AFOSR/AFRPL Rocket Propulsion Research Meeting Held at Lancaster, California on 12-15 March 1984. Abstracts and Agenda

DTIC Science & Technology

1984-02-01

MA 0900 28 HIGH TEMPERATURE MOLECULAR ABSORBERS FOR CW LASER PROPULSION. David 0 Rosen, David 0 Ham , and Lauren M Cowles, Physical Sciences Inc...been put into the dcvulopmunt of* computer codes uo wodel various aspects of rocket propellant behavior such a cobustion :..echawica and DSDT. However...Differential Scanning Calorimeter, and (2) thermal diffusivit- using U laser flash apparatus. All measurements are madc under digital computer contro

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

Fernandes, Ana; Pereira, Rita C.; Sousa, Jorge

The Instituto de Plasmas e Fusao Nuclear (IPFN) has developed dedicated re-configurable modules based on field programmable gate array (FPGA) devices for several nuclear fusion machines worldwide. Moreover, new Advanced Telecommunication Computing Architecture (ATCA) based modules developed by IPFN are already included in the ITER catalogue. One of the requirements for re-configurable modules operating in future nuclear environments including ITER is the remote update capability. Accordingly, this work presents an alternative method for FPGA remote programing to be implemented in new ATCA based re-configurable modules. FPGAs are volatile devices and their programming code is usually stored in dedicated flash memoriesmore » for properly configuration during module power-on. The presented method is capable to store new FPGA codes in Serial Peripheral Interface (SPI) flash memories using the PCIexpress (PCIe) network established on the ATCA back-plane, linking data acquisition endpoints and the data switch blades. The method is based on the Xilinx Quick Boot application note, adapted to PCIe protocol and ATCA based modules. (authors)« less

Multi-dimensional Core-Collapse Supernova Simulations with Neutrino Transport

NASA Astrophysics Data System (ADS)

Pan, Kuo-Chuan; Liebendörfer, Matthias; Hempel, Matthias; Thielemann, Friedrich-Karl

We present multi-dimensional core-collapse supernova simulations using the Isotropic Diffusion Source Approximation (IDSA) for the neutrino transport and a modified potential for general relativity in two different supernova codes: FLASH and ELEPHANT. Due to the complexity of the core-collapse supernova explosion mechanism, simulations require not only high-performance computers and the exploitation of GPUs, but also sophisticated approximations to capture the essential microphysics. We demonstrate that the IDSA is an elegant and efficient neutrino radiation transfer scheme, which is portable to multiple hydrodynamics codes and fast enough to investigate long-term evolutions in two and three dimensions. Simulations with a 40 solar mass progenitor are presented in both FLASH (1D and 2D) and ELEPHANT (3D) as an extreme test condition. It is found that the black hole formation time is delayed in multiple dimensions and we argue that the strong standing accretion shock instability before black hole formation will lead to strong gravitational waves.

50 CFR 300.5 - Facilitation of enforcement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... transmitted by flashing light directed at the vessel signaled. USCG units will normally use the flashing light..., flashing light, flags, whistle, horn or other means constitutes prima facie evidence of the offense of... International Code of Signals, may be sent by flashing light by an enforcement unit when conditions do not allow...

50 CFR 300.5 - Facilitation of enforcement.

Code of Federal Regulations, 2011 CFR

2011-10-01

... transmitted by flashing light directed at the vessel signaled. USCG units will normally use the flashing light..., flashing light, flags, whistle, horn or other means constitutes prima facie evidence of the offense of... International Code of Signals, may be sent by flashing light by an enforcement unit when conditions do not allow...

Modeling experimental plasma diagnostics in the FLASH code: Thomson scattering

NASA Astrophysics Data System (ADS)

Weide, Klaus; Flocke, Norbert; Feister, Scott; Tzeferacos, Petros; Lamb, Donald

2017-10-01

Spectral analysis of the Thomson scattering of laser light sent into a plasma provides an experimental method to quantify plasma properties in laser-driven plasma experiments. We have implemented such a synthetic Thomson scattering diagnostic unit in the FLASH code, to emulate the probe-laser propagation, scattering and spectral detection. User-defined laser rays propagate into the FLASH simulation region and experience scattering (change in direction and frequency) based on plasma parameters. After scattering, the rays propagate out of the interaction region and are spectrally characterized. The diagnostic unit can be used either during a physics simulation or in post-processing of simulation results. FLASH is publicly available at flash.uchicago.edu. U.S. DOE NNSA, U.S. DOE NNSA ASC, U.S. DOE Office of Science and NSF.

Spatial decoupling of targets and flashing stimuli for visual brain-computer interfaces

NASA Astrophysics Data System (ADS)

Waytowich, Nicholas R.; Krusienski, Dean J.

2015-06-01

Objective. Recently, paradigms using code-modulated visual evoked potentials (c-VEPs) have proven to achieve among the highest information transfer rates for noninvasive brain-computer interfaces (BCIs). One issue with current c-VEP paradigms, and visual-evoked paradigms in general, is that they require direct foveal fixation of the flashing stimuli. These interfaces are often visually unpleasant and can be irritating and fatiguing to the user, thus adversely impacting practical performance. In this study, a novel c-VEP BCI paradigm is presented that attempts to perform spatial decoupling of the targets and flashing stimuli using two distinct concepts: spatial separation and boundary positioning. Approach. For the paradigm, the flashing stimuli form a ring that encompasses the intended non-flashing targets, which are spatially separated from the stimuli. The user fixates on the desired target, which is classified using the changes to the EEG induced by the flashing stimuli located in the non-foveal visual field. Additionally, a subset of targets is also positioned at or near the stimulus boundaries, which decouples targets from direct association with a single stimulus. This allows a greater number of target locations for a fixed number of flashing stimuli. Main results. Results from 11 subjects showed practical classification accuracies for the non-foveal condition, with comparable performance to the direct-foveal condition for longer observation lengths. Online results from 5 subjects confirmed the offline results with an average accuracy across subjects of 95.6% for a 4-target condition. The offline analysis also indicated that targets positioned at or near the boundaries of two stimuli could be classified with the same accuracy as traditional superimposed (non-boundary) targets. Significance. The implications of this research are that c-VEPs can be detected and accurately classified to achieve comparable BCI performance without requiring potentially irritating direct foveation of flashing stimuli. Furthermore, this study shows that it is possible to increase the number of targets beyond the number of stimuli without degrading performance. Given the superior information transfer rate of c-VEP paradigms, these results can lead to the development of more practical and ergonomic BCIs.

A Fault-Tolerant Radiation-Robust Mass Storage Concept for Highly Scaled Flash Memory

NASA Astrophysics Data System (ADS)

Fuchs, Cristian M.; Trinitis, Carsten; Appel, Nicolas; Langer, Martin

2015-09-01

Future spacemissions will require vast amounts of data to be stored and processed aboard spacecraft. While satisfying operational mission requirements, storage systems must guarantee data integrity and recover damaged data throughout the mission. NAND-flash memories have become popular for space-borne high performance mass memory scenarios, though future storage concepts will rely upon highly scaled flash or other memory technologies. With modern flash memory, single bit erasure coding and RAID based concepts are insufficient. Thus, a fully run-time configurable, high performance, dependable storage concept, requiring a minimal set of logic or software. The solution is based on composite erasure coding and can be adjusted for altered mission duration or changing environmental conditions.

MHD Code Optimizations and Jets in Dense Gaseous Halos

NASA Astrophysics Data System (ADS)

Gaibler, Volker; Vigelius, Matthias; Krause, Martin; Camenzind, Max

We have further optimized and extended the 3D-MHD-code NIRVANA. The magnetized part runs in parallel, reaching 19 Gflops per SX-6 node, and has a passively advected particle population. In addition, the code is MPI-parallel now - on top of the shared memory parallelization. On a 512^3 grid, we reach 561 Gflops with 32 nodes on the SX-8. Also, we have successfully used FLASH on the Opteron cluster. Scientific results are preliminary so far. We report one computation of highly resolved cocoon turbulence. While we find some similarities to earlier 2D work by us and others, we note a strange reluctancy of cold material to enter the low density cocoon, which has to be investigated further.

AstroBlend: Visualization package for use with Blender

NASA Astrophysics Data System (ADS)

Naiman, J. P.

2015-12-01

AstroBlend is a visualization package for use in the three dimensional animation and modeling software, Blender. It reads data in via a text file or can use pre-fab isosurface files stored as OBJ or Wavefront files. AstroBlend supports a variety of codes such as FLASH (ascl:1010.082), Enzo (ascl:1010.072), and Athena (ascl:1010.014), and combines artistic 3D models with computational astrophysics datasets to create models and animations.

Phase equilibria computations of multicomponent mixtures at specified internal energy and volume

NASA Astrophysics Data System (ADS)

Myint, Philip C.; Nichols, Albert L., III; Springer, H. Keo

2017-06-01

Hydrodynamic simulation codes for high-energy density science applications often use internal energy and volume as their working variables. As a result, the codes must determine the thermodynamic state that corresponds to the specified energy and volume by finding the global maximum in entropy. This task is referred to as the isoenergetic-isochoric flash. Solving it for multicomponent mixtures is difficult because one must find not only the temperature and pressure consistent with the energy and volume, but also the number of phases present and the composition of the phases. The few studies on isoenergetic-isochoric flash that currently exist all require the evaluation of many derivatives that can be tedious to implement. We present an alternative approach that is based on a derivative-free method: particle swarm optimization. The global entropy maximum is found by running several instances of particle swarm optimization over different sets of randomly selected points in the search space. For verification, we compare the predicted temperature and pressure to results from the related, but simpler problem of isothermal-isobaric flash. All of our examples involve the equation of state we have recently developed for multiphase mixtures of the energetic materials HMX, RDX, and TNT. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Assessing Semantic Knowledge Using Computer-Based and Paper-Based Media

DTIC Science & Technology

1992-01-01

capitalized upon in this research. Computer-Based Assessment A computer-based game or test, FlashCards (Liggett & Federico, 1986), was adopt- ed and adapted...alterative forms did not have to be specifically or previously programmed as such. FlashCards is analogous to using real flash cards. That is, a...reflects their degree of confidence in their answer. Also, for each answer the student’s response latency is recorded and displayed. FlashCards quizzed

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)

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

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

Park, Seon-Yeon; Kim, Youngjae; Urgaonkar, Bhuvan

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 tomore » 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.« less

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

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

Boboila, Simona; Kim, Youngjae; Vazhkudai, Sudharshan S

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 bymore » 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.« less

Analysis on applicable error-correcting code strength of storage class memory and NAND flash in hybrid storage

NASA Astrophysics Data System (ADS)

Matsui, Chihiro; Kinoshita, Reika; Takeuchi, Ken

2018-04-01

A hybrid of storage class memory (SCM) and NAND flash is a promising technology for high performance storage. Error correction is inevitable on SCM and NAND flash because their bit error rate (BER) increases with write/erase (W/E) cycles, data retention, and program/read disturb. In addition, scaling and multi-level cell technologies increase BER. However, error-correcting code (ECC) degrades storage performance because of extra memory reading and encoding/decoding time. Therefore, applicable ECC strength of SCM and NAND flash is evaluated independently by fixing ECC strength of one memory in the hybrid storage. As a result, weak BCH ECC with small correctable bit is recommended for the hybrid storage with large SCM capacity because SCM is accessed frequently. In contrast, strong and long-latency LDPC ECC can be applied to NAND flash in the hybrid storage with large SCM capacity because large-capacity SCM improves the storage performance.

Effects of Combined Stellar Feedback on Star Formation in Stellar Clusters

NASA Astrophysics Data System (ADS)

Wall, Joshua Edward; McMillan, Stephen; Pellegrino, Andrew; Mac Low, Mordecai; Klessen, Ralf; Portegies Zwart, Simon

2018-01-01

We present results of hybrid MHD+N-body simulations of star cluster formation and evolution including self consistent feedback from the stars in the form of radiation, winds, and supernovae from all stars more massive than 7 solar masses. The MHD is modeled with the adaptive mesh refinement code FLASH, while the N-body computations are done with a direct algorithm. Radiation is modeled using ray tracing along long characteristics in directions distributed using the HEALPIX algorithm, and causes ionization and momentum deposition, while winds and supernova conserve momentum and energy during injection. Stellar evolution is followed using power-law fits to evolution models in SeBa. We use a gravity bridge within the AMUSE framework to couple the N-body dynamics of the stars to the gas dynamics in FLASH. Feedback from the massive stars alters the structure of young clusters as gas ejection occurs. We diagnose this behavior by distinguishing between fractal distribution and central clustering using a Q parameter computed from the minimum spanning tree of each model cluster. Global effects of feedback in our simulations will also be discussed.

Targeting an efficient target-to-target interval for P300 speller brain–computer interfaces

PubMed Central

Sellers, Eric W.; Wang, Xingyu

2013-01-01

Longer target-to-target intervals (TTI) produce greater P300 event-related potential amplitude, which can increase brain–computer interface (BCI) classification accuracy and decrease the number of flashes needed for accurate character classification. However, longer TTIs requires more time for each trial, which will decrease the information transfer rate of BCI. In this paper, a P300 BCI using a 7 × 12 matrix explored new flash patterns (16-, 18- and 21-flash pattern) with different TTIs to assess the effects of TTI on P300 BCI performance. The new flash patterns were designed to minimize TTI, decrease repetition blindness, and examine the temporal relationship between each flash of a given stimulus by placing a minimum of one (16-flash pattern), two (18-flash pattern), or three (21-flash pattern) non-target flashes between each target flashes. Online results showed that the 16-flash pattern yielded the lowest classification accuracy among the three patterns. The results also showed that the 18-flash pattern provides a significantly higher information transfer rate (ITR) than the 21-flash pattern; both patterns provide high ITR and high accuracy for all subjects. PMID:22350331

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

Normalized Temperature Contrast Processing in Infrared Flash Thermography

NASA Technical Reports Server (NTRS)

Koshti, Ajay M.

2016-01-01

The paper presents further development in normalized contrast processing used in flash infrared thermography method. Method of computing normalized image or pixel intensity contrast, and normalized temperature contrast are provided. Methods of converting image contrast to temperature contrast and vice versa are provided. Normalized contrast processing in flash thermography is useful in quantitative analysis of flash thermography data including flaw characterization and comparison of experimental results with simulation. Computation of normalized temperature contrast involves use of flash thermography data acquisition set-up with high reflectivity foil and high emissivity tape such that the foil, tape and test object are imaged simultaneously. Methods of assessing other quantitative parameters such as emissivity of object, afterglow heat flux, reflection temperature change and surface temperature during flash thermography are also provided. Temperature imaging and normalized temperature contrast processing provide certain advantages over normalized image contrast processing by reducing effect of reflected energy in images and measurements, therefore providing better quantitative data. Examples of incorporating afterglow heat-flux and reflection temperature evolution in flash thermography simulation are also discussed.

A Study and Taxonomy of Vulnerabilities in Web Based Animation and Interactivity Software

DTIC Science & Technology

2010-12-01

Flash Player is available as a plugin for most common Web browsers (Firefox, Mozilla, Netscape, Opera) and as an ActiveX control for Internet...script or HTML via (1) a swf file that uses the asfunction: protocol or (2) the navigateToURL function when used with the Flash Player ActiveX ...malicious page or open a malicious file. 2. Coding an Exploit The specific flaw exists in the Flash Player ActiveX Control’s handling of the

[The P300-based brain-computer interface: presentation of the complex "flash + movement" stimuli].

PubMed

Ganin, I P; Kaplan, A Ia

2014-01-01

The P300 based brain-computer interface requires the detection of P300 wave of brain event-related potentials. Most of its users learn the BCI control in several minutes and after the short classifier training they can type a text on the computer screen or assemble an image of separate fragments in simple BCI-based video games. Nevertheless, insufficient attractiveness for users and conservative stimuli organization in this BCI may restrict its integration into real information processes control. At the same time initial movement of object (motion-onset stimuli) may be an independent factor that induces P300 wave. In current work we checked the hypothesis that complex "flash + movement" stimuli together with drastic and compact stimuli organization on the computer screen may be much more attractive for user while operating in P300 BCI. In 20 subjects research we showed the effectiveness of our interface. Both accuracy and P300 amplitude were higher for flashing stimuli and complex "flash + movement" stimuli compared to motion-onset stimuli. N200 amplitude was maximal for flashing stimuli, while for "flash + movement" stimuli and motion-onset stimuli it was only a half of it. Similar BCI with complex stimuli may be embedded into compact control systems requiring high level of user attention under impact of negative external effects obstructing the BCI control.

FlashPhotol: Using a Flash Photolysis Apparatus Simulator to Introduce Students to the Kinetics of Transient Species and Fast Reactions

ERIC Educational Resources Information Center

Bigger, Stephen W.

2016-01-01

FlashPhotol is an educational software package that introduces students to the kinetics of transient species and fast reactions. This is achieved by means of a computer-simulated flash photolysis apparatus that comprises all major functional elements and that students can use to perform various experiments. The experimental interface presents a…

Computational fluid dynamics assessment: Volume 1, Computer simulations of the METC (Morgantown Energy Technology Center) entrained-flow gasifier: Final report

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

Celik, I.; Chattree, M.

1988-07-01

An assessment of the theoretical and numerical aspects of the computer code, PCGC-2, is made; and the results of the application of this code to the Morgantown Energy Technology Center (METC) advanced gasification facility entrained-flow reactor, ''the gasifier,'' are presented. PCGC-2 is a code suitable for simulating pulverized coal combustion or gasification under axisymmetric (two-dimensional) flow conditions. The governing equations for the gas and particulate phase have been reviewed. The numerical procedure and the related programming difficulties have been elucidated. A single-particle model similar to the one used in PCGC-2 has been developed, programmed, and applied to some simple situationsmore » in order to gain insight to the physics of coal particle heat-up, devolatilization, and char oxidation processes. PCGC-2 was applied to the METC entrained-flow gasifier to study numerically the flash pyrolysis of coal, and gasification of coal with steam or carbon dioxide. The results from the simulations are compared with measurements. The gas and particle residence times, particle temperature, and mass component history were also calculated and the results were analyzed. The results provide useful information for understanding the fundamentals of coal gasification and for assessment of experimental results performed using the reactor considered. 69 refs., 35 figs., 23 tabs.« less

A Method to Measure and Estimate Normalized Contrast in Infrared Flash Thermography

NASA Technical Reports Server (NTRS)

Koshti, Ajay M.

2016-01-01

The paper presents further development in normalized contrast processing used in flash infrared thermography method. Method of computing normalized image or pixel intensity contrast, and normalized temperature contrast are provided. Methods of converting image contrast to temperature contrast and vice versa are provided. Normalized contrast processing in flash thermography is useful in quantitative analysis of flash thermography data including flaw characterization and comparison of experimental results with simulation. Computation of normalized temperature contrast involves use of flash thermography data acquisition set-up with high reflectivity foil and high emissivity tape such that the foil, tape and test object are imaged simultaneously. Methods of assessing other quantitative parameters such as emissivity of object, afterglow heat flux, reflection temperature change and surface temperature during flash thermography are also provided. Temperature imaging and normalized temperature contrast processing provide certain advantages over normalized image contrast processing by reducing effect of reflected energy in images and measurements, therefore providing better quantitative data. Examples of incorporating afterglow heat-flux and reflection temperature evolution in flash thermography simulation are also discussed.

CCD high-speed videography system with new concepts and techniques

NASA Astrophysics Data System (ADS)

Zheng, Zengrong; Zhao, Wenyi; Wu, Zhiqiang

1997-05-01

A novel CCD high speed videography system with brand-new concepts and techniques is developed by Zhejiang University recently. The system can send a series of short flash pulses to the moving object. All of the parameters, such as flash numbers, flash durations, flash intervals, flash intensities and flash colors, can be controlled according to needs by the computer. A series of moving object images frozen by flash pulses, carried information of moving object, are recorded by a CCD video camera, and result images are sent to a computer to be frozen, recognized and processed with special hardware and software. Obtained parameters can be displayed, output as remote controlling signals or written into CD. The highest videography frequency is 30,000 images per second. The shortest image freezing time is several microseconds. The system has been applied to wide fields of energy, chemistry, medicine, biological engineering, aero- dynamics, explosion, multi-phase flow, mechanics, vibration, athletic training, weapon development and national defense engineering. It can also be used in production streamline to carry out the online, real-time monitoring and controlling.

Homemade Buckeye-Pi: A Learning Many-Node Platform for High-Performance Parallel Computing

NASA Astrophysics Data System (ADS)

Amooie, M. A.; Moortgat, J.

2017-12-01

We report on the "Buckeye-Pi" cluster, the supercomputer developed in The Ohio State University School of Earth Sciences from 128 inexpensive Raspberry Pi (RPi) 3 Model B single-board computers. Each RPi is equipped with fast Quad Core 1.2GHz ARMv8 64bit processor, 1GB of RAM, and 32GB microSD card for local storage. Therefore, the cluster has a total RAM of 128GB that is distributed on the individual nodes and a flash capacity of 4TB with 512 processors, while it benefits from low power consumption, easy portability, and low total cost. The cluster uses the Message Passing Interface protocol to manage the communications between each node. These features render our platform the most powerful RPi supercomputer to date and suitable for educational applications in high-performance-computing (HPC) and handling of large datasets. In particular, we use the Buckeye-Pi to implement optimized parallel codes in our in-house simulator for subsurface media flows with the goal of achieving a massively-parallelized scalable code. We present benchmarking results for the computational performance across various number of RPi nodes. We believe our project could inspire scientists and students to consider the proposed unconventional cluster architecture as a mainstream and a feasible learning platform for challenging engineering and scientific problems.

Computer controlled fluorometer device and method of operating same

DOEpatents

Kolber, Z.; Falkowski, P.

1990-07-17

A computer controlled fluorometer device and method of operating same, said device being made to include a pump flash source and a probe flash source and one or more sample chambers in combination with a light condenser lens system and associated filters and reflectors and collimators, as well as signal conditioning and monitoring means and a programmable computer means and a software programmable source of background irradiance that is operable according to the method of the invention to rapidly, efficiently and accurately measure photosynthetic activity by precisely monitoring and recording changes in fluorescence yield produced by a controlled series of predetermined cycles of probe and pump flashes from the respective probe and pump sources that are controlled by the computer means. 13 figs.

Computer controlled fluorometer device and method of operating same

DOEpatents

Kolber, Zbigniew; Falkowski, Paul

1990-01-01

A computer controlled fluorometer device and method of operating same, said device being made to include a pump flash source and a probe flash source and one or more sample chambers in combination with a light condenser lens system and associated filters and reflectors and collimators, as well as signal conditioning and monitoring means and a programmable computer means and a software programmable source of background irradiance that is operable according to the method of the invention to rapidly, efficiently and accurately measure photosynthetic activity by precisely monitoring and recording changes in fluorescence yield produced by a controlled series of predetermined cycles of probe and pump flashes from the respective probe and pump sources that are controlled by the computer means.

An alternative for presenting interactive dynamic data sets in electronic presentations: a scrollable flash movie loop.

PubMed

Yam, Chun-Shan

2007-11-01

The purpose of this article is to describe an alternative for creating scrollable movie loops for electronic presentations including PowerPoint. The alternative provided in this article enables academic radiologists to present scrollable movie loops in PowerPoint. The scrolling capability is created using Flash ActionScript. A Flash template with the required ActionScript code is provided. Users can simply download the template and follow the step-by-step demonstration to create scrollable movie loops. No previous ActionScript programming knowledge is necessary.

Study of the adaptive refinement on an open source 2D shallow-water flow solver using quadtree grid for flash flood simulations.

NASA Astrophysics Data System (ADS)

Kirstetter, G.; Popinet, S.; Fullana, J. M.; Lagrée, P. Y.; Josserand, C.

2015-12-01

The full resolution of shallow-water equations for modeling flash floods may have a high computational cost, so that majority of flood simulation softwares used for flood forecasting uses a simplification of this model : 1D approximations, diffusive or kinematic wave approximations or exotic models using non-physical free parameters. These kind of approximations permit to save a lot of computational time by sacrificing in an unquantified way the precision of simulations. To reduce drastically the cost of such 2D simulations by quantifying the lost of precision, we propose a 2D shallow-water flow solver built with the open source code Basilisk1, which is using adaptive refinement on a quadtree grid. This solver uses a well-balanced central-upwind scheme, which is at second order in time and space, and treats the friction and rain terms implicitly in finite volume approach. We demonstrate the validity of our simulation on the case of the flood of Tewkesbury (UK) occurred in July 2007, as shown on Fig. 1. On this case, a systematic study of the impact of the chosen criterium for adaptive refinement is performed. The criterium which has the best computational time / precision ratio is proposed. Finally, we present the power law giving the computational time in respect to the maximum resolution and we show that this law for our 2D simulation is close to the one of 1D simulation, thanks to the fractal dimension of the topography. [1] http://basilisk.fr/

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

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

Boboila, Simona; Kim, Youngjae; Vazhkudai, Sudharshan S

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 outsidemore » 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 Tensilica core). Efforts that take advantage of the available computing cycles on the processors on SSDs to run auxiliary tasks other than actual I/O requests are beginning to emerge. Kim et al. investigate database scan operations in the context of processing on the SSDs, and propose dedicated hardware logic to speed up scans. Also, cluster architectures have been explored, which consist of low-power embedded CPUs coupled with small local flash to achieve fast, parallel access to data. Processor utilization on SSD is highly dependent on workloads and, therefore, they can be idle during periods with no I/O accesses. We propose to use the available processing capability on the SSD to run tasks that can be offloaded from the host. This paper makes the following contributions: (1) We have investigated Active Flash and its potential to optimize the total energy cost, including power consumption on the host and the flash device; (2) We have developed analytical models to analyze the performance-energy tradeoffs for Active Flash, by treating the SSD as a blackbox, this is particularly valuable due to the proprietary nature of the SSD internal hardware; and (3) We have enhanced a well-known SSD simulator (from MSR) to implement 'on-the-fly' data compression using Active Flash. Our results provide a window into striking a balance between energy consumption and application performance.« less

Hazards of Colour Coding in Visual Approach Slope Indicators,

DTIC Science & Technology

1981-12-01

the glideslope. The central spot (the ’ meatball ’) is displaced above or below the datum lights when the pilot views from above or below the...undershoot is increasing or decreasing, the step changes in intensity may also be evident as a form of flash coding. Colour coding of the ’ meatball " in

Bayer Digester Optimization Studies using Computer Techniques

NASA Astrophysics Data System (ADS)

Kotte, Jan J.; Schleider, Victor H.

Theoretically required heat transfer performance by the multistaged flash heat reclaim system of a high pressure Bayer digester unit is determined for various conditions of discharge temperature, excess flash vapor and indirect steam addition. Solution of simultaneous heat balances around the digester vessels and the heat reclaim system yields the magnitude of available heat for representation of each case on a temperature-enthalpy diagram, where graphical fit of the number of flash stages fixes the heater requirements. Both the heat balances and the trial-and-error graphical solution are adapted to solution by digital computer techniques.

78 FR 77773 - Shipping Coordinating Committee; Notice of Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-24

... the International Code of safety for ships using gases or low flash-point fuels (IGF Code) Members of..., by fax at (202) 372-8283, or in writing at Commandant (CG-OES-1), U.S. Coast Guard Stop 7509, 2703...

Helium shell flashes and evolution of accreting white dwarfs

NASA Astrophysics Data System (ADS)

Fujimoto, M. Y.; Sugimoto, D.

1982-06-01

The evolution of accreting white dwarfs is investigated from the onset of accretion through the helium shell flash. Properties of the helium shell flashes are studied by means of a generalized theory of shell flash and by numerical computations, and it is found that the shell flash grows up to the strength of a supernova explosion when the mass of the helium zone is large enough on a massive white dwarf. Although accretion onto a hot white dwarf causes a weaker shell flash than those onto cool ones, a strong tendency exists for the strength to be determined mainly by the accretion rate. For fast accretion, the shell flashes are weak and triggered recurrently, while for slow accretion the helium shell flash, once triggered, develops into a detonation supernova.

Adaptive P300 based control system

PubMed Central

Jin, Jing; Allison, Brendan Z.; Sellers, Eric W.; Brunner, Clemens; Horki, Petar; Wang, Xingyu; Neuper, Christa

2015-01-01

An adaptive P300 brain-computer interface (BCI) using a 12 × 7 matrix explored new paradigms to improve bit rate and accuracy. During online use, the system adaptively selects the number of flashes to average. Five different flash patterns were tested. The 19-flash paradigm represents the typical row/column presentation (i.e., 12 columns and 7 rows). The 9- and 14-flash A & B paradigms present all items of the 12 × 7 matrix three times using either nine or 14 flashes (instead of 19), decreasing the amount of time to present stimuli. Compared to 9-flash A, 9-flash B decreased the likelihood that neighboring items would flash when the target was not flashing, thereby reducing interference from items adjacent to targets. 14-flash A also reduced adjacent item interference and 14-flash B additionally eliminated successive (double) flashes of the same item. Results showed that accuracy and bit rate of the adaptive system were higher than the non-adaptive system. In addition, 9- and 14-flash B produced significantly higher performance than their respective A conditions. The results also show the trend that the 14-flash B paradigm was better than the 19-flash pattern for naïve users. PMID:21474877

Modeling of Unit-Cells With Z-Pins Using FLASH: Pre-Processing and Post Processing

NASA Technical Reports Server (NTRS)

Krueger, Ronald

2005-01-01

Although the toughening properties of stitches, z-pins and similar structures have been studied extensively, investigations on the effect of z-pins on the in-plane properties of laminates are limited. A brief summary on the effect of z-pins on the in-plane tensile and compressive properties of composite laminates is presented together with a concise introduction into the finite element code FLASH. The remainder of the report illustrates the modeling aspect of unit cells with z-pins in FLASH and focuses on input and output data as well as post-processing of results.

Evaluating a Computer Flash-Card Sight-Word Recognition Intervention with Self-Determined Response Intervals in Elementary Students with Intellectual Disability

ERIC Educational Resources Information Center

Cazzell, Samantha; Skinner, Christopher H.; Ciancio, Dennis; Aspiranti, Kathleen; Watson, Tiffany; Taylor, Kala; McCurdy, Merilee; Skinner, Amy

2017-01-01

A concurrent multiple-baseline across-tasks design was used to evaluate the effectiveness of a computer flash-card sight-word recognition intervention with elementary-school students with intellectual disability. This intervention allowed the participants to self-determine each response interval and resulted in both participants acquiring…

Mobile computing device as tools for college student education: a case on flashcards application

NASA Astrophysics Data System (ADS)

Kang, Congying

2012-04-01

Traditionally, college students always use flash cards as a tool to remember massive knowledge, such as nomenclature, structures, and reactions in chemistry. Educational and information technology have enabled flashcards viewed on computers, like Slides and PowerPoint, works as tunnels of drilling and feedback for the learners. The current generation of students is more capable of information technology and mobile computing devices. For example, they use their Mobile phones much more intensively everyday day. Trends of using Mobile phone as an educational tool is analyzed and a educational technology initiative is proposed, which use Mobile phone flash cards applications to help students learn biology and chemistry. Experiments show that users responded positively to these mobile flash cards.

An electrocorticographic BCI using code-based VEP for control in video applications: a single-subject study

PubMed Central

Kapeller, Christoph; Kamada, Kyousuke; Ogawa, Hiroshi; Prueckl, Robert; Scharinger, Josef; Guger, Christoph

2014-01-01

A brain-computer-interface (BCI) allows the user to control a device or software with brain activity. Many BCIs rely on visual stimuli with constant stimulation cycles that elicit steady-state visual evoked potentials (SSVEP) in the electroencephalogram (EEG). This EEG response can be generated with a LED or a computer screen flashing at a constant frequency, and similar EEG activity can be elicited with pseudo-random stimulation sequences on a screen (code-based BCI). Using electrocorticography (ECoG) instead of EEG promises higher spatial and temporal resolution and leads to more dominant evoked potentials due to visual stimulation. This work is focused on BCIs based on visual evoked potentials (VEP) and its capability as a continuous control interface for augmentation of video applications. One 35 year old female subject with implanted subdural grids participated in the study. The task was to select one out of four visual targets, while each was flickering with a code sequence. After a calibration run including 200 code sequences, a linear classifier was used during an evaluation run to identify the selected visual target based on the generated code-based VEPs over 20 trials. Multiple ECoG buffer lengths were tested and the subject reached a mean online classification accuracy of 99.21% for a window length of 3.15 s. Finally, the subject performed an unsupervised free run in combination with visual feedback of the current selection. Additionally, an algorithm was implemented that allowed to suppress false positive selections and this allowed the subject to start and stop the BCI at any time. The code-based BCI system attained very high online accuracy, which makes this approach very promising for control applications where a continuous control signal is needed. PMID:25147509

Priority coding for control room alarms

DOEpatents

Scarola, Kenneth; Jamison, David S.; Manazir, Richard M.; Rescorl, Robert L.; Harmon, Daryl L.

1994-01-01

Indicating the priority of a spatially fixed, activated alarm tile on an alarm tile array by a shape coding at the tile, and preferably using the same shape coding wherever the same alarm condition is indicated elsewhere in the control room. The status of an alarm tile can change automatically or by operator acknowledgement, but tones and/or flashing cues continue to provide status information to the operator.

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.

Freeware eLearning Flash-ECG for learning electrocardiography.

PubMed

Romanov, Kalle; Kuusi, Timo

2009-06-01

Electrocardiographic (ECG) analysis can be taught in eLearning programmes with suitable software that permits the effective use of basic tools such as a ruler and a magnifier, required for measurements. The Flash-ECG (Research & Development Unit for Medical Education, University of Helsinki, Finland) was developed to enable teachers and students to use scanned and archived ECGs on computer screens and classroom projectors. The software requires only a standard web browser with a Flash plug-in and can be integrated with learning environments (Blackboard/WebCT, Moodle). The Flash-ECG is freeware and is available to medical teachers worldwide.

On Stellar Flash Echoes from Circular Rings

NASA Astrophysics Data System (ADS)

Nemiroff, Robert; Mukherjee, Oindabi

2018-01-01

A flash -- or any episode of variability -- that occurs in the vicinity of a circular ring might be seen several times later, simultaneously, as echoes on the ring. Effective images of the flash are created and annihilated in pairs, with as many as four flash images visible concurrently. Videos detailing sequences of image pair creation, tandem motion, and subsequent image annihilation are shown, given simple opacity and scattering assumptions. It is proven that, surprisingly, images from a second pair creation event always annihilate with images from the first. Caustic surfaces between flash locations yielding two and four images are computed. Although such ring echos surely occur, their practical detection might be difficult as it could require dedicated observing programs involving sensitive photometry of extended objects. Potential flash sources include planetary and interstellar gas and dust rings near and around variable stars, flare stars, novae, supernovae, and GRBs. Potentially recoverable information includes size, distance, temporal history, and angular isotropy of both the ring and flash.

An Implicit Solver on A Parallel Block-Structured Adaptive Mesh Grid for FLASH

NASA Astrophysics Data System (ADS)

Lee, D.; Gopal, S.; Mohapatra, P.

2012-07-01

We introduce a fully implicit solver for FLASH based on a Jacobian-Free Newton-Krylov (JFNK) approach with an appropriate preconditioner. The main goal of developing this JFNK-type implicit solver is to provide efficient high-order numerical algorithms and methodology for simulating stiff systems of differential equations on large-scale parallel computer architectures. A large number of natural problems in nonlinear physics involve a wide range of spatial and time scales of interest. A system that encompasses such a wide magnitude of scales is described as "stiff." A stiff system can arise in many different fields of physics, including fluid dynamics/aerodynamics, laboratory/space plasma physics, low Mach number flows, reactive flows, radiation hydrodynamics, and geophysical flows. One of the big challenges in solving such a stiff system using current-day computational resources lies in resolving time and length scales varying by several orders of magnitude. We introduce FLASH's preliminary implementation of a time-accurate JFNK-based implicit solver in the framework of FLASH's unsplit hydro solver.

NELIOTA: First temperature measurement of lunar impact flashes

NASA Astrophysics Data System (ADS)

Bonanos, A. Z.; Avdellidou, C.; Liakos, A.; Xilouris, E. M.; Dapergolas, A.; Koschny, D.; Bellas-Velidis, I.; Boumis, P.; Charmandaris, V.; Fytsilis, A.; Maroussis, A.

2018-04-01

We report the first scientific results from the NELIOTA (NEO Lunar Impacts and Optical TrAnsients) project, which has recently begun lunar monitoring observations with the 1.2-m Kryoneri telescope. NELIOTA aims to detect faint impact flashes produced by near-Earth meteoroids and asteroids and thereby help constrain the size-frequency distribution of near-Earth objects in the decimeter to meter range. The NELIOTA setup, consisting of two fast-frame cameras observing simultaneously in the R and I bands, enables - for the first time - direct analytical calculation of the flash temperatures. We present the first ten flashes detected, for which we find temperatures in the range 1600 to 3100 K, in agreement with theoretical values. Two of these flashes were detected on multiple frames in both filters and therefore yield the first measurements of the temperature drop for lunar flashes. In addition, we compute the impactor masses, which range between 100 g and 50 kg.

Fast evolving pair-instability supernovae

DOE PAGES

Kozyreva, Alexandra; Gilmer, Matthew; Hirschi, Raphael; ...

2016-10-06

With an increasing number of superluminous supernovae (SLSNe) discovered the ques- tion of their origin remains open and causes heated debates in the supernova commu- nity. Currently, there are three proposed mechanisms for SLSNe: (1) pair-instability supernovae (PISN), (2) magnetar-driven supernovae, and (3) models in which the su- pernova ejecta interacts with a circumstellar material ejected before the explosion. Based on current observations of SLSNe, the PISN origin has been disfavoured for a number of reasons. Many PISN models provide overly broad light curves and too reddened spectra, because of massive ejecta and a high amount of nickel. In themore » cur- rent study we re-examine PISN properties using progenitor models computed with the GENEC code. We calculate supernova explosions with FLASH and light curve evolu- tion with the radiation hydrodynamics code STELLA. We find that high-mass models (200 M⊙ and 250 M⊙) at relatively high metallicity (Z=0.001) do not retain hydro- gen in the outer layers and produce relatively fast evolving PISNe Type I and might be suitable to explain some SLSNe. We also investigate uncertainties in light curve modelling due to codes, opacities, the nickel-bubble effect and progenitor structure and composition.« less

Reconstruction of Axial Energy Deposition in Magnetic Liner Inertial Fusion Based on PECOS Shadowgraph Unfolds Using the AMR Code FLASH

NASA Astrophysics Data System (ADS)

Adams, Marissa; Jennings, Christopher; Slutz, Stephen; Peterson, Kyle; Gourdain, Pierre; U. Rochester-Sandia Collaboration

2017-10-01

Magnetic Liner Inertial Fusion (MagLIF) experiments incorporate a laser to preheat a deuterium filled capsule before compression via a magnetically imploding liner. In this work, we focus on the blast wave formed in the fuel during the laser preheat component of MagLIF, where approximately 1kJ of energy is deposited in 3ns into the capsule axially before implosion. To model blast waves directly relevant to experiments such as MagLIF, we inferred deposited energy from shadowgraphy of laser-only experiments preformed at the PECOS target chamber using the Z-Beamlet laser. These energy profiles were used to initialize 2-dimensional simulations using by the adaptive mesh refinement code FLASH. Gradients or asymmetries in the energy deposition may seed instabilities that alter the fuel's distribution, or promote mix, as the blast wave interacts with the liner wall. The AMR capabilities of FLASH allow us to study the development and dynamics of these instabilities within the fuel and their effect on the liner before implosion. Sandia Natl Labs is managed by NTES of Sandia, LLC., a subsidiary of Honeywell International, Inc, for the U.S. DOEs NNSA under contract DE-NA0003525.

Consequence analysis in LPG installation using an integrated computer package.

PubMed

Ditali, S; Colombi, M; Moreschini, G; Senni, S

2000-01-07

This paper presents the prototype of the computer code, Atlantide, developed to assess the consequences associated with accidental events that can occur in a LPG storage plant. The characteristic of Atlantide is to be simple enough but at the same time adequate to cope with consequence analysis as required by Italian legislation in fulfilling the Seveso Directive. The application of Atlantide is appropriate for LPG storage/transferring installations. The models and correlations implemented in the code are relevant to flashing liquid releases, heavy gas dispersion and other typical phenomena such as BLEVE/Fireball. The computer code allows, on the basis of the operating/design characteristics, the study of the relevant accidental events from the evaluation of the release rate (liquid, gaseous and two-phase) in the unit involved, to the analysis of the subsequent evaporation and dispersion, up to the assessment of the final phenomena of fire and explosion. This is done taking as reference simplified Event Trees which describe the evolution of accidental scenarios, taking into account the most likely meteorological conditions, the different release situations and other features typical of a LPG installation. The limited input data required and the automatic linking between the single models, that are activated in a defined sequence, depending on the accidental event selected, minimize both the time required for the risk analysis and the possibility of errors. Models and equations implemented in Atlantide have been selected from public literature or in-house developed software and tailored with the aim to be easy to use and fast to run but, nevertheless, able to provide realistic simulation of the accidental event as well as reliable results, in terms of physical effects and hazardous areas. The results have been compared with those of other internationally recognized codes and with the criteria adopted by Italian authorities to verify the Safety Reports for LPG installations. A brief of the theoretical basis of each model implemented in Atlantide and an example of application are included in the paper.

Variation of a Lightning NOx Indicator for National Climate Assessment

NASA Technical Reports Server (NTRS)

Koshak, William J.; McCaul, Eugene W., Jr.; Peterson, Harold S.; Vant-Hull, Brian

2014-01-01

During the past couple of years, an analysis tool was developed by the NASA Marshall Space Flight Center (MSFC) for the National Climate Assessment (NCA) program. The tool monitors and examines changes in lightning characteristics over the conterminous US (CONUS) on a continual basis. In this study, we have expanded the capability of the tool so that it can compute a new climate assessment variable that is called the Lightning NOx Indicator (LNI). Nitrogen oxides (NOx = NO + NO2) are known to indirectly influence our climate, and lightning NOx is the most important source of NOx in the upper troposphere (particularly in the tropics). The LNI is derived using Lightning Imaging Sensor (LIS) data and is computed by summing up the product of flash area x flash brightness over all flashes that occur in a particular region and period. Therefore, it is suggested that the LNI is a proxy to lightning NOx production. Specifically, larger flash areas are consistent with longer channel length and/or more energetic channels, and hence more NOx production. Brighter flashes are consistent with more energetic channels, and hence more NOx production. The location of the flash within the thundercloud and the optical scattering characteristics of the thundercloud are of course complicating factors. We analyze LIS data for the years 2003-2013 and provide geographical plots of the time-evolution of the LNI in order to determine if there are any significant changes or trends between like seasons, or from year to year.

Modeling heat and moisture transport in firefighter protective clothing during flash fire exposure

NASA Astrophysics Data System (ADS)

Chitrphiromsri, Patirop; Kuznetsov, Andrey V.

2005-01-01

In this paper, a model of heat and moisture transport in firefighter protective clothing during a flash fire exposure is presented. The aim of this study is to investigate the effect of coupled heat and moisture transport on the protective performance of the garment. Computational results show the distribution of temperature and moisture content in the fabric during the exposure to the flash fire as well as during the cool-down period. Moreover, the duration of the exposure during which the garment protects the firefighter from getting second and third degree burns from the flash fire exposure is numerically predicted. A complete model for the fire-fabric-air gap-skin system is presented.

Block-Parallel Data Analysis with DIY2

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

Morozov, Dmitriy; Peterka, Tom

DIY2 is a programming model and runtime for block-parallel analytics on distributed-memory machines. Its main abstraction is block-structured data parallelism: data are decomposed into blocks; blocks are assigned to processing elements (processes or threads); computation is described as iterations over these blocks, and communication between blocks is defined by reusable patterns. By expressing computation in this general form, the DIY2 runtime is free to optimize the movement of blocks between slow and fast memories (disk and flash vs. DRAM) and to concurrently execute blocks residing in memory with multiple threads. This enables the same program to execute in-core, out-of-core, serial,more » parallel, single-threaded, multithreaded, or combinations thereof. This paper describes the implementation of the main features of the DIY2 programming model and optimizations to improve performance. DIY2 is evaluated on benchmark test cases to establish baseline performance for several common patterns and on larger complete analysis codes running on large-scale HPC machines.« less

"Snow Soup" Students Take on Animation Creation

ERIC Educational Resources Information Center

Nikirk, Martin

2009-01-01

This article describes the process of producing "Snow Soup"--the 2009 Adobe Flash animation produced by the Computer Game Development and Animation seniors of Washington County Technical High School in Hagerstown, Maryland, for libraries in their area. In addition to the Flash product, the students produced two related Game Maker games, a printed…

Computer Animation with Adobe Flash Professional Cs6 in Newton’s Law

NASA Astrophysics Data System (ADS)

Aji, S. D.; Hudha, M. N.; Huda, C.; Gufran, G.

2018-01-01

The purpose of this research is to develop computer-based physics learning media with Adobe Flash Professional CS6 on Newton’s Law of physics subject for senior high school (SMA / MA) class X. Type of research applied is Research and Development with ADDIE development model covering 5 stages: Analysis (Analysis), Design (Design), Development (Production), Implementation (Implementation) and Evaluation (Evaluation). The results of this study were tested toward media experts, media specialists, physics teachers, and students test results with media outcomes that are declared very feasible.

Flash Kα radiography of laser-driven solid sphere compression for fast ignition

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

Sawada, H.; Lee, S.; Shiroto, T.

2016-06-20

Time-resolved compression of a laser-driven solid deuterated plastic sphere with a cone was measured with flash Kα x-ray radiography. A spherically converging shockwave launched by nanosecond GEKKO XII beams was used for compression while a flash of 4.51 keV Ti Kα x-ray backlighter was produced by a high-intensity, picosecond laser LFEX (Laser for Fast ignition EXperiment) near peak compression for radiography. Areal densities of the compressed core were inferred from two-dimensional backlit x-ray images recorded with a narrow-band spherical crystal imager. The maximum areal density in the experiment was estimated to be 87 ± 26 mg/cm 2. Lastly, the temporalmore » evolution of the experimental and simulated areal densities with a 2-D radiation-hydrodynamics code is in good agreement.« less

Flash Kα radiography of laser-driven solid sphere compression for fast ignition

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

Sawada, H.; Lee, S.; Nagatomo, H.

2016-06-20

Time-resolved compression of a laser-driven solid deuterated plastic sphere with a cone was measured with flash Kα x-ray radiography. A spherically converging shockwave launched by nanosecond GEKKO XII beams was used for compression while a flash of 4.51 keV Ti Kα x-ray backlighter was produced by a high-intensity, picosecond laser LFEX (Laser for Fast ignition EXperiment) near peak compression for radiography. Areal densities of the compressed core were inferred from two-dimensional backlit x-ray images recorded with a narrow-band spherical crystal imager. The maximum areal density in the experiment was estimated to be 87 ± 26 mg/cm{sup 2}. The temporal evolution of the experimental andmore » simulated areal densities with a 2-D radiation-hydrodynamics code is in good agreement.« less

Learning Rates and Known-to-Unknown Flash-Card Ratios: Comparing Effectiveness While Holding Instructional Time Constant

ERIC Educational Resources Information Center

Forbes, Bethany E.; Skinner, Christopher H.; Black, Michelle P.; Yaw, Jared; Booher, Joshua; Delisle, Jean

2013-01-01

Using alternating treatments designs, we compared learning rates across 2 computer-based flash-card interventions (3?min each): a traditional drill intervention with 15 unknown words and an interspersal intervention with 12 known words and 3 unknown words. Each student acquired more words under the traditional drill intervention. Discussion…

Adapting to Student Learning Styles: Engaging Students with Cell Phone Technology in Organic Chemistry Instruction

ERIC Educational Resources Information Center

Pursell, David P.

2009-01-01

Students of organic chemistry traditionally make 3 x 5 in. flash cards to assist learning nomenclature, structures, and reactions. Advances in educational technology have enabled flash cards to be viewed on computers, offering an endless array of drilling and feedback for students. The current generation of students is less inclined to use…

Abdominal adiposity and hot flashes among midlife women.

PubMed

Thurston, Rebecca C; Sowers, MaryFran R; Sutton-Tyrrell, Kim; Everson-Rose, Susan A; Lewis, Tené T; Edmundowicz, Daniel; Matthews, Karen A

2008-01-01

Two competing hypotheses suggest how adiposity may affect menopausal hot flashes. The "thin hypothesis" asserts that aromatization of androgens to estrogens in body fat should be associated with decreased hot flashes. Conversely, thermoregulatory models argue that body fat should be associated with increased hot flashes. The study objective was to examine associations between abdominal adiposity and hot flashes, including the role of reproductive hormones in these associations. The Study of Women's Health Across the Nation Heart Study (2001-2003) is an ancillary study to the Study of Women's Health Across the Nation, a community-based cohort study. Participants were 461 women (35% African American, 65% white) ages 45 to 58 years with an intact uterus and at least one ovary. Measures included a computed tomography scan to assess abdominal adiposity; reported hot flashes over the previous 2 weeks; and a blood sample for measurement of follicle-stimulating hormone, estradiol, and sex hormone-binding globulin-adjusted estradiol (free estradiol index). Associations were evaluated within multivariable logistic and linear regression models. Every 1-SD increase in total (odds ratio [OR]=1.28; 95% CI: 1.06-1.55) and subcutaneous (OR=1.30; 95% CI: 1.07-1.58) abdominal adiposity was associated with increased odds of hot flashes in age- and site-adjusted models. Visceral adiposity was not associated with hot flashes. Associations were not reduced when models included reproductive hormone concentrations. Increased abdominal adiposity, particularly subcutaneous adiposity, is associated with increased odds of hot flashes, favoring thermoregulatory models of hot flashes. Body fat may not protect women from hot flashes as once thought.

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.

Flashing characters with famous faces improves ERP-based brain-computer interface performance

NASA Astrophysics Data System (ADS)

Kaufmann, T.; Schulz, S. M.; Grünzinger, C.; Kübler, A.

2011-10-01

Currently, the event-related potential (ERP)-based spelling device, often referred to as P300-Speller, is the most commonly used brain-computer interface (BCI) for enhancing communication of patients with impaired speech or motor function. Among numerous improvements, a most central feature has received little attention, namely optimizing the stimulus used for eliciting ERPs. Therefore we compared P300-Speller performance with the standard stimulus (flashing characters) against performance with stimuli known for eliciting particularly strong ERPs due to their psychological salience, i.e. flashing familiar faces transparently superimposed on characters. Our results not only indicate remarkably increased ERPs in response to familiar faces but also improved P300-Speller performance due to a significant reduction of stimulus sequences needed for correct character classification. These findings demonstrate a promising new approach for improving the speed and thus fluency of BCI-enhanced communication with the widely used P300-Speller.

Wash water recovery system

NASA Technical Reports Server (NTRS)

Deckman, G.; Rousseau, J. (Editor)

1973-01-01

The Wash Water Recovery System (WWRS) is intended for use in processing shower bath water onboard a spacecraft. The WWRS utilizes flash evaporation, vapor compression, and pyrolytic reaction to process the wash water to allow recovery of potable water. Wash water flashing and foaming characteristics, are evaluated physical properties, of concentrated wash water are determined, and a long term feasibility study on the system is performed. In addition, a computer analysis of the system and a detail design of a 10 lb/hr vortex-type water vapor compressor were completed. The computer analysis also sized remaining system components on the basis of the new vortex compressor design.

Modifications of ORNL's computer programs MSF-21 and VTE-21 for the evaluation and rapid optimization of multistage flash and vertical tube evaporators

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

Glueckstern, P.; Wilson, J.V.; Reed, S.A.

1976-06-01

Design and cost modifications were made to ORNL's Computer Programs MSF-21 and VTE-21 originally developed for the rapid calculation and design optimization of multistage flash (MSF) and multieffect vertical tube evaporator (VTE) desalination plants. The modifications include additional design options to make possible the evaluation of desalting plants based on current technology (the original programs were based on conceptual designs applying advanced and not yet proven technological developments and design features) and new materials and equipment costs updated to mid-1975.

Weather, Climate, and Society: New Demands on Science and Services

NASA Technical Reports Server (NTRS)

2010-01-01

A new algorithm has been constructed to estimate the path length of lightning channels for the purpose of improving the model predictions of lightning NOx in both regional air quality and global chemistry/climate models. This algorithm was tested and applied to VHF signals detected by the North Alabama Lightning Mapping Array (NALMA). The accuracy of the algorithm was characterized by comparing algorithm output to the plots of individual discharges whose lengths were computed by hand. Several thousands of lightning flashes within 120 km of the NALMA network centroid were gathered from all four seasons, and were analyzed by the algorithm. The mean, standard deviation, and median statistics were obtained for all the flashes, the ground flashes, and the cloud flashes. Channel length distributions were also obtained for the different seasons.

Developing Computer Model-Based Assessment of Chemical Reasoning: A Feasibility Study

ERIC Educational Resources Information Center

Liu, Xiufeng; Waight, Noemi; Gregorius, Roberto; Smith, Erica; Park, Mihwa

2012-01-01

This paper reports a feasibility study on developing computer model-based assessments of chemical reasoning at the high school level. Computer models are flash and NetLogo environments to make simultaneously available three domains in chemistry: macroscopic, submicroscopic, and symbolic. Students interact with computer models to answer assessment…

A Hot Downflowing Model Atmosphere for Umbral Flashes and the Physical Properties of Their Dark Fibrils

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

Henriques, V. M. J.; Mathioudakis, M.; Socas-Navarro, H.

We perform non-LTE inversions in a large set of umbral flashes, including the dark fibrils visible within them, and in the quiescent umbra by using the inversion code NICOLE on a set of full Stokes high-resolution Ca ii λ 8542 observations of a sunspot at disk center. We find that the dark structures have Stokes profiles that are distinct from those of the quiescent and flashed regions. They are best reproduced by atmospheres that are more similar to the flashed atmosphere in terms of velocities, even if with reduced amplitudes. We also find two sets of solutions that finely fitmore » the flashed profiles: a set that is upflowing, featuring a transition region that is deeper than in the quiescent case and preceded by a slight dip in temperature, and a second solution with a hotter atmosphere in the chromosphere but featuring downflows close to the speed of sound at such heights. Such downflows may be related, or even dependent, on the presence of coronal loops, rooted in the umbra of sunspots, as is the case in the region analyzed. Similar loops have been recently observed to have supersonic downflows in the transition region and are consistent with the earlier “sunspot plumes,” which were invariably found to display strong downflows in sunspots. Finally, we find, on average, a magnetic field reduction in the flashed areas, suggesting that the shock pressure is moving field lines in the upper layers.« less

Imposing a Lagrangian Particle Framework on an Eulerian Hydrodynamics Infrastructure in Flash

NASA Technical Reports Server (NTRS)

Dubey, A.; Daley, C.; ZuHone, J.; Ricker, P. M.; Weide, K.; Graziani, C.

2012-01-01

In many astrophysical simulations, both Eulerian and Lagrangian quantities are of interest. For example, in a galaxy cluster merger simulation, the intracluster gas can have Eulerian discretization, while dark matter can be modeled using particles. FLASH, a component-based scientific simulation code, superimposes a Lagrangian framework atop an adaptive mesh refinement Eulerian framework to enable such simulations. The discretization of the field variables is Eulerian, while the Lagrangian entities occur in many different forms including tracer particles, massive particles, charged particles in particle-in-cell mode, and Lagrangian markers to model fluid structure interactions. These widely varying roles for Lagrangian entities are possible because of the highly modular, flexible, and extensible architecture of the Lagrangian framework. In this paper, we describe the Lagrangian framework in FLASH in the context of two very different applications, Type Ia supernovae and galaxy cluster mergers, which use the Lagrangian entities in fundamentally different ways.

Imposing a Lagrangian Particle Framework on an Eulerian Hydrodynamics Infrastructure in FLASH

NASA Astrophysics Data System (ADS)

Dubey, A.; Daley, C.; ZuHone, J.; Ricker, P. M.; Weide, K.; Graziani, C.

2012-08-01

In many astrophysical simulations, both Eulerian and Lagrangian quantities are of interest. For example, in a galaxy cluster merger simulation, the intracluster gas can have Eulerian discretization, while dark matter can be modeled using particles. FLASH, a component-based scientific simulation code, superimposes a Lagrangian framework atop an adaptive mesh refinement Eulerian framework to enable such simulations. The discretization of the field variables is Eulerian, while the Lagrangian entities occur in many different forms including tracer particles, massive particles, charged particles in particle-in-cell mode, and Lagrangian markers to model fluid-structure interactions. These widely varying roles for Lagrangian entities are possible because of the highly modular, flexible, and extensible architecture of the Lagrangian framework. In this paper, we describe the Lagrangian framework in FLASH in the context of two very different applications, Type Ia supernovae and galaxy cluster mergers, which use the Lagrangian entities in fundamentally different ways.

45 Gb/s low complexity optical front-end for soft-decision LDPC decoders.

PubMed

Sakib, Meer Nazmus; Moayedi, Monireh; Gross, Warren J; Liboiron-Ladouceur, Odile

2012-07-30

In this paper a low complexity and energy efficient 45 Gb/s soft-decision optical front-end to be used with soft-decision low-density parity-check (LDPC) decoders is demonstrated. The results show that the optical front-end exhibits a net coding gain of 7.06 and 9.62 dB for post forward error correction bit error rate of 10(-7) and 10(-12) for long block length LDPC(32768,26803) code. The performance over a hard decision front-end is 1.9 dB for this code. It is shown that the soft-decision circuit can also be used as a 2-bit flash type analog-to-digital converter (ADC), in conjunction with equalization schemes. At bit rate of 15 Gb/s using RS(255,239), LDPC(672,336), (672, 504), (672, 588), and (1440, 1344) used with a 6-tap finite impulse response (FIR) equalizer will result in optical power savings of 3, 5, 7, 9.5 and 10.5 dB, respectively. The 2-bit flash ADC consumes only 2.71 W at 32 GSamples/s. At 45 GSamples/s the power consumption is estimated to be 4.95 W.

CoNNeCT Baseband Processor Module Boot Code SoftWare (BCSW)

NASA Technical Reports Server (NTRS)

Yamamoto, Clifford K.; Orozco, David S.; Byrne, D. J.; Allen, Steven J.; Sahasrabudhe, Adit; Lang, Minh

2012-01-01

This software provides essential startup and initialization routines for the CoNNeCT baseband processor module (BPM) hardware upon power-up. A command and data handling (C&DH) interface is provided via 1553 and diagnostic serial interfaces to invoke operational, reconfiguration, and test commands within the code. The BCSW has features unique to the hardware it is responsible for managing. In this case, the CoNNeCT BPM is configured with an updated CPU (Atmel AT697 SPARC processor) and a unique set of memory and I/O peripherals that require customized software to operate. These features include configuration of new AT697 registers, interfacing to a new HouseKeeper with a flash controller interface, a new dual Xilinx configuration/scrub interface, and an updated 1553 remote terminal (RT) core. The BCSW is intended to provide a "safe" mode for the BPM when initially powered on or when an unexpected trap occurs, causing the processor to reset. The BCSW allows the 1553 bus controller in the spacecraft or payload controller to operate the BPM over 1553 to upload code; upload Xilinx bit files; perform rudimentary tests; read, write, and copy the non-volatile flash memory; and configure the Xilinx interface. Commands also exist over 1553 to cause the CPU to jump or call a specified address to begin execution of user-supplied code. This may be in the form of a real-time operating system, test routine, or specific application code to run on the BPM.

Overview of emerging nonvolatile memory technologies

PubMed Central

2014-01-01

Nonvolatile memory technologies in Si-based electronics date back to the 1990s. Ferroelectric field-effect transistor (FeFET) was one of the most promising devices replacing the conventional Flash memory facing physical scaling limitations at those times. A variant of charge storage memory referred to as Flash memory is widely used in consumer electronic products such as cell phones and music players while NAND Flash-based solid-state disks (SSDs) are increasingly displacing hard disk drives as the primary storage device in laptops, desktops, and even data centers. The integration limit of Flash memories is approaching, and many new types of memory to replace conventional Flash memories have been proposed. Emerging memory technologies promise new memories to store more data at less cost than the expensive-to-build silicon chips used by popular consumer gadgets including digital cameras, cell phones and portable music players. They are being investigated and lead to the future as potential alternatives to existing memories in future computing systems. Emerging nonvolatile memory technologies such as magnetic random-access memory (MRAM), spin-transfer torque random-access memory (STT-RAM), ferroelectric random-access memory (FeRAM), phase-change memory (PCM), and resistive random-access memory (RRAM) combine the speed of static random-access memory (SRAM), the density of dynamic random-access memory (DRAM), and the nonvolatility of Flash memory and so become very attractive as another possibility for future memory hierarchies. Many other new classes of emerging memory technologies such as transparent and plastic, three-dimensional (3-D), and quantum dot memory technologies have also gained tremendous popularity in recent years. Subsequently, not an exaggeration to say that computer memory could soon earn the ultimate commercial validation for commercial scale-up and production the cheap plastic knockoff. Therefore, this review is devoted to the rapidly developing new class of memory technologies and scaling of scientific procedures based on an investigation of recent progress in advanced Flash memory devices. PMID:25278820

Overview of emerging nonvolatile memory technologies.

PubMed

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

2014-01-01

Nonvolatile memory technologies in Si-based electronics date back to the 1990s. Ferroelectric field-effect transistor (FeFET) was one of the most promising devices replacing the conventional Flash memory facing physical scaling limitations at those times. A variant of charge storage memory referred to as Flash memory is widely used in consumer electronic products such as cell phones and music players while NAND Flash-based solid-state disks (SSDs) are increasingly displacing hard disk drives as the primary storage device in laptops, desktops, and even data centers. The integration limit of Flash memories is approaching, and many new types of memory to replace conventional Flash memories have been proposed. Emerging memory technologies promise new memories to store more data at less cost than the expensive-to-build silicon chips used by popular consumer gadgets including digital cameras, cell phones and portable music players. They are being investigated and lead to the future as potential alternatives to existing memories in future computing systems. Emerging nonvolatile memory technologies such as magnetic random-access memory (MRAM), spin-transfer torque random-access memory (STT-RAM), ferroelectric random-access memory (FeRAM), phase-change memory (PCM), and resistive random-access memory (RRAM) combine the speed of static random-access memory (SRAM), the density of dynamic random-access memory (DRAM), and the nonvolatility of Flash memory and so become very attractive as another possibility for future memory hierarchies. Many other new classes of emerging memory technologies such as transparent and plastic, three-dimensional (3-D), and quantum dot memory technologies have also gained tremendous popularity in recent years. Subsequently, not an exaggeration to say that computer memory could soon earn the ultimate commercial validation for commercial scale-up and production the cheap plastic knockoff. Therefore, this review is devoted to the rapidly developing new class of memory technologies and scaling of scientific procedures based on an investigation of recent progress in advanced Flash memory devices.

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.

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.

ACOUSTIC SIGNATURES OF THE HELIUM CORE FLASH

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

Bildsten, Lars; Paxton, Bill; Moore, Kevin

2012-01-15

All evolved stars with masses M {approx}< 2 M{sub Sun} undergo an initiating off-center helium core flash in their M{sub c} Almost-Equal-To 0.48 M{sub Sun} He core as they ascend the red giant branch (RGB). This off-center flash is the first of a few successive helium shell subflashes that remove the core electron degeneracy over 2 Myr, converting the object into a He-burning star. Though characterized by Thomas over 40 years ago, this core flash phase has yet to be observationally probed. Using the Modules for Experiments in Stellar Astrophysics (MESA) code, we show that red giant asteroseismology enabled bymore » space-based photometry (i.e., Kepler and CoRoT) can probe these stars during the flash. The rapid ({approx}< 10{sup 5} yr) contraction of the red giant envelope after the initiating flash dramatically improves the coupling of the p-modes to the core g-modes, making the detection of l = 1 mixed modes possible for these 2 Myr. This duration implies that 1 in 35 stars near the red clump in the H-R diagram will be in their core flash phase. During this time, the star has a g-mode period spacing of {Delta}P{sub g} Almost-Equal-To 70-100 s, lower than the {Delta}P{sub g} Almost-Equal-To 250 s of He-burning stars in the red clump, but higher than the RGB stars at the same luminosity. This places them in an underpopulated part of the large frequency spacing ({Delta}{nu}) versus {Delta}P{sub g} diagram that should ease their identification among the thousands of observed red giants.« less

Physics Flash August 2016

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

Kippen, Karen Elizabeth

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

Optimized design of embedded DSP system hardware supporting complex algorithms

NASA Astrophysics Data System (ADS)

Li, Yanhua; Wang, Xiangjun; Zhou, Xinling

2003-09-01

The paper presents an optimized design method for a flexible and economical embedded DSP system that can implement complex processing algorithms as biometric recognition, real-time image processing, etc. It consists of a floating-point DSP, 512 Kbytes data RAM, 1 Mbytes FLASH program memory, a CPLD for achieving flexible logic control of input channel and a RS-485 transceiver for local network communication. Because of employing a high performance-price ratio DSP TMS320C6712 and a large FLASH in the design, this system permits loading and performing complex algorithms with little algorithm optimization and code reduction. The CPLD provides flexible logic control for the whole DSP board, especially in input channel, and allows convenient interface between different sensors and DSP system. The transceiver circuit can transfer data between DSP and host computer. In the paper, some key technologies are also introduced which make the whole system work efficiently. Because of the characters referred above, the hardware is a perfect flat for multi-channel data collection, image processing, and other signal processing with high performance and adaptability. The application section of this paper presents how this hardware is adapted for the biometric identification system with high identification precision. The result reveals that this hardware is easy to interface with a CMOS imager and is capable of carrying out complex biometric identification algorithms, which require real-time process.

Dynamics of face and annular seals with two-phase flow

NASA Technical Reports Server (NTRS)

Hughes, William F.; Basu, Prithwish; Beatty, Paul A.; Beeler, Richard M.; Lau, Stephen

1989-01-01

A detailed study was made of face and annular seals under conditions where boiling, i.e., phase change of the leaking fluid, occurs within the seal. Many seals operate in this mode because of flashing due to pressure drop and/or heat input from frictional heating. High pressure, water pumps, industrial chemical pumps, and cryogenic pumps are mentioned as a few of many applications. The initial motivation was the LOX-GOX seals for the space shuttle main engine, but the study was expanded to include any face or annular seal where boiling occurs. Some of the distinctive behavior characteristics of two-phase seals were discussed, particularly their axial stability. While two-phase seals probably exhibit instability to disturbances of other degrees of freedom such as wobble, etc., under certain conditions, such analyses are too complex to be treated at present. Since an all liquid seal (with parallel faces) has a neutral axial stiffness curve, and is stabilized axially by convergent coning, other degrees of freedom stability analyses are necessary. However, the axial stability behavior of the two-phase seal is always a consideration no matter how well the seal is aligned and regardless of the speed. Hence, axial stability is thought of as the primary design consideration for two-phase seals and indeed the stability behavior under sub-cooling variations probably overshadows other concerns. The main thrust was the dynamic analysis of axial motion of two-phase face seals, principally the determination of axial stiffness, and the steady behavior of two-phase annular seals. The main conclusions are that seals with two-phase flow may be unstable if improperly balanced. Detailed theoretical analyses of low (laminar) and high (turbulent) leakage seals are presented along with computer codes, parametric studies, and in particular a simplified PC based code that allows for rapid performance prediction. A simplified combined computer code for the performance prediction over the laminar and turbulent ranges of a two-phase seal is described and documented. The analyses, results, and computer codes are summarized.

Method and apparatus for implementing material thermal property measurement by flash thermal imaging

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

Sun, Jiangang

A method and apparatus are provided for implementing measurement of material thermal properties including measurement of thermal effusivity of a coating and/or film or a bulk material of uniform property. The test apparatus includes an infrared camera, a data acquisition and processing computer coupled to the infrared camera for acquiring and processing thermal image data, a flash lamp providing an input of heat onto the surface of a two-layer sample with an enhanced optical filter covering the flash lamp attenuating an entire infrared wavelength range with a series of thermal images is taken of the surface of the two-layer sample.

Multi-Head Very High Power Strobe System For Motion Picture Special Effects

NASA Astrophysics Data System (ADS)

Lovoi, P. A.; Fink, Michael L.

1983-10-01

A very large camera synchronizable strobe system has been developed for motion picture special effects. This system, the largest ever built, was delivered to MGM/UA to be used in the movie "War Games". The system consists of 12 individual strobe heads and a power supply distribution system. Each strobe head operates independently and may be flashed up to 24 times per second under computer control. An energy of 480 Joules per flash is used in six strobe heads and 240 Joules per flash in the remaining six strobe heads. The beam pattern is rectangular with a FWHM of 60° x 48°.

Gobe: an interactive, web-based tool for comparative genomic visualization.

PubMed

Pedersen, Brent S; Tang, Haibao; Freeling, Michael

2011-04-01

Gobe is a web-based tool for viewing comparative genomic data. It supports viewing multiple genomic regions simultaneously. Its simple text format and flash-based rendering make it an interactive, exploratory research tool. Gobe can be used without installation through our web service, or downloaded and customized with stylesheets and javascript callback functions. Gobe is a flash application that runs in all modern web-browsers. The full source-code, including that for the online web application is available under the MIT license at: http://github.com/brentp/gobe. Sample applications are hosted at http://try-gobe.appspot.com/ and http://synteny.cnr.berkeley.edu/gobe-app/.

30 CFR 50.20-6 - Criteria-MSHA Form 7000-1, Section C.

Code of Federal Regulations, 2011 CFR

2011-07-01

... daughters, non-medical, non-therapeutic X-rays, radium); effects of nonionizing radiation (welding flash, ultra-violet rays, micro-waves, sunburn). (vi) Code 26—Disorders Associated with Repeated Trauma...). Examples: Poisoning by lead, mercury, cadmium, arsenic, or other metals, poisoning by carbon monoxide...

Using Flash Technology for Motivation and Assessment

ERIC Educational Resources Information Center

Deal, Walter F., III

2004-01-01

A visit to most any technology education laboratory or classroom will reveal that computers, software, and multimedia software are rapidly becoming a mainstay in learning about technology and technological literacy. Almost all technology labs have at least several computers dedicated to specialized software or hardware such as Computer-aided…

The challenge of forecasting impacts of flash floods: test of a simplified hydraulic approach and validation based on insurance claim data

NASA Astrophysics Data System (ADS)

Le Bihan, Guillaume; Payrastre, Olivier; Gaume, Eric; Moncoulon, David; Pons, Frédéric

2017-11-01

Up to now, flash flood monitoring and forecasting systems, based on rainfall radar measurements and distributed rainfall-runoff models, generally aimed at estimating flood magnitudes - typically discharges or return periods - at selected river cross sections. The approach presented here goes one step further by proposing an integrated forecasting chain for the direct assessment of flash flood possible impacts on inhabited areas (number of buildings at risk in the presented case studies). The proposed approach includes, in addition to a distributed rainfall-runoff model, an automatic hydraulic method suited for the computation of flood extent maps on a dense river network and over large territories. The resulting catalogue of flood extent maps is then combined with land use data to build a flood impact curve for each considered river reach, i.e. the number of inundated buildings versus discharge. These curves are finally used to compute estimated impacts based on forecasted discharges. The approach has been extensively tested in the regions of Alès and Draguignan, located in the south of France, where well-documented major flash floods recently occurred. The article presents two types of validation results. First, the automatically computed flood extent maps and corresponding water levels are tested against rating curves at available river gauging stations as well as against local reference or observed flood extent maps. Second, a rich and comprehensive insurance claim database is used to evaluate the relevance of the estimated impacts for some recent major floods.

Electron-beam dynamics for an advanced flash-radiography accelerator

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

Ekdahl, Carl August Jr.

2015-06-22

Beam dynamics issues were assessed for a new linear induction electron accelerator. 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. Beam physics issues were examined through theoretical analysis and computer simulations, including particle-in cell (PIC) codes. Beam instabilities investigated included beam breakup (BBU), image displacement, diocotron, parametric envelope, ion hose, and the resistive wall instability. Beam corkscrew motion and emittance growth frommore » beam mismatch were also studied. It was concluded that a beam with radiographic quality equivalent to the present accelerators at Los Alamos will result if the same engineering standards and construction details are upheld.« less

ASA-FTL: An adaptive separation aware flash translation layer for solid state drives

DOE PAGES

Xie, Wei; Chen, Yong; Roth, Philip C

2016-11-03

Here, the flash-memory based Solid State Drive (SSD) presents a promising storage solution for increasingly critical data-intensive applications due to its low latency (high throughput), high bandwidth, and low power consumption. Within an SSD, its Flash Translation Layer (FTL) is responsible for exposing the SSD’s flash memory storage to the computer system as a simple block device. The FTL design is one of the dominant factors determining an SSD’s lifespan and performance. To reduce the garbage collection overhead and deliver better performance, we propose a new, low-cost, adaptive separation-aware flash translation layer (ASA-FTL) that combines sampling, data clustering and selectivemore » caching of recency information to accurately identify and separate hot/cold data while incurring minimal overhead. We use sampling for light-weight identification of separation criteria, and our dedicated selective caching mechanism is designed to save the limited RAM resource in contemporary SSDs. Using simulations of ASA-FTL with both real-world and synthetic workloads, we have shown that our proposed approach reduces the garbage collection overhead by up to 28% and the overall response time by 15% compared to one of the most advanced existing FTLs. We find that the data clustering using a small sample size provides significant performance benefit while only incurring a very small computation and memory cost. In addition, our evaluation shows that ASA-FTL is able to adapt to the changes in the access pattern of workloads, which is a major advantage comparing to existing fixed data separation methods.« less

MIDAS: Software for the detection and analysis of lunar impact flashes

NASA Astrophysics Data System (ADS)

Madiedo, José M.; Ortiz, José L.; Morales, Nicolás; Cabrera-Caño, Jesús

2015-06-01

Since 2009 we are running a project to identify flashes produced by the impact of meteoroids on the surface of the Moon. For this purpose we are employing small telescopes and high-sensitivity CCD video cameras. To automatically identify these events a software package called MIDAS was developed and tested. This package can also perform the photometric analysis of these flashes and estimate the value of the luminous efficiency. Besides, we have implemented in MIDAS a new method to establish which is the likely source of the meteoroids (known meteoroid stream or sporadic background). The main features of this computer program are analyzed here, and some examples of lunar impact events are presented.

Blast-Loading Assessment of Multi-Energy Flash Computed Tomography (MEFCT) Diagnostic

DTIC Science & Technology

2016-08-01

Perrella JA, Sturgill JM. Design of a simple blast pressure gauge based on a heterodyne velocimetry measuring technique. Aberdeen Proving Ground (MD...position unless so designated by other authorized documents. Citation of manufacturer’s or trade names does not constitute an official endorsement or...of the radiation dose throughout the angular span of the 150-, 300-, and 450-kV flash X-ray sources used in the MEFCT diagnostic: left image shows

Diurnal rhythm and concordance between objective and subjective hot flashes: the Hilo Women's Health Study.

PubMed

Sievert, Lynnette L; Reza, Angela; Mills, Phoebe; Morrison, Lynn; Rahberg, Nichole; Goodloe, Amber; Sutherland, Michael; Brown, Daniel E

2010-01-01

The aims of this study were to test for a diurnal pattern in hot flashes in a multiethnic population living in a hot, humid environment and to examine the rates of concordance between objective and subjective measures of hot flashes using ambulatory and laboratory measures. Study participants aged 45 to 55 years were recruited from the general population of Hilo, HI. Women wore a Biolog hot flash monitor (UFI, Morro Bay, CA), kept a diary for 24 hours, and also participated in 3-hour laboratory measures (n = 199). Diurnal patterns were assessed using polynomial regression. For each woman, objectively recorded hot flashes that matched subjective experience were treated as true-positive readings. Subjective hot flashes were considered the standard for computing false-positive and false-negative readings. True-positive, false-positive, and false-negative readings were compared across ethnic groups by chi analyses. Frequencies of sternal, nuchal, and subjective hot flashes peaked at 1500 +/- 1 hours with no difference by ethnicity. Laboratory results supported the pattern seen in ambulatory monitoring. Sternal and nuchal monitoring showed the same frequency of true-positive measures, but nonsternal electrodes picked up more false-positive readings. Laboratory monitoring showed very low frequencies of false negatives. There were no ethnic differences in the frequency of true-positive or false-positive measures. Women of European descent were more likely to report hot flashes that were not objectively demonstrated (false-negative measures). The diurnal pattern and peak in hot flash occurrence in the hot humid environment of Hilo were similar to results from more temperate environments. Lack of variation in sternal versus nonsternal measures and in true-positive measures across ethnicities suggests no appreciable effect of population variation in sweating patterns.

Diurnal rhythm and concordance between objective and subjective hot flashes: The Hilo Women’s Health Study

PubMed Central

Sievert, Lynnette L.; Reza, Angela; Mills, Phoebe; Morrison, Lynn; Rahberg, Nichole; Goodloe, Amber; Sutherland, Michael; Brown, Daniel E.

2010-01-01

Objective To test for a diurnal pattern in hot flashes in a multi-ethnic population living in a hot, humid environment. To examine rates of concordance between objective and subjective measures of hot flashes using ambulatory and laboratory measures. Methods Study participants aged 45–55 were recruited from the general population of Hilo, Hawaii. Women wore a Biolog hot flash monitor, kept a diary for 24-hours, and also participated in 3-hour laboratory measures (n=199). Diurnal patterns were assessed using polynomial regression. For each woman, objectively recorded hot flashes that matched subjective experience were treated as true positive readings. Subjective hot flashes were considered the standard for computing false positive and false negative readings. True positive, false positive, and false negative readings were compared across ethnic groups by chi-square analyses. Results Frequencies of sternal, nuchal and subjective hot flashes peaked at 15:00 ± 1 hour with no difference by ethnicity. Laboratory results supported the pattern seen in ambulatory monitoring. Sternal and nuchal monitoring showed the same frequency of true positive measures, but non-sternal electrodes picked up more false positive readings. Laboratory monitoring showed very low frequencies of false negatives. There were no ethnic differences in the frequency of true positive or false positive measures. Women of European descent were more likely to report hot flashes that were not objectively demonstrated (false negative measures). Conclusions The diurnal pattern and peak in hot flash occurrence in the hot humid environment of Hilo was similar to results from more temperate environments. Lack of variation in sternal vs. non-sternal measures, and in true positive measures across ethnicities suggests no appreciable effect of population variation in sweating patterns. PMID:20220538

MemFlash device: floating gate transistors as memristive devices for neuromorphic computing

NASA Astrophysics Data System (ADS)

Riggert, C.; Ziegler, M.; Schroeder, D.; Krautschneider, W. H.; Kohlstedt, H.

2014-10-01

Memristive devices are promising candidates for future non-volatile memory applications and mixed-signal circuits. In the field of neuromorphic engineering these devices are especially interesting to emulate neuronal functionality. Therefore, new materials and material combinations are currently investigated, which are often not compatible with Si-technology processes. The underlying mechanisms of the device often remain unclear and are paired with low device endurance and yield. These facts define the current most challenging development tasks towards a reliable memristive device technology. In this respect, the MemFlash concept is of particular interest. A MemFlash device results from a diode configuration wiring scheme of a floating gate transistor, which enables the persistent device resistance to be varied according to the history of the charge flow through the device. In this study, we investigate the scaling conditions of the floating gate oxide thickness with respect to possible applications in the field of neuromorphic engineering. We show that MemFlash cells exhibit essential features with respect to neuromorphic applications. In particular, cells with thin floating gate oxides show a limited synaptic weight growth together with low energy dissipation. MemFlash cells present an attractive alternative for state-of-art memresitive devices. The emulation of associative learning is discussed by implementing a single MemFlash cell in an analogue circuit.

Teachers and Students' Conceptions of Computer-Based Models in the Context of High School Chemistry: Elicitations at the Pre-intervention Stage

NASA Astrophysics Data System (ADS)

Waight, Noemi; Gillmeister, Kristina

2014-04-01

This study examined teachers' and students' initial conceptions of computer-based models—Flash and NetLogo models—and documented how teachers and students reconciled notions of multiple representations featuring macroscopic, submicroscopic and symbolic representations prior to actual intervention in eight high school chemistry classrooms. Individual in-depth interviews were conducted with 32 students and 6 teachers. Findings revealed an interplay of complex factors that functioned as opportunities and obstacles in the implementation of technologies in science classrooms. Students revealed preferences for the Flash models as opposed to the open-ended NetLogo models. Altogether, due to lack of content and modeling background knowledge, students experienced difficulties articulating coherent and blended understandings of multiple representations. Concurrently, while the aesthetic and interactive features of the models were of great value, they did not sustain students' initial curiosity and opportunities to improve understandings about chemistry phenomena. Most teachers recognized direct alignment of the Flash model with their existing curriculum; however, the benefits were relegated to existing procedural and passive classroom practices. The findings have implications for pedagogical approaches that address the implementation of computer-based models, function of models, models as multiple representations and the role of background knowledge and cognitive load, and the role of teacher vision and classroom practices.

"Magnetic Reconnection Code: Applications to Sawtooth Oscillations, Error-Field Induced Islands, and the Dynamo Effect" - Final Technical Report

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

Fitzpatrick, Richard

2007-09-24

Dr. Fitzpatrick has written an MHD code in order to investigate the interaction of tearing modes with flow and external magnetic perturbations, which has been successfully benchmarked against both linear and nonlinear theory and used to investigate error-field penetration in flowing plasmas. The same code was used to investigate the so-called Taylor problem. He employed the University of Chicago's FLASH code to further investigate the Taylor problem, discovering a new aspect of the problem. Dr. Fitzpatrick has written a 2-D Hall MHD code and used it to investigate the collisionless Taylor problem. Dr. Waelbroeck has performed an investigation of themore » scaling of the error-field penetration threshold in collisionless plasmas. Paul Watson and Dr. Fitzpatrick have written a fully-implicit extended-MHD code using the PETSC framework. Five publications have resulted from this grant work.« less

A comparison among several P300 brain-computer interface speller paradigms.

PubMed

Fazel-Rezai, Reza; Gavett, Scott; Ahmad, Waqas; Rabbi, Ahmed; Schneider, Eric

2011-10-01

Since the brain-computer interface (BCI) speller was first proposed by Farwell and Donchin, there have been modifications in the visual aspects of P300 paradigms. Most of the changes are based on the original matrix format such as changes in the number of rows and columns, font size, flash/ blank time, and flash order. The improvement in the resulting accuracy and speed of such systems has always been the ultimate goal. In this study, we have compared several different speller paradigms including row-column, single character flashing, and two region-based paradigms which are not based on the matrix format. In the first region-based paradigm, at the first level, characters and symbols are distributed over seven regions alphabetically, while in the second region-based paradigm they are distributed in the most frequently used order. At the second level, each one of the regions is further subdivided into seven subsets. The experimental results showed that the average accuracy and user acceptability for two region-based paradigms were higher than those for traditional paradigms such as row/column and single character.

78 FR 60876 - Advisory Committee to the Director (ACD), Centers for Disease Control and Prevention (CDC)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Advisory... by teleconference. Please dial (877) 930-8819 and enter code 1579739. Web links: Windows Connection-2: http://wm.onlinevideoservice.com/CDC2 Flash Connection-4 (For Safari and Google Chrome Users): http...

78 FR 60876 - Advisory Committee to the Director (ACD), Centers for Disease Control and Prevention (CDC)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Advisory... by teleconference. Please dial (877) 930-8819 and enter code 1579739. Web Links Windows Connection-2: http://wm.onlinevideoservice.com/CDC2 . Flash Connection-4 (For Safari and Google Chrome Users): http...

Fabrication of universal serial bus flash disk type microfluidic chip electrophoresis and application for protein analysis under ultra low voltage

PubMed Central

Cong, Hailin; Xu, Xiaodan; Yu, Bing; Liu, Huwei

2016-01-01

A simple and effective universal serial bus (USB) flash disk type microfluidic chip electrophoresis (MCE) was developed by using poly(dimethylsiloxane) based soft lithography and dry film based printed circuit board etching techniques in this paper. The MCE had a microchannel diameter of 375 μm and an effective length of 25 mm. Equipped with a conventional online electrochemical detector, the device enabled effectively separation of bovine serum albumin, lysozyme, and cytochrome c in 80 s under the ultra low voltage from a computer USB interface. Compared with traditional capillary electrophoresis, the USB flash disk type MCE is not only portable and inexpensive but also fast with high separation efficiency. PMID:27042249

On the generation of umbral flashes and running penumbral waves.

NASA Technical Reports Server (NTRS)

Moore, R. L.

1973-01-01

From a review of the observed properties of umbral flashes and running penumbral waves it is proposed that the source of these periodic phenomena is the oscillatory convection which Danielson and Savage (1968) and Savage (1969) have shown is likely to occur in the superadiabatic subphotospheric layers of sunspot umbras. Periods and growth rates are computed for oscillatory modes arising in a simple two-layer model umbra. The results suggest that umbral flashes result from disturbances produced by oscillatory convection occurring in the upper subphotospheric layer of the umbra, where the superadiabatic temperature gradient is much enhanced over that in lower layers, while running penumbral waves are due to oscillations in a layer just below this upper layer.

A Computational Fluid Dynamic Model for a Novel Flash Ironmaking Process

NASA Astrophysics Data System (ADS)

Perez-Fontes, Silvia E.; Sohn, Hong Yong; Olivas-Martinez, Miguel

A computational fluid dynamic model for a novel flash ironmaking process based on the direct gaseous reduction of iron oxide concentrates is presented. The model solves the three-dimensional governing equations including both gas-phase and gas-solid reaction kinetics. The turbulence-chemistry interaction in the gas-phase is modeled by the eddy dissipation concept incorporating chemical kinetics. The particle cloud model is used to track the particle phase in a Lagrangian framework. A nucleation and growth kinetics rate expression is adopted to calculate the reduction rate of magnetite concentrate particles. Benchmark experiments reported in the literature for a nonreacting swirling gas jet and a nonpremixed hydrogen jet flame were simulated for validation. The model predictions showed good agreement with measurements in terms of gas velocity, gas temperature and species concentrations. The relevance of the computational model for the analysis of a bench reactor operation and the design of an industrial-pilot plant is discussed.

LLSURE: local linear SURE-based edge-preserving image filtering.

PubMed

Qiu, Tianshuang; Wang, Aiqi; Yu, Nannan; Song, Aimin

2013-01-01

In this paper, we propose a novel approach for performing high-quality edge-preserving image filtering. Based on a local linear model and using the principle of Stein's unbiased risk estimate as an estimator for the mean squared error from the noisy image only, we derive a simple explicit image filter which can filter out noise while preserving edges and fine-scale details. Moreover, this filter has a fast and exact linear-time algorithm whose computational complexity is independent of the filtering kernel size; thus, it can be applied to real time image processing tasks. The experimental results demonstrate the effectiveness of the new filter for various computer vision applications, including noise reduction, detail smoothing and enhancement, high dynamic range compression, and flash/no-flash denoising.

Determination of the Global-Average Charge Moment of a Lightning Flash Using Schumann Resonances and the LIS/OTD Lightning Data

NASA Astrophysics Data System (ADS)

Boldi, Robert; Williams, Earle; Guha, Anirban

2018-01-01

In this paper, we use (1) the 20 year record of Schumann resonance (SR) signals measured at West Greenwich Rhode Island, USA, (2) the 19 year Lightning Imaging Sensor (LIS)/Optical Transient Detector (OTD) lightning data, and (3) the normal mode equations for a uniform cavity model to quantify the relationship between the observed Schumann resonance modal intensity and the global-average vertical charge moment change M (C km) per lightning flash. This work, by integrating SR measurements with satellite-based optical measurements of global flash rate, accomplishes this quantification for the first time. To do this, we first fit the intensity spectra of the observed SR signals to an eight-mode, three parameter per mode, (symmetric) Lorentzian line shape model. Next, using the LIS/OTD lightning data and the normal mode equations for a uniform cavity model, we computed the expected climatological-daily-average intensity spectra. We then regressed the observed modal intensity values against the expected modal intensity values to find the best fit value of the global-average vertical charge moment change of a lightning flash (M) to be 41 C km per flash with a 99% confidence interval of ±3.9 C km per flash, independent of mode. Mode independence argues that the model adequately captured the modal intensity, the most important fit parameter herein considered. We also tested this relationship for the presence of residual modal intensity at zero lightning flashes per second and found no evidence that modal intensity is significantly different than zero at zero lightning flashes per second, setting an upper limit to the amount of nonlightning contributions to the observed modal intensity.

Normalized Temperature Contrast Processing in Flash Infrared Thermography

NASA Technical Reports Server (NTRS)

Koshti, Ajay M.

2016-01-01

The paper presents further development in normalized contrast processing of flash infrared thermography method by the author given in US 8,577,120 B1. The method of computing normalized image or pixel intensity contrast, and normalized temperature contrast are provided, including converting one from the other. Methods of assessing emissivity of the object, afterglow heat flux, reflection temperature change and temperature video imaging during flash thermography are provided. Temperature imaging and normalized temperature contrast imaging provide certain advantages over pixel intensity normalized contrast processing by reducing effect of reflected energy in images and measurements, providing better quantitative data. The subject matter for this paper mostly comes from US 9,066,028 B1 by the author. Examples of normalized image processing video images and normalized temperature processing video images are provided. Examples of surface temperature video images, surface temperature rise video images and simple contrast video images area also provided. Temperature video imaging in flash infrared thermography allows better comparison with flash thermography simulation using commercial software which provides temperature video as the output. Temperature imaging also allows easy comparison of surface temperature change to camera temperature sensitivity or noise equivalent temperature difference (NETD) to assess probability of detecting (POD) anomalies.

An Algorithm for Obtaining the Distribution of 1-Meter Lightning Channel Segment Altitudes for Application in Lightning NOx Production Estimation

NASA Technical Reports Server (NTRS)

Peterson, Harold; Koshak, William J.

2009-01-01

An algorithm has been developed to estimate the altitude distribution of one-meter lightning channel segments. The algorithm is required as part of a broader objective that involves improving the lightning NOx emission inventories of both regional air quality and global chemistry/climate models. The algorithm was tested and applied to VHF signals detected by the North Alabama Lightning Mapping Array (NALMA). The accuracy of the algorithm was characterized by comparing algorithm output to the plots of individual discharges whose lengths were computed by hand; VHF source amplitude thresholding and smoothing were applied to optimize results. Several thousands of lightning flashes within 120 km of the NALMA network centroid were gathered from all four seasons, and were analyzed by the algorithm. The mean, standard deviation, and median statistics were obtained for all the flashes, the ground flashes, and the cloud flashes. One-meter channel segment altitude distributions were also obtained for the different seasons.

Injury pattern of the Flash-Ball, a less-lethal weapon used for law enforcement: report of two cases and review of the literature.

PubMed

Wahl, Peter; Schreyer, Nicolas; Yersin, Bertrand

2006-10-01

Less-lethal weapons are used in law enforcement to neutralize combative individuals and to disperse riot crowds. Local police recently used such an impact weapon, the Flash-Ball, in two different situations. This gun fires large rubber bullets with kinetic energies around 200 J. Although it is designed to avoid skin penetration, impacts at such energies may still create major trauma with associated severe injuries to internal organs. This is a report of 2 patients shot with the Flash-Ball who required medical attention. One could be discharged quickly, but the other required hospitalization for heart and lung contusion. Both patients required advanced investigations including computed tomography (CT) scan. The medical literature on injuries induced by less-lethal impact weapons is reviewed. Impacts from the Flash-Ball can cause significant injury to internal organs, even without penetration. Investigations as for other high-energy blunt traumas are called for in these cases.

Lightning NOx Statistics Derived by NASA Lightning Nitrogen Oxides Model (LNOM) Data Analyses

NASA Technical Reports Server (NTRS)

Koshak, William; Peterson, Harold

2013-01-01

What is the LNOM? The NASA Marshall Space Flight Center (MSFC) Lightning Nitrogen Oxides Model (LNOM) [Koshak et al., 2009, 2010, 2011; Koshak and Peterson 2011, 2013] analyzes VHF Lightning Mapping Array (LMA) and National Lightning Detection Network(TradeMark) (NLDN) data to estimate the lightning nitrogen oxides (LNOx) produced by individual flashes. Figure 1 provides an overview of LNOM functionality. Benefits of LNOM: (1) Does away with unrealistic "vertical stick" lightning channel models for estimating LNOx; (2) Uses ground-based VHF data that maps out the true channel in space and time to < 100 m accuracy; (3) Therefore, true channel segment height (ambient air density) is used to compute LNOx; (4) True channel length is used! (typically tens of kilometers since channel has many branches and "wiggles"); (5) Distinction between ground and cloud flashes are made; (6) For ground flashes, actual peak current from NLDN used to compute NOx from lightning return stroke; (7) NOx computed for several other lightning discharge processes (based on Cooray et al., 2009 theory): (a) Hot core of stepped leaders and dart leaders, (b) Corona sheath of stepped leader, (c) K-change, (d) Continuing Currents, and (e) M-components; and (8) LNOM statistics (see later) can be used to parameterize LNOx production for regional air quality models (like CMAQ), and for global chemical transport models (like GEOS-Chem).

In situ flash x-ray high-speed computed tomography for the quantitative analysis of highly dynamic processes

NASA Astrophysics Data System (ADS)

Moser, Stefan; Nau, Siegfried; Salk, Manfred; Thoma, Klaus

2014-02-01

The in situ investigation of dynamic events, ranging from car crash to ballistics, often is key to the understanding of dynamic material behavior. In many cases the important processes and interactions happen on the scale of milli- to microseconds at speeds of 1000 m s-1 or more. Often, 3D information is necessary to fully capture and analyze all relevant effects. High-speed 3D-visualization techniques are thus required for the in situ analysis. 3D-capable optical high-speed methods often are impaired by luminous effects and dust, while flash x-ray based methods usually deliver only 2D data. In this paper, a novel 3D-capable flash x-ray based method, in situ flash x-ray high-speed computed tomography is presented. The method is capable of producing 3D reconstructions of high-speed processes based on an undersampled dataset consisting of only a few (typically 3 to 6) x-ray projections. The major challenges are identified, discussed and the chosen solution outlined. The application is illustrated with an exemplary application of a 1000 m s-1 high-speed impact event on the scale of microseconds. A quantitative analysis of the in situ measurement of the material fragments with a 3D reconstruction with 1 mm voxel size is presented and the results are discussed. The results show that the HSCT method allows gaining valuable visual and quantitative mechanical information for the understanding and interpretation of high-speed events.

Volumetric Real-Time Imaging Using a CMUT Ring Array

PubMed Central

Choe, Jung Woo; Oralkan, Ömer; Nikoozadeh, Amin; Gencel, Mustafa; Stephens, Douglas N.; O’Donnell, Matthew; Sahn, David J.; Khuri-Yakub, Butrus T.

2012-01-01

A ring array provides a very suitable geometry for forward-looking volumetric intracardiac and intravascular ultrasound imaging. We fabricated an annular 64-element capacitive micromachined ultrasonic transducer (CMUT) array featuring a 10-MHz operating frequency and a 1.27-mm outer radius. A custom software suite was developed to run on a PC-based imaging system for real-time imaging using this device. This paper presents simulated and experimental imaging results for the described CMUT ring array. Three different imaging methods—flash, classic phased array (CPA), and synthetic phased array (SPA)—were used in the study. For SPA imaging, two techniques to improve the image quality—Hadamard coding and aperture weighting—were also applied. The results show that SPA with Hadamard coding and aperture weighting is a good option for ring-array imaging. Compared with CPA, it achieves better image resolution and comparable signal-to-noise ratio at a much faster image acquisition rate. Using this method, a fast frame rate of up to 463 volumes per second is achievable if limited only by the ultrasound time of flight; with the described system we reconstructed three cross-sectional images in real-time at 10 frames per second, which was limited by the computation time in synthetic beamforming. PMID:22718870

Volumetric real-time imaging using a CMUT ring array.

PubMed

Choe, Jung Woo; Oralkan, Ömer; Nikoozadeh, Amin; Gencel, Mustafa; Stephens, Douglas N; O'Donnell, Matthew; Sahn, David J; Khuri-Yakub, Butrus T

2012-06-01

A ring array provides a very suitable geometry for forward-looking volumetric intracardiac and intravascular ultrasound imaging. We fabricated an annular 64-element capacitive micromachined ultrasonic transducer (CMUT) array featuring a 10-MHz operating frequency and a 1.27-mm outer radius. A custom software suite was developed to run on a PC-based imaging system for real-time imaging using this device. This paper presents simulated and experimental imaging results for the described CMUT ring array. Three different imaging methods--flash, classic phased array (CPA), and synthetic phased array (SPA)--were used in the study. For SPA imaging, two techniques to improve the image quality--Hadamard coding and aperture weighting--were also applied. The results show that SPA with Hadamard coding and aperture weighting is a good option for ring-array imaging. Compared with CPA, it achieves better image resolution and comparable signal-to-noise ratio at a much faster image acquisition rate. Using this method, a fast frame rate of up to 463 volumes per second is achievable if limited only by the ultrasound time of flight; with the described system we reconstructed three cross-sectional images in real-time at 10 frames per second, which was limited by the computation time in synthetic beamforming.

Collisionless stellar hydrodynamics as an efficient alternative to N-body methods

NASA Astrophysics Data System (ADS)

Mitchell, Nigel L.; Vorobyov, Eduard I.; Hensler, Gerhard

2013-01-01

The dominant constituents of the Universe's matter are believed to be collisionless in nature and thus their modelling in any self-consistent simulation is extremely important. For simulations that deal only with dark matter or stellar systems, the conventional N-body technique is fast, memory efficient and relatively simple to implement. However when extending simulations to include the effects of gas physics, mesh codes are at a distinct disadvantage compared to Smooth Particle Hydrodynamics (SPH) codes. Whereas implementing the N-body approach into SPH codes is fairly trivial, the particle-mesh technique used in mesh codes to couple collisionless stars and dark matter to the gas on the mesh has a series of significant scientific and technical limitations. These include spurious entropy generation resulting from discreteness effects, poor load balancing and increased communication overhead which spoil the excellent scaling in massively parallel grid codes. In this paper we propose the use of the collisionless Boltzmann moment equations as a means to model the collisionless material as a fluid on the mesh, implementing it into the massively parallel FLASH Adaptive Mesh Refinement (AMR) code. This approach which we term `collisionless stellar hydrodynamics' enables us to do away with the particle-mesh approach and since the parallelization scheme is identical to that used for the hydrodynamics, it preserves the excellent scaling of the FLASH code already demonstrated on peta-flop machines. We find that the classic hydrodynamic equations and the Boltzmann moment equations can be reconciled under specific conditions, allowing us to generate analytic solutions for collisionless systems using conventional test problems. We confirm the validity of our approach using a suite of demanding test problems, including the use of a modified Sod shock test. By deriving the relevant eigenvalues and eigenvectors of the Boltzmann moment equations, we are able to use high order accurate characteristic tracing methods with Riemann solvers to generate numerical solutions which show excellent agreement with our analytic solutions. We conclude by demonstrating the ability of our code to model complex phenomena by simulating the evolution of a two-armed spiral galaxy whose properties agree with those predicted by the swing amplification theory.

Intracellular ice formation in mouse zygotes and early morulae vs. cooling rate and temperature-experimental vs. theory.

PubMed

Jin, Bo; Seki, Shinsuke; Paredes, Estefania; Qiu, Juan; Shi, Yanbin; Zhang, Zhenqiang; Ma, Chao; Jiang, Shuyan; Li, Jiaqi; Yuan, Feng; Wang, Shu; Shao, Xiaoguang; Mazur, Peter

2016-10-01

In this study, mature female mice of the ICR strain were induced to superovultate, mated, and collected at either zygote or early morula stages. Embryos suspended in 1 M ethylene glycol in PBS containing 10 mg/L Snomax for 15 min, then transferred in sample holder to Linkam cryostage, cooled to and seeded at 7 °C, and then observed and photographed while being cooled to -70 °C at 0.5-20 °C/min. Intracellular ice formation (IIF) was observed as abrupt ''flashing''. Two types of flashing or IIF were observed in this study. Extracellular freezing occurred at a mean of -7.7 °C. In morulae, about 25% turned dark within ±1 °C of extracellular ice formation (EIF). These we refer to as "high temperature'' flashers. In zygotes, there were no high temperature flashers. All the zygotes flashed at temperatures well below the temperature for EIF. Presumably high temperature flashers were a consequence of membrane damage prior to EIF or damage from EIF. We shall not discuss them further. In the majority of cases, IIF occurred well below -7.7 °C; these we call ''low temperature'' flashers. None flashed with cooling rate (CR) of 0.5 °C/min in either zygotes or morulae. Nearly all flashed with CR of 4 °C/min or higher, but the distribution of temperatures is much broader with morulae than with zygotes. Also, the mean flashing temperature is much higher with morulae (-20.9 °C) than with zygotes (-40.3 °C). We computed the kinetics of water loss with respect to CR and temperature in both mouse zygotes and in morulae based on published estimates of Lp and it is Ea. The resulting dehydration curves combined with knowledge of the embryo nucleation temperature permits an estimate of the likelihood of IIF as a function of CR and subzero temperature. The agreement between these computed probabilities and the observed values are good. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

SSD Market Overview

NASA Astrophysics Data System (ADS)

Wong, G.

The unparalleled cost and form factor advantages of NAND flash memory has driven 35 mm photographic film, floppy disks and one-inch hard drives to extinction. Due to its compelling price/performance characteristics, NAND Flash memory is now expanding its reach into the once-exclusive domain of hard disk drives and DRAM in the form of Solid State Drives (SSDs). Driven by the proliferation of thin and light mobile devices and the need for near-instantaneous accessing and sharing of content through the cloud, SSDs are expected to become a permanent fixture in the computing infrastructure.

Plasma-material interaction in electrothermal and electromagnetic launchers

NASA Astrophysics Data System (ADS)

Bourham, M. A.; Gilligan, J. G.; Hankins, O. E.

1993-07-01

Various material surfaces have been exposed to high heat fluxes from 2 to 80 GW/sq m over 100 microsec duration using the electrothermal launcher, SIRENS. The vapor shield is effective in reducing the heat to the ablating surface, and the energy transmission factor through the vapor shield decreases as the incident heat flux increases. Results show good agreement with code predictions. Visible light emission spectra have been observed both in-bore and from the muzzle flash of the barrel, and from the flash of the source. Measurements of visible emission from the source indicate time averaged temperatures of 1 to 3 eV, and about 1 to 2 eV along the axis of the device, which agree with the theory and experimental measurements of the average heat flux and plasma conductivity.

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.

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.

Teaching Addition and Subtraction Operations with Schematic Place-Value Learning Aids & the Impact on Arithmetic Competency

ERIC Educational Resources Information Center

Kyriakidou-Christofidou, Athina

2016-01-01

The present mixed-methods quasi-experimental study (embedding a case study and a mixed factorial within-between ANOVA test), conducted in a private English school in Limassol, Cyprus, investigated how the use of the schematic learning aids (researcher-made color-coded flash-cards and grids) influence year-2 children's ability to read, write and…

Oceanic Lightning versus Continental Lightning: VLF Peak Current Discrepancies

NASA Astrophysics Data System (ADS)

Dupree, N. A., Jr.; Moore, R. C.

2015-12-01

Recent analysis of the Vaisala global lightning data set GLD360 suggests that oceanic lightning tends to exhibit larger peak currents than continental lightning (lightning occurring over land). The GLD360 peak current measurement is derived from distant measurements of the electromagnetic fields emanated during the lightning flash. Because the GLD360 peak current measurement is a derived quantity, it is not clear whether the actual peak currents of oceanic lightning tend to be larger, or whether the resulting electromagnetic field strengths tend to be larger. In this paper, we present simulations of VLF signal propagation in the Earth-ionosphere waveguide to demonstrate that the peak field values for oceanic lightning can be significantly stronger than for continental lightning. Modeling simulations are performed using the Long Wave Propagation Capability (LWPC) code to directly evaluate the effect of ground conductivity on VLF signal propagation in the 5-15 kHz band. LWPC is an inherently narrowband propagation code that has been modified to predict the broadband response of the Earth-Ionosphere waveguide to an impulsive lightning flash while preserving the ability of LWPC to account for an inhomogeneous waveguide. Furthermore, we evaluate the effect of return stroke speed on these results.

Type Ia Supernova Explosions from Hybrid Carbon-Oxygen-Neon White Dwarf Progenitors

NASA Astrophysics Data System (ADS)

Willcox, Donald E.; Townsley, Dean M.; Calder, Alan C.; Denissenkov, Pavel A.; Herwig, Falk

2016-11-01

Motivated by recent results in stellar evolution that predict the existence of hybrid white dwarf (WD) stars with a C-O core inside an O-Ne shell, we simulate thermonuclear (Type Ia) supernovae from these hybrid progenitors. We use the FLASH code to perform multidimensional simulations in the deflagration-to-detonation transition (DDT) explosion paradigm. Our hybrid progenitor models were produced with the MESA stellar evolution code and include the effects of the Urca process, and we map the progenitor model to the FLASH grid. We performed a suite of DDT simulations over a range of ignition conditions consistent with the progenitor’s thermal and convective structure assuming multiple ignition points. To compare the results from these hybrid WD stars to previous results from C-O WDs, we construct a set of C-O WD models with similar properties and similarly simulate a suite of explosions. We find that despite significant variability within each suite, trends distinguishing the explosions are apparent in their {}56{Ni} yields and the kinetic properties of the ejecta. We compare our results with other recent work that studies explosions from these hybrid progenitors.

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.

A Super-Resolution Algorithm for Enhancement of FLASH LIDAR Data: Flight Test Results

NASA Technical Reports Server (NTRS)

Bulyshev, Alexander; Amzajerdian, Farzin; Roback, Eric; Reisse Robert

2014-01-01

This paper describes the results of a 3D super-resolution algorithm applied to the range data obtained from a recent Flash Lidar helicopter flight test. The flight test was conducted by the NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project over a simulated lunar terrain facility at NASA Kennedy Space Center. ALHAT is developing the technology for safe autonomous landing on the surface of celestial bodies: Moon, Mars, asteroids. One of the test objectives was to verify the ability of 3D super-resolution technique to generate high resolution digital elevation models (DEMs) and to determine time resolved relative positions and orientations of the vehicle. 3D super-resolution algorithm was developed earlier and tested in computational modeling, and laboratory experiments, and in a few dynamic experiments using a moving truck. Prior to the helicopter flight test campaign, a 100mX100m hazard field was constructed having most of the relevant extraterrestrial hazard: slopes, rocks, and craters with different sizes. Data were collected during the flight and then processed by the super-resolution code. The detailed DEM of the hazard field was constructed using independent measurement to be used for comparison. ALHAT navigation system data were used to verify abilities of super-resolution method to provide accurate relative navigation information. Namely, the 6 degree of freedom state vector of the instrument as a function of time was restored from super-resolution data. The results of comparisons show that the super-resolution method can construct high quality DEMs and allows for identifying hazards like rocks and craters within the accordance of ALHAT requirements.

A super-resolution algorithm for enhancement of flash lidar data: flight test results

NASA Astrophysics Data System (ADS)

Bulyshev, Alexander; Amzajerdian, Farzin; Roback, Eric; Reisse, Robert

2013-03-01

This paper describes the results of a 3D super-resolution algorithm applied to the range data obtained from a recent Flash Lidar helicopter flight test. The flight test was conducted by the NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project over a simulated lunar terrain facility at NASA Kennedy Space Center. ALHAT is developing the technology for safe autonomous landing on the surface of celestial bodies: Moon, Mars, asteroids. One of the test objectives was to verify the ability of 3D super-resolution technique to generate high resolution digital elevation models (DEMs) and to determine time resolved relative positions and orientations of the vehicle. 3D super-resolution algorithm was developed earlier and tested in computational modeling, and laboratory experiments, and in a few dynamic experiments using a moving truck. Prior to the helicopter flight test campaign, a 100mX100m hazard field was constructed having most of the relevant extraterrestrial hazard: slopes, rocks, and craters with different sizes. Data were collected during the flight and then processed by the super-resolution code. The detailed DEM of the hazard field was constructed using independent measurement to be used for comparison. ALHAT navigation system data were used to verify abilities of super-resolution method to provide accurate relative navigation information. Namely, the 6 degree of freedom state vector of the instrument as a function of time was restored from super-resolution data. The results of comparisons show that the super-resolution method can construct high quality DEMs and allows for identifying hazards like rocks and craters within the accordance of ALHAT requirements.

Accounting for Rainfall Spatial Variability in Prediction of Flash Floods

NASA Astrophysics Data System (ADS)

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

2016-12-01

Flash floods are a particularly damaging natural hazard worldwide in terms of both fatalities and property damage. In the United States, the lack of a comprehensive database that catalogues information related to flash flood timing, location, causative rainfall, and basin geomorphology has hindered broad characterization studies. First a representative and long archive of more than 20,000 flooding events during 2002-2011 is used to analyze the spatial and temporal variability of flash floods. We also derive large number of spatially distributed geomorphological and climatological parameters such as basin area, mean annual precipitation, basin slope etc. to identify static basin characteristics that influence flood response. For the same period, the National Severe Storms Laboratory (NSSL) has produced a decadal archive of Multi-Radar/Multi-Sensor (MRMS) radar-only precipitation rates at 1-km spatial resolution with 5-min temporal resolution. This provides an unprecedented opportunity to analyze the impact of event-level precipitation variability on flooding using a big data approach. To analyze the impact of sub-basin scale rainfall spatial variability on flooding, certain indices such as the first and second scaled moment of rainfall, horizontal gap, vertical gap etc. are computed from the MRMS dataset. Finally, flooding characteristics such as rise time, lag time, and peak discharge are linked to derived geomorphologic, climatologic, and rainfall indices to identify basin characteristics that drive flash floods. Next the model is used to predict flash flooding characteristics all over the continental U.S., specifically over regions poorly covered by hydrological observations. So far studies involving rainfall variability indices have only been performed on a case study basis, and a large scale approach is expected to provide a deeper insight into how sub-basin scale precipitation variability affects flooding. 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).

Teachers and Students' Conceptions of Computer-Based Models in the Context of High School Chemistry: Elicitations at the Pre-Intervention Stage

ERIC Educational Resources Information Center

Waight, Noemi; Gillmeister, Kristina

2014-01-01

This study examined teachers' and students' initial conceptions of computer-based models--Flash and NetLogo models--and documented how teachers and students reconciled notions of multiple representations featuring macroscopic, submicroscopic and symbolic representations prior to actual intervention in eight high school chemistry…

Navigation-aid power systems

NASA Technical Reports Server (NTRS)

Goltz, G. L.; Kaiser, L. M.; Weiner, H.

1979-01-01

Design synthesis and performance analysis (DSPA) program package is collection of subroutines used for computation of design and performance characteristics of viable solar-array-charged battery powered system for flashing-lamp buoys employed as maritime aids to navigation.

Simulation of the vibrational chemistry and the infrared signature induced by a Sprite streamer in the mesosphere

NASA Astrophysics Data System (ADS)

Romand, F.; Payan, S.; Croize, L.

2017-12-01

Since their first observation in 1989, effect of TLEs on the atmospheric composition has become an open and important question. The lack of suitable experimental data is a shortcoming that hampers our understanding of the physics and chemistry induced by these effects. HALESIS (High-Altitude Luminous Events Studied by Infrared Spectro-imagery) is a future experiment dedicated to the measurement of the atmospheric perturbation induced by a TLE in the minutes following its occurrence, from a stratospheric balloon flying at an altitude of 25 km to 40 km. This work aims to quantify the local chemical impact of sprites in the stratosphere and mesosphere. In this paper, we will present the development of a tool which simulates (i) the impact of a sprite on the vibrational chemistry, (ii) the resulting infrared signature and (iii) the propagation of this signature through the atmosphere to an observer. First the Non Local Thermodynamic Equilibrium populations of a background atmosphere were computed using SAMM2 code. The initial thermodynamic and chemical description of atmosphere comes from the Whole Atmosphere community Climate Model (WACCM). Then a perturbation was applied to simulate a sprite. Chemistry due to TLEs was computed using Gordillo-Vazquez kinetic model. Rate coefficients that depend on the electron energy distribution function were calculated from collision cross-section data by solving the electron Boltzmann equation (BE). Time evolutions of the species densities and of vibrational populations in the non-thermal plasma consecutive to sprite discharge were simulated using the computer code ZDPlasKin (S. Pancheshn et al.). Finally, the resulting infrared signatures were propagated from the disturbed area through the atmosphere to an instrument placed in a limb line of sight using a line by line radiative transfer model. We will conclude that sprite could produce a significant infrared signature that last a few tens of seconds after the visible flash.

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.

Nuclear fusion and carbon flashes on neutron stars

NASA Technical Reports Server (NTRS)

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

1978-01-01

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

Development and Preliminary Application of Multi-channel Agricultural Science and Technology Consulting Service U Disk

NASA Astrophysics Data System (ADS)

Yu, W. S.; Luo, C. S.; Wei, Q. F.; Zheng, Y. M.; Cao, C. Z.

2017-12-01

To deal with the “last kilometer” problem during the agricultural science and technology information service, the USB flash disk “Zixuntong”, which integrated five major consulting channels, i.e., telephone consultation, mutual video, message consultation, online customer service and QQ group was developed on the bases of capital experts and date resources. Since the products have the computer and telephone USB interface and are combined with localized information resources, users can obtain useful information on any terminal without the restriction of network. Meanwhile, the cartoon appearance make it friendly and attractive to people. The USB flash disk was used to provide agricultural expert consulting services and obtained a good preliminary application achievement. Finally, we concluded the creative application of USB flash disk in agricultural consulting services and prospected the future development direction of agricultural mobile consultation.

Nondestructive Evaluation (NDE) for Inspection of Composite Sandwich Structures

NASA Technical Reports Server (NTRS)

Zalameda, Joseph N.; Parker, F. Raymond

2014-01-01

Composite honeycomb structures are widely used in aerospace applications due to their low weight and high strength advantages. Developing nondestructive evaluation (NDE) inspection methods are essential for their safe performance. Flash thermography is a commonly used technique for composite honeycomb structure inspections due to its large area and rapid inspection capability. Flash thermography is shown to be sensitive for detection of face sheet impact damage and face sheet to core disbond. Data processing techniques, using principal component analysis to improve the defect contrast, are discussed. Limitations to the thermal detection of the core are investigated. In addition to flash thermography, X-ray computed tomography is used. The aluminum honeycomb core provides excellent X-ray contrast compared to the composite face sheet. The X-ray CT technique was used to detect impact damage, core crushing, and skin to core disbonds. Additionally, the X-ray CT technique is used to validate the thermography results.

Program scheme using common source lines in channel stacked NAND flash memory with layer selection by multilevel operation

NASA Astrophysics Data System (ADS)

Kim, Do-Bin; Kwon, Dae Woong; Kim, Seunghyun; Lee, Sang-Ho; Park, Byung-Gook

2018-02-01

To obtain high channel boosting potential and reduce a program disturbance in channel stacked NAND flash memory with layer selection by multilevel (LSM) operation, a new program scheme using boosted common source line (CSL) is proposed. The proposed scheme can be achieved by applying proper bias to each layer through its own CSL. Technology computer-aided design (TCAD) simulations are performed to verify the validity of the new method in LSM. Through TCAD simulation, it is revealed that the program disturbance characteristics is effectively improved by the proposed scheme.

Reconstruction and numerical modelling of a flash flood event: Atrani 2010

NASA Astrophysics Data System (ADS)

Ciervo, F.; Papa, M. N.; Medina, V.; Bateman, A.

2012-04-01

The work intends to reproduce the flash-flood event that occurred in Atrani (Amalfi Coast - Southern Italy) on the 9 September 2010. In the days leading up to the event, intense low pressure system affected the North Europe attracting hot humid air masses from the Mediterranean areas and pushing them to the southern regions of Italy. These conditions contributed to the development of strong convective storm systems, Mesoscale Convective Systems (MCS) type. The development of intense convective rain cells, over an extremely confined areas, leaded to a cumulative daily rainfall of 129.2 mm; the maximum precipitation in 1hr was 19.4mm. The Dragone river is artificially forced to flow underneath the urban estate of Atrani through a culvert until it finally flows out into the sea. In correspondence of the culvert inlet a minor fraction of the water discharge (5.9m^3/s), skimming over the channel cover, flowed on the street and invaded the village. The channelized flow generated overpressure involving the breaking of the cover of culvert slab and caused a new discharge inlet (20 m^3/s) on the street modifying the downstream flood dynamics. Information acquired, soon after the event, through the local people interviews and the field measurements significantly contributed to the rainfall event reconstruction and to the characterization of the induced effects. In absence of hydrometric data, the support of the amateur videos was of crucial importance for the hydraulic model development and calibration. A geomorphology based rainfall-runoff model, WFIUH type (Instantaneous Unit Hydrograph Width Function), is implemented to extract the hydrograph of the hydrological event. All analysis are performed with GIS support basing on a Digital Terrain System (DTM) 5x5m. Two parameters have been used to calibrate the model: the average watershed velocity (Vmean = 0.08m/s) and hydrodynamic diffusivity (D=10E^-6 m^2/s). The model is calibrated basing on the peak discharge assessed value (98.5 m^3/s) and the observed hydrological response time (1hr). The flood hydrograph, thus obtained, constituted the upstream boundary condition for the simulation of the propagation processes in the urban area. The flow propagation has been simulated through 2D FLATModel code. FLATModel is a numerical code for solving the 2D system shallow-water equations; it belongs to the family of explicit Godunov schemes. In this work the code is tested on unstructured mesh. The unstructured mesh is particularly useful for detailed analysis and small scale hydraulic studies; it allows the adapting of digital surface to complex urban real estate improving significantly the resolution of the simulation results. The use of unstructured meshes also entails a significant reduction of the computational burden allowing the thickening of the cell domain where a better resolution is required. The results of simulations are in good agreement with the field observations, therefore the implemented approach seems suitable for the simulation and prediction of possible future flash flood events in similar context areas.

Experimental check of bremsstrahlung dosimetry predictions for 0.75 MeV electrons

NASA Astrophysics Data System (ADS)

Sanford, T. W. L.; Halbleib, J. A.; Beezhold, W.

Bremsstrahlung dose in CaF2 TLDs from the radiation produced by 0.75 MeV electrons incident on Ta/C targets is measured and compared with that calculated via the CYLTRAN Monte Carlo code. The comparison was made to validate the code, which is used to predict and analyze radiation environments of flash X-ray simulators measured by TLDs. Over a wide range of Ta target thicknesses and radiation angles the code is found to agree with the 5% measurements. For Ta thickness near those that optimize the radiation output, however, the code overestimates the radiation dose at small angles. Maximum overprediction is about 14 + or - 5%. The general agreement, nonetheless, gives confidence in using the code at this energy and in the TLD calibration procedure. For the bulk of the measurements, a standard TLD employing a 2.2 mm thick Al equilibrator was used. In this paper we also show that this thickness can significantly attenuate the free-field dose and introduces significant photon buildup in the equalibrator.

Cartographic production for the Florida Shelf Habitat (FLaSH) map study: generation of surface grids, contours, and KMZ files

USGS Publications Warehouse

Robbins, Lisa L.; Hansen, Mark; Raabe, Ellen; Knorr, Paul O.; Browne, Joseph

2007-01-01

The Florida shelf represents a finite source of economic resources, including commercial and recreational fisheries, tourism, recreation, sand and gravel resources, phosphate, and freshwater reserves. Yet the basic information needed to locate resources, or to interpret and utilize existing data, comes from many sources, dates, and formats. A multi-agency effort is underway to coordinate and prioritize the compilation of suitable datasets for an integrated information system of Florida’s coastal and ocean resources. This report and the associated data files represent part of the effort to make data accessible and useable with computer-mapping systems, web-based technologies, and user-friendly visualization tools. Among the datasets compiled and developed are seafloor imagery, marine sediment data, and existing bathymetric data. A U.S. Geological Survey-sponsored workshop in January 2007 resulted in the establishment of mapping priorities for the state. Bathymetry was identified as a common priority among agencies and researchers. State-of-the-art computer-mapping techniques and data-processing tools were used to develop shelf-wide raster and vector data layers. Florida Shelf Habitat (FLaSH) Mapping Project (http://coastal.er.usgs.gov/flash) endeavors to locate available data, identify data gaps, synthesize existing information, and expand our understanding of geologic processes in our dynamic coastal and marine systems.

Effect of Speed on Tire-Soil Interaction and Development of Towed Pneumatic Tire-Soil Model

DTIC Science & Technology

1974-10-01

rigid wheels were per- formed by several researchers under laboratory conditions (Refs. 20 through 22) using the flash X -ray technique. These experiments...Towed Tire-Soil Model ................................... 90 IX Conclusions and Recommendations .............. 95 X References...Velocity Fields ................................. A-1 x Section Page Appendix B - Computer Program Chart for Computation 3- of Tire Performance with

There's a Green Glob in Your Classroom.

ERIC Educational Resources Information Center

Dugdale, Sharon

1983-01-01

Discusses computer games (called intrinsic models) focusing on mathematics rather than on unrelated motivations (flashing lights or sounds). Games include "Green Globs," (equations/linear functions), "Darts"/"Torpedo" (fractions), "Escape" (graphing), and "Make-a-Monster" (equivalent fractions and…

The EDIT-COMGEOM Code

DTIC Science & Technology

1975-09-01

This report assumes a familiarity with the GIFT and MAGIC computer codes. The EDIT-COMGEOM code is a FORTRAN computer code. The EDIT-COMGEOM code...converts the target description data which was used in the MAGIC computer code to the target description data which can be used in the GIFT computer code

Training of perceptual-cognitive skills in offside decision making.

PubMed

Catteeuw, Peter; Gilis, Bart; Jaspers, Arne; Wagemans, Johan; Helsen, Werner

2010-12-01

This study investigates the effect of two off-field training formats to improve offside decision making. One group trained with video simulations and another with computer animations. Feedback after every offside situation allowed assistant referees to compensate for the consequences of the flash-lag effect and to improve their decision-making accuracy. First, response accuracy improved and flag errors decreased for both training groups implying that training interventions with feedback taught assistant referees to better deal with the flash-lag effect. Second, the results demonstrated no effect of format, although assistant referees rated video simulations higher for fidelity than computer animations. This implies that a cognitive correction to a perceptual effect can be learned also when the format does not correspond closely with the original perceptual situation. Off-field offside decision-making training should be considered as part of training because it is a considerable help to gain more experience and to improve overall decision-making performance.

Ultra-long Gamma-Ray Bursts from the Collapse of Blue Supergiant Stars: An End-to-end Simulation

NASA Astrophysics Data System (ADS)

Perna, Rosalba; Lazzati, Davide; Cantiello, Matteo

2018-05-01

Ultra-long gamma-ray bursts (ULGRBs) are a distinct class of GRBs characterized by durations of several thousands of seconds, about two orders of magnitude longer than those of standard long GRBs (LGRBs). The driving engine of these events has not yet been uncovered, and ideas range from magnetars, to tidal disruption events, to extended massive stars, such as blue super giants (BSG). BSGs, a possible endpoint of stellar evolution, are attractive for the relatively long freefall times of their envelopes, allowing accretion to power a long-lasting central engine. At the same time, their large radial extension poses a challenge to the emergence of a jet. Here, we perform an end-to-end simulation aimed at assessing the viability of BSGs as ULGRB progenitors. The evolution to the core-collapse of a BSG star model is calculated with the MESA code. We then compute the accretion rate for the fraction of envelope material with enough angular momentum to circularize and form an accretion disk, and input the corresponding power into a jet, which we evolve through the star envelope with the FLASH code. Our simulation shows that the jet can emerge, and the resulting light curves resemble those observed in ULGRBs, with durations T 90 ranging from ≈4000 s to ≈104 s, depending on the viewing angle.

Operational flash flood forecasting platform based on grid technology

NASA Astrophysics Data System (ADS)

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

2009-04-01

Flash flood events of south of France such as the 8th and 9th September 2002 in the Grand Delta territory caused important economic and human damages. Further to this catastrophic hydrological situation, a reform of flood warning services have been initiated (set in 2006). Thus, this political reform has transformed the 52 existing flood warning services (SAC) in 22 flood forecasting services (SPC), in assigning them territories more hydrological consistent and new effective hydrological forecasting mission. Furthermore, national central service (SCHAPI) has been created to ease this transformation and support local services in their new objectives. New functioning requirements have been identified: - SPC and SCHAPI carry the responsibility to clearly disseminate to public organisms, civil protection actors and population, crucial hydrologic information to better anticipate potential dramatic flood event, - a new effective hydrological forecasting mission to these flood forecasting services seems essential particularly for the flash floods phenomenon. Thus, models improvement and optimization was one of the most critical requirements. Initially dedicated to support forecaster in their monitoring mission, thanks to measuring stations and rainfall radar images analysis, hydrological models have to become more efficient in their capacity to anticipate hydrological situation. Understanding natural phenomenon occuring during flash floods mainly leads present hydrological research. Rather than trying to explain such complex processes, the presented research try to manage the well-known need of computational power and data storage capacities of these services. Since few years, Grid technology appears as a technological revolution in high performance computing (HPC) allowing large-scale resource sharing, computational power using and supporting collaboration across networks. Nowadays, EGEE (Enabling Grids for E-science in Europe) project represents the most important effort in term of grid technology development. This paper presents an operational flash flood forecasting platform which have been developed in the framework of CYCLOPS European project providing one of virtual organizations of EGEE project. This platform has been designed to enable multi-simulations processes to ease forecasting operations of several supervised watersheds on Grand Delta (SPC-GD) territory. Grid technology infrastructure, in providing multiple remote computing elements enables the processing of multiple rainfall scenarios, derived to the original meteorological forecasting transmitted by Meteo-France, and their respective hydrological simulations. First results show that from one forecasting scenario, this new presented approach can permit simulations of more than 200 different scenarios to support forecasters in their aforesaid mission and appears as an efficient hydrological decision-making tool. Although, this system seems operational, model validity has to be confirmed. So, further researches are necessary to improve models core to be more efficient in term of hydrological aspects. Finally, this platform could be an efficient tool for developing others modelling aspects as calibration or data assimilation in real time processing.

Turbulent spots and scalar flashes in pipe transition

NASA Astrophysics Data System (ADS)

Adrian, Ronald; Wu, Xiaohua; Moin, Parviz

2017-11-01

Recent study (Wu et al., PNAS, 1509451112, 2015) demonstrated the feasibility and accuracy of direct computation of the Osborne Reynolds' pipe transition experiment without the unphysical axially periodic boundary condition. Here we use this approach to address three questions: (1) What are the dynamics of turbulent spot generation in pipe transition? (2) How is the succession of scalar flashes, as observed and sketched by Osborne Reynolds, created? (3) What happens to the succession of flashes further downstream? In this study, the inlet disturbance is of radial-mode type imposed through a narrow, three-degree numerical wedge; and the simulation Reynolds number is 6500. Numerical dye is introduced at the inlet plane locally very close to the pipe axis, similar to the needle injection by O. Reynolds. Inception of infant turbulent spots occurs when normal, forward inclined hairpin packets form near the walls from the debris of the inlet perturbations. However, the young and mature turbulent spots consist almost exclusively of reverse, backward leaning hairpin vortices. Scalar flashes appear successively downstream and persist well into the fully-developed turbulent region. Their creation mechanism is addressed. RJA gratefully acknowledges support of the National Science Foundation with NSF Award CBET-0933848.

floodX: urban flash flood experiments monitored with conventional and alternative sensors

NASA Astrophysics Data System (ADS)

Moy de Vitry, Matthew; Dicht, Simon; Leitão, João P.

2017-09-01

The data sets described in this paper provide a basis for developing and testing new methods for monitoring and modelling urban pluvial flash floods. Pluvial flash floods are a growing hazard to property and inhabitants' well-being in urban areas. However, the lack of appropriate data collection methods is often cited as an impediment for reliable flood modelling, thereby hindering the improvement of flood risk mapping and early warning systems. The potential of surveillance infrastructure and social media is starting to draw attention for this purpose. In the floodX project, 22 controlled urban flash floods were generated in a flood response training facility and monitored with state-of-the-art sensors as well as standard surveillance cameras. With these data, it is possible to explore the use of video data and computer vision for urban flood monitoring and modelling. The floodX project stands out as the largest documented flood experiment of its kind, providing both conventional measurements and video data in parallel and at high temporal resolution. The data set used in this paper is available at https://doi.org/10.5281/zenodo.830513.

Simulations and model of the nonlinear Richtmyer–Meshkov instability

DOE PAGES

Dimonte, Guy; Ramaprabhu, P.

2010-01-21

The nonlinear evolution of the Richtmyer-Meshkov (RM) instability is investigated using numerical simulations with the FLASH code in two-dimensions (2D). The purpose of the simulations is to develop an empiricial nonlinear model of the RM instability that is applicable to inertial confinement fusion (ICF) and ejecta formation, namely, at large Atwood number A and scaled initial amplitude kh o (k ≡ wavenumber) of the perturbation. The FLASH code is first validated with a variety of RM experiments that evolve well into the nonlinear regime. They reveal that bubbles stagnate when they grow by an increment of 2/k and that spikesmore » accelerate for A > 0.5 due to higher harmonics that focus them. These results are then compared with a variety of nonlinear models that are based on potential flow. We find that the models agree with simulations for moderate values of A < 0.9 and kh o< 1, but not for the larger values that characterize ICF and ejecta formation. We thus develop a new nonlinear empirical model that captures the simulation results consistent with potential flow for a broader range of A and kh o. Our hope is that such empirical models concisely capture the RM simulations and inspire more rigorous solutions.« less

Accounting for rainfall spatial variability in the prediction of flash floods

NASA Astrophysics Data System (ADS)

Saharia, Manabendra; Kirstetter, Pierre-Emmanuel; Gourley, Jonathan J.; Hong, Yang; Vergara, Humberto; Flamig, Zachary L.

2017-04-01

Flash floods are a particularly damaging natural hazard worldwide in terms of both fatalities and property damage. In the United States, the lack of a comprehensive database that catalogues information related to flash flood timing, location, causative rainfall, and basin geomorphology has hindered broad characterization studies. First a representative and long archive of more than 15,000 flooding events during 2002-2011 is used to analyze the spatial and temporal variability of flash floods. We also derive large number of spatially distributed geomorphological and climatological parameters such as basin area, mean annual precipitation, basin slope etc. to identify static basin characteristics that influence flood response. For the same period, the National Severe Storms Laboratory (NSSL) has produced a decadal archive of Multi-Radar/Multi-Sensor (MRMS) radar-only precipitation rates at 1-km spatial resolution with 5-min temporal resolution. This provides an unprecedented opportunity to analyze the impact of event-level precipitation variability on flooding using a big data approach. To analyze the impact of sub-basin scale rainfall spatial variability on flooding, certain indices such as the first and second scaled moment of rainfall, horizontal gap, vertical gap etc. are computed from the MRMS dataset. Finally, flooding characteristics such as rise time, lag time, and peak discharge are linked to derived geomorphologic, climatologic, and rainfall indices to identify basin characteristics that drive flash floods. The database has been subjected to rigorous quality control by accounting for radar beam height and percentage snow in basins. So far studies involving rainfall variability indices have only been performed on a case study basis, and a large scale approach is expected to provide a deeper insight into how sub-basin scale precipitation variability affects flooding. 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).

The changing face of P300 BCIs: a comparison of stimulus changes in a P300 BCI involving faces, emotion, and movement.

PubMed

Jin, Jing; Allison, Brendan Z; Kaufmann, Tobias; Kübler, Andrea; Zhang, Yu; Wang, Xingyu; Cichocki, Andrzej

2012-01-01

One of the most common types of brain-computer interfaces (BCIs) is called a P300 BCI, since it relies on the P300 and other event-related potentials (ERPs). In the canonical P300 BCI approach, items on a monitor flash briefly to elicit the necessary ERPs. Very recent work has shown that this approach may yield lower performance than alternate paradigms in which the items do not flash but instead change in other ways, such as moving, changing colour or changing to characters overlaid with faces. The present study sought to extend this research direction by parametrically comparing different ways to change items in a P300 BCI. Healthy subjects used a P300 BCI across six different conditions. Three conditions were similar to our prior work, providing the first direct comparison of characters flashing, moving, and changing to faces. Three new conditions also explored facial motion and emotional expression. The six conditions were compared across objective measures such as classification accuracy and bit rate as well as subjective measures such as perceived difficulty. In line with recent studies, our results indicated that the character flash condition resulted in the lowest accuracy and bit rate. All four face conditions (mean accuracy >91%) yielded significantly better performance than the flash condition (mean accuracy = 75%). Objective results reaffirmed that the face paradigm is superior to the canonical flash approach that has dominated P300 BCIs for over 20 years. The subjective reports indicated that the conditions that yielded better performance were not considered especially burdensome. Therefore, although further work is needed to identify which face paradigm is best, it is clear that the canonical flash approach should be replaced with a face paradigm when aiming at increasing bit rate. However, the face paradigm has to be further explored with practical applications particularly with locked-in patients.

LNOx Estimates Directly from LIS Data

NASA Astrophysics Data System (ADS)

Koshak, W. J.; Vant-hull, B.; McCaul, E.

2014-12-01

Nitrogen oxides (NOx = NO + NO2) are known to indirectly influence climate since they affect the concentration of both atmospheric ozone (O3) and hydroxyl radicals (OH). In addition, lightning NOx (LNOx) is the most important source of NOx in the upper troposphere (particularly in the tropics). It is difficult to estimate LNOx because it is not easy to make measurements near the lightning channel, and the various NOx-producing mechanisms within a lightning flash are not fully understood. A variety of methods have been used to estimate LNOx production [e.g., in-situ observations, combined ground-based VHF lightning mapping and VLF/LF lightning locating observations, indirect retrievals using satellite Ozone Monitoring Instrument (OMI) observations, theoretical considerations, laboratory spark measurements, and rocket triggered lightning measurements]. The present study introduces a new approach for estimating LNOx that employs Lightning Imaging Sensor (LIS) data. LIS optical measurements are used to directly estimate the total energy of a flash; the total flash energy is then converted to LNOx production (in moles) by multiplying by a thermo-chemical yield. Hence, LNOx estimates on a flash-by-flash basis are obtained. A Lightning NOx Indicator (LNI) is computed by summing up the LIS-derived LNOx contributions from a region over a particular analysis period. Larger flash optical areas are consistent with longer channel length and/or more energetic channels, and hence more NOx production. Brighter flashes are consistent with more energetic channels, and hence more NOx production. The location of the flash within the thundercloud and the optical scattering characteristics of the thundercloud are complicating factors. LIS data for the years 2003-2013 were analyzed, and geographical plots of the time-evolution of the LNI over the southern tier states (i.e. upto 38o N) of CONUS were determined. Overall, the LNI trends downward over the 11 yr analysis period. The LNI has been added to the list of indicators presently provided by a sustaining assessment tool developed at the NASA Marshall Space Flight Center (MSFC) for monitoring lightning/climate interactions over the United States, as part of the National Climate Assessment (NCA) program.

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.

Shock Driven Multiphase Instabilities in Scramjet Applications

NASA Astrophysics Data System (ADS)

McFarland, Jacob

2016-11-01

Shock driven multiphase instabilities (SDMI) arise in many applications from dust production in supernovae to ejecta distribution in explosions. At the limit of small, fast reacting particles the instability evolves similar to the Richtmyer-Meshkov (RM) instability. However, as additional particle effects such as lag, phase change, and collisions become significant the required parameter space becomes much larger and the instability deviates significantly from the RM instability. In scramjet engines the SDMI arises during a cold start where liquid fuel droplets are injected and processed by shock and expansion waves. In this case the particle evaporation and mixing is important to starting and sustaining combustion, but the particles are large and slow to react, creating significant multiphase effects. This talk will examine multiphase mixing in scramjet relevant conditions in 3D multiphase hydrodynamic simulations using the FLASH code from the University of Chicago FLASH center.

Thermonuclear flashes on hydrogen/helium accreting carbon monoxide white dwarfs and structure of exotic nuclei

NASA Astrophysics Data System (ADS)

Mitchell, Joseph P.

We studied H-shell flashes on CO WDs accreting Hydrogen rich matter in regimes where they are believed to be on the border of stable accretion and of having dynamical mass loss. These systems are believed to be progenitors of SNe Ia, however, there is still some question of what range of accretion rates and WD masses allow for growth to the Chandrasekhar mass, if any do at all. Flashes that result in mass loss are also of interest as they enrich the Inter Stellar Medium. Use of an explicit hydro code has allowed for the observation of a new physical effect from wave dissipation. With our high time resolution, energy transport via waves, and detailed EOS, we found that at the onset of the flash, a reduction in the degeneracy pressure due to electron captures, results in a reduction of the total pressure. With a gravitational acceleration on the order of 108 in the shell, a reduction of the total pressure by 1% results in an in fall acceleration of 10 kms2 . With such a strong in fall, compressional heating results in a hotter flash, with results showing temperatures over a billion degrees in all models. These high temperatures had consequences on the nucleosynthesis, as they allowed for rp-breakout during the flash. The effect of a "double" flash was found in one model. This resulted when the flash stalled in the H-shell, resulting in high temperature burning in only a portion of the shell. Once the H was exhausted in the flash region, cooling occurred and there was contraction of the H exhausted region. This contraction caused an in fall of the un-exhausted region which via compressional heating resulted in the flash to occur in the un-exhausted region. Such an effect may happen in any progenitor system in which the flash stalls and compression afterwards is suitable for a re-start of the flash. This effect may be observable with the current generation of instruments. With the high temperatures found in the flashes, rp-breakout nucleosynthesis was found to occur. Occurrence of rp-nucleosynthesis in these objects may make important sources of the chemical enrichment of isotopes below the iron group that are not know to be synthesized in hydrostatic stellar burning. The existence of rp-breakout in the flashes, shows the importance of nuclear physics in these objects. More precise nuclear reaction rate data are needed for proper energy generation and chemical evolution. With the occurrence of rp-nucleosynthesis in our models, it is especially advantageous to study radioactive proton rich nuclei. These studies are not without many difficulties in the laboratory, as many of the studies require the use of low intensity radioactive beams making clean, high statistic studies difficult. To address this issue, the hybrid target technique was used. This target technique was found to be a great tool for studying resonant proton scattering with exotic beams. It has been used to measure elastic and inelastic excitation functions in the study of 8B via 7Be+p scattering, as well as 12N+p elastic scattering. With such success, the hybrid target technique can be a very useful tool for studying reactions that are important in the rp-process. We have studied the structure of the astrophysically important, radioactive isotope 8B. Three new resonances have been suggested, a 0+1,2+2 , and 1+2 which were predominantly in the inelastic channel and never before seen in previous studies. However, due to their high excitation energies and narrow width, none of the resonances are expected to effect the astrophysically important 7Be(p, gamma) reaction rate. Results were compared to continuum shell model as well as ab initio calculations and found to be in good agreement with both sets of predictions, with the notable exception of the 2+2 state. (Abstract shortened by UMI.)

Modeling of the Edwards pipe experiment

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

Tiselj, I.; Petelin, S.

1995-12-31

The Edwards pipe experiment is used as one of the basic benchmarks for the two-phase flow codes due to its simple geometry and the wide range of phenomena that it covers. Edwards and O`Brien filled 4-m-long pipe with liquid water at 7 MPa and 502 K and ruptured one end of the tube. They measured pressure and void fraction during the blowdown. Important phenomena observed were pressure rarefaction wave, flashing onset, critical two-phase flow, and void fraction wave. Experimental data were used to analyze the capabilities of the RELAP5/MOD3.1 six-equation two-phase flow model and to examine two different numerical schemes:more » one from the RELAP5/MOD3.1 code and one from our own code, which was based on characteristic upwind discretization.« less

Portable flash lamp reflectance analyzer system and method

NASA Technical Reports Server (NTRS)

Kalshoven, James Edward (Inventor)

1999-01-01

The system and method allow spectroscopic analysis of vegetation or the like without effects from changing sun and cloud conditions, undesired portions of the area of interest or atmospheric disturbances. The system (1) includes a light source (5) such as a xenon flash lamp, a telescope (7), a spectrometer (9), an analog/digital converter (11), a memory (13), a display (15), and an on-board microprocessor (17) or a port (19) for attachment to a laptop computer. The system is taken to an area of interest in the woods (step 41), the vegetation is illuminated from below (step 43) and data are taken (step 45).

Modeling of internal and near-nozzle flow for a GDI fuel injector

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

Saha, Kaushik; Som, Sibendu; Battistoni, Michele

A numerical study of two-phase flow inside the nozzle holes and the issuing spray jets for a multi-hole direct injection gasoline injector has been presented in this work. The injector geometry is representative of the Spray G nozzle, an eight-hole counterbore injector, from the Engine Combustion Network (ECN). Simulations have been carried out for a fixed needle lift. Effects of turbulence, compressibility and non-condensable gases have been considered in this work. Standard k -ε turbulence model has been used to model the turbulence. Homogeneous Relaxation Model (HRM) coupled with Volume of Fluid (VOF) approach has been utilized to capture themore » phase change phenomena inside and outside the injector nozzle. Three different boundary conditions for the outlet domain have been imposed to examine non-flashing and evaporative, non-flashing and non-evaporative and flashing conditions. Noticeable hole-to-hole variations have been observed in terms of mass flow rates for all the holes under all the operating conditions considered in this study. Inside the nozzle holes mild cavitation-like and in the near-nozzle region flash boiling phenomena have been predicted when liquid fuel is subjected to superheated ambiance. Under favorable conditions considerable flashing has been observed in the near-nozzle regions. An enormous volume is occupied by the gasoline vapor, stantial computational cost. Volume-averaging instead of mass-averaging is observed to be more effective, especially for finer mesh resolutions.« less

Portable Electromyograph

NASA Technical Reports Server (NTRS)

De Luca, Gianluca; De Luca, Carlo J.; Bergman, Per

2004-01-01

A portable electronic apparatus records electromyographic (EMG) signals in as many as 16 channels at a sampling rate of 1,024 Hz in each channel. The apparatus (see figure) includes 16 differential EMG electrodes (each electrode corresponding to one channel) with cables and attachment hardware, reference electrodes, an input/output-and-power-adapter unit, a 16-bit analog-to-digital converter, and a hand-held computer that contains a removable 256-MB flash memory card. When all 16 EMG electrodes are in use, full-bandwidth data can be recorded in each channel for as long as 8 hours. The apparatus is powered by a battery and is small enough that it can be carried in a waist pouch. The computer is equipped with a small screen that can be used to display the incoming signals on each channel. Amplitude and time adjustments of this display can be made easily by use of touch buttons on the screen. The user can also set up a data-acquisition schedule to conform to experimental protocols or to manage battery energy and memory efficiently. Once the EMG data have been recorded, the flash memory card is removed from the EMG apparatus and placed in a flash-memory- card-reading external drive unit connected to a personal computer (PC). The PC can then read the data recorded in the 16 channels. Preferably, before further analysis, the data should be stored in the hard drive of the PC. The data files are opened and viewed on the PC by use of special- purpose software. The software for operation of the apparatus resides in a random-access memory (RAM), with backup power supplied by a small internal lithium cell. A backup copy of this software resides on the flash memory card. In the event of loss of both main and backup battery power and consequent loss of this software, the backup copy can be used to restore the RAM copy after power has been restored. Accessories for this device are also available. These include goniometers, accelerometers, foot switches, and force gauges.

Complex computation in the retina

NASA Astrophysics Data System (ADS)

Deshmukh, Nikhil Rajiv

Elucidating the general principles of computation in neural circuits is a difficult problem requiring both a tractable model circuit as well as sophisticated measurement tools. This thesis advances our understanding of complex computation in the salamander retina and its underlying circuitry and furthers the development of advanced tools to enable detailed study of neural circuits. The retina provides an ideal model system for neural circuits in general because it is capable of producing complex representations of the visual scene, and both its inputs and outputs are accessible to the experimenter. Chapter 2 describes the biophysical mechanisms that give rise to the omitted stimulus response in retinal ganglion cells described in Schwartz et al., (2007) and Schwartz and Berry, (2008). The extra response to omitted flashes is generated at the input to bipolar cells, and is separable from the characteristic latency shift of the OSR apparent in ganglion cells, which must occur downstream in the circuit. Chapter 3 characterizes the nonlinearities at the first synapse of the ON pathway in response to high contrast flashes and develops a phenomenological model that captures the effect of synaptic activation and intracellular signaling dynamics on flash responses. This work is the first attempt to model the dynamics of the poorly characterized mGluR6 transduction cascade unique to ON bipolar cells, and explains the second lobe of the biphasic flash response. Complementary to the study of neural circuits, recent advances in wafer-scale photolithography have made possible new devices to measure the electrical and mechanical properties of neurons. Chapter 4 reports a novel piezoelectric sensor that facilitates the simultaneous measurement of electrical and mechanical signals in neural tissue. This technology could reveal the relationship between the electrical activity of neurons and their local mechanical environment, which is critical to the study of mechanoreceptors, neural development, and traumatic brain injury. Chapter 5 describes advances in the development, fabrication, and testing of a prototype silicon micropipette for patch clamp physiology. Nanoscale photolithography addresses some of the limitations of traditional glass patch electrodes, such as the rapid dialysis of the cell with internal solution, and provides a platform for integration of microfluidics and electronics into the device, which can enable novel experimental methodology.

How morphometric characteristics affect flow accumulation values

NASA Astrophysics Data System (ADS)

Farek, Vladimir

2014-05-01

Remote sensing methods (like aerial based LIDAR recording, land-use recording etc.) become continually more available and accurate. On the other hand in-situ surveying is still expensive. Above all in small, anthropogenically uninfluenced catchments, with poor, or non-existing surveying network could be remote sensing methods extremely useful. Overland flow accumulation (FA) values belong to important indicators of higher flash floods or soil erosion exposure. This value gives the number of cells of the Digital Elevation Model (DEM) grid, which are drained to each point of the catchment. This contribution deals with relations between basic geomorphological and morphometric characteristics (like hypsometric integral, Melton index of subcatchment etc.) and FA values. These relations are studied in the rocky sandstone landscapes of National park Ceské Svycarsko with the particular occurrence of broken relief. All calculations are based on high-resolution LIDAR DEM named Genesis created by TU Dresden. The main computational platform is GIS GRASS . The goal of the conference paper is to submit a quick method or indicators to estimate small particular subcatchments threatened by higher flash floods or soil erosion risks, without the necessity of using sophisticated rainfall-runoff models. There is a possibility to split catchments easily to small subcatchments (or use existing disjunction), compute basic characteristics and (with knowledge of links between this characteristics and FA values) identify, which particular subcatchment is potentially threatened by flash floods or soil erosion.

Pressure Studies of Protein Dynamics.

DTIC Science & Technology

1987-02-20

applicable ) Office of Naval Research ONR N00014-86-K-0270 kc. ADDRESS (City, State,and ZIP Code) 10. SOURCE OF FUNDING NUMBERS - PROGRAM PROJECT I TASK IWORK...Pressure Studies of Protein Dynamics 12. PERSONAL AUTHOR(S) Hans Frauenfelder and Robert D. Young 13a. TYPE OF REPORT |13b. TIME COVERED 114 DATE OF...relatioihbetween dynamic structure and function of protein protein dyna -bsey observing the phenomena induced by flash photolysis using near ultravfilet

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%.

FireWire: Hot New Multimedia Interface or Flash in the Pan?

ERIC Educational Resources Information Center

Learn, Larry L., Ed.

1995-01-01

Examines potential solutions to the problem of personal computer cabling and configuration and serial port performance, namely "FireWire" (P1394) and "Universal Serial Bus" (USB). Discusses interface design, technical capabilities, user friendliness, compatibility, costs, and future perspectives. (AEF)

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.

Results of comparative RBMK neutron computation using VNIIEF codes (cell computation, 3D statics, 3D kinetics). Final report

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

Grebennikov, A.N.; Zhitnik, A.K.; Zvenigorodskaya, O.A.

1995-12-31

In conformity with the protocol of the Workshop under Contract {open_quotes}Assessment of RBMK reactor safety using modern Western Codes{close_quotes} VNIIEF performed a neutronics computation series to compare western and VNIIEF codes and assess whether VNIIEF codes are suitable for RBMK type reactor safety assessment computation. The work was carried out in close collaboration with M.I. Rozhdestvensky and L.M. Podlazov, NIKIET employees. The effort involved: (1) cell computations with the WIMS, EKRAN codes (improved modification of the LOMA code) and the S-90 code (VNIIEF Monte Carlo). Cell, polycell, burnup computation; (2) 3D computation of static states with the KORAT-3D and NEUmore » codes and comparison with results of computation with the NESTLE code (USA). The computations were performed in the geometry and using the neutron constants presented by the American party; (3) 3D computation of neutron kinetics with the KORAT-3D and NEU codes. These computations were performed in two formulations, both being developed in collaboration with NIKIET. Formulation of the first problem maximally possibly agrees with one of NESTLE problems and imitates gas bubble travel through a core. The second problem is a model of the RBMK as a whole with imitation of control and protection system controls (CPS) movement in a core.« less

Flash Pyrolysis of t-Butyl Hydroperoxide and Di-t-butyl Peroxide: Evidence of Roaming in the Decomposition of Organic Hydroperoxides.

PubMed

Jones, Paul J; Riser, Blake; Zhang, Jingsong

2017-10-19

Thermal decomposition of t-butyl hydroperoxide and di-t-butyl peroxide was investigated using flash pyrolysis (in a short reaction time of <100 μs) and vacuum-ultraviolet (λ = 118.2 nm) single-photon ionization time-of-flight mass spectrometry (VUV-SPI-TOFMS) at temperatures up to 1120 K and quantum computational methods. Acetone and methyl radical were detected as the predominant products in the initial decomposition of di-t-butyl peroxide via O-O bond fission. In the initial dissociation of t-butyl hydroperoxide, acetone, methyl radical, isobutylene, and isobutylene oxide products were identified. The novel detection of the unimolecular formation of isobutylene oxide, as supported by the computational study, was found to proceed via a roaming hydroxyl radical facilitated by a hydrogen-bonded intermediate. This new pathway could provide a new class of reactions to consider in the modeling of the low temperature oxidation of alkanes.

Carbenes and Nitrenes: Recent Developments in Fundamental Chemistry.

PubMed

Wentrup, Curt

2018-05-29

There has been significant progress in the direct observation of carbenes, nitrenes, and many other reactive intermediates in recent years due to the application of matrix photolysis and flash vacuum pyrolysis linked with matrix isolation at cryogenic temperatures. Our understanding of singlet and triplet states has improved through the interplay of spectroscopy and computations. Bistable carbenes and nitrenes as well as many examples of tunneling have been discovered. Numerous rearrangements and fragmentations have been documented. This minireview aims to give an overview of some of these developments but will not generally cover laser flash photolysis and chemical reactions in liquid solution. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental and numerical investigation of reactive shock-accelerated flows

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

Bonazza, Riccardo

2016-12-20

The main goal of this program was to establish a qualitative and quantitative connection, based on the appropriate dimensionless parameters and scaling laws, between shock-induced distortion of astrophysical plasma density clumps and their earthbound analog in a shock tube. These objectives were pursued by carrying out laboratory experiments and numerical simulations to study the evolution of two gas bubbles accelerated by planar shock waves and compare the results to available astrophysical observations. The experiments were carried out in an vertical, downward-firing shock tube, 9.2 m long, with square internal cross section (25×25 cm 2). Specific goals were to quantify themore » effect of the shock strength (Mach number, M) and the density contrast between the bubble gas and its surroundings (usually quantified by the Atwood number, i.e. the dimensionless density difference between the two gases) upon some of the most important flow features (e.g. macroscopic properties; turbulence and mixing rates). The computational component of the work performed through this program was aimed at (a) studying the physics of multi-phase compressible flows in the context of astrophysics plasmas and (b) providing a computational connection between laboratory experiments and the astrophysical application of shock-bubble interactions. Throughout the study, we used the FLASH4.2 code to run hydrodynamical and magnetohydrodynamical simulations of shock bubble interactions on an adaptive mesh.« less

Architecture and Hardware Design of Lossless Compression Algorithms for Direct-Write Maskless Lithography Systems

DTIC Science & Technology

2010-04-29

magnitude greater than today’s high-definition video coding standards. Moreover, the micromirror devices of maskless lithography are smaller than those...be found in the literature [33]. In this architecture, the optical source flashes on a writer system, which consists of a micromirror array and a...the writer system. Due to the physical dimension constraints of the micromirror array and writer system, an entire wafer can be written in a few

Metal-poor stars. IV - The evolution of red giants.

NASA Technical Reports Server (NTRS)

Rood, R. T.

1972-01-01

Detailed evolutionary calculations for six Population-II red giants are presented. The first five of these models are followed from the zero age main sequence to the onset of the helium flash. The sixth model allows the effect of direct electron-neutrino interactions to be estimated. The updated input physics and evolutionary code are described briefly. The results of the calculations are presented in a manner pertinent to later stages of evolutions and suitable for comparison with observations.

MEMS For Rolling-Element Bearings

DTIC Science & Technology

2010-01-01

Layers Illustration (not to scale) 17 - 4PH Stainless Steel Cross-section from A-A’ Top view from B-B’ Au flash ~ 500 Å Ni ~ 25 µm B...B’ A A’ 17 - 4PH Stainless Steel Pre-metallization region Pre-metallization of steel substrate for bonding of MEMS strain sensor Figure RB6: Pre...Code: RES-04 Canton, OH 44706 - REPORT DOCUMENTATION PAGE b. ABSTRACT UU c. THIS PAGE UU 2. REPORT TYPE Final Report 17 . LIMITATION OF ABSTRACT UU

ELF Sferics Produced by Rocket-Triggered Lightning and Observed at Great Distances

NASA Astrophysics Data System (ADS)

Dupree, N. A.; Moore, R. C.; Fraser-Smith, A. C.

2013-12-01

Experimental observations of ELF radio atmospherics produced by rocket-triggered lightning flashes are used to analyze Earth-ionosphere waveguide excitation and propagation characteristics as a function of return stroke. Rocket-triggered lightning experiments are performed at the International Center for Lightning Research and Testing (ICLRT) located at Camp Blanding, Florida. Long-distance ELF observations are performed in California, Greenland, and Antarctica, although this work focuses on observations performed in Greenland. The lightning current waveforms directly measured at the base of the lightning channel (at the ICLRT) are used together with the Long Wavelength Propagation Capability (LWPC) code to predict the sferic waveform observed at the receiver locations under various ionospheric conditions. LWPC was developed by the Naval Ocean Systems Center over a period of many years. It is an inherently narrowband propagation code that has been modified to predict the broadband response of the Earth-ionosphere waveguide to an impulsive lightning flash while preserving the ability of LWPC to account for an inhomogeneous waveguide. This paper critically compares observations with model predictions, and in particular analyzes Earth-ionosphere waveguide excitation as a function of return stroke. The ability to infer source characteristics using observations at great distances may prove to greatly enhance the understanding of lightning processes that are associated with the production of transient luminous events (TLEs) as well as other ionospheric effects associated with lightning.

Development and application of the GIM code for the Cyber 203 computer

NASA Technical Reports Server (NTRS)

Stainaker, J. F.; Robinson, M. A.; Rawlinson, E. G.; Anderson, P. G.; Mayne, A. W.; Spradley, L. W.

1982-01-01

The GIM computer code for fluid dynamics research was developed. Enhancement of the computer code, implicit algorithm development, turbulence model implementation, chemistry model development, interactive input module coding and wing/body flowfield computation are described. The GIM quasi-parabolic code development was completed, and the code used to compute a number of example cases. Turbulence models, algebraic and differential equations, were added to the basic viscous code. An equilibrium reacting chemistry model and implicit finite difference scheme were also added. Development was completed on the interactive module for generating the input data for GIM. Solutions for inviscid hypersonic flow over a wing/body configuration are also presented.

Impact Flash Physics: Modeling and Comparisons With Experimental Results

NASA Astrophysics Data System (ADS)

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

2015-12-01

Hypervelocity impacts frequently generate an observable "flash" of light with two components: a short-duration spike due to emissions from vaporized material, and a long-duration peak due to thermal emissions from expanding hot debris. The intensity and duration of these peaks depend on the impact velocity, angle, and the target and projectile mass and composition. Thus remote sensing measurements of planetary impact flashes have the potential to constrain the properties of impacting meteors and improve our understanding of impact flux and cratering processes. Interpreting impact flash measurements requires a thorough understanding of how flash characteristics correlate with impact conditions. Because planetary-scale impacts cannot be replicated in the laboratory, numerical simulations are needed to provide this insight for the solar system. Computational hydrocodes can produce detailed simulations of the impact process, but they lack the radiation physics required to model the optical flash. The Johns Hopkins University Applied Physics Laboratory (APL) developed a model to calculate the optical signature from the hot debris cloud produced by an impact. While the phenomenology of the optical signature is understood, the details required to accurately model it are complicated by uncertainties in material and optical properties and the simplifications required to numerically model radiation from large-scale impacts. Comparisons with laboratory impact experiments allow us to validate our approach and to draw insight regarding processes that occur at all scales in impact events, such as melt generation. We used Sandia National Lab's CTH shock physics hydrocode along with the optical signature model developed at APL to compare with a series of laboratory experiments conducted at the NASA Ames Vertical Gun Range. The experiments used Pyrex projectiles to impact pumice powder targets with velocities ranging from 1 to 6 km/s at angles of 30 and 90 degrees with respect to horizontal. High-speed radiometer measurements were made of the time-dependent impact flash at wavelengths of 350-1100 nm. We will present comparisons between these measurements and the output of APL's model. The results of this validation allow us to determine basic relationships between observed optical signatures and impact conditions.

Feasibility and validation of virtual autopsy for dental identification using the Interpol dental codes.

PubMed

Franco, Ademir; Thevissen, Patrick; Coudyzer, Walter; Develter, Wim; Van de Voorde, Wim; Oyen, Raymond; Vandermeulen, Dirk; Jacobs, Reinhilde; Willems, Guy

2013-05-01

Virtual autopsy is a medical imaging technique, using full body computed tomography (CT), allowing for a noninvasive and permanent observation of all body parts. For dental identification clinically and radiologically observed ante-mortem (AM) and post-mortem (PM) oral identifiers are compared. The study aimed to verify if a PM dental charting can be performed on virtual reconstructions of full-body CT's using the Interpol dental codes. A sample of 103 PM full-body CT's was collected from the forensic autopsy files of the Department of Forensic Medicine University Hospitals, KU Leuven, Belgium. For validation purposes, 3 of these bodies underwent a complete dental autopsy, a dental radiological and a full-body CT examination. The bodies were scanned in a Siemens Definition Flash CT Scanner (Siemens Medical Solutions, Germany). The images were examined on 8- and 12-bit screen resolution as three-dimensional (3D) reconstructions and as axial, coronal and sagittal slices. InSpace(®) (Siemens Medical Solutions, Germany) software was used for 3D reconstruction. The dental identifiers were charted on pink PM Interpol forms (F1, F2), using the related dental codes. Optimal dental charting was obtained by combining observations on 3D reconstructions and CT slices. It was not feasible to differentiate between different kinds of dental restoration materials. The 12-bit resolution enabled to collect more detailed evidences, mainly related to positions within a tooth. Oral identifiers, not implemented in the Interpol dental coding were observed. Amongst these, the observed (3D) morphological features of dental and maxillofacial structures are important identifiers. The latter can become particularly more relevant towards the future, not only because of the inherent spatial features, yet also because of the increasing preventive dental treatment, and the decreasing application of dental restorations. In conclusion, PM full-body CT examinations need to be implemented in the PM dental charting protocols and the Interpol dental codes should be adapted accordingly. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Interrupted infusion of echocardiographic contrast as a basis for accurate measurement of myocardial perfusion: ex vivo validation and analysis procedures.

PubMed

Toledo, Eran; Collins, Keith A; Williams, Ursula; Lammertin, Georgeanne; Bolotin, Gil; Raman, Jai; Lang, Roberto M; Mor-Avi, Victor

2005-12-01

Echocardiographic quantification of myocardial perfusion is based on analysis of contrast replenishment after destructive high-energy ultrasound impulses (flash-echo). This technique is limited by nonuniform microbubble destruction and the dependency on exponential fitting of a small number of noisy time points. We hypothesized that brief interruptions of contrast infusion (ICI) would result in uniform contrast clearance followed by slow replenishment and, thus, would allow analysis from multiple data points without exponential fitting. Electrocardiographic-triggered images were acquired in 14 isolated rabbit hearts (Langendorff) at 3 levels of coronary flow (baseline, 50%, and 15%) during contrast infusion (Definity) with flash-echo and with a 20-second infusion interruption. Myocardial videointensity was measured over time from flash-echo sequences, from which characteristic constant beta was calculated using an exponential fit. Peak contrast inflow rate was calculated from ICI data using analysis of local time derivatives. Computer simulations were used to investigate the effects of noise on the accuracy of peak contrast inflow rate and beta calculations. ICI resulted in uniform contrast clearance and baseline replenishment times of 15 to 25 cardiac cycles. Calculated peak contrast inflow rate followed the changes in coronary flow in all hearts at both levels of reduced flow (P < .05) and had a low intermeasurement variability of 7 +/- 6%. With flash-echo, contrast clearance was less uniform and baseline replenishment times were only 4 to 6 cardiac cycles. beta Decreased significantly only at 15% flow, and had intermeasurement variability of 42 +/- 33%. Computer simulations showed that measurement errors in both perfusion indices increased with noise, but beta had larger errors at higher rates of contrast inflow. ICI provides the basis for accurate and reproducible quantification of myocardial perfusion using fast and robust numeric analysis, and may constitute an alternative to the currently used techniques.

Flash X-Ray Apparatus With Spectrum Control Functions For Medical Use And Fuji Computed Radiography

NASA Astrophysics Data System (ADS)

Isobe, H.; Sato, E.; Hayasi, Y.; Suzuki, M.; Arima, H.; Hoshino, F.

1985-02-01

Flash radiographic bio-medical studies at sub-microsecond intervals were performed by using both a new type of flash X-ray(FX) apparatus with spectrum control functions and Fuji Computed Radiography(FCR). This single flasher tends to have a comparatively long exposure time and the electric pulse width of the FX wave form is about 0.3,usec. The maximum FX dose is about 50mR at 1m per pulse, and the effective focal spot varies according to condenser charging voltage, A-C distance, etc., ranging from 1.0 to 3.0mm in diameter, but in the low dose rate region it can be reduced to less than 1.0mm in diameter. The FX dose is determined by the condenser charging voltage and the A-C distance, while the FX spectrum is determined by the average voltage of the FX tube and filters. Various clear FX images were obtained by controlling the spectrum and dose. FCR is a new storage medium for medical radiography developed by the Fuji Photo Film Co., Ltd. and this apparatus has various image forming functions: low dose radiography, film density control, image contrast control, subtraction management and others. We have used this new apparatus in conjunction with our FX radiography and have obtained some new and interesting biomedical radiograms: the edge enhancement image, the instantaneous enlarged image, and the single exposure energy subtraction image using the FX spectrum distribution.

Design and fabrication of memory devices based on nanoscale polyoxometalate clusters

NASA Astrophysics Data System (ADS)

Busche, Christoph; Vilà-Nadal, Laia; Yan, Jun; Miras, Haralampos N.; Long, De-Liang; Georgiev, Vihar P.; Asenov, Asen; Pedersen, Rasmus H.; Gadegaard, Nikolaj; Mirza, Muhammad M.; Paul, Douglas J.; Poblet, Josep M.; Cronin, Leroy

2014-11-01

Flash memory devices--that is, non-volatile computer storage media that can be electrically erased and reprogrammed--are vital for portable electronics, but the scaling down of metal-oxide-semiconductor (MOS) flash memory to sizes of below ten nanometres per data cell presents challenges. Molecules have been proposed to replace MOS flash memory, but they suffer from low electrical conductivity, high resistance, low device yield, and finite thermal stability, limiting their integration into current MOS technologies. Although great advances have been made in the pursuit of molecule-based flash memory, there are a number of significant barriers to the realization of devices using conventional MOS technologies. Here we show that core-shell polyoxometalate (POM) molecules can act as candidate storage nodes for MOS flash memory. Realistic, industry-standard device simulations validate our approach at the nanometre scale, where the device performance is determined mainly by the number of molecules in the storage media and not by their position. To exploit the nature of the core-shell POM clusters, we show, at both the molecular and device level, that embedding [(Se(IV)O3)2]4- as an oxidizable dopant in the cluster core allows the oxidation of the molecule to a [Se(V)2O6]2- moiety containing a {Se(V)-Se(V)} bond (where curly brackets indicate a moiety, not a molecule) and reveals a new 5+ oxidation state for selenium. This new oxidation state can be observed at the device level, resulting in a new type of memory, which we call `write-once-erase'. Taken together, these results show that POMs have the potential to be used as a realistic nanoscale flash memory. Also, the configuration of the doped POM core may lead to new types of electrical behaviour. This work suggests a route to the practical integration of configurable molecules in MOS technologies as the lithographic scales approach the molecular limit.

Spatio-temporal dimension of lightning flashes based on three-dimensional Lightning Mapping Array

NASA Astrophysics Data System (ADS)

López, Jesús A.; Pineda, Nicolau; Montanyà, Joan; Velde, Oscar van der; Fabró, Ferran; Romero, David

2017-11-01

3D mapping system like the LMA - Lightning Mapping Array - are a leap forward in lightning observation. LMA measurements has lead to an improvement on the analysis of the fine structure of lightning, allowing to characterize the duration and maximum extension of the cloud fraction of a lightning flash. During several years of operation, the first LMA deployed in Europe has been providing a large amount of data which now allows a statistical approach to compute the full duration and horizontal extension of the in-cloud phase of a lightning flash. The "Ebro Lightning Mapping Array" (ELMA) is used in the present study. Summer and winter lighting were analyzed for seasonal periods (Dec-Feb and Jun-Aug). A simple method based on an ellipse fitting technique (EFT) has been used to characterize the spatio-temporal dimensions from a set of about 29,000 lightning flashes including both summer and winter events. Results show an average lightning flash duration of 440 ms (450 ms in winter) and a horizontal maximum length of 15.0 km (18.4 km in winter). The uncertainties for summer lightning lengths were about ± 1.2 km and ± 0.7 km for the mean and median values respectively. In case of winter lightning, the level of uncertainty reaches up to 1 km and 0.7 km of mean and median value. The results of the successful correlation of CG discharges with the EFT method, represent 6.9% and 35.5% of the total LMA flashes detected in summer and winter respectively. Additionally, the median value of lightning lengths calculated through this correlative method was approximately 17 km for both seasons. On the other hand, the highest median ratios of lightning length to CG discharges in both summer and winter were reported for positive CG discharges.

Why Flash Type Matters: A Statistical Analysis

NASA Astrophysics Data System (ADS)

Mecikalski, Retha M.; Bitzer, Phillip M.; Carey, Lawrence D.

2017-09-01

While the majority of research only differentiates between intracloud (IC) and cloud-to-ground (CG) flashes, there exists a third flash type, known as hybrid flashes. These flashes have extensive IC components as well as return strokes to ground but are misclassified as CG flashes in current flash type analyses due to the presence of a return stroke. In an effort to show that IC, CG, and hybrid flashes should be separately classified, the two-sample Kolmogorov-Smirnov (KS) test was applied to the flash sizes, flash initiation, and flash propagation altitudes for each of the three flash types. The KS test statistically showed that IC, CG, and hybrid flashes do not have the same parent distributions and thus should be separately classified. Separate classification of hybrid flashes will lead to improved lightning-related research, because unambiguously classified hybrid flashes occur on the same order of magnitude as CG flashes for multicellular storms.

Demonstration of the Capabilities of the KINEROS2 – AGWA 3.0 Suite of Modeling Tools

EPA Science Inventory

This poster and computer demonstration illustrates a sampling of the wide range of applications that are possible using the KINEROS2 - AGWA suite of modeling tools. Applications include: 1) Incorporation of Low Impact Development (LID) features; 2) A real-time flash flood forecas...

CFS MATLAB toolbox: An experiment builder for continuous flash suppression (CFS) task.

PubMed

Nuutinen, Mikko; Mustonen, Terhi; Häkkinen, Jukka

2017-09-15

CFS toolbox is an open-source collection of MATLAB functions that utilizes PsychToolbox-3 (PTB-3). It is designed to allow a researcher to create and run continuous flash suppression experiments using a variety of experimental parameters (i.e., stimulus types and locations, noise characteristics, and experiment window settings). In a CFS experiment, one of the eyes at a time is presented with a dynamically changing noise pattern, while the other eye is concurrently presented with a static target stimulus, such as a Gabor patch. Due to the strong interocular suppression created by the dominant noise pattern mask, the target stimulus is rendered invisible for an extended duration. Very little knowledge of MATLAB is required for using the toolbox; experiments are generated by modifying csv files with the required parameters, and result data are output to text files for further analysis. The open-source code is available on the project page under a Creative Commons License ( http://www.mikkonuutinen.arkku.net/CFS_toolbox/ and https://bitbucket.org/mikkonuutinen/cfs_toolbox ).

Ensemble: a web-based system for psychology survey and experiment management.

PubMed

Tomic, Stefan T; Janata, Petr

2007-08-01

We provide a description of Ensemble, a suite of Web-integrated modules for managing and analyzing data associated with psychology experiments in a small research lab. The system delivers interfaces via a Web browser for creating and presenting simple surveys without the need to author Web pages and with little or no programming effort. The surveys may be extended by selecting and presenting auditory and/or visual stimuli with MATLAB and Flash to enable a wide range of psychophysical and cognitive experiments which do not require the recording of precise reaction times. Additionally, one is provided with the ability to administer and present experiments remotely. The software technologies employed by the various modules of Ensemble are MySQL, PHP, MATLAB, and Flash. The code for Ensemble is open source and available to the public, so that its functions can be readily extended by users. We describe the architecture of the system, the functionality of each module, and provide basic examples of the interfaces.

Ideal GLM-MHD: About the entropy consistent nine-wave magnetic field divergence diminishing ideal magnetohydrodynamics equations

NASA Astrophysics Data System (ADS)

Derigs, Dominik; Winters, Andrew R.; Gassner, Gregor J.; Walch, Stefanie; Bohm, Marvin

2018-07-01

The paper presents two contributions in the context of the numerical simulation of magnetized fluid dynamics. First, we show how to extend the ideal magnetohydrodynamics (MHD) equations with an inbuilt magnetic field divergence cleaning mechanism in such a way that the resulting model is consistent with the second law of thermodynamics. As a byproduct of these derivations, we show that not all of the commonly used divergence cleaning extensions of the ideal MHD equations are thermodynamically consistent. Secondly, we present a numerical scheme obtained by constructing a specific finite volume discretization that is consistent with the discrete thermodynamic entropy. It includes a mechanism to control the discrete divergence error of the magnetic field by construction and is Galilean invariant. We implement the new high-order MHD solver in the adaptive mesh refinement code FLASH where we compare the divergence cleaning efficiency to the constrained transport solver available in FLASH (unsplit staggered mesh scheme).

Variable Message Signs for road tunnel emergency evacuations.

PubMed

Ronchi, Enrico; Nilsson, Daniel; Modig, Henric; Walter, Anders Lindgren

2016-01-01

This paper investigates the design of Variable Message Signs (VMS) as a way-finding aid for road tunnel emergency evacuations. The use of the Theory of Affordances is suggested to provide recommendations on the design of VMS. A preliminary evaluation of 11 selected VMS systems was performed and 6 of them were further evaluated using an affordance-based within subject stated-preference questionnaire administered to a sample of 62 participants. Results are used to provide recommendations on the characteristics of the VMS systems, such as (1) size of the sign (large or small); (2) use of flashing lights; (3) colour scheme; (4) message coding (i.e., text, pictograms or a combination of them). The best performing VMS features for road tunnel emergency evacuation included the use of larger signs, flashing lights, the combination of emergency exit pictorial symbol in green in one panel and text in amber in the other panel. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

String flash-boiling in gasoline direct injection simulations with transient needle motion

DOE PAGES

Baldwin, Eli T.; Grover, Jr., Ronald O.; Parrish, Scott E.; ...

2016-09-06

A computational study was performed to investigate the influence of transient needle motion on gasoline direct injection (GDI) internal nozzle flow and near-field sprays. Simulations were conducted with a compressible Eulerian flow solver modeling liquid, vapor, and non-condensable gas phases with a diffuse interface. Variable rate generation and condensation of fuel vapor were captured using the homogeneous relaxation model (HRM). The non-flashing (spray G) and flashing (spray G2) conditions specified by the Engine Combustion Network were modeled using the nominal spray G nozzle geometry and transient needle lift and wobble were based upon ensemble averaged x-ray imaging preformed at Argonnemore » National Lab. The minimum needle lift simulated was 5 μm and dynamic mesh motion was achieved with Laplacian smoothing. The results were qualitatively validated against experimental imaging and the experimental rate of injection profile was captured accurately using pressure boundary conditions and needle motion to actu- ate the injection. Needle wobble was found to have no measurable effect on the flow. Low needle lift is shown to result in vapor generation as fuel rushes past the needle. In conclusion, the internal injector flow is shown to contain many transient and interacting vortices which cause perturbations in the spray angle, fluctuations in the mass flux, and frequently result in string flash-boiling.« less

String flash-boiling in gasoline direct injection simulations with transient needle motion

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

Baldwin, Eli T.; Grover, Jr., Ronald O.; Parrish, Scott E.

A computational study was performed to investigate the influence of transient needle motion on gasoline direct injection (GDI) internal nozzle flow and near-field sprays. Simulations were conducted with a compressible Eulerian flow solver modeling liquid, vapor, and non-condensable gas phases with a diffuse interface. Variable rate generation and condensation of fuel vapor were captured using the homogeneous relaxation model (HRM). The non-flashing (spray G) and flashing (spray G2) conditions specified by the Engine Combustion Network were modeled using the nominal spray G nozzle geometry and transient needle lift and wobble were based upon ensemble averaged x-ray imaging preformed at Argonnemore » National Lab. The minimum needle lift simulated was 5 μm and dynamic mesh motion was achieved with Laplacian smoothing. The results were qualitatively validated against experimental imaging and the experimental rate of injection profile was captured accurately using pressure boundary conditions and needle motion to actu- ate the injection. Needle wobble was found to have no measurable effect on the flow. Low needle lift is shown to result in vapor generation as fuel rushes past the needle. In conclusion, the internal injector flow is shown to contain many transient and interacting vortices which cause perturbations in the spray angle, fluctuations in the mass flux, and frequently result in string flash-boiling.« less

Pushing the P300-based brain-computer interface beyond 100 bpm: extending performance guided constraints into the temporal domain.

PubMed

Townsend, G; Platsko, V

2016-04-01

A new presentation paradigm for the P300-based brain-computer interface (BCI) referred to as the 'asynchronous paradigm' (ASP) is introduced and studied. It is based on the principle of performance guided constraints (Townsend et al 2012 Neurosci. Lett. 531 63-8) extended from the spatial domain into the temporal domain. The traditional constraint of flashing targets in predefined constant epochs of time is eliminated and targets flash asynchronously with timing based instead on constraints intended to improve performance. We propose appropriate temporal constraints to derive the ASP and compare its performance to that of the 'checkerboard paradigm' (CBP), which has previously been shown to be superior to the standard 'row/column paradigm' introduced by Farwell and Donchin (1988 Electroencephalogr. Clin. Neurophysiol. 70 510-23). Ten participants were tested in the ASP and CBP conditions both with traditional flashing items and with flashing faces in place of the targets (see Zhang et al 2012 J. Neural Eng. 9 026018; Kaufmann and Kübler 2014 J. Neural Eng. 11 ; Chen et al 2015 J. Neurosci. Methods 239 18-27). Eleven minutes of calibration data were used as input to a stepwise linear discriminant analysis to derive classification coefficients used for online classification. Accuracy was consistently high for both paradigms (87% and 93%) while information transfer rate was 45% higher for the ASP than the CBP. In a free spelling task, one subject spelled a 66 character sentence (from a 72 item matrix) with 100% accuracy in 3 min and 24 s demonstrating a practical throughput of 120 bits per minute (bpm) with a theoretical upper bound of 258 bpm. The subject repeated the task three times in a row without error. This work represents an advance in P300 speller technology and raises the ceiling that was being reached on P300-based BCIs. Most importantly, the research presented here is a novel and effective general strategy for organising timing for flashing items. The ASP is only one possible implementation of this work since in general it can be used to describe all previous existing presentation paradigms as well as any possible new ones. This may be especially important for people with neuromuscular disabilities.

Hydrogen and helium shell burning during white dwarf accretion

NASA Astrophysics Data System (ADS)

Cui, Xiao; Meng, Xiang-Cun; Han, Zhan-Wen

2018-05-01

Type Ia supernovae (SNe Ia) are believed to be thermonuclear explosions of carbon oxygen (CO) white dwarfs (WDs) with masses close to the Chandrasekhar mass limit. How a CO WD accretes matter and grows in mass to this limit is not well understood, hindering our understanding of SN Ia explosions and the reliability of using SNe Ia as a cosmological distance indicator. In this work, we employed the stellar evolution code MESA to simulate the accretion process of hydrogen-rich material onto a 1.0 M ⊙ CO WD at a high rate (over the Eddington limit) of 4.3 × 10‑7 M ⊙ yr‑1. The simulation demonstrates the characteristics of the double shell burning on top of the WD, with a hydrogen shell burning on top of a helium burning shell. The results show that helium shell burning is not steady (i.e. it flashes). Flashes from the helium shell are weaker than those in the case of accretion of helium-rich material onto a CO WD. The carbon to oxygen mass ratio resulting from the helium shell burning is higher than what was previously thought. Interestingly, the CO WD growing due to accretion has an outer part containing a small fraction of helium in addition to carbon and oxygen. The flashes become weaker and weaker as the accretion continues.

Implementation of a 3D mixing layer code on parallel computers

NASA Technical Reports Server (NTRS)

Roe, K.; Thakur, R.; Dang, T.; Bogucz, E.

1995-01-01

This paper summarizes our progress and experience in the development of a Computational-Fluid-Dynamics code on parallel computers to simulate three-dimensional spatially-developing mixing layers. In this initial study, the three-dimensional time-dependent Euler equations are solved using a finite-volume explicit time-marching algorithm. The code was first programmed in Fortran 77 for sequential computers. The code was then converted for use on parallel computers using the conventional message-passing technique, while we have not been able to compile the code with the present version of HPF compilers.

40 CFR 194.23 - Models and computer codes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Models and computer codes. 194.23... General Requirements § 194.23 Models and computer codes. (a) Any compliance application shall include: (1... obtain stable solutions; (iv) Computer models accurately implement the numerical models; i.e., computer...

40 CFR 194.23 - Models and computer codes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Models and computer codes. 194.23... General Requirements § 194.23 Models and computer codes. (a) Any compliance application shall include: (1... obtain stable solutions; (iv) Computer models accurately implement the numerical models; i.e., computer...

40 CFR 194.23 - Models and computer codes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Models and computer codes. 194.23... General Requirements § 194.23 Models and computer codes. (a) Any compliance application shall include: (1... obtain stable solutions; (iv) Computer models accurately implement the numerical models; i.e., computer...

40 CFR 194.23 - Models and computer codes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Models and computer codes. 194.23... General Requirements § 194.23 Models and computer codes. (a) Any compliance application shall include: (1... obtain stable solutions; (iv) Computer models accurately implement the numerical models; i.e., computer...

40 CFR 194.23 - Models and computer codes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Models and computer codes. 194.23... General Requirements § 194.23 Models and computer codes. (a) Any compliance application shall include: (1... obtain stable solutions; (iv) Computer models accurately implement the numerical models; i.e., computer...

Computer Description of Black Hawk Helicopter

DTIC Science & Technology

1979-06-01

Model Combinatorial Geometry Models Black Hawk Helicopter Helicopter GIFT Computer Code Geometric Description of Targets 20. ABSTRACT...description was made using the technique of combinatorial geometry (COM-GEOM) and will be used as input to the GIFT computer code which generates Tliic...rnHp The data used bv the COVART comtmter code was eenerated bv the Geometric Information for Targets ( GIFT )Z computer code. This report documents

High-Speed Photography with Computer Control.

ERIC Educational Resources Information Center

Winters, Loren M.

1991-01-01

Describes the use of a microcomputer as an intervalometer for the control and timing of several flash units to photograph high-speed events. Applies this technology to study the oscillations of a stretched rubber band, the deceleration of high-speed projectiles in water, the splashes of milk drops, and the bursts of popcorn kernels. (MDH)

Towards Transparent Computing: Content Authoring Using Open Standards

ERIC Educational Resources Information Center

Godwin-Jones, Robert

2014-01-01

With today's rapid developments in digital technologies, technical obsolescence can occur much faster than in the past. Who would have predicted five years ago that Adobe's Flash would have seen the rapid decline it has experienced as a development environment? Using open, internationally accepted standards for materials development is…

Miniature, mobile X-ray computed radiography system

DOEpatents

Watson, Scott A; Rose, Evan A

2017-03-07

A miniature, portable x-ray system may be configured to scan images stored on a phosphor. A flash circuit may be configured to project red light onto a phosphor and receive blue light from the phosphor. A digital monochrome camera may be configured to receive the blue light to capture an article near the phosphor.

From Floppies to Flash--Your Guide to Removable Media

ERIC Educational Resources Information Center

Berdinka, Matthew J.

2005-01-01

Technology that once involved a scary, mysterious machine the size of a small house now fits on desktops and commonly appears in offices, schools, and homes. Computers allow for processing, storing and transmitting data between two or more people virtually anywhere in the world. They also allow users to save documents, presentations, photos and…

Measuring hot flash phenomenonology using ambulatory prospective digital diaries

PubMed Central

Fisher, William I.; Thurston, Rebecca C.

2016-01-01

Objective This study provides the description, protocol, and results from a novel prospective ambulatory digital hot flash phenomenon diary. Methods This study included 152 midlife women with daily hot flashes who completed an ambulatory electronic hot flash diary continuously for the waking hours of 3 consecutive days. In this diary, women recorded their hot flashes and accompanying characteristics and associations as the hot flashes occurred. Results Self-reported hot flash severity on the digital diaries indicated that the majority of hot flashes were rated as mild (41.3%) or moderate (43.7%). Severe (13.1%) and very severe (1.8%) hot flashes were less common. Hot flash bother ratings were rated as mild (43%), or moderate (33.5%), with fewer hot flashes reported bothersome (17.5%) or very bothersome (6%). The majority of hot flashes were reported as occurring on the on the face (78.9%), neck (74.7%), and chest (61.3%). Prickly skin was reported concurrently with 32% of hot flashes, 7% with anxiety and 5% with nausea. A novel finding, 38% of hot flashes were accompanied by a premonitory aura. Conclusion A prospective electronic digital hot flash diary allows for a more precise quantitation of hot flashes while overcoming many of the limitations of commonly employed retrospective questionnaires and paper diaries. Unique insights into the phenomenology, loci and associated characteristics of hot flashes were obtained using this device. The digital hot flash phenomenology diary is recommended for future ambulatory studies of hot flashes as a prospective measure of the hot flash experience. PMID:27404030

Measuring hot flash phenomenonology using ambulatory prospective digital diaries.

PubMed

Fisher, William I; Thurston, Rebecca C

2016-11-01

This study provides the description, protocol, and results from a novel prospective ambulatory digital hot flash phenomenon diary. This study included 152 midlife women with daily hot flashes who completed an ambulatory electronic hot flash diary continuously for the waking hours of three consecutive days. In this diary, women recorded their hot flashes and accompanying characteristics and associations as the hot flashes occurred. Self-reported hot flash severity on the digital diaries indicated that the majority of hot flashes were rated as mild (41.3%) or moderate (43.7%). Severe (13.1%) and very severe (1.8%) hot flashes were less common. Hot flash bother ratings were rated as mild (43%), or moderate (33.5%), with fewer hot flashes reported bothersome (17.5%) or very bothersome (6%). The majority of hot flashes were reported as occurring on the face (78.9%), neck (74.7%), and chest (61.3%). Of all reported hot flashes, 32% occurred concurrently with prickly skin, 7% with anxiety, and 5% with nausea. A novel finding from the study was that 38% of hot flashes were accompanied by a premonitory aura. A prospective electronic digital hot flash diary allows for a more precise quantitation of hot flashes while overcoming many of the limitations of commonly used retrospective questionnaires and paper diaries. Unique insights into the phenomenology, loci, and associated characteristics of hot flashes were obtained using this device. The digital hot flash phenomenology diary is recommended for future ambulatory studies of hot flashes as a prospective measure of the hot flash experience.

NASA Tech Briefs, November 2007

NASA Technical Reports Server (NTRS)

2007-01-01

Topics include: Wireless Measurement of Contact and Motion Between Contact Surfaces; Wireless Measurement of Rotation and Displacement Rate; Portable Microleak-Detection System; Free-to-Roll Testing of Airplane Models in Wind Tunnels; Cryogenic Shrouds for Testing Thermal-Insulation Panels; Optoelectronic System Measures Distances to Multiple Targets; Tachometers Derived From a Brushless DC Motor; Algorithm-Based Fault Tolerance for Numerical Subroutines; Computational Support for Technology- Investment Decisions; DSN Resource Scheduling; Distributed Operations Planning; Phase-Oriented Gear Systems; Freeze Tape Casting of Functionally Graded Porous Ceramics; Electrophoretic Deposition on Porous Non- Conductors; Two Devices for Removing Sludge From Bioreactor Wastewater; Portable Unit for Metabolic Analysis; Flash Diffusivity Technique Applied to Individual Fibers; System for Thermal Imaging of Hot Moving Objects; Large Solar-Rejection Filter; Improved Readout Scheme for SQUID-Based Thermometry; Error Rates and Channel Capacities in Multipulse PPM; Two Mathematical Models of Nonlinear Vibrations; Simpler Adaptive Selection of Golomb Power-of- Two Codes; VCO PLL Frequency Synthesizers for Spacecraft Transponders; Wide Tuning Capability for Spacecraft Transponders; Adaptive Deadband Synchronization for a Spacecraft Formation; Analysis of Performance of Stereoscopic-Vision Software; Estimating the Inertia Matrix of a Spacecraft; Spatial Coverage Planning for Exploration Robots; and Increasing the Life of a Xenon-Ion Spacecraft Thruster.

Use of quantitative SPECT/CT reconstruction in 99mTc-sestamibi imaging of patients with renal masses.

PubMed

Jones, Krystyna M; Solnes, Lilja B; Rowe, Steven P; Gorin, Michael A; Sheikhbahaei, Sara; Fung, George; Frey, Eric C; Allaf, Mohamad E; Du, Yong; Javadi, Mehrbod S

2018-02-01

Technetium-99m ( 99m Tc)-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) has previously been shown to allow for the accurate differentiation of benign renal oncocytomas and hybrid oncocytic/chromophobe tumors (HOCTs) apart from other malignant renal tumor histologies, with oncocytomas/HOCTs showing high uptake and renal cell carcinoma (RCC) showing low uptake based on uptake ratios from non-quantitative single-photon emission computed tomography (SPECT) reconstructions. However, in this study, several tumors fell close to the uptake ratio cutoff, likely due to limitations in conventional SPECT/CT reconstruction methods. We hypothesized that application of quantitative SPECT/CT (QSPECT) reconstruction methods developed by our group would provide more robust separation of hot and cold lesions, serving as an imaging framework on which quantitative biomarkers can be validated for evaluation of renal masses with 99m Tc-sestamibi. Single-photon emission computed tomography data were reconstructed using the clinical Flash 3D reconstruction and QSPECT methods. Two blinded readers then characterized each tumor as hot or cold. Semi-quantitative uptake ratios were calculated by dividing lesion activity by background renal activity for both Flash 3D and QSPECT reconstructions. The difference between median (mean) hot and cold tumor uptake ratios measured 0.655 (0.73) with the QSPECT method and 0.624 (0.67) with the conventional method, resulting in increased separation between hot and cold tumors. Sub-analysis of 7 lesions near the separation point showed a higher absolute difference (0.16) between QPSECT and Flash 3D mean uptake ratios compared to the remaining lesions. Our finding of improved separation between uptake ratios of hot and cold lesions using QSPECT reconstruction lays the foundation for additional quantitative SPECT techniques such as SPECT-UV in the setting of renal 99m Tc-sestamibi and other SPECT/CT exams. With robust quantitative image reconstruction and biomarker analysis, there may be an expanded role for SPECT/CT imaging in renal masses and other pathologic conditions.

User manual for semi-circular compact range reflector code: Version 2

NASA Technical Reports Server (NTRS)

Gupta, Inder J.; Burnside, Walter D.

1987-01-01

A computer code has been developed at the Ohio State University ElectroScience Laboratory to analyze a semi-circular paraboloidal reflector with or without a rolled edge at the top and a skirt at the bottom. The code can be used to compute the total near field of the reflector or its individual components at a given distance from the center of the paraboloid. The code computes the fields along a radial, horizontal, vertical or axial cut at that distance. Thus, it is very effective in computing the size of the sweet spot for a semi-circular compact range reflector. This report describes the operation of the code. Various input and output statements are explained. Some results obtained using the computer code are presented to illustrate the code's capability as well as being samples of input/output sets.

Hanford meteorological station computer codes: Volume 9, The quality assurance computer codes

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

Burk, K.W.; Andrews, G.L.

1989-02-01

The Hanford Meteorological Station (HMS) was established in 1944 on the Hanford Site to collect and archive meteorological data and provide weather forecasts and related services for Hanford Site approximately 1/2 mile east of the 200 West Area and is operated by PNL for the US Department of Energy. Meteorological data are collected from various sensors and equipment located on and off the Hanford Site. These data are stored in data bases on the Digital Equipment Corporation (DEC) VAX 11/750 at the HMS (hereafter referred to as the HMS computer). Files from those data bases are routinely transferred to themore » Emergency Management System (EMS) computer at the Unified Dose Assessment Center (UDAC). To ensure the quality and integrity of the HMS data, a set of Quality Assurance (QA) computer codes has been written. The codes will be routinely used by the HMS system manager or the data base custodian. The QA codes provide detailed output files that will be used in correcting erroneous data. The following sections in this volume describe the implementation and operation of QA computer codes. The appendices contain detailed descriptions, flow charts, and source code listings of each computer code. 2 refs.« less

Control of a nursing bed based on a hybrid brain-computer interface.

PubMed

Nengneng Peng; Rui Zhang; Haihua Zeng; Fei Wang; Kai Li; Yuanqing Li; Xiaobin Zhuang

2016-08-01

In this paper, we propose an intelligent nursing bed system which is controlled by a hybrid brain-computer interface (BCI) involving steady-state visual evoked potential (SSVEP) and P300. Specifically, the hybrid BCI includes an asynchronous brain switch based on SSVEP and P300, and a P300-based BCI. The brain switch is used to turn on/off the control system of the electric nursing bed through idle/control state detection, whereas the P300-based BCI is for operating the nursing bed. At the beginning, the user may focus on one group of flashing buttons in the graphic user interface (GUI) of the brain switch, which can simultaneously evoke SSVEP and P300, to switch on the control system. Here, the combination of SSVEP and P300 is used for improving the performance of the brain switch. Next, the user can control the nursing bed using the P300-based BCI. The GUI of the P300-based BCI includes 10 flashing buttons, which correspond to 10 functional operations, namely, left-side up, left-side down, back up, back down, bedpan open, bedpan close, legs up, legs down, right-side up, and right-side down. For instance, he/she can focus on the flashing button "back up" in the GUI of the P300-based BCI to activate the corresponding control such that the nursing bed is adjusted up. Eight healthy subjects participated in our experiment, and obtained an average accuracy of 93.75% and an average false positive rate (FPR) of 0.15 event/min. The effectiveness of our system was thus demonstrated.

Measurement of g Using a Flashing LED

NASA Astrophysics Data System (ADS)

Terzella, T.; Sundermier, J.; Sinacore, J.; Owen, C.; Takai, H.

2008-10-01

In one of the classic free-fall experiments, a small mass is attached to a strip of paper tape and both are allowed to fall through a spark timer, where sparks are generated at regular time intervals. Students analyze marks (dots) left on the tape by the timer, thereby generating distance-versus-time data, which they analyze to extract the acceleration due to gravity g with good results. The apparatus, however, is cumbersome and often frustrating for students. High-tech versions of this experiment are done with an object dropped and followed by a motion sensor connected to a computer. The sensor relies on ultrasonic ranging to record distance and time data, which may then be displayed graphically. Students inspect the graphs to determine the value of g. Although the results are excellent, the emphasis on the computer's ability to collect and analyze data leaves little analysis for the students to perform.2 Furthermore, neither technique gives an intuitive display of what is happening. The motivation for our work was to overcome these issues by developing an innovative method for measuring g. In our version of the experiment, students drop a flashing LED at a known frequency and record its trajectory using long exposure photography with a digital camera. Proper choice of flashing LED timing parameters produces an image that allows for an accurate measurement of g and at the same time helps to explain what happens during free fall. The experiment remains high-tech in the sense that students learn to use updated equipment to record data and to carry out the analysis.

Suppressing flashes of items surrounding targets during calibration of a P300-based brain-computer interface improves performance

NASA Astrophysics Data System (ADS)

Frye, G. E.; Hauser, C. K.; Townsend, G.; Sellers, E. W.

2011-04-01

Since the introduction of the P300 brain-computer interface (BCI) speller by Farwell and Donchin in 1988, the speed and accuracy of the system has been significantly improved. Larger electrode montages and various signal processing techniques are responsible for most of the improvement in performance. New presentation paradigms have also led to improvements in bit rate and accuracy (e.g. Townsend et al (2010 Clin. Neurophysiol. 121 1109-20)). In particular, the checkerboard paradigm for online P300 BCI-based spelling performs well, has started to document what makes for a successful paradigm, and is a good platform for further experimentation. The current paper further examines the checkerboard paradigm by suppressing items which surround the target from flashing during calibration (i.e. the suppression condition). In the online feedback mode the standard checkerboard paradigm is used with a stepwise linear discriminant classifier derived from the suppression condition and one classifier derived from the standard checkerboard condition, counter-balanced. The results of this research demonstrate that using suppression during calibration produces significantly more character selections/min ((6.46) time between selections included) than the standard checkerboard condition (5.55), and significantly fewer target flashes are needed per selection in the SUP condition (5.28) as compared to the RCP condition (6.17). Moreover, accuracy in the SUP and RCP conditions remained equivalent (~90%). Mean theoretical bit rate was 53.62 bits/min in the suppression condition and 46.36 bits/min in the standard checkerboard condition (ns). Waveform morphology also showed significant differences in amplitude and latency.

User's manual for semi-circular compact range reflector code

NASA Technical Reports Server (NTRS)

Gupta, Inder J.; Burnside, Walter D.

1986-01-01

A computer code was developed to analyze a semi-circular paraboloidal reflector antenna with a rolled edge at the top and a skirt at the bottom. The code can be used to compute the total near field of the antenna or its individual components at a given distance from the center of the paraboloid. Thus, it is very effective in computing the size of the sweet spot for RCS or antenna measurement. The operation of the code is described. Various input and output statements are explained. Some results obtained using the computer code are presented to illustrate the code's capability as well as being samples of input/output sets.

Highly fault-tolerant parallel computation

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

Spielman, D.A.

We re-introduce the coded model of fault-tolerant computation in which the input and output of a computational device are treated as words in an error-correcting code. A computational device correctly computes a function in the coded model if its input and output, once decoded, are a valid input and output of the function. In the coded model, it is reasonable to hope to simulate all computational devices by devices whose size is greater by a constant factor but which are exponentially reliable even if each of their components can fail with some constant probability. We consider fine-grained parallel computations inmore » which each processor has a constant probability of producing the wrong output at each time step. We show that any parallel computation that runs for time t on w processors can be performed reliably on a faulty machine in the coded model using w log{sup O(l)} w processors and time t log{sup O(l)} w. The failure probability of the computation will be at most t {center_dot} exp(-w{sup 1/4}). The codes used to communicate with our fault-tolerant machines are generalized Reed-Solomon codes and can thus be encoded and decoded in O(n log{sup O(1)} n) sequential time and are independent of the machine they are used to communicate with. We also show how coded computation can be used to self-correct many linear functions in parallel with arbitrarily small overhead.« less

An emulator for minimizing computer resources for finite element analysis

NASA Technical Reports Server (NTRS)

Melosh, R.; Utku, S.; Islam, M.; Salama, M.

1984-01-01

A computer code, SCOPE, has been developed for predicting the computer resources required for a given analysis code, computer hardware, and structural problem. The cost of running the code is a small fraction (about 3 percent) of the cost of performing the actual analysis. However, its accuracy in predicting the CPU and I/O resources depends intrinsically on the accuracy of calibration data that must be developed once for the computer hardware and the finite element analysis code of interest. Testing of the SCOPE code on the AMDAHL 470 V/8 computer and the ELAS finite element analysis program indicated small I/O errors (3.2 percent), larger CPU errors (17.8 percent), and negligible total errors (1.5 percent).

Daily Physical Activity and Hot Flashes in the Study of Women's Health Across the Nation FLASHES Study

PubMed Central

Gibson, Carolyn; Matthews, Karen; Thurston, Rebecca

2014-01-01

Objective To examine the role of physical activity in menopausal hot flashes. Competing models conceptualize physical activity as a risk or protective factor for hot flashes. Few studies have examined this relationship prospectively using physiologic measures of hot flashes and physical activity. Design Over two 48 hour-periods, 51 participants wore a physiologic hot flash monitor and activity monitor, and reported their hot flashes in an electronic diary. Physiologic hot flashes, reported hot flashes and reported hot flashes without physiological corroboration were related to activity changes using hierarchical generalized linear modeling, adjusting for potential confounders. Setting Community. Patients Midlife women. Interventions None. Main Outcome Measures Physiologically-detected hot flashes and reported hot flashes with and without physiologic corroboration. Results Hot flash reports without physiologic corroboration were more likely after activity increases (OR 1.04, 95% CI: 1.00-1.10, p=.01), particularly among women with higher levels of depressive symptoms (interaction p=.02). No other types of hot flashes were related to physical activity. Conclusion Acute increases in physical activity were associated with increased reporting of hot flashes lacking physiologic corroboration, particularly among women with depressive symptoms. Clinicians should consider the role of symptom perception and reporting in relations between physical activity and hot flashes. PMID:24491454

Pacific Research Platform - Creation of a West Coast Big Data Freeway System Applied to the CONNected objECT (CONNECT) Data Mining Framework for Earth Science Knowledge Discovery

NASA Astrophysics Data System (ADS)

Sellars, S. L.; Nguyen, P.; Tatar, J.; Graham, J.; Kawsenuk, B.; DeFanti, T.; Smarr, L.; Sorooshian, S.; Ralph, M.

2017-12-01

A new era in computational earth sciences is within our grasps with the availability of ever-increasing earth observational data, enhanced computational capabilities, and innovative computation approaches that allow for the assimilation, analysis and ability to model the complex earth science phenomena. The Pacific Research Platform (PRP), CENIC and associated technologies such as the Flash I/O Network Appliance (FIONA) provide scientists a unique capability for advancing towards this new era. This presentation reports on the development of multi-institutional rapid data access capabilities and data pipeline for applying a novel image characterization and segmentation approach, CONNected objECT (CONNECT) algorithm to study Atmospheric River (AR) events impacting the Western United States. ARs are often associated with torrential rains, swollen rivers, flash flooding, and mudslides. CONNECT is computationally intensive, reliant on very large data transfers, storage and data mining techniques. The ability to apply the method to multiple variables and datasets located at different University of California campuses has previously been challenged by inadequate network bandwidth and computational constraints. The presentation will highlight how the inter-campus CONNECT data mining framework improved from our prior download speeds of 10MB/s to 500MB/s using the PRP and the FIONAs. We present a worked example using the NASA MERRA data to describe how the PRP and FIONA have provided researchers with the capability for advancing knowledge about ARs. Finally, we will discuss future efforts to expand the scope to additional variables in earth sciences.

A generalized one-dimensional computer code for turbomachinery cooling passage flow calculations

NASA Technical Reports Server (NTRS)

Kumar, Ganesh N.; Roelke, Richard J.; Meitner, Peter L.

1989-01-01

A generalized one-dimensional computer code for analyzing the flow and heat transfer in the turbomachinery cooling passages was developed. This code is capable of handling rotating cooling passages with turbulators, 180 degree turns, pin fins, finned passages, by-pass flows, tip cap impingement flows, and flow branching. The code is an extension of a one-dimensional code developed by P. Meitner. In the subject code, correlations for both heat transfer coefficient and pressure loss computations were developed to model each of the above mentioned type of coolant passages. The code has the capability of independently computing the friction factor and heat transfer coefficient on each side of a rectangular passage. Either the mass flow at the inlet to the channel or the exit plane pressure can be specified. For a specified inlet total temperature, inlet total pressure, and exit static pressure, the code computers the flow rates through the main branch and the subbranches, flow through tip cap for impingement cooling, in addition to computing the coolant pressure, temperature, and heat transfer coefficient distribution in each coolant flow branch. Predictions from the subject code for both nonrotating and rotating passages agree well with experimental data. The code was used to analyze the cooling passage of a research cooled radial rotor.

Evaluation of the fidelity of feature descriptor-based specimen tracking for automatic NDE data integration

NASA Astrophysics Data System (ADS)

Radkowski, Rafael; Holland, Stephen; Grandin, Robert

2018-04-01

This research addresses inspection location tracking in the field of nondestructive evaluation (NDE) using a computer vision technique to determine the position and orientation of typical NDE equipment in a test setup. The objective is the tracking accuracy for typical NDE equipment to facilitate automatic NDE data integration. Since the employed tracking technique relies on surface curvatures of an object of interest, the accuracy can be only experimentally determined. We work with flash-thermography and conducted an experiment in which we tracked a specimen and a thermography flash hood, measured the spatial relation between both, and used the relation as input to map thermography data onto a 3D model of the specimen. The results indicate an appropriate accuracy, however, unveiled calibration challenges.

Efficient Proximity Computation Techniques Using ZIP Code Data for Smart Cities †

PubMed Central

Murdani, Muhammad Harist; Hong, Bonghee

2018-01-01

In this paper, we are interested in computing ZIP code proximity from two perspectives, proximity between two ZIP codes (Ad-Hoc) and neighborhood proximity (Top-K). Such a computation can be used for ZIP code-based target marketing as one of the smart city applications. A naïve approach to this computation is the usage of the distance between ZIP codes. We redefine a distance metric combining the centroid distance with the intersecting road network between ZIP codes by using a weighted sum method. Furthermore, we prove that the results of our combined approach conform to the characteristics of distance measurement. We have proposed a general and heuristic approach for computing Ad-Hoc proximity, while for computing Top-K proximity, we have proposed a general approach only. Our experimental results indicate that our approaches are verifiable and effective in reducing the execution time and search space. PMID:29587366

Efficient Proximity Computation Techniques Using ZIP Code Data for Smart Cities †.

PubMed

Murdani, Muhammad Harist; Kwon, Joonho; Choi, Yoon-Ho; Hong, Bonghee

2018-03-24

In this paper, we are interested in computing ZIP code proximity from two perspectives, proximity between two ZIP codes ( Ad-Hoc ) and neighborhood proximity ( Top-K ). Such a computation can be used for ZIP code-based target marketing as one of the smart city applications. A naïve approach to this computation is the usage of the distance between ZIP codes. We redefine a distance metric combining the centroid distance with the intersecting road network between ZIP codes by using a weighted sum method. Furthermore, we prove that the results of our combined approach conform to the characteristics of distance measurement. We have proposed a general and heuristic approach for computing Ad-Hoc proximity, while for computing Top-K proximity, we have proposed a general approach only. Our experimental results indicate that our approaches are verifiable and effective in reducing the execution time and search space.

[Performance evaluation of CT automatic exposure control on fast dual spiral scan].

PubMed

Niwa, Shinji; Hara, Takanori; Kato, Hideki; Wada, Yoichi

2014-11-01

The performance of individual computed tomography automatic exposure control (CT-AEC) is very important for radiation dose reduction and image quality equalization in CT examinations. The purpose of this study was to evaluate the performance of CT-AEC in conventional pitch mode (Normal spiral) and fast dual spiral scan (Flash spiral) in a 128-slice dual-source CT scanner. To evaluate the response properties of CT-AEC in the 128-slice DSCT scanner, a chest phantom was placed on the patient table and was fixed at the center of the field of view (FOV). The phantom scan was performed using Normal spiral and Flash spiral scanning. We measured the effective tube current time product (Eff. mAs) of simulated organs in the chest phantom along the longitudinal (z) direction, and the dose dependence (distribution) of in-plane locations for the respective scan modes was also evaluated by using a 100-mm-long pencil-type ionization chamber. The dose length product (DLP) was evaluated using the value displayed on the console after scanning. It was revealed that the response properties of CT-AEC in Normal spiral scanning depend on the respective pitches and Flash spiral scanning is independent of the respective pitches. In-plane radiation dose of Flash spiral was lower than that of Normal spiral. The DLP values showed a difference of approximately 1.7 times at the maximum. The results of our experiments provide information for adjustments for appropriate scanning parameters using CT-AEC in a 128-slice DSCT scanner.

Adverse Effects of Induced Hot Flashes on Objectively Recorded and Subjectively Reported Sleep: Results of a Gonadotropin-Releasing Hormone Agonist Experimental Protocol

PubMed Central

Joffe, Hadine; White, David P.; Crawford, Sybil L.; McCurnin, Kristin E.; Economou, Nicole; Connors, Stephanie; Hall, Janet E.

2013-01-01

Objectives The impact of hot flashes on sleep is of great clinical interest, but results are inconsistent, especially when both hot flashes and sleep are measured objectively. Using objective and subjective measurements, we examined the impact of hot flashes on sleep by inducing hot flashes with a gonadotropin-releasing hormone agonist (GnRHa). Methods The GnRHa leuprolide was administered to 20 healthy premenopausal volunteers without hot flashes or sleep disturbances. Induced hot flashes were assessed objectively (skin-conductance monitor) and subjectively (daily diary) during one-month follow-up. Changes from baseline in objective (actigraphy) and subjective sleep quality (Pittsburgh Sleep Quality Index [PSQI]) were compared between women who did and did not develop objective hot flashes, and, in parallel analyses, subjective hot flashes. Results New-onset hot flashes were recorded in 14 (70%) and reported by 14 (70%) women (80% concordance). Estradiol was universally suppressed. Objective sleep efficiency worsened in women with objective hot flashes and improved in women without objective hot flashes (median decrease 2.6%, increase 4.2%, p=0.005). Subjective sleep quality worsened more in those with than without subjective hot flashes (median increase PSQI 2.5 vs. 1.0, p=0.03). Objective hot flashes were not associated with subjective sleep quality, nor were subjective symptoms linked to objective sleep measures. Conclusions This experimental model of induced hot flashes demonstrates a causal relationship between hot flashes and poor sleep quality. Objective hot flashes result in worse objective sleep efficiency, while subjective hot flashes worsen perceived sleep quality. PMID:23481119

Volume accumulator design analysis computer codes

NASA Technical Reports Server (NTRS)

Whitaker, W. D.; Shimazaki, T. T.

1973-01-01

The computer codes, VANEP and VANES, were written and used to aid in the design and performance calculation of the volume accumulator units (VAU) for the 5-kwe reactor thermoelectric system. VANEP computes the VAU design which meets the primary coolant loop VAU volume and pressure performance requirements. VANES computes the performance of the VAU design, determined from the VANEP code, at the conditions of the secondary coolant loop. The codes can also compute the performance characteristics of the VAU's under conditions of possible modes of failure which still permit continued system operation.

"Hour of Code": Can It Change Students' Attitudes toward Programming?

ERIC Educational Resources Information Center

Du, Jie; Wimmer, Hayden; Rada, Roy

2016-01-01

The Hour of Code is a one-hour introduction to computer science organized by Code.org, a non-profit dedicated to expanding participation in computer science. This study investigated the impact of the Hour of Code on students' attitudes towards computer programming and their knowledge of programming. A sample of undergraduate students from two…

Talking about Code: Integrating Pedagogical Code Reviews into Early Computing Courses

ERIC Educational Resources Information Center

Hundhausen, Christopher D.; Agrawal, Anukrati; Agarwal, Pawan

2013-01-01

Given the increasing importance of soft skills in the computing profession, there is good reason to provide students withmore opportunities to learn and practice those skills in undergraduate computing courses. Toward that end, we have developed an active learning approach for computing education called the "Pedagogical Code Review"…

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.

Hydrological disposition of flash flood and debris flows events in an Alpine watershed in Austria

NASA Astrophysics Data System (ADS)

Prenner, David; Kaitna, Roland; Mostbauer, Karin; Hrachowitz, Markus

2017-04-01

Debris flows and flash floods including intensive bedload transport represent severe hazards in the Alpine environment of Austria. For neither of these processes, explicit rainfall thresholds - even for specific regions - are available. This may be due to insufficient data on the temporal and spatial variation of precipitation, but probably also due to variations of the geomorphic and hydrological disposition of a watershed to produce such processes in the course of a rainfall event. In this contribution we investigate the importance of the hydrological system state for triggering debris flows and flash floods in the Ill/Suggadin watershed (500 km2), Austria, by analyzing the effects of dynamics in system state variables such as soil moisture, snow pack, or ground water level. The analysis is based on a semi-distributed conceptual rainfall-runoff model, spatially discretizing the watershed according to the available precipitation observations, elevation, topographic considerations and land cover. Input data are available from six weather stations on a daily basis ranging back to 1947. A Thiessen polygon decomposition results in six individual precipitation zones with a maximum area of about 130 km2. Elevation specific behavior of the quantities temperature and precipitation is covered through an elevation-resolved computation every 200 m. Spatial heterogeneity is considered by distinct hydrological response units for bare rock, forest, grassland, and riparian zone. To reduce numerical smearing on the hydrological results, the Implicit Euler scheme was used to discretize the balance equations. For model calibration we utilized runoff hydrographs, snow cover data as well as prior parameter and process constraints. The obtained hydrological output variables are linked to documented observed flash flood and debris flow events by means of a multivariate logistic regression. We present a summary about the daily hydrological disposition of experiencing a flash flood or debris flow event in each precipitation zone of the Ill/Suggadin region over almost 65 years. Furthermore, we will provide an interpretation of the occurred hydrological trigger patterns and show a frequency ranking. The outcomes of this study shall lead to an improved forecasting and differentiation of trigger conditions leading to debris flows and flash floods.

Micron MT29F128G08AJAAA 128GB Asynchronous Flash Memory Total Ionizing Dose Characterization Test Report

NASA Technical Reports Server (NTRS)

Campola, Michael; Wyrwas, Edward

2017-01-01

The purpose of this test was to characterize the Micron MT29F128G08AJAAAs parameter degradation for total dose response and to evaluate and compare lot date codes for sensitivity. In the test, the device was exposed to both low dose and high dose rate (HDR) irradiations using gamma radiation. Device parameters such as leakage currents, quantity of upset bits and overall chip and die health were investigated to determine which lot is more robust.

Guidelines for developing vectorizable computer programs

NASA Technical Reports Server (NTRS)

Miner, E. W.

1982-01-01

Some fundamental principles for developing computer programs which are compatible with array-oriented computers are presented. The emphasis is on basic techniques for structuring computer codes which are applicable in FORTRAN and do not require a special programming language or exact a significant penalty on a scalar computer. Researchers who are using numerical techniques to solve problems in engineering can apply these basic principles and thus develop transportable computer programs (in FORTRAN) which contain much vectorizable code. The vector architecture of the ASC is discussed so that the requirements of array processing can be better appreciated. The "vectorization" of a finite-difference viscous shock-layer code is used as an example to illustrate the benefits and some of the difficulties involved. Increases in computing speed with vectorization are illustrated with results from the viscous shock-layer code and from a finite-element shock tube code. The applicability of these principles was substantiated through running programs on other computers with array-associated computing characteristics, such as the Hewlett-Packard (H-P) 1000-F.

The Helicopter Antenna Radiation Prediction Code (HARP)

NASA Technical Reports Server (NTRS)

Klevenow, F. T.; Lynch, B. G.; Newman, E. H.; Rojas, R. G.; Scheick, J. T.; Shamansky, H. T.; Sze, K. Y.

1990-01-01

The first nine months effort in the development of a user oriented computer code, referred to as the HARP code, for analyzing the radiation from helicopter antennas is described. The HARP code uses modern computer graphics to aid in the description and display of the helicopter geometry. At low frequencies the helicopter is modeled by polygonal plates, and the method of moments is used to compute the desired patterns. At high frequencies the helicopter is modeled by a composite ellipsoid and flat plates, and computations are made using the geometrical theory of diffraction. The HARP code will provide a user friendly interface, employing modern computer graphics, to aid the user to describe the helicopter geometry, select the method of computation, construct the desired high or low frequency model, and display the results.

Enhanced fault-tolerant quantum computing in d-level systems.

PubMed

Campbell, Earl T

2014-12-05

Error-correcting codes protect quantum information and form the basis of fault-tolerant quantum computing. Leading proposals for fault-tolerant quantum computation require codes with an exceedingly rare property, a transversal non-Clifford gate. Codes with the desired property are presented for d-level qudit systems with prime d. The codes use n=d-1 qudits and can detect up to ∼d/3 errors. We quantify the performance of these codes for one approach to quantum computation known as magic-state distillation. Unlike prior work, we find performance is always enhanced by increasing d.

Convergence acceleration of the Proteus computer code with multigrid methods

NASA Technical Reports Server (NTRS)

Demuren, A. O.; Ibraheem, S. O.

1992-01-01

Presented here is the first part of a study to implement convergence acceleration techniques based on the multigrid concept in the Proteus computer code. A review is given of previous studies on the implementation of multigrid methods in computer codes for compressible flow analysis. Also presented is a detailed stability analysis of upwind and central-difference based numerical schemes for solving the Euler and Navier-Stokes equations. Results are given of a convergence study of the Proteus code on computational grids of different sizes. The results presented here form the foundation for the implementation of multigrid methods in the Proteus code.

Implementation of radiation shielding calculation methods. Volume 1: Synopsis of methods and summary of results

NASA Technical Reports Server (NTRS)

Capo, M. A.; Disney, R. K.

1971-01-01

The work performed in the following areas is summarized: (1) Analysis of Realistic nuclear-propelled vehicle was analyzed using the Marshall Space Flight Center computer code package. This code package includes one and two dimensional discrete ordinate transport, point kernel, and single scatter techniques, as well as cross section preparation and data processing codes, (2) Techniques were developed to improve the automated data transfer in the coupled computation method of the computer code package and improve the utilization of this code package on the Univac-1108 computer system. (3) The MSFC master data libraries were updated.

Nonuniform code concatenation for universal fault-tolerant quantum computing

NASA Astrophysics Data System (ADS)

Nikahd, Eesa; Sedighi, Mehdi; Saheb Zamani, Morteza

2017-09-01

Using transversal gates is a straightforward and efficient technique for fault-tolerant quantum computing. Since transversal gates alone cannot be computationally universal, they must be combined with other approaches such as magic state distillation, code switching, or code concatenation to achieve universality. In this paper we propose an alternative approach for universal fault-tolerant quantum computing, mainly based on the code concatenation approach proposed in [T. Jochym-O'Connor and R. Laflamme, Phys. Rev. Lett. 112, 010505 (2014), 10.1103/PhysRevLett.112.010505], but in a nonuniform fashion. The proposed approach is described based on nonuniform concatenation of the 7-qubit Steane code with the 15-qubit Reed-Muller code, as well as the 5-qubit code with the 15-qubit Reed-Muller code, which lead to two 49-qubit and 47-qubit codes, respectively. These codes can correct any arbitrary single physical error with the ability to perform a universal set of fault-tolerant gates, without using magic state distillation.

Game-Based Experiential Learning in Online Management Information Systems Classes Using Intel's IT Manager 3

ERIC Educational Resources Information Center

Bliemel, Michael; Ali-Hassan, Hossam

2014-01-01

For several years, we used Intel's flash-based game "IT Manager 3: Unseen Forces" as an experiential learning tool, where students had to act as a manager making real-time prioritization decisions about repairing computer problems, training and upgrading systems with better technologies as well as managing increasing numbers of technical…

Measurement Scale Influences in the Evaluation of Sight-Word Reading Interventions

ERIC Educational Resources Information Center

Yaw, Jared; Skinner, Christopher H.; Delisle, Jean; Skinner, Amy L.; Maurer, Kristin; Cihak, David; Wilhoit, Brian; Booher, Joshua

2014-01-01

Working with elementary students with disabilities, we used alternating treatment designs to evaluate and compare the effects of 2 computer-based flash card sight-word reading interventions, 1 with 1-s response intervals and another with 5-s response intervals. In Study 1, we held instructional time constant, applying both interventions for 3?min.…

48 CFR 2452.204-70 - Preservation of, and access to, contract records (tangible and electronically stored information...

Code of Federal Regulations, 2013 CFR

2013-10-01

... or data storage). ESI devices and media include, but are not be limited to: (1) Computers (mainframe...) Personal data assistants (PDAs); (5) External data storage devices including portable devices (e.g., flash drive); and (6) Data storage media (magnetic, e.g., tape; optical, e.g., compact disc, microfilm, etc...

48 CFR 2452.204-70 - Preservation of, and access to, contract records (tangible and electronically stored information...

Code of Federal Regulations, 2014 CFR

2014-10-01

... or data storage). ESI devices and media include, but are not be limited to: (1) Computers (mainframe...) Personal data assistants (PDAs); (5) External data storage devices including portable devices (e.g., flash drive); and (6) Data storage media (magnetic, e.g., tape; optical, e.g., compact disc, microfilm, etc...

Optimization strategies based on sequential quadratic programming applied for a fermentation process for butanol production.

PubMed

Pinto Mariano, Adriano; Bastos Borba Costa, Caliane; de Franceschi de Angelis, Dejanira; Maugeri Filho, Francisco; Pires Atala, Daniel Ibraim; Wolf Maciel, Maria Regina; Maciel Filho, Rubens

2009-11-01

In this work, the mathematical optimization of a continuous flash fermentation process for the production of biobutanol was studied. The process consists of three interconnected units, as follows: fermentor, cell-retention system (tangential microfiltration), and vacuum flash vessel (responsible for the continuous recovery of butanol from the broth). The objective of the optimization was to maximize butanol productivity for a desired substrate conversion. Two strategies were compared for the optimization of the process. In one of them, the process was represented by a deterministic model with kinetic parameters determined experimentally and, in the other, by a statistical model obtained using the factorial design technique combined with simulation. For both strategies, the problem was written as a nonlinear programming problem and was solved with the sequential quadratic programming technique. The results showed that despite the very similar solutions obtained with both strategies, the problems found with the strategy using the deterministic model, such as lack of convergence and high computational time, make the use of the optimization strategy with the statistical model, which showed to be robust and fast, more suitable for the flash fermentation process, being recommended for real-time applications coupling optimization and control.

Green's function methods in heavy ion shielding

NASA Technical Reports Server (NTRS)

Wilson, John W.; Costen, Robert C.; Shinn, Judy L.; Badavi, Francis F.

1993-01-01

An analytic solution to the heavy ion transport in terms of Green's function is used to generate a highly efficient computer code for space applications. The efficiency of the computer code is accomplished by a nonperturbative technique extending Green's function over the solution domain. The computer code can also be applied to accelerator boundary conditions to allow code validation in laboratory experiments.

Analytical modeling of operating characteristics of premixing-prevaporizing fuel-air mixing passages. Volume 2: User's manual

NASA Technical Reports Server (NTRS)

Anderson, O. L.; Chiappetta, L. M.; Edwards, D. E.; Mcvey, J. B.

1982-01-01

A user's manual describing the operation of three computer codes (ADD code, PTRAK code, and VAPDIF code) is presented. The general features of the computer codes, the input/output formats, run streams, and sample input cases are described.

Investigation of Natural Circulation Instability and Transients in Passively Safe Small Modular Reactors

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

Ishii, Mamoru

The NEUP funded project, NEUP-3496, aims to experimentally investigate two-phase natural circulation flow instability that could occur in Small Modular Reactors (SMRs), especially for natural circulation SMRs. The objective has been achieved by systematically performing tests to study the general natural circulation instability characteristics and the natural circulation behavior under start-up or design basis accident conditions. Experimental data sets highlighting the effect of void reactivity feedback as well as the effect of power ramp-up rate and system pressure have been used to develop a comprehensive stability map. The safety analysis code, RELAP5, has been used to evaluate experimental results andmore » models. Improvements to the constitutive relations for flashing have been made in order to develop a reliable analysis tool. This research has been focusing on two generic SMR designs, i.e. a small modular Simplified Boiling Water Reactor (SBWR) like design and a small integral Pressurized Water Reactor (PWR) like design. A BWR-type natural circulation test facility was firstly built based on the three-level scaling analysis of the Purdue Novel Modular Reactor (NMR) with an electric output of 50 MWe, namely NMR-50, which represents a BWR-type SMR with a significantly reduced reactor pressure vessel (RPV) height. The experimental facility was installed with various equipment to measure thermalhydraulic parameters such as pressure, temperature, mass flow rate and void fraction. Characterization tests were performed before the startup transient tests and quasi-steady tests to determine the loop flow resistance. The control system and data acquisition system were programmed with LabVIEW to realize the realtime control and data storage. The thermal-hydraulic and nuclear coupled startup transients were performed to investigate the flow instabilities at low pressure and low power conditions for NMR-50. Two different power ramps were chosen to study the effect of startup power density on the flow instability. The experimental startup transient results showed the existence of three different flow instability mechanisms, i.e., flashing instability, condensation induced flow instability, and density wave oscillations. In addition, the void-reactivity feedback did not have significant effects on the flow instability during the startup transients for NMR-50. ii Several initial startup procedures with different power ramp rates were experimentally investigated to eliminate the flow instabilities observed from the startup transients. Particularly, the very slow startup transient and pressurized startup transient tests were performed and compared. It was found that the very slow startup transients by applying very small power density can eliminate the flashing oscillations in the single-phase natural circulation and stabilize the flow oscillations in the phase of net vapor generation. The initially pressurized startup procedure was tested to eliminate the flashing instability during the startup transients as well. The pressurized startup procedure included the initial pressurization, heat-up, and venting process. The startup transient tests showed that the pressurized startup procedure could eliminate the flow instability during the transition from single-phase flow to two-phase flow at low pressure conditions. The experimental results indicated that both startup procedures were applicable to the initial startup of NMR. However, the pressurized startup procedures might be preferred due to short operating hours required. In order to have a deeper understanding of natural circulation flow instability, the quasi-steady tests were performed using the test facility installed with preheater and subcooler. The effect of system pressure, core inlet subcooling, core power density, inlet flow resistance coefficient, and void reactivity feedback were investigated in the quasi-steady state tests. The experimental stability boundaries were determined between unstable and stable flow conditions in the dimensionless stability plane of inlet subcooling number and Zuber number. To predict the stability boundary theoretically, linear stability analysis in the frequency domain was performed at four sections of the natural circulation test loop. The flashing phenomena in the chimney section was considered as an axially uniform heat source. And the dimensionless characteristic equation of the pressure drop perturbation was obtained by considering the void fraction effect and outlet flow resistance in the core section. The theoretical flashing boundary showed some discrepancies with previous experimental data from the quasi-steady state tests. In the future, thermal non-equilibrium was recommended to improve the accuracy of flashing instability boundary. As another part of the funded research, flow instabilities of a PWR-type SMR under low pressure and low power conditions were investigated experimentally as well. The NuScale reactor design was selected as the prototype for the PWR-type SMR. In order to experimentally study the natural circulation behavior of NuScale iii reactor during accidental scenarios, detailed scaling analyses are necessary to ensure that the scaled phenomena could be obtained in a laboratory test facility. The three-level scaling method is used as well to obtain the scaling ratios derived from various non-dimensional numbers. The design of the ideally scaled facility (ISF) was initially accomplished based on these scaling ratios. Then the engineering scaled facility (ESF) was designed and constructed based on the ISF by considering engineering limitations including laboratory space, pipe size, and pipe connections etc. PWR-type SMR experiments were performed in this well-scaled test facility to investigate the potential thermal hydraulic flow instability during the blowdown events, which might occur during the loss of coolant accident (LOCA) and loss of heat sink accident (LOHS) of the prototype PWR-type SMR. Two kinds of experiments, normal blowdown event and cold blowdown event, were experimentally investigated and compared with code predictions. The normal blowdown event was experimentally simulated since an initial condition where the pressure was lower than the designed pressure of the experiment facility, while the code prediction of blowdown started from the normal operation condition. Important thermal hydraulic parameters including reactor pressure vessel (RPV) pressure, containment pressure, local void fraction and temperature, pressure drop and natural circulation flow rate were measured and analyzed during the blowdown event. The pressure and water level transients are similar to the experimental results published by NuScale [51], which proves the capability of current loop in simulating the thermal hydraulic transient of real PWR-type SMR. During the 20000s blowdown experiment, water level in the core was always above the active fuel assemble during the experiment and proved the safety of natural circulation cooling and water recycling design of PWR-type SMR. Besides, pressure, temperature, and water level transient can be accurately predicted by RELAP5 code. However, the oscillations of natural circulation flow rate, water level and pressure drops were observed during the blowdown transients. This kind of flow oscillations are related to the water level and the location upper plenum, which is a path for coolant flow from chimney to steam generator and down comer. In order to investigate the transients start from the opening of ADS valve in both experimental and numerical way, the cold blow-down experiment is conducted. For the cold blowdown event, different from setting both reactor iv pressure vessel (RPV) and containment at high temperature and pressure, only RPV was heated close to the highest designed pressure and then open the ADS valve, same process was predicted using RELAP5 code. By doing cold blowdown experiment, the entire transients from the opening of ADS can be investigated by code and benchmarked with experimental data. Similar flow instability observed in the cold blowdown experiment. The comparison between code prediction and experiment data showed that the RELAP5 code can successfully predict the pressure void fraction and temperature transient during the cold blowdown event with limited error, but numerical instability exists in predicting natural circulation flow rate. Besides, the code is lack of capability in predicting the water level related flow instability observed in experiments.« less

Automated apparatus and method of generating native code for a stitching machine

NASA Technical Reports Server (NTRS)

Miller, Jeffrey L. (Inventor)

2000-01-01

A computer system automatically generates CNC code for a stitching machine. The computer determines the locations of a present stitching point and a next stitching point. If a constraint is not found between the present stitching point and the next stitching point, the computer generates code for making a stitch at the next stitching point. If a constraint is found, the computer generates code for changing a condition (e.g., direction) of the stitching machine's stitching head.

An electron-beam dose deposition experiment: TIGER 1-D simulation code versus thermoluminescent dosimetry

NASA Astrophysics Data System (ADS)

Murrill, Steven R.; Tipton, Charles W.; Self, Charles T.

1991-03-01

The dose absorbed in an integrated circuit (IC) die exposed to a pulse of low-energy electrons is a strong function of both electron energy and surrounding packaging materials. This report describes an experiment designed to measure how well the Integrated TIGER Series one-dimensional (1-D) electron transport simulation program predicts dose correction factors for a state-of-the-art IC package and package/printed circuit board (PCB) combination. These derived factors are compared with data obtained experimentally using thermoluminescent dosimeters (TLD's) and the FX-45 flash x-ray machine (operated in electron-beam (e-beam) mode). The results of this experiment show that the TIGER 1-D simulation code can be used to accurately predict FX-45 e-beam dose deposition correction factors for reasonably complex IC packaging configurations.

Computer codes developed and under development at Lewis

NASA Technical Reports Server (NTRS)

Chamis, Christos C.

1992-01-01

The objective of this summary is to provide a brief description of: (1) codes developed or under development at LeRC; and (2) the development status of IPACS with some typical early results. The computer codes that have been developed and/or are under development at LeRC are listed in the accompanying charts. This list includes: (1) the code acronym; (2) select physics descriptors; (3) current enhancements; and (4) present (9/91) code status with respect to its availability and documentation. The computer codes list is grouped by related functions such as: (1) composite mechanics; (2) composite structures; (3) integrated and 3-D analysis; (4) structural tailoring; and (5) probabilistic structural analysis. These codes provide a broad computational simulation infrastructure (technology base-readiness) for assessing the structural integrity/durability/reliability of propulsion systems. These codes serve two other very important functions: they provide an effective means of technology transfer; and they constitute a depository of corporate memory.

Waves generated by Asteroid impacts and their effects on US shorelines

NASA Astrophysics Data System (ADS)

Ezzedine, S. M.; Miller, P. L.; Dearborn, D. S.; Dennison, D. S.; Glascoe, L. G.; Antoun, T.

2013-12-01

On February 15, 2013 an undetected ~17-20-m diameter asteroid entered earth's atmosphere and, due to its large entry speed of 18.6 km/s and its shallow entry angle, the asteroid exploded in an airburst over Chelyabinsk, Russia, generating a bright flash, producing many small fragment meteorites and causing a powerful shock wave which released the equivalent of ~440 kt TNT of energy. About 16 hours after the Chelyabinsk asteroid, the elongated ~20m by ~40m (~30 m diameter) NEA 2012 DA14 with an estimated mass of 40 kt neared the earth surface at ~28,100km, ~2.2 earth's diameter. These two consecutive events, which were unrelated and had drastically different orbits, generated considerable attention and awareness from the public, confusion among the local residents, and raised the issue of emergency response and preparedness of local, state and government agencies. LLNL and other government agencies have performed numerical simulations of a postulated asteroid impact onto the ocean and generated data to support an emergency preparedness exercise. We illustrate the exercise through the application of several codes from source (asteroid entry) to ocean impact (splash rim) to wave generation, propagation and interaction with the shoreline. Using state-of-the-art high performance computing codes we simulate three impact sites; one site is located off the eat coat by Maryland's shoreline and two other sites on the west coast: the San Francisco bay and the Los Angeles bay shorelines, respectively. Simulations were conducted not only under deterministic conditions but also under conditions of uncertainty. Uncertainty assessment of flood hazards zones and structural integrity of infrastructures will be presented. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, and partially funded by the Laboratory Directed Research and Development Program at LLNL under tracking code 12-ERD-005.

Improving throughput for temporal target nomination using existing infrastructure

NASA Astrophysics Data System (ADS)

Raeth, Peter G.

2007-04-01

Earlier, we reported on predictive anomaly detection (PAD) for nominating targets within data streams generated by persistent sensing and surveillance. This technique is purely temporal and does not directly depend on the physics attendant on the sensed environment. Since PAD adapts to evolving data streams, there are no determinacy assumptions. We showed PAD to be general across sensor types, demonstrating it using synthetic chaotic data and in audio, visual, and infrared applications. Defense-oriented demonstrations included explosions, muzzle flashes, and missile and aircraft detection. Experiments were ground-based and air-to-air. As new sensors come on line, PAD offers immediate data filtering and target nomination. Its results can be taken individually, pixel by pixel, for spectral analysis and material detection/identification. They can also be grouped for shape analysis, target identification, and track development. PAD analyses reduce data volume by around 95%, depending on target number and size, while still retaining all target indicators. While PAD's code is simple when compared to physics codes, PAD tends to build a huge model. A PAD model for 512 x 640 frames may contain 19,660,800 Gaussian basis functions. (PAD models grow linearly with the number of pixels and the frequency content, in the FFT sense, of the sensed scenario's background data). PAD's complexity in terms of computational and data intensity is an example of what one sees in new algorithms now in the R&D pipeline, especially as DoD seeks capability that runs fully automatic, with little to no human interaction. Work is needed to improve algorithms' throughput while employing existing infrastructure, yet allowing for growth in the types of hardware employed. In this present paper, we discuss a generic cluster interface for legacy codes that can be partitioned at the data level. The discussion's foundation is the growth of PAD models to accommodate a particular scenario and the need to reduce false alarms while preserving all targets. The discussion closes with a view of future software and hardware opportunities.

Review on Monte-Carlo Tools for Simulating Relativistic Runaway Electron Avalanches and the Propagation of TerretrialTerrestrial-Gamma Ray Flashes in the Atmosphere

NASA Astrophysics Data System (ADS)

Sarria, D.

2016-12-01

The field of High Energy Atmospheric Physics (HEAP) includes the study of energetic events related to thunderstorms, such as Terrestrial Gamma-ray Flashes (TGF), associated electron-positron beams (TEB), gamma-ray glows and Thunderstorm Ground Enhancements (TGE). Understanding these phenomena requires accurate models for the interaction of particles with atmospheric air and electro-magnetic fields in the <100 MeV energy range. This study is the next step of the work presented in [C. Rutjes et al., 2016] that compared the performances of various codes in the absence of electro-magnetic fields. In the first part, we quantify simple but informative test cases of electrons in various electric field profiles. We will compare the avalanche length (of the Relativistic Runaway Electron Avalanche (RREA) process), the photon/electron spectra and spatial scattering. In particular, we test the effect of the low-energy threshold, that was found to be very important [Skeltved et al., 2014]. Note that even without a field, it was found to be important because of the straggling effect [C. Rutjes et al., 2016]. For this first part, we will be comparing GEANT4 (different flavours), FLUKA and the custom made code GRRR. In the second part, we test the propagation of these high energy particles in the atmosphere, from production altitude (around 10 km to 18 km) to satellite altitude (600 km). We use a simple and clearly fixed set-up for the atmospheric density, the geomagnetic field, the initial conditions, and the detection conditions of the particles. For this second part, we will be comparing GEANT4 (different flavours), FLUKA/CORSIKA and the custom made code MC-PEPTITA. References : C. Rutjes et al., 2016. Evaluation of Monte Carlo tools for high energy atmospheric physics. Geosci. Model Dev. Under review. Skeltved, A. B. et al., 2014. Modelling the relativistic runaway electron avalanche and the feedback mechanism with geant4. JGRA, doi :10.1002/2014JA020504.

An Analysis of Total Lightning Flash Rates Over Florida

NASA Astrophysics Data System (ADS)

Mazzetti, Thomas O.; Fuelberg, Henry E.

2017-12-01

Although Florida is known as the "Sunshine State", it also contains the greatest lightning flash densities in the United States. Flash density has received considerable attention in the literature, but lightning flash rate has received much less attention. We use data from the Earth Networks Total Lightning Network (ENTLN) to produce a 5 year (2010-2014) set of statistics regarding total flash rates over Florida and adjacent regions. Instead of tracking individual storms, we superimpose a 0.2° × 0.2° grid over the study region and count both cloud-to-ground (CG) and in-cloud (IC) flashes over 5 min intervals. Results show that the distribution of total flash rates is highly skewed toward small values, whereas the greatest rate is 185 flashes min-1. Greatest average annual flash rates ( 3 flashes min-1) are located near Orlando. The southernmost peninsula, North Florida, and the Florida Panhandle exhibit smaller average annual flash rates ( 1.5 flashes min-1). Large flash rates > 100 flashes min-1 can occur during any season, at any time during the 24 h period, and at any location within the domain. However, they are most likely during the afternoon and early evening in East Central Florida during the spring and summer months.

Transition from Target to Gaze Coding in Primate Frontal Eye Field during Memory Delay and Memory-Motor Transformation.

PubMed

Sajad, Amirsaman; Sadeh, Morteza; Yan, Xiaogang; Wang, Hongying; Crawford, John Douglas

2016-01-01

The frontal eye fields (FEFs) participate in both working memory and sensorimotor transformations for saccades, but their role in integrating these functions through time remains unclear. Here, we tracked FEF spatial codes through time using a novel analytic method applied to the classic memory-delay saccade task. Three-dimensional recordings of head-unrestrained gaze shifts were made in two monkeys trained to make gaze shifts toward briefly flashed targets after a variable delay (450-1500 ms). A preliminary analysis of visual and motor response fields in 74 FEF neurons eliminated most potential models for spatial coding at the neuron population level, as in our previous study (Sajad et al., 2015). We then focused on the spatiotemporal transition from an eye-centered target code (T; preferred in the visual response) to an eye-centered intended gaze position code (G; preferred in the movement response) during the memory delay interval. We treated neural population codes as a continuous spatiotemporal variable by dividing the space spanning T and G into intermediate T-G models and dividing the task into discrete steps through time. We found that FEF delay activity, especially in visuomovement cells, progressively transitions from T through intermediate T-G codes that approach, but do not reach, G. This was followed by a final discrete transition from these intermediate T-G delay codes to a "pure" G code in movement cells without delay activity. These results demonstrate that FEF activity undergoes a series of sensory-memory-motor transformations, including a dynamically evolving spatial memory signal and an imperfect memory-to-motor transformation.

Behavioral weight loss for the management of menopausal hot flashes: a pilot study.

PubMed

Thurston, Rebecca C; Ewing, Linda J; Low, Carissa A; Christie, Aimee J; Levine, Michele D

2015-01-01

Although adiposity has been considered to be protective against hot flashes, newer data suggest positive relationships between hot flashes and adiposity. No studies have been specifically designed to test whether weight loss reduces hot flashes. This pilot study aimed to evaluate the feasibility, acceptability, and initial efficacy of behavioral weight loss in reducing hot flashes. Forty overweight or obese women with hot flashes (≥ 4 hot flashes/d) were randomized to either behavioral weight loss intervention or wait-list control. Hot flashes were assessed before and after intervention via physiologic monitoring, diary, and questionnaire. Comparisons of changes in hot flashes and anthropometrics between conditions were performed via Wilcoxon tests. Study retention (83%) and intervention satisfaction (93.8%) were high. Most women (74.1%) reported that hot flash reduction was a major motivator for losing weight. Women randomized to the weight loss intervention lost more weight (-8.86 kg) than did women randomized to control (+0.23 kg; P < 0.0001). Women randomized to weight loss also showed greater reductions in questionnaire-reported hot flashes (2-wk hot flashes, -63.0) than did women in the control group (-28.0; P = 0.03)-a difference not demonstrated in other hot flash measures. Reductions in weight and hot flashes were significantly correlated (eg, r = 0.47, P = 0.006). This pilot study shows a behavioral weight loss program that is feasible, acceptable, and effective in producing weight loss among overweight or obese women with hot flashes. Findings indicate the importance of a larger study designed to test behavioral weight loss for hot flash reduction. Hot flash management could motivate women to engage in this health-promoting behavior.

Reactivity effects in VVER-1000 of the third unit of the kalinin nuclear power plant at physical start-up. Computations in ShIPR intellectual code system with library of two-group cross sections generated by UNK code

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

Zizin, M. N.; Zimin, V. G.; Zizina, S. N., E-mail: zizin@adis.vver.kiae.ru

2010-12-15

The ShIPR intellectual code system for mathematical simulation of nuclear reactors includes a set of computing modules implementing the preparation of macro cross sections on the basis of the two-group library of neutron-physics cross sections obtained for the SKETCH-N nodal code. This library is created by using the UNK code for 3D diffusion computation of first VVER-1000 fuel loadings. Computation of neutron fields in the ShIPR system is performed using the DP3 code in the two-group diffusion approximation in 3D triangular geometry. The efficiency of all groups of control rods for the first fuel loading of the third unit ofmore » the Kalinin Nuclear Power Plant is computed. The temperature, barometric, and density effects of reactivity as well as the reactivity coefficient due to the concentration of boric acid in the reactor were computed additionally. Results of computations are compared with the experiment.« less

Reactivity effects in VVER-1000 of the third unit of the kalinin nuclear power plant at physical start-up. Computations in ShIPR intellectual code system with library of two-group cross sections generated by UNK code

NASA Astrophysics Data System (ADS)

Zizin, M. N.; Zimin, V. G.; Zizina, S. N.; Kryakvin, L. V.; Pitilimov, V. A.; Tereshonok, V. A.

2010-12-01

The ShIPR intellectual code system for mathematical simulation of nuclear reactors includes a set of computing modules implementing the preparation of macro cross sections on the basis of the two-group library of neutron-physics cross sections obtained for the SKETCH-N nodal code. This library is created by using the UNK code for 3D diffusion computation of first VVER-1000 fuel loadings. Computation of neutron fields in the ShIPR system is performed using the DP3 code in the two-group diffusion approximation in 3D triangular geometry. The efficiency of all groups of control rods for the first fuel loading of the third unit of the Kalinin Nuclear Power Plant is computed. The temperature, barometric, and density effects of reactivity as well as the reactivity coefficient due to the concentration of boric acid in the reactor were computed additionally. Results of computations are compared with the experiment.

A Flash Flood Study on the Small Montaneous River Catchments in Western Romania

NASA Astrophysics Data System (ADS)

Győri, Maria-Mihaela; Haidu, Ionel; Humbert, Joël

2013-04-01

The present study focuses on flash flood modeling on several mountaneous catchments situated in Western Romania by the use of two methodologies, when rainfall and catchment characteristics are known. Hence, the Soil Conservation Service (SCS) Method and the Rational Method will be employed for the generation of the 1%, 2% and 10% historical flash flood hydrographs on the basis of data spanning from 1989-2009. The SCS Method has been applied on the three gauged catchments in the study area: Petris, Troas and Monorostia making use of the existing interconnection between GIS and the rainfall-runoff models. The DEM, soil data and land use preprocessing in GIS allowed a determination of the hydrologic parameters needed for the rainfall-runoff model, with special emphasis on determining the time of concentration, Lag time and the weighted Curve Number according to Antecedent Moisture Conditions II, adapted for the Romanian territory. HEC-HMS rainfall-runoff model (Hydrologic Engineering Center- Hydrologic Modeling System) facilitates the historical 1%, 2% and 10% flash flood hydrograph generation for the three afore mentioned watersheds. The model is calibrated against measured streamflow data from the three existing gauging stations. The results show a good match between the resulted hydrographs and the observed hydrographs under the form of the Peak Weighted Error RMS values. The hydrographs generated by surface runoff on the ungauged catchments in the area is based on an automation of a workflow in GIS, built with ArcGIS Model Builder graphical interface, as a large part of the functions needed were available as ArcGIS tools. The several components of this model calculate: the runoff depth in mm, the runoff coefficient, the travel time and finally the discharge module which is an application of the rational method, allowing the discharge computation for every cell within the catchment. The result consists of discharges for each isochrones that will be subsequently interpolated in order to obtain the hydrograph of the historical flash floods. The two methodologies employed offer the hydrologist the opportunity of computing the historical hydrographs be it on a section of the river at choice, or for every affluent within the small river basins studied, the graphical data being easily accessed both in GIS and HEC-HMS. The peak discharge values of the main rivers as well as those of their tributaries are of great importance in establishing the hydrologic hazard under the form of floodplain maps that are inexistent for the studied watersheds. Key words: flash flood modeling, ungauged catchments, GIS, HEC-HMS rainfall-runoff model. Aknowledgements This work was possible with the financial support of the Sectoral Operational Programme for Human Resources Development 2007-2013, co-financed by the European Social Fund, under the project number POSDRU/107/1.5/S/76841 with the title "Modern Doctoral Studies: Internationalization and Interdisciplinarity".

Users manual and modeling improvements for axial turbine design and performance computer code TD2-2

NASA Technical Reports Server (NTRS)

Glassman, Arthur J.

1992-01-01

Computer code TD2 computes design point velocity diagrams and performance for multistage, multishaft, cooled or uncooled, axial flow turbines. This streamline analysis code was recently modified to upgrade modeling related to turbine cooling and to the internal loss correlation. These modifications are presented in this report along with descriptions of the code's expanded input and output. This report serves as the users manual for the upgraded code, which is named TD2-2.

An Object-Oriented Approach to Writing Computational Electromagnetics Codes

NASA Technical Reports Server (NTRS)

Zimmerman, Martin; Mallasch, Paul G.

1996-01-01

Presently, most computer software development in the Computational Electromagnetics (CEM) community employs the structured programming paradigm, particularly using the Fortran language. Other segments of the software community began switching to an Object-Oriented Programming (OOP) paradigm in recent years to help ease design and development of highly complex codes. This paper examines design of a time-domain numerical analysis CEM code using the OOP paradigm, comparing OOP code and structured programming code in terms of software maintenance, portability, flexibility, and speed.

Spatial-temporal characteristics of lightning flash size in a supercell storm

NASA Astrophysics Data System (ADS)

Zhang, Zhixiao; Zheng, Dong; Zhang, Yijun; Lu, Gaopeng

2017-11-01

The flash sizes of a supercell storm, in New Mexico on October 5, 2004, are studied using the observations from the New Mexico Lightning Mapping Array and the Albuquerque, New Mexico, Doppler radar (KABX). First, during the temporal evolution of the supercell, the mean flash size is anti-correlated with the flash rate, following a unary power function, with a correlation coefficient of - 0.87. In addition, the mean flash size is linearly correlated with the area of reflectivity > 30 dBZ at 5 km normalized by the flash rate, with a correlation coefficient of 0.88. Second, in the horizontal, flash size increases along the direction from the region near the convection zone to the adjacent forward anvil. The region of minimum flash size usually corresponds to the region of maximum flash initiation and extent density. The horizontal correspondence between the mean flash size and the flash extent density can also be fitted by a unary power function, and the correlation coefficient is > 0.5 in 50% of the radar volume scans. Furthermore, the quality of fit is positively correlated to the convective intensity. Third, in the vertical direction, the height of the maximum flash initiation density is close to the height of maximum flash extent density, but corresponds to the height where the mean flash size is relatively small. In the discussion, the distribution of the small and dense charge regions when and where convection is vigorous in the storm, is deduced to be responsible for the relationship that flash size is temporally and spatially anti-correlated with flash rate and density, and the convective intensity.

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.

Perceived control and hot flashes in treatment-seeking breast cancer survivors and menopausal women.

PubMed

Carpenter, Janet S; Wu, Jingwei; Burns, Debra S; Yu, Menggang

2012-01-01

Lower perceived control over hot flashes has been linked to fewer coping strategies, more catastrophizing, and greater hot flash severity and distress in midlife women, yet this important concept has not yet been studied in breast cancer survivors. The aim of this study was to explore perceived control over hot flashes and hot flashes in breast cancer survivors compared with midlife women without cancer. Ninety-nine survivors and 138 midlife women completed questionnaires and a prospective, electronic hot flash diary. All data were collected at a baseline assessment before randomization in a behavioral intervention study. Both groups had moderate perceived control over hot flashes. Control was not significantly related to hot flash frequency but was significantly related to hot flash severity, bother, and interference in both groups. A significantly stronger association between control and hot flash interference was found for survivors than for midlife women. Survivors using hot flash treatments perceived less control than did survivors not using hot flash treatments, whereas the opposite was true in midlife women. Findings extend our knowledge of perceived control over hot flashes in both survivors and midlife women. Findings emphasize the importance of continued menopausal symptom assessment and management, support the importance of continuing nursing care even for survivors who are already using hot flash treatment, and suggest that nursing interventions aimed at improving perceived control over hot flashes may be more helpful for survivors than for midlife women.

Three-dimensional dynamic thermal imaging of structural flaws by dual-band infrared computed tomography

NASA Astrophysics Data System (ADS)

DelGrande, Nancy; Dolan, Kenneth W.; Durbin, Philip F.; Gorvad, Michael R.; Kornblum, B. T.; Perkins, Dwight E.; Schneberk, Daniel J.; Shapiro, Arthur B.

1993-11-01

We discuss three-dimensional dynamic thermal imaging of structural flaws using dual-band infrared (DBIR) computed tomography. Conventional (single-band) thermal imaging is difficult to interpret. It yields imprecise or qualitative information (e.g., when subsurface flaws produce weak heat flow anomalies masked by surface clutter). We use the DBIR imaging technique to clarify interpretation. We capture the time history of surface temperature difference patterns at the epoxy-glue disbond site of a flash-heated lap joint. This type of flawed structure played a significant role in causing damage to the Aloha Aircraft fuselage on the aged Boeing 737 jetliner. The magnitude of surface-temperature differences versus time for 0.1 mm air layer compared to 0.1 mm glue layer, varies from 0.2 to 1.6 degree(s)C, for simultaneously scanned front and back surfaces. The scans are taken every 42 ms from 0 to 8 s after the heat flash. By ratioing 3 - 5 micrometers and 8 - 12 micrometers DBIR images, we located surface temperature patterns from weak heat flow anomalies at the disbond site and remove the emissivity mask from surface paint of roughness variations. Measurements compare well with calculations based on TOPAX3D, a three-dimensional, finite element computer model. We combine infrared, ultrasound and x-ray imaging methods to study heat transfer, bond quality and material differences associated with the lap joint disbond site.

Computer Description of the Field Artillery Ammunition Supply Vehicle

DTIC Science & Technology

1983-04-01

Combinatorial Geometry (COM-GEOM) GIFT Computer Code Computer Target Description 2& AfTNACT (Cmne M feerve shb N ,neemssalyan ify by block number) A...input to the GIFT computer code to generate target vulnerability data. F.a- 4 ono OF I NOV 5S OLETE UNCLASSIFIED SECUOITY CLASSIFICATION OF THIS PAGE...Combinatorial Geometry (COM-GEOM) desrription. The "Geometric Information for Tarqets" ( GIFT ) computer code accepts the CO!-GEOM description and

48 CFR 252.227-7013 - Rights in technical data-Noncommercial items.

Code of Federal Regulations, 2011 CFR

2011-10-01

... causing a computer to perform a specific operation or series of operations. (3) Computer software means computer programs, source code, source code listings, object code listings, design details, algorithms... or will be developed exclusively with Government funds; (ii) Studies, analyses, test data, or similar...

48 CFR 252.227-7013 - Rights in technical data-Noncommercial items.

Code of Federal Regulations, 2012 CFR

2012-10-01

... causing a computer to perform a specific operation or series of operations. (3) Computer software means computer programs, source code, source code listings, object code listings, design details, algorithms... or will be developed exclusively with Government funds; (ii) Studies, analyses, test data, or similar...

48 CFR 252.227-7013 - Rights in technical data-Noncommercial items.

Code of Federal Regulations, 2014 CFR

2014-10-01

... causing a computer to perform a specific operation or series of operations. (3) Computer software means computer programs, source code, source code listings, object code listings, design details, algorithms... or will be developed exclusively with Government funds; (ii) Studies, analyses, test data, or similar...

48 CFR 252.227-7013 - Rights in technical data-Noncommercial items.

Code of Federal Regulations, 2010 CFR

2010-10-01

... causing a computer to perform a specific operation or series of operations. (3) Computer software means computer programs, source code, source code listings, object code listings, design details, algorithms... developed exclusively with Government funds; (ii) Studies, analyses, test data, or similar data produced for...

Synoptic-scale atmospheric conditions associated with flash flooding in watersheds of the Catskill Mountains, New York, USA

NASA Astrophysics Data System (ADS)

Teale, N. G.; Quiring, S. M.

2015-12-01

Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with flash flooding between 1987 and 2013 were examined. Flash floods were identified during this time period using USGS 15-minute discharge data at the Esopus Creek near Allaben, NY and Neversink River at Claryville, NY gauges. Overall, 25 flash floods were detected, occurring over 17 separate flash flood days. These flash flood days were compared to the days on which flash flood warnings encompassing the study area was issued by the National Weather Service. The success rate for which the flash flood warnings for Ulster County coincided with flash flood in the study watershed was 0.09, demonstrating the highly localized nature of flash flooding in the Catskill Mountain region. The synoptic-scale atmospheric patterns influencing the study area were characterized by a principal component analysis and k-means clustering of NCEP/NCAR 500 mb geopotential height reanalysis data. This procedure was executed in Spatial Synoptic Typer Tools 4.0. While 17 unique synoptic patterns were identified, only 3 types were strongly associated with flash flooding events. A strong southwesterly flow suggesting advection of moisture from the Atlantic Ocean and Gulf of Mexico is shown in composites of these 3 types. This multiscalar study thereby links flash flooding in the NYCWSS with synoptic-scale atmospheric circulation.Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with flash flooding between 1987 and 2013 were examined. Flash floods were identified during this time period using USGS 15-minute discharge data at the Esopus Creek near Allaben, NY and Neversink River at Claryville, NY gauges. Overall, 25 flash floods were detected, occurring over 17 separate flash flood days. These flash flood days were compared to the days on which flash flood warnings encompassing the study area was issued by the National Weather Service. The success rate for which the flash flood warnings for Ulster County coincided with flash flood in the study watershed was 0.09, demonstrating the highly localized nature of flash flooding in the Catskill Mountain region. The synoptic-scale atmospheric patterns influencing the study area were characterized by a principal component analysis and k-means clustering of NCEP/NCAR 500 mb geopotential height reanalysis data. This procedure was executed in Spatial Synoptic Typer Tools 4.0. While 17 unique synoptic patterns were identified, only 3 types were strongly associated with flash flooding events. A strong southwesterly flow suggesting advection of moisture from the Atlantic Ocean and Gulf of Mexico is shown in composites of these 3 types. This multiscalar study thereby links flash flooding in the NYCWSS with synoptic-scale atmospheric circulation.

Antenna pattern study, task 2

NASA Technical Reports Server (NTRS)

Harper, Warren

1989-01-01

Two electromagnetic scattering codes, NEC-BSC and ESP3, were delivered and installed on a NASA VAX computer for use by Marshall Space Flight Center antenna design personnel. The existing codes and certain supplementary software were updated, the codes installed on a computer that will be delivered to the customer, to provide capability for graphic display of the data to be computed by the use of the codes and to assist the customer in the solution of specific problems that demonstrate the use of the codes. With the exception of one code revision, all of these tasks were performed.

Longitudinal stability of MRI for mapping brain change using tensor-based morphometry.

PubMed

Leow, Alex D; Klunder, Andrea D; Jack, Clifford R; Toga, Arthur W; Dale, Anders M; Bernstein, Matt A; Britson, Paula J; Gunter, Jeffrey L; Ward, Chadwick P; Whitwell, Jennifer L; Borowski, Bret J; Fleisher, Adam S; Fox, Nick C; Harvey, Danielle; Kornak, John; Schuff, Norbert; Studholme, Colin; Alexander, Gene E; Weiner, Michael W; Thompson, Paul M

2006-06-01

Measures of brain change can be computed from sequential MRI scans, providing valuable information on disease progression, e.g., for patient monitoring and drug trials. Tensor-based morphometry (TBM) creates maps of these brain changes, visualizing the 3D profile and rates of tissue growth or atrophy, but its sensitivity depends on the contrast and geometric stability of the images. As part of the Alzheimer's Disease Neuroimaging Initiative (ADNI), 17 normal elderly subjects were scanned twice (at a 2-week interval) with several 3D 1.5 T MRI pulse sequences: high and low flip angle SPGR/FLASH (from which Synthetic T1 images were generated), MP-RAGE, IR-SPGR (N = 10) and MEDIC (N = 7) scans. For each subject and scan type, a 3D deformation map aligned baseline and follow-up scans, computed with a nonlinear, inverse-consistent elastic registration algorithm. Voxelwise statistics, in ICBM stereotaxic space, visualized the profile of mean absolute change and its cross-subject variance; these maps were then compared using permutation testing. Image stability depended on: (1) the pulse sequence; (2) the transmit/receive coil type (birdcage versus phased array); (3) spatial distortion corrections (using MEDIC sequence information); (4) B1-field intensity inhomogeneity correction (using N3). SPGR/FLASH images acquired using a birdcage coil had least overall deviation. N3 correction reduced coil type and pulse sequence differences and improved scan reproducibility, except for Synthetic T1 images (which were intrinsically corrected for B1-inhomogeneity). No strong evidence favored B0 correction. Although SPGR/FLASH images showed least deviation here, pulse sequence selection for the ADNI project was based on multiple additional image analyses, to be reported elsewhere.

Longitudinal stability of MRI for mapping brain change using tensor-based morphometry

PubMed Central

Leow, Alex D.; Klunder, Andrea D.; Jack, Clifford R.; Toga, Arthur W.; Dale, Anders M.; Bernstein, Matt A.; Britson, Paula J.; Gunter, Jeffrey L.; Ward, Chadwick P.; Whitwell, Jennifer L.; Borowski, Bret J.; Fleisher, Adam S.; Fox, Nick C.; Harvey, Danielle; Kornak, John; Schuff, Norbert; Studholme, Colin; Alexander, Gene E.; Weiner, Michael W.; Thompson, Paul M.

2007-01-01

Measures of brain change can be computed from sequential MRI scans, providing valuable information on disease progression, e.g., for patient monitoring and drug trials. Tensor-based morphometry (TBM) creates maps of these brain changes, visualizing the 3D profile and rates of tissue growth or atrophy, but its sensitivity depends on the contrast and geometric stability of the images. A s part of the Alzheimer’s Disease Neuroimaging Initiative (ADNI), 17 normal elderly subjects were scanned twice (at a 2-week interval) with several 3D 1.5 T MRI pulse sequences: high and low flip angle SPGR/FLASH (from which Synthetic T1 images were generated), MP-RAGE, IR-SPGR (N = 10) and MEDIC (N = 7) scans. For each subject and scan type, a 3D deformation map aligned baseline and follow-up scans, computed with a nonlinear, inverse-consistent elastic registration algorithm. Voxelwise statistics, in ICBM stereotaxic space, visualized the profile of mean absolute change and its cross-subject variance; these maps were then compared using permutation testing. Image stability depended on: (1) the pulse sequence; (2) the transmit/receive coil type (birdcage versus phased array); (3) spatial distortion corrections (using MEDIC sequence information); (4) B1-field intensity inhomogeneity correction (using N3). SPGR/FLASH images acquired using a birdcage coil had least overall deviation. N3 correction reduced coil type and pulse sequence differences and improved scan reproducibility, except for Synthetic T1 images (which were intrinsically corrected for B1-inhomogeneity). No strong evidence favored B0 correction. Although SPGR/FLASH images showed least deviation here, pulse sequence selection for the ADNI project was based on multiple additional image analyses, to be reported elsewhere. PMID:16480900

Hot Flashes and Quality of Life Among Breast Cancer Patients

DTIC Science & Technology

2006-08-01

hot flashes, 40.7% report at baseline, having used HRT and 26.8% used exercise to control hot flashes. The 12-month data indicates that 26.5% of the...entire sample who are experiencing hot flashes, tried or are using some form of HRT to control hot flashes with exercise still the most frequently...used approach to manage hot flashes with 44.2% of sample currently exercising . 15. SUBJECT TERMS Breast Cancer, Hot Flashes, Quality of Life

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

Duan, X; Grimes, J; Yu, L

Purpose: Focal spot blooming is an increase in the focal spot size at increased tube current and/or decreased tube potential. In this work, we evaluated the influence of tube current on the focal spot size at low kV for two CT systems, one of which used a tube designed to reduce blooming effects. Methods: A slit camera (10 micron slit) was used to measure focal spot size on two CT scanners from the same manufacturer (Siemens Somatom Force and Definition Flash) at 70 kV and low, medium and maximum tube currents, according to the capabilities of each system (Force: 100,more » 800 and 1300 mA; Flash: 100, 200 and 500 mA). Exposures were made with a stationary tube in service mode using a raised stand without table movement or flying focal spot technique. Focal spot size, nominally 0.8 and 1.2 mm, respectively, was measured parallel and perpendicular to the cathode-anode axis by calculating the full-width-at-half-maximum of the slit profile recording using computed radiographic plates. Results: Focal spot sizes perpendicular to the anode-cathode axis increased at the maximum mA by 5.7% on the Force and 39.1% on the Flash relative to that at the minimal mA, even though the mA was increased 13-fold on the Force and only 5- fold on the Flash. Focal spot size increased parallel to the anode-cathode axis by 70.4% on Force and 40.9% on Flash. Conclusion: For CT protocols using low kV, high mA is typically required. These protocols are relevant in children and smaller adults, and for dual-energy scanning. Technical measures to limit focal spot blooming are important in these settings to avoid reduced spatial resolution. The x-ray tube on a recently-introduced scanner appears to greatly reduce blooming effects, even at very high mA values. CHM has research support from Siemens Healthcare.« less

Physiologically assessed hot flashes and endothelial function among midlife women.

PubMed

Thurston, Rebecca C; Chang, Yuefang; Barinas-Mitchell, Emma; Jennings, J Richard; von Känel, Roland; Landsittel, Doug P; Matthews, Karen A

2017-08-01

Hot flashes are experienced by most midlife women. Emerging data indicate that they may be associated with endothelial dysfunction. No studies have tested whether hot flashes are associated with endothelial function using physiologic measures of hot flashes. We tested whether physiologically assessed hot flashes were associated with poorer endothelial function. We also considered whether age modified associations. Two hundred seventy-two nonsmoking women reporting either daily hot flashes or no hot flashes, aged 40 to 60 years, and free of clinical cardiovascular disease, underwent ambulatory physiologic hot flash and diary hot flash monitoring; a blood draw; and ultrasound measurement of brachial artery flow-mediated dilation to assess endothelial function. Associations between hot flashes and flow-mediated dilation were tested in linear regression models controlling for lumen diameter, demographics, cardiovascular disease risk factors, and estradiol. In multivariable models incorporating cardiovascular disease risk factors, significant interactions by age (P < 0.05) indicated that among the younger tertile of women in the sample (age 40-53 years), the presence of hot flashes (beta [standard error] = -2.07 [0.79], P = 0.01), and more frequent physiologic hot flashes (for each hot flash: beta [standard error] = -0.10 [0.05], P = 0.03, multivariable) were associated with lower flow-mediated dilation. Associations were not accounted for by estradiol. Associations were not observed among the older women (age 54-60 years) or for self-reported hot flash frequency, severity, or bother. Among the younger women, hot flashes explained more variance in flow-mediated dilation than standard cardiovascular disease risk factors or estradiol. Among younger midlife women, frequent hot flashes were associated with poorer endothelial function and may provide information about women's vascular status beyond cardiovascular disease risk factors and estradiol.

Menopausal Hot Flashes and Carotid Intima Media Thickness Among Midlife Women.

PubMed

Thurston, Rebecca C; Chang, Yuefang; Barinas-Mitchell, Emma; Jennings, J Richard; Landsittel, Doug P; Santoro, Nanette; von Känel, Roland; Matthews, Karen A

2016-12-01

There has been a longstanding interest in the role of menopause and its correlates in the development of cardiovascular disease (CVD) in women. Menopausal hot flashes are experienced by most midlife women; emerging data link hot flashes to CVD risk indicators. We tested whether hot flashes, measured via state-of-the-art physiologic methods, were associated with greater subclinical atherosclerosis as assessed by carotid ultrasound. We considered the role of CVD risk factors and estradiol concentrations in these associations. A total of 295 nonsmoking women free of clinical CVD underwent ambulatory physiologic hot flash assessments; a blood draw; and carotid ultrasound measurement of intima media thickness and plaque. Associations between hot flashes and subclinical atherosclerosis were tested in regression models controlling for CVD risk factors and estradiol. More frequent physiologic hot flashes were associated with higher carotid intima media thickness (for each additional hot flash: β [SE]=0.004 [0.001]; P=0.0001; reported hot flash: β [SE]=0.008 [0.002]; P=0.002, multivariable) and plaque (eg, for each additional hot flash, odds ratio [95% confidence interval] plaque index ≥2=1.07 [1.003-1.14]; P=0.04, relative to no plaque, multivariable] among women reporting daily hot flashes; associations were not accounted for by CVD risk factors or by estradiol. Among women reporting hot flashes, hot flashes accounted for more variance in intima media thickness than most CVD risk factors. Among women reporting daily hot flashes, frequent hot flashes may provide information about a woman's vascular status beyond standard CVD risk factors and estradiol. Frequent hot flashes may mark a vulnerable vascular phenotype among midlife women. © 2016 American Heart Association, Inc.

Menopausal Hot Flashes and Carotid Intima Media Thickness among Midlife Women

PubMed Central

Thurston, Rebecca C.; Chang, Yuefang; Barinas-Mitchell, Emma; Jennings, J. Richard; Landsittel, Doug P.; Santoro, Nanette; von Känel, Roland; Matthews, Karen A.

2016-01-01

Background and Purpose There has been a longstanding interest in the role of menopause and its correlates in the development of cardiovascular disease (CVD) in women. Menopausal hot flashes are experienced by most midlife women; emerging data link hot flashes to CVD risk indicators. We tested whether hot flashes, measured via state-of-the-art physiologic methods, were associated with greater subclinical atherosclerosis as assessed by carotid ultrasound. We considered the role of CVD risk factors and estradiol concentrations in these associations. Methods 295 nonsmoking women free of clinical CVD underwent ambulatory physiologic hot flash assessments; a blood draw; and carotid ultrasound measurement of IMT and plaque. Associations between hot flashes and subclinical atherosclerosis were tested in regression models controlling for CVD risk factors and estradiol. Results More frequent physiologic hot flashes were associated with higher carotid intima media thickness [IMT; for each additional hot flash: beta (standard error)=.004(.001), p=.0001; reported hot flash: beta (standard error)=.008(.002), p=.002, multivariable] and plaque [e.g., for each additional hot flash, odds ratio (95% confidence interval) plaque index ≥2=1.07(1.003–1.14, p=.04), relative to no plaque, multivariable] among women reporting daily hot flashes; associations were not accounted for by CVD risk factors or by estradiol. Among women reporting hot flashes, hot flashes accounted for more variance in IMT than most CVD risk factors. Conclusions Among women reporting daily hot flashes, frequent hot flashes may provide information about a woman’s vascular status beyond standard CVD risk factors and estradiol. Frequent hot flashes may mark a vulnerable vascular phenotype among midlife women. PMID:27834746

Behavioral Weight Loss for the Management of Menopausal Hot Flashes: A Pilot Study

PubMed Central

Thurston, Rebecca C.; Ewing, Linda J.; Low, Carissa A.; Christie, Aimee J.; Levine, Michele D.

2014-01-01

Objective Although adiposity has been considered protective against hot flashes, newer data suggest positive relations between flashes and adiposity. No studies have been specifically designed to test whether weight loss reduces hot flashes. This pilot study aimed to evaluate the feasibility, acceptability, and initial efficacy of behavioral weight loss to reduce hot flashes. Methods Forty overweight/obese women with hot flashes (≥4/day) were randomized to a behavioral weight loss intervention or to wait list control. Hot flashes were assessed pre- and post-intervention via physiologic monitor, diary, and questionnaire. Comparisons of changes in hot flashes and anthropometrics between conditions were tested via Wilcoxon tests. Results Study retention (83%) and intervention satisfaction (93.8%) were high. Most women (74.1%) reported that hot flash reduction was a main motivator to lose weight. Women randomized to the weight loss intervention lost more weight (-8.86 kg) than did women randomized to control (+0.23 kg, p<.0001). Women randomized to weight loss also showed greater reductions in questionnaire-reported hot flashes (2-week hot flashes: −63.0) than did women in the control (−28.0, p=.03), a difference not demonstrated in other hot flash measures. Reductions in weight and hot flashes were significantly correlated (e.g., r=.47, p=.006). Conclusions This pilot study showed a behavioral weight loss program to be feasible, acceptable, and effective in producing weight loss among overweight/obese women with hot flashes. Findings indicate the importance of a larger study designed to test behavioral weight loss for hot flash reduction. Hot flash management could motivate women to engage in this health-promoting behavior. PMID:24977456

48 CFR 252.227-7013 - Rights in technical data-Noncommercial items.

Code of Federal Regulations, 2013 CFR

2013-10-01

... causing a computer to perform a specific operation or series of operations. (3) Computer software means computer programs, source code, source code listings, object code listings, design details, algorithms... funds; (ii) Studies, analyses, test data, or similar data produced for this contract, when the study...

Parallel Computation of the Jacobian Matrix for Nonlinear Equation Solvers Using MATLAB

NASA Technical Reports Server (NTRS)

Rose, Geoffrey K.; Nguyen, Duc T.; Newman, Brett A.

2017-01-01

Demonstrating speedup for parallel code on a multicore shared memory PC can be challenging in MATLAB due to underlying parallel operations that are often opaque to the user. This can limit potential for improvement of serial code even for the so-called embarrassingly parallel applications. One such application is the computation of the Jacobian matrix inherent to most nonlinear equation solvers. Computation of this matrix represents the primary bottleneck in nonlinear solver speed such that commercial finite element (FE) and multi-body-dynamic (MBD) codes attempt to minimize computations. A timing study using MATLAB's Parallel Computing Toolbox was performed for numerical computation of the Jacobian. Several approaches for implementing parallel code were investigated while only the single program multiple data (spmd) method using composite objects provided positive results. Parallel code speedup is demonstrated but the goal of linear speedup through the addition of processors was not achieved due to PC architecture.

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

NASA Astrophysics Data System (ADS)

Bonacci, O.; Ljubenkov, I.; Roje-Bonacci, T.

2006-03-01

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

Multi- and unisensory visual flash illusions.

PubMed

Courtney, Jon R; Motes, Michael A; Hubbard, Timothy L

2007-01-01

The role of stimulus structure in multisensory and unisensory interactions was examined. When a flash (17 ms) was accompanied by multiple tones (each 7 ms, SOA < or =100 ms) multiple flashes were reported, and this effect has been suggested to reflect the role of stimulus continuity in multisensory interactions. In experiments 1 and 2 we examined if stimulus continuity would affect concurrently presented stimuli. When a relatively longer flash (317 ms) was accompanied by multiple tones (each 7 ms), observers reported perceiving multiple flashes. In experiment 3 we tested whether a flash presented near fixation would induce an illusory flash further in the periphery. One flash (17 ms) presented 5 degrees below fixation was reported as multiple flashes if presented with two flashes (each 17 ms, SOA =100 ms) 2 degrees above fixation. The extent to which these data support a phenomenological continuity principle and whether this principle applies to unisensory perception is discussed.

Interactions of numerical and temporal stimulus characteristics on the control of response location by brief flashes of light.

PubMed

Fetterman, J Gregor; Killeen, P Richard

2011-09-01

Pigeons pecked on three keys, responses to one of which could be reinforced after 3 flashes of the houselight, to a second key after 6, and to a third key after 12. The flashes were arranged according to variable-interval schedules. Response allocation among the keys was a function of the number of flashes. When flashes were omitted, transitions occurred very late. Increasing flash duration produced a leftward shift in the transitions along a number axis. Increasing reinforcement probability produced a leftward shift, and decreasing reinforcement probability produced a rightward shift. Intermixing different flash rates within sessions separated allocations: Faster flash rates shifted the functions sooner in real time, but later in terms of flash count, and conversely for slower flash rates. A model of control by fading memories of number and time was proposed.

User Instructions for the Systems Assessment Capability, Rev. 1, Computer Codes Volume 3: Utility Codes

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

Eslinger, Paul W.; Aaberg, Rosanne L.; Lopresti, Charles A.

2004-09-14

This document contains detailed user instructions for a suite of utility codes developed for Rev. 1 of the Systems Assessment Capability. The suite of computer codes for Rev. 1 of Systems Assessment Capability performs many functions.

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.

Visual Attention in Deaf and Normal Hearing Adults: Effects of Stimulus Compatibility

ERIC Educational Resources Information Center

Sladen, Douglas P.; Tharpe, Anne Marie; Ashmead, Daniel H.; Grantham, D. Wesley; Chun, Marvin M.

2005-01-01

Visual perceptual skills of deaf and normal hearing adults were measured using the Eriksen flanker task. Participants were seated in front of a computer screen while a series of target letters flanked by similar or dissimilar letters was flashed in front of them. Participants were instructed to press one button when they saw an "H," and another…

A Public + Private Mashup for Computer Science Education

ERIC Educational Resources Information Center

Wang, Kevin

2013-01-01

Getting called into the boss's office isn't always fun. Memories of trips to the school principal's office flash through one's mind. But the day last year that the author was called in to meet with their division vice president turned out to be a very good day. Executives at his company, Microsoft, had noticed the program he created in his spare…

The Location and Effects of Visual Hemisphere-Specific Stimulation on Reading Fluency in Children with the Characteristics of Dyslexia

ERIC Educational Resources Information Center

Koen, Bobbie Jean; Hawkins, Jacqueline; Zhu, Xi; Jansen, Ben; Fan, Weihua; Johnson, Sharon

2018-01-01

Fluency is used as an indicator of reading proficiency. Many students with reading disabilities are unable to benefit from typical interventions. This study is designed to replicate Lorusso, Facoetti, Paganoni, Pezzani, and Molteni's (2006) work using FlashWord, a computer program that tachistoscopically presents words in the right or left visual…

Remediating Number Combination and Word Problem Deficits Among Students With Mathematics Difficulties: A Randomized Control Trial

PubMed Central

Fuchs, Lynn S.; Powell, Sarah R.; Seethaler, Pamela M.; Cirino, Paul T.; Fletcher, Jack M.; Fuchs, Douglas; Hamlett, Carol L.; Zumeta, Rebecca O.

2009-01-01

The purposes of this study were to assess the efficacy of remedial tutoring for 3rd graders with mathematics difficulty, to investigate whether tutoring is differentially efficacious depending on students’ math difficulty status (mathematics difficulty alone vs. mathematics plus reading difficulty), to explore transfer from number combination (NC) remediation, and to examine the transportability of the tutoring protocols. At 2 sites, 133 students were stratified on mathematics difficulty status and site and then randomly assigned to 3 conditions: control (no tutoring), tutoring on automatic retrieval of NCs (i.e., Math Flash), or tutoring on word problems with attention to the foundational skills of NCs, procedural calculations, and algebra (i.e., Pirate Math). Tutoring occurred for 16 weeks, 3 sessions per week and 20–30 min per session. Math Flash enhanced fluency with NCs with transfer to procedural computation but without transfer to algebra or word problems. Pirate Math enhanced word problem skill as well as fluency with NCs, procedural computation, and algebra. Tutoring was not differentially efficacious as a function of students’ mathematics difficulty status. The tutoring protocols proved transportable across sites. PMID:19865600

Hot flash report and measurement among Bangladeshi migrants, their London neighbors, and their community of origin.

PubMed

Sievert, L L; Begum, K; Sharmeen, T; Murphy, L; Whitcomb, B W; Chowdhury, O; Muttukrishna, S; Bentley, G R

2016-12-01

To examine hot flashes in relation to climate and activity patterns, and to compare subjective and objective hot flashes among Bangladeshi immigrants to London, their white London neighbors, and women still living in their community of origin, Sylhet, Bangladesh ("sedentees"). Ninety-five women, aged 40-55, wore the Biolog ambulatory hot flash monitor. Objective measurements and subjective hot flash reports were examined in relation to demographic, reproductive, anthropometric, and lifestyle variables; temperature and humidity at 12:00 and 18:00; and time spent on housework and cooking. Concordance of objective and subjective hot flashes was assessed by Kappa statistics and by sensitivity of hot flash classification. During the study period, Bangladeshi sedentees reported more subjective hot flashes (p < .05), but there was no difference in number of objective hot flashes. White Londoners were more likely to describe hot flashes on their face and neck compared to Bangladeshis (p < .05). Sedentees were more likely to describe hot flashes on their feet (p < .05). Postmenopausal status, increasing parity, and high levels of housework were significant determinants of subjective hot flashes, while ambient temperature and humidity were not. Measures of subjective/objective concordance were low but similar across groups (10-20%). The proportion of objective hot flashes that were also self-reported was lowest among immigrants. Hot flashes were not associated with warmer temperatures, but were associated with housework and with site-specific patterns of cooking. The number of objective hot flash measures did not differ, but differences in subjective experience suggest the influence of culture. © 2016 Wiley Periodicals, Inc.

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.

How self-reported hot flashes may relate to affect, cognitive performance and sleep.

PubMed

Regestein, Quentin; Friebely, Joan; Schiff, Isaac

2015-08-01

To explain the controversy about whether midlife women who self-report hot flashes have relatively increased affective symptoms, poor cognitive performance or worse sleep. Retrospective data from 88 women seeking relief from bothersome day and night hot flashes were submitted to mixed linear regression modeling to find if estimated hot flashes, as measured by Women's Health Questionnaire (WHQ) items, or diary-documented hot flashes recorded daily, were associated with each other, or with affective, cognitive or sleep measures. Subjects averaged 6.3 daytime diary-documented hot flashes and 2.4 nighttime diary-documented hot flashes per 24h. Confounder-controlled diary-documented hot flashes but not estimated hot flashes were associated with increased Leeds anxiety scores (F=4.9; t=2.8; p=0.01) and Leeds depression scores (3.4; 2.5; 0.02), decreased Stroop Color-Word test performance (9.4; 3.5; 0.001), increased subjective sleep disturbance (effect size=0.83) and increased objective sleep disturbance (effect size=0.35). Hot flash effects were small to moderate in size. Univariate but not multivariate analyses revealed that all hot flash measures were associated with all affect measures. Different measures of hot flashes associated differently with affect, cognition and sleep. Only nighttime diary-document hot flash consistently correlated with any affect measures in multivariate analyses. The use of differing measures for hot flashes, affect, cognition and sleep may account for the continually reported inconsistencies in menopause study outcomes. This problem impedes forging a consensus on whether hot flashes correlate with neuropsychological symptoms. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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…

Global Patterns of Lightning Properties Derived by OTD and LIS

NASA Technical Reports Server (NTRS)

Beirle, Steffen; Koshak, W.; Blakeslee, R.; Wagner, T.

2014-01-01

The satellite instruments Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) provide unique empirical data about the frequency of lightning flashes around the globe (OTD), and the tropics (LIS), which 5 has been used before to compile a well received global climatology of flash rate densities. Here we present a statistical analysis of various additional lightning properties derived from OTD/LIS, i.e. the number of so-called "events" and "groups" per flash, as well as 10 the mean flash duration, footprint and radiance. These normalized quantities, which can be associated with the flash "strength", show consistent spatial patterns; most strikingly, oceanic flashes show higher values than continental flashes for all properties. Over land, regions with high (Eastern US) 15 and low (India) flash strength can be clearly identified. We discuss possible causes and implications of the observed regional differences. Although a direct quantitative interpretation of the investigated flash properties is difficult, the observed spatial patterns provide valuable information for the 20 interpretation and application of climatological flash rates. Due to the systematic regional variations of physical flash characteristics, viewing conditions, and/or measurement sensitivities, parametrisations of lightning NOx based on total flash rate densities alone are probably affected by regional biases.

Flash-sourcing or the rapid detection and characterisation of earthquake effects through clickstream data analysis

NASA Astrophysics Data System (ADS)

Bossu, R.; Mazet-Roux, G.; Roussel, F.; Frobert, L.

2011-12-01

Rapid characterisation of earthquake effects is essential for a timely and appropriate response in favour of victims and/or of eyewitnesses. In case of damaging earthquakes, any field observations that can fill the information gap characterising their immediate aftermath can contribute to more efficient rescue operations. This paper presents the last developments of a method called "flash-sourcing" addressing these issues. It relies on eyewitnesses, the first informed and the first concerned by an earthquake occurrence. More precisely, their use of the EMSC earthquake information website (www.emsc-csem.org) is analysed in real time to map the area where the earthquake was felt and identify, at least under certain circumstances zones of widespread damage. The approach is based on the natural and immediate convergence of eyewitnesses on the website who rush to the Internet to investigate cause of the shaking they just felt causing our traffic to increase The area where an earthquake was felt is mapped simply by locating Internet Protocol (IP) addresses during traffic surges. In addition, the presence of eyewitnesses browsing our website within minutes of an earthquake occurrence excludes the possibility of widespread damage in the localities they originate from: in case of severe damage, the networks would be down. The validity of the information derived from this clickstream analysis is confirmed by comparisons with EMS98 macroseismic map obtained from online questionnaires. The name of this approach, "flash-sourcing", is a combination of "flash-crowd" and "crowdsourcing" intending to reflect the rapidity of the data collation from the public. For computer scientists, a flash-crowd names a traffic surge on a website. Crowdsourcing means work being done by a "crowd" of people; It also characterises Internet and mobile applications collecting information from the public such as online macroseismic questionnaires. Like crowdsourcing techniques, flash-sourcing is a crowd-to-agency system, but unlike them it is not based on declarative information (e.g. answers to a questionnaire) but on implicit data, clickstream observed on our website. We present first the main improvements of the method, improved detection of traffic surges, and a way to instantly map areas affected by severe damage or network disruptions. The second part describes how the derived information improves and fastens public earthquake information and, beyond seismology, what it can teach us on public behaviour when facing an earthquake. Finally, the discussion will focus on the future evolutions and how flash-sourcing could ultimately improve earthquake response.

Characteristics of Lightning Within Electrified Snowfall Events Using Lightning Mapping Arrays

NASA Astrophysics Data System (ADS)

Schultz, Christopher J.; Lang, Timothy J.; Bruning, Eric C.; Calhoun, Kristin M.; Harkema, Sebastian; Curtis, Nathan

2018-02-01

This study examined 34 lightning flashes within four separate thundersnow events derived from lightning mapping arrays (LMAs) in northern Alabama, central Oklahoma, and Washington DC. The goals were to characterize the in-cloud component of each lightning flash, as well as the correspondence between the LMA observations and lightning data taken from national lightning networks like the National Lightning Detection Network (NLDN). Individual flashes were examined in detail to highlight several observations within the data set. The study results demonstrated that the structures of these flashes were primarily normal polarity. The mean area encompassed by this set of flashes is 375 km2, with a maximum flash extent of 2,300 km2, a minimum of 3 km2, and a median of 128 km2. An average of 2.29 NLDN flashes were recorded per LMA-derived lightning flash. A maximum of 11 NLDN flashes were recorded in association with a single LMA-derived flash on 10 January 2011. Additionally, seven of the 34 flashes in the study contain zero NLDN-identified flashes. Eleven of the 34 flashes initiated from tall human-made objects (e.g., communication towers). In at least six lightning flashes, the NLDN detected a return stroke from the cloud back to the tower and not the initial upward leader. This study also discusses lightning's interaction with the human-built environment and provides an example of lightning within heavy snowfall observed by Geostationary Operational Environmental Satellite-16's Geostationary Lightning Mapper.

Hot flashes in breast cancer survivors: Frequency, severity and impact.

PubMed

Chang, Hao-Yuan; Jotwani, Aparna C; Lai, Yeur-Hur; Jensen, Mark P; Syrjala, Karen L; Fann, Jesse R; Gralow, Julie

2016-06-01

To (1) determine the frequency and severity of hot flashes, (2) examine the associations between hot flash frequency and severity and quality of life, and (3) identify the predictors of hot flash activity in breast cancer survivors. The study used a cross-sectional design and mailed survey of 253 breast cancer survivors recruited from a cancer wellness clinic. Participants provided information regarding cancer history, hot flashes, pain intensity, sleep problems, physical functioning, and psychological functioning. About half of the survivors reported at least one hot flash in the past 24 h (45%) or past week (52%). The average frequency of hot flashes was 1.9 in the past 24 h and 1.8 in the past week. Hot flash severity was usually mild or asymptomatic. However, participants with hot flashes reported significantly more sleep problems and higher pain severity than those reporting no hot flashes. Moreover, the severity of hot flashes was associated with more sleep problems, higher pain severity, and more psychological dysfunction. History of hormonal suppression therapy and younger age predicted hot flash activity in the study sample. In breast cancer survivors, hot flashes are common and are associated with unpleasant symptoms and poor quality of life. Research is needed to determine if treatments that reduce the frequency and severity of hot flashes in breast cancer survivors also result in improvements in symptoms such as sleep problems, pain, and psychological dysfunction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hot flashes in breast cancer survivors: Frequency, severity and impact

PubMed Central

Chang, Hao-Yuan; Jotwani, Aparna C.; Lai, Yeur-Hur; Jensen, Mark P.; Syrjala, Karen L.; Fann, Jesse R.; Gralow, Julie

2018-01-01

Purposes To (1) determine the frequency and severity of hot flashes, (2) examine the associations be- tween hot flash frequency and severity and quality of life, and (3) identify the predictors of hot flash activity in breast cancer survivors. Methods The study used a cross-sectional design and mailed survey of 253 breast cancer survivors recruited from a cancer wellness clinic. Participants provided information regarding cancer history, hot flashes, pain intensity, sleep problems, physical functioning, and psychological functioning. Results About half of the survivors reported at least one hot flash in the past 24 h (45%) or past week (52%). The average frequency of hot flashes was 1.9 in the past 24 h and 1.8 in the past week. Hot flash severity was usually mild or asymptomatic. However, participants with hot flashes reported significantly more sleep problems and higher pain severity than those reporting no hot flashes. Moreover, the severity of hot flashes was associated with more sleep problems, higher pain severity, and more psychological dysfunction. History of hormonal suppression therapy and younger age predicted hot flash activity in the study sample. Conclusions In breast cancer survivors, hot flashes are common and are associated with unpleasant symptoms and poor quality of life. Research is needed to determine if treatments that reduce the frequency and severity of hot flashes in breast cancer survivors also result in improvements in symptoms such as sleep problems, pain, and psychological dysfunction. PMID:27065357

Characteristics of Lightning within Electrified Snowfall Events using Lightning Mapping Arrays.

PubMed

Schultz, Christopher J; Lang, Timothy J; Bruning, Eric C; Calhoun, Kristin M; Harkema, Sebastian; Curtis, Nathan

2018-02-27

This study examined 34 lightning flashes within four separate thundersnow events derived from lightning mapping arrays (LMAs) in northern Alabama, central Oklahoma, and Washington DC. The goals were to characterize the in-cloud component of each lightning flash, as well as the correspondence between the LMA observations and lightning data taken from national lightning networks like the National Lightning Detection Network (NLDN). Individual flashes were examined in detail to highlight several observations within the dataset. The study results demonstrated that the structures of these flashes were primarily normal polarity. The mean area encompassed by this set of flashes is 375 km 2 , with a maximum flash extent of 2300 km 2 , a minimum of 3 km 2 , and a median of 128 km 2 . An average of 2.29 NLDN flashes were recorded per LMA-derived lightning flash. A maximum of 11 NLDN flashes were recorded in association with a single LMA-derived flash on 10 January 2011. Additionally, seven of the 34 flashes in the study contain zero NLDN identified flashes. Eleven of the 34 flashes initiated from tall human-made objects (e.g., communication towers). In at least six lightning flashes, the NLDN detected a return stroke from the cloud back to the tower and not the initial upward leader. This study also discusses lightning's interaction with the human built environment and provides an example of lightning within heavy snowfall observed by GOES-16's Geostationary Lightning Mapper.

Development of a model and computer code to describe solar grade silicon production processes

NASA Technical Reports Server (NTRS)

Gould, R. K.; Srivastava, R.

1979-01-01

Two computer codes were developed for describing flow reactors in which high purity, solar grade silicon is produced via reduction of gaseous silicon halides. The first is the CHEMPART code, an axisymmetric, marching code which treats two phase flows with models describing detailed gas-phase chemical kinetics, particle formation, and particle growth. It can be used to described flow reactors in which reactants, mix, react, and form a particulate phase. Detailed radial gas-phase composition, temperature, velocity, and particle size distribution profiles are computed. Also, deposition of heat, momentum, and mass (either particulate or vapor) on reactor walls is described. The second code is a modified version of the GENMIX boundary layer code which is used to compute rates of heat, momentum, and mass transfer to the reactor walls. This code lacks the detailed chemical kinetics and particle handling features of the CHEMPART code but has the virtue of running much more rapidly than CHEMPART, while treating the phenomena occurring in the boundary layer in more detail.

FLASH2: Operation, beamlines, and photon diagnostics

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

Plönjes, Elke, E-mail: elke.ploenjes@desy.de; Faatz, Bart; Kuhlmann, Marion

2016-07-27

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

Comparison of two computer codes for crack growth analysis: NASCRAC Versus NASA/FLAGRO

NASA Technical Reports Server (NTRS)

Stallworth, R.; Meyers, C. A.; Stinson, H. C.

1989-01-01

Results are presented from the comparison study of two computer codes for crack growth analysis - NASCRAC and NASA/FLAGRO. The two computer codes gave compatible conservative results when the part through crack analysis solutions were analyzed versus experimental test data. Results showed good correlation between the codes for the through crack at a lug solution. For the through crack at a lug solution, NASA/FLAGRO gave the most conservative results.

Computational Predictions of the Performance Wright 'Bent End' Propellers

NASA Technical Reports Server (NTRS)

Wang, Xiang-Yu; Ash, Robert L.; Bobbitt, Percy J.; Prior, Edwin (Technical Monitor)

2002-01-01

Computational analysis of two 1911 Wright brothers 'Bent End' wooden propeller reproductions have been performed and compared with experimental test results from the Langley Full Scale Wind Tunnel. The purpose of the analysis was to check the consistency of the experimental results and to validate the reliability of the tests. This report is one part of the project on the propeller performance research of the Wright 'Bent End' propellers, intend to document the Wright brothers' pioneering propeller design contributions. Two computer codes were used in the computational predictions. The FLO-MG Navier-Stokes code is a CFD (Computational Fluid Dynamics) code based on the Navier-Stokes Equations. It is mainly used to compute the lift coefficient and the drag coefficient at specified angles of attack at different radii. Those calculated data are the intermediate results of the computation and a part of the necessary input for the Propeller Design Analysis Code (based on Adkins and Libeck method), which is a propeller design code used to compute the propeller thrust coefficient, the propeller power coefficient and the propeller propulsive efficiency.

Proceduracy: Computer Code Writing in the Continuum of Literacy

ERIC Educational Resources Information Center

Vee, Annette

2010-01-01

This dissertation looks at computer programming through the lens of literacy studies, building from the concept of code as a written text with expressive and rhetorical power. I focus on the intersecting technological and social factors of computer code writing as a literacy--a practice I call "proceduracy". Like literacy, proceduracy is a human…

Computer Code Aids Design Of Wings

NASA Technical Reports Server (NTRS)

Carlson, Harry W.; Darden, Christine M.

1993-01-01

AERO2S computer code developed to aid design engineers in selection and evaluation of aerodynamically efficient wing/canard and wing/horizontal-tail configurations that includes simple hinged-flap systems. Code rapidly estimates longitudinal aerodynamic characteristics of conceptual airplane lifting-surface arrangements. Developed in FORTRAN V on CDC 6000 computer system, and ported to MS-DOS environment.

Cloud Computing for Complex Performance Codes.

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

Appel, Gordon John; Hadgu, Teklu; Klein, Brandon Thorin

This report describes the use of cloud computing services for running complex public domain performance assessment problems. The work consisted of two phases: Phase 1 was to demonstrate complex codes, on several differently configured servers, could run and compute trivial small scale problems in a commercial cloud infrastructure. Phase 2 focused on proving non-trivial large scale problems could be computed in the commercial cloud environment. The cloud computing effort was successfully applied using codes of interest to the geohydrology and nuclear waste disposal modeling community.

APC: A New Code for Atmospheric Polarization Computations

NASA Technical Reports Server (NTRS)

Korkin, Sergey V.; Lyapustin, Alexei I.; Rozanov, Vladimir V.

2014-01-01

A new polarized radiative transfer code Atmospheric Polarization Computations (APC) is described. The code is based on separation of the diffuse light field into anisotropic and smooth (regular) parts. The anisotropic part is computed analytically. The smooth regular part is computed numerically using the discrete ordinates method. Vertical stratification of the atmosphere, common types of bidirectional surface reflection and scattering by spherical particles or spheroids are included. A particular consideration is given to computation of the bidirectional polarization distribution function (BPDF) of the waved ocean surface.

Magnitude of the impact of hot flashes on sleep in perimenopausal women

PubMed Central

de Zambotti, Massimiliano; Colrain, Ian M.; Javitz, Harold S.; Baker, Fiona C.

2014-01-01

Objective To quantify the impact of objectively-recorded hot flashes on objective sleep in perimenopausal women. Design Cross-sectional study. Participants underwent 1–5 laboratory-based polysomnographic recordings for a total of 63 nights, including sternal skin conductance measures, from which 222 hot flashes were identified according to established criteria. Data were analyzed with hierarchical mixed-effect models and Spearman correlations. Setting Sleep laboratory. Patients 34 perimenopausal women (Age±SD:50.4±2.7y). Intervention None. Main Outcome Measures Perceived and polysomnographic sleep measures (sleep quality, amount of wake after sleep onset and number of awakenings). Subjective (frequency and bother) and objective (frequency and amount of hot flash-associated wake time) hot flash measures. Results Women had an average of 3.5 (95%CI:2.8–4.2, range=1– 9) objective hot flashes per night. 69.4% of hot flashes were associated with an awakening. Hot flash-associated wake time per night was, on average, 16.6 min (95%CI:10.8–22.4), which accounted for 27.2% (SD 27.1) of total wakefulness per night. Hot flash-associated wake, but not frequency, was negatively associated with sleep efficiency and positively associated with wake after sleep onset. Also, self-reported wakefulness correlated with hot flash-associated wake, suggesting that women’s estimates of wakefulness are influenced by the amount of time spent awake in association with hot flashes during the night. More perceived and bothersome hot flashes correlated with more perceived wakefulness and awakenings and more objective hot flash-associated wake time and hot flash frequency. Conclusions The presence of physiological hot flashes accounts for a significant proportion of total objective wakefulness during the night in perimenopausal women. PMID:25256933

Adiposity and Hot Flashes in Midlife Women: A Modifying Role of Age

PubMed Central

Santoro, Nanette; Matthews, Karen A.

2011-01-01

Background: The nature of the relationship between adiposity and hot flashes has been debated, but it has not been examined using physiological measures of hot flashes. We examined associations between body size/composition and physiologically assessed hot flashes among women with hot flashes. Methods: A subcohort of women in the Study of Women's Health Across the Nation (n = 52; 25 African-American and 27 non-Hispanic Caucasian; ages, 54 to 63 yr) who reported hot flashes, had their uterus and ovaries, and were not taking medications impacting hot flashes were recruited in 2008–2009. Women completed anthropometric measures [bioimpedance analysis of total percentage of body fat, body mass index (BMI), waist circumference], a blood draw (estradiol, SHBG, FSH, dehydroepiandrosterone sulfate), and 4 d of ambulatory sternal skin conductance monitoring with diary (physiological and reported hot flashes, respectively). Associations between anthropometrics and hot flashes were estimated with generalized estimating equations with covariates age, race, and anxiety. Results: Higher BMI (odds ratio, 0.97; 95% confidence interval, 0.94–0.99; P < 0.05) and waist circumference (odds ratio, 0.98; 95% confidence interval, 0.97–0.99; P < 0.01) were associated with fewer physiological hot flashes. Interactions by age (P < 0.05) indicated that inverse associations of body fat, BMI, and waist circumference with hot flashes were most apparent among the oldest women in the sample. Estradiol and SHBG reduced but did not eliminate age-related variations in relations between body size/composition and hot flashes. Conclusion: Higher adiposity was associated with fewer physiological hot flashes among older women with hot flashes. A modifying role of age must be considered in understanding the role of adiposity in hot flashes. PMID:21778220

Adiposity and hot flashes in midlife women: a modifying role of age.

PubMed

Thurston, Rebecca C; Santoro, Nanette; Matthews, Karen A

2011-10-01

The nature of the relationship between adiposity and hot flashes has been debated, but it has not been examined using physiological measures of hot flashes. We examined associations between body size/composition and physiologically assessed hot flashes among women with hot flashes. A subcohort of women in the Study of Women's Health Across the Nation (n = 52; 25 African-American and 27 non-Hispanic Caucasian; ages, 54 to 63 yr) who reported hot flashes, had their uterus and ovaries, and were not taking medications impacting hot flashes were recruited in 2008-2009. Women completed anthropometric measures [bioimpedance analysis of total percentage of body fat, body mass index (BMI), waist circumference], a blood draw (estradiol, SHBG, FSH, dehydroepiandrosterone sulfate), and 4 d of ambulatory sternal skin conductance monitoring with diary (physiological and reported hot flashes, respectively). Associations between anthropometrics and hot flashes were estimated with generalized estimating equations with covariates age, race, and anxiety. Higher BMI (odds ratio, 0.97; 95% confidence interval, 0.94-0.99; P < 0.05) and waist circumference (odds ratio, 0.98; 95% confidence interval, 0.97-0.99; P < 0.01) were associated with fewer physiological hot flashes. Interactions by age (P < 0.05) indicated that inverse associations of body fat, BMI, and waist circumference with hot flashes were most apparent among the oldest women in the sample. Estradiol and SHBG reduced but did not eliminate age-related variations in relations between body size/composition and hot flashes. Higher adiposity was associated with fewer physiological hot flashes among older women with hot flashes. A modifying role of age must be considered in understanding the role of adiposity in hot flashes.

Initial Breakdown Pulse Amplitudes in Intracloud and Cloud-to-Ground Lightning Flashes

NASA Astrophysics Data System (ADS)

Marshall, T. C.; Smith, E. M.; Stolzenburg, M.; Karunarathne, S.; Siedlecki, R. D., II

2017-12-01

This study analyzes the largest initial breakdown (IB) pulse in flashes from three storms in Florida. The study was motivated in part by the possibility that IB pulses of IC flashes may cause of terrestrial gamma-ray flashes (TGFs). The range-normalized, zero-to-peak amplitude of the largest IB pulse within each flash was determined along with its altitude, duration, and occurrence time in the flash. Appropriate data were available for 40 intracloud (IC) and 32 cloud-to-ground (CG) flashes. Histograms of the magnitude of the largest IB pulse amplitude by flash type were similar, with mean (median) values of 1.49 (1.05) V/m for IC flashes and -1.35 (-0.87) V/m for CG flashes. The mean amplitude of the largest IC IB pulses are substantially smaller (roughly an order of magnitude smaller) than the few known pulse amplitudes of TGF events and TGF candidate events. The largest IB pulse in 30 IC flashes showed a weak inverse relation between pulse amplitude and altitude. Amplitude of the largest IB pulse for 25 CG flashes showed no altitude correlation. Duration of the largest IB pulse in ICs averaged twice as long as in CGs (96 μs versus 46 μs); all of the CG durations were <100 μs. Among the ICs, there is a positive relation between largest IB pulse duration and amplitude; the linear correlation coefficient is 0.385 with outliers excluded. The largest IB pulse in IC flashes typically occurred at a longer time after the first IB pulse (average 4.1 ms) than was the case in CG flashes (average 0.6 ms). In both flash types, the largest IB pulse was the first IB pulse in about 30% of the cases.

SUMO regulates proteasome-dependent degradation of FLASH/Casp8AP2

PubMed Central

Vennemann, Astrid; Hofmann, Thomas G.

2013-01-01

FLASH/Casp8AP2 is a huge multifunctional protein involved in multiple cellular processes, reaching from death receptor signaling to regulation of histone gene transcription and histone mRNA processing. Previous work has shown that FLASH localizes to Cajal bodies and promyelocytic leukemia (PML) bodies. However, the function of its nuclear body association remains unclear. Here we demonstrate that murine FLASH is covalently modified by SUMO at Lys residue 1792. Interestingly, ectopic expression of SUMO results in proteasome-dependent degradation of FLASH. A point mutant of FLASH with a mutated SUMO acceptor lysine residue, FLASHK1792R, is resistant to SUMO-induced degradation. Finally, we show that arsenic trioxide, a drug known to potentiate SUMO modification and degradation of PML, triggers recruitment of FLASH to PML bodies and concomitant loss of FLASH protein. Our data suggest that SUMO targets FLASH for proteasome-dependent degradation, which is associated with recruitment of FLASH to PML bodies. PMID:23673342

The October 2014 United States Treasury bond flash crash and the contributory effect of mini flash crashes

PubMed Central

Levine, Zachary S.; Floridi, Luciano

2017-01-01

We investigate the causal uncertainty surrounding the flash crash in the U.S. Treasury bond market on October 15, 2014, and the unresolved concern that no clear link has been identified between the start of the flash crash at 9:33 and the opening of the U.S. equity market at 9:30. We consider the contributory effect of mini flash crashes in equity markets, and find that the number of equity mini flash crashes in the three-minute window between market open and the Treasury Flash Crash was 2.6 times larger than the number experienced in any other three-minute window in the prior ten weekdays. We argue that (a) this statistically significant finding suggests that mini flash crashes in equity markets both predicted and contributed to the October 2014 U.S. Treasury Bond Flash Crash, and (b) mini-flash crashes are important phenomena with negative externalities that deserve much greater scholarly attention. PMID:29091931

Non-volatile memory for checkpoint storage

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

Blumrich, Matthias A.; Chen, Dong; Cipolla, Thomas M.

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, themore » non-volatile memory is a pluggable flash memory card.« less

Hypercube matrix computation task

NASA Technical Reports Server (NTRS)

Calalo, Ruel H.; Imbriale, William A.; Jacobi, Nathan; Liewer, Paulett C.; Lockhart, Thomas G.; Lyzenga, Gregory A.; Lyons, James R.; Manshadi, Farzin; Patterson, Jean E.

1988-01-01

A major objective of the Hypercube Matrix Computation effort at the Jet Propulsion Laboratory (JPL) is to investigate the applicability of a parallel computing architecture to the solution of large-scale electromagnetic scattering problems. Three scattering analysis codes are being implemented and assessed on a JPL/California Institute of Technology (Caltech) Mark 3 Hypercube. The codes, which utilize different underlying algorithms, give a means of evaluating the general applicability of this parallel architecture. The three analysis codes being implemented are a frequency domain method of moments code, a time domain finite difference code, and a frequency domain finite elements code. These analysis capabilities are being integrated into an electromagnetics interactive analysis workstation which can serve as a design tool for the construction of antennas and other radiating or scattering structures. The first two years of work on the Hypercube Matrix Computation effort is summarized. It includes both new developments and results as well as work previously reported in the Hypercube Matrix Computation Task: Final Report for 1986 to 1987 (JPL Publication 87-18).

PIAS1 interacts with FLASH and enhances its co-activation of c-Myb

PubMed Central

2011-01-01

Background FLASH is a huge nuclear protein involved in various cellular functions such as apoptosis signalling, NF-κB activation, S-phase regulation, processing of histone pre-mRNAs, and co-regulation of transcription. Recently, we identified FLASH as a co-activator of the transcription factor c-Myb and found FLASH to be tightly associated with active transcription foci. As a huge multifunctional protein, FLASH is expected to have many interaction partners, some which may shed light on its function as a transcriptional regulator. Results To find additional FLASH-associated proteins, we performed a yeast two-hybrid (Y2H) screening with FLASH as bait and identified the SUMO E3 ligase PIAS1 as an interaction partner. The association appears to involve two distinct interaction surfaces in FLASH. We verified the interaction by Y2H-mating, GST pulldowns, co-IP and ChIP. FLASH and PIAS1 were found to co-localize in nuclear speckles. Functional assays revealed that PIAS1 enhances the intrinsic transcriptional activity of FLASH in a RING finger-dependent manner. Furthermore, PIAS1 also augments the specific activity of c-Myb, and cooperates with FLASH to further co-activate c-Myb. The three proteins, FLASH, PIAS1, and c-Myb, are all co-localized with active RNA polymerase II foci, resembling transcription factories. Conclusions We conclude that PIAS1 is a common partner for two cancer-related nuclear factors, c-Myb and FLASH. Our results point to a functional cooperation between FLASH and PIAS1 in the enhancement of c-Myb activity in active nuclear foci. PMID:21338522

"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. © 2015 Society for Risk Analysis.

Hot Flashes and Carotid Intima Media Thickness among Midlife Women

PubMed Central

Thurston, Rebecca C.; Sutton-Tyrrell, Kim; Everson-Rose, Susan A.; Hess, Rachel; Powell, Lynda H.; Matthews, Karen A.

2010-01-01

Objective Emerging evidence suggests associations between menopausal hot flashes and cardiovascular risk. Whether hot flashes are associated with intima media thickness (IMT) or IMT changes over time is unknown. We hypothesized that reported hot flashes would be associated with greater IMT cross-sectionally and with greater IMT progression over two years. Methods Participants were 432 women ages 45-58 at baseline participating in SWAN Heart, an ancillary study to the Study of Women's Health Across the Nation. Measures at the SWAN Heart baseline and follow-up visit two years later included a carotid artery ultrasound, reported hot flashes (past two weeks: none, 1-5, ≥6 days), and a blood sample for measurement of estradiol. Results Women reporting hot flashes ≥6 days in the prior two weeks had significantly higher IMT than women without hot flashes at baseline (mean difference(SE), mm =0.02(0.01), p=0.03) and follow-up (mean difference(SE), mm =0.02(0.01), p=0.04) visits, controlling for demographic factors and cardiovascular risk factors. Reporting hot flashes at both study visits was associated with higher follow-up IMT relative to reporting hot flashes at neither visit (mean difference(SE), mm=0.03(0.01), p=0.03). Associations between hot flashes and IMT largely remained after adjusting for estradiol. An interaction between hot flashes and obesity status was observed (p=0.05) such that relations between hot flashes and IMT were observed principally among overweight/obese women. Hot flashes were not associated with IMT progression. Conclusions These findings provided some indication that women reporting hot flashes ≥6 days in the prior two weeks may have higher IMT than women without hot flashes, particularly for women who are overweight or obese. Further work should determine whether hot flashes mark adverse underlying vascular changes. PMID:21242820

50 CFR 600.730 - Facilitation of enforcement.

Code of Federal Regulations, 2011 CFR

2011-10-01

... transmitted by flashing light directed at the vessel signaled. USCG units will normally use the flashing light... your vessel instantly.” (Period (.) means a short flash of light; dash (-) means a long flash of light... authorized officer using loudhailer, radiotelephone, flashing light signal, or other means constitutes prima...

50 CFR 600.730 - Facilitation of enforcement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... transmitted by flashing light directed at the vessel signaled. USCG units will normally use the flashing light... your vessel instantly.” (Period (.) means a short flash of light; dash (-) means a long flash of light... authorized officer using loudhailer, radiotelephone, flashing light signal, or other means constitutes prima...

Calculation of Water Drop Trajectories to and About Arbitrary Three-Dimensional Bodies in Potential Airflow

NASA Technical Reports Server (NTRS)

Norment, H. G.

1980-01-01

Calculations can be performed for any atmospheric conditions and for all water drop sizes, from the smallest cloud droplet to large raindrops. Any subsonic, external, non-lifting flow can be accommodated; flow into, but not through, inlets also can be simulated. Experimental water drop drag relations are used in the water drop equations of motion and effects of gravity settling are included. Seven codes are described: (1) a code used to debug and plot body surface description data; (2) a code that processes the body surface data to yield the potential flow field; (3) a code that computes flow velocities at arrays of points in space; (4) a code that computes water drop trajectories from an array of points in space; (5) a code that computes water drop trajectories and fluxes to arbitrary target points; (6) a code that computes water drop trajectories tangent to the body; and (7) a code that produces stereo pair plots which include both the body and trajectories. Code descriptions include operating instructions, card inputs and printouts for example problems, and listing of the FORTRAN codes. Accuracy of the calculations is discussed, and trajectory calculation results are compared with prior calculations and with experimental data.

Utilizing GPUs to Accelerate Turbomachinery CFD Codes

NASA Technical Reports Server (NTRS)

MacCalla, Weylin; Kulkarni, Sameer

2016-01-01

GPU computing has established itself as a way to accelerate parallel codes in the high performance computing world. This work focuses on speeding up APNASA, a legacy CFD code used at NASA Glenn Research Center, while also drawing conclusions about the nature of GPU computing and the requirements to make GPGPU worthwhile on legacy codes. Rewriting and restructuring of the source code was avoided to limit the introduction of new bugs. The code was profiled and investigated for parallelization potential, then OpenACC directives were used to indicate parallel parts of the code. The use of OpenACC directives was not able to reduce the runtime of APNASA on either the NVIDIA Tesla discrete graphics card, or the AMD accelerated processing unit. Additionally, it was found that in order to justify the use of GPGPU, the amount of parallel work being done within a kernel would have to greatly exceed the work being done by any one portion of the APNASA code. It was determined that in order for an application like APNASA to be accelerated on the GPU, it should not be modular in nature, and the parallel portions of the code must contain a large portion of the code's computation time.

PASCO: Structural panel analysis and sizing code: Users manual - Revised

NASA Technical Reports Server (NTRS)

Anderson, M. S.; Stroud, W. J.; Durling, B. J.; Hennessy, K. W.

1981-01-01

A computer code denoted PASCO is described for analyzing and sizing uniaxially stiffened composite panels. Buckling and vibration analyses are carried out with a linked plate analysis computer code denoted VIPASA, which is included in PASCO. Sizing is based on nonlinear mathematical programming techniques and employs a computer code denoted CONMIN, also included in PASCO. Design requirements considered are initial buckling, material strength, stiffness and vibration frequency. A user's manual for PASCO is presented.

Computation of Reacting Flows in Combustion Processes

NASA Technical Reports Server (NTRS)

Keith, Theo G., Jr.; Chen, Kuo-Huey

1997-01-01

The main objective of this research was to develop an efficient three-dimensional computer code for chemically reacting flows. The main computer code developed is ALLSPD-3D. The ALLSPD-3D computer program is developed for the calculation of three-dimensional, chemically reacting flows with sprays. The ALL-SPD code employs a coupled, strongly implicit solution procedure for turbulent spray combustion flows. A stochastic droplet model and an efficient method for treatment of the spray source terms in the gas-phase equations are used to calculate the evaporating liquid sprays. The chemistry treatment in the code is general enough that an arbitrary number of reaction and species can be defined by the users. Also, it is written in generalized curvilinear coordinates with both multi-block and flexible internal blockage capabilities to handle complex geometries. In addition, for general industrial combustion applications, the code provides both dilution and transpiration cooling capabilities. The ALLSPD algorithm, which employs the preconditioning and eigenvalue rescaling techniques, is capable of providing efficient solution for flows with a wide range of Mach numbers. Although written for three-dimensional flows in general, the code can be used for two-dimensional and axisymmetric flow computations as well. The code is written in such a way that it can be run in various computer platforms (supercomputers, workstations and parallel processors) and the GUI (Graphical User Interface) should provide a user-friendly tool in setting up and running the code.

A microcontroller-based implantable nerve stimulator used for rats.

PubMed

Sha, Hong; Zheng, Zheng; Wang, Yan; Ren, Chaoshi

2005-01-01

A microcontroller-based stimulator that can be flexible programmed after it has been implanted into a rat was studied. Programmability enables implanted stimulators to generate customized, complex protocols for experiments. After implantation, a coded light pulse train that contains information of specific identification will unlock a certain stimulator. If a command that changing the parameters is received, the microcontroller will update its flash memory after it affirms the commands. The whole size of it is only 1.6 cubic centimeters, and it can work for a month. The devices have been successfully used in animal behavior experiments, especially on rats.

ELROI Extremely Low Resource Optical Identifier. A license plate for your satellite, and more.

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

Palmer, David

ELROI (Extremely Low Resource Optical Identifier) is a license plate for your satellite; a small tag that flashes an optical identification code that can be read by a small telescope on the ground. The final version of the tag will be the size of a thick postage stamp and fully autonomous: you can attach it to everything that goes into space, including small cubesats and inert debris like rocket stages, and it will keep blinking even after the satellite is shut down, reliably identifying the object from launch until re-entry.

Efficiently Communicating Rich Heterogeneous Geospatial Data from the FeMO2008 Dive Cruise with FlashMap on EarthRef.org

NASA Astrophysics Data System (ADS)

Minnett, R. C.; Koppers, A. A.; Staudigel, D.; Staudigel, H.

2008-12-01

EarthRef.org is comprehensive and convenient resource for Earth Science reference data and models. It encompasses four main portals: the Geochemical Earth Reference Model (GERM), the Magnetics Information Consortium (MagIC), the Seamount Biogeosciences Network (SBN), and the Enduring Resources for Earth Science Education (ERESE). Their underlying databases are publically available and the scientific community has contributed widely and is urged to continue to do so. However, the net result is a vast and largely heterogeneous warehouse of geospatial data ranging from carefully prepared maps of seamounts to geochemical data/metadata, daily reports from seagoing expeditions, large volumes of raw and processed multibeam data, images of paleomagnetic sampling sites, etc. This presents a considerable obstacle for integrating other rich media content, such as videos, images, data files, cruise tracks, and interoperable database results, without overwhelming the web user. The four EarthRef.org portals clearly lend themselves to a more intuitive user interface and has, therefore, been an invaluable test bed for the design and implementation of FlashMap, a versatile KML-driven geospatial browser written for reliability and speed in Adobe Flash. FlashMap allows layers of content to be loaded and displayed over a streaming high-resolution map which can be zoomed and panned similarly to Google Maps and Google Earth. Many organizations, from National Geographic to the USGS, have begun using Google Earth software to display geospatial content. However, Google Earth, as a desktop application, does not integrate cleanly with existing websites requiring the user to navigate away from the browser and focus on a separate application and Google Maps, written in Java Script, does not scale up reliably to large datasets. FlashMap remedies these problems as a web-based application that allows for seamless integration of the real-time display power of Google Earth and the flexibility of the web without losing scalability and control of the base maps. Our Flash-based application is fully compatible with KML (Keyhole Markup Language) 2.2, the most recent iteration of KML, allowing users with existing Google Earth KML files to effortlessly display their geospatial content embedded in a web page. As a test case for FlashMap, the annual Iron-Oxidizing Microbial Observatory (FeMO) dive cruise to the Loihi Seamount, in conjunction with data available from ongoing and published FeMO laboratory studies, showcases the flexibility of this single web-based application. With a KML 2.2 compatible web-service providing the content, any database can display results in FlashMap. The user can then hide and show multiple layers of content, potentially from several data sources, and rapidly digest a vast quantity of information to narrow the search results. This flexibility gives experienced users the ability to drill down to exactly the record they are looking for (SERC at Carleton College's educational application of FlashMap at http://serc.carleton.edu/sp/erese/activities/22223.html) and allows users familiar with Google Earth the ability to load and view geospatial data content within a browser from any computer with an internet connection.

NASA Rotor 37 CFD Code Validation: Glenn-HT Code

NASA Technical Reports Server (NTRS)

Ameri, Ali A.

2010-01-01

In order to advance the goals of NASA aeronautics programs, it is necessary to continuously evaluate and improve the computational tools used for research and design at NASA. One such code is the Glenn-HT code which is used at NASA Glenn Research Center (GRC) for turbomachinery computations. Although the code has been thoroughly validated for turbine heat transfer computations, it has not been utilized for compressors. In this work, Glenn-HT was used to compute the flow in a transonic compressor and comparisons were made to experimental data. The results presented here are in good agreement with this data. Most of the measures of performance are well within the measurement uncertainties and the exit profiles of interest agree with the experimental measurements.

Final report for the Tera Computer TTI CRADA

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

Davidson, G.S.; Pavlakos, C.; Silva, C.

1997-01-01

Tera Computer and Sandia National Laboratories have completed a CRADA, which examined the Tera Multi-Threaded Architecture (MTA) for use with large codes of importance to industry and DOE. The MTA is an innovative architecture that uses parallelism to mask latency between memories and processors. The physical implementation is a parallel computer with high cross-section bandwidth and GaAs processors designed by Tera, which support many small computation threads and fast, lightweight context switches between them. When any thread blocks while waiting for memory accesses to complete, another thread immediately begins execution so that high CPU utilization is maintained. The Tera MTAmore » parallel computer has a single, global address space, which is appealing when porting existing applications to a parallel computer. This ease of porting is further enabled by compiler technology that helps break computations into parallel threads. DOE and Sandia National Laboratories were interested in working with Tera to further develop this computing concept. While Tera Computer would continue the hardware development and compiler research, Sandia National Laboratories would work with Tera to ensure that their compilers worked well with important Sandia codes, most particularly CTH, a shock physics code used for weapon safety computations. In addition to that important code, Sandia National Laboratories would complete research on a robotic path planning code, SANDROS, which is important in manufacturing applications, and would evaluate the MTA performance on this code. Finally, Sandia would work directly with Tera to develop 3D visualization codes, which would be appropriate for use with the MTA. Each of these tasks has been completed to the extent possible, given that Tera has just completed the MTA hardware. All of the CRADA work had to be done on simulators.« less

birgHPC: creating instant computing clusters for bioinformatics and molecular dynamics.

PubMed

Chew, Teong Han; Joyce-Tan, Kwee Hong; Akma, Farizuwana; Shamsir, Mohd Shahir

2011-05-01

birgHPC, a bootable Linux Live CD has been developed to create high-performance clusters for bioinformatics and molecular dynamics studies using any Local Area Network (LAN)-networked computers. birgHPC features automated hardware and slots detection as well as provides a simple job submission interface. The latest versions of GROMACS, NAMD, mpiBLAST and ClustalW-MPI can be run in parallel by simply booting the birgHPC CD or flash drive from the head node, which immediately positions the rest of the PCs on the network as computing nodes. Thus, a temporary, affordable, scalable and high-performance computing environment can be built by non-computing-based researchers using low-cost commodity hardware. The birgHPC Live CD and relevant user guide are available for free at http://birg1.fbb.utm.my/birghpc.

Propagation of Reactions in Thermally-damaged PBX-9501

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

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

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

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 the...

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 the...

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.

OTD Observations of Continental US Ground and Cloud Flashes

NASA Technical Reports Server (NTRS)

Koshak, William

2007-01-01

Lightning optical flash parameters (e.g., radiance, area, duration, number of optical groups, and number of optical events) derived from almost five years of Optical Transient Detector (OTD) data are analyzed. Hundreds of thousands of OTD flashes occurring over the continental US are categorized according to flash type (ground or cloud flash) using US National Lightning Detection Network TM (NLDN) data. The statistics of the optical characteristics of the ground and cloud flashes are inter-compared on an overall basis, and as a function of ground flash polarity. A standard two-distribution hypothesis test is used to inter-compare the population means of a given lightning parameter for the two flash types. Given the differences in the statistics of the optical characteristics, it is suggested that statistical analyses (e.g., Bayesian Inference) of the space-based optical measurements might make it possible to successfully discriminate ground and cloud flashes a reasonable percentage of the time.

Menopausal Hot Flashes and White Matter Hyperintensities

PubMed Central

Thurston, Rebecca C.; Aizenstein, Howard J.; Derby, Carol A.; Sejdić, Ervin; Maki, Pauline M.

2015-01-01

Objective Hot flashes are the classic menopausal symptom. Emerging data links hot flashes to cardiovascular disease (CVD) risk, yet how hot flashes are related to brain health is poorly understood. We examined the relationship between hot flashes - measured via physiologic monitor and self-report - and white matter hyperintensities (WMH) among midlife women. Methods Twenty midlife women ages 40-60 without clinical CVD, with their uterus and both ovaries, and not taking hormone therapy were recruited. Women underwent 24 hours of ambulatory physiologic and diary hot flash monitoring to quantify hot flashes; magnetic resonance imaging to assess WMH burden; 72 hours of actigraphy and questionnaires to quantify sleep; and a blood draw, questionnaires, and physical measures to quantify demographics and CVD risk factors. Test of a priori hypotheses regarding relations between physiologically-monitored and self-reported wake and sleep hot flashes and WMH were conducted in linear regression models. Results More physiologically-monitored hot flashes during sleep were associated with greater WMH, controlling for age, race, and body mass index [beta(standard error)=.0002 (.0001), p=.03]. Findings persisted controlling for sleep characteristics and additional CVD risk factors. No relations were observed for self-reported hot flashes. Conclusions More physiologically-monitored hot flashes during sleep were associated with greater WMH burden among midlife women free of clinical CVD. Results suggest that relations between hot flashes and CVD risk observed in the periphery may extend to the brain. Future work should consider the unique role of sleep hot flashes in brain health. PMID:26057822

Some properties of negative cloud-to-ground flashes from observations of a local thunderstorm based on accurate-stroke-count studies

NASA Astrophysics Data System (ADS)

Zhu, Baoyou; Ma, Ming; Xu, Weiwei; Ma, Dong

2015-12-01

Properties of negative cloud-to-ground (CG) lightning flashes, in terms of number of strokes per flash, inter-stroke intervals and the relative intensity of subsequent and first strokes, were presented by accurate-stroke-count studies based on all 1085 negative flashes from a local thunderstorm. The percentage of single-stroke flashes and stroke multiplicity evolved significantly during the whole life cycle of the study thunderstorm. The occurrence probability of negative CG flashes decreased exponentially with the increasing number of strokes per flash. About 30.5% of negative CG flashes contained only one stroke and number of strokes per flash averaged 3.3. In a subset of 753 negative multiple-stroke flashes, about 41.4% contained at least one subsequent stroke stronger than the corresponding first stroke. Subsequent strokes tended to decrease in strength with their orders and the ratio of subsequent to first stroke peaks presented a geometric mean value of 0.52. Interestingly, negative CG flashes of higher multiplicity tended to have stronger initial strokes. 2525 inter-stroke intervals showed a more or less log-normal distribution and gave a geometric mean value of 62 ms. For CG flashes of particular multiplicity geometric mean inter-stroke intervals tended to decrease with the increasing number of strokes per flash, while those intervals associated with higher order strokes tended to be larger than those associated with low order strokes.

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

PubMed Central

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

2012-01-01

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

Transition from Target to Gaze Coding in Primate Frontal Eye Field during Memory Delay and Memory–Motor Transformation123

PubMed Central

Sajad, Amirsaman; Sadeh, Morteza; Yan, Xiaogang; Wang, Hongying

2016-01-01

Abstract The frontal eye fields (FEFs) participate in both working memory and sensorimotor transformations for saccades, but their role in integrating these functions through time remains unclear. Here, we tracked FEF spatial codes through time using a novel analytic method applied to the classic memory-delay saccade task. Three-dimensional recordings of head-unrestrained gaze shifts were made in two monkeys trained to make gaze shifts toward briefly flashed targets after a variable delay (450-1500 ms). A preliminary analysis of visual and motor response fields in 74 FEF neurons eliminated most potential models for spatial coding at the neuron population level, as in our previous study (Sajad et al., 2015). We then focused on the spatiotemporal transition from an eye-centered target code (T; preferred in the visual response) to an eye-centered intended gaze position code (G; preferred in the movement response) during the memory delay interval. We treated neural population codes as a continuous spatiotemporal variable by dividing the space spanning T and G into intermediate T–G models and dividing the task into discrete steps through time. We found that FEF delay activity, especially in visuomovement cells, progressively transitions from T through intermediate T–G codes that approach, but do not reach, G. This was followed by a final discrete transition from these intermediate T–G delay codes to a “pure” G code in movement cells without delay activity. These results demonstrate that FEF activity undergoes a series of sensory–memory–motor transformations, including a dynamically evolving spatial memory signal and an imperfect memory-to-motor transformation. PMID:27092335

Operations analysis (study 2.1). Program listing for the LOVES computer code

NASA Technical Reports Server (NTRS)

Wray, S. T., Jr.

1974-01-01

A listing of the LOVES computer program is presented. The program is coded partially in SIMSCRIPT and FORTRAN. This version of LOVES is compatible with both the CDC 7600 and the UNIVAC 1108 computers. The code has been compiled, loaded, and executed successfully on the EXEC 8 system for the UNIVAC 1108.

Analysis of the Length of Braille Texts in English Braille American Edition, the Nemeth Code, and Computer Braille Code versus the Unified English Braille Code

ERIC Educational Resources Information Center

Knowlton, Marie; Wetzel, Robin

2006-01-01

This study compared the length of text in English Braille American Edition, the Nemeth code, and the computer braille code with the Unified English Braille Code (UEBC)--also known as Unified English Braille (UEB). The findings indicate that differences in the length of text are dependent on the type of material that is transcribed and the grade…

A MATLAB based 3D modeling and inversion code for MT data

NASA Astrophysics Data System (ADS)

Singh, Arun; Dehiya, Rahul; Gupta, Pravin K.; Israil, M.

2017-07-01

The development of a MATLAB based computer code, AP3DMT, for modeling and inversion of 3D Magnetotelluric (MT) data is presented. The code comprises two independent components: grid generator code and modeling/inversion code. The grid generator code performs model discretization and acts as an interface by generating various I/O files. The inversion code performs core computations in modular form - forward modeling, data functionals, sensitivity computations and regularization. These modules can be readily extended to other similar inverse problems like Controlled-Source EM (CSEM). The modular structure of the code provides a framework useful for implementation of new applications and inversion algorithms. The use of MATLAB and its libraries makes it more compact and user friendly. The code has been validated on several published models. To demonstrate its versatility and capabilities the results of inversion for two complex models are presented.

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.

Don’t make cache too complex: A simple probability-based cache management scheme for SSDs

PubMed Central

Cho, Sangyeun; Choi, Jongmoo

2017-01-01

Solid-state drives (SSDs) have recently become a common storage component in computer systems, and they are fueled by continued bit cost reductions achieved with smaller feature sizes and multiple-level cell technologies. However, as the flash memory stores more bits per cell, the performance and reliability of the flash memory degrade substantially. To solve this problem, a fast non-volatile memory (NVM-)based cache has been employed within SSDs to reduce the long latency required to write data. Absorbing small writes in a fast NVM cache can also reduce the number of flash memory erase operations. To maximize the benefits of an NVM cache, it is important to increase the NVM cache utilization. In this paper, we propose and study ProCache, a simple NVM cache management scheme, that makes cache-entrance decisions based on random probability testing. Our scheme is motivated by the observation that frequently written hot data will eventually enter the cache with a high probability, and that infrequently accessed cold data will not enter the cache easily. Owing to its simplicity, ProCache is easy to implement at a substantially smaller cost than similar previously studied techniques. We evaluate ProCache and conclude that it achieves comparable performance compared to a more complex reference counter-based cache-management scheme. PMID:28358897

Don't make cache too complex: A simple probability-based cache management scheme for SSDs.

PubMed

Baek, Seungjae; Cho, Sangyeun; Choi, Jongmoo

2017-01-01

Solid-state drives (SSDs) have recently become a common storage component in computer systems, and they are fueled by continued bit cost reductions achieved with smaller feature sizes and multiple-level cell technologies. However, as the flash memory stores more bits per cell, the performance and reliability of the flash memory degrade substantially. To solve this problem, a fast non-volatile memory (NVM-)based cache has been employed within SSDs to reduce the long latency required to write data. Absorbing small writes in a fast NVM cache can also reduce the number of flash memory erase operations. To maximize the benefits of an NVM cache, it is important to increase the NVM cache utilization. In this paper, we propose and study ProCache, a simple NVM cache management scheme, that makes cache-entrance decisions based on random probability testing. Our scheme is motivated by the observation that frequently written hot data will eventually enter the cache with a high probability, and that infrequently accessed cold data will not enter the cache easily. Owing to its simplicity, ProCache is easy to implement at a substantially smaller cost than similar previously studied techniques. We evaluate ProCache and conclude that it achieves comparable performance compared to a more complex reference counter-based cache-management scheme.

Radiative Feedback of Forming Star Clusters on Their GMC Environments: Theory and Simulation

NASA Astrophysics Data System (ADS)

Howard, C. S.; Pudritz, R. E.; Harris, W. E.

2013-07-01

Star clusters form from dense clumps within a molecular cloud. Radiation from these newly formed clusters feeds back on their natal molecular cloud through heating and ionization which ultimately stops gas accretion into the cluster. Recent studies suggest that radiative feedback effects from a single cluster may be sufficient to disrupt an entire cloud over a short timescale. Simulating cluster formation on a large scale, however, is computationally demanding due to the high number of stars involved. For this reason, we present a model for representing the radiative output of an entire cluster which involves randomly sampling an initial mass function (IMF) as the cluster accretes mass. We show that this model is able to reproduce the star formation histories of observed clusters. To examine the degree to which radiative feedback shapes the evolution of a molecular cloud, we use the FLASH adaptive-mesh refinement hydrodynamics code to simulate cluster formation in a turbulent cloud. Unlike previous studies, sink particles are used to represent a forming cluster rather than individual stars. Our cluster model is then coupled with a raytracing scheme to treat radiative transfer as the clusters grow in mass. This poster will outline the details of our model and present preliminary results from our 3D hydrodynamical simulations.

A central compact object in Kes 79: the hypercritical regime and neutrino expectation

NASA Astrophysics Data System (ADS)

Bernal, C. G.; Fraija, N.

2016-11-01

We present magnetohydrodynamical simulations of a strong accretion on to magnetized proto-neutron stars for the Kesteven 79 (Kes 79) scenario. The supernova remnant Kes 79, observed with the Chandra ACIS-I instrument during approximately 8.3 h, is located in the constellation Aquila at a distance of 7.1 kpc in the galactic plane. It is a galactic and a very young object with an estimate age of 6 kyr. The Chandra image has revealed, for the first time, a point-like source at the centre of the remnant. The Kes 79 compact remnant belongs to a special class of objects, the so-called central compact objects (CCOs), which exhibits no evidence for a surrounding pulsar wind nebula. In this work, we show that the submergence of the magnetic field during the hypercritical phase can explain such behaviour for Kes 79 and others CCOs. The simulations of such regime were carried out with the adaptive-mesh-refinement code FLASH in two spatial dimensions, including radiative loss by neutrinos and an adequate equation of state for such regime. From the simulations, we estimate that the number of thermal neutrinos expected on the Hyper-Kamiokande Experiment is 733 ± 364. In addition, we compute the flavour ratio on Earth for a progenitor model.

Applications of automatic differentiation in computational fluid dynamics

NASA Technical Reports Server (NTRS)

Green, Lawrence L.; Carle, A.; Bischof, C.; Haigler, Kara J.; Newman, Perry A.

1994-01-01

Automatic differentiation (AD) is a powerful computational method that provides for computing exact sensitivity derivatives (SD) from existing computer programs for multidisciplinary design optimization (MDO) or in sensitivity analysis. A pre-compiler AD tool for FORTRAN programs called ADIFOR has been developed. The ADIFOR tool has been easily and quickly applied by NASA Langley researchers to assess the feasibility and computational impact of AD in MDO with several different FORTRAN programs. These include a state-of-the-art three dimensional multigrid Navier-Stokes flow solver for wings or aircraft configurations in transonic turbulent flow. With ADIFOR the user specifies sets of independent and dependent variables with an existing computer code. ADIFOR then traces the dependency path throughout the code, applies the chain rule to formulate derivative expressions, and generates new code to compute the required SD matrix. The resulting codes have been verified to compute exact non-geometric and geometric SD for a variety of cases. in less time than is required to compute the SD matrix using centered divided differences.

Fundamentals, current state of the development of, and prospects for further improvement of the new-generation thermal-hydraulic computational HYDRA-IBRAE/LM code for simulation of fast reactor systems

NASA Astrophysics Data System (ADS)

Alipchenkov, V. M.; Anfimov, A. M.; Afremov, D. A.; Gorbunov, V. S.; Zeigarnik, Yu. A.; Kudryavtsev, A. V.; Osipov, S. L.; Mosunova, N. A.; Strizhov, V. F.; Usov, E. V.

2016-02-01

The conceptual fundamentals of the development of the new-generation system thermal-hydraulic computational HYDRA-IBRAE/LM code are presented. The code is intended to simulate the thermalhydraulic processes that take place in the loops and the heat-exchange equipment of liquid-metal cooled fast reactor systems under normal operation and anticipated operational occurrences and during accidents. The paper provides a brief overview of Russian and foreign system thermal-hydraulic codes for modeling liquid-metal coolants and gives grounds for the necessity of development of a new-generation HYDRA-IBRAE/LM code. Considering the specific engineering features of the nuclear power plants (NPPs) equipped with the BN-1200 and the BREST-OD-300 reactors, the processes and the phenomena are singled out that require a detailed analysis and development of the models to be correctly described by the system thermal-hydraulic code in question. Information on the functionality of the computational code is provided, viz., the thermalhydraulic two-phase model, the properties of the sodium and the lead coolants, the closing equations for simulation of the heat-mass exchange processes, the models to describe the processes that take place during the steam-generator tube rupture, etc. The article gives a brief overview of the usability of the computational code, including a description of the support documentation and the supply package, as well as possibilities of taking advantages of the modern computer technologies, such as parallel computations. The paper shows the current state of verification and validation of the computational code; it also presents information on the principles of constructing of and populating the verification matrices for the BREST-OD-300 and the BN-1200 reactor systems. The prospects are outlined for further development of the HYDRA-IBRAE/LM code, introduction of new models into it, and enhancement of its usability. It is shown that the program of development and practical application of the code will allow carrying out in the nearest future the computations to analyze the safety of potential NPP projects at a qualitatively higher level.

Performance assessment of KORAT-3D on the ANL IBM-SP computer

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

Alexeyev, A.V.; Zvenigorodskaya, O.A.; Shagaliev, R.M.

1999-09-01

The TENAR code is currently being developed at the Russian Federal Nuclear Center (VNIIEF) as a coupled dynamics code for the simulation of transients in VVER and RBMK systems and other nuclear systems. The neutronic module in this code system is KORAT-3D. This module is also one of the most computationally intensive components of the code system. A parallel version of KORAT-3D has been implemented to achieve the goal of obtaining transient solutions in reasonable computational time, particularly for RBMK calculations that involve the application of >100,000 nodes. An evaluation of the KORAT-3D code performance was recently undertaken on themore » Argonne National Laboratory (ANL) IBM ScalablePower (SP) parallel computer located in the Mathematics and Computer Science Division of ANL. At the time of the study, the ANL IBM-SP computer had 80 processors. This study was conducted under the auspices of a technical staff exchange program sponsored by the International Nuclear Safety Center (INSC).« less

Computer-Based and Paper-Based Measurement of Recognition Performance

DTIC Science & Technology

1989-03-01

domains (e.g., ship silhouettes, electronic schemata, human anatomy ) to ascertain the universality of the validity and reliability results...specific graphic 4 database (e.g., ship silhouettes, human anatomy , electronic circuits, topography), con- tributes to its wide applicability. The game, then...seek implementation of FLASH and PICTURE in other content areas or subject-matter domains (e.g., ship silhouettes, electronic schemata, human anatomy ) to

A low-frequency near-field interferometric-TOA 3-D Lightning Mapping Array

NASA Astrophysics Data System (ADS)

Lyu, Fanchao; Cummer, Steven A.; Solanki, Rahulkumar; Weinert, Joel; McTague, Lindsay; Katko, Alex; Barrett, John; Zigoneanu, Lucian; Xie, Yangbo; Wang, Wenqi

2014-11-01

We report on the development of an easily deployable LF near-field interferometric-time of arrival (TOA) 3-D Lightning Mapping Array applied to imaging of entire lightning flashes. An interferometric cross-correlation technique is applied in our system to compute windowed two-sensor time differences with submicrosecond time resolution before TOA is used for source location. Compared to previously reported LF lightning location systems, our system captures many more LF sources. This is due mainly to the improved mapping of continuous lightning processes by using this type of hybrid interferometry/TOA processing method. We show with five station measurements that the array detects and maps different lightning processes, such as stepped and dart leaders, during both in-cloud and cloud-to-ground flashes. Lightning images mapped by our LF system are remarkably similar to those created by VHF mapping systems, which may suggest some special links between LF and VHF emission during lightning processes.

A microcomputer-based daily living activity recording system.

PubMed

Matsuoka, Shingo; Yonezawa, Yoshiharu; Maki, Hiromichi; Ogawa, Hidekuni; Hahn, Allen W; Thayer, Julian F; Caldwell, W Morton

2003-01-01

A new daily living activity recording system has been developed for monitoring health conditions and living patterns, such as respiration, posture, activity/rest ratios and general activity level. The system employs a piezoelectric sensor, a dual axis accelerometer, two low-power active filters, a low-power 8-bit single chip microcomputer and a 128 MB compact flash memory. The piezoelectric sensor, whose electrical polarization voltage is produced by mechanical strain, detects body movements. Its high-frequency output components reflect body movements produced by walking and running activities, while the low frequency components are mainly respiratory. The dual axis accelerometer detects, from body X and Y tilt angles, whether the patient is standing, sitting or lying down (prone, supine, left side or right side). The detected respiratory, behavior and posture signals are stored by the compact flash memory. After recording, these data are downloaded to a desktop computer and analyzed.

Thermodynamic Modeling and Optimization of the Copper Flash Converting Process Using the Equilibrium Constant Method

NASA Astrophysics Data System (ADS)

Li, Ming-zhou; Zhou, Jie-min; Tong, Chang-ren; Zhang, Wen-hai; Chen, Zhuo; Wang, Jin-liang

2018-05-01

Based on the principle of multiphase equilibrium, a mathematical model of the copper flash converting process was established by the equilibrium constant method, and a computational system was developed with the use of MetCal software platform. The mathematical model was validated by comparing simulated outputs, industrial data, and published data. To obtain high-quality blister copper, a low copper content in slag, and increased impurity removal rate, the model was then applied to investigate the effects of the operational parameters [oxygen/feed ratio (R OF), flux rate (R F), and converting temperature (T)] on the product weights, compositions, and the distribution behaviors of impurity elements. The optimized results showed that R OF, R F, and T should be controlled at approximately 156 Nm3/t, within 3.0 pct, and at approximately 1523 K (1250 °C), respectively.

A flash photolysis resonance fluorescence investigation of the reaction OH + CH3CCl3 yields H2O + CH2CCl3. [in troposphere

NASA Technical Reports Server (NTRS)

Kurylo, M. J.; Anderson, P. C.; Klais, O.

1979-01-01

The absolute rate constant for the reaction OH + CH3CCl3 yields H2O + CH2CCl3 was determined by the flash photolysis resonance fluorescence method from 253 to 363K. The use of the Arrhenius equation with atmospheric observational data on methyl chloroform nearly doubles the predicted tropospheric OH reaction sink strength for the removal of atmospheric gases whose lifetimes are controlled by OH. The increased use of methyl chloroform instead of the restricted trichloroethylene focused attention to its role in stratospheric ozone depletion, producing modeling analyses to determine the amount of released methyl chloroform which reaches the stratosphere. Since the primary atmospheric loss of CH3CCl3 is considered by reaction with OH radicals, these data are used to compute an average tropospheric OH concentration and the strength of the 'global tropospheric OH reaction sink'.

Profugus

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

Evans, Thomas; Hamilton, Steven; Slattery, Stuart

Profugus is an open-source mini-application (mini-app) for radiation transport and reactor applications. It contains the fundamental computational kernels used in the Exnihilo code suite from Oak Ridge National Laboratory. However, Exnihilo is production code with a substantial user base. Furthermore, Exnihilo is export controlled. This makes collaboration with computer scientists and computer engineers difficult. Profugus is designed to bridge that gap. By encapsulating the core numerical algorithms in an abbreviated code base that is open-source, computer scientists can analyze the algorithms and easily make code-architectural changes to test performance without compromising the production code values of Exnihilo. Profugus is notmore » meant to be production software with respect to problem analysis. The computational kernels in Profugus are designed to analyze performance, not correctness. Nonetheless, users of Profugus can setup and run problems with enough real-world features to be useful as proof-of-concept for actual production work.« less

Cardiac autonomic function and hot flashes among perimenopausal and postmenopausal women.

PubMed

Gibson, Carolyn J; Mendes, Wendy Berry; Schembri, Michael; Grady, Deborah; Huang, Alison J

2017-07-01

Abnormalities in autonomic function are posited to play a pathophysiologic role in menopausal hot flashes. We examined relationships between resting cardiac autonomic activity and hot flashes in perimenopausal and postmenopausal women. Autonomic function was assessed at baseline and 12 weeks among perimenopausal and postmenopausal women (n = 121, mean age 53 years) in a randomized trial of slow-paced respiration for hot flashes. Pre-ejection period (PEP), a marker of sympathetic activation, was measured with impedance cardiography. Respiratory sinus arrhythmia (RSA), a marker of parasympathetic activation, was measured with electrocardiography. Participants self-reported hot flash frequency and severity in 7-day symptom diaries. Analysis of covariance models were used to relate autonomic function and hot flash frequency and severity at baseline, and to relate changes in autonomic function to changes in hot flash frequency and severity over 12 weeks, adjusting for age, body mass index, and intervention assignment. PEP was not associated with hot flash frequency or severity at baseline or over 12 weeks (P > 0.05 for all). In contrast, there was a trend toward greater frequency of moderate-to-severe hot flashes with higher RSA at baseline (β = 0.43, P = 0.06), and a positive association between change in RSA and change in frequency of moderate-to-severe hot flashes over 12 weeks (β = 0.63, P = 0.04). Among perimenopausal and postmenopausal women with hot flashes, variations in hot flash frequency and severity were not explained by variations in resting sympathetic activation. Greater parasympathetic activation was associated with more frequent moderate-to-severe hot flashes, which may reflect increased sensitivity to perceiving hot flashes.

Pulsed photoacoustic detection of flash-induced oxygen evolution from intact leaves and its oscillations

PubMed Central

Canaani, Ora; Malkin, Shmuel; Mauzerall, David

1988-01-01

Photoacoustic signals from intact leaves, produced upon excitation with single-turnover flashes, were shown to be dependent on their position in the flash sequence. Compared to the signal obtained from the first flash, all the others were time-shifted and had increased amplitudes. The signal from the third flash had the largest deviation, whereas that from the second flash deviated only minimally. The amplitude difference of the signals relative to that from the first flash was measured at a convenient time point (5 ms) and showed oscillations of period 4, similar to the O2-evolution pattern from algae. These oscillations were strongly damped, tending to a steady state from about the seventh flash on. The extra photoacoustic signal (relative to the first flash) was shown to be inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea, heat treatment, or water infiltration. Its change with flash number, its saturation with increasing flash energy, and the above inhibition criteria indicate that it originates in pulsed O2 evolution. The sound wave produced by the first flash, however, arose by a photothermal mechanism only, as shown by its linear dependence on the flash intensity and insensitivity to the above treatments. The above flash pattern demonstrates that the photocycle of the S states (i.e., positive charge accumulation before two water molecules can be oxidized in a concerted way to produce molecular oxygen) occurs in intact leaves. It proves the applicability of the photoacoustic method for mechanistic studies of O2 evolution in leaves under physiological conditions. Water content of leaves is readily measured by this method. Images PMID:16593952

Understanding the complex relationships underlying hot flashes: a Bayesian network approach.

PubMed

Smith, Rebecca L; Gallicchio, Lisa M; Flaws, Jodi A

2018-02-01

The mechanism underlying hot flashes is not well-understood, primarily because of complex relationships between and among hot flashes and their risk factors. We explored those relationships using a Bayesian network approach based on a 2006 to 2015 cohort study of hot flashes among 776 female residents, 45 to 54 years old, in the Baltimore area. Bayesian networks were fit for each outcome (current hot flashes, hot flashes before the end of the study, hot flash severity, hot flash frequency, and age at first hot flashes) separately and together with a list of risk factors (estrogen, progesterone, testosterone, body mass index and obesity, race, income level, education level, smoking history, drinking history, and activity level). Each fitting was conducted separately on all women and only perimenopausal women, at enrollment and 4 years after enrollment. Hormone levels, almost always interrelated, were the most common variable linked to hot flashes; hormone levels were sometimes related to body mass index, but were not directly related to any other risk factors. Smoking was also frequently associated with increased likelihood of severe symptoms, but not through an antiestrogenic pathway. The age at first hot flashes was related only to race. All other factors were either not related to outcomes or were mediated entirely by race, hormone levels, or smoking. These models can serve as a guide for design of studies into the causal network underlying hot flashes.

Fast H.264/AVC FRExt intra coding using belief propagation.

PubMed

Milani, Simone

2011-01-01

In the H.264/AVC FRExt coder, the coding performance of Intra coding significantly overcomes the previous still image coding standards, like JPEG2000, thanks to a massive use of spatial prediction. Unfortunately, the adoption of an extensive set of predictors induces a significant increase of the computational complexity required by the rate-distortion optimization routine. The paper presents a complexity reduction strategy that aims at reducing the computational load of the Intra coding with a small loss in the compression performance. The proposed algorithm relies on selecting a reduced set of prediction modes according to their probabilities, which are estimated adopting a belief-propagation procedure. Experimental results show that the proposed method permits saving up to 60 % of the coding time required by an exhaustive rate-distortion optimization method with a negligible loss in performance. Moreover, it permits an accurate control of the computational complexity unlike other methods where the computational complexity depends upon the coded sequence.

2,445 Hours of Code: What I Learned from Facilitating Hour of Code Events in High School Libraries

ERIC Educational Resources Information Center

Colby, Jennifer

2015-01-01

This article describes a school librarian's experience with initiating an Hour of Code event for her school's student body. Hadi Partovi of Code.org conceived the Hour of Code "to get ten million students to try one hour of computer science" (Partovi, 2013a), which is implemented during Computer Science Education Week with a goal of…

Synchronizing Photography For High-Speed-Engine Research

NASA Technical Reports Server (NTRS)

Chun, K. S.

1989-01-01

Light flashes when shaft reaches predetermined angle. Synchronization system facilitates visualization of flow in high-speed internal-combustion engines. Designed for cinematography and holographic interferometry, system synchronizes camera and light source with predetermined rotational angle of engine shaft. 10-bit resolution of absolute optical shaft encoder adapted, and 2 to tenth power combinations of 10-bit binary data computed to corresponding angle values. Pre-computed angle values programmed into EPROM's (erasable programmable read-only memories) to use as angle lookup table. Resolves shaft angle to within 0.35 degree at rotational speeds up to 73,240 revolutions per minute.

Numerical algorithm comparison for the accurate and efficient computation of high-incidence vortical flow

NASA Technical Reports Server (NTRS)

Chaderjian, Neal M.

1991-01-01

Computations from two Navier-Stokes codes, NSS and F3D, are presented for a tangent-ogive-cylinder body at high angle of attack. Features of this steady flow include a pair of primary vortices on the leeward side of the body as well as secondary vortices. The topological and physical plausibility of this vortical structure is discussed. The accuracy of these codes are assessed by comparison of the numerical solutions with experimental data. The effects of turbulence model, numerical dissipation, and grid refinement are presented. The overall efficiency of these codes are also assessed by examining their convergence rates, computational time per time step, and maximum allowable time step for time-accurate computations. Overall, the numerical results from both codes compared equally well with experimental data, however, the NSS code was found to be significantly more efficient than the F3D code.

User's Manual for FEMOM3DR. Version 1.0

NASA Technical Reports Server (NTRS)

Reddy, C. J.

1998-01-01

FEMoM3DR is a computer code written in FORTRAN 77 to compute radiation characteristics of antennas on 3D body using combined Finite Element Method (FEM)/Method of Moments (MoM) technique. The code is written to handle different feeding structures like coaxial line, rectangular waveguide, and circular waveguide. This code uses the tetrahedral elements, with vector edge basis functions for FEM and triangular elements with roof-top basis functions for MoM. By virtue of FEM, this code can handle any arbitrary shaped three dimensional bodies with inhomogeneous lossy materials; and due to MoM the computational domain can be terminated in any arbitrary shape. The User's Manual is written to make the user acquainted with the operation of the code. The user is assumed to be familiar with the FORTRAN 77 language and the operating environment of the computers on which the code is intended to run.

Selection of a computer code for Hanford low-level waste engineered-system performance assessment

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

McGrail, B.P.; Mahoney, L.A.

Planned performance assessments for the proposed disposal of low-level waste (LLW) glass produced from remediation of wastes stored in underground tanks at Hanford, Washington will require calculations of radionuclide release rates from the subsurface disposal facility. These calculations will be done with the aid of computer codes. Currently available computer codes were ranked in terms of the feature sets implemented in the code that match a set of physical, chemical, numerical, and functional capabilities needed to assess release rates from the engineered system. The needed capabilities were identified from an analysis of the important physical and chemical process expected tomore » affect LLW glass corrosion and the mobility of radionuclides. The highest ranked computer code was found to be the ARES-CT code developed at PNL for the US Department of Energy for evaluation of and land disposal sites.« less

User's manual for a material transport code on the Octopus Computer Network

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

Naymik, T.G.; Mendez, G.D.

1978-09-15

A code to simulate material transport through porous media was developed at Oak Ridge National Laboratory. This code has been modified and adapted for use at Lawrence Livermore Laboratory. This manual, in conjunction with report ORNL-4928, explains the input, output, and execution of the code on the Octopus Computer Network.

Hot Flashes

MedlinePlus

... report menopausal hot flashes than do women of European descent. Hot flashes are less common in women of Japanese and Chinese descent than in white European women. Complications Nighttime hot flashes (night sweats) can ...

Performance analysis of three dimensional integral equation computations on a massively parallel computer. M.S. Thesis

NASA Technical Reports Server (NTRS)

Logan, Terry G.

1994-01-01

The purpose of this study is to investigate the performance of the integral equation computations using numerical source field-panel method in a massively parallel processing (MPP) environment. A comparative study of computational performance of the MPP CM-5 computer and conventional Cray-YMP supercomputer for a three-dimensional flow problem is made. A serial FORTRAN code is converted into a parallel CM-FORTRAN code. Some performance results are obtained on CM-5 with 32, 62, 128 nodes along with those on Cray-YMP with a single processor. The comparison of the performance indicates that the parallel CM-FORTRAN code near or out-performs the equivalent serial FORTRAN code for some cases.

Circulating interleukin-8 and tumor necrosis factor-α are associated with hot flashes in healthy postmenopausal women.

PubMed

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

2017-01-01

Hot flashes have been postulated to be linked to systemic inflammation. This study aimed to investigate the relationship between hot flashes, pro-inflammatory factors, and leukocytes in healthy, non-obese postmenopausal women. In this cross-sectional study, a total of 202 women aged 45-60 years were stratified into one of four groups according to their hot-flash status: never experienced hot flashes (Group N), mild hot flashes (Group m), moderate hot flashes (Group M), and severe hot flashes (Group S). Variables measured in this study included clinical parameters, hot flash experience, leukocytes, and fasting plasma levels of nine circulating cytokines/chemokines measured by using multiplex assays. Multiple linear regression analysis was used to evaluate the associations of hot flashes with these pro-inflammatory factors. The study was performed in a hospital medical center. The mean values of leukocyte number were not different between these four groups. The hot flash status had a positive tendency toward increased levels of circulating IL-6 (P-trend = 0.049), IL-8 (P-trend < 0.001), TNF-α (P-trend = 0.008), and MIP1β (P-trend = 0.04). Multivariate linear regression analysis revealed that hot-flash severity was significantly associated with IL-8 (P-trend < 0.001) and TNFα (P-trend = 0.007) among these nine cytokines/chemokines after adjustment for age, menopausal duration, BMI and FSH. Multivariate analysis further revealed that severe hot flashes were strongly associated with a higher IL-8 (% difference, 37.19%; 95% confidence interval, 14.98,63.69; P < 0.001) and TNFα (51.27%; 6.64,114.57; P < 0.05). The present study provides evidence that hot flashes are associated with circulating IL-8 and TNF-α in healthy postmenopausal women. It suggests that hot flashes might be related to low-grade systemic inflammation.

Expectancy after the first treatment and response to acupuncture for menopausal hot flashes.

PubMed

Ee, Carolyn C; Thuraisingam, Sharmala; Pirotta, Marie V; French, Simon D; Xue, Charlie C; Teede, Helena J

2017-01-01

Evidence on the impact of expectancy on acupuncture treatment response is conflicting. This secondary analysis of a randomized sham-controlled trial on acupuncture for menopausal hot flashes investigated whether treatment expectancy score was associated with hot flash score at end-of-treatment. Secondary analyses investigated whether there were associations between other pre-specified factors and hot flash score. Women experiencing moderately-severe hot flashes were randomized to receive 10 sessions of real or sham acupuncture over eight weeks. Hot flash score was collected using a seven-day hot flash diary, and expectancy using the modified Credibility and Expectancy Questionnaire immediately after the first treatment. Linear mixed-effects models with random intercepts were used to identify associations between expectancy score and hot flash score at end-of-treatment. Regression was also used to identify associations between pre-specified factors of interest and hot flash score. Because there was no difference between real and sham acupuncture for the primary outcome of hot flash score, both arms were combined in the analysis. 285 women returned the Credibility and Expectancy Questionnaire, and 283 women completed both expectancy measures. We found no evidence for an association between expectancy and hot flash score at end-of-treatment for individual cases in either acupuncture or sham group. Hot flash scores at end-of-treatment were 8.1 (95%CI, 3.0 to 13.2; P = 0.002) points lower in regular smokers compared to those who had never smoked, equivalent to four fewer moderate hot flashes a day. In our study of acupuncture for menopausal hot flashes, higher expectancy after the first treatment did not predict better treatment outcomes. Future research may focus on other determinants of outcomes in acupuncture such as therapist attention. The relationship between smoking and hot flashes is poorly understood and needs further exploration.

Circulating interleukin-8 and tumor necrosis factor-α are associated with hot flashes in healthy postmenopausal women

PubMed Central

Huang, Wan-Yu; Hsin, I-Lun; Chen, Dar-Ren; Chang, Chia-Chu; Kor, Chew-Teng; Chen, Ting-Yu

2017-01-01

Introduction Hot flashes have been postulated to be linked to systemic inflammation. This study aimed to investigate the relationship between hot flashes, pro-inflammatory factors, and leukocytes in healthy, non-obese postmenopausal women. Participants and design In this cross-sectional study, a total of 202 women aged 45–60 years were stratified into one of four groups according to their hot-flash status: never experienced hot flashes (Group N), mild hot flashes (Group m), moderate hot flashes (Group M), and severe hot flashes (Group S). Variables measured in this study included clinical parameters, hot flash experience, leukocytes, and fasting plasma levels of nine circulating cytokines/chemokines measured by using multiplex assays. Multiple linear regression analysis was used to evaluate the associations of hot flashes with these pro-inflammatory factors. Settings The study was performed in a hospital medical center. Results The mean values of leukocyte number were not different between these four groups. The hot flash status had a positive tendency toward increased levels of circulating IL-6 (P-trend = 0.049), IL-8 (P-trend < 0.001), TNF-α (P-trend = 0.008), and MIP1β (P-trend = 0.04). Multivariate linear regression analysis revealed that hot-flash severity was significantly associated with IL-8 (P-trend < 0.001) and TNFα (P-trend = 0.007) among these nine cytokines/chemokines after adjustment for age, menopausal duration, BMI and FSH. Multivariate analysis further revealed that severe hot flashes were strongly associated with a higher IL-8 (% difference, 37.19%; 95% confidence interval, 14.98,63.69; P < 0.001) and TNFα (51.27%; 6.64,114.57; P < 0.05). Conclusion The present study provides evidence that hot flashes are associated with circulating IL-8 and TNF-α in healthy postmenopausal women. It suggests that hot flashes might be related to low-grade systemic inflammation. PMID:28846735

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

NASA Astrophysics Data System (ADS)

Yuan, Xing; Wang, Linying; Ji, Peng

2017-04-01

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

Computer Description of the M561 Utility Truck

DTIC Science & Technology

1984-10-01

GIFT Computer Code Sustainabi1ity Predictions for Army Spare Components Requirements for Combat (SPARC) 20. ABSTRACT (Caotfmia «a NWM eitim ft...used as input to the GIFT computer code to generate target vulnerability data. DO FORM V JAM 73 1473 EDITION OF I NOV 65 IS OBSOLETE Unclass i f ied...anaLyiis requires input from the Geometric Information for Targets ( GIFT ) ’ computer code. This report documents the combina- torial geometry (Com-Geom

TEMPEST: A three-dimensional time-dependent computer program for hydrothermal analysis: Volume 2, Assessment and verification results

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

Eyler, L L; Trent, D S; Budden, M J

During the course of the TEMPEST computer code development a concurrent effort was conducted to assess the code's performance and the validity of computed results. The results of this work are presented in this document. The principal objective of this effort was to assure the code's computational correctness for a wide range of hydrothermal phenomena typical of fast breeder reactor application. 47 refs., 94 figs., 6 tabs.

Muzzle flash issues related to the Waco FLIR analysis

NASA Astrophysics Data System (ADS)

Grant, Barbara G.; Hardy, David T.

2001-09-01

The controversy surrounding the origin of flashes on the Mt. Carmel FLIR videotape acquired on April 19, 1993, is introduced. The characteristics of muzzle flash are reviewed. A comparative weapons description is offered. The temporal, spatial, and radiance characteristics of thermal infrared muzzle flash are addressed. Data acquired from a field experiment are presented. The authors conclude that the spatial characteristics of muzzle flash enable its detection by equipment such as the FLIR in use at Mt. Carmel on April 19, 1993; that while flashes obtained in the field appear highly radiant, measurements are necessary to quantify their values; and that the temporal behavior of muzzle flash deserves further study.

Initial Breakdown Pulse Parameters in Intracloud and Cloud-to-Ground Lightning Flashes

NASA Astrophysics Data System (ADS)

Smith, E. M.; Marshall, T. C.; Karunarathne, S.; Siedlecki, R.; Stolzenburg, M.

2018-02-01

This study analyzes the largest initial breakdown (IB) pulse in flashes from four storms in Florida; data from three sensor arrays are used. The range-normalized, zero-to-peak amplitude of the largest IB pulse was determined along with its altitude, duration, and timing within each flash. Appropriate data were available for 40 intracloud (IC) and 32 cloud-to-ground (CG) flashes. Histograms of amplitude of the largest IB pulse by flash type were similar, with mean (median) values of 1.49 (1.05) V/m for IC flashes and -1.35 (-0.87) V/m for CG flashes. The largest IB pulse in 30 IC flashes showed a weak inverse relation between pulse amplitude and altitude. Amplitude of the largest IB pulse for 25 CG flashes showed no altitude correlation. Duration of the largest IB pulse in ICs averaged twice as long as in CGs (96 μs versus 46 μs), and all of the CG durations were <100 μs. Among the ICs, there is a positive relation between largest IB pulse duration and amplitude; the linear correlation coefficient is 0.385 with outliers excluded. The largest IB pulse in IC flashes typically occurred at a longer time after the first IB pulse (average 4.1 ms) than was the case in CG flashes (average 0.6 ms). In both flash types, the largest IB pulse was the first IB pulse in about 30% of the cases. In one storm all 42 IC flashes with triggered data had IB pulses.

Fluid Management of and Flame Spread Across Liquid Pools

NASA Technical Reports Server (NTRS)

Ross, H. D.; Miller, F. J.

2001-01-01

The goal of our research on flame spread across pools of liquid fuel remains the quantitative identification of the mechanisms that control the rate and nature of flame spread when the initial temperature of the liquid pool is below the fuel's flash point temperature. As described in, four microgravity (mu-g) sounding rocket flights examined the effect of forced opposed airflow over a 2.5 cm deep x 2 cm wide x 30 cm long pool of 1-butanol. Among many unexpected findings, it was observed that the flame spread is much slower and steadier than in 1g where flame spread has a pulsating character. Our numerical model, restricted to two dimensions, had predicted faster, pulsating flame spread in mu-g. In a test designed to achieve a more 2-D experiment, our investigation of a shallow, wide pool (2 mm deep x 78 mm wide x 30 cm long) was unsuccessful in mu-g, due to an unexpectedly long time required to fill the tray. As such, the most recent Spread Across Liquids (SAL) sounding rocket experiment had two principal objectives: 1) determine if pulsating flame spread in deep fuel trays would occur under the conditions that a state-of-the-art computational combustion code and short-duration drop tower tests predict; and 2) determine if a long, rectangular, shallow fuel tray could achieve a visibly flat liquid surface across the whole tray without spillage in the mu-g time allotted. If the second objective was met, the shallow tray was to be ignited to determine the nature of flame spread in mu-g for this geometry. For the first time in the experiment series, two fuel trays - one deep (30 cm long x 2 cm wide x 25 mm deep) and one shallow (same length and width, but 2 mm deep)-- were flown. By doing two independent experiments in a single flight, a significant cost savings was realized. In parallel, the computational objective was to modify the code to improve agreement with earlier results. This last objective was achieved by modifying the fuel mass diffusivity and adding a parameter to correct for radiative and lateral heat loss.

A Bayesian Network approach for flash flood risk assessment

NASA Astrophysics Data System (ADS)

Boutkhamouine, Brahim; Roux, Hélène; Pérès, François

2017-04-01

Climate change is contributing to the increase of natural disasters such as extreme weather events. Sometimes, these events lead to sudden flash floods causing devastating effects on life and property. Most recently, many regions of the French Mediterranean perimeter have endured such catastrophic flood events; Var (October 2015), Ardèche (November 2014), Nîmes (October 2014), Hérault, Gard and Languedoc (September 2014), and Pyrenees mountains (Jun 2013). Altogether, it resulted in dozens of victims and property damages amounting to millions of euros. With this heavy loss in mind, development of hydrological forecasting and warning systems is becoming an essential element in regional and national strategies. Flash flood forecasting but also monitoring is a difficult task because small ungauged catchments ( 10 km2) are often the most destructive ones as for the extreme flash flood event of September 2002 in the Cévennes region (France) (Ruin et al., 2008). The problem of measurement/prediction uncertainty is particularly crucial when attempting to develop operational flash-flood forecasting methods. Taking into account the uncertainty related to the model structure itself, to the model parametrization or to the model forcing (spatio-temporal rainfall, initial conditions) is crucial in hydrological modelling. Quantifying these uncertainties is of primary importance for risk assessment and decision making. Although significant improvements have been made in computational power and distributed hydrologic modelling, the issue dealing with integration of uncertainties into flood forecasting remains up-to-date and challenging. In order to develop a framework which could handle these uncertainties and explain their propagation through the model, we propose to explore the potential of graphical models (GMs) and, more precisely, Bayesian Networks (BNs). These networks are Directed Acyclic Graphs (DAGs) in which knowledge of a certain phenomenon is represented by influencing variables. Each node of the graph corresponds to a variable and arcs represent the probabilistic dependencies between these variables. Both the quantification of the strength of these probabilistic dependencies and the computation of inferences are based on Bayes' theorem. In order to use BNs for the assessment of the flooding risks, the modelling work is divided into two parts. First, identifying all the factors controlling the flood generation. The qualitative explanation of this issue is then reached by establishing the cause and effect relationships between these factors. These underlying relationships are represented in what we call Conditional Probabilities Tables (CPTs). The next step is to estimate these CPTs using information coming from network of sensors, databases and expertise. By using this basic cognitive structure, we will be able to estimate the magnitude of flood risk in a small geographical area with a homogeneous hydrological system. The second part of our work will be dedicated to the estimation of this risk on the scale of a basin. To do so, we will create a spatio-temporal model able to take in consideration both spatial and temporal variability of all factors involved in the flood generation. Key words: Flash flood forecasting - Uncertainty modelling - flood risk management -Bayesian Networks.

The influence of commenting validity, placement, and style on perceptions of computer code trustworthiness: A heuristic-systematic processing approach.

PubMed

Alarcon, Gene M; Gamble, Rose F; Ryan, Tyler J; Walter, Charles; Jessup, Sarah A; Wood, David W; Capiola, August

2018-07-01

Computer programs are a ubiquitous part of modern society, yet little is known about the psychological processes that underlie reviewing code. We applied the heuristic-systematic model (HSM) to investigate the influence of computer code comments on perceptions of code trustworthiness. The study explored the influence of validity, placement, and style of comments in code on trustworthiness perceptions and time spent on code. Results indicated valid comments led to higher trust assessments and more time spent on the code. Properly placed comments led to lower trust assessments and had a marginal effect on time spent on code; however, the effect was no longer significant after controlling for effects of the source code. Low style comments led to marginally higher trustworthiness assessments, but high style comments led to longer time spent on the code. Several interactions were also found. Our findings suggest the relationship between code comments and perceptions of code trustworthiness is not as straightforward as previously thought. Additionally, the current paper extends the HSM to the programming literature. Copyright © 2018 Elsevier Ltd. All rights reserved.

Adiabatic topological quantum computing

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

Cesare, Chris; Landahl, Andrew J.; Bacon, Dave

Topological quantum computing promises error-resistant quantum computation without active error correction. However, there is a worry that during the process of executing quantum gates by braiding anyons around each other, extra anyonic excitations will be created that will disorder the encoded quantum information. Here, we explore this question in detail by studying adiabatic code deformations on Hamiltonians based on topological codes, notably Kitaev’s surface codes and the more recently discovered color codes. We develop protocols that enable universal quantum computing by adiabatic evolution in a way that keeps the energy gap of the system constant with respect to the computationmore » size and introduces only simple local Hamiltonian interactions. This allows one to perform holonomic quantum computing with these topological quantum computing systems. The tools we develop allow one to go beyond numerical simulations and understand these processes analytically.« less

Adiabatic topological quantum computing

DOE PAGES

Cesare, Chris; Landahl, Andrew J.; Bacon, Dave; ...

2015-07-31

Topological quantum computing promises error-resistant quantum computation without active error correction. However, there is a worry that during the process of executing quantum gates by braiding anyons around each other, extra anyonic excitations will be created that will disorder the encoded quantum information. Here, we explore this question in detail by studying adiabatic code deformations on Hamiltonians based on topological codes, notably Kitaev’s surface codes and the more recently discovered color codes. We develop protocols that enable universal quantum computing by adiabatic evolution in a way that keeps the energy gap of the system constant with respect to the computationmore » size and introduces only simple local Hamiltonian interactions. This allows one to perform holonomic quantum computing with these topological quantum computing systems. The tools we develop allow one to go beyond numerical simulations and understand these processes analytically.« less

Cloud-to-ground lightning and surface rainfall in warm-season Florida thunderstorms

USGS Publications Warehouse

Gungle, B.; Krider, E.P.

2006-01-01

Relationships between cloud-to-ground (CG) lightning and surface rainfall have been examined in nine isolated, warm-season thunderstorms on the east coast of central Florida. CG flashes and the associated rain volumes were measured as a function of time in storm-centered reference frames that followed each storm over a network of rain gauges. Values of the storm-average rain volume per CG flash ranged from 0.70 ?? 104 to 6.4 ?? 104 m3/CG flash, with a mean (and standard deviation) of 2.6 ?? 104 ?? 2.1 ?? 104 m3/CG flash. Values of the rain volume concurrent with CG flashes ranged from 0.11 ?? 104 to 4.9 ?? 104 m3/CG flash with a mean of 2.1 ?? 104 ?? 2.0 ?? 104 m3/CG flash. The lag-time between the peak CG flash rate and the peak rainfall rate (using 5 min bins), and the results of a lag correlation analysis, show that surface rainfall tends to follow the lightning (positive lag) by up to 20 min in six storms. In one storm the rainfall preceded the lightning by 5 min, and two storms had nonsignificant lags. Values of the lagged rain volume concurrent with CG flashes ranged from 0.43 ?? 104 to 4.9 ?? 104 m3/CG flash, and the mean was 1.9 ?? 104 ?? 1.7 ?? 104 m3/CG flash. For the five storms that produced 12 or more flashes and had significant lags, a plot of the optimum lag time versus the total number of CG flashes shows a linear trend (R2 = 0.56). The number of storms is limited, but the lag results do indicate that large storms tend to have longer lags. A linear fit to the lagged rain volume vs. the number of concurrent CG flashes has a slope of 1.9 ?? 104 m3/CG flash (R2 = 0.83). We conclude that warm-season Florida thunderstorms produce a roughly constant rain volume per CG flash and that CG lightning can be used to estimate the location and intensity of convective rainfall in that weather regime. Copyright 2006 by the American Geophysical Union.

Fast Computation of the Two-Point Correlation Function in the Age of Big Data

NASA Astrophysics Data System (ADS)

Pellegrino, Andrew; Timlin, John

2018-01-01

We present a new code which quickly computes the two-point correlation function for large sets of astronomical data. This code combines the ease of use of Python with the speed of parallel shared libraries written in C. We include the capability to compute the auto- and cross-correlation statistics, and allow the user to calculate the three-dimensional and angular correlation functions. Additionally, the code automatically divides the user-provided sky masks into contiguous subsamples of similar size, using the HEALPix pixelization scheme, for the purpose of resampling. Errors are computed using jackknife and bootstrap resampling in a way that adds negligible extra runtime, even with many subsamples. We demonstrate comparable speed with other clustering codes, and code accuracy compared to known and analytic results.

Data Movement Dominates: Final Report

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

Jacob, Bruce L.

Over the past three years in this project, what we have observed is that the primary reason for data movement in large-scale systems is that the per-node capacity is not large enough—i.e., one of the solutions to the data-movement problem (certainly not the only solution that is required, but a significant one nonetheless) is to increase per-node capacity so that inter-node traffic is reduced. This unfortunately is not as simple as it sounds. Today’s main memory systems for datacenters, enterprise computing systems, and supercomputers, fail to provide high per-socket capacity [Dirik & Jacob 2009; Cooper-Balis et al. 2012], except atmore » extremely high price points (factors of 10–100x the cost/bit of consumer main-memory systems) [Stokes 2008]. The reason is that our choice of technology for today’s main memory systems—i.e., DRAM, which we have used as a main-memory technology since the 1970s [Jacob et al. 2007]—can no longer keep up with our needs for density and price per bit. Main memory systems have always been built from the cheapest, densest, lowest-power memory technology available, and DRAM is no longer the cheapest, the densest, nor the lowest-power storage technology out there. It is now time for DRAM to go the way that SRAM went: move out of the way for a cheaper, slower, denser storage technology, and become a cache instead. This inflection point has happened before, in the context of SRAM yielding to DRAM. There was once a time that SRAM was the storage technology of choice for all main memories [Tomasulo 1967; Thornton 1970; Kidder 1981]. However, once DRAM hit volume production in the 1970s and 80s, it supplanted SRAM as a main memory technology because it was cheaper, and it was denser. It also happened to be lower power, but that was not the primary consideration of the day. At the time, it was recognized that DRAM was much slower than SRAM, but it was only at the supercomputer level (For instance the Cray X-MP in the 1980s and its follow-on, the Cray Y-MP, in the 1990s) that could one afford to build ever- larger main memories out of SRAM—the reasoning for moving to DRAM was that an appropriately designed memory hierarchy, built of DRAM as main memory and SRAM as a cache, would approach the performance of SRAM, at the price-per-bit of DRAM [Mashey 1999]. Today it is quite clear that, were one to build an entire multi-gigabyte main memory out of SRAM instead of DRAM, one could improve the performance of almost any computer system by up to an order of magnitude—but this option is not even considered, because to build that system would be prohibitively expensive. It is now time to revisit the same design choice in the context of modern technologies and modern systems. For reasons both technical and economic, we can no longer afford to build ever-larger main memory systems out of DRAM. Flash memory, on the other hand, is significantly cheaper and denser than DRAM and therefore should take its place. While it is true that flash is significantly slower than DRAM, one can afford to build much larger main memories out of flash than out of DRAM, and we show that an appropriately designed memory hierarchy, built of flash as main memory and DRAM as a cache, will approach the performance of DRAM, at the price-per-bit of flash. In our studies as part of this project, we have investigated Non-Volatile Main Memory (NVMM), a new main-memory architecture for large-scale computing systems, one that is specifically designed to address the weaknesses described previously. In particular, it provides the following features: non-volatility: The bulk of the storage is comprised of NAND flash, and in this organization DRAM is used only as a cache, not as main memory. Furthermore, the flash is journaled, which means that operations such as checkpoint/restore are already built into the system. 1+ terabytes of storage per socket: SSDs and DRAM DIMMs have roughly the same form factor (several square inches of PCB surface area), and terabyte SSDs are now commonplace. performance approaching that of DRAM: DRAM is used as a cache to the flash system. price-per-bit approaching that of NAND: Flash is currently well under $0.50 per gigabyte; DDR3 SDRAM is currently just over $10 per gigabyte [Newegg 2014]. Even today, one can build an easily affordable main memory system with a terabyte or more of NAND storage per CPU socket (which would be extremely expensive were one to use DRAM), and our cycle- accurate, full-system experiments show that this can be done at a performance point that lies within a factor of two of DRAM.« less

Patterning of wound-induced intercellular Ca2+ flashes in a developing epithelium

NASA Astrophysics Data System (ADS)

Narciso, Cody; Wu, Qinfeng; Brodskiy, Pavel; Garston, George; Baker, Ruth; Fletcher, Alexander; Zartman, Jeremiah

2015-10-01

Differential mechanical force distributions are increasingly recognized to provide important feedback into the control of an organ’s final size and shape. As a second messenger that integrates and relays mechanical information to the cell, calcium ions (Ca2+) are a prime candidate for providing important information on both the overall mechanical state of the tissue and resulting behavior at the individual-cell level during development. Still, how the spatiotemporal properties of Ca2+ transients reflect the underlying mechanical characteristics of tissues is still poorly understood. Here we use an established model system of an epithelial tissue, the Drosophila wing imaginal disc, to investigate how tissue properties impact the propagation of Ca2+ transients induced by laser ablation. The resulting intercellular Ca2+ flash is found to be mediated by inositol 1,4,5-trisphosphate and depends on gap junction communication. Further, we find that intercellular Ca2+ transients show spatially non-uniform characteristics across the proximal-distal axis of the larval wing imaginal disc, which exhibit a gradient in cell size and anisotropy. A computational model of Ca2+ transients is employed to identify the principle factors explaining the spatiotemporal patterning dynamics of intercellular Ca2+ flashes. The relative Ca2+ flash anisotropy is principally explained by local cell shape anisotropy. Further, Ca2+ velocities are relatively uniform throughout the wing disc, irrespective of cell size or anisotropy. This can be explained by the opposing effects of cell diameter and cell elongation on intercellular Ca2+ propagation. Thus, intercellular Ca2+ transients follow lines of mechanical tension at velocities that are largely independent of tissue heterogeneity and reflect the mechanical state of the underlying tissue.

Presentation and response timing accuracy in Adobe Flash and HTML5/JavaScript Web experiments.

PubMed

Reimers, Stian; Stewart, Neil

2015-06-01

Web-based research is becoming ubiquitous in the behavioral sciences, facilitated by convenient, readily available participant pools and relatively straightforward ways of running experiments: most recently, through the development of the HTML5 standard. Although in most studies participants give untimed responses, there is a growing interest in being able to record response times online. Existing data on the accuracy and cross-machine variability of online timing measures are limited, and generally they have compared behavioral data gathered on the Web with similar data gathered in the lab. For this article, we took a more direct approach, examining two ways of running experiments online-Adobe Flash and HTML5 with CSS3 and JavaScript-across 19 different computer systems. We used specialist hardware to measure stimulus display durations and to generate precise response times to visual stimuli in order to assess measurement accuracy, examining effects of duration, browser, and system-to-system variability (such as across different Windows versions), as well as effects of processing power and graphics capability. We found that (a) Flash and JavaScript's presentation and response time measurement accuracy are similar; (b) within-system variability is generally small, even in low-powered machines under high load; (c) the variability of measured response times across systems is somewhat larger; and (d) browser type and system hardware appear to have relatively small effects on measured response times. Modeling of the effects of this technical variability suggests that for most within- and between-subjects experiments, Flash and JavaScript can both be used to accurately detect differences in response times across conditions. Concerns are, however, noted about using some correlational or longitudinal designs online.

Formation and Assembly of Massive Star Clusters

NASA Astrophysics Data System (ADS)

McMillan, Stephen

The formation of stars and star clusters is a major unresolved problem in astrophysics. It is central to modeling stellar populations and understanding galaxy luminosity distributions in cosmological models. Young massive clusters are major components of starburst galaxies, while globular clusters are cornerstones of the cosmic distance scale and represent vital laboratories for studies of stellar dynamics and stellar evolution. Yet how these clusters form and how rapidly and efficiently they expel their natal gas remain unclear, as do the consequences of this gas expulsion for cluster structure and survival. Also unclear is how the properties of low-mass clusters, which form from small-scale instabilities in galactic disks and inform much of our understanding of cluster formation and star-formation efficiency, differ from those of more massive clusters, which probably formed in starburst events driven by fast accretion at high redshift, or colliding gas flows in merging galaxies. Modeling cluster formation requires simulating many simultaneous physical processes, placing stringent demands on both software and hardware. Simulations of galaxies evolving in cosmological contexts usually lack the numerical resolution to simulate star formation in detail. They do not include detailed treatments of important physical effects such as magnetic fields, radiation pressure, ionization, and supernova feedback. Simulations of smaller clusters include these effects, but fall far short of the mass of even single young globular clusters. With major advances in computing power and software, we can now directly address this problem. We propose to model the formation of massive star clusters by integrating the FLASH adaptive mesh refinement magnetohydrodynamics (MHD) code into the Astrophysical Multi-purpose Software Environment (AMUSE) framework, to work with existing stellar-dynamical and stellar evolution modules in AMUSE. All software will be freely distributed on-line, allowing open access to state-of- the-art simulation techniques within a modern, modular software environment. We will follow the gravitational collapse of 0.1-10 million-solar mass gas clouds through star formation and coalescence into a star cluster, modeling in detail the coupling of the gas and the newborn stars. We will study the effects of star formation by detecting accreting regions of gas in self-gravitating, turbulent, MHD, FLASH models that we will translate into collisional dynamical systems of stars modeled with an N-body code, coupled together in the AMUSE framework. Our FLASH models will include treatments of radiative transfer from the newly formed stars, including heating and radiative acceleration of the surrounding gas. Specific questions to be addressed are: (1) How efficiently does the gas in a star forming region form stars, how does this depend on mass, metallicity, and other parameters, and what terminates star formation? What observational predictions can be made to constrain our models? (2) How important are different mechanisms for driving turbulence and removing gas from a cluster: accretion, radiative feedback, and mechanical feedback? (3) How does the infant mortality rate of young clusters depend on the initial properties of the parent cloud? (4) What are the characteristic formation timescales of massive star clusters, and what observable imprints does the assembly process leave on their structure at an age of 10-20 Myr, when formation is essentially complete and many clusters can be observed? These studies are directly relevant to NASA missions at many electromagnetic wavelengths, including Chandra, GALEX, Hubble, and Spitzer. Each traces different aspects of cluster formation and evolution: X-rays trace supernovae, ultraviolet traces young stars, visible colors can distinguish between young blue stars and older red stars, and the infrared directly shows young embedded star clusters.

Modeling and numerical simulation of interior ballistic processes in a 120mm mortar system

NASA Astrophysics Data System (ADS)

Acharya, Ragini

Numerical Simulation of interior ballistic processes in gun and mortar systems is a very difficult and interesting problem. The mathematical model for the physical processes in the mortar systems consists of a system of non-linear coupled partial differential equations, which also contain non-homogeneity in form of the source terms. This work includes the development of a three-dimensional mortar interior ballistic (3D-MIB) code for a 120mm mortar system and its stage-wise validation with multiple sets of experimental data. The 120mm mortar system consists of a flash tube contained within an ignition cartridge, tail-boom, fin region, charge increments containing granular propellants, and a projectile payload. The ignition cartridge discharges hot gas-phase products and unburned granular propellants into the mortar tube through vent-holes on its surface. In view of the complexity of interior ballistic processes in the mortar propulsion system, the overall problem was solved in a modular fashion, i.e., simulating each physical component of the mortar propulsion system separately. These modules were coupled together with appropriate initial and boundary conditions. The ignition cartridge and mortar tube contain nitrocellulose-based ball propellants. Therefore, the gas dynamical processes in the 120mm mortar system are two-phase, which were simulated by considering both phases as an interpenetrating continuum. Mass and energy fluxes from the flash tube into the granular bed of ignition cartridge were determined from a semi-empirical technique. For the tail-boom section, a transient one-dimensional two-phase compressible flow solver based on method of characteristics was developed. The mathematical model for the interior ballistic processes in the mortar tube posed an initial value problem with discontinuous initial conditions with the characteristics of the Riemann problem due to the discontinuity of the initial conditions. Therefore, the mortar tube model was solved by using a high-resolution Godunov-type shock-capturing approach was used where the discretization is done directly on the integral formulation of the conservation laws. A linearized approximate Riemann Solver was modified in this work for the two-phase flows to compute fully non-linear wave interactions and to directly provide upwinding properties in the scheme. An entropy fix based on Harten-Heyman method was used with van Leer flux limiter for total variation diminishing. The three dimensional effects were simulated by incorporating an unsplit multi-dimensional wave propagation method, which accounted for discontinuities traveling in both normal and oblique coordinate directions. For each component, the predicted pressure-time traces showed significant pressure wave phenomena, which closely simulated the measured pressure-time traces obtained at PSU. The pressure-time traces at the breech-end of the mortar tube were obtained at Aberdeen Test Center with 0, 2, and 4 charge increments. The 3D-MIB code was also used to simulate the effect of flash tube vent-hole pattern on the pressure-wave phenomenon in the ignition cartridge. A comparison of the pressure difference between primer-end and projectile-end locations of the original and modified ignition cartridges with each other showed that the early-phase pressure-wave phenomenon can be significantly reduced with the modified pattern. The flow property distributions predicted by the 3D-MIB for 0, 2, and 4 charge increment cases as well the projectile dynamics predictions provided adequate validation of theory by experiments.

Design of convolutional tornado code

NASA Astrophysics Data System (ADS)

Zhou, Hui; Yang, Yao; Gao, Hongmin; Tan, Lu

2017-09-01

As a linear block code, the traditional tornado (tTN) code is inefficient in burst-erasure environment and its multi-level structure may lead to high encoding/decoding complexity. This paper presents a convolutional tornado (cTN) code which is able to improve the burst-erasure protection capability by applying the convolution property to the tTN code, and reduce computational complexity by abrogating the multi-level structure. The simulation results show that cTN code can provide a better packet loss protection performance with lower computation complexity than tTN code.

Brain blood flow and cardiovascular responses to hot flashes in postmenopausal women

PubMed Central

Lucas, Rebekah A. I.; Ganio, Matthew S.; Pearson, James; Crandall, Craig G.

2012-01-01

Objective This study tested two related hypotheses: 1) that brain blood flow is reduced during the postmenopausal hot flash; and, 2) the magnitude of this reduction in brain blood flow is greater during hot flashes where blood pressure is reduced. Methods Eleven healthy, normotensive, postmenopausal women rested in a temperature-controlled laboratory (~25°C) for approximately 120 minutes while waiting for a hot flash to occur. The onset of a hot flash was objectively identified by an abrupt increase in sternal sweat rate (capacitance hygrometry). Middle cerebral artery blood velocity (MCAv, transcranial Doppler) and mean arterial pressure (Finometer®) were measured continuously. Each hot flash was divided into 8 equal segments and the segment with the largest reduction in MCAv and mean arterial pressure identified for each hot flash. Results Twenty-five hot flashes occurred during the experimental sessions (lasting 6.2 ± 2.8 min, 3 ± 1 hot flashes per participant). Seventy-six percent of hot flashes were accompanied by a clear reduction (greater than 5%) in brain blood flow. For all hot flashes, the average maximum decrease in MCAv was 12 ± 9% (7 ± 6 cm.s−1). This value did not correlate with corresponding changes in mean arterial pressure (R=0.36). Conclusion These findings demonstrate that hot flashes are often accompanied by clear reductions in brain blood flow that do not correspond with acute reductions in mean arterial blood pressure. PMID:23435027

Are menopausal hot flashes an evolutionary byproduct of postpartum warming?

PubMed

Sievert, Lynnette Leidy; Masley, Allison

2015-04-01

Hot flashes are commonly associated with menopause, and some researchers have questioned whether the widespread phenomenon may somehow be adaptive. It has been hypothesized that hot flashes were selected to occur during the hypoestrogenic postpartum period as a mechanism to warm infants. The purpose of this study was to test whether postpartum hot flashes are similar to hot flashes associated with menopause and whether postpartum hot flashes are concordant with breast-feeding episodes. Women who gave birth within the past year (n = 20) and a comparison group of women who had not given birth in the past 2 years (n = 14) participated in interviews and anthropometric measures. All wore ambulatory skin conductance monitors for a mean of 6.5 hours during afternoons and early evenings. New mothers also recorded breast-feeding episodes. Objectively measured and subjectively reported hot flashes were compared between groups and in relation to breast-feeding and other variables. Age of infants ranged from 4 days to 11 months. New mothers were more likely to report feeling warmer than the comparison group (100% vs 7%) but were not significantly more likely to demonstrate hot flashes (35% vs 50%) or to report hot flashes (30% vs 21%) during the study period. Of 75 breast-feeding episodes, only 4% were concurrent with an objective hot flash, and only 9% were concurrent with a subjective hot flash. This study does not support the hypothesis that menopausal-like hot flashes evolved to warm infants during the postpartum period.

Three-dimensional turbopump flowfield analysis

NASA Technical Reports Server (NTRS)

Sharma, O. P.; Belford, K. A.; Ni, R. H.

1992-01-01

A program was conducted to develop a flow prediction method applicable to rocket turbopumps. The complex nature of a flowfield in turbopumps is described and examples of flowfields are discussed to illustrate that physics based models and analytical calculation procedures based on computational fluid dynamics (CFD) are needed to develop reliable design procedures for turbopumps. A CFD code developed at NASA ARC was used as the base code. The turbulence model and boundary conditions in the base code were modified, respectively, to: (1) compute transitional flows and account for extra rates of strain, e.g., rotation; and (2) compute surface heat transfer coefficients and allow computation through multistage turbomachines. Benchmark quality data from two and three-dimensional cascades were used to verify the code. The predictive capabilities of the present CFD code were demonstrated by computing the flow through a radial impeller and a multistage axial flow turbine. Results of the program indicate that the present code operated in a two-dimensional mode is a cost effective alternative to full three-dimensional calculations, and that it permits realistic predictions of unsteady loadings and losses for multistage machines.

High altitude chemically reacting gas particle mixtures. Volume 3: Computer code user's and applications manual. [rocket nozzle and orbital plume flow fields

NASA Technical Reports Server (NTRS)

Smith, S. D.

1984-01-01

A users manual for the RAMP2 computer code is provided. The RAMP2 code can be used to model the dominant phenomena which affect the prediction of liquid and solid rocket nozzle and orbital plume flow fields. The general structure and operation of RAMP2 are discussed. A user input/output guide for the modified TRAN72 computer code and the RAMP2F code is given. The application and use of the BLIMPJ module are considered. Sample problems involving the space shuttle main engine and motor are included.

Development of numerical methods for overset grids with applications for the integrated Space Shuttle vehicle

NASA Technical Reports Server (NTRS)

Chan, William M.

1995-01-01

Algorithms and computer code developments were performed for the overset grid approach to solving computational fluid dynamics problems. The techniques developed are applicable to compressible Navier-Stokes flow for any general complex configurations. The computer codes developed were tested on different complex configurations with the Space Shuttle launch vehicle configuration as the primary test bed. General, efficient and user-friendly codes were produced for grid generation, flow solution and force and moment computation.

Research in Computational Aeroscience Applications Implemented on Advanced Parallel Computing Systems

NASA Technical Reports Server (NTRS)

Wigton, Larry

1996-01-01

Improving the numerical linear algebra routines for use in new Navier-Stokes codes, specifically Tim Barth's unstructured grid code, with spin-offs to TRANAIR is reported. A fast distance calculation routine for Navier-Stokes codes using the new one-equation turbulence models is written. The primary focus of this work was devoted to improving matrix-iterative methods. New algorithms have been developed which activate the full potential of classical Cray-class computers as well as distributed-memory parallel computers.

ISSYS: An integrated synergistic Synthesis System

NASA Technical Reports Server (NTRS)

Dovi, A. R.

1980-01-01

Integrated Synergistic Synthesis System (ISSYS), an integrated system of computer codes in which the sequence of program execution and data flow is controlled by the user, is discussed. The commands available to exert such control, the ISSYS major function and rules, and the computer codes currently available in the system are described. Computational sequences frequently used in the aircraft structural analysis and synthesis are defined. External computer codes utilized by the ISSYS system are documented. A bibliography on the programs is included.

Solar-Powered Desalination: A Modelling and Experimental Study

NASA Astrophysics Data System (ADS)

Leblanc, Jimmy; Andrews, John

2007-10-01

Water shortage is becoming one of the major problems worldwide. As such, desalination technologies have been implemented to meet growing demands for fresh water. Among the desalination technologies, thermal desalination, including multi stage flash (MSF) and multi effect evaporation (MEE), is the current leading desalination process. Reverse osmosis (RO) is also being increasingly used. Despite technological improvements, thermal desalination and reverse osmosis continue to be intensive fossil-fuel consumers and contribute to increased levels of greenhouse gases. As energy costs rise, thermal desalination by solar energy and/or low cost waste heat is likely to become increasingly attractive. As part of a project investigating the productive use of saline land and the development of sustainable desalination systems, the feasibility of producing potable water from seawater or brackish water using desalination systems powered by renewable energy in the form of low-temperature solar-thermal sources has been studied. A salinity-gradient solar pond and an evacuated tube solar collector system have been used as heat sources. Solar ponds combine solar energy collection with long-term storage and can provide reliable thermal energy at temperature ranges from 50 to 90 °C. A visual basic computer model of the different multi-stage flash desalination processes coupled with a salinity-gradient solar pond was developed to determine which process is preferable in regards to performance and greenhouse impact. The governing mathematical equations are derived from mass balances, heat energy balances, and heat transfer characteristics. Using the results from the modelling, a small-scale solar-powered desalination system, capable of producing up to 500 litres of fresh water per day, was designed and manufactured. This single-stage flash system consists of two main units: the heat supply and storage system and the flash desalination unit. Two different condenser heat exchanger materials were investigated: copper-nickel and a commercially available plastic. The modelling and design of a three effects MEE system is also discussed. The effects of the important design and operating parameters (recovery ratio, thermal energy, parasitic electrical energy, distillate production and solar collection area) controlling the cost of fresh water determined both from the computer simulation and experimental results are presented and analysed in this paper. Future work in the overall research program is also outlined.

Post-Flash Validation of the new ACS/WFC Subarrays

NASA Astrophysics Data System (ADS)

Bellini, A.; Grogin, N. A.; Lim, P. L.; Golimowski, D.

2017-05-01

We made use of the new ACS/WFC subarray images of CAL-14410, taken taken with a large range of flash exposure times (0.1-30 seconds), to probe the temporal stability of the reference flash file and to validate the current post-flash correction pipeline of CALACS and ACS DESTRIPE PLUS on the new subarray modes. No statistically-significant deviations are found between the new post-flashed subarray exposures and the flash reference file, indicating that the LED lamp used to post-flash ACS images has been stable over several years. The current calibration pipelines (both CALACS and ACS DESTRIPE PLUS can be successfully used with the new subarray modes.

Flash Platform Examination

DTIC Science & Technology

2011-03-01

than would be performed in software”[108]. Uro Tinic, one of the Flash player’s engineers, further clarifies exactly what Flash player 10 hardware...www.adobe.com/products/flashplayer/features/ (Access date: 28 Sep 2009). [109] Uro , T. What Does GPU Acceleration Mean? (online), http...133] Shorten, A. (2009), Design to Development: Flash Catalyst to Flash Builder, In Proceedings of Adobe Max 2009, Los Angeles, CA. 142 DRDC

The Evolution and Structure of Extreme Optical Lightning Flashes.

PubMed

Peterson, Michael; Rudlosky, Scott; Deierling, Wiebke

2017-12-27

This study documents the composition, morphology, and motion of extreme optical lightning flashes observed by the Lightning Imaging Sensor (LIS). The furthest separation of LIS events (groups) in any flash is 135 km (89 km), the flash with the largest footprint had an illuminated area of 10,604 km 2 , and the most dendritic flash has 234 visible branches. The longest-duration convective LIS flash lasted 28 s and is overgrouped and not physical. The longest-duration convective-to-stratiform propagating flash lasted 7.4 s, while the longest-duration entirely stratiform flash lasted 4.3 s. The longest series of nearly consecutive groups in time lasted 242 ms. The most radiant recorded LIS group (i.e., "superbolt") is 735 times more radiant than the average group. Factors that impact these optical measures of flash morphology and evolution are discussed. While it is apparent that LIS can record the horizontal development of the lightning channel in some cases, radiative transfer within the cloud limits the flash extent and level of detail measured from orbit. These analyses nonetheless suggest that lightning imagers such as LIS and Geostationary Lightning Mapper can complement ground-based lightning locating systems for studying physical lightning phenomena across large geospatial domains.

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.

Determination of flash point in air and pure oxygen using an equilibrium closed bomb apparatus.

PubMed

Kong, Dehong; am Ende, David J; Brenek, Steven J; Weston, Neil P

2003-08-29

The standard closed testers for flash point measurements may not be feasible for measuring flash point in special atmospheres like oxygen because the test atmosphere cannot be maintained due to leakage and the laboratory safety can be compromised. To address these limitations we developed a new "equilibrium closed bomb" (ECB). The ECB generally gives lower flash point values than standard closed cup testers as shown by the results of six flammable liquids. The present results are generally in good agreement with the values calculated from the reported lower flammability limits and the vapor pressures. Our measurements show that increased oxygen concentration had little effect on the flash points of the tested flammable liquids. While generally regarded as non-flammable because of the lack of observed flash point in standard closed cup flash point testers, dichloromethane is known to form flammable mixtures. The flash point of dichloromethane in oxygen measured in the ECB is -7.1 degrees C. The flash point of dichloromethane in air is dependent on the type and energy of the ignition source. Further research is being carried out to establish the relationship between the flash point of dichloromethane and the energy of the ignition source.

Risk Factors for Extended Duration and Timing of Peak Severity of Hot Flashes

PubMed Central

Gallicchio, Lisa; Miller, Susan R.; Zacur, Howard A.; Flaws, Jodi A.

2016-01-01

Objective To identify risk factors associated with the duration of hot flashes and the time of peak hot flash severity in mid-life women. Methods A cohort of 647 women reporting hot flashes were followed for 1–7 years, with survey data and hormone measurements. Survival analysis determined the association of risk factors with the duration of hot flashes. Linear regression determined the association of risk factors with the time of peak severity. Final models were determined through stepwise model selection. Results Average hot flash duration was 2.5 years (range: 1–33), with peak severity on average at 2.96 years (range: 1–20). Duration of hot flashes was associated with race, education, menopause status, smoking history, BMI, alcohol consumption, leisure activity levels, and levels of estradiol and progesterone. In the final model, only race, alcohol consumption, leisure activity, and menopause were retained. White women had significantly shorter hot flash durations than non-white women. Women consuming at least 12 alcoholic drinks in the previous year had a significantly shorter duration of hot flashes with a smaller effect of hot flash duration on increasing in time to peak severity compared to those who consumed less than 12 alcoholic drinks in that year. Higher serum progesterone levels were associated with later peak severity if the duration of the hot flashes was less than 2 years and an earlier peak severity otherwise. Conclusions These results suggest that some behaviors (such as moderate alcohol consumption) are associated with shorter durations of hot flashes, and that progesterone was associated with the dynamics of hot flash severity. PMID:27149066

Metabolic Activity in the Insular Cortex and Hypothalamus Predicts Hot Flashes: An FDG-PET Study

PubMed Central

Deckersbach, Thilo; Lin, Nancy U.; Makris, Nikos; Skaar, Todd C.; Rauch, Scott L.; Dougherty, Darin D.; Hall, Janet E.

2012-01-01

Context: Hot flashes are a common side effect of adjuvant endocrine therapies (AET; leuprolide, tamoxifen, aromatase inhibitors) that reduce quality of life and treatment adherence in breast cancer patients. Because hot flashes affect only some women, preexisting neurobiological traits might predispose to their development. Previous studies have implicated the insula during the perception of hot flashes and the hypothalamus in thermoregulatory dysfunction. Objective: The aim of the study was to understand whether neurobiological factors predict hot flashes. Design: [18F]-Fluorodeoxyglucose (FDG) positron emission tomography (PET) brain scans coregistered with structural magnetic resonance imaging were used to determine whether metabolic activity in the insula and hypothalamic thermoregulatory and estrogen-feedback regions measured before and in response to AET predict hot flashes. Findings were correlated with CYP2D6 genotype because of CYP2D6 polymorphism associations with tamoxifen-induced hot flashes. Outcome Measures: We measured regional cerebral metabolic rate of glucose uptake (rCMRglu) in the insula and hypothalamus on FDG-PET. Results: Of 18 women without hot flashes who began AET, new-onset hot flashes were reported by 10 (55.6%) and were detected objectively in nine (50%) participants. Prior to the use of all AET, rCMRglu in the insula (P ≤ 0.01) and hypothalamic thermoregulatory (P = 0.045) and estrogen-feedback (P = 0.007) regions was lower in women who reported developing hot flashes. In response to AET, rCMRglu was further reduced in the insula in women developing hot flashes (P ≤ 0.02). Insular and hypothalamic rCMRglu levels were lower in intermediate than extensive CYP2D6 metabolizers. Conclusions: Trait neurobiological characteristics predict hot flashes. Genetic variability in CYP2D6 may underlie the neurobiological predisposition to hot flashes induced by AET. PMID:22723326

Flash nano-precipitation of polymer blends: a role for fluid flow?

NASA Astrophysics Data System (ADS)

Grundy, Lorena; Mason, Lachlan; Chergui, Jalel; Juric, Damir; Craster, Richard V.; Lee, Victoria; Prudhomme, Robert; Priestley, Rodney; Matar, Omar K.

2017-11-01

Porous structures can be formed by the controlled precipitation of polymer blends; ranging from porous matrices, with applications in membrane filtration, to porous nano-particles, with applications in catalysis, targeted drug delivery and emulsion stabilisation. Under a diffusive exchange of solvent for non-solvent, prevailing conditions favour the decomposition of polymer blends into multiple phases. Interestingly, dynamic structures can be `trapped' via vitrification prior to thermodynamic equilibrium. A promising mechanism for large-scale polymer processing is flash nano-precipitation (FNP). FNP particle formation has recently been modelled using spinodal decomposition theory, however the influence of fluid flow on structure formation is yet to be clarified. In this study, we couple a Navier-Stokes equation to a Cahn-Hilliard model of spinodal decomposition. The framework is implemented using Code BLUE, a massively scalable fluid dynamics solver, and applied to flows within confined impinging jet mixers. The present method is valid for a wide range of mixing timescales spanning FNP and conventional immersion precipitation processes. Results aid in the fabrication of nano-scale polymer particles with tuneable internal porosities. EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM), PETRONAS.

Simultaneous shape repulsion and global assimilation in the perception of aspect ratio

PubMed Central

Sweeny, Timothy D.; Grabowecky, Marcia; Suzuki, Satoru

2012-01-01

Although local interactions involving orientation and spatial frequency are well understood, less is known about spatial interactions involving higher level pattern features. We examined interactive coding of aspect ratio, a prevalent two-dimensional feature. We measured perception of two simultaneously flashed ellipses by randomly post-cueing one of them and having observers indicate its aspect ratio. Aspect ratios interacted in two ways. One manifested as an aspect-ratio-repulsion effect. For example, when a slightly tall ellipse and a taller ellipse were simultaneously flashed, the less tall ellipse appeared flatter and the taller ellipse appeared even taller. This repulsive interaction was long range, occurring even when the ellipses were presented in different visual hemifields. The other interaction manifested as a global assimilation effect. An ellipse appeared taller when it was a part of a global vertical organization than when it was a part of a global horizontal organization. The repulsion and assimilation effects temporally dissociated as the former slightly strengthened, and the latter disappeared when the ellipse-to-mask stimulus onset asynchrony was increased from 40 to 140 ms. These results are consistent with the idea that shape perception emerges from rapid lateral and hierarchical neural interactions. PMID:21248223

A Self-consistent Model for a Full Cycle of Recurrent Novae—Wind Mass-loss Rate and X-Ray Luminosity

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

Kato, Mariko; Saio, Hideyuki; Hachisu, Izumi, E-mail: mariko.kato@hc.st.keio.ac.jp

2017-04-01

An unexpectedly slow evolution in the pre-optical-maximum phase was suggested in the very short recurrence period of nova M31N 2008-12a. To obtain reasonable nova light curves we have improved our calculation method by consistently combining optically thick wind solutions of hydrogen-rich envelopes with white dwarf (WD) structures calculated by a Henyey-type evolution code. The wind mass-loss rate is properly determined with high accuracy. We have calculated light curve models for 1.2 M {sub ⊙} and 1.38 M {sub ⊙} WDs with mass accretion rates corresponding to recurrence periods of 10 yr and 1 yr, respectively. The outburst lasts 590/29 days,more » in which the pre-optical-maximum phase is 82/16 days, for 1.2/1.38 M {sub ⊙}, respectively. Optically thick winds start at the end of the X-ray flash and cease at the beginning of the supersoft X-ray phase. We also present supersoft X-ray light curves including a prompt X-ray flash and later supersoft X-ray phase.« less

User's manual for a two-dimensional, ground-water flow code on the Octopus computer network

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

Naymik, T.G.

1978-08-30

A ground-water hydrology computer code, programmed by R.L. Taylor (in Proc. American Society of Civil Engineers, Journal of Hydraulics Division, 93(HY2), pp. 25-33 (1967)), has been adapted to the Octopus computer system at Lawrence Livermore Laboratory. Using an example problem, this manual details the input, output, and execution options of the code.

Interactive Synthesis of Code Level Security Rules

DTIC Science & Technology

2017-04-01

Interactive Synthesis of Code-Level Security Rules A Thesis Presented by Leo St. Amour to The Department of Computer Science in partial fulfillment...of the requirements for the degree of Master of Science in Computer Science Northeastern University Boston, Massachusetts April 2017 DISTRIBUTION...Abstract of the Thesis Interactive Synthesis of Code-Level Security Rules by Leo St. Amour Master of Science in Computer Science Northeastern University

Agricultural Spraying

NASA Technical Reports Server (NTRS)

1986-01-01

AGDISP, a computer code written for Langley by Continuum Dynamics, Inc., aids crop dusting airplanes in targeting pesticides. The code is commercially available and can be run on a personal computer by an inexperienced operator. Called SWA+H, it is used by the Forest Service, FAA, DuPont, etc. DuPont uses the code to "test" equipment on the computer using a laser system to measure particle characteristics of various spray compounds.

The adaption and use of research codes for performance assessment

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

Liebetrau, A.M.

1987-05-01

Models of real-world phenomena are developed for many reasons. The models are usually, if not always, implemented in the form of a computer code. The characteristics of a code are determined largely by its intended use. Realizations or implementations of detailed mathematical models of complex physical and/or chemical processes are often referred to as research or scientific (RS) codes. Research codes typically require large amounts of computing time. One example of an RS code is a finite-element code for solving complex systems of differential equations that describe mass transfer through some geologic medium. Considerable computing time is required because computationsmore » are done at many points in time and/or space. Codes used to evaluate the overall performance of real-world physical systems are called performance assessment (PA) codes. Performance assessment codes are used to conduct simulated experiments involving systems that cannot be directly observed. Thus, PA codes usually involve repeated simulations of system performance in situations that preclude the use of conventional experimental and statistical methods. 3 figs.« less

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

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.

Topological color codes on Union Jack lattices: a stable implementation of the whole Clifford group

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

Katzgraber, Helmut G.; Theoretische Physik, ETH Zurich, CH-8093 Zurich; Bombin, H.

We study the error threshold of topological color codes on Union Jack lattices that allow for the full implementation of the whole Clifford group of quantum gates. After mapping the error-correction process onto a statistical mechanical random three-body Ising model on a Union Jack lattice, we compute its phase diagram in the temperature-disorder plane using Monte Carlo simulations. Surprisingly, topological color codes on Union Jack lattices have a similar error stability to color codes on triangular lattices, as well as to the Kitaev toric code. The enhanced computational capabilities of the topological color codes on Union Jack lattices with respectmore » to triangular lattices and the toric code combined with the inherent robustness of this implementation show good prospects for future stable quantum computer implementations.« less

Accurate Modeling of Ionospheric Electromagnetic Fields Generated by a Low-Altitude VLF Transmitter

DTIC Science & Technology

2007-08-31

latitude) for 3 different grid spacings. 14 8. Low-altitude fields produced by a 10-kHz source computed using the FD and TD codes. The agreement is...excellent, validating the new FD code. 16 9. High-altitude fields produced by a 10-kHz source computed using the FD and TD codes. The agreement is...again excellent. 17 10. Low-altitude fields produced by a 20-k.Hz source computed using the FD and TD codes. 17 11. High-altitude fields produced

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

PubMed

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

2017-01-01

Hot flashes have been postulated to be linked to the development of metabolic disorders. This study aimed to evaluate the relationship between hot flashes, adipocyte-derived hormones, and insulin resistance in healthy, non-obese postmenopausal women. In this cross-sectional study, a total of 151 women aged 45-60 years were stratified into one of three groups according to hot-flash status over the past three months: never experienced hot flashes (Group N), mild-to-moderate hot flashes (Group M), and severe hot flashes (Group S). Variables measured in this study included clinical parameters, hot flash experience, fasting levels of circulating glucose, lipid profiles, plasma insulin, and adipocyte-derived hormones. Multiple linear regression analysis was used to evaluate the associations of hot flashes with adipocyte-derived hormones, and with insulin resistance. The study was performed in a hospital medical center. The mean (standard deviation) of body-mass index was 22.8(2.7) for Group N, 22.6(2.6) for Group M, and 23.5(2.4) for Group S, respectively. Women in Group S displayed statistically significantly higher levels of leptin, fasting glucose, and insulin, and lower levels of adiponectin than those in Groups M and N. Multivariate linear regression analysis revealed that hot-flash severity was significantly associated with higher leptin levels, lower adiponectin levels, and higher leptin-to-adiponectin ratio. Univariate linear regression analysis revealed that hot-flash severity was strongly associated with a higher HOMA-IR index (% difference, 58.03%; 95% confidence interval, 31.00-90.64; p < 0.001). The association between hot flashes and HOMA-IR index was attenuated after adjusting for leptin or adiponectin and was no longer significant after simultaneously adjusting for leptin and adiponectin. The present study provides evidence that hot flashes are associated with insulin resistance in postmenopausal women. It further suggests that hot flash association with insulin resistance is dependent on the combination of leptin and adiponectin variables.

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.

Synchronized Electronic Shutter System (SESS) for Thermal Nondestructive Evaluation

NASA Technical Reports Server (NTRS)

Zalameda, Joseph N.

2001-01-01

The purpose of this paper is to describe a new method for thermal nondestructive evaluation. This method uses a synchronized electronic shutter system (SESS) to remove the heat lamp's influence on the thermal data during and after flash heating. There are two main concerns when using flash heating. The first concern is during the flash when the photons are reflected back into the camera. This tends to saturate the detectors and potentially introduces unknown and uncorrectable errors when curve fitting the data to a model. To address this, an electronically controlled shutter was placed over the infrared camera lens. Before firing the flash lamps, the shutter is opened to acquire the necessary background data for offset calibration. During flash heating, the shutter is closed to prevent the photons from the high intensity flash from saturating the camera's detectors. The second concern is after the flash heating where the lamps radiate heat after firing. This residual cooling introduces an unwanted transient thermal response into the data. To remove this residual effect, a shutter was placed over the flash lamps to block the infrared heat radiating from the flash head after heating. This helped to remove the transient contribution of the flash. The flash lamp shutters were synchronized electronically with the camera shutter. Results are given comparing the use of the thermal inspection with and without the shutter system.

Acupuncture as treatment of hot flashes and the possible role of calcitonin gene-related Peptide.

PubMed

Spetz Holm, Anna-Clara E; Frisk, Jessica; Hammar, Mats L

2012-01-01

The mechanisms behind hot flashes in menopausal women are not fully understood. The flashes in women are probably preceded by and actually initiated by a sudden downward shift in the set point for the core body temperature in the thermoregulatory center that is affected by sex steroids, β-endorphins, and other central neurotransmitters. Treatments that influence these factors may be expected to reduce hot flashes. Since therapy with sex steroids for hot flashes has appeared to cause a number of side effects and risks and women with hot flashes and breast cancer as well as men with prostate cancer and hot flashes are prevented from sex steroid therapy there is a great need for alternative therapies. Acupuncture affecting the opioid system has been suggested as an alternative treatment option for hot flashes in menopausal women and castrated men. The heat loss during hot flashes may be mediated by the potent vasodilator and sweat gland activator calcitonin gene-related peptide (CGRP) the concentration of which increases in plasma during flashes in menopausal women and, according to one study, in castrated men with flushes. There is also evidence for connections between the opioid system and the release of CGRP. In this paper we discuss acupuncture as a treatment alternative for hot flashes and the role of CGRP in this context.

A spatially collocated sound thrusts a flash into awareness

PubMed Central

Aller, Máté; Giani, Anette; Conrad, Verena; Watanabe, Masataka; Noppeney, Uta

2015-01-01

To interact effectively with the environment the brain integrates signals from multiple senses. It is currently unclear to what extent spatial information can be integrated across different senses in the absence of awareness. Combining dynamic continuous flash suppression (CFS) and spatial audiovisual stimulation, the current study investigated whether a sound facilitates a concurrent visual flash to elude flash suppression and enter perceptual awareness depending on audiovisual spatial congruency. Our results demonstrate that a concurrent sound boosts unaware visual signals into perceptual awareness. Critically, this process depended on the spatial congruency of the auditory and visual signals pointing towards low level mechanisms of audiovisual integration. Moreover, the concurrent sound biased the reported location of the flash as a function of flash visibility. The spatial bias of sounds on reported flash location was strongest for flashes that were judged invisible. Our results suggest that multisensory integration is a critical mechanism that enables signals to enter conscious perception. PMID:25774126

Application of adobe flash media to optimize jigsaw learning model on geometry material

NASA Astrophysics Data System (ADS)

Imam, P.; Imam, S.; Ikrar, P.

2018-05-01

This study aims to determine and describe the effectiveness of the application of adobe flash media for jigsaw learning model on geometry material. In this study, the modified jigsaw learning with adobe flash media is called jigsaw-flash model. This research was conducted in Surakarta. The research method used is mix method research with exploratory sequential strategy. The results of this study indicate that students feel more comfortable and interested in studying geometry material taught by jigsaw-flash model. In addition, students taught using the jigsaw-flash model are more active and motivated than the students who were taught using ordinary jigsaw models. This shows that the use of the jigsaw-flash model can increase student participation and motivation. It can be concluded that the adobe flash media can be used as a solution to reduce the level of student abstraction in learning mathematics.

Multidisciplinary High-Fidelity Analysis and Optimization of Aerospace Vehicles. Part 1; Formulation

NASA Technical Reports Server (NTRS)

Walsh, J. L.; Townsend, J. C.; Salas, A. O.; Samareh, J. A.; Mukhopadhyay, V.; Barthelemy, J.-F.

2000-01-01

An objective of the High Performance Computing and Communication Program at the NASA Langley Research Center is to demonstrate multidisciplinary shape and sizing optimization of a complete aerospace vehicle configuration by using high-fidelity, finite element structural analysis and computational fluid dynamics aerodynamic analysis in a distributed, heterogeneous computing environment that includes high performance parallel computing. A software system has been designed and implemented to integrate a set of existing discipline analysis codes, some of them computationally intensive, into a distributed computational environment for the design of a highspeed civil transport configuration. The paper describes the engineering aspects of formulating the optimization by integrating these analysis codes and associated interface codes into the system. The discipline codes are integrated by using the Java programming language and a Common Object Request Broker Architecture (CORBA) compliant software product. A companion paper presents currently available results.

Method and apparatus for offloading compute resources to a flash co-processing appliance

DOEpatents

Tzelnic, Percy; Faibish, Sorin; Gupta, Uday K.; Bent, John; Grider, Gary Alan; Chen, Hsing -bung

2015-10-13

Solid-State Drive (SSD) burst buffer nodes are interposed into a parallel supercomputing cluster to enable fast burst checkpoint of cluster memory to or from nearby interconnected solid-state storage with asynchronous migration between the burst buffer nodes and slower more distant disk storage. The SSD nodes also perform tasks offloaded from the compute nodes or associated with the checkpoint data. For example, the data for the next job is preloaded in the SSD node and very fast uploaded to the respective compute node just before the next job starts. During a job, the SSD nodes perform fast visualization and statistical analysis upon the checkpoint data. The SSD nodes can also perform data reduction and encryption of the checkpoint data.

Analysis of airborne antenna systems using geometrical theory of diffraction and moment method computer codes

NASA Technical Reports Server (NTRS)

Hartenstein, Richard G., Jr.

1985-01-01

Computer codes have been developed to analyze antennas on aircraft and in the presence of scatterers. The purpose of this study is to use these codes to develop accurate computer models of various aircraft and antenna systems. The antenna systems analyzed are a P-3B L-Band antenna, an A-7E UHF relay pod antenna, and traffic advisory antenna system installed on a Bell Long Ranger helicopter. Computer results are compared to measured ones with good agreement. These codes can be used in the design stage of an antenna system to determine the optimum antenna location and save valuable time and costly flight hours.

THC-MP: High performance numerical simulation of reactive transport and multiphase flow in porous media

NASA Astrophysics Data System (ADS)

Wei, Xiaohui; Li, Weishan; Tian, Hailong; Li, Hongliang; Xu, Haixiao; Xu, Tianfu

2015-07-01

The numerical simulation of multiphase flow and reactive transport in the porous media on complex subsurface problem is a computationally intensive application. To meet the increasingly computational requirements, this paper presents a parallel computing method and architecture. Derived from TOUGHREACT that is a well-established code for simulating subsurface multi-phase flow and reactive transport problems, we developed a high performance computing THC-MP based on massive parallel computer, which extends greatly on the computational capability for the original code. The domain decomposition method was applied to the coupled numerical computing procedure in the THC-MP. We designed the distributed data structure, implemented the data initialization and exchange between the computing nodes and the core solving module using the hybrid parallel iterative and direct solver. Numerical accuracy of the THC-MP was verified through a CO2 injection-induced reactive transport problem by comparing the results obtained from the parallel computing and sequential computing (original code). Execution efficiency and code scalability were examined through field scale carbon sequestration applications on the multicore cluster. The results demonstrate successfully the enhanced performance using the THC-MP on parallel computing facilities.

USAF Summer Research Program - 1993 Summer Research Extension Program Final Reports, Volume 1B, Armstrong Laboratory

DTIC Science & Technology

1994-11-01

For example, the Collimating scotopic components of the ERG flash response are significantly attenuated by retinitis pigmentosa [7]. It is possible... RETINAL DAMAGE Bernard S. Gerstman Associate Professor Department of Physics Florida International University University Park Miami, FL 33199 Final...and Florida International University April 1994 6-1 A COMPUTATIONAL THERMAL MODEL AND THEORETICAL THERMODYNAMIC MODEL OF LASER INDUCED RETINAL DAMAGE

Digital analysis of wind tunnel imagery to measure fluid thickness

NASA Technical Reports Server (NTRS)

Easton, Roger L., Jr.; Enge, James

1992-01-01

Documented here are the procedure and results obtained from the application of digital image processing techniques to the problem of measuring the thickness of a deicing fluid on a model airfoil during simulated takeoffs. The fluid contained a fluorescent dye and the images were recorded under flash illumination on photographic film. The films were digitized and analyzed on a personal computer to obtain maps of the fluid thickness.

Code of Ethical Conduct for Computer-Using Educators: An ICCE Policy Statement.

ERIC Educational Resources Information Center

Computing Teacher, 1987

1987-01-01

Prepared by the International Council for Computers in Education's Ethics and Equity Committee, this code of ethics for educators using computers covers nine main areas: curriculum issues, issues relating to computer access, privacy/confidentiality issues, teacher-related issues, student issues, the community, school organizational issues,…

46 CFR 35.20-30 - Flashing the rays of a searchlight or other blinding light-T/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

... VESSELS OPERATIONS Navigation § 35.20-30 Flashing the rays of a searchlight or other blinding light—T/ALL. No person shall flash, or cause to be flashed, the rays of a search light or other blinding light... 46 Shipping 1 2012-10-01 2012-10-01 false Flashing the rays of a searchlight or other blinding...

46 CFR 35.20-30 - Flashing the rays of a searchlight or other blinding light-T/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... VESSELS OPERATIONS Navigation § 35.20-30 Flashing the rays of a searchlight or other blinding light—T/ALL. No person shall flash, or cause to be flashed, the rays of a search light or other blinding light... 46 Shipping 1 2010-10-01 2010-10-01 false Flashing the rays of a searchlight or other blinding...

46 CFR 35.20-30 - Flashing the rays of a searchlight or other blinding light-T/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... VESSELS OPERATIONS Navigation § 35.20-30 Flashing the rays of a searchlight or other blinding light—T/ALL. No person shall flash, or cause to be flashed, the rays of a search light or other blinding light... 46 Shipping 1 2014-10-01 2014-10-01 false Flashing the rays of a searchlight or other blinding...

46 CFR 35.20-30 - Flashing the rays of a searchlight or other blinding light-T/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... VESSELS OPERATIONS Navigation § 35.20-30 Flashing the rays of a searchlight or other blinding light—T/ALL. No person shall flash, or cause to be flashed, the rays of a search light or other blinding light... 46 Shipping 1 2013-10-01 2013-10-01 false Flashing the rays of a searchlight or other blinding...

46 CFR 35.20-30 - Flashing the rays of a searchlight or other blinding light-T/ALL.

Code of Federal Regulations, 2011 CFR

2011-10-01

... VESSELS OPERATIONS Navigation § 35.20-30 Flashing the rays of a searchlight or other blinding light—T/ALL. No person shall flash, or cause to be flashed, the rays of a search light or other blinding light... 46 Shipping 1 2011-10-01 2011-10-01 false Flashing the rays of a searchlight or other blinding...

Smart Cards and remote entrusting

NASA Astrophysics Data System (ADS)

Aussel, Jean-Daniel; D'Annoville, Jerome; Castillo, Laurent; Durand, Stephane; Fabre, Thierry; Lu, Karen; Ali, Asad

Smart cards are widely used to provide security in end-to-end communication involving servers and a variety of terminals, including mobile handsets or payment terminals. Sometime, end-to-end server to smart card security is not applicable, and smart cards must communicate directly with an application executing on a terminal, like a personal computer, without communicating with a server. In this case, the smart card must somehow trust the terminal application before performing some secure operation it was designed for. This paper presents a novel method to remotely trust a terminal application from the smart card. For terminals such as personal computers, this method is based on an advanced secure device connected through the USB and consisting of a smart card bundled with flash memory. This device, or USB dongle, can be used in the context of remote untrusting to secure portable applications conveyed in the dongle flash memory. White-box cryptography is used to set the secure channel and a mechanism based on thumbprint is described to provide external authentication when session keys need to be renewed. Although not as secure as end-to-end server to smart card security, remote entrusting with smart cards is easy to deploy for mass-market applications and can provide a reasonable level of security.

Autonomous Aerial Refueling Ground Test Demonstration—A Sensor-in-the-Loop, Non-Tracking Method

PubMed Central

Chen, Chao-I; Koseluk, Robert; Buchanan, Chase; Duerner, Andrew; Jeppesen, Brian; Laux, Hunter

2015-01-01

An essential capability for an unmanned aerial vehicle (UAV) to extend its airborne duration without increasing the size of the aircraft is called the autonomous aerial refueling (AAR). This paper proposes a sensor-in-the-loop, non-tracking method for probe-and-drogue style autonomous aerial refueling tasks by combining sensitivity adjustments of a 3D Flash LIDAR camera with computer vision based image-processing techniques. The method overcomes the inherit ambiguity issues when reconstructing 3D information from traditional 2D images by taking advantage of ready to use 3D point cloud data from the camera, followed by well-established computer vision techniques. These techniques include curve fitting algorithms and outlier removal with the random sample consensus (RANSAC) algorithm to reliably estimate the drogue center in 3D space, as well as to establish the relative position between the probe and the drogue. To demonstrate the feasibility of the proposed method on a real system, a ground navigation robot was designed and fabricated. Results presented in the paper show that using images acquired from a 3D Flash LIDAR camera as real time visual feedback, the ground robot is able to track a moving simulated drogue and continuously narrow the gap between the robot and the target autonomously. PMID:25970254

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.

Phase II evaluation of S-adenosyl-L-methionine (SAMe) for the treatment of hot flashes.

PubMed

Kadakia, Kunal C; Loprinzi, Charles L; Atherton, Pamela J; Fee-Schroeder, Kelliann C; Sood, Amit; Barton, Debra L

2016-03-01

Hot flashes are a significant source of symptom burden that negatively impacts quality of life (QOL). For women who have contraindications to, or are unwilling to consider, estrogens or antidepressants for bothersome hot flashes, there are limited effective pharmacologic or complementary and alternative medicines. This single-arm phase II trial studied the efficacy of S-adenosyl-L-methionine (SAMe) for the treatment of hot flashes. Eligible women were required to have reported ≥14 hot flashes per week for ≥1 month. The patients were treated with SAMe at a dose of 400 mg twice daily to evaluate whether a reduction in hot flash score appeared to be better than the historical placebo response of approximately 25%. The women kept a daily hot flash diary during a baseline week and then daily during weeks 2-7. The primary endpoint was the change from baseline to week 7 in hot flash score and hot flash frequency. Secondary endpoints included toxicity analyses and the effect of SAMe on QOL. From October 28, 2010 to January 30, 2012, 43 women were treated with SAMe. The decrease in mean percent of baseline hot flash score and frequency was 35.4 and 32.6%, respectively. When compared to the historical placebo response of 25%, the effect of SAMe on hot flash score was not statistically significant (p = 0.09). Treatment was well tolerated with expected grade 1/2 gastrointestinal toxicity and no negative effect on QOL. The use of SAMe does not appear to significantly reduce hot flashes more than would be expected with a placebo.

Two types of flash drought over China and their connections with sub-seasonal to seasonal soil moisture drought

NASA Astrophysics Data System (ADS)

Wang, L.; Yuan, X.; Xie, Z.

2017-12-01

Flash drought has been receiving attention recently due to its rapid development and vast damage on crops in the growing season. Accompanied with heatwave and rainfall deficit, the soil moisture decreased rapidly in a short time and may lead to the failure of root water uptake and large-scale crops wither. There are two types of flash droughts according to the causes (Mo and Lettenmaier, 2016), i.e., heat wave flash drought and rainfall deficit flash drought. Here, based on pentad-mean surface air temperature and precipitation observations from over two thousand meteorological stations as well as soil moisture and ET estimations from three global reanalysis products, the characteristics and evolution of the two types of flash droughts over China are being explored. Heat wave flash drought is more likely to occur in humid and semi-humid areas, such as southern China, while rainfall deficit flash drought is more likely to occur in northern China. Unlike the traditional drought that persists for a few months to decades, the mean durations of both types of flash droughts are very short. We use monthly mean soil moisture to calculate sub-seasonal to seasonal (S2S) soil moisture drought, and compare its characteristics and preferred conditions such as the large-scale atmospheric circulation and oceanic anomaly for both types of flash droughts. The percentages of flash drought in different periods of S2S drought are also being explored to see the potential relationship between flash drought and S2S drought over different regions.

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

PubMed

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

2017-03-01

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

Onset conditions for flash sintering of UO 2

DOE PAGES

Raftery, Alicia M.; Pereira da Silva, João Gustavo; Byler, Darrin D.; ...

2017-06-22

In this paper, flash sintering was demonstrated on stoichiometric and non-stoichiometric uranium dioxide pellets at temperatures ranging from room temperature (26°C) up to 600°C. The onset conditions for flash sintering were determined for three stoichiometries (UO 2.00, UO 2.08, and UO 2.16) and analyzed against an established thermal runaway model. The presence of excess oxygen was found to enhance the flash sintering onset behavior of uranium dioxide, lowering the field required to flash and shortening the time required for a flash to occur. Finally, the results from this study highlight the effect of stoichiometry on the flash sintering behavior ofmore » uranium dioxide and will serve as the foundation for future studies on this material.« less

Onset conditions for flash sintering of UO2

NASA Astrophysics Data System (ADS)

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

2017-09-01

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

Embedding Secure Coding Instruction into the IDE: Complementing Early and Intermediate CS Courses with ESIDE

ERIC Educational Resources Information Center

Whitney, Michael; Lipford, Heather Richter; Chu, Bill; Thomas, Tyler

2018-01-01

Many of the software security vulnerabilities that people face today can be remediated through secure coding practices. A critical step toward the practice of secure coding is ensuring that our computing students are educated on these practices. We argue that secure coding education needs to be included across a computing curriculum. We are…

Differences in the Optical Characteristics of Continental US Ground and Cloud Flashes as Observed from Space

NASA Technical Reports Server (NTRS)

Koshak, William

2007-01-01

Continental US lightning flashes observed by the Optical Transient Detector (OTD) are categorized according to flash type (ground or cloud flash) using US National Lightning Detection Network (TM) (NLDN) data. The statistics of the ground and cloud flash optical parameters (e.g., radiance, area, duration, number of optical groups, and number of optical events) are inter-compared. On average, the ground flash cloud-top emissions are more radiant, illuminate a larger area, are longer lasting, and have more optical groups and optical events than those cloud-top emissions associated with cloud flashes. Given these differences, it is suggested that the methods of Bayesian Inference could be used to help discriminate between ground and cloud flashes. The ability to discriminate flash type on-orbit is highly desired since such information would help researchers and operational decision makers better assess the intensification, evolutionary state, and severe weather potential of thunderstorms. This work supports risk reduction activities presently underway for the future launch of the GOES-R Geostationary Lightning Mapper (GLM).

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.

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.

Lightning Channels of Cloud-to-Ground Flashes Neutralizing Multiple Charge Regions Inside Winter Thunderclouds

NASA Astrophysics Data System (ADS)

Akita, Manabu; Yoshida, Satoru; Nakamura, Yoshitaka; Morimoto, Takeshi; Ushio, Tomoo; Kawasaki, Zen-Ichiro; Wang, Daohong

Lightning Research Group of Osaka University (LRG-OU) has been developing and improving the VHF broadband digital interferometer (DITF) for thunderstorm observations. It enables us to locate the impulsive VHF radiation sources caused by lightning discharges with extremely high resolutions. As a result of the VHF observations during the 2007-2008 winter season in the Japan Sea coastal area, cloud-to-ground (CG) flashes that neutralize multiple charge regions inside thunderclouds are visualized by the VHF broadband DITF. The first flash is the positive CG flash that neutralizes multiple positive charge regions in a flash. The second flash is the bipolar lightning flash that neutralizes both positive and negative charge inside thunderclouds. In the case of bipolar lightning flashes, some tens millisecond after the return strokes, the subsequent negative breakdowns initiate from the proximities of the initiation points of the preceding negative stepped leaders. It was also found that the altitudes of negative charge regions are lower than 2km. The bipolar lightning flashes observed in this campaign neutralize positive charge after lowering the negative charge to the ground.

Calculation of water drop trajectories to and about arbitrary three-dimensional lifting and nonlifting bodies in potential airflow

NASA Technical Reports Server (NTRS)

Norment, H. G.

1985-01-01

Subsonic, external flow about nonlifting bodies, lifting bodies or combinations of lifting and nonlifting bodies is calculated by a modified version of the Hess lifting code. Trajectory calculations can be performed for any atmospheric conditions and for all water drop sizes, from the smallest cloud droplet to large raindrops. Experimental water drop drag relations are used in the water drop equations of motion and effects of gravity settling are included. Inlet flow can be accommodated, and high Mach number compressibility effects are corrected for approximately. Seven codes are described: (1) a code used to debug and plot body surface description data; (2) a code that processes the body surface data to yield the potential flow field; (3) a code that computes flow velocities at arrays of points in space; (4) a code that computes water drop trajectories from an array of points in space; (5) a code that computes water drop trajectories and fluxes to arbitrary target points; (6) a code that computes water drop trajectories tangent to the body; and (7) a code that produces stereo pair plots which include both the body and trajectories. Accuracy of the calculations is discussed, and trajectory calculation results are compared with prior calculations and with experimental data.

Debugging Techniques Used by Experienced Programmers to Debug Their Own Code.

DTIC Science & Technology

1990-09-01

IS. NUMBER OF PAGES code debugging 62 computer programmers 16. PRICE CODE debug programming 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 119...Davis, and Schultz (1987) also compared experts and novices, but focused on the way a computer program is represented cognitively and how that...of theories in the emerging computer programming domain (Fisher, 1987). In protocol analysis, subjects are asked to talk/think aloud as they solve

A COTS-Based Replacement Strategy for Aging Avionics Computers

DTIC Science & Technology

2001-12-01

Communication Control Unit. A COTS-Based Replacement Strategy for Aging Avionics Computers COTS Microprocessor Real Time Operating System New Native Code...Native Code Objec ts Native Code Thread Real - Time Operating System Legacy Function x Virtual Component Environment Context Switch Thunk Add-in Replace

PARAVT: Parallel Voronoi tessellation code

NASA Astrophysics Data System (ADS)

González, R. E.

2016-10-01

In this study, we present a new open source code for massive parallel computation of Voronoi tessellations (VT hereafter) in large data sets. The code is focused for astrophysical purposes where VT densities and neighbors are widely used. There are several serial Voronoi tessellation codes, however no open source and parallel implementations are available to handle the large number of particles/galaxies in current N-body simulations and sky surveys. Parallelization is implemented under MPI and VT using Qhull library. Domain decomposition takes into account consistent boundary computation between tasks, and includes periodic conditions. In addition, the code computes neighbors list, Voronoi density, Voronoi cell volume, density gradient for each particle, and densities on a regular grid. Code implementation and user guide are publicly available at https://github.com/regonzar/paravt.

Two-flash thresholds as a function of flash luminance and area.

DOT National Transportation Integrated Search

1968-09-01

The recent use of strobe lights in aviation suggests the possibility of using temporal patterns of short duration flashes as information-carrying signals. Under night flight conditions, two-flash thresholds were obtained using a two-interval, tempora...

Floods - Multiple Languages

MedlinePlus

... Arabic (العربية) Expand Section Floods and Flash Flooding - English PDF Floods and Flash Flooding - العربية (Arabic) PDF ... Bosnian (bosanski) Expand Section Floods and Flash Flooding - English PDF Floods and Flash Flooding - bosanski (Bosnian) PDF ...

The STAGS computer code

NASA Technical Reports Server (NTRS)

Almroth, B. O.; Brogan, F. A.

1978-01-01

Basic information about the computer code STAGS (Structural Analysis of General Shells) is presented to describe to potential users the scope of the code and the solution procedures that are incorporated. Primarily, STAGS is intended for analysis of shell structures, although it has been extended to more complex shell configurations through the inclusion of springs and beam elements. The formulation is based on a variational approach in combination with local two dimensional power series representations of the displacement components. The computer code includes options for analysis of linear or nonlinear static stress, stability, vibrations, and transient response. Material as well as geometric nonlinearities are included. A few examples of applications of the code are presented for further illustration of its scope.

Holonomic surface codes for fault-tolerant quantum computation

NASA Astrophysics Data System (ADS)

Zhang, Jiang; Devitt, Simon J.; You, J. Q.; Nori, Franco

2018-02-01

Surface codes can protect quantum information stored in qubits from local errors as long as the per-operation error rate is below a certain threshold. Here we propose holonomic surface codes by harnessing the quantum holonomy of the system. In our scheme, the holonomic gates are built via auxiliary qubits rather than the auxiliary levels in multilevel systems used in conventional holonomic quantum computation. The key advantage of our approach is that the auxiliary qubits are in their ground state before and after each gate operation, so they are not involved in the operation cycles of surface codes. This provides an advantageous way to implement surface codes for fault-tolerant quantum computation.

Comparison of two- and three-dimensional flow computations with laser anemometer measurements in a transonic compressor rotor

NASA Technical Reports Server (NTRS)

Chima, R. V.; Strazisar, A. J.

1982-01-01

Two and three dimensional inviscid solutions for the flow in a transonic axial compressor rotor at design speed are compared with probe and laser anemometers measurements at near-stall and maximum-flow operating points. Experimental details of the laser anemometer system and computational details of the two dimensional axisymmetric code and three dimensional Euler code are described. Comparisons are made between relative Mach number and flow angle contours, shock location, and shock strength. A procedure for using an efficient axisymmetric code to generate downstream pressure input for computationally expensive Euler codes is discussed. A film supplement shows the calculations of the two operating points with the time-marching Euler code.

Flashes and Floaters.

PubMed

Sharma, Priya; Sridhar, Jayanth; Mehta, Sonia

2015-09-01

Flashes and floaters are common ocular complaints. Flashes refer to aberrations of light that are seen in a patient's field of gaze. The flashes can be of varying sizes, colors, frequency, and durations, depending on the cause. Floaters are another common visual phenomenon caused by particles or debris in the vitreous gel of the eye that cause shadows and thus visual changes, especially against bright backgrounds and in brightly lit environments. Flashes and floaters can occur individually or together. This article discusses common causes of flashes and floaters to help with the triaging and management of these patients. Copyright © 2015 Elsevier Inc. All rights reserved.

The Evolution and Structure of Extreme Optical Lightning Flashes

PubMed Central

Peterson, Michael; Rudlosky, Scott; Deierling, Wiebke

2018-01-01

This study documents the composition, morphology, and motion of extreme optical lightning flashes observed by the Lightning Imaging Sensor (LIS). The furthest separation of LIS events (groups) in any flash is 135 km (89 km), the flash with the largest footprint had an illuminated area of 10,604 km2, and the most dendritic flash has 234 visible branches. The longest-duration convective LIS flash lasted 28 s and is overgrouped and not physical. The longest-duration convective-to-stratiform propagating flash lasted 7.4 s, while the longest-duration entirely stratiform flash lasted 4.3 s. The longest series of nearly consecutive groups in time lasted 242 ms. The most radiant recorded LIS group (i.e., “superbolt”) is 735 times more radiant than the average group. Factors that impact these optical measures of flash morphology and evolution are discussed. While it is apparent that LIS can record the horizontal development of the lightning channel in some cases, radiative transfer within the cloud limits the flash extent and level of detail measured from orbit. These analyses nonetheless suggest that lightning imagers such as LIS and Geostationary Lightning Mapper can complement ground-based lightning locating systems for studying physical lightning phenomena across large geospatial domains. PMID:29527425

Development of MCNPX-ESUT computer code for simulation of neutron/gamma pulse height distribution

NASA Astrophysics Data System (ADS)

Abolfazl Hosseini, Seyed; Vosoughi, Naser; Zangian, Mehdi

2015-05-01

In this paper, the development of the MCNPX-ESUT (MCNPX-Energy Engineering of Sharif University of Technology) computer code for simulation of neutron/gamma pulse height distribution is reported. Since liquid organic scintillators like NE-213 are well suited and routinely used for spectrometry in mixed neutron/gamma fields, this type of detectors is selected for simulation in the present study. The proposed algorithm for simulation includes four main steps. The first step is the modeling of the neutron/gamma particle transport and their interactions with the materials in the environment and detector volume. In the second step, the number of scintillation photons due to charged particles such as electrons, alphas, protons and carbon nuclei in the scintillator material is calculated. In the third step, the transport of scintillation photons in the scintillator and lightguide is simulated. Finally, the resolution corresponding to the experiment is considered in the last step of the simulation. Unlike the similar computer codes like SCINFUL, NRESP7 and PHRESP, the developed computer code is applicable to both neutron and gamma sources. Hence, the discrimination of neutron and gamma in the mixed fields may be performed using the MCNPX-ESUT computer code. The main feature of MCNPX-ESUT computer code is that the neutron/gamma pulse height simulation may be performed without needing any sort of post processing. In the present study, the pulse height distributions due to a monoenergetic neutron/gamma source in NE-213 detector using MCNPX-ESUT computer code is simulated. The simulated neutron pulse height distributions are validated through comparing with experimental data (Gohil et al. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 664 (2012) 304-309.) and the results obtained from similar computer codes like SCINFUL, NRESP7 and Geant4. The simulated gamma pulse height distribution for a 137Cs source is also compared with the experimental data.

EAC: A program for the error analysis of STAGS results for plates

NASA Technical Reports Server (NTRS)

Sistla, Rajaram; Thurston, Gaylen A.; Bains, Nancy Jane C.

1989-01-01

A computer code is now available for estimating the error in results from the STAGS finite element code for a shell unit consisting of a rectangular orthotropic plate. This memorandum contains basic information about the computer code EAC (Error Analysis and Correction) and describes the connection between the input data for the STAGS shell units and the input data necessary to run the error analysis code. The STAGS code returns a set of nodal displacements and a discrete set of stress resultants; the EAC code returns a continuous solution for displacements and stress resultants. The continuous solution is defined by a set of generalized coordinates computed in EAC. The theory and the assumptions that determine the continuous solution are also outlined in this memorandum. An example of application of the code is presented and instructions on its usage on the Cyber and the VAX machines have been provided.

CFD Modeling of Free-Piston Stirling Engines

NASA Technical Reports Server (NTRS)

Ibrahim, Mounir B.; Zhang, Zhi-Guo; Tew, Roy C., Jr.; Gedeon, David; Simon, Terrence W.

2001-01-01

NASA Glenn Research Center (GRC) is funding Cleveland State University (CSU) to develop a reliable Computational Fluid Dynamics (CFD) code that can predict engine performance with the goal of significant improvements in accuracy when compared to one-dimensional (1-D) design code predictions. The funding also includes conducting code validation experiments at both the University of Minnesota (UMN) and CSU. In this paper a brief description of the work-in-progress is provided in the two areas (CFD and Experiments). Also, previous test results are compared with computational data obtained using (1) a 2-D CFD code obtained from Dr. Georg Scheuerer and further developed at CSU and (2) a multidimensional commercial code CFD-ACE+. The test data and computational results are for (1) a gas spring and (2) a single piston/cylinder with attached annular heat exchanger. The comparisons among the codes are discussed. The paper also discusses plans for conducting code validation experiments at CSU and UMN.

On the error statistics of Viterbi decoding and the performance of concatenated codes

NASA Technical Reports Server (NTRS)

Miller, R. L.; Deutsch, L. J.; Butman, S. A.

1981-01-01

Computer simulation results are presented on the performance of convolutional codes of constraint lengths 7 and 10 concatenated with the (255, 223) Reed-Solomon code (a proposed NASA standard). These results indicate that as much as 0.8 dB can be gained by concatenating this Reed-Solomon code with a (10, 1/3) convolutional code, instead of the (7, 1/2) code currently used by the DSN. A mathematical model of Viterbi decoder burst-error statistics is developed and is validated through additional computer simulations.

New double-byte error-correcting codes for memory systems

NASA Technical Reports Server (NTRS)

Feng, Gui-Liang; Wu, Xinen; Rao, T. R. N.

1996-01-01

Error-correcting or error-detecting codes have been used in the computer industry to increase reliability, reduce service costs, and maintain data integrity. The single-byte error-correcting and double-byte error-detecting (SbEC-DbED) codes have been successfully used in computer memory subsystems. There are many methods to construct double-byte error-correcting (DBEC) codes. In the present paper we construct a class of double-byte error-correcting codes, which are more efficient than those known to be optimum, and a decoding procedure for our codes is also considered.

Performance Assessment of the Optical Transient Detector and Lightning Imaging Sensor. Part 2; Clustering Algorithm

NASA Technical Reports Server (NTRS)

Mach, Douglas M.; Christian, Hugh J.; Blakeslee, Richard; Boccippio, Dennis J.; Goodman, Steve J.; Boeck, William

2006-01-01

We describe the clustering algorithm used by the Lightning Imaging Sensor (LIS) and the Optical Transient Detector (OTD) for combining the lightning pulse data into events, groups, flashes, and areas. Events are single pixels that exceed the LIS/OTD background level during a single frame (2 ms). Groups are clusters of events that occur within the same frame and in adjacent pixels. Flashes are clusters of groups that occur within 330 ms and either 5.5 km (for LIS) or 16.5 km (for OTD) of each other. Areas are clusters of flashes that occur within 16.5 km of each other. Many investigators are utilizing the LIS/OTD flash data; therefore, we test how variations in the algorithms for the event group and group-flash clustering affect the flash count for a subset of the LIS data. We divided the subset into areas with low (1-3), medium (4-15), high (16-63), and very high (64+) flashes to see how changes in the clustering parameters affect the flash rates in these different sizes of areas. We found that as long as the cluster parameters are within about a factor of two of the current values, the flash counts do not change by more than about 20%. Therefore, the flash clustering algorithm used by the LIS and OTD sensors create flash rates that are relatively insensitive to reasonable variations in the clustering algorithms.

How do people perceive, understand, and anticipate responding to flash flood risks and warnings? Results from a public survey in Boulder, Colorado, USA

NASA Astrophysics Data System (ADS)

Morss, Rebecca E.; Mulder, Kelsey J.; Lazo, Jeffrey K.; Demuth, Julie L.

2016-10-01

This study investigates flash flood forecast and warning communication, interpretation, and decision making, using data from a survey of 418 members of the public in Boulder, Colorado, USA. Respondents to the public survey varied in their perceptions and understandings of flash flood risks in Boulder, and some had misconceptions about flash flood risks, such as the safety of crossing fast-flowing water. About 6% of respondents indicated consistent reversals of US watch-warning alert terminology. However, more in-depth analysis illustrates the multi-dimensional, situationally dependent meanings of flash flood alerts, as well as the importance of evaluating interpretation and use of warning information along with alert terminology. Some public respondents estimated low likelihoods of flash flooding given a flash flood warning; these were associated with lower anticipated likelihood of taking protective action given a warning. Protective action intentions were also lower among respondents who had less trust in flash flood warnings, those who had not made prior preparations for flash flooding, and those who believed themselves to be safer from flash flooding. Additional analysis, using open-ended survey questions about responses to warnings, elucidates the complex, contextual nature of protective decision making during flash flood threats. These findings suggest that warnings can play an important role not only by notifying people that there is a threat and helping motivate people to take protective action, but also by helping people evaluate what actions to take given their situation.

SOURCELESS STARTUP. A MACHINE CODE FOR COMPUTING LOW-SOURCE REACTOR STARTUPS

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

MacMillan, D.B.

1960-06-01

>A revision to the sourceless start-up code is presented. The code solves a system of differential equations encountered in computing the probability distribution of activity at an observed power level during reactor start-up from a very low source level. (J.R.D.)

Computer-assisted coding and clinical documentation: first things first.

PubMed

Tully, Melinda; Carmichael, Angela

2012-10-01

Computer-assisted coding tools have the potential to drive improvements in seven areas: Transparency of coding. Productivity (generally by 20 to 25 percent for inpatient claims). Accuracy (by improving specificity of documentation). Cost containment (by reducing overtime expenses, audit fees, and denials). Compliance. Efficiency. Consistency.

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.

Characteristic pulse trains of preliminary breakdown in four isolated small thunderstorms

NASA Astrophysics Data System (ADS)

Ma, Dong

2017-03-01

Using a low-frequency six-station local network, preliminary breakdown (PB) pulses not followed or followed by negative return stroke (RS), which are defined as PB-type and PB cloud-to-ground (PBCG)-type flashes, are analyzed based on four isolated small thunderstorms for the first time. On the basis of 22 PB-type flashes out of totally 2155 flashes, it indicates that the number of PB-type flashes is very small. At the early stage, PB-type flashes are observed in all four thunderstorms. At the active stage, PB-type flashes still can occur; meanwhile, there are few or no negative cloud-to-ground (CG) flashes. However, at the final stage no PB-type flashes occur. At the stage of distinct cell merging or splitting, PB-type flashes are also observed. Based on the 123 PBCG-type flashes, we discuss the percentage of PBCG-type flashes and also analyze the relationship between the electric field (E-field) amplitude of the largest pulse in the PB pulse train normalized to 100 km (PBA), the E-field amplitude of the first return stroke normalized to 100 km (RSA), the time interval between PBA and RSA (PB-RS interval), and the ratio between PBA and RSA (PB-RS ratio). We find that the percentage of PBCG-type flashes is not always dependent on PBA or PB-RS ratio; the type of thunderstorms may also have an impact on this percentage. None of the PB-RS intervals is less than 20 ms; we speculate that such long PB-RS interval is the feature of isolated small thunderstorms, but more observations are needed to further investigate this question.

Anxiogenic CO2 Stimulus Elicits Exacerbated Hot Flash-like Responses in a Rat Menopause Model and Hot Flashes in Menopausal Women

PubMed Central

Federici, Lauren M.; Roth, Sarah Dorsey; Krier, Connie; Fitz, Stephanie D.; Skaar, Todd; Shekhar, Anantha; Carpenter, Janet S.; Johnson, Philip L.

2016-01-01

Objective Since longitudinal studies determined that anxiety is a strong risk factor for hot flashes, we hypothesized that an anxiogenic stimulus that signals air hunger (hypercapnic, normoxic gas) would trigger an exacerbated hot flash-associated increase in tail skin temperature (TST) in a rat ovariectomy (OVEX) model of surgical menopause and hot flashes in symptomatic menopausal women. We also assessed TST responses in OVEX serotonin transporter (SERT)+/− rats that models a common polymorphism that is associated with increased climacteric symptoms in menopausal women and increases in anxiety traits. Methods OVEX and sham-OVEX rats (initial experiment) and wildtype and SERT+/− OVEX rats (subsequent experiment) were exposed to a 5 min infusion of 20%CO2 normoxic gas while measuring TST. Menopausal women were given brief 20% and 35%CO2 challenges, and hot flashes were self-reported and objectively verified. Results Compared to controls, OVEX rats had exacerbated increases in TST, and SERT+/− OVEX rats had prolonged TST increases following CO2. Most women reported mild/moderate hot flashes after CO2 challenges, and the hot flash severity to CO2 was positively correlated with daily hot flash frequency. Conclusions The studies demonstrate that this anxiogenic stimulus is capable of inducing cutaneous vasomotor responses in OVEX rats, and eliciting hot flashes in menopausal women. In rats, the severity of the response was mediated by loss of ovarian function and increased anxiety traits (SERT+/−), and, in women, by daily hot flash frequency. These findings may provide insights into anxiety related triggers and genetic risk factors for hot flashes in thermoneutral environments. PMID:27465717

Continuous transdermal nitroglycerin therapy for menopausal hot flashes: a single-arm, dose-escalation trial.

PubMed

Huang, Alison J; Cummings, Steven R; Schembri, Michael; Vittinghoff, Eric; Ganz, Peter; Grady, Deborah

2016-03-01

To describe the efficacy and tolerability of continuous nitroglycerin for treatment of hot flashes. Perimenopausal and postmenopausal women reporting at least seven hot flashes per day were recruited into a single-arm, dose-escalation trial of continuous transdermal nitroglycerin. Participants were started on a generic 0.1 mg/hour nitroglycerin patch applied daily without patch-free periods. During 4 weeks, participants escalated dosage weekly to 0.2, 0.4, or 0.6 mg/hour as tolerated, then discontinued nitroglycerin during the final week. Changes in hot flash frequency and severity were assessed using symptom diaries. Paired t tests examined change in outcomes between baseline and maximal-dose therapy and after discontinuation of nitroglycerin. Of the 19 participants, mean age was 51.4 (±4.3) years. Women reported an average 10.6 (±3.0) hot flashes and 7.1 (±3.8) moderate-to-severe hot flashes per day at baseline. Eleven women escalated to 0.6 mg/hour, three to 0.4 mg/hour, two to 0.2 mg/hour, and one remained on 0.1 mg/hour nitroglycerin. Two discontinued nitroglycerin before the first outcomes assessment. Among the remaining 17 women, the average daily frequency of hot flashes decreased by 54% and the average frequency of moderate-to-severe hot flashes decreased by 69% from baseline to maximum-dose therapy (P < 0.001 for both). After discontinuing nitroglycerin, participants reported an average 23% increase in frequency of any hot flashes (P = 0.041) and 96% increase in moderate-to-severe hot flashes (P < 0.001). Continuous nitroglycerin may substantially and reversibly decrease hot flash frequency and severity. If confirmed in a randomized blinded trial, it may offer a novel nonhormonal hot flash treatment.

Continuous Transdermal Nitroglycerin Therapy for Menopausal Hot Flashes: A Single-Arm Dose-Escalation Trial

PubMed Central

Huang, Alison J.; Cummings, Steven R.; Schembri, Michael; Vittinghoff, Eric; Ganz, Peter; Grady, Deborah

2015-01-01

Objective To describe the efficacy and tolerability of continuous nitroglycerin for treatment of hot flashes. Methods Peri- and postmenopausal women reporting at least 7 hot flashes per day were recruited into a single-arm, dose-escalation trial of continuous transdermal nitroglycerin. Participants were started on a generic 0.1 mg/hr nitroglycerin patch applied daily without patch-free periods. Over four weeks, participants escalated dosage weekly to 0.2, 0.4, or 0.6 mg/hr as tolerated, then discontinued nitroglycerin during the final week. Changes in hot flash frequency and severity were assessed using symptom diaries. Paired t-tests examined change in outcomes between baseline and maximal-dose therapy as well as after discontinuation of nitroglycerin. Results Of the 19 participants, mean age was 51.4 (±4.3) years. Women reported an average 10.6 (±3.0) hot flashes and 7.1 (±3.8) moderate-to-severe hot flashes per day at baseline. Eleven women escalated to 0.6 mg/hr, three to 0.4 mg/hr, two to 0.2 mg/hr, and one remained on 0.1 mg/hr nitroglycerin. Two discontinued nitroglycerin before the first outcomes assessment. Among the remaining 17 women, the average daily frequency of hot flashes decreased by 54% and the average frequency of moderate-to-severe hot flashes decreased by 69% from baseline to maximum-dose therapy (P<0.001 for both). After discontinuing nitroglycerin, participants reported an average 23% increase in frequency of any hot flashes (P=0.041) and 96% increase in moderate-to-severe hot flashes (P<0.001). Conclusions Continuous nitroglycerin may substantially and reversibly decrease hot flash frequency and severity. If confirmed in a randomized blinded trial, it may offer a novel non-hormonal hot flash treatment. PMID:26263283

Program Listings for EOSAEL 80-B and Ancillary Codes AGAUS and FLASH. Volume II. User’s Manual Supplement.

DTIC Science & Technology

1982-02-01

FORMAT(1X,39NINVALID INPUTS TO CWIC. IERR-1 RETURNED) CWC01450 IERR=1 CWCO01460 RETURN CWC6OI470 20 TInE=RV 1) CWCOI4SO XO=RV( 2) CJC 01490 H3=RV( 3...ERROR CHECKS AGXO1910 IF (IT.LE.0) IT=I AGXO192o IF (IT.GT.JDIMCK(1)) CALL DIMER( ) AGX01930 IF(JDIMCKcI).LT.65) WRITE(IOUT, 1295 AGX0940 C CHECK FOR...Office System Planning Corporation ATTN: DACS -BMT (Colonel Harry F. Ennis) ATTN: COL Hank Shelton 5001 Eisenhower Avenue 1500 Wilson Boulevard

The role of hot electrons in the dynamics of a laser-driven strong converging shock

DOE PAGES

Llor Aisa, E.; Ribeyre, X.; Duchateau, G.; ...

2017-11-30

Experiments on strong shock excitation in spherical plastic targets conducted at the Omega Laser Facility are interpreted with the radiation–hydrodynamics code CHIC to account for parametric instabilities excitation and hot-electron generation. The effects of hot electrons on the shock-pressure amplification and upstream preheat are analyzed. In this study, it is demonstrated that both effects contribute to an increase in shock velocity. Comparison of the measured laser reflectivity and shock flash time with numerical simulations make it possible to reconstitute the time history of the ablation and shock pressures. Finally, consequences of this analysis for the shock-ignition target design are discussed.

The role of hot electrons in the dynamics of a laser-driven strong converging shock

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

Llor Aisa, E.; Ribeyre, X.; Duchateau, G.

Experiments on strong shock excitation in spherical plastic targets conducted at the Omega Laser Facility are interpreted with the radiation–hydrodynamics code CHIC to account for parametric instabilities excitation and hot-electron generation. The effects of hot electrons on the shock-pressure amplification and upstream preheat are analyzed. In this study, it is demonstrated that both effects contribute to an increase in shock velocity. Comparison of the measured laser reflectivity and shock flash time with numerical simulations make it possible to reconstitute the time history of the ablation and shock pressures. Finally, consequences of this analysis for the shock-ignition target design are discussed.

Hypercube matrix computation task

NASA Technical Reports Server (NTRS)

Calalo, R.; Imbriale, W.; Liewer, P.; Lyons, J.; Manshadi, F.; Patterson, J.

1987-01-01

The Hypercube Matrix Computation (Year 1986-1987) task investigated the applicability of a parallel computing architecture to the solution of large scale electromagnetic scattering problems. Two existing electromagnetic scattering codes were selected for conversion to the Mark III Hypercube concurrent computing environment. They were selected so that the underlying numerical algorithms utilized would be different thereby providing a more thorough evaluation of the appropriateness of the parallel environment for these types of problems. The first code was a frequency domain method of moments solution, NEC-2, developed at Lawrence Livermore National Laboratory. The second code was a time domain finite difference solution of Maxwell's equations to solve for the scattered fields. Once the codes were implemented on the hypercube and verified to obtain correct solutions by comparing the results with those from sequential runs, several measures were used to evaluate the performance of the two codes. First, a comparison was provided of the problem size possible on the hypercube with 128 megabytes of memory for a 32-node configuration with that available in a typical sequential user environment of 4 to 8 megabytes. Then, the performance of the codes was anlyzed for the computational speedup attained by the parallel architecture.

Bistatic radar cross section of a perfectly conducting rhombus-shaped flat plate

NASA Astrophysics Data System (ADS)

Fenn, Alan J.

1990-05-01

The bistatic radar cross section of a perfectly conducting flat plate that has a rhombus shape (equilateral parallelogram) is investigated. The Ohio State University electromagnetic surface patch code (ESP version 4) is used to compute the theoretical bistatic radar cross section of a 35- x 27-in rhombus plate at 1.3 GHz over the bistatic angles 15 deg to 142 deg. The ESP-4 computer code is a method of moments FORTRAN-77 program which can analyze general configurations of plates and wires. This code has been installed and modified at Lincoln Laboratory on a SUN 3 computer network. Details of the code modifications are described. Comparisons of the method of moments simulations and measurements of the rhombus plate are made. It is shown that the ESP-4 computer code provides a high degree of accuracy in the calculation of copolarized and cross-polarized bistatic radar cross section patterns.

ASR4: A computer code for fitting and processing 4-gage anelastic strain recovery data

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

Warpinski, N.R.

A computer code for analyzing four-gage Anelastic Strain Recovery (ASR) data has been modified for use on a personal computer. This code fits the viscoelastic model of Warpinski and Teufel to measured ASR data, calculates the stress orientation directly, and computes stress magnitudes if sufficient input data are available. The code also calculates the stress orientation using strain-rosette equations, and its calculates stress magnitudes using Blanton's approach, assuming sufficient input data are available. The program is written in FORTRAN, compiled with Ryan-McFarland Version 2.4. Graphics use PLOT88 software by Plotworks, Inc., but the graphics software must be obtained by themore » user because of licensing restrictions. A version without graphics can also be run. This code is available through the National Energy Software Center (NESC), operated by Argonne National Laboratory. 5 refs., 3 figs.« less

Navier-Stokes Simulation of Homogeneous Turbulence on the CYBER 205

NASA Technical Reports Server (NTRS)

Wu, C. T.; Ferziger, J. H.; Chapman, D. R.; Rogallo, R. S.

1984-01-01

A computer code which solves the Navier-Stokes equations for three dimensional, time-dependent, homogenous turbulence has been written for the CYBER 205. The code has options for both 64-bit and 32-bit arithmetic. With 32-bit computation, mesh sizes up to 64 (3) are contained within core of a 2 million 64-bit word memory. Computer speed timing runs were made for various vector lengths up to 6144. With this code, speeds a little over 100 Mflops have been achieved on a 2-pipe CYBER 205. Several problems encountered in the coding are discussed.

The investigation of tethered satellite system dynamics

NASA Technical Reports Server (NTRS)

Lorenzini, E.

1985-01-01

The tether control law to retrieve the satellite was modified in order to have a smooth retrieval trajectory of the satellite that minimizes the thruster activation. The satellite thrusters were added to the rotational dynamics computer code and a preliminary control logic was implemented to simulate them during the retrieval maneuver. The high resolution computer code for modelling the three dimensional dynamics of untensioned tether, SLACK3, was made fully operative and a set of computer simulations of possible tether breakages was run. The distribution of the electric field around an electrodynamic tether in vacuo severed at some length from the shuttle was computed with a three dimensional electrodynamic computer code.

Experimental and computational surface and flow-field results for an all-body hypersonic aircraft

NASA Technical Reports Server (NTRS)

Lockman, William K.; Lawrence, Scott L.; Cleary, Joseph W.

1990-01-01

The objective of the present investigation is to establish a benchmark experimental data base for a generic hypersonic vehicle shape for validation and/or calibration of advanced computational fluid dynamics computer codes. This paper includes results from the comprehensive test program conducted in the NASA/Ames 3.5-foot Hypersonic Wind Tunnel for a generic all-body hypersonic aircraft model. Experimental and computational results on flow visualization, surface pressures, surface convective heat transfer, and pitot-pressure flow-field surveys are presented. Comparisons of the experimental results with computational results from an upwind parabolized Navier-Stokes code developed at Ames demonstrate the capabilities of this code.

Risk of long-term hot flashes after natural menopause: evidence from the Penn Ovarian Aging Study cohort.

PubMed

Freeman, Ellen W; Sammel, Mary D; Sanders, Richard J

2014-09-01

This study aims to estimate the risk of hot flashes relative to natural menopause and to evaluate the associations of hormone levels, behavioral variables, and demographic variables with the risk of hot flashes after menopause. We performed annual assessment of 255 women who were premenopausal at baseline and reached natural menopause within 16 years of follow-up. The prevalence of moderate/severe hot flashes increased in each premenopausal year, reaching a peak of 46% in the first 2 years after the final menstrual period (FMP). Hot flashes decreased slowly after menopause and did not return to premenopausal levels until 9 years after the FMP. The mean (SD) duration of moderate/severe hot flashes after the FMP was 4.6 (2.9) years (for any hot flashes, 4.9 [3.1] y). One third of women at 10 years or more after menopause continued to experience moderate/severe hot flashes. African-American women (obese and nonobese) and obese white women had significantly greater risks of hot flashes compared with nonobese white women (interaction, P = 0.01). In multivariable analysis, increasing follicle-stimulating hormone levels before the FMP (P < 0.001), decreasing estradiol (odds ratio, 0.87; 95% CI, 0.78-0.96; P = 0.008), and increasing anxiety (odds ratio, 1.05; 95% CI, 1.03-1.06; P < 0.001) were significant risk factors for hot flashes, whereas higher education levels were protective (odds ratio, 0.66; 95% CI, 0.47-0.91; P = 0.011). Moderate/severe hot flashes continue, on average, for nearly 5 years after menopause; more than one third of women observed for 10 years or more after menopause have moderate/severe hot flashes. Continuation of hot flashes for more than 5 years after menopause underscores the importance of determining individual risks/benefits when selecting hormone or nonhormone therapy for menopausal symptoms.

RISK OF LONG TERM HOT FLASHES AFTER NATURAL MENOPAUSE: EVIDENCE FROM THE PENN OVARIAN AGING COHORT

PubMed Central

Freeman, Ellen W.; Sammel, Mary D.; Sanders, Richard J.

2015-01-01

Objectives To estimate the risk of hot flashes relative to natural menopause and evaluate associations of hormone levels, behavioral and demographic variables with the risk of hot flashes following menopause. Methods Annual assessments of 255 women who were premenopausal at baseline and reached natural menopause during 16 years of follow-up. Results The prevalence of moderate/severe hot flashes increased in each premenopausal year, reaching a peak of 46% in the first two years after the final menstrual period (FMP). Hot flashes decreased slowly following menopause and did not return to premenopausal levels until 9 years after FMP. The mean duration of moderate/severe hot flashes after FMP was 4.6 (SD2.9) years (4.9, SD3.1 years for any hot flashes). One-third of women at 10 or more years following menopause continued to experience moderate/severe hot flashes. African American women (obese and non-obese) and obese white women had significantly greater risk of hot flashes compared to non-obese white women (interaction P=0.01). In multivariable analysis, increasing FSH levels before FMP (P<0.001), decreasing estradiol (OR 0.87, 95% CI: 0.78–0.96, P=0.008), and increasing anxiety (OR 1.05, 95% CI: 1.03–1.06, P<0.001) were significant risk factors for hot flashes, while higher education levels were protective (OR 0.66, 95% CI: 0.47–0.91, P=0.011). Conclusions Moderate/severe hot flashes continued on average for nearly 5 years following menopause; more than one- third of women observed for 10 or more years following menopause had moderate/severe hot flashes. Continuation of hot flashes for more than 5 years following menopause underscores the importance of determining individual risk/benefit when selecting hormone or non-hormonal therapy for menopausal symptoms. PMID:24473530

Computer search for binary cyclic UEP codes of odd length up to 65

NASA Technical Reports Server (NTRS)

Lin, Mao-Chao; Lin, Chi-Chang; Lin, Shu

1990-01-01

Using an exhaustive computation, the unequal error protection capabilities of all binary cyclic codes of odd length up to 65 that have minimum distances at least 3 are found. For those codes that can only have upper bounds on their unequal error protection capabilities computed, an analytic method developed by Dynkin and Togonidze (1976) is used to show that the upper bounds meet the exact unequal error protection capabilities.

A Combinatorial Geometry Computer Description of the MEP-021A Generator Set

DTIC Science & Technology

1979-02-01

Generator Computer Description Gasoline Generator GIFT MEP-021A 20. ABSTRACT fCbntteu* an rararaa eta* ft namamwaay anal Identify by block number) This... GIFT code is also stored on magnetic tape for future vulnerability analysis. 00,] 󈧚*7,1473 EDITION OF • NOV 65 IS OBSOLETE UNCLASSIFIED SECURITY...the Geometric Information for Targets ( GIFT ) computer code. The GIFT code traces shotlines through a COM-GEOM description from any specified attack

Optimizing a liquid propellant rocket engine with an automated combustor design code (AUTOCOM)

NASA Technical Reports Server (NTRS)

Hague, D. S.; Reichel, R. H.; Jones, R. T.; Glatt, C. R.

1972-01-01

A procedure for automatically designing a liquid propellant rocket engine combustion chamber in an optimal fashion is outlined. The procedure is contained in a digital computer code, AUTOCOM. The code is applied to an existing engine, and design modifications are generated which provide a substantial potential payload improvement over the existing design. Computer time requirements for this payload improvement were small, approximately four minutes in the CDC 6600 computer.

FLASH is essential during early embryogenesis and cooperates with p73 to regulate histone gene transcription.

PubMed

De Cola, A; Bongiorno-Borbone, L; Bianchi, E; Barcaroli, D; Carletti, E; Knight, R A; Di Ilio, C; Melino, G; Sette, C; De Laurenzi, V

2012-02-02

Replication-dependent histone gene expression is a fundamental process occurring in S-phase under the control of the cyclin-E/CDK2 complex. This process is regulated by a number of proteins, including Flice-Associated Huge Protein (FLASH) (CASP8AP2), concentrated in specific nuclear organelles known as HLBs. FLASH regulates both histone gene transcription and mRNA maturation, and its downregulation in vitro results in the depletion of the histone pull and cell-cycle arrest in S-phase. Here we show that the transcription factor p73 binds to FLASH and is part of the complex that regulates histone gene transcription. Moreover, we created a novel gene trap to disrupt FLASH in mice, and we show that homozygous deletion of FLASH results in early embryonic lethality, owing to arrest of FLASH(-/-) embryos at the morula stage. These results indicate that FLASH is an essential, non-redundant regulator of histone transcription and cell cycle during embryogenesis.

A pilot study of magnetic therapy for hot flashes after breast cancer.

PubMed

Carpenter, Janet S; Wells, Nancy; Lambert, Beth; Watson, Peggy; Slayton, Tami; Chak, Bapsi; Hepworth, Joseph T; Worthington, W Bradley

2002-04-01

The purpose of this randomized placebo-controlled crossover pilot study was to evaluate the effectiveness and acceptability of magnetic therapy for hot flashes among breast cancer survivors. Participants completed a 24-hour baseline hot-flash monitoring session, wore the magnetic devices or placebo for 3 days, completed an after-treatment hot-flash monitoring session, experienced a 10-day washout period, and then crossed over to the opposite study arm. Magnetic devices and placebos were placed on 6 acupressure sites corresponding to hot-flash relief. Complete data were available from 11 survivors of breast cancer. Results indicated magnetic therapy was no more effective than placebo in decreasing hot-flash severity, and contrary to expectations, placebo was significantly more effective than magnets in decreasing hot-flash frequency, bother, interference with daily activities, and overall quality of life. Implications for clinical practice and future research include the need to explore alternative interventions aimed at alleviating hot flashes in this population.

Obtaining the Grobner Initialization for the Ground Flash Fraction Retrieval Algorithm

NASA Technical Reports Server (NTRS)

Solakiewicz, R.; Attele, R.; Koshak, W.

2011-01-01

At optical wavelengths and from the vantage point of space, the multiple scattering cloud medium obscures one's view and prevents one from easily determining what flashes strike the ground. However, recent investigations have made some progress examining the (easier, but still difficult) problem of estimating the ground flash fraction in a set of N flashes observed from space In the study by Koshak, a Bayesian inversion method was introduced for retrieving the fraction of ground flashes in a set of flashes observed from a (low earth orbiting or geostationary) satellite lightning imager. The method employed a constrained mixed exponential distribution model to describe the lightning optical measurements. To obtain the optimum model parameters, a scalar function of three variables (one of which is the ground flash fraction) was minimized by a numerical method. This method has formed the basis of a Ground Flash Fraction Retrieval Algorithm (GoFFRA) that is being tested as part of GOES-R GLM risk reduction.

Fast repetition rate (FRR) flasher

DOEpatents

Kolber, Zbigniew; Falkowski, Paul

1997-02-11

A fast repetition rate (FRR) flasher suitable for high flash photolysis including kinetic chemical and biological analysis. The flasher includes a power supply, a discharge capacitor operably connected to be charged by the power supply, and a flash lamp for producing a series of flashes in response to discharge of the discharge capacitor. A triggering circuit operably connected to the flash lamp initially ionizes the flash lamp. A current switch is operably connected between the flash lamp and the discharge capacitor. The current switch has at least one insulated gate bipolar transistor for switching current that is operable to initiate a controllable discharge of the discharge capacitor through the flash lamp. Control means connected to the current switch for controlling the rate of discharge of the discharge capacitor thereby to effectively keep the flash lamp in an ionized state between Successive discharges of the discharge capacitor. Advantageously, the control means is operable to discharge the discharge capacitor at a rate greater than 10,000 Hz and even up to a rate greater than about 250,000 Hz.

Analysis of TRMM-LIS Lightning and Related Microphysics Using a Cell-Scale Database

NASA Technical Reports Server (NTRS)

Leroy, Anita; Petersen, Walter A.

2010-01-01

Previous studies of tropical lightning activity using Tropical Rainfall Measurement Mission (TRMM) Lightning Imaging Sensor (LIS) data performed analyses of lightning behavior over mesoscale "feature" scales or over uniform grids. In order to study lightning and the governing ice microphysics intrinsic to thunderstorms at a more process-specific scale (i.e., the scale over which electrification processes and lightning occur in a "unit" thunderstorm), a new convective cell-scale database was developed by analyzing and refining the University of Utah's Precipitation Features database and retaining precipitation data parameters computed from the TRMM precipitation radar (PR), microwave imager (TMI) and LIS instruments. The resulting data base was to conduct a limited four-year study of tropical continental convection occurring over the Amazon Basin, Congo, Maritime Continent and the western Pacific Ocean. The analysis reveals expected strong correlations between lightning flash counts per cell and ice proxies, such as ice water path, minimum and average 85GHz brightness temperatures, and 18dBz echo top heights above the freezing level in all regimes, as well as regime-specific relationships between lighting flash counts and PR-derived surface rainfall rates. Additionally, radar CFADs were used to partition the 3D structure of cells in each regime at different flash counts. The resulting cell-scale analyses are compared to previous mesoscale feature and gridded studies wherever possible.

Statistical Evolution of the Lightning Flash

NASA Astrophysics Data System (ADS)

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

2012-12-01

Natural lightning is one of the most fascinating and powerful electrical processes on Earth. To date, the physics behind this natural phenomenon are not fully understood, due primarily to the difficulty of obtaining measurements inside thunderstorms and to the wide range of timescales involved (from nanoseconds to seconds). Our aim is to use accurate lightning geo-location data from the National Lightning Detection Network (NLDN) to study statistical patterns in lightning, taking advantage of the fact that millions of lightning flashes occur around the globe every day. We present two sets of results, one involving the patterns of flashes in a storm, and a second involving the patterns of strokes in a flash. These patterns can provide a surrogate measure of the timescales and the spatial extents of the underlying physical processes. First, we study the timescales of charge buildup inside thunderstorms. We find that, following a lightning flash, the probability of another neighboring flash decreases and takes tens of seconds to recover. We find that this suppression effect is a function of flash type, stroke peak current, cloud-to-ground (CG) stroke multiplicity, and other lightning and geographical parameters. We find that the probabilities of subsequent flashes are more suppressed following oceanic lightning, or following flashes with higher peak currents and/or higher multiplicities (for CG flashes). Second, we use NLDN data to study the evolution of the strokes within a CG flash. A CG flash typically includes multiple return strokes, which can occur in the same channel or in multiple channels within a few kilometers. We cluster NLDN stroke data into flashes and produce the probability density function of subsequent strokes as a function of distance and time-delays relative to the previous stroke. Using this technique, we investigate processes which occur during the CG lightning flash with nanosecond to millisecond timescales. For instance, our results suggest that subsequent strokes that occur in a newly formed channel follow a pattern that propagates at a speed of ~200 km/s. We present our statistical techniques and discuss more thoroughly our work and results.