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Sample records for advanced flash memories

  1. Radiation Effects on Advanced Flash Memories

    NASA Technical Reports Server (NTRS)

    Nguyen, D. N.; Guertin, S.; Swift, G. M.; Johnston, A. H.

    1998-01-01

    Flash memories have evolved very rapidly in recent ears. New design techniques such as multilevel storage have been proposed to increase storage density, and are now available commercially. Threshold voltage distributions for single- and three-level technologies are compared. In order to implement this technology special circuitry must be added to allow the amount of charge stored in the floating gate to be controlled within narrow limits during the writing and also to detect the different amounts of charge during reading.

  2. TID and SEE Response of an Advanced Samsung 4G NAND Flash Memory

    NASA Technical Reports Server (NTRS)

    Oldham, Timothy R.; Friendlich, M.; Howard, J. W.; Berg, M. D.; Kim, H. S.; Irwin, T. L.; LaBel, K. A.

    2007-01-01

    Initial total ionizing dose (TID) and single event heavy ion test results are presented for an unhardened commercial flash memory, fabricated with 63 nm technology. Results are that the parts survive to a TID of nearly 200 krad (SiO2), with a tractable soft error rate of about 10(exp -l2) errors/bit-day, for the Adams Ten Percent Worst Case Environment.

  3. Evaluation of Radiation Effects in Flash Memories

    NASA Technical Reports Server (NTRS)

    Miyahira, T.; Swift, G.

    1998-01-01

    Features of flash memories: Flash memories are non-volatile; that is they do not require power to retain the information in its memory. They can be erased and written to while the device is still in the circuit.

  4. NAND FLASH Radiation Tolerant Intelligent Memory Stack (RTIMS FLASH)

    NASA Astrophysics Data System (ADS)

    Sellier, Charles; Wang, Pierre

    2014-08-01

    The NAND Flash Radiation Tolerant and Intelligent Memory Stack (RTIMS FLASH) is a User's Friendly, Plug-and- Play and Radiation Protected high density NAND Flash Memory. It provides a very high density, radiation hardened by design and non-volatile memory module suitable for all space applications such as commercial or scientific geo-stationary missions, earth observation, navigation, manned space vehicles and deep space scientific exploration. The Intelligent Memory Module embeds a very high density of non-volatile NAND Flash memory and one Intelligent Flash Memory Controller (FMC). The FMC provides the module with a full protection against the radiation effects such as SEL, SEFI and SEU. It's also granting the module with bad block immunity as well as high level service functions that will benefit to the user's applications.

  5. Non Volatile Flash Memory Radiation Tests

    NASA Technical Reports Server (NTRS)

    Irom, Farokh; Nguyen, Duc N.; Allen, Greg

    2012-01-01

    Commercial flash memory industry has experienced a fast growth in the recent years, because of their wide spread usage in cell phones, mp3 players and digital cameras. On the other hand, there has been increased interest in the use of high density commercial nonvolatile flash memories in space because of ever increasing data requirements and strict power requirements. Because of flash memories complex structure; they cannot be treated as just simple memories in regards to testing and analysis. It becomes quite challenging to determine how they will respond in radiation environments.

  6. Method for programming a flash memory

    DOEpatents

    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.

  7. Brief history of ETOX NOR flash memory.

    PubMed

    Lai, Stefan K

    2012-10-01

    NOR Flash memory grew from a simple concept in the 80's to worldwide revenue of US$4.8B in 2011. Stacked gate NOR (ETOX NOR at Intel) has highest revenue share of different NOR flash types. Cost reduction was made possible by continuous innovation along many fronts. Key enabler is Moore's Law scaling augmented by multiple self aligned techniques. Another key one is multilevel-cell technology giving 2 bits of information in a single cell. With emergence of NAND at much lower cost, NOR flash market is projected not to grow but NOR is still dominant memory for BIOS and program store in many electronic devices.

  8. FPGA Flash Memory High Speed Data Acquisition

    NASA Technical Reports Server (NTRS)

    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.

  9. Hold-up power supply for flash memory

    NASA Technical Reports Server (NTRS)

    Ott, William E. (Inventor)

    2004-01-01

    A hold-up power supply for flash memory systems is provided. The hold-up power supply provides the flash memory with the power needed to temporarily operate when a power loss exists. This allows the flash memory system to complete any erasures and writes, and thus allows it to shut down gracefully. The hold-up power supply detects when a power loss on a power supply bus is occurring and supplies the power needed for the flash memory system to temporally operate. The hold-up power supply stores power in at least one capacitor. During normal operation, power from a high voltage supply bus is used to charge the storage capacitors. When a power supply loss is detected, the power supply bus is disconnected from the flash memory system. A hold-up controller controls the power flow from the storage capacitors to the flash memory system. The hold-up controller uses feedback to assure that the proper voltage is provided from the storage capacitors to the flash memory system. This power supplied by the storage capacitors allows the flash memory system to complete any erasures and writes, and thus allows the flash memory system to shut down gracefully.

  10. Exploring Shared Memory Protocols in FLASH

    SciTech Connect

    Horowitz, Mark; Kunz, Robert; Hall, Mary; Lucas, Robert; Chame, Jacqueline

    2007-04-01

    ABSTRACT The goal of this project was to improve the performance of large scientific and engineering applications through collaborative hardware and software mechanisms to manage the memory hierarchy of non-uniform memory access time (NUMA) shared-memory machines, as well as their component individual processors. In spite of the programming advantages of shared-memory platforms, obtaining good performance for large scientific and engineering applications on such machines can be challenging. Because communication between processors is managed implicitly by the hardware, rather than expressed by the programmer, application performance may suffer from unintended communication – communication that the programmer did not consider when developing his/her application. In this project, we developed and evaluated a collection of hardware, compiler, languages and performance monitoring tools to obtain high performance on scientific and engineering applications on NUMA platforms by managing communication through alternative coherence mechanisms. Alternative coherence mechanisms have often been discussed as a means for reducing unintended communication, although architecture implementations of such mechanisms are quite rare. This report describes an actual implementation of a set of coherence protocols that support coherent, non-coherent and write-update accesses for a CC-NUMA shared-memory architecture, the Stanford FLASH machine. Such an approach has the advantages of using alternative coherence only where it is beneficial, and also provides an evolutionary migration path for improving application performance. We present data on two computations, RandomAccess from the HPC Challenge benchmarks and a forward solver derived from LS-DYNA, showing the performance advantages of the alternative coherence mechanisms. For RandomAccess, the non-coherent and write-update versions can outperform the coherent version by factors of 5 and 2.5, respectively. In LS-DYNA, we obtain

  11. Advanced mask technique to improve bit line CD uniformity of 90 nm node flash memory in low-k1 lithography

    NASA Astrophysics Data System (ADS)

    Kim, Jong-doo; Choi, Jae-young; Kim, Jea-hee; Han, Jae-won

    2008-10-01

    As devices size move toward 90nm technology node or below, defining uniform bit line CD of flash devices is one of the most challenging features to print in KrF lithography. There are two principal difficulties in defining bit line on wafer. One is insufficient process margin besides poor resolution compared with ArF lithography. The other is that asymmetric bit line should be made for OPC(Optical Proximity Correction) modeling. Therefore advanced ArF lithography scanner should be used for define bit line with RETs (Resolution Enhancement Techniques) such as immersion lithography, OPC, PSM(Phase Shift Mask), high NA(Numerical Aperture), OAI(Off-Axis Illumination), SRAF(Sub-resolution Assistant Feature), and mask biasing.. Like this, ArF lithography propose the method of enhancing resolution, however, we must spend an enormous amount of CoC(cost of ownership) to utilize ArF photolithography process than KrF. In this paper, we suggest method to improve of bit line CD uniformity, patterned by KrF lithographic process in 90nm sFlash(stand alone Flash) devices. We applied new scheme of mask manufacturing, which is able to realize 2 different types of mask, binary and phase-shift, into one plate. Finally, we could get the more uniform bit lines and we expect to get more stable properties then before applying this technique.

  12. Some Improvements in Utilization of Flash Memory Devices

    NASA Technical Reports Server (NTRS)

    Gender, Thomas K.; Chow, James; Ott, William E.

    2009-01-01

    Two developments improve the utilization of flash memory devices in the face of the following limitations: (1) a flash write element (page) differs in size from a flash erase element (block), (2) a block must be erased before its is rewritten, (3) lifetime of a flash memory is typically limited to about 1,000,000 erases, (4) as many as 2 percent of the blocks of a given device may fail before the expected end of its life, and (5) to ensure reliability of reading and writing, power must not be interrupted during minimum specified reading and writing times. The first development comprises interrelated software components that regulate reading, writing, and erasure operations to minimize migration of data and unevenness in wear; perform erasures during idle times; quickly make erased blocks available for writing; detect and report failed blocks; maintain the overall state of a flash memory to satisfy real-time performance requirements; and detect and initialize a new flash memory device. The second development is a combination of hardware and software that senses the failure of a main power supply and draws power from a capacitive storage circuit designed to hold enough energy to sustain operation until reading or writing is completed.

  13. Flash drive memory apparatus and method

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G. (Inventor)

    2010-01-01

    A memory apparatus includes a non-volatile computer memory, a USB mass storage controller connected to the non-volatile computer memory, the USB mass storage controller including a daisy chain component, a male USB interface connected to the USB mass storage controller, and at least one other interface for a memory device, other than a USB interface, the at least one other interface being connected to the USB mass storage controller.

  14. 76 FR 55417 - In the Matter of Certain Dynamic Random Access Memory and Nand Flash Memory Devices and Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-07

    ... COMMISSION In the Matter of Certain Dynamic Random Access Memory and Nand Flash Memory Devices and Products... States after importation of certain dynamic random access memory and NAND flash memory devices and... the sale within the United States after importation of certain dynamic random access memory and...

  15. Multi-Level Bitmap Indexes for Flash Memory Storage

    SciTech Connect

    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. Flash memory management system and method utilizing multiple block list windows

    NASA Technical Reports Server (NTRS)

    Chow, James (Inventor); Gender, Thomas K. (Inventor)

    2005-01-01

    The present invention provides a flash memory management system and method with increased performance. The flash memory management system provides the ability to efficiently manage and allocate flash memory use in a way that improves reliability and longevity, while maintaining good performance levels. The flash memory management system includes a free block mechanism, a disk maintenance mechanism, and a bad block detection mechanism. The free block mechanism provides efficient sorting of free blocks to facilitate selecting low use blocks for writing. The disk maintenance mechanism provides for the ability to efficiently clean flash memory blocks during processor idle times. The bad block detection mechanism provides the ability to better detect when a block of flash memory is likely to go bad. The flash status mechanism stores information in fast access memory that describes the content and status of the data in the flash disk. The new bank detection mechanism provides the ability to automatically detect when new banks of flash memory are added to the system. Together, these mechanisms provide a flash memory management system that can improve the operational efficiency of systems that utilize flash memory.

  17. Proton irradiation effects on 2Gb flash memory

    SciTech Connect

    Wester, William; Nelson, Charles; Marriner, John

    2004-08-18

    The authors report total ionizing dose and single event effects on 2Gb Samsung flash memory devices after exposure to 200 MeV protons to various doses up to 83 krad(Si). They characterize observed failures and single event upsets on 22 devices from two different lots. Devices from both lots are robust to greater than 20 krad(Si) although they see evidence for lot-to-lot variation where only one lot appears robust up to about 50 krad(Si). Single event upsets are observed at a relatively low rate and are consistent with single isolated bit flips within registers that transfer bits to and from the flash memory cells.

  18. Radiation Tests on 2Gb NAND Flash Memories

    NASA Technical Reports Server (NTRS)

    Nguyen, Duc N.; Guertin, Steven M.; Patterson, J. D.

    2006-01-01

    We report on SEE and TID tests of highly scaled Samsung 2Gbits flash memories. Both in-situ and biased interval irradiations were used to characterize the response of the total accumulated dose failures. The radiation-induced failures can be categorized as followings: single event upset (SEU) read errors in biased and unbiased modes, write errors, and single-event-functional-interrupt (SEFI) failures.

  19. 78 FR 55095 - Certain Flash Memory Chips and Products Containing Same; Institution of Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-09

    ... COMMISSION Certain Flash Memory Chips and Products Containing Same; Institution of Investigation AGENCY: U.S... the sale within the United States after importation of certain flash memory chips and products... memory chips and products containing the same by reason of infringement of one or more of claims 1-3...

  20. Solution processed molecular floating gate for flexible flash memories

    PubMed Central

    Zhou, Ye; Han, Su-Ting; Yan, Yan; Huang, Long-Biao; Zhou, Li; Huang, Jing; Roy, V. A. L.

    2013-01-01

    Solution processed fullerene (C60) molecular floating gate layer has been employed in low voltage nonvolatile memory device on flexible substrates. We systematically studied the charge trapping mechanism of the fullerene floating gate for both p-type pentacene and n-type copper hexadecafluorophthalocyanine (F16CuPc) semiconductor in a transistor based flash memory architecture. The devices based on pentacene as semiconductor exhibited both hole and electron trapping ability, whereas devices with F16CuPc trapped electrons alone due to abundant electron density. All the devices exhibited large memory window, long charge retention time, good endurance property and excellent flexibility. The obtained results have great potential for application in large area flexible electronic devices. PMID:24172758

  1. Characteristics of junctionless charge trap flash memory for 3D stacked NAND flash.

    PubMed

    Oh, Jinho; Na, Heedo; Park, Sunghoon; Sohn, Hyunchul

    2013-09-01

    The electrical characteristics of tunnel barrier engineered-charge trap flash (TBE-CTF) memory devices with junctionless (JL) source and drain (S/D) were investigated. The JL structure is composed of an n(+)-poly-Si based ultra-thin channel and S/D with identical doping concentrations. The band engineered Hf-silicate/Al2O3 tunnel barrier stack was applied to a JL-TBE-CTF memory device in order to enhance the field sensitivity. The Hf-silicate/Al2O3 tunnel barrier, HfO2 trap layer, and Al2O3 blocking layer were deposited by atomic layer deposition. The fabricated device exhibited a large memory window of 9.43 V, as well as high programming and erasing speeds. Moreover, it also showed adequate retention times and endurance properties. Hence, the JL-TBE-CTF memory (which has a low process complexity) is expected to be an appropriate structure for 3D stacked ultra-high density memory applications. PMID:24205672

  2. Effect of Radiation Exposure on the Retention of Commercial NAND Flash Memory

    NASA Technical Reports Server (NTRS)

    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.

  3. Graphene-quantum-dot nonvolatile charge-trap flash memories.

    PubMed

    Sin Joo, Soong; Kim, Jungkil; Kang, Soo Seok; Kim, Sung; Choi, Suk-Ho; Hwang, Sung Won

    2014-06-27

    Nonvolatile flash-memory capacitors containing graphene quantum dots (GQDs) of 6, 12, and 27 nm average sizes (d) between SiO2 layers for use as charge traps have been prepared by sequential processes: ion-beam sputtering deposition (IBSD) of 10 nm SiO2 on a p-type wafer, spin-coating of GQDs on the SiO2 layer, and IBSD of 20 nm SiO2 on the GQD layer. The presence of almost a single array of GQDs at a distance of ∼13 nm from the SiO2/Si wafer interface is confirmed by transmission electron microscopy and photoluminescence. The memory window estimated by capacitance-voltage curves is proportional to d for sweep voltages wider than  ± 3 V, and for d = 27 nm the GQD memories show a maximum memory window of 8 V at a sweep voltage of  ± 10 V. The program and erase speeds are largest at d = 12 and 27 nm, respectively, and the endurance and data-retention properties are the best at d = 27 nm. These memory behaviors can be attributed to combined effects of edge state and quantum confinement. PMID:24896068

  4. Advances in flash flood monitoring using UAVs

    NASA Astrophysics Data System (ADS)

    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.

  5. Radiation Tests of Highly scaled, High-Density, Commercial, Nonvolatile NAND Flash Memories--Update 2011

    NASA Technical Reports Server (NTRS)

    Irom, Farokh; Nguyen, Duc N.

    2011-01-01

    High-density, commercial, nonvolatile flash memories with NAND architecture are now available from several manufacturers. This report examines SEE effects and TID response in single-level cell (SLC) 32Gb and multi-level cell (MLC) 64Gb NAND flash memories manufactured by Micron Technology.

  6. Radiation Tests of Highly Scaled, High-Density, Commercial, Nonvolatile NAND Flash Memories - Update 2010

    NASA Technical Reports Server (NTRS)

    Irom, Farokh; Nguyen, Duc N.

    2010-01-01

    High-density, commercial, nonvolatile flash memories with NAND architecture are now available from several manufacturers. This report examines SEE effects and TID response in single-level cell (SLC) and multi-level cell (MLC) NAND flash memories manufactured by Micron Technology.

  7. Fault-tolerant NAND-flash memory module for next-generation scientific instruments

    NASA Astrophysics Data System (ADS)

    Lange, Tobias; Michel, Holger; Fiethe, Björn; Michalik, Harald; Walter, Dietmar

    2015-10-01

    Remote sensing instruments on today's space missions deliver a high amount of data which is typically evaluated on ground. Especially for deep space missions the telemetry downlink is very limited which creates the need for the scientific evaluation and thereby a reduction of data volume already on-board the spacecraft. A demanding example is the Polarimetric and Helioseismic Imager (PHI) instrument on Solar Orbiter. To enable on-board offline processing for data reduction, the instrument has to be equipped with a high capacity memory module. The module is based on non-volatile NAND-Flash technology, which requires more advanced operation than volatile DRAM. Unlike classical mass memories, the module is integrated into the instrument and allows readback of data for processing. The architecture and safe operation of such kind of memory module is described in the following paper.

  8. 78 FR 48188 - Certain Flash Memory Chips and Products Containing the Same Notice of Receipt of Complaint...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-07

    ... COMMISSION Certain Flash Memory Chips and Products Containing the Same Notice of Receipt of Complaint... complaint entitled Certain Flash Memory Chips and Products Containing the Same, DN 2971; the Commission is... certain flash memory chips and products containing the same. The complaint names as respondents...

  9. 75 FR 55604 - In the Matter of Certain Flash Memory Chips and Products Containing the Same; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-13

    ... COMMISSION In the Matter of Certain Flash Memory Chips and Products Containing the Same; Notice of... importation of certain flash memory chips and products containing the same by reason of infringement of... after importation of certain flash memory chips and products containing the same that infringe one...

  10. Comparison of TID Response and SEE Characterization of Single and Multi Level High Density NAND Flash Memories

    NASA Technical Reports Server (NTRS)

    Irom, Farokh; Nguyen, Duc N.; Harboe-Sorensen, Reno; Virtanen, Ari

    2009-01-01

    Heavy ion single-event measurements and TID response for 8Gb commercial NAND flash memories are reported. Radiation results of multi-level flash technology are compared with results from single-level flash technology. In general, these commercial high density memories appear to be much less susceptible to SEE and have better TID response compared to older generations of flash memories. The charge pump survived up to 600 krads.

  11. Investigation of Current Spike Phenomena During Heavy Ion Irradiation of NAND Flash Memories

    NASA Technical Reports Server (NTRS)

    Oldham, Timothy R.; Berg, Melanie; Friendlich, Mark; Wilcox, Ted; Seidleck, Christina; LaBel, Kenneth A.; Irom, Farokh; Buchner, Steven P.; McMorrow, Dale; Mavis, David G.; Eaton, Paul H.; Castillo, James

    2011-01-01

    A series of heavy ion and laser irradiations were performed to investigate previously reported current spikes in flash memories. High current events were observed, however, none matches the previously reported spikes. Plausible mechanisms are discussed.

  12. Memristive behavior in a junctionless flash memory cell

    SciTech Connect

    Orak, Ikram; Ürel, Mustafa; Dana, Aykutlu; Bakan, Gokhan

    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.

  13. Advanced image memory architecture

    NASA Astrophysics Data System (ADS)

    Vercillo, Richard; McNeill, Kevin M.

    1994-05-01

    A workstation for radiographic images, known as the Arizona Viewing Console (AVC), was developed at the University of Arizona Health Sciences Center in the Department of Radiology. This workstation has been in use as a research tool to aid us in investigating how a radiologist interacts with a workstation, to determine which image processing features are required to aid the radiologist, to develop user interfaces and to support psychophysical and clinical studies. Results from these studies have show a need to increase the current image memory's available storage in order to accommodate high resolution images. The current triple-ported image memory can be allocated to store any number of images up to a combined total of 4 million pixels. Over the past couple of years, higher resolution images have become easier to generate with the advent of laser digitizers and computed radiology systems. As part of our research, a larger 32 million pixel image memory for AVC has been designed to replace the existing image memory.

  14. Flash Memory Reliability: Read, Program, and Erase Latency Versus Endurance Cycling

    NASA Technical Reports Server (NTRS)

    Heidecker, Jason

    2010-01-01

    This report documents the efforts and results of the fiscal year (FY) 2010 NASA Electronic Parts and Packaging Program (NEPP) task for nonvolatile memory (NVM) reliability. This year's focus was to measure latency (read, program, and erase) of NAND Flash memories and determine how these parameters drift with erase/program/read endurance cycling.

  15. Radiation Tests of Highly Scaled, High-Density, Commercial, Nonvolatile NAND Flash Memories - Update 2012

    NASA Technical Reports Server (NTRS)

    Irom, Farokh; Allen, Gregory R.

    2012-01-01

    The space radiation environment poses a certain risk to all electronic components on Earth-orbiting and planetary mission spacecraft. In recent years, there has been increased interest in the use of high-density, commercial, nonvolatile flash memories in space because of ever-increasing data volumes and strict power requirements. They are used in a wide variety of spacecraft subsystems. At one end of the spectrum, flash memories are used to store small amounts of mission-critical data such as boot code or configuration files and, at the other end, they are used to construct multi-gigabyte data recorders that record mission science data. This report examines single-event effect (SEE) and total ionizing dose (TID) response in single-level cell (SLC) 32-Gb, multi-level cell (MLC) 64-Gb, and Triple-level (TLC) 64-Gb NAND flash memories manufactured by Micron Technology with feature size of 25 nm.

  16. 76 FR 41824 - In the Matter of Certain Flash Memory Chips And Products Containing Same; Notice of Commission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-15

    ... complaint filed by Spansion LLC of Sunnyvale, California (``Spansion''). 75 FR. 55604-5 (Sept 13, 2010). The... COMMISSION In the Matter of Certain Flash Memory Chips And Products Containing Same; Notice of Commission..., Certain Flash Memory Chips and Products Containing Same on the basis of a settlement agreement....

  17. 76 FR 4375 - In the Matter of Certain MLC Flash Memory Devices and Products Containing Same; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ...''). 74 FR 43723-4 (August 27, 2009). The complaint, as amended and supplemented, alleges violations of... COMMISSION In the Matter of Certain MLC Flash Memory Devices and Products Containing Same; Notice of... flash memory devices and products containing same by reason of infringement of certain claims of...

  18. 75 FR 11909 - In the Matter of: Certain Flash Memory Chips and Products Containing Same; Notice of Commission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-12

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION In the Matter of: Certain Flash Memory Chips and Products Containing Same; Notice of Commission... flash memory chips and products containing the same by reason of infringement of various claims...

  19. 78 FR 49287 - Certain Flash Memory Chips and Products Containing the Same Correction to Notice of Receipt of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-13

    ... FR 48188, August 7, 2013) of receipt of complaint entitled, Certain Flash Memory Chips and Products... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Flash Memory Chips and Products Containing the Same Correction to Notice of Receipt...

  20. Reducing latency overhead caused by using LDPC codes in NAND flash memory

    NASA Astrophysics Data System (ADS)

    Zhao, Wenzhe; Dong, Guiqiang; Sun, Hongbin; Zheng, Nanning; Zhang, Tong

    2012-12-01

    Semiconductor technology scaling makes NAND flash memory subject to continuous raw storage reliability degradation, leading to the demand for more and more powerful error correction codes. This inevitable trend makes conventional BCH code increasingly inadequate, and iterative coding solutions such as low-density parity-check (LDPC) codes become very natural alternative options. However, fine-grained soft-decision memory sensing must be used in order to fully leverage the strong error correction capability of LDPC codes, which results in significant data access latency overhead. This article presents a simple design technique that can reduce such latency overhead. The key is to cohesively exploit the NAND flash memory wear-out dynamics and impact of LDPC code structure on decoding performance. Based upon detailed memory device modeling and ASIC design, we carried out simulations to demonstrate the potential effectiveness of this design method and evaluate the involved trade-offs.

  1. Current status and advances in flash fire modeling

    SciTech Connect

    Rew, P.J.; Deaves, D.M.; Madison, T.

    1995-12-31

    When a dispersing cloud of flammable vapor is ignited, it can burn in a number of different ways. A flash fire or cloud fire occurs if ignition takes place within the flammable region of a gas cloud, generally at a point remote from the source. A review of the modeling of flash fires (cloud fires) is presented. The present understanding of flash fires is discussed through reference to past incidents and current models. Full scale flash fire trials are reviewed, providing a database of relevant experimental data. Outline proposals are given for improving the current prediction methodologies for the direct (burn fatalities) and indirect (escalation) effects of flash fires.

  2. Synergistic High Charge-Storage Capacity for Multi-level Flexible Organic Flash Memory

    NASA Astrophysics Data System (ADS)

    Kang, Minji; Khim, Dongyoon; Park, Won-Tae; Kim, Jihong; Kim, Juhwan; Noh, Yong-Young; Baeg, Kang-Jun; Kim, Dong-Yu

    2015-07-01

    Electret and organic floating-gate memories are next-generation flash storage mediums for printed organic complementary circuits. While each flash memory can be easily fabricated using solution processes on flexible plastic substrates, promising their potential for on-chip memory organization is limited by unreliable bit operation and high write loads. We here report that new architecture could improve the overall performance of organic memory, and especially meet high storage for multi-level operation. Our concept depends on synergistic effect of electrical characterization in combination with a polymer electret (poly(2-vinyl naphthalene) (PVN)) and metal nanoparticles (Copper). It is distinguished from mostly organic nano-floating-gate memories by using the electret dielectric instead of general tunneling dielectric for additional charge storage. The uniform stacking of organic layers including various dielectrics and poly(3-hexylthiophene) (P3HT) as an organic semiconductor, followed by thin-film coating using orthogonal solvents, greatly improve device precision despite easy and fast manufacture. Poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] as high-k blocking dielectric also allows reduction of programming voltage. The reported synergistic organic memory devices represent low power consumption, high cycle endurance, high thermal stability and suitable retention time, compared to electret and organic nano-floating-gate memory devices.

  3. Synergistic High Charge-Storage Capacity for Multi-level Flexible Organic Flash Memory

    PubMed Central

    Kang, Minji; Khim, Dongyoon; Park, Won-Tae; Kim, Jihong; Kim, Juhwan; Noh, Yong-Young; Baeg, Kang-Jun; Kim, Dong-Yu

    2015-01-01

    Electret and organic floating-gate memories are next-generation flash storage mediums for printed organic complementary circuits. While each flash memory can be easily fabricated using solution processes on flexible plastic substrates, promising their potential for on-chip memory organization is limited by unreliable bit operation and high write loads. We here report that new architecture could improve the overall performance of organic memory, and especially meet high storage for multi-level operation. Our concept depends on synergistic effect of electrical characterization in combination with a polymer electret (poly(2-vinyl naphthalene) (PVN)) and metal nanoparticles (Copper). It is distinguished from mostly organic nano-floating-gate memories by using the electret dielectric instead of general tunneling dielectric for additional charge storage. The uniform stacking of organic layers including various dielectrics and poly(3-hexylthiophene) (P3HT) as an organic semiconductor, followed by thin-film coating using orthogonal solvents, greatly improve device precision despite easy and fast manufacture. Poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] as high-k blocking dielectric also allows reduction of programming voltage. The reported synergistic organic memory devices represent low power consumption, high cycle endurance, high thermal stability and suitable retention time, compared to electret and organic nano-floating-gate memory devices. PMID:26201747

  4. Oxide degradation mechanism in stacked-gate flash memory using the cell array stress test

    NASA Astrophysics Data System (ADS)

    Tsai, Shih-Hung; Hung, Jui-Sheng; Wang, Na-Fu; Horng, Jui-Hong; Houng, Mau-Phon; Wang, Yeong-Her

    2003-09-01

    The generation of oxide charges and interface states during the program/erase operation in flash memory has been known to degrade the tunnel oxide quality. However, there is still no effective method to analyse the endurance and disturbed performance of the flash memory at the test level. So in this paper, a simple and fast method is applied to characterize the endurance and disturbed performance on a 98K bit flash cell array stress test structure. Based on this structure, the behaviour of the weakest part of the memory array after the program/erase operation can be easily observed. Moreover, the effects of the oxide charges and interface states generated are also discussed. Also, excess hole trapping in the oxide leads to fast charge loss during the disturbance test. The fast charge loss caused by holes is the more serious of these two failure mechanisms because the relatively low high-state VT can be corrected by circuit-level, program/erase-verified sequences. However, poor disturbance characteristics cause logical errors during the reading of an array.

  5. Reliability Degeneration Mechanisms of the 20-nm Flash Memories Due to the Word Line Stress.

    PubMed

    Jung, Hyun Soo; Ryu, Ju Tae; Yoo, Keon-Ho; Kim, T W

    2016-02-01

    The electrical characteristics of NAND flash memories with a high-k dielectric layer were simulated by using a full three-dimensional technology computer-aided design simulator. The occurrence rate of the errors in the flash memories increases with increasing program/erase cycles. To verify the word line stress effect, electron density in the floating gate of target cell and non-target cell, the drain current in the channel of non-target cell and depletion region of the non-target cell were simulated as a function of program/erase cycle, for various floating gate thicknesses. The electron density in the floating gate became decreased with increasing program/erase cycles. The reliability degradation occured by the increased depletion region at the bottom of the polysilicon floating gate in the continued program/erase cycle situation due to the word line stress. The degradation mechanisms for the program characteristics of 20-nm NAND flash memories were clarified by examining electron density, darin current and depletion region. PMID:27433643

  6. Surface engineering of reduced graphene oxide for controllable ambipolar flash memories.

    PubMed

    Han, Su-Ting; Zhou, Ye; Sonar, Prashant; Wei, Huaixin; Zhou, Li; Yan, Yan; Lee, Chun-Sing; Roy, V A L

    2015-01-28

    Tunable charge-trapping behaviors including unipolar charge trapping of one type of charge carrier and ambipolar trapping of both electrons and holes in a complementary manner is highly desirable for low power consumption multibit flash memory design. Here, we adopt a strategy of tuning the Fermi level of reduced graphene oxide (rGO) through self-assembled monolayer (SAM) functionalization and form p-type and n-type doped rGO with a wide range of manipulation on work function. The functionalized rGO can act as charge-trapping layer in ambipolar flash memories, and a dramatic transition of charging behavior from unipolar trapping of electrons to ambipolar trapping and eventually to unipolar trapping of holes was achieved. Adjustable hole/electron injection barriers induce controllable Vth shift in the memory transistor after programming operation. Finally, we transfer the ambipolar memory on flexible substrates and study their charge-trapping properties at various bending cycles. The SAM-functionalized rGO can be a promising candidate for next-generation nonvolatile memories.

  7. Fly-by-Light Advanced Systems Hardware (FLASH) program

    NASA Astrophysics Data System (ADS)

    Bedoya, Carlos A.

    1995-05-01

    hundreds of MHz are available. Applications of fiber optic buses would then result in the reduction of wires and connections because of reduction in the number of buses needed for information transfer due to the fact that a large number of different signals can be sent across one fiber by multiplexing each signal. The Advanced Research Projects Agency (ARPA) Technology Reinvestment Project (TRP) Fly-by-Light Advanced Systems Hardware (FLASH) program addresses the development of Fly-by-Light Technology in order to apply the benefits of fiber optics to military and commercial aircraft.

  8. Quantum memories: emerging applications and recent advances

    PubMed Central

    Heshami, Khabat; England, Duncan G.; Humphreys, Peter C.; Bustard, Philip J.; Acosta, Victor M.; Nunn, Joshua; Sussman, Benjamin J.

    2016-01-01

    Quantum light–matter interfaces are at the heart of photonic quantum technologies. Quantum memories for photons, where non-classical states of photons are mapped onto stationary matter states and preserved for subsequent retrieval, are technical realizations enabled by exquisite control over interactions between light and matter. The ability of quantum memories to synchronize probabilistic events makes them a key component in quantum repeaters and quantum computation based on linear optics. This critical feature has motivated many groups to dedicate theoretical and experimental research to develop quantum memory devices. In recent years, exciting new applications, and more advanced developments of quantum memories, have proliferated. In this review, we outline some of the emerging applications of quantum memories in optical signal processing, quantum computation and non-linear optics. We review recent experimental and theoretical developments, and their impacts on more advanced photonic quantum technologies based on quantum memories.

  9. Quantum memories: emerging applications and recent advances

    NASA Astrophysics Data System (ADS)

    Heshami, Khabat; England, Duncan G.; Humphreys, Peter C.; Bustard, Philip J.; Acosta, Victor M.; Nunn, Joshua; Sussman, Benjamin J.

    2016-11-01

    Quantum light-matter interfaces are at the heart of photonic quantum technologies. Quantum memories for photons, where non-classical states of photons are mapped onto stationary matter states and preserved for subsequent retrieval, are technical realizations enabled by exquisite control over interactions between light and matter. The ability of quantum memories to synchronize probabilistic events makes them a key component in quantum repeaters and quantum computation based on linear optics. This critical feature has motivated many groups to dedicate theoretical and experimental research to develop quantum memory devices. In recent years, exciting new applications, and more advanced developments of quantum memories, have proliferated. In this review, we outline some of the emerging applications of quantum memories in optical signal processing, quantum computation and non-linear optics. We review recent experimental and theoretical developments, and their impacts on more advanced photonic quantum technologies based on quantum memories.

  10. Quantum memories: emerging applications and recent advances

    PubMed Central

    Heshami, Khabat; England, Duncan G.; Humphreys, Peter C.; Bustard, Philip J.; Acosta, Victor M.; Nunn, Joshua; Sussman, Benjamin J.

    2016-01-01

    Quantum light–matter interfaces are at the heart of photonic quantum technologies. Quantum memories for photons, where non-classical states of photons are mapped onto stationary matter states and preserved for subsequent retrieval, are technical realizations enabled by exquisite control over interactions between light and matter. The ability of quantum memories to synchronize probabilistic events makes them a key component in quantum repeaters and quantum computation based on linear optics. This critical feature has motivated many groups to dedicate theoretical and experimental research to develop quantum memory devices. In recent years, exciting new applications, and more advanced developments of quantum memories, have proliferated. In this review, we outline some of the emerging applications of quantum memories in optical signal processing, quantum computation and non-linear optics. We review recent experimental and theoretical developments, and their impacts on more advanced photonic quantum technologies based on quantum memories. PMID:27695198

  11. A light writable microfluidic "flash memory": optically addressed actuator array with latched operation for microfluidic applications.

    PubMed

    Hua, Zhishan; Pal, Rohit; Srivannavit, Onnop; Burns, Mark A; Gulari, Erdogan

    2008-03-01

    This paper presents a novel optically addressed microactuator array (microfluidic "flash memory") with latched operation. Analogous to the address-data bus mediated memory address protocol in electronics, the microactuator array consists of individual phase-change based actuators addressed by localized heating through focused light patterns (address bus), which can be provided by a modified projector or high power laser pointer. A common pressure manifold (data bus) for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light "writing" during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs. The microfluidic flash memory can be re-configured by a new light illumination pattern and common pressure signal. The proposed approach can achieve actuation of arbitrary units in a large-scale array without the need for complex external equipment such as solenoid valves and electrical modules, which leads to significantly simplified system implementation and compact system size. The proposed work therefore provides a flexible, energy-efficient, and low cost multiplexing solution for microfluidic applications based on physical displacements. As an example, the use of the latched microactuator array as "normally closed" or "normally open" microvalves is demonstrated. The phase-change wax is fully encapsulated and thus immune from contamination issues in fluidic environments.

  12. Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets of NAND Flash Memory

    NASA Technical Reports Server (NTRS)

    Chen, Dakai; Wilcox, Edward; Ladbury, Raymond; Kim, Hak; Phan, Anthony; Seidleck, Christina; LaBel, Kenneth

    2016-01-01

    We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found the single-event upset (SEU) cross section varied inversely with fluence. The SEU cross section decreased with increasing fluence. We attribute the effect to the variable upset sensitivities of the memory cells. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, heavy ion irradiation of devices with variable upset sensitivity distribution using typical fluence levels may underestimate the cross section and on-orbit event rate.

  13. Evaluation of IDEALSmile for 90-nm FLASH memory contact holes imaging with ArF scanner

    NASA Astrophysics Data System (ADS)

    Cantu, Pietro; Capetti, Gianfranco; Loi, Sara; Lupo, Marco; Pepe, Annalisa; Saitoh, Kenji; Yamazoe, Kenji; Hasegawa, Yasuo; Iwasa, Junji; Toublan, Olivier R.

    2004-05-01

    According to sizes dictated by ITRS road map, contact holes are one of the most challenging features to be printed in the semiconductor manufacturing process. The development of 90[nm] technology FLASH memories requires a robust solution for printing contact holes down to 100[nm] on 200[nm] pitch. The delay of NGL development as well as open issues related to 157[nm] scanner introduction pushes the industry to find a solution for printing such tight features using existing ArF scanner. IDEALSmile technology from Canon was proven to be a good candidate for achieving such high resolution with sufficiently large through pitch process window using a binary mask, relatively simple to be manufactured, with a modified illumination and single exposure, with no impact on throughput and without any increase of cost of ownership. This paper analyses main issues related to the introduction of this new resolution enhancement technology on a real FLASH memory device, highlighting advantages as well as known problems still under investigation.

  14. Asymmetric programming: a highly reliable metadata allocation strategy for MLC NAND flash memory-based sensor systems.

    PubMed

    Huang, Min; Liu, Zhaoqing; Qiao, Liyan

    2014-01-01

    While the NAND flash memory is widely used as the storage medium in modern sensor systems, the aggressive shrinking of process geometry and an increase in the number of bits stored in each memory cell will inevitably degrade the reliability of NAND flash memory. In particular, it's critical to enhance metadata reliability, which occupies only a small portion of the storage space, but maintains the critical information of the file system and the address translations of the storage system. Metadata damage will cause the system to crash or a large amount of data to be lost. This paper presents Asymmetric Programming, a highly reliable metadata allocation strategy for MLC NAND flash memory storage systems. Our technique exploits for the first time the property of the multi-page architecture of MLC NAND flash memory to improve the reliability of metadata. The basic idea is to keep metadata in most significant bit (MSB) pages which are more reliable than least significant bit (LSB) pages. Thus, we can achieve relatively low bit error rates for metadata. Based on this idea, we propose two strategies to optimize address mapping and garbage collection. We have implemented Asymmetric Programming on a real hardware platform. The experimental results show that Asymmetric Programming can achieve a reduction in the number of page errors of up to 99.05% with the baseline error correction scheme.

  15. Asymmetric programming: a highly reliable metadata allocation strategy for MLC NAND flash memory-based sensor systems.

    PubMed

    Huang, Min; Liu, Zhaoqing; Qiao, Liyan

    2014-01-01

    While the NAND flash memory is widely used as the storage medium in modern sensor systems, the aggressive shrinking of process geometry and an increase in the number of bits stored in each memory cell will inevitably degrade the reliability of NAND flash memory. In particular, it's critical to enhance metadata reliability, which occupies only a small portion of the storage space, but maintains the critical information of the file system and the address translations of the storage system. Metadata damage will cause the system to crash or a large amount of data to be lost. This paper presents Asymmetric Programming, a highly reliable metadata allocation strategy for MLC NAND flash memory storage systems. Our technique exploits for the first time the property of the multi-page architecture of MLC NAND flash memory to improve the reliability of metadata. The basic idea is to keep metadata in most significant bit (MSB) pages which are more reliable than least significant bit (LSB) pages. Thus, we can achieve relatively low bit error rates for metadata. Based on this idea, we propose two strategies to optimize address mapping and garbage collection. We have implemented Asymmetric Programming on a real hardware platform. The experimental results show that Asymmetric Programming can achieve a reduction in the number of page errors of up to 99.05% with the baseline error correction scheme. PMID:25310473

  16. PIYAS-proceeding to intelligent service oriented memory allocation for flash based data centric sensor devices in wireless sensor networks.

    PubMed

    Rizvi, Sanam Shahla; Chung, Tae-Sun

    2010-01-01

    Flash memory has become a more widespread storage medium for modern wireless devices because of its effective characteristics like non-volatility, small size, light weight, fast access speed, shock resistance, high reliability and low power consumption. Sensor nodes are highly resource constrained in terms of limited processing speed, runtime memory, persistent storage, communication bandwidth and finite energy. Therefore, for wireless sensor networks supporting sense, store, merge and send schemes, an efficient and reliable file system is highly required with consideration of sensor node constraints. In this paper, we propose a novel log structured external NAND flash memory based file system, called Proceeding to Intelligent service oriented memorY Allocation for flash based data centric Sensor devices in wireless sensor networks (PIYAS). This is the extended version of our previously proposed PIYA [1]. The main goals of the PIYAS scheme are to achieve instant mounting and reduced SRAM space by keeping memory mapping information to a very low size of and to provide high query response throughput by allocation of memory to the sensor data by network business rules. The scheme intelligently samples and stores the raw data and provides high in-network data availability by keeping the aggregate data for a longer period of time than any other scheme has done before. We propose effective garbage collection and wear-leveling schemes as well. The experimental results show that PIYAS is an optimized memory management scheme allowing high performance for wireless sensor networks.

  17. PIYAS-Proceeding to Intelligent Service Oriented Memory Allocation for Flash Based Data Centric Sensor Devices in Wireless Sensor Networks

    PubMed Central

    Rizvi, Sanam Shahla; Chung, Tae-Sun

    2010-01-01

    Flash memory has become a more widespread storage medium for modern wireless devices because of its effective characteristics like non-volatility, small size, light weight, fast access speed, shock resistance, high reliability and low power consumption. Sensor nodes are highly resource constrained in terms of limited processing speed, runtime memory, persistent storage, communication bandwidth and finite energy. Therefore, for wireless sensor networks supporting sense, store, merge and send schemes, an efficient and reliable file system is highly required with consideration of sensor node constraints. In this paper, we propose a novel log structured external NAND flash memory based file system, called Proceeding to Intelligent service oriented memorY Allocation for flash based data centric Sensor devices in wireless sensor networks (PIYAS). This is the extended version of our previously proposed PIYA [1]. The main goals of the PIYAS scheme are to achieve instant mounting and reduced SRAM space by keeping memory mapping information to a very low size of and to provide high query response throughput by allocation of memory to the sensor data by network business rules. The scheme intelligently samples and stores the raw data and provides high in-network data availability by keeping the aggregate data for a longer period of time than any other scheme has done before. We propose effective garbage collection and wear-leveling schemes as well. The experimental results show that PIYAS is an optimized memory management scheme allowing high performance for wireless sensor networks. PMID:22315541

  18. PIYAS-proceeding to intelligent service oriented memory allocation for flash based data centric sensor devices in wireless sensor networks.

    PubMed

    Rizvi, Sanam Shahla; Chung, Tae-Sun

    2010-01-01

    Flash memory has become a more widespread storage medium for modern wireless devices because of its effective characteristics like non-volatility, small size, light weight, fast access speed, shock resistance, high reliability and low power consumption. Sensor nodes are highly resource constrained in terms of limited processing speed, runtime memory, persistent storage, communication bandwidth and finite energy. Therefore, for wireless sensor networks supporting sense, store, merge and send schemes, an efficient and reliable file system is highly required with consideration of sensor node constraints. In this paper, we propose a novel log structured external NAND flash memory based file system, called Proceeding to Intelligent service oriented memorY Allocation for flash based data centric Sensor devices in wireless sensor networks (PIYAS). This is the extended version of our previously proposed PIYA [1]. The main goals of the PIYAS scheme are to achieve instant mounting and reduced SRAM space by keeping memory mapping information to a very low size of and to provide high query response throughput by allocation of memory to the sensor data by network business rules. The scheme intelligently samples and stores the raw data and provides high in-network data availability by keeping the aggregate data for a longer period of time than any other scheme has done before. We propose effective garbage collection and wear-leveling schemes as well. The experimental results show that PIYAS is an optimized memory management scheme allowing high performance for wireless sensor networks. PMID:22315541

  19. 76 FR 25707 - In the Matter of Certain Flash Memory and Products Containing Same; Notice of Commission Decision...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-05

    ... Electronics Co. (``Samsung'') of Suwon City, South Korea on August 21, 2009. 74 FR 45469 (Sept. 2, 2009). The... 21, 2005, 70 FR 43251 (July 26, 2005). During this period, the subject articles would be entitled to... COMMISSION In the Matter of Certain Flash Memory and Products Containing Same; Notice of Commission...

  20. 75 FR 82071 - In the Matter of Certain Flash Memory Chips and Products Containing Same; Notice of Commission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-29

    .... and Spansion LLC both of Sunnyvale, California (collectively, ``Spansion''). 73 FR 77059-061 (Dec. 18... terminate several respondents from the investigation and to add certain entities as respondents. 75 FR 11909... COMMISSION In the Matter of Certain Flash Memory Chips and Products Containing Same; Notice of...

  1. 76 FR 13207 - In the Matter of Certain Flash Memory and Products Containing Same Notice of Request for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-10

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION In the Matter of Certain Flash Memory and Products Containing Same Notice of Request for Statements on the Public Interest Section 337 of the Tariff Act of 1930 provides that if the Commission...

  2. Tunneling current modulation by Ge incorporation into Si oxide films for flash memory applications

    SciTech Connect

    Ito, Toshihide; Mitani, Yuuichiro; Nakasaki, Yasushi; Koike, Masahiro; Konno, Takuya; Matsuba, Hiroshi; Kai, Tetsuya; Kaneko, Wakana; Ozawa, Yoshio

    2012-02-13

    Current-voltage characteristic for a Ge-incorporated Si oxide was investigated. Current enhancement was observed for the electric field larger than 10 MV/cm. Such a current enhancement only under high electric field is expected to improve programming performance without deteriorating reading performance. From secondary ion mass spectrometry and hard x-ray photoelectron spectroscopy analyses and current simulation, it is concluded that the Ge impurity in Ge{sup 4+} state around the tunnel oxide/substrate interface enhances the current by trap-assisted tunneling. The programming current enhancement induced by the Ge incorporation is expected to be one of the promising solutions for the next-generation flash memory.

  3. Effect with high density nano dot type storage layer structure on 20 nm planar NAND flash memory characteristics

    NASA Astrophysics Data System (ADS)

    Sasaki, Takeshi; Muraguchi, Masakazu; Seo, Moon-Sik; Park, Sung-kye; Endoh, Tetsuo

    2014-01-01

    The merits, concerns and design principle for the future nano dot (ND) type NAND flash memory cell are clarified, by considering the effect of storage layer structure on NAND flash memory characteristics. The characteristics of the ND cell for a NAND flash memory in comparison with the floating gate type (FG) is comprehensively studied through the read, erase, program operation, and the cell to cell interference with device simulation. Although the degradation of the read throughput (0.7% reduction of the cell current) and slower program time (26% smaller programmed threshold voltage shift) with high density (10 × 1012 cm-2) ND NAND are still concerned, the suppress of the cell to cell interference with high density (10 × 1012 cm-2) plays the most important part for scaling and multi-level cell (MLC) operation in comparison with the FG NAND. From these results, the design knowledge is shown to require the control of the number of nano dots rather than the higher nano dot density, from the viewpoint of increasing its memory capacity by MLC operation and suppressing threshold voltage variability caused by the number of dots in the storage layer. Moreover, in order to increase its memory capacity, it is shown the tunnel oxide thickness with ND should be designed thicker (>3 nm) than conventional designed ND cell for programming/erasing with direct tunneling mechanism.

  4. [Hypofractionation in locally advanced breast cancer: "flash" scheme].

    PubMed

    Padilha, Marisa; Gonçalves, Sara; Fardilha, Carlos; Melo, Gilberto; Miranda, Cristina; Alves, Paula

    2013-01-01

    de 68,7% (57 doentes), em quatro anos. Dez doentes (12%) morreram por progressão da doença ou persistência tumoral Em 42 doentes (50,6%) não se verificaram evidência ou progressão de doença e três doentes (3,6%) apresentaram melhoria clínica. Conclusões:O “Flash Mamário” é uma modalidade de tratamento segura, relativamente aos efeitos secundários, e opção terapêutica válida para doentes idosos ou com baixo Performance Status, com o diagnóstico de carcinoma localmente avançado ou estádio IIb ou IV, a título neoadjuvante ou paliativo. Há menor risco de recidiva/progressão, nos doentes com melhor estado geral, sendo a taxa de sobrevivência global maior.

  5. Defect reduction for semiconductor memory applications using jet and flash imprint lithography

    NASA Astrophysics Data System (ADS)

    Ye, Zhengmao; Luo, Kang; Irving, J. W.; Lu, Xiaoming; Zhang, Wei; Fletcher, Brian; Liu, Weijun; Xu, Frank; LaBrake, Dwayne; Resnick, Douglas; Sreenivasan, S. V.

    2013-03-01

    Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Jet and Flash Imprint Lithography (J-FIL) involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed leaving a patterned resist on the substrate. Acceptance of imprint lithography for manufacturing will require demonstration that it can attain defect levels commensurate with the defect specifications of high end memory devices. Typical defectivity targets are on the order of 0.10/cm2. In previous studies, we have focused on defects such as random non-fill defects occurring during the resist filling process and repeater defects caused by interactions with particles on the substrate. In this work, we attempted to identify the critical imprint defect types using a mask with NAND Flash-like patterns at dimensions as small as 26nm. The two key defect types identified were line break defects induced by small particulates and airborne contaminants which result in local adhesion failure. After identification, the root cause of the defect was determined, and corrective measures were taken to either eliminate or reduce the defect source. As a result, we have been able to reduce defectivity levels by more than three orders of magnitude in only 12 months and are now achieving defectivity adders as small as 2 adders per lot of wafers.

  6. 64 kbit Ferroelectric-Gate-Transistor-Integrated NAND Flash Memory with 7.5 V Program and Long Data Retention

    NASA Astrophysics Data System (ADS)

    Zhang, Xizhen; Takahashi, Mitsue; Takeuchi, Ken; Sakai, Shigeki

    2012-04-01

    A 64 kbit (kb) one-transistor-type ferroelectric memory array was fabricated and characterized. Pt/SrBi2Ta2O9/Hf-Al-O/Si ferroelectric-gate field-effect transistors (FeFETs) were used as the memory cells. The gate length and width were 5 and 5 µm, respectively. The array design was based on NAND flash memory organized as 8 word lines × 32 blocks × 256 bit lines. Erase, program, and nondestructive-read operations were demonstrated in every block. Threshold-voltage (Vth) reading of all the 64 kb memory cells showed a clear separation between their all-erased and all-programmed states. A checkerboard pattern was also programmed in a block and the two distinguishable Vth distributions were read out. The Vth retention of a block of 2 kb memory cells showed no significant degradation after two days.

  7. Investigation of Hafnium oxide/Copper resistive memory for advanced encryption applications

    NASA Astrophysics Data System (ADS)

    Beland, Laurent Karim

    The Advanced Encryption Standard (AES) is a widely used encryption algorithm to protect data and communications in today's digital age. Modern AES CMOS implementations require large amounts of dedicated logic and must be tuned for either performance or power consumption. A high throughput, low power, and low die area AES implementation is required in the growing mobile sector. An emerging non-volatile memory device known as resistive memory (ReRAM) is a simple metal-insulator-metal capacitor device structure with the ability to switch between two stable resistance states. Currently, ReRAM is targeted as a non-volatile memory replacement technology to eventually replace flash. Its advantages over flash include ease of fabrication, speed, and lower power consumption. In addition to memory, ReRAM can also be used in advanced logic implementations given its purely resistive behavior. The combination of a new non-volatile memory element ReRAM along with high performance, low power CMOS opens new avenues for logic implementations. This dissertation will cover the design and process implementation of a ReRAM-CMOS hybrid circuit, built using IBM's 10LPe process, for the improvement of hardware AES implementations. Further the device characteristics of ReRAM, specifically the HfO2/Cu memory system, and mechanisms for operation are not fully correlated. Of particular interest to this work is the role of material properties such as the stoichiometry, crystallinity, and doping of the HfO2 layer and their effect on the switching characteristics of resistive memory. Material properties were varied by a combination of atomic layer deposition and reactive sputtering of the HfO2 layer. Several studies will be discussed on how the above mentioned material properties influence switching parameters, and change the underlying physics of device operation.

  8. Active Flash: Performance-Energy Tradeoffs for Out-of-Core Processing on Non-Volatile Memory Devices

    SciTech Connect

    Boboila, Simona; Kim, Youngjae; Vazhkudai, Sudharshan S; Desnoyers, Peter; Shipman, Galen M

    2012-01-01

    In this abstract, we study the performance and energy tradeoffs involved in migrating data analysis into the flash device, a process we refer to as Active Flash. The Active Flash paradigm is similar to 'active disks', which has received considerable attention. Active Flash allows us to move processing closer to data, thereby minimizing data movement costs and reducing power consumption. It enables true out-of-core computation. The conventional definition of out-of-core solvers refers to an approach to process data that is too large to fit in the main memory and, consequently, requires access to disk. However, in Active Flash, processing outside the host CPU literally frees the core and achieves real 'out-of-core' analysis. Moving analysis to data has long been desirable, not just at this level, but at all levels of the system hierarchy. However, this requires a detailed study on the tradeoffs involved in achieving analysis turnaround under an acceptable energy envelope. To this end, we first need to evaluate if there is enough computing power on the flash device to warrant such an exploration. Flash processors require decent computing power to run the internal logic pertaining to the Flash Translation Layer (FTL), which is responsible for operations such as address translation, garbage collection (GC) and wear-leveling. Modern SSDs are composed of multiple packages and several flash chips within a package. The packages are connected using multiple I/O channels to offer high I/O bandwidth. SSD computing power is also expected to be high enough to exploit such inherent internal parallelism within the drive to increase the bandwidth and to handle fast I/O requests. More recently, SSD devices are being equipped with powerful processing units and are even embedded with multicore CPUs (e.g. ARM Cortex-A9 embedded processor is advertised to reach 2GHz frequency and deliver 5000 DMIPS; OCZ RevoDrive X2 SSD has 4 SandForce controllers, each with 780MHz max frequency

  9. A high efficiency all-PMOS charge pump for 3D NAND flash memory

    NASA Astrophysics Data System (ADS)

    Liyin, Fu; Yu, Wang; Qi, Wang; Zongliang, Huo

    2016-07-01

    For 3D vertical NAND flash memory, the charge pump output load is much larger than that of the planar NAND, resulting in the performance degradation of the conventional Dickson charge pump. Therefore, a novel all PMOS charge pump with high voltage boosting efficiency, large driving capability and high power efficiency for 3D V-NAND has been proposed. In this circuit, the Pelliconi structure is used to enhance the driving capability, two auxiliary substrate bias PMOS transistors are added to mitigate the body effect, and the degradation of the output voltage and boost efficiency caused by the threshold voltage drop is eliminated by dynamic gate control structure. Simulated results show that the proposed charge pump circuit can achieve the maximum boost efficiency of 86% and power efficiency of 50%. The output voltage of the proposed 9 stages charge pump can exceed 2 V under 2 MHz clock frequency in 2X nm 3D V-NAND technology. Our results provide guidance for the peripheral circuit design of high density 3D V-NAND integration.

  10. Impact of the array background pattern on cycling-induced threshold-voltage instabilities in nanoscale NAND Flash memories

    NASA Astrophysics Data System (ADS)

    Paolucci, G. M.; Bertuccio, M.; Monzio Compagnoni, C.; Beltrami, S.; Spinelli, A. S.; Lacaita, A. L.; Visconti, A.

    2015-11-01

    This paper highlights that cycling-induced threshold-voltage instabilities in nanoscale NAND Flash technologies display a non-negligible dependence on the background pattern of the memory array during idle/bake periods. Experimental results clearly reveal, in fact, that instabilities in a (victim) cell do not depend only on its memory state, but also on the memory state of its first neighboring (aggressor) cells. The magnitude of this new cell-to-cell interference effect, moreover, appears to depend on the memory state of the victim cell, decreasing with the increase of its threshold-voltage level. From all of the gathered experimental evidence a physical picture explaining the phenomenon is provided, which is, finally, confirmed with the help of numerical simulations.

  11. Electrical degradation mechanisms of nanoscale charge trap flash memories due to trapped charge in the oxide layer

    NASA Astrophysics Data System (ADS)

    Koh, Kyoung Wook; Kim, Dong Hun; Ryu, Ju Tae; Kim, Tae Whan; Yoo, Keon-Ho

    2015-08-01

    The deterioration of the electrical characteristics of charge trap flash (CTF) memories with a silicon-oxide-nitride-oxide-silicon (SONOS) structure due to the charge traps in the oxide layers attributed to the random trapping and detrapping processes was investigated. Simulation results for the CTF memories showed that the threshold voltage shift was decreased by the charge trapped in the oxide layers in the SONOS structure and that the charge trapped in the blocking oxide had more significant effects than that trapped in the tunneling oxide. The degradation effects of the charge trapped in the blocking oxide on the electrical characteristics of the CTF memories were clarified by examining the vertical electric field in the device.

  12. Advances in shape-memory polymer actuation

    NASA Astrophysics Data System (ADS)

    Leng, Jinsong; Liu, Yanju; Lan, Xin

    2009-03-01

    Shape memory polymer (SMP) is a promising smart material, which is able to perform a large deformation upon applying an external stimulus, such as heat, light and moisture, etc. In recent years, many investigations have been advanced in thermo-responsive SMP actuation, and several novel actuations have been applied in SMP. In this paper, the mechanism and demonstration of three types of SMP actuations (infrared laser, physical swelling effect and electricity) are presented. These novel actuation approaches may help SMP to fully reach its potential application. Firstly, for the infrared laser-activated SMP, it is concerned about the drive of SMP by infrared light. The infrared laser, transmitted through the optical fiber embedded in the SMP matrix, was chosen to drive the SMP. The working frequency of infrared laser was installed in 3-4μm. Moreover, this paper presents a study on the effects of solution on the glass transition temperature (Tg). It shows that the hydrogen bonding of SMP was aroused by the absorbed solution that significantly reduces transition temperature of polymer. In this way, the shape memory effect (SME) can undergo solution-driven shape recovery. Finally, the actuation of two types of electro-active SMP composites filled with electrically conductive powders (carbon black, nickel powers) have been carried out, and the SMP composite can be driven by applying a relatively low voltage.

  13. Dependence of Grain Size on the Performance of a Polysilicon Channel TFT for 3D NAND Flash Memory.

    PubMed

    Kim, Seung-Yoon; Park, Jong Kyung; Hwang, Wan Sik; Lee, Seung-Jun; Lee, Ki-Hong; Pyi, Seung Ho; Cho, Byung Jin

    2016-05-01

    We investigated the dependence of grain size on the performance of a polycrystalline silicon (poly-Si) channel TFT for application to 3D NAND Flash memory devices. It has been found that the device performance and memory characteristics are strongly affected by the grain size of the poly-Si channel. Higher on-state current, faster program speed, and poor endurance/reliability properties are observed when the poly-Si grain size is large. These are mainly attributed to the different local electric field induced by an oxide valley at the interface between the poly-Si channel and the gate oxide. In addition, the trap density at the gate oxide interface was successfully measured using a charge pumping method by the separation between the gate oxide interface traps and traps at the grain boundaries in the poly-Si channel. The poly-Si channel with larger grain size has lower interface trap density. PMID:27483868

  14. Two-dimensional molybdenum disulphide nanosheet-covered metal nanoparticle array as a floating gate in multi-functional flash memories.

    PubMed

    Han, Su-Ting; Zhou, Ye; Chen, Bo; Zhou, Li; Yan, Yan; Zhang, Hua; Roy, V A L

    2015-11-01

    Semiconducting two-dimensional materials appear to be excellent candidates for non-volatile memory applications. However, the limited controllability of charge trapping behaviors and the lack of multi-bit storage studies in two-dimensional based memory devices require further improvement for realistic applications. Here, we report a flash memory consisting of metal NPs-molybdenum disulphide (MoS2) as a floating gate by introducing a metal nanoparticle (NP) (Ag, Au, Pt) monolayer underneath the MoS2 nanosheets. Controlled charge trapping and long data retention have been achieved in a metal (Ag, Au, Pt) NPs-MoS2 floating gate flash memory. This controlled charge trapping is hypothesized to be attributed to band bending and a built-in electric field ξbi between the interface of the metal NPs and MoS2. The metal NPs-MoS2 floating gate flash memories were further proven to be multi-bit memory storage devices possessing a 3-bit storage capability and a good retention capability up to 10(4) s. We anticipate that these findings would provide scientific insight for the development of novel memory devices utilizing an atomically thin two-dimensional lattice structure.

  15. A 72% error reduction scheme based on temperature acceleration for long-term data storage applications: Cold flash and millennium memories

    NASA Astrophysics Data System (ADS)

    Yamazaki, Senju; Iwasaki, Tomoko Ogura; Hachiya, Shogo; Takahashi, Tomonori; Takeuchi, Ken

    2016-07-01

    A solid-state drive (SSD) with 1Xnm triple-level cell (TLC) NAND flash is proposed for low cost data storage applications with long-term data-retention requirements. Specifically, cold data storage requires 20 years data-retention with 100 write/erase (W/E) cycles, whereas digital archive storage requires 1000 years retention time with 1 W/E cycle. To achieve these requirements, a flexible-nLC scheme is proposed to improve the reliability of 1Xnm TLC NAND flash (Yamazaki et al., 2015). The proposed scheme combines two schemes, n-out-of-8 level cell (nLC) (Tanakamaru et al., 2014) and asymmetric coding (AC) (Tanakamaru et al., 2012) with the addition of a vertical flag. By measuring 1Xnm TLC NAND flash memory, the proposed scheme reduces errors by 72% and 69% for digital archive and cold flash respectively, compared to the conventional nLC scheme.

  16. Droplet evaporation-induced ferritin self-assembled monolayer as a template for nanocrystal flash memory

    NASA Astrophysics Data System (ADS)

    Kwon, Moonjae; Choi, Hyejung; Chang, Man; Jo, Minseok; Jung, Seung-Jae; Hwang, Hyunsang

    2007-05-01

    A nonvolatile nanocrystal (NC) memory containing a ferritin core was fabricated. A ferritin monolayer was formed through a droplet evaporation technique. High-pressure hydrogen (HP-H2) annealing effectively reduced iron oxide (Fe2O3) to form conductive iron NC. In addition, HP-H2 annealing also improved memory characteristics by passivation of the interface states at Si /HfO2. The authors observed good memory characteristics, including fast program/erase (P/E) operation, a memory window of 1.75V under ±6V, and a stable memory window up to 104s at 85°C.

  17. Advances in digital memory telemeters for artillery projectiles

    NASA Astrophysics Data System (ADS)

    Szabo, L. R.; Osborne, W. I.

    The purpose of this paper is to review the progress currently being made in the semiconductor field and how these recent advances can be utilized in digital memory telemeters for gathering data from various artillery projectiles. Topics to be presented include: basic design considerations, high-g packaging techniques, and the high-g hardening of critical electronic components. In addition, a prototype memory telemeter, which is under development for ARDC's 155mm Ballistic Simulator, and the firing data it has recorded to date are discussed. Finally, a look at future advances in IC technology and its impact on digital memory telemeters is presented.

  18. A Hierarchical Statistic Methodology for Advanced Memory System Evaluation

    SciTech Connect

    Sun, X.-J.; He, D.; Cameron, K.W.; Luo, Y.

    1999-04-12

    Advances in technology have resulted in a widening of the gap between computing speed and memory access time. Data access time has become increasingly important for computer system design. Various hierarchical memory architectures have been developed. The performance of these advanced memory systems, however, varies with applications and problem sizes. How to reach an optimal cost/performance design eludes researchers still. In this study, the authors introduce an evaluation methodology for advanced memory systems. This methodology is based on statistical factorial analysis and performance scalability analysis. It is two fold: it first determines the impact of memory systems and application programs toward overall performance; it also identifies the bottleneck in a memory hierarchy and provides cost/performance comparisons via scalability analysis. Different memory systems can be compared in terms of mean performance or scalability over a range of codes and problem sizes. Experimental testing has been performed extensively on the Department of Energy's Accelerated Strategic Computing Initiative (ASCI) machines and benchmarks available at the Los Alamos National Laboratory to validate this newly proposed methodology. Experimental and analytical results show this methodology is simple and effective. It is a practical tool for memory system evaluation and design. Its extension to general architectural evaluation and parallel computer systems are possible and should be further explored.

  19. Non-Volatile Flash Memory Characteristics of Tetralayer Nickel-Germanide Nanocrystals Embedded Structure.

    PubMed

    Panda, D; Panda, M

    2016-01-01

    Formation of tetralayer memory structure having nickel-germanide nanocrystals using a Ge/Ni multilayers is proposed. X-ray diffraction study shows the NiGe (002) phase formation after proper annealing. Cross sectional HRTEM clearly shows the sharpness and the size (~4-6 nm) of the stacked nanocrystals embedded in the oxide matrix. A large anti-clockwise hysteresis memory win- dow of 13.4 Volt at ± 15 Volt is observed for the optimized samples. This large memory window indicates for the MLC applications. Frequency independent C-V curve confirms about the charge storage in the nanocrystals. A good charge retention and endurance characteristics are exhibited upto 125 °C for the nonvolatile memory application. PMID:27398590

  20. Number of traps and trap depth position on statistical distribution of random telegraph noise in scaled NAND flash memory

    NASA Astrophysics Data System (ADS)

    Tomita, Toshihiro; Miyaji, Kousuke

    2016-04-01

    The dependence of random telegraph noise (RTN) amplitude distribution on the number of traps and trap depth position is investigated using three-dimensional Monte Carlo device simulation including random dopant fluctuation (RDF) in a 30 nm NAND multi level flash memory. The ΔV th tail distribution becomes broad at fixed double traps, indicating that the number of traps greatly affects the worst RTN characteristics. It is also found that for both fixed single and fixed double traps, the ΔV th distribution in the lowest cell threshold voltage (V th) state shows the broadest distribution among all cell V th states. This is because the drain current flows at the channel surface in the lowest cell V th state, while at a high cell V th, it flows at the deeper position owing to the fringing coupling between the control gate (CG) and the channel. In this work, the ΔV th distribution with the number of traps following the Poisson distribution is also considered to cope with the variations in trap number. As a result, it is found that the number of traps is an important factor for understanding RTN characteristics. In addition, considering trap position in the tunnel oxide thickness direction is also an important factor.

  1. High throughput Jet and Flash Imprint Lithography for semiconductor memory applications

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Fletcher, Brian; Thompson, Ecron; Liu, Weijun; Stachowiak, Tim; Khusnatdinov, Niyaz; Irving, J. W.; Longsine, Whitney; Traub, Matthew; Truskett, Van; LaBrake, Dwayne; Ye, Zhengmao

    2016-03-01

    Imprint lithography has been shown to be an effective technique for replication of nano-scale features. Jet and Flash* Imprint Lithography (J-FIL*) involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed, leaving a patterned resist on the substrate. There are two critical components to meeting throughput requirements for imprint lithography. Using a similar approach to what is already done for many deposition and etch processes, imprint stations can be clustered to enhance throughput. The FPA-1200NZ2C is a four station cluster system designed for high volume manufacturing. For a single station, throughput includes overhead, resist dispense, resist fill time (or spread time), exposure and separation. Resist exposure time and mask/wafer separation are well understood processing steps with typical durations on the order of 0.10 to 0.20 seconds. To achieve a total process throughput of 15 wafers per hour (wph) for a single station, it is necessary to complete the fluid fill step in 1.5 seconds. For a throughput of 20 wph, fill time must be reduced to only one second. There are several parameters that can impact resist filling. Key parameters include resist drop volume (smaller is better), system controls (which address drop spreading after jetting), Design for Imprint or DFI (to accelerate drop spreading) and material engineering (to promote wetting between the resist and underlying adhesion layer). In addition, it is mandatory to maintain fast filling, even for edge field imprinting. In this paper, we address the improvements made in all of these parameters to enable a 1.50 second filling process for a sub-20nm device like pattern and have demonstrated this capability

  2. Defect reduction for semiconductor memory applications using jet and flash imprint lithography

    NASA Astrophysics Data System (ADS)

    Ye, Zhengmao; Luo, Kang; Lu, Xiaoming; Fletcher, Brian; Liu, Weijun; Xu, Frank; LaBrake, Dwayne; Resnick, Douglas J.; Sreenivasan, S. V.

    2012-07-01

    Acceptance of imprint lithography for manufacturing will require demonstration that it can attain defect levels commensurate with the defect specifications of high-end memory devices. Defects occurring during imprinting can generally be broken into two categories; random defects and repeating defects. Examples of random defects include fluid phase imprint defects, such as bubbles, and solid phase imprint defects, such as line collapse. Examples of repeater defects include mask fabrication defects and particle induced defects. Previous studies indicated that soft particles cause nonrepeating defects. Hard particles, on the other hand, can cause either permanent resist plugging or mask damage. In a previous study, two specific defect types were examined; random nonfill defects occurring during the resist filling process and repeater defects caused by interactions with particles on the substrate. We attempted to identify the different types of imprint defect types using a mask with line/space patterns at dimensions as small as 26 nm. An Imprio 500 twenty-wafer per hour development tool was used to study the various defect types. The imprint defect density was reduced nearly four orders of magnitude, down to ˜4/cm2 in a period of two years following the availability of low defect imprint masks at 26-nm half-pitch. This reduction was achieved by identifying the root cause of various defects and then taking the appropriate corrective action.

  3. Technical Note: Advances in flash flood monitoring using unmanned aerial vehicles (UAVs)

    NASA Astrophysics Data System (ADS)

    Perks, Matthew T.; Russell, Andrew J.; Large, Andrew R. G.

    2016-10-01

    Unmanned aerial vehicles (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 phenomena 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, utilizing 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 to 0.13 m. The application of this approach to assess the hydraulic conditions present in the Alyth Burn, Scotland, during a 1 : 200 year flash flood resulted in the generation of an average 4.2 at a rate of 508 measurements s-1. Analysis of these vectors provides 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 ±0.15 m s-1. Little difference is observed in the uncertainty attached to out-of-bank velocities (±0.15 m s-1), and within-channel velocities (±0.16 m s-1), illustrating the consistency of the approach.

  4. Human sensory-evoked responses differ coincident with either "fusion-memory" or "flash-memory", as shown by stimulus repetition-rate effects

    PubMed Central

    Jewett, Don L; Hart, Toryalai; Larson-Prior, Linda J; Baird, Bill; Olson, Marram; Trumpis, Michael; Makayed, Katherine; Bavafa, Payam

    2006-01-01

    Background: A new method has been used to obtain human sensory evoked-responses whose time-domain waveforms have been undetectable by previous methods. These newly discovered evoked-responses have durations that exceed the time between the stimuli in a continuous stream, thus causing an overlap which, up to now, has prevented their detection. We have named them "A-waves", and added a prefix to show the sensory system from which the responses were obtained (visA-waves, audA-waves, somA-waves). Results: When A-waves were studied as a function of stimulus repetition-rate, it was found that there were systematic differences in waveshape at repetition-rates above and below the psychophysical region in which the sensation of individual stimuli fuse into a continuity. The fusion phenomena is sometimes measured by a "Critical Fusion Frequency", but for this research we can only identify a frequency-region [which we call the STZ (Sensation-Transition Zone)]. Thus, the A-waves above the STZ differed from those below the STZ, as did the sensations. Study of the psychophysical differences in auditory and visual stimuli, as shown in this paper, suggest that different stimulus features are detected, and remembered, at stimulation rates above and below STZ. Conclusion: The results motivate us to speculate that: 1) Stimulus repetition-rates above the STZ generate waveforms which underlie "fusion-memory" whereas rates below the STZ show neuronal processing in which "flash-memory" occurs. 2) These two memories differ in both duration and mechanism, though they may occur in the same cell groups. 3) The differences in neuronal processing may be related to "figure" and "ground" differentiation. We conclude that A-waves provide a novel measure of neural processes that can be detected on the human scalp, and speculate that they may extend clinical applications of evoked response recordings. If A-waves also occur in animals, it is likely that A-waves will provide new methods for

  5. Two-Bit/Cell Programming Characteristics of High-Density NOR-Type Flash Memory Device with Recessed Channel Structure and Spacer-Type Nitride Layer

    NASA Astrophysics Data System (ADS)

    Han, Kyoung-Rok; Lee, Jong-Ho

    2006-10-01

    The structure of novel 2-bit/cell silicon-oxide-nitride-oxide-silicon (SONOS) flash memory device was proposed and characterized for sub-50 nm non-volatile memory (NVM) technology. A proposed memory cell has spacer-type storage nodes on both sidewalls in a recessed channel region. It was shown that counter channel doping near the bottom of the recessed channel is very important and can improve the Vth margin for 2-bit/cell operation by ˜2.5 times. By controlling doping profiles of the channel doping and the counter channel doping in the recessed channel region, we could obtain the Vth margin more than ˜1.5 V.

  6. Hybrid inverse lithography techniques for advanced hierarchical memories

    NASA Astrophysics Data System (ADS)

    Xiao, Guangming; Hooker, Kevin; Irby, Dave; Zhang, Yunqiang; Ward, Brian; Cecil, Tom; Hall, Brett; Lee, Mindy; Kim, Dave; Lucas, Kevin

    2014-03-01

    greatly improve the ability of ILT to optimize advanced embedded memory designs while retaining significant hierarchy and cell design symmetry, therefore, have good turnaround time and CD uniformity. This paper will explain the enhancements which have been developed in order to overcome the traditional difficulties listed above. These enhancements are in the categories of local CD control, global chip processing options, process window benefit, turn-around time and hierarchy retention.

  7. Polarization control for enhanced defect detection on advanced memory devices

    NASA Astrophysics Data System (ADS)

    Lee, Byoung-Ho; Ihm, Dong-Chul; Yeo, Jeong-Ho; Gluk, Yael; Meshulach, Doron

    2006-03-01

    Dense repetitive wafer structures, such as memory cells, with a pitch below the wavelength of the illumination light may take on effective birefringent properties, especially in layers of high refractive index materials such as silicon or conductors. Such induced "form birefringence" effects may result in dependency of the optical response on the illumination polarization and direction. In such structures, control over the polarization of the light becomes important to enhance signal-to-noise ratio (SNR) of pattern defects. We present defect detection results and analysis using DUV laser illumination for different polarization configurations and collection perspectives on Flash RAM devices. Improvement in detection SNR of bridge defect type is observed with linear illumination polarization perpendicular to the pattern lines. Generally, for small design rules (smaller than wavelength) polarization effects become more evident. Also, for smaller defect sizes, detection strongly depends on control of the illumination polarization. Linear polarization perpendicular to the pattern showed penetration into the structure even though the pitch is smaller than the illumination wavelength.

  8. Overview of emerging nonvolatile memory technologies.

    PubMed

    Meena, Jagan Singh; Sze, Simon Min; Chand, Umesh; Tseng, Tseung-Yuen

    2014-01-01

    class of memory technologies and scaling of scientific procedures based on an investigation of recent progress in advanced Flash memory devices. PMID:25278820

  9. Overview of emerging nonvolatile memory technologies

    PubMed Central

    2014-01-01

    class of memory technologies and scaling of scientific procedures based on an investigation of recent progress in advanced Flash memory devices. PMID:25278820

  10. Electron-Beam Dynamics for an Advanced Flash-Radiography Accelerator

    SciTech Connect

    Ekdahl, Carl

    2015-11-17

    Beam dynamics issues were assessed for a new linear induction electron accelerator being designed for multipulse flash radiography of large explosively driven hydrodynamic experiments. Special attention was paid to equilibrium beam transport, possible emittance growth, and beam stability. Especially problematic would be high-frequency beam instabilities that could blur individual radiographic source spots, low-frequency beam motion that could cause pulse-to-pulse spot displacement, and emittance growth that could enlarge the source spots. Furthermore, beam physics issues were examined through theoretical analysis and computer simulations, including particle-in-cell codes. Beam instabilities investigated included beam breakup, image displacement, diocotron, parametric envelope, ion hose, and the resistive wall instability. The beam corkscrew motion and emittance growth from beam mismatch were also studied. It was concluded that a beam with radiographic quality equivalent to the present accelerators at Los Alamos National Laboratory will result if the same engineering standards and construction details are upheld.

  11. Electron-Beam Dynamics for an Advanced Flash-Radiography Accelerator

    SciTech Connect

    Ekdahl, Carl

    2015-12-01

    Beam dynamics issues were assessed for a new linear induction electron accelerator being designed for multipulse flash radiography of large explosively driven hydrodynamic experiments. Special attention was paid to equilibrium beam transport, possible emittance growth, and beam stability. Especially problematic would be high-frequency beam instabilities that could blur individual radiographic source spots, low-frequency beam motion that could cause pulse-to-pulse spot displacement, and emittance growth that could enlarge the source spots. Furthermore, beam physics issues were examined through theoretical analysis and computer simulations, including particle-in-cell codes. Beam instabilities investigated included beam breakup, image displacement, diocotron, parametric envelope, ion hose, and the resistive wall instability. The beam corkscrew motion and emittance growth from beam mismatch were also studied. It was concluded that a beam with radiographic quality equivalent to the present accelerators at Los Alamos National Laboratory will result if the same engineering standards and construction details are upheld.

  12. Electron-Beam Dynamics for an Advanced Flash-Radiography Accelerator

    DOE PAGES

    Ekdahl, Carl

    2015-11-17

    Beam dynamics issues were assessed for a new linear induction electron accelerator being designed for multipulse flash radiography of large explosively driven hydrodynamic experiments. Special attention was paid to equilibrium beam transport, possible emittance growth, and beam stability. Especially problematic would be high-frequency beam instabilities that could blur individual radiographic source spots, low-frequency beam motion that could cause pulse-to-pulse spot displacement, and emittance growth that could enlarge the source spots. Furthermore, beam physics issues were examined through theoretical analysis and computer simulations, including particle-in-cell codes. Beam instabilities investigated included beam breakup, image displacement, diocotron, parametric envelope, ion hose, and themore » resistive wall instability. The beam corkscrew motion and emittance growth from beam mismatch were also studied. It was concluded that a beam with radiographic quality equivalent to the present accelerators at Los Alamos National Laboratory will result if the same engineering standards and construction details are upheld.« less

  13. GaAs metal-oxide-semiconductor based non-volatile flash memory devices with InAs quantum dots as charge storage nodes

    SciTech Connect

    Islam, Sk Masiul Chowdhury, Sisir; Sarkar, Krishnendu; Nagabhushan, B.; Banerji, P.; Chakraborty, S.

    2015-06-24

    Ultra-thin InP passivated GaAs metal-oxide-semiconductor based non-volatile flash memory devices were fabricated using InAs quantum dots (QDs) as charge storing elements by metal organic chemical vapor deposition technique to study the efficacy of the QDs as charge storage elements. The grown QDs were embedded between two high-k dielectric such as HfO{sub 2} and ZrO{sub 2}, which were used for tunneling and control oxide layers, respectively. The size and density of the QDs were found to be 5 nm and 1.8×10{sup 11} cm{sup −2}, respectively. The device with a structure Metal/ZrO{sub 2}/InAs QDs/HfO{sub 2}/GaAs/Metal shows maximum memory window equivalent to 6.87 V. The device also exhibits low leakage current density of the order of 10{sup −6} A/cm{sup 2} and reasonably good charge retention characteristics. The low value of leakage current in the fabricated memory device is attributed to the Coulomb blockade effect influenced by quantum confinement as well as reduction of interface trap states by ultra-thin InP passivation on GaAs prior to HfO{sub 2} deposition.

  14. Subwavelength alignment mark signal analysis of advanced memory products

    NASA Astrophysics Data System (ADS)

    Yin, Xiaoming; Wong, Alfred K. K.; Wheeler, Donald C.; Williams, Gary; Lehner, Eric A.; Zach, Franz X.; Kim, Byeong Y.; Fukuzaki, Yuzo; Lu, Zhijian G.; Credendino, Santo; Wiltshire, Timothy J.

    2000-06-01

    The impact of alignment mark structure, mark geometry, and stepper alignment optical system on mark signal contrast was investigated using computer simulation. Several sub-wavelength poly silicon recessed film stack alignment targets of advanced memory products were studied. Stimulated alignment mark signals for both dark-field and bright-field systems using the rigorous electromagnetic simulation program TEMPEST showed excellent agreement with experimental data. For a dark-field alignment system, the critical parameters affecting signal contrast were found to be mark size and mark recess depth below silicon surface. On the other hand, film stack thickness and mark recess depth below/above silicon surface are the important parameters for a bright-field alignment system. From observed simulation results optimal process parameters are determined. Based on the simulation results some signal enhancement techniques will be discussed.

  15. VDNROM: A novel four-physical-bits/cell vertical channel dual-nitride-trapping-layers ROM for high density flash memory applications

    NASA Astrophysics Data System (ADS)

    Zhou, Falong; Cai, Yimao; Huang, Ru; Li, Yan; Shan, Xiaonan; Liu, Jia; Guo, Ao; Zhang, Xing; Wang, Yangyuan

    2007-11-01

    A novel vertical channel dual-nitride-trapping-layer ROM (VDNROM) flash memory with oxide-nitride-oxide-nitride-oxide (ONONO) dielectrics stack is proposed and experimentally demonstrated. Compared with the conventional planar NROM cell, since the cell area of the proposed vertical structure is independent of the gate length, the VDNROM structure can relax the limitation of the gate length scaling, and can have high capability of cell area shrinking. The fabrication process of this VDNROM device is basically compatible with planar CMOS technology. The VDNROM cell can be programmed and erased by the hot carrier injection to the localized trapping dual-nitride layers, so it can achieve a four-physical-bits storage capability each cell. The reliability behaviors including the cycling endurance and the bake retention at 150 °C have also been investigated and show the acceptable characteristics. The experiment results verify the VDNROM cell as a good candidate for high density applications.

  16. A 300MHz Embedded Flash Memory with Pipeline Architecture and Offset-Free Sense Amplifiers for Dual-Core Automotive Microcontrollers

    NASA Astrophysics Data System (ADS)

    Kajiyama, Shinya; Fujito, Masamichi; Kasai, Hideo; Mizuno, Makoto; Yamaguchi, Takanori; Shinagawa, Yutaka

    A novel 300MHz embedded flash memory for dual-core microcontrollers with a shared ROM architecture is proposed. One of its features is a three-stage pipeline read operation, which enables reduced access pitch and therefore reduces performance penalty due to conflict of shared ROM accesses. Another feature is a highly sensitive sense amplifier that achieves efficient pipeline operation with two-cycle latency one-cycle pitch as a result of a shortened sense time of 0.63ns. The combination of the pipeline architecture and proposed sense amplifiers significantly reduces access-conflict penalties with shared ROM and enhances performance of 32-bit RISC dual-core microcontrollers by 30%.

  17. An advanced CCD emulator with 32MB image memory

    NASA Astrophysics Data System (ADS)

    O'Connor, P.; Fried, J.; Kotov, I.

    2012-07-01

    As part of the LSST sensor development program we have developed an advanced CCD emulator for testing new multichannel readout electronics. The emulator, based on an Altera Stratix II FPGA for timing and control, produces 4 channels of simulated video waveforms in response to an appropriate sequence of horizontal and vertical clocks. It features 40MHz, 16-bit DACs for reset and video generation, 32MB of image memory for storage of arbitrary grayscale bitmaps, and provision to simulate reset and clock feedthrough ("glitches") on the video channels. Clock inputs are qualified for proper sequences and levels before video output is generated. Binning, region of interest, and reverse clock sequences are correctly recognized and appropriate video output will be produced. Clock transitions are timestamped and can be played back to a control PC. A simplified user interface is provided via a daughter card having an ARM M3 Cortex microprocessor and miniature color LCD display and joystick. The user can select video modes from stored bitmap images, or flat, gradient, bar, chirp, or checkerboard test patterns; set clock thresholds and video output levels; and set row/column formats for image outputs. Multiple emulators can be operated in parallel to simulate complex CCDs or CCD arrays.

  18. Why musical memory can be preserved in advanced Alzheimer's disease.

    PubMed

    Jacobsen, Jörn-Henrik; Stelzer, Johannes; Fritz, Thomas Hans; Chételat, Gael; La Joie, Renaud; Turner, Robert

    2015-08-01

    Musical memory is considered to be partly independent from other memory systems. In Alzheimer's disease and different types of dementia, musical memory is surprisingly robust, and likewise for brain lesions affecting other kinds of memory. However, the mechanisms and neural substrates of musical memory remain poorly understood. In a group of 32 normal young human subjects (16 male and 16 female, mean age of 28.0 ± 2.2 years), we performed a 7 T functional magnetic resonance imaging study of brain responses to music excerpts that were unknown, recently known (heard an hour before scanning), and long-known. We used multivariate pattern classification to identify brain regions that encode long-term musical memory. The results showed a crucial role for the caudal anterior cingulate and the ventral pre-supplementary motor area in the neural encoding of long-known as compared with recently known and unknown music. In the second part of the study, we analysed data of three essential Alzheimer's disease biomarkers in a region of interest derived from our musical memory findings (caudal anterior cingulate cortex and ventral pre-supplementary motor area) in 20 patients with Alzheimer's disease (10 male and 10 female, mean age of 68.9 ± 9.0 years) and 34 healthy control subjects (14 male and 20 female, mean age of 68.1 ± 7.2 years). Interestingly, the regions identified to encode musical memory corresponded to areas that showed substantially minimal cortical atrophy (as measured with magnetic resonance imaging), and minimal disruption of glucose-metabolism (as measured with (18)F-fluorodeoxyglucose positron emission tomography), as compared to the rest of the brain. However, amyloid-β deposition (as measured with (18)F-flobetapir positron emission tomography) within the currently observed regions of interest was not substantially less than in the rest of the brain, which suggests that the regions of interest were still in a very early stage of the expected course of

  19. Novel conformal organic antireflective coatings for advanced I-line lithography

    NASA Astrophysics Data System (ADS)

    Deshpande, Shreeram V.; Nowak, Kelly A.; Fowler, Shelly; Williams, Paul; Arjona, Mikko

    2001-08-01

    Flash memory chips are playing a critical role in semiconductor devices due to increased popularity of hand held electronic communication devices such as cell phones and PDAs (personal Digital Assistants). Flash memory offers two primary advantages in semiconductor devices. First, it offers flexibility of in-circuit programming capability to reduce the loss from programming errors and to significantly reduce commercialization time to market for new devices. Second, flash memory has a double density memory capability through stacked gate structures which increases the memory capability and thus saves significantly on chip real estate. However, due to stacked gate structures the requirements for manufacturing of flash memory devices are significantly different from traditional memory devices. Stacked gate structures also offer unique challenges to lithographic patterning materials such as Bottom Anti-Reflective Coating (BARC) compositions used to achieve CD control and to minimize standing wave effect in photolithography. To be applicable in flash memory manufacturing a BARC should form a conformal coating on high topography of stacked gate features as well as provide the normal anti-reflection properties for CD control. In this paper we report on a new highly conformal advanced i-line BARC for use in design and manufacture of flash memory devices. Conformal BARCs being significantly thinner in trenches than the planarizing BARCs offer the advantage of reducing BARC overetch and thus minimizing resist thickness loss.

  20. Post-Flash Calibration Darks for the Advanced Camera for Surveys Wide Field Channel (ACS/WFC)

    NASA Astrophysics Data System (ADS)

    Ogaz, S.; Anderson, J.; Golimowski, D.

    2015-06-01

    We present a summary and analysis of the changes made to the ACS/WFC dark reference files. As of January 15, 2015 the ACS team has begun to produce post- flashed dark reference files for the Wide Field Channel (WFC). This change was made to combat the charge transfer efficiency (CTE) losses caused by radiation damage that the two WFC CCDs have suffered since being put into orbit by artificially increasing the background in the dark images. This has resulted in several changes to the reference file pipeline, and an improved calibration dark.

  1. Materials and other needs for advanced phase change memory (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Sosa, Norma E.

    2015-09-01

    Phase change memory (PCM), with its long history, may now hold its brightest promise to date. This bright future is being fueled by the "push" from big data. PCM is a non-volatile memory technology used to create solid-state random access memory devices that operate based the resistance properties of materials. Employing the electrical resistance differences-as opposed to differences in charge stored-between the amorphous and crystalline phases of the material, PCM can store bits, namely one's and zero's. Indeed, owing to the method of storage, PCM can in fact be designed to hold multiple bits thus leading to a high-density technology twice the storage density and less than half the cost of DRAM, the main kind found in typical personal computers. It has been long known that PCM can fill a need gap that spans 3 decades in performance from DRAM to solid state drive (NAND Flash). Furthermore, PCM devices can lead to performance and reliability improvements essential to enabling significant steps forward to supporting big data centric computing. This talk will focus on the science and challenges of aggressive scaling to realize the density needed, how this scaling challenge is intertwined with materials needs for endurance into the giga-cycles, and the associated forefront research aiming to realizing multi-level functionality into these nanoscale programmable resistor devices.

  2. A Comprehensive Study on Energy Efficiency and Performance of Flash-based SSD

    SciTech Connect

    Park, Seon-Yeon; Kim, Youngjae; Urgaonkar, Bhuvan; Lee, Joonwon; Seo, Euiseong

    2011-01-01

    Use of flash memory as a storage medium is becoming popular in diverse computing environments. However, because of differences in interface, flash memory requires a hard-disk-emulation layer, called FTL (flash translation layer). Although the FTL enables flash memory storages to replace conventional hard disks, it induces significant computational and space overhead. Despite the low power consumption of flash memory, this overhead leads to significant power consumption in an overall storage system. In this paper, we analyze the characteristics of flash-based storage devices from the viewpoint of power consumption and energy efficiency by using various methodologies. First, we utilize simulation to investigate the interior operation of flash-based storage of flash-based storages. Subsequently, we measure the performance and energy efficiency of commodity flash-based SSDs by using microbenchmarks to identify the block-device level characteristics and macrobenchmarks to reveal their filesystem level characteristics.

  3. Advancing Reversible Shape Memory by Tuning Network Architecture

    NASA Astrophysics Data System (ADS)

    Li, Qiaoxi; Zhou, Jing; Vatankhah Varnosfaderani, Mohammad; Nykypanchuk, Dmytro; Gang, Oleg; Sheiko, Sergei; University of north carolina at chapel hill Collaboration; Brookhaven National Lab-CFN Collaboration

    Recently, reversible shape memory (RSM) has been realized in conventional semi-crystalline elastomers without applying any external force and synthetic programming. The mechanism is ascribed to counteraction between thermodynamically driven relaxation of a strained polymer network and kinetically preferred self-seeding recrystallization of constrained network strands. In order to maximize RSM's performance in terms of (i) range of reversible strain, (ii) rate of strain recovery, and (iii) relaxation time of reversibility, we have designed a systematic series of networks with different topologies and crosslinking densities, including purposely introduced dangling chains and irregular meshes. Within a broad range of crosslink density ca. 50-1000 mol/m3, we have demonstrated that the RSM's properties improve significantly with increasing crosslink density, regardless of network topology. Actually, one of the most irregular networks with densest crosslinking allowed achieving up to 80% of the programmed strain being fully reversible, fast recovery rate up to 0.05 K-1, and less than 15% decrease of reversibility after hours of annealing at partial melt state. With this understanding and optimization of RSM, we pursue an idea of shape control through self-assembly of shape-memory particles. For this purpose, 3D printing has been employed to prepare large assemblies of particles possessing specific shapes and morphologies.

  4. New Rule Use Drives the Relation between Working Memory Capacity and Raven's Advanced Progressive Matrices

    ERIC Educational Resources Information Center

    Wiley, Jennifer; Jarosz, Andrew F.; Cushen, Patrick J.; Colflesh, Gregory J. H.

    2011-01-01

    The correlation between individual differences in working memory capacity and performance on the Raven's Advanced Progressive Matrices (RAPM) is well documented yet poorly understood. The present work proposes a new explanation: that the need to use a new combination of rules on RAPM problems drives the relation between performance and working…

  5. Amityville Memorial High School History Journal Advance Placement History.

    ERIC Educational Resources Information Center

    Howlett, Charles F., Ed.

    The history of Amityville, New York, compiled by 11th and 12th grade advance placement history students, is presented in journal form. Six papers focus on: (1) South Oaks: The Long Island Home; (2) A History of Bethel African Methodist Episcopal Church, Amityville; (3) Amityville: A Vacationland; (4) Amityville School System from 1904 to Present;…

  6. Memory

    MedlinePlus

    ... it has to decide what is worth remembering. Memory is the process of storing and then remembering this information. There are different types of memory. Short-term memory stores information for a few ...

  7. Advancing reversible shape memory by tuning the polymer network architecture

    DOE PAGES

    Li, Qiaoxi; Zhou, Jing; Vatankhah-Varnoosfaderani, Mohammad; Nykypanchuk, Dmytro; Gang, Oleg; Sheiko, Sergei S.

    2016-02-02

    Because of counteraction of a chemical network and a crystalline scaffold, semicrystalline polymer networks exhibit a peculiar behavior—reversible shape memory (RSM), which occurs naturally without applying any external force and particular structural design. There are three RSM properties: (i) range of reversible strain, (ii) rate of strain recovery, and (iii) decay of reversibility with time, which can be improved by tuning the architecture of the polymer network. Different types of poly(octylene adipate) networks were synthesized, allowing for control of cross-link density and network topology, including randomly cross-linked network by free-radical polymerization, thiol–ene clicked network with enhanced mesh uniformity, and loosemore » network with deliberately incorporated dangling chains. It is shown that the RSM properties are controlled by average cross-link density and crystal size, whereas topology of a network greatly affects its extensibility. In conclusion, we have achieved 80% maximum reversible range, 15% minimal decrease in reversibility, and fast strain recovery rate up to 0.05 K–1, i.e., ca. 5% per 10 s at a cooling rate of 5 K/min.« less

  8. Memory.

    ERIC Educational Resources Information Center

    McKean, Kevin

    1983-01-01

    Discusses current research (including that involving amnesiacs and snails) into the nature of the memory process, differentiating between and providing examples of "fact" memory and "skill" memory. Suggests that three brain parts (thalamus, fornix, mammilary body) are involved in the memory process. (JN)

  9. Advanced methods for time-varying effective connectivity estimation in memory processes.

    PubMed

    Astolfi, L; Toppi, J; Wood, G; Kober, S; Risetti, M; Macchiusi, L; Salinari, S; Babiloni, F; Mattia, D

    2013-01-01

    Memory processes are based on large cortical networks characterized by non-stationary properties and time scales which represent a limitation to the traditional connectivity estimation methods. The recent development of connectivity approaches able to consistently describe the temporal evolution of large dimension connectivity networks, in a fully multivariate way, represents a tool that can be used to extract novel information about the processes at the basis of memory functions. In this paper, we applied such advanced approach in combination with the use of state-of-the-art graph theory indexes, computed on the connectivity networks estimated from high density electroencephalographic (EEG) data recorded in a group of healthy adults during the Sternberg Task. The results show how this approach is able to return a characterization of the main phases of the investigated memory task which is also sensitive to the increased length of the numerical string to be memorized. PMID:24110342

  10. Resistive switching behavior in Lu2O3 thin film for advanced flexible memory applications

    PubMed Central

    2014-01-01

    In this article, the resistive switching (RS) behaviors in Lu2O3 thin film for advanced flexible nonvolatile memory applications are investigated. Amorphous Lu2O3 thin films with a thickness of 20 nm were deposited at room temperature by radio-frequency magnetron sputtering on flexible polyethylene terephthalate substrate. The structural and morphological changes of the Lu2O3 thin film were characterized by x-ray diffraction, atomic force microscopy, and x-ray photoelectron spectroscopy analyses. The Ru/Lu2O3/ITO flexible memory device shows promising RS behavior with low-voltage operation and small distribution of switching parameters. The dominant switching current conduction mechanism in the Lu2O3 thin film was determined as bulk-controlled space-charge-limited-current with activation energy of traps of 0.33 eV. The oxygen vacancies assisted filament conduction model was described for RS behavior in Lu2O3 thin film. The memory reliability characteristics of switching endurance, data retention, good flexibility, and mechanical endurance show promising applications in future advanced memory. PMID:24387704

  11. Lunar Impact Flash Locations

    NASA Technical Reports Server (NTRS)

    Moser, D. E.; Suggs, R. M.; Kupferschmidt, L.; Feldman, J.

    2015-01-01

    A bright impact flash detected by the NASA Lunar Impact Monitoring Program in March 2013 brought into focus the importance of determining the impact flash location. A process for locating the impact flash, and presumably its associated crater, was developed using commercially available software tools. The process was successfully applied to the March 2013 impact flash and put into production on an additional 300 impact flashes. The goal today: provide a description of the geolocation technique developed.

  12. Data Movement Dominates: Advanced Memory Technology to Address the Real Exascale Power Problem

    SciTech Connect

    Bergman, Keren

    2014-08-28

    Energy is the fundamental barrier to Exascale supercomputing and is dominated by the cost of moving data from one point to another, not computation. Similarly, performance is dominated by data movement, not computation. The solution to this problem requires three critical technologies: 3D integration, optical chip-to-chip communication, and a new communication model. The central goal of the Sandia led "Data Movement Dominates" project aimed to develop memory systems and new architectures based on these technologies that have the potential to lower the cost of local memory accesses by orders of magnitude and provide substantially more bandwidth. Only through these transformational advances can future systems reach the goals of Exascale computing with a manageable power budgets. The Sandia led team included co-PIs from Columbia University, Lawrence Berkeley Lab, and the University of Maryland. The Columbia effort of Data Movement Dominates focused on developing a physically accurate simulation environment and experimental verification for optically-connected memory (OCM) systems that can enable continued performance scaling through high-bandwidth capacity, energy-efficient bit-rate transparency, and time-of-flight latency. With OCM, memory device parallelism and total capacity can scale to match future high-performance computing requirements without sacrificing data-movement efficiency. When we consider systems with integrated photonics, links to memory can be seamlessly integrated with the interconnection network-in a sense, memory becomes a primary aspect of the interconnection network. At the core of the Columbia effort, toward expanding our understanding of OCM enabled computing we have created an integrated modeling and simulation environment that uniquely integrates the physical behavior of the optical layer. The PhoenxSim suite of design and software tools developed under this effort has enabled the co-design of and performance evaluation photonics-enabled OCM

  13. Simple flash evaporator for making thin films of compounds

    SciTech Connect

    Hemanadhan, M.; Bapanayya, Ch.; Agarwal, S. C.

    2010-07-15

    A simple and compact arrangement for flash evaporation is described. It uses a cell phone vibrator for powder dispensing that can be incorporated into a vacuum deposition chamber without any major alterations. The performance of the flash evaporation system is checked by making thin films of the optical memory chalcogenide glass Ge{sub 2}Sb{sub 2}Te{sub 5} (GST). Energy dispersive x-ray analysis shows that the flash evaporation preserves the stoichiometry in thin films.

  14. Advanced error-prediction LDPC with temperature compensation for highly reliable SSDs

    NASA Astrophysics Data System (ADS)

    Tokutomi, Tsukasa; Tanakamaru, Shuhei; Iwasaki, Tomoko Ogura; Takeuchi, Ken

    2015-09-01

    To improve the reliability of NAND Flash memory based solid-state drives (SSDs), error-prediction LDPC (EP-LDPC) has been proposed for multi-level-cell (MLC) NAND Flash memory (Tanakamaru et al., 2012, 2013), which is effective for long retention times. However, EP-LDPC is not as effective for triple-level cell (TLC) NAND Flash memory, because TLC NAND Flash has higher error rates and is more sensitive to program-disturb error. Therefore, advanced error-prediction LDPC (AEP-LDPC) has been proposed for TLC NAND Flash memory (Tokutomi et al., 2014). AEP-LDPC can correct errors more accurately by precisely describing the error phenomena. In this paper, the effects of AEP-LDPC are investigated in a 2×nm TLC NAND Flash memory with temperature characterization. Compared with LDPC-with-BER-only, the SSD's data-retention time is increased by 3.4× and 9.5× at room-temperature (RT) and 85 °C, respectively. Similarly, the acceptable BER is increased by 1.8× and 2.3×, respectively. Moreover, AEP-LDPC can correct errors with pre-determined tables made at higher temperatures to shorten the measurement time before shipping. Furthermore, it is found that one table can cover behavior over a range of temperatures in AEP-LDPC. As a result, the total table size can be reduced to 777 kBytes, which makes this approach more practical.

  15. Secrets of a Flash Card-Carrying Teacher.

    ERIC Educational Resources Information Center

    Hawkes, Mel

    1983-01-01

    Eight ways to use flash cards in mathematics instruction are described. These games and other gimmicks help increase students' concentration, build memory skills, sharpen thinking skills, and enliven drills. (PP)

  16. SEMICONDUCTOR DEVICES: Erase voltage impact on 0.18 μm triple self-aligned split-gate flash memory endurance

    NASA Astrophysics Data System (ADS)

    Yaoqi, Dong; Weiran, Kong; Do, Nhan; Shiuh-Luen, Wang; Gabriel, Lee

    2010-06-01

    The erase voltage impact on the 0.18 μm triple self-aligned split-gate flash endurance is studied. An optimized erase voltage is necessary in order to achieve the best endurance. A lower erase voltage can cause more cell current degradation by increasing its sensitivity to the floating gate voltage drop, which is induced by tunnel oxide charge trapping during program/erase cycling. A higher erase voltage also aggravates the endurance degradation by introducing select gate oxide charge trapping. A progressive erase voltage method is proposed and demonstrated to better balance the two degradation mechanisms and thus further improve endurance performance.

  17. Memories.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  18. 0.6-1.0 V operation set/reset voltage (3 V) generator for three-dimensional integrated resistive random access memory and NAND flash hybrid solid-state drive

    NASA Astrophysics Data System (ADS)

    Tanaka, Masahiro; Hachiya, Shogo; Ishii, Tomoya; Ning, Sheyang; Tsurumi, Kota; Takeuchi, Ken

    2016-04-01

    A 0.6-1.0 V, 25.9 mm2 boost converter is proposed to generate resistive random access memory (ReRAM) write (set/reset) voltage for three-dimensional (3D) integrated ReRAM and NAND flash hybrid solid-state drive (SSD). The proposed boost converter uses an integrated area-efficient V BUF generation circuit to obtain short ReRAM sector write time, small circuit size, and small energy consumption simultaneously. In specific, the proposed boost converter reduces ReRAM sector write time by 65% compared with a conventional one-stage boost converter (Conventional 1) which uses 1.0 V operating voltage. On the other hand, by using the same ReRAM sector write time, the proposed boost converter reduces 49% circuit area and 46% energy consumption compared with a conventional two-stage boost converter (Conventional 2). In addition, by using the proposed boost converter, the operating voltage, V DD, can be reduced to 0.6 V. The lowest 159 nJ energy consumption can be obtained when V DD is 0.7 V.

  19. Flash protection controller

    DOEpatents

    Galbraith, Lee K.

    1981-01-01

    A controller provides a high voltage to maintain an electro-optic shutter in a transparent condition until a flash of light which would be harmful to personnel is sensed by a phototransistor. The controller then shorts the shutter to ground to minimize light transmission to the user and maintains light transmission at the pre-flash level for a predetermined time to allow the flash to subside. A log converter and differential trigger circuit keep the controller from being triggered by other light flashes which are not dangerous.

  20. Flash protection controller

    DOEpatents

    Galbraith, L.K.

    1979-12-07

    A controller provides a high voltage to maintain an electro-optic shutter in a transparent condition until a flash of light which would be harmful to personnel is sensed by a phototransistor. The controller then shorts the shutter to ground to minimize light transmission to the user and maintains light transmission at the pre-flash level for a predetermined time to allow the flash to subside. A log converter and differential trigger circuit keep the controller from being triggered by other light flashes which are not dangerous.

  1. Probing S-state advancements and recombination pathways in photosystem II with a global fit program for flash-induced oxygen evolution pattern.

    PubMed

    Pham, Long Vo; Messinger, Johannes

    2016-06-01

    The oxygen-evolving complex (OEC) in photosystem II catalyzes the oxidation of water to molecular oxygen. Four decades ago, measurements of flash-induced oxygen evolution have shown that the OEC steps through oxidation states S(0), S(1), S(2), S(3) and S(4) before O(2) is released and the S(0) state is reformed. The light-induced transitions between these states involve misses and double hits. While it is widely accepted that the miss parameter is S state dependent and may be further modulated by the oxidation state of the acceptor side, the traditional way of analyzing each flash-induced oxygen evolution pattern (FIOP) individually did not allow using enough free parameters to thoroughly test this proposal. Furthermore, this approach does not allow assessing whether the presently known recombination processes in photosystem II fully explain all measured oxygen yields during Si state lifetime measurements. Here we present a global fit program that simultaneously fits all flash-induced oxygen yields of a standard FIOP (2 Hz flash frequency) and of 11-18 FIOPs each obtained while probing the S(0), S(2) and S(3) state lifetimes in spinach thylakoids at neutral pH. This comprehensive data treatment demonstrates the presence of a very slow phase of S(2) decay, in addition to the commonly discussed fast and slow reduction of S(2) by YD and QB(-), respectively. Our data support previous suggestions that the S(0)→S(1) and S(1)→S(2) transitions involve low or no misses, while high misses occur in the S(2)→S(3) or S(3)→S(0) transitions. PMID:27033305

  2. Probing S-state advancements and recombination pathways in photosystem II with a global fit program for flash-induced oxygen evolution pattern.

    PubMed

    Pham, Long Vo; Messinger, Johannes

    2016-06-01

    The oxygen-evolving complex (OEC) in photosystem II catalyzes the oxidation of water to molecular oxygen. Four decades ago, measurements of flash-induced oxygen evolution have shown that the OEC steps through oxidation states S(0), S(1), S(2), S(3) and S(4) before O(2) is released and the S(0) state is reformed. The light-induced transitions between these states involve misses and double hits. While it is widely accepted that the miss parameter is S state dependent and may be further modulated by the oxidation state of the acceptor side, the traditional way of analyzing each flash-induced oxygen evolution pattern (FIOP) individually did not allow using enough free parameters to thoroughly test this proposal. Furthermore, this approach does not allow assessing whether the presently known recombination processes in photosystem II fully explain all measured oxygen yields during Si state lifetime measurements. Here we present a global fit program that simultaneously fits all flash-induced oxygen yields of a standard FIOP (2 Hz flash frequency) and of 11-18 FIOPs each obtained while probing the S(0), S(2) and S(3) state lifetimes in spinach thylakoids at neutral pH. This comprehensive data treatment demonstrates the presence of a very slow phase of S(2) decay, in addition to the commonly discussed fast and slow reduction of S(2) by YD and QB(-), respectively. Our data support previous suggestions that the S(0)→S(1) and S(1)→S(2) transitions involve low or no misses, while high misses occur in the S(2)→S(3) or S(3)→S(0) transitions.

  3. SEMICONDUCTOR DEVICES Novel multi-bit non-uniform channel charge trapping memory device with virtual-source NAND flash array

    NASA Astrophysics Data System (ADS)

    Haiming, Gu; Liyang, Pan; Peng, Zhu; Dong, Wu; Zhigang, Zhang; Jun, Xu

    2010-10-01

    In order to overcome the bit-to-bit interference of the traditional multi-level NAND type device, this paper firstly proposes a novel multi-bit non-uniform channel charge trapping memory (NUC-CTM) device with virtual-source NAND-type array architecture, which can effectively restrain the second-bit effect (SBE) and provide 3-bit per cell capability. Owing to the n- buffer region, the SBE induced threshold voltage window shift can be reduced to less than 400 mV and the minimum threshold voltage window between neighboring levels is larger than 750 mV for reliable 3-bit operation. A silicon-rich SiON is also investigated as a trapping layer to improve the retention reliability of the NUC-CTM.

  4. Flash-Type Discrimination

    NASA Technical Reports Server (NTRS)

    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.

  5. The Flash Grab Effect

    PubMed Central

    Cavanagh, Patrick; Anstis, Stuart

    2013-01-01

    When an object moves back and forth, its trajectory appears significantly shorter than it actually is. The object appears to stop and reverse well before its actual reversal point, as if there is some averaging of location within a window of about 100 ms (Sinico et al, 2009). Surprisingly, if a bar is flashed at the physical end point of the trajectory, right on top of the object, just as it reverses direction, the flash is also shifted – grabbed by the object – and is seen at the perceived endpoint of the trajectory rather than the physical endpoint. This can shift the perceived location of the flash by as much as 2 or 3 times its physical size and by up to several degrees of visual angle. We first show that the position shift of the flash is generated by the trajectory shortening, as the same shift is seen with or without the flash. The flash itself is only grabbed if it is presented within a small spatiotemporal attraction zone around the physical end point of the trajectory. Any flash falling in that zone is pulled toward the perceived endpoint. The effect scales linearly with speed, up to a maximum, and is independent of the contrast of the moving stimulus once it is above 5%. Finally, we demonstrate that this position shift requires attention. These results reveal a new “flash grab” effect in the family of motion-induced position shifts. Although it most resembles the flash drag effect, it differs from this in the following ways: 1) it has a different temporal profile, 2) it requires attention, 3) it is about 10 times larger. PMID:23872166

  6. Longitudinal Diagnostics of Short Bunches at FLASH

    SciTech Connect

    Khan, Shaukat

    2009-01-22

    Novel acceleration concepts such as laser- or beam-driven plasma acceleration require advanced diagnostic techniques to characterize and monitor the beam. A particular challenge is to measure bunch lengths of the order of 10 femtoseconds. Several methods are currently explored at the free-electron laser FLASH at DESY/Hamburg and will be discussed it this paper, such as electro-optical sampling, streaking bunches with a transversely deflecting cavity, and -most recently implemented at FLASH--the optical-replica synthesizer, a laser-based technique promising a time resolution of a few femtoseconds.

  7. Flashes and Floaters

    MedlinePlus

    ... either in the form of lightening bolts, shooting stars, sparks, or an arc of light to the ... against it that causes the sparks and shooting stars phenomenon. But flashes and floaters may have more ...

  8. Flash Bulletin: Fireflies

    ERIC Educational Resources Information Center

    Brown, Debbie

    1984-01-01

    Explains the flashes of light emitted by fireflies as competition, species-specific code, species identification and mating behavior and ecology. Suggests activities to conduct to study the insects and their behavior. (ERB)

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

    NASA Astrophysics Data System (ADS)

    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.

  10. 450mm wafer patterning with jet and flash imprint lithography

    NASA Astrophysics Data System (ADS)

    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.

  11. Active Flash: Out-of-core Data Analytics on Flash Storage

    SciTech Connect

    Boboila, Simona; Kim, Youngjae; Vazhkudai, Sudharshan S; Desnoyers, Peter; Shipman, Galen M

    2012-01-01

    Next generation science will increasingly come to rely on the ability to perform efficient, on-the-fly analytics of data generated by high-performance computing (HPC) simulations, modeling complex physical phenomena. Scientific computing workflows are stymied by the traditional chaining of simulation and data analysis, creating multiple rounds of redundant reads and writes to the storage system, which grows in cost with the ever-increasing gap between compute and storage speeds in HPC clusters. Recent HPC acquisitions have introduced compute node-local flash storage as a means to alleviate this I/O bottleneck. We propose a novel approach, Active Flash, to expedite data analysis pipelines by migrating to the location of the data, the flash device itself. We argue that Active Flash has the potential to enable true out-of-core data analytics by freeing up both the compute core and the associated main memory. By performing analysis locally, dependence on limited bandwidth to a central storage system is reduced, while allowing this analysis to proceed in parallel with the main application. In addition, offloading work from the host to the more power-efficient controller reduces peak system power usage, which is already in the megawatt range and poses a major barrier to HPC system scalability. We propose an architecture for Active Flash, explore energy and performance trade-offs in moving computation from host to storage, demonstrate the ability of appropriate embedded controllers to perform data analysis and reduction tasks at speeds sufficient for this application, and present a simulation study of Active Flash scheduling policies. These results show the viability of the Active Flash model, and its capability to potentially have a transformative impact on scientific data analysis.

  12. EDITORIAL: Van der Waals interactions in advanced materials, in memory of David C Langreth Van der Waals interactions in advanced materials, in memory of David C Langreth

    NASA Astrophysics Data System (ADS)

    Hyldgaard, Per; Rahman, Talat S.

    2012-10-01

    Solid State Commun. 17 1425 [4]Gunnarsson O and Lundqvist B I 1976 Exchange and correlation in atoms, molecules, and solids by the spin-density-functional formalism Phys. Rev. B 13 4274 [5]Langreth D C and Mehl M J 1981 Beyond the local-density approximation in calculations of ground-state electronic properties Phys. Rev. B 47 446 [6]Dion M, Rydberg H, Schröder E, Langreth D C and Lundqvist B I 2004 Van der Waals density functional for general geometries Phys. Rev. Lett. 92 246401 Thonhauser T, Cooper V R, Li S, Puzder A, Hyldgaard P and Langreth D C 2007 Van der Waals density functional: self-consistent potential and the nature of the van der Waals bond Phys. Rev. B 76 125112 [7]Lee K, Murray E D, Kong L, Lundqvist B I and Langreth D C 2010 A higher-accuracy van der Waals density functional Phys. Rev. B 82 081101 [8]Rapcewicz K and Ashcroft N W 1991 Fluctuation attraction in condensed matter: a nonlocal functional approach Phys. Rev. B 44 4032 Lundqvist B I, Andersson Y, Shao H, Chan S and Langreth D C 1995 Density functional theory including van der Waals forces Int. J. Quant. Chem. 56 247 [9]Langreth D C et al 2009 A density functional for sparse matter J. Phys.: Condens. Matter 21 084203 [10]For example, Kohn W, Meir Y and Makarov D E 1998 The exchange-correlation energy of a metallic surface Phys. Rev. Lett. 80 4153 Kurth S and Perdew J P 1999 Phys. Rev. B 59 10461 Dobson J F and Wang J 1999 Phys. Rev. Lett. 82 2123 Pitarke J M and Perdew J P 2003 Phys. Rev. B 67 045101 Vydrov O A and van Voorhi T 2009 Phys. Rev. Lett. 103 063004 [11]For example, Grimme S 2004 J. Comput. Phys. 25 1463 Tkatchenko A and Scheffler M 2009 Phys. Rev. Lett. 102 073005 Grimme S, Antony J, Ehrlich S and Krieg H 2010 J. Chem. Phys. 132 154004 [12]Burke K 2012 Perspectives on density functional theory J. Chem. Phys. 136 150901 Van der Waals interactions in advanced materials contents Van der Waals interactions in advanced materials, in memory of David C LangrethPer Hyldgaard and Talat S

  13. Flash fire propensity of materials

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    Flash fire test results on 86 materials, evaluated using the USF flash fire screening test, are presented. The materials which appear least prone to flash fires are PVC, polyphenylene oxide and sulfide, and polyether and polyaryl sulfone; these did not produce flash fires under these particular test conditions. The principal value of these screening tests at the present time is in identifying materials which appear prone to flash fires, and in identifying which formulations of a generic material are more or less prone to flash fires.

  14. 14. INTERIOR VIEW, DETAIL OF TRIMMED FLASH; FLASH IS EXCESS ...

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

    14. INTERIOR VIEW, DETAIL OF TRIMMED FLASH; FLASH IS EXCESS METAL EXTRUDED BETWEEN THE DIES USED TO FORGE THE BLADE END OF THE POST HOLE DIGGER - Warwood Tool Company, Foot of Nineteenth Street, Wheeling, Ohio County, WV

  15. The Relieving Effects of BrainPower Advanced, a Dietary Supplement, in Older Adults with Subjective Memory Complaints: A Randomized, Double-Blind, Placebo-Controlled Trial

    PubMed Central

    Zhu, Jingfen; Shi, Rong; Chen, Su; Dai, Lihua; Shen, Tian; Feng, Yi; Gu, Pingping; Shariff, Mina; Nguyen, Tuong; Ye, Yeats; Rao, Jianyu; Xing, Guoqiang

    2016-01-01

    Subjective memory complaints (SMCs) are common in older adults that can often predict further cognitive impairment. No proven effective agents are available for SMCs. The effect of BrainPower Advanced, a dietary supplement consisting of herbal extracts, nutrients, and vitamins, was evaluated in 98 volunteers with SMCs, averaging 67 years of age (47–88), in a randomized, double-blind, placebo-controlled trial. Subjective hypomnesis/memory loss (SML) and attention/concentration deficits (SAD) were evaluated before and after 12-week supplementation of BrainPower Advanced capsules (n = 47) or placebo (n = 51), using a 5-point memory questionnaire (1 = no/slight, 5 = severe). Objective memory function was evaluated using 3 subtests of visual/audio memory, abstraction, and memory recall that gave a combined total score. The BrainPower Advanced group had more cases of severe SML (severity ⩾ 3) (44/47) and severe SAD (43/47) than the placebo group (39/51 and 37/51, < 0.05, < 0.05, resp.) before the treatment. BrainPower Advanced intervention, however, improved a greater proportion of the severe SML (29.5%)(13/44) (P < 0.01) and SAD (34.9%)(15/43)(P < 0.01) than placebo (5.1% (2/39) and 13.5% (5/37), resp.). Thus, 3-month BrainPower Advanced supplementation appears to be beneficial to older adults with SMCs. PMID:27190539

  16. The Relieving Effects of BrainPower Advanced, a Dietary Supplement, in Older Adults with Subjective Memory Complaints: A Randomized, Double-Blind, Placebo-Controlled Trial.

    PubMed

    Zhu, Jingfen; Shi, Rong; Chen, Su; Dai, Lihua; Shen, Tian; Feng, Yi; Gu, Pingping; Shariff, Mina; Nguyen, Tuong; Ye, Yeats; Rao, Jianyu; Xing, Guoqiang

    2016-01-01

    Subjective memory complaints (SMCs) are common in older adults that can often predict further cognitive impairment. No proven effective agents are available for SMCs. The effect of BrainPower Advanced, a dietary supplement consisting of herbal extracts, nutrients, and vitamins, was evaluated in 98 volunteers with SMCs, averaging 67 years of age (47-88), in a randomized, double-blind, placebo-controlled trial. Subjective hypomnesis/memory loss (SML) and attention/concentration deficits (SAD) were evaluated before and after 12-week supplementation of BrainPower Advanced capsules (n = 47) or placebo (n = 51), using a 5-point memory questionnaire (1 = no/slight, 5 = severe). Objective memory function was evaluated using 3 subtests of visual/audio memory, abstraction, and memory recall that gave a combined total score. The BrainPower Advanced group had more cases of severe SML (severity ⩾ 3) (44/47) and severe SAD (43/47) than the placebo group (39/51 and 37/51, < 0.05, < 0.05, resp.) before the treatment. BrainPower Advanced intervention, however, improved a greater proportion of the severe SML (29.5%)(13/44) (P < 0.01) and SAD (34.9%)(15/43)(P < 0.01) than placebo (5.1% (2/39) and 13.5% (5/37), resp.). Thus, 3-month BrainPower Advanced supplementation appears to be beneficial to older adults with SMCs. PMID:27190539

  17. Core helium flash

    SciTech Connect

    Cole, P.W.; Deupree, R.G.

    1980-01-01

    The role of convection in the core helium flash is simulated by two-dimensional eddies interacting with the thermonuclear runaway. These eddies are followed by the explicit solution of the 2D conservation laws with a 2D finite difference hydrodynamics code. Thus, no phenomenological theory of convection such as the local mixing length theory is required. The core helium flash is violent, producing a deflagration wave. This differs from the detonation wave (and subsequent disruption of the entire star) produced in previous spherically symmetric violent core helium flashes as the second dimension provides a degree of relief which allows the expansion wave to decouple itself from the burning front. Our results predict that a considerable amount of helium in the core will be burned before the horizontal branch is reached and that some envelope mass loss is likely.

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

    PubMed Central

    Kim, Eung Seok; Choi, Hyun Il

    2011-01-01

    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. PMID:21845165

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

    PubMed

    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.

  20. A review of modeling techniques for advanced effects in shape memory alloy behavior

    NASA Astrophysics Data System (ADS)

    Cisse, Cheikh; Zaki, Wael; Ben Zineb, Tarak

    2016-10-01

    micro, micro-macro and macro scales focusing pseudoelastic and shape memory effects. The paper reviews and discusses various techniques used in the literature for modeling complex behaviors observed in shape memory alloys (SMAs) that go beyond the core pseudoelastic and shape memory effects. These behaviors, which will be collectively referred to herein as ‘secondary effects’, include mismatch between austenite and martensite moduli, martensite reorientation under nonproportional multiaxial loading, slip and transformation-induced plasticity and their influence on martensite transformation, strong thermomechanical coupling and the influence of loading rate, tensile-compressive asymmetry, and the formation of internal loops due to incomplete phase transformation. In addition, because of their importance for practical design considerations, the paper discusses functional and structural fatigue, and fracture mechanics of SMAs.

  1. Hybrid triple-level-cell/multi-level-cell NAND flash storage array with chip exchangeable method

    NASA Astrophysics Data System (ADS)

    Hachiya, Shogo; Johguchi, Koh; Miyaji, Kousuke; Takeuchi, Ken

    2014-01-01

    This paper proposes a mix-and-match design method for triple level cell (TLC)/multi level cell (MLC) NAND flash hybrid and exchangeable storage arrays. A TLC-NAND flash provides an low cost and high capacity memory solution. However the reliability and access latency of TLC NAND flash are degraded from MLC NAND flash. Additionally, the block unit write is preferable for TLC NAND flash since the write order is complicated due to narrow data margin and write disturbance. The proposed solution combines TLC and MLC NAND flash memories for a storage array. To reduce access to TLC NAND flash, the stored data is screened and only the static frozen data are stored into TLC NAND flash with a Round-Robin frozen data collection algorithm (RR-FDCA). Furthermore, the proposed chip exchanging method extends the solid-state drive (SSD) lifetime without system suspending. As a result, in spite of moderate characteristics of TLC NAND flash, the proposed storage array can achieve 29% write energy saving and 56% write performance enhancement with 17% cost reduction, compared with the conventional MLC-only SSD.

  2. Probabilistic Flash Flood Forecasting using Stormscale Ensembles

    NASA Astrophysics Data System (ADS)

    Hardy, J.; Gourley, J. J.; Kain, J. S.; Clark, A.; Novak, D.; Hong, Y.

    2013-12-01

    Flash flooding is one of the most costly and deadly natural hazards in the US and across the globe. The loss of life and property from flash floods could be mitigated with better guidance from hydrological models, but these models have limitations. For example, they are commonly initialized using rainfall estimates derived from weather radars, but the time interval between observations of heavy rainfall and a flash flood can be on the order of minutes, particularly for small basins in urban settings. Increasing the lead time for these events is critical for protecting life and property. Therefore, this study advances the use of quantitative precipitation forecasts (QPFs) from a stormscale NWP ensemble system into a distributed hydrological model setting to yield basin-specific, probabilistic flash flood forecasts (PFFFs). Rainfall error characteristics of the individual members are first diagnosed and quantified in terms of structure, amplitude, and location (SAL; Wernli et al., 2008). Amplitude and structure errors are readily correctable due to their diurnal nature, and the fine scales represented by the CAPS QPF members are consistent with radar-observed rainfall, mainly showing larger errors with afternoon convection. To account for the spatial uncertainty of the QPFs, we use an elliptic smoother, as in Marsh et al. (2012), to produce probabilistic QPFs (PQPFs). The elliptic smoother takes into consideration underdispersion, which is notoriously associated with stormscale ensembles, and thus, is good for targeting the approximate regions that may receive heavy rainfall. However, stormscale details contained in individual members are still needed to yield reasonable flash flood simulations. Therefore, on a case study basis, QPFs from individual members are then run through the hydrological model with their predicted structure and corrected amplitudes, but the locations of individual rainfall elements are perturbed within the PQPF elliptical regions using Monte

  3. Tuning the cache memory usage in tomographic reconstruction on standard computers with Advanced Vector eXtensions (AVX).

    PubMed

    Agulleiro, Jose-Ignacio; Fernandez, Jose-Jesus

    2015-06-01

    Cache blocking is a technique widely used in scientific computing to minimize the exchange of information with main memory by reusing the data kept in cache memory. In tomographic reconstruction on standard computers using vector instructions, cache blocking turns out to be central to optimize performance. To this end, sinograms of the tilt-series and slices of the volumes to be reconstructed have to be divided into small blocks that fit into the different levels of cache memory. The code is then reorganized so as to operate with a block as much as possible before proceeding with another one. This data article is related to the research article titled Tomo3D 2.0 - Exploitation of Advanced Vector eXtensions (AVX) for 3D reconstruction (Agulleiro and Fernandez, 2015) [1]. Here we present data of a thorough study of the performance of tomographic reconstruction by varying cache block sizes, which allows derivation of expressions for their automatic quasi-optimal tuning. PMID:26217710

  4. Constructing Patriotism: Teaching History and Memories in Global Worlds. Advances in Cultural Psychology: Constructing Human Development

    ERIC Educational Resources Information Center

    Carretero, Mario

    2011-01-01

    Memory construction and national identity are key issues in our societies, as well as it is patriotism. How can we nowadays believe and give sense to traditional narrations that explain the origins of nations and communities? How do these narrations function in a process of globalization? How should we remember the recent past? In the construction…

  5. Advances in Early Memory Development Research: Insights about the Dark Side of the Moon

    ERIC Educational Resources Information Center

    Courage, Mary L.; Howe, Mark L.

    2004-01-01

    Over the past three decades impressive progress has been made in documenting the development of encoding, storage, and retrieval processes in preverbal infants and children. This literature includes an extensive and diverse database as well as theoretical conjecture about the underlying processes that drive early memory development. A selective…

  6. Analog Nonvolatile Computer Memory Circuits

    NASA Technical Reports Server (NTRS)

    MacLeod, Todd

    2007-01-01

    In nonvolatile random-access memory (RAM) circuits of a proposed type, digital data would be stored in analog form in ferroelectric field-effect transistors (FFETs). This type of memory circuit would offer advantages over prior volatile and nonvolatile types: In a conventional complementary metal oxide/semiconductor static RAM, six transistors must be used to store one bit, and storage is volatile in that data are lost when power is turned off. In a conventional dynamic RAM, three transistors must be used to store one bit, and the stored bit must be refreshed every few milliseconds. In contrast, in a RAM according to the proposal, data would be retained when power was turned off, each memory cell would contain only two FFETs, and the cell could store multiple bits (the exact number of bits depending on the specific design). Conventional flash memory circuits afford nonvolatile storage, but they operate at reading and writing times of the order of thousands of conventional computer memory reading and writing times and, hence, are suitable for use only as off-line storage devices. In addition, flash memories cease to function after limited numbers of writing cycles. The proposed memory circuits would not be subject to either of these limitations. Prior developmental nonvolatile ferroelectric memories are limited to one bit per cell, whereas, as stated above, the proposed memories would not be so limited. The design of a memory circuit according to the proposal must reflect the fact that FFET storage is only partly nonvolatile, in that the signal stored in an FFET decays gradually over time. (Retention times of some advanced FFETs exceed ten years.) Instead of storing a single bit of data as either a positively or negatively saturated state in a ferroelectric device, each memory cell according to the proposal would store two values. The two FFETs in each cell would be denoted the storage FFET and the control FFET. The storage FFET would store an analog signal value

  7. Challenges of Computing with FLASH on Largest HPC Platforms

    NASA Astrophysics Data System (ADS)

    Dubey, A.; Daley, C.; Weide, K.

    2010-09-01

    FLASH is a highly capable multiphysics multiscale modular extensible code, originally designed for simulating reactive flows. FLASH consists of interoperable modules that can be combined to generate different applications such as simulations of novae, supernovae, X-Ray bursts, galaxy clusters, weakly compressible turbulence, and many other problems in astrophysics and other fields. FLASH has a wide user base, both within and outside the Flash Center, and is regularly used on largest available HPC platforms. With each new platform we encounter a new set of challenges, because the multiscale multiphysics nature of FLASH simulations exercise the machine's hardware and system software greatly. The increase in the degree of concurrency with each new hardware generation has imposed changes on some of FLASH's parallel algorithms. The pace of change has accelerated with the move towards petascale, and then to exascale. In this work we present some of our scaling hurdles and their solutions. In addition we discuss a more fundamental transition in the code to incorporate a hybrid shared and distributed memory model in preparation for the future million- to billion-way parallelism.

  8. EDITORIAL: Van der Waals interactions in advanced materials, in memory of David C Langreth Van der Waals interactions in advanced materials, in memory of David C Langreth

    NASA Astrophysics Data System (ADS)

    Hyldgaard, Per; Rahman, Talat S.

    2012-10-01

    sufficiently close to any corrugated—and/or any smooth—surface and thus enforce a strong vdW-type adhesion; it exploits what is then essentially a contact force (dominated by the attraction exerted in the near-surface regions) to defy the pull of gravity on its own bulk. This Journal of Physics: Condensed Matter special issue is dedicated to the memory of David C Langreth. David is a dearly missed friend and mentor who inspired many of us. He was an outstanding condensed matter theorist and a scholar who greatly influenced us through his many-particle-physics based insights into density functional theory (DFT), surface science and related areas. His seminal works range from conserving formulations of interacting nonequilibrium transport [1] and formal-scattering theory [2] to an explicit formulation [3] of the exact DFT exchange-correlation energy in the adiabatic connection formula (ACF), the latter also being derived independently by Gunnarsson and Lundqvist [4]. David's portfolio also includes an analysis [5] that helped catalyze and guide the development of DFT from the local-density approximation (LDA) to the formulations of generalized gradient approximations (GGAs). Another salient contribution of David's is in the area of vdW interactions in materials. He was a key architect of the vdW density functional (vdW-DF) method [6, 7]. This method was developed in a long-standing Rutgers-Chalmers collaboration between David's group and that of Bengt I Lundqvist, later extending to a wider group of researchers on both sides of the Atlantic. Plasmons are collective excitations that depend on electron-density variation. The plasmon response can be seen as defining the nature of the LDA [4] and their description can thus also be seen as contributing to the success of GGA. The vdW-DF method is a regular constraint-based density functional (for ground-state DFT) which is derived within the ACF framework and which emphasizes the electrodynamical nature of the coupling between

  9. Flash Rust & Waterjetting Study

    SciTech Connect

    DORSH, P.M..

    2001-11-14

    Certain areas of the primary wall in the AY-101 tank annulus are being cleaned with a remotely operated waterjet. There is some concern on how it will effect the surface of the tank wall after cleaning and how to prevent rust and corrosion from developing on the wall in the future. This study addresses the cause and effects of flash rust, which typically develops on steel surfaces after the waterjetting process.

  10. Coherent imaging at FLASH

    NASA Astrophysics Data System (ADS)

    Chapman, H. N.; Bajt, S.; Barty, A.; Benner, W. H.; Bogan, M. J.; Boutet, S.; Cavalleri, A.; Duesterer, S.; Frank, M.; Hajdu, J.; Hau-Riege, S. P.; Iwan, B.; Marchesini, S.; Sakdinawat, A.; Sokolowski-Tinten, K.; Seibert, M. M.; Timneanu, N.; Treusch, R.; Woods, B. W.

    2009-09-01

    We have carried out high-resolution single-pulse coherent diffractive imaging at the FLASH free-electron laser. The intense focused FEL pulse gives a high-resolution low-noise coherent diffraction pattern of an object before that object turns into a plasma and explodes. In particular we are developing imaging of biological specimens beyond conventional radiation damage resolution limits, developing imaging of ultrafast processes, and testing methods to characterize and perform single-particle imaging.

  11. Method of forming tiny silicon nitride spacer for flash EPROM

    NASA Astrophysics Data System (ADS)

    Liu, H. H.; Wu, K. C.; Hwang, Yuan-Ko; Chen, Shih-Shiung

    2001-04-01

    The silicon nitride spacer technology is widely used in split gate non-volatile memory device sand flash EPROM. A tiny spacer structure is formed on tunnel oxide layer adjacent to the sidewall of floating gate electrode to prevent write disturbance that caused by reverse tunneling. But the processing is very critical for such flash EPROM devices since the dimension the SN spacer are so small. It was influenced not only by SN spacer dry etching but also later photo-resistance strip process of implantation for threshold voltage adjustment. A new method of forming tiny SN spacer by using anisotropic dry etching and isotropic wet etching was presented in this paper.

  12. Optimal flash rate and duty cycle for flashing visual indicators.

    NASA Technical Reports Server (NTRS)

    Markowitz, J.

    1971-01-01

    This experiment examined the ability of observers to determine, as quickly as possible, whether a visual indicator was steadily on or flashing. Six flash rates (periods) were combined factorially with three duty cycles (on-off ratios) to define 18 ?types' of intermittent signals. Experimental sessions were divided into six runs of 100 trials, each run utilizing one of the six flash rates. On any given trial in a run, the probability of a steady signal occurring was 0.5 and the probability of a flashing signal occurring was 0.5. A different duty cycle was employed daily for each experimental session. In all, 400 trials were devoted to each of the flash rates at each duty cycle. Accuracy and latency of response were the dependent variables of interest. The results show that the observers view the light for an interval of time appropriate to the expected flash rate and duty cycle; whether they judge the light to be steady or intermittent depends upon whether the light is extinguished during the predetermined waiting period. Adoption of this temporal criterion delays responding in comparison to those tasks involving responses to light onset. The decision or response criteria held by the observers are also sensitive to the parameters of the flashing light: observers become increasingly willing to call a flashing light ?steady' as flash duration increases.

  13. Advances in the behavioural testing and network imaging of rodent recognition memory.

    PubMed

    Kinnavane, Lisa; Albasser, Mathieu M; Aggleton, John P

    2015-05-15

    Research into object recognition memory has been galvanised by the introduction of spontaneous preference tests for rodents. The standard task, however, contains a number of inherent shortcomings that reduce its power. Particular issues include the problem that individual trials are time consuming, so limiting the total number of trials in any condition. In addition, the spontaneous nature of the behaviour and the variability between test objects add unwanted noise. To combat these issues, the 'bow-tie maze' was introduced. Although still based on the spontaneous preference of novel over familiar stimuli, the ability to give multiple trials within a session without handling the rodents, as well as using the same objects as both novel and familiar samples on different trials, overcomes key limitations in the standard task. Giving multiple trials within a single session also creates new opportunities for functional imaging of object recognition memory. A series of studies are described that examine the expression of the immediate-early gene, c-fos. Object recognition memory is associated with increases in perirhinal cortex and area Te2 c-fos activity. When rats explore novel objects the pathway from the perirhinal cortex to lateral entorhinal cortex, and then to the dentate gyrus and CA3, is engaged. In contrast, when familiar objects are explored the pathway from the perirhinal cortex to lateral entorhinal cortex, and then to CA1, takes precedence. The switch to the perforant pathway (novel stimuli) from the temporoammonic pathway (familiar stimuli) may assist the enhanced associative learning promoted by novel stimuli.

  14. The future of memory

    NASA Astrophysics Data System (ADS)

    Marinella, M.

    In the not too distant future, the traditional memory and storage hierarchy of may be replaced by a single Storage Class Memory (SCM) device integrated on or near the logic processor. Traditional magnetic hard drives, NAND flash, DRAM, and higher level caches (L2 and up) will be replaced with a single high performance memory device. The Storage Class Memory paradigm will require high speed (< 100 ns read/write), excellent endurance (> 1012), nonvolatility (retention > 10 years), and low switching energies (< 10 pJ per switch). The International Technology Roadmap for Semiconductors (ITRS) has recently evaluated several potential candidates SCM technologies, including Resistive (or Redox) RAM, Spin Torque Transfer RAM (STT-MRAM), and phase change memory (PCM). All of these devices show potential well beyond that of current flash technologies and research efforts are underway to improve the endurance, write speeds, and scalabilities to be on-par with DRAM. This progress has interesting implications for space electronics: each of these emerging device technologies show excellent resistance to the types of radiation typically found in space applications. Commercially developed, high density storage class memory-based systems may include a memory that is physically radiation hard, and suitable for space applications without major shielding efforts. This paper reviews the Storage Class Memory concept, emerging memory devices, and possible applicability to radiation hardened electronics for space.

  15. Preliminary design of the BPM electronics memory scanner/dual boxcar averager for the Advanced Photon Source

    SciTech Connect

    Votaw, A.J.

    1992-12-31

    The memory scanner/dual boxcar averager are VXI modules that are part of the Advanced Photon Source (APS) beam position monitor (BPM) data acquisition system. Each pair of modules is designed to gather and process digital data from up to nine digital channels transmitting the BPM data from the storage ring (360 locations) and the synchrotron (80 locations). They store beam history in a buffer, store the latest scan of all channels, and provide boxcar averaged X and Y position data for the global orbit feedback system, provide boxcar average X and Y position data for beam diagnostics, and a buffered output of SCDU data as it is scanned for the beam abort interlock system. The system`s capability to support single pass, closed orbit and tune measurement functions will also be briefly described.

  16. Preliminary design of the BPM electronics memory scanner/dual boxcar averager for the Advanced Photon Source

    SciTech Connect

    Votaw, A.J.

    1992-01-01

    The memory scanner/dual boxcar averager are VXI modules that are part of the Advanced Photon Source (APS) beam position monitor (BPM) data acquisition system. Each pair of modules is designed to gather and process digital data from up to nine digital channels transmitting the BPM data from the storage ring (360 locations) and the synchrotron (80 locations). They store beam history in a buffer, store the latest scan of all channels, and provide boxcar averaged X and Y position data for the global orbit feedback system, provide boxcar average X and Y position data for beam diagnostics, and a buffered output of SCDU data as it is scanned for the beam abort interlock system. The system's capability to support single pass, closed orbit and tune measurement functions will also be briefly described.

  17. Flash Proton Radiography

    NASA Astrophysics Data System (ADS)

    Merrill, Frank E.

    Protons were first investigated as radiographic probes as high energy proton accelerators became accessible to the scientific community in the 1960s. Like the initial use of X-rays in the 1800s, protons were shown to be a useful tool for studying the contents of opaque materials, but the electromagnetic charge of the protons opened up a new set of interaction processes which complicated their use. These complications in combination with the high expense of generating protons with energies high enough to penetrate typical objects resulted in proton radiography becoming a novelty, demonstrated at accelerator facilities, but not utilized to their full potential until the 1990s at Los Alamos. During this time Los Alamos National Laboratory was investigating a wide range of options, including X-rays and neutrons, as the next generation of probes to be used for thick object flash radiography. During this process it was realized that the charge nature of the protons, which was the source of the initial difficulty with this idea, could be used to recover this technique. By introducing a magnetic imaging lens downstream of the object to be radiographed, the blur resulting from scattering within the object could be focused out of the measurements, dramatically improving the resolution of proton radiography of thick systems. Imaging systems were quickly developed and combined with the temporal structure of a proton beam generated by a linear accelerator, providing a unique flash radiography capability for measurements at Los Alamos National Laboratory. This technique has now been employed at LANSCE for two decades and has been adopted around the world as the premier flash radiography technique for the study of dynamic material properties.

  18. Flash evaporator systems test

    NASA Technical Reports Server (NTRS)

    Dietz, J. B.

    1976-01-01

    A flash evaporator heat rejection system representative of that proposed for the space shuttle orbiter underwent extensive system testing at the NASA Johnson Space Center (JSC) to determine its operational suitability and to establish system performance/operational characteristics for use in the shuttle system. During the tests the evaporator system demonstrated its suitability to meet the shuttle requirements by: (1) efficient operation with 90 to 95% water evaporation efficiency, (2) control of outlet temperature to 40 + or - 2 F for partial heat load operation, (3) stability of control system for rapid changes in Freon inlet temperature, and (4) repeated dormant-to-active device operation without any startup procedures.

  19. Methods of flash sintering

    DOEpatents

    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.

  20. Memory Dysfunction

    PubMed Central

    Matthews, Brandy R.

    2015-01-01

    Purpose of Review: This article highlights the dissociable human memory systems of episodic, semantic, and procedural memory in the context of neurologic illnesses known to adversely affect specific neuroanatomic structures relevant to each memory system. Recent Findings: Advances in functional neuroimaging and refinement of neuropsychological and bedside assessment tools continue to support a model of multiple memory systems that are distinct yet complementary and to support the potential for one system to be engaged as a compensatory strategy when a counterpart system fails. Summary: Episodic memory, the ability to recall personal episodes, is the subtype of memory most often perceived as dysfunctional by patients and informants. Medial temporal lobe structures, especially the hippocampal formation and associated cortical and subcortical structures, are most often associated with episodic memory loss. Episodic memory dysfunction may present acutely, as in concussion; transiently, as in transient global amnesia (TGA); subacutely, as in thiamine deficiency; or chronically, as in Alzheimer disease. Semantic memory refers to acquired knowledge about the world. Anterior and inferior temporal lobe structures are most often associated with semantic memory loss. The semantic variant of primary progressive aphasia (svPPA) is the paradigmatic disorder resulting in predominant semantic memory dysfunction. Working memory, associated with frontal lobe function, is the active maintenance of information in the mind that can be potentially manipulated to complete goal-directed tasks. Procedural memory, the ability to learn skills that become automatic, involves the basal ganglia, cerebellum, and supplementary motor cortex. Parkinson disease and related disorders result in procedural memory deficits. Most memory concerns warrant bedside cognitive or neuropsychological evaluation and neuroimaging to assess for specific neuropathologies and guide treatment. PMID:26039844

  1. Flash pyrolysis of coal with reactive and non-reactive gases. [Methanolysis and flash pyrolysis

    SciTech Connect

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

    1985-06-01

    The purpose of this research is to perform a systematic study of the yield and distribution of products on the flash or rapid pyrolysis of various ranks of coal with non-reactive (N/sub 2/, Ar, He) and with reactive gases (H/sub 2/, CH/sub 4/, CO, CO/sub 2/, and H/sub 2/O) in an entrained flow reactor. A body of information has been obtained on the flash hydropyrolysis of coals with the use of H/sub 2/ gas. Data is in the process of being obtained with the other gases. The use of methane as a pyrolyzing gas has indicated a reaction with coal and has led to developing the process of flash methanolysis of coal. The addition of steam leads to the flash hydrolysis of coal. In addition to obtaining a better understanding of the gasification of coal, the developed process chemistry data can be used to design and evaluate advanced gasification processes. 7 figs.

  2. Vacuum flash evaporated polymer composites

    DOEpatents

    Affinito, John D.; Gross, Mark E.

    1997-01-01

    A method for fabrication of polymer composite layers in a vacuum is disclosed. More specifically, the method of dissolving salts in a monomer solution, vacuum flash evaporating the solution, condensing the flash evaporated solution as a liquid film, and forming the condensed liquid film into a polymer composite layer on a substrate is disclosed.

  3. Vacuum flash evaporated polymer composites

    DOEpatents

    Affinito, J.D.; Gross, M.E.

    1997-10-28

    A method for fabrication of polymer composite layers in a vacuum is disclosed. More specifically, the method of dissolving salts in a monomer solution, vacuum flash evaporating the solution, condensing the flash evaporated solution as a liquid film, and forming the condensed liquid film into a polymer composite layer on a substrate is disclosed.

  4. Geomorphological factors of flash floods

    NASA Astrophysics Data System (ADS)

    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.

  5. Flash on disk for low-power multimedia computing

    NASA Astrophysics Data System (ADS)

    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.

  6. Optimizing the performance of advanced nonvolatile memories using differentiated cell source and drain implants

    NASA Astrophysics Data System (ADS)

    Duncan, Martin; Pansana, P.

    1995-09-01

    In order to satisfy the twin requirements of increased performance at low cost, a novel architecture that allows the differentiation of the source and drain implants of an EPROM cell without any additional processing steps has been developed. This cell is more immune to electrical stress than a standard cell during both programming and read cycles. In addition, this cell is inherently electrically shorter and therefore can be used to reduce die size in advanced EPROM devices.

  7. Advanced compilation techniques in the PARADIGM compiler for distributed-memory multicomputers

    NASA Technical Reports Server (NTRS)

    Su, Ernesto; Lain, Antonio; Ramaswamy, Shankar; Palermo, Daniel J.; Hodges, Eugene W., IV; Banerjee, Prithviraj

    1995-01-01

    The PARADIGM compiler project provides an automated means to parallelize programs, written in a serial programming model, for efficient execution on distributed-memory multicomputers. .A previous implementation of the compiler based on the PTD representation allowed symbolic array sizes, affine loop bounds and array subscripts, and variable number of processors, provided that arrays were single or multi-dimensionally block distributed. The techniques presented here extend the compiler to also accept multidimensional cyclic and block-cyclic distributions within a uniform symbolic framework. These extensions demand more sophisticated symbolic manipulation capabilities. A novel aspect of our approach is to meet this demand by interfacing PARADIGM with a powerful off-the-shelf symbolic package, Mathematica. This paper describes some of the Mathematica routines that performs various transformations, shows how they are invoked and used by the compiler to overcome the new challenges, and presents experimental results for code involving cyclic and block-cyclic arrays as evidence of the feasibility of the approach.

  8. Quick-low-density parity check and dynamic threshold voltage optimization in 1X nm triple-level cell NAND flash memory with comprehensive analysis of endurance, retention-time, and temperature variation

    NASA Astrophysics Data System (ADS)

    Doi, Masafumi; Tokutomi, Tsukasa; Hachiya, Shogo; Kobayashi, Atsuro; Tanakamaru, Shuhei; Ning, Sheyang; Ogura Iwasaki, Tomoko; Takeuchi, Ken

    2016-08-01

    NAND flash memory’s reliability degrades with increasing endurance, retention-time and/or temperature. After a comprehensive evaluation of 1X nm triple-level cell (TLC) NAND flash, two highly reliable techniques are proposed. The first proposal, quick low-density parity check (Quick-LDPC), requires only one cell read in order to accurately estimate a bit-error rate (BER) that includes the effects of temperature, write and erase (W/E) cycles and retention-time. As a result, 83% read latency reduction is achieved compared to conventional AEP-LDPC. Also, W/E cycling is extended by 100% compared with conventional Bose-Chaudhuri-Hocquenghem (BCH) error-correcting code (ECC). The second proposal, dynamic threshold voltage optimization (DVO) has two parts, adaptive V Ref shift (AVS) and V TH space control (VSC). AVS reduces read error and latency by adaptively optimizing the reference voltage (V Ref) based on temperature, W/E cycles and retention-time. AVS stores the optimal V Ref’s in a table in order to enable one cell read. VSC further improves AVS by optimizing the voltage margins between V TH states. DVO reduces BER by 80%.

  9. Quick-low-density parity check and dynamic threshold voltage optimization in 1X nm triple-level cell NAND flash memory with comprehensive analysis of endurance, retention-time, and temperature variation

    NASA Astrophysics Data System (ADS)

    Doi, Masafumi; Tokutomi, Tsukasa; Hachiya, Shogo; Kobayashi, Atsuro; Tanakamaru, Shuhei; Ning, Sheyang; Ogura Iwasaki, Tomoko; Takeuchi, Ken

    2016-08-01

    NAND flash memory’s reliability degrades with increasing endurance, retention-time and/or temperature. After a comprehensive evaluation of 1X nm triple-level cell (TLC) NAND flash, two highly reliable techniques are proposed. The first proposal, quick low-density parity check (Quick-LDPC), requires only one cell read in order to accurately estimate a bit-error rate (BER) that includes the effects of temperature, write and erase (W/E) cycles and retention-time. As a result, 83% read latency reduction is achieved compared to conventional AEP-LDPC. Also, W/E cycling is extended by 100% compared with conventional Bose–Chaudhuri–Hocquenghem (BCH) error-correcting code (ECC). The second proposal, dynamic threshold voltage optimization (DVO) has two parts, adaptive V Ref shift (AVS) and V TH space control (VSC). AVS reduces read error and latency by adaptively optimizing the reference voltage (V Ref) based on temperature, W/E cycles and retention-time. AVS stores the optimal V Ref’s in a table in order to enable one cell read. VSC further improves AVS by optimizing the voltage margins between V TH states. DVO reduces BER by 80%.

  10. Memory-efficient table look-up optimized algorithm for context-based adaptive variable length decoding in H.264/advanced video coding

    NASA Astrophysics Data System (ADS)

    Wang, Jianhua; Cheng, Lianglun; Wang, Tao; Peng, Xiaodong

    2016-03-01

    Table look-up operation plays a very important role during the decoding processing of context-based adaptive variable length decoding (CAVLD) in H.264/advanced video coding (AVC). However, frequent table look-up operation can result in big table memory access, and then lead to high table power consumption. Aiming to solve the problem of big table memory access of current methods, and then reduce high power consumption, a memory-efficient table look-up optimized algorithm is presented for CAVLD. The contribution of this paper lies that index search technology is introduced to reduce big memory access for table look-up, and then reduce high table power consumption. Specifically, in our schemes, we use index search technology to reduce memory access by reducing the searching and matching operations for code_word on the basis of taking advantage of the internal relationship among length of zero in code_prefix, value of code_suffix and code_lengh, thus saving the power consumption of table look-up. The experimental results show that our proposed table look-up algorithm based on index search can lower about 60% memory access consumption compared with table look-up by sequential search scheme, and then save much power consumption for CAVLD in H.264/AVC.

  11. FLASH LIDAR Based Relative Navigation

    NASA Technical Reports Server (NTRS)

    Brazzel, Jack; Clark, Fred; Milenkovic, Zoran

    2014-01-01

    Relative navigation remains the most challenging part of spacecraft rendezvous and docking. In recent years, flash LIDARs, have been increasingly selected as the go-to sensors for proximity operations and docking. Flash LIDARS are generally lighter and require less power that scanning Lidars. Flash LIDARs do not have moving parts, and they are capable of tracking multiple targets as well as generating a 3D map of a given target. However, there are some significant drawbacks of Flash Lidars that must be resolved if their use is to be of long-term significance. Overcoming the challenges of Flash LIDARs for navigation-namely, low technology readiness level, lack of historical performance data, target identification, existence of false positives, and performance of vision processing algorithms as intermediaries between the raw sensor data and the Kalman filter-requires a world-class testing facility, such as the Lockheed Martin Space Operations Simulation Center (SOSC). Ground-based testing is a critical step for maturing the next-generation flash LIDAR-based spacecraft relative navigation. This paper will focus on the tests of an integrated relative navigation system conducted at the SOSC in January 2014. The intent of the tests was to characterize and then improve the performance of relative navigation, while addressing many of the flash LIDAR challenges mentioned above. A section on navigation performance and future recommendation completes the discussion.

  12. Compact 3D flash lidar video cameras and applications

    NASA Astrophysics Data System (ADS)

    Stettner, Roger

    2010-04-01

    The theory and operation of Advanced Scientific Concepts, Inc.'s (ASC) latest compact 3D Flash LIDAR Video Cameras (3D FLVCs) and a growing number of technical problems and solutions are discussed. The solutions range from space shuttle docking, planetary entry, decent and landing, surveillance, autonomous and manned ground vehicle navigation and 3D imaging through particle obscurants.

  13. Flash Smelting of Lead Concentrates

    NASA Astrophysics Data System (ADS)

    Nermes, Esko O.; Talonen, Timo T.

    1982-11-01

    Oxygen-autogenous flash smelting of lead concentrates followed by slag reduction by injection coal in an electric furnace has been developed and is ready for commercial application. Pilot-plant studies demonstrate that the process works. Pilot studies have established process characteristics. The process is easily controlled. Process equipment and operation are based on the extensive experience with Outokumpu flash smelting technology in smelting copper and nickel. The process equipment is small, even for high capacities. Flash smelter and electric furnace equipment are designed for close fit in order to meet the environmental control requirements.

  14. An energy-efficient SIMD DSP with multiple VLIW configurations and an advanced memory access unit for LTE-A modem LSIs

    NASA Astrophysics Data System (ADS)

    Tomono, Mitsuru; Ito, Makiko; Nomura, Yoshitaka; Mouri, Makoto; Hirose, Yoshio

    2015-12-01

    Energy efficiency is the most important factor in the design of wireless modem LSIs for mobile handset systems. We have developed an energy-efficient SIMD DSP for LTE-A modem LSIs. Our DSP has mainly two hardware features in order to reduce energy consumption. The first one is multiple VLIW configurations to minimize accesses to instruction memories. The second one is an advanced memory access unit to realize complex memory accesses required for wireless baseband processing. With these features, performance of our DSP is about 1.7 times faster than a base DSP on average for standard LTE-A Libraries. Our DSP achieves about 20% improvement in energy efficiency compared to a base DSP for LTE-A modem LSIs.

  15. Advanced Engine Cycles Analyzed for Turbofans With Variable-Area Fan Nozzles Actuated by a Shape Memory Alloy

    NASA Technical Reports Server (NTRS)

    Berton, Jeffrey J.

    2002-01-01

    Advanced, large commercial turbofan engines using low-fan-pressure-ratio, very high bypass ratio thermodynamic cycles can offer significant fuel savings over engines currently in operation. Several technological challenges must be addressed, however, before these engines can be designed. To name a few, the high-diameter fans associated with these engines pose a significant packaging and aircraft installation challenge, and a large, heavy gearbox is often necessary to address the differences in ideal operating speeds between the fan and the low-pressure turbine. Also, the large nacelles contribute aerodynamic drag penalties and require long, heavy landing gear when mounted on conventional, low wing aircraft. Nevertheless, the reduced fuel consumption rates of these engines are a compelling economic incentive, and fans designed with low pressure ratios and low tip speeds offer attractive noise-reduction benefits. Another complication associated with low-pressure-ratio fans is their need for variable flow-path geometry. As the design fan pressure ratio is reduced below about 1.4, an operational disparity is set up in the fan between high and low flight speeds. In other words, between takeoff and cruise there is too large a swing in several key fan parameters-- such as speed, flow, and pressure--for a fan to accommodate. One solution to this problem is to make use of a variable-area fan nozzle (VAFN). However, conventional, hydraulically actuated variable nozzles have weight, cost, maintenance, and reliability issues that discourage their use with low-fan-pressure-ratio engine cycles. United Technologies Research, in cooperation with NASA, is developing a revolutionary, lightweight, and reliable shape memory alloy actuator system that can change the on-demand nozzle exit area by up to 20 percent. This "smart material" actuation technology, being studied under NASA's Ultra-Efficient Engine Technology (UEET) Program and Revolutionary Concepts in Aeronautics (Rev

  16. The Management of Advanced Germ Cell Tumors in 2016: The Memorial Sloan Kettering Approach.

    PubMed

    Funt, Samuel A; Feldman, Darren R; Bosl, George J

    2016-07-01

    The high cure rate of patients with advanced germ cell tumors is the result of effective cisplatin-based chemotherapy; both previously untreated and relapsing patients can be cured. Risk stratification is particularly important in previously untreated patients. While retrospective salvage therapy analyses suggest that a number of clinical factors are associated with outcome, the appropriate selection of patients for, and the sequencing of, conventional- and high-dose regimens are subjects of debate because of the introduction of paclitaxel and different approaches to the administration of high-dose chemotherapy. This therapeutic landscape has been molded in part by our current understanding of treatment-associated toxicity. In this paper, we review the use of serum tumor markers in risk assignment and response evaluation; the treatment of previously untreated and relapsing patients; the role of surgical resection of residual disease, including retroperitoneal node dissection; and the importance of clinical trials for addressing unanswered questions and testing new therapies. Management controversies and possible future treatment enhancements that incorporate serum tumor marker decline and tumor genomics will also be discussed. PMID:27422113

  17. Honeywell optical investigations on FLASH program

    NASA Astrophysics Data System (ADS)

    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.

  18. Menopausal hot flashes: Randomness or rhythmicity

    NASA Astrophysics Data System (ADS)

    Kronenberg, Fredi

    1991-10-01

    Menopausal hot flashes are episodes of flushing, increased heart rate, skin blood flow and skin temperature, and a sensation of heat. The thermoregulatory and cardiovascular concomitants of hot flashes are associated with peaks in the levels of various hormones and neurotransmitters in the peripheral circulation. Although hot flashes affect about 75% of women, and are the primary reason that women at menopause seek medical attention, the mechanism of hot flashes is still not understood. Hot flashes vary in frequency and intensity both within and between individuals, and have been thought of as occurring randomly. Yet, some women report that their hot flashes are worse at a particular time of day or year. Initial examination of subjects' recordings of their hot flashes showed diurnal patterns of hot flash occurrence. There also seems to be a diurnal rhythm of hot flash intensity. Continuous physiological monitoring of hot flashes is facilitating the analysis of these patterns, which is revealing circadian and ultradian periodicities. The occurrence of hot flashes can be modulated by external and internal factors, including ambient temperature and fever. Rhythms of thermoregulatory and endocrine functions also may influence hot flash patterns. Examination of the interrelationships between the various systems of the body involved in hot flashes, and a multidisciplinary approach to the analysis of hot flash patterns, will aid our understanding of this complex phenomenon.

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Electronic Flash In Data Acquisition

    NASA Astrophysics Data System (ADS)

    Miller, C. E.

    1982-02-01

    Photographic acquisition of data often may be simplified, or the data quality improved upon by employing electronic flash sources with traditional equipment or techniques. The relatively short flash duration compared to movie camera shutters, or to the long integration time of video camera provides improved spatial resolution through blur reduction, particularly important as image movement becomes a significant fraction of film format dimension. Greater accuracy typically is achieved in velocity and acceleration determinations by using a stroboscopic light source rather than a movie camera frame-rate control as a time standard. Electrical efficiency often is an important advantage of electronic flash sources since almost any necessary light level for exposure may be produced, yet the source typically is "off" most of the time. Various synchronization techniques greatly expand the precise control of exposure. Biomechanical and sports equipment studies may involve velocities up to 200 feet-per-second, and often will have associated very rapid actions of interest. The need for brief exposures increases H.s one "ZOOMS in on the action." In golf, for example, the swing may be examined using 100 microsecond (Us) flashes at rates of 60 or 120 flashes-per-second (FPS). Accurate determination of linear and rotational velocity of the ball requires 10 Us flashes at 500-1,000 FPS, while sub-Us flashes at 20,000-50,000 FPS are required to resolve the interaction of the ball and the club, head. Some seldom. used techniques involving streak photography are described, with enhanced results obtained by combining strobe with the usual continuous light source. The combination of strobe and a fast electro-mechanical shutter is considered for Us photography under daylight conditions.

  1. Nonvolatile Memory Technology for Space Applications

    NASA Technical Reports Server (NTRS)

    Oldham, Timothy R.; Irom, Farokh; Friendlich, Mark; Nguyen, Duc; Kim, Hak; Berg, Melanie; LaBel, Kenneth A.

    2010-01-01

    This slide presentation reviews several forms of nonvolatile memory for use in space applications. The intent is to: (1) Determine inherent radiation tolerance and sensitivities, (2) Identify challenges for future radiation hardening efforts, (3) Investigate new failure modes and effects, and technology modeling programs. Testing includes total dose, single event (proton, laser, heavy ion), and proton damage (where appropriate). Test vehicles are expected to be a variety of non-volatile memory devices as available including Flash (NAND and NOR), Charge Trap, Nanocrystal Flash, Magnetic Memory (MRAM), Phase Change--Chalcogenide, (CRAM), Ferroelectric (FRAM), CNT, and Resistive RAM.

  2. From silicon to organic nanoparticle memory devices.

    PubMed

    Tsoukalas, D

    2009-10-28

    After introducing the operational principle of nanoparticle memory devices, their current status in silicon technology is briefly presented in this work. The discussion then focuses on hybrid technologies, where silicon and organic materials have been combined together in a nanoparticle memory device, and finally concludes with the recent development of organic nanoparticle memories. The review is focused on the nanoparticle memory concept as an extension of the current flash memory device. Organic nanoparticle memories are at a very early stage of research and have not yet found applications. When this happens, it is expected that they will not directly compete with mature silicon technology but will find their own areas of application.

  3. Flashing light in microalgae biotechnology.

    PubMed

    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. PMID:26747205

  4. Flashing light in microalgae biotechnology.

    PubMed

    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.

  5. Flash sintering of ceramic materials

    NASA Astrophysics Data System (ADS)

    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.

  6. Review of Emerging New Solid-State Non-Volatile Memories

    NASA Astrophysics Data System (ADS)

    Fujisaki, Yoshihisa

    2013-04-01

    The integration limit of flash memories is approaching, and many new types of memory to replace conventional flash memories have been proposed. Unlike flash memories, new nonvolatile memories do not require storage of electric charges. The possibility of phase-change random-access memories (PCRAMs) or resistive-change RAMs (ReRAMs) replacing ultrahigh-density NAND flash memories has been investigated; however, many issues remain to be overcome, making the replacement difficult. Nonetheless, ferroelectric RAMs (FeRAMs) and magnetoresistive RAMs (MRAMs) are gradually penetrating into fields where the shortcomings of flash memories, such as high operating voltage, slow rewriting speed, and limited number of rewrites, make their use inconvenient. For instance, FeRAMs are widely used in ICs that require low power consumption such as smart cards and wireless tags. MRAMs are used in many kinds of controllers in industrial equipment that require high speed and unlimited rewrite operations. For successful application of new non-volatile semiconductor memories, such memories must be practically utilized in new fields in which flash memories are not applicable, and their technologies must be further developed.

  7. Researchers Identify Genes Linked to Hot Flashes

    MedlinePlus

    ... fullstory_161579.html Researchers Identify Genes Linked to Hot Flashes Mutations found in women of all races, ... Some women may be genetically predisposed to suffer hot flashes before or during menopause, a new study ...

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

    PubMed Central

    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

  9. Memory and the brain.

    PubMed

    Robertson, Lee T

    2002-01-01

    This review summarizes some of the recent advances in the neurobiology of memory. Current research helps us to understand how memories are created and, conversely, how our memories can be influenced by stress, drugs, and aging. An understanding of how memories are encoded by the brain may also lead to new ideas about how to maximize the long-term retention of important information. There are multiple memory systems with different functions and, in this review, we focus on the conscious recollection of one's experience of events and facts and on memories tied to emotional responses. Memories are also classified according to time: from short-term memory, lasting only seconds or minutes, to long-term memory, lasting months or years. The advent of new functional neuroimaging methods provides an opportunity to gain insight into how the human brain supports memory formation. Each memory system has a distinct anatomical organization, where different parts of the brain are recruited during phases of memory storage. Within the brain, memory is a dynamic property of populations of neurons and their interconnections. Memories are laid down in our brains via chemical changes at the neuron level. An understanding of the neurobiology of memory may stimulate health educators to consider how various teaching methods conform to the process of memory formation. PMID:12358099

  10. Undergraduate Separations Utilizing Flash Chromatography

    NASA Astrophysics Data System (ADS)

    Horowitz, G.

    2000-02-01

    This article describes the procedures used to carry out four flash chromatography experiments: the isolation of the carotenes, chlorophylls and xanthophylls from a spinach extract; the separation of ß-carotene from tetraphenyl cyclopentadienone; the isolation of (+) and (-) carvone from caraway and spearmint oil; and the purification of benzil from benzoin. Apparatus used is nonbreakable, easy to use, and inexpensive.

  11. Energy optimization in flash smelting

    SciTech Connect

    Partelpoeg, E.H.

    1985-01-01

    The copper smelting industry has been replacing old reverberatory furnaces with energy-efficient flash furnaces. While this in itself has been a significant move towards reduced energy costs, there is yet no industry consensus as to which mode of flash smelting is optimum. It is possible to model copper smelting, the ensuring converting step, and acid production with linear equations and inequalities. These equations include mass and heat balances, and energy and cost equations. The matrix of equations and inequalities can be entered into a linear programming routine to determine minimum costs. Such a model was developed and the results indicate that optimum smelting parameters include the following. (1) The grade of matte is 65% Cu. (2) The flash furnace operates autogenously with no air preheat. The flash furnace air is oxygen enriched to approximately 40 volume % O/sub 2/. (3) Total energy cost (1985 dollars and prices) for smelting, converting, and acid production is approximately $10 per tonne concentrate. The general model employed to obtain these optimum conditions can be modified to represent unique smelting conditions.

  12. Multi-stage flash degaser

    DOEpatents

    Rapier, P.M.

    1980-06-26

    A multi-stage flash degaser is incorporated in an energy conversion system 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 in order that the heat exchanger and a turbine and condenser of the system can operate at optimal efficiency.

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

    NASA Astrophysics Data System (ADS)

    Taverne, Paul; Pronk, C. (Kees)

    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 particular, Joshi and Holzmann's mini-challenge to build a verifiable file store. We have designed a simple robust file store and implemented it in the form of a Promela model. A test harness is used to exercise the file store in a number of ways. Model checking technology has been extensively used to verify the correctness of our implementation. A distinguishing feature of our approach is the (bounded) exhaustive verification of power loss recovery.

  14. From Secure Memories to Smart Card Security

    NASA Astrophysics Data System (ADS)

    Handschuh, Helena; Trichina, Elena

    Non-volatile memory is essential in most embedded security applications. It will store the key and other sensitive materials for cryptographic and security applications. In this chapter, first an overview is given of current flash memory architectures. Next the standard security features which form the basis of so-called secure memories are described in more detail. Smart cards are a typical embedded application that is very vulnerable to attacks and that at the same time has a high need for secure non-volatile memory. In the next part of this chapter, the secure memories of so-called flash-based high-density smart cards are described. It is followed by a detailed analysis of what the new security challenges for such objects are.

  15. Multi-stage flash degaser

    DOEpatents

    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.

  16. Flash photography-induced maculopathy

    PubMed Central

    Veugelen, Tim; Coutteel, Carine; Leys, Anita

    2011-01-01

    Objective: To report a flash photography-induced maculopathy. Methods: A professional photographer blinded himself accidentally and he consulted 3 days after the event with a scotoma in his dominant left eye. A unilateral acute light-induced maculopathy with hemorrhage was observed. The lesion was studied with colour photography, fluorescein and indocyanin angiography, autofluorescence imaging and repeated optical coherence tomography (OCT) imaging. Results: At age 43, this professional photographer was blinded by the flash light of his camera and subsequently realized he had a scotoma in his dominant eye. Three days after the event visual acuity (VA) was 20/70 and an acute light-induced maculopathy was noted. Another three days later, VA was 20/50 and the lesions were less prominent. After one month, the photographer still had problems making sharp pictures, VA was 20/25 and a macular scar was observed. During further follow-up, he regained full vision and experienced no professional problems. Conclusions: This case illustrates that the light of flash photography can accidentally hit an eye and induce a light-induced maculopathy.

  17. Flash photography-induced maculopathy

    PubMed Central

    Veugelen, Tim; Coutteel, Carine; Leys, Anita

    2011-01-01

    Objective: To report a flash photography-induced maculopathy. Methods: A professional photographer blinded himself accidentally and he consulted 3 days after the event with a scotoma in his dominant left eye. A unilateral acute light-induced maculopathy with hemorrhage was observed. The lesion was studied with colour photography, fluorescein and indocyanin angiography, autofluorescence imaging and repeated optical coherence tomography (OCT) imaging. Results: At age 43, this professional photographer was blinded by the flash light of his camera and subsequently realized he had a scotoma in his dominant eye. Three days after the event visual acuity (VA) was 20/70 and an acute light-induced maculopathy was noted. Another three days later, VA was 20/50 and the lesions were less prominent. After one month, the photographer still had problems making sharp pictures, VA was 20/25 and a macular scar was observed. During further follow-up, he regained full vision and experienced no professional problems. Conclusions: This case illustrates that the light of flash photography can accidentally hit an eye and induce a light-induced maculopathy. PMID:27625926

  18. The vertical lobe of cephalopods: an attractive brain structure for understanding the evolution of advanced learning and memory systems.

    PubMed

    Shomrat, T; Turchetti-Maia, A L; Stern-Mentch, N; Basil, J A; Hochner, B

    2015-09-01

    In this review we show that the cephalopod vertical lobe (VL) provides a good system for assessing the level of evolutionary convergence of the function and organization of neuronal circuitry for mediating learning and memory in animals with complex behavior. The pioneering work of JZ Young described the morphological convergence of the VL with the mammalian hippocampus, cerebellum and the insect mushroom body. Studies in octopus and cuttlefish VL networks suggest evolutionary convergence into a universal organization of connectivity as a divergence-convergence ('fan-out fan-in') network with activity-dependent long-term plasticity mechanisms. Yet, these studies also show that the properties of the neurons, neurotransmitters, neuromodulators and mechanisms of long-term potentiation (LTP) induction and maintenance are highly variable among different species. This suggests that complex networks may have evolved independently multiple times and that even though memory and learning networks share similar organization and cellular processes, there are many molecular ways of constructing them.

  19. Flash Galaxy Cluster Merger, Simulated using the Flash Code, Mass Ratio 1:1

    ScienceCinema

    None

    2016-07-12

    Since structure in the universe forms in a bottom-up fashion, with smaller structures merging to form larger ones, modeling the merging process in detail is crucial to our understanding of cosmology. At the current epoch, we observe clusters of galaxies undergoing mergers. It is seen that the two major components of galaxy clusters, the hot intracluster gas and the dark matter, behave very differently during the course of a merger. Using the N-body and hydrodynamics capabilities in the FLASH code, we have simulated a suite of representative galaxy cluster mergers, including the dynamics of both the dark matter, which is collisionless, and the gas, which has the properties of a fluid. 3-D visualizations such as these demonstrate clearly the different behavior of these two components over time. Credits: Science: John Zuhone (Harvard-Smithsonian Center for Astrophysics Visualization: Jonathan Gallagher (Flash Center, University of Chicago)

 This research used resources of the Argonne Leadership Computing Facility at Argonne National Laboratory, which is supported by the Office of Science of the U.S. Dept. of Energy (DOE) under contract DE-AC02-06CH11357. This research was supported by the National Nuclear Security Administration's (NNSA) Advanced Simulation and Computing (ASC) Academic Strategic Alliance Program (ASAP).

  20. Mask replication using jet and flash imprint lithography

    NASA Astrophysics Data System (ADS)

    Selinidis, Kosta S.; Jones, Chris; Doyle, Gary F.; Brown, Laura; Imhof, Joseph; LaBrake, Dwayne L.; Resnick, Douglas J.; Sreenivasan, S. V.

    2011-11-01

    The Jet and Flash Imprint Lithography (J-FILTM) process uses 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 memory markets including Flash memory and patterned media for hard disk drives. It is anticipated that the lifetime of a single template (for patterned media) or mask (for semiconductor) will be on the order of 104 - 105imprints. This suggests that tens of thousands of templates/masks will be required to satisfy the needs of a manufacturing environment. Electron-beam patterning is too slow to feasibly deliver these volumes, but instead can provide a high quality "master" mask which can be replicated many times with an imprint lithography tool. This strategy has the capability to produce the required supply of "working" templates/masks. In this paper, we review the development of the mask form factor, imprint replication tools and the semiconductor mask replication process. A PerfectaTM MR5000 mask replication tool has been developed specifically to pattern replica masks from an ebeam written master. Performance results, including image placement, critical dimension uniformity, and pattern transfer are covered in detail.

  1. Photomultiplier reception of satellite beacon flashes.

    PubMed

    Abby, D G; Wirtanen, T E

    1969-03-01

    Experiments have been performed on the electrooptical detection of flashes from satellite-borne beacons for the purposes of establishing the time of flash at the observing site, measurement of received pulse shape, and relative measurement of received energy. Initial observations have been made of the beacons carried by the geodetic satellite GEOS-B. Time of flash has been obtained to a precision of 0.1 msec. Pulse shape and energy measurements have been made for various slant ranges and at various voltages on the photomultiplier circuits. Continued testing is directed toward microsecond timing of flash reception.

  2. Sub-seasonal forecasting of flash droughts in China

    NASA Astrophysics Data System (ADS)

    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

  3. Vertically Integrated Nanowire-Based Unified Memory.

    PubMed

    Lee, Byung-Hyun; Ahn, Dae-Chul; Kang, Min-Ho; Jeon, Seung-Bae; Choi, Yang-Kyu

    2016-09-14

    A vertically integrated nanowire-based device for multifunctional unified memory that combine dynamic random access memory (DRAM) and flash memory in a single transistor is demonstrated for the first time. The device utilizes a gate-all-around (GAA) structure that completely surrounds the nanowire; the structure is built on a bulk silicon wafer. A vertically integrated unified memory (VIUM) device composed of five-story channels was fabricated via the one-route all-dry etching process (ORADEP) with reliable reproducibility, stiction-free stability, and high uniformity. In each DRAM and flash memory operation, the five-story VIUM showed a remarkably enhanced sensing current drivability compared with one-story unified memory (UM) characteristics. In addition to each independent memory mode, the switching endurance of the VIUM was evaluated in the unified mode, which alternatively activates two memory modes, resulting in an even higher sensing memory window than that of the UM. In addition to our previous work on a logic transistor joining high performance with good scalability, this work describes a novel memory hierarchy design with high functionality for system-on-chip (SoC) architectures, demonstrating the practicality and versatility of the vertically integrated nanowire configuration for use in various applications.

  4. Vertically Integrated Nanowire-Based Unified Memory.

    PubMed

    Lee, Byung-Hyun; Ahn, Dae-Chul; Kang, Min-Ho; Jeon, Seung-Bae; Choi, Yang-Kyu

    2016-09-14

    A vertically integrated nanowire-based device for multifunctional unified memory that combine dynamic random access memory (DRAM) and flash memory in a single transistor is demonstrated for the first time. The device utilizes a gate-all-around (GAA) structure that completely surrounds the nanowire; the structure is built on a bulk silicon wafer. A vertically integrated unified memory (VIUM) device composed of five-story channels was fabricated via the one-route all-dry etching process (ORADEP) with reliable reproducibility, stiction-free stability, and high uniformity. In each DRAM and flash memory operation, the five-story VIUM showed a remarkably enhanced sensing current drivability compared with one-story unified memory (UM) characteristics. In addition to each independent memory mode, the switching endurance of the VIUM was evaluated in the unified mode, which alternatively activates two memory modes, resulting in an even higher sensing memory window than that of the UM. In addition to our previous work on a logic transistor joining high performance with good scalability, this work describes a novel memory hierarchy design with high functionality for system-on-chip (SoC) architectures, demonstrating the practicality and versatility of the vertically integrated nanowire configuration for use in various applications. PMID:27579769

  5. Modeling of SONOS Memory Cell Erase Cycle

    NASA Technical Reports Server (NTRS)

    Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat H.

    2011-01-01

    Utilization of Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) nonvolatile semiconductor memories as a flash memory has many advantages. These electrically erasable programmable read-only memories (EEPROMs) utilize low programming voltages, have a high erase/write cycle lifetime, are radiation hardened, and are compatible with high-density scaled CMOS for low power, portable electronics. In this paper, the SONOS memory cell erase cycle was investigated using a nonquasi-static (NQS) MOSFET model. Comparisons were made between the model predictions and experimental data.

  6. SONOS Nonvolatile Memory Cell Programming Characteristics

    NASA Technical Reports Server (NTRS)

    MacLeod, Todd C.; Phillips, Thomas A.; Ho, Fat D.

    2010-01-01

    Silicon-oxide-nitride-oxide-silicon (SONOS) nonvolatile memory is gaining favor over conventional EEPROM FLASH memory technology. This paper characterizes the SONOS write operation using a nonquasi-static MOSFET model. This includes floating gate charge and voltage characteristics as well as tunneling current, voltage threshold and drain current characterization. The characterization of the SONOS memory cell predicted by the model closely agrees with experimental data obtained from actual SONOS memory cells. The tunnel current, drain current, threshold voltage and read drain current all closely agreed with empirical data.

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

    MedlinePlus

    ... ency/patientinstructions/000826.htm Cancer treatment: dealing with hot flashes and night sweats To use the sharing ... JavaScript. Certain types of cancer treatments can cause hot flashes and night sweats. Hot flashes are when ...

  8. Child maltreatment and memory.

    PubMed

    Goodman, Gail S; Quas, Jodi A; Ogle, Christin M

    2010-01-01

    Exposure to childhood trauma, especially child maltreatment, has important implications for memory of emotionally distressing experiences. These implications stem from cognitive, socio-emotional, mental health, and neurobiological consequences of maltreatment and can be at least partially explained by current theories concerning the effects of childhood trauma. In this review, two main hypotheses are advanced: (a) Maltreatment in childhood is associated with especially robust memory for emotionally distressing material in many individuals, but (b) maltreatment can impair memory for such material in individuals who defensively avoid it. Support for these hypotheses comes from research on child abuse victims' memory and suggestibility regarding distressing but nonabusive events, memory for child abuse itself, and autobiographical memory. However, more direct investigations are needed to test precisely when and how childhood trauma affects memory for emotionally significant, distressing experiences. Legal implications and future directions are discussed.

  9. Au Contraire: Gifted in a Flash (Mob)

    ERIC Educational Resources Information Center

    Delisle, James R.

    2012-01-01

    A "flash mob" is defined by Wikipedia as "a large group of people who assemble suddenly in a public place, perform an unusual and pointless act for a brief time, then disperse." Fueled by social media and Smartphones, flash mobs have been used, primarily, as entertaining diversions by addicted techies with (apparently) tons of time on their hands.…

  10. Flash Expansion Threshold in Whirligig Swarms

    PubMed Central

    Romey, William L.; Lamb, Alicia R.

    2015-01-01

    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. PMID:26301958

  11. The flash-lag effect and equiluminance.

    PubMed

    Chappell, Mark; Hine, Trevor J; Hardwick, David

    2002-06-01

    An object briefly flashed adjacent to the path of another moving object appears to spatially lag the moving object in the direction of its motion: the 'flash-lag effect'. A simple differential lag model account of this effect suggests that it occurs because the moving object activates motion detectors in the faster magnocellular pathway, whereas the flashed object does not. This model was tested by reducing M-pathway involvement using isoluminant stimuli. All four participants, who were university undergraduate students, were exposed to eight conditions, involving all possible combinations of moving and flashing objects coloured either white or green, shown against either a grey or a black background. Green objects were equiluminant with the grey background. The magnitude of the flash-lag effect was found using the method of constant stimuli. No reliable support was found for the hypothesis that equiluminance of the moving object reduces the flash-lag effect. Instead an interaction was found where there was an effect of equiluminance on the flash, but only when the moving object was not equiluminant. Such data is problematic for this and other simple differential lag models of the flash-lag effect.

  12. Flash Expansion Threshold in Whirligig Swarms.

    PubMed

    Romey, William L; Lamb, Alicia R

    2015-01-01

    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.

  13. Organic flash cycles for efficient power production

    DOEpatents

    Ho, Tony; Mao, Samuel S.; Greif, Ralph

    2016-03-15

    This disclosure provides systems, methods, and apparatus related to an Organic Flash Cycle (OFC). In one aspect, a modified OFC system includes a pump, a heat exchanger, a flash evaporator, a high pressure turbine, a throttling valve, a mixer, a low pressure turbine, and a condenser. The heat exchanger is coupled to an outlet of the pump. The flash evaporator is coupled to an outlet of the heat exchanger. The high pressure turbine is coupled to a vapor outlet of the flash evaporator. The throttling valve is coupled to a liquid outlet of the flash evaporator. The mixer is coupled to an outlet of the throttling valve and to an outlet of the high pressure turbine. The low pressure turbine is coupled to an outlet of the mixer. The condenser is coupled to an outlet of the low pressure turbine and to an inlet of the pump.

  14. Working Memory Load Attenuates Emotional Enhancement in Recognition Memory

    PubMed Central

    Miendlarzewska, Ewa A.; van Elswijk, Gijs; Cannistraci, Carlo V.; van Ee, Raymond

    2013-01-01

    Emotionally arousing stimuli are perceived and remembered better than neutral stimuli. Under threat, this negativity bias is further increased. We investigated whether working memory (WM) load can attenuate incidental memory for emotional images. Two groups of participants performed the N-back task with two WM load levels. In one group, we induced anxiety using a threat of shock paradigm to increase attentional processing of negative information. During task performance we incidentally and briefly flashed emotional distracter images which prolonged response times in both load conditions. A subsequent unannounced immediate recognition memory test revealed that when load at exposure had been low, recognition was better for negative items in both participant groups. This enhancement, however, was attenuated under high load, leaving performance on neutral items unchanged regardless of the threat of shock manipulation. We conclude that both in threat and in normal states WM load at exposure can attenuate immediate emotional memory enhancement. PMID:23515565

  15. Theoretical Characterizaiton of Visual Signatures (Muzzle Flash)

    NASA Astrophysics Data System (ADS)

    Kashinski, D. O.; Scales, A. N.; Vanderley, D. L.; Chase, G. M.; di Nallo, O. E.; Byrd, E. F. C.

    2014-05-01

    We are investigating the accuracy of theoretical models used to predict the visible, ultraviolet and infrared spectra of product materials ejected from the muzzle of currently fielded systems. Recent advances in solid propellants has made the management of muzzle signature (flash) a principle issue in weapons development across the calibers. A priori prediction of the electromagnetic spectra of formulations will allow researchers to tailor blends that yield desired signatures and determine spectrographic detection ranges. We are currently employing quantum chemistry methods at various levels of sophistication to optimize molecular geometries, compute vibrational frequencies, and determine the optical spectra of specific gas-phase molecules and radicals of interest. Electronic excitations are being computed using Time Dependent Density Functional Theory (TD-DFT). A comparison of computational results to experimental values found in the literature is used to assess the affect of basis set and functional choice on calculation accuracy. The current status of this work will be presented at the conference. Work supported by the ARL, and USMA.

  16. Small SWAP 3D imaging flash ladar for small tactical unmanned air systems

    NASA Astrophysics Data System (ADS)

    Bird, Alan; Anderson, Scott A.; Wojcik, Michael; Budge, Scott E.

    2015-05-01

    The Space Dynamics Laboratory (SDL), working with Naval Research Laboratory (NRL) and industry leaders Advanced Scientific Concepts (ASC) and Hood Technology Corporation, has developed a small SWAP (size, weight, and power) 3D imaging flash ladar (LAser Detection And Ranging) sensor system concept design for small tactical unmanned air systems (STUAS). The design utilizes an ASC 3D flash ladar camera and laser in a Hood Technology gyro-stabilized gimbal system. The design is an autonomous, intelligent, geo-aware sensor system that supplies real-time 3D terrain and target images. Flash ladar and visible camera data are processed at the sensor using a custom digitizer/frame grabber with compression. Mounted in the aft housing are power, controls, processing computers, and GPS/INS. The onboard processor controls pointing and handles image data, detection algorithms and queuing. The small SWAP 3D imaging flash ladar sensor system generates georeferenced terrain and target images with a low probability of false return and <10 cm range accuracy through foliage in real-time. The 3D imaging flash ladar is designed for a STUAS with a complete system SWAP estimate of <9 kg, <0.2 m3 and <350 W power. The system is modeled using LadarSIM, a MATLAB® and Simulink®- based ladar system simulator designed and developed by the Center for Advanced Imaging Ladar (CAIL) at Utah State University. We will present the concept design and modeled performance predictions.

  17. [Nikola Tesla: flashes of inspiration].

    PubMed

    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.

  18. Luminosities for Final Flash Stars

    NASA Astrophysics Data System (ADS)

    Hinkle, Kenneth; Joyce, Richard; Lebzelter, Thomas

    2010-08-01

    A brief yet common evolutionary process is a post-AGB final episode of helium shell burning. This occurs after a low mass star has ejected a planetary nebula and has started on the white dwarf track. Seven stars are now classified with varying degrees of certainty as one of these ``final flash'' objects. Two of these have actually been observed to eject a shell of gas first as a pseudo-photosphere and then as a thick dust envelope. The dust envelopes are expanding at ~100 km s^-1. We propose AO imaging of the circumstellar shells to measure changes from images recorded a decade or more ago. From these changes we will determine geometric parallaxes and hence luminosities. The luminosity will be compared to stellar evolution models. In an additional challenge to models we will calibrate the He I emission line flux and through this the mass loss rate from the fast stellar wind.

  19. [Nikola Tesla: flashes of inspiration].

    PubMed

    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. PMID:23307357

  20. NUCLEAR FLASH TYPE STEAM GENERATOR

    DOEpatents

    Johns, F.L.; Gronemeyer, E.C.; Dusbabek, M.R.

    1962-09-01

    A nuclear steam generating apparatus is designed so that steam may be generated from water heated directly by the nuclear heat source. The apparatus comprises a pair of pressure vessels mounted one within the other, the inner vessel containing a nuclear reactor heat source in the lower portion thereof to which water is pumped. A series of small ports are disposed in the upper portion of the inner vessel for jetting heated water under pressure outwardly into the atmosphere within the interior of the outer vessel, at which time part of the jetted water flashes into steam. The invention eliminates the necessity of any intermediate heat transfer medium and components ordinarily required for handling that medium. (AEC)

  1. Radiometry of flashing LED sources

    NASA Astrophysics Data System (ADS)

    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%.

  2. Mechanical memory

    DOEpatents

    Gilkey, Jeffrey C.; Duesterhaus, Michelle A.; Peter, Frank J.; Renn, Rosemarie A.; Baker, Michael S.

    2006-08-15

    A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

  3. Mechanical memory

    DOEpatents

    Gilkey, Jeffrey C.; Duesterhaus, Michelle A.; Peter, Frank J.; Renn, Rosemarie A.; Baker, Michael S.

    2006-05-16

    A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

  4. Illuminating Flash Point: Comprehensive Prediction Models.

    PubMed

    Le, Tu C; Ballard, Mathew; Casey, Phillip; Liu, Ming S; Winkler, David A

    2015-01-01

    Flash point is an important property of chemical compounds that is widely used to evaluate flammability hazard. However, there is often a significant gap between the demand for experimental flash point data and their availability. Furthermore, the determination of flash point is difficult and costly, particularly for some toxic, explosive, or radioactive compounds. The development of a reliable and widely applicable method to predict flash point is therefore essential. In this paper, the construction of a quantitative structure - property relationship model with excellent performance and domain of applicability is reported. It uses the largest data set to date of 9399 chemically diverse compounds, with flash point spanning from less than -130 °C to over 900 °C. The model employs only computed parameters, eliminating the need for experimental data that some earlier computational models required. The model allows accurate prediction of flash point for a broad range of compounds that are unavailable or not yet synthesized. This single model with a very broad range of chemical and flash point applicability will allow accurate predictions of this important property to be made for a broad range of new materials. PMID:27490859

  5. Flash Droughts over the United States

    NASA Astrophysics Data System (ADS)

    Lettenmaier, D. P.; Mo, K. C.

    2015-12-01

    Flash drought refers to relatively short periods of warm surface temperature and anomalously low and rapid decreasing soil moisture (SM). Based on the physical mechanisms associated with flash droughts, we classify them into two categories: heat wave and precipitation (P) deficit flash droughts. We analyze the flash droughts based on the observations and the land surface model reconstructed soil moisture (SM) and evaporation (ET) from 1916 to 2013. Heat wave flash droughts are most likely to occur over the Midwest and the Pacific Northwest during the growing season. They do not occur often. The maximum frequency of occurrence is only 4%. Heat wave flash drought is temperature driven. High temperatures increase the transpiration and drive down soil moisture and cause drought to occur. The P deficit flash droughts are more common than the heat wave droughts and the maximum frequency of occurrence is about 8- 10 %. They are most likely to occur over the southern United States with a maximum over the Southern Plains. They are P driven. Heat waves are caused by P deficits. P deficits drive down SM and cause ET to decreases and temperature to increase.

  6. Nanographene charge trapping memory with a large memory window

    NASA Astrophysics Data System (ADS)

    Meng, Jianling; Yang, Rong; Zhao, Jing; He, Congli; Wang, Guole; Shi, Dongxia; Zhang, Guangyu

    2015-11-01

    Nanographene is a promising alternative to metal nanoparticles or semiconductor nanocrystals for charge trapping memory. In general, a high density of nanographene is required in order to achieve high charge trapping capacity. Here, we demonstrate a strategy of fabrication for a high density of nanographene for charge trapping memory with a large memory window. The fabrication includes two steps: (1) direct growth of continuous nanographene film; and (2) isolation of the as-grown film into high-density nanographene by plasma etching. Compared with directly grown isolated nanographene islands, abundant defects and edges are formed in nanographene under argon or oxygen plasma etching, i.e. more isolated nanographene islands are obtained, which provides more charge trapping sites. As-fabricated nanographene charge trapping memory shows outstanding memory properties with a memory window as wide as ∼9 V at a relative low sweep voltage of ±8 V, program/erase speed of ∼1 ms and robust endurance of >1000 cycles. The high-density nanographene charge trapping memory provides an outstanding alternative for downscaling technology beyond the current flash memory.

  7. Inadvertently programmed bits in Samsung 128 Mbit flash devices: a flaky investigation

    NASA Technical Reports Server (NTRS)

    Swift, G.

    2002-01-01

    JPL's X2000 avionics design pioneers new territory by specifying a non-volatile memory (NVM) board based on flash memories. The Samsung 128Mb device chosen was found to demonstrate bit errors (mostly program disturbs) and block-erase failures that increase with cycling. Low temperature, certain pseudo- random patterns, and, probably, higher bias increase the observable bit errors. An experiment was conducted to determine the wearout dependence of the bit errors to 100k cycles at cold temperature using flight-lot devices (some pre-irradiated). The results show an exponential growth rate, a wide part-to-part variation, and some annealing behavior.

  8. 49 CFR 234.217 - Flashing light units.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Flashing light units. 234.217 Section 234.217..., Inspection, and Testing Maintenance Standards § 234.217 Flashing light units. (a) Each flashing light unit.... (b) Each flashing light unit shall be maintained to prevent dust and moisture from entering...

  9. 49 CFR 234.217 - Flashing light units.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Flashing light units. 234.217 Section 234.217..., Inspection, and Testing Maintenance Standards § 234.217 Flashing light units. (a) Each flashing light unit.... (b) Each flashing light unit shall be maintained to prevent dust and moisture from entering...

  10. Light flash phenomena induced by HzE particles

    NASA Technical Reports Server (NTRS)

    Mcnulty, P. J.; Pease, V. P.

    1980-01-01

    Astronauts and Apollo and Skylab missions have reported observing a variety of visual phenomena when their eyes are closed and adapted to darkness. These phenomena have been collectively labelled as light flashes. Visual phenomena which are similar in appearance to those observed in space have been demonstrated at the number of accelerator facilities by expressing the eyes of human subjects to beams of various types of radiation. In some laboratory experiments Cerenkov radiation was found to be the basis for the flashes observed while in other experiments Cerenkov radiation could apparently be ruled out. Experiments that differentiate between Cerenkov radiation and other possible mechanisms for inducing visual phenomena was then compared. The phenomena obtained in the presence and absence of Cerenkov radiation were designed and conducted. A new mechanism proposed to explain the visual phenomena observed by Skylab astronauts as they passed through the South Atlantic Anomaly, namely nuclear interactions in and near the sensitive layer of the retina, is covered. Also some studies to search for similar transient effects of space radiation on sensors and microcomputer memories are described.

  11. Computational Models of Human Performance: Validation of Memory and Procedural Representation in Advanced Air/Ground Simulation

    NASA Technical Reports Server (NTRS)

    Corker, Kevin M.; Labacqz, J. Victor (Technical Monitor)

    1997-01-01

    The Man-Machine Interaction Design and Analysis System (MIDAS) under joint U.S. Army and NASA cooperative is intended to assist designers of complex human/automation systems in successfully incorporating human performance capabilities and limitations into decision and action support systems. MIDAS is a computational representation of multiple human operators, selected perceptual, cognitive, and physical functions of those operators, and the physical/functional representation of the equipment with which they operate. MIDAS has been used as an integrated predictive framework for the investigation of human/machine systems, particularly in situations with high demands on the operators. We have extended the human performance models to include representation of both human operators and intelligent aiding systems in flight management, and air traffic service. The focus of this development is to predict human performance in response to aiding system developed to identify aircraft conflict and to assist in the shared authority for resolution. The demands of this application requires representation of many intelligent agents sharing world-models, coordinating action/intention, and cooperative scheduling of goals and action in an somewhat unpredictable world of operations. In recent applications to airborne systems development, MIDAS has demonstrated an ability to predict flight crew decision-making and procedural behavior when interacting with automated flight management systems and Air Traffic Control. In this paper, we describe two enhancements to MIDAS. The first involves the addition of working memory in the form of an articulatory buffer for verbal communication protocols and a visuo-spatial buffer for communications via digital datalink. The second enhancement is a representation of multiple operators working as a team. This enhanced model was used to predict the performance of human flight crews and their level of compliance with commercial aviation communication

  12. An Inexpensive, Foolproof Apparatus for Flash Chromatography.

    ERIC Educational Resources Information Center

    Thompson, Wayne J.; Hanson, Bryan A.

    1984-01-01

    Describes a new, modified "flash chromatography" apparatus which overcomes difficulties found in conventional apparatus. For example, an expensive teflon pressure valve is not necessary in the modified version. The apparatus is suitable as an instructional tool in undergraduate courses. (JN)

  13. Photoinactivation of photosystem II by flashing light.

    PubMed

    Szilárd, András; Sass, László; Hideg, Eva; Vass, Imre

    2005-06-01

    Inhibition of Photosystem II (PS II) activity by single turnover visible light flashes was studied in thylakoid membranes isolated form spinach. Flash illumination results in decreased oxygen evolving activity of PS II, which effect is most pronounced when the water-oxidizing complex is in the S2 and S3 states, and increases with increasing time delay between the subsequent flashes. By applying the fluorescent spin-trap DanePy, we detected the production of singlet oxygen, whose amount was increasing with increasing flash spacing. These findings were explained in the framework of a model, which assumes that recombination of the S2QB - and S3QB - states generate the triplet state of the reaction center chlorophyll and lead to the production of singlet oxygen.

  14. Quality control in the "flash" process.

    PubMed

    1985-03-01

    This article has briefly discussed the three basic types of sterilization monitoring systems--mechanical, chemical, and biological. Mechanical indicators help tell you that the sterilizer is working. Chemical indicators provide you with immediate information in each "flash" load that the conditions necessary for steam sterilization were present. Biological indicators tell you that microorganisms were killed. For maximum assurance that the conditions necessary for steam sterilization are present and that non-sterile instruments are not inadvertently used, each "flash" sterilizer should be monitored daily with biological indicators and each "flash" load with chemical indicators. This quality control monitoring program should give the O.R. staff confidence that their "flash" sterilization process is working. PMID:10271096

  15. A Simple Lightning Flash Polarity Discriminating Counter.

    ERIC Educational Resources Information Center

    Devan, K. R. S.; Jayaratne, E. R.

    1990-01-01

    Described are the apparatus and procedures needed for a demonstration of a determination of the polarity of charges carried by individual ground flashes of lightning. Discussed are materials, apparatus construction, and experimental results. (CW)

  16. A global flash flood forecasting system

    NASA Astrophysics Data System (ADS)

    Baugh, Calum; Pappenberger, Florian; Wetterhall, Fredrik; Hewson, Tim; Zsoter, Ervin

    2016-04-01

    The sudden and devastating nature of flash flood events means it is imperative to provide early warnings such as those derived from Numerical Weather Prediction (NWP) forecasts. Currently such systems exist on basin, national and continental scales in Europe, North America and Australia but rely on high resolution NWP forecasts or rainfall-radar nowcasting, neither of which have global coverage. To produce global flash flood forecasts this work investigates the possibility of using forecasts from a global NWP system. In particular we: (i) discuss how global NWP can be used for flash flood forecasting and discuss strengths and weaknesses; (ii) demonstrate how a robust evaluation can be performed given the rarity of the event; (iii) highlight the challenges and opportunities in communicating flash flood uncertainty to decision makers; and (iv) explore future developments which would significantly improve global flash flood forecasting. The proposed forecast system uses ensemble surface runoff forecasts from the ECMWF H-TESSEL land surface scheme. A flash flood index is generated using the ERIC (Enhanced Runoff Index based on Climatology) methodology [Raynaud et al., 2014]. This global methodology is applied to a series of flash floods across southern Europe. Results from the system are compared against warnings produced using the higher resolution COSMO-LEPS limited area model. The global system is evaluated by comparing forecasted warning locations against a flash flood database of media reports created in partnership with floodlist.com. To deal with the lack of objectivity in media reports we carefully assess the suitability of different skill scores and apply spatial uncertainty thresholds to the observations. To communicate the uncertainties of the flash flood system output we experiment with a dynamic region-growing algorithm. This automatically clusters regions of similar return period exceedence probabilities, thus presenting the at-risk areas at a spatial

  17. Flash Flood Trail near Parras, Coahuila, Mexico

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Evidence of a recent flash flood can be seen in the form of light brown sediment that flowed down gullies and mountain sides forming ponds of debris over agricultural areas in the broad valley near the town of Parras (26.5N, 102.5W). This part of Mexico has extensive vineyards, orchards and both dry land and irrigated agriculture. Based on the photo, it appears that flash flood waters damaged some 300 square miles of property in this area alone.

  18. QSPR modeling of flash points: an update.

    PubMed

    Katritzky, Alan R; Stoyanova-Slavova, Iva B; Dobchev, Dimitar A; Karelson, Mati

    2007-09-01

    Quantitative structure-property relationship (QSPR) models for the flash points of 758 organic compounds are developed using geometrical, topological, quantum mechanical and electronic descriptors calculated by CODESSA PRO software. Multilinear regression models link the structures to their reported flash point values. We also report a nonlinear model based on an artificial neural network. The results are discussed in the light of the main factors that influence the property under investigation and its modeling.

  19. Non-volatile memory for checkpoint storage

    SciTech Connect

    Blumrich, Matthias A.; Chen, Dong; Cipolla, Thomas M.; Coteus, Paul W.; Gara, Alan; Heidelberger, Philip; Jeanson, Mark J.; Kopcsay, Gerard V.; Ohmacht, Martin; Takken, Todd E.

    2014-07-22

    A system, method and computer program product for supporting system initiated checkpoints in high performance parallel computing systems and storing of checkpoint data to a non-volatile memory storage device. The system and method generates selective control signals to perform checkpointing of system related data in presence of messaging activity associated with a user application running at the node. The checkpointing is initiated by the system such that checkpoint data of a plurality of network nodes may be obtained even in the presence of user applications running on highly parallel computers that include ongoing user messaging activity. In one embodiment, the non-volatile memory is a pluggable flash memory card.

  20. Radiation Test Challenges for Scaled Commerical Memories

    NASA Technical Reports Server (NTRS)

    LaBel, Kenneth A.; Ladbury, Ray L.; Cohn, Lewis M.; Oldham, Timothy

    2007-01-01

    As sub-100nm CMOS technologies gather interest, the radiation effects performance of these technologies provide a significant challenge. In this talk, we shall discuss the radiation testing challenges as related to commercial memory devices. The focus will be on complex test and failure modes emerging in state-of-the-art Flash non-volatile memories (NVMs) and synchronous dynamic random access memories (SDRAMs), which are volatile. Due to their very high bit density, these device types are highly desirable for use in the natural space environment. In this presentation, we shall discuss these devices with emphasis on considerations for test and qualification methods required.

  1. Imaging Flash Lidar for Safe Landing on Solar System Bodies and Spacecraft Rendezvous and Docking

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Roback, Vincent E.; Bulyshev, Alexander E.; Brewster, Paul F.; Carrion, William A; Pierrottet, Diego F.; Hines, Glenn D.; Petway, Larry B.; Barnes, Bruce W.; Noe, Anna M.

    2015-01-01

    NASA has been pursuing flash lidar technology for autonomous, safe landing on solar system bodies and for automated rendezvous and docking. During the final stages of the landing from about 1 kilometer to 500 meters above the ground, the flash lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes. The onboard flight computer can then use the 3-D map of terrain to guide the vehicle to a safe location. As an automated rendezvous and docking sensor, the flash lidar can provide relative range, velocity, and bearing from an approaching spacecraft to another spacecraft or a space station. NASA Langley Research Center has developed and demonstrated a flash lidar sensor system capable of generating 16,000 pixels range images with 7 centimeters precision, at 20 Hertz frame rate, from a maximum slant range of 1800 m from the target area. This paper describes the lidar instrument and presents the results of recent flight tests onboard a rocket-propelled free-flyer vehicle (Morpheus) built by NASA Johnson Space Center. The flights were conducted at a simulated lunar terrain site, consisting of realistic hazard features and designated landing areas, built at NASA Kennedy Space Center specifically for this demonstration test. This paper also provides an overview of the plan for continued advancement of the flash lidar technology aimed at enhancing its performance to meet both landing and automated rendezvous and docking applications.

  2. Determining the state of non-volatile memory cells with floating gate using scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Hanzii, D.; Kelm, E.; Luapunov, N.; Milovanov, R.; Molodcova, G.; Yanul, M.; Zubov, D.

    2013-01-01

    During a failure analysis of integrated circuits, containing non-volatile memory, it is often necessary to determine its contents while Standard memory reading procedures are not applicable. This article considers how the state of NVM cells with floating gate can be determined using scanning probe microscopy. Samples preparation and measuring procedure are described with the example of Microchip microcontrollers with the EPROM memory (PIC12C508) and flash-EEPROM memory (PIC16F876A).

  3. Physical principles and current status of emerging non-volatile solid state memories

    NASA Astrophysics Data System (ADS)

    Wang, L.; Yang, C.-H.; Wen, J.

    2015-07-01

    Today the influence of non-volatile solid-state memories on persons' lives has become more prominent because of their non-volatility, low data latency, and high robustness. As a pioneering technology that is representative of non-volatile solidstate memories, flash memory has recently seen widespread application in many areas ranging from electronic appliances, such as cell phones and digital cameras, to external storage devices such as universal serial bus (USB) memory. Moreover, owing to its large storage capacity, it is expected that in the near future, flash memory will replace hard-disk drives as a dominant technology in the mass storage market, especially because of recently emerging solid-state drives. However, the rapid growth of the global digital data has led to the need for flash memories to have larger storage capacity, thus requiring a further downscaling of the cell size. Such a miniaturization is expected to be extremely difficult because of the well-known scaling limit of flash memories. It is therefore necessary to either explore innovative technologies that can extend the areal density of flash memories beyond the scaling limits, or to vigorously develop alternative non-volatile solid-state memories including ferroelectric random-access memory, magnetoresistive random-access memory, phase-change random-access memory, and resistive random-access memory. In this paper, we review the physical principles of flash memories and their technical challenges that affect our ability to enhance the storage capacity. We then present a detailed discussion of novel technologies that can extend the storage density of flash memories beyond the commonly accepted limits. In each case, we subsequently discuss the physical principles of these new types of non-volatile solid-state memories as well as their respective merits and weakness when utilized for data storage applications. Finally, we predict the future prospects for the aforementioned solid-state memories for

  4. Word line program disturbance based data retention error recovery strategy for MLC NAND Flash

    NASA Astrophysics Data System (ADS)

    Ma, Haozhi; Pan, Liyang; Song, Changlai; Gao, Zhongyi; Wu, Dong; Xu, Jun

    2015-07-01

    NAND Flash has been widely used as storage solutions for portable system due to improvement on data throughput, power consumption and mechanical reliability. However, NAND Flash presents inevitable decline in reliability due to scaling down and multi-level cell (MLC) technology. High data retention error rate in highly stressed blocks causes a trend of stronger ECC deployed in system, with higher hardware overhead and spare bits cost. In this paper, a word line program disturbance (WPD) based data retention error recovery strategy, which induces extra electron injection to compensate floating gate electron leakage during long retention time, is proposed to reduce the data retention error rate and improve the retention reliability of highly scaled MLC NAND Flash memories. The proposed strategy is applied on 2×-nm MLC NAND Flash and the device one-year retention error rate after 3 K, 4 K, 5 K and 6 K P/E cycled decreases by 75.7%, 79.3%, 82.3% and 83.3%, respectively.

  5. Flash LIDAR Systems for Planetary Exploration

    NASA Astrophysics Data System (ADS)

    Dissly, Richard; Weinberg, J.; Weimer, C.; Craig, R.; Earhart, P.; Miller, K.

    2009-01-01

    Ball Aerospace offers a mature, highly capable 3D flash-imaging LIDAR system for planetary exploration. Multi mission applications include orbital, standoff and surface terrain mapping, long distance and rapid close-in ranging, descent and surface navigation and rendezvous and docking. Our flash LIDAR is an optical, time-of-flight, topographic imaging system, leveraging innovations in focal plane arrays, readout integrated circuit real time processing, and compact and efficient pulsed laser sources. Due to its modular design, it can be easily tailored to satisfy a wide range of mission requirements. Flash LIDAR offers several distinct advantages over traditional scanning systems. The entire scene within the sensor's field of view is imaged with a single laser flash. This directly produces an image with each pixel already correlated in time, making the sensor resistant to the relative motion of a target subject. Additionally, images may be produced at rates much faster than are possible with a scanning system. And because the system captures a new complete image with each flash, optical glint and clutter are easily filtered and discarded. This allows for imaging under any lighting condition and makes the system virtually insensitive to stray light. Finally, because there are no moving parts, our flash LIDAR system is highly reliable and has a long life expectancy. As an industry leader in laser active sensor system development, Ball Aerospace has been working for more than four years to mature flash LIDAR systems for space applications, and is now under contract to provide the Vision Navigation System for NASA's Orion spacecraft. Our system uses heritage optics and electronics from our star tracker products, and space qualified lasers similar to those used in our CALIPSO LIDAR, which has been in continuous operation since 2006, providing more than 1.3 billion laser pulses to date.

  6. Single Particle Difraction at FLASH

    SciTech Connect

    Bogan, M.; Boutet, S.; Starodub, Dmitri; Decorwin-Martin, Philippe; Chapman, H.; Bajt, S.; Schulz, J.; Hajdu, Janos; Seibert, M.M.; Iwan, Bianca; Timneanu, Nicusor; Marchesini, Stefano; Barty, Anton; Benner, W.Henry; Frank, Matthias; Hau-Riege, Stefan P.; Woods, Bruce; 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.

  7. Memory Matters

    MedlinePlus

    ... different parts. Some of them are important for memory. The hippocampus (say: hih-puh-KAM-pus) is one of the more important parts of the brain that processes memories. Old information and new information, or memories, are ...

  8. The first confirmed Perseid lunar impact flash

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Masahisa; Ohnishi, Kouji; Takamura, Yuzaburo; Masuda, Hiroshi; Sakai, Yoshihito; Ida, Miyoshi; Adachi, Makoto; Ishida, Masayuki

    2006-06-01

    The first confirmed lunar impact flash due to a non-Leonid meteoroid is reported. The observed Perseid meteoroid impact occurred at 18 h28 m27 s on August 11, 2004 (UT). The selenographic coordinates of the lunar impact flash are 48±1° N and 72±2° E, and the flash had a visual magnitude of ca. 9.5 with duration of about 1/30 s. The mass of the impactor is estimated to have been 12 g based on a nominal model with conversion efficiency from kinetic to optical energy of 2×10. Extrapolation of a power law size-frequency distribution fitting the sub-centimeter Perseid meteoric particles to large meteoroids suggests that several flashes should have been observed at this optical efficiency. The detection of only one flash may indicate that the optical efficiency for Perseid lunar impact is much lower, or that the slope of the size distribution differs between large meteoroids and typical sub-centimeter meteoric particles.

  9. Lightning flash multiplicity in eastern Mediterranean thunderstorms

    NASA Astrophysics Data System (ADS)

    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.

  10. Firefly light flashing: oxygen supply mechanism.

    PubMed

    Tsai, Yueh-Lin; Li, Chia-Wei; Hong, Tzay-Ming; Ho, Jen-Zon; Yang, En-Cheng; Wu, Wen-Yen; Margaritondo, G; Hsu, Su-Ting; Ong, Edwin B L; Hwu, Y

    2014-12-19

    Firefly luminescence is an intriguing phenomenon with potential technological applications, whose biochemistry background was only recently established. The physics side of this phenomenon, however, was still unclear, specifically as far as the oxygen supply mechanism for light flashing is concerned. This uncertainty is due to the complex microscopic structure of the tracheal system: without fully knowing its geometry, one cannot reliably test the proposed mechanisms. We solved this problem using synchrotron phase contrast microtomography and transmission x-ray microscopy, finding that the oxygen consumption corresponding to mitochondria functions exceeds the maximum rate of oxygen diffusion from the tracheal system to the photocytes. Furthermore, the flashing mechanism uses a large portion of this maximum rate. Thus, the flashing control requires passivation of the mitochondria functions, e.g., by nitric oxide, and switching of the oxygen supply from them to photoluminescence.

  11. Firefly Light Flashing: Oxygen Supply Mechanism

    NASA Astrophysics Data System (ADS)

    Tsai, Yueh-Lin; Li, Chia-Wei; Hong, Tzay-Ming; Ho, Jen-Zon; Yang, En-Cheng; Wu, Wen-Yen; Margaritondo, G.; Hsu, Su-Ting; Ong, Edwin B. L.; Hwu, Y.

    2014-12-01

    Firefly luminescence is an intriguing phenomenon with potential technological applications, whose biochemistry background was only recently established. The physics side of this phenomenon, however, was still unclear, specifically as far as the oxygen supply mechanism for light flashing is concerned. This uncertainty is due to the complex microscopic structure of the tracheal system: without fully knowing its geometry, one cannot reliably test the proposed mechanisms. We solved this problem using synchrotron phase contrast microtomography and transmission x-ray microscopy, finding that the oxygen consumption corresponding to mitochondria functions exceeds the maximum rate of oxygen diffusion from the tracheal system to the photocytes. Furthermore, the flashing mechanism uses a large portion of this maximum rate. Thus, the flashing control requires passivation of the mitochondria functions, e.g., by nitric oxide, and switching of the oxygen supply from them to photoluminescence.

  12. A void distribution model-flashing flow

    SciTech Connect

    Riznic, J.; Ishii, M.; Afgan, N.

    1987-01-01

    A new model for flashing flow based on wall nucleations is proposed here and the model predictions are compared with some experimental data. In order to calculate the bubble number density, the bubble number transport equation with a distributed source from the wall nucleation sites was used. Thus it was possible to avoid the usual assumption of a constant bubble number density. Comparisons of the model with the data shows that the model based on the nucleation site density correlation appears to be acceptable to describe the vapor generation in the flashing flow. For the limited data examined, the comparisons show rather satisfactory agreement without using a floating parameter to adjust the model. This result indicated that, at least for the experimental conditions considered here, the mechanistic predictions of the flashing phenomenon is possible on the present wall nucleation based model.

  13. Menopause: Not All Hot Flashes Are Created Equal

    MedlinePlus

    ... gov/news/fullstory_160027.html Menopause: Not All Hot Flashes Are Created Equal Weight, race, education and ... 2016 FRIDAY, July 22, 2016 (HealthDay News) -- The hot flashes and night sweats of menopause don't ...

  14. Non-Volatile Memory Technology Symposium 2001: Proceedings

    NASA Technical Reports Server (NTRS)

    Aranki, Nazeeh; Daud, Taher; Strauss, Karl

    2001-01-01

    This publication contains the proceedings for the Non-Volatile Memory Technology Symposium 2001 that was held on November 7-8, 2001 in San Diego, CA. The proceedings contains a a wide range of papers that cover current and new memory technologies including Flash memories, Magnetic Random Access Memories (MRAM and GMRAM), Ferro-electric RAM (FeRAM), and Chalcogenide RAM (CRAM). The papers presented in the proceedings address the use of these technologies for space applications as well as radiation effects and packaging issues.

  15. Memory Palaces

    ERIC Educational Resources Information Center

    Wood, Marianne

    2007-01-01

    This article presents a lesson called Memory Palaces. A memory palace is a memory tool used to remember information, usually as visual images, in a sequence that is logical to the person remembering it. In his book, "In the Palaces of Memory", George Johnson calls them "...structure(s) for arranging knowledge. Lots of connections to language arts,…

  16. 49 CFR 234.217 - Flashing light units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Flashing light units. 234.217 Section 234.217... light units. (a) Each flashing light unit shall be properly positioned and aligned and shall be visible to a highway user approaching the crossing. (b) Each flashing light unit shall be maintained...

  17. Modular, Microprocessor-Controlled Flash Lighting System

    NASA Technical Reports Server (NTRS)

    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

  18. Sight-Word Practice in a Flash!

    ERIC Educational Resources Information Center

    Erwin, Robin W., Jr.

    2016-01-01

    For learners who need sight-word practice, including young students and struggling readers, digital flash cards may promote automatic word recognition when used as a supplemental activity to regular reading instruction. A novel use of common presentation software efficiently supports this practice strategy.

  19. Assessment of flash flood warning procedures

    NASA Astrophysics Data System (ADS)

    Johnson, Lynn E.

    2000-01-01

    Assessment of four alternate flash flood warning procedures was conducted to ascertain their suitability for forecast operations using radar-rainfall imagery. The procedures include (1) areal mean basin effective rainfall, (2) unit hydrograph, (3) time-area, and (4) 2-D numerical modeling. The Buffalo Creek flash flood of July 12, 1996, was used as a case study for application of each of the procedures. A significant feature of the Buffalo Creek event was a forest fire that occurred a few months before the flood and significantly affected watershed runoff characteristics. Objectives were to assess the applicability of the procedures for watersheds having spatial and temporal scale similarities to Buffalo Creek, to compare their technical characteristics, and to consider forecaster usability. Geographic information system techniques for hydrologic database development and flash flood potential computations are illustrated. Generalizations of the case study results are offered relative to their suitability for flash flood forecasting operations. Although all four methods have relative advantages, their application to the Buffalo Creek event resulted in mixed performance. Failure of any method was due primarily to uncertainties of the land surface response (i.e., burn area imperviousness). Results underscore the need for model calibration; a difficult requirement for real-time forecasting.

  20. High-Fidelity Flash Lidar Model Development

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

    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.

  1. FLASH2 photon diagnostics and beamline concepts

    NASA Astrophysics Data System (ADS)

    Kuhlmann, M.; Plönjes, E.

    2013-05-01

    FLASH2 is a major extention to the soft X-ray free-electron laser FLASH at DESY. An additional variable-gap undulator line in a new separate tunnel and a new experimental hall will turn FLASH into a multi-beamline FEL user facility. Years of experience as single user facility have high impact on the planned photon diagnostics. Online measurements of intensity, position, wavelength, wavefront, and pulse length are optimized as well as photon beam manipulation tools such as a gas absorber and filters. The beamline system will be set up to cover a wide wavelength range with beamlines capable to deliver down to 0.8 nm in the 5th harmonic and 1st harmonics in the water window to cover the user community's high intrest in this wavelength range. In addition, other beamlines will cover the longer wavelengths from 6 nm - 40 nm and beyond. Proven concepts like the optical laser pump-and-probe instrument are taken over from the current operation scheme in an established way. Permanent endstations with specialized beamline layouts are foreseen. Civil construction and installations in the new FLASH2 tunnel are on-going, first beam is expected for end of 2013, and a first user experiment is anticipated for summer 2014.

  2. Flash flood modelling for ungauged catchments

    NASA Astrophysics Data System (ADS)

    Garambois, P.-A.; Roux, H.; Larnier, K.; Dartus, D.

    2012-04-01

    Flash flood is a very intense and quick hydrologic response of a catchment to rainfall. This phenomenon has a high spatial-temporal variability as its generating storm, often hitting small catchments (few km2). Data collected by (Gaume et al. 2009) about 500 flash floods over the last 50 years showed that they could occur everywhere in Europe and more often in the Mediterranean regions, Alpine regions and continental Europe. Given the small spatial-temporal scales and high variability of flash floods, their prediction remains a hard exercise as the necessary data are often scarce. Flash flood prediction on ungauged catchments is one of the challenges of hydrological modelling as defined by (Sivapalan et al. 2003). Several studies have been headed up with the MARINE model (Modélisation de l'Anticipation du Ruissellement et des Inondations pour des évèNements Extrêmes) for the Gard region (France), (Roux et al. 2011), (Castaings et al. 2009). This physically based spatially distributed rainfall runoff model is dedicated to flash flood prediction. The study aims at finding a methodology for flash flood prediction at ungauged locations in the Cévennes-Vivarais region in particular. The regionalization method is based on multiple calibrations on gauged catchments in order to extract model structures (model + parameter values) for each catchment. Several mathematical methods (multiple regressions, transfer functions, krigging…) will then be tested to calculate a regional parameter set. The study also investigates the usability of additional hydrologic indices at different time scales to constrain model predictions from parameters obtained using these indices, and this independently of the model considered. These hydrologic indices gather information on hydrograph shape or catchment dynamic for instance. Results explaining global catchments behaviour are expected that way. The spatial-temporal variability of storms is also described through indices and linked with

  3. Initiation Locations of Lightning Flashes in Two Florida Thunderstorms

    NASA Astrophysics Data System (ADS)

    Marshall, T. C.; Karunarathna, N.; Stolzenburg, M.; Karunarathne, S.

    2015-12-01

    In this presentation we investigate the initiation locations of all intracloud (IC) and cloud-to-ground (CG) lightning flashes in two small thunderstorms which occurred over NASA/Kennedy Space Center on July 22, 2011. Initiation points of 47 of the 58 lightning flashes (19 IC and 28 CG) were identified using the first initial breakdown (IB) pulse of each flash measured with E-change data. In this study 32 of the flashes had an LDAR2 (VHF) location coincident with the first IB pulse. For 15 flashes we used Position By Fast Antenna or PBFA [Karunarathne et al., 2013, JGR Atmospheres] to determine the location of the first IB pulse. (The remaining flashes had neither LDAR2 nor PBFA locations of the first IB pulse.) All these initiation points were then mapped onto radar reflectivity of the parent thundercloud. The initiation points of the flashes tend to cluster in specific regions in thundercloud. Lightning activity in both thunderstorms lasted 35 minutes, and all the flash initiation points in each storm occurred within a horizontal region of 4 km by 8 km. Flash initiation altitudes for IC flashes of the two thunderstorms ranged from 5.1 km to 12.1 km altitude while for CG flashes the altitude ranged from 4.6 km to 8.1 km. Based on available radar data for 14 IC flashes and 27 CG flashes, all but one of the IC flashes originated in 10 dBZ - 30 dBZ reflectivity regions while 22 of the CG flashes originated in 30 dBZ - 40 dBZ reflectivities. During the lifetimes of these two storms, no Narrow Bipolar Events occurred.

  4. Flash Diffusivity Technique Applied to Individual Fibers

    NASA Technical Reports Server (NTRS)

    Mayeaux, Brian; Yowell, Leonard; Wang, Hsin

    2007-01-01

    A variant of the flash diffusivity technique has been devised for determining the thermal diffusivities, and thus the thermal conductivities, of individual aligned fibers. The technique is intended especially for application to nanocomposite fibers, made from narrower fibers of polyphenylene benzobisthiazole (PBZT) and carbon nanotubes. These highly aligned nanocomposite fibers could exploit the high thermal conductivities of carbon nanotubes for thermal-management applications. In the flash diffusivity technique as practiced heretofore, one or more heat pulse(s) is (are) applied to the front face of a plate or disk material specimen and the resulting time-varying temperature on the rear face is measured. Usually, the heat pulse is generated by use of a xenon flash lamp, and the variation of temperature on the rear face is measured by use of an infrared detector. The flash energy is made large enough to produce a usefully high temperature rise on the rear face, but not so large as to significantly alter the specimen material. Once the measurement has been completed, the thermal diffusivity of the specimen is computed from the thickness of the specimen and the time dependence of the temperature variation on the rear face. Heretofore, the infrared detector used in the flash diffusivity technique has been a single-point detector, which responds to a spatial average of the thermal radiation from the rear specimen surface. Such a detector cannot distinguish among regions of differing diffusivity within the specimen. Moreover, two basic assumptions of the thermaldiffusivity technique as practiced heretofore are that the specimen is homogeneous and that heat flows one-dimensionally from the front to the rear face. These assumptions are not valid for an inhomogeneous (composite) material.

  5. Microdose Induced Data Loss on Floating Gate Memories

    NASA Technical Reports Server (NTRS)

    Guertin, Steven M.; Nguyen, Duc M.; Patterson, Jeffrey D.

    2006-01-01

    Heavy ion irradiation of flash memories shows loss of stored data. The fluence dependence is indicative of microdose effects. Other qualitative factors identifying the effect as microdose are discussed. The data is presented, and compared to statistical results of a microdose target-based model.

  6. An unusual characteristic "flower-like" pattern: flash suppressor burns.

    PubMed

    Gurcan, Altun

    2012-04-01

    The case on contact shots from firearms with a flash suppressor is rare. When a rifle fitted with a flash suppressor is fired, the emerging soot-laden gas in the barrel escapes from the slits of the flash suppressor. If the shot is contact or near contact, the flash suppressor will produce a characteristic "flower-like" pattern of seared, blackened zones around the entrance. This paper presents the injury pattern of the flash suppressor in a 29-year-old man who committed suicide with a G3 automatic infantry rifle.

  7. Global optical lightning flash rates determined with the Forte satellite

    SciTech Connect

    Light, T.; Davis, S. M.; Boeck, W. L.; Jacobson, A. R.; Suszcynsky, D. M.

    2003-01-01

    Using FORTE photodiode detector (PDD) observations of lightning, we have determined the geographic distribution of nighttime flash rate density. We estimate the PDD flash detection efficiency to be 62% for total lightning through comparison to lightning observations by the TRMM satellite's Lightning Imaging Sensor (LIS), using cases in which FORTE and TRMM viewed the same storm. We present here both seasonal and l,ot,al flash rate maps. We examine some characteristics of the optical emissions of lightning in both high and low flash rate environments, and find that while lightning occurs less frequently over ocean, oceanic lightning flashes are somewhat more powerful, on average, than those over land.

  8. Progress in mask replication using jet and flash imprint lithography

    NASA Astrophysics Data System (ADS)

    Selinidis, Kosta S.; Brooks, Cynthia B.; Doyle, Gary F.; Brown, Laura; Jones, Chris; Imhof, Joseph; LaBrake, Dwayne L.; Resnick, Douglas J.; Sreenivasan, S. V.

    2011-04-01

    The Jet and Flash Imprint Lithography (J-FILTM) process uses 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 memory markets including Flash memory and patterned media for hard disk drives. It is anticipated that the lifetime of a single template (for patterned media) or mask (for semiconductor) will be on the order of 104 - 105imprints. This suggests that tens of thousands of templates/masks will be required to satisfy the needs of a manufacturing environment. Electron-beam patterning is too slow to feasibly deliver these volumes, but instead can provide a high quality "master" mask which can be replicated many times with an imprint lithography tool. This strategy has the capability to produce the required supply of "working" templates/masks. In this paper, we review the development of the mask form factor, imprint replication tools and processes specifically for semiconductor applications. The requirements needed for semiconductors dictate the need for a well defined form factor for both master and replica masks which is also compatible with the existing mask infrastructure established for the 6025 semi standard, 6" x 6" x 0.25" photomasks. Complying with this standard provides the necessary tooling needed for mask fabrication processes, cleaning, metrology, and inspection. The replica form factor has additional features specific to imprinting such as a pre-patterned mesa. A PerfectaTM MR5000 mask replication tool has been developed specifically to pattern replica masks from an e-beam written master. The system specifications include a throughput of four replicas per hour with an added image placement component of 5nm, 3sigma and a critical dimension uniformity error of less than 1nm, 3sigma. A new process has been developed to fabricate replicas with high contrast alignment marks so that designs for imprint can fit within current

  9. Technology breakthroughs in high performance metal-oxide-semiconductor devices for ultra-high density, low power non-volatile memory applications

    NASA Astrophysics Data System (ADS)

    Hong, Augustin Jinwoo

    Non-volatile memory devices have attracted much attention because data can be retained without power consumption more than a decade. Therefore, non-volatile memory devices are essential to mobile electronic applications. Among state of the art non-volatile memory devices, NAND flash memory has earned the highest attention because of its ultra-high scalability and therefore its ultra-high storage capacity. However, human desire as well as market competition requires not only larger storage capacity but also lower power consumption for longer battery life time. One way to meet this human desire and extend the benefits of NAND flash memory is finding out new materials for storage layer inside the flash memory, which is called floating gate in the state of the art flash memory device. In this dissertation, we study new materials for the floating gate that can lower down the power consumption and increase the storage capacity at the same time. To this end, we employ various materials such as metal nanodot, metal thin film and graphene incorporating complementary-metal-oxide-semiconductor (CMOS) compatible processes. Experimental results show excellent memory effects at relatively low operating voltages. Detailed physics and analysis on experimental results are discussed. These new materials for data storage can be promising candidates for future non-volatile memory application beyond the state of the art flash technologies.

  10. Utilization of 3-D Imaging Flash Lidar Technology for Autonomous Safe Landing on Planetary Bodies

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Vanek, Michael; Petway, Larry; Pierrotter, Diego; Busch, George; Bulyshev, Alexander

    2010-01-01

    NASA considers Flash Lidar a critical technology for enabling autonomous safe landing of future large robotic and crewed vehicles on the surface of the Moon and Mars. Flash Lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes during the final stages of descent and landing. The onboard flight computer can use the 3-D map of terrain to guide the vehicle to a safe site. The capabilities of Flash Lidar technology were evaluated through a series of static tests using a calibrated target and through dynamic tests aboard a helicopter and a fixed wing aircraft. The aircraft flight tests were performed over Moon-like terrain in the California and Nevada deserts. This paper briefly describes the Flash Lidar static and aircraft flight test results. These test results are analyzed against the landing application requirements to identify the areas of technology improvement. The ongoing technology advancement activities are then explained and their goals are described.

  11. Phenomenology of the sound-induced flash illusion.

    PubMed

    Abadi, Richard V; Murphy, Jonathan S

    2014-07-01

    Past studies, using pairings of auditory tones and visual flashes, which were static and coincident in space but variable in time, demonstrated errors in judging the temporal patterning of the visual flashes-the sound-induced flash illusion. These errors took one of the two forms: under-reporting (sound-induced fusion) or over-reporting (sound-induced fission) of the flash numbers. Our study had three objectives: to examine the robustness of both illusions and to consider the effects of stimulus set and response bias. To this end, we used an extended range of fixed spatial location flash-tone pairings, examined stimuli that were variable in space and time and measured confidence in judging flash numbers. Our results indicated that the sound-induced flash illusion is a robust percept, a finding underpinned by the confidence measures. Sound-induced fusion was found to be more robust than sound-induced fission and a most likely outcome when high numbers of flashes were incorporated within an incongruent flash-tone pairing. Conversely, sound-induced fission was the most likely outcome for the flash-tone pairing which contained two flashes. Fission was also shown to be strongly driven by stimuli confounds such as categorical boundary conditions (e.g. flash-tone pairings with ≤2 flashes) and compressed response options. These findings suggest whilst both fission and fusion are associated with 'auditory driving', the differences in the occurrence and strength of the two illusions not only reflect the separate neuronal mechanisms underlying audio and visual signal processing, but also the test conditions that have been used to investigate the sound-induced flash illusion.

  12. Matter Flashed at Ultra Speed

    NASA Astrophysics Data System (ADS)

    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

  13. Improving Memory Characteristics of Hydrogenated Nanocrystalline Silicon Germanium Nonvolatile Memory Devices by Controlling Germanium Contents.

    PubMed

    Kim, Jiwoong; Jang, Kyungsoo; Phu, Nguyen Thi Cam; Trinh, Thanh Thuy; Raja, Jayapal; Kim, Taeyong; Cho, Jaehyun; Kim, Sangho; Park, Jinjoo; Jung, Junhee; Lee, Youn-Jung; Yi, Junsin

    2016-05-01

    Nonvolatile memory (NVM) with silicon dioxide/silicon nitride/silicon oxynitride (ONO(n)) charge trap structure is a promising flash memory technology duo that will fulfill process compatibility for system-on-panel displays, down-scaling cell size and low operation voltage. In this research, charge trap flash devices were fabricated with ONO(n) stack gate insulators and an active layer using hydrogenated nanocrystalline silicon germanium (nc-SiGe:H) films at a low temperature. In this study, the effect of the interface trap density on the performance of devices, including memory window and retention, was investigated. The electrical characteristics of NVM devices were studied controlling Ge content from 0% to 28% in the nc-SiGe:H channel layer. The optimal Ge content in the channel layer was found to be around 16%. For nc-SiGe:H NVM with 16% Ge content, the memory window was 3.13 V and the retention data exceeded 77% after 10 years under the programming condition of 15 V for 1 msec. This showed that the memory window increased by 42% and the retention increased by 12% compared to the nc-Si:H NVM that does not contain Ge. However, when the Ge content was more than 16%, the memory window and retention property decreased. Finally, this research showed that the Ge content has an effect on the interface trap density and this enabled us to determine the optimal Ge content. PMID:27483856

  14. Vicarious memories.

    PubMed

    Pillemer, David B; Steiner, Kristina L; Kuwabara, Kie J; Thomsen, Dorthe Kirkegaard; Svob, Connie

    2015-11-01

    People not only have vivid memories of their own personal experiences, but also vicarious memories of events that happened to other people. To compare the phenomenological and functional qualities of personal and vicarious memories, college students described a specific past event that they had recounted to a parent or friend, and also an event that a friend or parent had recounted to them. Although ratings of memory vividness, emotional intensity, visualization, and physical reactions were higher for personal than for vicarious memories, the overall pattern of ratings was similar. Participants' ratings also indicated that vicarious memories serve many of the same life functions as personal memories, although at lower levels of intensity. The findings suggest that current conceptions of autobiographical memory, which focus on past events that happened directly to the self, should be expanded to include detailed mental representations of specific past events that happened to other people.

  15. Towards Terabit Memories

    NASA Astrophysics Data System (ADS)

    Hoefflinger, Bernd

    Memories have been the major yardstick for the continuing validity of Moore's law. In single-transistor-per-Bit dynamic random-access memories (DRAM), the number of bits per chip pretty much gives us the number of transistors. For decades, DRAM's have offered the largest storage capacity per chip. However, DRAM does not scale any longer, both in density and voltage, severely limiting its power efficiency to 10 fJ/b. A differential DRAM would gain four-times in density and eight-times in energy. Static CMOS RAM (SRAM) with its six transistors/cell is gaining in reputation because it scales well in cell size and operating voltage so that its fundamental advantage of speed, non-destructive read-out and low-power standby could lead to just 2.5 electrons/bit in standby and to a dynamic power efficiency of 2aJ/b. With a projected 2020 density of 16 Gb/cm², the SRAM would be as dense as normal DRAM and vastly better in power efficiency, which would mean a major change in the architecture and market scenario for DRAM versus SRAM. Non-volatile Flash memory have seen two quantum jumps in density well beyond the roadmap: Multi-Bit storage per transistor and high-density TSV (through-silicon via) technology. The number of electrons required per Bit on the storage gate has been reduced since their first realization in 1996 by more than an order of magnitude to 400 electrons/Bit in 2010 for a complexity of 32Gbit per chip at the 32 nm node. Chip stacking of eight chips with TSV has produced a 32GByte solid-state drive (SSD). A stack of 32 chips with 2 b/cell at the 16 nm node will reach a density of 2.5 Terabit/cm². Non-volatile memory with a density of 10 × 10 nm²/Bit is the target for widespread development. Phase-change memory (PCM) and resistive memory (RRAM) lead in cell density, and they will reach 20 Gb/cm² in 2D and higher with 3D chip stacking. This is still almost an order-of-magnitude less than Flash. However, their read-out speed is ~10-times faster, with as yet

  16. Electronic control of germanium telluride (GeTe) phase transition for electronic memory applications

    NASA Astrophysics Data System (ADS)

    Gwin, Alex H.; Coutu, Ronald A.

    2014-03-01

    Germanium telluride (GeTe) is a phase change material (PCM) that undergoes an exponential decrease in resistance from room temperature to its transition temperature at approximately 200 °C. Its resistivity decreases by as much as six orders of magnitude between amorphous and crystalline phases as it is heated. Chalcogenides such as GeTe have been utilized typically in nonvolatile optical memories such as CDs, DVDs, and Blu-ray discs, where the change in reflectivity between phases gives enough contrast for ON and OFF bits. Research over the past several years has begun to characterize the electronic control of PCM thin films for advanced electronic memory applications. By applying a voltage to control its resistance and crystallinity, GeTe has become a candidate for ultra-fast switching electronic memory, perhaps as an alternative to Flash memory. In this research, micro-scale PCM cells were fabricated using RF sputtering of a GeTe target and electron-beam evaporation on c-Si, SiO2/Si, Si3N4/Si, and Al2O3. Characterizations of the crystallization process were completed with spectroscopic ellipsometry (SE), varied voltage, and varied temperature in order to draw a comparison of the switching mechanism between thermally and electronically induced transition. The results show an optical contrast of Δn + iΔk = -0.858 + i1.056. Heat conduction experiments prove a growthdominated crystallization and fracturing of conductive crystallites when deposited on Al2O3. PCM cells exhibit memory-like I-V curves for smaller cell dimensions according to the trap-limited conduction model in chalcogenides. RF structures show the capability of being utilized as improved RF switches.

  17. Measurement limits in flash thermography

    NASA Astrophysics Data System (ADS)

    Shepard, Steven M.; Lhota, James R.; Ahmed, Tasdiq

    2009-05-01

    Although active thermography has traditionally been regarded as a qualitative NDT method, its potential for quantitative measurement of thermophysical properties including wall thickness, flaw size and depth, thermal diffusivity or effusivity has been the subject of numerous investigations. Enabled by improvements in IR camera technology and fast, abundant and inexpensive computing power for advanced signal processing, measurement results have been reported using a variety of excitation and signal processing schemes. Results are often presented as a correlation between thermography data and nominal properties or independent measurements by another "validated" method. However, given the diffusion mechanism that underlies thermography, and the quantization and sampling conditions implicit in using an IR camera as a temperature sensor, there are definite limits to what can be achieved in a thermography measurement. While many benefits can be achieved with improved instrumentation, efficient energy insertion or optimized signal processing, ultimately, the limits imposed by diffusion and instrumentation take precedence, and cannot be circumvented. In this paper, the effects of camera frame rate and sensitivity on measurement of the thickness of a slab are examined, using basic 1-dimensional diffusion approximations.

  18. Electrical Safety and Arc Flash Protections

    SciTech Connect

    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.

  19. Synchronized Flashing Lights For Approach And Docking

    NASA Technical Reports Server (NTRS)

    Book, Michael L.; Howard, Richard T.; Bryan, Thomas C.; Bell, Joseph L.

    1994-01-01

    Proposed optoelectronic system for guiding vehicle in approaching and docking with another vehicle includes active optical targets (flashing lights) on approached vehicle synchronized with sensor and image-processing circuitry on approaching vehicle. Conceived for use in automated approach and docking of two spacecraft. Also applicable on Earth to manually controlled and automated approach and docking of land vehicles, aircraft, boats, and submersible vehicles, using GPS or terrestrial broadcast time signals for synchronization. Principal advantage: optical power reduced, with consequent enhancement of safety.

  20. Flash evaporation of liquid monomer particle mixture

    DOEpatents

    Affinito, John D.; Darab, John G.; Gross, Mark E.

    1999-01-01

    The present invention is a method of making a first solid composite polymer layer. The method has the steps of (a) mixing a liquid monomer with particles substantially insoluble in the liquid monomer forming a monomer particle mixture; (b) flash evaporating the particle mixture and forming a composite vapor; and (c) continuously cryocondensing said composite vapor on a cool substrate and cross-linking the cryocondensed film thereby forming the polymer layer.

  1. Flash evaporation of liquid monomer particle mixture

    DOEpatents

    Affinito, J.D.; Darab, J.G.; Gross, M.E.

    1999-05-11

    The present invention is a method of making a first solid composite polymer layer. The method has the steps of (a) mixing a liquid monomer with particles substantially insoluble in the liquid monomer forming a monomer particle mixture; (b) flash evaporating the particle mixture and forming a composite vapor; and (c) continuously cryocondensing said composite vapor on a cool substrate and cross-linking the cryocondensed film thereby forming the polymer layer. 3 figs.

  2. Do All Lightning Flashes Have Initial Breakdown Pulses?

    NASA Astrophysics Data System (ADS)

    Marshall, Thomas; Stolzenburg, Maribeth; Karunarathne, Sumedhe; Karunarathna, Nadeeka

    2013-04-01

    The initial breakdown (IB) stage of lightning flashes typically occurs in the first 5-15 ms of a flash. The IB stage is characterized in electric field change (E-change) records by a sequence of pulses (called "classic" IB pulses), each with relatively large amplitude and duration of tens of microseconds. Nag and Rakov [JGR, 2008] investigated the IB stage of cloud to ground (CG) lightning flashes in Florida thunderstorms and found that only 18% of CG flashes had classic IB pulses. Nag and Rakov [GRL, 2009] hypothesized that CG flashes without classic IB pulses initiated in thunderstorms with a weak or non-existent lower positive cloud charge. In this presentation we show the results of studying E-change data of 127 negative CG flashes and 90 intracloud (IC) flashes recorded at the Kennedy Space Center in Florida in the summers of 2010 and 2011. In 2011 we deployed 10 E-change sensors spread across an area of 70 km x 100 km; in 2010 5 E-change sensors were deployed over a smaller area. The bandwidth of the E-change sensors was 0.16 Hz - 2.6 MHz; the data were digitized at 12 bits with a sampling rate of 1, 5, or 10 MHz and a typical record length of 500 ms, including 150 ms of pre-trigger data. The analysis focuses on flashes that occurred within 30 km of at least one sensor. We find that all 127 CG flashes and all 90 IC flashes began with classic IB pulses, though the amplitude of these pulses varies significantly from flash to flash. For flashes with weak IB pulses, the more distant sensors did not always detect the IB pulses seen by closer sensors.

  3. Flash floods in Catalonia: a recurrent situation

    NASA Astrophysics Data System (ADS)

    Llasat, M. C.; Llasat-Botija, M.; Rodriguez, A.; Lindbergh, S.

    2010-09-01

    This work focuses on the analysis and characterization of the flash flood events occurring during summer in Catalonia. To this aim, a database with information about the social impact produced by all flood events recorded in Catalonia between 1982 and 2007 has been built. The social impact was obtained systematically on the basis of news press data and, occasionally, on the basis of insurance data. Flood events have been classified into ordinary, extraordinary and catastrophic floods, following the proposal of Llasat et al.~(2005). However, bearing in mind flash flood effects, some new categories concerning casualties and car damage have also been introduced. The spatial and temporal distribution of these flood events has been analyzed and, in an effort to better estimate the social impact and vulnerability, some indicators have been defined and analyzed for a specific region. These indicators allow an analysis of spacial and temporal trends as well as characterization of the events. Results show a flash-flood increase in summer and early autumn, mainly due to inter-annual and intra-annual changes in population density.

  4. FILTR: Flash Isotope Library and Training Resource

    SciTech Connect

    Campbell, D; Trombino, D

    2007-07-26

    The subject of radiation detection is replete with complex concepts and challenging nomenclature. Furthermore, a daunting variety of radioactive isotopes may be encountered during the routine operation of a radiation detector. Individuals tasked with searching for illicit sources of radiation must remain vigilant while navigating through more frequently encountered mundane and legitimate radioactive sources. The Flash Isotope Library and Training Resource (FILTR) is being developed as an easily accessible and intuitive reference tool to manage the high volume of complex information required for this task. FILTR is an extended version of the Primary Utility for Nuclear Terminology (PUNT) software developed by the Counter Measures Test Beds group at Lawrence Livermore National Laboratory for the United States Secret Service. Authored in the Flash multimedia development environment, FILTR contains detailed information on potentially encountered isotopes as well as training on radiation and operational procedures. Reference material is organized to present critical information quickly while facilitating more in-depth investigation through an intuitive interface and engaging content. FILTR is being developed for a diverse audience of law enforcement organizations and government agencies and a wide range of skill sets from expert analysts to officers whose primary role is not radiation detection. Additionally, the wide compatibility of Flash content will allow FILTR to be readily accessible through the growing number of multi-media enabled electronic devices, including PDAs and cellular phones.

  5. Natural lightning flashes: from observation to modeling

    NASA Astrophysics Data System (ADS)

    Defer, E.; Farges, T.; Barthe, C.; Bovalo, C.; Pinty, J.-P.; Chong, M.; Soula, S.; Ortéga, P.

    2011-12-01

    Different ground-based and space-based sensors are currently used to characterize and locate Earth lightning flashes like VHF mappers, VLF systems with short or long baseline, optical CCD camera and more recently microphone arrays. Concurrent observations with such equipments offer a unique description of the different processes occurring during the life of a lightning flash (triggering phase, leader development and junction phase). While the detection of lightning flashes becomes mature, more challenging investigations are still needed on i{)} Lightning Nitrogen Oxide (LINOx) production and on ii{)} the modeling of natural lightning discharges, even if ''engineer'' lightning schemes combined with electrification schemes are already implemented in numerical cloud resolving models. The PEACH project, the Atmospheric Electricity component of the upcoming field experiment HyMeX, will offer a unique opportunity for the European community to document and characterize the Mediterranean lightning activity with observations and modeling from the lightning scale to the regional scale and to gather the French community in preparation for the validation of future space-based missions like TARANIS and MTG-LI and for the interpretation of their lightning observations.

  6. The 20 February 2010 Madeira flash flood

    NASA Astrophysics Data System (ADS)

    Miranda, P. M. A.; Tomé, R.; Azevedo, E. B.; Cardoso, R. M.

    2010-09-01

    On February 20, 2010, Madeira Island was struck by a violent rain storm, which led to a major flash flood leading to more than 50 casualties and an estimated property loss above 1G€. The storm was not well forecasted by the Institute of Meteorology, based on the global ECMWF forecast. However, the operational forecasts made by our group at the University of Lisbon, with MM5 and WRF at 2 km resolution, consistently indicated heavy precipitation for that day, starting on the 72h from 18 February at 00 UTC, and including all intermediate forecasts, issued every 12h, until the day of the event. At the same time, many important details of the forecasts, concerning in particular the timing of precipitation in low level stations, have discrepancies with observations. In the present study we analyze not only the quality of the high resolution forecasts of the rain storm, with the two models at different resolutions, but also review the MM5 model performance in all forecasts from 2006 to 2010, where other important orographic precipitation events have occurred, but no flash flood was triggered. The analysis emphasizes the relative importance of the state of the terrain, due to accumulated precipitation in days and weeks before a major rain storm, in the occurrence of flash floods.

  7. Flash LIDAR Emulator for HIL Simulation

    NASA Technical Reports Server (NTRS)

    Brewster, Paul F.

    2010-01-01

    NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project is building a system for detecting hazards and automatically landing controlled vehicles safely anywhere on the Moon. The Flash Light Detection And Ranging (LIDAR) sensor is used to create on-the-fly a 3D map of the unknown terrain for hazard detection. As part of the ALHAT project, a hardware-in-the-loop (HIL) simulation testbed was developed to test the data processing, guidance, and navigation algorithms in real-time to prove their feasibility for flight. Replacing the Flash LIDAR camera with an emulator in the testbed provided a cheaper, safer, more feasible way to test the algorithms in a controlled environment. This emulator must have the same hardware interfaces as the LIDAR camera, have the same performance characteristics, and produce images similar in quality to the camera. This presentation describes the issues involved and the techniques used to create a real-time flash LIDAR emulator to support HIL simulation.

  8. Imaging Flash Lidar for Autonomous Safe Landing and Spacecraft Proximity Operation

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Roback, Vincent E.; Brewster, Paul F.; Hines, Glenn D.; Bulyshev, Alexander E.

    2016-01-01

    3-D Imaging flash lidar is recognized as a primary candidate sensor for safe precision landing on solar system bodies (Moon, Mars, Jupiter and Saturn moons, etc.), and autonomous rendezvous proximity operations and docking/capture necessary for asteroid sample return and redirect missions, spacecraft docking, satellite servicing, and space debris removal. During the final stages of landing, from about 1 km to 500 m above the ground, the flash lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes. The onboard fli1ght computer can then use the 3-D map of terrain to guide the vehicle to a safe location. As an automated rendezvous and docking sensor, the flash lidar can provide relative range, velocity, and bearing from an approaching spacecraft to another spacecraft or a space station from several kilometers distance. NASA Langley Research Center has developed and demonstrated a flash lidar sensor system capable of generating 16k pixels range images with 7 cm precision, at a 20 Hz frame rate, from a maximum slant range of 1800 m from the target area. This paper describes the lidar instrument design and capabilities as demonstrated by the closed-loop flight tests onboard a rocket-propelled free-flyer vehicle (Morpheus). Then a plan for continued advancement of the flash lidar technology will be explained. This proposed plan is aimed at the development of a common sensor that with a modest design adjustment can meet the needs of both landing and proximity operation and docking applications.

  9. The neurobiology of the human memory.

    PubMed

    Fietta, Pierluigi; Fietta, Pieranna

    2011-01-01

    Memory can be defined as the ability to acquire, process, store, and retrieve information. Memory is indispensable for learning, adaptation, and survival of every living organism. In humans, the remembering process has acquired great flexibility and complexity, reaching close links with other mental functions, such as thinking and emotions. Changes in synaptic connectivity and interactions among multiple neural networks provide the neurobiological substrates for memory encoding, retention, and consolidation. Memory may be categorized as short-term and long-term memory (according to the storage temporal duration), as implicit and explicit memory (with respect to the consciousness of remembering), as declarative (knowing that [fact]) and procedural (knowing how [skill]) memory, or as sensory (echoic, iconic and haptil), semantic, and episodic memory (according to the various remembering domains). Significant advances have been obtained in understanding memory neurobiology, but much remains to be learned in its cognitive, psychological, and phenomenological aspects. PMID:22220356

  10. Memory protection

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1988-01-01

    Accidental overwriting of files or of memory regions belonging to other programs, browsing of personal files by superusers, Trojan horses, and viruses are examples of breakdowns in workstations and personal computers that would be significantly reduced by memory protection. Memory protection is the capability of an operating system and supporting hardware to delimit segments of memory, to control whether segments can be read from or written into, and to confine accesses of a program to its segments alone. The absence of memory protection in many operating systems today is the result of a bias toward a narrow definition of performance as maximum instruction-execution rate. A broader definition, including the time to get the job done, makes clear that cost of recovery from memory interference errors reduces expected performance. The mechanisms of memory protection are well understood, powerful, efficient, and elegant. They add to performance in the broad sense without reducing instruction execution rate.

  11. Non-volatile memory based on the ferroelectric photovoltaic effect

    PubMed Central

    Guo, Rui; You, Lu; Zhou, Yang; Shiuh Lim, Zhi; Zou, Xi; Chen, Lang; Ramesh, R.; Wang, Junling

    2013-01-01

    The quest for a solid state universal memory with high-storage density, high read/write speed, random access and non-volatility has triggered intense research into new materials and novel device architectures. Though the non-volatile memory market is dominated by flash memory now, it has very low operation speed with ~10 μs programming and ~10 ms erasing time. Furthermore, it can only withstand ~105 rewriting cycles, which prevents it from becoming the universal memory. Here we demonstrate that the significant photovoltaic effect of a ferroelectric material, such as BiFeO3 with a band gap in the visible range, can be used to sense the polarization direction non-destructively in a ferroelectric memory. A prototype 16-cell memory based on the cross-bar architecture has been prepared and tested, demonstrating the feasibility of this technique. PMID:23756366

  12. Non-volatile memory based on the ferroelectric photovoltaic effect

    NASA Astrophysics Data System (ADS)

    Guo, Rui; You, Lu; Zhou, Yang; Shiuh Lim, Zhi; Zou, Xi; Chen, Lang; Ramesh, R.; Wang, Junling

    2013-06-01

    The quest for a solid state universal memory with high-storage density, high read/write speed, random access and non-volatility has triggered intense research into new materials and novel device architectures. Though the non-volatile memory market is dominated by flash memory now, it has very low operation speed with ~10 μs programming and ~10 ms erasing time. Furthermore, it can only withstand ~105 rewriting cycles, which prevents it from becoming the universal memory. Here we demonstrate that the significant photovoltaic effect of a ferroelectric material, such as BiFeO3 with a band gap in the visible range, can be used to sense the polarization direction non-destructively in a ferroelectric memory. A prototype 16-cell memory based on the cross-bar architecture has been prepared and tested, demonstrating the feasibility of this technique.

  13. Quantum memory Quantum memory

    NASA Astrophysics Data System (ADS)

    Le Gouët, Jean-Louis; Moiseev, Sergey

    2012-06-01

    Interaction of quantum radiation with multi-particle ensembles has sparked off intense research efforts during the past decade. Emblematic of this field is the quantum memory scheme, where a quantum state of light is mapped onto an ensemble of atoms and then recovered in its original shape. While opening new access to the basics of light-atom interaction, quantum memory also appears as a key element for information processing applications, such as linear optics quantum computation and long-distance quantum communication via quantum repeaters. Not surprisingly, it is far from trivial to practically recover a stored quantum state of light and, although impressive progress has already been accomplished, researchers are still struggling to reach this ambitious objective. This special issue provides an account of the state-of-the-art in a fast-moving research area that makes physicists, engineers and chemists work together at the forefront of their discipline, involving quantum fields and atoms in different media, magnetic resonance techniques and material science. Various strategies have been considered to store and retrieve quantum light. The explored designs belong to three main—while still overlapping—classes. In architectures derived from photon echo, information is mapped over the spectral components of inhomogeneously broadened absorption bands, such as those encountered in rare earth ion doped crystals and atomic gases in external gradient magnetic field. Protocols based on electromagnetic induced transparency also rely on resonant excitation and are ideally suited to the homogeneous absorption lines offered by laser cooled atomic clouds or ion Coulomb crystals. Finally off-resonance approaches are illustrated by Faraday and Raman processes. Coupling with an optical cavity may enhance the storage process, even for negligibly small atom number. Multiple scattering is also proposed as a way to enlarge the quantum interaction distance of light with matter. The

  14. Hydrogeomorphic response to extreme rainfall in headwater systems: Flash floods and debris flows

    NASA Astrophysics Data System (ADS)

    Borga, Marco; Stoffel, Markus; Marchi, Lorenzo; Marra, Francesco; Jakob, Matthias

    2014-10-01

    Flash floods and debris flows develop at space and time scales that conventional observation systems for rainfall, streamflow and sediment discharge are not able to monitor. Consequently, the atmospheric, hydrological and geomorphic controls on these hydrogeomorphic processes are poorly understood, leading to highly uncertain warning and risk management. On the other hand, remote sensing of precipitation and numerical weather predictions have become the basis of several flood forecasting systems, enabling increasingly accurate detection of hazardous events. The objective of this paper is to provide a review on current European and international research on early warning systems for flash floods and debris flows. We expand upon these themes by identifying: (a) the state of the art; (b) knowledge gaps; and (c) suggested research directions to advance warning capabilities for extreme hydrogeomorphic processes. We also suggest three areas in which advancements in science will have immediate and important practical consequence, namely development of rainfall estimation and nowcasting schemes suited to the specific space-time scales, consolidating physical, engineering and social datasets of flash floods and debris-flows, integration of methods for multiple hydrogeomorphic hazard warning.

  15. Declarative memory.

    PubMed

    Riedel, Wim J; Blokland, Arjan

    2015-01-01

    Declarative Memory consists of memory for events (episodic memory) and facts (semantic memory). Methods to test declarative memory are key in investigating effects of potential cognition-enhancing substances--medicinal drugs or nutrients. A number of cognitive performance tests assessing declarative episodic memory tapping verbal learning, logical memory, pattern recognition memory, and paired associates learning are described. These tests have been used as outcome variables in 34 studies in humans that have been described in the literature in the past 10 years. Also, the use of episodic tests in animal research is discussed also in relation to the drug effects in these tasks. The results show that nutritional supplementation of polyunsaturated fatty acids has been investigated most abundantly and, in a number of cases, but not all, show indications of positive effects on declarative memory, more so in elderly than in young subjects. Studies investigating effects of registered anti-Alzheimer drugs, cholinesterase inhibitors in mild cognitive impairment, show positive and negative effects on declarative memory. Studies mainly carried out in healthy volunteers investigating the effects of acute dopamine stimulation indicate enhanced memory consolidation as manifested specifically by better delayed recall, especially at time points long after learning and more so when drug is administered after learning and if word lists are longer. The animal studies reveal a different picture with respect to the effects of different drugs on memory performance. This suggests that at least for episodic memory tasks, the translational value is rather poor. For the human studies, detailed parameters of the compositions of word lists for declarative memory tests are discussed and it is concluded that tailored adaptations of tests to fit the hypothesis under study, rather than "off-the-shelf" use of existing tests, are recommended. PMID:25977084

  16. Shape memory polymer foams

    NASA Astrophysics Data System (ADS)

    Santo, Loredana

    2016-02-01

    Recent advances in shape memory polymer (SMP) foam research are reviewed. The SMPs belong to a new class of smart polymers which can have interesting applications in microelectromechanical systems, actuators and biomedical devices. They can respond to specific external stimulus changing their configuration and then remember the original shape. In the form of foams, the shape memory behaviour can be enhanced because they generally have higher compressibility. Considering also the low weight, and recovery force, the SMP foams are expected to have great potential applications primarily in aerospace. This review highlights the recent progress in characterization, evaluation, and proposed applications of SMP foams mainly for aerospace applications.

  17. A Comparison of Sprite Locations to Flash Structure

    NASA Astrophysics Data System (ADS)

    Stanley, M. A.; Ashcraft, T.; Krehbiel, P. R.; Rison, W.; Edens, H. E.; Cummer, S. A.; Lyons, W. A.

    2014-12-01

    Previous studies have shown that sprites can be horizontally offset byover 40 km from the parent stroke while VHF lightning maps show thatthe center of a sprite cluster generally occurs above recent portionsof the flash. However, a detailed comparison of individual spriteelement locations in relation to flash structure is currently lacking.In this presentation, I will show the results of such comparisons forvarious sprite-producing flashes in a 3 year study period between 2012and 2014. It will be shown that while there is a general correlationbetween the sprites and the active portion of a flash, it is notuncommon for the individual sprite element plan positions to belocated outside of the flash boundary. The horizontal distancebetween such sprite elements and the flash boundary rarely exceedsmuch more than 10 km. The implications of these results in regards tovarious potential seeding mechanisms for sprites will be discussed.

  18. Positive cloud-to-ground lightning flashes in severe storms

    NASA Technical Reports Server (NTRS)

    Rust, W. D.; Macgorman, D. R.; Arnold, R. T.

    1981-01-01

    The occurrence of cloud-to-ground flashes that effectively lower positive charge to earth (+CG flash) over flat terrain has been documented in the mature stage of severe thunderstorms. Of the 31 documented +CG flashes, most had only one return stroke. Zero-to-peak rise times for the strokes averaged 7 microsec. The +CG flashes averaged 520 ms in duration, with 25 percent lasting more than 800 ms. Many of these had field changes suggestive of continuing current. Positive flashes have been observed to emanate from several regions of severe storms: high on the back of the main storm tower, through the wall cloud, and from the downshear anvil. Visually most of these positive flashes have emanated from high in the storm, and acoustic mapping of two shows thunder sources to a height of about 15 km.

  19. Arc Flash Boundary Calculations Using Computer Software Tools

    SciTech Connect

    Gibbs, M.D.

    2005-01-07

    Arc Flash Protection boundary calculations have become easier to perform with the availability of personal computer software. These programs incorporate arc flash protection boundary formulas for different voltage and current levels, calculate the bolted fault current at each bus, and use built in time-current coordination curves to determine the clearing time of protective devices in the system. Results of the arc flash protection boundary calculations can be presented in several different forms--as an annotation to the one-line diagram, as a table of arc flash protection boundary distances, and as printed placards to be attached to the appropriate equipment. Basic arc flash protection boundary principles are presented in this paper along with several helpful suggestions for performing arc flash protection boundary calculations.

  20. Susceptibility to the Flash-Beep Illusion Is Increased in Children Compared to Adults

    ERIC Educational Resources Information Center

    Innes-Brown, Hamish; Barutchu, Ayla; Shivdasani, Mohit N.; Crewther, David P.; Grayden, David B.; Paolini, Antonio

    2011-01-01

    Audio-visual integration was studied in children aged 8-17 (N = 30) and adults (N = 22) using the "flash-beep illusion" paradigm, where the presentation of two beeps causes a single flash to be perceived as two flashes ("fission" illusion), and a single beep causes two flashes to be perceived as one flash ("fusion" illusion). Children reported…

  1. Nonvolatile organic transistor memory devices based on nanostructured polymeric materials

    NASA Astrophysics Data System (ADS)

    Lu, Mau-Shen; Lu, Chien; Li, Meng-Hsien; Liu, Cheng-Liang; Chen, Wen-Chang

    2014-10-01

    We report the characteristics of ferroelectric field effect transistor (FeFET) nonvolatile flash memory devices using aligned P(VDF-TrFE) electrospun nanofibers as the dielectric layer. These FeFET devices showed reliable memory behaviors and memory window proportional to the quantity of aligned nanofibers containing the ferroelectric β-phase crystalline domain. Moreover, the FeFET devices using nanofibers exhibited the long-term stability in the data retention larger than 104 s with the ON/OFF ratio of ~103, and the multiple switching operation stability up to 100 cycles.

  2. Sensitivity and kinetics of mouse rod flash responses determined in vivo from paired-flash electroretinograms

    PubMed Central

    Hetling, John R; Pepperberg, David R

    1999-01-01

    Electroretinograms (ERGs) were recorded corneally from C57BL/6J mice using a paired-flash procedure in which a brief test flash at time zero was followed at time tprobe by a bright probe flash of fixed strength, and in which the probe response amplitude was determined at time t=tprobe+ 6 ms. Probe responses obtained in a series of paired-flash trials were analysed to derive A(t), a family of amplitudes that putatively represents the massed response of the rod photoreceptors to the test flash. A central aim was to obtain a mathematical description of the normalized derived response A(t)/Amo as a function of Itest, the test flash strength. With fixed tprobe (80 ≤tprobe≤ 1200 ms), A(t)/Amo was described by the saturating exponential function [1 - exp(-ktItest)], where kt is a time-dependent sensitivity parameter. For t= 86 ms, a time near the peak of A(t), k86 was 7·0 ± 1·2 (scotopic cd s m−2)−1 (mean ± s.d.; n= 4). A(t)/Amo data were analysed in relation to the equation below, a time-generalized form of the above exponential function in which (k86Itest) is replaced by the product [k86Itestu(t)], and where u(t) is independent of the test flash strength. The function u(t) was modelled as the product of a scaling factor γ, an activation term 1 - exp[-α(t - td)2]}, and a decay term exp(-t/τω):where td is a brief delay, τω is an exponential time constant, and α characterizes the acceleration of the activation term. For Itest up to ∼2·57 scotopic cd s m−2, the overall time course of A(t) was well described by the above equation with γ= 2·21, td= 3·1 ms, τω= 132 ms and α= 2·32 × 10−4 ms−2. An approximate halving of α improved the fit of the above equation to ERG a-wave and A(t)/Amo data obtained at t about 0-20 ms. Kinetic and sensitivity properties of A(t) suggest that it approximates the in vivo massed photocurrent response of the rods to a test flash, and imply that u(t) in the above equation is the approximate kinetic description of

  3. Development of template and mask replication using jet and flash imprint lithography

    NASA Astrophysics Data System (ADS)

    Brooks, Cynthia; Selinidis, Kosta; Doyle, Gary; Brown, Laura; LaBrake, Dwayne; Resnick, Douglas J.; Sreenivasan, S. V.

    2010-09-01

    The Jet and Flash Imprint Lithography (J-FILTM)1-7 process uses 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 memory markets including Flash memory and patterned media for hard disk drives. It is anticipated that the lifetime of a single template (for patterned media) or mask (for semiconductor) will be on the order of 104 - 105 imprints. This suggests that tens of thousands of templates/masks will be required. It is not feasible to employ electronbeam patterning directly to deliver these volumes. Instead, a "master" template - created by directly patterning with an electron-beam tool - will be replicated many times with an imprint lithography tool to produce the required supply of "working" templates/masks. In this paper, we review the development of the pattern transfer process for both template and mask replicas. Pattern transfer of resolutions down to 25nm has been demonstrated for bit patterned media replication. In addition, final resolution on a semiconductor mask of 28nm has been confirmed. The early results on both etch depth and CD uniformity are promising, but more extensive work is required to characterize the pattern transfer process.

  4. The Kinematic and Microphysical Control of Storm Integrated Lightning Flash Extent

    NASA Technical Reports Server (NTRS)

    Carey, Lawrence D.; Peterson, Harold S.; Schultz, Elise V.; Matthee, Retha; Schultz, Christopher J.; Petersen, Walter A,; Bain, Lamont

    2012-01-01

    Objective: To investigate the kinematic and microphysical control of lightning properties, particularly those that may govern the production of nitrogen oxides (NOx) in thunderstorms, such as flash rate, type (intracloud [IC] vs. cloud-to-ground [CG] ) and extent. Data and Methodology: a) NASA MSFC Lightning Nitrogen Oxides Model (LNOM) is applied to North Alabama Lightning Mapping Array (NALMA) and Vaisala National Lightning Detection Network(TradeMark) (NLDN) observations following ordinary convective cells through their lifecycle. b) LNOM provides estimates of flash type, channel length distributions, lightning segment altitude distributions (SADs) and lightning NOx production profiles (Koshak et al. 2012). c) LNOM lightning characteristics are compared to the evolution of updraft and precipitation properties inferred from dual-Doppler (DD) and polarimetric radar analyses of UAHuntsville Advanced Radar for Meteorological and Operational Research (ARMOR, Cband, polarimetric) and KHTX (S-band, Doppler).

  5. Advanced computing

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Advanced concepts in hardware, software and algorithms are being pursued for application in next generation space computers and for ground based analysis of space data. The research program focuses on massively parallel computation and neural networks, as well as optical processing and optical networking which are discussed under photonics. Also included are theoretical programs in neural and nonlinear science, and device development for magnetic and ferroelectric memories.

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

    PubMed

    Miller, Heather G; Li, Rose Maria

    2004-06-01

    to moving this area forward. Scientific advances are being made increasingly at the interfaces of traditional disciplines, and approaches to science are becoming more integrative. Finding appropriate collaborators from other disciplines is not necessarily easy, and meeting a collaborator from another discipline is only the first step in building a multidisciplinary research team. Effective teams begin with compelling reasons for their existence, but further incentives must be developed to ensure full realization of their potential. The success of team science depends on individuals who are comfortable with boundary-crossing activities. Working as part of a team that is seeking solutions to complex problems requires a willingness to work in an interdisciplinary environment, to collaborate with different types of organizations, and to recognize the importance of a variety of roles in the project. It is likely that a multidisciplinary approach to hot flash research would be helpful given the number of physiologic, clinical, and behavioral factors involved. For example, psychologists and sociologists could contribute to identifying factors that may influence the placebo effect, such as pill color; developing and validating questionnaire items and diary formats; ascertaining the effect of mode of data collection on the quality of the resulting data; and determining the best ways to provide information to subjects. However, if they were part of a multidisciplinary team that included basic scientists, clinicians, and bioengineers, different questions might be asked, and better tools might be developed to collect both subjective and objective data on hot flashes. The increasing emphasis on collaborative science is also embraced at the NIH level. Since May 2002, the NIH has been engaged in a series of activities collectively known as the "NIH Roadmap," whose goal, in keeping with the NIH mission of uncovering new knowledge about the prevention, detection, diagnosis, and

  7. An Improved B+ Tree for Flash File Systems

    NASA Astrophysics Data System (ADS)

    Havasi, Ferenc

    Nowadays mobile devices such as mobile phones, mp3 players and PDAs are becoming evermore common. Most of them use flash chips as storage. To store data efficiently on flash, it is necessary to adapt ordinary file systems because they are designed for use on hard disks. Most of the file systems use some kind of search tree to store index information, which is very important from a performance aspect. Here we improved the B+ search tree algorithm so as to make flash devices more efficient. Our implementation of this solution saves 98%-99% of the flash operations, and is now the part of the Linux kernel.

  8. A fast and low-power microelectromechanical system-based non-volatile memory device

    PubMed Central

    Lee, Sang Wook; Park, Seung Joo; Campbell, Eleanor E. B.; Park, Yung Woo

    2011-01-01

    Several new generation memory devices have been developed to overcome the low performance of conventional silicon-based flash memory. In this study, we demonstrate a novel non-volatile memory design based on the electromechanical motion of a cantilever to provide fast charging and discharging of a floating-gate electrode. The operation is demonstrated by using an electromechanical metal cantilever to charge a floating gate that controls the charge transport through a carbon nanotube field-effect transistor. The set and reset currents are unchanged after more than 11 h constant operation. Over 500 repeated programming and erasing cycles were demonstrated under atmospheric conditions at room temperature without degradation. Multinary bit programming can be achieved by varying the voltage on the cantilever. The operation speed of the device is faster than a conventional flash memory and the power consumption is lower than other memory devices. PMID:21364559

  9. Virtual memory

    NASA Technical Reports Server (NTRS)

    Denning, P. J.

    1986-01-01

    Virtual memory was conceived as a way to automate overlaying of program segments. Modern computers have very large main memories, but need automatic solutions to the relocation and protection problems. Virtual memory serves this need as well and is thus useful in computers of all sizes. The history of the idea is traced, showing how it has become a widespread, little noticed feature of computers today.

  10. Muzzle flash localization for the dismounted soldier

    NASA Astrophysics Data System (ADS)

    Kennedy Scott, Will

    2015-05-01

    The ability to accurately and rapidly know the precise location of enemy fire would be a substantial capability enhancement to the dismounted soldier. Acoustic gun-shot detections systems can provide an approximate bearing but it is desired to precisely know the location (direction and range) of enemy fire; for example to know from `which window' the fire is coming from. Funded by the UK MOD (via Roke Manor Research) QinetiQ is developing an imaging solution built around an InGaAs camera. This paper presents work that QinetiQ has undertaken on the Muzzle Flash Locator system. Key technical challenges that have been overcome are explained and discussed in this paper. They include; the design of the optical sensor and processing hardware to meet low size, weight and power requirements; the algorithm approach required to maintain sensitivity whilst rejecting false alarms from sources such as close passing insects and sun glint from scene objects; and operation on the move. This work shows that such a sensor can provide sufficient sensitivity to detect muzzle flash events to militarily significant ranges and that such a system can be combined with an acoustic gunshot detection system to minimize the false alarm rate. The muzzle flash sensor developed in this work operates in real-time and has a field of view of approximately 29° (horizontal) by 12° (vertical) with a pixel resolution of 0.13°. The work has demonstrated that extension to a sensor with realistic angular rotation rate is feasible.

  11. Potential Use of a Bayesian Network for Discriminating Flash Type from Future GOES-R Geostationary Lightning Mapper (GLM) data

    NASA Technical Reports Server (NTRS)

    Solakiewiz, Richard; Koshak, William

    2008-01-01

    Continuous monitoring of the ratio of cloud flashes to ground flashes may provide a better understanding of thunderstorm dynamics, intensification, and evolution, and it may be useful in severe weather warning. The National Lighting Detection Network TM (NLDN) senses ground flashes with exceptional detection efficiency and accuracy over most of the continental United States. A proposed Geostationary Lightning Mapper (GLM) aboard the Geostationary Operational Environmental Satellite (GOES-R) will look at the western hemisphere, and among the lightning data products to be made available will be the fundamental optical flash parameters for both cloud and ground flashes: radiance, area, duration, number of optical groups, and number of optical events. Previous studies have demonstrated that the optical flash parameter statistics of ground and cloud lightning, which are observable from space, are significantly different. This study investigates a Bayesian network methodology for discriminating lightning flash type (ground or cloud) using the lightning optical data and ancillary GOES-R data. A Directed Acyclic Graph (DAG) is set up with lightning as a "root" and data observed by GLM as the "leaves." This allows for a direct calculation of the joint probability distribution function for the lighting type and radiance, area, etc. Initially, the conditional probabilities that will be required can be estimated from the Lightning Imaging Sensor (LIS) and the Optical Transient Detector (OTD) together with NLDN data. Directly manipulating the joint distribution will yield the conditional probability that a lightning flash is a ground flash given the evidence, which consists of the observed lightning optical data [and possibly cloud data retrieved from the GOES-R Advanced Baseline Imager (ABI) in a more mature Bayesian network configuration]. Later, actual GLM and NLDN data can be used to refine the estimates of the conditional probabilities used in the model; i.e., the Bayesian

  12. CCD Memory

    NASA Technical Reports Server (NTRS)

    Janesick, James R.; Elliot, Tom; Norris, Dave; Vescelus, Fred

    1987-01-01

    CCD memory device yields over 6.4 x 10 to the eighth power levels of information on single chip. Charge-coupled device (CCD) demonstrated to operate as either read-only-memory (ROM) or photon-programmable memory with capacity of 640,000 bits, with each bit capable of being weighted to more than 1,000 discrete analog levels. Larger memory capacities now possible using proposed approach in conjunction with CCD's now being fabricated, which yield over 4 x 10 to the ninth power discrete levels of information on single chip.

  13. Terrestrial Gamma-Ray Flashes (TGFs)

    NASA Technical Reports Server (NTRS)

    Fishman, Gerald J.

    2010-01-01

    This slide presentation reviews the observation of Terrestrial Gamma Ray Flashes (TGFs) by Gamma-Ray Telescopes. These were: (1) BATSE /Compton Observatory, (2) Solar Spectroscopic Imager, (3) AGILE Gamma-ray Telescope, and (4) Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope. It contains charts which display the counts over time, a map or the TGFs observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). and a map showing the latitude and longitude of 85 of the TGFs observed by the Fermi GBM.

  14. Fermi GBM Observations of Terrestrial Gamma Flashes

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.; Briggs, M. S.; Connaughton, V.; Fishman, G. J.; Bhat, P. N.; Paciesas, W. S.; Preece, R. D.; Kippen, R. M.; vonKienlin, A.; Dwyer, J. R.; Smith, D. M.; Holzworth, R.

    2010-01-01

    In its first two years of operation, the Fermi Gamma Ray Burst Monitor (GBM) has observed 79 Terrestrial Gamma Flashes (TGFs). The thick Bismuth Germanate (BGO) detectors are excellent for TGF spectroscopy, having a high probability of recording the full energy of an incident photon, spanning a broad energy range from 150 keV to 40 MeV, and recording a large number of photons per TGF. Correlations between GBM TGF triggers and lightning sferics detected with the World-Wide Lightning Location Network indicate that TGFs and lightning are simultaneous to within tens of microseconds.

  15. Apollo-Soyuz light-flash observations.

    PubMed

    Budinger, T F; Tobias, C A; Huesman, R H; Upham, F T; Wieskamp, T F; Hoffman, R A

    1977-01-01

    While dark adapted, two Apollo-Soyuz astronauts saw eighty-two light flash events during a complete 51 degrees orbit which passed near the north magnetic pole and through the South Atlantic Anomaly. The frequency of events at the polar parts of the orbit is 25 times that noted in equatorial latitudes and no increased frequency was noted in the South Atlantic Anomaly at the 225-km altitude. The expected flux of heavy particles at the northern and southern points is 1-2 min-1 per eye, and the efficiency for seeing HZE particles which were below the Cerenkov threshold is 50%.

  16. Flash floods in Catalonia: a recurrent situation

    NASA Astrophysics Data System (ADS)

    Llasat, M. C.; Lindbergh, S.; Llasat-Botija, M.; Rodríguez, A.; Zaragoza, A.

    2009-09-01

    A database with information about the social impact produced by all the flood events recorded in Catalonia between 1982 and 2007 has been built. Original information comes from the INUNGAMA database (1900-2000) presented by Barnolas and Llasat (2007), the PRESSGAMA database (1982-2007) (Llasat et al., in rev.) and information from different published works (Barriendos et al, 2003; Barriendos and Pomés, 1993). Social impact has been obtained systematically in basis to news press data and, occasionally, in basis to insurance data. Flood events have been classified in ordinary floods, extraordinary floods and catastrophic ones, following the proposal of Llasat et al (2005). However, having in mind the flash floods effects, some new categories concerning casualties and car damages have also been introduced. The spatial and temporal distribution of these flood events has been analysed. Results have been compared with those obtained for the period 1900-2000 (Barnolas and Llasat, 2007) and 1350-2000 (Barrera et al, 2006). In order to better estimate the social impact and vulnerability some indicators have been defined and analyzed for some specific cases and a specific region. Besides the indicators applied in the INUNCAT Plan to obtain a cartography of flood risk in Catalonia, other ones like the number of cars affected or the number of request received by the meteorological service, has been also taken into account. These indicators allow analyzing global and temporal trends as well as characterizing the events. The selected region has been the Maresme, which is a flood prone region with a great density of population and that experiences every year one or more flash floods. The annual number of floods shows a positive trend that cannot be justified by the rainfall trend. Both vulnerability and hazard components have been considered and a discussion about the flood prevention measures is presented. The third part of this work has been centred in the analysis and

  17. Characteristics of flash initiations in a supercell cluster with tornadoes

    NASA Astrophysics Data System (ADS)

    Zheng, Dong; MacGorman, Donald R.

    2016-01-01

    Flash initiations within a supercell cluster during 10-11 May 2010 in Oklahoma were investigated based on observations from the Oklahoma Lightning Mapping Array and the Norman, Oklahoma, polarimetric radar (KOUN). The flash initiations at positions dominated by graupel, dry snow, small hail and crystals accounted for 44.3%, 44.1%, 8.0% and 3.0% of the total flashes, respectively. During the tornadic stage of the southern supercell in the cluster, flash initiations associated with graupel occupied the main body, the right flank and the forward flank of the supercell, while those associated with dry snow dominated the outskirts of the adjacent forward anvil, right anvil and rear anvil. The flash initiations associated with small hail were concentrated around the main updraft, particularly toward its front side. Highly dense flash initiations were located in the regions overlying the differential reflectivity (ZDR) arc and right anvil. The average initial height of the flashes decreased gradually from the rear to the front and from the right to the left flanks, while the height range over which initiations occurred reached a maximum at the front of the updraft. The flashes that were initiated in the adjacent forward anvils were largest on average, followed by those in the regions ahead of the updraft and near the ZDR arc. This study supports the concept of charge pockets and further deduces that the pockets in the right anvil are the most abundant and compact due to the frequent flash initiations, small-sized flashes and thin layers including flash initiations.

  18. Aging, Spatial Disparity, and the Sound-Induced Flash Illusion

    PubMed Central

    DeLoss, Denton J.; Andersen, George J.

    2015-01-01

    The present study examined age-related differences in multisensory integration and the effect of spatial disparity on the sound-induced flash illusion—-an illusion used in previous research to assess age-related differences in multisensory integration. Prior to participation in the study, both younger and older participants demonstrated their ability to detect 1–2 visual flashes and 1–2 auditory beep presented unimodally. After passing the pre-test, participants were then presented 1–2 flashes paired with 0–2 beeps that originated from one of five speakers positioned equidistantly 100cm from the participant. One speaker was positioned directly below the screen, two speakers were positioned 50cm to the left and right from the center of the screen, and two more speakers positioned to the left and right 100cm from the center of the screen. Participants were told to report the number of flashes presented and to ignore the beeps. Both age groups showed a significant effect of the beeps on the perceived number of flashes. However, neither younger nor older individuals showed any significant effect of spatial disparity on the sound-induced flash illusion. The presence of a congruent number of beeps increased accuracy for both older and younger individuals. Reaction time data was also analyzed. As expected, older individuals showed significantly longer reaction times when compared to younger individuals. In addition, both older and younger individuals showed a significant increase in reaction time for fusion trials, where two flashes and one beep are perceived as a single flash, as compared to congruent single flash trials. This increase in reaction time was not found for fission trials, where one flash and two beeps were perceived as two flashes. This suggests that processing may differ for the two forms for fission as compared to fusion illusions. PMID:26619352

  19. An FPGA-Based Test-Bed for Reliability and Endurance Characterization of Non-Volatile Memory

    NASA Technical Reports Server (NTRS)

    Rao, Vikram; Patel, Jagdish; Patel, Janak; Namkung, Jeffrey

    2001-01-01

    Memory technologies are divided into two categories. The first category, nonvolatile memories, are traditionally used in read-only or read-mostly applications because of limited write endurance and slow write speed. These memories are derivatives of read only memory (ROM) technology, which includes erasable programmable ROM (EPROM), electrically-erasable programmable ROM (EEPROM), Flash, and more recent ferroelectric non-volatile memory technology. Nonvolatile memories are able to retain data in the absence of power. The second category, volatile memories, are random access memory (RAM) devices including SRAM and DRAM. Writing to these memories is fast and write endurance is unlimited, so they are most often used to store data that change frequently, but they cannot store data in the absence of power. Nonvolatile memory technologies with better future potential are FRAM, Chalcogenide, GMRAM, Tunneling MRAM, and Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) EEPROM.

  20. Macromedia Flash as a Tool for Mathematics Teaching and Learning

    ERIC Educational Resources Information Center

    Garofalo, Joe; Summers, Tim

    2004-01-01

    Macromedia Flash is a powerful and robust development tool. Because of its graphical, sound, and animation capabilities (and ubiquitous browser plug-in), major companies employ it in their website development (see www.nike.com or www.espn.com). These same features also make Flash a valuable environment for building multi-representational "movies"…

  1. Acceleration of electrons during the flash phase of solar flares

    NASA Technical Reports Server (NTRS)

    Kane, S. R.

    1974-01-01

    The characteristics of the electron acceleration process operating during the flash phase of solar flares are deduced from the high time resolution observations of impulsive solar X rays greater than or equal to 10 keV and other flash phase emissions from small solar flares, and the implications of these findings are discussed.

  2. Kinetics of Reactions of Monomeric Nitrosomethane Induced by Flash Photolysis.

    ERIC Educational Resources Information Center

    Kozubek, H.; And Others

    1984-01-01

    Describes an experiment in which the kinetics of dimerization of nitrosamine induced by a flash of light is measured. The experiment can be performed with a commercial ultraviolet-VIS spetrophotometer with easy to make modifications. The experiment demonstrates a flash photolysis system not always available in university chemistry laboratories.…

  3. Two probable optical flashes from gamma-ray bursters

    NASA Technical Reports Server (NTRS)

    Schaefer, B. E.; Bradt, H. V.; Barat, C.; Hurley, K.; Niel, M.; Vedrenne, G.; Cline, T. L.; Desai, U.; Teegarden, B. J.; Evans, W. D.

    1984-01-01

    Two images on archival photographic plates which are most likely records of optical flashes from gamma-ray bursters (GRBs) were examined. One of these images appears on a 1901 plate in the field of the Nov. 5, 1979 GRB, while the other is in the field of the Jan. 13, 1979 GRB on a plate exposed in 1944. The 1901 optical transient image is circular in shape, while all normal star images are trailed by 8 in. No optical transients are found in a control region which is 34.3 times larger than the GRB error regions examined. Independent limits on the optical flash rate from the sky yield a probability of less than 0.0001 that any one of the optical transients is due to a background flash. A total exposure of 2.7 years was examined for GRB flashes at known GRB locations on the Harvard plates and a total of three GRB flashes were seen, that the average recurrence time scale for optical flashes is roughly one year. The optical fluence of these optical flashes was measured. For the three currently known GRB optical flashes, the ratio of gamma-ray fluence (from a modern burst) to the optical fluence (from a archival burst) were measured to be 800, 900, and 900.

  4. Two probable optical flashes from gamma-ray bursters

    NASA Technical Reports Server (NTRS)

    Schaefer, B. E.; Bradt, H. V.; Barat, C.; Hurley, K.; Niel, M.; Vedrenne, G.; Cline, T. L.; Desai, U. D.; Teegarden, B. J.; Evans, W. D.

    1984-01-01

    Two images on archival photographic plates which are most likely records of optical flashes from gamma-ray bursters (GRBs) were examined. One of these images appears on a 1901 plate in the field of the 5 Nov. 1979 GRB, while the other is in the field of the 13 Jan. 1979 GRB on a plate exposed in 1944. The 1901 optical transient image is circular in shape, while all normal star images are trailed by 8 in. No optical transients are found in a control region which is 34.3 times larger than the GRB error regions examined. Independent limits on the optical flash rate from the sky yield a probability of less than 0.0001 that any one of the optical transients is due to a background flash. A total exposure of 2.7 years was examined for GRB flashes at known GRB locations on the Harvard plates and a total of three GRB flashes were seen, that the average recurrence time scale for optical flashes is roughly one year. The optical fluence of these optical flashes was measured. For the three currently known GRB optical flashes, the ratio of gamma-ray fluence (from a modern burst) to the optical fluence (from a archival burst) were measured to be 800, 900, and 900.

  5. On the proportion of upward flashes to lightning research towers

    NASA Astrophysics Data System (ADS)

    Smorgonskiy, Alexander; Rachidi, Farhad; Rubinstein, Marcos; Diendorfer, Gerhard; Schulz, Wolfgang

    2013-07-01

    We compare in this paper direct measurements obtained on the towers on San Salvatore Mountain (Switzerland) and on the Gaisberg Mountain (Austria). They are situated in similar topographical environments but in different lightning activity zones. Direct measurements of lightning currents on these towers have revealed a major difference in terms of the number of downward flashes. While measurements made by Berger and co-workers revealed a significant number of downward flashes on the two towers on San Salvatore Mountain, more recent observations on the Gaisberg and Peissenberg towers were essentially composed of upward flashes. We use in this paper a new method to estimate the proportion of upward/downward flashes to a given tower, based on the data from lightning location systems. The analysis using the proposed method explains the discrepancy in terms of the measured number of downward flashes in the Gaisberg and San Salvatore towers. The analysis presented reveals also that in the evaluation of the percentage of upward flashes initiated from a tall structure, different parameters should be carefully examined, namely (i) the value of the ground flash density, (ii) the topographical conditions, and (iii) the presence of other tall structures in the region from which upward flashes might be initiated.

  6. Treatment of Menopausal Hot Flashes with 5-Hydroxytryptophan

    PubMed Central

    Freedman, Robert R.

    2010-01-01

    Objective Much recent research has focused on nonhormonal treatments for menopausal hot flashes. The purpose of the present study was to determine the effects of 5-Hydroxytroptophan (5-HTP), the immediate precursor of serotonin, upon menopausal hot flashes. Selective, serotonergic, reuptake inhibitors (SSRI’s), which increase the amount of serotonin in the synaptic gap, have shown some promise in the amelioration of hot flashes. Methods We administered 5-HTP or placebo, in double-blind fashion, to 24 postmenopausal women reporting frequent hot flashes. Treatment outcome was measured using a miniature, electronic, hot flash recorder. Results No significant effects of 150 mg/day 5-HTP upon hot flash frequency were found. The 5-HTP group had 23.8 ± 5.7 (SD) hot flashes/24 hours prior to treatment and 18.5 ± 9.6 at the end of treatment. The placebo group had 18.5 ± 9.6 before treatment and 22.6 ± 12.4 at treatment completion. Conclusions At the dose given, 5-HTP does not significantly ameliorate frequency of menopausal hot flashes, as measured objectively with an electronic recorder. Given the small size, this study must be considered preliminary in nature. PMID:20031347

  7. Negative cloud-to-ground lightning flashes in Malaysia

    NASA Astrophysics Data System (ADS)

    Baharudin, Z. A.; Ahmad, Noor Azlinda; Mäkelä, J. S.; Fernando, Mahendra; Cooray, Vernon

    2014-02-01

    The characteristics of the negative cloud-to-ground lightning flashes in Malaysia are studied by analyzing the electric fields generated by the whole flash in nanosecond resolution. A total of 405 strokes obtained from 100 successive negative cloud-to-ground lightning flashes were analyzed, which were recorded from seven convective thunderstorms during the southwest monsoon period, i.e. from April to June 2009. It was found that the total number of interstroke intervals has an arithmetic mean value of 86 ms, a geometric mean value of 67 ms and does not depend on the return stroke order. Of the 100 negative ground flashes, 38 flashes (38%) have at least one subsequent return-stroke (SRS) whose electric field peak was greater than that of the first return-stroke (RS). Furthermore, 58 (19%) out of 305 SRS have electric field peak larger than those of the first RS. The arithmetic and geometric mean ratio between the peak electric field of the SRS and the peak electric field of the first RS are 0.7 and 0.6, respectively. The percentage of single-stroke flashes was 16% while the mean number of strokes per flash and maximum number of stroke per flash were 4 and 14, respectively.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Technical Reports Server (NTRS)

    Swift, Wesley; Suggs, Robert; Cooke, William

    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, 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.

  10. Behavioral Treatment of Menopausal Hot Flashes: Evaluation by Objective Methods.

    ERIC Educational Resources Information Center

    Germaine, Leonard M.; Freedman, Robert R.

    1984-01-01

    Used latency to hot flash onset under heat stress to evaluate the effects of relaxation treatment or a control procedure in 14 menopausal women. Following treatment, the latency to hot flash onset during heat stress was increased in relaxation subjects. Reported symptom frequency was significantly reduced in relaxation subjects. (BH)

  11. Genetic Polymorphisms, Hormone Levels, and Hot Flashes in Midlife Women

    PubMed Central

    Schilling, Chrissy; Gallicchio, Lisa; Miller, Susan R.; Langenberg, Patricia; Zacur, Howard; Flaws, Jodi A.

    2007-01-01

    Objective Hot flashes disrupt the lives of millions of women each year. Although hot flashes are a public health concern, little is known about risk factors that predispose women to hot flashes. Thus, the objective of this study was to examine whether sex steroid hormone levels and genetic polymorphisms in hormone biosynthesis and degradation enzymes are associated with the risk of hot flashes. Methods In a cross-sectional study design, midlife women aged 45 to 54 years (n=639) were recruited from Baltimore and its surrounding counties. Participants completed a questionnaire and donated a blood sample for steroid hormone analysis and genotyping. The associations between genetic polymorphisms and hormone levels, as well as the associations between genetic polymorphisms, hormone levels, and hot flashes were examined using statistical models. Results A polymorphism in CYP1B1 was associated with lower dehydroepiandrosterone-sulfate (DHEA-S) and progesterone levels, while a polymorphism in CYP19 (aromatase) was associated with higher testosterone and DHEA-S levels. Lower progesterone and sex hormone binding globulin levels, lower free estradiol index, and a higher ratio of total androgens to total estrogens were associated with the experiencing of hot flashes. A polymorphism in CYP1B1 and a polymorphism in 3βHSD were both associated with hot flashes. Conclusion Some genetic polymorphisms may be associated with altered levels of hormones in midlife women. Further, selected genetic polymorphisms and altered hormone levels may be associated with the risk of hot flashes in midlife women. PMID:17187946

  12. Locating Initial Breakdown Pulses of Lightning Flashes

    NASA Astrophysics Data System (ADS)

    Karunarathne, S.; Marshall, T.; Stolzenburg, M.; Betz, H.; Wieczorek, G.

    2010-12-01

    Lightning flashes often begin with a series of bipolar pulses, 1-5 us in width, called initial breakdown pulses or characteristic pulses. In this presentation we show electric field change data of initial breakdown pulses collected with a network of 5 flat-plate antennas with a bandwidth of 0 - 5 MHz. These pulses were obtained at the NASA/Kennedy Space Center (KSC) during the summer of 2010. The (x, y, z, t) positions of these pulses have been determined using a time of arrival technique [Koshak and Solakiewicz, JGR, 1996] for several lightning flashes. In addition, we also collected magnetic field change data with a LINET system [e.g., Betz et al., GRL, 2004], which consisted of 7 crossed-loop sensors having a bandwidth of 5 - 200 kHz; the pulse locations detected by this system were also determined by time of arrival. The locations of the initial breakdown pulses from both systems will be compared to locations of VHF lightning sources made with the KSC LDAR2 system (with a center frequency of 63 MHz and a bandwidth of 6 MHz). Possible implications of the pulse locations derived from the three different sets of sensors on lightning initiation and propagation will be discussed.

  13. Flash Infrared Thermography Contrast Data Analysis Technique

    NASA Technical Reports Server (NTRS)

    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.

  14. Flash vacuum pyrolysis of lignin model compounds

    SciTech Connect

    Cooney, M.J.; Britt, P.F.; Buchanan, A.C. III

    1997-03-01

    Despite the extensive research into the pyrolysis of lignin, the underlying chemical reactions that lead to product formation are poorly understood. Detailed mechanistic studies on the pyrolysis of biomass and lignin under conditions relevant to current process conditions could provide insight into utilizing this renewable resource for the production of chemicals and fuel. Currently, flash or fast pyrolysis is the most promising process to maximize the yields of liquid products (up to 80 wt %) from biomass by rapidly heating the substrate to moderate temperatures, typically 500{degrees}C, for short residence times, typically less than two seconds. To provide mechanistic insight into the primary reaction pathways under process relevant conditions, we are investigating the flash vacuum pyrolysis (FVP) of lignin model compounds that contain a {beta}-ether. linkage and {alpha}- or {gamma}-alcohol, which are key structural elements in lignin. The dominant products from the FVP of PhCH{sub 2}CH{sub 2}OPh (PPE), PhC(OH)HCH{sub 2}OPh, and PhCH{sub 2}CH(CH{sub 2}OH)OPh at 500{degrees}C can be attributed to homolysis of the weakest bond in the molecule (C-O bond) or 1,2-elimination. Surprisingly, the hydroxy-substituent dramatically increases the decomposition of PPE. It is proposed that internal hydrogen bonding is accelerating the reaction.

  15. Memory systems.

    PubMed

    Eichenbaum, Howard

    2010-07-01

    The idea that there are multiple memory systems can be traced to early philosophical considerations and introspection. However, the early experimental work considered memory a unitary phenomenon and focused on finding the mechanism upon which memory is based. A full reconciliation of debates about that mechanism, and a coincidental rediscovery of the idea of multiple memory systems, emerged from studies in the cognitive neuroscience of memory. This research has identified three major forms of memory that have distinct operating principles and are supported by different brain systems. These include: (1) a cortical-hippocampal circuit that mediates declarative memory, our capacity to recollect facts and events; (2) procedural memory subsystems involving a cortical-striatal circuit that mediates habit formation and a brainstem-cerebellar circuit that mediates sensorimotor adaptations; and (3) a circuit involving subcortical and cortical pathways through the amygdala that mediates the attachment of affective status and emotional responses to previously neutral stimuli. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website.

  16. Collaging Memories

    ERIC Educational Resources Information Center

    Wallach, Michele

    2011-01-01

    Even middle school students can have memories of their childhoods, of an earlier time. The art of Romare Bearden and the writings of Paul Auster can be used to introduce ideas about time and memory to students and inspire works of their own. Bearden is an exceptional role model for young artists, not only because of his astounding art, but also…

  17. Episodic Memories

    ERIC Educational Resources Information Center

    Conway, Martin A.

    2009-01-01

    An account of episodic memories is developed that focuses on the types of knowledge they represent, their properties, and the functions they might serve. It is proposed that episodic memories consist of "episodic elements," summary records of experience often in the form of visual images, associated to a "conceptual frame" that provides a…

  18. The Kinematic and Microphysical Control of Storm Integrated Lightning Flash Extent

    NASA Astrophysics Data System (ADS)

    Carey, L. D.; Koshak, W. J.; Peterson, H. S.; Schultz, E. V.; Matthee, R.; Schultz, C. J.; Petersen, W. A.; Bain, L.

    2012-12-01

    (non-severe multi-cell) over Northern Alabama. The LNOM lightning characteristics are compared to the evolution of updraft and precipitation properties inferred from dual-Doppler and polarimetric radar analyses applied to observations from a nearby Doppler radar network, including the UAHuntsville Advanced Radar for Meteorological and Operational Research (ARMOR, C-band, polarimetric). The LNOM estimated SAD and lightning NOx production profiles are placed in the context of radar derived profiles of vertical motion, precipitation types and amounts. Finally, these analyses are used to determine if storm integrated flash channel extent is as well correlated to volumetric updraft and precipitation ice characteristics in the mixed phase region as flash rate for these individual convective cells.

  19. The Kinematic and Microphysical Control of Storm Integrated Lightning Flash Extent

    NASA Technical Reports Server (NTRS)

    Carey, Lawrence; Koshak, William; Petersen, Harold; Schultz, Elise; Schultz, Chris; Matthee, Retha; Bain, Lamont

    2012-01-01

    (non-severe multi-cell) over Northern Alabama. The LNOM lightning characteristics are compared to the evolution of updraft and precipitation properties inferred from dual-Doppler and polarimetric radar analyses applied to observations from a nearby Doppler radar network, including the UA Huntsville Advanced Radar for Meteorological and Operational Research (ARMOR, C-band, polarimetric). The LNOM estimated SAD and lightning NOx production profiles are placed in the context of radar derived profiles of vertical motion, precipitation types and amounts. Finally, these analyses are used to determine if storm integrated flash channel extent is as well correlated to volumetric updraft and precipitation ice characteristics in the mixed phase region as flash rate for these individual convective cells.

  20. Estimation of the relative severity of floods in small ungauged catchments for preliminary observations on flash flood preparedness: a case study in Korea.

    PubMed

    Kim, Eung Seok; Choi, Hyun Il

    2012-04-01

    An increase in the occurrence of sudden local flooding of great volume and short duration has caused significant danger and loss of life and property in Korea as well as many other parts of the World. Since such floods usually accompanied by rapid runoff and debris flow rise quite quickly with little or no advance warning to prevent flood damage, this study presents a new flash flood indexing methodology to promptly provide preliminary observations regarding emergency preparedness and response to flash flood disasters in small ungauged catchments. Flood runoff hydrographs are generated from a rainfall-runoff model for the annual maximum rainfall series of long-term observed data in the two selected small ungauged catchments. The relative flood severity factors quantifying characteristics of flood runoff hydrographs are standardized by the highest recorded maximum value, and then averaged to obtain the flash flood index only for flash flood events in each study catchment. It is expected that the regression equations between the proposed flash flood index and rainfall characteristics can provide the basis database of the preliminary information for forecasting the local flood severity in order to facilitate flash flood preparedness in small ungauged catchments.

  1. Neural correlates of conceptual implicit memory and their contamination of putative neural correlates of explicit memory.

    PubMed

    Voss, Joel L; Paller, Ken A

    2007-04-01

    During episodic recognition tests, meaningful stimuli such as words can engender both conscious retrieval (explicit memory) and facilitated access to meaning that is distinct from the awareness of remembering (conceptual implicit memory). Neuroimaging investigations of one type of memory are frequently subject to the confounding influence of the other type of memory, thus posing a serious impediment to theoretical advances in this area. We used minimalist visual shapes (squiggles) to attempt to overcome this problem. Subjective ratings of squiggle meaningfulness varied idiosyncratically, and behavioral indications of conceptual implicit memory were evident only for stimuli given higher ratings. These effects did not result from perceptual-based fluency or from explicit remembering. Distinct event-related brain potentials were associated with conceptual implicit memory and with explicit memory by virtue of contrasts based on meaningfulness ratings and memory judgments, respectively. Frontal potentials from 300 to 500 msec after the onset of repeated squiggles varied systematically with perceived meaningfulness. Explicit memory was held constant in this contrast, so these potentials were taken as neural correlates of conceptual implicit memory. Such potentials can contaminate putative neural correlates of explicit memory, in that they are frequently attributed to the expression of explicit memory known as familiarity. These findings provide the first neural dissociation of these two memory phenomena during recognition testing and underscore the necessity of taking both types of memory into account in order to obtain valid neural correlates of specific memory functions. PMID:17412965

  2. Molecular memory based on nanowire-molecular wire heterostructures.

    PubMed

    Li, Chao; Lei, Bo; Fan, Wendy; Zhang, Daihua; Meyyappan, M; Zhou, Chongwu

    2007-01-01

    This article reviews the recent research of molecular memory based on self-assembled nanowire-molecular wire heterostructures. These devices exploit a novel concept of using redox-active molecules as charge storage flash nodes for nanowire transistors, and thus boast many advantages such as room-temperature processing and nanoscale device area. Various key elements of this technology will be reviewed, including the synthesis of the nanowires and molecular wires, and fabrication and characterization of the molecular memory devices. In particular, multilevel memory has been demonstrated using In2O3 nanowires with self-assembled Fe-bis(terpyridine) molecules, which serve to multiple the charge storage density without increasing the device size. Furthermore, in-depth studies on memory devices made with different molecules or with different functionalization techniques will be reviewed and analyzed. These devices represent a conceptual breakthrough in molecular memory and may work as building blocks for future beyond-CMOS nanoelectronic circuits.

  3. Memory conformity affects inaccurate memories more than accurate memories.

    PubMed

    Wright, Daniel B; Villalba, Daniella K

    2012-01-01

    After controlling for initial confidence, inaccurate memories were shown to be more easily distorted than accurate memories. In two experiments groups of participants viewed 50 stimuli and were then presented with these stimuli plus 50 fillers. During this test phase participants reported their confidence that each stimulus was originally shown. This was followed by computer-generated responses from a bogus participant. After being exposed to this response participants again rated the confidence of their memory. The computer-generated responses systematically distorted participants' responses. Memory distortion depended on initial memory confidence, with uncertain memories being more malleable than confident memories. This effect was moderated by whether the participant's memory was initially accurate or inaccurate. Inaccurate memories were more malleable than accurate memories. The data were consistent with a model describing two types of memory (i.e., recollective and non-recollective memories), which differ in how susceptible these memories are to memory distortion.

  4. Making FLASH an Open Code for the Academic High-Energy Density Physics Community

    NASA Astrophysics Data System (ADS)

    Lamb, D. Q.; Couch, S. M.; Dubey, A.; Gopal, S.; Graziani, C.; Lee, D.; Weide, K.; Xia, G.

    2010-11-01

    High-energy density physics (HEDP) is an active and growing field of research. DOE has recently decided to make FLASH a code for the academic HEDP community. FLASH is a modular and extensible compressible spatially adaptive hydrodynamics code that incorporates capabilities for a broad range of physical processes, performs well on a wide range of existing advanced computer architectures, and has a broad user base. A rigorous software maintenance process allows the code to operate simultaneously in production and development modes. We summarize the work we are doing to add HEDP capabilities to FLASH. We are adding (1) Spitzer conductivity, (2) super time-stepping to handle the disparity between diffusion and advection time scales, and (3) a description of electrons, ions, and radiation (in the diffusion approximation) by 3 temperatures (3T) to both the hydrodynamics and the MHD solvers. We are also adding (4) ray tracing, (5) laser energy deposition, and (6) a multi-species equation of state incorporating ionization to the hydrodynamics solver; and (7) Hall MHD, and (8) the Biermann battery term to the MHD solver.

  5. Additions and Improvements to the FLASH Code for Simulating High Energy Density Physics Experiments

    NASA Astrophysics Data System (ADS)

    Lamb, D. Q.; Daley, C.; Dubey, A.; Fatenejad, M.; Flocke, N.; Graziani, C.; Lee, D.; Tzeferacos, P.; Weide, K.

    2015-11-01

    FLASH is an open source, finite-volume Eulerian, spatially adaptive radiation hydrodynamics and magnetohydrodynamics code that incorporates capabilities for a broad range of physical processes, performs well on a wide range of computer architectures, and has a broad user base. Extensive capabilities have been added to FLASH to make it an open toolset for the academic high energy density physics (HEDP) community. We summarize these capabilities, with particular emphasis on recent additions and improvements. These include advancements in the optical ray tracing laser package, with methods such as bi-cubic 2D and tri-cubic 3D interpolation of electron number density, adaptive stepping and 2nd-, 3rd-, and 4th-order Runge-Kutta integration methods. Moreover, we showcase the simulated magnetic field diagnostic capabilities of the code, including induction coils, Faraday rotation, and proton radiography. We also describe several collaborations with the National Laboratories and the academic community in which FLASH has been used to simulate HEDP experiments. This work was supported in part at the University of Chicago by the DOE NNSA ASC through the Argonne Institute for Computing in Science under field work proposal 57789; and the NSF under grant PHY-0903997.

  6. Experimental evaluation of a solar fired flash pyrolysis of biomass reactor

    SciTech Connect

    Antal, M.J. Jr.; Edwards, W.E.; Steenblik, R.A.; Brown, C.T.; Knight, J.A.; Elston, L.W.; Hurst, D.R.

    1981-01-01

    A Princeton-Georgia Institute of Technology flash pyrolysis of biomass test program was conducted at the DOE Advanced Components Test Facility (CTF) at Georgia Tech in August 1980. The 400 kWth solar thermal facility was used to provide a source of highly concentrated radiant energy for the flash pyrolysis of four types of biomass in a steam counterflow quartz reactor. The biomass materials were microcrystalline cellulose, hardwood sawdust, ground corn cob, and Kraft lignin. The experiments at Princeton and Georgia Tech suggest the use of concentrated radiant energy as a selective means for the production of either a hydrocarbon rich synthesis gas or sugar related syrups from biomass by flash pyrolysis. Experiments at Princeton have indicated that sugar related syrups are selectively produced when the biomass particles are rapidly heated by radiation in a cool gaseous environment. The gas temperatures in the reactor during the test program at Georgia Tech were relatively high, which selectively turned the chemistry toward the production of hydrocarbon rich synthesis gases.

  7. Role of model resolution and microphysical properties in simulating flash flood induce storms

    NASA Astrophysics Data System (ADS)

    Bartsotas, Nikolaos; Solomos, Stavros; Nikolopoulos, Efthymios I.; Anagnostou, Emmanouil; Kallos, George

    2013-04-01

    Flash flood induce storms are mainly of convective nature and develop at small space and short time scales making their predictability a particularly challenging task. The tremendous societal and economical impact of this hazard necessitates the development of accurate forecasting systems in order to advance warnings and mitigate the risk. To be able to develop a forecasting system that can accurately represent flash flood storms, we need to understand the key elements that control the generation and evolution of this type of events. This study examines the effect of topographic representation, model grid resolution and cloud microphysical properties in simulating three major flash flood storms that occurred in Northern Italy. To simulate those heavy precipitation events, the high-resolution integrated atmospheric model RAMS / ICLAMS was used with grid resolutions of 250 m, in order to properly resolve the complex physical processes and convective activity. In addition, a high resolution topography dataset of 3 arcsec from the NASA SRTM mission was implemented in the model. The sensitivity of microphysical properties and aerosol cloud interactions towards convection and precipitation over the area were examined through various model setups and simulations. The specific properties proved to play a significant role in the correct estimation of spatial distribution and quantity of precipitation, as indicated from the comparison of the model outputs with bias adjusted radar data.

  8. Memory and Self–Neuroscientific Landscapes

    PubMed Central

    Markowitsch, Hans J.

    2013-01-01

    Relations between memory and the self are framed from a number of perspectives—developmental aspects, forms of memory, interrelations between memory and the brain, and interactions between the environment and memory. The self is seen as dividable into more rudimentary and more advanced aspects. Special emphasis is laid on memory systems and within them on episodic autobiographical memory which is seen as a pure human form of memory that is dependent on a proper ontogenetic development and shaped by the social environment, including culture. Self and episodic autobiographical memory are seen as interlocked in their development and later manifestation. Aside from content-based aspects of memory, time-based aspects are seen along two lines—the division between short-term and long-term memory and anterograde—future-oriented—and retrograde—past-oriented memory. The state dependency of episodic autobiographical is stressed and implications of it—for example, with respect to the occurrence of false memories and forensic aspects—are outlined. For the brain level, structural networks for encoding, consolidation, storage, and retrieval are discussed both by referring to patient data and to data obtained in normal participants with functional brain imaging methods. It is elaborated why descriptions from patients with functional or dissociative amnesia are particularly apt to demonstrate the facets in which memory, self, and personal temporality are interwoven. PMID:24967303

  9. Mapping Flash Flood Severity in the United States

    NASA Astrophysics Data System (ADS)

    Saharia, M.; Kirstetter, P. E.; Gourley, J. J.; Hong, Y.; Vergara, H. J.

    2015-12-01

    Flash floods have been a major natural hazard in terms of both fatalities and property damage. In the United States, flash floods have only been characterized on a case study basis due to the lack of a comprehensive database matching flood characteristics with geospatial and geomorphologic information. To characterize the ability of a basin to produce flash floods, a new variable called "Flashiness" is derived from the slope of the rising limb in hydrograph time series. It is the basis to document and predict the flash flood potential and severity over the U.S. First a representative and long archive of flood events spanning 78 years is used to analyze the spatial and temporal variability of observed flashiness. The areas and seasons prone to flash floods are documented, highlighting the flash flood alley in Texas, Appalachians, West Coast, and North American monsoon in Arizona etc. Then the flashiness is linked to geomorphologic and climatologic attributes to identify the basin characteristics driving the ability to produce flash floods. The significant impact of characteristics such as slope, precipitation, and basin area are quantified. Next the model is used to predict flashiness all over the continental U.S., specifically over regions poorly covered by hydrological observations. It highlights ungauged areas prone to flash floods such as parts of Florida, Southern Wisconsin, Montana and South Dakota etc. Finally these findings are validated using the National Weather Service storm reports and a historical flood fatalities database. This analysis framework will serve as a baseline for evaluating distributed hydrologic model simulations such as the Flooded Locations And Simulated Hydrographs Project (FLASH) (http://flash.ou.edu).

  10. Flood hazard assessment in areas prone to flash flooding

    NASA Astrophysics Data System (ADS)

    Kvočka, Davor; Falconer, Roger A.; Bray, Michaela

    2016-04-01

    Contemporary climate projections suggest that there will be an increase in the occurrence of high-intensity rainfall events in the future. These precipitation extremes are usually the main cause for the emergence of extreme flooding, such as flash flooding. Flash floods are among the most unpredictable, violent and fatal natural hazards in the world. Furthermore, it is expected that flash flooding will occur even more frequently in the future due to more frequent development of extreme weather events, which will greatly increase the danger to people caused by flash flooding. This being the case, there will be a need for high resolution flood hazard maps in areas susceptible to flash flooding. This study investigates what type of flood hazard assessment methods should be used for assessing the flood hazard to people caused by flash flooding. Two different types of flood hazard assessment methods were tested: (i) a widely used method based on an empirical analysis, and (ii) a new, physically based and experimentally calibrated method. Two flash flood events were considered herein, namely: the 2004 Boscastle flash flood and the 2007 Železniki flash flood. The results obtained in this study suggest that in the areas susceptible to extreme flooding, the flood hazard assessment should be conducted using methods based on a mechanics-based analysis. In comparison to standard flood hazard assessment methods, these physically based methods: (i) take into account all of the physical forces, which act on a human body in floodwater, (ii) successfully adapt to abrupt changes in the flow regime, which often occur for flash flood events, and (iii) rapidly assess a flood hazard index in a relatively short period of time.

  11. Mechanisms of cutaneous vasodilation during the postmenopausal hot flash

    PubMed Central

    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

  12. Features of positive ground flashes observed in Kathmandu Nepal

    NASA Astrophysics Data System (ADS)

    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.

  13. The evolving roles of memory immune cells in transplantation

    PubMed Central

    Chen, Wenhao; Ghobrial, Rafik M.; Li, Xian C.

    2015-01-01

    Memory cells are the products of immune responses but also exert significant impact on subsequent immunity and immune tolerance, thus placing them in a unique position in transplant research. Memory cells are heterogeneous, including not only memory T cells but also memory B cells and innate memory cells. Memory cells are a critical component of protective immunity against invading pathogens, especially in immunosuppressed patients, but they also mediate graft loss and tolerance resistance. Recent studies suggest that some memory cells unexpectedly act as regulatory cells, promoting rather than hindering transplant survival. This functional diversity makes therapeutic targeting of memory cells a challenging task in transplantation. In this article we highlight recent advances in our understanding of memory cells, focusing on diversity of memory cells and mechanisms involved in their induction and functions. We also provide a broad overview on the challenges and opportunities in targeting memory cells in the induction of transplant tolerance. PMID:26102615

  14. Luminosity with Intracloud-Type Initial Breakdown Pulses and Terrestrial Gamma-ray Flash Candidates

    NASA Astrophysics Data System (ADS)

    Stolzenburg, Maribeth; Marshall, Thomas; Karunarathne, Sumedhe; Orville, Richard

    2016-04-01

    High-speed video data for three hybrid lightning flashes show luminosity increases at visible wavelengths that are time-correlated with large, intracloud (IC) type initial breakdown (IB) pulses in electric field change (E-change) data. In one case, a diffuse luminosity increase is visible for 280-300 us, apparently centered near 9 km altitude. At the same time, locations of VHF sources and E-change pulses indicate breakdown activity occurring at altitudes of 9.2-10.2 km altitude, and the initial leader was developing rapidly upward. The second case has a diffuse luminosity increase at the time of three large IC-type IB pulses, while the initial leader is advancing upward from about 7 km altitude. In the third example, a series of luminosity bursts are visible at the times of several large-amplitude IC-type IB pulses, although the center of the activity is apparently above the video frame. In all three hybrid flashes, the luminous IC-type IB pulses are relatively complicated and large in E-change amplitude, and most have distinct electrostatic offset at horizontal distances of 20-25 km from a sensor. Such large amplitude IB pulses have been associated with the production of terrestrial gamma ray flashes (TGFs) in prior work [Marshall et al., 2013, doi:10.1002/jgrd.50866]. No satellite or ground-based TGF observations were available for these events, hence it is not known if these TGF candidates produced gammas or other high energy radiation. This presentation describes the video and E-change observations during the intracloud and cloud-to-ground initial breakdown periods of these flashes and implications for TGF production.

  15. Kinematic and Microphysical Control of Lightning Flash Rate over Northern Alabama

    NASA Technical Reports Server (NTRS)

    Carey, Lawrence D.; Bain, Anthony L.; Matthee, Retha; Schultz, Christopher J.; Schultz, Elise V.; Deierling, Wiebke; Petersen, Walter A.

    2015-01-01

    The Deep Convective Clouds and Chemistry (DC3) experiment seeks to examine the relationship between deep convection and the production of nitrogen oxides (NO (sub x)) via lightning (LNO (sub x)). A critical step in estimating LNO (sub x) production in a cloud-resolving model (CRM) without explicit lightning is to estimate the flash rate from available model parameters that are statistically and physically correlated. As such, the objective of this study is to develop, improve and evaluate lightning flash rate parameterizations in a variety of meteorological environments and storm types using radar and lightning mapping array (LMA) observations taken over Northern Alabama from 2005-2012, including during DC3. UAH's Advanced Radar for Meteorological and Operational Research (ARMOR) and the Weather Surveillance Radar - 1988 Doppler (WSR 88D) located at Hytop (KHTX) comprises the dual-Doppler and polarimetric radar network, which has been in operation since 2004. The northern Alabama LMA (NA LMA) in conjunction with Vaisala's National Lightning Detection Network (NLDN) allow for a detailed depiction of total lightning during this period. This study will integrate ARMOR-KHTX dual Doppler/polarimetric radar and NA LMA lightning observations from past and ongoing studies, including the more recent DC3 results, over northern Alabama to form a large data set of 15-20 case days and over 20 individual storms, including both ordinary multicell and supercell convection. Several flash rate parameterizations will be developed and tested, including those based on 1) graupel/small hail volume; 2) graupel/small hail mass, and 3) convective updraft volume. Sensitivity of the flash rate parameterizations to storm intensity, storm morphology and environmental conditions will be explored.

  16. Effects of ISI and flash duration on the identification of briefly flashed stimuli.

    PubMed

    Rucci, Michele; Beck, Jacob

    2005-01-01

    The identification accuracy of briefly flashed stimuli followed by an interstimulus interval (ISI) of variable length was compared to that obtained with longer flashes that prolonged the exposure of the stimulus throughout the ISI. The interval between the onset of the stimulus and the onset of the mask (stimulus onset asynchrony (SOA)) was the same in the two conditions. Consistent with a dependence of visual identification on SOA, the percentages of correct identification in the two conditions were approximately similar at all SOAs irrespective of the level of noise, stimulus familiarity, and stimulus complexity. However, departures from the onset-onset rule were also present. While the two conditions yielded virtually identical identification accuracy with an SOA of 80 ms, small but significant differences were found for shorter and longer intervals. Possible theoretical explanations of the results are presented.

  17. Characterization of the self magnetic pinch diode at high voltages for flash radiography.

    SciTech Connect

    Cordova, Steve Ray; Portillo, Salvador; Oliver, Bryan Velten; Threadgold, James R.; Crotch, Ian; Ziska, Derek Raymond

    2008-10-01

    The Sandia Laboratories Advanced Radiographic Technologies Department, in collaboration with the United Kingdom Atomic Weapons Establishment, has been conducting research into the development of the Self-Magnetic-Pinched diode as an x-ray source suitable for flash radiographic experiments. We have demonstrated that this source is capable of meeting and exceeding the initial requirements of 250 rads (measured at one meter) with a 2.75 mm source spot-size. Recent experiments conducted on the RITS-6 accelerator have demonstrated the ability of this diode to meet intermediate requirements with a sub 3 mm source spot size and a dose in excess of 400 rads at one meter.

  18. Article coated with flash bonded superhydrophobic particles

    DOEpatents

    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.

  19. Fermi GBM Observations of Terrestrial Gamma Flashes

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.; Briggs, M. S.; Fishman, G. J.; Bhat, P. N.; Paciesas, W. S.; Preece, R.; Kippen, R. M.; von Kienlin, A.; Dwyer, J. R.; Smith, D. M.; Holzworth, R.

    2010-01-01

    In its first two years of operation, the Fermi Gamma Ray Burst Monitor (GBM) has observed more than 77 Terrestrial Gamma Flashes (TGFs). The thick Bismuth Germanate (BGO) detectors are excellent for TGF spectroscopy, having a high probability of recording the full energy of an incident photon, spanning a broad energy range from 150 keV to 40 MeV, and recording a large number of photons per TGF. Correlations between GBM TGF triggers and lightning sferics detected with the World-Wide Lightning Location Network indicate that TGFs and lightning are simultaneous to within tens of microseconds. The energy spectra of some TGFs have strong 511 keV positron annihilation lines, indicating that these TGFs contain a large fraction of positrons

  20. Flash photolysis-shock tube studies

    SciTech Connect

    Michael, J.V.

    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.

  1. Correlated observations of three triggered lightning flashes

    NASA Technical Reports Server (NTRS)

    Idone, V. P.; Orville, R. E.; Hubert, P.; Barret, L.; Eybert-Berard, A.

    1984-01-01

    Three triggered lightning flashes, initiated during the Thunderstorm Research International Program (1981) at Langmuir Laboratory, New Mexico, are examined on the basis of three-dimensional return stroke propagation speeds and peak currents. Nonlinear relationships result between return stroke propagation speed and stroke peak current for 56 strokes, and between return stroke propagation speed and dart leader propagation speed for 32 strokes. Calculated linear correlation coefficients include dart leader propagation speed and ensuing return stroke peak current (32 strokes; r = 0.84); and stroke peak current and interstroke interval (69 strokes; r = 0.57). Earlier natural lightning data do not concur with the weak positive correlation between dart leader propagation speed and interstroke interval. Therefore, application of triggered lightning results to natural lightning phenomena must be made with certain caveats. Mean values are included for the three-dimensional return stroke propagation speed and for the three-dimensional dart leader propagation speed.

  2. Scannerless loss modulated flash color range imaging

    DOEpatents

    Sandusky, John V.; Pitts, Todd Alan

    2008-09-02

    Scannerless loss modulated flash color range imaging methods and apparatus are disclosed for producing three dimensional (3D) images of a target within a scene. Apparatus and methods according to the present invention comprise a light source providing at least three wavelengths (passbands) of illumination that are each loss modulated, phase delayed and simultaneously directed to illuminate the target. Phase delayed light backscattered from the target is spectrally filtered, demodulated and imaged by a planar detector array. Images of the intensity distributions for the selected wavelengths are obtained under modulated and unmodulated (dc) illumination of the target, and the information contained in the images combined to produce a 3D image of the target.

  3. Scannerless loss modulated flash color range imaging

    DOEpatents

    Sandusky, John V.; Pitts, Todd Alan

    2009-02-24

    Scannerless loss modulated flash color range imaging methods and apparatus are disclosed for producing three dimensional (3D) images of a target within a scene. Apparatus and methods according to the present invention comprise a light source providing at least three wavelengths (passbands) of illumination that are each loss modulated, phase delayed and simultaneously directed to illuminate the target. Phase delayed light backscattered from the target is spectrally filtered, demodulated and imaged by a planar detector array. Images of the intensity distributions for the selected wavelengths are obtained under modulated and unmodulated (dc) illumination of the target, and the information contained in the images combined to produce a 3D image of the target.

  4. An 'Anomalous' Triggered Lightning Flash in Florida

    NASA Astrophysics Data System (ADS)

    Gamerota, W. R.; Uman, M. A.; Hill, J. D.; Pilkey, J. T.; Ngin, T.; Jordan, D. M.; Mata, C.; Mata, A.

    2012-12-01

    Classical (grounded wire) rocket-and-wire triggered lightning flashes whose leaders do not traverse the path of the wire remnants are sometimes referred to as 'anomalous'. We present high-speed video images captured at 10 kilo-frames per second (kfps), with supporting data, to characterize an 'anomalous' rocket-triggered lightning flash that occurred on 15 May 2012 at the International Center for Lightning Research and Testing (ICLRT) in north-central Florida. The event begins as a classical rocket-triggered lightning flash with an upward positive leader (UPL) initiating from the tip of the wire at a height of about 280 m above ground level. The top 259 m of the trailing wire explodes 2.7 s after the rocket exits the launch tube, while the bottom 17 m of the wire does not explode (does not become luminous). Approximately 1.4 ms after wire explosion, a stepped leader initiates a few meters above the top of the wire remnants and propagates downward, attaching to the top of a grounded utility pole 2.1 ms after initiation and 117 m southwest of the launching facility. Beginning 600 μs prior to this sustained stepped leader development, attempted stepped leaders (luminous steps emanating from the UPL channel above the wire remnants) are observed in three locations: 20 m and 5 m above the top of the wire remnants and at the top of the wire remnants. Correlated electric field derivative (dE/dt), channel-base current, and high-speed video captured at 300 kfps reveal an electrical discharge of peak current 365 A initiating from about 17 m above the launching facility, apparently the top of the unexploded triggering wire, when the stepped leader is no more than 60 m above ground level. There are significant differences between the 'anomalous' triggered lightning flash described here and those observed in New Mexico and in France in the late 1970s and early 1980s: First, the time duration between explosion of our wire and the sustained stepped leader development a few meters

  5. MENOPAUSAL HOT FLASHES: MECHANISMS, ENDOCRINOLOGY, TREATMENT

    PubMed Central

    Freedman, Robert R.

    2015-01-01

    Hot flashes (HFs) are a rapid and exaggerated heat dissipation response, consisting of profuse sweating, peripheral vasodilation, and feelings of intense, internal heat. They are triggered by small elevations in core body temperature (Tc) acting within a greatly reduced thermoneutral zone, i.e., the Tc region between the upper (sweating) and lower (shivering) thresholds. This is due in part, but not entirely, to estrogen depletion at menopause. Elevated central sympathetic activation, mediated through α2-adrenergic receptors, is one factor responsible for narrowing of the thermoneutral zone. Procedures which reduce this activation, such as paced respiration and clonidine administration, ameliorate HFs as will peripheral cooling. HFs are responsible for some, but not all, of the sleep disturbance reported during menopause. Recent work calls into question the role of serotonin in HFs. PMID:24012626

  6. Phthalate metabolite levels and menopausal hot flashes in midlife women.

    PubMed

    Ziv-Gal, Ayelet; Gallicchio, Lisa; Chiang, Catheryne; Ther, Sara N; Miller, Susan R; Zacur, Howard A; Dills, Russell L; Flaws, Jodi A

    2016-04-01

    During the menopausal transition, a woman's reproductive capacity declines, her hormone milieu changes, and her risk of hot flashes increases. Exposure to phthalates, which can be found in personal care products, can also result in altered reproductive function. Here, we investigated the associations between phthalate metabolite levels and midlife hot flashes. Eligible women (45-54 years of age) provided detailed information on hot flashes history and donated urine samples (n=195). Urinary phthalate metabolite levels were measured by HPLC-MS/MS. A higher total sum of phthalate metabolites commonly found in personal care products was associated with an increased risk of ever experiencing hot flashes (odds ratio (OR)=1.45; 95% confidence interval (CI)=1.07-1.96), hot flashes in the past 30days (OR=1.43; 95%CI=1.04-1.96), and more frequent hot flashes (OR=1.47; 95%CI=1.06-2.05). These data suggest that some phthalate exposures from personal care products are associated with menopausal hot flashes in women.

  7. Modulation of tropical cyclone flash density by environmental factors

    NASA Astrophysics Data System (ADS)

    Lugo, A.; Abarca, S.; Kucienska, B.; Oropeza, F.; Raga, G.

    2012-12-01

    While lightning flash density has been successfully used to document azimuthal and radial distribution of convective activity in tropical cyclones, there have been less successful attempts to link flash density changes to storm intensity change. The latter efforts have been more often focused on major hurricanes and in isolation from environmental phenomena that modulate flash occurrence. Major hurricanes have more neutral vertical stratification than weaker storms and therefore, have fewer flashes. Other factors, such as the concentration of cloud condensation nuclei from continental origin, the diurnal cycle and sea surface temperature (SST), among others, will heavily modulate the lightning flash density. The Eastern Pacific basin is ideally located to study the effects of these different environmental modulators on tropical cyclones. The off-shore flow from Mexico results in a large variability of cloud condensation nuclei concentration and there is also a large range in sea surface temperatures. Note that most tropical cyclones in the basin dissipate as a result of the encounter of colder SSTs and drier air advected into the inner core . We present an analysis of lightning flash density in 96 tropical cyclones in the Eastern Pacific between 2005 and 2011. We use the best track dataset to determine location and intensity of the tropical cyclones, the World Wide Lightning Location Network to characterize flash density, MODIS (on board of the Terra and Aqua satellites) to determine the aerosol optical depth (as a proxy for cloud condensation nuclei content), and AMSR-E for sea surface temperatures. Preliminary results indicate a heavy modulation of flash density inside tropical cyclones by cloud condensation nuclei and a cap of the largest flash density as a function of sea surface temperatures.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  10. NFPA 70E: Performing the electrical flash hazard analysis.

    PubMed

    Wallace, W Jon

    2005-08-01

    Arc flash hazards pose a serious risk to employee safety; proper safe work practices must be utilized. Electrical equipment > or = 50 volts must be deenergized and locked out/tagged out prior to servicing and maintenance unless doing so would increase hazards or is infeasible. Remember, convenience is not an acceptable reason for keeping equipment energized during servicing and maintenance. If electrical equipment must remain energized during Servicing and maintenance, NFPA 70E should be consulted to determine flash hazard boundaries as well as required PPE. Finally, circuit breakers and electrical disconnects must be marked to warn qualified employees of potential arc flash hazards. PMID:16212025

  11. Gamma ray flashes add to mystery of upper atmosphere

    NASA Astrophysics Data System (ADS)

    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.

  12. Investigating of Memory - Colours of Intellectually Disabled Children and Virtual Game Addict Students

    NASA Astrophysics Data System (ADS)

    Sik Lányi, Cecília

    We describe an investigation of memory colours. For this investigation Flash test software was developed. 75 observers used this test software in 4 groups: average elementary school children (aged: 8-9 years), intellectually disabled children (age: 9-15), virtual game addict university students (average age: 20) and university students who play with VR games rarely or never (average age: 20). In this pilot test we investigated the difference of memory colours of these 4 groups.

  13. Resistive switching memory devices based on electrical conductance tuning in poly(4-vinyl phenol)-oxadiazole composites.

    PubMed

    Sun, Yanmei; Miao, Fengjuan; Li, Rui; Wen, Dianzhong

    2015-11-28

    Nonvolatile memory devices, based on electrical conductance tuning in thin films of poly(4-vinyl phenol) (PVP) and 2-(4-tert-butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole (PBD) composites, are fabricated. The current-voltage characteristics of the fabricated devices show different electrical conductance behaviors, such as the write-once read-many-times (WORM) memory effect, the rewritable flash memory effect and insulator behavior, which depend on the content of PBD in the PVP + PBD composites. The OFF and ON states of the WORM and rewritable flash memory devices are stable under a constant voltage stress or a continuous pulse voltage stress at a read voltage. The memory mechanism is deduced from the modeling of the nature of currents in both states in the devices. PMID:26490192

  14. Updating memories--the role of prediction errors in memory reconsolidation.

    PubMed

    Exton-McGuinness, Marc T J; Lee, Jonathan L C; Reichelt, Amy C

    2015-02-01

    Memories are not static imprints of past experience, but rather are dynamic entities which enable us to predict outcomes of future situations and inform appropriate behaviours. In order to maintain the relevance of existing memories to our daily lives, memories can be updated with new information via a process of reconsolidation. In this review we describe recent experimental advances in the reconsolidation of both appetitive and aversive memory, and explore the neuronal mechanisms that underpin the conditions under which reconsolidation will occur. We propose that a prediction error signal, originating from dopaminergic midbrain neurons, is necessary for destabilisation and subsequent reconsolidation of a memory. PMID:25453746

  15. Updating memories--the role of prediction errors in memory reconsolidation.

    PubMed

    Exton-McGuinness, Marc T J; Lee, Jonathan L C; Reichelt, Amy C

    2015-02-01

    Memories are not static imprints of past experience, but rather are dynamic entities which enable us to predict outcomes of future situations and inform appropriate behaviours. In order to maintain the relevance of existing memories to our daily lives, memories can be updated with new information via a process of reconsolidation. In this review we describe recent experimental advances in the reconsolidation of both appetitive and aversive memory, and explore the neuronal mechanisms that underpin the conditions under which reconsolidation will occur. We propose that a prediction error signal, originating from dopaminergic midbrain neurons, is necessary for destabilisation and subsequent reconsolidation of a memory.

  16. Working Memory Capacity and the Antisaccade Task: Individual Differences in Voluntary Saccade Control

    ERIC Educational Resources Information Center

    Unsworth, Nash; Schrock, Josef C.; Engle, Randall W.

    2004-01-01

    Performance on antisaccade trials requires the inhibition of a prepotent response (i.e., don't look at the flashing cue) and the generation and execution of a correct saccade in the opposite direction. The authors attempted to further specify the role of working memory (WM) span differences in the antisaccade task. They tested high- and low-span…

  17. Phonological and Sensory Short-Term Memory Are Correlates and Both Affected in Developmental Dyslexia

    ERIC Educational Resources Information Center

    Laasonen, Marja; Virsu, Veijo; Oinonen, Suvi; Sandbacka, Mirja; Salakari, Anita; Service, Elisabet

    2012-01-01

    We investigated whether poor short-term memory (STM) in developmental dyslexia affects the processing of sensory stimulus sequences in addition to phonological material. STM for brief binary non-verbal stimuli (light flashes, tone bursts, finger touches, and their crossmodal combinations) was studied in 20 Finnish adults with dyslexia and 24…

  18. Role of External Beam Radiotherapy in Patients With Advanced or Recurrent Nonanaplastic Thyroid Cancer: Memorial Sloan-Kettering Cancer Center Experience

    SciTech Connect

    Terezakis, Stephanie A. Lee, Kyungmouk S.; Ghossein, Ronald A.; Rivera, Michael; Tuttle, Robert M.; Wolden, Suzanne L.; Zelefsky, Michael J.; Wong, Richard J.; Patel, Snehal G.; Pfister, David G.; Shaha, Ashok R.; Lee, Nancy Y.

    2009-03-01

    Purpose: External beam radiotherapy (EBRT) plays a controversial role in the management of nonanaplastic thyroid cancer. We reviewed our institution's outcomes in patients treated with EBRT for advanced or recurrent nonanaplastic thyroid cancer. Methods and Materials: Between April 1989 and April 2006, 76 patients with nonanaplastic thyroid cancer were treated with EBRT. The median follow-up for the surviving patients was 35.3 months (range, 4.2-178.4). The lesions were primarily advanced and included Stage T2 in 5 (7%), T3 in 5 (7%), and T4 in 64 (84%) patients. Stage N1 disease was present in 60 patients (79%). Distant metastases before EBRT were identified in 27 patients (36%). The median total EBRT dose delivered was 6,300 cGy. The histologic features examined included medullary in 12 patients (16%) and nonmedullary in 64 (84%). Of the 76 patients, 71 (93%) had undergone surgery before RT, and radioactive iodine treatment was used in 56 patients (74%). Results: The 2- and 4-year overall locoregional control rate for all histologic types was 86% and 72%, respectively, and the 2- and 4-year overall survival rate for all patients was 74% and 55%, respectively. No significant differences were found in locoregional control, overall survival, or distant metastases-free survival for patients with complete resection, microscopic residual disease, or gross residual disease. Grade 3 acute mucositis and dysphagia occurred in 14 (18%) and 24 (32%) patients, respectively. Late adverse toxicity was notable for percutaneous endoscopic gastrostomy tube use in 4 patients (5%). Conclusion: The results of our study have shown that EBRT is effective for locoregional control of selected locally advanced or recurrent nonanaplastic thyroid malignancies, with acceptable acute toxicity.

  19. Future Development of Dense Ferroelectric Memories for Space Applications

    NASA Technical Reports Server (NTRS)

    Philpy, Stephen C.; Derbenwick, Gary F.

    2001-01-01

    The availability of high density, radiation tolerant, nonvolatile memories is critical for space applications. Ferroelectric memories, when fabricated with radiation hardened complementary metal oxide semiconductors (CMOS), can be manufactured and packaged to provide high density replacements for Flash memory, which is not radiation tolerant. Previous work showed ferroelectric memory cells to be resistant to single event upsets and proton irradiation, and ferroelectric storage capacitors to be resistant to neutron exposure. In addition to radiation hardness, the fast programming times, virtually unlimited endurance, and low voltage, low power operation make ferroelectric memories ideal for space missions. Previously, a commercial double level metal 64-kilobit ferroelectric memory was presented. Although the capabilities of radiation hardened wafer fabrication facilities lag behind those of the most modern commercial wafer fabrication facilities, several paths to achieving radiation tolerant, dense ferroelectric memories are emerging. Both short and long term solutions are presented in this paper. Although worldwide major semiconductor companies are introducing commercial ferroelectric memories, funding limitations must be overcome to proceed with the development of high density, radiation tolerant ferroelectric memories.

  20. EDITORIAL: Non-volatile memory based on nanostructures Non-volatile memory based on nanostructures

    NASA Astrophysics Data System (ADS)

    Kalinin, Sergei; Yang, J. Joshua; Demming, Anna

    2011-06-01

    Non-volatile memory refers to the crucial ability of computers to store information once the power source has been removed. Traditionally this has been achieved through flash, magnetic computer storage and optical discs, and in the case of very early computers paper tape and punched cards. While computers have advanced considerably from paper and punched card memory devices, there are still limits to current non-volatile memory devices that restrict them to use as secondary storage from which data must be loaded and carefully saved when power is shut off. Denser, faster, low-energy non-volatile memory is highly desired and nanostructures are the critical enabler. This special issue on non-volatile memory based on nanostructures describes some of the new physics and technology that may revolutionise future computers. Phase change random access memory, which exploits the reversible phase change between crystalline and amorphous states, also holds potential for future memory devices. The chalcogenide Ge2Sb2Te5 (GST) is a promising material in this field because it combines a high activation energy for crystallization and a relatively low crystallization temperature, as well as a low melting temperature and low conductivity, which accommodates localized heating. Doping is often used to lower the current required to activate the phase change or 'reset' GST but this often aggravates other problems. Now researchers in Korea report in-depth studies of SiO2-doped GST and identify ways of optimising the material's properties for phase-change random access memory [1]. Resistance switching is an area that has attracted a particularly high level of interest for non-volatile memory technology, and a great deal of research has focused on the potential of TiO2 as a model system in this respect. Researchers at HP labs in the US have made notable progress in this field, and among the work reported in this special issue they describe means to control the switch resistance and show

  1. A Developmental Psychopathology Model of Overgeneral Autobiographical Memory

    ERIC Educational Resources Information Center

    Valentino, Kristin

    2011-01-01

    Overgeneral memory (OGM) is a phenomenon that refers to difficulty retrieving specific autobiographical memories. The tendency to be overgeneral in autobiographical memory recall has been commonly observed among individuals with emotional disorders compared to those without emotional disorders. Despite significant advances in identifying…

  2. Immunological memory to viral infection.

    PubMed

    Slifka, Mark K

    2004-08-01

    Immunological memory is defined by the ability of a host to remember a past encounter with a specific pathogen and to respond to it in an effective manner upon re-exposure. How long immunological memory can be maintained in the absence of re-infection continues to be a subject of great controversy. Recent studies on immunity following smallpox vaccination demonstrate that T-cell memory declines steadily with a half-life of 8-15 years, whereas antiviral antibody responses are maintained for up to 75 years without appreciable decline. By combining recent advances in quantitative immunology with historical accounts of protection against smallpox dating back to the time of Edward Jenner, we are gaining a better understanding of the duration and magnitude of immunological memory and how it relates to protective immunity. PMID:15245737

  3. 2. SECTIONAL BOILER '#4 IDEAL RED FLASH.' Hot Springs ...

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

    2. SECTIONAL BOILER '#4 IDEAL RED FLASH.' - Hot Springs National Park, Bathhouse Row, Ozark Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

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

    NASA Technical Reports Server (NTRS)

    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.

  5. Impact of rainfall spatial variability on Flash Flood Forecasting

    NASA Astrophysics Data System (ADS)

    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

  6. Heavy rainfall induced flash flood management

    NASA Astrophysics Data System (ADS)

    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

  7. Ultrafast Coherent Diffractive Imaging at FLASH

    SciTech Connect

    Chapman, H N

    2006-11-29

    Using the FLASH facility we have demonstrated high-resolution coherent diffractive imaging with single soft-X-ray free-electron laser pulses [1]. The intense focused FEL pulse gives a high resolution low-noise coherent diffraction pattern of an object before that object turns into a plasma and explodes. Our experiments are an important milestone in the development of single-particle diffractive imaging with future X-ray free-electron lasers [2, 3]. Our apparatus provides a new and unique tool at FLASH to perform imaging of biological specimens beyond conventional radiation damage resolution limits [2, 4] and to acquire images of ultrafast processes initiated by an FEL pulse or other laser pulse. Coherent diffractive imaging is an ideal method for high-resolution ultrafast imaging with an FEL. Since no optical element is required, the method can in principle be scaled to atomic resolution with short enough wavelength. Spatial and temporal coherence are necessary to ensure that the scattered light waves from all positions across the sample are correlated when they interfere at the detector, giving rise to a coherent diffraction pattern that can be phased and inverted to give a high-resolution image of the sample. In contrast to crystals, where scattering from the many unit cells constructively interfere to give Bragg spots, the coherent diffraction pattern of a non-periodic object is continuous. Such a coherent diffraction pattern contains as much as twice the information content of the pattern of its crystallized periodic counterpart--exactly the amount of information needed to solve the phase problem and deterministically invert the pattern to yield an image of the object [5, 6]. The computer algorithm that performs this function replaces the analogue computations of a lens: summing the complex-valued amplitudes of scattered waves to form an image at a particular plane. Our experimental geometry is shown in Fig. 1. We focus a coherent X-ray pulse from the FLASH

  8. Roll-to-roll nanopatterning using jet and flash imprint lithography

    NASA Astrophysics Data System (ADS)

    Ahn, Sean; Ganapathisubramanian, Maha; Miller, Mike; Yang, Jack; Choi, Jin; Xu, Frank; Resnick, Douglas J.; Sreenivasan, S. V.

    2012-03-01

    The ability to pattern materials at the nanoscale can enable a variety of applications ranging from high density data storage, displays, photonic devices and CMOS integrated circuits to emerging applications in the biomedical and energy sectors. These applications require varying levels of pattern control, short and long range order, and have varying cost tolerances. Extremely large area R2R manufacturing on flexible substrates is ubiquitous for applications such as paper and plastic processing. It combines the benefits of high speed and inexpensive substrates to deliver a commodity product at low cost. The challenge is to extend this approach to the realm of nanopatterning and realize similar benefits. The cost of manufacturing is typically driven by speed (or throughput), tool complexity, cost of consumables (materials used, mold or master cost, etc.), substrate cost, and the downstream processing required (annealing, deposition, etching, etc.). In order to achieve low cost nanopatterning, it is imperative to move towards high speed imprinting, less complex tools, near zero waste of consumables and low cost substrates. The Jet and Flash Imprint Lithography (J-FILTM) process uses 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 memory markets including Flash memory and patterned media for hard disk drives. In this paper we address the key challenges for roll based nanopatterning by introducing a novel concept: Ink Jet based Roll-to-Roll Nanopatterning. To address this challenge, we have introduced a J-FIL based demonstrator product, the LithoFlex 100. Topics that are discussed in the paper include tool design and process performance. In addition, we have used the LithoFlex 100 to fabricate high performance wire grid polarizers on flexible polycarbonate (PC) films. Transmission of better than 80% and extinction ratios on the order of

  9. Fear Memory.

    PubMed

    Izquierdo, Ivan; Furini, Cristiane R G; Myskiw, Jociane C

    2016-04-01

    Fear memory is the best-studied form of memory. It was thoroughly investigated in the past 60 years mostly using two classical conditioning procedures (contextual fear conditioning and fear conditioning to a tone) and one instrumental procedure (one-trial inhibitory avoidance). Fear memory is formed in the hippocampus (contextual conditioning and inhibitory avoidance), in the basolateral amygdala (inhibitory avoidance), and in the lateral amygdala (conditioning to a tone). The circuitry involves, in addition, the pre- and infralimbic ventromedial prefrontal cortex, the central amygdala subnuclei, and the dentate gyrus. Fear learning models, notably inhibitory avoidance, have also been very useful for the analysis of the biochemical mechanisms of memory consolidation as a whole. These studies have capitalized on in vitro observations on long-term potentiation and other kinds of plasticity. The effect of a very large number of drugs on fear learning has been intensively studied, often as a prelude to the investigation of effects on anxiety. The extinction of fear learning involves to an extent a reversal of the flow of information in the mentioned structures and is used in the therapy of posttraumatic stress disorder and fear memories in general. PMID:26983799

  10. Fear Memory.

    PubMed

    Izquierdo, Ivan; Furini, Cristiane R G; Myskiw, Jociane C

    2016-04-01

    Fear memory is the best-studied form of memory. It was thoroughly investigated in the past 60 years mostly using two classical conditioning procedures (contextual fear conditioning and fear conditioning to a tone) and one instrumental procedure (one-trial inhibitory avoidance). Fear memory is formed in the hippocampus (contextual conditioning and inhibitory avoidance), in the basolateral amygdala (inhibitory avoidance), and in the lateral amygdala (conditioning to a tone). The circuitry involves, in addition, the pre- and infralimbic ventromedial prefrontal cortex, the central amygdala subnuclei, and the dentate gyrus. Fear learning models, notably inhibitory avoidance, have also been very useful for the analysis of the biochemical mechanisms of memory consolidation as a whole. These studies have capitalized on in vitro observations on long-term potentiation and other kinds of plasticity. The effect of a very large number of drugs on fear learning has been intensively studied, often as a prelude to the investigation of effects on anxiety. The extinction of fear learning involves to an extent a reversal of the flow of information in the mentioned structures and is used in the therapy of posttraumatic stress disorder and fear memories in general.

  11. Is external memory memory? Biological memory and extended mind.

    PubMed

    Michaelian, Kourken

    2012-09-01

    Clark and Chalmers (1998) claim that an external resource satisfying the following criteria counts as a memory: (1) the agent has constant access to the resource; (2) the information in the resource is directly available; (3) retrieved information is automatically endorsed; (4) information is stored as a consequence of past endorsement. Research on forgetting and metamemory shows that most of these criteria are not satisfied by biological memory, so they are inadequate. More psychologically realistic criteria generate a similar classification of standard putative external memories, but the criteria still do not capture the function of memory. An adequate account of memory function, compatible with its evolution and its roles in prospection and imagination, suggests that external memory performs a function not performed by biological memory systems. External memory is thus not memory. This has implications for: extended mind theorizing, ecological validity of memory research, the causal theory of memory.

  12. Enhanced ethylene production via flash methanolysis of coal

    SciTech Connect

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

    1984-01-01

    In an on-going pyrolysis research project at the Brookhaven National Laboratory, the methods to increase the yield of ethylene through flash methanolysis of coal is being investigated. Flash methanolysis is defined as pyrolysis of coal under pressure in an atmosphere of methane. This study attempts to identify the influence of important process variables such as reaction temperature, gas pressure, solids residence time, gas/solids ratio etc. on the production characteristics of ethylene and other pyrolysis products.

  13. Enhanced ethylene production via flash methanolysis of coal

    SciTech Connect

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

    1984-04-01

    In an on-going pyrolysis research project at the Brookhaven National Laboratory, the methods to increase the yield of ethylene through flash methanolysis of coal is being investigated. Flash methanolysis is defined as pyrolysis of coal under pressure in an atmosphere of methane. This study attempts to identify the influence of important process variables such as reaction temperature, gas pressure, solids residence time, gas/solids ratio etc. on the production characteristics of ethylene and other pyrolysis products.

  14. Light flashes in cancer patients treated with heavy ions.

    PubMed

    Schardt, Dieter; Kavatsyuk, Oksana; Krämer, Michael; Durante, Marco

    2013-05-01

    Light flashes (phosphenes) are reported by most of the astronauts during spaceflight and patients treated with radiotherapy for brain tumors. They are induced by cosmic ray traversals, but the target area is unknown. With a correlation analysis of the visual sensation and the position of the beam in patients treated with energetic carbon ions for skull base tumors, we demonstrate here that light flashes are elicited only when the energetic particles hit the retina. PMID:22939278

  15. Quick Method for Making Colored-Flame Flash Paper

    NASA Astrophysics Data System (ADS)

    Solomon, Sally; Hur, Chinhyu; Lee, Alan; Smith, Kurt

    1995-12-01

    A very fast method for making flash paper similar in size and burning properties to the commercial type is described here. Detailed instructions are given for the preparation, storage, and lighting of flash paper that burns with single colors (red, orange, yellow, green, blue, and violet) or with combinations of these colors. This method requires no more than an hour from the mixing of the nitrating acids to the lighting of the paper and eliminates prolonged drying procedures.

  16. Prospective Evaluation of Hot Flashes during Pregnancy and Postpartum

    PubMed Central

    Thurston, Rebecca C.; Luther, James F.; Wisniewski, Stephen R.; Eng, Heather; Wisner, Katherine L.

    2014-01-01

    Objective To determine the prevalence, course, and risk factors for hot flashes during pregnancy and postpartum. Study Design Women (N=429) were assessed prospectively during pregnancy (weeks 20, 30, 36) and up to a year after delivery (weeks 2, 12, 26, 52). A clinical interview, physical measurements, and questionnaires were administered at each visit. Results Thirty-five percent of women reported hot flashes during pregnancy and 29% reported hot flashes after delivery. In multivariable binomial mixed effects models, women who were younger (per year: OR(95%CI): 0.94(0.88–0.99)), had a higher pre-pregnancy body mass index (BMI; per unit increase: OR(95%CI): 1.05(1.01–1.10)), and had less than a college education (OR(95%CI): 2.58(1.19–5.60); vs. college) were more likely to report hot flashes during pregnancy. Higher depressive symptoms were associated with hot flashes during pregnancy (per unit increase: OR(95%CI): 1.08(1.04–1.13)) and after birth (OR(95%CI): 1.19(1.14–1.25), multivariable models). Conclusion Hot flashes, typically considered a menopausal symptom, were reported by over a third of women during pregnancy and/or postpartum. Predictors of hot flashes during this reproductive transition, including depressive symptoms, low education, and higher BMI are similar to those experienced during menopause. Future work should investigate the role of hormonal and affective factors in hot flashes during pregnancy and postpartum. PMID:24035604

  17. Spectral measurements of muzzle flash with multispectral and hyperspectral sensor

    NASA Astrophysics Data System (ADS)

    Kastek, M.; Dulski, R.; Trzaskawka, P.; Piątkowski, T.; Polakowski, H.

    2011-08-01

    The paper presents some practical aspects of the measurements of muzzle flash signatures. Selected signatures of sniper shot in typical scenarios has been presented. Signatures registered during all phases of muzzle flash were analyzed. High precision laboratory measurements were made in a special ballistic laboratory and as a result several flash patterns were registered. The field measurements of a muzzle flash were also performed. During the tests several infrared cameras were used, including the measurement class devices with high accuracy and frame rates. The registrations were made in NWIR, SWIR and LWIR spectral bands simultaneously. An ultra fast visual camera was also used for visible spectra registration. Some typical infrared shot signatures were presented. Beside the cameras, the LWIR imaging spectroradiometer HyperCam was also used during the laboratory experiments and the field tests. The signatures collected by the HyperCam device were useful for the determination of spectral characteristics of the muzzle flash, whereas the analysis of thermal images registered during the tests provided the data on temperature distribution in the flash area. As a result of the measurement session the signatures of several types handguns, machine guns and sniper rifles were obtained which will be used in the development of passive infrared systems for sniper detection.

  18. Use of gabapentin in patients experiencing hot flashes.

    PubMed

    Brown, Jamie N; Wright, Betsy R

    2009-01-01

    Hot flashes occur frequently in menopausal women and in women with breast cancer, diminishing their quality of life. A report from the Women's Health Initiative published in 2002 raised concerns about the long-term safety of estrogen therapy. As a result, nonhormonal alternatives have emerged as preferred treatments. Gabapentin is an anticonvulsant that the United States Food and Drug Administration approved as an adjunct therapy for partial seizures and postherpetic neuralgia. Somnolence, dizziness, ataxia, fatigue, nystagmus, and peripheral edema are adverse effects commonly associated with gabapentin in the treatment of epilepsy and postherpetic neuralgia. The North American Menopause Society and the American College of Obstetricians and Gynecologists recommend the use of gabapentin as an option for managing hot flashes in women who are unwilling to take estrogen-containing supplements. To evaluate the efficacy and safety of gabapentin for the treatment of hot flashes in women with menopause and/or breast cancer, we performed a search of the MEDLINE database (1966-March 2008) and International Pharmaceutical Abstracts, as well as manually searching reference articles for relevant articles and abstracts; 10 clinical studies were identified. Although the studies were few, all showed gabapentin to be safe and effective in the treatment of hot flashes. At doses used to control hot flashes, gabapentin was well tolerated, with drowsiness as its most reported adverse effect. Gabapentin can be considered effective in the treatment of hot flashes and should be considered a reasonable alternative when estrogen therapy is not desired. PMID:19113798

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

    PubMed

    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. PMID:25594906

  20. Locating Preliminary Breakdown Pulses in Lightning Flashes

    NASA Astrophysics Data System (ADS)

    Karunarathne, S.; Marshall, T.; Stolzenburg, M.

    2011-12-01

    Lightning flashes often begin with a series of bipolar pulses, 1-5 us in width, called initial breakdown pulses or characteristic pulses. In 2010 we showed that these pulses can be located (find x, y, z, t) using Time of arrival method (TOA) [Koshak and Solakiewicz, JGR, 1996]. Electric field change data was obtained at the NASA/Kennedy Space Center (KSC) during the summer of 2010 at 5 stations with a band width of 0-0.5MHz and time accuracy of 1us. We concluded that in order to increase the accuracy positions; time accuracy, band width and number of stations should be increased. In summer of 2011, we placed electric field change meters with band width of 0-5Mhz and time accuracy of 0.1us at the KSC. We have doubled the number of stations (10 stations). We use TOA technique with different algorithm to locate positions of beginning pulses with greater accuracy. The locations will be compared to locations of VHF lightning sources made with the KSC LDAR2 system (which has a center frequency of 63 MHz and a bandwidth of 6 MHz). A monte-carlo method will be used to calculate the error of the locations. A statistical comparison between our TOA positions and LDAR2 positions will be presented along with possible physical connections between the preliminary breakdown pulses, the LDAD2 sources, and the developing lightning leader.

  1. Flash microwave synthesis of trevorite nanoparticles

    SciTech Connect

    Bousquet-Berthelin, C. Chaumont, D.; Stuerga, D.

    2008-03-15

    Nickel ferrite nanoparticles have several possible applications as cathode materials for rechargeable batteries, named 'lithium-ion' batteries. In this study, NiFe{sub 2}O{sub 4} was prepared by microwave induced thermohydrolysis. The obtained nanoparticles were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), BET method, transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS). All the results show that the microwave one-step flash synthesis leads in a very short time to NiFe{sub 2}O{sub 4} nanoparticles with elementary particles size close to 4-5 nm, and high specific surfaces (close to 240 m{sup 2}/g). Thus, microwave heating appears as an efficient source of energy to produce quickly nanoparticles with complex composition as ferrite. - Graphical abstract: At the end of the 20th century, a new concept of battery was introduced, named 'Li ion', where electrodes are both lithium-storage materials. Compounds with a spinel structure are so investigated and microwave heating appears as an efficient source of energy to produce nanoparticles in a very short time and at low temperature, with controlled size (4-5 nm) and high specific area (240 m{sup 2}/g). Legend: Pictogram represents our original microwave reactor, the RAMO (French acronym of Reacteur Autoclave Micro-Onde), containing the reactants and submitted to the microwave irradiation. Multicolor candy represents obtained material.

  2. Flash Nanoprecipitation: Particle Structure and Stability

    PubMed Central

    Pustulka, Kevin M.; Wohl, Adam R.; Lee, Han Seung; Michel, Andrew R.; Han, Jing; Hoye, Thomas R.; McCormick, Alon V.; Panyam, Jayanth; Macosko, Christopher W.

    2013-01-01

    Flash nanoprecipitation (FNP) is a process that, through rapid mixing, stabilizes an insoluble low molecular weight compound in a nano-sized, polymer-stabilized delivery vehicle. The polymeric components are typically amphiphilic diblock copolymers (BCPs). In order to fully exploit the potential of FNP, factors affecting particle structure, size, and stability must be understood. Here we show that polymer type, hydrophobicity and crystallinity of the small molecule, and small molecule loading levels all affect particle size and stability. Of the four block copolymers (BCP) that we have studied here, poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) (PEG-b-PLGA) was most suitable for potential drug delivery applications due to its ability to give rise to stable nanoparticles, its biocompatibility, and its degradability. We found little difference in particle size when using PLGA block sizes over the range of 5 to 15kDa. The choice of hydrophobic small molecule was important, as molecules with a calculated water-octanol partition coefficient (clogP) below 6 gave rise to particles that were unstable and underwent rapid Ostwald ripening. Studies probing the internal structure of nanoparticles were also performed. Analysis of differential scanning calorimetry (DSC), cryogenic transmission electron microscopy (cryo-TEM), and 1H-NMR experiments support a three-layer core-shell-corona nanoparticle structure. PMID:24053447

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

    PubMed

    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.

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

    PubMed

    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. PMID:26369521

  5. Retracing Memories

    ERIC Educational Resources Information Center

    Harrison, David L.

    2005-01-01

    There are plenty of paths to poetry but few are as accessible as retracing ones own memories. When students are asked to write about something they remember, they are given them the gift of choosing from events that are important enough to recall. They remember because what happened was funny or scary or embarrassing or heartbreaking or silly.…

  6. Fueling Memories

    PubMed Central

    Powell, Jonathan D.; Pollizzi, Kristen

    2012-01-01

    A hallmark of the adaptive immune response is rapid and robust activation upon rechallenge. In the current issue of Immunity van der Windt et al. (2012) provide an important link between mitochondrial respiratory capacity and the development of CD8+ T cell memory. PMID:22284413

  7. Memory Loss

    ERIC Educational Resources Information Center

    Cassebaum, Anne

    2011-01-01

    In four decades of teaching college English, the author has watched many good teaching jobs morph into second-class ones. Worse, she has seen the memory and then the expectation of teaching jobs with decent status, security, and salary depart along with principles and collegiality. To help reverse this downward spiral, she contends that what is…

  8. Reproductive History and Hot Flashes in Perimenopausal Women

    PubMed Central

    Nakano, Karen; Pinnow, Ellen; Flaws, Jodi A.; Sorkin, John D.

    2012-01-01

    Abstract Background Hot flashes affect up to 75% of women undergoing the menopausal transition. They are among the most common health problems for perimenopausal women and are associated with a decrease in quality of life. The goal of this study was to examine the associations between reproductive history variables and midlife hot flashes. Methods Data were analyzed from 388 perimenopausal women who participated in the Midlife Health Study, a population-based, cross-sectional study of 639 women aged 45–54 years living in the Baltimore metropolitan region. Results The unadjusted analyses showed that none of the reproductive history variables analyzed, including age at menarche, number of live births, ever having been pregnant, age at first birth, age at last pregnancy, and history of oral contraceptive use, were associated with ever experiencing hot flashes. However, after adjusting for race, age group, marital status, education, employment, total family income, smoking and alcohol status, and body mass index (BMI), age at last pregnancy was significantly associated with moderate to severe hot flashes. Specifically, participants who were ≥36 years of age at last pregnancy were less likely to report moderate or severe hot flashes than those ≤35 years of age at last pregnancy (odds ratio 0.36, 95% confidence interval 0.16, 0.84). Conclusions In this study, in general, characteristics of reproductive history were not associated with midlife hot flashes. However, there are a number of potentially modifiable factors that are associated with the occurrence of hot flashes. Thus, alternatives may be available when hormone treatment is contraindicated. PMID:22283476

  9. CTE characterization with post-flashed darks

    NASA Astrophysics Data System (ADS)

    Anderson, Jay

    2013-10-01

    This internal-orbit calibration program will take a combination of short {100s} and long {800s} darks with various levels of post-flash in order to re-calibrate the WFC3/UVIS CTE model. When a similar set of these images was taken in mid-2012, there were not as many warm pixels as there are now and CTE losses were lower. Furthermore, this program will explore a finer spacing of charge injection to help us understand exactly what happens above the "sweet-spot" background of 12 electrons. Once the model is recalibrated using this data set {which should be taken in early 2014}, we can feel confident in making the pixel-based correction part of the pipeline.The observations will be straightforward. We will take short 100s darks with PF levels of: 0, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 100, 115, and 130, and 150 electrons -- 30 levels in all. We will also take 800s darks {can't fit longer} with a PF level of about 100e. We should be able to take two shorts and one deep in each orbit, this will take a total of 15 orbits. This will give us 15 long darks, which can be averaged together to get the noise down.It would be best if this program could be scheduled to be executed over the course of only a few days, since I would prefer not to have much change in the dark during acquisition of the data set.

  10. Use of positron emission tomography scan response to guide treatment change for locally advanced gastric cancer: the Memorial Sloan Kettering Cancer Center experience

    PubMed Central

    Won, Elizabeth; Shah, Manish A.; Schöder, Heiko; Strong, Vivian E.; Coit, Daniel G.; Brennan, Murray F.; Kelsen, David P.; Janjigian, Yelena Y.; Tang, Laura H.; Capanu, Marinela; Rizk, Nabil P.; Allen, Peter J.; Bains, Manjit S.

    2016-01-01

    Background Early metabolic response on 18-fluorodeoxyglucose-positron emission tomography (FDG-PET) during neoadjuvant chemotherapy is PET non-responders have poor outcomes whether continuing chemotherapy or proceeding directly to surgery. Use of PET may identify early treatment failure, sparing patients from inactive therapy and allowing for crossover to alternative therapies. We examined the effectiveness of PET directed switching to salvage chemotherapy in the PET non-responders. Methods Patients with locally advanced resectable FDG-avid gastric or gastroesophageal junction (GEJ) adenocarcinoma received bevacizumab 15 mg/kg, epirubicin 50 mg/m2, cisplatin 60 mg/m2 day 1, and capecitabine 625 mg/m2 bid (ECX) every 21 days. PET scan was obtained at baseline and after cycle 1. PET responders, (i.e., ≥35% reduction in FDG uptake at the primary tumor) continued ECX + bev. Non-responders switched to docetaxel 30 mg/m2, irinotecan 50 mg/mg2 day 1 and 8 plus bevacizumab every 21 days for 2 cycles. Patients then underwent surgery. The primary objective was to improve the 2-year disease free survival (DFS) from 30% (historical control) to 53% in the non-responders. Results Twenty evaluable patients enrolled before the study closed for poor accrual. Eleven were PET responders and the 9 non-responders switched to the salvage regimen. With a median follow-up of 38.2 months, the 2-year DFS was 55% [95% confidence interval (CI), 30–85%] in responders compared with 56% in the non-responder group (95% CI, 20–80%, P=0.93). Conclusions The results suggest that changing chemotherapy regimens in PET non-responding patients may improve outcomes. Results from this pilot trial are hypothesis generating and suggest that PET directed neoadjuvant therapy merits evaluation in a larger trial. PMID:27563439

  11. Dielectric elastomer memory

    NASA Astrophysics Data System (ADS)

    O'Brien, Benjamin M.; McKay, Thomas G.; Xie, Sheng Q.; Calius, Emilio P.; Anderson, Iain A.

    2011-04-01

    Life shows us that the distribution of intelligence throughout flexible muscular networks is a highly successful solution to a wide range of challenges, for example: human hearts, octopi, or even starfish. Recreating this success in engineered systems requires soft actuator technologies with embedded sensing and intelligence. Dielectric Elastomer Actuator(s) (DEA) are promising due to their large stresses and strains, as well as quiet flexible multimodal operation. Recently dielectric elastomer devices were presented with built in sensor, driver, and logic capability enabled by a new concept called the Dielectric Elastomer Switch(es) (DES). DES use electrode piezoresistivity to control the charge on DEA and enable the distribution of intelligence throughout a DEA device. In this paper we advance the capabilities of DES further to form volatile memory elements. A set reset flip-flop with inverted reset line was developed based on DES and DEA. With a 3200V supply the flip-flop behaved appropriately and demonstrated the creation of dielectric elastomer memory capable of changing state in response to 1 second long set and reset pulses. This memory opens up applications such as oscillator, de-bounce, timing, and sequential logic circuits; all of which could be distributed throughout biomimetic actuator arrays. Future work will include miniaturisation to improve response speed, implementation into more complex circuits, and investigation of longer lasting and more sensitive switching materials.

  12. Spatial memory and animal movement.

    PubMed

    Fagan, William F; Lewis, Mark A; Auger-Méthé, Marie; Avgar, Tal; Benhamou, Simon; Breed, Greg; LaDage, Lara; Schlägel, Ulrike E; Tang, Wen-wu; Papastamatiou, Yannis P; Forester, James; Mueller, Thomas

    2013-10-01

    Memory is critical to understanding animal movement but has proven challenging to study. Advances in animal tracking technology, theoretical movement models and cognitive sciences have facilitated research in each of these fields, but also created a need for synthetic examination of the linkages between memory and animal movement. Here, we draw together research from several disciplines to understand the relationship between animal memory and movement processes. First, we frame the problem in terms of the characteristics, costs and benefits of memory as outlined in psychology and neuroscience. Next, we provide an overview of the theories and conceptual frameworks that have emerged from behavioural ecology and animal cognition. Third, we turn to movement ecology and summarise recent, rapid developments in the types and quantities of available movement data, and in the statistical measures applicable to such data. Fourth, we discuss the advantages and interrelationships of diverse modelling approaches that have been used to explore the memory-movement interface. Finally, we outline key research challenges for the memory and movement communities, focusing on data needs and mathematical and computational challenges. We conclude with a roadmap for future work in this area, outlining axes along which focused research should yield rapid progress.

  13. Lunar Impact Flash Locations from NASA's Lunar Impact Monitoring Program

    NASA Technical Reports Server (NTRS)

    Moser, D. E.; Suggs, R. M.; Kupferschmidt, L.; Feldman, J.

    2015-01-01

    Meteoroids are small, natural bodies traveling through space, fragments from comets, asteroids, and impact debris from planets. Unlike the Earth, which has an atmosphere that slows, ablates, and disintegrates most meteoroids before they reach the ground, the Moon has little-to-no atmosphere to prevent meteoroids from impacting the lunar surface. Upon impact, the meteoroid's kinetic energy is partitioned into crater excavation, seismic wave production, and the generation of a debris plume. A flash of light associated with the plume is detectable by instruments on Earth. Following the initial observation of a probable Taurid impact flash on the Moon in November 2005,1 the NASA Meteoroid Environment Office (MEO) began a routine monitoring program to observe the Moon for meteoroid impact flashes in early 2006, resulting in the observation of over 330 impacts to date. The main objective of the MEO is to characterize the meteoroid environment for application to spacecraft engineering and operations. The Lunar Impact Monitoring Program provides information about the meteoroid flux in near-Earth space in a size range-tens of grams to a few kilograms-difficult to measure with statistical significance by other means. A bright impact flash detected by the program in March 2013 brought into focus the importance of determining the impact flash location. Prior to this time, the location was estimated to the nearest half-degree by visually comparing the impact imagery to maps of the Moon. Better accuracy was not needed because meteoroid flux calculations did not require high-accuracy impact locations. But such a bright event was thought to have produced a fresh crater detectable from lunar orbit by the NASA spacecraft Lunar Reconnaissance Orbiter (LRO). The idea of linking the observation of an impact flash with its crater was an appealing one, as it would validate NASA photometric calculations and crater scaling laws developed from hypervelocity gun testing. This idea was

  14. Expression of the nos gene and Firefly Flashing: A Test of the Nitric-Oxide-Mediated Flash Control Model

    PubMed Central

    Ohtsuki, Hajime; Yokoyama, Jun; Ohba, Nobuyoshi; Ohmiya, Yoshihiro; Kawata, Masakado

    2014-01-01

    Fireflies (Coleoptera: Lampyridae) emit various types of light that differ among species and populations of the same species. Their lights are assumed to be biological properties that play important ecological and evolutionary roles. Some species in the Lampyridae emit periodic luminescence, the patterns of which are characterized by species-specific intervals. In previous work, it was predicted that the nitric oxide (NO) regulates the oxygen supply required for the bioluminescence reaction of fireflies. Here, the expression of the NO synthase (NOS) mRNA in some fireflies was examined to verify the predictive model of nitric-oxide-mediated flash control in these insects. The expression of the nos gene in the lantern organ was observed not only in nocturnal flashing species but also in diurnal non-flashing species. It was shown that the expression levels of nos were higher in the lantern of Luciola cruciata (Motschulsky) larvae, which that emits continuous light, than in other body parts, although expression in the lantern of the adults, who flash periodically, was not high. Furthermore, there was no significant difference in expression levels among adults of Luciola cruciata characterized by different flashing intervals. The data do not support the model of an NO-mediated flash control mechanism, during which oxygen becomes available for the luciferin-luciferase reaction through NO-mediated inhibition of mitochondrial respiration. It is also indicated that flash patterns do not co-vary with NOS production. However, high nos expression in the larval lantern suggests that NO may play a role in producing continuous light by functioning as a neurotransmitter signal for bioluminescence. PMID:25373203

  15. Expression of the nos gene and firefly flashing: a test of the nitric-oxide-mediated flash control model.

    PubMed

    Ohtsuki, Hajime; Yokoyama, Jun; Ohba, Nobuyoshi; Ohmiya, Yoshihiro; Kawata, Masakado

    2014-04-19

    Fireflies (Coleoptera: Lampyridae) emit various types of light that differ among species and populations of the same species. Their lights are assumed to be biological properties that play important ecological and evolutionary roles. Some species in the Lampyridae emit periodic luminescence, the patterns of which are characterized by species-specific intervals. In previous work, it was predicted that the nitric oxide (NO) regulates the oxygen supply required for the bioluminescence reaction of fireflies. Here, the expression of the NO synthase (NOS) mRNA in some fireflies was examined to verify the predictive model of nitric-oxide-mediated flash control in these insects. The expression of the nos gene in the lantern organ was observed not only in nocturnal flashing species but also in diurnal non-flashing species. It was shown that the expression levels of nos were higher in the lantern of Luciola cruciata (Motschulsky) larvae, which that emits continuous light, than in other body parts, although expression in the lantern of the adults, who flash periodically, was not high. Furthermore, there was no significant difference in expression levels among adults of Luciola cruciata characterized by different flashing intervals. The data do not support the model of an NO-mediated flash control mechanism, during which oxygen becomes available for the luciferin-luciferase reaction through NO-mediated inhibition of mitochondrial respiration. It is also indicated that flash patterns do not co-vary with NOS production. However, high nos expression in the larval lantern suggests that NO may play a role in producing continuous light by functioning as a neurotransmitter signal for bioluminescence.

  16. Flash pyrolysis of oil shale with various gases

    SciTech Connect

    Steinberg, M.; Fallon, P.T.

    1983-10-01

    The flash pyrolysis of Colorado Oil Shale with methane at a temperature of 800/sup 0/C and pressure of 500 psi appears to give the highest yield of hydrocarbon gas and liquid followed by hydrogen and lowest with helium. In the methane pyrolysis over 54.5% of the carbon in the kerogen is converted to ethylene and benzene. The flash pyrolysis with hydrogen (flash hydropyrolysis) of the oil shale at increasing temperatures showed a rapidly increasing amount of methane formed and a decrease in ethane formation, while the BTX (benzene mainly) yield remained at approximately 10%. At 950/sup 0/C and 500 psi almost all (97.0%) of the carbon in the kerogen is converted to liquid and gaseous hydrocarbons. Experiments with a mixture of a New Mexico sub-bituminous coal and oil shale under flash hydropyrolysis and methane pyrolysis conditions indicated higher yields of methane and ethylene and slightly lower yields of benzene than predicted by partial additive calculations. These exploratory experiments appear to be of sufficient interest to warrant a fuller investigation of the interaction of the natural resources, oil shale, coal and natural gas under flash pyrolysis conditions.

  17. An Evaluation of Flash Cells Used in Critical Applications

    NASA Technical Reports Server (NTRS)

    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.

  18. Study of Beijiang catchment flash-flood forecasting model

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Li, J.; Huang, S.; Dong, Y.

    2015-05-01

    Beijiang catchment is a small catchment in southern China locating in the centre of the storm areas of the Pearl River Basin. Flash flooding in Beijiang catchment is a frequently observed disaster that caused direct damages to human beings and their properties. Flood forecasting is the most effective method for mitigating flash floods, the goal of this paper is to develop the flash flood forecasting model for Beijiang catchment. The catchment property data, including DEM, land cover types and soil types, which will be used for model construction and parameter determination, are downloaded from the website freely. Based on the Liuxihe Model, a physically based distributed hydrological model, a model for flash flood forecasting of Beijiang catchment is set up. The model derives the model parameters from the terrain properties, and further optimized with the observed flooding process, which improves the model performance. The model is validated with a few observed floods occurred in recent years, and the results show that the model is reliable and is promising for flash flood forecasting.

  19. A Unified Flash Flood Database across the United States

    USGS Publications Warehouse

    Gourley, Jonathan J.; Hong, Yang; Flamig, Zachary L.; Arthur, Ami; Clark, Robert; Calianno, Martin; Ruin, Isabelle; Ortel, Terry W.; Wieczorek, Michael E.; Kirstetter, Pierre-Emmanuel; Clark, Edward; Krajewski, Witold F.

    2013-01-01

    Despite flash flooding being one of the most deadly and costly weather-related natural hazards worldwide, individual datasets to characterize them in the United States are hampered by limited documentation and can be difficult to access. This study is the first of its kind to assemble, reprocess, describe, and disseminate a georeferenced U.S. database providing a long-term, detailed characterization of flash flooding in terms of spatiotemporal behavior and specificity of impacts. The database is composed of three primary sources: 1) the entire archive of automated discharge observations from the U.S. Geological Survey that has been reprocessed to describe individual flooding events, 2) flash-flooding reports collected by the National Weather Service from 2006 to the present, and 3) witness reports obtained directly from the public in the Severe Hazards Analysis and Verification Experiment during the summers 2008–10. Each observational data source has limitations; a major asset of the unified flash flood database is its collation of relevant information from a variety of sources that is now readily available to the community in common formats. It is anticipated that this database will be used for many diverse purposes, such as evaluating tools to predict flash flooding, characterizing seasonal and regional trends, and improving understanding of dominant flood-producing processes. We envision the initiation of this community database effort will attract and encompass future datasets.

  20. Dendrogeomorphic reconstruction of flash floods in the Patagonian Andes

    NASA Astrophysics Data System (ADS)

    Casteller, Alejandro; Stoffel, Markus; Crespo, Sebastián; Villalba, Ricardo; Corona, Christophe; Bianchi, Emilio

    2015-01-01

    Flash floods represent a significant natural hazard in small mountainous catchments of the Patagonian Andes and have repeatedly caused loss to life and infrastructure. At the same time, however, documentary records of past events remain fairly scarce and highly fragmentary in most cases. In this study, we therefore reconstruct the spatiotemporal patterns of past flash flood activity along the Los Cipreses torrent (Neuquén, Argentina) using dendrogeomorphic methods. Based on samples from Austrocedrus chilensis, Pseudotsuga menziesii, and Nothofagus dombeyi, we document 21 flash flood events covering the period A.D. 1890-2009 and reconstruct mean recurrence intervals of events at the level of individual trees being impacted, which varies from 4 to 93 years. Results show that trees tend to be older (younger) in sectors of the torrent with gentler (steeper) slope gradients. Potential triggers of flash floods were analyzed using daily temperature and precipitation data from a nearby weather station. Weather conditions leading to flash floods are abundant precipitations during one to three consecutive days, combined with temperatures above the rain/snow threshold (2 °C) in the whole watershed.

  1. Kinematics of illumination patterns and light echoes from flashes.

    PubMed

    Zhong, Qi

    2016-09-01

    Flash-induced light echoes-the observation of light reflected from a burst-have been observed in astronomical settings for more than a century and have been observed in the laboratory recently. Because of the flight time of light, perceived light echoes are different from real light illumination patterns on a scattering plane, neglecting interreflections and non-opaque scattering effects. The shape and motion of real illumination patterns are studied from a spherical flash. Then, ellipsoids of constant time delay for a specifically chosen coordinate system are applied. Generally, perceived light echoes are elliptical annular rings and the center of a light echo will not start at the flash, which leads to light echoes moving angularly toward the flash instead of away from it, a phenomenon actually recorded by other groups. The brightness of perceived light echoes was studied, and maximum brightness occurred close to the flash's projective point on the scattering plane. Two specific examples are given and a magnification effect between perceived echoes and real illumination patterns is proposed. PMID:27607505

  2. Risk Factors, Pathophysiology, and Treatment of Hot Flashes in Cancer

    PubMed Central

    Fisher, William I.; Johnson, Aimee K.; Elkins, Gary R.; Otte, Julie L.; Burns, Debra S.; Yu, Menggang; Carpenter, Janet S.

    2012-01-01

    Hot flashes are prevalent and severe symptoms that can interfere with mood, sleep, and quality of life for women and men with cancer. The purpose of this article is to review existing literature on the risk factors, pathophysiology, and treatment of hot flashes in persons with cancer. Electronic searches were conducted to identify relevant, English-language literature published through June 15, 2012. Results indicated that risk factors for hot flashes in cancer include patient-related factors (eg, age, race/ethnicity, educational level, smoking history, cardiovascular risk including BMI, and genetics) and disease-related factors (eg, cancer diagnosis, and dose/type of treatment). In addition, although the pathophysiology of hot flashes has remained elusive, these symptoms are likely attributable to disruptions in thermoregulation and neurochemicals. Therapies that have been offered or tested fall into 4 broad categories: pharmacological, nutraceutical, surgical, and complementary/behavioral strategies. The evidence base for this broad range of therapies varies, with some treatments not yet having been fully tested or showing equivocal results. The evidence base surrounding all therapies is evaluated to enhance hot flash treatment decision making by clinicians and patients. PMID:23355109

  3. Post-trial flicker stimulation interferes with spatial memory in the Morris water maze.

    PubMed

    Buresová, O; Panakhova, E; Bures, J

    1985-05-23

    Rats (n = 20) trained under monocular viewing conditions in the working memory version of Morris water maze task received daily a single acquisition trial with a new location of the invisible escape platform followed after 15 min by a single retrieval trial. Escape latency decreased by 50% during retrieval. Flash stimulation (20 Hz, 0.6 J) during the entire 15-min delay disrupted retention, but this effect was not observed when the flashes started 3 or 5 min after acquisition. It is concluded that successful place learning requires a brief interference-free post-acquisition interval.

  4. Variability of flashes and background luminances of clinical electroretinography stimuli across 14 UK centres

    NASA Astrophysics Data System (ADS)

    Hamilton, R.; Abdlseaed, A. Al; Healey, J.; Neveu, M. M.; Brown, L.; Keating, D.; McBain, V. A.; Sculfor, D.; Thompson, D. A.

    2013-08-01

    Three different flash strengths (dim, 0.01 cd s m-2; strong, 3 cd s m-2; strongest, 10 or 30 cd s m-2) and one adapting field luminance (30 cd m-2) are used for clinical electroretinograms (ERGs). To quantify their variability for local, LED-flash protocols, and for an ISCEV-specified, xenon-flash protocol, photometric measurements were made at 14 ERG centres across the UK. For local protocols, flashes were within a median of 0.01 log units of nominal, target levels and six, nine, eight and eight of 14 centres were within ISCEV tolerance (±0.05 log units) for dim, strong, strongest flashes and backgrounds, respectively. For the ISCEV-specified protocol, flashes were within a median of 0.02, 0.001 and 0.01 log units of ISCEV target dim, strong and strongest flashes, and fewer (5/12, 7/13, 3/13 and 11/13) centres were within ISCEV tolerance for dim, strong and strongest flashes and backgrounds, respectively. Paired LED-xenon comparison for a subset of centres showed close agreement. Variability of flashes was less for LED than xenon flashtube sources for strong and strongest flashes; for the strongest flash, LED flashes were closer to target values than xenon flashes. These data support a recommendation of LED use for clinical electroretinography.

  5. Advanced real-time dynamic scene generation techniques for improved performance and fidelity

    NASA Astrophysics Data System (ADS)

    Bowden, Mark H.; Buford, James A.; Mayhall, Anthony J.

    2000-07-01

    Recent advances in real-time synthetic scene generation for Hardware-in-the-loop (HWIL) testing at the U.S. Army Aviation and Missile Command (AMCOM) Aviation and Missile Research, Development, and Engineering Center (AMRDEC) improve both performance and fidelity. Modeling ground target scenarios requires tradeoffs because of limited texture memory for imagery and limited main memory for elevation data. High- resolution insets have been used in the past to provide better fidelity in specific areas, such as in the neighborhood of a target. Improvements for ground scenarios include smooth transitions for high-resolution insets to reduce high spatial frequency artifacts at the borders of the inset regions and dynamic terrain paging to support large area databases. Transport lag through the scene generation system, including sensor emulation and interface components, has been dealt with in the past through the use of sub-window extraction from oversize scenes. This compensates for spatial effects of transport lag but not temporal effects. A new system has been developed and used successfully to compensate for a flashing coded beacon in the scene. Other techniques have been developed to synchronize the scene generator with the seeker under test (SUT) and to model atmospheric effects, sensor optic and electronics, and angular emissivity attenuation.

  6. A study of thunderstorm microphysical properties and lightning flash counts associated with terrestrial gamma-ray flashes

    NASA Astrophysics Data System (ADS)

    Barnes, D. E.; Splitt, M. E.; Dwyer, J. R.; Lazarus, S.; Smith, D. M.; Rassoul, H. K.

    2015-04-01

    The terrestrial gamma ray flash (TGF) is an emission of highly energetic radiation produced by or at least in close association with lightning. Previous investigations attempted to isolate the production mechanisms and production altitude(s) of TGFs as well as macrophysical characteristics, while thunderstorm microphysical characteristics were largely ignored. This investigation into thunderstorms and their hydrometeor and flash characteristics utilize temporal and spatial coincident satellite passes between the Reuven Ramaty High Energy Solar Spectroscopic Imager and the Tropical Rainfall Measuring Mission to determine the bulk (or footprint) microphysical properties of two types of study events, the thunderstorm complexes which are associated with TGFs (TGF case) and the thunderstorm complexes which did not produce a TGF detected by Reuven Ramaty High Energy Solar Spectroscopic Imager during the pass (non-TGF case). Results are presented for two different comparison methods. The first case utilizes geographic region weighted by TGF distribution, and the second is based on TGF percentage of occurrence when compared to total flash count of data set. Results show that the associated storms around the TGF location possess differences in the hydrometeor concentrations: cloud liquid water, cloud ice, precipitation water, and precipitation ice. These results take place at different levels of the atmosphere, including the mixed phase region. Additionally, results will show that TGFs are a consistent percentage of observed flashes as the rate of TGFs as a function of Lightning Imaging Sensor flash count is relatively constant.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. FLASH magnetohydrodynamic simulations of shock-generated magnetic field experiments

    NASA Astrophysics Data System (ADS)

    Tzeferacos, P.; Fatenejad, M.; Flocke, N.; Gregori, G.; Lamb, D. Q.; Lee, D.; Meinecke, J.; Scopatz, A.; Weide, K.

    2012-12-01

    We report the results of benchmark FLASH magnetohydrodynamic (MHD) simulations of experiments conducted by the University of Oxford High Energy Density Laboratory Astrophysics group and its collaborators at the Laboratoire pour l'Utilisation des Lasers Intenses (LULI). In these experiments, a long-pulse laser illuminates a target in a chamber filled with Argon gas, producing shock waves that generate magnetic fields via the Biermann battery mechanism. We first outline the implementation of 2D cylindrical geometry in the unsplit MHD solver in FLASH and present results of verification tests. We then describe the results of benchmark 2D cylindrical MHD simulations of the LULI experiments using FLASH that explore the impact of external fields along with the possibility of magnetic field amplification by turbulence that is associated with the shock waves and that is induced by a grid placed in the gas-filled chamber.

  9. Flash trajectory imaging of target 3D motion

    NASA Astrophysics Data System (ADS)

    Wang, Xinwei; Zhou, Yan; Fan, Songtao; He, Jun; Liu, Yuliang

    2011-03-01

    We present a flash trajectory imaging technique which can directly obtain target trajectory and realize non-contact measurement of motion parameters by range-gated imaging and time delay integration. Range-gated imaging gives the range of targets and realizes silhouette detection which can directly extract targets from complex background and decrease the complexity of moving target image processing. Time delay integration increases information of one single frame of image so that one can directly gain the moving trajectory. In this paper, we have studied the algorithm about flash trajectory imaging and performed initial experiments which successfully obtained the trajectory of a falling badminton. Our research demonstrates that flash trajectory imaging is an effective approach to imaging target trajectory and can give motion parameters of moving targets.

  10. Flash Points of Secondary Alcohol and n-Alkane Mixtures.

    PubMed

    Esina, Zoya N; Miroshnikov, Alexander M; Korchuganova, Margarita R

    2015-11-19

    The flash point is one of the most important characteristics used to assess the ignition hazard of mixtures of flammable liquids. To determine the flash points of mixtures of secondary alcohols with n-alkanes, it is necessary to calculate the activity coefficients. In this paper, we use a model that allows us to obtain enthalpy of fusion and enthalpy of vaporization data of the pure components to calculate the liquid-solid equilibrium (LSE) and vapor-liquid equilibrium (VLE). Enthalpy of fusion and enthalpy of vaporization data of secondary alcohols in the literature are limited; thus, the prediction of these characteristics was performed using the method of thermodynamic similarity. Additionally, the empirical models provided the critical temperatures and boiling temperatures of the secondary alcohols. The modeled melting enthalpy and enthalpy of vaporization as well as the calculated LSE and VLE flash points were determined for the secondary alcohol and n-alkane mixtures. PMID:26491811

  11. PNNL 331 Building Arc Flash Team Investigation Report

    SciTech Connect

    Deichman, Mark L.; Drewrey, John C.; Hodges, Hurtis; Madson, Vernon J.; Minton, Allen L.; Montgomery, Daniel M.; Olson, Marvin E.; Rojas, Pedro H.; Sanan, Sanjay K.; Sharp, Reed D.; Sparks, Bobby R.; Swearingen, Gary L.

    2006-06-06

    On Friday, April 21, 2006, a PNNL electrician was performing repair of an electrical system for the 331 Building chilled water pump (CHWP) No.2, when an electrical arc flash occurred inside a 480V combination motor starter. The electrician was taken to the on-site medical provider for evaluation and was released for return to work without restriction. The electrician was not shocked, but did receive a minor, superficial (first degree) burn on the left wrist. This report, the result of a thorough review by the 331 Building Arc Flash Assessment Team, provides an in-depth look at the steps leading up to the arc-flash and recommendations and opportunities for improvement.

  12. Recent Flash X-Ray Injector Modeling

    SciTech Connect

    Houck, T; Blackfield, D; Burke, J; Chen, Y; Javedani, J; Paul, A C

    2004-11-10

    The injector of the Flash X-Ray (FXR) accelerator has a significantly larger than expected beam emittance. A computer modeling effort involving three different injector design codes was undertaken to characterize the FXR injector and determine the cause of the large emittance. There were some variations between the codes, but in general the simulations were consistent and pointed towards a much smaller normalized, rms emittance (36 cm-mr) than what was measured (193 cm-mr) at the exit of the injector using a pepperpot technique. The simulations also indicated that the present diode design was robust with respect to perturbations to the nominal design. Easily detected mechanical alignment/position errors and magnet errors did not lead to appreciable increase in the simulated emittance. The physics of electron emission was not modeled by any of the codes and could be the source of increased emittance. The nominal simulation assumed uniform Child-Langmuir Law emission from the velvet cathode and no shroud emission. Simulations that looked at extreme non-uniform cathode and shroud emission scenarios resulted in doubling of the emittance. An alternative approach was to question the pepperpot measurement. Simulations of the measurement showed that the pepperpot aperture foil could double the emittance with respect to the non-disturbed beam. This leads to a diplomatic explanation of the discrepancy between predicted and measured emittance where the fault is shared. The measured value is too high due to the effect of the diagnostic on the beam and the simulations are too low because of unaccounted cathode and/or shroud emission physics. Fortunately there is a relatively simple experiment that can resolve the emittance discrepancy. If the large measured emittance value is correct, the beam envelope is emittance dominated at modest values of focusing field and beam radius. Measurements of the beam envelope on an imaging foil at the exit of the injector would lead to an

  13. A Real-Time Web Services Hub to Improve Situation Awareness during Flash Flood Events

    NASA Astrophysics Data System (ADS)

    Salas, F. R.; Liu, F.; Maidment, D. R.; Hodges, B. R.

    2011-12-01

    The central Texas corridor is one of the most flash flood-prone regions in the United States. Over the years, flash floods have resulted in hundreds of flood fatalities and billions of dollars in property damage. In order to mitigate risk to residents and infrastructure during flood events, both citizens and emergency responders need to exhibit proactive behavior instead of reactive. Real-time and forecasted flood information is fairly limited and hard to come by at varying spatial scales. The University of Texas at Austin has collaborated with IBM Research-Austin and ESRI to build a distributed real-time flood information system through a framework that leverages large scale data management and distribution, Open Geospatial Consortium standardized web services, and smart map applications. Within this paradigm, observed precipitation data encoded in WaterML is ingested into HEC-HMS and then delivered to a high performance hydraulic routing software package developed by IBM that utilizes the latest advancements in VLSI design, numerical linear algebra and numerical integration techniques on contemporary multicore architecture to solve fully dynamic Saint Venant equations at both small and large scales. In this paper we present a real-time flood inundation map application that in conjunction with a web services Hub, seamlessly integrates hydrologic information available through both public and private data services, model services and mapping services. As a case study for this project, we demonstrate how this system has been implemented in the City of Austin, Texas.

  14. Thermal Conductivity Measurement of Xe-Implanted Uranium Dioxide Thick Films using Multilayer Laser Flash Analysis

    SciTech Connect

    Nelson, Andrew T.

    2012-08-30

    The Fuel Cycle Research and Development program's Advanced Fuels campaign is currently pursuing use of ion beam assisted deposition to produce uranium dioxide thick films containing xenon in various morphologies. To date, this technique has provided materials of interest for validation of predictive fuel performance codes and to provide insight into the behavior of xenon and other fission gasses under extreme conditions. In addition to the structural data provided by such thick films, it may be possible to couple these materials with multilayer laser flash analysis in order to measure the impact of xenon on thermal transport in uranium dioxide. A number of substrate materials (single crystal silicon carbide, molybdenum, and quartz) containing uranium dioxide films ranging from one to eight microns in thickness were evaluated using multilayer laser flash analysis in order to provide recommendations on the most promising substrates and geometries for further investigation. In general, the uranium dioxide films grown to date using ion beam assisted deposition were all found too thin for accurate measurement. Of the substrates tested, molybdenum performed the best and looks to be the best candidate for further development. Results obtained within this study suggest that the technique does possess the necessary resolution for measurement of uranium dioxide thick films, provided the films are grown in excess of fifty microns. This requirement is congruent with the material needs when viewed from a fundamental standpoint, as this length scale of material is required to adequately sample grain boundaries and possible second phases present in ceramic nuclear fuel.

  15. Multisensory Integration, Aging, and the Sound-Induced Flash Illusion

    PubMed Central

    DeLoss, Denton J.; Pierce, Russell S.; Andersen, George J.

    2013-01-01

    The present study examined age-related differences in multisensory integration and the role of attention in age-related differences in multisensory integration. The sound-induced flash illusion---the misperception of the number of visual flashes due to the simultaneous presentation of a different number of auditory beeps---was used to examine the strength of multisensory integration in older and younger observers. The effects of integration were examined when discriminating 1–3 flashes, 1–3 beeps, or 1–3 flashes presented with 1–3 beeps. Stimulus conditions were blocked according to these conditions, with baseline (unisensory) performance assessed during the multisensory block. Older participants demonstrated greater multisensory integration--a greater influence of the beeps when judging the number of visual flashes--than younger observers. In a second experiment, the role of attention was assessed using a go/no-go paradigm. The results of Experiment 2 replicated those of Experiment 1. In addition, the strength of the illusion was modulated by the sensory domain of the go/no-go task, though this did not differ by age group. In the visual go/no-go task we found a decrease in the illusion, while in the auditory go/no-go task we found an increase in the illusion. These results demonstrate that older individuals exhibit increased multisensory integration compared to younger individuals. Attention was also found to modulate the strength of the sound-induced flash illusion. However, the results also suggest that attention was not likely to be a factor in the age-related differences in multisensory integration. PMID:23978009

  16. Flash heat simulation events in the north Mediterranean basin

    NASA Astrophysics Data System (ADS)

    Mazon, Jordi; Pino, David

    2013-04-01

    According to the definition of flash heat event proposed by Mazon et al. in the European Meteorology Meeting (2011 and 2012) from the studied case produced in the Northeast of the Iberian peninsula on 27th August 20120, some other flash heat events have been detected by automatic weather stations around the in the Mediterranean basin (South Italy, Crete island, South Greece and the northeast of the Iberian peninsula). Flash heat event covers those events in which a large increase of temperature last a spatial and temporal scale between heat wave (defined by the WMO as a phenomenon in which the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature by 5°C, with respect to the 1961-1990 period) and heat burst (defined by the AMS as a rare atmospheric event characterized by gusty winds and a rapid increase in temperature and decrease in humidity that can last some minutes). Thus flash heat event may be considered as a rapid modification of the temperature that last several hours, lower than 48 hours, but usually less than 24 hours. Two different flash heat events have been simulated with the WRF mesoscale model in the Mediterranean basin. The results show that two different mechanisms are the main causes of these flash heat events. The first one occurred on 23rd March 2008 in Crete Island due to a strong Foehn effect caused by a strong south and southeast wind, in which the maximum temperature increased during some hours on the night at 32°C. The second one occurred on 1st August 2012 in the northeast of the Iberian Peninsula, caused by a rapid displacement of warm a ridge from North Africa that lasted around 24 hours.

  17. 46 CFR 113.25-10 - Emergency red-flashing lights.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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...

  18. 46 CFR 113.25-10 - Emergency red-flashing lights.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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...

  19. 46 CFR 113.25-10 - Emergency red-flashing lights.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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...

  20. Special technical services for investigation of light flash phenomena

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Details are presented of an investigation aimed at an explanation of the phenomenon of light flashes observed by Apollo crew members. The various theories considered include: penetration of the eye by cosmic particles resulting in retinal stimulation; production of phosphenes or sensations of light through ionization or excitation; appearance of heavily ionized single tracks misinterpreted as light flashes; Cerenkov radiation; and direct excitation of neural tissue by penetrating cosmic rays. It is concluded that the latter two theories are the likeliest mechanisms for the development of a definitive explanation.

  1. Parallel data analysis in a multichannel flash-ADC-system

    SciTech Connect

    Eckerlin, G.; Elsen, E.; Schmitt, H.V.D.; Wagner, A.; Walter, P.V.; Zimmer, M.

    1987-02-01

    Parallel analysis of drift chamber signals with M68000 processors has proven to be an efficient way to deal with the tremendous data flow generated by high speed (100 MHz) Flash-ADCs in real time. The authors report on the experience gained with a network of 34 processors, placed in 3 VME crates, to read out the 3072 Flash-ADC channels of the JADE Jet-Chamber at PETRA (1). The properties of such a system are compared to more conventional readout schemes for drift chambers.

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

    PubMed

    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. PMID:27400996

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

    PubMed Central

    2016-01-01

    Abstract 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. PMID:27400996

  4. [Skin memory: the clinical implications].

    PubMed

    Gaide, Olivier

    2016-03-30

    Activated T lymphocytes give rise to daughter cells that can persist for decades in our body, while retaining their ability to provide a strong immune response. Recent advances have highlighted the fact that a significant portion of these memory cells are found directly in peripheral tissues and lack the capacity to migrate to the blood. We have recently shown that these cells, called Tissue Resident Memory T cells (T(RM)), play a major role in the immune response, regardless of the antigenic challenge. They have a backup of circulating central memory T cells (T(CM)) that bear the exact same T cell receptor. For the clinician, this knowledge is very useful as it allows a better understanding and better choice of therapeutics for several cutaneous diseases, such as contact dermatitis and cutaneous T cell lymphoma (Mycosis Fungoides vs Sezary). PMID:27172692

  5. Hybrid Flexible Resistive Random Access Memory-Gated Transistor for Novel Nonvolatile Data Storage.

    PubMed

    Han, Su-Ting; Zhou, Ye; Chen, Bo; Wang, Chundong; Zhou, Li; Yan, Yan; Zhuang, Jiaqing; Sun, Qijun; Zhang, Hua; Roy, V A L

    2016-01-20

    Here, a single-device demonstration of novel hybrid architecture is reported to achieve programmable transistor nodes which have analogies to flash memory by incorporating a resistive switching random access memory (RRAM) device as a resistive switch gate for field effect transistor (FET) on a flexible substrate. A high performance flexible RRAM with a three-layered structure is fabricated by utilizing solution-processed MoS2 nanosheets sandwiched between poly(methyl methacrylate) polymer layers. Gate coupling with the pentacene-based transistor can be controlled by the RRAM memory state to produce a nonprogrammed state (inactive) and a programmed state (active) with a well-defined memory window. Compared to the reference flash memory device based on the MoS2 floating gate, the hybrid device presents robust access speed and retention ability. Furthermore, the hybrid RRAM-gated FET is used to build an integrated logic circuit and a wide logic window in inverter logic is achieved. The controllable, well-defined memory window, long retention time, and fast access speed of this novel hybrid device may open up new possibilities of realizing fully functional nonvolatile memory for high-performance flexible electronics.

  6. Hybrid Flexible Resistive Random Access Memory-Gated Transistor for Novel Nonvolatile Data Storage.

    PubMed

    Han, Su-Ting; Zhou, Ye; Chen, Bo; Wang, Chundong; Zhou, Li; Yan, Yan; Zhuang, Jiaqing; Sun, Qijun; Zhang, Hua; Roy, V A L

    2016-01-20

    Here, a single-device demonstration of novel hybrid architecture is reported to achieve programmable transistor nodes which have analogies to flash memory by incorporating a resistive switching random access memory (RRAM) device as a resistive switch gate for field effect transistor (FET) on a flexible substrate. A high performance flexible RRAM with a three-layered structure is fabricated by utilizing solution-processed MoS2 nanosheets sandwiched between poly(methyl methacrylate) polymer layers. Gate coupling with the pentacene-based transistor can be controlled by the RRAM memory state to produce a nonprogrammed state (inactive) and a programmed state (active) with a well-defined memory window. Compared to the reference flash memory device based on the MoS2 floating gate, the hybrid device presents robust access speed and retention ability. Furthermore, the hybrid RRAM-gated FET is used to build an integrated logic circuit and a wide logic window in inverter logic is achieved. The controllable, well-defined memory window, long retention time, and fast access speed of this novel hybrid device may open up new possibilities of realizing fully functional nonvolatile memory for high-performance flexible electronics. PMID:26578160

  7. SunFlash -- An entirely new concept for building-integrated PV. Final technical report, October 1997--June 1998

    SciTech Connect

    Farber, M.A.

    1998-10-01

    This project team has investigated an innovative and entirely new building product concept, the SunFlash, incorporating a photovoltaic module with integral mounting and sealing for watertight building integration. It can be used as a roof-integrated shingle for slant roofs, for vertical curtain walls, or in other applications. Key features of the SunFlash include the following: an integrated module concept whereby the module, backskin, edge seal and mounting and sealing are all a single molded unit of the same material; an extension of this concept to include the possibility of molded-in electrical connections; a novel encapsulant material with better adhesion, sealing, thermal creep, and UV stability properties than EVA; a crystalline silicon, glass-front module incorporating the advanced string ribbon solar cells; and accessories and features, including a module-integrated inverter, laminated exit wiring, mounting, and raceway wiring, that provide high-performance consistent with building practice. The objective of the SunFlash is a standardized, cost-effective, long-lasting solution to integrating and water-sealing modules into residential and commercial buildings, both new and retrofit.

  8. Characterization of an Autonomous Non-Volatile Ferroelectric Memory Latch

    NASA Technical Reports Server (NTRS)

    John, Caroline S.; MacLeod, Todd C.; Evans, Joe; Ho, Fat D.

    2011-01-01

    We present the electrical characterization of an autonomous non-volatile ferroelectric memory latch using the principle that when an electric field is applied to a ferroelectriccapacitor,the positive and negative remnant polarization charge states of the capacitor are denoted as either data 0 or data 1. The properties of the ferroelectric material to store an electric polarization in the absence of an electric field make the device non-volatile. Further the memory latch is autonomous as it operates with the ground, power and output node connections, without any externally clocked control line. The unique quality of this latch circuit is that it can be written when powered off. The advantages of this latch over flash memories are: a) It offers unlimited reads/writes b) works on symmetrical read/write cycles. c) The latch is asynchronous. The circuit was initially developed by Radiant Technologies Inc., Albuquerque, New Mexico.

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

    ERIC Educational Resources Information Center

    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…

  10. 46 CFR 167.65-5 - Flashing the rays of a searchlight or other blinding light.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Flashing the rays of a searchlight or other blinding...) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Special Operating Requirements § 167.65-5 Flashing the rays of a searchlight or other blinding light. Flashing the rays of a searchlight or other blinding...

  11. 46 CFR 167.65-5 - Flashing the rays of a searchlight or other blinding light.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Flashing the rays of a searchlight or other blinding...) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Special Operating Requirements § 167.65-5 Flashing the rays of a searchlight or other blinding light. Flashing the rays of a searchlight or other blinding...

  12. 46 CFR 167.65-5 - Flashing the rays of a searchlight or other blinding light.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Flashing the rays of a searchlight or other blinding...) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Special Operating Requirements § 167.65-5 Flashing the rays of a searchlight or other blinding light. Flashing the rays of a searchlight or other blinding...

  13. 46 CFR 167.65-5 - Flashing the rays of a searchlight or other blinding light.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Flashing the rays of a searchlight or other blinding...) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Special Operating Requirements § 167.65-5 Flashing the rays of a searchlight or other blinding light. Flashing the rays of a searchlight or other blinding...

  14. 46 CFR 167.65-5 - Flashing the rays of a searchlight or other blinding light.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Flashing the rays of a searchlight or other blinding...) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Special Operating Requirements § 167.65-5 Flashing the rays of a searchlight or other blinding light. Flashing the rays of a searchlight or other blinding...

  15. Shape recognition elicited by microsecond flashes is not based on photon quantity

    PubMed Central

    Greene, Ernest

    2014-01-01

    It is generally thought that the perceptual impact of a brief flash of light is determined by the quantity of photons the flash delivers. This means that only the total quantity of photons is important below a critical duration of about 30–100 ms. Recent findings have challenged this concept and the present work provides additional evidence that it is not correct. The first experiment reported here delivered a given quantity of photons in under 200 μs, either as a single threshold-intensity flash or as multiple flashes at the same intensity. The single flash was ineffective at eliciting recognition, but multiple flashes became progressively more effective as the number of flashes was increased. A second experiment varied the number of 10 μs flashes. The effectiveness of multiple flashes was far higher than would be expected on the basis of the total quantity of photons being delivered. The results of both experiments suggest that the brief transitions of intensity provided by the flashes are far more important than the quantity of photons. A final experiment examined the combined impact from two threshold-intensity flashes as the interstimulus interval was increased. The pair members were able to combine their influence for at least 100 ms. These results call for more attention to how very brief light flashes generate signals that convey image content. PMID:25469213

  16. 49 CFR 234.253 - Flashing light units and lamp voltage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Flashing light units and lamp voltage. 234.253 Section 234.253 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD....253 Flashing light units and lamp voltage. (a) Each flashing light unit shall be inspected...

  17. 49 CFR 234.253 - Flashing light units and lamp voltage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Flashing light units and lamp voltage. 234.253 Section 234.253 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD....253 Flashing light units and lamp voltage. (a) Each flashing light unit shall be inspected...

  18. 46 CFR 113.25-10 - Emergency red-flashing lights.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Emergency red-flashing lights. 113.25-10 Section 113.25... 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...

  19. 46 CFR 113.25-10 - Emergency red-flashing lights.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Emergency red-flashing lights. 113.25-10 Section 113.25... 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...

  20. Sparse distributed memory and related models

    NASA Technical Reports Server (NTRS)

    Kanerva, Pentti

    1992-01-01

    Described here is sparse distributed memory (SDM) as a neural-net associative memory. It is characterized by two weight matrices and by a large internal dimension - the number of hidden units is much larger than the number of input or output units. The first matrix, A, is fixed and possibly random, and the second matrix, C, is modifiable. The SDM is compared and contrasted to (1) computer memory, (2) correlation-matrix memory, (3) feet-forward artificial neural network, (4) cortex of the cerebellum, (5) Marr and Albus models of the cerebellum, and (6) Albus' cerebellar model arithmetic computer (CMAC). Several variations of the basic SDM design are discussed: the selected-coordinate and hyperplane designs of Jaeckel, the pseudorandom associative neural memory of Hassoun, and SDM with real-valued input variables by Prager and Fallside. SDM research conducted mainly at the Research Institute for Advanced Computer Science (RIACS) in 1986-1991 is highlighted.

  1. (U) Computation acceleration using dynamic memory

    SciTech Connect

    Hakel, Peter

    2014-10-24

    Many computational applications require the repeated use of quantities, whose calculations can be expensive. In order to speed up the overall execution of the program, it is often advantageous to replace computation with extra memory usage. In this approach, computed values are stored and then, when they are needed again, they are quickly retrieved from memory rather than being calculated again at great cost. Sometimes, however, the precise amount of memory needed to store such a collection is not known in advance, and only emerges in the course of running the calculation. One problem accompanying such a situation is wasted memory space in overdimensioned (and possibly sparse) arrays. Another issue is the overhead of copying existing values to a new, larger memory space, if the original allocation turns out to be insufficient. In order to handle these runtime problems, the programmer therefore has the extra task of addressing them in the code.

  2. Optically transparent high temperature shape memory polymers.

    PubMed

    Xiao, Xinli; Qiu, Xueying; Kong, Deyan; Zhang, Wenbo; Liu, Yanju; Leng, Jinsong

    2016-03-21

    Optically transparent shape memory polymers (SMPs) have potential in advanced optoelectronic and other common shape memory applications, and here optically transparent shape memory polyimide is reported for the first time. The polyimide possesses a glass transition temperature (Tg) of 171 °C, higher than the Tg of other transparent SMPs reported, and the influence of molecular structure on Tg is discussed. The 120 μm thick polyimide film exhibits transmittance higher than 81% in 450-800 nm, and the possible mechanism of its high transparency is analyzed, which will benefit further research on other transparent high temperature SMPs. The transparent polyimide showed excellent thermomechanical properties and shape memory performances, and retained high optical transparency after many shape memory cycles. PMID:26686222

  3. Non-Volatile Memory Technology Symposium 2000: Proceedings

    NASA Technical Reports Server (NTRS)

    Aranki, Nazeeh (Editor)

    2000-01-01

    This publication contains the proceedings for the Non-Volatile Memory Technology Symposium 2000 that was held on November 15-16, 2000 in Arlington, Virginia. The proceedings contains a wide range of papers that cover the presentations of myriad advances in the nonvolatile memory technology during the recent past including memory cell design, simulations, radiation environment, and emerging memory technologies. The papers presented in the proceedings address the design challenges and applications and deals with newer, emerging memory technologies as well as related issues of radiation environment and die packaging.

  4. EDITORIAL: Non-volatile memory based on nanostructures Non-volatile memory based on nanostructures

    NASA Astrophysics Data System (ADS)

    Kalinin, Sergei; Yang, J. Joshua; Demming, Anna

    2011-06-01

    Non-volatile memory refers to the crucial ability of computers to store information once the power source has been removed. Traditionally this has been achieved through flash, magnetic computer storage and optical discs, and in the case of very early computers paper tape and punched cards. While computers have advanced considerably from paper and punched card memory devices, there are still limits to current non-volatile memory devices that restrict them to use as secondary storage from which data must be loaded and carefully saved when power is shut off. Denser, faster, low-energy non-volatile memory is highly desired and nanostructures are the critical enabler. This special issue on non-volatile memory based on nanostructures describes some of the new physics and technology that may revolutionise future computers. Phase change random access memory, which exploits the reversible phase change between crystalline and amorphous states, also holds potential for future memory devices. The chalcogenide Ge2Sb2Te5 (GST) is a promising material in this field because it combines a high activation energy for crystallization and a relatively low crystallization temperature, as well as a low melting temperature and low conductivity, which accommodates localized heating. Doping is often used to lower the current required to activate the phase change or 'reset' GST but this often aggravates other problems. Now researchers in Korea report in-depth studies of SiO2-doped GST and identify ways of optimising the material's properties for phase-change random access memory [1]. Resistance switching is an area that has attracted a particularly high level of interest for non-volatile memory technology, and a great deal of research has focused on the potential of TiO2 as a model system in this respect. Researchers at HP labs in the US have made notable progress in this field, and among the work reported in this special issue they describe means to control the switch resistance and show

  5. Design of a Multi-Level/Analog Ferroelectric Memory Device

    NASA Technical Reports Server (NTRS)

    MacLeod, Todd C.; Phillips, Thomas A.; Ho, Fat D.

    2006-01-01

    Increasing the memory density and utilizing the dove1 characteristics of ferroelectric devices is important in making ferroelectric memory devices more desirable to the consumer. This paper describes a design that allows multiple levels to be stored in a ferroelectric based memory cell. It can be used to store multiple bits or analog values in a high speed nonvolatile memory. The design utilizes the hysteresis characteristic of ferroelectric transistors to store an analog value in the memory cell. The design also compensates for the decay of the polarization of the ferroelectric material over time. This is done by utilizing a pair of ferroelectric transistors to store the data. One transistor is used as a reference to determine the amount of decay that has occurred since the pair was programmed. The second transistor stores the analog value as a polarization value between zero and saturated. The design allows digital data to be stored as multiple bits in each memory cell. The number of bits per cell that can be stored will vary with the decay rate of the ferroelectric transistors and the repeatability of polarization between transistors. It is predicted that each memory cell may be able to store 8 bits or more. The design is based on data taken from actual ferroelectric transistors. Although the circuit has not been fabricated, a prototype circuit is now under construction. The design of this circuit is different than multi-level FLASH or silicon transistor circuits. The differences between these types of circuits are described in this paper. This memory design will be useful because it allows higher memory density, compensates for the environmental and ferroelectric aging processes, allows analog values to be directly stored in memory, compensates for the thermal and radiation environments associated with space operations, and relies only on existing technologies.

  6. Measuring and Estimating Normalized Contrast in Infrared Flash Thermography

    NASA Technical Reports Server (NTRS)

    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.

  7. Clinical Inquiry: Which nonhormonal treatments are effective for hot flashes?

    PubMed

    Kelsberg, Gary; Maragh, Leticia; Safranek, Sarah

    2016-05-01

    Selective serotonin reuptake inhibitors (SSRIs [fluoxetine, sertraline, paroxetine]) and the selective norepinephrine reuptake inhibitor (SNRI) venlafaxine, as well as clonidine and gabapentin, reduce hot flashes by about 25% (approximately one per day) in women with and without a history of breast cancer. No studies compare medications against each other to determine a single best option. PMID:27275942

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

    PubMed

    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.

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

    PubMed

    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.

  10. Spectral unfolds of PITHON Flash X-ray source.

    SciTech Connect

    Zarick, Thomas Andrew; Sheridan, Timothy J.; Hartman, E. Frederick; Riordan, John C.

    2007-11-01

    Using a differential absorption spectrometer we obtained experimental spectral information for the PITHON Flash X-ray Machine located in San Leandro, California at L-3 Communications. Spectral information we obtained pertained to the 200 keV to 800 keV endpoint operation of PITHON. We also obtained data on the temporal behavior of high energy and low energy spectral content.

  11. Measuring x-ray spectra of flash radiographic sources

    SciTech Connect

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

    2015-11-02

    The x-ray spectra of flash radiographic sources is difficult to measure. The sources measured were Radiographic Integrated Test Stand-6 (370 rad at 1 m; 50 ns pulse) and Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) (550 rad at 1 m; 50 ns pulse). Features of the Compton spectrometer are described, and spectra are shown. Additional slides present data on instrumental calibration.

  12. DETAIL OF TYPICAL ALUMINUM FLASHING AT THE BOTTOM OF AN ...

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

    DETAIL OF TYPICAL ALUMINUM FLASHING AT THE BOTTOM OF AN EXTERIOR WALL AT UNIT B. VIEW FACING NORTH - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Duplex Type 1, Acacia Road, Birch Circle, and Cedar Drive, Pearl City, Honolulu County, HI

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

    PubMed

    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.

  14. Thermal diffusivity of nonflat plates using the flash method

    SciTech Connect

    Salazar, Agustin; Fuente, Raquel; Apinaniz, Estibaliz; Mendioroz, Arantza

    2011-01-15

    The flash method is the standard technique to measure the thermal diffusivity of solid samples. It consists of heating the front surface of an opaque sample by a brief light pulse and detecting the temperature evolution at its rear surface. The thermal diffusivity is obtained by measuring the time corresponding to the half maximum of the temperature rise, which only depends on the sample thickness and thermal diffusivity through a simple formula. Up to now, the flash method has been restricted to flat samples. In this work, we extend the flash method to measure the thermal diffusivity of nonflat samples. In particular, we focus on plates with cylindrical and spherical shapes. The theoretical model indicates that the same expression for flat samples can also be applied to cylindrical and spherical plates, except for extremely curved samples. Accordingly, a curvature limit for the application of the expression for flat samples is established. Flash measurements on lead foils of cylindrical shape confirm the validity of the model.

  15. An evaluation of three biological indicator systems in flash sterilization.

    PubMed

    Kotilainen, H R; Gantz, N M

    1987-08-01

    An evaluation of two flash-sterilization-specific biological indicators (BI) and a traditional spore strip indicator was performed to assess sensitivity and reliability as reflected in survive/kill ratios. The BIs tested included: 3M's Attest #1261, Amsco's Proof Flash, and Castle Tec Test. Survival after "come-up" time alone, (0 exposure) and one-, two-, and three-minute exposures at 273 degrees F in a gravity displacement sterilizer was measured by media color change or turbidity after incubation at 55 degrees C. Each cycle was replicated three times on two separate days with six of each BI per run. Positive BIs were subcultured as necessary. Proof Flash presented technical difficulties due to incomplete or impossible crushing of media vials, unexpected media color changes, and evaporation of media. Tec Test was not sufficiently resistant as survivors were not detected at any exposure time. The Attest had 100% survival at zero and one-minute exposures and 94% survival after the two-minute exposure. No survivors were detected after the three-minute exposure. Although each institution should evaluate BIs for their own use independently, the data indicate that Attest #1261 monitored the three-minute flash cycles more satisfactorily than the other BIs tested. PMID:3115909

  16. Characterization of flash floods induced by tropical cyclones in Mexico

    NASA Astrophysics Data System (ADS)

    Real-Rangel, R. A.; Pedrozo-Acuña, A.

    2015-12-01

    This study investigates the role of tropical cyclones (hurricanes, tropical storms and depressions) in the generation of flash floods in Mexico. For this, a severity assessment during several cyclonic events for selected catchments was estimated through the evaluation of a flash flood index recently proposed by Kim and Kim (2014). This classification is revised, considering the forcing and areal extent of torrential rainfall generated by the incidence of tropical cyclones on the studied catchments, enabling the further study of the flood regime in catchments located in tropical regions. The analysis incorporates characteristics of the flood hydrographs such as the hydrograph shape (rising curve gradient, magnitude of the peak discharge and flood response time) in order to identify flash-flood prone areas. Results show the Qp-A scaling relationship in catchments that were impacted by tropical cyclones, enabling their comparison against floods generated by other meteorological events (e.g. convective and orographic storms). Results will inform on how peak flows relationships are modified by cyclonic events and highlighting the contribution of cyclonic precipitation to flash-flooding susceptibility.

  17. Method and apparatus for flash evaporation of liquids

    DOEpatents

    Bharathan, D.

    1984-01-01

    A vertical tube flash evaporator for introducing a super-heated liquid into a flash evaporation chamber includes a vertical inlet tube with a flared diffuser portion at its upper outlet end. A plurality of annular screens are positioned in axially spaced-apart relation to each other around the periphery of the vertical tube and below the diffuser portion thereof. The screens are preferably curved upward in a cup-shaped configuration. These flash evaporators are shown in an ocean thermal energy conversion unit designed for generating electric power from differential temperature gradients in ocean water. The method of use of the flash evaporators of this invention includes flowing liquid upwardly through the vertical tube into the diffuser where initial expansion and boiling occurs quite violently and explosively. Unvaporized liquid sheets and drops collide with each other to enhance surface renewal and evaporation properties, and liquid flowing over the outlet end of the diffuser falls onto the curved screens for further surface renewal and evaporation.

  18. Method and apparatus for flash evaporation of liquids

    DOEpatents

    Bharathan, Desikan

    1984-01-01

    A vertical tube flash evaporator for introducing a superheated liquid into a flash evaporation chamber includes a vertical inlet tube with a flared diffuser portion at its upper outlet end. A plurality of annular screens are positioned in axially spaced-apart relation to each other around the periphery of the vertical tube and below the diffuser portion thereof. The screens are preferably curved upward in a cup-shaped configuration. These flash evaporators are shown in an ocean thermal energy conversion unit designed for generating electric power from differential temperature gradients in ocean water. The method of use of the flash evaporators of this invention includes flowing liquid upwardly through the vertical tube into the diffuser where initial expansion and boiling occurs quite violently and explosively. Unvaporized liquid sheets and drops collide with each other to enhance surface renewal and evaporation properties, and liquid flowing over the outlet end of the diffuser falls onto the curved screens for further surface renewal and evaporation.

  19. Ultrafast-Contactless Flash Sintering using Plasma Electrodes.

    PubMed

    Saunders, Theo; Grasso, Salvatore; 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 °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 mm(3) was sintered to full density with limited grain growth. PMID:27273255

  20. Ultrafast-Contactless Flash Sintering using Plasma Electrodes

    PubMed Central

    Saunders, Theo; Grasso, Salvatore; 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 °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. PMID:27273255

  1. Recognizing Words and Reading Sentences with Microsecond Flash Displays

    PubMed Central

    Greene, Ernest

    2016-01-01

    Strings of dots can be used to construct easily identifiable letters, and these in turn can be used to write words and sentences. Prior work found that respondents could identify individual letters when all the dots were simultaneously flashed for an ultra-brief duration. Four of the experiments reported here constructed five-letter words with these dot-letters and a fifth experiment used them to write complete sentences. Respondents were able to recognize individual words that were displayed with a single, simultaneous ultra-brief flash of all the letters. Further, sentences could be efficiently read with a sequence of simultaneous flashes at a frequency that produced perceptual fusion. One experiment determined the frequency range that would produce flicker-fusion. Two experiments established the relation of intensity to probability of recognition with single flashes and with fused-flicker frequencies. Another established the intensities at which flicker-fused and steady displays were judged to be equal in brightness. The final experiment used those flicker-fused and steady intensities to display sentences. The two display conditions were read with equal efficiency, even though the flicker-fused displays provided light stimulation only 0.003% of the time. PMID:26800027

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Evaluation of nickel flash smelting through piloting and simulation

    SciTech Connect

    Varnas, S.R.; Koh, P.T.L.; Kemori, N.

    1998-12-01

    An extensive study of the nickel flash smelting process has been undertaken. It is aimed at the optimization of the burner design to improve the smelting performance and to increase the throughput of the rebuilt furnace. A design-based mathematical model was developed to simulate the operation of the four burners and the reaction shaft of the flash furnace at Western Mining Corporation Ltd.`s Kalgoorlie Nickel Smelter. A modified single burner version of the model was validated against data obtained from the pilot plant at the Pyrometallurgical Research Centre (PRC) of the Sumitomo Metal Mining Co.`s Toyo Smelter. The approach taken involved experimental measurements of key process parameters in the pilot plant and detailed numerical simulation of the fluid flow, heat transfer, and combustion in the entire burner-shaft complex. Several burner designs have been tested experimentally at the pilot plant and theoretically through computer simulation. The main outcome of the study was the development of an experimentally validated mathematical model of the flash smelter providing a new powerful design tool. The insight gained about the process from the application of this tool led to the design of a more efficient nickel flash smelting process.

  4. [Sleep-wake cycle and memory consolidation].

    PubMed

    Baratti, Carlos M; Boccia, Mariano M; Blake, Mariano G; Acosta, Gabriela B

    2007-01-01

    Although several hypothesis and theories have been advanced as explanations for the functions of sleep, a unified theory of sleep function remains elusive. Sleep has been implicated in the plastic cerebral changes that underlie learning and memory, in particular those related to memory consolidation of recently acquired new information. Despite steady accumulations of positive findings over the last ten years, the precise role of sleep in memory and brain plasticity is unproven at all. This situation might be solved by more integrated approaches that combine behavioral and neurophysiological measurements in well described in vivo models of neuronal activity and brain plasticity.

  5. [Sleep-wake cycle and memory consolidation].

    PubMed

    Baratti, Carlos M; Boccia, Mariano M; Blake, Mariano G; Acosta, Gabriela B

    2007-01-01

    Although several hypothesis and theories have been advanced as explanations for the functions of sleep, a unified theory of sleep function remains elusive. Sleep has been implicated in the plastic cerebral changes that underlie learning and memory, in particular those related to memory consolidation of recently acquired new information. Despite steady accumulations of positive findings over the last ten years, the precise role of sleep in memory and brain plasticity is unproven at all. This situation might be solved by more integrated approaches that combine behavioral and neurophysiological measurements in well described in vivo models of neuronal activity and brain plasticity. PMID:18219403

  6. 77 FR 74222 - Certain Dynamic Random Access Memory and NAND Flash Memory Devices and Products Containing Same...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-13

    ... Ventures II LLC, all of Bellevue, Washington. 76 FR 55417-18. The complaint alleges violations of section... to review initial determinations (``IDs'') (Order Nos. 70, 71, and 72) of the presiding... to review the ALJ's IDs (Order Nos. 18 and 58) terminating the investigation as to Pantech and...

  7. The determination of the core mass at the helium flash in globular cluster stars

    NASA Technical Reports Server (NTRS)

    Sweigart, Allen V.

    1994-01-01

    Evolutionary sequences for the red giant branch (RGB) phase of a representative globular cluster star have been computed in order to investigate the reliability of the current canonical values of the core mass M(sub c) at the helium flash. These computations were motivated by recent suggestions that the canonical values of M(sub c) may be systematically too small due to the numerical algorithms for shifting the hydrogen shell and advancing the chemical composition during the RGB phase. Our results show that these algorithms do not, in fact, introduce a significant error in the values of M(sub c). Moreover, we demonstrate that a procedure for advancing the chemical composition which is implicit only in the hydrogen abundance will systematically underestimate the amount of hydrogen fuel consumption between RGB models and therefore should not be used in RGB computations. Overall we estimate the uncertainty in the core masses of Sweigart & Gross (1978) due to numerical effects to be approximately equals 0.003 solar mass. From a consideration of the available canonical models we conclude that a change in the canonical values of M(sub c) by a few 10(exp -2) solar mass would require either a substantial change in the canonical input physics or some noncanonical effect such as rotation. Finally our models show that the use of short time steps can significantly increase the extent of the inner tail of the hydrogen shell. This effect may enhance the likelihood of hydrogen mixing following a helium shell flash in an asymptotic giant branch star.

  8. Enhanced ethylene production via flash methanolysis of coal

    SciTech Connect

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

    1983-12-01

    According to a recent report, an estimated 31 billion pounds of ethylene was produced in the US alone. Ethylene is an important raw material in the vast plastic and polymer markets. An upward trend in the demand for ethylene has been predicted for the future years. Currently, ethylene is produced mainly through thermal and catalytic hydrocracking of ethane and other hydrocarbons. Although a large amount of work has been performed on the production of gaseous and liquid fuels from coal, much less attention has been focused on the production of ehtylene using coal as the raw material. In an on-going pyrolysis research project at the Brookhaven National Laboratory, methods for increasing the yield of ethylene through flash methanolysis of coal are being investigated. Flash methanolysis is defined as pyrolysis of coal under pressure in an atmosphere of methane. This study attempts to identify the influence of important process variables such as reaction temperature, gas pressure, solids residence time, gas/solids ratio etc on the production of ethylene and other pyrolysis products. We have shown that there are definite advantages in the use of methane as an atmosphere in the flash pyrolysis of coal. At temperatures higher than 800/sup 0/C, 2 to 5 times greater yields of ethylene are obtainable in methane atmosphere compared to flash pyrolysis in an inert helium atmosphere. An enhancement in the yield of ethylene and BTX are important raw materials in the vast polymer and plastic markets, flash methanolysis of coal has potential process applications. 5 references, 4 figures, 6 tables.

  9. Temporal integration of light flashes by the human circadian system

    PubMed Central

    Najjar, Raymond P.; Zeitzer, Jamie M.

    2016-01-01

    BACKGROUND. Beyond image formation, the light that is detected by retinal photoreceptors influences subcortical functions, including circadian timing, sleep, and arousal. The physiology of nonimage-forming (NIF) photoresponses in humans is not well understood; therefore, the development of therapeutic interventions based on this physiology, such as bright light therapy to treat chronobiological disorders, remains challenging. METHODS. Thirty-nine participants were exposed to 60 minutes of either continuous light (n = 8) or sequences of 2-millisecond light flashes (n = 31) with different interstimulus intervals (ISIs; ranging from 2.5 to 240 seconds). Melatonin phase shift and suppression, along with changes in alertness and sleepiness, were assessed. RESULTS. We determined that the human circadian system integrates flash sequences in a nonlinear fashion with a linear rise to a peak response (ISI = 7.6 ± 0.53 seconds) and a power function decrease following the peak of responsivity. At peak ISI, flashes were at least 2-fold more effective in phase delaying the circadian system as compared with exposure to equiluminous continuous light 3,800 times the duration. Flashes did not change melatonin concentrations or alertness in an ISI-dependent manner. CONCLUSION. We have demonstrated that intermittent light is more effective than continuous light at eliciting circadian changes. These findings cast light on the phenomenology of photic integration and suggest a dichotomous retinohypothalamic network leading to circadian phase shifting and other NIF photoresponses. Further clinical trials are required to judge the practicality of light flash protocols. TRIAL REGISTRATION. Clinicaltrials.gov NCT01119365. FUNDING. National Heart, Lung, and Blood Institute (1R01HL108441-01A1) and Department of Veterans Affairs Sierra Pacific Mental Illness Research, Education, and Clinical Center. PMID:26854928

  10. A Comparison of Radiometric Calibration Techniques for Lunar Impact Flashes

    NASA Technical Reports Server (NTRS)

    Suggs, R.

    2016-01-01

    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., 2000 [1], Bouley, et al., 2012.[2], Suggs, et al. 2014 [3], Rembold and Ryan 2015 [4], Ortiz, et al. 2015 [5]). 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. An estimate of the color of the impact flash is also needed to correct it to the chosen passband. Magnitudes corrected to standard filters are then used to determine the luminous energy in the filter passband according to the stellar atmosphere calibrations of Bessell et al., 1998 [6]. Figure 1 illustrates the problem. The camera pass band is the wide black curve and the blue, green, red, and magenta curves show the band passes of the Johnson-Cousins B, V, R, and I filters for which we have calibration star magnitudes. The blackbody curve of an impact flash of temperature 2800K (Nemtchinov, et al., 1998 [7]) is the dashed line. This paper compares the various photometric calibration techniques and how they address the color corrections necessary for the 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 flux of meteoroids in the 10s of grams to kilogram size range.

  11. Upper limits of flash flood stream power in Europe

    NASA Astrophysics Data System (ADS)

    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

  12. Flash flood warning based on fully dynamic hydrology modelling

    NASA Astrophysics Data System (ADS)

    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

  13. Analysis of the energy distribution of interface traps related to tunnel oxide degradation using charge pumping techniques for 3D NAND flash applications

    SciTech Connect

    An, Ho-Myoung; Kim, Hee-Dong; Kim, Tae Geun

    2013-12-15

    Graphical abstract: The degradation tendency extracted by CP technique was almost the same in both the bulk-type and TFT-type cells. - Highlights: • D{sub it} is directly investigated from bulk-type and TFT-type CTF memory. • Charge pumping technique was employed to analyze the D{sub it} information. • To apply the CP technique to monitor the reliability of the 3D NAND flash. - Abstract: The energy distribution and density of interface traps (D{sub it}) are directly investigated from bulk-type and thin-film transistor (TFT)-type charge trap flash memory cells with tunnel oxide degradation, under program/erase (P/E) cycling using a charge pumping (CP) technique, in view of application in a 3-demension stackable NAND flash memory cell. After P/E cycling in bulk-type devices, the interface trap density gradually increased from 1.55 × 10{sup 12} cm{sup −2} eV{sup −1} to 3.66 × 10{sup 13} cm{sup −2} eV{sup −1} due to tunnel oxide damage, which was consistent with the subthreshold swing and transconductance degradation after P/E cycling. Its distribution moved toward shallow energy levels with increasing cycling numbers, which coincided with the decay rate degradation with short-term retention time. The tendency extracted with the CP technique for D{sub it} of the TFT-type cells was similar to those of bulk-type cells.

  14. Semantic representations in the temporal pole predict false memories.

    PubMed

    Chadwick, Martin J; Anjum, Raeesa S; Kumaran, Dharshan; Schacter, Daniel L; Spiers, Hugo J; Hassabis, Demis

    2016-09-01

    Recent advances in neuroscience have given us unprecedented insight into the neural mechanisms of false memory, showing that artificial memories can be inserted into the memory cells of the hippocampus in a way that is indistinguishable from true memories. However, this alone is not enough to explain how false memories can arise naturally in the course of our daily lives. Cognitive psychology has demonstrated that many instances of false memory, both in the laboratory and the real world, can be attributed to semantic interference. Whereas previous studies have found that a diverse set of regions show some involvement in semantic false memory, none have revealed the nature of the semantic representations underpinning the phenomenon. Here we use fMRI with representational similarity analysis to search for a neural code consistent with semantic false memory. We find clear evidence that false memories emerge from a similarity-based neural code in the temporal pole, a region that has been called the "semantic hub" of the brain. We further show that each individual has a partially unique semantic code within the temporal pole, and this unique code can predict idiosyncratic patterns of memory errors. Finally, we show that the same neural code can also predict variation in true-memory performance, consistent with an adaptive perspective on false memory. Taken together, our findings reveal the underlying structure of neural representations of semantic knowledge, and how this semantic structure can both enhance and distort our memories.

  15. Semantic representations in the temporal pole predict false memories.

    PubMed

    Chadwick, Martin J; Anjum, Raeesa S; Kumaran, Dharshan; Schacter, Daniel L; Spiers, Hugo J; Hassabis, Demis

    2016-09-01

    Recent advances in neuroscience have given us unprecedented insight into the neural mechanisms of false memory, showing that artificial memories can be inserted into the memory cells of the hippocampus in a way that is indistinguishable from true memories. However, this alone is not enough to explain how false memories can arise naturally in the course of our daily lives. Cognitive psychology has demonstrated that many instances of false memory, both in the laboratory and the real world, can be attributed to semantic interference. Whereas previous studies have found that a diverse set of regions show some involvement in semantic false memory, none have revealed the nature of the semantic representations underpinning the phenomenon. Here we use fMRI with representational similarity analysis to search for a neural code consistent with semantic false memory. We find clear evidence that false memories emerge from a similarity-based neural code in the temporal pole, a region that has been called the "semantic hub" of the brain. We further show that each individual has a partially unique semantic code within the temporal pole, and this unique code can predict idiosyncratic patterns of memory errors. Finally, we show that the same neural code can also predict variation in true-memory performance, consistent with an adaptive perspective on false memory. Taken together, our findings reveal the underlying structure of neural representations of semantic knowledge, and how this semantic structure can both enhance and distort our memories. PMID:27551087

  16. Semantic representations in the temporal pole predict false memories

    PubMed Central

    Chadwick, Martin J.; Anjum, Raeesa S.; Kumaran, Dharshan; Schacter, Daniel L.; Spiers, Hugo J.; Hassabis, Demis

    2016-01-01

    Recent advances in neuroscience have given us unprecedented insight into the neural mechanisms of false memory, showing that artificial memories can be inserted into the memory cells of the hippocampus in a way that is indistinguishable from true memories. However, this alone is not enough to explain how false memories can arise naturally in the course of our daily lives. Cognitive psychology has demonstrated that many instances of false memory, both in the laboratory and the real world, can be attributed to semantic interference. Whereas previous studies have found that a diverse set of regions show some involvement in semantic false memory, none have revealed the nature of the semantic representations underpinning the phenomenon. Here we use fMRI with representational similarity analysis to search for a neural code consistent with semantic false memory. We find clear evidence that false memories emerge from a similarity-based neural code in the temporal pole, a region that has been called the “semantic hub” of the brain. We further show that each individual has a partially unique semantic code within the temporal pole, and this unique code can predict idiosyncratic patterns of memory errors. Finally, we show that the same neural code can also predict variation in true-memory performance, consistent with an adaptive perspective on false memory. Taken together, our findings reveal the underlying structure of neural representations of semantic knowledge, and how this semantic structure can both enhance and distort our memories. PMID:27551087

  17. An unusual characteristic “flower-like” pattern: flash suppressor burns

    PubMed Central

    Gurcan, Altun

    2012-01-01

    The case on contact shots from firearms with a flash suppressor is rare. When a rifle fitted with a flash suppressor is fired, the emerging soot-laden gas in the barrel escapes from the slits of the flash suppressor. If the shot is contact or near contact, the flash suppressor will produce a characteristic “flower-like” pattern of seared, blackened zones around the entrance. This paper presents the injury pattern of the flash suppressor in a 29-year-old man who committed suicide with a G3 automatic infantry rifle. PMID:23935280

  18. Memory Retrieval and Interference: Working Memory Issues

    ERIC Educational Resources Information Center

    Radvansky, Gabriel A.; Copeland, David E.

    2006-01-01

    Working memory capacity has been suggested as a factor that is involved in long-term memory retrieval, particularly when that retrieval involves a need to overcome some sort of interference (Bunting, Conway, & Heitz, 2004; Cantor & Engle, 1993). Previous work has suggested that working memory is related to the acquisition of information during…

  19. Episodic memory, semantic memory, and amnesia.

    PubMed

    Squire, L R; Zola, S M

    1998-01-01

    Episodic memory and semantic memory are two types of declarative memory. There have been two principal views about how this distinction might be reflected in the organization of memory functions in the brain. One view, that episodic memory and semantic memory are both dependent on the integrity of medial temporal lobe and midline diencephalic structures, predicts that amnesic patients with medial temporal lobe/diencephalic damage should be proportionately impaired in both episodic and semantic memory. An alternative view is that the capacity for semantic memory is spared, or partially spared, in amnesia relative to episodic memory ability. This article reviews two kinds of relevant data: 1) case studies where amnesia has occurred early in childhood, before much of an individual's semantic knowledge has been acquired, and 2) experimental studies with amnesic patients of fact and event learning, remembering and knowing, and remote memory. The data provide no compelling support for the view that episodic and semantic memory are affected differently in medial temporal lobe/diencephalic amnesia. However, episodic and semantic memory may be dissociable in those amnesic patients who additionally have severe frontal lobe damage.

  20. High performance wire grid polarizers using jet and flashTM imprint lithography

    NASA Astrophysics Data System (ADS)

    Ahn, Sean; Yang, Jack; Miller, Mike; Ganapathisubramanian, Maha; Menezes, Marlon; Choi, Jin; Xu, Frank; Resnick, Douglas J.; Sreenivasan, S. V.

    2013-03-01

    The ability to pattern materials at the nanoscale can enable a variety of applications ranging from high density data storage, displays, photonic devices and CMOS integrated circuits to emerging applications in the biomedical and energy sectors. These applications require varying levels of pattern control, short and long range order, and have varying cost tolerances. Extremely large area roll to roll (R2R) manufacturing on flexible substrates is ubiquitous for applications such as paper and plastic processing. It combines the benefits of high speed and inexpensive substrates to deliver a commodity product at low cost. The challenge is to extend this approach to the realm of nanopatterning and realize similar benefits. The cost of manufacturing is typically driven by speed (or throughput), tool complexity, cost of consumables (materials used, mold or master cost, etc.), substrate cost, and the downstream processing required (annealing, deposition, etching, etc.). In order to achieve low cost nanopatterning, it is imperative to move towards high speed imprinting, less complex tools, near zero waste of consumables and low cost substrates. The Jet and Flash Imprint Lithography (J-FILTM) process uses 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 memory markets including Flash memory and patterned media for hard disk drives. In this paper we have developed a roll based J-FIL process and applied it to technology demonstrator tool, the LithoFlex 100, to fabricate large area flexible bilayer wire grid polarizers (WGP) and high performance WGPs on rigid glass substrates. Extinction ratios of better than 10000 were obtained for the glass-based WGPs. Two simulation packages were also employed to understand the effects of pitch, aluminum thickness and pattern defectivity on the optical performance of the WGP devices. It was determined that the