Rapid high-resolution spin- and angle-resolved photoemission spectroscopy with pulsed laser source and time-of-flight spectrometer

NASA Astrophysics Data System (ADS)

Gotlieb, K.; Hussain, Z.; Bostwick, A.; Lanzara, A.; Jozwiak, C.

2013-09-01

A high-efficiency spin- and angle-resolved photoemission spectroscopy (spin-ARPES) spectrometer is coupled with a laboratory-based laser for rapid high-resolution measurements. The spectrometer combines time-of-flight (TOF) energy measurements with low-energy exchange scattering spin polarimetry for high detection efficiencies. Samples are irradiated with fourth harmonic photons generated from a cavity-dumped Ti:sapphire laser that provides high photon flux in a narrow bandwidth, with a pulse timing structure ideally matched to the needs of the TOF spectrometer. The overall efficiency of the combined system results in near-EF spin-resolved ARPES measurements with an unprecedented combination of energy resolution and acquisition speed. This allows high-resolution spin measurements with a large number of data points spanning multiple dimensions of interest (energy, momentum, photon polarization, etc.) and thus enables experiments not otherwise possible. The system is demonstrated with spin-resolved energy and momentum mapping of the L-gap Au(111) surface states, a prototypical Rashba system. The successful integration of the spectrometer with the pulsed laser system demonstrates its potential for simultaneous spin- and time-resolved ARPES with pump-probe based measurements.

High Resolution Imaging of Very Low Mass Spectral Binaries: Three Resolved Systems and Detection of Orbital Motion in an L/T Transition Binary

NASA Astrophysics Data System (ADS)

Bardalez Gagliuffi, Daniella C.; Gelino, Christopher R.; Burgasser, Adam J.

2015-11-01

We present high resolution Laser Guide Star Adaptive Optics imaging of 43 late-M, L and T dwarf systems with Keck/NIRC2. These include 17 spectral binary candidates, systems whose spectra suggest the presence of a T dwarf secondary. We resolve three systems: 2MASS J1341-3052, SDSS J1511+0607 and SDSS J2052-1609 the first two are resolved for the first time. All three have projected separations <8 AU and estimated periods of 14-80 years. We also report a preliminary orbit determination for SDSS J2052-1609 based on six epochs of resolved astrometry between 2005 and 2010. Among the 14 unresolved spectral binaries, 5 systems were confirmed binaries but remained unresolved, implying a minimum binary fraction of {47}-11+12% for this sample. Our inability to resolve most of the spectral binaries, including the confirmed binaries, supports the hypothesis that a large fraction of very low mass systems have relatively small separations and are missed with direct imaging. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

Depth-resolved ballistic imaging in a low-depth-of-field optical Kerr gated imaging system

NASA Astrophysics Data System (ADS)

Zheng, Yipeng; Tan, Wenjiang; Si, Jinhai; Ren, YuHu; Xu, Shichao; Tong, Junyi; Hou, Xun

2016-09-01

We demonstrate depth-resolved imaging in a ballistic imaging system, in which a heterodyned femtosecond optical Kerr gate is introduced to extract useful imaging photons for detecting an object hidden in turbid media and a compound lens is proposed to ensure both the depth-resolved imaging capability and the long working distance. Two objects of about 15-μm widths hidden in a polystyrene-sphere suspension have been successfully imaged with approximately 600-μm depth resolution. Modulation-transfer-function curves with the object in and away from the object plane have also been measured to confirm the depth-resolved imaging capability of the low-depth-of-field (low-DOF) ballistic imaging system. This imaging approach shows potential for application in research of the internal structure of highly scattering fuel spray.

Depth-resolved ballistic imaging in a low-depth-of-field optical Kerr gated imaging system

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

Zheng, Yipeng; Tan, Wenjiang, E-mail: tanwenjiang@mail.xjtu.edu.cn; Si, Jinhai

2016-09-07

We demonstrate depth-resolved imaging in a ballistic imaging system, in which a heterodyned femtosecond optical Kerr gate is introduced to extract useful imaging photons for detecting an object hidden in turbid media and a compound lens is proposed to ensure both the depth-resolved imaging capability and the long working distance. Two objects of about 15-μm widths hidden in a polystyrene-sphere suspension have been successfully imaged with approximately 600-μm depth resolution. Modulation-transfer-function curves with the object in and away from the object plane have also been measured to confirm the depth-resolved imaging capability of the low-depth-of-field (low-DOF) ballistic imaging system. Thismore » imaging approach shows potential for application in research of the internal structure of highly scattering fuel spray.« less

Minimum resolvable power contrast model

NASA Astrophysics Data System (ADS)

Qian, Shuai; Wang, Xia; Zhou, Jingjing

2018-01-01

Signal-to-noise ratio and MTF are important indexs to evaluate the performance of optical systems. However,whether they are used alone or joint assessment cannot intuitively describe the overall performance of the system. Therefore, an index is proposed to reflect the comprehensive system performance-Minimum Resolvable Radiation Performance Contrast (MRP) model. MRP is an evaluation model without human eyes. It starts from the radiance of the target and the background, transforms the target and background into the equivalent strips,and considers attenuation of the atmosphere, the optical imaging system, and the detector. Combining with the signal-to-noise ratio and the MTF, the Minimum Resolvable Radiation Performance Contrast is obtained. Finally the detection probability model of MRP is given.

34 CFR 303.172 - Lead agency procedures for resolving complaints.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false Lead agency procedures for resolving complaints. 303.172 Section 303.172 Education Regulations of the Offices of the Department of Education (Continued... System-Application Requirements § 303.172 Lead agency procedures for resolving complaints. Each...

State National Pollutant Discharge Elimination System (NPDES) Program Withdrawal Petitions

EPA Pesticide Factsheets

Search for pending and resolved NPDES withdrawal petitions by state, region, date, or keyword. Pending means EPA has received the petition and is working with the state and petitioner to resolve it. Withdrew petition means that the petitioner has withdrawn the petition they submitted. Resolved means that EPA has resolved the issues raised in the petition and has denied the petition. Partially resolved means that EPA has partially denied the petition by resolving some of the issues, while continuing to work with the state and petitioner on other pending issues. Program withdrawn would apply if, after conducting investigations, EPA withdrew a state's NPDES authority.

48 CFR 229.101 - Resolving tax problems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Resolving tax problems..., DEPARTMENT OF DEFENSE GENERAL CONTRACTING REQUIREMENTS TAXES General 229.101 Resolving tax problems. (a... information on fuel excise taxes, see PGI 229.101(b). (c) For guidance on directing a contractor to litigate...

48 CFR 2052.242-71 - Procedures for Resolving Differing Professional Views.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Differing Professional Views. 2052.242-71 Section 2052.242-71 Federal Acquisition Regulations System NUCLEAR... Clauses 2052.242-71 Procedures for Resolving Differing Professional Views. As prescribed in 2042.570-2(b... contracting officer. Procedures for Resolving NRC Contractor Differing Professional Views (DPVs) (OCT 1999) (a...

48 CFR 30.606 - Resolving cost impacts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Resolving cost impacts. 30... impacts. (a) General. (1) The CFAO shall coordinate with the affected contracting officers before negotiating and resolving the cost impact when the estimated cost impact on any of their contracts is at least...

"Structure and dynamics in complex chemical systems: Gaining new insights through recent advances in time-resolved spectroscopies.” ACS Division of Physical Chemistry Symposium presented at the Fall National ACS Meeting in Boston, MA, August 2015

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

Crawford, Daniel

8-Session Symposium on STRUCTURE AND DYNAMICS IN COMPLEX CHEMICAL SYSTEMS: GAINING NEW INSIGHTS THROUGH RECENT ADVANCES IN TIME-RESOLVED SPECTROSCOPIES. The intricacy of most chemical, biochemical, and material processes and their applications are underscored by the complex nature of the environments in which they occur. Substantial challenges for building a global understanding of a heterogeneous system include (1) identifying unique signatures associated with specific structural motifs within the heterogeneous distribution, and (2) resolving the significance of each of multiple time scales involved in both small- and large-scale nuclear reorganization. This symposium focuses on the progress in our understanding of dynamics inmore » complex systems driven by recent innovations in time-resolved spectroscopies and theoretical developments. Such advancement is critical for driving discovery at the molecular level facilitating new applications. Broad areas of interest include: Structural relaxation and the impact of structure on dynamics in liquids, interfaces, biochemical systems, materials, and other heterogeneous environments.« less

Characterizing the Resolved M6 Dwarf Twin LP 318-218AB

NASA Astrophysics Data System (ADS)

Moreno Hilario, Elizabeth; Burgasser, Adam J.; Bardalez Gagliuffi, Daniella; Tamiya, Tomoki

2017-01-01

The lowest-mass stars and brown dwarfs are among the most common objects in the Milky Way Galaxy, but theories of their formation and evolution remain poorly constrained. Binary systems are important for understanding the formation of these objects and for making direct orbit and mass measurements to validate evolutionary theories. We report the discovery of LP 318-218, a high proper motion late M dwarf, as a near equal-brightness binary system with a separation of 0.72 arcseconds. Resolved near-infrared spectroscopy confirms the components as nearly identical M6 twins. We using our resolved photometry and spectroscopy to estimate the distance, projected separation and tangential velocity of the system, and confirm common proper motion. We also perform atmosphere model fits to the resolved spectra to assess their physical properties. We place LP 318-218 in context with other widely-separated late M dwarf binaries.

Depth-resolved incoherent and coherent wide-field high-content imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

So, Peter T.

2016-03-01

Recent advances in depth-resolved wide-field imaging technique has enabled many high throughput applications in biology and medicine. Depth resolved imaging of incoherent signals can be readily accomplished with structured light illumination or nonlinear temporal focusing. The integration of these high throughput systems with novel spectroscopic resolving elements further enable high-content information extraction. We will introduce a novel near common-path interferometer and demonstrate its uses in toxicology and cancer biology applications. The extension of incoherent depth-resolved wide-field imaging to coherent modality is non-trivial. Here, we will cover recent advances in wide-field 3D resolved mapping of refractive index, absorbance, and vibronic components in biological specimens.

42 CFR 51.32 - Resolving disputes.

Code of Federal Regulations, 2010 CFR

2010-10-01

... reasonable time, the P&A system may pursue alternative remedies, including initiating legal action. (e) A P&A... Services § 51.32 Resolving disputes. (a) Each P&A system is encouraged to develop and employ techniques... the family member, or (3) Legally incompetent and the legal guardian, conservator or other legal...

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

Morales, F. Y.; Bryden, G.; Werner, M. W.

We present dual-band Herschel /PACS imaging for 59 main-sequence stars with known warm dust ( T {sub warm} ∼ 200 K), characterized by Spitzer . Of 57 debris disks detected at Herschel wavelengths (70 and/or 100 and 160 μ m), about half have spectral energy distributions (SEDs) that suggest two-ring disk architectures mirroring that of the asteroid–Kuiper Belt geometry; the rest are consistent with single belts of warm, asteroidal material. Herschel observations spatially resolve the outer/cold dust component around 14 A-type and 4 solar-type stars with two-belt systems, 15 of which for the first time. Resolved disks are typically observedmore » with radii >100 AU, larger than expected from a simple blackbody fit. Despite the absence of narrow spectral features for ice, we find that the shape of the continuum, combined with resolved outer/cold dust locations, can help constrain the grain size distribution and hint at the dust’s composition for each resolved system. Based on the combined Spitzer /IRS+Multiband Imaging Photometer (5-to-70 μ m) and Herschel /PACS (70-to-160 μ m) data set, and under the assumption of idealized spherical grains, we find that over half of resolved outer/cold belts are best fit with a mixed ice/rock composition. Minimum grain sizes are most often equal to the expected radiative blowout limit, regardless of composition. Three of four resolved systems around the solar-type stars, however, tend to have larger minimum grains compared to expectation from blowout ( f {sub MB} = a {sub min}/ a {sub BOS} ∼ 5). We also probe the disk architecture of 39 Herschel -unresolved systems by modeling their SEDs uniformly, and find them to be consistent with 31 single- and 8 two-belt debris systems.« less

340 nm pulsed UV LED system for europium-based time-resolved fluorescence detection of immunoassays.

PubMed

Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter; Petersen, Paul Michael; Pedersen, Christian

2016-09-19

We report on the design, development and investigation of an optical system based on UV light emitting diode (LED) excitation at 340 nm for time-resolved fluorescence detection of immunoassays. The system was tested to measure cardiac marker Troponin I with a concentration of 200 ng/L in immunoassay. The signal-to-noise ratio was comparable to state-of-the-art Xenon flash lamp based unit with equal excitation energy and without overdriving the LED. We performed a comparative study of the flash lamp and the LED based system and discussed temporal, spatial, and spectral features of the LED excitation for time-resolved fluorimetry. Optimization of the suggested key parameters of the LED promises significant increase of the signal-to-noise ratio and hence of the sensitivity of immunoassay systems.

Microphysics in the Multi-Scale Modeling Systems with Unified Physics

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo; Chern, J.; Lamg, S.; Matsui, T.; Shen, B.; Zeng, X.; Shi, R.

2011-01-01

In recent years, exponentially increasing computer power has extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 km2 in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale model can be run in grid size similar to cloud resolving model through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (l) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, the microphysics developments of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling system to study the heavy precipitation processes will be presented.

Spatio-temporally resolved spectral measurements of laser-produced plasma and semiautomated spectral measurement-control and analysis software

NASA Astrophysics Data System (ADS)

Cao, S. Q.; Su, M. G.; Min, Q.; Sun, D. X.; O'Sullivan, G.; Dong, C. Z.

2018-02-01

A spatio-temporally resolved spectral measurement system of highly charged ions from laser-produced plasmas is presented. Corresponding semiautomated computer software for measurement control and spectral analysis has been written to achieve the best synchronicity possible among the instruments. This avoids the tedious comparative processes between experimental and theoretical results. To demonstrate the capabilities of this system, a series of spatio-temporally resolved experiments of laser-produced Al plasmas have been performed and applied to benchmark the software. The system is a useful tool for studying the spectral structures of highly charged ions and for evaluating the spatio-temporal evolution of laser-produced plasmas.

Resolving components of wind accreting systems: a case study of Mira AB

NASA Astrophysics Data System (ADS)

Karovska, M.

2004-12-01

Mass transfer in many systems occurs by wind interaction rather then by tidal interaction, because the primary does not fill its Roche surface. The nearby detached binary Mira AB provides a unique laboratory for studying wind accretion processes because this system can be resolved and the interacting components can be studied individually, which is not possible in most accreting systems. The study of Mira AB wind accretion and mass transfer may therefore help understand the accretion processes in many other astronomical systems.

Depth-resolved dual-beamlet vibrometry based on Fourier domain low coherence interferometry

PubMed Central

Choudhury, Niloy; Chen, Fangyi; Wang, Ruikang K.; Jacques, Steven L.; Nuttall, Alfred L.

2013-01-01

Abstract. We present an optical vibrometer based on delay-encoded, dual-beamlet phase-sensitive Fourier domain interferometric system to provide depth-resolved subnanometer scale vibration information from scattering biological specimens. System characterization, calibration, and preliminary vibrometry with biological specimens were performed. The proposed system has the potential to provide both amplitude and direction of vibration of tissue microstructures on a single two-dimensional plane. PMID:23455961

New approaches to the analysis of complex samples using fluorescence lifetime techniques and organized media

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

Hertz, P.R.

Fluorescence spectroscopy is a highly sensitive and selective tool for the analysis of complex systems. In order to investigate the efficacy of several steady state and dynamic techniques for the analysis of complex systems, this work focuses on two types of complex, multicomponent samples: petrolatums and coal liquids. It is shown in these studies dynamic, fluorescence lifetime-based measurements provide enhanced discrimination between complex petrolatum samples. Additionally, improved quantitative analysis of multicomponent systems is demonstrated via incorporation of organized media in coal liquid samples. This research provides the first systematic studies of (1) multifrequency phase-resolved fluorescence spectroscopy for dynamic fluorescence spectralmore » fingerprinting of complex samples, and (2) the incorporation of bile salt micellar media to improve accuracy and sensitivity for characterization of complex systems. In the petroleum studies, phase-resolved fluorescence spectroscopy is used to combine spectral and lifetime information through the measurement of phase-resolved fluorescence intensity. The intensity is collected as a function of excitation and emission wavelengths, angular modulation frequency, and detector phase angle. This multidimensional information enhances the ability to distinguish between complex samples with similar spectral characteristics. Examination of the eigenvalues and eigenvectors from factor analysis of phase-resolved and steady state excitation-emission matrices, using chemometric methods of data analysis, confirms that phase-resolved fluorescence techniques offer improved discrimination between complex samples as compared with conventional steady state methods.« less

A robust model predictive control algorithm for uncertain nonlinear systems that guarantees resolvability

NASA Technical Reports Server (NTRS)

Acikmese, Ahmet Behcet; Carson, John M., III

2006-01-01

A robustly stabilizing MPC (model predictive control) algorithm for uncertain nonlinear systems is developed that guarantees resolvability. With resolvability, initial feasibility of the finite-horizon optimal control problem implies future feasibility in a receding-horizon framework. The control consists of two components; (i) feed-forward, and (ii) feedback part. Feed-forward control is obtained by online solution of a finite-horizon optimal control problem for the nominal system dynamics. The feedback control policy is designed off-line based on a bound on the uncertainty in the system model. The entire controller is shown to be robustly stabilizing with a region of attraction composed of initial states for which the finite-horizon optimal control problem is feasible. The controller design for this algorithm is demonstrated on a class of systems with uncertain nonlinear terms that have norm-bounded derivatives and derivatives in polytopes. An illustrative numerical example is also provided.

Vertical resolving power of a satellite temperature sounding system

NASA Technical Reports Server (NTRS)

Thompson, O. E.

1979-01-01

The paper examines the vertical resolving power of satellite temperature retrieval systems. Attention is given to sounding instrument proposed by Kaplan, et al., (1977) which has been conceived to have greatly improved vertical resolving capabilities. Two types of tests are reported. The first, based on the work of Conrath (1972), involves a theoretical assessment of the manner by which the ambient temperature profile is averaged over height in order to produce an estimate of temperature at a given level. The second test is empirical involving the actual retrieval of temperature signals superimposed on a standard atmosphere with an emphasis on determining the minimum separation of the signals for which the sounder system is still capable of distinguishing individual signals.

Automatic Scheduling and Planning (ASAP) in future ground control systems

NASA Technical Reports Server (NTRS)

Matlin, Sam

1988-01-01

This report describes two complementary approaches to the problem of space mission planning and scheduling. The first is an Expert System or Knowledge-Based System for automatically resolving most of the activity conflicts in a candidate plan. The second is an Interactive Graphics Decision Aid to assist the operator in manually resolving the residual conflicts which are beyond the scope of the Expert System. The two system designs are consistent with future ground control station activity requirements, support activity timing constraints, resource limits and activity priority guidelines.

Using Multi-Scale Modeling Systems and Satellite Data to Study the Precipitation Processes

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo; Chern, J.; Lamg, S.; Matsui, T.; Shen, B.; Zeng, X.; Shi, R.

2011-01-01

In recent years, exponentially increasing computer power has extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 km2 in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale model can be run in grid size similar to cloud resolving model through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (l) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, the recent developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling system to study the precipitating systems and hurricanes/typhoons will be presented. The high-resolution spatial and temporal visualization will be utilized to show the evolution of precipitation processes. Also how to use of the multi-satellite simulator tqimproy precipitation processes will be discussed.

Dissociable neural systems resolve conflict from emotional versus nonemotional distracters.

PubMed

Egner, Tobias; Etkin, Amit; Gale, Seth; Hirsch, Joy

2008-06-01

The human brain protects the processing of task-relevant stimuli from interference ("conflict") by task-irrelevant stimuli via attentional biasing mechanisms. The lateral prefrontal cortex has been implicated in resolving conflict between competing stimuli by selectively enhancing task-relevant stimulus representations in sensory cortices. Conversely, recent data suggest that conflict from emotional distracters may be resolved by an alternative route, wherein the rostral anterior cingulate cortex inhibits amygdalar responsiveness to task-irrelevant emotional stimuli. Here we tested the proposal of 2 dissociable, distracter-specific conflict resolution mechanisms, by acquiring functional magnetic resonance imaging data during resolution of conflict from either nonemotional or emotional distracters. The results revealed 2 distinct circuits: a lateral prefrontal "cognitive control" system that resolved nonemotional conflict and was associated with enhanced processing of task-relevant stimuli in sensory cortices, and a rostral anterior cingulate "emotional control" system that resolved emotional conflict and was associated with decreased amygdalar responses to emotional distracters. By contrast, activations related to both emotional and nonemotional conflict monitoring were observed in a common region of the dorsal anterior cingulate. These data suggest that the neuroanatomical networks recruited to overcome conflict vary systematically with the nature of the conflict, but that they may share a common conflict-detection mechanism.

Fluorescence hyperspectral imaging (fHSI) using a spectrally resolved detector array

PubMed Central

Luthman, Anna Siri; Dumitru, Sebastian; Quiros‐Gonzalez, Isabel; Joseph, James

2017-01-01

Abstract The ability to resolve multiple fluorescent emissions from different biological targets in video rate applications, such as endoscopy and intraoperative imaging, has traditionally been limited by the use of filter‐based imaging systems. Hyperspectral imaging (HSI) facilitates the detection of both spatial and spectral information in a single data acquisition, however, instrumentation for HSI is typically complex, bulky and expensive. We sought to overcome these limitations using a novel robust and low cost HSI camera based on a spectrally resolved detector array (SRDA). We integrated this HSI camera into a wide‐field reflectance‐based imaging system operating in the near‐infrared range to assess the suitability for in vivo imaging of exogenous fluorescent contrast agents. Using this fluorescence HSI (fHSI) system, we were able to accurately resolve the presence and concentration of at least 7 fluorescent dyes in solution. We also demonstrate high spectral unmixing precision, signal linearity with dye concentration and at depth in tissue mimicking phantoms, and delineate 4 fluorescent dyes in vivo. Our approach, including statistical background removal, could be directly generalised to broader spectral ranges, for example, to resolve tissue reflectance or autofluorescence and in future be tailored to video rate applications requiring snapshot HSI data acquisition. PMID:28485130

Multi-scale spectrally resolved quantitative fluorescence imaging system: towards neurosurgical guidance in glioma resection

NASA Astrophysics Data System (ADS)

Xie, Yijing; Thom, Maria; Miserocchi, Anna; McEvoy, Andrew W.; Desjardins, Adrien; Ourselin, Sebastien; Vercauteren, Tom

2017-02-01

In glioma resection surgery, the detection of tumour is often guided by using intraoperative fluorescence imaging notably with 5-ALA-PpIX, providing fluorescent contrast between normal brain tissue and the gliomas tissue to achieve improved tumour delineation and prolonged patient survival compared with the conventional white-light guided resection. However, the commercially available fluorescence imaging system relies on surgeon's eyes to visualise and distinguish the fluorescence signals, which unfortunately makes the resection subjective. In this study, we developed a novel multi-scale spectrally-resolved fluorescence imaging system and a computational model for quantification of PpIX concentration. The system consisted of a wide-field spectrally-resolved quantitative imaging device and a fluorescence endomicroscopic imaging system enabling optical biopsy. Ex vivo animal tissue experiments as well as human tumour sample studies demonstrated that the system was capable of specifically detecting the PpIX fluorescent signal and estimate the true concentration of PpIX in brain specimen.

Short-period cyclic loading system for in situ X-ray observation of anelastic properties at high pressure.

PubMed

Yoshino, Takashi; Yamazaki, Daisuke; Tange, Yoshinori; Higo, Yuji

2016-10-01

To determine the anelastic properties of materials of the Earth's interior, a short-period cyclic loading system was installed for in situ X-ray radiographic observation under high pressure to the multi-anvil deformation DIA press at the bending magnet beam line BL04B1 at SPring-8. The hydraulic system equipped with a piston controlled by a solenoid was designed so as to enable producing smooth sinusoidal stress in a wide range of oscillation period from 0.2 to 100 s and generating variable amplitudes. Time resolved X-ray radiography imaging of the sample and reference material provides their strain as a function of time during cyclic loading. A synchrotron X-ray radiation source allows us to resolve their strain variation with time even at the short period (<1 s). The minimum resolved strain is as small as 10 -4 , and the shortest oscillation period to detect small strain is 0.5 s. Preliminary experimental results exhibited that the new system can resolve attenuation factor Q -1 at upper mantle conditions. These results are in quantitative agreement with previously reported data obtained at lower pressures.

Debris Disks as Tracers of Nearby Planetary Systems

NASA Technical Reports Server (NTRS)

Stapelfeldt, Karl

2012-01-01

Many main-sequence stars possess tenuous circumstellar dust clouds believed to trace extrasolar analogs of the Sun's asteroid and Kuiper Belts. While most of these "debris disks" are known only from far-infrared photometry, dozens are now spatially resolved. In this talk, I'll review the observed structural properties of debris disks as revealed by imaging with the Hubble, Spitzer, and Herschel Space Telescopes. I will show how modeling of the far-infrared spectral energy distributions of resolved disks can be used to constrain their dust particle sizes and albedos. I will review cases of disks whose substructures suggest planetary perturbations, including a newly-discovered eccentric ring system. I'll conclude with thoughts on the potential of upcoming and proposed facilities to resolve similar structures around a greatly expanded sample of nearby debris systems.

U.S. GODAE: Global Ocean Prediction With the HYbrid Coordinate Ocean Model (HYCOM)

DTIC Science & Technology

2009-06-01

REPORT DATE (DD-MM- YYYY) 12-08-2009 2. REPORT TYPE Journal Article 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE U.S. GODAE: Global ...the lerformance and application of eddy-resolving, real-time global - and basin-scale ocean prediction systems using the HYbrid Coordinate Ocean...prediction system outputs. In addnion to providing real-time, eddy-resolving global - and basin-scale ocean prediction systems for the US Navy and NOAA, this

Applying the Toyota Production System: using a patient safety alert system to reduce error.

PubMed

Furman, Cathie; Caplan, Robert

2007-07-01

In 2002, Virginia Mason Medical Center (VMMC) adapted the Toyota Production System, also known as lean manufacturing. To translate the techniques of zero defects and stopping the line into health care, the Patient Safety Alert (PSA) system requires any employee who encounters a situation that is likely to harm a patient to make an immediate report and to cease any activity that could cause further harm (stopping the line). IMPLEMENTING THE PSA SYSTEM--STOPPING THE LINE: If any VMMC employee's practice or conduct is deemed capable of causing harm to a patient, a PSA can cause that person to be stopped from working until the problem is resolved. A policy statement, senior executive commitment, dedicated resources, a 24-hour hotline, and communication were all key features of implementation. As of December 2006, 6,112 PSA reports were received: 20% from managers, 8% from physicians, 44% from nurses, and 23% from nonclinical support personnel, for example. The number of reports received per month increased from an average of 3 in 2002 to 285 in 2006. Most reports were processed within 24 hours and were resolved within 2 to 3 weeks. Implementing the PSA system has drastically increased the number of safety concerns that are resolved at VMMC, while drastically reducing the time it takes to resolve them. Transparent discussion and feedback have helped promote staff acceptance and participation.

Dynamic evolution of light-induced orientation of dye-doped liquid crystals in liquid phase studied by time-resolved optically heterodyned optical Kerr effect technique.

PubMed

Yang, Pei; Liu, Liying; Xu, Lei

2008-02-28

Transient evolution of light-induced molecular reorientation both in 1-amino-anthraquinone (1AAQ) dye and azobenzene doped isotropic liquid crystals (LCs) were studied by time-resolved optically heterodyned optical Kerr effect method. The results give clear direct experimental proof that under short pulse (30 ps) excitation, LC molecules orientate toward the excitation light polarization direction in the 1AAQ/LC system. However, LC molecular orientation becomes orthogonal to the light polarization in azobenzene/LC system. Time-resolved excited-state absorption of 1AAQ and wavelength dependent excited-state absorption of azobenzene were also observed and their contributions to the early dynamics of the third order optical responses of the two systems were confirmed. A simplified two-level mean-field theory was derived to reveal the intensity dependence of orientation enhancement factor in azobenzene/LC system considering the photoisomerization process.

Using Multi-Scale Modeling Systems and Satellite Data to Study the Precipitation Processes

NASA Technical Reports Server (NTRS)

Tao, Wei--Kuo; Chern, J.; Lamg, S.; Matsui, T.; Shen, B.; Zeng, X.; Shi, R.

2010-01-01

In recent years, exponentially increasing computer power extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 sq km in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale models can be run in grid size similar to cloud resolving models through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model). (2) a regional scale model (a NASA unified weather research and forecast, W8F). (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, a review of developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling systems to study the interactions between clouds, precipitation, and aerosols will be presented. Also how to use the multi-satellite simulator to improve precipitation processes will be discussed.

Using Multi-Scale Modeling Systems to Study the Precipitation Processes

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo

2010-01-01

In recent years, exponentially increasing computer power has extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 km2 in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale model can be run in grid size similar to cloud resolving model through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF), and (4) a land modeling system. The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, a review of developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling system to study the interactions between clouds, precipitation, and aerosols will be presented. Also how to use of the multi-satellite simulator to improve precipitation processes will be discussed.

The time resolved SBS and SRS research in heavy water and its application in CARS

NASA Astrophysics Data System (ADS)

Liu, Jinbo; Gai, Baodong; Yuan, Hong; Sun, Jianfeng; Zhou, Xin; Liu, Di; Xia, Xusheng; Wang, Pengyuan; Hu, Shu; Chen, Ying; Guo, Jingwei; Jin, Yuqi; Sang, Fengting

2018-05-01

We present the time-resolved character of stimulated Brillouin scattering (SBS) and backward stimulated Raman scattering (BSRS) in heavy water and its application in Coherent Anti-Stokes Raman Scattering (CARS) technique. A nanosecond laser from a frequency-doubled Nd: YAG laser is introduced into a heavy water cell, to generate SBS and BSRS beams. The SBS and BSRS beams are collinear, and their time resolved characters are studied by a streak camera, experiment show that they are ideal source for an alignment-free CARS system, and the time resolved property of SBS and BSRS beams could affect the CARS efficiency significantly. By inserting a Dye cuvette to the collinear beams, the time-overlapping of SBS and BSRS could be improved, and finally the CARS efficiency is increased, even though the SBS energy is decreased. Possible methods to improve the efficiency of this CARS system are discussed too.

Time-resolved spectroscopy using a chopper wheel as a fast shutter

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

Wang, Shicong; Wendt, Amy E.; Boffard, John B.

Widely available, small form-factor, fiber-coupled spectrometers typically have a minimum exposure time measured in milliseconds, and thus cannot be used directly for time-resolved measurements at the microsecond level. Spectroscopy at these faster time scales is typically done with an intensified charge coupled device (CCD) system where the image intensifier acts as a “fast” electronic shutter for the slower CCD array. In this paper, we describe simple modifications to a commercially available chopper wheel system to allow it to be used as a “fast” mechanical shutter for gating a fiber-coupled spectrometer to achieve microsecond-scale time-resolved optical measurements of a periodically pulsedmore » light source. With the chopper wheel synchronized to the pulsing of the light source, the time resolution can be set to a small fraction of the pulse period by using a chopper wheel with narrow slots separated by wide spokes. Different methods of synchronizing the chopper wheel and pulsing of the light sources are explored. The capability of the chopper wheel system is illustrated with time-resolved measurements of pulsed plasmas.« less

Scrounging by foragers can resolve the paradox of enrichment

PubMed Central

2017-01-01

Theoretical models of predator–prey systems predict that sufficient enrichment of prey can generate large amplitude limit cycles, paradoxically causing a high risk of extinction (the paradox of enrichment). Although real ecological communities contain many gregarious species, whose foraging behaviour should be influenced by socially transmitted information, few theoretical studies have examined the possibility that social foraging might resolve this paradox. I considered a predator population in which individuals play the producer–scrounger foraging game in one-prey-one-predator and two-prey-one-predator systems. I analysed the stability of a coexisting equilibrium point in the one-prey system and that of non-equilibrium dynamics in the two-prey system. The results revealed that social foraging could stabilize both systems, and thereby resolve the paradox of enrichment when scrounging behaviour (i.e. kleptoparasitism) is prevalent in predators. This suggests a previously neglected mechanism underlying a powerful effect of group-living animals on the sustainability of ecological communities. PMID:28405371

Improvements in brain activation detection using time-resolved diffuse optical means

NASA Astrophysics Data System (ADS)

Montcel, Bruno; Chabrier, Renee; Poulet, Patrick

2005-08-01

An experimental method based on time-resolved absorbance difference is described. The absorbance difference is calculated over each temporal step of the optical signal with the time-resolved Beer-Lambert law. Finite element simulations show that each step corresponds to a different scanned zone and that cerebral contribution increases with the arrival time of photons. Experiments are conducted at 690 and 830 nm with a time-resolved system consisting of picosecond laser diodes, micro-channel plate photo-multiplier tube and photon counting modules. The hemodynamic response to a short finger tapping stimulus is measured over the motor cortex. Time-resolved absorbance difference maps show that variations in the optical signals are not localized in superficial regions of the head, which testify for their cerebral origin. Furthermore improvements in the detection of cerebral activation is achieved through the increase of variations in absorbance by a factor of almost 5 for time-resolved measurements as compared to non-time-resolved measurements.

Method and System for Name Resolution Across Heterogeneous Architectures

NASA Technical Reports Server (NTRS)

Sevilla, Spencer (Inventor); Garcia-Luna-Aceves, Jose J. (Inventor); Mahadevan, Priya (Inventor)

2018-01-01

One embodiment of the present invention provides a system for resolving a name request in a network comprising a plurality of groups that use different name-resolution schemes. During operation, the system receives, at a first group, the name request; identifies a parent group of the first group, which is a member of the parent group; and in response to failing to resolve the name request within the first group, forwards the name request to the identified parent group.

Spread spectrum time-resolved diffuse optical measurement system for enhanced sensitivity in detecting human brain activity

NASA Astrophysics Data System (ADS)

Mehta, Kalpesh; Hasnain, Ali; Zhou, Xiaowei; Luo, Jianwen; Penney, Trevor B.; Chen, Nanguang

2017-04-01

Diffuse optical spectroscopy (DOS) and imaging methods have been widely applied to noninvasive detection of brain activity. We have designed and implemented a low cost, portable, real-time one-channel time-resolved DOS system for neuroscience studies. Phantom experiments were carried out to test the performance of the system. We further conducted preliminary human experiments and demonstrated that enhanced sensitivity in detecting neural activity in the cortex could be achieved by the use of late arriving photons.

Space-time resolving vacuum ultraviolet spectrometer based on a rotating polyhedral mirror

NASA Astrophysics Data System (ADS)

Lin, Xiaodong; Xie, Jikang

2000-05-01

Using a rotating polyhedral mirror and a vacuum ultraviolet (VUV) monochromater, a space-time resolving VUV diagnostic system is developed. Measurement of the O VI (103.2 nm) radiation on the HT-6M tokamak shows that the time resolution of the system is better than 4 ms and the space resolution is better than 2 cm. Compared with traditional instruments, this system has improved measurement efficiency, and error from shot-to-shot discharge variations is avoided.

Use of a Prototype Airborne Separation Assurance System for Resolving Near-Term Conflicts During Autonomous Aircraft Operations

NASA Technical Reports Server (NTRS)

Barhydt, Richard; Eischeid, Todd M.; Palmer, Michael T.; Wing, David J.

2003-01-01

NASA is currently investigating a new concept of operations for the National Airspace System, designed to improve capacity while maintaining or improving current levels of safety. This concept, known as Distributed Air/Ground Traffic Management (DAGTM), allows appropriately equipped autonomous aircraft to maneuver freely for flight optimization while resolving conflicts with other traffic and staying out of special use airspace and hazardous weather. In order to perform these tasks, pilots use prototype conflict detection, prevention, and resolution tools, collectively known as an Airborne Separation Assurance System (ASAS). While ASAS would normally allow pilots to resolve conflicts before they become hazardous, evaluation of system performance in sudden, near-term conflicts is needed in order to determine concept feasibility. An experiment was conducted in NASA Langley's Air Traffic Operations Lab to evaluate the prototype ASAS for enabling pilots to resolve near-term conflicts and examine possible operational effects associated with the use of lower separation minimums. Sixteen commercial airline pilots flew a total of 32 traffic scenarios that required them to use prototype ASAS tools to resolve close range pop-up conflicts. Required separation standards were set at either 3 or 5 NM lateral spacing, with 1000 ft vertical separation being used for both cases. Reducing the lateral separation from 5 to 3 NM did not appear to increase operational risk, as indicated by the proximity to the intruder aircraft. Pilots performed better when they followed tactical guidance cues provided by ASAS than when they didn't follow the guidance. In an effort to improve compliance rate, ASAS design changes are currently under consideration. Further studies will of evaluate these design changes and consider integration issues between ASAS and existing Airborne Collision Avoidance Systems (ACAS).

A Multi-scale Modeling System with Unified Physics to Study Precipitation Processes

NASA Astrophysics Data System (ADS)

Tao, W. K.

2017-12-01

In recent years, exponentially increasing computer power has extended Cloud Resolving Model (CRM) integrations from hours to months, the number of computational grid points from less than a thousand to close to ten million. Three-dimensional models are now more prevalent. Much attention is devoted to precipitating cloud systems where the crucial 1-km scales are resolved in horizontal domains as large as 10,000 km in two-dimensions, and 1,000 x 1,000 km2 in three-dimensions. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that NWP and mesoscale model can be run in grid size similar to cloud resolving model through nesting technique. Recently, a multi-scale modeling system with unified physics was developed at NASA Goddard. It consists of (1) a cloud-resolving model (Goddard Cumulus Ensemble model, GCE model), (2) a regional scale model (a NASA unified weather research and forecast, WRF), and (3) a coupled CRM and global model (Goddard Multi-scale Modeling Framework, MMF). The same microphysical processes, long and short wave radiative transfer and land processes and the explicit cloud-radiation, and cloud-land surface interactive processes are applied in this multi-scale modeling system. This modeling system has been coupled with a multi-satellite simulator to use NASA high-resolution satellite data to identify the strengths and weaknesses of cloud and precipitation processes simulated by the model. In this talk, a review of developments and applications of the multi-scale modeling system will be presented. In particular, the results from using multi-scale modeling system to study the precipitation, processes and their sensitivity on model resolution and microphysics schemes will be presented. Also how to use of the multi-satellite simulator to improve precipitation processes will be discussed.

Frequency-resolved optical gating system with a tellurium crystal for characterizing free-electron lasers in the wavelength range of 10-30 {mu}m

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

Iijima, Hokuto; Nagai, Ryoji; Nishimori, Nobuyuki

2009-12-15

A second-harmonic generation frequency-resolved optical gating (SHG-FROG) system has been developed for the complete characterization of laser pulses in the wavelength range of 10-30 {mu}m. A tellurium crystal is used so that spectrally resolved autocorrelation signals with a good signal-to-noise ratio are obtained. Pulses (wavelength {approx}22 {mu}m) generated from a free-electron laser are measured by the SHG-FROG system. The SHG intensity profile and the spectrum obtained by FROG measurements are well consistent with those of independent measurements of the pulse length and spectrum. The pulse duration and spectral width determined from the FROG trace are 0.6 ps and 5.2 THzmore » at full width half maximum, respectively.« less

Time-resolved UV-excited microarray reader for fluorescence energy transfer (FRET) measurements

NASA Astrophysics Data System (ADS)

Orellana, Adelina; Hokkanen, Ari P.; Pastinen, Tomi; Takkinen, Kristina; Soderlund, Hans

2001-05-01

Analytical systems based on immunochemistry are largely used in medical diagnostics and in biotechnology. There is a significant pressure to develop the present assay formats to become easier to use, faster, and less reagent consuming. Further developments towards high density array--like multianalyte measurement systems would be valuable. To this aim we have studied the applicability of fluorescence resonance energy transfer and time-resolved fluorescence resonance energy transfer in immunoassays on microspots and in microwells. We have used engineered recombinant antibodies detecting the pentameric protein CRP as a model analyte system, and tested different assay formats. We describe also the construction of a time-resolved scanning epifluorometer with which we could measure the FRET interaction between the slow fluorescence decay from europium chelates and its energy transfer to the rapidly decaying fluorophore Cy5.

Efficient calculation of open quantum system dynamics and time-resolved spectroscopy with distributed memory HEOM (DM-HEOM).

PubMed

Kramer, Tobias; Noack, Matthias; Reinefeld, Alexander; Rodríguez, Mirta; Zelinskyy, Yaroslav

2018-06-11

Time- and frequency-resolved optical signals provide insights into the properties of light-harvesting molecular complexes, including excitation energies, dipole strengths and orientations, as well as in the exciton energy flow through the complex. The hierarchical equations of motion (HEOM) provide a unifying theory, which allows one to study the combined effects of system-environment dissipation and non-Markovian memory without making restrictive assumptions about weak or strong couplings or separability of vibrational and electronic degrees of freedom. With increasing system size the exact solution of the open quantum system dynamics requires memory and compute resources beyond a single compute node. To overcome this barrier, we developed a scalable variant of HEOM. Our distributed memory HEOM, DM-HEOM, is a universal tool for open quantum system dynamics. It is used to accurately compute all experimentally accessible time- and frequency-resolved processes in light-harvesting molecular complexes with arbitrary system-environment couplings for a wide range of temperatures and complex sizes. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Executing CLIPS expert systems in a distributed environment

NASA Technical Reports Server (NTRS)

Taylor, James; Myers, Leonard

1990-01-01

This paper describes a framework for running cooperating agents in a distributed environment to support the Intelligent Computer Aided Design System (ICADS), a project in progress at the CAD Research Unit of the Design Institute at the California Polytechnic State University. Currently, the systems aids an architectural designer in creating a floor plan that satisfies some general architectural constraints and project specific requirements. At the core of ICADS is the Blackboard Control System. Connected to the blackboard are any number of domain experts called Intelligent Design Tools (IDT). The Blackboard Control System monitors the evolving design as it is being drawn and helps resolve conflicts from the domain experts. The user serves as a partner in this system by manipulating the floor plan in the CAD system and validating recommendations made by the domain experts. The primary components of the Blackboard Control System are two expert systems executed by a modified CLIPS shell. The first is the Message Handler. The second is the Conflict Resolver. The Conflict Resolver synthesizes the suggestions made by the domain experts, which can be either CLIPS expert systems, or compiled C programs. In DEMO1, the current ICADS prototype, the CLIPS domain expert systems are Acoustics, Lighting, Structural, and Thermal; the compiled C domain experts are the CAD system and the User Interface.

42 CFR 51.32 - Resolving disputes.

Code of Federal Regulations, 2012 CFR

2012-10-01

... such as those involving negotiation, conciliation and mediation to resolve disputes early in the... process involving negotiation, mediation and conciliation. Consistent with State and Federal laws and... system shall be held to the standard of exhaustion of remedies provided under State and Federal law. The...

42 CFR 51.32 - Resolving disputes.

Code of Federal Regulations, 2014 CFR

2014-10-01

... such as those involving negotiation, conciliation and mediation to resolve disputes early in the... process involving negotiation, mediation and conciliation. Consistent with State and Federal laws and... system shall be held to the standard of exhaustion of remedies provided under State and Federal law. The...

42 CFR 51.32 - Resolving disputes.

Code of Federal Regulations, 2011 CFR

2011-10-01

... such as those involving negotiation, conciliation and mediation to resolve disputes early in the... process involving negotiation, mediation and conciliation. Consistent with State and Federal laws and... system shall be held to the standard of exhaustion of remedies provided under State and Federal law. The...

42 CFR 51.32 - Resolving disputes.

Code of Federal Regulations, 2013 CFR

2013-10-01

... such as those involving negotiation, conciliation and mediation to resolve disputes early in the... process involving negotiation, mediation and conciliation. Consistent with State and Federal laws and... system shall be held to the standard of exhaustion of remedies provided under State and Federal law. The...

Ada as an implementation language for knowledge based systems

NASA Technical Reports Server (NTRS)

Rochowiak, Daniel

1990-01-01

Debates about the selection of programming languages often produce cultural collisions that are not easily resolved. This is especially true in the case of Ada and knowledge based programming. The construction of programming tools provides a desirable alternative for resolving the conflict.

Iao: The New Adaptive Optics Visible Imaging and Photometric System for AEOS

DTIC Science & Technology

2008-09-01

observations of binary stars, asteroids and planets such as Mercury and Mars [2,3,4]. The Visible Imager is also used to take time resolved photometry ...role it takes high spatial resolution imagery of resolved targets. These targets are primarily low Earth orbiting satellites acquired for the...albedo pattern: Comparing the AEOS and TES data sets [5] D.T. Hall et al. 2007, Journal of Spacecraft and Rockets, 44, 910-919, Time - Resolved I-Band

Highly time-resolved imaging of combustion and pyrolysis product concentrations in solid fuel combustion: NO formation in a burning cigarette.

PubMed

Zimmermann, Ralf; Hertz-Schünemann, Romy; Ehlert, Sven; Liu, Chuan; McAdam, Kevin; Baker, Richard; Streibel, Thorsten

2015-02-03

The highly dynamic, heterogeneous combustion process within a burning cigarette was investigated by a miniaturized extractive sampling probe (microprobe) coupled to photoionization mass spectrometry using soft laser single photon ionization (SPI) for online real-time detection of molecular ions of combustion and pyrolysis products. Research cigarettes smoked by a smoking machine are used as a reproducible model system for solid-state biomass combustion, which up to now is not addressable by current combustion-diagnostic tools. By combining repetitively recorded online measurement sequences from different sampling locations in an imaging approach, highly time- and space-resolved quantitative distribution maps of, e.g., nitrogen monoxide, benzene, and oxygen concentrations were obtained at a near microscopic level. The obtained quantitative distribution maps represent a time-resolved, movie-like imaging of the respective compound's formation and destruction zones in the various combustion and pyrolysis regions of a cigarette during puffing. Furthermore, spatially resolved kinetic data were ascertainable. The here demonstrated methodology can also be applied to various heterogenic combustion/pyrolysis or reaction model systems, such as fossil- or biomass-fuel pellet combustion or to a positional resolved analysis of heterogenic catalytic reactions.

Graphics Processing Units (GPU) and the Goddard Earth Observing System atmospheric model (GEOS-5): Implementation and Potential Applications

NASA Technical Reports Server (NTRS)

Putnam, William M.

2011-01-01

Earth system models like the Goddard Earth Observing System model (GEOS-5) have been pushing the limits of large clusters of multi-core microprocessors, producing breath-taking fidelity in resolving cloud systems at a global scale. GPU computing presents an opportunity for improving the efficiency of these leading edge models. A GPU implementation of GEOS-5 will facilitate the use of cloud-system resolving resolutions in data assimilation and weather prediction, at resolutions near 3.5 km, improving our ability to extract detailed information from high-resolution satellite observations and ultimately produce better weather and climate predictions

Resolved shear stress intensity coefficient and fatigue crack growth in large crystals

NASA Technical Reports Server (NTRS)

Chen, Q.; Liu, H. W.

1988-01-01

Fatigue crack growth tests were carried out on large-grain Al 7029 aluminum alloy and the finite element method was used to calculate the stress field near the tip of a zigzag crack. The resolved shear stresses on all 12 slip systems were computed, and the resolved shear stress intensity coefficient (RSSIC) was defined. The RSSIC was used to analyze the irregular crack path and was correlated with the rate of single-slip-plane shear crack growth. Fatigue crack growth was found to be caused primarily by shear decohesion at a crack tip. When the RSSIC on a single-slip system was much larger than all the others, the crack followed a single-slip plane. When the RSSICs on two conjugate slip systems were comparable, a crack grew in a zigzag manner on these planes and the macrocrack-plane bisected the two active slip planes. The maximum RSSIC on the most active slip system is proposed as a parameter to correlate with the shear fatigue crack growth rate in large crystals.

Resolved Dual-Frequency Observations of the Debris Disk Around AU Mic: Strengths of Bodies in the Collisional Cascade

NASA Astrophysics Data System (ADS)

Carter, Evan; Hughes, A. Meredith; Daley, Cail; Flaherty, Kevin; Pan, Margaret; Schlichting, Hilke; Chiang, Eugene; MacGregor, Meredith Ann; Wilner, David; Dent, Bill; Carpenter, John; Andrews, Sean; Moor, Attila; Kospal, Agnes

2018-01-01

Debris disks are hallmarks of mature planetary systems, with second-generation dust produced via collisions between pluto-like planetesimals. The vertical structure of a debris disk encodes unique information about the dynamical state of the system, particularly at millimeter wavelengths where gravitational effects dominate over the effects of stellar radiation. We present 450 μm Atacama Large Millimeter/sub-millimeter Array (ALMA) observations of the edge-on debris disk around AU Mic, a nearby (d = 9.91 ± 0.10 pc) M1-type star. The 0.3'' angular resolution of the data allows us to spatially resolve the scale height of the disk, complementing previous observations at a wavelength of 1.3 mm. By resolving the vertical structure of the disk at these two widely-separated frequencies, we are able to spatially resolve the spectral index and study variations in the grain size distribution as a function of disk radius. The comparison of scale heights for two different wavelengths and therefore particle sizes also constrains the velocity dispersion as a function of grain size, which allows us to probe the strengths of bodies in the collisional cascade for the first time outside the Solar System.

Pinned, optically aligned diagnostic dock for use on the Z facility.

PubMed

Gomez, M R; Rochau, G A; Bailey, J E; Dunham, G S; Kernaghan, M D; Gard, P; Robertson, G K; Owen, A C; Argo, J W; Nielsen, D S; Lake, P W

2012-10-01

The pinned optically aligned diagnostic dock (PODD) is a multi-configuration diagnostic platform designed to measure x-ray emission on the Z facility. The PODD houses two plasma emission acquisition (PEA) systems, which are aligned with a set of precision machined pins. The PEA systems are modular, allowing a single diagnostic housing to support several different diagnostics. The PEA configurations fielded to date include both time-resolved and time-integrated, 1D spatially resolving, elliptical crystal spectrometers, and time-integrated, 1D spatially resolving, convex crystal spectrometers. Additional proposed configurations include time-resolved, monochromatic mirrored pinhole imagers and arrays of filtered x-ray diodes, diamond photo-conducting diode detectors, and bolometers. The versatility of the PODD system will allow the diagnostic configuration of the Z facility to be changed without significantly adding to the turn-around time of the machine. Additionally, the PODD has been designed to allow instrument setup to be completed entirely off-line, leaving only a refined alignment process to be performed just prior to a shot, which is a significant improvement over the instrument the PODD replaces. Example data collected with the PODD are presented.

Extrahepatic portosystemic shunt in congenital absence of the portal vein depicted by time-resolved contrast-enhanced MR angiography.

PubMed

Goo, Hyun Woo

2007-07-01

Congenital absence of the portal vein is a rare malformation in which mesenteric and splenic venous flow bypasses the liver and drains into various sites in the systemic venous system via an extrahepatic portosystemic shunt. In an 11-year-old girl with congenital absence of the portal vein, the detailed anatomy of the extrahepatic portosystemic shunt is demonstrated by time-resolved contrast-enhanced MR angiography.

New developments in laser-based photoemission spectroscopy and its scientific applications: a key issues review

NASA Astrophysics Data System (ADS)

Zhou, Xingjiang; He, Shaolong; Liu, Guodong; Zhao, Lin; Yu, Li; Zhang, Wentao

2018-06-01

The significant progress in angle-resolved photoemission spectroscopy (ARPES) in last three decades has elevated it from a traditional band mapping tool to a precise probe of many-body interactions and dynamics of quasiparticles in complex quantum systems. The recent developments of deep ultraviolet (DUV, including ultraviolet and vacuum ultraviolet) laser-based ARPES have further pushed this technique to a new level. In this paper, we review some latest developments in DUV laser-based photoemission systems, including the super-high energy and momentum resolution ARPES, the spin-resolved ARPES, the time-of-flight ARPES, and the time-resolved ARPES. We also highlight some scientific applications in the study of electronic structure in unconventional superconductors and topological materials using these state-of-the-art DUV laser-based ARPES. Finally we provide our perspectives on the future directions in the development of laser-based photoemission systems.

Software defined photon counting system for time resolved x-ray experiments.

PubMed

Acremann, Y; Chembrolu, V; Strachan, J P; Tyliszczak, T; Stöhr, J

2007-01-01

The time structure of synchrotron radiation allows time resolved experiments with sub-100 ps temporal resolution using a pump-probe approach. However, the relaxation time of the samples may require a lower repetition rate of the pump pulse compared to the full repetition rate of the x-ray pulses from the synchrotron. The use of only the x-ray pulse immediately following the pump pulse is not efficient and often requires special operation modes where only a few buckets of the storage ring are filled. We designed a novel software defined photon counting system that allows to implement a variety of pump-probe schemes at the full repetition rate. The high number of photon counters allows to detect the response of the sample at multiple time delays simultaneously, thus improving the efficiency of the experiment. The system has been successfully applied to time resolved scanning transmission x-ray microscopy. However, this technique is applicable more generally.

Parallel, Asynchronous Executive (PAX): System concepts, facilities, and architecture

NASA Technical Reports Server (NTRS)

Jones, W. H.

1983-01-01

The Parallel, Asynchronous Executive (PAX) is a software operating system simulation that allows many computers to work on a single problem at the same time. PAX is currently implemented on a UNIVAC 1100/42 computer system. Independent UNIVAC runstreams are used to simulate independent computers. Data are shared among independent UNIVAC runstreams through shared mass-storage files. PAX has achieved the following: (1) applied several computing processes simultaneously to a single, logically unified problem; (2) resolved most parallel processor conflicts by careful work assignment; (3) resolved by means of worker requests to PAX all conflicts not resolved by work assignment; (4) provided fault isolation and recovery mechanisms to meet the problems of an actual parallel, asynchronous processing machine. Additionally, one real-life problem has been constructed for the PAX environment. This is CASPER, a collection of aerodynamic and structural dynamic problem simulation routines. CASPER is not discussed in this report except to provide examples of parallel-processing techniques.

ALMA 1.3 Millimeter Map of the HD 95086 System -- A Young Analog of the HR 8799 System

NASA Astrophysics Data System (ADS)

Su, Kate; MacGregor, Meredith Ann; Booth, Mark; Wilner, David; Malhotra, Renu; Morrison, Sarah; OST STDT

2018-01-01

Planets and minor bodies such as asteroids, Kuiper-belt objects and comets are integral components of a planetary system. Interactions among them leave clues about the formation process of a planetary system. The signature of such interactions is best illustrated through resolved observations of its debris disk. Here we present ALMA 1.3 mm observations of HD 95086, a young analog of the HR 8799 system, that hosts a directly imaged giant planet b and a massive debris disk with both asteroid- and Kuiper-belt analogs. The location of the Kuiper-belt analog is resolved for the first time. Our deep ALMA map also reveals a bright source located near the edge of the ring. The properties of the source, based on limited data, are consistent with it being a luminous star-forming galaxy at high redshift. We will discuss future, resolved observations of debris disks, highlighting the potential of the Origins Space Telescope (OST), one of the four science and technology definition studies commissioned by NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey.

48 CFR 2052.242-70 - Resolving differing professional views.

Code of Federal Regulations, 2010 CFR

2010-10-01

... resolution of differing professional views (DPVs) of health and safety related concerns associated with the... professional views. 2052.242-70 Section 2052.242-70 Federal Acquisition Regulations System NUCLEAR REGULATORY....242-70 Resolving differing professional views. As prescribed in 2042.570-1, the contracting officer...

Continued Development of Internet Protocols under the IBM OS/MVS operating System

DTIC Science & Technology

1986-03-10

this contract, the UCLA Office of Academic Computing (OAC) continued its participation in the Internet research effort of * DARPA. OAC’s effort has...is adapted and condensed from TR51. 1.2 NAME RESOLVER The Internet research community is installing a system of name resolvers and name servers...several attributes favoring their use within the ACP. • The "C" language is heavily used within the DARPA Internet research community, giving it an

Orientation and temperature dependence of some mechanical properties of the single-crystal nickel-base superalloy Rene N4. I - Tensile behavior

NASA Technical Reports Server (NTRS)

Miner, R. V.; Gayda, J.; Gabb, T. P.; Voigt, R. C.

1986-01-01

Single crystal specimens of a nickel-base superalloy with axes near 001, 011, and -112 were tested in tension at room temperature, 760, and 980 C. The alloy Rene N-4, was developed for gas turbine engine blades and has the nominal composition 3.7 Al, 4.2 Ti, 4 Ta, 0.5 Nb, 6 W, 1.5 Mo, 9 Cr, 7.5 Co, balance Ni, (all in weight percent). Analysis of slip band traces, specimen axis rotation, and dislocation Burgers vectors showed that at 760 and 980 C primary cube slip supplanted normal octahedral slip for the -112 line-oriented specimens. The other two orientations, which have lower resolved shear stresses on the cube system, exhibited octahedral slip at all three temperatures. The critical resolved shear stress is considerably greater on the cube system than on the octahedral system at room temperature. However, at 760 and 980 C the critical resolved shear stresses on the two systems are about the same. While the room temperature and 980 C yield strengths for the two orientations exhibiting octahedral slip could be rationalized on the basis of resolved shear stress, those at 760 C could not. Such violations of Schmid's law have previously been observed in other superalloys and single phase gamma-prime.

Enhanced visible and near-infrared capabilities of the JET mirror-linked divertor spectroscopy system

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

Lomanowski, B. A., E-mail: b.a.lomanowski@durham.ac.uk; Sharples, R. M.; Meigs, A. G.

2014-11-15

The mirror-linked divertor spectroscopy diagnostic on JET has been upgraded with a new visible and near-infrared grating and filtered spectroscopy system. New capabilities include extended near-infrared coverage up to 1875 nm, capturing the hydrogen Paschen series, as well as a 2 kHz frame rate filtered imaging camera system for fast measurements of impurity (Be II) and deuterium Dα, Dβ, Dγ line emission in the outer divertor. The expanded system provides unique capabilities for studying spatially resolved divertor plasma dynamics at near-ELM resolved timescales as well as a test bed for feasibility assessment of near-infrared spectroscopy.

RESOLVE's Field Demonstration on Mauna Kea, Hawaii 2010

NASA Technical Reports Server (NTRS)

Captain, Janine; Quinn, Jacqueline; Moss, Thomas; Weis, Kyle

2010-01-01

In cooperation with the Canadian Space Agency, and the Northern Centre for Advanced Technology, Inc., NASA has undertaken the In-Situ Resource Utilization (ISRU) project called RESOLVE (Regolith and Environment Science & Oxygen and Lunar Volatile Extraction). This project is an Earth-based lunar precursor demonstration of a system that could be sent to explore permanently shadowed polar lunar craters, where it would drill into regolith, quantify the volatiles that are present, and extract oxygen by hydrogen reduction of iron oxides. The resulting water could be electrolyzed into oxygen to support exploration and hydrogen, which would be recycled through the process. The RESOLVE chemical processing system was mounted on a Canadian Space Agency mobility chasis and successfully demonstrated on Hawaii's Mauna Kea volcano in February 2010. The RESOLVE unit is the initial prototype of a robotic prospecting mission to the Moon. RESOLVE is designed to go to the poles of the Moon to "ground truth" the form and concentration of the hydrogen/water/hydroxyl that has been seen from orbit (M3, Lunar Prospector and LRO) and to test technologies to extract oxygen from the lunar regolith. RESOLVE has the ability to capture a one-meter core sample of lunar regolith and heat it to determine the volatiles that may be released and then demonstrate the production of oxygen from minerals found in the regolith. The RESOLVE project, which is led by KSC, is a multi-center and multi-organizational effort that includes representatives from KSC, JSC, GRC, the Canadian Space Agency, and the Northern Center for Advanced Technology (NORCAT). This paper details the results obtained from four days of lunar analog testing that included gas chromatograph analysis for volatile components, remote control of chemistry and drilling operations via satalite communications, and real-time water quantification using a novel capacitance measurement technique.

Selective identification of specialized pro-resolving lipid mediators from their biosynthetic double di-oxygenation isomers.

PubMed

Hansen, Trond V; Dalli, Jesmond; Serhan, Charles N

The n-3 polyunsaturated fatty acids are substrates for lipoxygenases and cyclooxygenases. During inflammatory processes, these enzymes form several distinct families of oxygenated polyunsaturated fatty acids coined specialized pro-resolving lipid mediators. Structural elucidation of these natural products using LC-MS/MS based metabololipidomics with the pico- to nanogram amounts of biosynthetic material available have been performed. The specialized pro-resolving lipid mediators display stereospecific and potent anti-inflammatory and pro-resolving actions. Most often the different families among these mediators are chemically characterized by two or three chiral, secondary alcohols, separated by either an E,E,Z -triene or an E,Z,E,E -tetraenemoiety. The lipoxygenases also form other oxygenated polyunsaturated natural products, coined double di-oxygenation products, that are constitutional isomers of the protectin and maresin families of specialized pro-resolving lipid mediators. Very often these products exhibit similar chromatographic properties and mass spectrometrical fragment ions as the pro-resolving mediators. In addition, the double di-oxygenation products are sometimes formed in larger amounts than the specialized pro-resolving lipid mediators. Thus, it is not always possible to distinguish between the specialized pro-resolving mediators and their double di-oxygenation isomers in biological systems, using LC/MS-based techniques. Herein, a convenient and easy-to-use protocol to meet this challenge is presented.

Effects of multiple scattering on time- and depth-resolved signals in airborne lidar systems

NASA Technical Reports Server (NTRS)

Punjabi, A.; Venable, D. D.

1986-01-01

A semianalytic Monte Carlo radiative transfer model (SALMON) is employed to probe the effects of multiple-scattering events on the time- and depth-resolved lidar signals from homogeneous aqueous media. The effective total attenuation coefficients in the single-scattering approximation are determined as functions of dimensionless parameters characterizing the lidar system and the medium. Results show that single-scattering events dominate when these parameters are close to their lower bounds and that when their values exceed unity multiple-scattering events dominate.

Zebra Stripes through the Eyes of Their Predators, Zebras, and Humans.

PubMed

Melin, Amanda D; Kline, Donald W; Hiramatsu, Chihiro; Caro, Tim

2016-01-01

The century-old idea that stripes make zebras cryptic to large carnivores has never been examined systematically. We evaluated this hypothesis by passing digital images of zebras through species-specific spatial and colour filters to simulate their appearance for the visual systems of zebras' primary predators and zebras themselves. We also measured stripe widths and luminance contrast to estimate the maximum distances from which lions, spotted hyaenas, and zebras can resolve stripes. We found that beyond ca. 50 m (daylight) and 30 m (twilight) zebra stripes are difficult for the estimated visual systems of large carnivores to resolve, but not humans. On moonless nights, stripes are difficult for all species to resolve beyond ca. 9 m. In open treeless habitats where zebras spend most time, zebras are as clearly identified by the lion visual system as are similar-sized ungulates, suggesting that stripes cannot confer crypsis by disrupting the zebra's outline. Stripes confer a minor advantage over solid pelage in masking body shape in woodlands, but the effect is stronger for humans than for predators. Zebras appear to be less able than humans to resolve stripes although they are better than their chief predators. In conclusion, compared to the uniform pelage of other sympatric herbivores it appears highly unlikely that stripes are a form of anti-predator camouflage.

Phase-ambiguity resolution for QPSK modulation systems. Part 2: A method to resolve offset QPSK

NASA Technical Reports Server (NTRS)

Nguyen, Tien Manh

1989-01-01

Part 2 presents a new method to resolve the phase-ambiguity for Offset QPSK modulation systems. When an Offset Quaternary Phase-Shift-Keyed (OQPSK) communications link is utilized, the phase ambiguity of the reference carrier must be resolved. At the transmitter, two different unique words are separately modulated onto the quadrature carriers. At the receiver, the recovered carrier may have one of four possible phases, 0, 90, 180, or 270 degrees, referenced to the nominally correct phase. The IF portion of the channel may cause a phase-sense reversal, i.e., a reversal in the direction of phase rotation for a specified bit pattern. Hence, eight possible phase relationships (the so-called eight ambiguous phase conditions) between input and output of the demodulator must be resolved. Using the In-phase (I)/Quadrature (Q) channel reversal correcting property of an OQPSK Costas loop with integrated symbol synchronization, four ambiguous phase conditions are eliminated. Thus, only four possible ambiguous phase conditions remain. The errors caused by the remaining ambiguous phase conditions can be corrected by monitoring and detecting the polarity of the two unique words. The correction of the unique word polarities results in the complete phase-ambiguity resolution for the OQPSK system.

Polarization resolved angular optical scattering of aerosol particles

NASA Astrophysics Data System (ADS)

Redding, B.; Pan, Y.; Wang, C.; Videen, G.; Cao, Hui

2014-05-01

Real-time detection and identification of bio-aerosol particles are crucial for the protection against chemical and biological agents. The strong elastic light scattering properties of airborne particles provides a natural means for rapid, non-invasive aerosol characterization. Recent theoretical predictions suggested that variations in the polarization dependent angular scattering cross section could provide an efficient means of classifying different airborne particles. In particular, the polarization dependent scattering cross section of aggregate particles is expected to depend on the shape of the primary particles. In order to experimentally validate this prediction, we built a high throughput, sampling system, capable of measuring the polarization resolved angular scattering cross section of individual aerosol particles flowing through an interrogating volume with a single shot of laser pulse. We calibrated the system by comparing the polarization dependent scattering cross section of individual polystyrene spheres with that predicted by Mie theory. We then used the system to study different particles types: Polystyrene aggregates composed 500 nm spheres and Bacillus subtilis (BG, Anthrax simulant) spores composed of elongated 500 nm × 1000 nm cylinder-line particles. We found that the polarization resolved scattering cross section depends on the shape of the constituent elements of the aggregates. This work indicates that the polarization resolved scattering cross section could be used for rapid discrimination between different bio-aerosol particles.

Resonance fluorescence in the resolvent-operator formalism

NASA Astrophysics Data System (ADS)

Debierre, V.; Harman, Z.

2017-10-01

The Mollow spectrum for the light scattered by a driven two-level atom is derived in the resolvent operator formalism. The derivation is based on the construction of a master equation from the resolvent operator of the atom-field system. We show that the natural linewidth of the excited atomic level remains essentially unmodified, to a very good level of approximation, even in the strong-field regime, where Rabi flopping becomes relevant inside the self-energy loop that yields the linewidth. This ensures that the obtained master equation and the spectrum derived matches that of Mollow.

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

Steele, Amy; Hughes, A. Meredith; Carpenter, John

The presence of debris disks around young main-sequence stars hints at the existence and structure of planetary systems. Millimeter-wavelength observations probe large grains that trace the location of planetesimal belts. The Formation and Evolution of Planetary Systems Spitzer Legacy survey of nearby young solar analogues yielded a sample of five debris disk-hosting stars with millimeter flux suitable for interferometric follow-up. We present observations with the Submillimeter Array (SMA) and the Combined Array for Research in Millimeter-wave Astronomy at ∼2″ resolution that spatially resolve the debris disks around these nearby (d ∼ 50 pc) stars. Two of the five disks (HDmore » 377, HD 8907) are spatially resolved for the first time and one (HD 104860) is resolved at millimeter wavelengths for the first time. We combine our new observations with archival SMA and Atacama Large Millimeter/Submillimeter Array data to enable a uniform analysis of the full five-object sample. We simultaneously model the broadband photometric data and resolved millimeter visibilities to constrain the dust temperatures and disk morphologies, and perform a Markov Chain Monte Carlo analysis to fit for basic structural parameters. We find that the radii and widths of the cold outer belts exhibit properties consistent with scaled-up versions of the Solar System's Kuiper Belt. All the disks exhibit characteristic grain sizes comparable to the blowout size, and all the resolved observations of emission from large dust grains are consistent with an axisymmetric dust distribution to within the uncertainties. These results are consistent with comparable studies carried out at infrared wavelengths.« less

Theory of time-resolved photoelectron imaging. Comparison of a density functional with a time-dependent density functional approach

NASA Astrophysics Data System (ADS)

Suzuki, Yoshi-ichi; Seideman, Tamar; Stener, Mauro

2004-01-01

Time-resolved photoelectron differential cross sections are computed within a quantum dynamical theory that combines a formally exact solution of the nuclear dynamics with density functional theory (DFT)-based approximations of the electronic dynamics. Various observables of time-resolved photoelectron imaging techniques are computed at the Kohn-Sham and at the time-dependent DFT levels. Comparison of the results serves to assess the reliability of the former method and hence its usefulness as an economic approach for time-domain photoelectron cross section calculations, that is applicable to complex polyatomic systems. Analysis of the matrix elements that contain the electronic dynamics provides insight into a previously unexplored aspect of femtosecond-resolved photoelectron imaging.

Scanning photoelectron microscope for nanoscale three-dimensional spatial-resolved electron spectroscopy for chemical analysis.

PubMed

Horiba, K; Nakamura, Y; Nagamura, N; Toyoda, S; Kumigashira, H; Oshima, M; Amemiya, K; Senba, Y; Ohashi, H

2011-11-01

In order to achieve nondestructive observation of the three-dimensional spatially resolved electronic structure of solids, we have developed a scanning photoelectron microscope system with the capability of depth profiling in electron spectroscopy for chemical analysis (ESCA). We call this system 3D nano-ESCA. For focusing the x-ray, a Fresnel zone plate with a diameter of 200 μm and an outermost zone width of 35 nm is used. In order to obtain the angular dependence of the photoelectron spectra for the depth-profile analysis without rotating the sample, we adopted a modified VG Scienta R3000 analyzer with an acceptance angle of 60° as a high-resolution angle-resolved electron spectrometer. The system has been installed at the University-of-Tokyo Materials Science Outstation beamline, BL07LSU, at SPring-8. From the results of the line-scan profiles of the poly-Si/high-k gate patterns, we achieved a total spatial resolution better than 70 nm. The capability of our system for pinpoint depth-profile analysis and high-resolution chemical state analysis is demonstrated. © 2011 American Institute of Physics

Forecasting the absolute and relative shortage of physicians in Japan using a system dynamics model approach

PubMed Central

2013-01-01

Background In Japan, a shortage of physicians, who serve a key role in healthcare provision, has been pointed out as a major medical issue. The healthcare workforce policy planner should consider future dynamic changes in physician numbers. The purpose of this study was to propose a physician supply forecasting methodology by applying system dynamics modeling to estimate future absolute and relative numbers of physicians. Method We constructed a forecasting model using a system dynamics approach. Forecasting the number of physician was performed for all clinical physician and OB/GYN specialists. Moreover, we conducted evaluation of sufficiency for the number of physicians and sensitivity analysis. Result & conclusion As a result, it was forecast that the number of physicians would increase during 2008–2030 and the shortage would resolve at 2026 for all clinical physicians. However, the shortage would not resolve for the period covered. This suggests a need for measures for reconsidering the allocation system of new entry physicians to resolve maldistribution between medical departments, in addition, for increasing the overall number of clinical physicians. PMID:23981198

Forecasting the absolute and relative shortage of physicians in Japan using a system dynamics model approach.

PubMed

Ishikawa, Tomoki; Ohba, Hisateru; Yokooka, Yuki; Nakamura, Kozo; Ogasawara, Katsuhiko

2013-08-27

In Japan, a shortage of physicians, who serve a key role in healthcare provision, has been pointed out as a major medical issue. The healthcare workforce policy planner should consider future dynamic changes in physician numbers. The purpose of this study was to propose a physician supply forecasting methodology by applying system dynamics modeling to estimate future absolute and relative numbers of physicians. We constructed a forecasting model using a system dynamics approach. Forecasting the number of physician was performed for all clinical physician and OB/GYN specialists. Moreover, we conducted evaluation of sufficiency for the number of physicians and sensitivity analysis. As a result, it was forecast that the number of physicians would increase during 2008-2030 and the shortage would resolve at 2026 for all clinical physicians. However, the shortage would not resolve for the period covered. This suggests a need for measures for reconsidering the allocation system of new entry physicians to resolve maldistribution between medical departments, in addition, for increasing the overall number of clinical physicians.

Evaluation of the Community Multiscale Air Quality (CMAQ) modeling system against size-resolved measurements of inorganic particle composition across sites in North America

EPA Science Inventory

This work evaluates particle size-composition distributions simulated by the Community Multiscale Air Quality (CMAQ) model using Micro-Orifice Uniform Deposit Impactor (MOUDI) measurements at 18 sites across North America. Size-resolved measurements of particulate SO₄<...

Time-resolved fluorescence microscopy to study biologically related applications using sol-gel derived and cellular media

NASA Astrophysics Data System (ADS)

Toury, Marion; Chandler, Lin; Allison, Archie; Campbell, David; McLoskey, David; Holmes-Smith, A. Sheila; Hungerford, Graham

2011-03-01

Fluorescence microscopy provides a non-invasive means for visualising dynamic protein interactions. As well as allowing the calculation of kinetic processes via the use of time-resolved fluorescence, localisation of the protein within cells or model systems can be monitored. These fluorescence lifetime images (FLIM) have become the preferred technique for elucidating protein dynamics due to the fact that the fluorescence lifetime is an absolute measure, in the main independent of fluorophore concentration and intensity fluctuations caused by factors such as photobleaching. In this work we demonstrate the use of a time-resolved fluorescence microscopy, employing a high repetition rate laser excitation source applied to study the influence of a metal surface on fluorescence tagged protein and to elucidate viscosity using the fluorescence lifetime probe DASPMI. These were studied in a cellular environment (yeast) and in a model system based on a sol-gel derived material, in which silver nanostructures were formed in situ using irradiation from a semiconductor laser in CW mode incorporated on a compact time-resolved fluorescence microscope (HORIBA Scientific DeltaDiode and DynaMyc).

Portable double-sided pulsed laser heating system for time-resolved geoscience and materials science applications.

PubMed

Aprilis, G; Strohm, C; Kupenko, I; Linhardt, S; Laskin, A; Vasiukov, D M; Cerantola, V; Koemets, E G; McCammon, C; Kurnosov, A; Chumakov, A I; Rüffer, R; Dubrovinskaia, N; Dubrovinsky, L

2017-08-01

A portable double-sided pulsed laser heating system for diamond anvil cells has been developed that is able to stably produce laser pulses as short as a few microseconds with repetition frequencies up to 100 kHz. In situ temperature determination is possible by collecting and fitting the thermal radiation spectrum for a specific wavelength range (particularly, between 650 nm and 850 nm) to the Planck radiation function. Surface temperature information can also be time-resolved by using a gated detector that is synchronized with the laser pulse modulation and space-resolved with the implementation of a multi-point thermal radiation collection technique. The system can be easily coupled with equipment at synchrotron facilities, particularly for nuclear resonance spectroscopy experiments. Examples of applications include investigations of high-pressure high-temperature behavior of iron oxides, both in house and at the European Synchrotron Radiation Facility using the synchrotron Mössbauer source and nuclear inelastic scattering.

Classification of Clouds and Deep Convection from GEOS-5 Using Satellite Observations

NASA Technical Reports Server (NTRS)

Putman, William; Suarez, Max

2010-01-01

With the increased resolution of global atmospheric models and the push toward global cloud resolving models, the resemblance of model output to satellite observations has become strikingly similar. As we progress with our adaptation of the Goddard Earth Observing System Model, Version 5 (GEOS-5) as a high resolution cloud system resolving model, evaluation of cloud properties and deep convection require in-depth analysis beyond a visual comparison. Outgoing long-wave radiation (OLR) provides a sufficient comparison with infrared (IR) satellite imagery to isolate areas of deep convection. We have adopted a binning technique to generate a series of histograms for OLR which classify the presence and fraction of clear sky versus deep convection in the tropics that can be compared with a similar analyses of IR imagery from composite Geostationary Operational Environmental Satellite (GOES) observations. We will present initial results that have been used to evaluate the amount of deep convective parameterization required within the model as we move toward cloud system resolving resolutions of 10- to 1-km globally.

Electronic structure of heavy fermion system CePt 2In 7 from angle-resolved photoemission spectroscopy

DOE PAGES

Shen, Bing; Yu, Li; Liu, Kai; ...

2017-06-01

We have carried out high-resolution angle-resolved photoemission measurements on the Cebased heavy fermion compound CePt 2In 7 that exhibits stronger two-dimensional character than the prototypical heavy fermion system CeCoIn 5. Multiple Fermi surface sheets and a complex band structure are clearly resolved. We have also performed detailed band structure calculations on CePt 2In 7. The good agreement found between our measurements and the calculations suggests that the band renormalization effect is rather weak in CePt 2In 7. A comparison of the common features of the electronic structure of CePt 2In 7 and CeCoIn5 indicates that CeCoIn 5 shows a muchmore » stronger band renormalization effect than CePt 2In 7. These results provide new information for understanding the heavy fermion behaviors and unconventional superconductivity in Ce-based heavy fermion systems.« less

Automated Conflict Resolution For Air Traffic Control

NASA Technical Reports Server (NTRS)

Erzberger, Heinz

2005-01-01

The ability to detect and resolve conflicts automatically is considered to be an essential requirement for the next generation air traffic control system. While systems for automated conflict detection have been used operationally by controllers for more than 20 years, automated resolution systems have so far not reached the level of maturity required for operational deployment. Analytical models and algorithms for automated resolution have been traffic conditions to demonstrate that they can handle the complete spectrum of conflict situations encountered in actual operations. The resolution algorithm described in this paper was formulated to meet the performance requirements of the Automated Airspace Concept (AAC). The AAC, which was described in a recent paper [1], is a candidate for the next generation air traffic control system. The AAC's performance objectives are to increase safety and airspace capacity and to accommodate user preferences in flight operations to the greatest extent possible. In the AAC, resolution trajectories are generated by an automation system on the ground and sent to the aircraft autonomously via data link .The algorithm generating the trajectories must take into account the performance characteristics of the aircraft, the route structure of the airway system, and be capable of resolving all types of conflicts for properly equipped aircraft without requiring supervision and approval by a controller. Furthermore, the resolution trajectories should be compatible with the clearances, vectors and flight plan amendments that controllers customarily issue to pilots in resolving conflicts. The algorithm described herein, although formulated specifically to meet the needs of the AAC, provides a generic engine for resolving conflicts. Thus, it can be incorporated into any operational concept that requires a method for automated resolution, including concepts for autonomous air to air resolution.

Resolvent-based modeling of passive scalar dynamics in wall-bounded turbulence

NASA Astrophysics Data System (ADS)

Dawson, Scott; Saxton-Fox, Theresa; McKeon, Beverley

2017-11-01

The resolvent formulation of the Navier-Stokes equations expresses the system state as the output of a linear (resolvent) operator acting upon a nonlinear forcing. Previous studies have demonstrated that a low-rank approximation of this linear operator predicts many known features of incompressible wall-bounded turbulence. In this work, this resolvent model for wall-bounded turbulence is extended to include a passive scalar field. This formulation allows for a number of additional simplifications that reduce model complexity. Firstly, it is shown that the effect of changing scalar diffusivity can be approximated through a transformation of spatial wavenumbers and temporal frequencies. Secondly, passive scalar dynamics may be studied through the low-rank approximation of a passive scalar resolvent operator, which is decoupled from velocity response modes. Thirdly, this passive scalar resolvent operator is amenable to approximation by semi-analytic methods. We investigate the extent to which this resulting hierarchy of models can describe and predict passive scalar dynamics and statistics in wall-bounded turbulence. The support of AFOSR under Grant Numbers FA9550-16-1-0232 and FA9550-16-1-0361 is gratefully acknowledged.

High time resolved electron temperature measurements by using the multi-pass Thomson scattering system in GAMMA 10/PDX.

PubMed

Yoshikawa, Masayuki; Yasuhara, Ryo; Ohta, Koichi; Chikatsu, Masayuki; Shima, Yoriko; Kohagura, Junko; Sakamoto, Mizuki; Nakashima, Yousuke; Imai, Tsuyoshi; Ichimura, Makoto; Yamada, Ichihiro; Funaba, Hisamichi; Minami, Takashi

2016-11-01

High time resolved electron temperature measurements are useful for fluctuation study. A multi-pass Thomson scattering (MPTS) system is proposed for the improvement of both increasing the TS signal intensity and time resolution. The MPTS system in GAMMA 10/PDX has been constructed for enhancing the Thomson scattered signals for the improvement of measurement accuracy. The MPTS system has a polarization-based configuration with an image relaying system. We optimized the image relaying optics for improving the multi-pass laser confinement and obtaining the stable MPTS signals over ten passing TS signals. The integrated MPTS signals increased about five times larger than that in the single pass system. Finally, time dependent electron temperatures were obtained in MHz sampling.

Promoting Health by Addressing Basic Needs: Effect of Problem Resolution on Contacting Health Referrals.

PubMed

Thompson, Tess; Kreuter, Matthew W; Boyum, Sonia

2016-04-01

Members of vulnerable populations have heightened needs for health services. One advantage of integrating health risk assessment and referrals into social service assistance systems such as 2-1-1 is that such systems help callers resolve problems in other areas (e.g., housing). Callers to 2-1-1 in Missouri (N= 1,090) with at least one behavioral risk factor or cancer screening need were randomly assigned to one of three health referral interventions: verbal referrals only, verbal referrals + a tailored mailed reminder, or verbal referrals + telephone health navigator. After 1 month, we assessed whether the nonhealth problems that prompted the 2-1-1 call had been resolved. Logistic regression estimated effects of having the problem resolved on calling a health referral. Callers were predominantly female (85%) and had a high school education or less (61%); nearly half (47%) had incomes under $10,000. The most common service requests were for utility assistance (35%), home/family problems (23%), and rent/mortgage assistance (12%). At follow-up, 38% of callers reported that all problems prompting their 2-1-1 call had been resolved, and 24% reported calling a health referral. Resolving all problems prompting the 2-1-1 call was associated with a higher odds of contacting a health referral (odds ratio = 1.44, 95% confidence interval [1.02, 2.05]) compared to people whose problems were not resolved. Multifaceted interventions that help meet non-health-related needs and provide support in reaching health-related goals may promote health in vulnerable populations. © 2015 Society for Public Health Education.

Promoting Health by Addressing Basic Needs: Effect of Problem Resolution on Contacting Health Referrals

PubMed Central

Thompson, Tess; Kreuter, Matthew; Boyum, Sonia

2016-01-01

Members of vulnerable populations have heightened needs for health services. One advantage of integrating health risk assessment and referrals into social service assistance systems such as 2-1-1 is that such systems help callers resolve problems in other areas (e.g. housing). Callers to 2-1-1 in Missouri (N=1090) with at least one behavioral risk factor or cancer screening need were randomly assigned to one of three health referral interventions: verbal referrals only, verbal referrals + a tailored mailed reminder, or verbal referrals + telephone health navigator. After one month, we assessed whether the non-health problems that prompted the 2-1-1 call had been resolved. Logistic regression estimated effects of having the problem resolved on calling a health referral. Callers were predominantly female (85%) and had a high school education or less (61%); nearly half (47%) had incomes under $10,000. The most common service requests were for utility assistance (35%), home/family problems (23%), and rent/mortgage assistance (12%). At follow-up, 38% of callers reported that all problems prompting their 2-1-1 call had been resolved, and 24% reported calling a health referral. Resolving all problems prompting the 2-1-1 call was associated with a higher odds of contacting a health referral (OR = 1.44, 95% CI 1.02-2.05) compared to people whose problems were not resolved. Multifaceted interventions that help meet non-health-related needs and provide support in reaching health-related goals may promote health in vulnerable populations. PMID:26293458

20 CFR 658.412 - Complaint resolution.

Code of Federal Regulations, 2010 CFR

2010-04-01

... GOVERNING THE JOB SERVICE SYSTEM Job Service Complaint System State Agency Js Complaint System § 658.412 Complaint resolution. (a) A JS-related complaint is resolved when: (1) The complainant indicates...

Application of the Group Foliation Method to the Complex Monge-Ampère Equation

NASA Astrophysics Data System (ADS)

Nutku, Y.; Sheftel, M. B.

2001-04-01

We apply the method of group foliation to the complex Monge-Ampère equation ( CMA 2) to establish a regular framework for finding its non-invariant solutions. We employ an infinite symmetry subgroup of CMA 2 to produce a foliation of the solution space into orbits of solutions with respect to this group and a corresponding splitting of CMA 2 into an automorphic system and a resolvent system. We propose a new approach to group foliation which is based on the commutator algebra of operators of invariant differentiation. This algebra together with its Jacobi identities provides the commutator representation of the resolvent system.

Time-resolved energy spectrum measurement of a linear induction accelerator with the magnetic analyzer

NASA Astrophysics Data System (ADS)

Wang, Yuan; Jiang, Xiao-Guo; Yang, Guo-Jun; Chen, Si-Fu; Zhang, Zhuo; Wei, Tao; Li, Jin

2015-01-01

We recently set up a time-resolved optical beam diagnostic system. Using this system, we measured the high current electron beam energy in the accelerator under construction. This paper introduces the principle of the diagnostic system, describes the setup, and shows the results. A bending beam line was designed using an existing magnetic analyzer with a 300 mm-bending radius and a 60° bending angle at hard-edge approximation. Calculations show that the magnitude of the beam energy is about 18 MeV, and the energy spread is within 2%. Our results agree well with the initial estimates deduced from the diode voltage approach.

Selection, Development and Results for The RESOLVE Regolith Volatiles Characterization Analytical System

NASA Technical Reports Server (NTRS)

Lueck, Dale E.; Captain, Janine E.; Gibson, Tracy L.; Peterson, Barbara V.; Berger, Cristina M.; Levine, Lanfang

2008-01-01

The RESOLVE project requires an analytical system to identify and quantitate the volatiles released from a lunar drill core sample as it is crushed and heated to 150 C. The expected gases and their range of concentrations were used to assess Gas Chromatography (GC) and Mass Spectrometry (MS), along with specific analyzers for use on this potential lunar lander. The ability of these systems to accurately quantitate water and hydrogen in an unknown matrix led to the selection of a small MEMS commercial process GC for use in this project. The modification, development and testing of this instrument for the specific needs of the project is covered.

A Goddard Multi-Scale Modeling System with Unified Physics

NASA Technical Reports Server (NTRS)

Tao, W.K.; Anderson, D.; Atlas, R.; Chern, J.; Houser, P.; Hou, A.; Lang, S.; Lau, W.; Peters-Lidard, C.; Kakar, R.;

Spatially resolved Spectroscopy of Europa’s Large-scale Compositional Units at 3-4 μm with Keck NIRSPEC

NASA Astrophysics Data System (ADS)

Fischer, P. D.; Brown, M. E.; Trumbo, S. K.; Hand, K. P.

2017-01-01

We present spatially resolved spectroscopic observations of Europa’s surface at 3-4 μm obtained with the near-infrared spectrograph and adaptive optics system on the Keck II telescope. These are the highest quality spatially resolved reflectance spectra of Europa’s surface at 3-4 μm. The observations spatially resolve Europa’s large-scale compositional units at a resolution of several hundred kilometers. The spectra show distinct features and geographic variations associated with known compositional units; in particular, large-scale leading hemisphere chaos shows a characteristic longward shift in peak reflectance near 3.7 μm compared to icy regions. These observations complement previous spectra of large-scale chaos, and can aid efforts to identify the endogenous non-ice species.

Photometry of resolved galaxies. IV - Holmberg I and Holmberg II

NASA Technical Reports Server (NTRS)

Hoessel, J. G.; Danielson, G. E.

1984-01-01

Colors and magnitudes are presented for 279 resolved stars in the Holmberg I dwarf galaxy and 468 resolved stars in Holmberg II. Both systems are Magellanic type dwarf members of the M81-NGC 2403 Group, which lies at approximately 3 Mpc from the Local Group. The photometry was done in the GRI passbands using CCD detectors. Color-magnitude diagrams and luminosity functions are constructed; these are compared with results for several Local Group galaxies and with theoretical work. Holmberg I is found to have a low present star formation rate, while Holmberg II is very active at present.

The Global Ocean Forecast System, Version 3.0 (GOFS 3.0) or the Hybrid Coordinate Ocean Model (HYCOM)

DTIC Science & Technology

2012-04-10

System (GOFS) V3.0 – 1/12 HYCOM/NCODA: Phase I‖ by Metzger et al., dated 26 November 2008 (NRL/MR/7320—08- 9148). The HYbrid Coordinate Ocean...C. Lozano, H.L. Tolman, A. Srinivasan, S. Hankin, P. Cornillon, R. Weisberg, A. Barth, R. He, F. Werner, and J. Wilkin , 2009. U.S. GODAE: Global...E.J. Metzger, J.F. Shriver, O.M. Smedstad, A.J. Wallcraft, and C.N. Barron, 2008 : Eddy-resolving global ocean prediction. In "Eddy-Resolving Ocean

Novel system for picosecond photoemission spectroscopy

NASA Astrophysics Data System (ADS)

Haight, R.; Silberman, J. A.; Lilie, M. I.

1988-09-01

This article describes a laser-based source and detection scheme for performing time-resolved photoemission studies of materials. The pulsed laser source produces intense picosecond pulses of coherent radiation that are nearly continuously tunable from the near infrared to photon energies up to 13 eV. To achieve high sensitivity, a novel multianode time-of-flight spectrometer has been built that generates an angularly resolved intensity versus kinetic energy spectrum with better than 100-meV resolution. The source and detector provide an opportunity to study the electronic dynamics of excited systems on a picosecond time scale.

The chemosensory brain requires a distributed cellular mechanism to harness information and resolve conflicts - is consciousness the forum?

PubMed

Lathe, Richard

2016-01-01

The central nervous system (CNS) evolved from a chemosensory epithelium, but a simple epithelium has limited means to resolve conflicts between early drives (e.g., approach vs. avoid). Understanding the role of "consciousness" as a resolution device, with specific focus on chemosensation and the olfactory system, is of appeal. I argue that consciousness is not the adjudicator, but is instead the forum that brings conflicting (conscious) inputs into a form that allows them to be (unconsciously) compared/contrasted, guiding rational action.

Photon-number-resolving SSPDs with system detection efficiency over 50% at telecom range

NASA Astrophysics Data System (ADS)

Zolotov, P.; Divochiy, A.; Vakhtomin, Yu.; Moshkova, M.; Morozov, P.; Seleznev, V.; Smirnov, K.

2018-02-01

We used technology of making high-efficiency superconducting single-photon detectors as a basis for improvement of photon-number-resolving devices. By adding optical cavity and using an improved NbN superconducting film, we enhanced previously reported system detection efficiency at telecom range for such detectors. Our results show that implementation of optical cavity helps to develop four-section device with quantum efficiency over 50% at 1.55 µm. Performed experimental studies of detecting multi-photon optical pulses showed irregularities over defining multi-photon through single-photon quantum efficiency.

Angular measurement system

NASA Technical Reports Server (NTRS)

Currie, J. R.; Kissel, R. R.

1986-01-01

A system for the measurement of shaft angles is disclosed wherein a synchro resolver is sequentially pulsed, and alternately, a sine and then a cosine representative voltage output of it are sampled. Two like type, sine or cosine, succeeding outputs (V sub S1, V sub S2) are averaged and algebraically related to the opposite type output pulse (V sub c) occurring between the averaged pulses to provide a precise indication of the angle of a shaft coupled to the resolver at the instant of the occurrence of the intermediately occurring pulse (V sub c).

Further Constraints on the Presence of a Debris Disk in the Multiplanet System Gliese 876

DTIC Science & Technology

2008-06-01

planets and satellites : general – stars: individual (Gl 876) 1. INTRODUCTION The M4 dwarf star Gl 876 harbors one of the nearest mul- tiplanet...Space Telescope search for dust disks around 123 late-type dwarfs. However, the nearby M dwarf AU Mic shows a well- resolved debris disk, whose radius is...et al. (2006). If the Gl 876 system were to contain a debris disk, the extent of which exceeds just ∼5 AU (which is our resolving power at 4.69 pc

Local position control: A new concept for control of manipulators

NASA Technical Reports Server (NTRS)

Kelly, Frederick A.

1988-01-01

Resolved motion rate control is currently one of the most frequently used methods of manipulator control. It is currently used in the Space Shuttle remote manipulator system (RMS) and in prosthetic devices. Position control is predominately used in locating the end-effector of an industrial manipulator along a path with prescribed timing. In industrial applications, resolved motion rate control is inappropriate since position error accumulates. This is due to velocity being the control variable. In some applications this property is an advantage rather than a disadvantage. It may be more important for motion to end as soon as the input command is removed rather than reduce the position error to zero. Local position control is a new concept for manipulator control which retains the important properties of resolved motion rate control, but reduces the drift. Local position control can be considered to be a generalization of resolved position and resolved rate control. It places both control schemes on a common mathematical basis.

Preliminary evaluation of evaluation of the efficiency of aircraft liquid waste treatment using resolvable sanitizing liquid: a case study in Changchun.

PubMed

Xu, Jianling; Yang, Jiaqi; Zhao, Nan; Sheng, Lianxi; Zhao, Yuanhui; Tang, Zhanhui

2011-12-01

The physical, chemical, and biological indices of aircraft liquid wastes collected from multiple airplanes at Longjia Airport, Changchun, China were measured according to "Integrated Wastewater Discharge Standard," evaluating treatment efficiency of resolvable sanitizing liquid. The results indicate that, after being treated by the resolvable sanitizing liquid, the indices of all first-class pollutants met the requirements of the standard, while among the second-class pollutants, the suspension content, biochemical oxygen demand after 5 days, and chemical oxygen demand as well as the contents of amino nitrogen, total phosphorus, anionic surfactants, total copper, absorbable organic halogen, and phenolic compounds did not reach the discharge standard. Particularly, the level of fecal coliform bacteria in the aircraft liquid wastes can meet the standard specification by adding more than 1 mL/L resolvable sanitizing liquid. The aircraft wastewater treated by resolvable sanitizing liquid cannot be directly discharged back into the environment as well as urban drainage systems.

Conflict resolution in multi-agent hybrid systems

DOT National Transportation Integrated Search

1996-12-01

A conflict resolution architecture for multi-agent hybrid systems with emphasis on Air Traffic Management Systems (ATMS) is presented. In such systems, conflicts arise in the form of potential collisions which are resolved locally by inter-agent coor...

Models of Persuasion Dialogue

NASA Astrophysics Data System (ADS)

Prakken, Henry

This chapter1 reviews formal dialogue systems for persuasion. In persuasion dialogues two or more participants try to resolve a conflict of opinion, each trying to persuade the other participants to adopt their point of view. Dialogue systems for persuasion regulate how such dialogues can be conducted and what their outcome is. Good dialogue systems ensure that conflicts of view can be resolved in a fair and effective way [6]. The term ‘persuasion dialogue’ was coined by Walton [13] as part of his influential classification of dialogues into six types according to their goal. While persuasion aims to resolve a difference of opinion, negotiation tries to resolve a conflict of interest by reaching a deal, information seeking aims at transferring information, deliberationdeliberation wants to reach a decision on a course of action, inquiry is aimed at “growth of knowledge and agreement” and quarrel is the verbal substitute of a fight. This classification leaves room for shifts of dialogues of one type to another. In particular, other types of dialogues can shift to persuasion when a conflict of opinion arises. For example, in information-seeking a conflict of opinion could arise on the credibility of a source of information, in deliberation the participants may disagree about likely effects of plans or actions and in negotiation they may disagree about the reasons why a proposal is in one’s interest.

Correlation, temperature and disorder: Recent developments in the one-step description of angle-resolved photoemission

NASA Astrophysics Data System (ADS)

Braun, Jürgen; Minár, Ján; Ebert, Hubert

2018-04-01

Various apparative developments extended the potential of angle-resolved photoemission spectroscopy tremendously during the last two decades. Modern experimental arrangements consisting of new photon sources, analyzers and detectors supply not only extremely high angle and energy resolution but also spin resolution. This provides an adequate platform to study in detail new materials like low-dimensional magnetic structures, Rashba systems, topological insulator materials or high TC superconductors. The interest in such systems has grown enormously not only because of their technological relevance but even more because of exciting new physics. Furthermore, the use of photon energies from few eV up to several keV makes this experimental technique a rather unique tool to investigate the electronic properties of solids and surfaces. The following article reviews the corresponding recent theoretical developments in the field of angle-resolved photoemission with a special emphasis on correlation effects, temperature and relativistic aspects. The most successful theoretical approach to deal with angle-resolved photoemission is the so-called spectral function or one-step formulation of the photoemission process. Nowadays, the one-step model allows for photocurrent calculations for photon energies ranging from a few eV to more than 10 keV, to deal with arbitrarily ordered and disordered systems, to account for finite temperatures, and considering in addition strong correlation effects within the dynamical mean-field theory or similar advanced approaches.

Zebra Stripes through the Eyes of Their Predators, Zebras, and Humans

PubMed Central

Melin, Amanda D.; Kline, Donald W.; Hiramatsu, Chihiro; Caro, Tim

2016-01-01

The century-old idea that stripes make zebras cryptic to large carnivores has never been examined systematically. We evaluated this hypothesis by passing digital images of zebras through species-specific spatial and colour filters to simulate their appearance for the visual systems of zebras’ primary predators and zebras themselves. We also measured stripe widths and luminance contrast to estimate the maximum distances from which lions, spotted hyaenas, and zebras can resolve stripes. We found that beyond ca. 50 m (daylight) and 30 m (twilight) zebra stripes are difficult for the estimated visual systems of large carnivores to resolve, but not humans. On moonless nights, stripes are difficult for all species to resolve beyond ca. 9 m. In open treeless habitats where zebras spend most time, zebras are as clearly identified by the lion visual system as are similar-sized ungulates, suggesting that stripes cannot confer crypsis by disrupting the zebra’s outline. Stripes confer a minor advantage over solid pelage in masking body shape in woodlands, but the effect is stronger for humans than for predators. Zebras appear to be less able than humans to resolve stripes although they are better than their chief predators. In conclusion, compared to the uniform pelage of other sympatric herbivores it appears highly unlikely that stripes are a form of anti-predator camouflage. PMID:26799935

Qualitative fusion technique based on information poor system and its application to factor analysis for vibration of rolling bearings

NASA Astrophysics Data System (ADS)

Xia, Xintao; Wang, Zhongyu

2008-10-01

For some methods of stability analysis of a system using statistics, it is difficult to resolve the problems of unknown probability distribution and small sample. Therefore, a novel method is proposed in this paper to resolve these problems. This method is independent of probability distribution, and is useful for small sample systems. After rearrangement of the original data series, the order difference and two polynomial membership functions are introduced to estimate the true value, the lower bound and the supper bound of the system using fuzzy-set theory. Then empirical distribution function is investigated to ensure confidence level above 95%, and the degree of similarity is presented to evaluate stability of the system. Cases of computer simulation investigate stable systems with various probability distribution, unstable systems with linear systematic errors and periodic systematic errors and some mixed systems. The method of analysis for systematic stability is approved.

MONSTIR II: A 32-channel, multispectral, time-resolved optical tomography system for neonatal brain imaging

NASA Astrophysics Data System (ADS)

Cooper, Robert J.; Magee, Elliott; Everdell, Nick; Magazov, Salavat; Varela, Marta; Airantzis, Dimitrios; Gibson, Adam P.; Hebden, Jeremy C.

2014-05-01

We detail the design, construction and performance of the second generation UCL time-resolved optical tomography system, known as MONSTIR II. Intended primarily for the study of the newborn brain, the system employs 32 source fibres that sequentially transmit picosecond pulses of light at any four wavelengths between 650 and 900 nm. The 32 detector channels each contain an independent photo-multiplier tube and temporally correlated photon-counting electronics that allow the photon transit time between each source and each detector position to be measured with high temporal resolution. The system's response time, temporal stability, cross-talk, and spectral characteristics are reported. The efficacy of MONSTIR II is demonstrated by performing multi-spectral imaging of a simple phantom.

Development of a Cloud Resolving Model for Heterogeneous Supercomputers

NASA Astrophysics Data System (ADS)

Sreepathi, S.; Norman, M. R.; Pal, A.; Hannah, W.; Ponder, C.

2017-12-01

A cloud resolving climate model is needed to reduce major systematic errors in climate simulations due to structural uncertainty in numerical treatments of convection - such as convective storm systems. This research describes the porting effort to enable SAM (System for Atmosphere Modeling) cloud resolving model on heterogeneous supercomputers using GPUs (Graphical Processing Units). We have isolated a standalone configuration of SAM that is targeted to be integrated into the DOE ACME (Accelerated Climate Modeling for Energy) Earth System model. We have identified key computational kernels from the model and offloaded them to a GPU using the OpenACC programming model. Furthermore, we are investigating various optimization strategies intended to enhance GPU utilization including loop fusion/fission, coalesced data access and loop refactoring to a higher abstraction level. We will present early performance results, lessons learned as well as optimization strategies. The computational platform used in this study is the Summitdev system, an early testbed that is one generation removed from Summit, the next leadership class supercomputer at Oak Ridge National Laboratory. The system contains 54 nodes wherein each node has 2 IBM POWER8 CPUs and 4 NVIDIA Tesla P100 GPUs. This work is part of a larger project, ACME-MMF component of the U.S. Department of Energy(DOE) Exascale Computing Project. The ACME-MMF approach addresses structural uncertainty in cloud processes by replacing traditional parameterizations with cloud resolving "superparameterization" within each grid cell of global climate model. Super-parameterization dramatically increases arithmetic intensity, making the MMF approach an ideal strategy to achieve good performance on emerging exascale computing architectures. The goal of the project is to integrate superparameterization into ACME, and explore its full potential to scientifically and computationally advance climate simulation and prediction.

SU-F-T-462: Lessons Learned From a Machine Incident Reporting System

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

Sutlief, S; Hoisak, J

Purpose: Linear accelerators must operate with minimal downtime. Machine incident logs are a crucial tool to meet this requirement. They providing a history of service and demonstrate whether a fix is working. This study investigates the information content of a large department linear accelerator incident log. Methods: Our department uses an electronic reporting system to provide immediate information to both key department staff and the field service department. This study examines reports for five linac logs during 2015. The report attributes for analysis include frequency, level of documentation, who solved the problem, and type of fix used. Results: Of themore » reports, 36% were documented as resolved. In another 25% the resolution allowed treatment to proceed although the reported problem recurred within days. In 5% only intermediate troubleshooting was documented. The remainder lacked documentation. In 60% of the reports, radiation therapists resolved the problem, often by clearing the appropriate faults or reinitializing a software or hardware service. 22% were resolved by physics and 10% by field service engineers. The remaining 8% were resolved by IT, Facilities, or resolved spontaneously. Typical fixes, in order of scope, included clearing the fault and moving on, closing and re-opening the patient session or software, cycling power to a sub-unit, recalibrating a device (e.g., optical surface imaging), and calling in Field Service (usually resolving the problem through maintenance or component replacement). Conclusion: The reports with undocumented resolution represent a missed opportunity for learning. Frequency of who resolves a problem scales with the proximity of the person’s role (therapist, physicist, or service engineer), which is inversely related to the permanence of the resolution. Review of lessons learned from machine incident logs can form the basis for guidance to radiation therapists and medical physicists to minimize equipment downtime and ensure safe operation.« less

High speed photography, videography, and photonics III; Proceedings of the Meeting, San Diego, CA, August 22, 23, 1985

NASA Technical Reports Server (NTRS)

Ponseggi, B. G. (Editor); Johnson, H. C. (Editor)

1985-01-01

Papers are presented on the picosecond electronic framing camera, photogrammetric techniques using high-speed cineradiography, picosecond semiconductor lasers for characterizing high-speed image shutters, the measurement of dynamic strain by high-speed moire photography, the fast framing camera with independent frame adjustments, design considerations for a data recording system, and nanosecond optical shutters. Consideration is given to boundary-layer transition detectors, holographic imaging, laser holographic interferometry in wind tunnels, heterodyne holographic interferometry, a multispectral video imaging and analysis system, a gated intensified camera, a charge-injection-device profile camera, a gated silicon-intensified-target streak tube and nanosecond-gated photoemissive shutter tubes. Topics discussed include high time-space resolved photography of lasers, time-resolved X-ray spectrographic instrumentation for laser studies, a time-resolving X-ray spectrometer, a femtosecond streak camera, streak tubes and cameras, and a short pulse X-ray diagnostic development facility.

Speckle Interferometry at the Blanco and SOAR Telescopes in 2008 and 2009

NASA Technical Reports Server (NTRS)

Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.

2010-01-01

The results of speckle interferometric measurements of binary and multiple stars conducted in 2008 and 2009 at the Blanco and Southern Astrophysical Research (SOAR) 4 m telescopes in Chile are presented. A tot al of 1898 measurements of 1189 resolved pairs or sub-systems and 394 observations of 285 un-resolved targets are listed. We resolved for the first time 48 new pairs, 21 of which are new sub-systems in close visual multiple stars. Typical internal measurement precision is 0.3 mas in both coordinates, typical companion detection capability is delta m approximately 4.2 at 0.15 degree separation. These data were obtained with a new electron-multiplication CCD camera; data processing is described in detail, including estimation of magnitude difference, observational errors, detection limits, and analysis of artifacts. We comment on some newly discovered pairs and objects of special interest.

Dental caries imaging using hyperspectral stimulated Raman scattering microscopy

NASA Astrophysics Data System (ADS)

Wang, Zi; Zheng, Wei; Jian, Lin; Huang, Zhiwei

2016-03-01

We report the development of a polarization-resolved hyperspectral stimulated Raman scattering (SRS) imaging technique based on a picosecond (ps) laser-pumped optical parametric oscillator system for label-free imaging of dental caries. In our imaging system, hyperspectral SRS images (512×512 pixels) in both fingerprint region (800-1800 cm-1) and high-wavenumber region (2800-3600 cm-1) are acquired in minutes by scanning the wavelength of OPO output, which is a thousand times faster than conventional confocal micro Raman imaging. SRS spectra variations from normal enamel to caries obtained from the hyperspectral SRS images show the loss of phosphate and carbonate in the carious region. While polarization-resolved SRS images at 959 cm-1 demonstrate that the caries has higher depolarization ratio. Our results demonstrate that the polarization resolved-hyperspectral SRS imaging technique developed allows for rapid identification of the biochemical and structural changes of dental caries.

SPECKLE INTERFEROMETRY AT THE BLANCO AND SOAR TELESCOPES IN 2008 AND 2009

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

Tokovinin, Andrei; Mason, Brian D.; Hartkopf, William I.

2010-02-15

The results of speckle interferometric measurements of binary and multiple stars conducted in 2008 and 2009 at the Blanco and SOAR 4 m telescopes in Chile are presented. A total of 1898 measurements of 1189 resolved pairs or sub-systems and 394 observations of 285 un-resolved targets are listed. We resolved for the first time 48 new pairs, 21 of which are new sub-systems in close visual multiple stars. Typical internal measurement precision is 0.3 mas in both coordinates, typical companion detection capability is {delta}m {approx} 4.2 at 0.''15 separation. These data were obtained with a new electron-multiplication CCD camera; datamore » processing is described in detail, including estimation of magnitude difference, observational errors, detection limits, and analysis of artifacts. We comment on some newly discovered pairs and objects of special interest.« less

4D blood flow mapping using SPIM-microPIV in the developing zebrafish heart

NASA Astrophysics Data System (ADS)

Zickus, Vytautas; Taylor, Jonathan M.

2018-02-01

Fluid-structure interaction in the developing heart is an active area of research in developmental biology. However, investigation of heart dynamics is mostly limited to computational uid dynamics simulations using heart wall structure information only, or single plane blood ow information - so there is a need for 3D + time resolved data to fully understand cardiac function. We present an imaging platform combining selective plane illumination microscopy (SPIM) with micro particle image velocimetry (μPIV) to enable 3D-resolved flow mapping in a microscopic environment, free from many of the sources of error and bias present in traditional epi uorescence-based μPIV systems. By using our new system in conjunction with optical heart beat synchronization, we demonstrate the ability obtain non-invasive 3D + time resolved blood flow measurements in the heart of a living zebrafish embryo.

Confocal depth-resolved fluorescence micro-X-ray absorption spectroscopy for the study of cultural heritage materials: a new mobile endstation at the Beijing Synchrotron Radiation Facility

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

Chen, Guang; Chu, Shengqi; Sun, Tianxi

A confocal fluorescence endstation for depth-resolved micro-X-ray absorption spectroscopy is described. A polycapillary half-lens defines the incident beam path and a second polycapillary half-lens at 90° defines the probe sample volume. An automatic alignment program based on an evolutionary algorithm is employed to make the alignment procedure efficient. This depth-resolved system was examined on a general X-ray absorption spectroscopy (XAS) beamline at the Beijing Synchrotron Radiation Facility. Sacrificial red glaze (AD 1368–1644) china was studied to show the capability of the instrument. As a mobile endstation to be applied on multiple beamlines, the confocal system can improve the function andmore » flexibility of general XAS beamlines, and extend their capabilities to a wider user community.« less

Manipulations of Wavefront Propagation: Useful Methods and Applications for Interferometric Measurements and Scanning

PubMed Central

Novoselski, Eitan; Yifrach, Ariel; Lanzmann, Emmanuel; Arieli, Yoel

2017-01-01

Phase measurements obtained by high-coherence interferometry are restricted by the 2π ambiguity, to height differences smaller than λ/2. A further restriction in most interferometric systems is for focusing the system on the measured object. We present two methods that overcome these restrictions. In the first method, different segments of a measured wavefront are digitally propagated and focused locally after measurement. The divergent distances, by which the diverse segments of the wavefront are propagated in order to achieve a focused image, provide enough information so as to resolve the 2π ambiguity. The second method employs an interferogram obtained by a spectrum constituting a small number of wavelengths. The magnitude of the interferogram's modulations is utilized to resolve the 2π ambiguity. Such methods of wavefront propagation enable several applications such as focusing and resolving the 2π ambiguity, as described in the article. PMID:29109825

Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE): Lunar Advanced Volatile Analysis (LAVA) Integration and Testing - Evaluation of Lee Valve

NASA Technical Reports Server (NTRS)

Bower, Hannah; Cryderman, Kate; Captain, Janine

2016-01-01

The Resource Prospector (RP) mission with the Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE) payload will prospect for water within the lunar regolith and provide a proof of concept for In-Situ Resource Utilization (ISRU) techniques, which could be used on future lunar and Martian missions. One system within the RESOLVE payload is the Lunar Advanced Volatiles Analysis (LAVA) subsystem, which consists of a Fluid Sub System (FSS) that transports volatiles to the Gas Chromatograph-Mass Spectrometer (GC-MS) instrument. In order for the FSS to transport precise and accurate amounts of volatiles to the GC-MS instrumentation, high performance valves are used within the system. The focus of this investigation is to evaluate the redesigned Lee valve. Further work is needed to continue to evaluate the Lee valve. Initial data shows that the valve could meet our requirements however further work is required to raise the TRL to an acceptable level to be included in the flight design of the system. At this time the risk is too high to change our baseline design to include these non-latching Lee solenoid valves.

Overcoming Robot-Arm Joint Singularities

NASA Technical Reports Server (NTRS)

Barker, L. K.; Houck, J. A.

1986-01-01

Kinematic equations allow arm to pass smoothly through singular region. Report discusses mathematical singularities in equations of robotarm control. Operator commands robot arm to move in direction relative to its own axis system by specifying velocity in that direction. Velocity command then resolved into individual-joint rotational velocities in robot arm to effect motion. However, usual resolved-rate equations become singular when robot arm is straightened.

Site-resolved imaging of a bosonic Mott insulator using ytterbium atoms

NASA Astrophysics Data System (ADS)

Miranda, Martin; Inoue, Ryotaro; Tambo, Naoki; Kozuma, Mikio

2017-10-01

We demonstrate site-resolved imaging of a strongly correlated quantum system without relying on laser cooling techniques during fluorescence imaging. We observe the formation of Mott shells in the insulating regime and realize thermometry in an atomic cloud. This work proves the feasibility of the noncooled approach and opens the door to extending the detection technology to new atomic species.

SPATIALLY RESOLVED SPECTROSCOPY OF EUROPA’S LARGE-SCALE COMPOSITIONAL UNITS AT 3–4 μ m WITH KECK NIRSPEC

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

Fischer, P. D.; Brown, M. E.; Trumbo, S. K.

2017-01-01

We present spatially resolved spectroscopic observations of Europa’s surface at 3–4 μ m obtained with the near-infrared spectrograph and adaptive optics system on the Keck II telescope. These are the highest quality spatially resolved reflectance spectra of Europa’s surface at 3–4 μ m. The observations spatially resolve Europa’s large-scale compositional units at a resolution of several hundred kilometers. The spectra show distinct features and geographic variations associated with known compositional units; in particular, large-scale leading hemisphere chaos shows a characteristic longward shift in peak reflectance near 3.7 μ m compared to icy regions. These observations complement previous spectra of large-scalemore » chaos, and can aid efforts to identify the endogenous non-ice species.« less

Cloud-System Resolving Models: Status and Prospects

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo; Moncreiff, Mitch

2008-01-01

Cloud-system resolving models (CRM), which are based on the nonhydrostatic equations of motion and typically have a grid-spacing of about a kilometer, originated as cloud-process models in the 1970s. This paper reviews the status and prospects of CRMs across a wide range of issues, such as microphysics and precipitation; interaction between clouds and radiation; and the effects of boundary-layer and surface-processes on cloud systems. Since CRMs resolve organized convection, tropical waves and the large-scale circulation, there is the prospect for several advances in both basic knowledge of scale-interaction requisite to parameterizing mesoscale processes in climate models. In superparameterization, CRMs represent convection, explicitly replacing many of the assumptions necessary in contemporary parameterization. Global CRMs have been run on an experimental basis, giving prospect to a new generation of climate weather prediction in a decade, and climate models due course. CRMs play a major role in the retrieval of surface-rain and latent heating from satellite measurements. Finally, enormous wide dynamic ranges of CRM simulations present new challenges for model validation against observations.

In-situ straining and time-resolved electron tomography data acquisition in a transmission electron microscope.

PubMed

Hata, S; Miyazaki, S; Gondo, T; Kawamoto, K; Horii, N; Sato, K; Furukawa, H; Kudo, H; Miyazaki, H; Murayama, M

2017-04-01

This paper reports the preliminary results of a new in-situ three-dimensional (3D) imaging system for observing plastic deformation behavior in a transmission electron microscope (TEM) as a directly relevant development of the recently reported straining-and-tomography holder [Sato K et al. (2015) Development of a novel straining holder for transmission electron microscopy compatible with single tilt-axis electron tomography. Microsc. 64: 369-375]. We designed an integrated system using the holder and newly developed straining and image-acquisition software and then developed an experimental procedure for in-situ straining and time-resolved electron tomography (ET) data acquisition. The software for image acquisition and 3D visualization was developed based on the commercially available ET software TEMographyTM. We achieved time-resolved 3D visualization of nanometer-scale plastic deformation behavior in a Pb-Sn alloy sample, thus demonstrating the capability of this system for potential applications in materials science. © The Author 2016. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Fourier-domain angle-resolved low coherence interferometry for clinical detection of dysplasia

NASA Astrophysics Data System (ADS)

Terry, Neil G.; Zhu, Yizheng; Wax, Adam

2010-02-01

Improved methods for detecting dysplasia, or pre-cancerous growth are a current clinical need, particularly in the esophagus. The currently accepted method of random biopsy and histological analysis provides only a limited examination of tissue in question while being coupled with a long time delay for diagnosis. Light scattering spectroscopy, in contrast, allows for inspection of the cellular structure and organization of tissue in vivo. Fourier-domain angle-resolved low-coherence interferometry (a/LCI) is a novel light scattering spectroscopy technique that provides quantitative depth-resolved morphological measurements of the size and optical density of the examined cell nuclei, which are characteristic biomarkers of dysplasia. Previously, clinical viability of the a/LCI system was demonstrated through analysis of ex vivo human esophageal tissue in Barrett's esophagus patients using a portable a/LCI, as was the development of a clinical a/LCI system. Data indicating the feasibility of the technique in other organ sites (colon, oral cavity) will be presented. We present an adaptation of the a/LCI system that will be used to investigate the presence of dysplasia in vivo in Barrett's esophagus patients.

Application of a high-repetition-rate laser diagnostic system for single-cycle-resolved imaging in internal combustion engines.

PubMed

Hult, Johan; Richter, Mattias; Nygren, Jenny; Aldén, Marcus; Hultqvist, Anders; Christensen, Magnus; Johansson, Bengt

2002-08-20

High-repetition-rate laser-induced fluorescence measurements of fuel and OH concentrations in internal combustion engines are demonstrated. Series of as many as eight fluorescence images, with a temporal resolution ranging from 10 micros to 1 ms, are acquired within one engine cycle. A multiple-laser system in combination with a multiple-CCD camera is used for cycle-resolved imaging in spark-ignition, direct-injection stratified-charge, and homogeneous-charge compression-ignition engines. The recorded data reveal unique information on cycle-to-cycle variations in fuel transport and combustion. Moreover, the imaging system in combination with a scanning mirror is used to perform instantaneous three-dimensional fuel-concentration measurements.

Portable measurement system for real-time acquisition and analysis of in-vivo spatially resolved reflectance in the subdiffusive regime

NASA Astrophysics Data System (ADS)

Naglič, Peter; Ivančič, Matic; Pernuš, Franjo; Likar, Boštjan; Bürmen, Miran

2018-02-01

A measurement system was developed to acquire and analyze subdiffusive spatially resolved reflectance using an optical fiber probe with short source-detector separations. Since subdiffusive reflectance significantly depends on the scattering phase function, the analysis of the acquired reflectance is based on a novel inverse Monte Carlo model that allows estimation of phase function related parameters in addition to the absorption and reduced scattering coefficients. In conjunction with our measurement system, the model allowed real-time estimation of optical properties, which we demonstrate for a case of dynamically induced changes in human skin by applying pressure with an optical fiber probe.

Trapezium Systems and Stellar Jets in 30 Doradus

NASA Astrophysics Data System (ADS)

Walborn, Nolan

1999-07-01

30 Doradus is the nearest and best resolved extragalactic starburst, hence a paradigm for the phenomenon. Recent NICMOS observations of the new stellar generation being triggered by the outflows from R136 establish 30 Dor as a prime region for investigation of massive-star formation as well. Since 1" already subtends 50, 000 AU at 50 kpc, HST makes unique contributions to the study of 30 Dor. A recent groundbased spectral-classification study has provided new insights into the stellar content of 30 Dor, but many of the targets are resolved into multiple systems in the available WFPC2 images. We propose to obtain spatially resolved STIS blue spectroscopy of some of the newly found multiple systems, which is essential to determine accurate stellar tempertures and masses. Several systems each in the new and previous stellar generations are included. The HST spatial resolution also reduces the contamination of t he stellar spectra by the nebula r emission lines, which is a critical advantage. We also propose dithered PC nebular-line images of the young Trapezium systems Knots 1-3, which interact strongly with the surrounding interstellar medium, forming several parsec-scale jets. Finally, we shall do two WFPC2 pointings with continuum filters, to complete the coverage of the field, which currently limits the search for multiple systems and the illuminating comparisons with IR and other data.

A Herschel resolved far-infrared dust ring around HD 207129

NASA Astrophysics Data System (ADS)

Marshall, J. P.; Löhne, T.; Montesinos, B.; Krivov, A. V.; Eiroa, C.; Absil, O.; Bryden, G.; Maldonado, J.; Mora, A.; Sanz-Forcada, J.; Ardila, D.; Augereau, J.-Ch.; Bayo, A.; Del Burgo, C.; Danchi, W.; Ertel, S.; Fedele, D.; Fridlund, M.; Lebreton, J.; González-García, B. M.; Liseau, R.; Meeus, G.; Müller, S.; Pilbratt, G. L.; Roberge, A.; Stapelfeldt, K.; Thébault, P.; White, G. J.; Wolf, S.

2011-05-01

Context. Dusty debris discs around main sequence stars are thought to be the result of continuous collisional grinding of planetesimals in the system. The majority of these systems are unresolved and analysis of the dust properties is limited by the lack of information regarding the dust location. Aims: The Herschel DUNES key program is observing 133 nearby, Sun-like stars (<20 pc, FGK spectral type) in a volume limited survey to constrain the absolute incidence of cold dust around these stars by detection of far infrared excess emission at flux levels comparable to the Edgeworth-Kuiper belt (EKB). Methods: We have observed the Sun-like star HD 207129 with Herschel PACS and SPIRE. In all three PACS bands we resolve a ring-like structure consistent with scattered light observations. Using α Boötis as a reference point spread function (PSF), we deconvolved the images, clearly resolving the inner gap in the disc at both 70 and 100 μm. Results: We have resolved the dust-producing planetesimal belt of a debris disc at 100 μm for the first time. We measure the radial profile and fractional luminosity of the disc, and compare the values to those of discs around stars of similar age and/or spectral type, placing this disc in context of other resolved discs observed by Herschel/DUNES. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Expert Systems: An Overview.

ERIC Educational Resources Information Center

Adiga, Sadashiv

1984-01-01

Discusses: (1) the architecture of expert systems; (2) features that distinguish expert systems from conventional programs; (3) conditions necessary to select a particular application for the development of successful expert systems; (4) issues to be resolved when building expert systems; and (5) limitations. Examples of selected expert systems…

Probing for Exoplanets Hiding in Dusty Debris Disks: Disk Imaging, Characterization, and Exploration with HST-STIS Multi-roll Coronagraphy

NASA Technical Reports Server (NTRS)

Schneider, Glenn; Grady, Carol A.; Hines, Dean C.; Stark, Christopher C.; Debes, John; Carson, Joe; Kuchner, Marc J.; Perrin, Marshall; Weinberger, Alycia; Wisniewski, John P.;

Probing for exoplanets hiding in dusty debris disks: Disk imaging, characterization, and exploration with HST/STIS multi-roll coronagraphy

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

Schneider, Glenn; Hinz, Phillip M.; Grady, Carol A.

Spatially resolved scattered-light images of circumstellar debris in exoplanetary systems constrain the physical properties and orbits of the dust particles in these systems. They also inform on co-orbiting (but unseen) planets, the systemic architectures, and forces perturbing the starlight-scattering circumstellar material. Using Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS) broadband optical coronagraphy, we have completed the observational phase of a program to study the spatial distribution of dust in a sample of 10 circumstellar debris systems and 1 'mature' protoplanetrary disk, all with HST pedigree, using point-spread-function-subtracted multi-roll coronagraphy. These observations probe stellocentric distances ≥5 AU for the nearestmore » systems, and simultaneously resolve disk substructures well beyond corresponding to the giant planet and Kuiper Belt regions within our own solar system. They also disclose diffuse very low-surface-brightness dust at larger stellocentric distances. Herein we present new results inclusive of fainter disks such as HD 92945 (F {sub disk}/F {sub star} = 5 × 10{sup –5}), confirming, and better revealing, the existence of a narrow inner debris ring within a larger diffuse dust disk. Other disks with ring-like substructures and significant asymmetries and complex morphologies include HD 181327, for which we posit a spray of ejecta from a recent massive collision in an exo-Kuiper Belt; HD 61005, suggested to be interacting with the local interstellar medium; and HD 15115 and HD 32297, also discussed in the context of putative environmental interactions. These disks and HD 15745 suggest that debris system evolution cannot be treated in isolation. For AU Mic's edge-on disk, we find out-of-plane surface brightness asymmetries at ≥5 AU that may implicate the existence of one or more planetary perturbers. Time-resolved images of the MP Mus protoplanetary disk provide spatially resolved temporal variability in the disk illumination. These and other new images from our HST/STIS GO/12228 program enable direct inter-comparison of the architectures of these exoplanetary debris systems in the context of our own solar system.« less

Periodicity in Age-Resolved Populations

NASA Astrophysics Data System (ADS)

Esipov, Sergei

We discuss the interplay between the non-linear diffusion and age-resolved population dynamics. Depending on the age properties of collective migration the system may exhibit continuous joint expansion of all ages or continuous expansion with age segregation. Between these two obvious limiting regimes there is an interesting window of periodic expansion, which has been previously used by us in modeling bacterial colonies of Proteus mirabilis. In order to test whether the age-dependent collective migration leads to periodicity in other systems we performed a Fourier analysis of historical data on ethnic expansions and found multiple co-existing periods of activity.

A construction of unimodular equiangular tight frames from resolvable Steiner systems

NASA Astrophysics Data System (ADS)

Jasper, John

2013-09-01

An equiangular tight frame (ETF) is an M x N matrix which has orthogonal equal norm rows, equal norm columns, and the inner products of all pairs of columns have the same modulus. In this paper we study ETFs in which all of the entries are unimodular, and in particular pth roots of unity. A new construction of unimodular ETFs based on resolvable Steiner systems is presented. This construction gives many new examples of unimodular ETFs. In particular, an new infinite class of ETFs with entries in f1;-1g is presented.

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

Newsom, R. K.; Sivaraman, C.; Shippert, T. R.

Wind speed and direction, together with pressure, temperature, and relative humidity, are the most fundamental atmospheric state parameters. Accurate measurement of these parameters is crucial for numerical weather prediction. Vertically resolved wind measurements in the atmospheric boundary layer are particularly important for modeling pollutant and aerosol transport. Raw data from a scanning coherent Doppler lidar system can be processed to generate accurate height-resolved measurements of wind speed and direction in the atmospheric boundary layer.

Standard Terminal Automation Replacement System Human Factors Review Volume 1

DOT National Transportation Integrated Search

1997-12-18

The Federal Aviation Administration formed a Standard Terminal Automation Replacement : System (STARS) Working Group to identify and resolve human factors concerns with the Early : Display Capability (EDC) system before it is introduced in the field....

Design and demonstration of a system for the deposition of atomic-oxygen durable coatings for reflective solar dynamic power system concentrators

NASA Technical Reports Server (NTRS)

Mcclure, Donald J.

1988-01-01

A system for the vacuum deposition of atomic-oxygen durable coatings for reflective solar dynamic power systems (SDPS) concentrators was designed and demonstrated. The design issues pertinent to SDPS were developed by the Government Aerospace Systems Division of the Harris Corporation and are described in NASA-CR-179489. Both design and demonstration phases have been completed. At the time of this report the deposition system was ready for coating of facets for SDPS concentrators. The materials issue relevant to the coating work were not entirely resolved. These issues can only be resolved when substrates which are comparable to those which will be used in flight hardware are available. The substrates available during the contract period were deficient in the areas of surface roughness and contamination. These issues are discussed more thoroughly in the body of the report.

A Power Efficient Exaflop Computer Design for Global Cloud System Resolving Climate Models.

NASA Astrophysics Data System (ADS)

Wehner, M. F.; Oliker, L.; Shalf, J.

2008-12-01

Exascale computers would allow routine ensemble modeling of the global climate system at the cloud system resolving scale. Power and cost requirements of traditional architecture systems are likely to delay such capability for many years. We present an alternative route to the exascale using embedded processor technology to design a system optimized for ultra high resolution climate modeling. These power efficient processors, used in consumer electronic devices such as mobile phones, portable music players, cameras, etc., can be tailored to the specific needs of scientific computing. We project that a system capable of integrating a kilometer scale climate model a thousand times faster than real time could be designed and built in a five year time scale for US$75M with a power consumption of 3MW. This is cheaper, more power efficient and sooner than any other existing technology.

Research on Optimization of Pooling System and Its Application in Drug Supply Chain Based on Big Data Analysis

PubMed Central

2017-01-01

Reform of drug procurement is being extensively implemented and expanded in China, especially in today's big data environment. However, the pattern of supply mode innovation lags behind procurement improvement. Problems in financial strain and supply break frequently occur, which affect the stability of drug supply. Drug Pooling System is proposed and applied in a few pilot cities to resolve these problems. From the perspective of supply chain, this study analyzes the process of setting important parameters and sets out the tasks of involved parties in a pooling system according to the issues identified in the pilot run. The approach is based on big data analysis and simulation using system dynamic theory and modeling of Vensim software to optimize system performance. This study proposes a theoretical framework to resolve problems and attempts to provide a valuable reference for future application of pooling systems. PMID:28293258

A CMOS Time-Resolved Fluorescence Lifetime Analysis Micro-System

PubMed Central

Rae, Bruce R.; Muir, Keith R.; Gong, Zheng; McKendry, Jonathan; Girkin, John M.; Gu, Erdan; Renshaw, David; Dawson, Martin D.; Henderson, Robert K.

2009-01-01

We describe a CMOS-based micro-system for time-resolved fluorescence lifetime analysis. It comprises a 16 × 4 array of single-photon avalanche diodes (SPADs) fabricated in 0.35 μm high-voltage CMOS technology with in-pixel time-gated photon counting circuitry and a second device incorporating an 8 × 8 AlInGaN blue micro-pixellated light-emitting diode (micro-LED) array bump-bonded to an equivalent array of LED drivers realized in a standard low-voltage 0.35 μm CMOS technology, capable of producing excitation pulses with a width of 777 ps (FWHM). This system replaces instrumentation based on lasers, photomultiplier tubes, bulk optics and discrete electronics with a PC-based micro-system. Demonstrator lifetime measurements of colloidal quantum dot and Rhodamine samples are presented. PMID:22291564

Time-resolved single-shot terahertz time-domain spectroscopy for ultrafast irreversible processes

NASA Astrophysics Data System (ADS)

Zhai, Zhao-Hui; Zhong, Sen-Cheng; Li, Jun; Zhu, Li-Guo; Meng, Kun; Li, Jiang; Liu, Qiao; Peng, Qi-Xian; Li, Ze-Ren; Zhao, Jian-Heng

2016-09-01

Pulsed terahertz spectroscopy is suitable for spectroscopic diagnostics of ultrafast events. However, the study of irreversible or single shot ultrafast events requires ability to record transient properties at multiple time delays, i.e., time resolved at single shot level, which is not available currently. Here by angular multiplexing use of femtosecond laser pulses, we developed and demonstrated a time resolved, transient terahertz time domain spectroscopy technique, where burst mode THz pulses were generated and then detected in a single shot measurement manner. The burst mode THz pulses contain 2 sub-THz pulses, and the time gap between them is adjustable up to 1 ns with picosecond accuracy, thus it can be used to probe the single shot event at two different time delays. The system can detect the sub-THz pulses at 0.1 THz-2.5 THz range with signal to noise ratio (SNR) of ˜400 and spectrum resolution of 0.05 THz. System design was described here, and optimizations of single shot measurement of THz pulses were discussed in detail. Methods to improve SNR were also discussed in detail. A system application was demonstrated where pulsed THz signals at different time delays of the ultrafast process were successfully acquired within single shot measurement. This time resolved transient terahertz time domain spectroscopy technique provides a new diagnostic tool for irreversible or single shot ultrafast events where dynamic information can be extracted at terahertz range within one-shot experiment.

Time-resolved single-shot terahertz time-domain spectroscopy for ultrafast irreversible processes.

PubMed

Zhai, Zhao-Hui; Zhong, Sen-Cheng; Li, Jun; Zhu, Li-Guo; Meng, Kun; Li, Jiang; Liu, Qiao; Peng, Qi-Xian; Li, Ze-Ren; Zhao, Jian-Heng

2016-09-01

Pulsed terahertz spectroscopy is suitable for spectroscopic diagnostics of ultrafast events. However, the study of irreversible or single shot ultrafast events requires ability to record transient properties at multiple time delays, i.e., time resolved at single shot level, which is not available currently. Here by angular multiplexing use of femtosecond laser pulses, we developed and demonstrated a time resolved, transient terahertz time domain spectroscopy technique, where burst mode THz pulses were generated and then detected in a single shot measurement manner. The burst mode THz pulses contain 2 sub-THz pulses, and the time gap between them is adjustable up to 1 ns with picosecond accuracy, thus it can be used to probe the single shot event at two different time delays. The system can detect the sub-THz pulses at 0.1 THz-2.5 THz range with signal to noise ratio (SNR) of ∼400 and spectrum resolution of 0.05 THz. System design was described here, and optimizations of single shot measurement of THz pulses were discussed in detail. Methods to improve SNR were also discussed in detail. A system application was demonstrated where pulsed THz signals at different time delays of the ultrafast process were successfully acquired within single shot measurement. This time resolved transient terahertz time domain spectroscopy technique provides a new diagnostic tool for irreversible or single shot ultrafast events where dynamic information can be extracted at terahertz range within one-shot experiment.

The effect of plastic strain on the evolution of crystallographic texture in Zircaloy-2

NASA Astrophysics Data System (ADS)

Ballinger, R. G.; Lucas, G. E.; Pelloux, R. M.

1984-09-01

The evolution of crystallographic texture during plastic deformation was investigated in Zircaloy-2 using X-ray and metallographic techniques. Inverse pole figures, the resolved fraction of basal poles, and the volume fraction of twinned material, were determined as a function of plastic strain for several strain paths and initial textures at 298 K and 623 K. Incremental transverse platic strain ratios ( R) were mesured as a function of plastic strain. Texture rotation occurs early in the deformation process, after as little as 1.5% plastic strain. For compressive plastic strains, the resolved fraction of basal poles increases in the direction parallel to the strain axis. For tensile plastic strains, the resolved fraction of basal poles decreases in the direction parallel to the strain axis. The rate of change of the resolved fraction of basal poles with plastic strain is a function of the initial resolved fraction of basal poles. The texture rotation can be explained by considering the operation of the principal tensile twinning systems, {101¯2}<1¯011>.

A time-resolved image sensor for tubeless streak cameras

NASA Astrophysics Data System (ADS)

Yasutomi, Keita; Han, SangMan; Seo, Min-Woong; Takasawa, Taishi; Kagawa, Keiichiro; Kawahito, Shoji

2014-03-01

This paper presents a time-resolved CMOS image sensor with draining-only modulation (DOM) pixels for tube-less streak cameras. Although the conventional streak camera has high time resolution, the device requires high voltage and bulky system due to the structure with a vacuum tube. The proposed time-resolved imager with a simple optics realize a streak camera without any vacuum tubes. The proposed image sensor has DOM pixels, a delay-based pulse generator, and a readout circuitry. The delay-based pulse generator in combination with an in-pixel logic allows us to create and to provide a short gating clock to the pixel array. A prototype time-resolved CMOS image sensor with the proposed pixel is designed and implemented using 0.11um CMOS image sensor technology. The image array has 30(Vertical) x 128(Memory length) pixels with the pixel pitch of 22.4um. .

Detecting aromatic compounds on planetary surfaces using ultraviolet time-resolved fluorescence spectroscopy

NASA Astrophysics Data System (ADS)

Eshelman, E.; Daly, M. G.; Slater, G.; Cloutis, E.

2018-02-01

Many aromatic organic molecules exhibit strong and characteristic fluorescence when excited with ultraviolet radiation. As laser excitation in the ultraviolet generates both fluorescence and resonantly enhanced Raman scattering of aromatic vibrational modes, combined Raman and fluorescence instruments have been proposed to search for organic compounds on Mars. In this work the time-resolved fluorescence of a suite of 24 compounds composed of 2-5 ringed alternant, non-alternant, and heterocyclic PAHs was measured. Fluorescence instrumentation with similar specifications to a putative flight instrument was capable of observing the fluorescence decay of these compounds with a sub-ns resolution. Incorporating time-resolved capabilities was also found to increase the ability to discriminate between individual PAHs. Incorporating time-resolved fluorescence capabilities into an ultraviolet gated Raman system intended for a rover or lander can increase the ability to detect and characterize PAHs on planetary surfaces.

Accelerated simulation of stochastic particle removal processes in particle-resolved aerosol models

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

Curtis, J.H.; Michelotti, M.D.; Riemer, N.

2016-10-01

Stochastic particle-resolved methods have proven useful for simulating multi-dimensional systems such as composition-resolved aerosol size distributions. While particle-resolved methods have substantial benefits for highly detailed simulations, these techniques suffer from high computational cost, motivating efforts to improve their algorithmic efficiency. Here we formulate an algorithm for accelerating particle removal processes by aggregating particles of similar size into bins. We present the Binned Algorithm for particle removal processes and analyze its performance with application to the atmospherically relevant process of aerosol dry deposition. We show that the Binned Algorithm can dramatically improve the efficiency of particle removals, particularly for low removalmore » rates, and that computational cost is reduced without introducing additional error. In simulations of aerosol particle removal by dry deposition in atmospherically relevant conditions, we demonstrate about 50-times increase in algorithm efficiency.« less

Standard Terminal Automation Replacement System Human Factors Review Supporting Documents Volume 2

DOT National Transportation Integrated Search

1997-12-18

The Federal Aviation Administration formed a Standard Terminal Automation Replacement : System (STARS) Working Group to identify and resolve human factors concerns with the Early : Display Capability (EDC) system before it is introduced in the field....

Advancements in Dual-Pump Broadband CARS for Supersonic Combustion Measurements

NASA Technical Reports Server (NTRS)

Tedder, Sarah Augusta Umberger

2010-01-01

Space- and time-resolved measurements of temperature and species mole fractions of nitrogen, oxygen, and hydrogen were obtained with a dual-pump coherent anti-Stokes Raman spectroscopy (CARS) system in hydrogen-fueled supersonic combustion free jet flows. These measurements were taken to provide time-resolved fluid properties of turbulent supersonic combustion for use in the creation and verification of computational fluid dynamic (CFD) models. CFD models of turbulent supersonic combustion flow currently facilitate the design of air-breathing supersonic combustion ramjet (scramjet) engines. Measurements were made in supersonic axi-symmetric free jets of two scales. First, the measurement system was tested in a laboratory environment using a laboratory-scale burner (approx.10 mm at nozzle exit). The flow structures of the laboratory-burner were too small to be resolved with the CARS measurements volume, but the composition and temperature of the jet allowed the performance of the system to be evaluated. Subsequently, the system was tested in a burner that was approximately 6 times larger, whose length scales are better resolved by the CARS measurement volume. During both these measurements, weaknesses of the CARS system, such as sensitivity to vibrations and beam steering and inability to measure temperature or species concentrations in hydrogen fuel injection regions were indentified. Solutions were then implemented in improved CARS systems. One of these improved systems is a dual-pump broadband CARS technique called, Width Increased Dual-pump Enhanced CARS (WIDECARS). The two lowest rotational energy levels of hydrogen detectable by WIDECARS are H2 S(3) and H2 S(4). The detection of these lines gives the system the capability to measure temperature and species concentrations in regions of the flow containing pure hydrogen fuel at room temperature. WIDECARS is also designed for measurements of all the major species (except water) in supersonic combustion flows fueled with hydrogen and hydrogen/ethylene mixtures (N2, O2, H2, C2H4, CO, and CO2). This instrument can characterize supersonic combustion fueled with surrogate fuel mixtures of hydrogen and ethylene. This information can lead to a better understanding of the chemistry and performance of supersonic combustion fueled with cracked jet propulsion (JP)-type fuel.

MicroCT with energy-resolved photon-counting detectors

PubMed Central

Wang, X; Meier, D; Mikkelsen, S; Maehlum, G E; Wagenaar, D J; Tsui, BMW; Patt, B E; Frey, E C

2011-01-01

The goal of this paper was to investigate the benefits that could be realistically achieved on a microCT imaging system with an energy-resolved photon-counting x-ray detector. To this end, we built and evaluated a prototype microCT system based on such a detector. The detector is based on cadmium telluride (CdTe) radiation sensors and application-specific integrated circuit (ASIC) readouts. Each detector pixel can simultaneously count x-ray photons above six energy thresholds, providing the capability for energy-selective x-ray imaging. We tested the spectroscopic performance of the system using polychromatic x-ray radiation and various filtering materials with Kabsorption edges. Tomographic images were then acquired of a cylindrical PMMA phantom containing holes filled with various materials. Results were also compared with those acquired using an intensity-integrating x-ray detector and single-energy (i.e. non-energy-selective) CT. This paper describes the functionality and performance of the system, and presents preliminary spectroscopic and tomographic results. The spectroscopic experiments showed that the energy-resolved photon-counting detector was capable of measuring energy spectra from polychromatic sources like a standard x-ray tube, and resolving absorption edges present in the energy range used for imaging. However, the spectral quality was degraded by spectral distortions resulting from degrading factors, including finite energy resolution and charge sharing. We developed a simple charge-sharing model to reproduce these distortions. The tomographic experiments showed that the availability of multiple energy thresholds in the photon-counting detector allowed us to simultaneously measure target-to-background contrasts in different energy ranges. Compared with single-energy CT with an integrating detector, this feature was especially useful to improve differentiation of materials with different attenuation coefficient energy dependences. PMID:21464527

Conceptual design of novel IP-conveyor-belt Weissenberg-mode data-collection system with multi-readers for macromolecular crystallography. A comparison between Galaxy and Super Galaxy.

PubMed

Sakabe, N; Sakabe, K; Sasaki, K

2004-01-01

Galaxy is a Weissenberg-type high-speed high-resolution and highly accurate fully automatic data-collection system using two cylindrical IP-cassettes each with a radius of 400 mm and a width of 450 mm. It was originally developed for static three-dimensional analysis using X-ray diffraction and was installed on bending-magnet beamline BL6C at the Photon Factory. It was found, however, that Galaxy was also very useful for time-resolved protein crystallography on a time scale of minutes. This has prompted us to design a new IP-conveyor-belt Weissenberg-mode data-collection system called Super Galaxy for time-resolved crystallography with improved time and crystallographic resolution over that achievable with Galaxy. Super Galaxy was designed with a half-cylinder-shaped cassette with a radius of 420 mm and a width of 690 mm. Using 1.0 A incident X-rays, these dimensions correspond to a maximum resolutions of 0.71 A in the vertical direction and 1.58 A in the horizontal. Upper and lower screens can be used to set the frame size of the recorded image. This function is useful not only to reduce the frame exchange time but also to save disk space on the data server. The use of an IP-conveyor-belt and many IP-readers make Super Galaxy well suited for time-resolved, monochromatic X-ray crystallography at a very intense third-generation SR beamline. Here, Galaxy and a conceptual design for Super Galaxy are described, and their suitability for use as data-collection systems for macromolecular time-resolved monochromatic X-ray crystallography are compared.

MicroCT with energy-resolved photon-counting detectors.

PubMed

Wang, X; Meier, D; Mikkelsen, S; Maehlum, G E; Wagenaar, D J; Tsui, B M W; Patt, B E; Frey, E C

2011-05-07

The goal of this paper was to investigate the benefits that could be realistically achieved on a microCT imaging system with an energy-resolved photon-counting x-ray detector. To this end, we built and evaluated a prototype microCT system based on such a detector. The detector is based on cadmium telluride (CdTe) radiation sensors and application-specific integrated circuit (ASIC) readouts. Each detector pixel can simultaneously count x-ray photons above six energy thresholds, providing the capability for energy-selective x-ray imaging. We tested the spectroscopic performance of the system using polychromatic x-ray radiation and various filtering materials with K-absorption edges. Tomographic images were then acquired of a cylindrical PMMA phantom containing holes filled with various materials. Results were also compared with those acquired using an intensity-integrating x-ray detector and single-energy (i.e. non-energy-selective) CT. This paper describes the functionality and performance of the system, and presents preliminary spectroscopic and tomographic results. The spectroscopic experiments showed that the energy-resolved photon-counting detector was capable of measuring energy spectra from polychromatic sources like a standard x-ray tube, and resolving absorption edges present in the energy range used for imaging. However, the spectral quality was degraded by spectral distortions resulting from degrading factors, including finite energy resolution and charge sharing. We developed a simple charge-sharing model to reproduce these distortions. The tomographic experiments showed that the availability of multiple energy thresholds in the photon-counting detector allowed us to simultaneously measure target-to-background contrasts in different energy ranges. Compared with single-energy CT with an integrating detector, this feature was especially useful to improve differentiation of materials with different attenuation coefficient energy dependences.

A hierarchically distributed architecture for fault isolation expert systems on the space station

NASA Technical Reports Server (NTRS)

Miksell, Steve; Coffer, Sue

1987-01-01

The Space Station Axiomatic Fault Isolating Expert Systems (SAFTIES) system deals with the hierarchical distribution of control and knowledge among independent expert systems doing fault isolation and scheduling of Space Station subsystems. On its lower level, fault isolation is performed on individual subsystems. These fault isolation expert systems contain knowledge about the performance requirements of their particular subsystem and corrective procedures which may be involved in repsonse to certain performance errors. They can control the functions of equipment in their system and coordinate system task schedules. On a higher level, the Executive contains knowledge of all resources, task schedules for all systems, and the relative priority of all resources and tasks. The executive can override any subsystem task schedule in order to resolve use conflicts or resolve errors that require resources from multiple subsystems. Interprocessor communication is implemented using the SAFTIES Communications Interface (SCI). The SCI is an application layer protocol which supports the SAFTIES distributed multi-level architecture.

High-harmonic spectroscopy of ultrafast many-body dynamics in strongly correlated systems

NASA Astrophysics Data System (ADS)

Silva, R. E. F.; Blinov, Igor V.; Rubtsov, Alexey N.; Smirnova, O.; Ivanov, M.

2018-05-01

We bring together two topics that, until now, have been the focus of intense but non-overlapping research efforts. The first concerns high-harmonic generation in solids, which occurs when an intense light field excites a highly non-equilibrium electronic response in a semiconductor or a dielectric. The second concerns many-body dynamics in strongly correlated systems such as the Mott insulator. We show that high-harmonic generation can be used to time-resolve ultrafast many-body dynamics associated with an optically driven phase transition, with accuracy far exceeding one cycle of the driving light field. Our work paves the way for time-resolving highly non-equilibrium many-body dynamics in strongly correlated systems, with few femtosecond accuracy.

Time-resolved measurements in diffuse reflectance: effects of the instrument response function of different detection systems on the depth sensitivity

NASA Astrophysics Data System (ADS)

Puszka, Agathe; Planat-Chrétien, Anne; Berger, Michel; Hervé, Lionel; Dinten, Jean-Marc

2014-02-01

We demonstrate the loss of depth sensitivity induced by the instrument response function on reflectance time-resolved diffuse optical tomography through the comparison of 3 detection systems: on one hand a photomultiplier tube (PMT) and a hybrid PMT coupled with a time-correlated single-photon counting card and on the other hand a high rate intensified camera. We experimentally evaluate the depth sensitivity achieved for each detection module with an absorbing inclusion embedded in a turbid medium. The different interfiber distances of 5, 10 and 15 mm are considered. Finally, we determine a maximal depth reached for each detection system by using 3D tomographic reconstructions based on the Mellin-Laplace transform.

Resolving Phase Ambiguities In OQPSK

NASA Technical Reports Server (NTRS)

Nguyen, Tien M.

1991-01-01

Improved design for modulator and demodulator in offset-quaternary-phase-key-shifting (OQPSK) communication system enables receiver to resolve ambiguity in estimated phase of received signal. Features include unique-code-word modulation and detection and digital implementation of Costas loop in carrier-recovery subsystem. Enchances performance of carrier-recovery subsystem, reduces complexity of receiver by removing redundant circuits from previous design, and eliminates dependence of timing in receiver upon parallel-to-serial-conversion clock.

Goddard Cumulus Ensemble (GCE) Model: Application for Understanding Precipitation Processes

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo

2002-01-01

One of the most promising methods to test the representation of cloud processes used in climate models is to use observations together with Cloud Resolving Models (CRMs). The CRMs use more sophisticated and realistic representations of cloud microphysical processes, and they can reasonably well resolve the time evolution, structure, and life cycles of clouds and cloud systems (size about 2-200 km). The CRMs also allow explicit interaction between out-going longwave (cooling) and incoming solar (heating) radiation with clouds. Observations can provide the initial conditions and validation for CRM results. The Goddard Cumulus Ensemble (GCE) Model, a cloud-resolving model, has been developed and improved at NASA/Goddard Space Flight Center over the past two decades. Dr. Joanne Simpson played a central role in GCE modeling developments and applications. She was the lead author or co-author on more than forty GCE modeling papers. In this paper, a brief discussion and review of the application of the GCE model to (1) cloud interactions and mergers, (2) convective and stratiform interaction, (3) mechanisms of cloud-radiation interaction, (4) latent heating profiles and TRMM, and (5) responses of cloud systems to large-scale processes are provided. Comparisons between the GCE model's results, other cloud-resolving model results and observations are also examined.

Angle-resolved effective potentials for disk-shaped molecules

NASA Astrophysics Data System (ADS)

Heinemann, Thomas; Palczynski, Karol; Dzubiella, Joachim; Klapp, Sabine H. L.

2014-12-01

We present an approach for calculating coarse-grained angle-resolved effective pair potentials for uniaxial molecules. For integrating out the intramolecular degrees of freedom we apply umbrella sampling and steered dynamics techniques in atomistically-resolved molecular dynamics (MD) computer simulations. Throughout this study we focus on disk-like molecules such as coronene. To develop the methods we focus on integrating out the van der Waals and intramolecular interactions, while electrostatic charge contributions are neglected. The resulting coarse-grained pair potential reveals a strong temperature and angle dependence. In the next step we fit the numerical data with various Gay-Berne-like potentials to be used in more efficient simulations on larger scales. The quality of the resulting coarse-grained results is evaluated by comparing their pair and many-body structure as well as some thermodynamic quantities self-consistently to the outcome of atomistic MD simulations of many-particle systems. We find that angle-resolved potentials are essential not only to accurately describe crystal structures but also for fluid systems where simple isotropic potentials start to fail already for low to moderate packing fractions. Further, in describing these states it is crucial to take into account the pronounced temperature dependence arising in selected pair configurations due to bending fluctuations.

Time-resolved Spectroscopy of RS CVn Binaries and dMe Flare Stars

NASA Astrophysics Data System (ADS)

Brown, Alexander

One of the most striking feature of the first two years of EUVE spectroscopy is the frequent occurrence of largescale coronal variability, in the form of stellar flares and slower changes in activity level due to rotational modulation and evolution of active regions. We propose EUVE observations of a set of RS CVn and dMe star binaries, most with short (< 2 days) periods, to investigate the coronal conditions and physical processes associated with this variability. EUVE flare outbursts have mostly been long duration events lasting many satellite orbits and been readily studied using time-resolved spectroscopy. Our targets are the dMe binaries YY Gem, CC Eri and Gliese 2123, and the RS CVn systems EI Eri, AR Psc, and TY Pyx. YY Gem and TY Pyx are eclipsing systems and Deep Survey photometry will be used to investigate the size of the coronal emitting regions. Situated 73 arcmin from YY Gem is Castor (Alpha Gem) another X-ray source that can be observed (and spatially resolved) simultaneously. We shall use the DS lightcurve to guide our time resolved spectral analysis. Changes in the coronal emission measure as a function of temperature and possibly changes in coronal density will be used to constrain magnetic loop models.

Comparison between two time-resolved approaches for prostate cancer diagnosis: high rate imager vs. photon counting system

NASA Astrophysics Data System (ADS)

Boutet, J.; Debourdeau, M.; Laidevant, A.; Hervé, L.; Dinten, J.-M.

2010-02-01

Finding a way to combine ultrasound and fluorescence optical imaging on an endorectal probe may improve early detection of prostate cancer. A trans-rectal probe adapted to fluorescence diffuse optical tomography measurements was developed by our team. This probe is based on a pulsed NIR laser source, an optical fiber network and a time-resolved detection system. A reconstruction algorithm was used to help locate and quantify fluorescent prostate tumors. In this study, two different kinds of time-resolved detectors are compared: High Rate Imaging system (HRI) and a photon counting system. The HRI is based on an intensified multichannel plate and a CCD Camera. The temporal resolution is obtained through a gating of the HRI. Despite a low temporal resolution (300ps), this system allows a simultaneous acquisition of the signal from a large number of detection fibers. In the photon counting setup, 4 photomultipliers are connected to a Time Correlated Single Photon Counting (TCSPC) board, providing a better temporal resolution (0.1 ps) at the expense of a limited number of detection fibers (4). At last, we show that the limited number of detection fibers of the photon counting setup is enough for a good localization and dramatically improves the overall acquisition time. The photon counting approach is then validated through the localization of fluorescent inclusions in a prostate-mimicking phantom.

Non-Nuclear Testing of Space Nuclear Systems at NASA MSFC

NASA Technical Reports Server (NTRS)

Houts, Michael G.; Pearson, Boise J.; Aschenbrenner, Kenneth C.; Bradley, David E.; Dickens, Ricky; Emrich, William J.; Garber, Anne; Godfroy, Thomas J.; Harper, Roger T.; Martin, Jim J.;

Developing a clinically viable angle-resolved low coherence interferometry optical biopsy system

NASA Astrophysics Data System (ADS)

Pyhtila, John W.

2007-12-01

Non-invasive optical biopsy techniques, which interrogate tissue in situ, offer a potential method to improve the detection of dysplasia, a pre-cancerous tissue state. Specifically, monitoring of Barrett's esophagus (BE) patients for dysplasia, currently done through systematic biopsy, can be improved by increasing the proportion of at-risk tissue examined. Angle-resolved low coherence interferometry (a/LCI) is an optical spectroscopic technique which measures the depth resolved nuclear morphology of tissue, a key biomarker for identifying dysplasia. Using an animal carcinogenesis model, it was shown that a/LCI can detect dysplasia with great sensitivity and specificity. However, for the clinical application of a/LCI, numerous hurdles must be overcome. This dissertation presents the development of three new a/LCI systems which incrementally address the three main obstacles preventing the clinical application of a/LCI. First, data acquisition time is reduced by implementing a frequency-domain detection scheme using an imaging spectrograph that collects the complete depth resolved angular scattering distribution in parallel. This advance reduces data collection time to a clinically acceptable 40 ms. Second, a fiber probe is developed to enable the endoscopic application of a/LCI. The probe incorporates a single fiber for delivering light and a coherent fiber bundle for collecting the angular distribution of scattered light. Third, a portable device is created through miniaturization of the optical design, and a flexible fiber probe is created using polarization maintaining fiber to deliver the light. These advances allow for the clinical application of the system to ex vivo human tissue samples. The performance of each described system is evaluated through a number of validation studies, including the sizing of polystyrene microspheres, a typical model used in light scattering studies, and the measurement of in vitro cell nuclear diameters, accomplished with sub-wavelength precision and accuracy. The culmination of this work is the first human study using a/LCI in which it is demonstrated that a/LCI depth resolved nuclear morphology measurements provide an excellent means to identify dysplasia in BE patients. The described results demonstrate the great potential for the in vivo application of a/LCI as a targeting mechanism for the detection of dysplasia in Barrett's esophagus patients.

A Survey of the High Order Multiplicity of Nearby Solar-Type Binary Stars with Robo-AO

DTIC Science & Technology

2015-01-20

auxiliary images are not used for astrometry or photometry , but are helpful for verifying compan- ion detection and for resolving the 180◦ ambiguity of...pair Ba,Bb was resolved by Robo-AO three times at 0.′′16 with Δi = 0.87m, Δr = 0.97m, and Δz = 0.52m. This corresponds to a mass for Bb of ∼0.6M. We...known quintuple system. The component E (STF 2032AE, E=HIP 79551=GJ 615.2C) is resolved here at 0.′′4 (but not for the first time : Ea,Eb=YSC 152

Resolving the vacuum fluctuations of an optomechanical system using an artificial atom

NASA Astrophysics Data System (ADS)

Lecocq, F.; Teufel, J. D.; Aumentado, J.; Simmonds, R. W.

2015-08-01

Heisenberg’s uncertainty principle results in one of the strangest quantum behaviours: a mechanical oscillator can never truly be at rest. Even at a temperature of absolute zero, its position and momentum are still subject to quantum fluctuations. However, direct energy detection of the oscillator in its ground state makes it seem motionless, and in linear position measurements detector noise can masquerade as mechanical fluctuations. Thus, how can we resolve quantum fluctuations? Here, we parametrically couple a micromechanical oscillator to a microwave cavity to prepare the system in its quantum ground state and then amplify the remaining vacuum fluctuations into real energy quanta. We monitor the photon/phonon-number distributions using a superconducting qubit, allowing us to resolve the quantum vacuum fluctuations of the macroscopic oscillator’s motion. Our results further demonstrate the ability to control a long-lived mechanical oscillator using a non-Gaussian resource, directly enabling applications in quantum information processing and enhanced detection of displacement and forces.

Final design of the Energy-Resolved Neutron Imaging System “RADEN” at J-PARC

NASA Astrophysics Data System (ADS)

Shinohara, T.; Kai, T.; Oikawa, K.; Segawa, M.; Harada, M.; Nakatani, T.; Ooi, M.; Aizawa, K.; Sato, H.; Kamiyama, T.; Yokota, H.; Sera, T.; Mochiki, K.; Kiyanagi, Y.

2016-09-01

A new pulsed-neutron instrument, named the Energy-Resolved Neutron Imaging System “RADEN”, has been constructed at the beam line of BL22 in the Materials and Life Science Experimental Facility (MLF) of J-PARC. The primary purpose of this instrument is to perform energy-resolved neutron imaging experiments through the effective utilization of the pulsed nature of the neutron beam, making this the world's first instrument dedicated to pulsed neutron imaging experiments. RADEN was designed to cover a broad energy range: from cold neutrons with energy down to 1.05 meV (or wavelength up to 8.8 Å) with a good wavelength resolution of 0.20% to high-energy neutrons with energy of several tens keV (or wavelength of 10-3 Å). In addition, this instrument is intended to perform state-of-the-art neutron radiography and tomography experiments in Japan. Hence, a maximum beam size of 300 mm square and a high L/D value of up to 7500 are provided.

Localized states in advanced dielectrics from the vantage of spin- and symmetry-polarized tunnelling across MgO.

PubMed

Schleicher, F; Halisdemir, U; Lacour, D; Gallart, M; Boukari, S; Schmerber, G; Davesne, V; Panissod, P; Halley, D; Majjad, H; Henry, Y; Leconte, B; Boulard, A; Spor, D; Beyer, N; Kieber, C; Sternitzky, E; Cregut, O; Ziegler, M; Montaigne, F; Beaurepaire, E; Gilliot, P; Hehn, M; Bowen, M

2014-08-04

Research on advanced materials such as multiferroic perovskites underscores promising applications, yet studies on these materials rarely address the impact of defects on the nominally expected materials property. Here, we revisit the comparatively simple oxide MgO as the model material system for spin-polarized solid-state tunnelling studies. We present a defect-mediated tunnelling potential landscape of localized states owing to explicitly identified defect species, against which we examine the bias and temperature dependence of magnetotransport. By mixing symmetry-resolved transport channels, a localized state may alter the effective barrier height for symmetry-resolved charge carriers, such that tunnelling magnetoresistance decreases most with increasing temperature when that state is addressed electrically. Thermal excitation promotes an occupancy switchover from the ground to the excited state of a defect, which impacts these magnetotransport characteristics. We thus resolve contradictions between experiment and theory in this otherwise canonical spintronics system, and propose a new perspective on defects in dielectrics.

Determination of blood oxygenation in the brain by time-resolved reflectance spectroscopy: influence of the skin, skull, and meninges

NASA Astrophysics Data System (ADS)

Hielscher, Andreas H.; Liu, Hanli; Wang, Lihong V.; Tittel, Frank K.; Chance, Britton; Jacques, Steven L.

1994-07-01

Near infrared light has been used for the determination of blood oxygenation in the brain but little attention has been paid to the fact that the states of blood oxygenation in arteries, veins, and capillaries differ substantially. In this study, Monte Carlo simulations for a heterogeneous system were conducted, and near infrared time-resolved reflectance measurements were performed on a heterogeneous tissue phantom model. The model was made of a solid polyester resin, which simulates the tissue background. A network of tubes was distributed uniformly through the resin to simulate the blood vessels. The time-resolved reflectance spectra were taken with different absorbing solutions filled in the network. Based on the simulation and experimental results, we investigated the dependence of the absorption coefficient obtained from the heterogeneous system on the absorption of the actual absorbing solution filled in the tubes. We show that light absorption by the brain should result from the combination of blood and blood-free tissue background.

Molecular Imaging for Breast Cancer Using Magnetic Resonance-Guided Positron Emission Mammography and Excitation-Resolved Near-Infrared Fluorescence Imaging

NASA Astrophysics Data System (ADS)

Cho, Jaedu

The aim of this work is to develop novel breast-specific molecular imaging techniques for management of breast cancer. In this dissertation, we describe two novel molecular imaging approaches for breast cancer management. In Part I, we introduce our multimodal molecular imaging approach for breast cancer therapy monitoring using magnetic resonance imaging and positron emission mammography (MR/PEM). We have focused on the therapy monitoring technique for aggressive cancer molecular subtypes, which is challenging due to time constraint. Breast cancer therapy planning relies on a fast and accurate monitoring of functional and anatomical change. We demonstrate a proof-of-concept of sequential dual-modal magnetic resonance and positron emission mammography (MR/PEM) for the cancer therapy monitoring. We have developed dedicated breast coils with breast compression mechanism equipped with MR-compatible PEM detector heads. We have designed a fiducial marker that allows straightforward image registration of data obtained from MRI and PEM. We propose an optimal multimodal imaging procedure for MR/PEM. In Part II, we have focused on the development of a novel intraoperative near-infrared fluorescence imaging system (NIRF) for image-guided breast cancer surgery. Conventional spectrally-resolved NIRF systems are unable to resolve various NIR fluorescence dyes for the following reasons. First, the fluorescence spectra of viable NIR fluorescence dyes are heavily overlapping. Second, conventional emission-resolved NIRF suffers from a trade-off between the fluence rate and the spectral resolution. Third, the multiple scattering in tissue degrades not only the spatial information but also the spectral contents by the red-shift. We develop a wavelength-swept laser-based NIRF system that can resolve the excitation shift of various NIR fluorescence dyes without substantial loss of the fluence rate. A linear ratiometric model is employed to measure the relative shift of the excitation spectrum of a fluorescence dye.

Misconceptions about case-mix payments for nursing homes.

PubMed

Grimaldi, P L

1987-04-01

Despite the increasing use of case-mix payment systems for skilled and intermediate nursing home care (at least 10 state Medicaid programs have adopted or are considering adopting such a system), misconceptions about such systems still exist. Unless these inaccurate perceptions are corrected, a state may adopt a system that fails to realize its goals. Some of these misconceptions include the beliefs that case-mix payment systems: Apply to all nursing homes costs; Will benefit hospital-based facilities; Will resolve the access problems of heavy care public patients; Will result in higher statewide payment rates because patient characteristics are factored directly into the calculations. In fact, case-mix adjustments are applied only to costs that can be traced directly to patients' impairments. Nursing services and some ancillary services are dependent on case mix, while administrative and support services are largely independent of case mix. Capital costs usually can be ignored in formulating the case-mix adjustment. Although hospital-based facilities frequently have sicker patients than freestanding facilities, studies show that only a portion of the cost differential is explained by case-mix differences. In the case of heavy-care patients, some believe that case-mix payment systems will resolve access problems by paying higher rates in response to the higher treatment costs. Access may not improve, however, if the new rates are lower than those paid by comparable private patients. Perhaps a loosening in the certificate-of-need process will also be needed to resolve the access problem.(ABSTRACT TRUNCATED AT 250 WORDS)

A Framework to Learn Physics from Atomically Resolved Images

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

Vlcek, L.; Maksov, A.; Pan, M.

Here, we present a generalized framework for physics extraction, i.e., knowledge, from atomically resolved images, and show its utility by applying it to a model system of segregation of chalcogen atoms in an FeSe 0.45Te 0.55 superconductor system. We emphasize that the framework can be used for any imaging data for which a generative physical model exists. Consider that a generative physical model can produce a very large number of configurations, not all of which are observable. By applying a microscope function to a sub-set of this generated data, we form a simulated dataset on which statistics can be computed.

Spatially Resolved Spectroscopy of the PMS Quadruple GG Tau: Evidence for a Substellar Companion

NASA Astrophysics Data System (ADS)

White, R. J.; Ghez, A. M.; Schultz, G.; Reid, I. N.

1998-05-01

We present spatially resolved optical spectra from HST (FOS) and the Keck Telescope (HIRES & LRIS) of the components of the quadruple PMS system GG Tau. According to the latest PMS evolutionary models, the coldest component of this system, GG Tau/c B, appears to be substellar with a preliminary mass of only 50 M_J. This putative brown dwarf is especially intriguing as it shows clear signatures of accretion. The components of this quadruple, which span a wide range in mass, are used to test theoretical low mass PMS evolutionary models under the assumption that the components should be coeval.

Resolved shear stress intensity coefficient and fatigue crack growth in large crystals

NASA Technical Reports Server (NTRS)

Chen, QI; Liu, Hao-Wen

1988-01-01

Fatigue crack growth in large grain Al alloy was studied. Fatigue crack growth is caused primarily by shear decohesion due to dislocation motion in the crack tip region. The crack paths in the large crystals are very irregular and zigzag. The crack planes are often inclined to the loading axis both in the inplane direction and the thickness direction. The stress intensity factors of such inclined cracks are approximated from the two dimensional finite element calculations. The plastic deformation in a large crystal is highly anisotropic, and dislocation motion in such crystals are driven by the resolved shear stress. The resolved shear stress intensity coefficient in a crack solid, RSSIC, is defined, and the coefficients for the slip systems at a crack tip are evaluated from the calculated stress intensity factors. The orientations of the crack planes are closely related to the slip planes with the high RSSIC values. If a single slip system has a much higher RSSIC than all the others, the crack will follow the slip plane, and the slip plane becomes the crack plane. If two or more slip systems have a high RSSIC, the crack plane is the result of the decohesion processes on these active slip planes.

Resolving Structural Isomers of Monosaccharide Methyl Glycosides Using Drift Tube and Traveling Wave Ion Mobility Mass Spectrometry

PubMed Central

Li, Hongli; Giles, Kevin; Bendiak, Brad; Kaplan, Kimberly; Siems, William F.; Hill, Herbert H.

2013-01-01

Monosaccharide structural isomers including sixteen methyl-D-glycopyranosides and four methyl-N-acetylhexosamines were subjected to ion mobility measurements by electrospray ion mobility mass spectrometry. Two ion mobility-MS systems were employed: atmospheric pressure drift tube ion mobility time-of-flight mass spectrometry and a Synapt G2 HDMS system which incorporates a low pressure traveling wave ion mobility separator. All the compounds were investigated as [M+Na]+ ions in the positive mode. A majority of the monosaccharide structural isomers exhibited different mobility drift times in either system, depending on differences in their anomeric and stereochemical configurations. In general, drift time patterns (relative drift times of isomers) matched between the two instruments. Higher resolving power was observed using the atmospheric pressure drift tube. Collision cross section values of monosaccharide structural isomers were directly calculated from the atmospheric pressure ion mobility experiments and a collision cross section calibration curve was made for the traveling wave ion mobility instrument. Overall, it was demonstrated that ion mobility-mass spectrometry using either drift tube or traveling wave ion mobility is a valuable technique for resolving subtle variations in stereochemistry among the sodium adducts of monosaccharide methyl glycosides. PMID:22339760

Modeling and optimization of a time-resolved proton radiographic imaging system for proton cancer treatment

NASA Astrophysics Data System (ADS)

Han, Bin

This dissertation describes a research project to test the clinical utility of a time-resolved proton radiographic (TRPR) imaging system by performing comprehensive Monte Carlo simulations of a physical device coupled with realistic lung cancer patient anatomy defined by 4DCT for proton therapy. A time-resolved proton radiographic imaging system was modeled through Monte Carlo simulations. A particle-tracking feature was employed to evaluate the performance of the proton imaging system, especially in its ability to visualize and quantify proton range variations during respiration. The Most Likely Path (MLP) algorithm was developed to approximate the multiple Coulomb scattering paths of protons for the purpose of image reconstruction. Spatial resolution of ˜ 1 mm and range resolution of 1.3% of the total range were achieved using the MLP algorithm. Time-resolved proton radiographs of five patient cases were reconstructed to track tumor motion and to calculate water equivalent length variations. By comparing with direct 4DCT measurement, the accuracy of tumor tracking was found to be better than 2 mm in five patient cases. Utilizing tumor tracking information to reduce margins to the planning target volume, a gated treatment plan was compared with un-gated treatment plan. The equivalent uniform dose (EUD) and the normal tissue complication probability (NTCP) were used to quantify the gain in the quality of treatments. The EUD of the OARs was found to be reduced up to 11% and the corresponding NTCP of organs at risk (OARs) was found to be reduced up to 16.5%. These results suggest that, with image guidance by proton radiography, dose to OARs can be reduced and the corresponding NTCPs can be significantly reduced. The study concludes that the proton imaging system can accurately track the motion of the tumor and detect the WEL variations, leading to potential gains in using image-guided proton radiography for lung cancer treatments.

The relational clinical database: a possible solution to the star wars in registry systems.

PubMed

Michels, D K; Zamieroski, M

1990-12-01

In summary, having data from other service areas available in a relational clinical database could resolve many of the problems existing in today's registry systems. Uniting sophisticated information systems into a centralized database system could definitely be a corporate asset in managing the bottom line.

Systems Engineering

NASA Technical Reports Server (NTRS)

Pellerano, Fernando

2015-01-01

This short course provides information on what systems engineering is and how the systems engineer guides requirements, interfaces with the discipline leads, and resolves technical issues. There are many system-wide issues that either impact or are impacted by the thermal subsystem. This course will introduce these issues and illustrate them with real life examples.

Unsteady Transonic Flow Past Airfoils in Rigid Body Motion.

DTIC Science & Technology

1981-03-01

coordinate system. Numerical experiments show that the scheme is very stable and is able to resolve the highly non- linear transonic effects for flutter...Numerical experiments show that the scheme is very stable and is able to resolve the highly nonlinear transonic effects for flutter analysis within...of attack, the angle between the flight direction and the airfoil chord. The effect of chanqinthe angle of attack of a conventional symmetric airfoil

Unresolved versus resolved: testing the validity of young simple stellar population models with VLT/MUSE observations of NGC 3603

NASA Astrophysics Data System (ADS)

Kuncarayakti, H.; Galbany, L.; Anderson, J. P.; Krühler, T.; Hamuy, M.

2016-09-01

Context. Stellar populations are the building blocks of galaxies, including the Milky Way. The majority, if not all, extragalactic studies are entangled with the use of stellar population models given the unresolved nature of their observation. Extragalactic systems contain multiple stellar populations with complex star formation histories. However, studies of these systems are mainly based upon the principles of simple stellar populations (SSP). Hence, it is critical to examine the validity of SSP models. Aims: This work aims to empirically test the validity of SSP models. This is done by comparing SSP models against observations of spatially resolved young stellar population in the determination of its physical properties, that is, age and metallicity. Methods: Integral field spectroscopy of a young stellar cluster in the Milky Way, NGC 3603, was used to study the properties of the cluster as both a resolved and unresolved stellar population. The unresolved stellar population was analysed using the Hα equivalent width as an age indicator and the ratio of strong emission lines to infer metallicity. In addition, spectral energy distribution (SED) fitting using STARLIGHT was used to infer these properties from the integrated spectrum. Independently, the resolved stellar population was analysed using the colour-magnitude diagram (CMD) to determine age and metallicity. As the SSP model represents the unresolved stellar population, the derived age and metallicity were tested to determine whether they agree with those derived from resolved stars. Results: The age and metallicity estimate of NGC 3603 derived from integrated spectroscopy are confirmed to be within the range of those derived from the CMD of the resolved stellar population, including other estimates found in the literature. The result from this pilot study supports the reliability of SSP models for studying unresolved young stellar populations. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 60.A-9344.

Rail Transit Fare Collection : Policy and Technology Assessment

DOT National Transportation Integrated Search

1982-12-01

In an attempt to resolve reliability problems, lower operation and maintenance costs, and simplify fare collection, transit authorities are focusing on their fare collection systems. Many transit properties have existing fare collection systems which...

Law and Literature: An African Example.

ERIC Educational Resources Information Center

Kendall, Diane S.

1981-01-01

Presents a learning activity in which secondary students read about and analyze the legal institutions of an African tribe called the Ibo. Students compare the Ibo's precolonial system of resolving disputes with the U.S. system. (AM)

47 CFR 76.1713 - Complaint resolution.

Code of Federal Regulations, 2010 CFR

2010-10-01

... local franchising authority and the cable system operator. ... system operators shall establish a process for resolving complaints from subscribers about the quality of... for inspection by the Commission and franchising authorities, upon request. These records shall be...

Appropriate Minimal Dose of Gadobutrol for 3D Time-Resolved MRA of the Supra-Aortic Arteries: Comparison with Conventional Single-Phase High-Resolution 3D Contrast-Enhanced MRA.

PubMed

Bak, S H; Roh, H G; Moon, W-J; Choi, J W; An, H S

2017-07-01

The development of nephrogenic systemic fibrosis and neural tissue deposition is gadolinium dose-dependent. The purpose of this study was to determine the appropriate minimal dose of gadobutrol with time-resolved MRA to assess supra-aortic arterial stenosis with contrast-enhanced MRA as a reference standard. Four hundred sixty-two consecutive patients underwent both standard-dose contrast-enhanced MRA and low-dose time-resolved MRA and were classified into 3 groups; group A (a constant dose of 1 mL for time-resolved MRA), group B (2 mL), or group C (3 mL). All studies were independently evaluated by 2 radiologists for image quality by using a 5-point scale (from 0 = failure to 4 = excellent), grading of arterial stenosis (0 = normal, 1 = mild [<30%], 2 = moderate [30%-69%], 3 = severe to occlusion [≥70%]), and signal-to-noise ratio. The image quality of time-resolved MRA was similar to that of contrast-enhanced MRA in groups B and C, but it was inferior to contrast-enhanced MRA in group A. For the grading of arterial stenosis, there was an excellent correlation between contrast-enhanced MRA and time-resolved MRA ( R = 0.957 for group A, R = 0.988 for group B, R = 0.991 for group C). The SNR of time-resolved MRA tended to be lower than that of contrast-enhanced MRA in groups A and B. However, SNR was higher for time-resolved MRA compared with contrast-enhanced MRA in group C. Low-dose time-resolved MRA is feasible in the evaluation of supra-aortic stenosis and could be used as an alternative to contrast-enhanced MRA for a diagnostic technique in high-risk populations. © 2017 by American Journal of Neuroradiology.

30 CFR 260.130 - What criteria does MMS use for selecting bidding systems and bidding system components?

Code of Federal Regulations, 2011 CFR

2011-07-01

... system or tract, or may present a conflict that we will have to resolve in the process of bidding system... bidding systems and bidding system components? 260.130 Section 260.130 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OUTER CONTINENTAL...

Simultaneous CARS and Interferometric Rayleigh Scattering

NASA Technical Reports Server (NTRS)

Bivolaru, Daniel; Danehy, Paul M.; Grinstead, Keith D., Jr.; Tedder, Sarah; Cutler, Andrew D.

2006-01-01

This paper reports for the first time the combination of a dual-pump coherent anti-Stokes Raman scattering system with an interferometric Rayleigh scattering system (CARS - IRS) to provide time-resolved simultaneous measurement of multiple properties in combustion flows. The system uses spectrally narrow green (seeded Nd:YAG at 532 nm) and yellow (552.9 nm) pump beams and a spectrally-broad red (607 nm) beam as the Stokes beam. A spectrometer and a planar Fabry-Perot interferometer used in the imaging mode are used to record the spectrally broad CARS spectra and the spontaneous Rayleigh scattering spectra, respectively. Time-resolved simultaneous measurement of temperature, absolute mole fractions of N2, O2, and H2, and two components of velocity in a Hencken burner flame were performed to demonstrate the technique.

TBA-like integral equations from quantized mirror curves

NASA Astrophysics Data System (ADS)

Okuyama, Kazumi; Zakany, Szabolcs

2016-03-01

Quantizing the mirror curve of certain toric Calabi-Yau (CY) three-folds leads to a family of trace class operators. The resolvent function of these operators is known to encode topological data of the CY. In this paper, we show that in certain cases, this resolvent function satisfies a system of non-linear integral equations whose structure is very similar to the Thermodynamic Bethe Ansatz (TBA) systems. This can be used to compute spectral traces, both exactly and as a semiclassical expansion. As a main example, we consider the system related to the quantized mirror curve of local P2. According to a recent proposal, the traces of this operator are determined by the refined BPS indices of the underlying CY. We use our non-linear integral equations to test that proposal.

Resolving quanta of collective spin excitations in a millimeter-sized ferromagnet

PubMed Central

Lachance-Quirion, Dany; Tabuchi, Yutaka; Ishino, Seiichiro; Noguchi, Atsushi; Ishikawa, Toyofumi; Yamazaki, Rekishu; Nakamura, Yasunobu

2017-01-01

Combining different physical systems in hybrid quantum circuits opens up novel possibilities for quantum technologies. In quantum magnonics, quanta of collective excitation modes in a ferromagnet, called magnons, interact coherently with qubits to access quantum phenomena of magnonics. We use this architecture to probe the quanta of collective spin excitations in a millimeter-sized ferromagnetic crystal. More specifically, we resolve magnon number states through spectroscopic measurements of a superconducting qubit with the hybrid system in the strong dispersive regime. This enables us to detect a change in the magnetic moment of the ferromagnet equivalent to a single spin flipped among more than 1019 spins. Our demonstration highlights the strength of hybrid quantum systems to provide powerful tools for quantum sensing and quantum information processing. PMID:28695204

Integrated experimental setup for angle resolved photoemission spectroscopy of transuranic materials

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

Graham, Kevin S.; Joyce, John J.; Durakiewicz, Tomasz

2013-09-15

We have developed the Angle Resolved Photoemission Spectroscopy (ARPES) system for transuranic materials. The ARPES transuranic system is an endstation upgrade to the Laser Plasma Light Source (LPLS) at Los Alamos National Laboratory. The LPLS is a tunable light source for photoemission with a photon energy range covering the vacuum ultraviolet (VUV) and soft x-ray regions (27–140 eV). The LPLS was designed and developed for transuranic materials. Transuranic photoemission is currently not permitted at the public synchrotrons worldwide in the VUV energy range due to sample encapsulation requirements. With the addition of the ARPES capability to the LPLS system theremore » is an excellent opportunity to explore new details centered on the electronic structure of actinide and transuranic materials.« less

Recent Advances in Fluorescence Lifetime Analytical Microsystems: Contact Optics and CMOS Time-Resolved Electronics.

PubMed

Wei, Liping; Yan, Wenrong; Ho, Derek

2017-12-04

Fluorescence spectroscopy has become a prominent research tool with wide applications in medical diagnostics and bio-imaging. However, the realization of combined high-performance, portable, and low-cost spectroscopic sensors still remains a challenge, which has limited the technique to the laboratories. A fluorescence lifetime measurement seeks to obtain the characteristic lifetime from the fluorescence decay profile. Time-correlated single photon counting (TCSPC) and time-gated techniques are two key variations of time-resolved measurements. However, commercial time-resolved analysis systems typically contain complex optics and discrete electronic components, which lead to bulkiness and a high cost. These two limitations can be significantly mitigated using contact sensing and complementary metal-oxide-semiconductor (CMOS) implementation. Contact sensing simplifies the optics, whereas CMOS technology enables on-chip, arrayed detection and signal processing, significantly reducing size and power consumption. This paper examines recent advances in contact sensing and CMOS time-resolved circuits for the realization of fully integrated fluorescence lifetime measurement microsystems. The high level of performance from recently reported prototypes suggests that the CMOS-based contact sensing microsystems are emerging as sound technologies for application-specific, low-cost, and portable time-resolved diagnostic devices.

Recent Advances in Fluorescence Lifetime Analytical Microsystems: Contact Optics and CMOS Time-Resolved Electronics

PubMed Central

Yan, Wenrong; Ho, Derek

2017-01-01

Fluorescence spectroscopy has become a prominent research tool with wide applications in medical diagnostics and bio-imaging. However, the realization of combined high-performance, portable, and low-cost spectroscopic sensors still remains a challenge, which has limited the technique to the laboratories. A fluorescence lifetime measurement seeks to obtain the characteristic lifetime from the fluorescence decay profile. Time-correlated single photon counting (TCSPC) and time-gated techniques are two key variations of time-resolved measurements. However, commercial time-resolved analysis systems typically contain complex optics and discrete electronic components, which lead to bulkiness and a high cost. These two limitations can be significantly mitigated using contact sensing and complementary metal-oxide-semiconductor (CMOS) implementation. Contact sensing simplifies the optics, whereas CMOS technology enables on-chip, arrayed detection and signal processing, significantly reducing size and power consumption. This paper examines recent advances in contact sensing and CMOS time-resolved circuits for the realization of fully integrated fluorescence lifetime measurement microsystems. The high level of performance from recently reported prototypes suggests that the CMOS-based contact sensing microsystems are emerging as sound technologies for application-specific, low-cost, and portable time-resolved diagnostic devices. PMID:29207568

Imaging and image restoration of an on-axis three-mirror Cassegrain system with wavefront coding technology.

PubMed

Guo, Xiaohu; Dong, Liquan; Zhao, Yuejin; Jia, Wei; Kong, Lingqin; Wu, Yijian; Li, Bing

2015-04-01

Wavefront coding (WFC) technology is adopted in the space optical system to resolve the problem of defocus caused by temperature difference or vibration of satellite motion. According to the theory of WFC, we calculate and optimize the phase mask parameter of the cubic phase mask plate, which is used in an on-axis three-mirror Cassegrain (TMC) telescope system. The simulation analysis and the experimental results indicate that the defocused modulation transfer function curves and the corresponding blurred images have a perfect consistency in the range of 10 times the depth of focus (DOF) of the original TMC system. After digital image processing by a Wiener filter, the spatial resolution of the restored images is up to 57.14 line pairs/mm. The results demonstrate that the WFC technology in the TMC system has superior performance in extending the DOF and less sensitivity to defocus, which has great value in resolving the problem of defocus in the space optical system.

Scanning system for angle-resolved low-coherence interferometry.

PubMed

Steelman, Zachary A; Ho, Derek; Chu, Kengyeh K; Wax, Adam

2017-11-15

Angle-resolved low-coherence interferometry (a/LCI) detects precancer by enabling depth-resolved measurements of nuclear morphology in vivo. A significant limitation of a/LCI is the point-probe nature of the method, sampling <0.5  mm 2 before probe relocation is necessary. In this work, we demonstrate a scanning method capable of assessing an area >100  mm 2 without repositioning. By utilizing a reflection-only three-optic rotator prism and a two-axis scanning mirror, we demonstrate radial scans of a sample with a linear range of 12 mm and a full rotational range of 180°. Use of this design will improve the diagnostic utility of a/LCI for wide-area screening of tissue health.

A scanning system for angle-resolved low-coherence interferometry

PubMed Central

Steelman, Zachary A.; Ho, Derek; Chu, Kengyeh K.; Wax, Adam

2018-01-01

Angle-resolved low-coherence interferometry (a/LCI) detects precancer by enabling depth-resolved measurements of nuclear morphology in vivo. A significant limitation of a/LCI is the point-probe nature of the method, sampling <0.5 mm2 before probe relocation is necessary. In this work, we demonstrate a scanning method capable of assessing an area >100 mm2 without repositioning. By utilizing a reflection-only three-optic rotator (ROTOR) prism and two-axis scanning mirror, we demonstrate radial scans of a sample with a linear range of 12 mm and a full rotational range of 180°. Use of this design will improve the diagnostic utility of a/LCI for wide-area screening of tissue health. PMID:29140317

Optimal systems of geoscience surveying A preliminary discussion

NASA Astrophysics Data System (ADS)

Shoji, Tetsuya

2006-10-01

In any geoscience survey, each survey technique must be effectively applied, and many techniques are often combined optimally. An important task is to get necessary and sufficient information to meet the requirement of the survey. A prize-penalty function quantifies effectiveness of the survey, and hence can be used to determine the best survey technique. On the other hand, an information-cost function can be used to determine the optimal combination of survey techniques on the basis of the geoinformation obtained. Entropy is available to evaluate geoinformation. A simple model suggests the possibility that low-resolvability techniques are generally applied at early stages of survey, and that higher-resolvability techniques should alternate with lower-resolvability ones with the progress of the survey.

Analysis of Automated Aircraft Conflict Resolution and Weather Avoidance

NASA Technical Reports Server (NTRS)

Love, John F.; Chan, William N.; Lee, Chu Han

2009-01-01

This paper describes an analysis of using trajectory-based automation to resolve both aircraft and weather constraints for near-term air traffic management decision making. The auto resolution algorithm developed and tested at NASA-Ames to resolve aircraft to aircraft conflicts has been modified to mitigate convective weather constraints. Modifications include adding information about the size of a gap between weather constraints to the routing solution. Routes that traverse gaps that are smaller than a specific size are not used. An evaluation of the performance of the modified autoresolver to resolve both conflicts with aircraft and weather was performed. Integration with the Center-TRACON Traffic Management System was completed to evaluate the effect of weather routing on schedule delays.

The Resolved Stellar Populations Early Release Science Program

NASA Astrophysics Data System (ADS)

Weisz, Daniel; Anderson, J.; Boyer, M.; Cole, A.; Dolphin, A.; Geha, M.; Kalirai, J.; Kallivayalil, N.; McQuinn, K.; Sandstrom, K.; Williams, B.

2017-11-01

We propose to obtain deep multi-band NIRCam and NIRISS imaging of three resolved stellar systems within 1 Mpc (NOI 104). We will use this broad science program to optimize observational setups and to develop data reduction techniques that will be common to JWST studies of resolved stellar populations. We will combine our expertise in HST resolved star studies with these observations to design, test, and release point spread function (PSF) fitting software specific to JWST. PSF photometry is at the heart of resolved stellar populations studies, but is not part of the standard JWST reduction pipeline. Our program will establish JWST-optimized methodologies in six scientific areas: star formation histories, measurement of the sub-Solar mass stellar IMF, extinction maps, evolved stars, proper motions, and globular clusters, all of which will be common pursuits for JWST in the local Universe. Our observations of globular cluster M92, ultra-faint dwarf Draco II, and star-forming dwarf WLM, will be of high archival value for other science such as calibrating stellar evolution models, measuring properties of variable stars, and searching for metal-poor stars. We will release the results of our program, including PSF fitting software, matched HST and JWST catalogs, clear documentation, and step-by-step tutorials (e.g., Jupyter notebooks) for data reduction and science application, to the community prior to the Cycle 2 Call for Proposals. We will host a workshop to help community members plan their Cycle 2 observations of resolved stars. Our program will provide blueprints for the community to efficiently reduce and analyze JWST observations of resolved stellar populations.

Preventing Chaos.

ERIC Educational Resources Information Center

Pineda, Ernest M.

1999-01-01

Discusses ways to help resolve the Y2K problem and avoid disruptions in school security and safety. Discusses computer software testing and validation to determine its functionality after year's end, and explores system remediation of non-compliant fire and security systems. (GR)

Small Body GN&C Research Report: A Robust Model Predictive Control Algorithm with Guaranteed Resolvability

NASA Technical Reports Server (NTRS)

Acikmese, Behcet A.; Carson, John M., III

2005-01-01

A robustly stabilizing MPC (model predictive control) algorithm for uncertain nonlinear systems is developed that guarantees the resolvability of the associated finite-horizon optimal control problem in a receding-horizon implementation. The control consists of two components; (i) feedforward, and (ii) feedback part. Feed-forward control is obtained by online solution of a finite-horizon optimal control problem for the nominal system dynamics. The feedback control policy is designed off-line based on a bound on the uncertainty in the system model. The entire controller is shown to be robustly stabilizing with a region of attraction composed of initial states for which the finite-horizon optimal control problem is feasible. The controller design for this algorithm is demonstrated on a class of systems with uncertain nonlinear terms that have norm-bounded derivatives, and derivatives in polytopes. An illustrative numerical example is also provided.

In vivo volumetric depth-resolved vasculature imaging of human limbus and sclera with 1 μm swept source phase-variance optical coherence angiography

NASA Astrophysics Data System (ADS)

Poddar, Raju; Zawadzki, Robert J.; Cortés, Dennis E.; Mannis, Mark J.; Werner, John S.

2015-06-01

We present in vivo volumetric depth-resolved vasculature images of the anterior segment of the human eye acquired with phase-variance based motion contrast using a high-speed (100 kHz, 105 A-scans/s) swept source optical coherence tomography system (SSOCT). High phase stability SSOCT imaging was achieved by using a computationally efficient phase stabilization approach. The human corneo-scleral junction and sclera were imaged with swept source phase-variance optical coherence angiography and compared with slit lamp images from the same eyes of normal subjects. Different features of the rich vascular system in the conjunctiva and episclera were visualized and described. This system can be used as a potential tool for ophthalmological research to determine changes in the outflow system, which may be helpful for identification of abnormalities that lead to glaucoma.

Differentiation of Volatile Profiles from Stockpiled Almonds at Varying Relative Humidity Levels Using Benchtop and Portable GC-MS.

PubMed

Beck, John J; Willett, Denis S; Gee, Wai S; Mahoney, Noreen E; Higbee, Bradley S

2016-12-14

Contamination by aflatoxin, a toxic metabolite produced by Aspergillus fungi ubiquitous in California almond and pistachio orchards, results in millions of dollars of lost product annually. Current detection of aflatoxin relies on destructive, expensive, and time-intensive laboratory-based methods. To explore an alternative method for the detection of general fungal growth, volatile emission profiles of almonds at varying humidities were sampled using both static SPME and dynamic needle-trap SPE followed by benchtop and portable GC-MS analysis. Despite the portable SPE/GC-MS system detecting fewer volatiles than the benchtop system, both systems resolved humidity treatments and identified potential fungal biomarkers at extremely low water activity levels. This ability to resolve humidity levels suggests that volatile profiles from germinating fungal spores could be used to create an early warning, nondestructive, portable detection system of fungal growth.

High-intensity power-resolved radiation imaging of an operational nuclear reactor.

PubMed

Beaumont, Jonathan S; Mellor, Matthew P; Villa, Mario; Joyce, Malcolm J

2015-10-09

Knowledge of the neutron distribution in a nuclear reactor is necessary to ensure the safe and efficient burnup of reactor fuel. Currently these measurements are performed by in-core systems in what are extremely hostile environments and in most reactor accident scenarios it is likely that these systems would be damaged. Here we present a compact and portable radiation imaging system with the ability to image high-intensity fast-neutron and gamma-ray fields simultaneously. This system has been deployed to image radiation fields emitted during the operation of a TRIGA test reactor allowing a spatial visualization of the internal reactor conditions to be obtained. The imaged flux in each case is found to scale linearly with reactor power indicating that this method may be used for power-resolved reactor monitoring and for the assay of ongoing nuclear criticalities in damaged nuclear reactors.

Evidence for Unresolved Exoplanet-hosting Binaries in Gaia DR2

NASA Astrophysics Data System (ADS)

Evans, Daniel F.

2018-05-01

This note describes an effort to detect additional stellar sources in known transiting exoplanet (TEP) systems, which are unresolved or barely resolved in the Gaia Data Release 2 (DR2) catalogue. The presence of multiple unresolved stars in photometric and spectroscopic observations of a transiting planetary system biases measurements of the planet's radius, mass, and atmospheric conditions. In addition to the effect on individual planetary systems, the presence of unresolved stars across the sample of known exoplanets biases our overall understanding of planetary systems, due to the systematic underestimation of both masses and radii. This work uses the Astrometric Goodness of Fit in the Along-Scan direction (GOF_AL) and the Astrometric Excess Noise as indicators of poorly-resolved binaries. Many known close binaries in the exoplanet host star sample have highly significant GOF_AL and Astrometric Excess Noise values, such as WASP-20AB with Astrometric Excess Noise significant at $4720\\sigma$ and GOF_AL=124.

High-intensity power-resolved radiation imaging of an operational nuclear reactor

PubMed Central

Beaumont, Jonathan S.; Mellor, Matthew P.; Villa, Mario; Joyce, Malcolm J.

2015-01-01

Knowledge of the neutron distribution in a nuclear reactor is necessary to ensure the safe and efficient burnup of reactor fuel. Currently these measurements are performed by in-core systems in what are extremely hostile environments and in most reactor accident scenarios it is likely that these systems would be damaged. Here we present a compact and portable radiation imaging system with the ability to image high-intensity fast-neutron and gamma-ray fields simultaneously. This system has been deployed to image radiation fields emitted during the operation of a TRIGA test reactor allowing a spatial visualization of the internal reactor conditions to be obtained. The imaged flux in each case is found to scale linearly with reactor power indicating that this method may be used for power-resolved reactor monitoring and for the assay of ongoing nuclear criticalities in damaged nuclear reactors. PMID:26450669

Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography

DOE PAGES

Nogly, Przemyslaw; Panneels, Valerie; Nelson, Garrett; ...

2016-08-22

Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 Å resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1 ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1 mg per collected time point. Accumulation of M intermediate within themore » crystal lattice is confirmed by time-resolved visible absorption spectroscopy. Furthermore, this study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX.« less

Compressive hyperspectral time-resolved wide-field fluorescence lifetime imaging

NASA Astrophysics Data System (ADS)

Pian, Qi; Yao, Ruoyang; Sinsuebphon, Nattawut; Intes, Xavier

2017-07-01

Spectrally resolved fluorescence lifetime imaging and spatial multiplexing have offered information content and collection-efficiency boosts in microscopy, but efficient implementations for macroscopic applications are still lacking. An imaging platform based on time-resolved structured light and hyperspectral single-pixel detection has been developed to perform quantitative macroscopic fluorescence lifetime imaging (MFLI) over a large field of view (FOV) and multiple spectral bands simultaneously. The system makes use of three digital micromirror device (DMD)-based spatial light modulators (SLMs) to generate spatial optical bases and reconstruct N by N images over 16 spectral channels with a time-resolved capability (∼40 ps temporal resolution) using fewer than N2 optical measurements. We demonstrate the potential of this new imaging platform by quantitatively imaging near-infrared (NIR) Förster resonance energy transfer (FRET) both in vitro and in vivo. The technique is well suited for quantitative hyperspectral lifetime imaging with a high sensitivity and paves the way for many important biomedical applications.

Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography

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

Nogly, Przemyslaw; Panneels, Valerie; Nelson, Garrett

Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 Å resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1 ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1 mg per collected time point. Accumulation of M intermediate within themore » crystal lattice is confirmed by time-resolved visible absorption spectroscopy. Furthermore, this study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX.« less

Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography

PubMed Central

Nogly, Przemyslaw; Panneels, Valerie; Nelson, Garrett; Gati, Cornelius; Kimura, Tetsunari; Milne, Christopher; Milathianaki, Despina; Kubo, Minoru; Wu, Wenting; Conrad, Chelsie; Coe, Jesse; Bean, Richard; Zhao, Yun; Båth, Petra; Dods, Robert; Harimoorthy, Rajiv; Beyerlein, Kenneth R.; Rheinberger, Jan; James, Daniel; DePonte, Daniel; Li, Chufeng; Sala, Leonardo; Williams, Garth J.; Hunter, Mark S.; Koglin, Jason E.; Berntsen, Peter; Nango, Eriko; Iwata, So; Chapman, Henry N.; Fromme, Petra; Frank, Matthias; Abela, Rafael; Boutet, Sébastien; Barty, Anton; White, Thomas A.; Weierstall, Uwe; Spence, John; Neutze, Richard; Schertler, Gebhard; Standfuss, Jörg

2016-01-01

Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 Å resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1 ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1 mg per collected time point. Accumulation of M intermediate within the crystal lattice is confirmed by time-resolved visible absorption spectroscopy. This study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX. PMID:27545823

Polychromatic microdiffraction characterization of defect gradients in severely deformed materials.

PubMed

Barabash, Rozaliya I; Ice, Gene E; Liu, Wenjun; Barabash, Oleg M

2009-01-01

This paper analyzes local lattice rotations introduced in severely deformed polycrystalline titanium by friction stir welding. Nondestructive three-dimensional (3D) spatially resolved polychromatic X-ray microdiffraction, is used to resolve the local crystal structure of the restructured surface from neighboring local structures in the sample material. The measurements reveal strong gradients of strain and geometrically necessary dislocations near the surface and illustrate the potential of polychromatic microdiffraction for the study of deformation in complex materials systems.

Elucidating light-induced charge accumulation in an artificial analogue of methane monooxygenase enzymes using time-resolved X-ray absorption spectroscopy

DOE PAGES

Moonshiram, Dooshaye; Picon, Antonio; Vazquez-Mayagoitia, Alvaro; ...

2017-02-08

Here, we report the use of time-resolved X-ray absorption spectroscopy in the ns–μs time scale to track the light induced two electron transfer processes in a multi-component photocatalytic system, consisting of [Ru(bpy) 3] 2+/ a diiron(III,III) model/triethylamine. EXAFS analysis with DFT calculations confirms the structural configurations of the diiron(III,III) and reduced diiron(II,II) states.

Nanocrystals of [Cu3(btc)2] (HKUST-1): a combined time-resolved light scattering and scanning electron microscopy study.

PubMed

Zacher, Denise; Liu, Jianing; Huber, Klaus; Fischer, Roland A

2009-03-07

The formation of [Cu(3)(btc)(2)] (HKUST-1; btc = 1,3,5-benzenetricarboxylate) nanocrystals from a super-saturated mother solution at room temperature was monitored by time-resolved light scattering (TLS); the system is characterized by a rapid growth up to a size limit of 200 nm within a few minutes, and the size and shape of the crystallites were also determined by scanning electron microscopy (SEM).

Elucidating light-induced charge accumulation in an artificial analogue of methane monooxygenase enzymes using time-resolved X-ray absorption spectroscopy

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

Moonshiram, Dooshaye; Picon, Antonio; Vazquez-Mayagoitia, Alvaro

Here, we report the use of time-resolved X-ray absorption spectroscopy in the ns–μs time scale to track the light induced two electron transfer processes in a multi-component photocatalytic system, consisting of [Ru(bpy) 3] 2+/ a diiron(III,III) model/triethylamine. EXAFS analysis with DFT calculations confirms the structural configurations of the diiron(III,III) and reduced diiron(II,II) states.

Capillary array scanner for time-resolved detection and identification of fluorescently labelled DNA fragments.

PubMed

Neumann, M; Herten, D P; Dietrich, A; Wolfrum, J; Sauer, M

2000-02-25

The first capillary array scanner for time-resolved fluorescence detection in parallel capillary electrophoresis based on semiconductor technology is described. The system consists essentially of a confocal fluorescence microscope and a x,y-microscope scanning stage. Fluorescence of the labelled probe molecules was excited using a short-pulse diode laser emitting at 640 nm with a repetition rate of 50 MHz. Using a single filter system the fluorescence decays of different labels were detected by an avalanche photodiode in combination with a PC plug-in card for time-correlated single-photon counting (TCSPC). The time-resolved fluorescence signals were analyzed and identified by a maximum likelihood estimator (MLE). The x,y-microscope scanning stage allows for discontinuous, bidirectional scanning of up to 16 capillaries in an array, resulting in longer fluorescence collection times per capillary compared to scanners working in a continuous mode. Synchronization of the alignment and measurement process were developed to allow for data acquisition without overhead. Detection limits in the subzeptomol range for different dye molecules separated in parallel capillaries have been achieved. In addition, we report on parallel time-resolved detection and separation of more than 400 bases of single base extension DNA fragments in capillary array electrophoresis. Using only semiconductor technology the presented technique represents a low-cost alternative for high throughput DNA sequencing in parallel capillaries.

Development of a clinical Fourier-domain angle resolved low coherence interferometry system for in vivo measurements

NASA Astrophysics Data System (ADS)

Terry, Neil G.; Zhu, Yizheng; Brown, William J.; Wax, Adam

2008-02-01

Improved methods for detecting dysplasia, or pre-cancerous growth are a current clinical need, particularly in the esophagus. The currently accepted method of random biopsy and histological analysis provides only a limited examination of tissue in question while being coupled with a long time delay for diagnosis. Optical scattering spectroscopy, in contrast, allows for inspection of the cellular structure and organization of tissue in vivo. Fourierdomain angle-resolved low-coherence interferometry (a/LCI) is a novel scattering spectroscopy technique that provides quantitative depth-resolved morphological measurements of the size and optical density of the examined cell nuclei, which are characteristic biomarkers of dysplasia. Previously, the clinical viability of the a/LCI system was demonstrated by analysis of ex vivo human esophageal tissue in Barrett's esophagus patients using a portable a/LCI system. We present an adaptation of the portable a/LCI instrument that can be used in the accessory channel of a gastroscope, allowing for in vivo measurements to be taken. Modifications to the previous generation system include the use of an improved imaging spectrometer allowing for subsecond acquisition times and the redesign of the delivery fiber and imaging optics in order to fit in the accessory channel of a gastroscope. Accurate sizing of polystyrene microspheres and other preliminary results are presented, demonstrating promise as a clinically viable tool.

Investigating mechanically induced phase response of the tissue by using high-speed phase-resolved optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ling, Yuye; Hendon, Christine P.

2017-02-01

Phase-resolved optical coherence tomography (OCT), a functional extension of OCT, provides depth-resolved phase information with extra contrast. In cardiology, changes in the mechanical properties have been associated with tissue remodeling and disease progression. Here we present the capability of profiling structural deformation of the sample in vivo by using a highly stable swept source OCT system The system, operating at 1300 nm, has an A-line acquisition rate of 200 kHz. We measured the phase noise floor to be 6.5 pm±3.2 pm by placing a cover slip in the sample arm, while blocking the reference arm. We then conducted a vibrational frequency test by measuring the phase response from a polymer membrane stimulated by a pure tone acoustic wave from 10 kHz to 80 kHz. The measured frequency response agreed with the known stimulation frequency with an error < 0.005%. We further measured the phase response of 7 fresh swine hearts obtained from Green Village Packing Company through a mechanical stretching test, within 24 hours of sacrifice. The heart tissue was cut into a 1 mm slices and fixed on two motorized stages. We acquired 100,000 consecutive M-scans, while the sample is stretched at a constant velocity of 10 um/s. The depth-resolved phase image presents linear phase response over time at each depth, but the slope varies among tissue types. Our future work includes refining our experiment protocol to quantitatively measured the elastic modulus of the tissue in vivo and building a tissue classifier based on depth-resolved phase information.

Novel physical chemistry approaches in biophysical researches with advanced application of lasers: Detection and manipulation.

PubMed

Iwata, Koichi; Terazima, Masahide; Masuhara, Hiroshi

2018-02-01

Novel methodologies utilizing pulsed or intense CW irradiation obtained from lasers have a major impact on biological sciences. In this article, recent development in biophysical researches fully utilizing the laser irradiation is described for three topics, time-resolved fluorescence spectroscopy, time-resolved thermodynamics, and manipulation of the biological assemblies by intense laser irradiation. First, experimental techniques for time-resolved fluorescence spectroscopy are concisely explained in Section 2. As an example of the recent application of time-resolved fluorescence spectroscopy to biological systems, evaluation of the viscosity of lipid bilayer membranes is described. The results of the spectroscopic experiments strongly suggest the presence of heterogeneous membrane structure with two different viscosity values in liposomes formed by a single phospholipid. Section 3 covers the time-resolved thermodynamics. Thermodynamical properties are important to characterize biomolecules. However, measurement of these quantities for short-lived intermediate species has been impossible by traditional thermodynamical techniques. Recently, development of a spectroscopic method based on the transient grating method enables us to measure these quantities and also to elucidate reaction kinetics which cannot be detected by other spectroscopic methods. The principle of the measurements and applications to some protein reactions are reviewed. Manipulation and fabrication of supramolecues, amino acids, proteins, and living cells by intense laser irradiation are described in Section 4. Unconventional assembly, crystallization and growth, amyloid fibril formation, and living cell manipulation are achieved by CW laser trapping and femtosecond laser-induced cavitation bubbling. Their spatio-temporal controllability is opening a new avenue in the relevant molecular and bioscience research fields. This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato. Copyright © 2017. Published by Elsevier B.V.

Evaluation of Collaterals and Clot Burden Using Time-Resolved C-Arm Conebeam CT Angiography in the Angiography Suite: A Feasibility Study.

PubMed

Yang, P; Niu, K; Wu, Y; Struffert, T; Doerfler, A; Holter, P; Aagaard-Kienitz, B; Strother, C; Chen, G-H

2017-04-01

The assessment of collaterals and clot burden in patients with acute ischemic stroke provides important information about treatment options and clinical outcome. Time-resolved C-arm conebeam CT angiography has the potential to provide accurate and reliable evaluations of collaterals and clot burden in the angiographic suite. Experience with this technique is extremely limited, and feasibility studies are needed to validate this technique. Our purpose was to present such a feasibility study. Ten C-arm conebeam CT perfusion datasets from 10 subjects with acute ischemic stroke acquired before endovascular treatment were retrospectively processed to generate time-resolved conebeam CTA. From time-resolved conebeam CTA, 2 experienced readers evaluated the clot burden and collateral flow in consensus by using previously reported scoring systems and assessed the clinical value of this novel imaging technique independently. Interobserver agreement was analyzed by using the intraclass correlation analysis method. Clot burden and collateral flow can be assessed by using the commonly accepted scoring systems for all eligible cases. Additional clinical information (eg, the quantitative dynamic information of collateral flow) can be obtained from this new imaging technique. Two readers agreed that time-revolved C-arm conebeam CTA is the preferred method for evaluating the clot burden and collateral flow compared with other conventional imaging methods. Comprehensive evaluations of clot burden and collateral flow are feasible by using time-resolved C-arm conebeam CTA data acquired in the angiography suite. This technique further enriches the imaging tools in the angiography suite to enable a "one-stop- shop" imaging workflow for patients with acute ischemic stroke. © 2017 by American Journal of Neuroradiology.

Endogenous pro-resolving and anti-inflammatory lipid mediators: a new pharmacologic genus

PubMed Central

Serhan, C N; Chiang, N

2008-01-01

Complete resolution of an acute inflammatory response and its return to homeostasis are essential for healthy tissues. Here, we overview ongoing efforts to characterize cellular and molecular mechanisms that govern the resolution of self-limited inflammation. Systematic temporal analyses of evolving inflammatory exudates using mediator lipidomics-informatics, proteomics, and cellular trafficking with murine resolving exudates demonstrate novel endogenous pathways of local-acting mediators that share both anti-inflammatory and pro-resolving properties. In murine systems, resolving-exudate leukocytes switch their phenotype to actively generate new families of mediators from major omega-3 fatty acids EPA and DHA termed resolvins and protectins. Recent advances on their biosynthesis and actions are reviewed with a focus on the E-series resolvins (RvE1, RvE2), D series resolvins (RvD1, RvD2) and the protectins including neuroprotectin D1/protectin D1 (NPD1/PD1) as well as their aspirin-triggered epimeric forms. Members of each new family demonstrate potent stereo-specific actions, joining the lipoxins as endogenous local signals that govern resolution and endogenous anti-inflammation mechanisms. In addition to their origins and roles in resolution biology in the immune system, recent findings indicate that these new mediator families also display potent protective actions in lung, kidney, and eye as well as enhance microbial clearance. Thus, these endogenous agonists of resolution pathways constitute a novel genus of chemical mediators that possess pro-resolving, anti-inflammatory, and antifibrotic as well as host-directed antimicrobial actions. These may be useful in the design of new therapeutics and treatments for diseases with the underlying trait of uncontrolled inflammation and redox organ stress. PMID:17965751

Distributed Architecture for the Object-Oriented Method for Interoperability

DTIC Science & Technology

2003-03-01

Collaborative Environment. ......................121 Figure V-2. Distributed OOMI And The Collaboration Centric Paradigm. .....................123 Figure V...of systems are formed into a system federation to resolve differences in modeling. An OOMI Integrated Development Environment (OOMI IDE) lends ...space for the creation of possible distributed systems is partitioned into User Centric systems, Processing/Storage Centric systems, Implementation

Minimum detectable gas concentration performance evaluation method for gas leak infrared imaging detection systems.

PubMed

Zhang, Xu; Jin, Weiqi; Li, Jiakun; Wang, Xia; Li, Shuo

2017-04-01

Thermal imaging technology is an effective means of detecting hazardous gas leaks. Much attention has been paid to evaluation of the performance of gas leak infrared imaging detection systems due to several potential applications. The minimum resolvable temperature difference (MRTD) and the minimum detectable temperature difference (MDTD) are commonly used as the main indicators of thermal imaging system performance. This paper establishes a minimum detectable gas concentration (MDGC) performance evaluation model based on the definition and derivation of MDTD. We proposed the direct calculation and equivalent calculation method of MDGC based on the MDTD measurement system. We build an experimental MDGC measurement system, which indicates the MDGC model can describe the detection performance of a thermal imaging system to typical gases. The direct calculation, equivalent calculation, and direct measurement results are consistent. The MDGC and the minimum resolvable gas concentration (MRGC) model can effectively describe the performance of "detection" and "spatial detail resolution" of thermal imaging systems to gas leak, respectively, and constitute the main performance indicators of gas leak detection systems.

Real-Time Eddy-Resolving Ocean Prediction in the Caribbean

NASA Astrophysics Data System (ADS)

Hurlburt, H. E.; Smedstad, O. M.; Shriver, J. F.; Townsend, T. L.; Murphy, S. J.

2001-12-01

A {1/16}o eddy-resolving, nearly global ocean prediction system has been developed by the Naval Research Laboratory (NRL), Stennis Space Center, MS. It has been run in real-time by the Naval Oceanographic Office (NAVO), Stennis Space Center, MS since 18 Oct 2000 with daily updates for the nowcast and 30-day forecasts performed every Wednesday. The model has ~8 km resolution in the Caribbean region and assimilates real-time altimeter sea surface height (SSH) data from ERS-2, GFO and TOPEX/POSEIDON plus multi-channel sea surface temperature (MCSST) from satellite IR. Real-time and archived results from the system can be seen at web site: http://www7320.nrlssc.navy.mil/global\

The Track Imaging Cerenkov Experiment

NASA Technical Reports Server (NTRS)

Wissel, S. A.; Byrum, K.; Cunningham, J. D.; Drake, G.; Hays, E.; Horan, D.; Kieda, D.; Kovacs, E.; Magill, S.; Nodulman, L.;

Time-resolved x-ray spectra from laser-generated high-density plasmas

NASA Astrophysics Data System (ADS)

Andiel, U.; Eidmann, Klaus; Witte, Klaus-Juergen

2001-04-01

We focused frequency doubled ultra short laser pulses on solid C, F, Na and Al targets, K-shell emission was systematically investigated by time resolved spectroscopy using a sub-ps streak camera. A large number of laser shots can be accumulated when triggering the camera with an Auston switch system at very high temporal precision. The system provides an outstanding time resolution of 1.7ps accumulating thousands of laser shots. The time duration of the He-(alpha) K-shell resonance lines was observed in the range of (2-4)ps and shows a decrease with the atomic number. The experimental results are well reproduced by hydro code simulations post processed with an atomic kinetics code.

Time-resolved spectroscopic imaging reveals the fundamentals of cellular NADH fluorescence.

PubMed

Li, Dong; Zheng, Wei; Qu, Jianan Y

2008-10-15

A time-resolved spectroscopic imaging system is built to study the fluorescence characteristics of nicotinamide adenine dinucleotide (NADH), an important metabolic coenzyme and endogenous fluorophore in cells. The system provides a unique approach to measure fluorescence signals in different cellular organelles and cytoplasm. The ratios of free over protein-bound NADH signals in cytosol and nucleus are slightly higher than those in mitochondria. The mitochondrial fluorescence contributes about 70% of overall cellular fluorescence and is not a completely dominant signal. Furthermore, NADH signals in mitochondria, cytosol, and the nucleus respond to the changes of cellular activity differently, suggesting that cytosolic and nuclear fluorescence may complicate the well-known relationship between mitochondrial fluorescence and cellular metabolism.

5D-intravital tomography as a novel tool for non-invasive in-vivo analysis of human skin

NASA Astrophysics Data System (ADS)

König, Karsten; Weinigel, Martin; Breunig, Hans G.; Gregory, Axel; Fischer, Peter; Kellner-Höfer, Marcel; Bückle, Rainer; Schwarz, Martin; Riemann, Iris; Stracke, Frank; Huck, Volker; Gorzelanny, Christian; Schneider, Stefan W.

2010-02-01

Some years ago, CE-marked clinical multiphoton systems for 3D imaging of human skin with subcellular resolution have been launched. These tomographs provide optical biopsies with submicron resolution based on two-photon excited autofluorescence (NAD(P)H, flavoproteins, keratin, elastin, melanin, porphyrins) and second harmonic generation by collagen. The 3D tomograph was now transferred into a 5D imaging system by the additional detection of the emission spectrum and the fluorescence lifetime based on spatially and spectrally resolved time-resolved single photon counting. The novel 5D intravital tomograph (5D-IVT) was employed for the early detection of atopic dermatitis and the analysis of treatment effects.

Lattice-Assisted Spectroscopy: A Generalized Scanning Tunneling Microscope for Ultracold Atoms.

PubMed

Kantian, A; Schollwöck, U; Giamarchi, T

2015-10-16

We propose a scheme to measure the frequency-resolved local particle and hole spectra of any optical lattice-confined system of correlated ultracold atoms that offers single-site addressing and imaging, which is now an experimental reality. Combining perturbation theory and time-dependent density matrix renormalization group simulations, we quantitatively test and validate this approach of lattice-assisted spectroscopy on several one-dimensional example systems, such as the superfluid and Mott insulator, with and without a parabolic trap, and finally on edge states of the bosonic Su-Schrieffer-Heeger model. We highlight extensions of our basic scheme to obtain an even wider variety of interesting and important frequency resolved spectra.

Resolved Observations of the Patroclus-Menoetius Binary

NASA Astrophysics Data System (ADS)

Noll, Keith S.; Grundy, William M.; Buie, Marc W.; Levison, Harold F.

2017-10-01

The Trojan binary (617) Patroclus-Menoetius is one of the targets of the Lucy Discovery mission. Lucy is scheduled to launch in October 2021. We observed this system with the Hubble Space Telescope in May and June 2017 in order to resolve the individual components and use the relative positions to update the binary orbit. The updated orbit is required to predict the upcoming mutual event season. A precise determination of the orbit phase, period, orbit plane and pole position that will result from observations of mutual events is essential for planning the Lucy mission’s encounter with this system. We present results of the successful HST observations including preliminary predictions for mutual events observable in semester 2018A.

Optical sensor system for time-resolved quantification of methane concentrations: Validation measurements in a rapid compression machine

NASA Astrophysics Data System (ADS)

Bauke, Stephan; Golibrzuch, Kai; Wackerbarth, Hainer; Fendt, Peter; Zigan, Lars; Seefeldt, Stefan; Thiele, Olaf; Berg, Thomas

2018-05-01

Lowering greenhouse gas emissions is one of the most challenging demands of today's society. Especially, the automotive industry struggles with the development of more efficient internal combustion (IC) engines. As an alternative to conventional fuels, methane has the potential for a significant emission reduction. In methane fuelled engines, the process of mixture formation, which determines the properties of combustion after ignition, differs significantly from gasoline and diesel engines and needs to be understood and controlled in order to develop engines with high efficiency. This work demonstrates the development of a gas sensing system that can serve as a diagnostic tool for measuring crank-angle resolved relative air-fuel ratios in methane-fuelled near-production IC engines. By application of non-dispersive infrared absorption spectroscopy at two distinct spectral regions in the ν3 absorption band of methane around 3.3 μm, the system is able to determine fuel density and temperature simultaneously. A modified spark plug probe allows for straightforward application at engine test stations. Here, the application of the detection system in a rapid compression machine is presented, which enables validation and characterization of the system on well-defined gas mixtures under engine-like dynamic conditions. In extension to a recent proof-of-principle study, a refined data analysis procedure is introduced that allows the correction of artefacts originating from mechanical distortions of the sensor probe. In addition, the measured temperatures are compared to data obtained with a commercially available system based on the spectrally resolved detection of water absorption in the near infrared.

Hardware-In-The-Loop Power Extraction Using Different Real-Time Platforms (Postprint)

DTIC Science & Technology

2008-11-01

each real - time operating system . However, discrepancies in test results obtained from the NI system can be resolved. This paper briefly details...same model in native Simulink. These results show that each real - time operating system can be configured to accurately run transient Simulink models

A Reference and Referral System Using Expert System Techniques.

ERIC Educational Resources Information Center

Vickery, Alina; And Others

1987-01-01

Describes PLEXUS, an expert system for information retrieval related to gardening, designed at the University of London for use in public libraries. Focusing on the semantic problems encountered, methods used in artificial intelligence and information science to resolve them are discussed, including classification and facet analysis. (Author/LRW)

Resolving Relationship Problems in Communication Disorders Treatment: A Systems Approach.

ERIC Educational Resources Information Center

Stone, Judith R.

1992-01-01

Systems concepts from general systems theory and family therapy literature are presented as analytical tools to help professionals understand and change interactions with their clients having communication disorders. Two case examples that illustrate relationship problems are presented, and approaches taken to their resolution are described.…

Evaluating Clouds in Long-Term Cloud-Resolving Model Simulations with Observational Data

NASA Technical Reports Server (NTRS)

Zeng, Xiping; Tao, Wei-Kuo; Zhang, Minghua; Peters-Lidard, Christa; Lang, Stephen; Simpson, Joanne; Kumar, Sujay; Xie, Shaocheng; Eastman, Joseph L.; Shie, Chung-Lin;

Application of the space-resolving flux detector for radiation measurements from an octahedral-aperture spherical hohlraum

NASA Astrophysics Data System (ADS)

Xie, Xufei; Du, Huabing; Chen, Jinwen; Liu, Shenye; Li, Zhichao; Yang, Dong; Huang, Yunbao; Ren, Kuan; Hou, Lifei; Li, Sanwei; Guo, Liang; Jiang, Xiaohua; Huo, Wenyi; Chen, Yaohua; Ren, Guoli; Lan, Ke; Wang, Feng; Jiang, Shaoen; Ding, Yongkun

2018-06-01

Space-resolving flux detection is an important technique for the diagnostic of the radiation field within the hohlraum in inertial confinement fusion, especially for the radiation field diagnostic in the novel spherical hohlraum with octahedral six laser entrance holes (LEHs), where localized measurements are necessary for the discrimination of the radiation flux from different LEHs. A novel space-resolving flux detector (SRFD) is developed at the SG-III laser facility for the radiation flux measurement in the first campaign of the octahedral spherical hohlraum energetics experiment. The principle and configuration of the SRFD system is introduced. The radiation flux from the wall of a gas-filled octahedral spherical hohlraum is measured for the first time by placing the SRFD system at the equatorial position of the SG-III laser facility, aiming at the hohlraum wall through one of the six LEHs. The absolute radiation flux from the re-emission area on the hohlraum wall is measured, and good consistency is found between the experimental data and the calculated data from a three-dimensional view factor analysis.

Doppler-free spectroscopy of the atomic rubidium fine structure using ultrafast spatial coherent control method

NASA Astrophysics Data System (ADS)

Kim, Minhyuk; Kim, Kyungtae; Lee, Woojun; Kim, Hyosub; Ahn, Jaewook

2017-04-01

Spectral programming solutions for the ultrafast spatial coherent control (USCC) method to resolve the fine-structure energy levels of atomic rubidium are reported. In USCC, a pair of counter-propagating ultrashort laser pulses are programmed to make a two-photon excitation pattern specific to particular transition pathways and atom species, thus allowing the involved transitions resolvable in space simultaneously. With a proper spectral phase and amplitude modulation, USCC has been also demonstrated for the systems with many intermediate energy levels. Pushing the limit of system complexity even further, we show here an experimental demonstration of the rubidium fine-structure excitation pattern resolvable by USCC. The spectral programming solution for the given USCC is achieved by combining a double-V-shape spectral phase function and a set of phase steps, where the former distinguishes the fine structure and the latter prevents resonant transitions. The experimental results will be presented along with its application in conjunction with the Doppler-free frequency-comb spectroscopy for rubidium hyperfine structure measurements. Samsung Science and Technology Foundation [SSTFBA1301-12].

Rediscovery of the doldrums in storm-resolving simulations over the tropical Atlantic

NASA Astrophysics Data System (ADS)

Klocke, Daniel; Brueck, Matthias; Hohenegger, Cathy; Stevens, Bjorn

2017-12-01

The doldrums — a zone of calm and variable winds in the deep tropics between the trades — were of key importance to nineteenth century maritime travel. As a result, the region was a focus in atmospheric science at that time. However, as sailing ships were replaced by steamboats, scientific interest shifted to the heavy precipitating storms within the doldrums: the deep convective systems of the intertropical convergence zone. Now, in storm-system-resolving simulations over a period of two months that cover a large part of the tropical Atlantic, the doldrums are one of the most prominent features. The doldrums are substantially less pronounced in coarser-resolution simulations that use a parameterization for convection, despite their large-scale extent. We conclude that explicitly representing the storm scale dynamics and their coupling to the surface wind on the storm-system scales helps to maintain the systems of winds that define the doldrums. We suggest that the lack of these wind systems could explain the persistent tropical precipitation biases in climate models.

Characterization of a time-resolved non-contact scanning diffuse optical imaging system exploiting fast-gated single-photon avalanche diode detection

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

Di Sieno, Laura, E-mail: laura.disieno@polimi.it; Dalla Mora, Alberto; Contini, Davide

2016-03-15

We present a system for non-contact time-resolved diffuse reflectance imaging, based on small source-detector distance and high dynamic range measurements utilizing a fast-gated single-photon avalanche diode. The system is suitable for imaging of diffusive media without any contact with the sample and with a spatial resolution of about 1 cm at 1 cm depth. In order to objectively assess its performances, we adopted two standardized protocols developed for time-domain brain imagers. The related tests included the recording of the instrument response function of the setup and the responsivity of its detection system. Moreover, by using liquid turbid phantoms with absorbingmore » inclusions, depth-dependent contrast and contrast-to-noise ratio as well as lateral spatial resolution were measured. To illustrate the potentialities of the novel approach, the characteristics of the non-contact system are discussed and compared to those of a fiber-based brain imager.« less

Vacuum Ultraviolet Photoionization of Complex Chemical Systems

DOE PAGES

Kostko, Oleg; Bandyopadhyay, Biswajit; Ahmed, Musahid

2016-02-24

Tunable vacuum ultraviolet (VUV) radiation coupled to mass spectrometry is applied to the study of complex chemical systems in this paper. The identification of novel reactive intermediates and radicals is revealed in flame, pulsed photolysis, and pyrolysis reactors, leading to the elucidation of spectroscopy, reaction mechanisms, and kinetics. Mass-resolved threshold photoelectron photoion coincidence measurements provide unprecedented access to vibrationally resolved spectra of free radicals present in high-temperature reactors. Photoionization measurements in water clusters, nucleic acid base dimers, and their complexes with water provide signatures of proton transfer in hydrogen-bonded and π-stacked systems. Experimental and theoretical methods to track ion–molecule reactionsmore » and fragmentation pathways in intermolecular and intramolecular hydrogen-bonded systems in sugars and alcohols are described. Photoionization of laser-ablated molecules, clusters, and their reaction products inform thermodynamics and spectroscopy that are relevant to astrochemistry and catalysis. Finally, new directions in coupling VUV radiation to interrogate complex chemical systems are discussed.« less

Site-Resolved Imaging with the Fermi Gas Microscope

NASA Astrophysics Data System (ADS)

Huber, Florian Gerhard

The recent development of quantum gas microscopy for bosonic rubidium atoms trapped in optical lattices has made it possible to study local structure and correlations in quantum many-body systems. Quantum gas microscopes are a perfect platform to perform quantum simulation of condensed matter systems, offering unprecedented control over both internal and external degrees of freedom at a single-site level. In this thesis, this technique is extended to fermionic particles, paving the way to fermionic quantum simulation, which emulate electrons in real solids. Our implementation uses lithium, the lightest atom amenable to laser cooling. The absolute timescales of dynamics in optical lattices are inversely proportional to the mass. Therefore, experiments are more than six times faster than for the only other fermionic alkali atom, potassium, and more then fourteen times faster than an equivalent rubidium experiment. Scattering and collecting a sufficient number of photons with our high-resolution imaging system requires continuous cooling of the atoms during the fluorescence imaging. The lack of a resolved excited hyperfine structure on the D2 line of lithium prevents efficient conventional sub-Doppler cooling. To address this challenge we have applied a Raman sideband cooling scheme and achieved the first site-resolved imaging of ultracold fermions in an optical lattice.

The role of strain hardening in the transition from dislocation-mediated to frictional deformation of marbles within the Karakoram Fault Zone, NW India

NASA Astrophysics Data System (ADS)

Wallis, David; Lloyd, Geoffrey E.; Hansen, Lars N.

2018-02-01

The onset of frictional failure and potentially seismogenic deformation in carbonate rocks undergoing exhumation within fault zones depends on hardening processes that reduce the efficiency of aseismic dislocation-mediated deformation as temperature decreases. However, few techniques are available for quantitative analysis of dislocation slip system activity and hardening in natural tectonites. Electron backscatter diffraction maps of crystal orientations offer one such approach via determination of Schmid factors, if the palaeostress conditions can be inferred and the critical resolved shear stresses of slip systems are constrained. We analyse calcite marbles deformed in simple shear within the Karakoram Fault Zone, NW India, to quantify changes in slip system activity as the rocks cooled during exhumation. Microstructural evidence demonstrates that between ∼300 °C and 200-250 °C the dominant deformation mechanisms transitioned from dislocation-mediated flow to twinning and frictional failure. However, Schmid factor analysis, considering critical resolved shear stresses for yield of undeformed single crystals, indicates that the fraction of grains with sufficient resolved shear stress for glide apparently increased with decreasing temperature. Misorientation analysis and previous experimental data indicate that strain-dependent work hardening is responsible for this apparent inconsistency and promoted the transition from dislocation-mediated flow to frictional, and potentially seismogenic, deformation.

An x-ray fluorescence imaging system for gold nanoparticle detection.

PubMed

Ricketts, K; Guazzoni, C; Castoldi, A; Gibson, A P; Royle, G J

2013-11-07

Gold nanoparticles (GNPs) may be used as a contrast agent to identify tumour location and can be modified to target and image specific tumour biological parameters. There are currently no imaging systems in the literature that have sufficient sensitivity to GNP concentration and distribution measurement at sufficient tissue depth for use in in vivo and in vitro studies. We have demonstrated that high detecting sensitivity of GNPs can be achieved using x-ray fluorescence; furthermore this technique enables greater depth imaging in comparison to optical modalities. Two x-ray fluorescence systems were developed and used to image a range of GNP imaging phantoms. The first system consisted of a 10 mm(2) silicon drift detector coupled to a slightly focusing polycapillary optic which allowed 2D energy resolved imaging in step and scan mode. The system has sensitivity to GNP concentrations as low as 1 ppm. GNP concentrations different by a factor of 5 could be resolved, offering potential to distinguish tumour from non-tumour. The second system was designed to avoid slow step and scan image acquisition; the feasibility of excitation of the whole specimen with a wide beam and detection of the fluorescent x-rays with a pixellated controlled drift energy resolving detector without scanning was investigated. A parallel polycapillary optic coupled to the detector was successfully used to ascertain the position where fluorescence was emitted. The tissue penetration of the technique was demonstrated to be sufficient for near-surface small-animal studies, and for imaging 3D in vitro cellular constructs. Previous work demonstrates strong potential for both imaging systems to form quantitative images of GNP concentration.

Continuous Flow Hygroscopicity-Resolved Relaxed Eddy Accumulation (Hy-Res REA) Method of Measuring Size-Resolved Sea-Salt Particle Fluxes

NASA Astrophysics Data System (ADS)

Meskhidze, N.; Royalty, T. M.; Phillips, B.; Dawson, K. W.; Petters, M. D.; Reed, R.; Weinstein, J.; Hook, D.; Wiener, R.

2017-12-01

The accurate representation of aerosols in climate models requires direct ambient measurement of the size- and composition-dependent particle production fluxes. Here we present the design, testing, and analysis of data collected through the first instrument capable of measuring hygroscopicity-based, size-resolved particle fluxes using a continuous-flow Hygroscopicity-Resolved Relaxed Eddy Accumulation (Hy-Res REA) technique. The different components of the instrument were extensively tested inside the US Environmental Protection Agency's Aerosol Test Facility for sea-salt and ammoniums sulfate particle fluxes. The new REA system design does not require particle accumulation, therefore avoids the diffusional wall losses associated with long residence times of particles inside the air collectors of the traditional REA devices. The Hy-Res REA system used in this study includes a 3-D sonic anemometer, two fast-response solenoid valves, two Condensation Particle Counters (CPCs), a Scanning Mobility Particle Sizer (SMPS), and a Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA). A linear relationship was found between the sea-salt particle fluxes measured by eddy covariance and REA techniques, with comparable theoretical (0.34) and measured (0.39) proportionality constants. The sea-salt particle detection limit of the Hy-Res REA flux system is estimated to be 6x105 m-2s-1. For the conditions of ammonium sulfate and sea-salt particles of comparable source strength and location, the continuous-flow Hy-Res REA instrument was able to achieve better than 90% accuracy of measuring the sea-salt particle fluxes. In principle, the instrument can be applied to measure fluxes of particles of variable size and distinct hygroscopic properties (i.e., mineral dust, black carbon, etc.).

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

Jatana, Gurneesh; Geckler, Sam; Koeberlein, David

We designed and developed a 4-probe multiplexed multi-species absorption spectroscopy sensor system for gas property measurements on the intake side of commercial multi-cylinder internal-combustion (I.C.) engines; the resulting cycle- and cylinder-resolved concentration, temperature and pressure measurements are applicable for assessing spatial and temporal variations in the recirculated exhaust gas (EGR) distribution at various locations along the intake gas path, which in turn is relevant to assessing cylinder charge uniformity, control strategies, and CFD models. Furthermore, the diagnostic is based on absorption spectroscopy and includes an H 2O absorption system (utilizing a 1.39 m distributed feedback (DFB) diode laser) for measuringmore » gas temperature, pressure, and H 2O concentration, and a CO 2 absorption system (utilizing a 2.7 m DFB laser) for measuring CO 2 concentration. The various lasers, optical components and detectors were housed in an instrument box, and the 1.39- m and 2.7- m lasers were guided to and from the engine-mounted probes via optical fibers and hollow waveguides, respectively. The 5kHz measurement bandwidth allows for near-crank angle resolved measurements, with a resolution of 1.2 crank angle degrees at 1000 RPM. Our use of compact stainless steel measurement probes enables simultaneous multi-point measurements at various locations on the engine with minimal changes to the base engine hardware; in addition to resolving large-scale spatial variations via simultaneous multi-probe measurements, local spatial gradients can be resolved by translating individual probes. Along with details of various sensor design features and performance, we also demonstrate validation of the spectral parameters of the associated CO 2 absorption transitions using both a multi-pass heated cell and the sensor probes.« less

Quantum Control of a Nitrogen-Vacancy Center using Surface Acoustic Waves in the Resolved Sideband Limit

NASA Astrophysics Data System (ADS)

Golter, David; Oo, Thein; Amezcua, Maira; Wang, Hailin

Micro-electromechanical systems research is producing increasingly sophisticated tools for nanophononic applications. Such technology is well-suited for achieving chip-based, integrated acoustic control of solid-state quantum systems. We demonstrate such acoustic control in an important solid-state qubit, the diamond nitrogen-vacancy (NV) center. Using an interdigitated transducer to generate a surface acoustic wave (SAW) field in a bulk diamond, we observe phonon-assisted sidebands in the optical excitation spectrum of a single NV center. This exploits the strong strain sensitivity of the NV excited states. The mechanical frequencies far exceed the relevant optical linewidths, reaching the resolved-sideband regime. This enables us to use the SAW field for driving Rabi oscillations on the phonon-assisted optical transition. These results stimulate the further integration of SAW-based technologies with the NV center system.

A Case of Subacute Encephalopathy Developing After Treatment With Clofarabine and Methotrexate That Resolved With Corticosteroids.

PubMed

Tzachanis, Dimitrios; Haider, Mintallah; Papazisis, Georgios

2016-01-01

This is the case of a 24-year-old woman with relapsed acute undifferentiated leukemia who developed subacute encephalopathy with hemiparesis and dysarthria after treatment with high dose and intrathecal methotrexate, clofarabine, and cytarabine that resolved rapidly and completely after the administration of corticosteroids. We hypothesize that clofarabine might predispose to methotrexate-induced central nervous system toxicity by increasing endothelial permeability (capillary leak syndrome) and suggest that corticosteroids are effective in the treatment of this type of encephalopathy.

Spin-Resolved Circularly Polarised Resonant Photoemission: Cu as a Model System

NASA Astrophysics Data System (ADS)

Brookes, N. B.

A brief introduction to the technique of spin resolved resonant photoemission using circularly polarised soft x-rays is given. The method is illustrated by considering the simple case of Cu2+. Starting from CuO we show how the same ideas can be applied to more complex and interesting cases, such as the model compound Sr2CuO2Cl2 and an optimally doped high temperature superconductor, Bi2Sr2CaCu2O8+δ.

Comparing Yb-fiber and Ti:Sapphire lasers for depth resolved imaging of human skin (Conference Presentation)

NASA Astrophysics Data System (ADS)

Balu, Mihaela; Saytashev, Ilyas; Hou, Jue; Dantus, Marcos; Tromberg, Bruce J.

2016-02-01

We report on a direct comparison between Ti:Sapphire and Yb fiber lasers for depth-resolved label-free multimodal imaging of human skin. We found that the penetration depth achieved with the Yb laser was 80% greater than for the Ti:Sapphire. Third harmonic generation (THG) imaging with Yb laser excitation provides additional information about skin structure. Our results indicate the potential of fiber-based laser systems for moving into clinical use.

Structure for identifying, locating and quantifying physical phenomena

DOEpatents

Richardson, John G.

2006-10-24

A method and system for detecting, locating and quantifying a physical phenomena such as strain or a deformation in a structure. A minimum resolvable distance along the structure is selected and a quantity of laterally adjacent conductors is determined. Each conductor includes a plurality of segments coupled in series which define the minimum resolvable distance along the structure. When a deformation occurs, changes in the defined energy transmission characteristics along each conductor are compared to determine which segment contains the deformation.

Method and apparatus for identifying, locating and quantifying physical phenomena and structure including same

DOEpatents

Richardson, John G.

2006-01-24

A method and system for detecting, locating and quantifying a physical phenomena such as strain or a deformation in a structure. A minimum resolvable distance along the structure is selected and a quantity of laterally adjacent conductors is determined. Each conductor includes a plurality of segments coupled in series which define the minimum resolvable distance along the structure. When a deformation occurs, changes in the defined energy transmission characteristics along each conductor are compared to determine which segment contains the deformation.

Control of experimental uncertainties in filtered Rayleigh scattering measurements

NASA Technical Reports Server (NTRS)

Forkey, Joseph N.; Finkelstein, N. D.; Lempert, Walter R.; Miles, Richard B.

1995-01-01

Filtered Rayleigh Scattering is a technique which allows for measurement of velocity, temperature, and pressure in unseeded flows, spatially resolved in 2-dimensions. We present an overview of the major components of a Filtered Rayleigh Scattering system. In particular, we develop and discuss a detailed theoretical model along with associated model parameters and related uncertainties. Based on this model, we then present experimental results for ambient room air and for a Mach 2 free jet, including spatially resolved measurements of velocity, temperature, and pressure.

Evaluating adaptive co-management as conservation conflict resolution: Learning from seals and salmon.

PubMed

Butler, J R A; Young, J C; McMyn, I A G; Leyshon, B; Graham, I M; Walker, I; Baxter, J M; Dodd, J; Warburton, C

2015-09-01

By linking iterative learning and knowledge generation with power-sharing, adaptive co-management (ACM) provides a potential solution to resolving complex social-ecological problems. In this paper we evaluate ACM as a mechanism for resolving conservation conflict using a case study in Scotland, where seal and salmon fishery stakeholders have opposing and entrenched objectives. ACM emerged in 2002, successfully resolving this long-standing conflict. Applying evaluation approaches from the literature, in 2011 we interviewed stakeholders to characterise the evolution of ACM, and factors associated with its success over 10 years. In common with other ACM cases, triggers for the process were shifts in slow variables controlling the system (seal and salmon abundance, public perceptions of seal shooting), and exogenous shocks (changes in legal mandates, a seal disease outbreak). Also typical of ACM, three phases of evolution were evident: emerging local leadership preparing the system for change, a policy window of opportunity, and stakeholder partnerships building the resilience of the system. Parameters maintaining ACM were legal mechanisms and structures, legal power held by government, and the willingness of all stakeholders to reach a compromise and experiment with an alternative governance approach. Results highlighted the critical role of government power and support in resolving conservation conflict, which may constrain the extent of local stakeholder-driven ACM. The evaluation also demonstrated how, following perceived success, the trajectory of ACM has shifted to a 'stakeholder apathy' phase, with declining leadership, knowledge exchange, stakeholder engagement, and system resilience. We discuss remedial actions required to revive the process, and the importance of long term government resourcing and alternative financing schemes for successful conflict resolution. Based on the results we present a generic indicator framework and participatory method for the longitudinal evaluation of ACM applied to conservation conflict resolution. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Design and development of a probe-based multiplexed multi-species absorption spectroscopy sensor for characterizing transient gas-parameter distributions in the intake systems of I.C. engines

DOE PAGES

Jatana, Gurneesh; Geckler, Sam; Koeberlein, David; ...

2016-09-01

We designed and developed a 4-probe multiplexed multi-species absorption spectroscopy sensor system for gas property measurements on the intake side of commercial multi-cylinder internal-combustion (I.C.) engines; the resulting cycle- and cylinder-resolved concentration, temperature and pressure measurements are applicable for assessing spatial and temporal variations in the recirculated exhaust gas (EGR) distribution at various locations along the intake gas path, which in turn is relevant to assessing cylinder charge uniformity, control strategies, and CFD models. Furthermore, the diagnostic is based on absorption spectroscopy and includes an H 2O absorption system (utilizing a 1.39 m distributed feedback (DFB) diode laser) for measuringmore » gas temperature, pressure, and H 2O concentration, and a CO 2 absorption system (utilizing a 2.7 m DFB laser) for measuring CO 2 concentration. The various lasers, optical components and detectors were housed in an instrument box, and the 1.39- m and 2.7- m lasers were guided to and from the engine-mounted probes via optical fibers and hollow waveguides, respectively. The 5kHz measurement bandwidth allows for near-crank angle resolved measurements, with a resolution of 1.2 crank angle degrees at 1000 RPM. Our use of compact stainless steel measurement probes enables simultaneous multi-point measurements at various locations on the engine with minimal changes to the base engine hardware; in addition to resolving large-scale spatial variations via simultaneous multi-probe measurements, local spatial gradients can be resolved by translating individual probes. Along with details of various sensor design features and performance, we also demonstrate validation of the spectral parameters of the associated CO 2 absorption transitions using both a multi-pass heated cell and the sensor probes.« less

How do I resolve problems reading the binary data?

Atmospheric Science Data Center

2014-12-08

... affecting compilation would be differing versions of the operating system and compilers the read software are being run on. Big ... Unix machines are Big Endian architecture while Linux systems are Little Endian architecture. Data generated on a Unix machine are ...

Spatially resolved scatter measurement of diffractive micromirror arrays.

PubMed

Sicker, Cornelius; Heber, Jörg; Berndt, Dirk

2016-06-01

Spatial light modulators (SLMs) support flexible system concepts in modern optics and especially phase-only SLMs such as micromirror arrays (MMAs) appear attractive for many applications. In order to achieve a precise phase modulation, which is crucial for optical performance, careful characterization and calibration of SLM devices is required. We examine an intensity-based measurement concept, which promises distinct advantages by means of a spatially resolved scatter measurement that is combined with the MMA's diffractive principle. Measurements yield quantitative results, which are consistent with measurements of micromirror roughness components, by white-light interferometry. They reveal relative scatter as low as 10^-4, which corresponds to contrast ratios up to 10,000. The potential of the technique to resolve phase changes in the subnanometer range is experimentally demonstrated.

Nonlinear forcing in the resolvent analysis of wall-turbulence

NASA Astrophysics Data System (ADS)

Rosenberg, Kevin; Lozano Duran, Adrian; Towne, Aaron; McKeon, Beverley

2016-11-01

The resolvent analysis of McKeon and Sharma formulates the Navier-Stokes equations as an input/output system in which the nonlinearity is treated as a forcing that acts upon the linear dynamics to yield a velocity response across wavenumber/frequency space. DNS data for a low Reynolds number turbulent channel (Reτ = 180) is used to investigate the structure of the nonlinear forcing directly. Specifically, we explore the spatio-temporal scales where the forcing is active and analyze its interplay with the linear amplification mechanisms present in the resolvent operator. This work could provide insight into self-sustaining processes in wall-turbulence and inform the modeling of scale interactions in large eddy simulations. We gratefully acknowledge Stanford's Center for Turbulence Research for support of this work.

Periorbital hemangiomas.

PubMed

Goldberg, N S; Rosanova, M A

1992-10-01

1. Any hemangioma that involves the upper or lower lid and leads to partial closure in infancy may interfere with or prevent development of normal binocular vision in a matter of days to weeks. 2. Hemangiomas least likely to interfere with vision are lower lid lesions occupying one third of the lid margin or less, not extending beyond the eyelid region, and resolving early. 3. Hemangiomas associated with deprivation amblyopia (with or without anisometropia) are lesions occupying more than one half of the lid margin, extending beyond the eyelid region, resolving late, and obstructing the visual axis. 4. Hemangiomas associated with isolated anisometropic amblyopia are local but bulky lesions that are usually but not always restricted to the upper lid, closing the eye partly and resolving late. 5. The treatment of choice for periorbital hemangiomas is corticosteroids, either systemic or intralesional.

Time-resolved rhodopsin activation currents in a unicellular expression system.

PubMed Central

Sullivan, J M; Shukla, P

1999-01-01

The early receptor current (ERC) is the charge redistribution occurring in plasma membrane rhodopsin during light activation of photoreceptors. Both the molecular mechanism of the ERC and its relationship to rhodopsin conformational activation are unknown. To investigate whether the ERC could be a time-resolved assay of rhodopsin structure-function relationships, the distinct sensitivity of modern electrophysiological tools was employed to test for flash-activated ERC signals in cells stably expressing normal human rod opsin after regeneration with 11-cis-retinal. ERCs are similar in waveform and kinetics to those found in photoreceptors. The action spectrum of the major R(2) charge motion is consistent with a rhodopsin photopigment. The R(1) phase is not kinetically resolvable and the R(2) phase, which overlaps metarhodopsin-II formation, has a rapid risetime and complex multiexponential decay. These experiments demonstrate, for the first time, kinetically resolved electrical state transitions during activation of expressed visual pigment in a unicellular environment (single or fused giant cells) containing only 6 x 10(6)-8 x 10(7) molecules of rhodopsin. This method improves measurement sensitivity 7 to 8 orders of magnitude compared to other time-resolved techniques applied to rhodopsin to study the role particular amino acids play in conformational activation and the forces that govern those transitions. PMID:10465746

Is the Young UY Auriga System a Triple?

NASA Astrophysics Data System (ADS)

Wittal, Matthew; Prato, Lisa A.; Schaefer, Gail; Ciardi, David R.; Thomas, Allen; Biddle, Lauren; Avilez, Ian; Muzzio, Ryan; Patience, Jennifer; Beichman, Charles

2017-01-01

In an effort to understand the nature of the young binary, UY Aur, we examined the variable behavior of the entire, unresolved 0.9 arcsecond system, as well as the behavior of the angularly resolved, individual A and B components. UY Aur is an approximately 2 Myr old, classical T Tauri in the Taurus-Auriga star forming region and is one of a handful of young systems to host a primordial circumbinary disk, as well as individual circumstellar disks. Using the the facility infrared, high-resolution NIRSPEC spectrograph behind the adaptive optics system at the 10-meter Keck II telescope, we observed a dramatic change in the spectra of UY Aur B between 2003 and 2010. We also identified flux variability in the individual components of 1—2 magnitudes, particularly in the secondary star, on the basis of historical photometry. Thermal dust and line emission observed with millimeter interferometry indicates complex dynamical behavior of the circumbinary and circumstellar dust and led Tang et al. (2014) to speculate that UY Aur B may itself be a binary. Our adaptive optics imaging with the Keck II telescope showed no evidence for a close companion to the B component, although the marked change in our spectra of this star suggest that it could be a spectroscopic binary. We are currently limited by the paucity of angularly resolved observations, both photometric and spectroscopic, hampering the interpretation of the data. High-cadence, angularly resolved spectroscopy and photometry will be required to confirm the potential higher-order multiplicity of this system. This research was supported in part by NSF grants AST-1461200 and AST-1313399.

High speed CMOS acquisition system based on FPGA embedded image processing for electro-optical measurements

NASA Astrophysics Data System (ADS)

Rosu-Hamzescu, Mihnea; Polonschii, Cristina; Oprea, Sergiu; Popescu, Dragos; David, Sorin; Bratu, Dumitru; Gheorghiu, Eugen

2018-06-01

Electro-optical measurements, i.e., optical waveguides and plasmonic based electrochemical impedance spectroscopy (P-EIS), are based on the sensitive dependence of refractive index of electro-optical sensors on surface charge density, modulated by an AC electrical field applied to the sensor surface. Recently, P-EIS has emerged as a new analytical tool that can resolve local impedance with high, optical spatial resolution, without using microelectrodes. This study describes a high speed image acquisition and processing system for electro-optical measurements, based on a high speed complementary metal-oxide semiconductor (CMOS) sensor and a field-programmable gate array (FPGA) board. The FPGA is used to configure CMOS parameters, as well as to receive and locally process the acquired images by performing Fourier analysis for each pixel, deriving the real and imaginary parts of the Fourier coefficients for the AC field frequencies. An AC field generator, for single or multi-sine signals, is synchronized with the high speed acquisition system for phase measurements. The system was successfully used for real-time angle-resolved electro-plasmonic measurements from 30 Hz up to 10 kHz, providing results consistent to ones obtained by a conventional electrical impedance approach. The system was able to detect amplitude variations with a relative variation of ±1%, even for rather low sampling rates per period (i.e., 8 samples per period). The PC (personal computer) acquisition and control software allows synchronized acquisition for multiple FPGA boards, making it also suitable for simultaneous angle-resolved P-EIS imaging.

Graph Theoretic Foundations of Multibody Dynamics Part I: Structural Properties

PubMed Central

Jain, Abhinandan

2011-01-01

This is the first part of two papers that use concepts from graph theory to obtain a deeper understanding of the mathematical foundations of multibody dynamics. The key contribution is the development of a unifying framework that shows that key analytical results and computational algorithms in multibody dynamics are a direct consequence of structural properties and require minimal assumptions about the specific nature of the underlying multibody system. This first part focuses on identifying the abstract graph theoretic structural properties of spatial operator techniques in multibody dynamics. The second part paper exploits these structural properties to develop a broad spectrum of analytical results and computational algorithms. Towards this, we begin with the notion of graph adjacency matrices and generalize it to define block-weighted adjacency (BWA) matrices and their 1-resolvents. Previously developed spatial operators are shown to be special cases of such BWA matrices and their 1-resolvents. These properties are shown to hold broadly for serial and tree topology multibody systems. Specializations of the BWA and 1-resolvent matrices are referred to as spatial kernel operators (SKO) and spatial propagation operators (SPO). These operators and their special properties provide the foundation for the analytical and algorithmic techniques developed in the companion paper. We also use the graph theory concepts to study the topology induced sparsity structure of these operators and the system mass matrix. Similarity transformations of these operators are also studied. While the detailed development is done for the case of rigid-link multibody systems, the extension of these techniques to a broader class of systems (e.g. deformable links) are illustrated. PMID:22102790

The Resolvent Algebra of Non-relativistic Bose Fields: Observables, Dynamics and States

NASA Astrophysics Data System (ADS)

Buchholz, Detlev

2018-05-01

The structure of the gauge invariant (particle number preserving) C*-algebra generated by the resolvents of a non-relativistic Bose field is analyzed. It is shown to form a dense subalgebra of the bounded inverse limit of a directed system of approximately finite dimensional C*-algebras. Based on this observation, it is proven that the closure of the gauge invariant algebra is stable under the dynamics induced by Hamiltonians involving pair potentials. These facts allow to proceed to a description of interacting Bosons in terms of C*-dynamical systems. It is outlined how the present approach leads to simplifications in the construction of infinite bosonic states and sheds new light on topics in many body theory.

UAS Conflict-Avoidance Using Multiagent RL with Abstract Strategy Type Communication

NASA Technical Reports Server (NTRS)

Rebhuhn, Carrie; Knudson, Matt; Tumer, Kagan

2014-01-01

The use of unmanned aerial systems (UAS) in the national airspace is of growing interest to the research community. Safety and scalability of control algorithms are key to the successful integration of autonomous system into a human-populated airspace. In order to ensure safety while still maintaining efficient paths of travel, these algorithms must also accommodate heterogeneity of path strategies of its neighbors. We show that, using multiagent RL, we can improve the speed with which conflicts are resolved in cases with up to 80 aircraft within a section of the airspace. In addition, we show that the introduction of abstract agent strategy types to partition the state space is helpful in resolving conflicts, particularly in high congestion.

Announced Strategy Types in Multiagent RL for Conflict-Avoidance in the National Airspace

NASA Technical Reports Server (NTRS)

Rebhuhn, Carrie; Knudson, Matthew D.; Tumer, Kagan

2014-01-01

The use of unmanned aerial systems (UAS) in the national airspace is of growing interest to the research community. Safety and scalability of control algorithms are key to the successful integration of autonomous system into a human-populated airspace. In order to ensure safety while still maintaining efficient paths of travel, these algorithms must also accommodate heterogeneity of path strategies of its neighbors. We show that, using multiagent RL, we can improve the speed with which conflicts are resolved in cases with up to 80 aircraft within a section of the airspace. In addition, we show that the introduction of abstract agent strategy types to partition the state space is helpful in resolving conflicts, particularly in high congestion.

Time-resolved spectrophotometry of the AM Herculis system E2003 + 225

NASA Technical Reports Server (NTRS)

Mccarthy, Patrick; Bowyer, Stuart; Clarke, John T.

1986-01-01

Time-resolved, medium-resolution photometry is reported for the binary system E2003 + 225 over a complete orbital period in 1984. The object was 1.5-2 mag fainter than when viewed earlier in 1984. The fluxes, equivalent widths and full widths at FWHM for dominant lines are presented for four points in the cycle. A coincidence of emission lines and a 4860 A continuum line was observed for the faster component, which had a 500 km/sec velocity amplitude that was symmetric around the zero line. An aberrant emission line component, i.e., stationary narrow emission lines displaced about 9 A from the rest wavelengths, is modeled as Zeeman splitting of emission from material close to the primary.

NEP systems engineering efforts in FY-92: Plans and status

NASA Technical Reports Server (NTRS)

Doherty, Michael P.; Gilland, James H.

1992-01-01

A system engineering effort has been initiated by NASA in FY-92 to define, address, and resolve issues associated with the use of Nuclear Electric Propulsion (NEP) for megawatt (MW) space propulsion applications associated with the Space Exploration Initiative (SEI). It is intended that key technical issues will be addressed by activities conducted in the early years of a project in NEP, with the objective of resolving such issues. Also, in response to more recent programmatic direction, a concept definition activity for 100 kilowatt NEP is being initiated. This paper will present key issues associated with megawatt NEP, and the plans and status for their resolution, and present the scope and rationale for the 100 kilowatt concept definition activity.

Prototype solar heated hot water systems and double-walled heat exchangers: A collection of quarterly reports

NASA Technical Reports Server (NTRS)

1978-01-01

The plan schedule and status of multiple objectives to be achieved in the development, manufacture, installation, and maintenance of two solar heated hot water prototype systems and two heat exchangers are reported. A computer program developed to resolve problems and evaluate system performance is described.

The Inner 25 au Debris Distribution in the ϵ Eri System

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

Su, Kate Y. L.; Rieke, George H.; Ballering, Nicholas P.

Debris disk morphology is wavelength dependent due to the wide range of particle sizes and size-dependent dynamics influenced by various forces. Resolved images of nearby debris disks reveal complex disk structures that are difficult to distinguish from their spectral energy distributions. Therefore, multi-wavelength resolved images of nearby debris systems provide an essential foundation to understand the intricate interplay between collisional, gravitational, and radiative forces that govern debris disk structures. We present the Stratospheric Observatory for Infrared Astronomy (SOFIA) 35 μ m resolved disk image of ϵ Eri, the closest debris disk around a star similar to the early Sun. Combiningmore » with the Spitzer resolved image at 24 μ m and 15–38 μ m excess spectrum, we examine two proposed origins of the inner debris in ϵ Eri: (1) in situ planetesimal belt(s) and (2) dragged-in grains from the cold outer belt. We find that the presence of in situ dust-producing planetesmial belt(s) is the most likely source of the excess emission in the inner 25 au region. Although a small amount of dragged-in grains from the cold belt could contribute to the excess emission in the inner region, the resolution of the SOFIA data is high enough to rule out the possibility that the entire inner warm excess results from dragged-in grains, but not enough to distinguish one broad inner disk from two narrow belts.« less

Lunar Water Resource Demonstration

NASA Technical Reports Server (NTRS)

Muscatello, Anthony C.

2008-01-01

In cooperation with the Canadian Space Agency, the Northern Centre for Advanced Technology, Inc., the Carnegie-Mellon University, JPL, and NEPTEC, NASA has undertaken the In-Situ Resource Utilization (ISRU) project called RESOLVE. This project is a ground demonstration of a system that would be sent to explore permanently shadowed polar lunar craters, drill into the regolith, determine what volatiles are present, and quantify them in addition to recovering oxygen by hydrogen reduction. The Lunar Prospector has determined these craters contain enhanced hydrogen concentrations averaging about 0.1%. If the hydrogen is in the form of water, the water concentration would be around 1%, which would translate into billions of tons of water on the Moon, a tremendous resource. The Lunar Water Resource Demonstration (LWRD) is a part of RESOLVE designed to capture lunar water and hydrogen and quantify them as a backup to gas chromatography analysis. This presentation will briefly review the design of LWRD and some of the results of testing the subsystem. RESOLVE is to be integrated with the Scarab rover from CMIJ and the whole system demonstrated on Mauna Kea on Hawaii in November 2008. The implications of lunar water for Mars exploration are two-fold: 1) RESOLVE and LWRD could be used in a similar fashion on Mars to locate and quantify water resources, and 2) electrolysis of lunar water could provide large amounts of liquid oxygen in LEO, leading to lower costs for travel to Mars, in addition to being very useful at lunar outposts.

An enhanced droplet-based liquid microjunction surface sampling system coupled with HPLC-ESI-MS/MS for spatially resolved analysis

DOE PAGES

Van Berkel, Gary J.; Weiskittel, Taylor M.; Kertesz, Vilmos

2014-11-07

Droplet-based liquid microjunction surface sampling coupled with high-performance liquid chromatography (HPLC)-electrospray ionization (ESI)-tandem mass spectrometry (MS/MS) for spatially resolved analysis provides the possibility of effective analysis of complex matrix samples and can provide a greater degree of chemical information from a single spot sample than is typically possible with a direct analysis of an extract. Described here is the setup and enhanced capabilities of a discrete droplet liquid microjunction surface sampling system employing a commercially available CTC PAL autosampler. The system enhancements include incorporation of a laser distance sensor enabling unattended analysis of samples and sample locations of dramatically disparatemore » height as well as reliably dispensing just 0.5 μL of extraction solvent to make the liquid junction to the surface, wherein the extraction spot size was confined to an area about 0.7 mm in diameter; software modifications improving the spatial resolution of sampling spot selection from 1.0 to 0.1 mm; use of an open bed tray system to accommodate samples as large as whole-body rat thin tissue sections; and custom sample/solvent holders that shorten sampling time to approximately 1 min per sample. Lastly, the merit of these new features was demonstrated by spatially resolved sampling, HPLC separation, and mass spectral detection of pharmaceuticals and metabolites from whole-body rat thin tissue sections and razor blade (“crude”) cut mouse tissue.« less

Time-resolved imaging of the MALDI linear-TOF ion cloud: direct visualization and exploitation of ion optical phenomena using a position- and time-sensitive detector.

PubMed

Ellis, Shane R; Soltwisch, Jens; Heeren, Ron M A

2014-05-01

In this study, we describe the implementation of a position- and time-sensitive detection system (Timepix detector) to directly visualize the spatial distributions of the matrix-assisted laser desorption ionization ion cloud in a linear-time-of-flight (MALDI linear-ToF) as it is projected onto the detector surface. These time-resolved images allow direct visualization of m/z-dependent ion focusing effects that occur within the ion source of the instrument. The influence of key parameters, namely extraction voltage (E(V)), pulsed-ion extraction (PIE) delay, and even the matrix-dependent initial ion velocity was investigated and were found to alter the focusing properties of the ion-optical system. Under certain conditions where the spatial focal plane coincides with the detector plane, so-called x-y space focusing could be observed (i.e., the focusing of the ion cloud to a small, well-defined spot on the detector). Such conditions allow for the stigmatic ion imaging of intact proteins for the first time on a commercial linear ToF-MS system. In combination with the ion-optical magnification of the system (~100×), a spatial resolving power of 11–16 μm with a pixel size of 550 nm was recorded within a laser spot diameter of ~125 μm. This study demonstrates both the diagnostic and analytical advantages offered by the Timepix detector in ToF-MS.

An enhanced droplet-based liquid microjunction surface sampling system coupled with HPLC-ESI-MS/MS for spatially resolved analysis

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

Van Berkel, Gary J.; Weiskittel, Taylor M.; Kertesz, Vilmos

Droplet-based liquid microjunction surface sampling coupled with high-performance liquid chromatography (HPLC)-electrospray ionization (ESI)-tandem mass spectrometry (MS/MS) for spatially resolved analysis provides the possibility of effective analysis of complex matrix samples and can provide a greater degree of chemical information from a single spot sample than is typically possible with a direct analysis of an extract. Described here is the setup and enhanced capabilities of a discrete droplet liquid microjunction surface sampling system employing a commercially available CTC PAL autosampler. The system enhancements include incorporation of a laser distance sensor enabling unattended analysis of samples and sample locations of dramatically disparatemore » height as well as reliably dispensing just 0.5 μL of extraction solvent to make the liquid junction to the surface, wherein the extraction spot size was confined to an area about 0.7 mm in diameter; software modifications improving the spatial resolution of sampling spot selection from 1.0 to 0.1 mm; use of an open bed tray system to accommodate samples as large as whole-body rat thin tissue sections; and custom sample/solvent holders that shorten sampling time to approximately 1 min per sample. Lastly, the merit of these new features was demonstrated by spatially resolved sampling, HPLC separation, and mass spectral detection of pharmaceuticals and metabolites from whole-body rat thin tissue sections and razor blade (“crude”) cut mouse tissue.« less

Application of spectroscopy and super-resolution microscopy: Excited state

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

Bhattacharjee, Ujjal

Photophysics of inorganic materials and organic molecules in complex systems have been extensively studied with absorption and emission spectroscopy.1-4 Steady-state and time-resolved fluorescence studies are commonly carried out to characterize excited-state properties of fluorophores. Although steady-state fluorescence measurements are widely used for analytical applications, time-resolved fluorescence measurements provide more detailed information about excited-state properties and the environment in the vicinity of the fluorophore. Many photophysical processes, such as photoinduced electron transfer (PET), rotational reorientation, solvent relaxation, and energy transfer, occur on a nanosecond (10 -9 s) timescale, thus affecting the lifetime of the fluorophores. Moreover, time-resolved microscopy methods, such asmore » lifetimeimaging, combine the benefits of the microscopic measurement and information-rich, timeresolved data. Thus, time-resolved fluorescence spectroscopy combined with microscopy can be used to quantify these processes and to obtain a deeper understanding of the chemical surroundings of the fluorophore in a small area under investigation. This thesis discusses various photophysical and super-resolution microscopic studies of organic and inorganic materials, which have been outlined below.« less

Simulation of Wave and Current Processes Using Novel, Phase Resolving Models

DTIC Science & Technology

2013-09-30

fundamental technical approach is to represent nearshore water wave systems by retaining Boussinesq scaling assumptions, but without any assumption of... Boussinesq approach that allows for much more freedom in determining the system properties. The resulting systems can have two forms: a classic...of a pressure-Poisson approach to Boussinesq systems . The wave generation-absorption system has now been shown to provide highly accurate results

Iterative Repair Planning for Spacecraft Operations Using the Aspen System

NASA Technical Reports Server (NTRS)

Rabideau, G.; Knight, R.; Chien, S.; Fukunaga, A.; Govindjee, A.

2000-01-01

This paper describes the Automated Scheduling and Planning Environment (ASPEN). ASPEN encodes complex spacecraft knowledge of operability constraints, flight rules, spacecraft hardware, science experiments and operations procedures to allow for automated generation of low level spacecraft sequences. Using a technique called iterative repair, ASPEN classifies constraint violations (i.e., conflicts) and attempts to repair each by performing a planning or scheduling operation. It must reason about which conflict to resolve first and what repair method to try for the given conflict. ASPEN is currently being utilized in the development of automated planner/scheduler systems for several spacecraft, including the UFO-1 naval communications satellite and the Citizen Explorer (CX1) satellite, as well as for planetary rover operations and antenna ground systems automation. This paper focuses on the algorithm and search strategies employed by ASPEN to resolve spacecraft operations constraints, as well as the data structures for representing these constraints.

Mechanistic characterization of chloride interferences in electrothermal atomization systems

USGS Publications Warehouse

Shekiro, J.M.; Skogerboe, R.K.; Taylor, Howard E.

1988-01-01

A computer-controlled spectrometer with a photodiode array detector has been used for wavelength and temperature resolved characterization of the vapor produced by an electrothermal atomizer. The system has been used to study the chloride matrix interference on the atomic absorption spectrometric determination of manganese and copper. The suppression of manganese and copper atom populations by matrix chlorides such as those of calcium and magnesium is due to the gas-phase formation of an analyte chloride species followed by the diffusion of significant fractions of these species from the atom cell prior to completion of the atomization process. The analyte chloride species cannot be formed when matrix chlorides with metal-chloride bond dissociation energies above those of the analyte chlorides are the principal entitles present. The results indicate that multiple wavelength spectrometry used to obtain temperature-resolved spectra is a viable tool in the mechanistic characterization of interference effects observed with electrothermal atomization systems. ?? 1988 American Chemical Society.

A versatile soft X-ray transmission system for time resolved in situ microscopy with chemical contrast.

PubMed

Forsberg, J; Englund, C-J; Duda, L-C

2009-08-01

We present the design and operation of a versatile soft X-ray transmission system for time resolved in situ microscopy with chemical contrast. The utility of the setup is demonstrated by results from following a corrosion process of iron in saline environment, subjected to a controlled humid atmosphere. The system includes a transmission flow-cell reactor that allows for in situ microscopic probing with soft X-rays. We employ a full field technique by using a nearly collimated X-ray beam that produces an unmagnified projection of the transmitted soft X-rays (below 1.1 keV) which is magnified and recorded by an optical CCD camera. Time lapse series with chemical contrast allow us to follow and interpret the chemical processes in detail. The obtainable lateral resolution is a few mum, sufficient to detect filiform corrosion on iron.

The SPS concept - An overview of status and outlook. [Satellite Power System

NASA Technical Reports Server (NTRS)

Schwenk, F. C.

1980-01-01

The satellite power system (SPS) concept has been reviewed and assessed in a concept development and evaluation program. This paper presents the results of the assessment in systems definition, environmental factors, social impacts, and comparison of future energy systems. Although no insurmountable objections to SPS have been identified, there remain issues that can be resolved only through further research.

Designing a Retirement System for Federal Workers Covered by Social Security.

ERIC Educational Resources Information Center

Library of Congress, Washington, DC. Congressional Research Service.

A study examined principal cost and benefit issues to be resolved in designing a new retirement system for Federal workers covered by Social Security. The new Federal system would be built on the base of Social Security and would take into account the Social Security program's taxes and benefits. The current Civil Service Retirement System (CSRS)…

340nm UV LED excitation in time-resolved fluorescence system for europium-based immunoassays detection

NASA Astrophysics Data System (ADS)

Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter; Pedersen, Christian

2017-02-01

In immunoassay analyzers for in-vitro diagnostics, Xenon flash lamps have been widely used as excitation light sources. Recent advancements in UV LED technology and its advantages over the flash lamps such as smaller footprint, better wall-plug efficiency, narrow emission spectrum, and no significant afterglow, have made them attractive light sources for gated detection systems. In this paper, we report on the implementation of a 340 nm UV LED based time-resolved fluorescence system based on europium chelate as a fluorescent marker. The system performance was tested with the immunoassay based on the cardiac marker, TnI. The same signal-to-noise ratio as for the flash lamp based system was obtained, operating the LED below specified maximum current. The background counts of the system and its main contributors were measured and analyzed. The background of the system of the LED based unit was improved by 39% compared to that of the Xenon flash lamp based unit, due to the LEDs narrower emission spectrum and longer pulse width. Key parameters of the LED system are discussed to further optimize the signal-to-noise ratio and signal-to-background, and hence the sensitivity of the instrument.

Human Factors Considerations for Safe Recovery from Faults In Flight Control Systems

NASA Technical Reports Server (NTRS)

Pritchett, Amy; Belcastro, C. M. (Technical Monitor)

2003-01-01

It is now possible - and important - to develop systems to help resolve Flight Control System (FCS) faults. From a human factors viewpoint, it is imperative that these systems take on roles, and provide functions, that are the most supportive to the pilot, given the stress, time pressure and workload they may experience following a FCS fault. FCS fault recovery systems may provide several different functions, including alerting, control assistance, and decision aiding. The biggest human factors questions are in the role suitable for the technology, and its specific functioning to achieve that role. Specifically, for these systems to be effective, they must meet the fundamental requirements that (1) they alert pilots to problems early enough that the pilot can reasonably resolve the fault and regain control of the aircraft and that (2) if the aircraft s handling qualities are severely degraded the HMS provide the appropriate stability augmentation to help the pilot stabilize and control the aircraft. This project undertook several research steps to develop such systems, focusing on the capabilities of pilots and on realistically attainable technologies. The ability to estimate which functions are the most valuable will help steer system development in the directions that can establish the highest safety levels.

An approach to knowledge structuring for advanced phases of the Technical and Management Information System (TMIS)

NASA Technical Reports Server (NTRS)

Goranson, H. T.

1986-01-01

The Technical and Management Information System (TMIS) must employ on enlightened approach to its object structure, but basic issues in conceptual structuring remain to be resolved. Sirius outlines the necessary agenda and reports on progress toward solutions.

47 CFR 95.861 - Interference.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO...-219 MHz Service system, the licensees of both systems must cooperate and resolve the problem by... CTS(s) or RTU(s) causing the problem(s) must discontinue operation. (f) The boundary of the 218-219...

47 CFR 95.861 - Interference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO...-219 MHz Service system, the licensees of both systems must cooperate and resolve the problem by... CTS(s) or RTU(s) causing the problem(s) must discontinue operation. (f) The boundary of the 218-219...

Emission Enhancement in Quantum Emitters - Plasmonic Nanostructures Systems

NASA Astrophysics Data System (ADS)

Muqri, Aeshah; Suh, Jae Yong; Michogan Technological University Team

In this poster, the emission enhancement probed by spectroscopic and dynamic means will be presented. Systems composed of quantum emitters ensembles in the vicinity of plasmonic structures were fabricated. Their coupling strength were investigated by measuring the reflection, steady state photoluminescence, and time resolved fluorescence.

Photon-Number-Resolving Transition-Edge Sensors for the Metrology of Quantum Light Sources

NASA Astrophysics Data System (ADS)

Schmidt, M.; von Helversen, M.; López, M.; Gericke, F.; Schlottmann, E.; Heindel, T.; Kück, S.; Reitzenstein, S.; Beyer, J.

2018-05-01

Low-temperature photon-number-resolving detectors allow for direct access to the photon number distribution of quantum light sources and can thus be exploited to explore the photon statistics, e.g., solid-state-based non-classical light sources. In this work, we report on the setup and calibration of a detection system based on fiber-coupled tungsten transition-edge sensors (W-TESs). Our stand-alone system comprises two W-TESs, read out by two 2-stage-SQUID current sensors, operated in a compact detector unit that is integrated in an adiabatic demagnetization refrigerator. Fast low-noise analog amplifiers and digitizers are used for signal acquisition. The detection efficiency of the single-mode fiber-coupled detector system in the spectral region of interest (850-950 nm) is determined to be larger than 87 %. The presented detector system opens up new routes in the characterization of quantum light sources for quantum information, quantum-enhanced sensing and quantum metrology.

Non-Nuclear Testing of Fission Technologies at NASA MSFC

NASA Technical Reports Server (NTRS)

Houts, Robert G.; Pearson, J. Boise; Aschenbrenner, Kenneth C.; Bradley, David E.; Dickens, Ricky E.; Emrich, William J.; Garber, Anne E.; Godfroy, Thomas J.; Harper, Roger T.; Martin, Jim J.;

Holographic flow diagnostics for the Space Shuttle main engine

NASA Technical Reports Server (NTRS)

1992-01-01

Summarized here are the results of an effort to produce holograms of the exhaust from the Space Shuttle Main Engine (SSME) being tested on a test stand at the Marshall Space Flight Center (MSFC). The effort took place from December 1990 to January 1992, during which seven trips were made from MetroLaser to MSFC. A brief outline of each trip is given. Due to the suspension of the SSME program in Huntsville and unexpected complications in resolving safety issues, the proposed holography system was not operated until November 1991. A NASA 100 mW Argon laser was installed in the holography system for an October engine test while these safety issues were being resolved. A video camera shadowgraph was made during this test, which was shut down prematurely after 20 seconds. System problems precluded successful operation of the holography system until the January 1992 engine test. No hologram resulted during this test due to heavy fog conditions around the engine.

Fiber optic sensing technology for detecting gas hydrate formation and decomposition.

PubMed

Rawn, C J; Leeman, J R; Ulrich, S M; Alford, J E; Phelps, T J; Madden, M E

2011-02-01

A fiber optic-based distributed sensing system (DSS) has been integrated with a large volume (72 l) pressure vessel providing high spatial resolution, time-resolved, 3D measurement of hybrid temperature-strain (TS) values within experimental sediment-gas hydrate systems. Areas of gas hydrate formation (exothermic) and decomposition (endothermic) can be characterized through this proxy by time series analysis of discrete data points collected along the length of optical fibers placed within a sediment system. Data are visualized as an animation of TS values along the length of each fiber over time. Experiments conducted in the Seafloor Process Simulator at Oak Ridge National Laboratory clearly indicate hydrate formation and dissociation events at expected pressure-temperature conditions given the thermodynamics of the CH(4)-H(2)O system. The high spatial resolution achieved with fiber optic technology makes the DSS a useful tool for visualizing time-resolved formation and dissociation of gas hydrates in large-scale sediment experiments.

Specialty Task Force: A Strategic Component to Electronic Health Record (EHR) Optimization.

PubMed

Romero, Mary Rachel; Staub, Allison

2016-01-01

Post-implementation stage comes after an electronic health record (EHR) deployment. Analyst and end users deal with the reality that some of the concepts and designs initially planned and created may not be complementary to the workflow; creating anxiety, dissatisfaction, and failure with early adoption of system. Problems encountered during deployment are numerous and can vary from simple to complex. Redundant ticket submission creates backlog for Information Technology personnel resulting in delays in resolving concerns with EHR system. The process of optimization allows for evaluation of system and reassessment of users' needs. A solid and well executed optimization infrastructure can help minimize unexpected end-user disruptions and help tailor the system to meet regulatory agency goals and practice standards. A well device plan to resolve problems during post implementation is necessary for cost containment and to streamline communication efforts. Creating a specialty specific collaborative task force is efficacious and expedites resolution of users' concerns through a more structured process.

Fiber optic sensing technology for detecting gas hydrate formation and decomposition

NASA Astrophysics Data System (ADS)

Rawn, C. J.; Leeman, J. R.; Ulrich, S. M.; Alford, J. E.; Phelps, T. J.; Madden, M. E.

2011-02-01

A fiber optic-based distributed sensing system (DSS) has been integrated with a large volume (72 l) pressure vessel providing high spatial resolution, time-resolved, 3D measurement of hybrid temperature-strain (TS) values within experimental sediment-gas hydrate systems. Areas of gas hydrate formation (exothermic) and decomposition (endothermic) can be characterized through this proxy by time series analysis of discrete data points collected along the length of optical fibers placed within a sediment system. Data are visualized as an animation of TS values along the length of each fiber over time. Experiments conducted in the Seafloor Process Simulator at Oak Ridge National Laboratory clearly indicate hydrate formation and dissociation events at expected pressure-temperature conditions given the thermodynamics of the CH4-H2O system. The high spatial resolution achieved with fiber optic technology makes the DSS a useful tool for visualizing time-resolved formation and dissociation of gas hydrates in large-scale sediment experiments.

Light-induced radical formation and isomerization of an aromatic thiol in solution followed by time-resolved x-ray absorption spectroscopy at the sulfur K-edge

DOE PAGES

Ochmann, Miguel; von Ahnen, Inga; Cordones, Amy A.; ...

2017-02-20

Here, we applied time-resolved sulfur-1s absorption spectroscopy to a model aromatic thiol system as a promising method for tracking chemical reactions in solution. Sulfur-1s absorption spectroscopy allows tracking multiple sulfur species with a time resolution of ~70 ps at synchrotron radiation facilities. Experimental transient spectra combined with high-level electronic structure theory allow identification of a radical and two thione isomers, which are generated upon illumination with 267 nm radiation. Moreover, the regioselectivity of the thione isomerization is explained by the resulting radical frontier orbitals. This work demonstrates the usefulness and potential of time-resolved sulfur-1s absorption spectroscopy for tracking multiple chemicalmore » reaction pathways and transient products of sulfur-containing molecules in solution.« less

Translational control of a graphically simulated robot arm by kinematic rate equations that overcome elbow joint singularity

NASA Technical Reports Server (NTRS)

Barker, L. K.; Houck, J. A.; Carzoo, S. W.

1984-01-01

An operator commands a robot hand to move in a certain direction relative to its own axis system by specifying a velocity in that direction. This velocity command is then resolved into individual joint rotational velocities in the robot arm to effect the motion. However, the usual resolved-rate equations become singular when the robot arm is straightened. To overcome this elbow joint singularity, equations were developed which allow continued translational control of the robot hand even though the robot arm is (or is nearly) fully extended. A feature of the equations near full arm extension is that an operator simply extends and retracts the robot arm to reverse the direction of the elbow bend (difficult maneuver for the usual resolved-rate equations). Results show successful movement of a graphically simulated robot arm.

Time-resolved X-ray excited optical luminescence using an optical streak camera

NASA Astrophysics Data System (ADS)

Ward, M. J.; Regier, T. Z.; Vogt, J. M.; Gordon, R. A.; Han, W.-Q.; Sham, T. K.

2013-03-01

We report the development of a time-resolved XEOL (TR-XEOL) system that employs an optical streak camera. We have conducted TR-XEOL experiments at the Canadian Light Source (CLS) operating in single bunch mode with a 570 ns dark gap and 35 ps electron bunch pulse, and at the Advanced Photon Source (APS) operating in top-up mode with a 153 ns dark gap and 33.5 ps electron bunch pulse. To illustrate the power of this technique we measured the TR-XEOL of solid-solution nanopowders of gallium nitride - zinc oxide, and for the first time have been able to resolve near-band-gap (NBG) optical luminescence emission from these materials. Herein we will discuss the development of the streak camera TR-XEOL technique and its application to the study of these novel materials.

Velocity measurement using frequency domain interferometer and chirped pulse laser

NASA Astrophysics Data System (ADS)

Ishii, K.; Nishimura, Y.; Mori, Y.; Hanayama, R.; Kitagawa, Y.; Sekine, T.; Sato, N.; Kurita, T.; Kawashima, T.; Sunahara, A.; Sentoku, Y.; Miura, E.; Iwamoto, A.; Sakagami, H.

2017-02-01

An ultra-intense short pulse laser induces a shock wave in material. The pressure of shock compression is stronger than a few tens GPa. To characterize shock waves, time-resolved velocity measurement in nano- or pico-second time scale is needed. Frequency domain interferometer and chirped pulse laser provide single-shot time-resolved measurement. We have developed a laser-driven shock compression system and frequency domain interferometer with CPA laser. In this paper, we show the principle of velocity measurement using a frequency domain interferometer and a chirped pulse laser. Next, we numerically calculated spectral interferograms and show the time-resolved velocity measurement can be done from the phase analysis of spectral interferograms. Moreover we conduct the laser driven shock generation and shock velocity measurement. From the spectral fringes, we analyze the velocities of the sample and shockwaves.

Improving the accuracy and efficiency of time-resolved electronic spectra calculations: cellular dephasing representation with a prefactor.

PubMed

Zambrano, Eduardo; Šulc, Miroslav; Vaníček, Jiří

2013-08-07

Time-resolved electronic spectra can be obtained as the Fourier transform of a special type of time correlation function known as fidelity amplitude, which, in turn, can be evaluated approximately and efficiently with the dephasing representation. Here we improve both the accuracy of this approximation-with an amplitude correction derived from the phase-space propagator-and its efficiency-with an improved cellular scheme employing inverse Weierstrass transform and optimal scaling of the cell size. We demonstrate the advantages of the new methodology by computing dispersed time-resolved stimulated emission spectra in the harmonic potential, pyrazine, and the NCO molecule. In contrast, we show that in strongly chaotic systems such as the quartic oscillator the original dephasing representation is more appropriate than either the cellular or prefactor-corrected methods.

A stretch/compress scheme for a high temporal resolution detector for the magnetic recoil spectrometer time (MRSt)

DOE PAGES

Hilsabeck, T. J.; Frenje, J. A.; Hares, J. D.; ...

2016-08-02

Here we present a time-resolved detector concept for the magnetic recoil spectrometer for time-resolved measurements of the NIF neutron spectrum. The measurement is challenging due to the time spreading of the recoil protons (or deuterons) as they transit an energy dispersing magnet system. Ions arrive at the focal plane of the magnetic spectrometer over an interval of tens of nanoseconds. We seek to measure the time-resolved neutron spectrum with 20 ps precision by manipulating an electron signal derived from the ions. A stretch-compress scheme is employed to remove transit time skewing while simultaneously reducing the bandwidth requirements for signal recording.more » Simulation results are presented along with design concepts for structures capable of establishing the required electromagnetic fields.« less

A stretch/compress scheme for a high temporal resolution detector for the magnetic recoil spectrometer time (MRSt)

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

Hilsabeck, T. J.; Frenje, J. A.; Hares, J. D.

Here we present a time-resolved detector concept for the magnetic recoil spectrometer for time-resolved measurements of the NIF neutron spectrum. The measurement is challenging due to the time spreading of the recoil protons (or deuterons) as they transit an energy dispersing magnet system. Ions arrive at the focal plane of the magnetic spectrometer over an interval of tens of nanoseconds. We seek to measure the time-resolved neutron spectrum with 20 ps precision by manipulating an electron signal derived from the ions. A stretch-compress scheme is employed to remove transit time skewing while simultaneously reducing the bandwidth requirements for signal recording.more » Simulation results are presented along with design concepts for structures capable of establishing the required electromagnetic fields.« less

Light-induced radical formation and isomerization of an aromatic thiol in solution followed by time-resolved x-ray absorption spectroscopy at the sulfur K-edge

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

Ochmann, Miguel; von Ahnen, Inga; Cordones, Amy A.

Here, we applied time-resolved sulfur-1s absorption spectroscopy to a model aromatic thiol system as a promising method for tracking chemical reactions in solution. Sulfur-1s absorption spectroscopy allows tracking multiple sulfur species with a time resolution of ~70 ps at synchrotron radiation facilities. Experimental transient spectra combined with high-level electronic structure theory allow identification of a radical and two thione isomers, which are generated upon illumination with 267 nm radiation. Moreover, the regioselectivity of the thione isomerization is explained by the resulting radical frontier orbitals. This work demonstrates the usefulness and potential of time-resolved sulfur-1s absorption spectroscopy for tracking multiple chemicalmore » reaction pathways and transient products of sulfur-containing molecules in solution.« less

Measurement and evaluation of the radiative properties of a thin solid fuel

NASA Technical Reports Server (NTRS)

Pettegrew, Richard; Street, Kenneth; Pitch, Nancy; Tien, James; Morrison, Phillip

2003-01-01

Accurate modeling of combustion systems requires knowledge of the radiative properties of the system. Gas phase properties are well known, but detailed knowledge of surface properties is limited. Recent work has provided spectrally resolved data for some solid fuels, but only for the unburned material at room temperature, and for limited sets of previously burned and quenched samples. Due to lack of knowledge of the spectrally resolved properties at elevated temperatures, as well as processing limitations in the modeling effort, graybody values are typically used for the fuels surface radiative properties. However, the spectrally resolved properties for the fuels at room temperature can be used to give a first-order correction for temperature effects on the graybody values. Figure 1 shows a sample of the spectrally resolved emittance/absorptance for a thin solid fuel of the type commonly used in combustion studies, from approximately 2 to 20 microns. This plot clearly shows a strong spectral dependence across the entire range. By definition, the emittance is the ratio of the emitted energy to that of a blackbody at the same temperature. Therefore, to determine a graybody emittance for this material, the spectrally resolved data must be applied to a blackbody curve. The total area under the resulting curve is ratioed to the total area under the blackbody curve to yield the answer. Due to the asymmetry of the spectrally resolved emittance and the changing shape of the blackbody curve as the temperature increases, the relative importance of the emittance value at any given wavelength will change as a function of temperature. Therefore, the graybody emittance value for a given material will change as a function of temperature even if the spectral dependence of the radiative properties remains unchanged. This is demonstrated in Figures 2 and 3, which are plots of the spectrally resolved emittance for KimWipes (shown in Figure 1) multiplied by the blackbody curves for 300 K (Figure 2) and 800 K (Figure 3). Each figure also shows the blackbody curve for that temperature. Ratioing the areas under the curve for each of these figures give a graybody emittance of 0.64 at 300 K, and 0.46 at 800 K. It is recognized that materials undergoing pyrolysis will change in composition as they heat up, and that the radiative properties of the materials may have inherent temperature dependence. Both of these effects will contribute to changes in the radiative characteristics of a given material, and are not accounted for here. However, this paper demonstrates the temperature dependence of graybody radiative properties, and provides a method for a first-order correction (for temperature) to the graybody values if the spectrally resolved properties are known.

ISM DUST GRAINS AND N-BAND SPECTRAL VARIABILITY IN THE SPATIALLY RESOLVED SUBARCSECOND BINARY UY Aur

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

Skemer, Andrew J.; Close, Laird M.; Hinz, Philip M.

2010-03-10

The 10 {mu}m silicate feature is an essential diagnostic of dust-grain growth and planet formation in young circumstellar disks. The Spitzer Space Telescope has revolutionized the study of this feature, but due to its small (85 cm) aperture, it cannot spatially resolve small/medium-separation binaries ({approx}<3''; {approx}< 420 AU) at the distances of the nearest star-forming regions ({approx}140 pc). Large, 6-10 m ground-based telescopes with mid-infrared instruments can resolve these systems. In this paper, we spatially resolve the 0.''88 binary, UY Aur, with MMTAO/BLINC-MIRAC4 mid-infrared spectroscopy. We then compare our spectra to Spitzer/IRS (unresolved) spectroscopy, and resolved images from IRTF/MIRAC2, Keck/OSCIR,more » and Gemini/Michelle, which were taken over the past decade. We find that UY Aur A has extremely pristine, interstellar medium (ISM)-like grains and that UY Aur B has an unusually shaped silicate feature, which is probably the result of blended emission and absorption from foreground extinction in its disk. We also find evidence for variability in both UY Aur A and UY Aur B by comparing synthetic photometry from our spectra with resolved imaging from previous epochs. The photometric variability of UY Aur A could be an indication that the silicate emission itself is variable, as was recently found in EX Lupi. Otherwise, the thermal continuum is variable, and either the ISM-like dust has never evolved, or it is being replenished, perhaps by UY Aur's circumbinary disk.« less

Path-length-resolved dynamic light scattering in highly scattering random media: The transition to diffusing wave spectroscopy

NASA Astrophysics Data System (ADS)

Bizheva, Kostadinka K.; Siegel, Andy M.; Boas, David A.

1998-12-01

We used low coherence interferometry to measure Brownian motion within highly scattering random media. A coherence gate was applied to resolve the optical path-length distribution and to separate ballistic from diffusive light. Our experimental analysis provides details on the transition from single scattering to light diffusion and its dependence on the system parameters. We found that the transition to the light diffusion regime occurs at shorter path lengths for media with higher scattering anisotropy or for larger numerical aperture of the focusing optics.

A Lidar for Making Range Resolved CO2 Measurements within the Planetary Boundary Layer

NASA Technical Reports Server (NTRS)

Burris, John; Riris, Haris; Andrews, Arlyn; Krainak, Mike; Sun, Xiaoli; Abshire, Jim; Colarco, Amelia; Heaps, William

2006-01-01

A ground based differential absorption lidar is under development at NASA's Goddard Space Flight Center to make range resolved measurements of CO2 within the planetary boundary layer. This is a direct detection lidar designed for both photon counting and analog use. Technology being developed for this instrument will be discussed including efforts in fiber lasers, optical parametric amplifiers and both InGaAs and HgCdTe solid-state detectors. The capabilities of this system are investigated and preliminary results presented.

Determining the orientation of a chiral substrate using full-hemisphere angle-resolved photoelectron spectroscopy.

PubMed

Tadich, A; Riley, J; Thomsen, L; Cowie, B C C; Gladys, M J

2011-10-21

Chiral interfaces and substrates are of increasing importance in the field of enantioselective chemistry. To fully understand the enantiospecific interactions between chiral adsorbate molecules and the chiral substrate, it is vital that the chiral orientation of the substrate is known. In this Letter we demonstrate that full-hemisphere angle-resolved photoemission permits straightforward identification of the orientation of a chiral surface. The technique can be applied to any solid state system for which photoemission measurements are possible. © 2011 American Physical Society

Let's talk conflict: using mediation in healthcare security disputes.

PubMed

Armstrong, Brad

2013-01-01

Healthcare security administrators face weekly, if not daily challenges and conflict. This article considers that security leaders must anticipate disputes in highly complex healthcare systems. When disputes cannot be resolved by organizational efforts, security administrators may be in a position to recommend or participate in mediation. Here the concept of mediation is introduced to healthcare security leaders as a viable means to resolve disputes with patients, visitors, and the community. This includes a description of the facilitative versus evaluative mediation processes, as well as pragmatic guidance when preparing for mediation.

A MEMS-based high frequency x-ray chopper.

PubMed

Siria, A; Dhez, O; Schwartz, W; Torricelli, G; Comin, F; Chevrier, J

2009-04-29

Time-resolved x-ray experiments require intensity modulation at high frequencies (advanced rotating choppers have nowadays reached the kHz range). We here demonstrate that a silicon microlever oscillating at 13 kHz with nanometric amplitude can be used as a high frequency x-ray chopper. We claim that using micro-and nanoelectromechanical systems (MEMS and NEMS), it will be possible to achieve higher frequencies in excess of hundreds of megahertz. Working at such a frequency can open a wealth of possibilities in chemistry, biology and physics time-resolved experiments.

Global positioning system network analysis with phase ambiguity resolution applied to crustal deformation studies in California

NASA Technical Reports Server (NTRS)

Dong, Da-Nan; Bock, Yehuda

1989-01-01

An efficient algorithm is developed for multisession adjustment of GPS data with simultaneous orbit determination and ambiguity resolution. Application of the algorithm to the analysis of data from a five-year campaign in progress in southern and central California to monitor tectonic motions using observations by GPS satellites, demonstrates improvements in estimates of station position and satellite orbits when the phase ambiguities are resolved. Most of the phase ambiguities in the GPS network were resolved, particularly for all the baselines of geophysical interest in California.

Size and Crystallographic Orientation Effects on the Mechanical Behavior of 4H-SiC Micro-/nano-pillars

NASA Astrophysics Data System (ADS)

Guo, Xiaolei; Guo, Qiang; Li, Zhiqiang; Fan, Genlian; Xiong, Ding-Bang; Su, Yishi; Zhang, Jie; Tan, Zhanqiu; Guo, Cuiping; Zhang, Di

2018-02-01

Single crystalline 4H-SiC micro-/nano-pillars of various sizes and different crystallographic orientations were fabricated and tested by uniaxial compression. The pillars with zero shear stress resolved on the basal slip system were found to fracture in a brittle manner without showing significant size dependence, while the pillars with non-zero resolved shear stress showed a "smaller is stronger" behavior and a jerky plastic flow. These observations were interpreted by homogeneous dislocation nucleation and dislocation glide on the basal plane.

A High Resolution Scale-of-four

DOE R&D Accomplishments Database

Fitch, V.

1949-08-25

A high resolution scale-of-four has been developed to be used in conjunction with the nuclear particle detection devices in applications where the counting rate is unusually high. Specifically, it is intended to precede the commercially available medium resolution scaling circuits and so decrease the resolving time of the counting system. The circuit will function reliably on continuously recurring pulses separated by less than 0.1 microseconds. It will resolve two pulses (occurring at a moderate repetition rate) which are spaced at 0.04 microseconds. A five-volt input signal is sufficient to actuate the device.

Capillary electrophoresis-high resolution sector field inductively coupled plasma mass spectrometry.

PubMed

Sonke, Jeroen E; Salters, Vincent J M

2007-08-03

The background and applications of high resolution sector field inductively coupled plasma mass spectrometry (HR-ICP-MS) as a detector for capillary (CE) and gel electrophoretic separations are reviewed. Notable progress has been made in the fields of bioinorganic and environmental (geo-) chemistry. Metallomics, the study of metal species interactions and functions in biological systems, puts substantial technical demands on speciation analysis. The combination of high species resolving power (CE) and high sensitivity-high mass resolving power (HR-ICP-MS) provides a solid base to meet such demands.

Integrated Modeling of Aerosol, Cloud, Precipitation and Land Processes at Satellite-Resolved Scales

NASA Technical Reports Server (NTRS)

Peters-Lidard, Christa; Tao, Wei-Kuo; Chin, Mian; Braun, Scott; Case, Jonathan; Hou, Arthur; Kumar, Anil; Kumar, Sujay; Lau, William; Matsui, Toshihisa;

Surface-geophysical techniques used to detect existing and infilled scour holes near bridge piers

USGS Publications Warehouse

Placzek, Gary; Haeni, F.P.

1995-01-01

Surface-geophysical techniques were used with a position-recording system to study riverbed scour near bridge piers. From May 1989 to May 1993. Fathometers, fixed- and swept-frequency con- tinuous seismic-reflection profiling (CSP) systems, and a ground-penetrating radar (GPR) system were used with a laser-positioning system to measure the depth and extent of existing and infilled scour holes near bridge piers. Equipment was purchased commercially and modified when necessary to interface the components and (or) to improve their performance. Three 200-kHz black-and-white chart- recording Fathometers produced profiles of the riverbed that included existing scour holes and exposed pier footings. The Fathometers were used in conjunction with other geophysical techniques to help interpret the geophysical data. A 20-kHz color Fathometer delineated scour-hole geometry and, in some cases, the thickness of fill material in the hole. The signal provided subbottom information as deep as 10 ft in fine-grained materials and resolved layers of fill material as thin as 1 foot thick. Fixed-frequency and swept-frequency CSP systems were evaluated. The fixed-frequency system used a 3.5-, 7.0-, or 14-kHz signal. The 3.5-kHz signal pene- trated up to 50 ft of fine-grained material and resolved layers as thin as 2.5-ft thick. The 14-kHz signal penetrated up to 20 ft of fine-grained material and resolved layers as thin as 1-ft thick. The swept-frequency systems used a signal that swept from 2- to 16-kHz. With this system, up to 50 ft of penetration was achieved, and fill material as thin as 1 ft was resolved. Scour-hole geometry, exposed pier footings, and fill thickness in scour holes were detected with both CSP systems. The GPR system used an 80-, 100-, or 300-megahertz signal. The technique produced records in water up to 15 ft deep that had a specific conductance less than 200x11ms/cm. The 100-MHz signal penetrated up to 40 ft of resistive granular material and resolved layers as thin as 2-ft thick. Scour-hole geometry, the thickness of fill material in scour holes, and riverbed deposition were detected using this technique. Processing techniques were applied after data collection to assist with the interpretation of the data. Data were transferred from the color Fathometer, CSP, and GPR systems to a personal computer, and a commercially available software package designed to process GPR data was used to process the GPR and CSP data. Digital filtering, predictive-deconvolution, and migration algorithms were applied to some of the data. The processed data were displayed and printed as color amplitude or wiggle-trace plots. These processing methods eased and improved the interpretation of some of the data, but some interference from side echoes from bridge piers and multiple reflections remained in the data. The surface-geophysical techniques were applied at six bridge sites in Connecticut. Each site had different water depths, specific conductance, and riverbed materials. Existing and infilled scour holes, exposed pier footings, and riverbed deposition were detected by the surveys. The interpretations of the geophysical data were confirmed by comparing the data with lithologic and (or) probing data.

Informed Choice? The New English Student Funding System and Widening Participation

ERIC Educational Resources Information Center

Adnett, Nick; Tlupova, Diana

2008-01-01

The new English system of student finance seeks to resolve a higher education policy trilemma created by government's desire to switch more of the costs on to students, whilst seeking to promote both increased and widening participation. The rationale for this new funding system is based upon orthodox economic analysis which, the authors argue,…

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

Heinemann, Thomas, E-mail: thomas.heinemann@tu-berlin.de; Klapp, Sabine H. L., E-mail: klapp@physik.tu-berlin.de; Palczynski, Karol, E-mail: karol.palczynski@helmholtz-berlin.de

We present an approach for calculating coarse-grained angle-resolved effective pair potentials for uniaxial molecules. For integrating out the intramolecular degrees of freedom we apply umbrella sampling and steered dynamics techniques in atomistically-resolved molecular dynamics (MD) computer simulations. Throughout this study we focus on disk-like molecules such as coronene. To develop the methods we focus on integrating out the van der Waals and intramolecular interactions, while electrostatic charge contributions are neglected. The resulting coarse-grained pair potential reveals a strong temperature and angle dependence. In the next step we fit the numerical data with various Gay-Berne-like potentials to be used in moremore » efficient simulations on larger scales. The quality of the resulting coarse-grained results is evaluated by comparing their pair and many-body structure as well as some thermodynamic quantities self-consistently to the outcome of atomistic MD simulations of many-particle systems. We find that angle-resolved potentials are essential not only to accurately describe crystal structures but also for fluid systems where simple isotropic potentials start to fail already for low to moderate packing fractions. Further, in describing these states it is crucial to take into account the pronounced temperature dependence arising in selected pair configurations due to bending fluctuations.« less

An ultra-high vacuum scanning tunneling microscope operating at sub-Kelvin temperatures and high magnetic fields for spin-resolved measurements

NASA Astrophysics Data System (ADS)

Salazar, C.; Baumann, D.; Hänke, T.; Scheffler, M.; Kühne, T.; Kaiser, M.; Voigtländer, R.; Lindackers, D.; Büchner, B.; Hess, C.

2018-06-01

We present the construction and performance of an ultra-low-temperature scanning tunneling microscope (STM), working in ultra-high vacuum (UHV) conditions and in high magnetic fields up to 9 T. The cryogenic environment of the STM is generated by a single-shot 3He magnet cryostat in combination with a 4He dewar system. At a base temperature (300 mK), the cryostat has an operation time of approximately 80 h. The special design of the microscope allows the transfer of the STM head from the cryostat to a UHV chamber system, where samples and STM tips can be easily exchanged. The UHV chambers are equipped with specific surface science treatment tools for the functionalization of samples and tips, including high-temperature treatments and thin film deposition. This, in particular, enables spin-resolved tunneling measurements. We present test measurements using well-known samples and tips based on superconductors and metallic materials such as LiFeAs, Nb, Fe, and W. The measurements demonstrate the outstanding performance of the STM with high spatial and energy resolution as well as the spin-resolved capability.

Toward picosecond time-resolved X-ray absorption studies of interfacial photochemistry

NASA Astrophysics Data System (ADS)

Gessner, Oliver; Mahl, Johannes; Neppl, Stefan

2016-05-01

We report on the progress toward developing a novel picosecond time-resolved transient X-ray absorption spectroscopy (TRXAS) capability for time-domain studies of interfacial photochemistry. The technique is based on the combination of a high repetition rate picosecond laser system with a time-resolved X-ray fluorescent yield setup that may be used for the study of radiation sensitive materials and X-ray spectroscopy compatible photoelectrochemical (PEC) cells. The mobile system is currently deployed at the Advanced Light Source (ALS) and may be used in all operating modes (two-bunch and multi-bunch) of the synchrotron. The use of a time-stamping technique enables the simultaneous recording of TRXAS spectra with delays between the exciting laser pulses and the probing X-ray pulses spanning picosecond to nanosecond temporal scales. First results are discussed that demonstrate the viability of the method to study photoinduced dynamics in transition metal-oxide semiconductor (SC) samples under high vacuum conditions and at SC-liquid electrolyte interfaces during photoelectrochemical water splitting. Opportunities and challenges are outlined to capture crucial short-lived intermediates of photochemical processes with the technique. This work was supported by the Department of Energy Office of Science Early Career Research Program.

Hybrid Optical-Ultrasonic Technique for Biomedical Diagnostics

PubMed Central

Marcu, L.; Sun, Y.; Stephens, D.; Park, J.; Farwell, D. G.; Shung, K. K.

2010-01-01

We report the development of a diagnostic system combining time-resolved fluorescence spectroscopy and ultrasound backscatter microscopy and its application in diagnosis of tumors and atherosclerotic disease. This system allows for concurrent evaluation of distinct compositional, functional, and micro-anatomical features of normal and diseased tissues. PMID:21918737

A rapid high-resolution method for resolving DNA topoisomers.

PubMed

Mitchenall, Lesley A; Hipkin, Rachel E; Piperakis, Michael M; Burton, Nicolas P; Maxwell, Anthony

2018-01-16

Agarose gel electrophoresis has been the mainstay technique for the analysis of DNA samples of moderate size. In addition to separating linear DNA molecules, it can also resolve different topological forms of plasmid DNAs, an application useful for the analysis of the reactions of DNA topoisomerases. However, gel electrophoresis is an intrinsically low-throughput technique and suffers from other potential disadvantages. We describe the application of the QIAxcel Advanced System, a high-throughput capillary electrophoresis system, to separate DNA topoisomers, and compare this technique with gel electrophoresis. We prepared a range of topoisomers of plasmids pBR322 and pUC19, and a 339 bp DNA minicircle, and compared their separation by gel electrophoresis and the QIAxcel System. We found superior resolution with the QIAxcel System, and that quantitative analysis of topoisomer distributions was straightforward. We show that the QIAxcel system has advantages in terms of speed, resolution and cost, and can be applied to DNA circles of various sizes. It can readily be adapted for use in compound screening against topoisomerase targets.

Time-Resolved Diffuse Optical Spectroscopy and Imaging Using Solid-State Detectors: Characteristics, Present Status, and Research Challenges.

PubMed

Alayed, Mrwan; Deen, M Jamal

2017-09-14

Diffuse optical spectroscopy (DOS) and diffuse optical imaging (DOI) are emerging non-invasive imaging modalities that have wide spread potential applications in many fields, particularly for structural and functional imaging in medicine. In this article, we review time-resolved diffuse optical imaging (TR-DOI) systems using solid-state detectors with a special focus on Single-Photon Avalanche Diodes (SPADs) and Silicon Photomultipliers (SiPMs). These TR-DOI systems can be categorized into two types based on the operation mode of the detector (free-running or time-gated). For the TR-DOI prototypes, the physical concepts, main components, figures-of-merit of detectors, and evaluation parameters are described. The performance of TR-DOI prototypes is evaluated according to the parameters used in common protocols to test DOI systems particularly basic instrumental performance (BIP). In addition, the potential features of SPADs and SiPMs to improve TR-DOI systems and expand their applications in the foreseeable future are discussed. Lastly, research challenges and future developments for TR-DOI are discussed for each component in the prototype separately and also for the entire system.

On the formation of anions: frequency-, angle-, and time-resolved photoelectron imaging of the menadione radical anion† †Electronic supplementary information (ESI) available: A summary of the ground-state geometries and molecular orbitals from the ab initio calculations; fitted residuals from the FA-PI simulation; plots of all spectra included in the frequency-resolved two-dimensional figure; and example time-resolved PE spectra from the 3.10 + 1.55 eV pump-probe experiments. See DOI: 10.1039/c4sc03491k Click here for additional data file.

PubMed Central

Bull, James N.; West, Christopher W.

2015-01-01

Frequency-, angle-, and time-resolved photoelectron imaging of gas-phase menadione (vitamin K3) radical anions was used to show that quasi-bound resonances of the anion can act as efficient doorway states to produce metastable ground electronic state anions on a sub-picosecond timescale. Several anion resonances have been experimentally observed and identified with the assistance of ab initio calculations, and ground state anion recovery was observed across the first 3 eV above threshold. Time-resolved measurements revealed the mechanism of electronic ground state anion formation, which first involves a cascade of very fast internal conversion processes to a bound electronic state that, in turn, decays by slower internal conversion to the ground state. Autodetachment processes from populated resonances are inefficient compared with electronic relaxation through internal conversion. The mechanistic understanding gained provides insight into the formation of radical anions in biological and astrochemical systems. PMID:29560245

An ultrafast angle-resolved photoemission apparatus for measuring complex materials

NASA Astrophysics Data System (ADS)

Smallwood, Christopher L.; Jozwiak, Christopher; Zhang, Wentao; Lanzara, Alessandra

2012-12-01

We present technical specifications for a high resolution time- and angle-resolved photoemission spectroscopy setup based on a hemispherical electron analyzer and cavity-dumped solid state Ti:sapphire laser used to generate pump and probe beams, respectively, at 1.48 and 5.93 eV. The pulse repetition rate can be tuned from 209 Hz to 54.3 MHz. Under typical operating settings the system has an overall energy resolution of 23 meV, an overall momentum resolution of 0.003 Å-1, and an overall time resolution of 310 fs. We illustrate the system capabilities with representative data on the cuprate superconductor Bi2Sr2CaCu2O8+δ. The descriptions and analyses presented here will inform new developments in ultrafast electron spectroscopy.

Phase ambiguity resolution for offset QPSK modulation systems

NASA Technical Reports Server (NTRS)

Nguyen, Tien M. (Inventor)

1991-01-01

A demodulator for Offset Quaternary Phase Shift Keyed (OQPSK) signals modulated with two words resolves eight possible combinations of phase ambiguity which may produce data error by first processing received I(sub R) and Q(sub R) data in an integrated carrier loop/symbol synchronizer using a digital Costas loop with matched filters for correcting four of eight possible phase lock errors, and then the remaining four using a phase ambiguity resolver which detects the words to not only reverse the received I(sub R) and Q(sub R) data channels, but to also invert (complement) the I(sub R) and/or Q(sub R) data, or to at least complement the I(sub R) and Q(sub R) data for systems using nontransparent codes that do not have rotation direction ambiguity.

Metalation of positively charged water soluble mesoporphyrins studied via time-resolved SERRS spectroscopy

NASA Astrophysics Data System (ADS)

Procházka, Marek; Hanzliková, Jana; Štěpánek, Josef; Baumruk, Vladimir

1997-06-01

Time-resolved SERRS spectra of 5,10,15,20-tetrakis[4-(trimethylammonio)phenyl]21 H,23 H-porphine (TMAP) were recorded (using a multichannel Raman spectrometer) in various SERS-active Ag colloid/porphyrin systems. Data treatment based on a factor analysis was used to decompose all the SERRS spectra into two main components: SERRS spectrum of the free base TMAP and that of its Ag metalated form. The metalation kinetics obtained in this way was found to be highly dependent on the presence of phosphate anions, citrate and/or Triton X-100 in the colloidal system. The results are analogous to those previously obtained for 5,10,15,20-tetrakis(1-methyl-4-pyridyl)21 H,23 H-porphine, a porphyrin with a substantially stronger tendency towards metalation.

Scale-free flow of life: on the biology, economics, and physics of the cell

PubMed Central

Kurakin, Alexei

2009-01-01

The present work is intended to demonstrate that most of the paradoxes, controversies, and contradictions accumulated in molecular and cell biology over many years of research can be readily resolved if the cell and living systems in general are re-interpreted within an alternative paradigm of biological organization that is based on the concepts and empirical laws of nonequilibrium thermodynamics. In addition to resolving paradoxes and controversies, the proposed re-conceptualization of the cell and biological organization reveals hitherto unappreciated connections among many seemingly disparate phenomena and observations, and provides new and powerful insights into the universal principles governing the emergence and organizational dynamics of living systems on each and every scale of biological organizational hierarchy, from proteins and cells to economies and ecologies. PMID:19416527

Airborne profiling of ice thickness using a short pulse radar

NASA Technical Reports Server (NTRS)

Vickers, R. S.; Heighway, J. E.; Gedney, R. T.

1973-01-01

This paper describes helicopter-borne measurements of ice thickness in Lake Superior, Lake St. Clair, and the St. Clair river as part of NASA's program to develop an ice information system. The profiler described is a high resolution, nonimaging, short pulse radar, operating at a carrier frequency of 2.7 GHz. The system can resolve reflective surfaces separated by as little as 10 cm and permits measurement of the distance between resolvable surfaces with an accuracy of about 1 cm. Data samples are given for measurements both in a static (helicopter hovering), and a traverse mode. Ground truth measurements taken by an ice auger team traveling with the helicopter are compared with the remotely sensed data and the accuracy of the profiler is discussed based on these measurements.

Convective Systems Over the Japan Sea: Cloud-Resolving Model Simulations

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo; Yoshizaki, Masanori; Shie, Chung-Lin; Kato, Teryuki

2002-01-01

Wintertime observations of MCSs (Mesoscale Convective Systems) over the Sea of Japan - 2001 (WMO-01) were collected from January 12 to February 1, 2001. One of the major objectives is to better understand and forecast snow systems and accompanying disturbances and the associated key physical processes involved in the formation and development of these disturbances. Multiple observation platforms (e.g., upper-air soundings, Doppler radar, wind profilers, radiometers, etc.) during WMO-01 provided a first attempt at investigating the detailed characteristics of convective storms and air pattern changes associated with winter storms over the Sea of Japan region. WMO-01 also provided estimates of the apparent heat source (Q1) and apparent moisture sink (Q2). The vertical integrals of Q1 and Q2 are equal to the surface precipitation rates. The horizontal and vertical adjective components of Q1 and Q2 can be used as large-scale forcing for the Cloud Resolving Models (CRMs). The Goddard Cumulus Ensemble (GCE) model is a CRM (typically run with a 1-km grid size). The GCE model has sophisticated microphysics and allows explicit interactions between clouds, radiation, and surface processes. It will be used to understand and quantify precipitation processes associated with wintertime convective systems over the Sea of Japan (using data collected during the WMO-01). This is the first cloud-resolving model used to simulate precipitation processes in this particular region. The GCE model-simulated WMO-01 results will also be compared to other GCE model-simulated weather systems that developed during other field campaigns (i.e., South China Sea, west Pacific warm pool region, eastern Atlantic region and central USA).

The Market System: Does It Work?

ERIC Educational Resources Information Center

O'Neill, James B.

Included in this student booklet are a variety of learning activities for secondary students which will aid their understanding of the United States economic system. Basic concepts are introduced which show how a market mechanism resolves the conflict between finite resources and infinite desires, how supply and demand interact, and how…

Guidelines for the Development of Computerized Student Information Systems.

ERIC Educational Resources Information Center

Armes, Nancy, Ed.; And Others

Designed to provide guidelines for the development of computerized student information systems, this report raises policy issues and questions to be resolved at the campus level and describes a variety of computer-generated reports and records that can assist in educational decision making and planning. Introductory material discusses the…

48 CFR 1403.101-70 - Technical evaluators and advisors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Technical evaluators and advisors. 1403.101-70 Section 1403.101-70 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... resolved with the servicing Ethics Counselor. (c) During the evaluation process, each evaluator and advisor...

Multiple Systems for Cognitive Control: Evidence from a Hybrid Prime-Simon Task

ERIC Educational Resources Information Center

Schlaghecken, Friederike; Refaat, Malik; Maylor, Elizabeth A.

2011-01-01

Cognitive control resolves conflicts between appropriate and inappropriate response tendencies. Is this achieved by a unitary all-purpose conflict control system, or do independent subsystems deal with different aspects of conflicting information? In a fully factorial hybrid prime-Simon task, participants responded to the identity of targets…

48 CFR 1419.506 - Withdrawing or modifying small business set-asides.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Withdrawing or modifying small business set-asides. 1419.506 Section 1419.506 Federal Acquisition Regulations System DEPARTMENT... such disagreements and the recommendation of the BUDS in order to provide assistance in resolving the...

High Temperature Mechanisms for Venus Exploration

NASA Astrophysics Data System (ADS)

Ji, Jerri; Narine, Roop; Kumar, Nishant; Singh, Sase; Gorevan, Steven

Future Venus missions, including New Frontiers Venus In-Situ Explorer and three Flagship Missions - Venus Geophysical Network, Venus Mobile Explorer and Venus Surface Sample Return all focus on searching for evidence of past climate change both on the surface and in the atmospheric composition as well as in the interior dynamics of the planet. In order to achieve these goals and objectives, many key technologies need to be developed for the Venus extreme environment. These key technologies include sample acquisition systems and other high-temperature mechanisms and mobility systems capable of extended operation when directly exposed to the Venus surface or lower atmosphere environment. Honeybee Robotics has developed two types of high temperature motors, the materials and components in both motors were selected based on the requirement to survive temperatures above a minimum of 460° C, at earth atmosphere. The prototype Switched Reluctance Motor (SRM) has been operated non-continuously for over 20 hours at Venus-like conditions (460° C temperature, mostly CO2 gas environment) and it remains functional. A drilling system, actuated by two SRMs was tested in Venus-like conditions, 460° C temperature and mostly CO2 gas environment, for more than 15 hours. The drill successfully completed three tests by drilling into chalk up to 6 inches deep in each test. A first generation Brushless DC (BLDC) Motor and high temperature resolver were also tested and the feasibility of the designs was demonstrated by the extended operation of both devices under Venus-like condition. Further development of the BLDC motor and resolver continues and these devices will, ultimately, be integrated into the development of a high temperature sample acquisition scoop and high temperature joint (awarded SBIR Phase II in October, 2007). Both the SR and BLDC motors will undergo extensive testing at Venus temperature and pressure (TRL6) and are expected to be mission ready before the next New Frontiers AO release. Scalable high temperature motor, resolver and bearing developments allow for creation of long lasting sample acquisition systems, booms, robot arms and even mobility systems that operate outside of an environment-controlled landed platform on the surface of Venus. The SR and BLDC motors are no longer expected to limit the life of Venus surface operations. With the accompanying high temperature bearing and other mechanisms development, surface operations will be limited only by available power. Therefore, the motor and resolver's capability to survive for hours (and potentially longer) in the environment is a major benefit to future Venus science missions and they also allow time for communication ground loops to optimize sample target selection and the possibility for acquiring multiple samples from the surface. The extreme temperature motors, resolver and other high temperature mechanisms therefore revolutionize the exploration of Venus.

48 CFR 35.006 - Contracting methods and contract type.

Code of Federal Regulations, 2010 CFR

2010-10-01

... short-duration fixed-price contract may be useful for developing system design concepts, resolving... contracts as designs become more firmly established, risks are reduced, and production tooling, equipment...

Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

NASA Astrophysics Data System (ADS)

Mayr, Lukas; Rameshan, Raffael; Klötzer, Bernhard; Penner, Simon; Rameshan, Christoph

2014-05-01

An ultra-high vacuum (UHV) setup for "real" and "inverse" model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, "magic angle") and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown.

Resolving z ~2 galaxy using adaptive coadded source plane reconstruction

NASA Astrophysics Data System (ADS)

Sharma, Soniya; Richard, Johan; Kewley, Lisa; Yuan, Tiantian

2018-06-01

Natural magnification provided by gravitational lensing coupled with Integral field spectrographic observations (IFS) and adaptive optics (AO) imaging techniques have become the frontier of spatially resolved studies of high redshift galaxies (z>1). Mass models of gravitational lenses hold the key for understanding the spatially resolved source–plane (unlensed) physical properties of the background lensed galaxies. Lensing mass models very sensitively control the accuracy and precision of source-plane reconstructions of the observed lensed arcs. Effective source-plane resolution defined by image-plane (observed) point spread function (PSF) makes it challenging to recover the unlensed (source-plane) surface brightness distribution.We conduct a detailed study to recover the source-plane physical properties of z=2 lensed galaxy using spatially resolved observations from two different multiple images of the lensed target. To deal with PSF’s from two data sets on different multiple images of the galaxy, we employ a forward (Source to Image) approach to merge these independent observations. Using our novel technique, we are able to present a detailed analysis of the source-plane dynamics at scales much better than previously attainable through traditional image inversion methods. Moreover, our technique is adapted to magnification, thus allowing us to achieve higher resolution in highly magnified regions of the source. We find that this lensed system is highly evident of a minor merger. In my talk, I present this case study of z=2 lensed galaxy and also discuss the applications of our algorithm to study plethora of lensed systems, which will be available through future telescopes like JWST and GMT.

An Optimization Principle for Deriving Nonequilibrium Statistical Models of Hamiltonian Dynamics

NASA Astrophysics Data System (ADS)

Turkington, Bruce

2013-08-01

A general method for deriving closed reduced models of Hamiltonian dynamical systems is developed using techniques from optimization and statistical estimation. Given a vector of resolved variables, selected to describe the macroscopic state of the system, a family of quasi-equilibrium probability densities on phase space corresponding to the resolved variables is employed as a statistical model, and the evolution of the mean resolved vector is estimated by optimizing over paths of these densities. Specifically, a cost function is constructed to quantify the lack-of-fit to the microscopic dynamics of any feasible path of densities from the statistical model; it is an ensemble-averaged, weighted, squared-norm of the residual that results from submitting the path of densities to the Liouville equation. The path that minimizes the time integral of the cost function determines the best-fit evolution of the mean resolved vector. The closed reduced equations satisfied by the optimal path are derived by Hamilton-Jacobi theory. When expressed in terms of the macroscopic variables, these equations have the generic structure of governing equations for nonequilibrium thermodynamics. In particular, the value function for the optimization principle coincides with the dissipation potential that defines the relation between thermodynamic forces and fluxes. The adjustable closure parameters in the best-fit reduced equations depend explicitly on the arbitrary weights that enter into the lack-of-fit cost function. Two particular model reductions are outlined to illustrate the general method. In each example the set of weights in the optimization principle contracts into a single effective closure parameter.

The multiplicity of massive stars: A high angular resolution survey with the HST fine guidance sensor

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

Aldoretta, E. J.; Gies, D. R.; Henry, T. J.

2015-01-01

We present the results of an all-sky survey made with the Fine Guidance Sensor on the Hubble Space Telescope to search for angularly resolved binary systems among massive stars. The sample of 224 stars is comprised mainly of Galactic O- and B-type stars and luminous blue variables, plus a few luminous stars in the Large Magellanic Cloud. The FGS TRANS mode observations are sensitive to the detection of companions with an angular separation between 0.″01 and 1.″0 and brighter than △m=5. The FGS observations resolved 52 binary and 6 triple star systems and detected partially resolved binaries in 7 additionalmore » targets (43 of these are new detections). These numbers yield a companion detection frequency of 29% for the FGS survey. We also gathered literature results on the numbers of close spectroscopic binaries and wider astrometric binaries among the sample, and we present estimates of the frequency of multiple systems and the companion frequency for subsets of stars residing in clusters and associations, field stars, and runaway stars. These results confirm the high multiplicity fraction, especially among massive stars in clusters and associations. We show that the period distribution is approximately flat in increments of logP. We identify a number of systems of potential interest for long-term orbital determinations, and we note the importance of some of these companions for the interpretation of the radial velocities and light curves of close binaries that have third companions.« less

A Spatially Resolved Plerionic X-Ray Nebula around PSR B0540-69.

PubMed

Gotthelf; Wang

2000-04-01

We present a high-resolution Chandra X-ray observation of PSR B0540-69, the Crab-like 50 ms pulsar in the Large Magellanic Cloud. We use phase-resolved imaging to decompose the extended X-ray emission, as expected of a synchrotron nebula, from the pointlike emission of the pulsar. The image of the pulsed X-ray emission shows a well-defined point-spread function of the observation, while the resolved nebula has a morphology and size remarkably similar to the Crab nebula, including evidence for a jetlike feature from PSR B0540-69. The patchy outer shell, which most likely represents the expanding blast wave of the supernova, is reminiscent of that seen in radio. Based on morphology, size, and energetics, there can be little doubt that SNR B0540-69 is an analogous system to the Crab but located in our neighboring galaxy.

Deep Raman spectroscopy for the non-invasive standoff detection of concealed chemical threat agents.

PubMed

Izake, Emad L; Cletus, Biju; Olds, William; Sundarajoo, Shankaran; Fredericks, Peter M; Jaatinen, Esa

2012-05-30

Deep Raman spectroscopy has been utilized for the standoff detection of concealed chemical threat agents from a distance of 15 m under real life background illumination conditions. By using combined time and space resolved measurements, various explosive precursors hidden in opaque plastic containers were identified non-invasively. Our results confirm that combined time and space resolved Raman spectroscopy leads to higher selectivity towards the sub-layer over the surface layer as well as enhanced rejection of fluorescence from the container surface when compared to standoff spatially offset Raman spectroscopy. Raman spectra that have minimal interference from the packaging material and good signal-to-noise ratio were acquired within 5 s of measurement time. A new combined time and space resolved Raman spectrometer has been designed with nanosecond laser excitation and gated detection, making it of lower cost and complexity than picosecond-based laboratory systems. Copyright © 2012 Elsevier B.V. All rights reserved.

KSC-2012-3264

NASA Image and Video Library

2012-05-10

CAPE CANAVERAL, Fla. – NASA systems engineer Jim Smith assembles the prototype lander for NASA’s Regolith and Environment Science and Oxygen and Lunar Volatile Extraction, or RESOLVE, project in a test facility behind the Operations and Checkout Building at NASA’s Kennedy Space Center in Florida. RESOLVE consists of a rover and drill provided by the Canadian Space Agency to support a NASA payload that is designed to prospect for water, ice and other lunar resources. RESOLVE also will demonstrate how future explorers can take advantage of resources at potential landing sites by manufacturing oxygen from soil. NASA will be conducting field tests in July outside of Hilo, Hawaii, with equipment and concept vehicles that demonstrate how explorers might prospect for resources and make their own oxygen for survival while on other planetary bodies. For more information, visit http://www.nasa.gov/exploration/analogs/index.html. Photo credit: NASA/Ben Smegelsky

Time-Resolved C-Arm Computed Tomographic Angiography Derived From Computed Tomographic Perfusion Acquisition: New Capability for One-Stop-Shop Acute Ischemic Stroke Treatment in the Angiosuite.

PubMed

Yang, Pengfei; Niu, Kai; Wu, Yijing; Struffert, Tobias; Dorfler, Arnd; Schafer, Sebastian; Royalty, Kevin; Strother, Charles; Chen, Guang-Hong

2015-12-01

Multimodal imaging using cone beam C-arm computed tomography (CT) may shorten the delay from ictus to revascularization for acute ischemic stroke patients with a large vessel occlusion. Largely because of limited temporal resolution, reconstruction of time-resolved CT angiography (CTA) from these systems has not yielded satisfactory results. We evaluated the image quality and diagnostic value of time-resolved C-arm CTA reconstructed using novel image processing algorithms. Studies were done under an Institutional Review Board approved protocol. Postprocessing of data from 21 C-arm CT dynamic perfusion acquisitions from 17 patients with acute ischemic stroke were done to derive time-resolved C-arm CTA images. Two observers independently evaluated image quality and diagnostic content for each case. ICC and receiver-operating characteristic analysis were performed to evaluate interobserver agreement and diagnostic value of this novel imaging modality. Time-resolved C-arm CTA images were successfully generated from 20 data sets (95.2%, 20/21). Two observers agreed well that the image quality for large cerebral arteries was good but was more limited for small cerebral arteries (distal to M1, A1, and P1). receiver-operating characteristic curves demonstrated excellent diagnostic value for detecting large vessel occlusions (area under the curve=0.987-1). Time-resolved CTAs derived from C-arm CT perfusion acquisitions provide high quality images that allowed accurate diagnosis of large vessel occlusions. Although image quality of smaller arteries in this study was not optimal ongoing modifications of the postprocessing algorithm will likely remove this limitation. Adding time-resolved C-arm CTAs to the capabilities of the angiography suite further enhances its suitability as a one-stop shop for care for patients with acute ischemic stroke. © 2015 American Heart Association, Inc.

Development of Adaptive Kanji Learning System for Mobile Phone

ERIC Educational Resources Information Center

Li, Mengmeng; Ogata, Hiroaki; Hou, Bin; Hashimoto, Satoshi; Liu, Yuqin; Uosaki, Noriko; Yano, Yoneo

2010-01-01

This paper describes an adaptive learning system based on mobile phone email to support the study of Japanese Kanji. In this study, the main emphasis is on using the adaptive learning to resolve one common problem of the mobile-based email or SMS language learning systems. To achieve this goal, the authors main efforts focus on three aspects:…

Developing the Systems Engineering Experience Accelerator (SEEA) Prototype and Roadmap

DTIC Science & Technology

2012-10-24

system attributes. These metrics track non-requirements performance, typically relate to production cost per unit, maintenance costs, training costs...immediately implement lessons learned from the training experience to the job, assuming the culture allows this. 1.3 MANAGEMENT PLAN/TECHNICAL OVERVIEW...resolving potential conflicts as they arise. Incrementally implement and continuously integrate capability in priority order, to ensure that final system

Report on Research

DTIC Science & Technology

1989-06-01

Force systems require a resolved information on the optical thorough understanding of the propaga- extinction coefficient. Measurements of tion path , the...Depolarization as Function of Snow Density. Measurement System ). (It correlated well with the ( Multi -scatter scale length information is usable to extinction ...data on the effect of optically thin cirrus clouds on long - path infrared transmit- tance. Future system designers will have access to this new

Advanced Communications Technology Satellite Now Operating in an Inclined Orbit

NASA Technical Reports Server (NTRS)

Bauer, Robert A.

1999-01-01

The Advanced Communications Technology Satellite (ACTS) system has been modified to support operation in an inclined orbit that is virtually transparent to users, and plans are to continue this final phase of its operation through September 2000. The next 2 years of ACTS will provide a new opportunity for using the technologies that this system brought online over 5 years ago and that are still being used to resolve the technical issues that face NASA and the satellite industry in the area of seamless networking and interoperability with terrestrial systems. New goals for ACTS have been defined that align the program with recent changes in NASA and industry. ACTS will be used as a testbed to: Show how NASA and other Government agencies can use commercial systems for 1. future support of their operations Test, characterize, and resolve technical issues in using advanced communications 2. protocols such as asynchronous transfer mode (ATM) and transmission control protocol/Internet protocol (TCP/IP) over long latency links as found when interoperating satellites with terrestrial systems Evaluate narrow-spot-beam Ka-band satellite operation in an inclined orbit 3. Verify Ka-band satellite technologies since no other Ka-band system is yet 4. available in the United States

Multiscale Cloud System Modeling

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo; Moncrieff, Mitchell W.

2009-01-01

The central theme of this paper is to describe how cloud system resolving models (CRMs) of grid spacing approximately 1 km have been applied to various important problems in atmospheric science across a wide range of spatial and temporal scales and how these applications relate to other modeling approaches. A long-standing problem concerns the representation of organized precipitating convective cloud systems in weather and climate models. Since CRMs resolve the mesoscale to large scales of motion (i.e., 10 km to global) they explicitly address the cloud system problem. By explicitly representing organized convection, CRMs bypass restrictive assumptions associated with convective parameterization such as the scale gap between cumulus and large-scale motion. Dynamical models provide insight into the physical mechanisms involved with scale interaction and convective organization. Multiscale CRMs simulate convective cloud systems in computational domains up to global and have been applied in place of contemporary convective parameterizations in global models. Multiscale CRMs pose a new challenge for model validation, which is met in an integrated approach involving CRMs, operational prediction systems, observational measurements, and dynamical models in a new international project: the Year of Tropical Convection, which has an emphasis on organized tropical convection and its global effects.

Detailed Characterization of a Nanosecond-Lived Excited State: X-ray and Theoretical Investigation of the Quintet State in Photoexcited [Fe(terpy)2]2+

PubMed Central

2015-01-01

Theoretical predictions show that depending on the populations of the Fe 3dxy, 3dxz, and 3dyz orbitals two possible quintet states can exist for the high-spin state of the photoswitchable model system [Fe(terpy)2]2+. The differences in the structure and molecular properties of these 5B2 and 5E quintets are very small and pose a substantial challenge for experiments to resolve them. Yet for a better understanding of the physics of this system, which can lead to the design of novel molecules with enhanced photoswitching performance, it is vital to determine which high-spin state is reached in the transitions that follow the light excitation. The quintet state can be prepared with a short laser pulse and can be studied with cutting-edge time-resolved X-ray techniques. Here we report on the application of an extended set of X-ray spectroscopy and scattering techniques applied to investigate the quintet state of [Fe(terpy)2]2+ 80 ps after light excitation. High-quality X-ray absorption, nonresonant emission, and resonant emission spectra as well as X-ray diffuse scattering data clearly reflect the formation of the high-spin state of the [Fe(terpy)2]2+ molecule; moreover, extended X-ray absorption fine structure spectroscopy resolves the Fe–ligand bond-length variations with unprecedented bond-length accuracy in time-resolved experiments. With ab initio calculations we determine why, in contrast to most related systems, one configurational mode is insufficient for the description of the low-spin (LS)–high-spin (HS) transition. We identify the electronic structure origin of the differences between the two possible quintet modes, and finally, we unambiguously identify the formed quintet state as 5E, in agreement with our theoretical expectations. PMID:25838847

Detailed Characterization of a Nanosecond-Lived Excited State: X-ray and Theoretical Investigation of the Quintet State in Photoexcited [Fe(terpy) 2 ] 2+

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

Vankó, György; Bordage, Amélie; Pápai, Mátyás

2015-03-19

Theoretical predictions show that depending on the populations of the Fe 3dxy, 3dxz, and 3dyz orbitals two possible quintet states can exist for the high-spin state of the photoswitchable model system [Fe(terpy)2]2+. The differences in the structure and molecular properties of these 5B2 and 5E quintets are very small and pose a substantial challenge for experiments to resolve them. Yet for a better understanding of the physics of this system, which can lead to the design of novel molecules with enhanced photoswitching performance, it is vital to determine which high-spin state is reached in the transitions that follow the lightmore » excitation. The quintet state can be prepared with a short laser pulse and can be studied with cutting-edge time-resolved X-ray techniques. Here we report on the application of an extended set of X-ray spectroscopy and scattering techniques applied to investigate the quintet state of [Fe(terpy)2]2+ 80 ps after light excitation. High-quality X-ray absorption, nonresonant emission, and resonant emission spectra as well as X-ray diffuse scattering data clearly reflect the formation of the high-spin state of the [Fe(terpy)2]2+ molecule; moreover, extended X-ray absorption fine structure spectroscopy resolves the Fe-ligand bond-length variations with unprecedented bondlength accuracy in time-resolved experiments. With ab initio calculations we determine why, in contrast to most related systems, one configurational mode is insufficient for the description of the low-spin (LS)-high-spin (HS) transition. We identify the electronic structure origin of the differences between the two possible quintet modes, and finally, we unambiguously identify the formed quintet state as 5E, in agreement with our theoretical expectations.« less

Signatures of Pleiotropy, Economy and Convergent Evolution in a Domain-Resolved Map of Human–Virus Protein–Protein Interaction Networks

PubMed Central

Garamszegi, Sara; Franzosa, Eric A.; Xia, Yu

2013-01-01

A central challenge in host-pathogen systems biology is the elucidation of general, systems-level principles that distinguish host-pathogen interactions from within-host interactions. Current analyses of host-pathogen and within-host protein-protein interaction networks are largely limited by their resolution, treating proteins as nodes and interactions as edges. Here, we construct a domain-resolved map of human-virus and within-human protein-protein interaction networks by annotating protein interactions with high-coverage, high-accuracy, domain-centric interaction mechanisms: (1) domain-domain interactions, in which a domain in one protein binds to a domain in a second protein, and (2) domain-motif interactions, in which a domain in one protein binds to a short, linear peptide motif in a second protein. Analysis of these domain-resolved networks reveals, for the first time, significant mechanistic differences between virus-human and within-human interactions at the resolution of single domains. While human proteins tend to compete with each other for domain binding sites by means of sequence similarity, viral proteins tend to compete with human proteins for domain binding sites in the absence of sequence similarity. Independent of their previously established preference for targeting human protein hubs, viral proteins also preferentially target human proteins containing linear motif-binding domains. Compared to human proteins, viral proteins participate in more domain-motif interactions, target more unique linear motif-binding domains per residue, and contain more unique linear motifs per residue. Together, these results suggest that viruses surmount genome size constraints by convergently evolving multiple short linear motifs in order to effectively mimic, hijack, and manipulate complex host processes for their survival. Our domain-resolved analyses reveal unique signatures of pleiotropy, economy, and convergent evolution in viral-host interactions that are otherwise hidden in the traditional binary network, highlighting the power and necessity of high-resolution approaches in host-pathogen systems biology. PMID:24339775

Detailed Characterization of a Nanosecond-Lived Excited State: X-ray and Theoretical Investigation of the Quintet State in Photoexcited [Fe(terpy) 2 ] 2+

DOE PAGES

Vanko, Gyorgy; Bordage, Amelie; Papai, Matyas; ...

2015-03-19

Theoretical predictions show that depending on the populations of the Fe 3d xy, 3d xz, and 3d yz orbitals two possible quintet states can exist for the high-spin state of the photoswitchable model system [Fe(terpy) 2] 2+. The differences in the structure and molecular properties of these 5B2 and 5E quintets are very small and pose a substantial challenge for experiments to resolve them. Yet for a better understanding of the physics of this system, which can lead to the design of novel molecules with enhanced photoswitching performance, it is vital to determine which high-spin state is reached in themore » transitions that follow the light excitation. The quintet state can be prepared with a short laser pulse and can be studied with cutting-edge time-resolved X-ray techniques. Here we report on the application of an extended set of X-ray spectroscopy and scattering techniques applied to investigate the quintet state of [Fe(terpy) 2] 2+ 80 ps after light excitation. High-quality X-ray absorption, nonresonant emission, and resonant emission spectra as well as X-ray diffuse scattering data clearly reflect the formation of the high-spin state of the [Fe(terpy) 2] 2+ molecule; moreover, extended X-ray absorption fine structure spectroscopy resolves the Fe–ligand bond-length variations with unprecedented bond-length accuracy in time-resolved experiments. With ab initio calculations we determine why, in contrast to most related systems, one configurational mode is insufficient for the description of the low-spin (LS)–high-spin (HS) transition. We identify the electronic structure origin of the differences between the two possible quintet modes, and finally, we unambiguously identify the formed quintet state as 5E, in agreement with our theoretical expectations.« less

Signatures of pleiotropy, economy and convergent evolution in a domain-resolved map of human-virus protein-protein interaction networks.

PubMed

Garamszegi, Sara; Franzosa, Eric A; Xia, Yu

2013-01-01

A central challenge in host-pathogen systems biology is the elucidation of general, systems-level principles that distinguish host-pathogen interactions from within-host interactions. Current analyses of host-pathogen and within-host protein-protein interaction networks are largely limited by their resolution, treating proteins as nodes and interactions as edges. Here, we construct a domain-resolved map of human-virus and within-human protein-protein interaction networks by annotating protein interactions with high-coverage, high-accuracy, domain-centric interaction mechanisms: (1) domain-domain interactions, in which a domain in one protein binds to a domain in a second protein, and (2) domain-motif interactions, in which a domain in one protein binds to a short, linear peptide motif in a second protein. Analysis of these domain-resolved networks reveals, for the first time, significant mechanistic differences between virus-human and within-human interactions at the resolution of single domains. While human proteins tend to compete with each other for domain binding sites by means of sequence similarity, viral proteins tend to compete with human proteins for domain binding sites in the absence of sequence similarity. Independent of their previously established preference for targeting human protein hubs, viral proteins also preferentially target human proteins containing linear motif-binding domains. Compared to human proteins, viral proteins participate in more domain-motif interactions, target more unique linear motif-binding domains per residue, and contain more unique linear motifs per residue. Together, these results suggest that viruses surmount genome size constraints by convergently evolving multiple short linear motifs in order to effectively mimic, hijack, and manipulate complex host processes for their survival. Our domain-resolved analyses reveal unique signatures of pleiotropy, economy, and convergent evolution in viral-host interactions that are otherwise hidden in the traditional binary network, highlighting the power and necessity of high-resolution approaches in host-pathogen systems biology.

Power Efficient Hydraulic Systems. Volume 1. Study Phase

DTIC Science & Technology

1988-07-01

AIRCRAFT SUBSYSTEMS TABLE 14. Baseline aircraft systems o HYDRAULIC SYSTEM o ELECTRICAL SYSTEM o 8000 PSI, 3 INDEPENDENT SYSTEMS o HVDC POWER o APU...neither aluminum nor titanium provide good wear surfaces. Hydraulic fittings and valve bodies appear to be excellent candidates for PM technology...Actuator Bodies Savings Over Steel ys. Time of Heat and 25% Over Treatment To Be Resolved T1-3AL-2.5V - Heat Treatment May Cause - Excellent

Ultrafast measurements of chlorine dioxide photochemistry

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

Ludowise, P.D.

Time-resolved mass spectrometry and time-resolved photoelectron spectroscopy are used to study the ultrafast photodissociation dynamics of chlorine dioxide, an important constituent in stratospheric ozone depletion. Chapter 1 introduces these pump/probe techniques, in which a femtosecond pump pulse excites a molecule to a dissociative state. At a later time, a second femtosecond probe pulse ionizes the molecule. The resulting mass and photoelectron spectra are acquired as a function of the delay between the pump and probe pulses, which follows the evolution of the molecule on the excited state. A comparison to other techniques used to study reaction dynamics is discussed. Chaptermore » 2 includes a detailed description of the design and construction of the experimental apparatus, which consists of a femtosecond laser system, a molecular beam time-of-flight spectrometer, and a data acquisition system. The time-of-flight spectrometer is specifically designed to have a short flight distance to maximize the photoelectron collection efficiency without degrading the resolution, which is limited by the bandwidth of the femtosecond laser system. Typical performance of the apparatus is demonstrated in a study of the time-resolved photoelectron spectroscopy of nitric oxide. The results of the time-resolved mass spectrometry experiments of chlorine dioxide are presented in Chapter 3. Upon excitation to the A {sup 2}A{sub 2} state near 3.2 eV, the molecule dissociates through an indirect two-step mechanism. The direct dissociation channel has been predicted to be open, but is not observed. A quantum beat is observed in the OClO{sup +} species, which is described as a vibrational coherence of the optically prepared A {sup 2}A{sub 2} state. Chapter 4 presents the results of the time-resolved photoelectron experiments of chlorine dioxide. At short delay time, the quantum beat of the OClO{sup +} species is observed in the X {sup 1}A{sub 1} state of the ion. At infinite delay, the signal is dominated by the ClO{sup +} ion, observed in a variety of electronic states. The photoelectron data is shown to support the indirect two-step dissociation mechanism derived from the mass results. Conclusions of the mass and photoelectron results are discussed in context of the stratospheric ozone depletion problem.« less

Time-resolved photoelectron spectroscopy of IR-driven electron dynamics in a charge transfer model system.

PubMed

Falge, Mirjam; Fröbel, Friedrich Georg; Engel, Volker; Gräfe, Stefanie

2017-08-02

If the adiabatic approximation is valid, electrons smoothly adapt to molecular geometry changes. In contrast, as a characteristic of diabatic dynamics, the electron density does not follow the nuclear motion. Recently, we have shown that the asymmetry in time-resolved photoelectron spectra serves as a tool to distinguish between these dynamics [Falge et al., J. Phys. Chem. Lett., 2012, 3, 2617]. Here, we investigate the influence of an additional, moderately intense infrared (IR) laser field, as often applied in attosecond time-resolved experiments, on such asymmetries. This is done using a simple model for coupled electronic-nuclear motion. We calculate time-resolved photoelectron spectra and their asymmetries and demonstrate that the spectra directly map the bound electron-nuclear dynamics. From the asymmetries, we can trace the IR field-induced population transfer and both the field-driven and intrinsic (non-)adiabatic dynamics. This holds true when considering superposition states accompanied by electronic coherences. The latter are observable in the asymmetries for sufficiently short XUV pulses to coherently probe the coupled states. It is thus documented that the asymmetry is a measure for phases in bound electron wave packets and non-adiabatic dynamics.

Development of a New Time-Resolved Laser-Induced Fluorescence Technique

NASA Astrophysics Data System (ADS)

Durot, Christopher; Gallimore, Alec

2012-10-01

We are developing a time-resolved laser-induced fluorescence (LIF) technique to interrogate the ion velocity distribution function (VDF) of EP thruster plumes down to the microsecond time scale. Better measurements of dynamic plasma processes will lead to improvements in simulation and prediction of thruster operation and erosion. We present the development of the new technique and results of initial tests. Signal-to-noise ratio (SNR) is often a challenge for LIF studies, and it is only more challenging for time-resolved measurements since a lock-in amplifier cannot be used with a long time constant. The new system uses laser modulation on the order of MHz, which enables the use of electronic filtering and phase-sensitive detection to improve SNR while preserving time-resolved information. Statistical averaging over many cycles to further improve SNR is done in the frequency domain. This technique can have significant advantages, including (1) larger spatial maps enabled by shorter data acquisition time and (2) the ability to average data without creating a phase reference by modifying the thruster operating condition with a periodic cutoff in discharge current, which can modify the ion velocity distribution.

In-pile Thermal Conductivity Characterization with Time Resolved Raman

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

Wang, Xinwei; Hurley, David H.

The project is designed to achieve three objectives: (1) Develop a novel time resolved Raman technology for direct measurement of fuel and cladding thermal conductivity. (2) Validate and improve the technology development by measuring ceramic materials germane to the nuclear industry. (3) Conduct instrumentation development to integrate optical fiber into our sensing system for eventual in-pile measurement. We have developed three new techniques: time-domain differential Raman (TD-Raman), frequency-resolved Raman (FR-Raman), and energy transport state-resolved Raman (ET-Raman). The TD-Raman varies the laser heating time and does simultaneous Raman thermal probing, the FR-Raman probes the material’s thermal response under periodical laser heatingmore » of different frequencies, and the ET-Raman probes the thermal response under steady and pulsed laser heating. The measurement capacity of these techniques have been fully assessed and verified by measuring micro/nanoscale materials. All these techniques do not need the data of laser absorption and absolute material temperature rise, yet still be able to measure the thermal conductivity and thermal diffusivity with unprecedented accuracy. It is expected they will have broad applications for in-pile thermal characterization of nuclear materials based on pure optical heating and sensing.« less

ISM Dust Grains and N-band Spectral Variability in the Spatially Resolved Subarcsecond Binary UY Aur

NASA Astrophysics Data System (ADS)

Skemer, Andrew J.; Close, Laird M.; Hinz, Philip M.; Hoffmann, William F.; Greene, Thomas P.; Males, Jared R.; Beck, Tracy L.

2010-03-01

The 10 μm silicate feature is an essential diagnostic of dust-grain growth and planet formation in young circumstellar disks. The Spitzer Space Telescope has revolutionized the study of this feature, but due to its small (85 cm) aperture, it cannot spatially resolve small/medium-separation binaries (lsim3''; <~ 420 AU) at the distances of the nearest star-forming regions (~140 pc). Large, 6-10 m ground-based telescopes with mid-infrared instruments can resolve these systems. In this paper, we spatially resolve the 0farcs88 binary, UY Aur, with MMTAO/BLINC-MIRAC4 mid-infrared spectroscopy. We then compare our spectra to Spitzer/IRS (unresolved) spectroscopy, and resolved images from IRTF/MIRAC2, Keck/OSCIR, and Gemini/Michelle, which were taken over the past decade. We find that UY Aur A has extremely pristine, interstellar medium (ISM)-like grains and that UY Aur B has an unusually shaped silicate feature, which is probably the result of blended emission and absorption from foreground extinction in its disk. We also find evidence for variability in both UY Aur A and UY Aur B by comparing synthetic photometry from our spectra with resolved imaging from previous epochs. The photometric variability of UY Aur A could be an indication that the silicate emission itself is variable, as was recently found in EX Lupi. Otherwise, the thermal continuum is variable, and either the ISM-like dust has never evolved, or it is being replenished, perhaps by UY Aur's circumbinary disk. The observations reported here were partially obtained at the Infrared Telescope Facility, which is operated by the University of Hawaii under Cooperative Agreement no. NCC 5-538 with the National Aeronautics and Space Administration, Science Mission Directorate, Planetary Astronomy Program.

Mathematical Models to Determine Stable Behavior of Complex Systems

NASA Astrophysics Data System (ADS)

Sumin, V. I.; Dushkin, A. V.; Smolentseva, T. E.

2018-05-01

The paper analyzes a possibility to predict functioning of a complex dynamic system with a significant amount of circulating information and a large number of random factors impacting its functioning. Functioning of the complex dynamic system is described as a chaotic state, self-organized criticality and bifurcation. This problem may be resolved by modeling such systems as dynamic ones, without applying stochastic models and taking into account strange attractors.

Patient assessment systems using the World Wide Web.

PubMed

Kohane, I S

1997-02-01

Of the major issues in developing a Web patient assessment system, I have emphasized two main points. First, the World Wide Web can provide substantial leverage in the development of online patient assessment systems. Second, although the existence of Internet technologies does not alter the need to resolve issues that preceded their arrival, current trends suggest that in the home and the office, patient assessment systems will increasingly employ Internet technologies.

Time-resolved SERS for characterizing extracellular vesicles

NASA Astrophysics Data System (ADS)

Rojalin, Tatu; Saari, Heikki; Somersalo, Petter; Laitinen, Saara; Turunen, Mikko; Viitala, Tapani; Wachsmann-Hogiu, Sebastian; Smith, Zachary J.; Yliperttula, Marjo

2017-02-01

The aim of this work is to develop a platform for characterizing extracellular vesicles (EV) by using gold-polymer nanopillar SERS arrays simultaneously circumventing the photoluminescence-related disadvantages of Raman with a time-resolved approach. EVs are rich of biochemical information reporting of, for example, diseased state of the biological system. Currently, straightforward, label-free and fast EV characterization methods with low sample consumption are warranted. In this study, SERS spectra of red blood cell and platelet derived EVs were successfully measured and their biochemical contents analyzed using multivariate data analysis techniques. The developed platform could be conveniently used for EV analytics in general.

Application of the Lucy–Richardson Deconvolution Procedure to High Resolution Photoemission Spectra

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

Rameau, J.; Yang, H.-B.; Johnson, P.D.

2010-07-01

Angle-resolved photoemission has developed into one of the leading probes of the electronic structure and associated dynamics of condensed matter systems. As with any experimental technique the ability to resolve features in the spectra is ultimately limited by the resolution of the instrumentation used in the measurement. Previously developed for sharpening astronomical images, the Lucy-Richardson deconvolution technique proves to be a useful tool for improving the photoemission spectra obtained in modern hemispherical electron spectrometers where the photoelectron spectrum is displayed as a 2D image in energy and momentum space.

Frequency-resolved Monte Carlo.

PubMed

López Carreño, Juan Camilo; Del Valle, Elena; Laussy, Fabrice P

2018-05-03

We adapt the Quantum Monte Carlo method to the cascaded formalism of quantum optics, allowing us to simulate the emission of photons of known energy. Statistical processing of the photon clicks thus collected agrees with the theory of frequency-resolved photon correlations, extending the range of applications based on correlations of photons of prescribed energy, in particular those of a photon-counting character. We apply the technique to autocorrelations of photon streams from a two-level system under coherent and incoherent pumping, including the Mollow triplet regime where we demonstrate the direct manifestation of leapfrog processes in producing an increased rate of two-photon emission events.

Analysis of Recombination in CdTe Heterostructures With Time-Resolved Two-Photon Excitation Microscopy

DOE PAGES

Kuciauskas, Darius; Wernsing, Keith; Jensen, Soren Alkaersig; ...

2016-11-01

Here, we used time-resolved photoluminescence microscopy to analyze charge carrier transport and recombination in CdTe double heterostructures fabricated by molecular beam epitaxy (MBE). This allowed us to determine the charge carrier mobility in this system, which was found to be 500-625 cm 2/(V s). Charge carrier lifetimes in the 15-100 ns range are limited by the interface recombination, and the data indicate higher interface recombination velocity near extended defects. This study describes a new method to analyze the spatial distribution of the interface recombination velocity and the interface defects in semiconductor heterostructures.

Time Resolved Digital PIV Measurements of Flow Field Cyclic Variation in an Optical IC Engine

NASA Astrophysics Data System (ADS)

Jarvis, S.; Justham, T.; Clarke, A.; Garner, C. P.; Hargrave, G. K.; Halliwell, N. A.

2006-07-01

Time resolved digital particle image velocimetry (DPIV) experimental data is presented for the in-cylinder flow field development of a motored four stroke spark ignition (SI) optical internal combustion (IC) engine. A high speed DPIV system was employed to quantify the velocity field development during the intake and compression stroke at an engine speed of 1500 rpm. The results map the spatial and temporal development of the in-cylinder flow field structure allowing comparison between traditional ensemble average and cycle average flow field structures. Conclusions are drawn with respect to engine flow field cyclic variations.

Thickness determination of thin solid films by angle-resolved X-ray fluorescence spectrometry using monochromatized synchrotron radiation

NASA Astrophysics Data System (ADS)

Schmitt, W.; Drotbohm, P.; Rothe, J.; Hormes, J.; Ottermann, C. R.; Bange, K.

1995-05-01

Thickness measurements by the method of angle-resolved, self-ratio X-ray fluorescence spectrometry (AR/SR/XFS) have been carried out on thin solid films using monochromatized synchrotron radiation at the Bonn storage ring ELSA. Synchrotron radiation was monochromatized by means of a double-crystal monochromator and fluorescence radiation was detected by a Si(Li) semiconductor detector. The results for sample systems consisting of Au on Si, Cr on SiO2 and TiO2 on alkali-free glass are very satisfactory and agree well with results obtained by other methods.

Microscope mode secondary ion mass spectrometry imaging with a Timepix detector.

PubMed

Kiss, Andras; Jungmann, Julia H; Smith, Donald F; Heeren, Ron M A

2013-01-01

In-vacuum active pixel detectors enable high sensitivity, highly parallel time- and space-resolved detection of ions from complex surfaces. For the first time, a Timepix detector assembly was combined with a secondary ion mass spectrometer for microscope mode secondary ion mass spectrometry (SIMS) imaging. Time resolved images from various benchmark samples demonstrate the imaging capabilities of the detector system. The main advantages of the active pixel detector are the higher signal-to-noise ratio and parallel acquisition of arrival time and position. Microscope mode SIMS imaging of biomolecules is demonstrated from tissue sections with the Timepix detector.

Time-resolved coherent Raman spectroscopy by high-speed pump-probe delay scanning.

PubMed

Domingue, S R; Winters, D G; Bartels, R A

2014-07-15

Using a spinning window pump-probe delay scanner, we demonstrate a means of acquiring time-resolved vibrational spectra at rates up to 700 Hz. The time-dependent phase shift accumulated by the probe pulse in the presence of a coherently vibrating sample gives rise to a Raman-induced frequency shifting readily detectable in a balanced detector. This rapid delay scanning system represents a 23-fold increase in averaging speed and is >10× faster than state-of-the-art voice coil delay lines. These advancements make pump-probe spectroscopy a more practical means of imaging complex media.

Analysis of Recombination in CdTe Heterostructures With Time-Resolved Two-Photon Excitation Microscopy

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

Kuciauskas, Darius; Wernsing, Keith; Jensen, Soren Alkaersig

Here, we used time-resolved photoluminescence microscopy to analyze charge carrier transport and recombination in CdTe double heterostructures fabricated by molecular beam epitaxy (MBE). This allowed us to determine the charge carrier mobility in this system, which was found to be 500-625 cm 2/(V s). Charge carrier lifetimes in the 15-100 ns range are limited by the interface recombination, and the data indicate higher interface recombination velocity near extended defects. This study describes a new method to analyze the spatial distribution of the interface recombination velocity and the interface defects in semiconductor heterostructures.

10 CFR 603.660 - Other audit requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Affecting Participants' Financial, Property, and Purchasing Systems Financial Matters § 603.660 Other audit... working papers until the matter is resolved and final action taken). (g) Who will have access to the IPA's...

Measurement of wood/plant cell or composite material attributes with computer assisted tomography

DOEpatents

West, Darrell C.; Paulus, Michael J.; Tuskan, Gerald A.; Wimmer, Rupert

2004-06-08

A method for obtaining wood-cell attributes from cellulose containing samples includes the steps of radiating a cellulose containing sample with a beam of radiation. Radiation attenuation information is collected from radiation which passes through the sample. The source is rotated relative to the sample and the radiation and collecting steps repeated. A projected image of the sample is formed from the collected radiation attenuation information, the projected image including resolvable features of the cellulose containing sample. Cell wall thickness, cell diameter (length) and cell vacoule diameter can be determined. A system for obtaining physical measures from cellulose containing samples includes a radiation source, a radiation detector, and structure for rotating the source relative to said sample. The system forms an image of the sample from the radiation attenuation information, the image including resolvable features of the sample.

[Realistic possibilities of utilization of a personal computer in the office of a general practitioner].

PubMed

Masopust, V

1991-04-01

In May 1990 work on the programme "Computer system of the health community doctor Mic DOKI was" completed which resolves more than 70 basic tasks pertaining to the keeping of health documentation by health community doctors; it resolves automatically the entire administrative work in the health community, makes it possible to evaluate the activity of doctors and nurses it will facilitate the work of control organs of future health insurance companies and contribute to investigations of the health status of the population. Despite some problems ensuing from the contemporary economic situation of the country, the validity of contemporary health regulations and minimal training of our health personnel in the use of personal computers computerization of the health community system can be considered an asset to the reform of the health services which is under way.

Time Resolved Detectors and Measurements for Accelerators and Beamlines at the Australian Synchrotron

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

Boland, M. J.; School of Physics, University of Melbourne, Parkville, Victoria 3010; Rassool, R. P.

2010-06-23

Time resolved experiments require precision timing equipment and careful configuration of the machine and the beamline. The Australian Synchrotron has a state of the art timing system that allows flexible, real-time control of the machine and beamline timing parameters to target specific electron bunches. Results from a proof-of-principle measurement with a pulsed laser and a streak camera on the optical diagnostic beamline will be presented. The timing system was also used to fast trigger the PILATUS detector on an x-ray beamline to measure the fill pattern dependent effects of the detector. PILATUS was able to coarsely measure the fill patternmore » in the storage ring which implies that fill pattern intensity variations need to be corrected for when using the detector in this mode.« less

Materials identification using a small-scale pixellated x-ray diffraction system

NASA Astrophysics Data System (ADS)

O'Flynn, D.; Crews, C.; Drakos, I.; Christodoulou, C.; Wilson, M. D.; Veale, M. C.; Seller, P.; Speller, R. D.

2016-05-01

A transmission x-ray diffraction system has been developed using a pixellated, energy-resolving detector (HEXITEC) and a small-scale, mains operated x-ray source (Amptek Mini-X). HEXITEC enables diffraction to be measured without the requirement of incident spectrum filtration, or collimation of the scatter from the sample, preserving a large proportion of the useful signal compared with other diffraction techniques. Due to this efficiency, sufficient molecular information for material identification can be obtained within 5 s despite the relatively low x-ray source power. Diffraction data are presented from caffeine, hexamine, paracetamol, plastic explosives and narcotics. The capability to determine molecular information from aspirin tablets inside their packaging is demonstrated. Material selectivity and the potential for a sample classification model is shown with principal component analysis, through which each different material can be clearly resolved.

Angle-resolved photoemission spectroscopy with quantum gas microscopes

NASA Astrophysics Data System (ADS)

Bohrdt, A.; Greif, D.; Demler, E.; Knap, M.; Grusdt, F.

2018-03-01

Quantum gas microscopes are a promising tool to study interacting quantum many-body systems and bridge the gap between theoretical models and real materials. So far, they were limited to measurements of instantaneous correlation functions of the form 〈O ̂(t ) 〉 , even though extensions to frequency-resolved response functions 〈O ̂(t ) O ̂(0 ) 〉 would provide important information about the elementary excitations in a many-body system. For example, single-particle spectral functions, which are usually measured using photoemission experiments in electron systems, contain direct information about fractionalization and the quasiparticle excitation spectrum. Here, we propose a measurement scheme to experimentally access the momentum and energy-resolved spectral function in a quantum gas microscope with currently available techniques. As an example for possible applications, we numerically calculate the spectrum of a single hole excitation in one-dimensional t -J models with isotropic and anisotropic antiferromagnetic couplings. A sharp asymmetry in the distribution of spectral weight appears when a hole is created in an isotropic Heisenberg spin chain. This effect slowly vanishes for anisotropic spin interactions and disappears completely in the case of pure Ising interactions. The asymmetry strongly depends on the total magnetization of the spin chain, which can be tuned in experiments with quantum gas microscopes. An intuitive picture for the observed behavior is provided by a slave-fermion mean-field theory. The key properties of the spectra are visible at currently accessible temperatures.

Resolving Ethical Issues when Conducting Sexuality Education

ERIC Educational Resources Information Center

Bruess, Clint E.; Greenberg, Jerrold S.

2008-01-01

Ethical issues about conducting sexuality education often arise. This paper describes one system of ethics and how the sexuality educator can use that system to determine whether an action is moral or immoral and, therefore, the appropriate action to take for that sexuality educator to be consistent with his or her values. Ethical principles are…

Comprehension of Competing Argument Marking Systems in Two Australian Mixed Languages

ERIC Educational Resources Information Center

O'Shannessy, Carmel; Meakins, Felicity

2012-01-01

Crosslinguistic influence has been seen in bilingual adult and child learners when compared to monolingual learners. For speakers of Light Warlpiri and Gurindji Kriol there is no monolingual group for comparison, yet crosslinguistic influence can be seen in how the speakers resolve competition between case-marking and word order systems in each…

Gated frequency-resolved optical imaging with an optical parametric amplifier

DOEpatents

Cameron, S.M.; Bliss, D.E.; Kimmel, M.W.; Neal, D.R.

1999-08-10

A system for detecting objects in a turbid media utilizes an optical parametric amplifier as an amplifying gate for received light from the media. An optical gating pulse from a second parametric amplifier permits the system to respond to and amplify only ballistic photons from the object in the media. 13 figs.

Gated frequency-resolved optical imaging with an optical parametric amplifier

DOEpatents

Cameron, Stewart M.; Bliss, David E.; Kimmel, Mark W.; Neal, Daniel R.

1999-01-01

A system for detecting objects in a turbid media utilizes an optical parametric amplifier as an amplifying gate for received light from the media. An optical gating pulse from a second parametric amplifier permits the system to respond to and amplify only ballistic photons from the object in the media.

AI challenges for spacecraft control programs

NASA Technical Reports Server (NTRS)

Lightfoot, Patricia

1986-01-01

The application of AI technology to the spacecraft and experiment command and control systems environment is proposed. The disadvantages of the present methods for analyzing and resolving spacecraft experiment command and control problems are discussed. The potential capabilities and advantages of using AI for the spacecraft and experiment command and control systems are described.

The Direct Support Workforce Crisis: Can Unions Help Resolve This?

ERIC Educational Resources Information Center

Taylor, Steven J.

2008-01-01

Problems faced by the developmental disability service system in recruiting and retaining direct support staff are exacerbated by demands from competing service industries, including long term supports for the increasing aging population in the United States. Many factors account for high turnover and vacancy rates in the community service system,…

Measuring the quantum geometric tensor in two-dimensional photonic and exciton-polariton systems

NASA Astrophysics Data System (ADS)

Bleu, O.; Solnyshkov, D. D.; Malpuech, G.

2018-05-01

We propose theoretically a method that allows to measure all the components of the quantum geometric tensor (the metric tensor and the Berry curvature) in a photonic system. The method is based on standard optical measurements. It applies to two-band systems, which can be mapped to a pseudospin, and to four-band systems, which can be described by two entangled pseudospins. We apply this method to several specific cases. We consider a 2D planar cavity with two polarization eigenmodes, where the pseudospin measurement can be performed via polarization-resolved photoluminescence. We also consider the s band of a staggered honeycomb lattice with polarization-degenerate modes (scalar photons), where the sublattice pseudospin can be measured by performing spatially resolved interferometric measurements. We finally consider the s band of a honeycomb lattice with polarized (spinor) photons as an example of a four-band model. We simulate realistic experimental situations in all cases. We find the photon eigenstates by solving the Schrödinger equation including pumping and finite lifetime, and then simulate the measurements to finally extract realistic mappings of the k-dependent tensor components.

User-based representation of time-resolved multimodal public transportation networks.

PubMed

Alessandretti, Laura; Karsai, Márton; Gauvin, Laetitia

2016-07-01

Multimodal transportation systems, with several coexisting services like bus, tram and metro, can be represented as time-resolved multilayer networks where the different transportation modes connecting the same set of nodes are associated with distinct network layers. Their quantitative description became possible recently due to openly accessible datasets describing the geo-localized transportation dynamics of large urban areas. Advancements call for novel analytics, which combines earlier established methods and exploits the inherent complexity of the data. Here, we provide a novel user-based representation of public transportation systems, which combines representations, accounting for the presence of multiple lines and reducing the effect of spatial embeddedness, while considering the total travel time, its variability across the schedule, and taking into account the number of transfers necessary. After the adjustment of earlier techniques to the novel representation framework, we analyse the public transportation systems of several French municipal areas and identify hidden patterns of privileged connections. Furthermore, we study their efficiency as compared to the commuting flow. The proposed representation could help to enhance resilience of local transportation systems to provide better design policies for future developments.

Mesoscopic-microscopic spatial stochastic simulation with automatic system partitioning.

PubMed

Hellander, Stefan; Hellander, Andreas; Petzold, Linda

2017-12-21

The reaction-diffusion master equation (RDME) is a model that allows for efficient on-lattice simulation of spatially resolved stochastic chemical kinetics. Compared to off-lattice hard-sphere simulations with Brownian dynamics or Green's function reaction dynamics, the RDME can be orders of magnitude faster if the lattice spacing can be chosen coarse enough. However, strongly diffusion-controlled reactions mandate a very fine mesh resolution for acceptable accuracy. It is common that reactions in the same model differ in their degree of diffusion control and therefore require different degrees of mesh resolution. This renders mesoscopic simulation inefficient for systems with multiscale properties. Mesoscopic-microscopic hybrid methods address this problem by resolving the most challenging reactions with a microscale, off-lattice simulation. However, all methods to date require manual partitioning of a system, effectively limiting their usefulness as "black-box" simulation codes. In this paper, we propose a hybrid simulation algorithm with automatic system partitioning based on indirect a priori error estimates. We demonstrate the accuracy and efficiency of the method on models of diffusion-controlled networks in 3D.

User-based representation of time-resolved multimodal public transportation networks

PubMed Central

Alessandretti, Laura; Gauvin, Laetitia

2016-01-01

Multimodal transportation systems, with several coexisting services like bus, tram and metro, can be represented as time-resolved multilayer networks where the different transportation modes connecting the same set of nodes are associated with distinct network layers. Their quantitative description became possible recently due to openly accessible datasets describing the geo-localized transportation dynamics of large urban areas. Advancements call for novel analytics, which combines earlier established methods and exploits the inherent complexity of the data. Here, we provide a novel user-based representation of public transportation systems, which combines representations, accounting for the presence of multiple lines and reducing the effect of spatial embeddedness, while considering the total travel time, its variability across the schedule, and taking into account the number of transfers necessary. After the adjustment of earlier techniques to the novel representation framework, we analyse the public transportation systems of several French municipal areas and identify hidden patterns of privileged connections. Furthermore, we study their efficiency as compared to the commuting flow. The proposed representation could help to enhance resilience of local transportation systems to provide better design policies for future developments. PMID:27493773

Ethical considerations for a better collaboration between architects and structural engineers: design of buildings with reinforced concrete frame systems in earthquake zones.

PubMed

Hurol, Yonca

2014-06-01

Architects design building structures, although structural design is the profession of structural engineers. Thus, it is better for architects and structural engineers to collaborate starting from the initial phases of the architectural design. However, this is not very common because of the contradictory design processes and value systems held within the two professions. This article provides a platform upon which architects and structural engineers can resolve the value conflicts between them by analysing phases of the structural design of reinforced concrete frame systems in architecture, the criteria of the structural design for each phase and determining the conflicting values for each criterion. The results shown in the article demonstrate that the architectural design of structures is a complex process, which is based on contradictory values and value systems. Finally, the article suggests to architects and structural engineers to use Value Sensitive Design and to choose an appropriate team leader in order to resolve the unethical conflict between them and to avoid any unreasonable decision making.

Double silicone tube intubation for the management of partial lacrimal system obstruction.

PubMed

Demirci, Hakan; Elner, Victor M

2008-02-01

To evaluate the effectiveness of double silicone intubation for the management of partial lacrimal drainage system obstruction in adults. Observational retrospective case series. Twenty-four eyes of 18 consecutive adult patients with partial lacrimal system obstruction managed at the University of Michigan. Retrospective review of symptoms and signs, duration of silicone intubation, and complications. Resolution of tearing. Preoperative tearing, negative Jones I testing, positive Jones II testing, and resistance to positive-pressure irrigation were present in all eyes (100%). The first silicone tube was removed after a mean of 11+/-7 months, and the second tube after 16+/-6 months. Postoperatively, at a mean of 21+/-9 months after removal of both tubes, tearing remained resolved in 19 eyes (79%) and remained improved in 2 eyes (8%). In eyes with resolved tearing, Jones I testing became positive, and there was no resistance to positive-pressure irrigation. Persistent tearing in 3 eyes (13%) required treatment with external dacryocystorhinostomy. The only complication was peripunctal pyogenic granulomas in 2 eyes. Double silicone intubation is an effective minimally invasive technique for treatment of partial lacrimal system obstruction in adults.

Interaction between attentional systems and episodic memory encoding: the impact of conflict on binding of information.

PubMed

Sperduti, Marco; Armougum, Allan; Makowski, Dominique; Blondé, Philippe; Piolino, Pascale

2017-12-01

Episodic memory (EM) is defined as a long-term memory system that stores information that can be retrieved along with details of the context of the original events (binding). Several studies have shown that manipulation of attention during encoding can impact subsequent memory performance. An influential model of attention distinguishes between three partially independent attentional networks: the alerting, the orienting and the executive or conflict resolution component. To date, the impact of the engagement of these sub-systems during encoding on item and relational context binding has not been investigated. Here, we developed a new task combining the Attentional Network Test and an incidental episodic memory encoding task to study this issue. We reported that when the alerting network was not solicited, resolving conflict hindered item encoding. Moreover, resolving conflict, independently of the cueing condition, had a negative impact on context binding. These novel findings could have a potential impact in the understanding EM formation, and memory disorders in different populations, including healthy elderly people.

A versatile fiber-optic coupled system for sensitive optical spectroscopy in strong ambient light

NASA Astrophysics Data System (ADS)

Sinha, Sudarson Sekhar; Verma, Pramod Kumar; Makhal, Abhinandan; Pal, Samir Kumar

2009-05-01

In this work we describe design and use of a fiber-optic based optical system for the spectroscopic studies on the samples under the presence of strong ambient light. The system is tested to monitor absorption, emission, and picosecond-resolved fluorescence transients simultaneously with a time interval of 500 ms for several hours on a biologically important sample (vitamin B2) under strong UV light. An efficient stray-light rejection ratio of the setup is achieved by the confocal geometry of the excitation and detection channels. It is demonstrated using this setup that even low optical signal from a liquid sample under strong UV-exposure for the picosecond-resolved fluorescence transient measurement can reliably be detected by ultrasensitive microchannel plate photomultiplier tube solid state detector. The kinetics of photodeterioration of vitamin B2 measured using our setup is consistent with that reported in the literature. Our present studies also justify the usage of tungsten light than the fluorescent light for the healthy preservation of food with vitamin B2.

Research and development on performance models of thermal imaging systems

NASA Astrophysics Data System (ADS)

Wang, Ji-hui; Jin, Wei-qi; Wang, Xia; Cheng, Yi-nan

2009-07-01

Traditional ACQUIRE models perform the discrimination tasks of detection (target orientation, recognition and identification) for military target based upon minimum resolvable temperature difference (MRTD) and Johnson criteria for thermal imaging systems (TIS). Johnson criteria is generally pessimistic for performance predict of sampled imager with the development of focal plane array (FPA) detectors and digital image process technology. Triangle orientation discrimination threshold (TOD) model, minimum temperature difference perceived (MTDP)/ thermal range model (TRM3) Model and target task performance (TTP) metric have been developed to predict the performance of sampled imager, especially TTP metric can provides better accuracy than the Johnson criteria. In this paper, the performance models above are described; channel width metrics have been presented to describe the synthesis performance including modulate translate function (MTF) channel width for high signal noise to ration (SNR) optoelectronic imaging systems and MRTD channel width for low SNR TIS; the under resolvable questions for performance assessment of TIS are indicated; last, the development direction of performance models for TIS are discussed.

A Herschel-Resolved Debris Disk Around the Nearby G Star HIP 32480

NASA Technical Reports Server (NTRS)

Stapelfeldt, K.

2011-01-01

The Herschel Space Observatory is providing unprecedented sensitivity and angular resolution in the far-infrared. The DUNES Key Project (DUst around NEarby Stars, PI Carlos Eiroa) has finished its survey of 133 FGK stars within 25 pc of the Sun using the PACS photometer at 100 and 160 microns. We report the detection of a resolved debris ring around HIP 32480, a G0 star 16.5 parsecs distant. The ring is almost 300 AU in diameter and inclined 30 degrees from edge-on. We present a thermal emission model for the system that fits the Spitzer spectroscopy and Herschel images of the system. We find a minimum grainsize of approximately 4 microns in the main ring and a distinct warm dust population interior to it. Faint detached emission features just outside the ring may trace a separate, more distant ring in the system. The non-detection of the ring in archival HST/ACS coronagraphic images limits the dust grain albedo in the ring to be no more than 10%.

A Resolved Debris Disk Around the Nearby G Star HIP 32480

NASA Technical Reports Server (NTRS)

Stapelfeldt, K. R.; Bryden, G. C.; Marshall, J.; Eiroa, C.; Absil, O.; Mora, A.; Krist, J. E.; Su, K. Y. L.

2012-01-01

The Herschel Space Observatory is providing unprecedented sensitivity and angular resolution in the far-infrared. The DUNES Key Project (DUst around NEarby Stars, PI Carlos Eiroa) has finished its survey of 133 FGK stars within 25 pc of the Sun using the PACS photometer at 100 and 160 microns. We report the detection of a resolved debris ring around HIP 32480, a GO star 16.5 parsecs distant. The ring is almost 300 AU in diameter and inclined 30 degrees from edge-on. We present a thermal emission model for the system that fits the Spitzer spectroscopy and Herschel images of the system. We find a minimum grain-size of 4 microns in the main ring and a distinct warm dust population interior to it. Faint detached emission features just outside the ring may trace a separate, more distant ring in the system. The non-detection of the ring in archival HST/ACS coronagraphic images limits the dust grain albedo in the ring to be no more than 10%.

Super-resolved microsphere-assisted Mirau digital holography by oblique illumination

NASA Astrophysics Data System (ADS)

Abbasian, Vahid; Ganjkhani, Yasaman; Akhlaghi, Ehsan A.; Anand, Arun; Javidi, Bahram; Moradi, Ali-Reza

2018-06-01

In this paper, oblique illumination is used to improve the lateral resolution and edge sharpness in microsphere (MS)-assisted Mirau digital holographic microscopy (Mirau-DHM). Abbe showed that tilting the illumination light allows entrance of higher spatial frequencies into the imaging system thus increasing the resolution power. We extended the idea to common-path DHM, based on Mirau objective, toward super-resolved 3D imaging. High magnification Mirau objectives are very expensive and low-magnification ones suffer from low resolution, therefore, any attempt to increase the effective resolution of the system may be of a great interest. We have already demonstrated the effective resolution increasing of a Mirau-DHM system by incorporating a transparent MS within the working distance of the objective. Here, we show that by integrating a MS-assisted Mirau-DHM with the oblique illumination even higher resolutions can be achieved. We have applied the technique for various samples and have shown the increase in the lateral resolution for the both cases of Mirau-DHM with and without the MS.

Localized oscillatory states in magnetoconvection.

PubMed

Buckley, Matthew C; Bushby, Paul J

2013-02-01

Localized states are found in many pattern forming systems. The aim of this paper is to investigate the occurrence of oscillatory localized states in two-dimensional Boussinesq magnetoconvection. Initially considering an idealized model, in which the vertical structure of the system has been simplified by a projection onto a small number of Fourier modes, we find that these states are restricted to the low ζ regime (where ζ represents the ratio of the magnetic to thermal diffusivities). These states always exhibit bistability with another nontrivial solution branch; in other words, they show no evidence of subcritical behavior. This is due to the weak flux expulsion that is exhibited by these time-dependent solutions. Using the results of this parameter survey, we locate corresponding states in a fully resolved two-dimensional system, although the mode of oscillation is more complex in this case. This is the first time that a localized oscillatory state, of this kind, has been found in a fully resolved magnetoconvection simulation.

Application of the multiple PRF technique to resolve Doppler centroid estimation ambiguity for spaceborne SAR

NASA Technical Reports Server (NTRS)

Chang, C. Y.; Curlander, J. C.

1992-01-01

Estimation of the Doppler centroid ambiguity is a necessary element of the signal processing for SAR systems with large antenna pointing errors. Without proper resolution of the Doppler centroid estimation (DCE) ambiguity, the image quality will be degraded in the system impulse response function and the geometric fidelity. Two techniques for resolution of DCE ambiguity for the spaceborne SAR are presented; they include a brief review of the range cross-correlation technique and presentation of a new technique using multiple pulse repetition frequencies (PRFs). For SAR systems, where other performance factors control selection of the PRF's, an algorithm is devised to resolve the ambiguity that uses PRF's of arbitrary numerical values. The performance of this multiple PRF technique is analyzed based on a statistical error model. An example is presented that demonstrates for the Shuttle Imaging Radar-C (SIR-C) C-band SAR, the probability of correct ambiguity resolution is higher than 95 percent for antenna attitude errors as large as 3 deg.

QAIT: a quality assurance issue tracking tool to facilitate the improvement of clinical data quality.

PubMed

Zhang, Yonghong; Sun, Weihong; Gutchell, Emily M; Kvecher, Leonid; Kohr, Joni; Bekhash, Anthony; Shriver, Craig D; Liebman, Michael N; Mural, Richard J; Hu, Hai

2013-01-01

In clinical and translational research as well as clinical trial projects, clinical data collection is prone to errors such as missing data, and misinterpretation or inconsistency of the data. A good quality assurance (QA) program can resolve many such errors though this requires efficient communications between the QA staff and data collectors. Managing such communications is critical to resolving QA problems but imposes a major challenge for a project involving multiple clinical and data processing sites. We have developed a QA issue tracking (QAIT) system to support clinical data QA in the Clinical Breast Care Project (CBCP). This web-based application provides centralized management of QA issues with role-based access privileges. It has greatly facilitated the QA process and enhanced the overall quality of the CBCP clinical data. As a stand-alone system, QAIT can supplement any other clinical data management systems and can be adapted to support other projects. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

A fast data acquisition system for the study of transient events by high repetition rate time-of-flight mass spectrometry

NASA Technical Reports Server (NTRS)

Lincoln, K. A.; Bechtel, R. D.

1986-01-01

Recent advances in commercially available data acquisition electronics embodying high speed A/D conversion coupled to increased memory storage have now made practical (at least within time intervals of a third of a millisecond or more) the capturing of all of the data generated by a high repetition rate time-of-flight mass spectrometer producing complete spectra every 25 to 35 microseconds. Such a system was assembled and interfaced with a personal computer for control and management of data. The applications are described for recording time-resolved spectra of individual vapor plumes induced from the pulsed-laser heating of material. Each laser pulse triggers the system to generate automatically a 3-dimensional (3-D) presentation of the time-resolved spectra with m/z labeling of the major mass peaks, plus an intensity versus time display of both the laser pulse and the resulting vapor pulse. The software also permits storing of data and its presentation in various additional forms.

Analysis of a general circulation model. II - Distribution of kinetic energy in the South Atlantic and Kuroshio/Oyashio systems

NASA Technical Reports Server (NTRS)

Garraffo, Zulema; Garzoli, Silvia L.; Haxby, William; Olson, Donald

1992-01-01

It was found (Garzoli et al., 1992) that the general circulation model of Semtner and Chervin (1992) provides accurate descriptions of the Brazil-Malvinas and the Kuroshio/Oyashio confluence systems, except for the fact that the model prediction shows less variability than that present in observations. This paper investigates the problem of model variability by analyzing the mean and the eddy kinetic energy from the model and comparing the values with the Geosat altimeter observations for the South Atlantic Ocean and for the Kuroshio system. It is found that, while the model shows transient eddy activity in the areas that overlap the Geosat observations, the energy level of the model transient motions is considerably smaller following an arch along the bottom topography. The same was found from the comparisons made with values obtained from FGGE and surface drifters. It is suggested that the model is poorly resolving instabilities in the confluence front, and is not resolving other transients appearing in regions of marked topography.

Simulating pump-probe photoelectron and absorption spectroscopy on the attosecond timescale with time-dependent density functional theory.

PubMed

De Giovannini, Umberto; Brunetto, Gustavo; Castro, Alberto; Walkenhorst, Jessica; Rubio, Angel

2013-05-10

Molecular absorption and photoelectron spectra can be efficiently predicted with real-time time-dependent density functional theory. We show herein how these techniques can be easily extended to study time-resolved pump-probe experiments, in which a system response (absorption or electron emission) to a probe pulse is measured in an excited state. This simulation tool helps with the interpretation of fast-evolving attosecond time-resolved spectroscopic experiments, in which electronic motion must be followed at its natural timescale. We show how the extra degrees of freedom (pump-pulse duration, intensity, frequency, and time delay), which are absent in a conventional steady-state experiment, provide additional information about electronic structure and dynamics that improve characterization of a system. As an extension of this approach, time-dependent 2D spectroscopy can also be simulated, in principle, for large-scale structures and extended systems. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biosonar resolving power: echo-acoustic perception of surface structures in the submillimeter range.

PubMed

Simon, Ralph; Knörnschild, Mirjam; Tschapka, Marco; Schneider, Annkathrin; Passauer, Nadine; Kalko, Elisabeth K V; von Helversen, Otto

2014-01-01

The minimum distance for which two points still can be separated from each other defines the resolving power of a visual system. In an echo-acoustic context, the resolving power is usually measured as the smallest perceivable distance of two reflecting surfaces on the range axis and is found to be around half a millimeter for bats employing frequency modulated (FM) echolocation calls. Only few studies measured such thresholds with physical objects, most often bats were trained on virtual echoes i.e., echoes generated and played back by a computer; moreover, bats were sitting while they received the stimuli. In these studies differences in structure depth between 200 and 340 μm were found. However, these low thresholds were never verified for free-flying bats and real physical objects. Here, we show behavioral evidence that the echo-acoustic resolving power for surface structures in fact can be as low as measured for computer generated echoes and even lower, sometimes below 100 μm. We found this exceptional fine discrimination ability only when one of the targets showed spectral interferences in the frequency range of the bats' echolocation call while the other target did not. This result indicates that surface structure is likely to be perceived as a spectral quality rather than being perceived strictly in the time domain. Further, it points out that sonar resolving power directly depends on the highest frequency/shortest wavelength of the signal employed.

Biosonar resolving power: echo-acoustic perception of surface structures in the submillimeter range

PubMed Central

Simon, Ralph; Knörnschild, Mirjam; Tschapka, Marco; Schneider, Annkathrin; Passauer, Nadine; Kalko, Elisabeth K. V.; von Helversen, Otto

2014-01-01

The minimum distance for which two points still can be separated from each other defines the resolving power of a visual system. In an echo-acoustic context, the resolving power is usually measured as the smallest perceivable distance of two reflecting surfaces on the range axis and is found to be around half a millimeter for bats employing frequency modulated (FM) echolocation calls. Only few studies measured such thresholds with physical objects, most often bats were trained on virtual echoes i.e., echoes generated and played back by a computer; moreover, bats were sitting while they received the stimuli. In these studies differences in structure depth between 200 and 340 μm were found. However, these low thresholds were never verified for free-flying bats and real physical objects. Here, we show behavioral evidence that the echo-acoustic resolving power for surface structures in fact can be as low as measured for computer generated echoes and even lower, sometimes below 100 μm. We found this exceptional fine discrimination ability only when one of the targets showed spectral interferences in the frequency range of the bats′ echolocation call while the other target did not. This result indicates that surface structure is likely to be perceived as a spectral quality rather than being perceived strictly in the time domain. Further, it points out that sonar resolving power directly depends on the highest frequency/shortest wavelength of the signal employed. PMID:24616703

Tropical Waves and the Quasi-Biennial Oscillation in a 7-km Global Climate Simulation

NASA Technical Reports Server (NTRS)

Holt, Laura A.; Alexander, M. Joan; Coy, Lawrence; Molod, Andrea; Putman, William; Pawson, Steven

2016-01-01

This study investigates tropical waves and their role in driving a quasi-biennial oscillation (QBO)-like signal in stratospheric winds in a global 7-km-horizontal-resolution atmospheric general circulation model. The Nature Run (NR) is a 2-year global mesoscale simulation of the Goddard Earth Observing System Model, version 5 (GEOS-5). In the tropics, there is evidence that the NR supports a broad range of convectively generated waves. The NR precipitation spectrum resembles the observed spectrum in many aspects, including the preference for westward-propagating waves. However, even with very high horizontal resolution and a healthy population of resolved waves, the zonal force provided by the resolved waves is still too low in the QBO region and parameterized gravity wave drag is the main driver of the NR QBO-like oscillation (NRQBO). The authors suggest that causes include coarse vertical resolution and excessive dissipation. Nevertheless, the very-high-resolution NR provides an opportunity to analyze the resolved wave forcing of the NR-QBO. In agreement with previous studies, large-scale Kelvin and small-scale waves contribute to the NRQBO driving in eastward shear zones and small-scale waves dominate the NR-QBO driving in westward shear zones. Waves with zonal wavelength,1000 km account for up to half of the small-scale (,3300 km) resolved wave forcing in eastward shear zones and up to 70% of the small-scale resolved wave forcing in westward shear zones of the NR-QBO.

The Space Infrared Interferometric Telescope (SPIRIT): Mission Study Results

DTIC Science & Technology

2006-01-01

how planetary systems form it is essential to obtain spatially-resolved far-IR observations of protostars and protoplanetary disks . At the distance...accomplish three primary scientific objectives: (1) Learn how planetary systems form from protostellar disks , and how they acquire their chemical...organization; (2) Characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets

ATTACK WARNING: Better Management Required to Resolve NORAD Integration Deficiencies

DTIC Science & Technology

1989-07-01

protocols, Cumbersome Integration different manufacturers’ computer systems can communicate with eachother . The warning and assessment subsystems...by treating TW/AA system as a single system subject to program review and oversight by the Defense Acquisition Board. Within this management...restore the unit to operation quickly enough after a power loss to meet NORAD mis- sion requirements. The Air Force intends to have the contractor

The Systemic Approach to Technological Education: Effects of Transferred Learning in Resolving a Physics Problem

ERIC Educational Resources Information Center

Andreucci, Colette; Chatoney, Marjolaine; Ginestie, Jacques

2012-01-01

The purpose of this study is to verify whether pupils (15-16 years old) who have received technology education on a systemic approach of industrial systems, are better than other pupils (of the same age but from other academic domains such as literary ones or ones that are economics-based) at solving physical science problems which involve…

A model framework to represent plant-physiology and rhizosphere processes in soil profile simulation models

NASA Astrophysics Data System (ADS)

Vanderborght, J.; Javaux, M.; Couvreur, V.; Schröder, N.; Huber, K.; Abesha, B.; Schnepf, A.; Vereecken, H.

2013-12-01

Plant roots play a crucial role in several key processes in soils. Besides their impact on biogeochemical cycles and processes, they also have an important influence on physical processes such as water flow and transport of dissolved substances in soils. Interaction between plant roots and soil processes takes place at different scales and ranges from the scale of an individual root and its directly surrounding soil or rhizosphere over the scale of a root system of an individual plant in a soil profile to the scale of vegetation patterns in landscapes. Simulation models that are used to predict water flow and solute transport in soil-plant systems mainly focus on the individual plant root system scale, parameterize single-root scale phenomena, and aggregate the root system scale to the vegetation scale. In this presentation, we will focus on the transition from the single root to the root system scale. Using high resolution non-invasive imaging techniques and methods, gradients in soil properties and states around roots and their difference from the bulk soil properties could be demonstrated. Recent developments in plant sciences provide new insights in the mechanisms that control water fluxes in plants and in the adaptation of root properties or root plasticity to changing soil conditions. However, since currently used approaches to simulate root water uptake neither resolve these small scale processes nor represent processes and controls within the root system, transferring this information to the whole soil-plant system scale is a challenge. Using a simulation model that describes flow and transport processes in the soil, resolves flow and transport towards individual roots, and describes flow and transport within the root system, such a transfer could be achieved. We present a few examples that illustrate: (i) the impact of changed rhizosphere hydraulic properties, (ii) the effect of root hydraulic properties and root system architecture, (iii) the regulation of plant transpiration by root-zone produced plant hormones, and (iv) the impact of salt accumulation at the soil-root interface on root water uptake. We further propose a framework how this process knowledge could be implemented in root zone simulation models that do not resolve small scale processes.

Optimization and comprehensive characterization of metal hydride based hydrogen storage systems using in-situ Neutron Radiography

NASA Astrophysics Data System (ADS)

Börries, S.; Metz, O.; Pranzas, P. K.; Bellosta von Colbe, J. M.; Bücherl, T.; Dornheim, M.; Klassen, T.; Schreyer, A.

2016-10-01

For the storage of hydrogen, complex metal hydrides are considered as highly promising with respect to capacity, reversibility and safety. The optimization of corresponding storage tanks demands a precise and time-resolved investigation of the hydrogen distribution in scaled-up metal hydride beds. In this study it is shown that in situ fission Neutron Radiography provides unique insights into the spatial distribution of hydrogen even for scaled-up compacts and therewith enables a direct study of hydrogen storage tanks. A technique is introduced for the precise quantification of both time-resolved data and a priori material distribution, allowing inter alia for an optimization of compacts manufacturing process. For the first time, several macroscopic fields are combined which elucidates the great potential of Neutron Imaging for investigations of metal hydrides by going further than solely 'imaging' the system: A combination of in-situ Neutron Radiography, IR-Thermography and thermodynamic quantities can reveal the interdependency of different driving forces for a scaled-up sodium alanate pellet by means of a multi-correlation analysis. A decisive and time-resolved, complex influence of material packing density is derived. The results of this study enable a variety of new investigation possibilities that provide essential information on the optimization of future hydrogen storage tanks.

Search for Feo and Pyroxene on MERCURY?S Surface

NASA Astrophysics Data System (ADS)

Sprague, Ann L.; Emery, Joshua P.

Results from spectral observations of Mercury's surface in the wavelength range 0.8 to 5.5 micrometers will be reported. The data were obtained at the NASA Infrared Telescope Facility on Mauna Kea Hawaii. We used SpeX a long slit imaging system developed at the IRTF for high resolving power spatially resolved spectroscopy throughout the solar system. We aligned the spectral slit with Mercury's geographic longitude and systematically moved it across the Earth-facing disk to obtain multiple disk-resolved spectral images. The entire data set provides spatial coverage of the Earth-facing disk limited only by atmospheric turbulence and the diffraction limit for each wavelength. We used SpeX in two spectral regions in the R 2000 mode. In the first case between 0.8 and 2.5 micrometer to search for the 0.9 to 1.0 micrometer reflectance absorption feature caused by the Fe2+ electronic transfer in FeO. We also measured the 4.5 to 5.5 micrometer flux from Mercury. This is a region of diagnostic features caused by the presence of volume scattering in pyroxene and olivine. These data will be compared to previous observations that showed an anomalous emission feature at 5.5 micrometer and to others that exhibited a feature closely resembling that from pyroxene.

The use of dopants in high field asymmetric waveform spectrometry.

PubMed

Ross, Stuart K; McDonald, Gwenda; Marchant, Sarah

2008-05-01

Ion mobility spectrometry (IMS) is proven core technology for the gas-phase detection of chemical warfare (CW) agents. One disadvantage of IMS technology is that ions of similar mobility cannot readily be resolved, resulting in false alarm responses and a loss of user confidence. High field asymmetric waveform spectrometry (HiFAWS) is an emerging technology for the gas-phase detection of CW agents. Of particular interest is the potential of a HiFAWS-based platform to reduce the number of false alarms by resolving ions that cannot be discriminated using IMS. It has been demonstrated that a water clustering/declustering mechanism can be a dominant process in HiFAWS. Ions that cannot be discriminated in IMS because they possess the same low field mobility value can be resolved using HiFAWS due to differences in the extent of low field ion solvation and high field ion desolvation. When operating in complex environments such as those potentially experienced in military and security arenas, IMS systems commonly employ internal dopants to reduce the number of background responses. It is possible that HiFAWS systems may also require the use of internal dopants for the same reason. It has been demonstrated that dopants employed for use in IMS may not be suitable for use in HiFAWS.

Phases and interfaces from real space atomically resolved data: Physics-based deep data image analysis

DOE PAGES

Vasudevan, Rama K.; Ziatdinov, Maxim; Jesse, Stephen; ...

2016-08-12

Advances in electron and scanning probe microscopies have led to a wealth of atomically resolved structural and electronic data, often with ~1–10 pm precision. However, knowledge generation from such data requires the development of a physics-based robust framework to link the observed structures to macroscopic chemical and physical descriptors, including single phase regions, order parameter fields, interfaces, and structural and topological defects. Here, we develop an approach based on a synergy of sliding window Fourier transform to capture the local analog of traditional structure factors combined with blind linear unmixing of the resultant 4D data set. This deep data analysismore » is ideally matched to the underlying physics of the problem and allows reconstruction of the a priori unknown structure factors of individual components and their spatial localization. We demonstrate the principles of this approach using a synthetic data set and further apply it for extracting chemical and physically relevant information from electron and scanning tunneling microscopy data. Furthermore, this method promises to dramatically speed up crystallographic analysis in atomically resolved data, paving the road toward automatic local structure–property determinations in crystalline and quasi-ordered systems, as well as systems with competing structural and electronic order parameters.« less

Characterizing a pulse-resolved dosimetry system for complex radiotherapy beams using organic scintillators.

PubMed

Beierholm, Anders R; Ottosson, Rickard O; Lindvold, Lars R; Behrens, Claus F; Andersen, Claus E

2011-05-21

A fast-readout dosimetry system based on fibre-coupled organic scintillators has been developed for the purpose of conducting point measurements of absorbed dose in radiotherapy beams involving high spatial and temporal dose gradients. The system measures the dose for each linac radiation pulse with millimetre spatial resolution. To demonstrate the applicability of the system in complex radiotherapy fields, output factors and per cent depth dose measurements were performed in solid water for a 6 MV photon beam and compared with Monte Carlo simulated doses for square fields down to 0.6 cm × 0.6 cm size. No significant differences between measurements and simulations were observed. The temporal resolution of the system was demonstrated by measuring dose per pulse, beam start-up transients and the quality factor for 6 MV. The precision of dose per pulse measurements was within 2.7% (1 SD) for a 10 cm × 10 cm field at 10 cm depth. The dose per pulse behaviour compared well with linac target current measurements and accumulated dose measurements, and the system was able to resolve transient dose delivery differences between two Varian linac builds. The system therefore shows promise for reference dosimetry and quality assurance of complex radiotherapy treatments.

A Study on Electric Power Smoothing System for Lead-Acid Battery of Stand-Alone Natural Energy Power System Using EDLC

NASA Astrophysics Data System (ADS)

Jia, Yan; Shibata, Ryosuke; Yamamura, Naoki; Ishida, Muneaki

To resolve energy shortage and global warming problem, renewable natural resource and its power system has been gradually generalizing. However, the power fluctuation suppressing in short period and the balance control of consumption and supply in long period are two of main problems that need to be resolved urgently in natural energy power system. In Stand-alone Natural Energy Power System (SNEPS) with power energy storage devices, power fluctuation in short period is one of the main reasons that recharge cycle times increase and lead-acid battery early failure. Hence, to prolong the service life of lead-acid battery and improve power quality through suppressing the power fluctuation, we proposed a method of electric power smoothing for lead-acid battery of SNEPS using bi-directional Buck/Boost converter and Electric Double Layer Capacitor (EDLC) in this paper. According to the test data of existing SNEPS, a power fluctuation condition is selected and as an example to analyze the validity of the proposed method. The analysis of frequency characteristics indicates the power fluctuation is suppressed a desired range in the target frequency region. The experimental results of confirmed the feasibility of the proposed system and the results well satisfy the requirement of system design.

Final Draft of RACER Audit

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

Paige, Karen Schultz; Gomez, Penelope E.

This document describes the approach Waste and Environmental Services - Environmental Data and Analysis plans to take to resolve the issues presented in a recent audit of the WES-EDA Environmental Database relative to the RACER database. A majority of the issues discovered in the audit will be resolved in May 2011 when the WES-EDA Environmental Database, along with other LANL databases, are integrated and moved to a new vendor providing an Environmental Information Management (EIM) system that allows reporting capabilities for all users directly from the database. The EIM system will reside in a publicly accessible LANL cloud-based software system.more » When this transition occurs, the data quality, completeness, and access will change significantly. In the remainder of this document, this new structure will be referred to as the LANL Cloud System In general, our plan is to address the issues brought up in this audit in three ways: (1) Data quality issues such as units and detection status, which impinge upon data usability, will be resolved as soon possible so that data quality is maintained. (2) Issues requiring data cleanup, such as look up tables, legacy data, locations, codes, and significant data discrepancies, will be addressed as resources permit. (3) Issues associated with data feed problems will be eliminated by the LANL Cloud System, because there will be no data feed. As discussed in the paragraph above, in the future the data will reside in a publicly accessible system. Note that report writers may choose to convert, adapt, or simplify the information they receive officially through our data base, thereby introducing data discrepancies between the data base and the public report. It is not always possible to incorporate and/or correct these errors when they occur. Issues in the audit will be discussed in the order in which they are presented in the audit report. Clarifications will also be noted as the audit report was a draft document, at the time of this response.« less

Development of Fast Response In-situ Sensors for Simultaneous Measurements of Seawater Carbon Dioxide Parameters

NASA Astrophysics Data System (ADS)

Wang, A. Z.; Sonnichsen, F. N.; Chu, S. N.; Bradley, A. M.; Hoering, K.

2016-02-01

The marine CO2 (inorganic carbon) system is characterized by four primary parameters - total dissolved inorganic carbon (DIC), total alkalinity (TA), partial pressure of CO2 (pCO2), and pH. These parameters are central to the study of the marine carbon cycle and ocean acidification. Simultaneous measurements of two of the four CO2 parameters are required to fully resolve the seawater CO2 system, and DIC is one of the preferred parameters. A self-calibrating, in-situ sensor, Channelized Optical System (CHANOS), has recently been developed to provide simultaneous measurements of both DIC and pH, resolving carbonate chemistry with a single system. CHANOS is among the first to achieve simultaneous, in-situ measurements of a desired pair of CO2 parameters. DIC and pH channels both use flow-through, spectrophotometric methods to detect relative absorbances of the acid and base forms of a pH-sensitive indicator. The precision of CHANOS in laboratory and in-situ tests are ±0.002 and ±3.0 µmol kg-1 for pH and DIC, respectively. In-situ comparison with bottle sampling and analyses indicate that the accuracies for pH and DIC are ±0.004 and ±5.0 µmol kg-1, respectively. It has been demonstrated that CHANOS can make in-situ, climatology-quality measurements to resolve the CO2 system in dynamic aquatic environments. To further improve response time of the sensor, especially for DIC measurements, a new generation of CHANOS-DIC is under development. The new system adapts the recently developed spectrophotometric DIC method to achieve flow-through CO2 equilibration between an acidified sample and an indicator solution with a response time as fast as 22s. Continuous measurements are also achievable. Because of the fast response of CHANOS measurements, it is versatile and suitable for deployments on both fixed (e.g. buoys) and mobile (e.g., AUV, ROV, and profilers) platforms.

Design and test of a high power electromechanical actuator for thrust vector control

NASA Technical Reports Server (NTRS)

Cowan, J. R.; Myers, W. N.

1992-01-01

NASA-Marshall is involved in the development of electromechanical actuators (EMA) for thrust-vector control (TVC) system testing and implementation in spacecraft control/gimballing systems, with a view to the replacement of hydraulic hardware. TVC system control is furnished by solid state controllers and power supplies; a pair of resolvers supply position feedback to the controller for precise positioning. Performance comparisons between EMA and hydraulic TVC systems are performed.

Design and test of a high power electromechanical actuator for thrust vector control

NASA Astrophysics Data System (ADS)

Cowan, J. R.; Myers, W. N.

1992-07-01

NASA-Marshall is involved in the development of electromechanical actuators (EMA) for thrust-vector control (TVC) system testing and implementation in spacecraft control/gimballing systems, with a view to the replacement of hydraulic hardware. TVC system control is furnished by solid state controllers and power supplies; a pair of resolvers supply position feedback to the controller for precise positioning. Performance comparisons between EMA and hydraulic TVC systems are performed.

A theoretical framework for convergence and continuous dependence of estimates in inverse problems for distributed parameter systems

NASA Technical Reports Server (NTRS)

Banks, H. T.; Ito, K.

1988-01-01

Numerical techniques for parameter identification in distributed-parameter systems are developed analytically. A general convergence and stability framework (for continuous dependence on observations) is derived for first-order systems on the basis of (1) a weak formulation in terms of sesquilinear forms and (2) the resolvent convergence form of the Trotter-Kato approximation. The extension of this framework to second-order systems is considered.

Industry-relevant magnetron sputtering and cathodic arc ultra-high vacuum deposition system for in situ x-ray diffraction studies of thin film growth using high energy synchrotron radiation.

PubMed

Schroeder, J L; Thomson, W; Howard, B; Schell, N; Näslund, L-Å; Rogström, L; Johansson-Jõesaar, M P; Ghafoor, N; Odén, M; Nothnagel, E; Shepard, A; Greer, J; Birch, J

2015-09-01

We present an industry-relevant, large-scale, ultra-high vacuum (UHV) magnetron sputtering and cathodic arc deposition system purposefully designed for time-resolved in situ thin film deposition/annealing studies using high-energy (>50 keV), high photon flux (>10(12) ph/s) synchrotron radiation. The high photon flux, combined with a fast-acquisition-time (<1 s) two-dimensional (2D) detector, permits time-resolved in situ structural analysis of thin film formation processes. The high-energy synchrotron-radiation based x-rays result in small scattering angles (<11°), allowing large areas of reciprocal space to be imaged with a 2D detector. The system has been designed for use on the 1-tonne, ultra-high load, high-resolution hexapod at the P07 High Energy Materials Science beamline at PETRA III at the Deutsches Elektronen-Synchrotron in Hamburg, Germany. The deposition system includes standard features of a typical UHV deposition system plus a range of special features suited for synchrotron radiation studies and industry-relevant processes. We openly encourage the materials research community to contact us for collaborative opportunities using this unique and versatile scientific instrument.

Wide-field spectrally resolved quantitative fluorescence imaging system: toward neurosurgical guidance in glioma resection

NASA Astrophysics Data System (ADS)

Xie, Yijing; Thom, Maria; Ebner, Michael; Wykes, Victoria; Desjardins, Adrien; Miserocchi, Anna; Ourselin, Sebastien; McEvoy, Andrew W.; Vercauteren, Tom

2017-11-01

In high-grade glioma surgery, tumor resection is often guided by intraoperative fluorescence imaging. 5-aminolevulinic acid-induced protoporphyrin IX (PpIX) provides fluorescent contrast between normal brain tissue and glioma tissue, thus achieving improved tumor delineation and prolonged patient survival compared with conventional white-light-guided resection. However, commercially available fluorescence imaging systems rely solely on visual assessment of fluorescence patterns by the surgeon, which makes the resection more subjective than necessary. We developed a wide-field spectrally resolved fluorescence imaging system utilizing a Generation II scientific CMOS camera and an improved computational model for the precise reconstruction of the PpIX concentration map. In our model, the tissue's optical properties and illumination geometry, which distort the fluorescent emission spectra, are considered. We demonstrate that the CMOS-based system can detect low PpIX concentration at short camera exposure times, while providing high-pixel resolution wide-field images. We show that total variation regularization improves the contrast-to-noise ratio of the reconstructed quantitative concentration map by approximately twofold. Quantitative comparison between the estimated PpIX concentration and tumor histopathology was also investigated to further evaluate the system.

Time-Resolved Diffuse Optical Spectroscopy and Imaging Using Solid-State Detectors: Characteristics, Present Status, and Research Challenges

PubMed Central

Alayed, Mrwan

2017-01-01

Diffuse optical spectroscopy (DOS) and diffuse optical imaging (DOI) are emerging non-invasive imaging modalities that have wide spread potential applications in many fields, particularly for structural and functional imaging in medicine. In this article, we review time-resolved diffuse optical imaging (TR-DOI) systems using solid-state detectors with a special focus on Single-Photon Avalanche Diodes (SPADs) and Silicon Photomultipliers (SiPMs). These TR-DOI systems can be categorized into two types based on the operation mode of the detector (free-running or time-gated). For the TR-DOI prototypes, the physical concepts, main components, figures-of-merit of detectors, and evaluation parameters are described. The performance of TR-DOI prototypes is evaluated according to the parameters used in common protocols to test DOI systems particularly basic instrumental performance (BIP). In addition, the potential features of SPADs and SiPMs to improve TR-DOI systems and expand their applications in the foreseeable future are discussed. Lastly, research challenges and future developments for TR-DOI are discussed for each component in the prototype separately and also for the entire system. PMID:28906462

Safety and Convergence Analysis of Intersecting Aircraft Flows Under Decentralized Collision Avoidance

NASA Astrophysics Data System (ADS)

Dallal, Ahmed H.

Safety is an essential requirement for air traffic management and control systems. Aircraft are not allowed to get closer to each other than a specified safety distance, to avoid any conflicts and collisions between aircraft. Forecast analysis predicts a tremendous increase in the number of flights. Subsequently, automated tools are needed to help air traffic controllers resolve air born conflicts. In this dissertation, we consider the problem of conflict resolution of aircraft flows with the assumption that aircraft are flowing through a fixed specified control volume at a constant speed. In this regard, several centralized and decentralized resolution rules have been proposed for path planning and conflict avoidance. For the case of two intersecting flows, we introduce the concept of conflict touches, and a collaborative decentralized conflict resolution rule is then proposed and analyzed for two intersecting flows. The proposed rule is also able to resolved airborne conflicts that resulted from resolving another conflict via the domino effect. We study the safety conditions under the proposed conflict resolution and collision avoidance rule. Then, we use Lyapunov analysis to analytically prove the convergence of conflict resolution dynamics under the proposed rule. The analysis show that, under the proposed conflict resolution rule, the system of intersecting aircraft flows is guaranteed to converge to safe, conflict free, trajectories within a bounded time. Simulations are provided to verify the analytically derived conclusions and study the convergence of the conflict resolution dynamics at different encounter angles. Simulation results show that lateral deviations taken by aircraft in each flow, to resolve conflicts, are bounded, and aircraft converged to safe and conflict free trajectories, within a finite time.

Efficient super-resolution image reconstruction applied to surveillance video captured by small unmanned aircraft systems

NASA Astrophysics Data System (ADS)

He, Qiang; Schultz, Richard R.; Chu, Chee-Hung Henry

2008-04-01

The concept surrounding super-resolution image reconstruction is to recover a highly-resolved image from a series of low-resolution images via between-frame subpixel image registration. In this paper, we propose a novel and efficient super-resolution algorithm, and then apply it to the reconstruction of real video data captured by a small Unmanned Aircraft System (UAS). Small UAS aircraft generally have a wingspan of less than four meters, so that these vehicles and their payloads can be buffeted by even light winds, resulting in potentially unstable video. This algorithm is based on a coarse-to-fine strategy, in which a coarsely super-resolved image sequence is first built from the original video data by image registration and bi-cubic interpolation between a fixed reference frame and every additional frame. It is well known that the median filter is robust to outliers. If we calculate pixel-wise medians in the coarsely super-resolved image sequence, we can restore a refined super-resolved image. The primary advantage is that this is a noniterative algorithm, unlike traditional approaches based on highly-computational iterative algorithms. Experimental results show that our coarse-to-fine super-resolution algorithm is not only robust, but also very efficient. In comparison with five well-known super-resolution algorithms, namely the robust super-resolution algorithm, bi-cubic interpolation, projection onto convex sets (POCS), the Papoulis-Gerchberg algorithm, and the iterated back projection algorithm, our proposed algorithm gives both strong efficiency and robustness, as well as good visual performance. This is particularly useful for the application of super-resolution to UAS surveillance video, where real-time processing is highly desired.

Effect of the chest wall on the measurement of hemoglobin concentrations by near-infrared time-resolved spectroscopy in normal breast and cancer.

PubMed

Yoshizawa, Nobuko; Ueda, Yukio; Nasu, Hatsuko; Ogura, Hiroyuki; Ohmae, Etsuko; Yoshimoto, Kenji; Takehara, Yasuo; Yamashita, Yutaka; Sakahara, Harumi

2016-11-01

Optical imaging and spectroscopy using near-infrared light have great potential in the assessment of tumor vasculature. We previously measured hemoglobin concentrations in breast cancer using a near-infrared time-resolved spectroscopy system. The purpose of the present study was to evaluate the effect of the chest wall on the measurement of hemoglobin concentrations in normal breast tissue and cancer. We measured total hemoglobin (tHb) concentration in both cancer and contralateral normal breast using a near-infrared time-resolved spectroscopy system in 24 female patients with breast cancer. Patients were divided into two groups based on menopausal state. The skin-to-chest wall distance was determined using ultrasound images obtained with an ultrasound probe attached to the spectroscopy probe. The apparent tHb concentration of normal breast increased when the skin-to-chest wall distance was less than 20 mm. The tHb concentration in pre-menopausal patients was higher than that in post-menopausal patients. Although the concentration of tHb in cancer tissue was statistically higher than that in normal breast, the contralateral normal breast showed higher tHb concentration than cancer in 9 of 46 datasets. When the curves of tHb concentrations as a function of the skin-to-chest wall distance in normal breast were applied for pre- and post-menopausal patients separately, all the cancer lesions plotted above the curves. The skin-to-chest wall distance affected the measurement of tHb concentration of breast tissue by near-infrared time-resolved spectroscopy. The tHb concentration of breast cancer tissue was more precisely evaluated by considering the skin-to-chest wall distance.

Time, Dynamics and Chaos: Integrating Poincare's 'Non-Integrable Systems'

DOE R&D Accomplishments Database

Prigogine, I.

1990-10-01

This report discusses the nature of time. The author attempts to resolve the conflict between the concept of time reversibility in classical and quantum mechanics with the macroscopic world's irreversibility of time. (LSP)

Adaptive Photothermal Emission Analysis Techniques for Robust Thermal Property Measurements of Thermal Barrier Coatings

NASA Astrophysics Data System (ADS)

Valdes, Raymond

The characterization of thermal barrier coating (TBC) systems is increasingly important because they enable gas turbine engines to operate at high temperatures and efficiency. Phase of photothermal emission analysis (PopTea) has been developed to analyze the thermal behavior of the ceramic top-coat of TBCs, as a nondestructive and noncontact method for measuring thermal diffusivity and thermal conductivity. Most TBC allocations are on actively-cooled high temperature turbine blades, which makes it difficult to precisely model heat transfer in the metallic subsystem. This reduces the ability of rote thermal modeling to reflect the actual physical conditions of the system and can lead to higher uncertainty in measured thermal properties. This dissertation investigates fundamental issues underpinning robust thermal property measurements that are adaptive to non-specific, complex, and evolving system characteristics using the PopTea method. A generic and adaptive subsystem PopTea thermal model was developed to account for complex geometry beyond a well-defined coating and substrate system. Without a priori knowledge of the subsystem characteristics, two different measurement techniques were implemented using the subsystem model. In the first technique, the properties of the subsystem were resolved as part of the PopTea parameter estimation algorithm; and, the second technique independently resolved the subsystem properties using a differential "bare" subsystem. The confidence in thermal properties measured using the generic subsystem model is similar to that from a standard PopTea measurement on a "well-defined" TBC system. Non-systematic bias-error on experimental observations in PopTea measurements due to generic thermal model discrepancies was also mitigated using a regression-based sensitivity analysis. The sensitivity analysis reported measurement uncertainty and was developed into a data reduction method to filter out these "erroneous" observations. It was found that the adverse impact of bias-error can be greatly reduced, leaving measurement observations with only random Gaussian noise in PopTea thermal property measurements. Quantifying the influence of the coating-substrate interface in PopTea measurements is important to resolving the thermal conductivity of the coating. However, the reduced significance of this interface in thicker coating systems can give rise to large uncertainties in thermal conductivity measurements. A first step towards improving PopTea measurements for such circumstances has been taken by implementing absolute temperature measurements using harmonically-sustained two-color pyrometry. Although promising, even small uncertainties in thermal emission observations were found to lead to significant noise in temperature measurements. However, PopTea analysis on bulk graphite samples were able to resolve its thermal conductivity to the expected literature values.

Seafloor Geodetic Monitoring of the Central Andean Subduction Zone: The Geosea Array

NASA Astrophysics Data System (ADS)

Kopp, H.; Lange, D.; Contreras Reyes, E.; Behrmann, J. H.; McGuire, J. J.; Flueh, E. R.

2014-12-01

Seafloor geodesy has been identified as one of the central tools in marine geosciences to monitor seafloor deformation at high resolution. To quantify strain accumulation and assess the resultant hazard potential we urgently need systems to resolve seafloor crustal deformation. The GeoSEA (Geodetic Earthquake Observatory on the Seafloor) array consists of a seafloor transponder network comprising a total of 35 units and a wave glider acting as a surface unit (GeoSURF) to ensure satellite correspondence, data transfer and monitor system health. For horizontal direct path measurements, the system utilizes acoustic ranging techniques with a ranging precision better than 15 mm and long term stability over 2 km distance. Vertical motion is obtained from pressure gauges. Integrated inclinometers monitor station settlement in two horizontal directions. Travel time between instruments and the local water sound velocity will be recorded autonomously subsea without system or human intervention for up to 3.5 years. Data from the autonomous network on the seafloor can be retrieved via the integrated high-speed acoustic telemetry link without recovering the seafloor units. In late 2015 GeoSEA will be installed on the Iquique segment of the South America - Nazca convergent plate boundary to monitor crustal deformation. The Iquique seismic gap experienced the 2014 Mw 8.1 Pisagua earthquake, which apparently occurred within a local locking minimum. It is thus crucial to better resolve resolve strain in the forearc between the mainland and the trench in order to improve our understanding of forearc deformation required for hazard assessment. Mobile autonomous seafloor arrays for continuous measurement of active seafloor deformation in hazard zones have the potential to lead to transformative discoveries of plate boundary/fault zone tectonic processes and address a novel element of marine geophysical research.

Advances of a Brillouin Scattering Lidar System for the Detection of Temperature Profiles in the Ocean: Laboratory Measurements and Field Test

NASA Astrophysics Data System (ADS)

Walther, T.; Rupp, D.; Friman, S.; Trees, C.; Fournier, G.

2016-02-01

Recently we have demonstrated the feasibility of remotely measuring temperature profiles in water under a laboratory environment employing our real-time Brillouin Scattering LIDAR (BSL) system. The working principle is based on the frequency and time resolved detection of the backscattered spontaneous Brillouin signal of a short light pulse fired into the ocean. The light source consists of a frequency-doubled fiber-amplified External Cavity Diode Laser (ECDL) providing high-energy, Fourier transform-limited laser pulses in the green spectral range. The Brillouin shift is detected with high accuracy (low uncertainty) by employing an edge filter based on an Excited State Faraday Anomalous Dispersion Optical Filter (ESFADOF). Time-resolution allows for the depth resolution and the frequency resolved shift is proportional to the speed of sound. Thus, the temperature profile can be extracted from the measurements. In our laboratory setup we were able to resolve water temperatures with a mean accuracy of up to 0.07 oC and a spatial resolution of 1 m depending on the amount of averaging. In order to prepare the system for a first field test under realistic conditions on the coast of the Mediterranean at CMRE in La Spezia, almost all of the components have been upgraded. This first test is planned for November 2015. We will present the above mentioned measurements, details about the upgrades and report on our experiences during this maritime field test.Ultimately, the plan is to operate the system from a mobile platform, e.g., a helicopter or vessel, in order to precisely determine the temperature of the surface mixed layer of the ocean with high spatial resolution.

Time-Resolved Records of Magnetic Activity on the Pallasite Parent Body and Psyche

NASA Astrophysics Data System (ADS)

Bryson, J. F. J.; Nichols, C. I. O.; Herrero-Albillos, J.; Kronast, F.; Kasama, T.; Alimadadi, H.; van der Laan, G.; Nimmo, F.; Harrison, R. J.

2014-12-01

Although many small bodies apparently generated dynamo fields in the early solar system, the nature and temporal evolution of these fields has remained enigmatic. Time-resolved records of the Earth's planetary field have been essential in understanding the dynamic history of our planet, and equivalent information from asteroids could provide a unique insight into the development of the solar system. Here we present time-resolved records of magnetic activity on the main-group pallasite parent body and (16) Psyche, obtained using newly-developed nanomagnetic imaging techniques. For the pallasite parent body, the inferred field direction remained relatively constant and the intensity was initially stable at ~100 μT before it decreased in two discrete steps down to 0 μT. We interpret this behaviour as due to vigorous dynamo activity driven by compositional convection in the core, ultimately transitioning from a dipolar to multipolar field as the inner core grew from the bottom-up. For Psyche (measured from IVA iron meteorites), the inferred field direction reversed, while the intensity remained stable at >50 μT. Psyche cooled rapidly as an unmantled core, although the resulting thermal convection alone cannot explain these observations. Instead, this behaviour required top-down core solidification, and is attributed either to compositional convection (if the core also solidified from the bottom-up) or convection generated directly by top-down solidification (e.g. Fe-snow). The mechanism governing convection in small body cores is an open question (due partly to uncertainties in the direction of core solidification), and these observations suggest that unconventional (i.e. not thermal) mechanisms acted in the early solar system. These mechanisms are very efficient at generating convection, implying a long-lasting and widespread epoch of dynamo activity among small bodies in the early solar system.

Analysis of geological materials containing uranium using laser-induced breakdown spectroscopy (LIBS)

NASA Astrophysics Data System (ADS)

Barefield, James E.; Judge, Elizabeth J.; Campbell, Keri R.; Colgan, James P.; Kilcrease, David P.; Johns, Heather M.; Wiens, Roger C.; McInroy, Rhonda E.; Martinez, Ronald K.; Clegg, Samuel M.

2016-06-01

Laser induced breakdown spectroscopy (LIBS) is a rapid atomic emission spectroscopy technique that can be configured for a variety of applications including space, forensics, and industry. LIBS can also be configured for stand-off distances or in-situ, under vacuum, high pressure, atmospheric or different gas environments, and with different resolving-power spectrometers. The detection of uranium in a complex geological matrix under different measurement schemes is explored in this paper. Although many investigations have been completed in an attempt to detect and quantify uranium in different matrices at in-situ and standoff distances, this work detects and quantifies uranium in a complex matrix under Martian and ambient air conditions. Investigation of uranium detection using a low resolving-power LIBS system at stand-off distances (1.6 m) is also reported. The results are compared to an in-situ LIBS system with medium resolving power and under ambient air conditions. Uranium has many thousands of emission lines in the 200-800 nm spectral region. In the presence of other matrix elements and at lower concentrations, the limit of detection of uranium is significantly reduced. The two measurement methods (low and high resolving-power spectrometers) are compared for limit of detection (LOD). Of the twenty-one potential diagnostic uranium emission lines, seven (409, 424, 434, 435, 436, 591, and 682 nm) have been used to determine the LOD for pitchblende in a dunite matrix using the ChemCam test bed LIBS system. The LOD values determined for uranium transitions in air are 409.013 nm (24,700 ppm), 424.167 nm (23,780 ppm), 434.169 nm (24,390 ppm), 435.574 nm (35,880 ppm), 436.205 nm (19,340 ppm), 591.539 nm (47,310 ppm), and 682.692 nm (18,580 ppm). The corresponding LOD values determined for uranium transitions in 7 Torr CO2 are 424.167 nm (25,760 ppm), 434.169 nm (40,800 ppm), 436.205 nm (32,050 ppm), 591.539 nm (15,340 ppm), and 682.692 nm (29,080 ppm). The LOD values determine for uranium emission lines using the medium resolving power (10,000 λ/Δλ) LIBS system for the dunite matrix in air are 409.013 nm (6120 ppm), 424.167 nm (5356 ppm), 434.169 nm (5693 ppm), 435.574 nm (6329 ppm), 436.205 nm (2142 ppm), and 682.692 nm (10,741 ppm). The corresponding LOD values determined for uranium transitions in a SiO2 matrix are 409.013 nm (272 ppm), 424.167 nm (268 ppm), 434.169 nm (402 ppm), 435.574 nm (1067 ppm), 436.205 nm (482 ppm), and 682.692 nm (720 ppm). The impact of spectral resolution, atmospheric conditions, matrix elements, and measurement distances on LOD is discussed. The measurements will assist one in selecting the proper system components based upon the application and the required analytical performance.

Ecological Status of the St. Louis River System, as Informed by Spatially Comprehensive Surveys and Comparison to Coastal Wetlands Elsewhere

EPA Science Inventory

Extensive data on biota and the physical/chemical environment were collected across the lower St. Louis River in 2004-2007 as part of multiple studies undertaken by EPA. The 2005-2007 work provides a spatially highly-resolved assessment of conditions across the system, while the ...

Gaps and Barriers in Services for Children in State Mental Health Plans

ERIC Educational Resources Information Center

Gould, Sara R.; Beals-Erickson, Sarah E.; Roberts, Michael C.

2012-01-01

Significant gaps exist in children's mental healthcare, and barriers prevent access to existing services. Current federal initiatives call for state governmental agencies to recognize and resolve deficits in their systems of care. Previous work has acknowledged some of the problems in meeting the mental health needs of children within a system of…

Conceptualizing Personality as a Cognitive-Affective Processing System: A Framework for Models of Maladaptive Behavior Patterns and Change

ERIC Educational Resources Information Center

Shoda, Yuichi; Smith, Ronald E.

2004-01-01

This article outlines a conceptualization of personality as a cognitive-affective processing system (CAPS) and explores its implications for understanding disorders and pursuing therapeutic change. The CAPS conception of personality was proposed in 1995 in order to resolve a long-standing paradox in personality and social psychology, namely, the…

Resolving drivers of variability in estuarine metabolism from sustained observations of water quality in the SE US

EPA Science Inventory

We examine trends in water quality in long-term monitoring (10-15 y) data collected at 5 estuarine systems of NOAA’s National Estuarine Research Reserve System: Grand Bay, MS; Weeks Bay, AL; Apalachicola Bay, FL; Rookery Bay, FL, and Guana Tolomatos and Matanzas Rivers, FL. These...

Development of a visible-light-sensitized europium complex for time-resolved fluorometric application.

PubMed

Jiang, Lina; Wu, Jing; Wang, Guilan; Ye, Zhiqiang; Zhang, Wenzhu; Jin, Dayong; Yuan, Jingli; Piper, James

2010-03-15

The time-resolved luminescence bioassay technique using luminescent lanthanide complexes as labels is a highly sensitive and widely used bioassay method for clinical diagnostics and biotechnology. A major drawback of the current technique is that the luminescent lanthanide labels require UV excitation (typically less than 360 nm), which can damage living biological systems and is holding back further development of time-resolved luminescence instruments. Herein we describe two approaches for preparing a visible-light-sensitized Eu(3+) complex in aqueous media for time-resolved fluorometric applications: a dissociation enhancement aqueous solution that can be excited by visible light for ethylenediaminetetraacetate (EDTA)-Eu(3+) detection and a visible-light-sensitized water-soluble Eu(3+) complex conjugated bovine serum albumin (BSA) for biolabeling and time-resolved luminescence bioimaging. In the first approach, a weakly acidic aqueous solution consisting of 4,4'-bis(1'',1'',1'',2'',2'',3'',3''-heptafluoro-4'',6''-hexanedion-6''-yl)-o-terphenyl (BHHT), 2-(N,N-diethylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3,5-triazine (DPBT), and Triton X-100 was prepared. This solution shows a strong luminescence enhancement effect for EDTA-Eu(3+) with a wide excitation wavelength range from UV to visible light (a maximum at 387 nm) and a long luminescence lifetime (520 micros), to provide a novel dissociation enhancement solution for time-resolved luminescence detection of EDTA-Eu(3+). In the second approach, a ternary Eu(3+) complex, 4,4'-bis(1'',1'',1'',2'',2'',3'',3''-heptafluoro-4'',6''-hexanedion-6''-yl)-chlorosulfo-o-terphenyl (BHHCT)-Eu(3+)-DPBT, was covalently bound to BSA to form a water-soluble BSA-BHHCT-Eu(3+)-DPBT conjugate. This biocompatible conjugate is of the visible-light excitable feature in aqueous media with a wide excitation wavelength range from UV to visible light (a maximum at 387 nm), a long luminescence lifetime (460 micros), and a higher quantum yield (27%). The conjugate was successfully used for streptavidin (SA) labeling and time-resolved luminescence imaging detection of three environmental pathogens, Giardia lamblia , Cryptosporidium muris , and Cryptosporidium parvum , in water samples. Our strategy gives a general idea for designing a visible-light-sensitized Eu(3+) complex for time-resolved luminescence bioassay applications.

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

Owens, J.J.; Nejedlik, J.F.; Vogt, J.W.

The SNAP II system consists of a reactor heat source, a mercury Rankine engine, and an alternator. The problems involved in selecting materials for the SNAP II mercury system were studied. A discussion is given of the corrosion mechanisms involved in a system in which mercury is the working fluid. The problem resolves itself into selecting materials with the best combination of engineering properties for the application and highest resistance to mercury corrosion at the anticipated temperature. (auth)

Laser-induced fluorescence imaging of subsurface tissue structures with a volume holographic spatial-spectral imaging system.

PubMed

Luo, Yuan; Gelsinger-Austin, Paul J; Watson, Jonathan M; Barbastathis, George; Barton, Jennifer K; Kostuk, Raymond K

2008-09-15

A three-dimensional imaging system incorporating multiplexed holographic gratings to visualize fluorescence tissue structures is presented. Holographic gratings formed in volume recording materials such as a phenanthrenquinone poly(methyl methacrylate) photopolymer have narrowband angular and spectral transmittance filtering properties that enable obtaining spatial-spectral information within an object. We demonstrate this imaging system's ability to obtain multiple depth-resolved fluorescence images simultaneously.

Unmanned Aerial Systems: Air Force and Army Should Improve Strategic Human Capital Planning for Pilot Workforces

DTIC Science & Technology

2017-01-01

UNMANNED AERIAL SYSTEMS Air Force and Army Should Improve Strategic Human Capital Planning for Pilot Workforces...Should Improve Strategic Human Capital Planning for Pilot Workforces What GAO Found The Air Force and the Army have not fully applied four of the five...key principles for effective strategic human capital planning for managing pilots of unmanned aerial systems (UAS) that are important for resolving

MSTAR: an absolute metrology sensor with sub-micron accuracy for space-based applications

NASA Technical Reports Server (NTRS)

Peters, Robert D.; Lay, Oliver P.; Dubovitsky, Serge; Burger, Johan P.; Jeganathan, Muthu

2004-01-01

The MSTAR sensor is a new system for measuring absolute distance, capable of resolving the integer cycle ambiguity of standard interferometers, and making it possible to measure distance with subnanometer accuracy.

Arbitration Is Good for You and Teachers, So Learn to Do It Right.

ERIC Educational Resources Information Center

Singer, David, Jr.

1986-01-01

Arbitration is an effective way to resolve disagreements between school systems and their employee unions. A practicing arbitrator offers some suggestions that encourage the best use of the arbitration process. (MLF)

Single-frequency 3D synthetic aperture imaging with dynamic metasurface antennas.

PubMed

Boyarsky, Michael; Sleasman, Timothy; Pulido-Mancera, Laura; Diebold, Aaron V; Imani, Mohammadreza F; Smith, David R

2018-05-20

Through aperture synthesis, an electrically small antenna can be used to form a high-resolution imaging system capable of reconstructing three-dimensional (3D) scenes. However, the large spectral bandwidth typically required in synthetic aperture radar systems to resolve objects in range often requires costly and complex RF components. We present here an alternative approach based on a hybrid imaging system that combines a dynamically reconfigurable aperture with synthetic aperture techniques, demonstrating the capability to resolve objects in three dimensions (3D), with measurements taken at a single frequency. At the core of our imaging system are two metasurface apertures, both of which consist of a linear array of metamaterial irises that couple to a common waveguide feed. Each metamaterial iris has integrated within it a diode that can be biased so as to switch the element on (radiating) or off (non-radiating), such that the metasurface antenna can produce distinct radiation profiles corresponding to different on/off patterns of the metamaterial element array. The electrically large size of the metasurface apertures enables resolution in range and one cross-range dimension, while aperture synthesis provides resolution in the other cross-range dimension. The demonstrated imaging capabilities of this system represent a step forward in the development of low-cost, high-performance 3D microwave imaging systems.

Toward GEOS-6, A Global Cloud System Resolving Atmospheric Model

NASA Technical Reports Server (NTRS)

Putman, William M.

2010-01-01

NASA is committed to observing and understanding the weather and climate of our home planet through the use of multi-scale modeling systems and space-based observations. Global climate models have evolved to take advantage of the influx of multi- and many-core computing technologies and the availability of large clusters of multi-core microprocessors. GEOS-6 is a next-generation cloud system resolving atmospheric model that will place NASA at the forefront of scientific exploration of our atmosphere and climate. Model simulations with GEOS-6 will produce a realistic representation of our atmosphere on the scale of typical satellite observations, bringing a visual comprehension of model results to a new level among the climate enthusiasts. In preparation for GEOS-6, the agency's flagship Earth System Modeling Framework [JDl] has been enhanced to support cutting-edge high-resolution global climate and weather simulations. Improvements include a cubed-sphere grid that exposes parallelism; a non-hydrostatic finite volume dynamical core, and algorithm designed for co-processor technologies, among others. GEOS-6 represents a fundamental advancement in the capability of global Earth system models. The ability to directly compare global simulations at the resolution of spaceborne satellite images will lead to algorithm improvements and better utilization of space-based observations within the GOES data assimilation system

Phototaxis and the origin of visual eyes

PubMed Central

Randel, Nadine

2016-01-01

Vision allows animals to detect spatial differences in environmental light levels. High-resolution image-forming eyes evolved from low-resolution eyes via increases in photoreceptor cell number, improvements in optics and changes in the neural circuits that process spatially resolved photoreceptor input. However, the evolutionary origins of the first low-resolution visual systems have been unclear. We propose that the lowest resolving (two-pixel) visual systems could initially have functioned in visual phototaxis. During visual phototaxis, such elementary visual systems compare light on either side of the body to regulate phototactic turns. Another, even simpler and non-visual strategy is characteristic of helical phototaxis, mediated by sensory–motor eyespots. The recent mapping of the complete neural circuitry (connectome) of an elementary visual system in the larva of the annelid Platynereis dumerilii sheds new light on the possible paths from non-visual to visual phototaxis and to image-forming vision. We outline an evolutionary scenario focusing on the neuronal circuitry to account for these transitions. We also present a comprehensive review of the structure of phototactic eyes in invertebrate larvae and assign them to the non-visual and visual categories. We propose that non-visual systems may have preceded visual phototactic systems in evolution that in turn may have repeatedly served as intermediates during the evolution of image-forming eyes. PMID:26598725

Time-resolved fluorescence study of exciplex formation in diastereomeric naproxen-pyrrolidine dyads.

PubMed

Khramtsova, Ekaterina A; Plyusnin, Viktor F; Magin, Ilya M; Kruppa, Alexander I; Polyakov, Nikolay E; Leshina, Tatyana V; Nuin, Edurne; Marin, M Luisa; Miranda, Miguel A

2013-12-19

The influence of chirality on the elementary processes triggered by excitation of the (S,S)- and (R,S)- diastereoisomers of naproxen-pyrrolidine (NPX-Pyr) dyads has been studied by time-resolved fluorescence in acetonitrile-benzene mixtures. In these systems, the quenching of the (1)NPX*-Pyr singlet excited state occurs through electron transfer and exciplex formation. Fluorescence lifetimes and quantum yields revealed a significant difference (around 20%) between the (S,S)- and (R,S)- diastereomers. In addition, the quantum yields of exciplexes differed by a factor of 2 regardless of solvent polarity. This allows us to suggest a similar influence of the chiral centers on the local charge transfer resulting in exciplex and full charge separation that leads to ion-biradicals. A simplified scheme is proposed to estimate a set of rate constant values (k1-k5) for the elementary stages in each solvent system.

Time-resolved IUE studies of cataclysmic variables. I - Eclipsing systems IP Peg, PG 1030+590, and V1315 Aql

NASA Technical Reports Server (NTRS)

Szkody, Paula

1987-01-01

IUE time-resolved spectra of the high-inclination cataclysmic variables IP Peg, PG 1030+590, and V1315 Aql are analyzed in order to determine the characteristics of the disk, hotspots, and white dwarfs. The UV continuum flux distributions are generally flatter than systems of low inclination and high mass-transfer rate, and the white dwarfs/inner disk appear to be relatively cool (15,000-19,000 K) for their orbital periods, possibly because the boundary layers are blocked from view. The continuum fluxes increase at spot phases, with the spot providing the dominant flux in IP Peg. The spot temperatures range from hot (20,000 K) in IP Peg, and perhaps in PG 1030+590, to cool (11,000 K) in V1315 Aql. The C IV emission lines show slightly larger decreases at spot phases than during eclipse, which implies an extended stream area.

Quantifying electronic band interactions in van der Waals materials using angle-resolved reflected-electron spectroscopy.

PubMed

Jobst, Johannes; van der Torren, Alexander J H; Krasovskii, Eugene E; Balgley, Jesse; Dean, Cory R; Tromp, Rudolf M; van der Molen, Sense Jan

2016-11-29

High electron mobility is one of graphene's key properties, exploited for applications and fundamental research alike. Highest mobility values are found in heterostructures of graphene and hexagonal boron nitride, which consequently are widely used. However, surprisingly little is known about the interaction between the electronic states of these layered systems. Rather pragmatically, it is assumed that these do not couple significantly. Here we study the unoccupied band structure of graphite, boron nitride and their heterostructures using angle-resolved reflected-electron spectroscopy. We demonstrate that graphene and boron nitride bands do not interact over a wide energy range, despite their very similar dispersions. The method we use can be generally applied to study interactions in van der Waals systems, that is, artificial stacks of layered materials. With this we can quantitatively understand the 'chemistry of layers' by which novel materials are created via electronic coupling between the layers they are composed of.

Characterisation of a cryostat using simultaneous, single-beam multiple-surface laser vibrometry

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

Kissinger, Thomas; Charrett, Thomas O. H.; James, Stephen W.

2016-06-28

A novel range-resolved interferometric signal processing technique that uses sinusoidal optical frequency modulation is applied to multi-surface vibrometry, demonstrating simultaneous optical measurements of vibrations on two surfaces using a single, collimated laser beam, with a minimum permissible distance of 3.5 cm between surfaces. The current system, using a cost-effective laser diode and a fibre-coupled, downlead insensitive setup, allows an interferometric fringe rate of up to 180 kHz to be resolved with typical displacement noise levels of 8 pm · Hz{sup −05}. In this paper, the system is applied to vibrometry measurements of a table-top cryostat, with concurrent measurements of the optical widowmore » and the sample holder target inside. This allows the separation of common-mode vibrations of the whole cryostat from differential vibrations between the window and the target, allowing any resonances to be identified.« less

Systemic lupus erythematosus with organic brain syndrome: serial electroencephalograms accurately evaluate therapeutic efficacy.

PubMed

Kato, Takashi; Shiratori, Kyoji; Kobashigawa, Tsuyoshi; Hidaka, Yuji

2006-01-01

A 48-year-old man with systemic lupus erythematosus developed organic brain syndrome. High-dose prednisolone was ineffective, and somnolence without focal signs rapidly developed. Electroencephalogram (EEG) demonstrated a slow basic rhythm (3 Hz), but brain magnetic resonance imaging was normal. Somnolence resolved soon after performing plasma exchange (two sessions). However, memory dysfunction persisted, with EEG demonstrating mild abnormalities (7-8 Hz basic rhythm). Double-filtration plasmapheresis (three sessions) was done, followed by intravenous cyclophosphamide. Immediately after the first plasmapheresis session, memory dysfunction began to improve. After the second dose of cyclophosphamide, intellectual function resolved completely and EEG findings also normalized (basic rhythm of 10 Hz waves). Serial EEG findings precisely reflected the neurological condition and therapeutic efficacy in this patient. In contrast, protein levels in cerebrospinal fluid remained high and did not seem to appropriately reflect the neurological condition in this patient.

Autonomous Operations Planner: A Flexible Platform for Research in Flight-Deck Support for Airborne Self-Separation

NASA Technical Reports Server (NTRS)

Karr, David A.; Vivona, Robert A.; DePascale, Stephen M.; Wing, David J.

2012-01-01

The Autonomous Operations Planner (AOP), developed by NASA, is a flexible and powerful prototype of a flight-deck automation system to support self-separation of aircraft. The AOP incorporates a variety of algorithms to detect and resolve conflicts between the trajectories of its own aircraft and traffic aircraft while meeting route constraints such as required times of arrival and avoiding airspace hazards such as convective weather and restricted airspace. This integrated suite of algorithms provides flight crew support for strategic and tactical conflict resolutions and conflict-free trajectory planning while en route. The AOP has supported an extensive set of experiments covering various conditions and variations on the self-separation concept, yielding insight into the system s design and resolving various challenges encountered in the exploration of the concept. The design of the AOP will enable it to continue to evolve and support experimentation as the self-separation concept is refined.

Calcium neuroimaging in behaving zebrafish larvae using a turn-key light field camera

NASA Astrophysics Data System (ADS)

Cruz Perez, Carlos; Lauri, Antonella; Symvoulidis, Panagiotis; Cappetta, Michele; Erdmann, Arne; Westmeyer, Gil Gregor

2015-09-01

Reconstructing a three-dimensional scene from multiple simultaneously acquired perspectives (the light field) is an elegant scanless imaging concept that can exceed the temporal resolution of currently available scanning-based imaging methods for capturing fast cellular processes. We tested the performance of commercially available light field cameras on a fluorescent microscopy setup for monitoring calcium activity in the brain of awake and behaving reporter zebrafish larvae. The plenoptic imaging system could volumetrically resolve diverse neuronal response profiles throughout the zebrafish brain upon stimulation with an aversive odorant. Behavioral responses of the reporter fish could be captured simultaneously together with depth-resolved neuronal activity. Overall, our assessment showed that with some optimizations for fluorescence microscopy applications, commercial light field cameras have the potential of becoming an attractive alternative to custom-built systems to accelerate molecular imaging research on cellular dynamics.

Calcium neuroimaging in behaving zebrafish larvae using a turn-key light field camera.

PubMed

Perez, Carlos Cruz; Lauri, Antonella; Symvoulidis, Panagiotis; Cappetta, Michele; Erdmann, Arne; Westmeyer, Gil Gregor

2015-09-01

Reconstructing a three-dimensional scene from multiple simultaneously acquired perspectives (the light field) is an elegant scanless imaging concept that can exceed the temporal resolution of currently available scanning-based imaging methods for capturing fast cellular processes. We tested the performance of commercially available light field cameras on a fluorescent microscopy setup for monitoring calcium activity in the brain of awake and behaving reporter zebrafish larvae. The plenoptic imaging system could volumetrically resolve diverse neuronal response profiles throughout the zebrafish brain upon stimulation with an aversive odorant. Behavioral responses of the reporter fish could be captured simultaneously together with depth-resolved neuronal activity. Overall, our assessment showed that with some optimizations for fluorescence microscopy applications, commercial light field cameras have the potential of becoming an attractive alternative to custom-built systems to accelerate molecular imaging research on cellular dynamics.

Theory of tunneling spectroscopy for chiral topological superconductors

NASA Astrophysics Data System (ADS)

Ii, Akihiro; Yamakage, Ai; Yada, Keiji; Sato, Masatoshi; Tanaka, Yukio

2012-11-01

We study the charge conductance of an interface between a normal metal and a superconducting quantum anomalous Hall system, based on the recursive Green's function. The angle-resolved conductance γ(ky,eV) with momentum ky parallel to the interface and bias voltage V shows a rich structure depending on the Chern number N of the system. We find that when the bias voltage is tuned to the energy dispersion of the edge mode, eV=Eedge(ky), the angle-resolved conductance γ(ky,Eedge(ky)) shows a pronounced even-odd effect; the conductance vanishes for N=0 or 2, while it takes the universal value 2e2/h for N=1. In particular, in the N=2 phase, we find that the conductance γ(ky,Eedge(ky)) becomes 0 due to the interference of two degenerate Majorana edge modes, although the corresponding surface spectral weight remains nonzero.

Precipitation Processes developed during ARM (1997), TOGA COARE (1992), GATE (1974), SCSMEX (1998), and KWAJEX (1999), Consistent 2D, semi-3D and 3D Cloud Resolving Model Simulations

NASA Technical Reports Server (NTRS)

Tao, Wei-Kuo; Hou, A.; Atlas, R.; Starr, D.; Sud, Y.

2003-01-01

Real clouds and cloud systems are inherently three-dimensional (3D). Because of the limitations in computer resources, however, most cloud-resolving models (CRMs) today are still two-dimensional (2D). A few 3D CRMs have been used to study the response of clouds to large-scale forcing. In these 3D simulations, the model domain was small, and the integration time was 6 hours. The major objectives of this paper are: (1) to assess the performance of the super-parameterization technique (i.e. is 2D or semi-3D CRM appropriate for the super-parameterization?); (2) calculate and examine the surface energy (especially radiation) and water budgets; (3) identify the differences and similarities in the organization and entrainment rates of convection between simulated 2D and 3D cloud systems.

Protection from Induced Space Environments Effects on the International Space Station

NASA Technical Reports Server (NTRS)

Soares, Carlos; Mikatarian, Ron; Stegall, Courtney; Schmidl, Danny; Huang, Alvin; Olsen, Randy; Koontz, Steven

2010-01-01

The International Space Station (ISS) is one of the largest, most complex multinational scientific projects in history and protection from induced space environments effects is critical to its long duration mission as well as to the health of the vehicle and safety of on-orbit operations. This paper discusses some of the unique challenges that were encountered during the design, assembly and operation of the ISS and how they were resolved. Examples are provided to illustrate the issues and the risk mitigation strategies that were developed to resolve these issues. Of particular importance are issues related with the interaction of multiple spacecraft as in the case of ISS and Visiting Vehicles transporting crew, hardware elements, cargo and scientific payloads. These strategies are applicable to the development of future long duration space systems, not only during design, but also during assembly and operation of these systems.

Revealing of photon-number splitting attack on quantum key distribution system by photon-number resolving devices

NASA Astrophysics Data System (ADS)

Gaidash, A. A.; Egorov, V. I.; Gleim, A. V.

2016-08-01

Quantum cryptography allows distributing secure keys between two users so that any performed eavesdropping attempt would be immediately discovered. However, in practice an eavesdropper can obtain key information from multi-photon states when attenuated laser radiation is used as a source of quantum states. In order to prevent actions of an eavesdropper, it is generally suggested to implement special cryptographic protocols, like decoy states or SARG04. In this paper, we describe an alternative method based on monitoring photon number statistics after detection. We provide a useful rule of thumb to estimate approximate order of difference of expected distribution and distribution in case of attack. Formula for calculating a minimum value of total pulses or time-gaps to resolve attack is shown. Also formulas for actual fraction of raw key known to Eve were derived. This method can therefore be used with any system and even combining with mentioned special protocols.

Spatially resolved penetration depth measurements and vortex manipulation in the ferromagnetic superconductor ErNi 2 B 2 C

DOE PAGES

Wulferding, Dirk; Yang, Ilkyu; Yang, Jinho; ...

2015-07-31

We present a local probe study of the magnetic superconductor ErNi 2B 2C, using magnetic force microscopy at sub-Kelvin temperatures. ErNi 2B 2C is an ideal system to explore the effects of concomitant superconductivity and ferromagnetism. At 500 mK, far below the transition to a weakly ferromagnetic state, we directly observe a structured magnetic background on the micrometer scale. We determine spatially resolved absolute values of the magnetic penetration depth λ and study its temperature dependence as the system undergoes magnetic phase transitions from paramagnetic to antiferromagnetic, and to weak ferromagnetic, all within the superconducting regime. We estimate the absolutemore » pinning force of Abrikosov vortices, which shows a position dependence and temperature dependence as well, and discuss the possibility of the purported spontaneous vortex formation.« less

Sub-10 fs Time-Resolved Vibronic Optical Microscopy

PubMed Central

2016-01-01

We introduce femtosecond wide-field transient absorption microscopy combining sub-10 fs pump and probe pulses covering the complete visible (500–650 nm) and near-infrared (650–950 nm) spectrum with diffraction-limited optical resolution. We demonstrate the capabilities of our system by reporting the spatially- and spectrally-resolved transient electronic response of MAPbI3–xClx perovskite films and reveal significant quenching of the transient bleach signal at grain boundaries. The unprecedented temporal resolution enables us to directly observe the formation of band-gap renormalization, completed in 25 fs after photoexcitation. In addition, we acquire hyperspectral Raman maps of TIPS pentacene films with sub-400 nm spatial and sub-15 cm–1 spectral resolution covering the 100–2000 cm–1 window. Our approach opens up the possibility of studying ultrafast dynamics on nanometer length and femtosecond time scales in a variety of two-dimensional and nanoscopic systems. PMID:27934055

Electronic and Vibrational Coherence in Charge-Transfer Reactions

NASA Astrophysics Data System (ADS)

Scherer, Norbert

1996-03-01

The ultrafast dynamics associated with optically-induced intervalence charge-transfer reactions in solution and protein environments are reported. These studies include the Fe^(II)-Fe^(III) MMCT complex Prussian blue and the mixed valence dimer (CN)_5Ru^(II)CNRuRu^(III)(NH_3)_5. The protein systems include blue copper proteins and the bacterial photosynthetic reaction center. The experimental approaches include photon echo, wavelength-resolved pump-probe and anisotropy measurements performed with 12-16fs duration optical pulses. Complicated time-domain waveforms reflect the several different p[rocesses and time scales for relaxation of coherences (both electronic and vibrational) and populations within these systems. The photon echo and anisotropy results probe electronic coherence and dephasing prior to back electron transfer. Wavelength-resolved pump-probe results reveal vibrational modes coupled to the CT-coordinate as well as formation of new product states or vibrational cooling in the ground state following back electron transfer.

Vibrational frequencies and dephasing times in excited electronic states by femtosecond time-resolved four-wave mixing

NASA Astrophysics Data System (ADS)

Joo, Taiha; Albrecht, A. C.

1993-06-01

Time-resolved degenerate four-wave mixing (TRDFWM) for an electronically resonant system in a phase-matching configuration that measures population decay is reported. Because the spectral width of input light exceeds the vibrational Bohr frequency of a strong Raman active mode, the vibrational coherence produces strong oscillations in the TRDFWM signal together with the usual population decay from the excited electronic state. The data are analyzed in terms of a four-level system: ground and excited electronic states each split by a vibrational quantum of a Raman active mode. Absolute frequencies and their dephasing times of the vibrational modes at ≈590 cm -1 are obtained for the excited as well as the ground electronic state. The vibrational dephasing rate in the excited electronic state is about an order of magnitude faster than that in the ground state, the origin of which is speculated upon.

VLTI and KI Interferometric Observations of Massive Evolved Stars and Their Dusty Circumstellar Environments

NASA Astrophysics Data System (ADS)

Wallace, Debra J.; Danchi, W. C.; Rajagopal, J.; Chesneau, O.; Lopez, B.; Menut, J.; Monnier, J.; Tuthill, P.; Ireland, M.; Barry, R.; Richardson, L. J.

2007-12-01

Recent aperture-masking and interferometric observations of late-type WC Wolf-Rayet stars strongly support the theory that dust formation in these objects is a result of colliding winds in binary systems. To explore and quantify this possible explanation, we have conducted a high-resolution interferometric survey of late-type massive stars utilizing the VLTI, KI, IOTA, and FGS1r interferometers. We present here the motivation for this study. We also present the first results from the MIDI instrument on the VLTI, and the KI and IOTA observations. Our VLTI study is aimed primarily at resolving and characterizing the dust around the WC9 star WR 85a and the LBV WR 122, both dust-producing but at different phases of massive star evolution. Our IOTA and KI interferometric observations resolve the WR star WR 137 into a dust-producing binary system.

A versatile and reconfigurable setup for all-terahertz time-resolved pump-probe spectroscopy.

PubMed

Elezzabi, A Y; Maraghechi, P

2012-05-01

A versatile optical setup for all-terahertz (THz) time resolved pump-probe spectroscopy was designed and tested. By utilizing a dual THz pulse generator emitter module, independent and synchronized THz radiation pump and probe pulses were produced, thus eliminating the need for THz beam splitters and the limitations associated with their implementation. The current THz setup allows for precise control of the electric fields splitting ratio between the THz radiation pump and probe pulses, as well as in-phase, out-of-phase, and polarization dependent pump-probe spectroscopy. Since the present THz pump-probe setup does not require specialized THz radiation optical components, such as phase shifters, polarization rotators, or wide bandwidth beam splitters, it can be easily implemented with minimal alterations to a conventional THz time domain spectroscopy system. The present setup is valuable for studying the time dynamics of THz coherent phenomena in solid-state, chemical, and biological systems.

A methodology to enhance electromagnetic compatibility in joint military operations

NASA Astrophysics Data System (ADS)

Buckellew, William R.

The development and validation of an improved methodology to identify, characterize, and prioritize potential joint EMI (electromagnetic interference) interactions and identify and develop solutions to reduce the effects of the interference are discussed. The methodology identifies potential EMI problems using results from field operations, historical data bases, and analytical modeling. Operational expertise, engineering analysis, and testing are used to characterize and prioritize the potential EMI problems. Results can be used to resolve potential EMI during the development and acquisition of new systems and to develop engineering fixes and operational workarounds for systems already employed. The analytic modeling portion of the methodology is a predictive process that uses progressive refinement of the analysis and the operational electronic environment to eliminate noninterfering equipment pairs, defer further analysis on pairs lacking operational significance, and resolve the remaining EMI problems. Tests are conducted on equipment pairs to ensure that the analytical models provide a realistic description of the predicted interference.

Time-resolved optical spectroscopic quantification of red blood cell damage caused by cardiovascular devices

NASA Astrophysics Data System (ADS)

Sakota, D.; Sakamoto, R.; Sobajima, H.; Yokoyama, N.; Yokoyama, Y.; Waguri, S.; Ohuchi, K.; Takatani, S.

2008-02-01

Cardiovascular devices such as heart-lung machine generate un-physiological level of shear stress to damage red blood cells, leading to hemolysis. The diagnostic techniques of cell damages, however, have not yet been established. In this study, the time-resolved optical spectroscopy was applied to quantify red blood cell (RBC) damages caused by the extracorporeal circulation system. Experimentally, the fresh porcine blood was subjected to varying degrees of shear stress in the rotary blood pump, followed with measurement of the time-resolved transmission characteristics using the pico-second pulses at 651 nm. The propagated optical energy through the blood specimen was detected using a streak camera. The data were analyzed in terms of the mean cell volume (MCV) and mean cell hemoglobin concentration (MCHC) measured separately versus the energy and propagation time of the light pulses. The results showed that as the circulation time increased, the MCV increased with decrease in MCHC. It was speculated that the older RBCs with smaller size and fragile membrane properties had been selectively destroyed by the shear stress. The time-resolved optical spectroscopy is a useful technique in quantifying the RBCs' damages by measuring the energy and propagation time of the ultra-short light pulses through the blood.

Bypassing the energy-time uncertainty in time-resolved photoemission

NASA Astrophysics Data System (ADS)

Randi, Francesco; Fausti, Daniele; Eckstein, Martin

2017-03-01

The energy-time uncertainty is an intrinsic limit for time-resolved experiments imposing a tradeoff between the duration of the light pulses used in experiments and their frequency content. In standard time-resolved photoemission, this limitation maps directly onto a tradeoff between the time resolution of the experiment and the energy resolution that can be achieved on the electronic spectral function. Here we propose a protocol to disentangle the energy and time resolutions in photoemission. We demonstrate that dynamical information on all time scales can be retrieved from time-resolved photoemission experiments using suitably shaped light pulses of quantum or classical nature. As a paradigmatic example, we study the dynamical buildup of the Kondo peak, a narrow feature in the electronic response function arising from the screening of a magnetic impurity by the conduction electrons. After a quench, the electronic screening builds up on timescales shorter than the inverse width of the Kondo peak and we demonstrate that the proposed experimental scheme could be used to measure the intrinsic time scales of such electronic screening. The proposed approach provides an experimental framework to access the nonequilibrium response of collective electronic properties beyond the spectral uncertainty limit and will enable the direct measurement of phenomena such as excited Higgs modes and, possibly, the retarded interactions in superconducting systems.

First Optical observation of a microquasar at sub-milliarsec scale: SS 433 resolved by VLTI/GRAVITY

NASA Astrophysics Data System (ADS)

Petrucci, P.; Waisberg, I.; Lebouquin, J.; Dexter, J.; Dubus, G.; Perraut, K.; Kervella, P.; Gravity Collaboration

2017-10-01

We present the first Optical observation at sub-milliarcsec (mas) scale of the famous microquasar SS 433 obtained with the GRAVITY instrument on the VLTI interferometer. This observation reveals the SS 433 inner regions with unprecedent details: The K-band continuum emitting region is dominated by a marginally resolved point source (< 1 mas) embedded inside a diffuse background accounting for 10% of the total flux. The significant visibility drop across the jet lines present in the K-band spectrum, together with the small and nearly identical phases for all baselines, point toward a jet that is offset by < 0.5 mas from the continuum source and resolved in the direction of propagation, with a size of ˜2 mas. Jet emission so close to the central binary system implies that line locking, if relevant to explain the 0.26c jet velocity, operates on elements heavier than hydrogen. Concerning The Brγ line, it is better resolved than the continuum and the S-shape phase signal present across the line suggests an East-West oriented geometry alike the jet direction and supporting a (polar) disk wind origin. This observation show the potentiality of Optical interferometry to constrain the inner regions of high energy sources like microquasars.

Real-time eye motion correction in phase-resolved OCT angiography with tracking SLO

PubMed Central

Braaf, Boy; Vienola, Kari V.; Sheehy, Christy K.; Yang, Qiang; Vermeer, Koenraad A.; Tiruveedhula, Pavan; Arathorn, David W.; Roorda, Austin; de Boer, Johannes F.

2012-01-01

In phase-resolved OCT angiography blood flow is detected from phase changes in between A-scans that are obtained from the same location. In ophthalmology, this technique is vulnerable to eye motion. We address this problem by combining inter-B-scan phase-resolved OCT angiography with real-time eye tracking. A tracking scanning laser ophthalmoscope (TSLO) at 840 nm provided eye tracking functionality and was combined with a phase-stabilized optical frequency domain imaging (OFDI) system at 1040 nm. Real-time eye tracking corrected eye drift and prevented discontinuity artifacts from (micro)saccadic eye motion in OCT angiograms. This improved the OCT spot stability on the retina and consequently reduced the phase-noise, thereby enabling the detection of slower blood flows by extending the inter-B-scan time interval. In addition, eye tracking enabled the easy compounding of multiple data sets from the fovea of a healthy volunteer to create high-quality eye motion artifact-free angiograms. High-quality images are presented of two distinct layers of vasculature in the retina and the dense vasculature of the choroid. Additionally we present, for the first time, a phase-resolved OCT angiogram of the mesh-like network of the choriocapillaris containing typical pore openings. PMID:23304647

Time-Resolved Optical Measurements of Fuel-Air Mixedness in Windowless High Speed Research Combustors

NASA Technical Reports Server (NTRS)

Nguyen, Quang-Viet

1998-01-01

Fuel distribution measurements in gas turbine combustors are needed from both pollution and fuel-efficiency standpoints. In addition to providing valuable data for performance testing and engine development, measurements of fuel distributions uniquely complement predictive numerical simulations. Although equally important as spatial distribution, the temporal distribution of the fuel is an often overlooked aspect of combustor design and development. This is due partly to the difficulties in applying time-resolved diagnostic techniques to the high-pressure, high-temperature environments inside gas turbine engines. Time-resolved measurements of the fuel-to-air ratio (F/A) can give researchers critical insights into combustor dynamics and acoustics. Beginning in early 1998, a windowless technique that uses fiber-optic, line-of-sight, infrared laser light absorption to measure the time-resolved fluctuations of the F/A (refs. 1 and 2) will be used within the premixer section of a lean-premixed, prevaporized (LPP) combustor in NASA Lewis Research Center's CE-5 facility. The fiber-optic F/A sensor will permit optical access while eliminating the need for film-cooled windows, which perturb the flow. More importantly, the real-time data from the fiber-optic F/A sensor will provide unique information for the active feedback control of combustor dynamics. This will be a prototype for an airborne sensor control system.

Multi-contrast light profile microscopy for the depth-resolved imaging of the properties of multi-ply thin films.

PubMed

Power, J F

2009-06-01

Light profile microscopy (LPM) is a direct method for the spectral depth imaging of thin film cross-sections on the micrometer scale. LPM uses a perpendicular viewing configuration that directly images a source beam propagated through a thin film. Images are formed in dark field contrast, which is highly sensitive to subtle interfacial structures that are invisible to reference methods. The independent focusing of illumination and imaging systems allows multiple registered optical sources to be hosted on a single platform. These features make LPM a powerful multi-contrast (MC) imaging technique, demonstrated in this work with six modes of imaging in a single instrument, based on (1) broad-band elastic scatter; (2) laser excited wideband luminescence; (3) coherent elastic scatter; (4) Raman scatter (three channels with RGB illumination); (5) wavelength resolved luminescence; and (6) spectral broadband scatter, resolved in immediate succession. MC-LPM integrates Raman images with a wider optical and morphological picture of the sample than prior art microprobes. Currently, MC-LPM resolves images at an effective spectral resolution better than 9 cm(-1), at a spatial resolution approaching 1 microm, with optics that operate in air at half the maximum numerical aperture of the prior art microprobes.

A new hybrid electrospray Fourier transform mass spectrometer: design and performance characteristics.

PubMed

O'connor, Peter B; Pittman, Jason L; Thomson, Bruce A; Budnik, Bogdan A; Cournoyer, Jason C; Jebanathirajah, Judith; Lin, Cheng; Moyer, Susanne; Zhao, Cheng

2006-01-01

A new hybrid electrospray quadrupole Fourier transform mass spectrometry (FTMS) instrument design is shown and characterized. This instrument involves coupling an electrospray source and mass-resolving quadrupole, ion accumulation, and collision cell linear ion trap system developed by MDS Sciex with a home-built ion guide and ion cyclotron resonance (ICR) cell. The iterative progression of this design is shown. The final design involves a set of hexapole ion guides to transfer the ions from the accumulation/collision trap through the magnetic field gradient and into the cell. These hexapole ion guides are separated by a thin gate valve and two conduction limits to maintain the required <10(-9) mbar vacuum for FTICR. Low-attomole detection limits for a pure peptide are shown, 220 000 resolving power in broadband mode and 820 000 resolving power in narrow-band mode are demonstrated, and mass accuracy in the <2 ppm range is routinely available provided the signal is abundant, cleanly resolved, and internally calibrated. This instrument design provides high experimental flexibility, allowing Q2 CAD, SORI-CAD, IRMPD, and ECD experiments with selected ion accumulation as well as experiments such as nozzle skimmer dissociation. Initial top-down mass spectrometry experiments on a protein is shown using ECD.

Time-resolved High Spectral Resolution Observation of 2MASSW J0746425+200032AB

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

Wang, Ji; Mawet, Dimitri; Prato, Lisa, E-mail: ji.wang@caltech.edu

Many brown dwarfs (BDs) exhibit photometric variability at levels from tenths to tens of percents. The photometric variability is related to magnetic activity or patchy cloud coverage, characteristic of BDs near the L–T transition. Time-resolved spectral monitoring of BDs provides diagnostics of cloud distribution and condensate properties. However, current time-resolved spectral studies of BDs are limited to low spectral resolution ( R ∼ 100) with the exception of the study of Luhman 16 AB at a resolution of 100,000 using the VLT+CRIRES. This work yielded the first map of BD surface inhomogeneity, highlighting the importance and unique contribution of highmore » spectral resolution observations. Here, we report on the time-resolved high spectral resolution observations of a nearby BD binary, 2MASSW J0746425+200032AB. We find no coherent spectral variability that is modulated with rotation. Based on simulations, we conclude that the coverage of a single spot on 2MASSW J0746425+200032AB is smaller than 1% or 6.25% if spot contrast is 50% or 80% of its surrounding flux, respectively. Future high spectral resolution observations aided by adaptive optics systems can put tighter constraints on the spectral variability of 2MASSW J0746425+200032AB and other nearby BDs.« less

Time-resolved study of formate on Ni( 1 1 1 ) by picosecond SFG spectroscopy

NASA Astrophysics Data System (ADS)

Kusafuka, K.; Noguchi, H.; Onda, K.; Kubota, J.; Domen, K.; Hirose, C.; Wada, A.

2002-04-01

Time-resolved vibrational measurements were carried out on formate (HCOO) adsorbed on Ni(1 1 1) surface by combining the sum-frequency generation method and picosecond laser system (time resolution of 6 ps). Rapid intensity decrease (within the time resolution) followed by intensity recovery (time constant of several tens of ps) of CH stretching signal was observed when picosecond 800 nm pulse was irradiated on the sample surface. From the results of temperature and pump fluence dependences of temporal behaviour of signal intensity, we concluded that the observed intensity change was induced by non-thermal process. Mechanism of the temporal intensity change was discussed.

Excitation-resolved cone-beam x-ray luminescence tomography.

PubMed

Liu, Xin; Liao, Qimei; Wang, Hongkai; Yan, Zhuangzhi

2015-07-01

Cone-beam x-ray luminescence computed tomography (CB-XLCT), as an emerging imaging technique, plays an important role in in vivo small animal imaging studies. However, CB-XLCT suffers from low-spatial resolution due to the ill-posed nature of reconstruction. We improve the imaging performance of CB-XLCT by using a multiband excitation-resolved imaging scheme combined with principal component analysis. To evaluate the performance of the proposed method, the physical phantom experiment is performed with a custom-made XLCT/XCT imaging system. The experimental results validate the feasibility of the method, where two adjacent nanophosphors (with an edge-to-edge distance of 2.4 mm) can be located.

High-accuracy resolver-to-digital conversion via phase locked loop based on PID controller

NASA Astrophysics Data System (ADS)

Li, Yaoling; Wu, Zhong

2018-03-01

The problem of resolver-to-digital conversion (RDC) is transformed into the problem of angle tracking control, and a phase locked loop (PLL) method based on PID controller is proposed in this paper. This controller comprises a typical PI controller plus an incomplete differential which can avoid the amplification of higher-frequency noise components by filtering the phase detection error with a low-pass filter. Compared with conventional ones, the proposed PLL method makes the converter a system of type III and thus the conversion accuracy can be improved. Experimental results demonstrate the effectiveness of the proposed method.

Priority Queuing on the Docket: Universality of Judicial Dispute Resolution Timing

NASA Astrophysics Data System (ADS)

Mukherjee, Satyam; Whalen, Ryan

2018-01-01

This paper analyzes court priority queuing behavior by examining the time lapse between when a case enters a court’s docket and when it is ultimately disposed of. Using data from the Supreme courts of the United States, Massachusetts, and Canada we show that each court’s docket features a slow decay with a decreasing tail. This demonstrates that, in each of the courts examined, the vast majority of cases are resolved relatively quickly, while there remains a small number of outlier cases that take an extremely long time to resolve. We discuss the implications for this on legal systems, the study of the law, and future research.

Flame propagation in two-dimensional solids: Particle-resolved studies with complex plasmas

NASA Astrophysics Data System (ADS)

Yurchenko, S. O.; Yakovlev, E. V.; Couëdel, L.; Kryuchkov, N. P.; Lipaev, A. M.; Naumkin, V. N.; Kislov, A. Yu.; Ovcharov, P. V.; Zaytsev, K. I.; Vorob'ev, E. V.; Morfill, G. E.; Ivlev, A. V.

2017-10-01

Using two-dimensional (2D) complex plasmas as an experimental model system, particle-resolved studies of flame propagation in classical 2D solids are carried out. Combining experiments, theory, and molecular dynamics simulations, we demonstrate that the mode-coupling instability operating in 2D complex plasmas reveals all essential features of combustion, such as an activated heat release, two-zone structure of the self-similar temperature profile ("flame front"), as well as thermal expansion of the medium and temperature saturation behind the front. The presented results are of relevance for various fields ranging from combustion and thermochemistry, to chemical physics and synthesis of materials.

Multiplane and Spectrally-Resolved Single Molecule Localization Microscopy with Industrial Grade CMOS cameras.

PubMed

Babcock, Hazen P

2018-01-29

This work explores the use of industrial grade CMOS cameras for single molecule localization microscopy (SMLM). We show that industrial grade CMOS cameras approach the performance of scientific grade CMOS cameras at a fraction of the cost. This makes it more economically feasible to construct high-performance imaging systems with multiple cameras that are capable of a diversity of applications. In particular we demonstrate the use of industrial CMOS cameras for biplane, multiplane and spectrally resolved SMLM. We also provide open-source software for simultaneous control of multiple CMOS cameras and for the reduction of the movies that are acquired to super-resolution images.

Time-resolved serial crystallography captures high-resolution intermediates of photoactive yellow protein

DOE PAGES

Tenboer, Jason; Basu, Shibom; Zatsepin, Nadia; ...

2014-12-05

We report that serial femtosecond crystallography using ultrashort pulses from X-ray Free Electron Lasers (XFELs) offers the possibility to study light-triggered dynamics of biomolecules. Using microcrystals of the blue light photoreceptor, photoactive yellow protein, as a model system, we present high resolution, time-resolved difference electron density maps of excellent quality with strong features, which allow the determination of structures of reaction intermediates to 1.6 Å resolution. These results open the way to the study of reversible and non-reversible biological reactions on time scales as short as femtoseconds under conditions which maximize the extent of reaction initiation throughout the crystal.

Isolated upper eyelid retraction: a sign of idiopathic inflammatory orbital disease.

PubMed

Shome, Debraj; Toshniwal, Svetlana; Jain, Vandana; Natarajan, Sundaram; Vemuganti, Geeta K

2008-01-01

A 41-year-old woman was examined for left upper eyelid retraction. Remaining ocular and systemic examination was unremarkable. Orbital CT demonstrated an ill-defined, extraconal, superior orbital soft-tissue mass involving the levator palpebrae superioris muscle. Incisional biopsy with histopathology demonstrated idiopathic orbital inflammation. The patient was started on a gradually tapering dose of oral steroids, for 6 weeks. On follow-up, the eyelid retraction had resolved. We report this case to demonstrate that idiopathic inflammatory orbital disease, localized to the superior orbit, may cause isolated upper eyelid retraction without associated proptosis. This condition resolves with medical therapy, leading to symmetrical palpebral apertures.

Birefringence and vascular imaging of in vivo human skin by Jones-matrix optical coherence tomography

NASA Astrophysics Data System (ADS)

Li, En; Makita, Shuichi; Hong, Young-Joo; Kasaragod, Deepa; Yasuno, Yoshiaki

2017-02-01

A customized 1310-nm Jones-matrix optical coherence tomography (JM-OCT) for dermatological investigation was constructed and used for in vivo normal human skin tissue imaging. This system can simultaneously measure the threedimensional depth-resolved local birefringence, complex-correlation based OCT angiography (OCT-A), degree-ofpolarization- uniformity (DOPU) and scattering OCT intensity. By obtaining these optical properties of tissue, the morphology, vasculature, and collagen content of skin can be deduced and visualized. Structures in the deep layers of the epithelium were observed with depth-resolved local birefringence and polarization uniformity images. These results suggest high diagnostic and investigative potential of JM-OCT for dermatology.

Implications of Systematic Observations for the Nature of the Multiple System with the Be star o Cassiopeae and its Circumstellar Environment

DTIC Science & Technology

2010-01-01

Interferometer, which allowed the binary components to be spatially resolved for the first time . The interferometric observations lead to the detection of a... resolved for the first time . The interferometric observations lead to the detection of a secondary, about 3 mag fainter than the primary. The possible...114.3084–54 356.5029 54 175.3724 30 6.472± 0.008 6.721± 0.008 6.820± 0.009 0.249 0.099 Table B.2. All-sky UBV photometry of o Cas with known times of ob

What is system control?

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

Hirst, E.; Kirby, B.

1999-11-01

Just as the aviation industry needs air-traffic controllers to manage the movement of airplanes for safety and commerce, so too, the electricity industry requires system operators. The electrical-system-control functions encompass a range of activities that support commercial transactions and maintain bulk-power reliability. As part of a project for the Edison Electric Institute, the authors examined the functions and costs of system control and the issues that need to be resolved in a restructured electricity industry (Hirst and Kirby 1998).

Flight contaminant trace analyser. Phase 1: Chromatographic input system

NASA Technical Reports Server (NTRS)

1975-01-01

The development of a chromatographic column capable of resolving compounds associated with spacecraft atmospheres is presented. Consideration is given to sampling techniques, column parameters and operation, and column interface with a mass spectrometer. A capillary column coated with a mixture of polyalkylene glycols is found to provide the best selectivity for resolving multicomponent mixtures found in spacecraft atmospheres. Temperature programming and isothermal operation of the column are evaluated and it is found that temperature programming has a shorter analysis time for a given carrier gas flow rate and overall superior resolution. It is observed that hydrogen provides a 15% savings in analysis time over helium. Following the optimization of column operational parameters, a mixed phase Ucon capillary is prepared for evaluation during the column test period in which the test sample is automatically analyzed. Analysis of the multicomponent test mixture is completed within 45 minutes provided temperature programming is used. All but two of the test compounds are well resolved.

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

Choquet, Élodie; Perrin, Marshall D.; Chen, Christine H.

We present the first images of four debris disks observed in scattered light around the young (4–250 Myr old) M dwarfs TWA 7 and TWA 25, the K6 star HD 35650, and the G2 star HD 377. We obtained these images by reprocessing archival Hubble Space Telescope NICMOS coronagraph data with modern post-processing techniques as part of the Archival Legacy Investigation of Circumstellar Environments program. All four disks appear faint and compact compared with other debris disks resolved in scattered light. The disks around TWA 25, HD 35650, and HD 377 appear very inclined, while TWA 7's disk is viewed nearly face-on. The surface brightness of HD 35650's diskmore » is strongly asymmetric. These new detections raise the number of disks resolved in scattered light around M and late-K stars from one (the AU Mic system) to four. This new sample of resolved disks enables comparative studies of heretofore scarce debris disks around low-mass stars relative to solar-type stars.« less

Eight-channel time-resolved tissue oximeter for functional muscle studies

NASA Astrophysics Data System (ADS)

Cubeddu, Rinaldo; Biscotti, Giovanni; Pifferi, Antonio; Taroni, Paola; Torricelli, Alessandro; Ferrari, Marco; Quaresima, Valentina

2003-07-01

A portable instrument for tissue oximetry based on time-resolved reflectance spectroscopy was developed. The output pulses of 2 laser diodes (683 and 785 nm, 80 MHz pulse repetition rate, 1 mW average power, 100 ps FWHM) are delayed and coupled into a multimode graded-index fiber (50/125 μm and injected into the tissue. The reflectance photons are collected by 8 independent 1 mm fibers and detected by a 16-anode photomultiplier. A time-correlated single photon counting PC board is used for the parallel acquisition of the curves. Simultaneous estimate of the transport scattering and absorption coefficients is achieved by best fitting of time-resolved reflectance curves with a standard model of Diffusion Theory. The performances of the system were tested on phantoms in terms of stability, reproducibility among channels, and accuracy in the determination of the optical properties. Preliminary in vivo measurements were performed on healthy volunteers to monitor spatial changes in calf (medical and lateral gastrocnemius) oxygen hemoglobin saturation and blood volume during dynamic plantar flexion exercise.

Motor Oil Classification Based on Time-Resolved Fluorescence

PubMed Central

Mu, Taotao; Chen, Siying; Zhang, Yinchao; Guo, Pan; Chen, He; Meng, Fandong

2014-01-01

A time-resolved fluorescence (TRF) technique is presented for classifying motor oils. The system is constructed with a third harmonic Nd:YAG laser, a spectrometer, and an intensified charge coupled device (ICCD) camera. Steady-state and time-resolved fluorescence (TRF) measurements are reported for several motor oils. It is found that steady-state fluorescence is insufficient to distinguish the motor oil samples. Then contour diagrams of TRF intensities (CDTRFIs) are acquired to serve as unique fingerprints to identify motor oils by using the distinct TRF of motor oils. CDTRFIs are preferable to steady-state fluorescence spectra for classifying different motor oils, making CDTRFIs a particularly choice for the development of fluorescence-based methods for the discrimination and characterization of motor oils. The two-dimensional fluorescence contour diagrams contain more information, not only the changing shapes of the LIF spectra but also the relative intensity. The results indicate that motor oils can be differentiated based on the new proposed method, which provides reliable methods for analyzing and classifying motor oils. PMID:24988439