flash flood events of south of France such as the 8th and 9th September 2002 in the Grand Delta territory caused important economic and human damages. Further to this catastrophic hydrological situation, a reform of flood warning services have been initiated (set in 2006). Thus, this political reform has transformed the 52 existing flood warning services (SAC) in 22 flood forecasting services (SPC), in assigning them territories more hydrological consistent and new effective hydrological forecasting mission. Furthermore, national central service (SCHAPI) has been created to ease this transformation and support local services in their new objectives. New functioning requirements have been identified: - SPC and SCHAPI carry the responsibility to clearly disseminate to public organisms, civil protection actors and population, crucial hydrologic information to better anticipate potential dramatic flood event, - a new effective hydrological forecasting mission to these flood forecasting services seems essential particularly for the flash floods phenomenon. Thus, models improvement and optimization was one of the most critical requirements. Initially dedicated to support forecaster in their monitoring mission, thanks to measuring stations and rainfall radar images analysis, hydrological models have to become more efficient in their capacity to anticipate hydrological situation. Understanding natural phenomenon occuring during flash floods mainly leads present hydrological research. Rather than trying to explain such complex processes, the presented research try to manage the well-known need of computational power and data storage capacities of these services. Since few years, Grid technology appears as a technological revolution in high performance computing (HPC) allowing large-scale resource sharing, computational power using and supporting collaboration across networks. Nowadays, EGEE (Enabling Grids for E-science in Europe) project represents the most important

  5. Ultrasfast Dynamics in Dense Hydrogen Explored at Flash

    Energy Technology Data Exchange (ETDEWEB)

    Hilbert, V; Zastrau, U; Neumayer, P; Hochhaus, D; Toleikis, S; Harmand, M; Przystawik, A; Tschentscher, T; Glenzer, S H; Doeppner, T; Fortmann, C; White, T; Gregori, G; Gode, S; Tiggesbaumker, J; Skruszewicz, S; Meiwes-Broer, K H; Sperling, P; Redmer, R; Forster, E

    2011-08-01

    The short pulse duration and high intensity of the FLASH (Free-electron LASer in Hamburg) allows us to generate and probe homogeneous warm dense non-equilibrium hydrogen within a single extreme ultraviolet (EUV) light pulse. By analyzing the spectrum of the 13.5 nm Thomson scattered light we determine the plasma temperature and density. We find that classical models of this interaction are in good agreement with our dense plasma conditions. In a FEL-pump FEL-probe experiment droplets of liquid hydrogen and their scattering behavior for different pump-probe setups were observed under 20{sup o} and 90{sup o}. We find that the scattering behavior of the scattered intensity depends on the scattering angle.

  6. Numerical simulation analysis of Guixi copper flash smelting furnace

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A numerical simulation analysis for reactions of chalcopyrite and pyrite particles coupled with momentum, heat and mass transfer between the particle and gas in a flash smelting furnace is presented. In the simulation, the equations governing the gas flow are solved numerically by Eular method. The particle phase is introduced into the gas flow by the particle-source-in-cell technique (PSIC). Predictions including the fluid flow field, temperature field, concentration field of gas phase and the tracks of particles have been obtained by the numerical simulation. The visualized results show that the reaction of sulfide particles is almost completed in the upper zone of the shaft within 1.5 m far from the central jet distributor (CJD) type concentrate burner. The simulation results are in good agreement with data obtained from a series of experiments and tests in the plant and the error is less than 2%.

  7. Numerical modeling of Jinlong CJD burner copper flash smelting furnace

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Fluid flow, heat transfer and combustion in Jinlong CJD concentrate burner flash smelting furnace have been investigated by numerical modeling and flow visualization. The modeling is based on the Eulerian approach for the gas flow equations and the Lagrangian approach for the particles. Interaction between the gas phase and particle phase, such as frictional forces, heat and mass transfer, are included by the addition of sources and sinks. The modeling results including the fluid flow field, temperature field, concentration field of gas phase and the trajectories of particles have been obtained. The predicted results are in good agreement with the data obtained from a series of experiments and tests in the Jinlong Copper Smelter and the temperature error is less than 20 K.

  8. Cuinse2 Thin Film For Solar Cell By Flash Evaporation

    Directory of Open Access Journals (Sweden)

    A.H. Soepardjo

    2009-11-01

    Full Text Available Deposition of thin films for material solar cell CuInSe2 are relatively simple. In this research mainly focused on the use of flash evaporation method, and the material created can then be characterized by optical and electrical properties. The optical characterization is done by X-ray Diffraction (XRD, Energy Dispersive Spectroscopy (EDS, and transmission and reflection by UV-VIS spectrophotometry. Electrical characterization is done by utilizing the Hall effect equipment. From these characterization, the atomic structure, absorption coefficient, energy gap, material type, composition of each elements and the mobility of CuInSe2 can be measured and determined. During process evaporation were carried out at substrate temperatures the range between 20ºC-415ºC.

  9. Tunable cobalt nanoparticle synthesis by intense pulse flash annealing

    Directory of Open Access Journals (Sweden)

    Aaron Mosey

    2017-05-01

    Full Text Available Magnetically susceptible materials can serve as a basis for the directed assembly of nanoscale network devices which can be used to extract energy from phase change materials. So far, matrix production cost has been a prohibitive factor in the realization of real world applications. Here we report a cost-effective method to synthesize magnetic nanoparticles. Samples were fabricated by sputtering magnetic thin films on carbon nanotube substrates followed by xenon intense pulsed light flash annealing. The results indicate that spatially ordered magnetic spheres can be tuned by various parameters such as initial thin film thickness, xenon lamp exposure excitation energy, local surface geometries, and the presence of an external magnetic field during annealing.

  10. Tunable cobalt nanoparticle synthesis by intense pulse flash annealing

    Science.gov (United States)

    Mosey, Aaron; Gaire, Babu; Kim, Jeongwhan; Ryu, Jong Eun; Cheng, Ruihua

    2017-05-01

    Magnetically susceptible materials can serve as a basis for the directed assembly of nanoscale network devices which can be used to extract energy from phase change materials. So far, matrix production cost has been a prohibitive factor in the realization of real world applications. Here we report a cost-effective method to synthesize magnetic nanoparticles. Samples were fabricated by sputtering magnetic thin films on carbon nanotube substrates followed by xenon intense pulsed light flash annealing. The results indicate that spatially ordered magnetic spheres can be tuned by various parameters such as initial thin film thickness, xenon lamp exposure excitation energy, local surface geometries, and the presence of an external magnetic field during annealing.

  11. Warm dense matter and Thomson scattering at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Faeustlin, Roland Rainer

    2010-05-15

    X-ray free electron lasers are powerful tools to investigate moderately to strongly correlated solid density low temperature plasmas, named warm dense matter. These plasmas are of most interest for astrophysics and laser plasma interaction, particularly inertial confinement fusion. This work utilizes the ultrashort soft x-ray pulse duration and high brilliance of the free electron laser in Hamburg, FLASH, to generate warm dense matter and to study its ultrafast processes. The techniques applied are absorption measurement, emission spectroscopy and Thomson scattering. Radiative hydrodynamics and Thomson scattering simulations are used to investigate the impact of temperature and density gradients in the sample and to fit the experimental data. The measurements result in a comprehensive picture of soft x-ray matter interaction related to warm dense matter and yield insight into ultrafast equilibration and relaxation mechanisms, in particular impact ionization and radiative recombination. (orig.)

  12. LIQUIDARMOR CM Flashing and Sealant, High Impact Technology Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Hun, Diana E [ORNL; Bhandari, Mahabir S [ORNL

    2016-12-01

    Air leakage is responsible for about 1.1 quads of energy or 6% of the total energy used by commercial buildings in the US. Consequently, infiltration and exfiltration are among the largest envelope-related contributors to the heating, ventilation, and air conditioning loads in commercial buildings. New air sealing technologies have recently emerged that aim to improve the performance of air barrier systems by simplifying their installation procedure. LIQUIDARMORTM CM Flashing and Sealant is an example of these new advanced material technologies. This technology is a spray-applied sealant and liquid flashing and can span gaps that are up to ¼ in. wide without a supporting material. ORNL verified the performance of LIQUIDARMORTM CM with field tests and energy simulations from a building in which LIQUIDARMORTM CM was one of components of the air barrier system. The Homeland Security Training Center (HTC) at the College of DuPage in Glen Ellyn, IL, served as the demonstration site. Blower door test results show the average air leakage rate in the demonstration site to be 0.15 cfm/ft2 at 1.57 psf, or 63% lower than the 0.4 cfm at 1.57 psf specified in the 2015 International Energy Conservation Code (IECC). According to simulation results, HTC lowered its annual heating and cooling cost by about $3,000 or 9% compared to a similar building that lacked an air barrier system. This demonstration project serves as an example of the level of building envelope airtightness that can be achieved by using air barrier materials that are properly installed, and illustrates the energy and financial savings that such an airtight envelope could attain.

  13. Green FLASH: energy efficient real-time control for AO

    Science.gov (United States)

    Gratadour, D.; Dipper, N.; Biasi, R.; Deneux, H.; Bernard, J.; Brule, J.; Dembet, R.; Doucet, N.; Ferreira, F.; Gendron, E.; Laine, M.; Perret, D.; Rousset, G.; Sevin, A.; Bitenc, U.; Geng, D.; Younger, E.; Andrighettoni, M.; Angerer, G.; Patauner, C.; Pescoller, D.; Porta, F.; Dufourcq, G.; Flaischer, A.; Leclere, J.-B.; Nai, A.; Palazzari, P.; Pretet, D.; Rouaud, C.

    2016-07-01

    The main goal of Green Flash is to design and build a prototype for a Real-Time Controller (RTC) targeting the European Extremely Large Telescope (E-ELT) Adaptive Optics (AO) instrumentation. The E-ELT is a 39m diameter telescope to see first light in the early 2020s. To build this critical component of the telescope operations, the astronomical community is facing technical challenges, emerging from the combination of high data transfer bandwidth, low latency and high throughput requirements, similar to the identified critical barriers on the road to Exascale. With Green Flash, we will propose technical solutions, assess these enabling technologies through prototyping and assemble a full scale demonstrator to be validated with a simulator and tested on sky. With this R&D program we aim at feeding the E-ELT AO systems preliminary design studies, led by the selected first-light instruments consortia, with technological validations supporting the designs of their RTC modules. Our strategy is based on a strong interaction between academic and industrial partners. Components specifications and system requirements are derived from the AO application. Industrial partners lead the development of enabling technologies aiming at innovative tailored solutions with potential wide application range. The academic partners provide the missing links in the ecosystem, targeting their application with mainstream solutions. This increases both the value and market opportunities of the developed products. A prototype harboring all the features is used to assess the performance. It also provides the proof of concept for a resilient modular solution to equip a large scale European scientific facility, while containing the development cost by providing opportunities for return on investment.

  14. Flash Flooding and 'Muddy Floods' on Arable Land

    Science.gov (United States)

    Boardman, J.

    2012-04-01

    Flash flooding is often associated with upland, grazed catchments. It does, however, occur in lowland arable-dominated areas. In southern England, notable examples have occurred at Rottingdean (Brighton) in 1987, at Faringdon (Oxfordshire) in 1993 and at Breaky Bottom vineyard (near Brighton) in 1987 and 2000. All resulted in damage to nearby property. Runoff was largely from recently cultivated ground. The characteristics of such floods are: Rapid runoff from bare soil surfaces. Saturated excess overland flow is likely in the early parts of storms but high intensity rainfall on loamy soils results in crusting and Hortonian overland flow; High rates of erosion; Sediment transport to downvalley sites causing property damage ('muddy flooding'). Muddy floods are known from several areas of Europe e.g. Belgium, northern France, South Limburg (Netherlands) and Slovakia (Boardman et al 2006). In other areas they occur but have gone unreported or are classified under different terms. The necessary conditions for occurrence are areas of arable land which is bare at times of the year when there is a risk of storms. For muddy floods to cause damage (and hence be reported), vulnerable property must lie downstream from such areas of arable land. In some areas the incidence of muddy floods relates to autumn and early winter rainfall and winter cereal crops (e.g. southern England). In continental Europe, flooding is more common in summer and is associated with convectional storms and land uses including sugar beet, maize and potatoes. Predictions of increased numbers of high-intensity storms with future climate change, suggest that arable areas will continue to generate both flash floods and muddy floods.

  15. Flash flood characterisation of the Haor area of Bangladesh

    Science.gov (United States)

    Bhattacharya, B.; Suman, A.

    2012-04-01

    Haors are large bowl-shaped flood plain depressions located mostly in north-eastern part of Bangladesh covering about 25% of the entire region. During dry season haors are used for agriculture and during rainy season it is used as fisheries. Haors have profound ecological importance. About 8000 migratory wild birds visit the area annually. Some of the haors are declared at Ramsar sites. Haors are frequently affected by the flash floods due to hilly topography and steep slope of the rivers draining the area. These flash floods spill onto low-lying flood plain lands in the region, inundating crops, damaging infrastructure by erosion and often causing loss of lives and properties. Climate change is exacerbating the situation. For appropriate risk mitigation mechanism it is necessary to explore flood characteristics of that region. The area is not at all studied well. Under a current project a numerical 1D2D model based on MIKE Flood is developed to study the flooding characteristics and estimate the climate change impacts on the haor region. Under this study the progression of flood levels at some key haors in relation to the water level data at specified gauges in the region is analysed. As the region is at the border with India so comparing with the gauges at the border with India is carried out. The flooding in the Haor area is associated with the rainfall in the upstream catchment in India (Meghalaya, Barak and Tripura basins in India). The flood propagation in some of the identified haors in relation to meteorological forcing in the three basins in India is analysed as well. Subsequently, a ranking of haors is done based on individual risks. Based on the IPCC recommendation the precipitation scenario in the upstream catchments under climate change is considered. The study provides the fundamental inputs for preparing a flood risk management plan of the region.

  16. 450mm wafer patterning with jet and flash imprint lithography

    Science.gov (United States)

    Thompson, Ecron; Hellebrekers, Paul; Hofemann, Paul; LaBrake, Dwayne L.; Resnick, Douglas J.; Sreenivasan, S. V.

    2013-09-01

    The next step in the evolution of wafer size is 450mm. Any transition in sizing is an enormous task that must account for fabrication space, environmental health and safety concerns, wafer standards, metrology capability, individual process module development and device integration. For 450mm, an aggressive goal of 2018 has been set, with pilot line operation as early as 2016. To address these goals, consortiums have been formed to establish the infrastructure necessary to the transition, with a focus on the development of both process and metrology tools. Central to any process module development, which includes deposition, etch and chemical mechanical polishing is the lithography tool. In order to address the need for early learning and advance process module development, Molecular Imprints Inc. has provided the industry with the first advanced lithography platform, the Imprio® 450, capable of patterning a full 450mm wafer. The Imprio 450 was accepted by Intel at the end of 2012 and is now being used to support the 450mm wafer process development demands as part of a multi-year wafer services contract to facilitate the semiconductor industry's transition to lower cost 450mm wafer production. The Imprio 450 uses a Jet and Flash Imprint Lithography (J-FILTM) process that employs drop dispensing of UV curable resists to assist high resolution patterning for subsequent dry etch pattern transfer. The technology is actively being used to develop solutions for markets including NAND Flash memory, patterned media for hard disk drives and displays. This paper reviews the recent performance of the J-FIL technology (including overlay, throughput and defectivity), mask development improvements provided by Dai Nippon Printing, and the application of the technology to a 450mm lithography platform.

  17. Measuring the electron bunch timing with femtosecond resolution at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Bock, Marie Kristin

    2013-03-15

    Bunch arrival time monitors (BAMs) are an integral part of the laser-based synchronisation system which is being developed at the Free Electron Laser in Hamburg (FLASH).The operation principle comprises the measurement of the electron bunch arrival time relative to the optical timing reference, which is provided by actively length-stabilised fibre-links of the synchronisation system. The monitors are foreseen to be used as a standard diagnostic tool, not only for FLASH but also for the future European X-Ray Free-Electron Laser (European XFEL). The present bunch arrival time monitors have evolved from proof-of-principle experiments to beneficial diagnostic devices, which are almost permanently available during standard machine operation. This achievement has been a major objective of this thesis. The developments went in parallel to improvements in the reliable and low-maintenance operation of the optical synchronisation system. The key topics of this thesis comprised the characterisation and optimisation of the opto-mechanical front-ends of both, the fibre-links and the BAMs. The extent of applications involving the bunch arrival time information has been enlarged, providing automated measurements for properties of the RF acceleration modules, for instance, the RF on-crest phase determination and the measurement of energy fluctuations. Furthermore, two of the currently installed BAMs are implemented in an active phase and gradient stabilisation of specific modules in order to minimise the arrival time jitter of the electron bunches at the location of the FEL undulators, which is crucial for a high timing resolution of pump-probe experiments.

  18. An early warning system for flash floods in Egypt

    Science.gov (United States)

    Cools, J.; Abdelkhalek, A.; El Sammany, M.; Fahmi, A. H.; Bauwens, W.; Huygens, M.

    2009-09-01

    This paper describes the development of the Flash Flood Manager, abbreviated as FlaFloM. The Flash Flood Manager is an early warning system for flash floods which is developed under the EU LIFE project FlaFloM. It is applied to Wadi Watier located in the Sinai peninsula (Egypt) and discharges in the Red Sea at the local economic and tourist hub of Nuweiba city. FlaFloM consists of a chain of four modules: 1) Data gathering module, 2) Forecasting module, 3) Decision support module or DSS and 4) Warning module. Each module processes input data and consequently send the output to the following module. In case of a flash flood emergency, the final outcome of FlaFloM is a flood warning which is sent out to decision-makers. The ‘data gathering module’ collects input data from different sources, validates the input, visualise data and exports it to other modules. Input data is provided ideally as water stage (h), discharge (Q) and rainfall (R) through real-time field measurements and external forecasts. This project, however, as occurs in many arid flash flood prone areas, was confronted with a scarcity of data, and insufficient insight in the characteristics that release a flash flood. Hence, discharge and water stage data were not available. Although rainfall measurements are available through classical off line rain gauges, the sparse rain gauges network couldn’t catch the spatial and temporal characteristics of rainfall events. To overcome this bottleneck, we developed rainfall intensity raster maps (mm/hr) with an hourly time step and raster cell of 1*1km. These maps are derived through downscaling from two sources of global instruments: the weather research and forecasting model (WRF) and satellite estimates from the Tropical Rainfall Measuring Mission (TRMM). The ‘forecast module’ comprises three numerical models that, using data from the gathering module performs simulations on command: a rainfall-runoff model, a river flow model, and a flood model. A

  19. Permeability transition pore-mediated mitochondrial superoxide flashes regulate cortical neural progenitor differentiation.

    Science.gov (United States)

    Hou, Yan; Mattson, Mark P; Cheng, Aiwu

    2013-01-01

    In the process of neurogenesis, neural progenitor cells (NPCs) cease dividing and differentiate into postmitotic neurons that grow dendrites and an axon, become excitable, and establish synapses with other neurons. Mitochondrial biogenesis and aerobic metabolism provide energy substrates required to support the differentiation, growth and synaptic activity of neurons. Mitochondria may also serve signaling functions and, in this regard, it was recently reported that mitochondria can generate rapid bursts of superoxide (superoxide flashes), the frequency of which changes in response to environmental conditions and signals including oxygen levels and Ca(2+) fluxes. Here we show that the frequency of mitochondrial superoxide flashes increases as embryonic cerebral cortical neurons differentiate from NPCs, and provide evidence that the superoxide flashes serve a signaling function that is critical for the differentiation process. The superoxide flashes are mediated by mitochondrial permeability transition pore (mPTP) opening, and pharmacological inhibition of the mPTP suppresses neuronal differentiation. Moreover, superoxide flashes and neuronal differentiation are inhibited by scavenging of mitochondrial superoxide. Conversely, manipulations that increase superoxide flash frequency accelerate neuronal differentiation. Our findings reveal a regulatory role for mitochondrial superoxide flashes, mediated by mPTP opening, in neuronal differentiation.

  20. An investigation of life circumstances associated with the experience of hot flashes in Campeche, Mexico.

    Science.gov (United States)

    Huicochea-Gómez, Laura; Sievert, Lynnette Leidy; Cahuich-Campos, Diana; Brown, Daniel E

    2017-01-01

    The purpose of this study was to better understand the experience of calores (hot flashes) in the state of Campeche, Mexico, and characteristics of women's lives. This study was carried out to understand the sociocultural context of women's lives before conducting a larger semistructured survey in the same communities. Eighty-five women from rural and urban settings participated in open-ended interviews about the menopausal transition, with particular attention to hot flashes. Univariate and logistic regression analyses identified potential determinants of hot flashes. Qualitative responses were analyzed for central themes from the 40 women who experienced "calores" associated with menopause at the time of interview. The word "calores" was used to describe a variety of sensations and experiences related to the hot climate, infections, going in and out of air-conditioning, emotional stress, and physical exertion, as well as the symptom associated with menopause. In quantitative analyses, the likelihood of experiencing hot flashes varied by menopause status and rural/urban residence. In qualitative analyses, themes that characterized the lives of women with hot flashes were as follows: the search for, and the availability of, biomedical care; presence or absence of networks of social support; marital status and quality of the relationship; and occupational stress. Hot flash questionnaires can elicit different symptom frequencies depending on the language used and the sociocultural context of women's lives. Qualitative findings suggest that the themes most likely to influence the perception and experience of hot flashes in Campeche are biomedicine, social support, marriage, and stress.

  1. Digital Device Architecture and the Safe Use of Flash Devices in Munitions

    Science.gov (United States)

    Katz, Richard B.; Flowers, David; Bergevin, Keith

    2017-01-01

    Flash technology is being utilized in fuzed munition applications and, based on the development of digital logic devices in the commercial world, usage of flash technology will increase. Digital devices of interest to designers include flash-based microcontrollers and field programmable gate arrays (FPGAs). Almost a decade ago, a study was undertaken to determine if flash-based microcontrollers could be safely used in fuzes and, if so, how should such devices be applied. The results were documented in the Technical Manual for the Use of Logic Devices in Safety Features. This paper will first review the Technical Manual and discuss the rationale behind the suggested architectures for microcontrollers and a brief review of the concern about data retention in flash cells. An architectural feature in the microcontroller under study will be discussed and its use will show how to screen for weak or failed cells during manufacture, storage, or immediately prior to use. As was done for microcontrollers a decade ago, architectures for a flash-based FPGA will be discussed, showing how it can be safely used in fuzes. Additionally, architectures for using non-volatile (including flash-based) storage will be discussed for SRAM-based FPGAs.

  2. Analytic Perturbation Method for Estimating Ground Flash Fraction from Satellite Lightning Observations

    Science.gov (United States)

    Koshak, William; Solakiewicz, Richard

    2013-01-01

    An analytic perturbation method is introduced for estimating the lightning ground flash fraction in a set of N lightning flashes observed by a satellite lightning mapper. The value of N is large, typically in the thousands, and the observations consist of the maximum optical group area produced by each flash. The method is tested using simulated observations that are based on Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) data. National Lightning Detection NetworkTM (NLDN) data is used to determine the flash-type (ground or cloud) of the satellite-observed flashes, and provides the ground flash fraction truth for the simulation runs. It is found that the mean ground flash fraction retrieval errors are below 0.04 across the full range 0-1 under certain simulation conditions. In general, it is demonstrated that the retrieval errors depend on many factors (i.e., the number, N, of satellite observations, the magnitude of random and systematic measurement errors, and the number of samples used to form certain climate distributions employed in the model).

  3. Evaluating Non-In-Place Update Techniques for Flash-Based Transaction Processing Systems

    Science.gov (United States)

    Wang, Yongkun; Goda, Kazuo; Kitsuregawa, Masaru

    Recently, flash memory is emerging as the storage device. With price sliding fast, the cost per capacity is approaching to that of SATA disk drives. So far flash memory has been widely deployed in consumer electronics even partly in mobile computing environments. For enterprise systems, the deployment has been studied by many researchers and developers. In terms of the access performance characteristics, flash memory is quite different from disk drives. Without the mechanical components, flash memory has very high random read performance, whereas it has a limited random write performance because of the erase-before-write design. The random write performance of flash memory is comparable with or even worse than that of disk drives. Due to such a performance asymmetry, naive deployment to enterprise systems may not exploit the potential performance of flash memory at full blast. This paper studies the effectiveness of using non-in-place-update (NIPU) techniques through the IO path of flash-based transaction processing systems. Our deliberate experiments using both open-source DBMS and commercial DBMS validated the potential benefits; x3.0 to x6.6 performance improvement was confirmed by incorporating non-in-place-update techniques into file system without any modification of applications or storage devices.

  4. Perceived shifts of flashed stimuli by visible and invisible object motion.

    Science.gov (United States)

    Watanabe, Katsumi; Sato, Takashi R; Shimojo, Shinsuke

    2003-01-01

    Perceived positions of flashed stimuli can be altered by motion signals in the visual field-position capture (Whitney and Cavanagh, 2000 Nature Neuroscience 3 954-959). We examined whether position capture of flashed stimuli depends on the spatial relationship between moving and flashed stimuli, and whether the phenomenal permanence of a moving object behind an occluding surface (tunnel effect; Michotte 1950 Acta Psychologica 7 293-322) can produce position capture. Observers saw two objects (circles) moving vertically in opposite directions, one in each visual hemifield. Two horizontal bars were simultaneously flashed at horizontally collinear positions with the fixation point at various timings. When the movement of the object was fully visible, the flashed bar appeared shifted in the motion direction of the circle. But this position-capture effect occurred only when the bar was presented ahead of or on the moving circle. Even when the motion trajectory was covered by an opaque surface and the bar was flashed after complete occlusion of the circle, the position-capture effect was still observed, though the positional asymmetry was less clear. These results show that movements of both visible and 'hidden' objects can modulate the perception of positions of flashed stimuli and suggest that a high-level representation of 'objects in motion' plays an important role in the position-capture effect.

  5. Mortality from flash floods: a review of national weather service reports, 1969-81.

    Science.gov (United States)

    French, J; Ing, R; Von Allmen, S; Wood, R

    1983-01-01

    Of all weather-related disasters that occur in the United States, floods are the main cause of death, and most flood-related deaths are attributed to flash floods. Whenever a weather-related disaster involves 30 or more deaths or more than $100 million in property damage, the National Weather Service (NWS) forms a survey team to investigate the disaster and write a report of findings. All NWS survey reports on flash floods issued during 1969-81 were reviewed to determine the mortality resulting from such floods, the effect of warnings on mortality, and the circumstances contributing to death. A total of 1,185 deaths were associated with 32 flash floods, an average of 37 deaths per flash flood. The highest average number of deaths per event was associated with the four flash floods in which dams broke after heavy rains. Although there were 18 flash floods in 1977-81 and only 14 in 1969-76, the number of deaths was 2 1/2 times greater during the earlier period. More than twice as many deaths were associated with flash floods for which the survey team considered the warnings inadequate than with those with warnings considered adequate. Ninety-three percent of the deaths were due to drowning and 42 percent of these drownings were car related. The other drownings occurred in homes, at campsites, or when persons were crossing bridges and streams. The need for monitoring dams during periods of heavy rainfall is highlighted.

  6. Increasing flash droughts over China during the recent global warming hiatus.

    Science.gov (United States)

    Wang, Linying; Yuan, Xing; Xie, Zhenghui; Wu, Peili; Li, Yaohui

    2016-08-11

    The recent global warming slowdown or hiatus after the big El Niño event in 1997/98 raises the questions of whether terrestrial hydrological cycle is being decelerated and how do the hydrological extremes respond to the hiatus. However, the rapidly developing drought events that are termed as "flash droughts" accompanied by extreme heat, low soil moisture and high evapotranspiration (ET), occurred frequently around the world, and caused devastating impacts on crop yields and water supply. Here, we investigate the long-term trend and variability of flash droughts over China. Flash droughts are most likely to occur over humid and semi-humid regions, such as southern and northeastern China. Flash drought averaged over China increased by 109% from 1979 to 2010, and the increase was mainly due to a long term warming of temperature (50%), followed by the contributions from decreasing soil moisture and increasing ET. There was a slight drop in temperature after 1997, but the increasing trend of flash droughts was tripled. Further results indicate that the decreasing temperature was compensated by the accelerated drying trends of soil moisture and enhanced ET, leading to an acceleration of flash droughts during the warming hiatus. The anthropogenic warming in the next few decades may exacerbate future flash drought conditions in China.

  7. Increasing flash droughts over China during the recent global warming hiatus

    Science.gov (United States)

    Wang, Linying; Yuan, Xing; Xie, Zhenghui; Wu, Peili; Li, Yaohui

    2016-08-01

    The recent global warming slowdown or hiatus after the big El Niño event in 1997/98 raises the questions of whether terrestrial hydrological cycle is being decelerated and how do the hydrological extremes respond to the hiatus. However, the rapidly developing drought events that are termed as “flash droughts” accompanied by extreme heat, low soil moisture and high evapotranspiration (ET), occurred frequently around the world, and caused devastating impacts on crop yields and water supply. Here, we investigate the long-term trend and variability of flash droughts over China. Flash droughts are most likely to occur over humid and semi-humid regions, such as southern and northeastern China. Flash drought averaged over China increased by 109% from 1979 to 2010, and the increase was mainly due to a long term warming of temperature (50%), followed by the contributions from decreasing soil moisture and increasing ET. There was a slight drop in temperature after 1997, but the increasing trend of flash droughts was tripled. Further results indicate that the decreasing temperature was compensated by the accelerated drying trends of soil moisture and enhanced ET, leading to an acceleration of flash droughts during the warming hiatus. The anthropogenic warming in the next few decades may exacerbate future flash drought conditions in China.

  8. Relationships between cloud-to-ground flashes and hydrometeors in a thunderstorm in Fujian province

    Science.gov (United States)

    Zhang, Tinglong; Zhao, Guo; Wei, Changxiong; Gao, Yi; Yu, Hai; Zhou, Fangcong

    2017-02-01

    A local severe thunderstorm, occurring near the coastal region in Fujian province, China, was chosen to study the relationships between hydrometeors and cloud-to-ground (CG) flash activities. This thunderstorm case study was carried out by using vehicle-mounted X-band dual-polarization radar on August 28, 2009. On the basis of polarimetric parameters, the hydrometeors were identified by fuzzy logic hydrometeor classification (FLHC). The results show that the thunderstorm grew into a squall line with a maximum flash rate of 85 fl/5 min in mature stage. Negative CG constituted approximately 97.3% of total CG flashes. More than 90% of the CG flashes occurred in the convective regions, and less than 10% occurred in the stratiform region. The strong echo volume in convective region had a positive linear correlation with the CG flashes rate. Seven types of hydrometeors, namely, rain (RN), aggregates (AG), low-density graupel (LDG), high-density graupel (HDG), vertically aligned ice crystals (VI), drizzle-light rain (DR), and ice crystals (IC), have been classified; the first five of the hydrometeors are predominant in the thunderstorm. RN is located mainly in regions warmer than 0 °C; the HDG is located in the middle and lower regions colder than 0 °C; and LDG and VI mainly appear in the upper portion of the thunderstorm. The ice hydrometeors seemly had a close relation with CG flashes because the total CG flash rates had a strong positive correlation with the grid number of AG, LDG, HDG, and VI in the convective region. However, the sufficient ice hydrometeors did not produce frequent CG flashes in the stratiform region. It suggests that the dynamic structure is also very important for triggering lightning flashes.

  9. Mitochondrial Flash: Integrative Reactive Oxygen Species and pH Signals in Cell and Organelle Biology

    Science.gov (United States)

    Gong, Guohua; Wang, Xianhua; Wei-LaPierre, Lan; Cheng, Heping; Dirksen, Robert

    2016-01-01

    Abstract Significance: Recent breakthroughs in mitochondrial research have advanced, reshaped, and revolutionized our view of the role of mitochondria in health and disease. These discoveries include the development of novel tools to probe mitochondrial biology, the molecular identification of mitochondrial functional proteins, and the emergence of new concepts and mechanisms in mitochondrial function regulation. The discovery of “mitochondrial flash” activity has provided unique insights not only into real-time visualization of individual mitochondrial redox and pH dynamics in live cells but has also advanced understanding of the excitability, autonomy, and integration of mitochondrial function in vivo. Recent Advances: The mitochondrial flash is a transient and stochastic event confined within an individual mitochondrion and is observed in a wide range of organisms from plants to Caenorhabditis elegans to mammals. As flash events involve multiple transient concurrent changes within the mitochondrion (e.g., superoxide, pH, and membrane potential), a number of different mitochondrial targeted fluorescent indicators can detect flash activity. Accumulating evidence indicates that flash events reflect integrated snapshots of an intermittent mitochondrial process arising from mitochondrial respiration chain activity associated with the transient opening of the mitochondrial permeability transition pore. Critical Issues: We review the history of flash discovery, summarize current understanding of flash biology, highlight controversies regarding the relative roles of superoxide and pH signals during a flash event, and bring forth the integration of both signals in flash genesis. Future Directions: Investigations using flash as a biomarker and establishing its role in cell signaling pathway will move the field forward. Antioxid. Redox Signal. 25, 534–549. PMID:27245241

  10. A Novel Dual Traffic/Flash Flood Monitoring System Using Passive Infrared/Ultrasonic Sensors

    KAUST Repository

    Mousa, Mustafa

    2015-10-19

    Floods are the most common type of natural disaster, causing thousands of casualties every year. Among these events, urban flash floods are particularly deadly because of the short timescales on which they occur, and because of the high concentration of population in cities. Since most flash flood casualties are caused by a lack of information, it is critical to generate accurate and detailed warnings of flash floods. However, deploying an infrastructure that solely monitor flash floods makes little economic sense, since the average periodicity of catastrophic flash floods exceeds the lifetime of a typical sensor network. To address this issue, we propose a new sensing device that can simultaneously monitor urban flash floods and another phenomenon of interest (traffic congestion on the present case). This sensing device is based on the combination of an ultrasonic rangefinder with one or multiple remote temperature sensors. We show an implementation of this device, and illustrate its performance in both traffic flow and flash flood sensing. Field data shows that the sensor can detect vehicles with a 99% accuracy, in addition to estimating their speed and classifying them in function of their length. The same sensor can also monitor urban water levels with an accuracy of less than 2 cm. Two of the sensors have been deployed in a flood prone area, where they captured the only (minor) flash flood that occurred over the one-year test period, with no false detection, and an agreement in the estimated water level estimate (during the flash flood event) of about 2 cm.

  11. Local algorithms on dense two-frame stereo matching

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; LI Xuemei; WANG Shuozhen

    2012-01-01

    Stereo matching is a fundamental and crucial problem in computer vision. In the last decades, many researchers have been working on it and made great progress. Generally stereo algorithms can be classified into local methods and global methods. In this paper, the challenges of stereo matching are first introduced, and then we focus on local approaches which have simpler structures and higher efficiency than global ones. Local algorithms generally perform four steps: cost computation, cost aggregation, disparity computation and disparity refinement. Every step is deeply investigated, and most work focuses on cost aggregation. We studied most of the classical local methods and divide them into several classes. The classification well illustrates the development history of local stereo correspondence and shows the essence of local matching along with its important and difficult points. At the end we give the future development trend of local methods.

  12. Flash flow pyrolysis: mimicking flash vacuum pyrolysis in a high-temperature/high-pressure liquid-phase microreactor environment.

    Science.gov (United States)

    Cantillo, David; Sheibani, Hassan; Kappe, C Oliver

    2012-03-02

    Flash vacuum pyrolysis (FVP) is a gas-phase continuous-flow technique where a substrate is sublimed through a hot quartz tube under high vacuum at temperatures of 400-1100 °C. Thermal activation occurs mainly by molecule-wall collisions with contact times in the region of milliseconds. As a preparative method, FVP is used mainly to induce intramolecular high-temperature transformations leading to products that cannot easily be obtained by other methods. It is demonstrated herein that liquid-phase high-temperature/high-pressure (high-T/p) microreactor conditions (160-350 °C, 90-180 bar) employing near- or supercritical fluids as reaction media can mimic the results obtained using preparative gas-phase FVP protocols. The high-T/p liquid-phase "flash flow pyrolysis" (FFP) technique was applied to the thermolysis of Meldrum's acid derivatives, pyrrole-2,3-diones, and pyrrole-2-carboxylic esters, producing the expected target heterocycles in high yields with residence times between 10 s and 10 min. The exact control over flow rate (and thus residence time) using the liquid-phase FFP method allows a tuning of reaction selectivities not easily achievable using FVP. Since the solution-phase FFP method does not require the substrate to be volatile any more--a major limitation in classical FVP--the transformations become readily scalable, allowing higher productivities and space-time yields compared with gas-phase protocols. Differential scanning calorimetry measurements and extensive DFT calculations provided essential information on pyrolysis energy barriers and the involved reaction mechanisms. A correlation between computed activation energies and experimental gas-phase FVP (molecule-wall collisions) and liquid-phase FFP (molecule-molecule collisions) pyrolysis temperatures was derived.

  13. Flash programming for the social & behavioral sciences a simple guide to sophisticated online surveys and experiments

    CERN Document Server

    Weinstein, Yana

    2012-01-01

    Adobe Flash is one of the most popular languages for animated web content, and recently social and behavioral scientists have started to take advantage of it to collect data online. Flash Programming for the Social and Behavioral Sciences: A Simple Guide to Sophisticated Online Surveys and Experiments is a unique, step-by-step guide to using Adobe Flash to develop experiments and other research tools. Each chapter presents a set of techniques required for one aspect of programming an experiment, with students following instructions in italics and working through the code inclu

  14. Increasing the computational speed of flash calculations with applications for compositional, transient simulations

    DEFF Research Database (Denmark)

    Rasmussen, Claus P.; Krejbjerg, Kristian; Michelsen, Michael Locht

    2006-01-01

    Approaches are presented for reducing the computation time spent on flash calculations in compositional, transient simulations. In a conventional flash calculation, the majority of the simulation time is spent on stability analysis, even for systems far into the single-phase region. A criterion has...... been implemented for deciding when it is justified to bypass the stability analysis. With the implementation of the developed time-saving initiatives, it has been shown for a number of compositional, transient pipeline simulations that a reduction of the computation time spent on flash calculations...

  15. Flash, word, powerpoint, ps combination to the advantage of teaching courseware

    Institute of Scientific and Technical Information of China (English)

    张弟龙

    2014-01-01

    The current,multiFlash,word,ppt,ps teaching has become an essential of modem means of education. and Flashsoftware.multimedia courseware is the most representative one of the tools.TI1iS article iS by analysis and comparison of Flash andPowerPoint software in the production of the different characteristics of courseware that produced in PowerPoint to insert flashanimation iS the front-line teachers are the most commonly used method of courseware production.Finally,several flash software andother applications in the teaching mode.

  16. A NEW APPROACH TO DESIGN LOW POWER CMOS FLASH A/D CONVERTER

    Directory of Open Access Journals (Sweden)

    Sudakar S. Chauhan

    2011-07-01

    Full Text Available In the present paper, a 4-bit flash analog to digital converter for low power SoC application is presented.CMOS inverter has been used as a comparator and by adjusting the ratio of channel width and length, theswitching threshold of the CMOS inverter is varied to detect the input analog signal. The simulation resultsshow that this proposed 4-bit flash ADC consumes about 12.4 mW at 200M sample/s with 3.3V supplyvoltage in TSMC 0.35 μm process. Compared with the traditional flash ADC, this proposed method canreduce about 78% in power consumption.

  17. Report on in-situ studies of flash sintering of uranium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Raftery, Alicia Marie [MST-8: MATERIALS SCIENCE IN RADIATION & DYNAMICS EXTREMES

    2017-01-24

    Flash sintering is a novel type of field assisted sintering that uses an electric field and current to provide densification of materials on very short time scales. The potential for field assisted sintering techniques to be used in producing nuclear fuel is gaining recognition due to the potential economic benefits and improvements in material properties. The flash sintering behavior has so far been linked to applied and material parameters, but the underlying mechanisms active during flash sintering have yet to be identified. This report summarizes the efforts to investigate flash sintering of uranium dioxide using dilatometer studies at Los Alamos National Laboratory and two separate sets of in-situ studies at Brookhaven National Laboratory’s NSLS-II XPD-1 beamline. The purpose of the dilatometer studies was to understand individual parameter (applied and material) effects on the flash behavior and the purpose of the in-situ studies was to better understand the mechanisms active during flash sintering. As far as applied parameters, it was found that stoichiometry, or oxygen-to-metal ratio, has a significant effect on the flash behavior (time to flash and speed of flash). Composite systems were found to have degraded sintering behavior relative to pure UO2. The critical field studies are complete for UO2.00 and will be analyzed against an existing model for comparison. The in-situ studies showed that the strength of the field and current are directly related to the sample temperature, with temperature-driven phase changes occurring at high values. The existence of an ‘incubation time’ has been questioned, due to a continuous change in lattice parameter values from the moment that the field is applied. Some results from the in-situ experiments, which should provide evidence regarding ion migration, are still being analyzed. Some preliminary conclusions can be made from these results with regard to using field assisted sintering to

  18. Analysis of the Lehman Brothers collapse and the Flash Crash event by applying wavelets methodologies

    Science.gov (United States)

    Beccar-Varela, Maria P.; Mariani, Maria C.; Tweneboah, Osei K.; Florescu, Ionut

    2017-05-01

    In this study, we apply a wavelet methodology initially developed for geophysical data to financial data. Specifically, the method distinguishes between natural tectonic earthquakes and man made explosions. We exemplify using time series data from two financial events: the Lehman Brothers collapse and the Flash Crash event. We conclude that the Lehman Brothers collapse behaves like a natural earthquake while the Flash Crash event behaves like a human made explosion. This study may imply that the Lehman Brothers type events may be predicted, while sudden Flash Crash type events are not predictable.

  19. Rapid sintering of anisotropic, nanograined Nd-Fe-B by flash-spark plasma sintering

    Science.gov (United States)

    Castle, Elinor; Sheridan, Richard; Grasso, Salvatore; Walton, Allan; Reece, Mike

    2016-11-01

    A Spark Plasma Sintering (SPS) furnace was used to Flash-Sinter (FS) Nd-Fe-Dy-Co-B-Ga melt spun permanent magnetic material. During the 10 s "Flash" process (heating rate 2660 K min-1), sample sintering (to theoretical density) and deformation (54% height reduction) occurred. This produced texturing and significant magnetic anisotropy, comparable to conventional die-upset magnets; yet with much greater coercivities (>1600 kA m-1) due to the nanoscale characteristics of the plate-like sintered grains. These preliminary results suggest that Flash-SPS could provide a new processing route for the mass production of highly anisotropic, nanocrystalline magnetic materials with high coercivity.

  20. SEMICONDUCTOR INTEGRATED CIRCUITS A low-voltage sense amplifier for high-performance embedded flash memory

    Science.gov (United States)

    Jiang, Liu; Xueqiang, Wang; Qin, Wang; Dong, Wu; Zhigang, Zhang; Liyang, Pan; Ming, Liu

    2010-10-01

    This paper presents a sense amplifier scheme for low-voltage embedded flash (eFlash) memory applications. The topology of the sense amplifier is based on current mode comparison. Moreover, an offset-voltage elimination technique is employed to improve the sensing performance under a small memory cell current. The proposed sense amplifier is designed based on a GSMC 130 nm eFlash process, and the sense time is 0.43 ns at 1.5 V, corresponding to a 46% improvement over the conventional technologies.

  1. Bipolar lightning flashes observed at the Säntis Tower: Do we need to modify the traditional classification?

    Science.gov (United States)

    Azadifar, Mohammad; Rachidi, Farhad; Rubinstein, Marcos; Rakov, Vladimir A.; Paolone, Mario; Pavanello, Davide

    2016-12-01

    We present and discuss current waveforms associated with 13 bipolar lightning flashes recorded at the Säntis Tower during the period from June 2010 to January 2015. During this period, a total of 427 flashes were recorded, of which 13 (3%) were classified as bipolar flashes. The majority of the recorded flashes (10 out of 13) exhibited a polarity reversal during the initial continuous current, therefore belonging to Category I according to the classification proposed by Rakov (2003). Of the three remaining flashes, two were characterized by different polarities of the initial stage current and the following return stroke or strokes (Category II), and one flash involved return strokes of opposite polarity within the same flash (Category III). In Category I bipolar flashes, the polarity reversal is usually assumed to be associated with in-cloud processes. However, two of our 10 Category I flashes appeared to be each a sequence of two upward discharges of opposite polarity, initiated from the tower within tens of milliseconds of each other. This is the first time that such a sequence has been observed from the same tower. We suggest that the traditional classification of bipolar flashes should be modified to distinguish between two types of Category I flashes: those in which the polarity reversal during the initial stage is associated with in-cloud processes (Category Ia) and those in which the polarity reversal is due to initiation of two opposite-polarity leaders from the tower (Category Ib).

  2. Measuring hot flashes: summary of a National Institutes of Health workshop.

    Science.gov (United States)

    Miller, Heather G; Li, Rose Maria

    2004-06-01

    The etiology and mechanism of hot flashes remain incompletely understood. Future studies of hormonal and neurologic systems may provide promising leads to improve our understanding of the basic phenomenon and perhaps also shed light on the placebo effect. However, this is likely a complex undertaking. Critical to this effort is the ability to reliably identify when a hot flash has occurred. The leading objective measure in use today--sternal skin conductance monitoring--has some limitations in ambulatory settings. However, a more severe limitation is the inability of sternal skin conductance to provide any information on duration, intensity, and interference with activities. Ultimately, researchers desire a convenient and cost-effective sensor for monitoring hot flashes without cumbersome electrodes that might become compromised if a subject experiences extensive sweating or takes a shower and one that can capture data continuously for relatively long periods of observation. However, researchers also need well-characterized methods for collecting self-reported data. If the primary concern is helping women with hot flashes find relief, then subjective measures collected through diaries or interviews cannot be dismissed. Given the importance of this information, it would make sense to undertake methodologic research to ensure that the best possible systems are used to collect valid and reliable information. The factors that we want to measure with respect to hot flashes are likely to change over time as more is learned about the underlying phenomenon. This will probably be an evolutionary process, one involving decisions about what biological factors will be most useful for the task at hand, what technologies might be available or easily adaptable, which measures should be bundled together to maximize the precision of data collected with the available technology, and the analysis of the data to generate new hypotheses and perhaps the need for new measurement tools

  3. Long-lasting but Dim Brethren of Cosmic Flashes

    Science.gov (United States)

    2006-08-01

    Astronomers, using ESO's Very Large Telescope, have for the first time made the link between an X-ray flash and a supernova. Such flashes are the little siblings of gamma-ray bursts (GRB) and this discovery suggests the existence of a population of events less luminous than 'classical' GRBs, but possibly much more numerous. "This extends the GRB-supernova connection to X-ray flashes and fainter supernovae, implying a common origin," said Elena Pian, (INAF, Italy), lead-author of one of the four papers related to this event appearing in the 31 August issue of Nature. The event began on 18 February 2006: the NASA/PPARC/ASI Swift satellite detected an unusual gamma-ray burst, about 25 times closer and 100 times longer than the typical gamma-ray burst. GRBs release in a few seconds more energy than that of the Sun during its entire lifetime of more than 10,000 million years. The GRBs are thus the most powerful events since the Big Bang known in the Universe. ESO PR Photo 33/06 ESO PR Photo 33/06 The Field around SN2006aj The explosion, called GRB 060218 after the date it was discovered, originated in a star-forming galaxy about 440 million light-years away toward the constellation Aries. This is the second-closest gamma-ray burst ever detected. Moreover, the burst of gamma rays lasted for nearly 2,000 seconds; most bursts last a few milliseconds to tens of seconds. The explosion was surprisingly dim, however. A team of astronomers has found hints of a budding supernova. Using, among others, ESO's Very Large Telescope (VLT) in Chile, the scientists have watched the afterglow of this burst grow brighter in optical light. This brightening, along with other telltale spectral characteristics in the light, strongly suggests that a supernova was unfolding. Within days, the supernova became apparent. The observations with the VLT started on 21 February 2006, just three days after the discovery. Spectroscopy was then performed nearly daily for seventeen days, providing the

  4. In situ determination of binary alloy melt compositions in the LHDAC by X- Radiography

    Science.gov (United States)

    Lord, O. T.; Walter, M. J.; Walker, D.; Clark, S. M.

    2008-12-01

    Constraining the light element in Earth's molten outer core requires an understanding of the melting phase relations in iron-light element binary systems. For example, it is critical to determine the composition of liquids at binary eutectics. Typically such measurements are carried out after the sample has been quenched in temperature and pressure. Such 'cook and look' methods possibly suffer from systematic errors introduced by exsolution of the light element from the melt on quench and error in the reintegration of the liquid composition [1]. Here, we present a novel method for the determination of melt compositions in iron-light element binary systems in situ in the LHDAC at simultaneous high-pressure, high-temperature conditions. Samples consist of a light element bearing compound, such as FeO, surrounded by a pure iron ring, forming a donut ~100 μm in diameter and ~15 μm thick. The donuts are loaded into stainless steel gaskets in the DAC, sandwiched between discs fabricated from sol-gel deposited nanocrystalline Al2O3 with similar dimensions to the donut. Pressure is monitored by ruby fluorescence during compression. The sample is heated at the boundary between the iron and light element compound using two 100 W IR lasers in a double-sided configuration at beamline 12.2.2 at the Advanced Light Source. Temperature is measured by spectroradiometry. Before, during and after melting, X-radiographic images of the sample are taken by shining a defocused beam of synchrotron X-rays through the sample and onto a CdWO4 phosphor. The visible light from the phosphor is then focused onto a high resolution CCD, where absorption contrast images are recorded. The absorption of the molten region is then determined, and it's composition calculated by linear interpolation between the absorption of the two solid end members. As a test of the reliability of the method we measured the Fe-FeS eutectic to 20 GPa and our results are in good agreement with previous studies that are based on various ex situ techniques. We measured the eutectic composition between Fe and Fe3C up to 44 GPa, and found that the carbon content of the eutectic drops rapidly above about 10 GPa, dropping to less that 1 wt% by 44 GPa. This result is generally consistent with the thermodynamic calculations of Wood [2]. Experiments on the Fe-FeSi eutectic yielded an increase in the Si content of the eutectic to 35 GPa, consistent with data from large volume press experiments [3] Notably, melting experiments at 35-43 GPa and ~2500 K on a boundary between Fe and FeO failed to yield evidence of a melt with a composition distinguishable from pure iron. However, an experiment at 12 GPa and 2700 K between Fe and FeO(OH) did yield a melt with a composition intermediate between the two end members. This suggests that O solubility in the Fe-O eutectic melt is low at mid-mantle pressures, but that H may dissolve into the melt by itself or in combination with O. [1] Walker, D., 2005. Core-Mantle chemical issues. Canad. Min., 43, 1553-1564 [2] Wood, B. J., 1993. Carbon in the core. Earth Planet Sci. Lett., 117, 593-607 [3] Kuwayama, Y. & Hirose, K., 2004. Phase relations in the system Fe-FeSi at 21 GPa. Am. Min., 89, 273-276.

  5. Aspects of radiation protection during chest X-radiography; Strahlenhygienische Aspekte bei der Roentgenuntersuchung des Thorax

    Energy Technology Data Exchange (ETDEWEB)

    Seidenbusch, M.C.; Schneider, K. [Dr. von Haunersches Kinderspital, Klinikum der Universitaet Muenchen, Institut fuer Klinische Radiologie - Kinderradiologie, Muenchen (Germany)

    2015-07-15

    Radiation safety in conventional X-ray diagnostics is based on the concepts of justification, optimization of an X-ray examination and limitation of the radiation exposure achieved during the examination. Optimization of an X-ray examination has to be considered as a multimodal process in which all technical components of the X-ray equipment have to be adapted to each other and also have to be adapted to the anthropometric characteristics of patients and the clinical indications. In this article the technical components of a conventional pediatric chest X-radiograph are presented, and recommendations for optimizing chest X-rays in children are provided. The following measures are of prime importance: correct x-ray beam limitation, using the posteroanterior projection when possible and not using anti-scatter grids in children under approximately 8 years old. In pediatric radiology chest x-rays that are taken not at the peak of inspiration can also be of some diagnostic significance. Optimization of an X-ray examination inevitably results in the limitation of radiation exposure. (orig.) [German] Die Strahlenhygiene in der konventionellen radiologischen Diagnostik basiert auf der Trias Rechtfertigung, Optimierung bzw. Limitierung der Roentgenuntersuchung bzw. Strahlenexposition. Die Optimierung einer Roentgenuntersuchung ist als multimodaler Prozess aufzufassen, in welchem saemtliche technische Komponenten der Roentgeneinrichtung sowohl miteinander als auch mit den anthropometrischen Eigenschaften des Patienten und der klinischen Fragestellung abzustimmen sind. Im vorliegenden Beitrag werden die technischen Komponenten bei der konventionellen Roentgenuntersuchung des paediatrischen Thorax in ihrer Beziehung zueinander dargestellt und Empfehlungen fuer eine Optimierung der konventionellen Thoraxaufnahme bei Kindern ausgesprochen. Die wichtigsten Massnahmen bestehen in einer korrekten Einblendung, in der Anfertigung der Aufnahmen im posteroanterioren Strahlengang und im Verzicht auf Streustrahlenraster etwa bis zum 8. Lebensjahr. Auch sind in der Kinderradiologie Thoraxaufnahmen selbst bei suboptimaler Inspiration haeufig noch diagnostisch verwertbar. Die Optimierung einer Roentgenuntersuchung bewirkt fast zwangslaeufig eine Limitierung der Strahlenexposition. (orig.)

  6. Implementing the national AIGA flash flood warning system in France

    Science.gov (United States)

    Organde, Didier; Javelle, Pierre; Demargne, Julie; Arnaud, Patrick; Caseri, Angelica; Fine, Jean-Alain; de Saint Aubin, Céline

    2015-04-01

    The French national hydro-meteorological and flood forecasting centre (SCHAPI) aims to implement a national flash flood warning system to improve flood alerts for small-to-medium (up to 1000 km2) ungauged basins. This system is based on the AIGA method, co-developed by IRSTEA these last 10 years. The method, initially set up for the Mediterranean area, is based on a simple event-based hourly hydrologic distributed model run every 15 minutes (Javelle et al. 2014). The hydrologic model ingests operational radar-gauge rainfall grids from Météo-France at a 1-km² resolution to produce discharges for successive outlets along the river network. Discharges are then compared to regionalized flood quantiles of given return periods and warnings (expressed as the range of the return period estimated in real-time) are provided on a river network map. The main interest of the method is to provide forecasters and emergency services with a synthetic view in real time of the ongoing flood situation, information that is especially critical in ungauged flood prone areas. In its enhanced national version, the hourly event-based distributed model is coupled to a continuous daily rainfall-runoff model which provides baseflow and a soil moisture index (for each 1-km² pixel) at the beginning of the hourly simulation. The rainfall-runoff models were calibrated on a selection of 700 French hydrometric stations with Météo-France radar-gauge reanalysis dataset for the 2002-2006 period. To estimate model parameters for ungauged basins, the 2 hydrologic models were regionalised by testing both regressions (using different catchment attributes, such as catchment area, soil type, and climate characteristic) and spatial proximity techniques (transposing parameters from neighbouring donor catchments), as well as different homogeneous hydrological areas. The most valuable regionalisation method was determined for each model through jack-knife cross-validation. The system performance was then

  7. 基于Flash AS3和XML实现的图书馆管理系统%Library management system based on XML and Flash AS3

    Institute of Scientific and Technical Information of China (English)

    肖洋; 何斌; 李军峰

    2012-01-01

      该系统采用Flash AS3开发,专为触摸屏设计的一款新型图书馆管理系统,功能全面,采用XML作为数据库后台,实现系统的跨平台性,利用JS使得系统脱离Flash沙盒,以达到修改数据的目的,具有很好的应用价值。%  The system is a new library management system using flash AS3 to develop, specially designed for touch screen, it was comprehensive functions, using XML database as background, cross-platform of the system was realized, to achieve the objective of modifying data, using JS made the system break away from the Flash sandbox, so it is very good value.

  8. The reproductive and developmental toxicity of High Flash Aromatic Naphtha.

    Science.gov (United States)

    McKee, R H; Wong, Z A; Schmitt, S; Beatty, P; Swanson, M; Schreiner, C A; Schardein, J L

    1990-01-01

    Catalytic reforming is a refining process that converts naphthenes to aromatics by dehydrogenation to make higher octane gasoline blending components. A portion of this wide boiling range hydrocarbon stream can be separated by distillation and used for other purposes. One such application is a mixture of predominantly 9-carbon aromatic molecules (C9 aromatics, primarily isomers of ethyltoluene and trimethylbenzene), which is removed and used as a solvent--High Flash Aromatic Naphtha. A program was initiated to assess the toxicological properties of High Flash Aromatic Naphtha since there may be human exposure through inhalation or external body contact. The current study was conducted to assess the potential for developmental toxicity in the mouse and for reproductive toxicity in the rat. In the developmental toxicity study in CD-1 mice, exposure of dams by inhalation to near lethal levels (1500 ppm) resulted in fetal mortality, reduced weight, delayed ossification, and an increased incidence of cleft palate. At 500 ppm, a level at which maternal weight gain was slightly reduced, fetal weight gain was also reduced, but there was no other evidence of developmental effects. The lowest exposure level (100 ppm) did not cause any maternal or developmental toxicity. There was no consistent evidence of reproductive toxicity in rats, even at exposure levels which resulted in significantly reduced parental weight gain. In addition, when parental exposure was stopped on GD (gestation day) 20, birth weights as well as postnatal survival were generally similar to control values, even in the 1500 ppm exposure group. Postnatal weight gain was also similar to controls early in weaning, but, if maternal exposure was reinitiated, weight gain was reduced in the high exposure group. However, when exposure was continued until delivery, pups in the high exposure group exhibited reduced litter size, birth weight and poor survival. Thus it was likely that the reduction in fetal weight

  9. AIRIX: a new tool for flash radiography in detonics

    Science.gov (United States)

    Cavailler, Claude

    2001-04-01

    AIRIX is an induction linear accelerator which will be used for flash radiography in Commissariat A L'Energie Atomique In France. Designed to produce an X-ray dose of some hundreds Rads at 1 meter with an X-ray focal spot size diameter of less than 2 mm (LANL-CEA DAM definition), this facility consists in a 3,8 MeV/2 kA pulsed electron injector and 15,4 MeV induction accelerator powered by 32 high voltage generators. A prototype of this accelerator, called PIVAIR, has been studied and realized in CEA CESTA near Bordeaux. PIVAIR is a validation step for AIRIX at 8 MeV. It includes an injector (3,6 MeV, 3,2 kA, 60 ns) and 16 induction cells supplied by 8 high voltage generators (250 kV, 70 ns). Two different technologies of induction cells have been tested (Rexolite insulator or ferrite Under Vacuum). We have chosen ferrite under vacuum cells technology after comparison of results on beam transport and reliability tests. A focusing experiment at 7.2 MeV of the electron beam has been achieved during summer 1997. We have begun to produce X-rays in October 1997. A dose level of 50 Rad at 1 meter has been achieved with an X-ray spot size diameter of 3.5 to 4 mm (LANL-CEA DAM definition). Static flash radiography of very dense object have been achieved from November 1997 until February 1998. We have been able to test in situ new kinds of very high sensitive X-ray detectors and to check they had reached our very ambitious goals: quantum efficiency at 5 MeV > 50% instead of 1% for luminous screens and film, sensitivity radiographic luminous screens and films), dynamic range > 100, resolution radiograph of the device explosion under test with the high stopping power detector located in a blast protection set behind the device. In this communication we will present all these techniques which correspond to a significant effort of CEA begun in 1992. AIRIX facility will be available to run detonics experiments before end of 2000.

  10. Relativistic outflow from two thermonuclear shell flashes on neutron stars

    Science.gov (United States)

    in't Zand, J. J. M.; Keek, L.; Cavecchi, Y.

    2014-08-01

    We study the exceptionally short (32-43 ms) precursors of two intermediate-duration thermonuclear X-ray bursts observed with the Rossi X-ray Timing Explorer from the neutron stars in 4U 0614+09 and 2S 0918-549. They exhibit photon fluxes that surpass those at the Eddington limit later in the burst by factors of 2.6 to 3.1. We are able to explain both the short duration and the super-Eddington flux by mildly relativistic outflow velocities of 0.1c to 0.3c subsequent to the thermonuclear shell flashes on the neutron stars. These are the highest velocities ever measured from any thermonuclear flash. The precursor rise times are also exceptionally short: about 1 ms. This is inconsistent with predictions for nuclear flames spreading laterally as deflagrations and suggests detonations instead. This is the first time that a detonation is suggested for such a shallow ignition column depth (yign ≈ 1010 g cm-2). The detonation would possibly require a faster nuclear reaction chain, such as bypassing the α-capture on 12C with the much faster 12C(p,γ)13N(α,p)16O process previously proposed. We confirm the possibility of a detonation, albeit only in the radial direction, through the simulation of the nuclear burning with a large nuclear network and at the appropriate ignition depth, although it remains to be seen whether the Zel'dovich criterion is met. A detonation would also provide the fast flame spreading over the surface of the neutron star to allow for the short rise times. This needs to be supported by future two-dimensional calculations of flame spreading at the relevant column depth. As an alternative to the detonation scenario, we speculate on the possibility that the whole neutron star surface burns almost instantly in the auto-ignition regime. This is motivated by the presence of 150 ms precursors with 30 ms rise times in some superexpansion bursts from 4U 1820-30 at low ignition column depths of ~108 g cm-2.

  11. Microfocusing at the PG1 beamline at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Dziarzhytski, Siarhei, E-mail: siarhei.dziarzhytski@desy.de [DESY, Notkestrasse 85, 22067 Hamburg (Germany); Gerasimova, Natalia [European XFEL GmbH, Albert-Einstein-Ring 19, 22761 Hamburg (Germany); Goderich, Rene [University of South Florida (United States); Mey, Tobias [Laser Laboratorium Göttingen eV, Hans-Adolf-Krebs-Weg 1, 37077 Göttingen (Germany); Reininger, Ruben [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Rübhausen, Michael [University of Hamburg and Center for Free-Electron Laser Science, Notkestrasse 85, 22607 Hamburg (Germany); Siewert, Frank [Institute for Nanometre Optics and Technology at Helmholtz Zentrum Berlin/BESSY II, Albert-Einstein-Strasse 15, 12489 Berlin (Germany); Weigelt, Holger; Brenner, Günter [DESY, Notkestrasse 85, 22067 Hamburg (Germany)

    2016-01-01

    The Kirkpatrick–Baez (KB) refocusing mirrors unit at the PG1 beamline at FLASH has been newly designed, developed and fully commissioned. The vertical focal size of the KB optics is measured to be 5.8 ± 1 µm FWHM and the horizontal 6 ± 2 µm FWHM; astigmatism has been minimized to below 1 mm between waist positions. Such a tight focus is essential for the VUV double Raman spectrometer as it serves as an entrance slit for the first monochromator and defines its resolution to a very large extent. The Raman spectrometer is a permanent end-station at the PG1 beamline, dedicated to inelastic soft X-ray scattering experiments. The Kirkpatrick–Baez (KB) refocusing mirror system installed at the PG1 branch of the plane-grating monochromator beamline at the soft X-ray/XUV free-electron laser in Hamburg (FLASH) is designed to provide tight aberration-free focusing down to 4 µm × 6 µm full width at half-maximum (FWHM) on the sample. Such a focal spot size is mandatory to achieve ultimate resolution and to guarantee best performance of the vacuum-ultraviolet (VUV) off-axis parabolic double-monochromator Raman spectrometer permanently installed at the PG1 beamline as an experimental end-station. The vertical beam size on the sample of the Raman spectrometer, which operates without entrance slit, defines and limits the energy resolution of the instrument which has an unprecedented design value of 2 meV for photon energies below 70 eV and about 15 meV for higher energies up to 200 eV. In order to reach the designed focal spot size of 4 µm FWHM (vertically) and to hold the highest spectrometer resolution, special fully motorized in-vacuum manipulators for the KB mirror holders have been developed and the optics have been aligned employing wavefront-sensing techniques as well as ablative imprints analysis. Aberrations like astigmatism were minimized. In this article the design and layout of the KB mirror manipulators, the alignment procedure as well as microfocus

  12. Relation between flash point of a emulsfied fuel and its internal phase ratio

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Yasuhide; Hirai, Eiji; Kawara, Nobuhiro; Nakagawa, Yoshihiro

    1988-04-15

    Flash points of emulsified fuels (O/W type) were measured changing volume blending ratio of oil (internal phase ratio). As a result the following facts were revealed. (1) The testing method for flash point of petroleum products by tag closed tester regulated by JIS is inadequate for a sample of poor thermal convection such as a creamy emulsified fuel. (2) Emulsified fuel becomes creamy, when its internal phase ratio becomes more than 60 to 70 %, Such a creamy emulsified fuel is possible to catch fire at lower temperature as a whole, for it tends to get high temperature locally by flame approaching etc. This fact is important from a standpoint of safety engineering. (3) Flash point of emulsified fuel does not depend on its internal phase ratio provided that it is measured at uniform temperature, it seems to be constant. And its constant flash point is higher than of the corresponding pure fuel by a little. (8 figs, 5 refs)

  13. Gone in a Flash: Manipulation of Audiovisual Temporal Integration Using Transcranial Magnetic Stimulation

    Directory of Open Access Journals (Sweden)

    Roy eHamilton

    2013-09-01

    Full Text Available While converging evidence implicates the right inferior parietal lobule in audiovisual integration, its role has not been fully elucidated by direct manipulation of cortical activity. Replicating and extending an experiment initially reported by Kamke, Vieth, Cottrell, and Mattingley (2012, we employed the sound-induced flash illusion, in which a single visual flash, when accompanied by two auditory tones, is misperceived as multiple flashes (Wilson, 1987; Shams, et al., 2000. Slow repetitive (1Hz TMS administered to the right angular gyrus, but not the right supramarginal gyrus, induced a transient decrease in the Peak Perceived Flashes (PPF, reflecting reduced susceptibility to the illusion. This finding independently confirms that perturbation of networks involved in multisensory integration can result in a more veridical representation of asynchronous auditory and visual events and that cross-modal integration is an active process in which the objective is the identification of a meaningful constellation of inputs, at times at the expense of accuracy.

  14. Effect of Radiation Exposure on the Retention of Commercial NAND Flash Memory

    Science.gov (United States)

    Oldham, Timothy R.; Chen, D.; Friendlich, M.; Carts, M. A.; Seidleck, C. M.; LaBel, K. A.

    2011-01-01

    We have compared the data retention of irradiated commercial NAND flash memories with that of unirradiated controls. Under some circumstanc es, radiation exposure has a significant effect on the retention of f lash memories.

  15. Analysis of Moon impact flashes detected during the 2012 and 2013 Perseids

    CERN Document Server

    Madiedo, José M; Organero, Faustino; Ana-Hernández, Leonor; Fonseca, Fernando; Morales, Nicolás; Cabrera-Caño, Jesús

    2015-01-01

    We present the results of our Moon impact flashes detection campaigns performed around the maximum activity period of the Perseid meteor shower in 2012 and 2013. Just one flash produced by a Perseid meteoroid was detected in 2012 because of very unfavourable geometric conditions, but 12 of these were confirmed in 2013. The visual magnitude of the flashes ranged between 6.6 and 9.3. A luminous efficiency of 1.8 $\\times$ 10$^{-3}$ has been estimated for meteoroids from this stream. According to this value, impactor masses would range between 1.9 and 190 g. In addition, we propose a criterion to establish, from a statistical point of view, the likely origin of impact flashes recorded on the lunar surface.

  16. Electrical activation of ultra-shallow B and BF 2 implanted silicon by flash anneal

    Science.gov (United States)

    Yoo, Woo Sik; Kang, Kitaek

    2005-08-01

    Ultra-shallow ion implanted Si wafers, both with and without Ge pre-amorphization, were annealed using xenon arc flash lamps. The duration of flash illumination was controlled between 1 ms and 20 ms. Changes in sheet resistance and dopant profiles after flash anneal were measured and investigated, along with crystal defect densities. Sheet resistance was measured using a four-point probe. Dopant depth profiling and defect characterization were done using secondary ion mass spectroscopy (SIMS) and cross-sectional transmission electron microscopy (XTEM). Sheet resistance values of 250-350 Ω/sq. at a junction depth of 24 nm (at B concentration of 1.0 × 1018 cm-3) were achieved. No significant dopant diffusion was observed after the Xe arc flash lamp annealing.

  17. THE FREQUENCY OF OCCURRENCE OF FLASH FLOODS ON THE RIVERS IN THE LAND OF DORNA

    Directory of Open Access Journals (Sweden)

    MIHALCA Izabela Amalia

    2015-06-01

    Full Text Available Flash floods are extreme natural phenomena that determine numerous property damage and loss of human life on both global and local level. In order to highlight not only the frequency of occurrence of floods on the rivers in the Land of Dorna but also their effects on the community, we set ourselves to perform a secondary analysis of data provided by Siret River Basin Administration. As a result, one can observe that the highest frequency of occurrence of flash floods in the region of Dorna is in the spring. During the same period of time (from 1993 to 2003 there were recorded only significant property damages after the flash floods. At the end of this paper we suggested a series of coherent measures in order to combat the negative effects of flash floods.

  18. MyNewsFlash: A System for Near Real-Time Variable Star Monitoring and Alerts

    Science.gov (United States)

    Price, A.; Turner, R.; Malatesta, K.; Simonsen, M. A.

    2004-12-01

    MyNewsFlash is an automated and customizable system for distributing timely variable star data. It supplies near real-time reports to the user of the latest activity of a variable star or class of stars. The stars it monitors, the frequency of report delivery, the delivery format, and more features are all completely customizable so the reader receives only reports of information he or she wants and nothing more or less. In addition, manually-generated alerts called Special MyNewsFlashes are occasionally sent out with additional information on special or abnormal behavior of a variable star. MyNewsFlash evolved from the AAVSO News Flash, an electronic publication dedicated to outbursts of popular cataclysmic variable stars

  19. Observations of the spatial and temporal distribution of lightning flash sizes

    Science.gov (United States)

    Bruning, E. C.; Berkseth, S.; Salinas, V.; Chmielewski, V.; Ware, P. J.

    2015-12-01

    Recent work has shown that lightning flash sizes exhibit organization that parallels the meteorological organization of thunderstorms. Two- or three-dimensional grids of flash size and rate allow for spatial diagnosis of actively convecting regions and those with advection- or sedimentation-dominated motions. A time series of statistical moments of the flash size distribution is useful in discrimination of stages in the cellular lifecycle. Finally, ensembles of flashes exhibit a scale-dependent distribution of electrical energy like that of a turbulent energy cascade. The role of turbulence in organizing charge into small pockets is under ongoing investigation as part of the Kinematic Texture and Lightning Experiment (KTaL), where the primary observational tools are the TTU Ka-band mobile Doppler radars and the West Texas Lightning Mapping Array. Preliminary results from these new field observations will be discussed and used to illustrate the methods of interpretation described above.

  20. Robust Image Denoising using a Virtual Flash Image for Monte Carlo Ray Tracing

    DEFF Research Database (Denmark)

    Moon, Bochang; Jun, Jong Yun; Lee, JongHyeob

    2013-01-01

    parameters. To highlight the benefits of our method, we apply our method to two Monte Carlo ray tracing methods, photon mapping and path tracing, with various input scenes. We demonstrate that using virtual flash images and homogeneous pixels with a standard denoising method outperforms state-of-the-art......We propose an efficient and robust image-space denoising method for noisy images generated by Monte Carlo ray tracing methods. Our method is based on two new concepts: virtual flash images and homogeneous pixels. Inspired by recent developments in flash photography, virtual flash images emulate...... values. While denoising each pixel, we consider only homogeneous pixels—pixels that are statistically equivalent to each other. This makes it possible to define a stochastic error bound of our method, and this bound goes to zero as the number of ray samples goes to infinity, irrespective of denoising...

  1. Gone in a flash: manipulation of audiovisual temporal integration using transcranial magnetic stimulation

    Science.gov (United States)

    Hamilton, Roy H.; Wiener, Martin; Drebing, Daniel E.; Coslett, H. Branch

    2013-01-01

    While converging evidence implicates the right inferior parietal lobule in audiovisual integration, its role has not been fully elucidated by direct manipulation of cortical activity. Replicating and extending an experiment initially reported by Kamke et al. (2012), we employed the sound-induced flash illusion, in which a single visual flash, when accompanied by two auditory tones, is misperceived as multiple flashes (Wilson, 1987; Shams et al., 2000). Slow repetitive (1 Hz) TMS administered to the right angular gyrus, but not the right supramarginal gyrus, induced a transient decrease in the Peak Perceived Flashes (PPF), reflecting reduced susceptibility to the illusion. This finding independently confirms that perturbation of networks involved in multisensory integration can result in a more veridical representation of asynchronous auditory and visual events and that cross-modal integration is an active process in which the objective is the identification of a meaningful constellation of inputs, at times at the expense of accuracy. PMID:24062701

  2. Gone in a flash: manipulation of audiovisual temporal integration using transcranial magnetic stimulation.

    Science.gov (United States)

    Hamilton, Roy H; Wiener, Martin; Drebing, Daniel E; Coslett, H Branch

    2013-01-01

    While converging evidence implicates the right inferior parietal lobule in audiovisual integration, its role has not been fully elucidated by direct manipulation of cortical activity. Replicating and extending an experiment initially reported by Kamke et al. (2012), we employed the sound-induced flash illusion, in which a single visual flash, when accompanied by two auditory tones, is misperceived as multiple flashes (Wilson, 1987; Shams et al., 2000). Slow repetitive (1 Hz) TMS administered to the right angular gyrus, but not the right supramarginal gyrus, induced a transient decrease in the Peak Perceived Flashes (PPF), reflecting reduced susceptibility to the illusion. This finding independently confirms that perturbation of networks involved in multisensory integration can result in a more veridical representation of asynchronous auditory and visual events and that cross-modal integration is an active process in which the objective is the identification of a meaningful constellation of inputs, at times at the expense of accuracy.

  3. Perturbation of convection-permitting NWP forecasts for flash-flood ensemble forecasting

    National Research Council Canada - National Science Library

    Vincendon, B; Ducrocq, V; Nuissier, O; Vié, B

    2011-01-01

      Mediterranean intense weather events often lead to devastating flash-floods. Extending the forecasting lead times further than the watershed response times, implies the use of numerical weather prediction (NWP...

  4. SNR efficiency of combined bipolar gradient echoes: Comparison of three-dimensional FLASH, MPRAGE, and multiparameter mapping with VFA-FLASH and MP2RAGE.

    Science.gov (United States)

    Jutras, Jean-David; Wachowicz, Keith; Gilbert, Guillaume; De Zanche, Nicola

    2017-06-01

    High-bandwidth bipolar multiecho gradient echo sequences are increasingly popular in structural brain imaging because of reduced water-fat shifts, lower susceptibility effects, and improved signal-to-noise ratio (SNR) efficiency. In this study, we investigated the performance of three three-dimensional multiecho sequences (MPRAGE, MP2RAGE, and FLASH) with scan times technique with multiecho FLASH (VFA-FLASH). Multiecho sequences were optimized to yield equivalent contrast and improved SNR compared with their single-echo counterparts. Theoretical SNR gains were verified with measurements in a multilayered phantom. Robust image processing pipelines extracted PD, T1 , and T2* maps from MP2RAGE or VFA-FLASH, and the corresponding SNR was measured with varying SENSE accelerations (R = 1-5) and number of echoes (N = 1-12). All sequences were tested on four healthy volunteers. Multiecho sequences achieved SNR gains of 1.3-1.6 over single-echo sequences. MP2RAGE yielded comparable T1 -to-noise ratio to VFA-FLASH, but significantly lower SNR (sampling bandwidths. VFA-FLASH surpasses MP2RAGE in its ability to map three parameters with high SNR and 1-mm isotropic resolution in a clinically relevant scan time (∼8:30 min), whereas MP2RAGE yields lower intersubject variability in T1 . Magn Reson Med 77:2186-2202, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  5. An Evaluation of Lightning Flash Rate Parameterizations Based on Observations of Colorado Storms during DC3

    Science.gov (United States)

    Basarab, B.; Fuchs, B.; Rutledge, S. A.

    2013-12-01

    Predicting lightning activity in thunderstorms is important in order to accurately quantify the production of nitrogen oxides (NOx = NO + NO2) by lightning (LNOx). Lightning is an important global source of NOx, and since NOx is a chemical precursor to ozone, the climatological impacts of LNOx could be significant. Many cloud-resolving models rely on parameterizations to predict lightning and LNOx since the processes leading to charge separation and lightning discharge are not yet fully understood. This study evaluates predicted flash rates based on existing lightning parameterizations against flash rates observed for Colorado storms during the Deep Convective Clouds and Chemistry Experiment (DC3). Evaluating lightning parameterizations against storm observations is a useful way to possibly improve the prediction of flash rates and LNOx in models. Additionally, since convective storms that form in the eastern plains of Colorado can be different thermodynamically and electrically from storms in other regions, it is useful to test existing parameterizations against observations from these storms. We present an analysis of the dynamics, microphysics, and lightning characteristics of two case studies, severe storms that developed on 6 and 7 June 2012. This analysis includes dual-Doppler derived horizontal and vertical velocities, a hydrometeor identification based on polarimetric radar variables using the CSU-CHILL radar, and insight into the charge structure using observations from the northern Colorado Lightning Mapping Array (LMA). Flash rates were inferred from the LMA data using a flash counting algorithm. We have calculated various microphysical and dynamical parameters for these storms that have been used in empirical flash rate parameterizations. In particular, maximum vertical velocity has been used to predict flash rates in some cloud-resolving chemistry simulations. We diagnose flash rates for the 6 and 7 June storms using this parameterization and compare

  6. Cross Hallway Detection and Indoor Localization Using Flash Laser Detection and Ranging

    Science.gov (United States)

    2012-06-14

    systems in the past, like interferometry or line-scanning LADAR have a varied history of utilization. However, flash LADAR provides several advantages over...utilization in navigation. 2.6.1 Line-Scanning LADAR Research. Line-scanning LADAR has a longer history of use than flash LADAR, as these systems have...Martin A and Robert C Bolles. “Random sample consensus: a paradigm for model fitting with applications to image analysis and automated cartography

  7. A European precipitation index for extreme rain-storm and flash flood early warning

    OpenAIRE

    ALFIERI LORENZO; THIELEN DEL POZO Jutta

    2012-01-01

    Extreme rain-storms are known for triggering devastating flash floods in various regions of Europe and particularly along the Mediterranean coasts. Despite recent notable advances in weather forecasting, most operational early warning systems for extreme rainstorms and flash floods are based on rainfall estimation, rather than on forecasts. As a result, warning lead times are bounded to few hours and warnings are usually issued when the event is already taking place. This work proposes a n...

  8. Initial electrification to the first lightning flash in New Mexico thunderstorms

    Science.gov (United States)

    Stolzenburg, Maribeth; Marshall, Thomas C.; Krehbiel, Paul R.

    2015-11-01

    The initial electrification of three New Mexico thunderstorms is examined using in situ and remote measurements. The earliest deflection of electric field (E) measured at the surface was 5-8.6 min before the first flash and coincident with the development of substantial radar reflectivity (40 dBZ) above -5°C. Rapid growth of surface E (>5 V/m/s) started 2.4-3.1 min before the first flash, when 40 dBZ reflectivities reached above the -15°C level. In two cases with clear surface E records, radar reflectivity indicators (40 dBZ echo through -10°C and echo top through -15°C) would yield longer warning times before the first flash than the E record. The first flash in each storm initiated at altitudes between 7.4 and 8.8 km; hence, the temperatures where the largest (negative) E for normal intracloud lightning initiation had developed during the initial electrification were -10°C to -20°C. Negative and positive charge regions associated with the first flash in each cell were centered at -8°C to -16°C (6.9-8.0 km) and -20°C to -24°C (9.0-9.2 km), respectively. In two cases, balloon data indicate the only substantial charge regions present before the first flash were those involved in the flash. Another case shows an initial period of opposite polarity E deflection at the surface coincident with substantial low-level positive charge within the cloud, although this charge was not involved in the first 8 min (first 17 flashes) of lightning activity. The findings support the notion that the initial electrification resulted from charging via the noninductive ice-ice collisional mechanism.

  9. The Study on the Effects of Pimpinella anisum on Relief and Recurrence of Menopausal Hot Flashes.

    Science.gov (United States)

    Nahidi, Fatemeh; Kariman, Nourossadat; Simbar, Masoumeh; Mojab, Faraz

    2012-01-01

    With respect to the high incidence of hot flash in postmenopausal women and the controversies regarding its treatment, this double-blind clinical trial was conducted to determine the effects of Pimpinella anisum on hot flashes in these women referring to rural and urban health centers of Qazvin Province in 2009. Seventy-two women with hot flashes were randomly selected according to the predetermined criteria and divided into two experimental and control groups. Their medical records at health centers were used for sampling. Each woman in the experimental group took a capsule containing 330 mg Pimpinella anisum 3 times a day while in the control group, women took 3 capsules, each containing 330 mg potato starch, over 4 weeks and after that, they were following up for 4 weeks. Before taking the capsules, they were assessed for 2 weeks about the frequency and severity of hot flashes. Data were collected through a questionnaire and an information form. Content validity method was used for validity of the tools. ANOVA and Student›s t-test were applied for statistical analysis. In the experimental group, the frequency and severity of hot flashes before the treatment were 4.21% and 56.21% and, after that, were 1.06% and 14.44% at the end of the fourth week respectively. No change was found in the frequency and severity of hot flashes in the control group. The frequency and severity of hot flashes was decreased during 4 weeks of follow up period. P. anisum is effective on the frequency and severity of hot flashes in postmenopausal women.

  10. Economic assessment of flash co-pyrolysis of short rotation coppice and biopolymer waste streams.

    Science.gov (United States)

    Kuppens, T; Cornelissen, T; Carleer, R; Yperman, J; Schreurs, S; Jans, M; Thewys, T

    2010-12-01

    The disposal problem associated with phytoextraction of farmland polluted with heavy metals by means of willow requires a biomass conversion technique which meets both ecological and economical needs. Combustion and gasification of willow require special and costly flue gas treatment to avoid re-emission of the metals in the atmosphere, whereas flash pyrolysis mainly results in the production of (almost) metal free bio-oil with a relatively high water content. Flash co-pyrolysis of biomass and waste of biopolymers synergistically improves the characteristics of the pyrolysis process: e.g. reduction of the water content of the bio-oil, more bio-oil and less char production and an increase of the HHV of the oil. This research paper investigates the economic consequences of the synergistic effects of flash co-pyrolysis of 1:1 w/w ratio blends of willow and different biopolymer waste streams via cost-benefit analysis and Monte Carlo simulations taking into account uncertainties. In all cases economic opportunities of flash co-pyrolysis of biomass with biopolymer waste are improved compared to flash pyrolysis of pure willow. Of all the biopolymers under investigation, polyhydroxybutyrate (PHB) is the most promising, followed by Eastar, Biopearls, potato starch, polylactic acid (PLA), corn starch and Solanyl in order of decreasing profits. Taking into account uncertainties, flash co-pyrolysis is expected to be cheaper than composting biopolymer waste streams, except for corn starch. If uncertainty increases, composting also becomes more interesting than flash co-pyrolysis for waste of Solanyl. If the investment expenditure is 15% higher in practice than estimated, the preference for flash co-pyrolysis compared to composting biopolymer waste becomes less clear. Only when the system of green current certificates is dismissed, composting clearly is a much cheaper processing technique for disposing of biopolymer waste.

  11. Fracture of flash oxidized, yttria-doped sintered reaction-bonded silicon nitride

    Science.gov (United States)

    Govila, R. K.

    1987-01-01

    The oxidation behavior of a slip cast, yttria-doped, sintered reaction-bonded silicon nitride after 'flash oxidation' was investigated. It was found that both the static oxidation resistance and flexural stress rupture life (creep deformation) were improved at 1000 C in air compared to those of the same material without flash oxidation. Stress rupture data at high temperatures (1000 to 1200 C) are presented to indicate applied stress levels for oxidation-dependent and independent failures.

  12. Flash sintering of dielectric nanoparticles as a percolation phenomenon through a softened film

    OpenAIRE

    Chaim, Rachman; Chevallier, Geoffroy; Weibel, Alicia; Estournès, Claude

    2017-01-01

    International audience; Recent work [Biesuz et al., J. Appl. Phys. 120, 145107 (2016)] showed analogies between the flash sintering and dielectric breakdown in α-aluminas pre-sintered to different densities. Here, we show that flash sintering of dielectric nanoparticles can be described as a universal behavior by the percolation model. The electrical system is composed of particles and their contact point resistances, the latter softened first due to preferred local Joule heating and thermal ...

  13. Flash pulmonary edema in patients with renal artery stenosis--the Pickering Syndrome

    DEFF Research Database (Denmark)

    Pelta, Anna; Andersen, Ulrik B; Just, Sven

    2010-01-01

    We report the prevalence of flash pulmonary edema in patients consecutively referred for balloon angioplasty of uni- or bilateral renal artery stenosis (PTRA), and describe the characteristics of this special fraction of the patients. We further report two unusual cases.......We report the prevalence of flash pulmonary edema in patients consecutively referred for balloon angioplasty of uni- or bilateral renal artery stenosis (PTRA), and describe the characteristics of this special fraction of the patients. We further report two unusual cases....

  14. Lightning Flash Initiation Locations in Four Storms over Land and Ocean

    Science.gov (United States)

    Stolzenburg, Maribeth; Karunarathna, Nadeeka; Marshall, Thomas; Karunarathne, Sumedhe

    2017-04-01

    This study examines initiation locations of intracloud (IC) and cloud-to-ground (CG) lightning in four storms that occurred near Kennedy Space Center, Florida, on one day. One unicellular and two multicellular thunderstorms occurred over land, and one multicellular storm was 30 km offshore. The storm over ocean was visible on radar 47-51 minutes before its first flash (of 17 total); first radar echoes in the storms over land were just 23, 12, and 16 minutes prior to their first flashes (of 34, 16, and 9 total). Initiation points of 66 flashes were identified using the first initial breakdown (IB) pulse location from electric field change measurements or a VHF source coincident with the first IB pulse; the other ten flashes occurred without enough data to similarly locate the initiation. Most of the IC initiations were above the echo core and above 7.5 km altitude, while nearly all the CG initiations were beside or atop the core and below 6.8 km. The off-shore storm had similar lightning duration, IC:CG ratio, and initiation altitudes as the storms over land, but it took that storm much longer to get from first radar echo to first flash and from first flash to first CG. In both regions, early and mature stage flash initiation locations were tightly clustered in small horizontal areas covering just 10-30% of the entire radar reflectivity areas in these small storms. In this presentation, we focus on comparison of temporal trends in the flash initiation altitudes among the storms and the radar reflectivity structure near the initiation locations.

  15. Membrane and Flashing Condition Indexes for Modified Bitumen Roofs: Inspection and Distress Manual

    Science.gov (United States)

    2010-03-01

    ER D C/ CE R L TR -1 0 -5 Membrane and Flashing Condition Indexes for Modified Bitumen Roofs Inspection and Distress Manual David M...ERDC/CERL TR-10-5 March 2010 Membrane and Flashing Condition Indexes for Modified Bitumen Roofs Inspection and Distress Manual David M...Compliance” ERDC/CERL TR-10-5 ii Abstract: The U.S. Army is currently responsible for maintaining mil- lions of square feet of modified bitumen roofing

  16. Ozone Formation in Laser Flash Photolysis of Oxoacids and Oxoanions of Chlorine and Bromine

    DEFF Research Database (Denmark)

    Kläning, Ulrik; Sehested, Knud; Wolff, Thomas

    1984-01-01

    The kinetics of ozone formation in the photolysis of oxygen-containing solutions of HClO, ClO–, ClO–2, ClO–3, HBrO, BrO– and BrO–3 has been studied by laser flash photolysis and conventional flash photolysis. The usual assumption, that ozone only forms in the reaction of oxygen atoms in the spin-...

  17. Erzeugung und Transport von Doppelpaket-Elektronenstrahlen im FLASH Linearbeschleuniger(Generation and transport of double-bunch electron beams in the FLASH beamline)

    OpenAIRE

    Entrena, Carlos

    2014-01-01

    ZusammenfassungDer Freie-Elektronen Laser in Hamburg (FLASH) ist Teil des Forschungszentrum DeutschesElektronen-Synchrotron (DESY). Sein Linearbeschleuniger erzeugt Elektronenpakete hoher Qualitätmit einer maximalen Energie von 1.2 GeV, die kurze, hochintensive Röntgenblitze mit einerWellenlänge von 4.2 nm bis 45 nm im SASE Prozess produzieren. Unter anderem, diese Eigenschaftenmachen FLASH zu einer der weltweit führenden Freie-Elektronen Lasern neben LinacCoheren Light Source (beim SLAC in S...

  18. 嵌入式系统的Flash ROM读写方法研究%Research on the Read-write of Flash ROM in Embedded System

    Institute of Scientific and Technical Information of China (English)

    杜文蛟

    2012-01-01

    This article proposed and confirmed a kind of method that read and write Flashrom of Lpc2136 in embedded system. It can be used to save important parameters. The transition procedure of the global variables between Ram and Flash is discussed in detail.%为提高微控制器的应用性能,以菲利普LPC2100系列微控制器为例,提出一种在嵌入式系统中读写LPC2136的Flash ROM方法,详细讨论全局变量在RAM和Flash之间的传送过程。

  19. Imaging superoxide flash and metabolism-coupled mitochondrial permeability transition in living animals

    Institute of Scientific and Technical Information of China (English)

    Huaqiang Fang; Min Chen; Yi Ding; Wei Shang; Jiejia Xu; Xing Zhang; Wanrui Zhang

    2011-01-01

    The mitochondrion is essential for energy metabolism and production of reactive oxygen species (ROS).In intact cells,respiratory mitochondria exhibit spontaneous "superoxide flashes",the quantal ROS-producing events consequential to transient mitochondrial permeability transition (tMPT).Here we perform the first in vivo imaging of mitochondrial superoxide flashes and tMPT activity in living mice expressing the superoxide biosensor mt-cpYFP,and demonstrate their coupling to whole-body glucose metabolism.Robust tMPT/superoxide flash activity occurred in skeletal muscle and sciatic nerve of anesthetized transgenic mice.In skeletal muscle,imaging tMPT/superoxide flashes revealed labyrinthine three-dimensional networks of mitochondria that operate synchronously.The tMPT/superoxide flash activity surged in response to systemic glucose challenge or insulin stimulation,in an apparently frequency-modulated manner and involving also a shift in the gating mode of tMPT.Thus,in vivo imaging of tMPT-dependent mitochondrial ROS signals and the discovery of the metabolism-tMPT-superoxide flash coupling mark important technological and conceptual advances for the study of mitochondrial function and ROS signaling in health and disease.

  20. Reduced susceptibility to the sound-induced flash fusion illusion in schizophrenia.

    Science.gov (United States)

    Vanes, Lucy D; White, Thomas P; Wigton, Rebekah L; Joyce, Dan; Collier, Tracy; Shergill, Sukhi S

    2016-11-30

    Schizophrenia is characterised by the presence of abnormal complex sensory perceptual experiences. Such experiences could arise as a consequence of dysfunctional multisensory integration. We used the sound-induced flash illusion paradigm, which probes audiovisual integration using elementary visual and auditory cues, in a sample of individuals with schizophrenia (n=40) and matched controls (n=22). Signal detection theory analyses were performed to characterise patients' and controls' sensitivity in distinguishing 1 and 2 flashes under varying auditory conditions. Both groups experienced significant fission illusions (whereby one visual flash, accompanied by two auditory beeps, is misperceived as two flashes) and fusion illusions (whereby two flashes, accompanied by one beep, are perceived as one flash). Patients showed significantly lower fusion illusion rates compared to HC, while the fission illusion occurred similarly frequently in both groups. However, using an SDT approach, we compared illusion conditions with unimodal visual conditions, and found that illusory visual perception was overall more strongly influenced by auditory input in HC compared to patients for both illusions. This suggests that multisensory integration may be impaired on a low perceptual level in SZ.

  1. OPTIMIZING THE USE OF AN SPI FLASH PROM IN MICROBLAZE-BASED EMBEDDED SYSTEMS

    Directory of Open Access Journals (Sweden)

    Ahmed Hanafi

    2013-11-01

    Full Text Available This paper aims to simplify FPGA designs that incorporate Embedded Software Systems using a soft core Processor. It describes a simple solution to reduce the need of multiple non-volatile memory devices by using one SPI (Serial Peripheral Interface Flash PROM for FPGA configuration data, software code (Processor applications, and miscellaneous user data. We have thus developed a design based on a MicroBlaze soft processor implemented on a Xilinx Spartan-6 FPGA SP605 Evaluation Kit. The hardware architecture with SPI flash was designed using the Xilinx Platform Studio (XPS and the software applications, including the bootloader, was developed with Xilinx Software Development Kit (SDK. ISE Design Tools prepared by Xilinx Company, is employed to create the files used to program flash memory which are SREC (S-record file associated with software code, Hexadecimal file for user data, and bootloader file to configure the FPGA and allows software applications stored in flash memory to be executed when the system is powered on. Reading access to the SPI Flash memory is simplified by the use of Xilinx In-System Flash (ISF library.

  2. Prediction of the Flash Point of Binary and Ternary Straight-Chain Alkane Mixtures

    Directory of Open Access Journals (Sweden)

    X. Li

    2014-01-01

    Full Text Available The flash point is an important physical property used to estimate the fire hazard of a flammable liquid. To avoid the occurrence of fire or explosion, many models are used to predict the flash point; however, these models are complex, and the calculation process is cumbersome. For pure flammable substances, the research for predicting the flash point is systematic and comprehensive. For multicomponent mixtures, especially a hydrocarbon mixture, the current research is insufficient to predict the flash point. In this study, a model was developed to predict the flash point of straight-chain alkane mixtures using a simple calculation process. The pressure, activity coefficient, and other associated physicochemical parameters are not required for the calculation in the proposed model. A series of flash points of binary and ternary mixtures of straight-chain alkanes were determined. The results of the model present consistent experimental results with an average absolute deviation for the binary mixtures of 0.7% or lower and an average absolute deviation for the ternary mixtures of 1.03% or lower.

  3. FlaME: Flash Molecular Editor - a 2D structure input tool for the web

    Directory of Open Access Journals (Sweden)

    Dallakian Pavel

    2011-02-01

    Full Text Available Abstract Background So far, there have been no Flash-based web tools available for chemical structure input. The authors herein present a feasibility study, aiming at the development of a compact and easy-to-use 2D structure editor, using Adobe's Flash technology and its programming language, ActionScript. As a reference model application from the Java world, we selected the Java Molecular Editor (JME. In this feasibility study, we made an attempt to realize a subset of JME's functionality in the Flash Molecular Editor (FlaME utility. These basic capabilities are: structure input, editing and depiction of single molecules, data import and export in molfile format. Implementation The result of molecular diagram sketching in FlaME is accessible in V2000 molfile format. By integrating the molecular editor into a web page, its communication with the HTML elements on this page is established using the two JavaScript functions, getMol( and setMol(. In addition, structures can be copied to the system clipboard. Conclusion A first attempt was made to create a compact single-file application for 2D molecular structure input/editing on the web, based on Flash technology. With the application examples presented in this article, it could be demonstrated that the Flash methods are principally well-suited to provide the requisite communication between the Flash object (application and the HTML elements on a web page, using JavaScript functions.

  4. Numerical Experiments for Nuclear Flashes toward Superbursts in an Accreting Neutron Star

    Directory of Open Access Journals (Sweden)

    Masa-aki Hashimoto

    2014-01-01

    Full Text Available We show that the superburst would be originated from thermonuclear burning ignited by accumulated fuels in the deep layers compared to normal X-ray bursts. Two cases are investigated for models related to superbursts by following thermal evolution of a realistic neutron star: helium flash and carbon flash accompanied with many normal bursts. For a helium flash, the burst shows the long duration when the accretion rate is low compared with the observation. The flash could become a superburst if the burning develops to the deflagration and/or detonation. For a carbon flash accompanied with many normal bursts, after successive 2786 normal bursts during 1.81 × 109 s, the temperature reaches the deflagration temperature. This is due to the produced carbon which amount reaches to ≈0.1 in the mass fraction. The flash will develop to dynamical phenomena of the deflagration and/or detonation, which may lead to a superburst.

  5. The Ensemble Framework for Flash Flood Forecasting: Global and CONUS Applications

    Science.gov (United States)

    Flamig, Z.; Vergara, H. J.; Clark, R. A.; Gourley, J. J.; Kirstetter, P. E.; Hong, Y.

    2015-12-01

    The Ensemble Framework for Flash Flood Forecasting (EF5) is a distributed hydrologic modeling framework combining water balance components such as the Variable Infiltration Curve (VIC) and Sacramento Soil Moisture Accounting (SAC-SMA) with kinematic wave channel routing. The Snow-17 snow pack model is included as an optional component in EF5 for basins where snow impacts are important. EF5 also contains the Differential Evolution Adaptive Metropolis (DREAM) parameter estimation scheme for model calibration. EF5 is made to be user friendly and as such training has been developed into a weeklong course. This course has been tested in modeling workshops held in Namibia and Mexico. EF5 has also been applied to specialized applications including the Flooded Locations and Simulated Hydrographs (FLASH) project. FLASH aims to provide flash flood monitoring and forecasting over the CONUS using Multi-Radar Multi-Sensor precipitation forcing. Using the extensive field measurements database from the 10,000 USGS measurement locations across the CONUS, parameters were developed for the kinematic wave routing in FLASH. This presentation will highlight FLASH performance over the CONUS on basins less than 1,000 km2 and discuss the development of simulated streamflow climatology over the CONUS for data mining applications. A global application of EF5 has also been developed using satellite based precipitation measurements combined with numerical weather prediction forecasts to produce flood and impact forecasts. The performance of this global system will be assessed and future plans detailed.

  6. Parietal disruption alters audiovisual binding in the sound-induced flash illusion.

    Science.gov (United States)

    Kamke, Marc R; Vieth, Harrison E; Cottrell, David; Mattingley, Jason B

    2012-09-01

    Selective attention and multisensory integration are fundamental to perception, but little is known about whether, or under what circumstances, these processes interact to shape conscious awareness. Here, we used transcranial magnetic stimulation (TMS) to investigate the causal role of attention-related brain networks in multisensory integration between visual and auditory stimuli in the sound-induced flash illusion. The flash illusion is a widely studied multisensory phenomenon in which a single flash of light is falsely perceived as multiple flashes in the presence of irrelevant sounds. We investigated the hypothesis that extrastriate regions involved in selective attention, specifically within the right parietal cortex, exert an influence on the multisensory integrative processes that cause the flash illusion. We found that disruption of the right angular gyrus, but not of the adjacent supramarginal gyrus or of a sensory control site, enhanced participants' veridical perception of the multisensory events, thereby reducing their susceptibility to the illusion. Our findings suggest that the same parietal networks that normally act to enhance perception of attended events also play a role in the binding of auditory and visual stimuli in the sound-induced flash illusion.

  7. Does underwater flash photography affect the behaviour, movement and site persistence of seahorses?

    Science.gov (United States)

    Harasti, D; Gladstone, W

    2013-11-01

    The effect of flash photography on seahorse species has never been tested. An experiment was established to test the effect of flash photography and the handling of Hippocampus whitei, a medium-sized seahorse species endemic to Australia, on their behavioural responses, movements and site persistence. A total of 24 H. whitei were utilized in the experiment with eight in each of the three treatments (flash photography, handling and control). The effect of underwater flash photography on H. whitei movements was not significant; however, the effect of handling H. whitei to take a photograph had a significant effect on their short-term behavioural responses to the photographer. Kaplan-Meier log-rank test revealed that there was no significant difference in site persistence of H. whitei from each of the three treatments and that flash photography had no long-term effects on their site persistence. It is concluded that the use of flash photography by divers is a safe and viable technique with H. whitei, particularly if photographs can be used for individual identification purposes.

  8. Increased Expression of CCN2 in the Red Flashing Light-Induced Myopia in Guinea Pigs

    Directory of Open Access Journals (Sweden)

    Hong Wang

    2013-01-01

    Full Text Available Visual environment plays an important role in the occurrence of myopia. We previously showed that the different flashing lights could result in distinct effects on the ocular growth and development of myopia. CCN2 has been reported to regulate various cellular functions and biological processes. However, whether CCN2 signaling was involved in the red flashing light-induced myopia still remains unknown. In the present study, we investigated the effects of the red flashing lights exposure on the refraction and axial length of the eyes in vivo and then evaluated their effects on the expression of CCN2 and TGF-β in sclera tissues. Our data showed that the eyes exposed to the red flashing light became more myopic with a significant increase of the axial length and decrease of the refraction. Both CCN2 and TGF-β, as well as p38 MAPK and PI3K, were highly expressed in the sclera tissues exposed to the red flashing light. Both CCN2 and TGF-β were found to have the same gene expression profile in vivo. In conclusion, our findings found that CCN2 signaling pathway plays an important role in the red flashing light-induced myopia in vivo. Moreover, our study establishes a useful animal model for experimental myopia research.

  9. Risk of long-term hot flashes after natural menopause: evidence from the Penn Ovarian Aging Study cohort.

    Science.gov (United States)

    Freeman, Ellen W; Sammel, Mary D; Sanders, Richard J

    2014-09-01

    This study aims to estimate the risk of hot flashes relative to natural menopause and to evaluate the associations of hormone levels, behavioral variables, and demographic variables with the risk of hot flashes after menopause. We performed annual assessment of 255 women who were premenopausal at baseline and reached natural menopause within 16 years of follow-up. The prevalence of moderate/severe hot flashes increased in each premenopausal year, reaching a peak of 46% in the first 2 years after the final menstrual period (FMP). Hot flashes decreased slowly after menopause and did not return to premenopausal levels until 9 years after the FMP. The mean (SD) duration of moderate/severe hot flashes after the FMP was 4.6 (2.9) years (for any hot flashes, 4.9 [3.1] y). One third of women at 10 years or more after menopause continued to experience moderate/severe hot flashes. African-American women (obese and nonobese) and obese white women had significantly greater risks of hot flashes compared with nonobese white women (interaction, P = 0.01). In multivariable analysis, increasing follicle-stimulating hormone levels before the FMP (P menopause; more than one third of women observed for 10 years or more after menopause have moderate/severe hot flashes. Continuation of hot flashes for more than 5 years after menopause underscores the importance of determining individual risks/benefits when selecting hormone or nonhormone therapy for menopausal symptoms.

  10. Activated carbon from flash pyrolysis of eucalyptus residue.

    Science.gov (United States)

    Grima-Olmedo, C; Ramírez-Gómez, Á; Gómez-Limón, D; Clemente-Jul, C

    2016-09-01

    Forestry waste (eucalyptus sp) was converted into activated carbon by initial flash pyrolysis followed carbonization and CO2 activation. These residues were obtained from a pilot plant in Spain that produces biofuel, the biochar represented 10-15% in weight. It was observed that the highest activation was achieved at a temperature of 800 °C, the specific surface increased with time but, on the contrary, high loss of matter was observed. At 600 °C, although there was an important increase of the specific surface and the volume of micropores, at this temperature it was observed that the activation time was not an influential parameter. Finally, at 400 °C it was observed that the activation process was not very significant. Assessing the average pore diameter it was found that the lowest value corresponded to the activation temperature of 600 °C, which indicated the development of microporosity. When the activation temperature increases up to 800 °C the pore diameter increased developing mesoporosity.

  11. AGILE Observations of Terrestrial Gamma-Ray Flashes

    CERN Document Server

    Marisaldi, M; Labanti, C; Bulgarelli, A; Gianotti, F; Trifoglio, M; Tavani, M; Argan, A; Del Monte, E; Longo, F; Barbiellini, G; Giuliani, A; Trois, A

    2011-01-01

    The AGILE satellite, operating since mid 2007 and primarily devoted to high-energy astrophysics, is one of the only three currently operating space instruments capable of detecting Terrestrial Gamma-Ray Flashes (TGFs), together with RHESSI and $Fermi$-GBM. Thanks to the AGILE Mini-Calorimeter instrument energy range extended up to 100MeV and its flexible trigger logic on sub-millisecond time scales, AGILE is detecting more than 10 TGFs/month, adding a wealth of observations which pose severe constrains on production models. The main AGILE discoveries in TGF science during two and a half years of observations are the following: 1) the TGF spectrum extends well above 40 MeV, 2) the high energy tail of the TGF spectrum is harder than expected and cannot be easily explained by previous theoretical models, 3) TGFs can be localized from space using high-energy photons detected by the AGILE gamma-ray imaging detector. In this presentation we will describe the characteristics of the 2.5-years AGILE TGF sample, focusi...

  12. Suppression of COTR in electron beam imaging diagnosis at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Minjie

    2012-05-15

    The Free-Electron Laser in Hamburg (FLASH) demands electron beams with high peak current to generate high-brilliant, coherent X-ray pulses. Magnetic chicanes are used for longitudinal compression of the electron bunches to achieve the required high peak current. During bunch compression process, microstructures with a modulation length comparable to the visible light can be induced inside the bunch. This leads to coherent emission of optical transition radiation (OTR), which may impede the widely used beam diagnostic based on OTR imaging. In this thesis, two methods of using incoherent scintillation light are proposed to circumvent the problem of coherence effects in beam imaging diagnostics. The method of temporal separation has been proved experimentally to have successfully suppressed coherence effects. The longitudinal beam profiles measured using this method are in good agreement with reference measurements, verifying further the reliability of the method. The method of spatial separation has been investigated in preparation studies, from which an improved experimental setup has been designed.

  13. RF radiation observations of positive cloud-to-ground flashes

    Science.gov (United States)

    Shao, X. M.; Rhodes, C. T.; Holden, D. N.

    1999-04-01

    During the summers of 1995 and 1996 we conducted broadband HF-UHF and narrowband VHF radio frequency (RF) observations of positive cloud-to-ground (+CG) flashes at Langmuir and Los Alamos laboratories, New Mexico. These observations indicate that positive leaders to ground produce no or very weak radiation from HF to UHF. The broadband system was able to record 2 ms data each time it was triggered. For a +CG the system was usually triggered by the return stroke, and a 1 ms pretrigger period was coincident with the positive leader process. It was commonly observed that no or little radiation was associated with the leader process in the 1 ms pretrigger period. The narrowband VHF system employed a logarithmic power amplifier and recorded one 1 s data each time it was triggered. The narrowband observations show that strong and often continuous radiation occurs at the beginning of the +CGs, but the radiation usually becomes intermittent and impulsive during the last few tens of milliseconds preceding the return strokes. The observations for most of the +CGs also show complete lack of radiation a few ms before the beginning of the return strokes, suggesting that the ongoing downward positive leaders were quiet at VHF, at least during the final few ms. The results of this study for natural positive leaders are in agreement with the results obtained from laboratory gap discharges and rocket-triggered lightning.

  14. The back-story on FlashForward

    CERN Multimedia

    2009-01-01

    Micro black holes that consume the world, strangelets that trigger a runaway reaction, and even an antimatter bomb to blow up the Vatican. If you thought you’d heard all the possible ways the LHC might cause cataclysmic disaster, think again: how about shifting the entire consciousness of humanity 21 years into the future? This is the plot of science-fiction author Robert Sawyer’s novel FlashForward, which is currently being transformed into a big-budget TV series. The Bulletin caught up with the author to find out more. The LHC is just about to start its first operation with lead ions. Suddenly the entire population of the world blacks out for about two minutes. During this time, every person on the planet experiences his life 21 years in the future. They wake up again in the present to see the mass destruction caused by this worldwide blackout, and are left to ponder over what they saw in the future. This is the plot of science-fiction author Robert Sawyer’s n...

  15. Q-Switching the Flash Ti: Sapphire Laser

    Energy Technology Data Exchange (ETDEWEB)

    Cone, Kelly

    2003-09-05

    The Stanford Linear Accelerator Center (SLAC) uses a flash lamp pumped Ti:Sapphire laser to generate the electron beam inside of the Linac. This laser system was installed at the SLAC Polarized Light Source in 1993. During the past, the system has been upgraded in several steps (eg. installation of Rhodium coated reflectors, cavity redesign, and remote controlled wavelength tunability). Q-switching the laser cavity to increase the peak pulse energy was successfully investigated and further improves the capabilities of the laser system for future polarized beam experiments. Two Pockels cells were used to perform the Q-switch and various diagnostics were used to characterize the modified laser pulse. The timing in relation to the laser trigger, pulse width, and pulse shape applied to the Q-switching Pockels cells (PC) were optimized. No damage to the laser cavity or optical elements occurred. At optimal conditions of Q-switching, the pulse energy of the laser increased from 0.4 mJ to over 3 mJ in a 300 ns pulse. The Q-switched pulse energy can be further increased by extending the hold-off pulse applied to the PC. The laser pulse produced by the Q-switch was long enough (full width half maximum (FWHM) > 200 ns) for pulse shaping and demonstrated good intensity stability (< 0.5% jitter). The increase in output power suggests that Q-switching will be used for future accelerator projects.

  16. Mitochondrial flashes regulate ATP homeostasis in the heart.

    Science.gov (United States)

    Wang, Xianhua; Zhang, Xing; Wu, Di; Huang, Zhanglong; Hou, Tingting; Jian, Chongshu; Yu, Peng; Lu, Fujian; Zhang, Rufeng; Sun, Tao; Li, Jinghang; Qi, Wenfeng; Wang, Yanru; Gao, Feng; Cheng, Heping

    2017-07-10

    The maintenance of a constant ATP level ('set-point') is a vital homeostatic function shared by eukaryotic cells. In particular, mammalian myocardium exquisitely safeguards its ATP set-point despite 10-fold fluctuations in cardiac workload. However, the exact mechanisms underlying this regulation of ATP homeostasis remain elusive. Here we show mitochondrial flashes (mitoflashes), recently discovered dynamic activity of mitochondria, play an essential role for the auto-regulation of ATP set-point in the heart. Specifically, mitoflashes negatively regulate ATP production in isolated respiring mitochondria and, their activity waxes and wanes to counteract the ATP supply-demand imbalance caused by superfluous substrate and altered workload in cardiomyocytes. Moreover, manipulating mitoflash activity is sufficient to inversely shift the otherwise stable ATP set-point. Mechanistically, the Bcl-xL-regulated proton leakage through F1Fo-ATP synthase appears to mediate the coupling between mitoflash production and ATP set-point regulation. These findings indicate mitoflashes appear to constitute a digital auto-regulator for ATP homeostasis in the heart.

  17. Memristive behavior in a junctionless flash memory cell

    Energy Technology Data Exchange (ETDEWEB)

    Orak, Ikram [Vocational School of Health Services, Bingöl University, 12000 Bingöl (Turkey); Department of Physics, Faculty of Science and Art, Bingöl University, 12000 Bingöl (Turkey); Ürel, Mustafa; Dana, Aykutlu, E-mail: aykutlu@unam.bilkent.edu.tr [UNAM Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey); Bakan, Gokhan [Faculty of Engineering, Antalya International University, 07190 Antalya (Turkey)

    2015-06-08

    We report charge storage based memristive operation of a junctionless thin film flash memory cell when it is operated as a two terminal device by grounding the gate. Unlike memristors based on nanoionics, the presented device mode, which we refer to as the flashristor mode, potentially allows greater control over the memristive properties, allowing rational design. The mode is demonstrated using a depletion type n-channel ZnO transistor grown by atomic layer deposition (ALD), with HfO{sub 2} as the tunnel dielectric, Al{sub 2}O{sub 3} as the control dielectric, and non-stoichiometric silicon nitride as the charge storage layer. The device exhibits the pinched hysteresis of a memristor and in the unoptimized device, R{sub off}/R{sub on} ratios of about 3 are presented with low operating voltages below 5 V. A simplified model predicts R{sub off}/R{sub on} ratios can be improved significantly by adjusting the native threshold voltage of the devices. The repeatability of the resistive switching is excellent and devices exhibit 10{sup 6 }s retention time, which can, in principle, be improved by engineering the gate stack and storage layer properties. The flashristor mode can find use in analog information processing applications, such as neuromorphic computing, where well-behaving and highly repeatable memristive properties are desirable.

  18. Enhanced detection of Terrestrial Gamma-Ray Flashes by AGILE

    Science.gov (United States)

    Marisaldi, M.; Argan, A.; Ursi, A.; Gjesteland, T.; Fuschino, F.; Labanti, C.; Galli, M.; Tavani, M.; Pittori, C.; Verrecchia, F.; D'Amico, F.; Ostgaard, N.; Mereghetti, S.; Campana, R.; Cattaneo, P.; Bulgarelli, A.; Colafrancesco, S.; Dietrich, S.; Longo, F.; Gianotti, F.; Giommi, P.; Rappoldi, A.; Trifoglio, M.; Trois, A.

    2015-12-01

    At the end of March 2015 the onboard configuration of the AGILE satellite was modified in order to disable the veto signal of the anticoincidence shield for the minicalorimeter instrument. The motivation for such a change was the understanding that the dead time induced by the anticoincidence prevented the detection of a large fraction of Terrestrial Gamma-ray Flashes (TGFs), especially the short duration ones. We present here the characteristics of the new TGF sample after several months of stable operations with the new configuration. The configuration change was highly successful resulting in the detection of about 100 TGFs/month, an increase of a factor about 11 in TGFs detection rate with respect to previous configuration. As expected, the largest fraction of the new events has short duration, with a median duration of 80 microseconds. We also obtain a sample of events with simultaneous association, within 100 microseconds, with lightning sferics detected by the World Wide Lightning Location Network (WWLLN), confirming previous results reported by the Fermi mission. Given the high detection rate and the AGILE very low (+/-2.5°) orbital inclination, the new configuration provides the largest TGF detection rate surface density (TGFs / km2 / year) to date, opening space for correlation studies with lightning and atmospheric parameters on short spatial and temporal scales along the equatorial region. Eventually, the events with associated simultaneous WWLLN sferics provide a highly reliable sample to probe the long-standing issue of the TGF maximal energy.

  19. Ni-Flash-Coated Galvannealed Steel Sheet with Improved Properties

    Science.gov (United States)

    Pradhan, D.; Dutta, M.; Venugopalan, T.

    2016-11-01

    In the last several years, automobile industries have increasingly focused on galvannealed (GA) steel sheet due to their superior properties such as weldability, paintability and corrosion protection. To improve the properties further, different coatings on GA have been reported. In this context, an electroplating process (flash coating) of bright and adherent Ni plating was developed on GA steel sheet for covering the GA defects and enhancing the performances such as weldability, frictional behavior, corrosion resistance and phosphatability. For better illustration, a comparative study with bare GA steel sheet has also been carried out. The maximum electroplating current density of 700 A/m2 yielded higher cathode current efficiency of 95-98%. The performances showed that Ni-coated (coating time 5-7 s) GA steel sheet has better spot weldability, lower dynamic coefficient of friction (0.07 in lubrication) and three times more corrosion resistance compared to bare GA steel sheet. Plate-like crystal of phosphate coating with size of 10-25 µm was obtained on the Ni-coated GA. The main phase in the phosphate compound was identified as hopeite (63.4 wt.%) along with other phases such as spencerite (28.3 wt.%) and phosphophyllite (8.3 wt.%).

  20. Physical Properties of a Sunspot Chromosphere with Umbral Flashes

    CERN Document Server

    Rodríguez, J de la Cruz; Socas-Navarro, H; van Noort, M

    2013-01-01

    We present new high-resolution spectro-polarimetric Ca II 8542 observations of umbral flashes in sunspots. At nearly 0.18", and spanning about one hour of continuous observation, this is the most detailed dataset published thus far. Our study involves both LTE and non-LTE inversions (but includes also a weak field analysis as a sanity check) to quantify temperatures, mass flows and the full magnetic field vector geometry. We confirm earlier reports that UFs have very fine structure with hot and cool material intermixed at sub-arcsecond scales. The shock front is roughly 1000 K hotter than the surrounding material. We do not observe significant fluctuations of the field in the umbra. In the penumbra, however, the passage of the running penumbral waves alter the magnetic field strength by some 200 G (peak-to-peak amplitude) but it does not change the field orientation (at least not significantly within our sensitivity of a few degrees). We find a trend of decreasing high-frequency modulation power for more incl...

  1. Activated carbon from flash pyrolysis of eucalyptus residue

    Directory of Open Access Journals (Sweden)

    Grima-Olmedo C

    2016-09-01

    Full Text Available Forestry waste (eucalyptus sp was converted into activated carbon by initial flash pyrolysis followed carbonization and CO2 activation. These residues were obtained from a pilot plant in Spain that produces biofuel, the biochar represented 10–15% in weight. It was observed that the highest activation was achieved at a temperature of 800 °C, the specific surface increased with time but, on the contrary, high loss of matter was observed. At 600 °C, although there was an important increase of the specific surface and the volume of micropores, at this temperature it was observed that the activation time was not an influential parameter. Finally, at 400 °C it was observed that the activation process was not very significant. Assessing the average pore diameter it was found that the lowest value corresponded to the activation temperature of 600 °C, which indicated the development of microporosity. When the activation temperature increases up to 800 °C the pore diameter increased developing mesoporosity.

  2. Flash Vacuum Pyrolysis of Azides, Triazoles, and Tetrazoles.

    Science.gov (United States)

    Wentrup, Curt

    2017-03-08

    Flash vacuum pyrolysis (FVP) of azides is an extremely valuable method of generating nitrenes and studying their thermal rearrangements. The nitrenes can in many cases be isolated in low-temperature matrices and observed spectroscopically. NH and methyl, alkyl, aralkyl, vinyl, cyano, aryl and N-heteroaryl, acyl, carbamoyl, alkoxycarbonyl, imidoyl, boryl, silyl, phosphonyl, and sulfonyl nitrenes are included. FVP of triazoloazines generates diazomethylazines and azinylcarbenes, which often rearrange to the energetically more stable arylnitrenes. N2 elimination from monocyclic 1,2,3-triazoles can generate iminocarbenes, 1H-azirines, ketenimines, and cyclization products, and 1,2,4-triazoles are precursors of nitrile ylides. Benzotriazoles are preparatively useful precursors of cyanocyclopentadienes, carbazoles, and aza-analogues. FVP of 5-aryltetrazoles can result in double N2 elimination with formation of arylcarbenes or of heteroarylcarbenes, which again rearrange to arylnitrenes. Many 5-substituted and 2,5-disubstituted tetrazoles are excellent precursors of nitrile imines (propargylic, allenic, or carbenic), which are isolable at low temperatures in some cases (e.g., aryl- and silylnitrile imines) or rearrange to carbodiimides. 1,5-Disubstituted tetrazoles are precursors of imidoylnitrenes, which also rearrange to carbodiimides or add intramolecularly to aryl substituents to yield indazoles and related compounds. Where relevant for the mechanistic understanding, pyrolysis under flow conditions or in solution or the solid state will be mentioned. Results of photolysis reactions and computational chemistry complementing the FVP results will also be mentioned in several places.

  3. Flash flood area mapping utilising SENTINEL-1 radar data

    Science.gov (United States)

    Psomiadis, Emmanouil

    2016-10-01

    The new European Observatory radar data of polar orbiting satellite system Sentinel-1 provide a continuous and systematic data acquisition, enabling flood events monitoring and mapping. The study area is the basin of Sperchios River in Fthiotida Prefecture, Central Greece, having an increased ecological, environmental and socio-economic interest. The catchment area and especially the river delta, faces several problems and threats caused by anthropogenic activities and natural processes. The geomorphology of Sperchios catchment area and the drainage network formation provoke the creation of floods. A large flash flood event took place in late January early February 2015 following an intense and heavy rainfall that occurred in the area. Two space born radar images, obtained from Sentinel-1 covering the same area, one before and another one during the flood event, were processed. Two different methods were utilized so as to produce flood hazard maps, which demonstrate the inundated areas. The results of the two methods were similar and the flooded area was detected and delineated ideally.

  4. A program to improve solar blind UV (ultraviolet) flash lamps

    Science.gov (United States)

    Miller, W. J.

    1983-10-01

    A study was conducted of UV light sources, particularly Xenon/H2 flash lamps, in an effort to achieve higher efficiencies in the upper end of the solar blind wavelength region for application to UV communication devices. Lamps containing a number of inert gases with and without added H2, were subjected to detailed spectroscopic examination and their UV output efficiencies compared to that of conventional commercially available lamps of similar physical configuration. A highly versatile power supply capable of delivering very short pulses at variable frequency and power level was designed and built for this purpose. It incorporates the capacity of hold off capacitor recharge for specifiable times between pulses in order to minimize premature lamp firing which produces holdover and renders the source useless for Fm or pulse position modulation operation. Modest increases in efficiency were achieved by increasing Xe pressure and operating the lamps at the highest power and voltage levels compatible with the structural strength of the lamp and frequency range selected for operation.

  5. Ni-Flash-Coated Galvannealed Steel Sheet with Improved Properties

    Science.gov (United States)

    Pradhan, D.; Dutta, M.; Venugopalan, T.

    2016-09-01

    In the last several years, automobile industries have increasingly focused on galvannealed (GA) steel sheet due to their superior properties such as weldability, paintability and corrosion protection. To improve the properties further, different coatings on GA have been reported. In this context, an electroplating process (flash coating) of bright and adherent Ni plating was developed on GA steel sheet for covering the GA defects and enhancing the performances such as weldability, frictional behavior, corrosion resistance and phosphatability. For better illustration, a comparative study with bare GA steel sheet has also been carried out. The maximum electroplating current density of 700 A/m2 yielded higher cathode current efficiency of 95-98%. The performances showed that Ni-coated (coating time 5-7 s) GA steel sheet has better spot weldability, lower dynamic coefficient of friction (0.07 in lubrication) and three times more corrosion resistance compared to bare GA steel sheet. Plate-like crystal of phosphate coating with size of 10-25 µm was obtained on the Ni-coated GA. The main phase in the phosphate compound was identified as hopeite (63.4 wt.%) along with other phases such as spencerite (28.3 wt.%) and phosphophyllite (8.3 wt.%).

  6. Memristive behavior in a junctionless flash memory cell

    Science.gov (United States)

    Orak, Ikram; Ürel, Mustafa; Bakan, Gokhan; Dana, Aykutlu

    2015-06-01

    We report charge storage based memristive operation of a junctionless thin film flash memory cell when it is operated as a two terminal device by grounding the gate. Unlike memristors based on nanoionics, the presented device mode, which we refer to as the flashristor mode, potentially allows greater control over the memristive properties, allowing rational design. The mode is demonstrated using a depletion type n-channel ZnO transistor grown by atomic layer deposition (ALD), with HfO2 as the tunnel dielectric, Al2O3 as the control dielectric, and non-stoichiometric silicon nitride as the charge storage layer. The device exhibits the pinched hysteresis of a memristor and in the unoptimized device, Roff/Ron ratios of about 3 are presented with low operating voltages below 5 V. A simplified model predicts Roff/Ron ratios can be improved significantly by adjusting the native threshold voltage of the devices. The repeatability of the resistive switching is excellent and devices exhibit 106 s retention time, which can, in principle, be improved by engineering the gate stack and storage layer properties. The flashristor mode can find use in analog information processing applications, such as neuromorphic computing, where well-behaving and highly repeatable memristive properties are desirable.

  7. The challenge of predicting flash floods from thunderstorm rainfall.

    Science.gov (United States)

    Gupta, Hosin; Sorooshian, Soroosh; Gao, Xiaogang; Imam, Bisher; Hsu, Kuo-Lin; Bastidas, Luis; Li, Jailun; Mahani, Shayesteh

    2002-07-15

    A major characteristic of the hydrometeorology of semi-arid regions is the occurrence of intense thunderstorms that develop very rapidly and cause severe flooding. In summer, monsoon air mass is often of subtropical origin and is characterized by convective instability. The existing observational network has major deficiencies for those regions in providing information that is important to run-off generation. Further, because of the complex interactions between the land surface and the atmosphere, mesoscale atmospheric models are currently able to reproduce only general features of the initiation and development of convective systems. In our research, several interrelated components including the use of satellite data to monitor precipitation, data assimilation of a mesoscale regional atmospheric model, modification of the land component of the mesoscale model to better represent the semi-arid region surface processes that control run-off generation, and the use of ensemble forecasting techniques to improve forecasts of precipitation and run-off potential are investigated. This presentation discusses our ongoing research in this area; preliminary results including an investigation related to the unprecedented flash floods that occurred across the Las Vegas valley (Nevada, USA) in July of 1999 are discussed.

  8. Flash visual evoked potentials in diurnal birds of prey

    Directory of Open Access Journals (Sweden)

    Maurizio Dondi

    2016-07-01

    Full Text Available The objective of this pilot study was to evaluate the feasibility of Flash Visual Evoked Potentials (FVEPs testing in birds of prey in a clinical setting and to describe the protocol and the baseline data for normal vision in this species. FVEP recordings were obtained from 6 normal adult birds of prey: n. 2 Harris’s Hawks (Parabuteo unicinctus, n. 1 Lanner Falcon (Falco biarmicus, n. 2 Gyrfalcons (Falco rusticolus and n. 1 Saker Falcon (Falco cherrug. Before carrying out VEP tests, all animals underwent neurologic and ophthalmic routine examination. Waveforms were analysed to identify reproducible peaks from random variation of baseline. At least three positive and negative peaks were highlighted in all tracks with elevated repeatability. Measurements consisted of the absolute and relative latencies of these peaks (P1, N1, P2, N2, P3, and N3 and their peak-to-peak amplitudes. Both the peak latency and wave morphology achieved from normal animals were similar to those obtained previously in other animal species. This test can be easily and safely performed in a clinical setting in birds of prey and could be useful for an objective assessment of visual function.

  9. Dislocation Motion and the Microphysics of Flash Heating and Weakening of Faults during Earthquakes

    Directory of Open Access Journals (Sweden)

    Elena Spagnuolo

    2016-07-01

    Full Text Available Earthquakes are the result of slip along faults and are due to the decrease of rock frictional strength (dynamic weakening with increasing slip and slip rate. Friction experiments simulating the abrupt accelerations (>>10 m/s2, slip rates (~1 m/s, and normal stresses (>>10 MPa expected at the passage of the earthquake rupture along the front of fault patches, measured large fault dynamic weakening for slip rates larger than a critical velocity of 0.01–0.1 m/s. The dynamic weakening corresponds to a decrease of the friction coefficient (defined as the ratio of shear stress vs. normal stress up to 40%–50% after few millimetres of slip (flash weakening, almost independently of rock type. The microstructural evolution of the sliding interfaces with slip may yield hints on the microphysical processes responsible for flash weakening. At the microscopic scale, the frictional strength results from the interaction of micro- to nano-scale surface irregularities (asperities which deform during fault sliding. During flash weakening, the visco-plastic and brittle work on the asperities results in abrupt frictional heating (flash heating and grain size reduction associated with mechano-chemical reactions (e.g., decarbonation in CO2-bearing minerals such as calcite and dolomite; dehydration in water-bearing minerals such as clays, serpentine, etc. and phase transitions (e.g., flash melting in silicate-bearing rocks. However, flash weakening is also associated with grain size reduction down to the nanoscale. Using focused ion beam scanning and transmission electron microscopy, we studied the micro-physical mechanisms associated with flash heating and nanograin formation in carbonate-bearing fault rocks. Experiments were conducted on pre-cut Carrara marble (99.9% calcite cylinders using a rotary shear apparatus at conditions relevant to seismic rupture propagation. Flash heating and weakening in calcite-bearing rocks is associated with a shock-like stress

  10. The benefit of high-resolution operational weather forecasts for flash flood warning

    Directory of Open Access Journals (Sweden)

    J. Younis

    2008-07-01

    Full Text Available In Mediterranean Europe, flash flooding is one of the most devastating hazards in terms of loss of human life and infrastructures. Over the last two decades, flash floods have caused damage costing a billion Euros in France alone. One of the problems of flash floods is that warning times are very short, leaving typically only a few hours for civil protection services to act. This study investigates if operationally available short-range numerical weather forecasts together with a rainfall-runoff model can be used for early indication of the occurrence of flash floods.

    One of the challenges in flash flood forecasting is that the watersheds are typically small, and good observational networks of both rainfall and discharge are rare. Therefore, hydrological models are difficult to calibrate and the simulated river discharges cannot always be compared with ground measurements. The lack of observations in most flash flood prone basins, therefore, necessitates the development of a method where the excess of the simulated discharge above a critical threshold can provide the forecaster with an indication of potential flood hazard in the area, with lead times of the order of weather forecasts.

    This study is focused on the Cévennes-Vivarais region in the Southeast of the Massif Central in France, a region known for devastating flash floods. This paper describes the main aspects of using numerical weather forecasting for flash flood forecasting, together with a threshold – exceedance. As a case study the severe flash flood event which took place on 8–9 September 2002 has been chosen.

    Short-range weather forecasts, from the Lokalmodell of the German national weather service, are used as input for the LISFLOOD model, a hybrid between a conceptual and physically based rainfall-runoff model. Results of the study indicate that high resolution operational weather forecasting combined with a rainfall-runoff model could be useful to

  11. Super Resolution Image Enhancement for a Flash Lidar: Back Projection Method

    Science.gov (United States)

    Bulyshev, Alexander; Hines, Glenn; Vanek, Michael; Amzajerdian, Farzin; Reisse, Robert; Pierrottet, Diego

    2010-01-01

    In this paper a new image processing technique for flash LIDAR data is presented as a potential tool to enable safe and precise spacecraft landings in future robotic or crewed lunar and planetary missions. Flash LIDARs can generate, in real-time, range data that can be interpreted as a 3-dimensional (3-D) image and transformed into a corresponding digital elevation map (DEM). The NASA Autonomous Landing and Hazard Avoidance (ALHAT) project is capitalizing on this new technology by developing, testing and analyzing flash LIDARs to detect hazardous terrain features such as craters, rocks, and slopes during the descent phase of spacecraft landings. Using a flash LIDAR for this application looks very promising, however through theoretical and simulation analysis the ALHAT team has determined that a single frame, or mosaic, of flash LIDAR data may not be sufficient to build a landing site DEM with acceptable spatial resolution, precision, size, or for a mosaic, in time, to meet current system requirements. One way to overcome this potential limitation is by enhancing the flash LIDAR output images. We propose a new super-resolution algorithm applicable to flash LIDAR range data that will create a DEM with sufficient accuracy, precision and size to meet current ALHAT requirements. The performance of our super-resolution algorithm is analyzed by processing data generated during a series of simulation runs by a high fidelity model of a flash LIDAR imaging a high resolution synthetic lunar elevation map. The flash LIDAR model is attached to a simulated spacecraft by a gimbal that points the LIDAR to a target landing site. For each simulation run, a sequence of flash LIDAR frames is recorded and processed as the spacecraft descends toward the landing site. Each run has a different trajectory profile with varying LIDAR look angles of the terrain. We process the output LIDAR frames using our SR algorithm and the results show that the achieved level of accuracy and precision of

  12. The Realization of Virtual Reality Based on Flash Action Script%基于Flash Action Script的虚拟现实的实现

    Institute of Scientific and Technical Information of China (English)

    翟彤

    2007-01-01

    Flash是美国的MACROMEDIA公司推出的优秀网页动画设计软件,是一种交互式动画设计工具.本文介绍了Flash软件的优点及其特点,探析了基于Flash Action Script的虚拟现实的实现.

  13. A Unique Equation to Estimate Flash Points of Selected Pure Liquids Application to the Correction of Probably Erroneous Flash Point Values

    Science.gov (United States)

    Catoire, Laurent; Naudet, Valérie

    2004-12-01

    A simple empirical equation is presented for the estimation of closed-cup flash points for pure organic liquids. Data needed for the estimation of a flash point (FP) are the normal boiling point (Teb), the standard enthalpy of vaporization at 298.15 K [ΔvapH°(298.15 K)] of the compound, and the number of carbon atoms (n) in the molecule. The bounds for this equation are: -100⩽FP(°C)⩽+200; 250⩽Teb(K)⩽650; 20⩽Δvap H°(298.15 K)/(kJ mol-1)⩽110; 1⩽n⩽21. Compared to other methods (empirical equations, structural group contribution methods, and neural network quantitative structure-property relationships), this simple equation is shown to predict accurately the flash points for a variety of compounds, whatever their chemical groups (monofunctional compounds and polyfunctional compounds) and whatever their structure (linear, branched, cyclic). The same equation is shown to be valid for hydrocarbons, organic nitrogen compounds, organic oxygen compounds, organic sulfur compounds, organic halogen compounds, and organic silicone compounds. It seems that the flash points of organic deuterium compounds, organic tin compounds, organic nickel compounds, organic phosphorus compounds, organic boron compounds, and organic germanium compounds can also be predicted accurately by this equation. A mean absolute deviation of about 3 °C, a standard deviation of about 2 °C, and a maximum absolute deviation of 10 °C are obtained when predictions are compared to experimental data for more than 600 compounds. For all these compounds, the absolute deviation is equal or lower than the reproductibility expected at a 95% confidence level for closed-cup flash point measurement. This estimation technique has its limitations concerning the polyhalogenated compounds for which the equation should be used with caution. The mean absolute deviation and maximum absolute deviation observed and the fact that the equation provides unbiaised predictions lead to the conclusion that

  14. Modeling terrestrial gamma ray flashes produced by relativistic feedback discharges

    Science.gov (United States)

    Liu, Ningyu; Dwyer, Joseph R.

    2013-05-01

    This paper reports a modeling study of terrestrial gamma ray flashes (TGFs) produced by relativistic feedback discharges. Terrestrial gamma ray flashes are intense energetic radiation originating from the Earth's atmosphere that has been observed by spacecraft. They are produced by bremsstrahlung interactions of energetic electrons, known as runaway electrons, with air atoms. An efficient physical mechanism for producing large fluxes of the runaway electrons to make the TGFs is the relativistic feedback discharge, where seed runaway electrons are generated by positrons and X-rays, products of the discharge itself. Once the relativistic feedback discharge becomes self-sustaining, an exponentially increasing number of relativistic electron avalanches propagate through the same high-field region inside the thundercloud until the electric field is partially discharged by the ionization created by the discharge. The modeling results indicate that the durations of the TGF pulses produced by the relativistic feedback discharge vary from tens of microseconds to several milliseconds, encompassing all durations of the TGFs observed so far. In addition, when a sufficiently large potential difference is available in thunderclouds, a self-propagating discharge known as the relativistic feedback streamer can be formed, which propagates like a conventional positive streamer. For the relativistic feedback streamer, the positive feedback mechanism of runaway electron production by the positrons and X-rays plays a similar role as the photoionization for the conventional positive streamer. The simulation results of the relativistic feedback streamer show that a sequence of TGF pulses with varying durations can be produced by the streamer. The relativistic streamer may initially propagate with a pulsed manner and turn into a continuous propagation mode at a later stage. Milliseconds long TGF pulses can be produced by the feedback streamer during its continuous propagation. However

  15. Terrestrial gamma-ray flash production by lightning

    Science.gov (United States)

    Carlson, Brant E.

    Terrestrial gamma-ray flashes (TGFs) are brief flashes of gamma-rays originating in the Earth's atmosphere and observed by satellites. First observed in 1994 by the Burst And Transient Source Experiment on board the Compton Gamma-Ray Observatory, TGFs consist of one or more ˜1 ms pulses of gamma-rays with a total fluence of ˜1/cm2, typically observed when the satellite is near active thunderstorms. TGFs have subsequently been observed by other satellites to have a very hard spectrum (harder than dN/d E ∝ 1/ E ) that extends from below 25 keV to above 20 MeV. When good lightning data exists, TGFs are closely associated with measurable lightning discharge. Such discharges are typically observed to occur within 300 km of the sub-satellite point and within several milliseconds of the TGF observation. The production of these intense energetic bursts of photons is the puzzle addressed herein. The presence of high-energy photons implies a source of bremsstrahlung, while bremsstrahlung implies a source of energetic electrons. As TGFs are associated with lightning, fields produced by lightning are naturally suggested to accelerate these electrons. Initial ideas about TGF production involved electric fields high above thunderstorms as suggested by upper atmospheric lightning research and the extreme energies required for lower-altitude sources. These fields, produced either quasi-statically by charges in the cloud and ionosphere or dynamically by radiation from lightning strokes, can indeed drive TGF production, but the requirements on the source lightning are too extreme and therefore not common enough to account for all existing observations. In this work, studies of satellite data, the physics of energetic electron and photon production, and consideration of lightning physics motivate a new mechanism for TGF production by lightning current pulses. This mechanism is then developed and used to make testable predictions. TGF data from satellite observations are compared

  16. A high repetition rate XUV seeding source for FLASH2

    Energy Technology Data Exchange (ETDEWEB)

    Willner, Arik

    2012-05-15

    Improved performance of free-electron laser (FEL) light sources in terms of timing stability, pulse shape and spectral properties of the amplified FEL pulses is of interest in material science, the fields of ultrafast dynamics, biology, chemistry and even special branches in industry. A promising scheme for such an improvement is direct seeding with high harmonic generation (HHG) in a noble gas target. A free-electron laser seeded by an external extreme ultraviolet (XUV) source is planned for FLASH2 at DESY in Hamburg. The requirements for the XUV/soft X-ray source can be summarized as follows: A repetition rate of at least 100 kHz in a 10 Hz burst is needed at variable wavelengths from 10 to 40 nm and pulse energies of several nJ within a single laser harmonic. This application requires a laser amplifier system with exceptional parameters, mJ-level pulse energy, 10-15 fs pulse duration at 100 kHz (1 MHz) burst repetition rate. A new optical parametric chirped-pulse amplification (OPCPA) system is under development in order to meet these requirements, and very promising results have been achieved in the last three years. In parallel to this development, a new HHG concept is necessary to sustain high average power of the driving laser system and to generate harmonics with high conversion efficiencies. Currently, the highest conversion efficiency with HHG has been demonstrated using gas-filled capillary targets. For our application, only a free-jet target can be used for HHG, in order to overcome damage threshold limitations of HHG target optics at a high repetition rate. A novel dual-gas multijet gas target has been developed and first experiments show remarkable control of the degree of phase matching forming the basis for improved control of the harmonic photon flux and the XUV pulse characteristics. The basic idea behind the dual-gas concept is the insertion of matching zones in between multiple HHG sources. These matching sections are filled with hydrogen which

  17. Numerical simulations of the bi-level and branched structure of intracloud lightning flashes

    Institute of Scientific and Technical Information of China (English)

    TAN Yongbo; TAO Shanchang; ZHU Baoyou; MA Ming; LU Weitao

    2006-01-01

    Intracloud (IC) lightning flashes have been simulated in fine resolution (12.5 m) by using a bidirectional stochastic lightning parameterization scheme within 2-dimensional domain. The simulated results show that the IC flashes have a bilevel channel structure and the altitudes of the horizontal channels are at the same heights of potential wells, which are supported by the previous VHF source observations and balloon soundings of electric field profile in the thundercloud. Further conclusions are: (1) After an IC flash is initiated near the boundary between positve and nagetive charge zone, the negative (or positive) leader tends to propagate into the positive (or negative) charge zone.Both types of positive and negative IC flashes have been reproduced and their polarity depends on the up and down disposition of the positive and negative charge regions. (2) The extension range of leaders is correlative with the cloud charge distribution. The leader is possible to extend through the inverted charge region all over where it is extending, but keeps away from the isolated charge area of the same polarity. (3) The channel structures also depend on the electric potential distributions in the thundercloud. Before propagating into the central area of potential wells, the leader tends to extend along the direction with the maximum of potential gradient. Once extending away from the center of potential wells, the leader tends to extend along the direction with the slowest potential change. (4)The IC flash channels have the fractal feature with fractal dimension 1.45 before leaders pass through the central area of charge regions. The exponent decreases rapidly once leaders extend into the low-density charge regions. (5) The induced charges of opposite polarity are deposited in the leader channels within preexisting positive and negative charge regions during IC flash discharges. This causes a new and complicated charge distribution in the thundercloud, and the potential

  18. High Risk Flash Flood Rainstorm Mapping Based on Regional L-moments Approach

    Science.gov (United States)

    Ding, Hui; Liao, Yifan; Lin, Bingzhang

    2017-04-01

    Difficulties and complexities in elaborating flash flood early-warning and forecasting system prompt hydrologists to develop some techniques to substantially reduce the disastrous outcome of a flash flood in advance. An ideal to specify those areas that are subject at high risk to flash flood in terms of rainfall intensity in a relatively large region is proposed in this paper. It is accomplished through design of the High Risk Flash Flood Rainstorm Area (HRFFRA) based on statistical analysis of historical rainfall data, synoptic analysis of prevailing storm rainfalls as well as the field survey of historical flash flood events in the region. A HRFFRA is defined as the area potentially under hitting by higher intense-precipitation for a given duration with certain return period that may cause a flash flood disaster in the area. This paper has presented in detail the development of the HRFFRA through the application of the end-to-end Regional L-moments Approach (RLMA) to precipitation frequency analysis in combination with the technique of spatial interpolation in Jiangxi Province, South China Mainland. Among others, the concept of hydrometeorologically homogenous region, the precision of frequency analysis in terms of parameter estimation, the accuracy of quantiles in terms of uncertainties and the consistency adjustments of quantiles over durations and space, etc., have been addressed. At the end of this paper, the mapping of the HRFFRA and an internet-based visualized user-friendly data-server of the HRFFRA are also introduced. Key words: HRFFRA; Flash Flood; RLMA; rainfall intensity; Hydrometeorological homogenous region.

  19. Highly conductive copper nano/microparticles ink via flash light sintering for printed electronics

    Science.gov (United States)

    Joo, Sung-Jun; Hwang, Hyun-Jun; Kim, Hak-Sung

    2014-07-01

    In this study, the size effect of copper particles on the flash light sintering of copper (Cu) ink was investigated using Cu nanoparticles (20-50 nm diameter) and microparticles (2 μm diameter). Also, the mixed Cu nano-/micro-inks were fabricated, and the synergetic effects between the Cu nano-ink and micro-ink on flash light sintering were assessed. The ratio of nanoparticles to microparticles in Cu ink and the several flash light irradiation conditions (irradiation energy density, pulse number, on-time, and off-time) were optimized to obtain high conductivity of Cu films. In order to precisely monitor the milliseconds-long flash light sintering process, in situ monitoring of electrical resistance and temperature changes of Cu films was conducted during the flash light irradiation using a real-time Wheatstone bridge electrical circuit, thermocouple-based circuit, and a high-rate data acquisition system. Also, several microscopic and spectroscopic characterization techniques such as scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy were used to characterize the flash light sintered Cu nano-/micro-films. In addition, the sheet resistance of Cu film was measured using a four-point probe method. This work revealed that the optimal ratio of nanoparticles to microparticles is 50:50 wt%, and the optimally fabricated and flash light sintered Cu nano-/micro-ink films have the lowest resistivity (80 μΩ cm) among nano-ink, micro-ink, or nano-micro mixed films.

  20. Flash flooding in small urban watersheds: Storm event hydrologic response

    Science.gov (United States)

    Yang, Long; Smith, James A.; Baeck, Mary Lynn; Zhang, Yan

    2016-06-01

    We analyze flash flooding in small urban watersheds, with special focus on the roles of rainfall variability, antecedent soil moisture, and urban storm water management infrastructure in storm event hydrologic response. Our results are based on empirical analyses of high-resolution rainfall and discharge observations over Harry's Brook watershed in Princeton, New Jersey, during 2005-2006, as well as numerical experiments with the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model. We focus on two subwatersheds of Harry's Brook, a 1.1 km2 subwatershed which was developed prior to modern storm water management regulations, and a 0.5 km2 subwatershed with an extensive network of storm water detention ponds. The watershed developed prior to modern storm water regulations is an "end-member" in urban flood response, exhibiting a frequency of flood peaks (with unit discharge exceeding 1 m3 s-1 km-2) that is comparable to the "flashiest" watersheds in the conterminous U.S. Observational analyses show that variability in storm event water balance is strongly linked to peak rain rates at time intervals of less than 30 min and only weakly linked to antecedent soil moisture conditions. Peak discharge for both the 1.1 and 0.5 km2 subwatersheds are strongly correlated with rainfall rate averaged over 1-30 min. Hydrologic modeling analyses indicate that the sensitivity of storm event hydrologic response to spatial rainfall variability decreases with storm intensity. Temporal rainfall variability is relatively more important than spatial rainfall variability in representing urban flood response, especially for extreme storm events.