A gravitational lens candidate with an unusually red optical counterpart

NASA Technical Reports Server (NTRS)

Hewitt, J. N.; Turner, E. L.; Lawrence, C. R.; Schneider, D. P.; Brody, J. P.

1992-01-01

The properties of the strong radio source MG0414 + 0534 are described. It is found to display many of the properties expected in a gravitational lens system. At radio wavelengths and 0.5-arcsec resolution, MG0414 + 0534 is made up of four compact components whose unusual configuration and relative flux densities are similar to those found in confirmed four-image gravitational lens systems. At optical wavelengths three objects are detected, consistent with there being optical objects at the positions of the radio components, given the lower optical resolution. The radio and optical centroid positions agree within the astrometric errors, and the relative ordering of the fluxes is the same. The colors and radiooptical spectral indices are similar, but there are differences larger than the photometric errors and the measured variability (about 30 percent). Extinction by dust might simultaneously explain the unusually red color and the absence of light from a lens.

Reconstructing the prevailing meteorological and optical environment during the time of the Titanic disaster

NASA Astrophysics Data System (ADS)

Basu, Sukanta; Nunalee, Christopher G.; He, Ping; Fiorino, Steven T.; Vorontsov, Mikhail A.

2014-10-01

In this paper, we reconstruct the meteorological and optical environment during the time of Titanic's disaster utilizing a state-of-the-art meteorological model, a ray-tracing code, and a unique public-domain dataset called the Twentieth Century Global Reanalysis. With high fidelity, our simulation captured the occurrence of an unusually high Arctic pressure system over the disaster site with calm wind. It also reproduced the movement of a polar cold front through the region bringing a rapid drop in air temperature. The simulated results also suggest that unusual meteorological conditions persisted several hours prior to the Titanic disaster which contributed to super-refraction and intermittent optical turbulence. However, according to the simulations, such anomalous conditions were not present at the time of the collision of Titanic with an iceberg.

Voyager 2 Uranus targeting strategy

NASA Technical Reports Server (NTRS)

Cesarone, R. J.; Gray, D. L.; Potts, C. L.; Francis, K.

1986-01-01

One of the major challenges involved in the Voyager 2 Uranus flyby is to deliver the spacecraft to an appropriate aimpoint at the optimum time, so as to maximize the science return of the mission, while yet keeping propellant expenditure low. An unusual targeting strategy has been devised to satisfy these requirements. Its complexity arises from the great distance of the planet Uranus and the limited performance capabilities of Voyager. This selected strategy is developed in relation to a set of candidate strategies, mission requirements and shifting science objectives. The analysis of these candidates is conducted via a Monte Carlo simulation, the results of which yield data for the comparative evaluation and eventual and selection of the actual targeting strategy to be employed.

Refractory inclusions in the Ornans C30 chondrite

NASA Technical Reports Server (NTRS)

Davis, A. M.

1985-01-01

Several types of metedorites contain unusual objects 10 micrometers to 2 centimeters across that are enriched in refractory elements such as calcium, aluminum and titanium. These objects, commonly known as refractory inclusions, are most abundant in the meteorites known as carbonaceous chondrites. The refractory inclusions that have been found in the Ornans metedorite, a member of a little-studied group of carbonaceous chondrites are described. Some refractory inclusions in Ornans resemble those found in other meteorites, while others are unlike any seen before. The unusual inclusions in Ornans contain minerals with extraordinary enrichments in highly refractory elements.

Conceptual Issues in Quantifying Unusualness and Conceiving Stochastic Experiments: Insights from Students' Experiences in Designing Sampling Simulations

ERIC Educational Resources Information Center

Saldanha, Luis

2016-01-01

This article reports on a classroom teaching experiment that engaged a group of high school students in designing sampling simulations within a computer microworld. The simulation-design activities aimed to foster students' abilities to conceive of contextual situations as stochastic experiments, and to engage them with the logic of hypothesis…

The Use of Virtual Reality for Creating Unusual Environmental Stimulation to Motivate Students to Explore Creative Ideas

ERIC Educational Resources Information Center

Lau, Kung Wong; Lee, Pui Yuen

2015-01-01

This paper discusses the roles of simulation in creativity education and how to apply immersive virtual environments to enhance students' learning experiences in university, through the provision of interactive simulations. An empirical study of a simulated virtual reality was carried out in order to investigate the effectiveness of providing…

Integration of World Knowledge and Temporary Information about Changes in an Object's Environmental Location during Different Stages of Sentence Comprehension

PubMed Central

Chen, Xuqian; Yang, Wei; Ma, Lijun; Li, Jiaxin

2018-01-01

Recent findings have shown that information about changes in an object's environmental location in the context of discourse is stored in working memory during sentence comprehension. However, in these studies, changes in the object's location were always consistent with world knowledge (e.g., in “The writer picked up the pen from the floor and moved it to the desk,” the floor and the desk are both common locations for a pen). How do people accomplish comprehension when the object-location information in working memory is inconsistent with world knowledge (e.g., a pen being moved from the floor to the bathtub)? In two visual world experiments, with a “look-and-listen” task, we used eye-tracking data to investigate comprehension of sentences that described location changes under different conditions of appropriateness (i.e., the object and its location were typically vs. unusually coexistent, based on world knowledge) and antecedent context (i.e., contextual information that did vs. did not temporarily normalize unusual coexistence between object and location). Results showed that listeners' retrieval of the critical location was affected by both world knowledge and working memory, and the effect of world knowledge was reduced when the antecedent context normalized unusual coexistence of object and location. More importantly, activation of world knowledge and working memory seemed to change during the comprehension process. These results are important because they demonstrate that interference between world knowledge and information in working memory, appears to be activated dynamically during sentence comprehension. PMID:29520249

Integration of World Knowledge and Temporary Information about Changes in an Object's Environmental Location during Different Stages of Sentence Comprehension.

PubMed

Chen, Xuqian; Yang, Wei; Ma, Lijun; Li, Jiaxin

2018-01-01

Recent findings have shown that information about changes in an object's environmental location in the context of discourse is stored in working memory during sentence comprehension. However, in these studies, changes in the object's location were always consistent with world knowledge (e.g., in "The writer picked up the pen from the floor and moved it to the desk," the floor and the desk are both common locations for a pen). How do people accomplish comprehension when the object-location information in working memory is inconsistent with world knowledge (e.g., a pen being moved from the floor to the bathtub)? In two visual world experiments, with a "look-and-listen" task, we used eye-tracking data to investigate comprehension of sentences that described location changes under different conditions of appropriateness (i.e., the object and its location were typically vs. unusually coexistent, based on world knowledge) and antecedent context (i.e., contextual information that did vs. did not temporarily normalize unusual coexistence between object and location). Results showed that listeners' retrieval of the critical location was affected by both world knowledge and working memory, and the effect of world knowledge was reduced when the antecedent context normalized unusual coexistence of object and location. More importantly, activation of world knowledge and working memory seemed to change during the comprehension process. These results are important because they demonstrate that interference between world knowledge and information in working memory, appears to be activated dynamically during sentence comprehension.

[Clear cell carcinoma of the ovary simulating a yolk sac tumor].

PubMed

Bahri, Ibticem; Boudawara, Tahya; Khabir, Abdelmajid; Beyrouti, Mohamed Issam; Frikha, Mounir; Jlidi, Rachid

2003-04-01

Clear cell carcinoma (CCC) of the ovary is uncommon. In young patients, this tumor may simulate a yolk sac tumor. In this case, the morphologic distinction between these tumors is often difficult but the immunohistochemical staining for CA125 and alpha foeto protein (AFP) and the response to chemotherapy are particularly helpful to resolve this problem of differential diagnosis. We report a case of a 17 year old patient who was operated for a tumor of the right ovary. The diagnosis of a yolk sac tumor was first suggested. However, because of the non response to chemotherapy, a second laparotomy was performed; the definitive pathologic examination concluded to the diagnosis of a CCC of the ovary. The young age and the immunohistochemical staining for AFP are unusual and misleading features for a CCC. Our objective about this particular case is to discuss the anatomoclinical aspects of the CCC of the ovary and to prove the role of immunohistochemistry in the differential diagnosis.

Theoretical study of the ionospheric plasma cave in the equatorial ionization anomaly region

NASA Astrophysics Data System (ADS)

Chen, Yu-Tsung; Lin, C. H.; Chen, C. H.; Liu, J. Y.; Huba, J. D.; Chang, L. C.; Liu, H.-L.; Lin, J. T.; Rajesh, P. K.

2014-12-01

This paper investigates the physical mechanism of an unusual equatorial electron density structure, plasma cave, located underneath the equatorial ionization anomaly by using theoretical simulations. The simulation results provide important new understanding of the dynamics of the equatorial ionosphere. It has been suggested previously that unusual E>⇀×B>⇀ drifts might be responsible for the observed plasma cave structure, but model simulations in this paper suggest that the more likely cause is latitudinal meridional neutral wind variations. The neutral winds are featured by two divergent wind regions at off-equator latitudes and a convergent wind region around the magnetic equator, resulting in plasma divergences and convergence, respectively, to form the plasma caves structure. The tidal-decomposition analysis further suggests that the cave related meridional neutral winds and the intensity of plasma cave are highly associated with the migrating terdiurnal tidal component of the neutral winds.

Peripheral vision cues : their effect on pilot performance during instrument landing approaches and recoveries from unusual attitudes.

DOT National Transportation Integrated Search

1968-05-01

The study explores the effects of peripheral vision cues on the performance of a 20 ATR pilots during simulated instrument landing approaches in a Boeing 720 jet aircraft simulator. Recoveries from unusal attitudes were also investigated. Results of ...

Explaining Away the Body: Experiences of Supernaturally Caused Touch and Touch on Non-Hand Objects within the Rubber Hand Illusion

PubMed Central

2010-01-01

Background In rubber hand illusions and full body illusions, touch sensations are projected to non-body objects such as rubber hands, dolls or virtual bodies. The robustness, limits and further perceptual consequences of such illusions are not yet fully explored or understood. A number of experiments are reported that test the limits of a variant of the rubber hand illusion. Methodology/Principal Findings A variant of the rubber hand illusion is explored, in which the real and foreign hands are aligned in personal space. The presence of the illusion is ascertained with participants' scores and temperature changes of the real arm. This generates a basic illusion of touch projected to a foreign arm. Participants are presented with further, unusual visuotactile stimuli subsequent to onset of the basic illusion. Such further visuotactile stimulation is found to generate very unusual experiences of supernatural touch and touch on a non-hand object. The finding of touch on a non-hand object conflicts with prior findings, and to resolve this conflict a further hypothesis is successfully tested: that without prior onset of the basic illusion this unusual experience does not occur. Conclusions/Significance A rubber hand illusion is found that can arise when the real and the foreign arm are aligned in personal space. This illusion persists through periods of no tactile stimulation and is strong enough to allow very unusual experiences of touch felt on a cardboard box and experiences of touch produced at a distance, as if by supernatural causation. These findings suggest that one's visual body image is explained away during experience of the illusion and they may be of further importance to understanding the role of experience in delusion formation. The findings of touch on non-hand objects may help reconcile conflicting results in this area of research. In addition, new evidence is provided that relates to the recently discovered psychologically induced temperature changes that occur during the illusion. PMID:20195378

An unusually strong Einstein ring in the radio source PKS1830 - 211

NASA Technical Reports Server (NTRS)

Jauncey, D. L.; Reynolds, J. E.; Tzioumis, A. K.; Murphy, D. W.; Preston, R. A.; Jones, D. L.; Meier, D. L.; Hoard, D. W.; Lobdell, E. T.; Skjerve, L.

1991-01-01

High-resolution radio images of PKS1830 - 211 are obtained to study the possibility that the double structure is a gravitationally lensed object. The VLBI observations, taken from interferometric radiotelescope networks, reveal an elliptical ring that connects two bright spots of similar composition. Because the lens and the lensed object are closely aligned, and because of the structure of the two spots, the source is concluded to be a radio Einstein ring. The source is found to be close to the galactic plane, and the lens and the lensed object are extragalactic. The source is also found to be unusually bright, suggesting that it is aligned with a bright background source or amplified by some mechanism related to a source that is not so bright.

Endodontic management of an unusual foreign body in a maxillary central incisor.

PubMed

Chand, Keerthi; Joesph, Sam; Varughese, Jolly Mary; Nair, Mali G; Prasanth, Santhosh

2013-09-01

The discovery of foreign bodies in the teeth is often diagnosed accidentally. It is commonly seen in children. These foreign objects may act as a potential source of infection and may later lead to a painful condition. Detailed case history, clinical and radiographic examinations are necessary to come to a conclusion about the nature, size, and location of the foreign body, and the difficulty involved in its retrieval. This paper discusses the types of foreign objects found in and around the teeth and reports an unusual case of a stapler pin in the root canal of a tooth, its retrieval, and associated management of the involved teeth.

Spectroscopy of asteroids in unusual orbits

NASA Technical Reports Server (NTRS)

Cochran, W. D.; Cochran, A. L.; Barker, E. S.

1986-01-01

Medium-resolution spectroscopy of a collection of nonmain-belt asteroids has been obtained in order to search for possible cometlike spectral features. The asteroids include nine earth approachers, two Trojans, and the unusual object 2060 Chiron. All spectra were obtained and reduced in the same manner as comet data in the McDonald Observatory Faint Comet Survey. No indication of cometary activity was found in any of the asteroids observed.

[Searching for Rare Celestial Objects Automatically from Stellar Spectra of the Sloan Digital Sky Survey Data Release Eight].

PubMed

Si, Jian-min; Luo, A-li; Wu, Fu-zhao; Wu, Yi-hong

2015-03-01

There are many valuable rare and unusual objects in spectra dataset of Sloan Digital Sky Survey (SDSS) Data Release eight (DR8), such as special white dwarfs (DZ, DQ, DC), carbon stars, white dwarf main-sequence binaries (WDMS), cataclysmic variable (CV) stars and so on, so it is extremely significant to search for rare and unusual celestial objects from massive spectra dataset. A novel algorithm based on Kernel dense estimation and K-nearest neighborhoods (KNN) has been presented, and applied to search for rare and unusual celestial objects from 546 383 stellar spectra of SDSS DR8. Their densities are estimated using Gaussian kernel density estimation, the top 5 000 spectra in descend order by their densities are selected as rare objects, and the top 300 000 spectra in ascend order by their densities are selected as normal objects. Then, KNN were used to classify the rest objects, and simultaneously K nearest neighbors of the 5 000 rare spectra are also selected as rare objects. As a result, there are totally 21 193 spectra selected as initial rare spectra, which include error spectra caused by deletion, redden, bad calibration, spectra consisting of different physically irrelevant components, planetary nebulas, QSOs, special white dwarfs (DZ, DQ, DC), carbon stars, white dwarf main-sequence binaries (WDMS), cataclysmic variable (CV) stars and so on. By cross identification with SIMBAD, NED, ADS and major literature, it is found that three DZ white dwarfs, one WDMS, two CVs with company of G-type star, three CVs candidates, six DC white dwarfs, one DC white dwarf candidate and one BL Lacertae (BL lac) candidate are our new findings. We also have found one special DA white dwarf with emission lines of Ca II triple and Mg I, and one unknown object whose spectrum looks like a late M star with emission lines and its image looks like a galaxy or nebula.

Maya: A Simulation of Mayan Civilization during the Seventh Century.

ERIC Educational Resources Information Center

Roth, Peter

This simulation allows students to explore the lives of the great rulers of the Mayan culture. Students learn the mysterious history of the Maya by decoding glyphs, investigating the unusual religion of the Maya, unraveling the complex Mayan calendar, and discovering the Mayan number system's secret meanings. Specific cooperation skills are taught…

Analysis of Braking Behavior of Train Drivers to Detect Unusual Driving

NASA Astrophysics Data System (ADS)

Marumo, Yoshitaka; Tsunashima, Hitoshi; Kojima, Takashi; Hasegawa, Yasushi

The safety devices for train systems are activated in emergency situations when a risk becomes obvious, and the emergency brake is applied. If such systems are faulty, the drivers' operating errors may cause immediate accidents. So it is necessary to evaluate potential risks by detecting improper driving behavior before overt risks appear. This study analyzes the driving behavior of train drivers using a train-driving simulator. We focus on braking behavior when approaching a station. Two methods for detecting unusual braking operation are examined by giving drivers mental calculation problems as a mental workload. The first is a method monitoring the driver's brake handle operation, and the second is a method measuring vehicle deceleration. These methods make it possible to detect unusual driving.

Endodontic management of an unusual foreign body in a maxillary central incisor

PubMed Central

Chand, Keerthi; Joesph, Sam; Varughese, Jolly Mary; Nair, Mali G; Prasanth, Santhosh

2013-01-01

The discovery of foreign bodies in the teeth is often diagnosed accidentally. It is commonly seen in children. These foreign objects may act as a potential source of infection and may later lead to a painful condition. Detailed case history, clinical and radiographic examinations are necessary to come to a conclusion about the nature, size, and location of the foreign body, and the difficulty involved in its retrieval. This paper discusses the types of foreign objects found in and around the teeth and reports an unusual case of a stapler pin in the root canal of a tooth, its retrieval, and associated management of the involved teeth. PMID:24082582

A survey for variable young stars with small telescopes: First results from HOYS-CAPS

NASA Astrophysics Data System (ADS)

Froebrich, D.; Campbell-White, J.; Scholz, A.; Eislöffel, J.; Zegmott, T.; Billington, S. J.; Donohoe, J.; Makin, S. V.; Hibbert, R.; Newport, R. J.; Pickard, R.; Quinn, N.; Rodda, T.; Piehler, G.; Shelley, M.; Parkinson, S.; Wiersema, K.; Walton, I.

2018-05-01

Variability in Young Stellar Objects (YSOs) is one of their primary characteristics. Long-term, multi-filter, high-cadence monitoring of large YSO samples is the key to understand the partly unusual light-curves that many of these objects show. Here we introduce and present the first results of the HOYS-CAPScitizen science project which aims to perform such monitoring for nearby (d < 1 kpc) and young (age < 10 Myr) clusters and star forming regions, visible from the northern hemisphere, with small telescopes. We have identified and characterised 466 variable (413 confirmed young) stars in 8 young, nearby clusters. All sources vary by at least 0.2 mag in V, have been observed at least 15 times in V, R and I in the same night over a period of about 2 yrs and have a Stetson index of larger than 1. This is one of the largest samples of variable YSOs observed over such a time-span and cadence in multiple filters. About two thirds of our sample are classical T-Tauri stars, while the rest are objects with depleted or transition disks. Objects characterised as bursters show by far the highest variability. Dippers and objects whose variability is dominated by occultations from normal interstellar dust or dust with larger grains (or opaque material) have smaller amplitudes. We have established a hierarchical clustering algorithm based on the light-curve properties which allows the identification of the YSOs with the most unusual behaviour, and to group sources with similar properties. We discuss in detail the light-curves of the unusual objects V2492 Cyg, V350 Cep and 2MASS J21383981+5708470.

Recognizing familiar objects by hand and foot: Haptic shape perception generalizes to inputs from unusual locations and untrained body parts.

PubMed

Lawson, Rebecca

2014-02-01

The limits of generalization of our 3-D shape recognition system to identifying objects by touch was investigated by testing exploration at unusual locations and using untrained effectors. In Experiments 1 and 2, people found identification by hand of real objects, plastic 3-D models of objects, and raised line drawings placed in front of themselves no easier than when exploration was behind their back. Experiment 3 compared one-handed, two-handed, one-footed, and two-footed haptic object recognition of familiar objects. Recognition by foot was slower (7 vs. 13 s) and much less accurate (9 % vs. 47 % errors) than recognition by either one or both hands. Nevertheless, item difficulty was similar across hand and foot exploration, and there was a strong correlation between an individual's hand and foot performance. Furthermore, foot recognition was better with the largest 20 of the 80 items (32 % errors), suggesting that physical limitations hampered exploration by foot. Thus, object recognition by hand generalized efficiently across the spatial location of stimuli, while object recognition by foot seemed surprisingly good given that no prior training was provided. Active touch (haptics) thus efficiently extracts 3-D shape information and accesses stored representations of familiar objects from novel modes of input.

Climate, not conflict, explains extreme Middle East dust storm

DOE PAGES

Parolari, Anthony J.; Li, Dan; Bou-Zeid, Elie; ...

2016-11-08

The recent dust storm in the Middle East (Sepember 2015) was publicized in the media as a sign of an impending 'Dust Bowl.' Its severity, demonstrated by extreme aerosol optical depth in the atmosphere in the 99th percentile compared to historical data, was attributed to the ongoing regional conflict. However, surface meteorological and remote sensing data, as well as regional climate model simulations, support an alternative hypothesis: the historically unprecedented aridity played a more prominent role, as evidenced by unusual climatic and meteorological conditions prior to and during the storm. Remotely sensed normalized difference vegetation index demonstrates that vegetation covermore » was high in 2015 relative to the prior drought and conflict periods, suggesting that agricultural activity was not diminished during that year, thus negating the media narrative. Instead, meteorological simulations using the Weather Research and Forecasting (WRF) model show that the storm was associated with a cyclone and 'Shamal' winds, typical for dust storm generation in this region, that were immediately followed by an unusual wind reversal at low levels that spread dust west to the Mediterranean Coast. These unusual meteorological conditions were aided by a significant reduction in the critical shear stress due to extreme dry and hot conditions, thereby enhancing dust availability for erosion during this storm. Concluding, unusual aridity, combined with unique synoptic weather patterns, enhanced dust emission and westward long-range transport across the region, thus generating the extreme storm.« less

Climate, not conflict, explains extreme Middle East dust storm

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

Parolari, Anthony J.; Li, Dan; Bou-Zeid, Elie

The recent dust storm in the Middle East (Sepember 2015) was publicized in the media as a sign of an impending 'Dust Bowl.' Its severity, demonstrated by extreme aerosol optical depth in the atmosphere in the 99th percentile compared to historical data, was attributed to the ongoing regional conflict. However, surface meteorological and remote sensing data, as well as regional climate model simulations, support an alternative hypothesis: the historically unprecedented aridity played a more prominent role, as evidenced by unusual climatic and meteorological conditions prior to and during the storm. Remotely sensed normalized difference vegetation index demonstrates that vegetation covermore » was high in 2015 relative to the prior drought and conflict periods, suggesting that agricultural activity was not diminished during that year, thus negating the media narrative. Instead, meteorological simulations using the Weather Research and Forecasting (WRF) model show that the storm was associated with a cyclone and 'Shamal' winds, typical for dust storm generation in this region, that were immediately followed by an unusual wind reversal at low levels that spread dust west to the Mediterranean Coast. These unusual meteorological conditions were aided by a significant reduction in the critical shear stress due to extreme dry and hot conditions, thereby enhancing dust availability for erosion during this storm. Concluding, unusual aridity, combined with unique synoptic weather patterns, enhanced dust emission and westward long-range transport across the region, thus generating the extreme storm.« less

Simulation analysis of a wildfire suppression system

Treesearch

Abílio Pereira Pacheco; João Claro; Tiago Oliveira

2013-01-01

Rekindles and false alarms are unusually high in the Portuguese wildfire management system, representing a high burden on suppression resources in particular, and fire management resources in general. In 20,049 occurrences that the suppression system handled in the summer of 2010, 12.5% were false alarms and 15.0% were rekindles. We present a discreteevent simulation...

Detection of the supercycle in V4140 Sagittarii: First eclipsing ER Ursae Majoris-like object

NASA Astrophysics Data System (ADS)

Kato, Taichi; Hambsch, Franz-Josef; Cook, Lewis M.

2018-05-01

We observed the deeply eclipsing SU UMa-type dwarf nova V4140 Sgr and established the very short supercycle of 69.7(3) d. There were several short outbursts between superoutbursts. These values, together with the short orbital period (0.06143 d), were similar to, but not as extreme as, those of ER UMa-type dwarf novae. The object is thus the first, long sought, eclipsing ER UMa-like object. This ER UMa-like nature can naturally explain the high (apparent) quiescent viscosity and unusual temperature profile in quiescence, which were claimed observational features against the thermal-tidal instability model. The apparently unusual outburst behavior can be reasonably explained by a combination of this ER UMa-like nature and the high orbital inclination, and there is no need to introduce mass transfer bursts from its donor star.

Detection of the supercycle in V4140 Sagittarii: First eclipsing ER Ursae Majoris-like object

NASA Astrophysics Data System (ADS)

Kato, Taichi; Hambsch, Franz-Josef; Cook, Lewis M.

2018-06-01

We observed the deeply eclipsing SU UMa-type dwarf nova V4140 Sgr and established the very short supercycle of 69.7(3) d. There were several short outbursts between superoutbursts. These values, together with the short orbital period (0.06143 d), were similar to, but not as extreme as, those of ER UMa-type dwarf novae. The object is thus the first, long sought, eclipsing ER UMa-like object. This ER UMa-like nature can naturally explain the high (apparent) quiescent viscosity and unusual temperature profile in quiescence, which were claimed observational features against the thermal-tidal instability model. The apparently unusual outburst behavior can be reasonably explained by a combination of this ER UMa-like nature and the high orbital inclination, and there is no need to introduce mass transfer bursts from its donor star.

Rheology of Active Fluids

NASA Astrophysics Data System (ADS)

Saintillan, David

2018-01-01

An active fluid denotes a viscous suspension of particles, cells, or macromolecules able to convert chemical energy into mechanical work by generating stresses on the microscale. By virtue of this internal energy conversion, these systems display unusual macroscopic rheological signatures, including a curious transition to an apparent superfluid-like state where internal activity exactly compensates viscous dissipation. These behaviors are unlike those of classical complex fluids and result from the coupling of particle configurations with both externally applied flows and internally generated fluid disturbances. Focusing on the well-studied example of a suspension of microswimmers, this review summarizes recent experiments, models, and simulations in this area and highlights the critical role played by the rheological response of these active materials in a multitude of phenomena, from the enhanced transport of passive suspended objects to the emergence of spontaneous flows and collective motion.

Neural correlates of observing pretend play in which one object is represented as another

PubMed Central

Whitehead, Charles; Marchant, Jennifer L.; Craik, David

2009-01-01

Observers were scanned while they watched a video of an actor using an object. Three conditions were contrasted in which the same object was used: (i) normally (e.g. using a tennis racket to hit a ball), (ii) in an unusual way (e.g. using a tennis racket to strain spaghetti), (iii) in a pretend play (e.g. playing a tennis racket like a banjo). Observing real and unusual uses of objects activated areas previously seen in studies of tool use including areas associated with a mirror system for action. Observing pretend play activated additional areas previously associated with theory of mind tasks and listening to narrative, including medial prefrontal cortex, posterior superior temporal sulcus and temporal poles. After presentation of each video, observers were asked to name the object as used in the preceding action video (e.g. racket, sieve or banjo). Naming the pretend object elicited activity in medial prefrontal cortex. These results are consistent with proposals that pretend play is a form of communicative narrative, associated with the ability to mentalize. However, this leaves open the question as to whether pretence or mentalizing is the more basic process. PMID:19535615

Dynamical sequestration of the Moon-forming impactor in co-orbital resonance with Earth

NASA Astrophysics Data System (ADS)

Kortenkamp, Stephen J.; Hartmann, William K.

2016-09-01

Recent concerns about the giant impact hypothesis for the origin of the Moon, and an associated "isotope crisis" may be assuaged if the impactor was a local object that formed near Earth. We investigated a scenario that may meet this criterion, with protoplanets assumed to originate in 1:1 co-orbital resonance with Earth. Using N-body numerical simulations we explored the dynamical consequences of placing Mars-mass companions in various co-orbital configurations with a proto-Earth of 0.9 Earth-masses (M⊕). We modeled 162 different configurations, some with just the four terrestrial planets and others that included the four giant planets. In both the 4- and 8-planet models we found that a single Mars-mass companion typically remained a stable co-orbital of Earth for the entire 250 million year (Myr) duration of our simulations (59 of 68 unique simulations). In an effort to destabilize such a system we carried out an additional 94 simulations that included a second Mars-mass co-orbital companion. Even with two Mars-mass companions sharing Earth's orbit about two-thirds of these models (66) also remained stable for the entire 250 Myr duration of the simulations. Of the 28 2-companion models that eventually became unstable 24 impacts were observed between Earth and an escaping co-orbital companion. The average delay we observed for an impact of a Mars-mass companion with Earth was 102 Myr, and the longest delay was 221 Myr. In 40% of the 8-planet models that became unstable (10 out of 25) Earth collided with the nearly equal mass Venus to form a super-Earth (loosely defined here as mass ≥1.7 M⊕). These impacts were typically the final giant impact in the system and often occurred after Earth and/or Venus has accreted one or more of the other large objects. Several of the stable configurations involved unusual 3-planet hierarchical co-orbital systems.

Unusual self-electrocution simulating judicial electrocution by an adolescent.

PubMed

Murty, O P

2008-06-01

Electrocution is one of the rarest modes of suicide. In this case, one school going adolescent committed suicide by electrocution using bare electric wire. This is a rare case of suicidal death by applying live wires around the wrists, simulating the act of judicial electrocution. He positioned himself on armed chair and placed the nude wire loops from a cable around both wrists and switched on the current by plugging in to nearest socket by foot. There were linear electric contact wounds completely encircling around the both wrists. In addition to these linear electric burns all around wrists, there were electrical burns over both hands. This death highlights the need of supervision and close watch on children for self-destructing activities and behavior. This case also highlights unusual method adopted by adolescent to end his life.

Flight simulator evaluation of a novel flight instrument display to minimize the risks of spatial disorientation.

PubMed

Braithwaite, M G; Durnford, S J; Groh, S L; Jones, H D; Higdon, A A; Estrada, A; Alvarez, E A

1998-08-01

Spatial disorientation (SD) in flight remains a major source of attrition. Many SD accidents would occur regardless of the instrument display in use, since the aircrew are simply not looking at the instruments. However, there are a number of accidents which might be amenable to improved instrument displays. In an attempt to improve maintenance and reattainment of correct orientation with a reduced cognitive workload, a novel instrument display has been developed. This paper describes an assessment of the display in a UH-60 helicopter flight simulator. This study tested the hypothesis that during instrument flight and recovery from unusual attitudes, the novel display permits a more accurate maintenance and reestablishment of flight parameters than the standard flight instruments. There were 16 male aviators who flew a simulated instrument flight profile and recovery from unusual attitudes using both the standard flight instruments and the novel display. The two display formats were tested both with and without a secondary task. When compared with the standard instruments, both control of flight parameters and recovery from unusual attitudes were significantly improved when using the novel display. Analysis of the secondary task scores showed that cognitive workload was reduced when using the novel display compared with the standard instruments. Results from all aspects of the assessment indicated benefits of the new display. Future testing should be carried out during real flight, and the display should be further developed to be used in a head-up or helmet-mounted device.

Consequences of localized frustration for the folding mechanism of the IM7 protein

PubMed Central

Sutto, Ludovico; Lätzer, Joachim; Hegler, Joseph A.; Ferreiro, Diego U.; Wolynes, Peter G.

2007-01-01

In the laboratory, IM7 has been found to have an unusual folding mechanism in which an “on-pathway” intermediate with nonnative interactions is formed. We show that this intermediate is a consequence of an unusual cluster of highly frustrated interactions in the native structure. This cluster is involved in the binding of IM7 to its target, Colicin E7. Redesign of residues in this cluster to eliminate frustration is predicted by simulations to lead to faster folding without the population of an intermediate ensemble. PMID:18077415

Big Jump of Record Warm Global Mean Surface Temperature in 2014-2016 Related to Unusually Large Oceanic Heat Releases

NASA Astrophysics Data System (ADS)

Yin, Jianjun; Overpeck, Jonathan; Peyser, Cheryl; Stouffer, Ronald

2018-01-01

A 0.24°C jump of record warm global mean surface temperature (GMST) over the past three consecutive record-breaking years (2014-2016) was highly unusual and largely a consequence of an El Niño that released unusually large amounts of ocean heat from the subsurface layer of the northwestern tropical Pacific. This heat had built up since the 1990s mainly due to greenhouse-gas (GHG) forcing and possible remote oceanic effects. Model simulations and projections suggest that the fundamental cause, and robust predictor of large record-breaking events of GMST in the 21st century, is GHG forcing rather than internal climate variability alone. Such events will increase in frequency, magnitude, and duration, as well as impact, in the future unless GHG forcing is reduced.

The Early Years: Science Tickets

ERIC Educational Resources Information Center

Ashbrook, Peggy

2007-01-01

Teachers can spark interest in a science topic by using "science tickets"--special objects offered to children as a way to transition to the science room or into a small group to do a science activity. Objects ranging from ordinary (shells, leaves, or sticks) to unusual (photos, crystals, or plastic worms) appeal to young children's curiosity and…

Simultaneous concentration and purification through gradient deformation chromatography

NASA Technical Reports Server (NTRS)

Velayudhan, A.; Hendrickson, R. L.; Ladisch, M. R.; Mitchell, C. A. (Principal Investigator)

1995-01-01

Mobile-phase additives, commonly used to modulate absorbate retention in gradient elution chromatography, are usually assumed to be either linearly retained or unretained. Previous theoretical work from our laboratory has shown that these modulators, such as salts in ion-exchange and hydrophobic interaction chromatography and organic modifiers in reversed-phase chromatography, can absorb nonlinearly, giving rise to gradient deformation. Consequently, adsorbate peaks that elute in the vicinity of the head of the deformed gradient may exhibit unusual shapes, form shoulders, and/or be concentrated. These effects for a reversed-phase sorbent with aqueous acetonitrile (ACN) as the modulator are verified experimentally. Gradient deformation is demonstrated experimentally and agrees with simulations based on ACN isotherm parameters that are independently determined from batch equilibrium studies using the layer model. Unusual absorbate peak shapes were found experimentally for single-component injections of phenylalanine, similar to those calculated by the simulations. A binary mixture of tryptophan and phenylalanine is used to demonstrate simultaneous concentration and separation, again in agreement with simulations. The possibility of gradient deformation in ion-exchange and hydrophobic interaction chromatography is discussed.

Meteorology and Wake Vortex Influence on American Airlines FL-587 Accident

NASA Technical Reports Server (NTRS)

Proctor, Fred H.; Hamilton, David W.; Rutishauser, David K.; Switzer, George F.

2004-01-01

The atmospheric environment surrounding the crash of American Airlines Flight 587 is investigated. Examined are evidence for any unusual atmospheric conditions and the potential for encounters with aircraft wake vortices. Computer simulations are carried out with two different vortex prediction models and a Large Eddy Simulation model. Wind models are proposed for studying aircraft and pilot response to the wake vortex encounter.

An Unusual Transorbital Penetrating Injury and Principles of Management

PubMed Central

Dekker, Andrew Peter; El-Sawy, Abdel Hamid; Rejali, Darius Stephen

2014-01-01

The objective of this study was to present an unusual low velocity transorbital penetrating injury. The study design was a clinical record (case report). A 38-year-old gentleman tripped and fell face first onto the wing of an ornamental brass eagle. This penetrated the inferomedial aspect of the right orbit, breaching the lamina papyracea to extend into the ethmoid sinuses and reaching the dura of the anterior cranial fossa. The foreign body was removed in theater under a joint ophthalmology and ENT procedure. The patient was left with reduced visual acuity in the right eye but no other long-term sequelae. Transorbital penetrating injury presents unusual challenges to investigation and management requiring a multidisciplinary approach to prevent significant morbidity and mortality. If managed well the prognosis is good. PMID:25383154

An unusual transorbital penetrating injury and principles of management.

PubMed

Dekker, Andrew Peter; El-Sawy, Abdel Hamid; Rejali, Darius Stephen

2014-12-01

The objective of this study was to present an unusual low velocity transorbital penetrating injury. The study design was a clinical record (case report). A 38-year-old gentleman tripped and fell face first onto the wing of an ornamental brass eagle. This penetrated the inferomedial aspect of the right orbit, breaching the lamina papyracea to extend into the ethmoid sinuses and reaching the dura of the anterior cranial fossa. The foreign body was removed in theater under a joint ophthalmology and ENT procedure. The patient was left with reduced visual acuity in the right eye but no other long-term sequelae. Transorbital penetrating injury presents unusual challenges to investigation and management requiring a multidisciplinary approach to prevent significant morbidity and mortality. If managed well the prognosis is good.

Clear cell hidradenocarcinoma--a case report with unusual in situ malignant changes.

PubMed

Al-Irhayim, B

1984-05-01

Clear cell hidradenocarcinoma is a rare tumour, the histogenesis of which has been much debated in the past. However, it is now considered a tumour of sweat gland origin. Presented herewith is a report of a case with unusual histological features of in situ malignant changes within sweat glands. These changes very closely simulate lobular cancerisation of the breast. On reviewing the English literature on the histopathology of sweat gland tumours, we have not found similar histological findings. These histological findings provide supportive evidence of the sweat gland origin of these tumours.

The N-Simplex and Its Generalizations towards Fractals

ERIC Educational Resources Information Center

Kosi-Ulbl, Irena; Pagon, Dusan

2002-01-01

Nature is full of different crystals and many of them have shapes of regular geometric objects. Those in which the fractal structure of a geometric object can be recognized are especially unusual. In this paper a generalization of one of these shapes is described: a formation, based on an n-dimensional simplex. The construction of an n-dimensional…

What's in the Bag (and Why?): Tangibilia for the Classroom.

ERIC Educational Resources Information Center

Ogier, James M.

A classroom technique designed for developing German second language vocabulary is expanded on for additional classroom functions and activities. The method uses a bag containing a variety of objects. The objects are drawn out of the bag and discussed in class. The contents of the bag should be unpredictable and unusual, and they should be changed…

Harnessing out-of-plane deformation to design 3D architected lattice metamaterials with tunable Poisson's ratio.

PubMed

Li, Tiantian; Hu, Xiaoyi; Chen, Yanyu; Wang, Lifeng

2017-08-21

Auxetic materials exhibiting a negative Poisson's ratio are of great research interest due to their unusual mechanical responses and a wide range of potential deployment. Efforts have been devoted to exploring novel 2D and 3D auxetic structures through rational design, optimization, and taking inspiration from nature. Here we report a 3D architected lattice system showing a negative Poisson's ratio over a wide range of applied uniaxial stretch. 3D printing, experimental tests, numerical simulation, and analytical modeling are implemented to quantify the evolution of the Poisson's ratio and reveal the underlying mechanisms responsible for this unusual behavior. We further show that the auxetic behavior can be controlled by tailoring the geometric features of the ligaments. The findings reported here provide a new routine to design architected metamaterial systems exhibiting unusual properties and having a wide range of potential applications.

Synthetic Vision System Commercial Aircraft Flight Deck Display Technologies for Unusual Attitude Recovery

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Ellis, Kyle E.; Arthur, Jarvis J.; Nicholas, Stephanie N.; Kiggins, Daniel

2017-01-01

A Commercial Aviation Safety Team (CAST) study of 18 worldwide loss-of-control accidents and incidents determined that the lack of external visual references was associated with a flight crew's loss of attitude awareness or energy state awareness in 17 of these events. Therefore, CAST recommended development and implementation of virtual day-Visual Meteorological Condition (VMC) display systems, such as synthetic vision systems, which can promote flight crew attitude awareness similar to a day-VMC environment. This paper describes the results of a high-fidelity, large transport aircraft simulation experiment that evaluated virtual day-VMC displays and a "background attitude indicator" concept as an aid to pilots in recovery from unusual attitudes. Twelve commercial airline pilots performed multiple unusual attitude recoveries and both quantitative and qualitative dependent measures were collected. Experimental results and future research directions under this CAST initiative and the NASA "Technologies for Airplane State Awareness" research project are described.

In situ biasing and off-axis electron holography of a ZnO nanowire

NASA Astrophysics Data System (ADS)

den Hertog, Martien; Donatini, Fabrice; McLeod, Robert; Monroy, Eva; Sartel, Corinne; Sallet, Vincent; Pernot, Julien

2018-01-01

Quantitative characterization of electrically active dopants and surface charges in nano-objects is challenging, since most characterization techniques using electrons [1-3], ions [4] or field ionization effects [5-7] study the chemical presence of dopants, which are not necessarily electrically active. We perform cathodoluminescence and voltage contrast experiments on a contacted and biased ZnO nanowire with a Schottky contact and measure the depletion length as a function of reverse bias. We compare these results with state-of-the-art off-axis electron holography in combination with electrical in situ biasing on the same nanowire. The extension of the depletion length under bias observed in scanning electron microscopy based techniques is unusual as it follows a linear rather than square root dependence, and is therefore difficult to model by bulk equations or finite element simulations. In contrast, the analysis of the axial depletion length observed by holography may be compared with three-dimensional simulations, which allows estimating an n-doping level of 1 × 1018 cm-3 and negative sidewall surface charge of 2.5 × 1012 cm-2 of the nanowire, resulting in a radial surface depletion to a depth of 36 nm. We found excellent agreement between the simulated diameter of the undepleted core and the active thickness observed in the experimental data. By combining TEM holography experiments and finite element simulation of the NW electrostatics, the bulk-like character of the nanowire core is revealed.

Dynamical Sequestration of the Moon-Forming Impactor in Co-Orbital Resonance with Earth

NASA Astrophysics Data System (ADS)

Kortenkamp, Stephen J.; Hartmann, William J.

2015-11-01

Recent concerns about the giant impact hypothesis for the origin of the moon, and an associated “isotope crisis” are assuaged if the impactor was a local object that formed near Earth and the impact occurred relatively late. We investigated a scenario that may meet these criteria, with the moon-forming impactor originating in 1:1 co-orbital resonance with Earth. Using N-body numerical simulations we explored the dynamical consequences of placing Mars-mass companions in various co-orbital configurations with a proto-Earth having 90% of its current mass. We modeled configurations that include the four terrestrial planets as well as configurations that also include the four giant planets. In both the 4- and 8-planet models we found that a single additional Mars-mass companion typically remains a stable co-orbital of Earth for the entire 250 million year (Myr) duration of our simulations (33 of 34 simulations). In an effort to destabilize such a system we carried out an additional 45 simulations that included a second Mars-mass co-orbital companion. Even with two Mars-mass companions sharing Earth’s orbit most of these models (28) also remained stable for the entire 250 Myr duration of the simulations. Of the 17 two-companion models that eventually became unstable 12 impacts were observed between Earth and an escaping co-orbital companion. The average delay we observed for an impact of a Mars-mass companion with Earth was 101 Myr, and the longest delay was 221 Myr. Several of the stable simulations involved unusual 3-planet co-orbital configurations that could exhibit interesting observational signatures in plantetary transit surveys.

Preschoolers' encoding of rational actions: the role of task features and verbal information.

PubMed

Pfeifer, Caroline; Elsner, Birgit

2013-10-01

In the current study, we first investigated whether preschoolers imitate selectively across three imitation tasks. Second, we examined whether preschoolers' selective imitation is influenced by differences in the modeled actions and/or by the situational context. Finally, we investigated how verbal cues given by the model affect preschoolers' imitation. Participants (3- to 5-year-olds) watched an adult performing an unusual action in three imitation tasks (touch light, house, and obstacle). In two conditions, the model either was or was not restricted by situational constraints. In addition, the model verbalized either the goal that was to be achieved, the movement, or none of the action components. Preschoolers always acted on the objects without constraints. Results revealed differences in preschoolers' selective imitation across the tasks. In the house task, they showed the selective imitation pattern that has been interpreted as rational, imitating the unusual action more often in the no-constraint condition than in the constraint condition. In contrast, in the touch light task, preschoolers imitated the unusual head touch irrespective of the model's constraints or of the verbal cues that had been presented. Finally, in the obstacle task, children mostly emulated the observed goal irrespective of the presence of the constraint, but they increased their imitation of the unusual action when the movement had been emphasized. Overall, our data suggest that preschoolers adjust their imitative behavior to context-specific information about objects, actions, and their interpretations of the model's intention to teach something. Copyright © 2012 Elsevier Inc. All rights reserved.

The relationships between the arrangement of teeth, root resorption, and dental maturity in bovine mandibular incisors

PubMed Central

An, Jin-kyu; Ono, Takashi

2017-01-01

Objective The objective of this study is to investigate the eruption pattern and root resorption of the bovine anterior dentition in relation to growth-related parameters based on dental maturity. Methods A cross-sectional study was conducted on 110 bovine anterior mandibles by using standard radiography, cone-beam computed tomography (CBCT), and actual measurements. We determined the relationships between the stages of dental maturity by using a modification of Demirjian's method and various growth-related parameters, such as the activity of the root-resorbing tissue and mobility of the deciduous teeth. The correlation of growth-related parameters with interdental spacing and distal unusual root resorption (DRR) of the deciduous fourth incisor was assessed. The cause of mesial unusual root resorption (MRR) of the deciduous fourth incisor was determined on the basis of the arrangement of the permanent third incisor. Results An independent t-test and chi-square test indicated significant differences in growth-related parameters associated with dental arch length discrepancy and factors related to the shedding of deciduous teeth between the low and high dental maturity groups. The samples with interdental spacing and DRR showed a larger sum of mesiodistal permanent crown widths and higher dental maturity than did the respective controls. Samples with MRR tended to show a lingually rotated distal tip of the adjacent tooth crown. Conclusions Dental maturity has relevance to the interdental spaces and unusual root resorption of mixed dentition. The position of the adjacent tooth crown on CBCT may be correlated with the occurrence of unusual root resorption of the incisor. PMID:29090124

The non-trusty clown attack on model-based speaker recognition systems

NASA Astrophysics Data System (ADS)

Farrokh Baroughi, Alireza; Craver, Scott

2015-03-01

Biometric detectors for speaker identification commonly employ a statistical model for a subject's voice, such as a Gaussian Mixture Model, that combines multiple means to improve detector performance. This allows a malicious insider to amend or append a component of a subject's statistical model so that a detector behaves normally except under a carefully engineered circumstance. This allows an attacker to force a misclassification of his or her voice only when desired, by smuggling data into a database far in advance of an attack. Note that the attack is possible if attacker has access to database even for a limited time to modify victim's model. We exhibit such an attack on a speaker identification, in which an attacker can force a misclassification by speaking in an unusual voice, and replacing the least weighted component of victim's model by the most weighted competent of the unusual voice of the attacker's model. The reason attacker make his or her voice unusual during the attack is because his or her normal voice model can be in database, and by attacking with unusual voice, the attacker has the option to be recognized as himself or herself when talking normally or as the victim when talking in the unusual manner. By attaching an appropriately weighted vector to a victim's model, we can impersonate all users in our simulations, while avoiding unwanted false rejections.

Numerical and Analytical Assessment of a Coupled Rotating Detonation Engine and Turbine Experiment

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.; Naples, Andrew

2017-01-01

An analysis is presented of an experimental rig comprising a rotating detonation engine (RDE) with bypass ejector flow coupled to a downstream turbine. The analysis used a validated computational fluid dynamics RDE simulation combined with straightforward algebraic mixing equations for the bypass flow. The objectives of the analysis were to supplement and interpret the necessarily sparse measurements from the rig, and to assess the performance of the RDE itself, which was not instrumented in this installation. The analysis is seen to agree reasonably well with available data. It shows that the RDE is operating in an unusual fashion, with subsonic flow throughout the exhaust plane. The detonation event itself is producing a total pressure rise relative to the pre-detonative pressure; however, the length of the device and the substantial flow restriction at the inlet yield an overall pressure loss. This is not surprising since the objective of the rig test was primarily aimed at investigating RDE turbine interactions, and not on performance optimization. Furthermore, the RDE was designed for fundamental detonation studies and not performance. Nevertheless, the analysis indicates that with some small alterations to the design, an RDE with an overall pressure rise is possible.

Numerical and Analytical Assessment of a Coupled Rotating Detonation Engine and Turbine Experiment

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.; Naples, Andrew

2017-01-01

An analysis is presented of an experimental rig comprising a rotating detonation engine (RDE) with bypass flow coupled to a downstream turbine. The analysis used a validated computational fluid dynamics RDE simulation combined with straightforward algebraic mixing equations for the bypass flow. The objectives of the analysis were to supplement and interpret the necessarily sparse measurements from the rig, and to assess the performance of the RDE itself (which was not instrumented in this installation). The analysis is seen to agree reasonably well with available data. It shows that the RDE is operating in an unusual fashion, with subsonic flow throughout the exhaust plane. The detonation event itself is producing a total pressure rise relative to the pre-detonative pressure; however, the length of the device and the substantial flow restriction at the inlet yield an overall pressure loss. This is not surprising since the objective of the rig test was primarily aimed at investigating RDEturbine interactions, and not on performance optimization. Furthermore, the RDE was designed for fundamental detonation studies and not performance. Nevertheless, the analysis indicates that with some small alterations to the design, an RDE with an overall pressure rise is possible.

Numerical and Analytical Assessment of a Coupled Rotating Detonation Engine and Turbine Experiment

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.; Naples, Andrew

2017-01-01

An analysis is presented of an experimental rig comprising a rotating detonation engine (RDE) with bypass ejector flow coupled to a downstream turbine. The analysis used a validated computational fluid dynamics RDE simulation combined with straightforward algebraic mixing equations for the bypass flow. The objectives of the analysis were to supplement and interpret the necessarily sparse measurements from the rig, and to assess the performance of the RDE itself, which was not instrumented in this installation. The analysis is seen to agree reasonably well with available data. It shows that the RDE is operating in an unusual fashion, with subsonic flow throughout the exhaust plane. The detonation event itself is producing a total pressure rise relative to the pre-detonative pressure; however, the length of the device and the substantial flow restriction at the inlet yield an overall pressure loss. This is not surprising since the objective of the rig test was primarily aimed at investigating RDE/turbine interactions, and not on performance optimization. Furthermore, the RDE was designed for fundamental detonation studies and not performance. Nevertheless, the analysis indicates that with some small alterations to the design, an RDE with an overall pressure rise is possible.

Teacher's Guide to Imagination Unlimited. The MATCH Book Project; Prototype Edition.

ERIC Educational Resources Information Center

Williams, Susan; Williamson, Sharon

The idea of this box of multimedia instructional materials is to surround the children with curious and wonderful objects and experiences which will stimulate them to self-expression. The kit provides a set of unusual objects: two movies about a rainshower, one from a weatherman's point of view and one as seen through the eyes of an artist; a set…

Food Preference, Acceptance and Consumption in a Simulated, Isolated- Duty Station

DTIC Science & Technology

1977-05-01

study food habits in a controlled isolation environment ,the fo6d choice and consumption behavior of the crew of a simulated, isolated-duty sta...Instructions for Consumption Diary 78 Appendix C: Food Items on Preference Survey List which were not on Menu 80 Appendix D: Item Name Changes Made to...U 1 SUMMARY The effectiveness of isolated duty stations depends on unusually careful planning to compensate for storage and logistical limitations

Apollo program flight summary report: Apollo missions AS-201 through Apollo 16, revision 11

NASA Technical Reports Server (NTRS)

Holcomb, J. K.

1972-01-01

A summary of the Apollo flights from AS-201 through Apollo 16 is presented. The following subjects are discussed for each flight: (1) mission primary objectives, (2) principle objectives of the launch vehicle and spacecraft, (3) secondary objectives of the launch vehicle and spacecraft, (4) unusual features of the mission, (5) general information on the spacecraft and launch vehicle, (6) space vehicle and pre-launch data, and (7) recovery data.

The Unusual Minimum of Cycle 23: Observations and Interpretation

NASA Astrophysics Data System (ADS)

Martens, Petrus C.; Nandy, D.; Munoz-Jaramillo, A.

2009-05-01

The current minimum of cycle 23 is unusual in its long duration, the very low level to which Total Solar Irradiance (TSI) has fallen, and the small flux of the open polar fields. The deep minimum of TSI seems to be related to an unprecedented dearth of polar faculae, and hence to the small amount of open flux. Based upon surface flux transport models it has been suggested that the causes of these phenomena may be an unusually vigorous meridional flow, or even a deviation from Joy's law resulting in smaller Joy angles than usual for emerging flux in cycle 23. There is also the possibility of a connection with the recently inferred emergence in polar regions of bipoles that systematically defy Hale's law. Much speculation has been going on as to the consequences of this exceptional minimum: are we entering another global minimum, is this the end of the 80 year period of exceptionally high solar activity, or is this just a statistical hiccup? Dynamo simulations are underway that may help answer this question. As an aside it must be mentioned that the current minimum of TSI puts an upper limit in the TSI input for global climate simulations during the Maunder minimum, and that a possible decrease in future solar activity will result in a very small but not insignificant reduction in the pace of global warming.

The First Stars: A Low-Mass Formation Mode

NASA Technical Reports Server (NTRS)

Stacy, Athena; Bromm, Volker

2014-01-01

We perform numerical simulations of the growth of a Population III stellar system under photodissociating feedback. We start from cosmological initial conditions at z = 100, self-consistently following the formation of a minihalo at z = 15 and the subsequent collapse of its central gas to high densities. The simulations resolve scales as small as approx. 1 AU, corresponding to gas densities of 10(exp 16)/cu cm. Using sink particles to represent the growing protostars, we evolve the stellar system for the next 5000 yr. We find that this emerging stellar group accretes at an unusually low rate compared with minihalos which form at earlier times (z = 20-30), or with lower baryonic angular momentum. The stars in this unusual system will likely reach masses ranging from <1Stellar Mass to approx. 5 Stellar Mass by the end of their main-sequence lifetimes, placing them in the mass range for which stars will undergo an asymptotic giant branch (AGB) phase. Based upon the simulation, we predict the rare existence of Population III stars that have survived to the present day and have been enriched by mass overflow from a previous AGB companion.

Distant Galaxies in Goods North

NASA Image and Video Library

2014-01-07

The view is a composite of images taken in visible and near-infrared light by NASA Hubble Space Telescope. Researchers have circled four unusually red objects that appear as they existed just 500 million years after the big bang.

Airport and superficial femoral artery obstruction due to a wandering coronary stent: the possibility of airport detection of modern implant metals.

PubMed

Teijink, J A W; van Herwaarden, J A; van den Berg, J C; Overtoom, T C; Moll, F L

2004-06-01

In the treatment of coronary artery disease, peripheral loss of a coronary stent is an unusual complication. We present the case of a patient who suggested that his right leg claudication was caused by a slipped coronary stent 2 years previously. The patient was convinced about this unusual finding based on an airport security check. Examination proved him to be right. However, the ability to detect an object using eddy currents is dependent on the object's permeability and its conductivity. Ferrous (iron) content is not the critical factor. Modern implant materials and processing techniques result in implants that are difficult to magnetize i.e. their permeability is very low. In addition their conductivity is very low. This enables modern implants to escape detection at airports. For this reason the event at the airport, as described by our patient, is considered coincidental.

A Carbonaceous Chondrite Based Simulant of Phobos

NASA Technical Reports Server (NTRS)

Rickman, Douglas L.; Patel, Manish; Pearson, V.; Wilson, S.; Edmunson, J.

2016-01-01

In support of an ESA-funded concept study considering a sample return mission, a simulant of the Martian moon Phobos was needed. There are no samples of the Phobos regolith, therefore none of the four characteristics normally used to design a simulant are explicitly known for Phobos. Because of this, specifications for a Phobos simulant were based on spectroscopy, other remote measurements, and judgment. A composition based on the Tagish Lake meteorite was assumed. The requirement that sterility be achieved, especially given the required organic content, was unusual and problematic. The final design mixed JSC-1A, antigorite, pseudo-agglutinates and gilsonite. Sterility was achieved by radiation in a commercial facility.

Unusual foreign bodies in the orofacial region.

PubMed

Passi, Sidhi; Sharma, Neeraj

2012-01-01

Foreign bodies may be deposited in the oral cavity either by traumatic injury or iatrogenically. Among the commonly encountered iatrogenic foreign bodies are restorative materials like amalgam, obturation materials, broken instruments, needles, and so forth. The discovery of foreign bodies in the teeth is a special situation, which is often diagnosed accidentally. Detailed case history, clinical and radiographic examinations are necessary to come to a conclusion about the nature, size, location of the foreign body, and the difficulty involved in its retrieval. It is more common to find this situation in children as it is a well-known fact that children often tend to have the habit of placing foreign objects in the mouth. Sometimes the foreign objects get stuck in the root canals of the teeth, which the children do not reveal to their parents due to fear. These foreign objects may act as a potential source of infection and may later lead to a painful condition. This paper discusses the presence of unusual foreign bodies-a tip of the metallic compass, stapler pin, copper strip, and a broken sewing needle impregnated in the gingiva and their management.

Unusual Foreign Bodies in the Orofacial Region

PubMed Central

Passi, Sidhi; Sharma, Neeraj

2012-01-01

Foreign bodies may be deposited in the oral cavity either by traumatic injury or iatrogenically. Among the commonly encountered iatrogenic foreign bodies are restorative materials like amalgam, obturation materials, broken instruments, needles, and so forth. The discovery of foreign bodies in the teeth is a special situation, which is often diagnosed accidentally. Detailed case history, clinical and radiographic examinations are necessary to come to a conclusion about the nature, size, location of the foreign body, and the difficulty involved in its retrieval. It is more common to find this situation in children as it is a well-known fact that children often tend to have the habit of placing foreign objects in the mouth. Sometimes the foreign objects get stuck in the root canals of the teeth, which the children do not reveal to their parents due to fear. These foreign objects may act as a potential source of infection and may later lead to a painful condition. This paper discusses the presence of unusual foreign bodies—a tip of the metallic compass, stapler pin, copper strip, and a broken sewing needle impregnated in the gingiva and their management. PMID:22830058

The weapon focus effect is weaker with Black versus White male perpetrators.

PubMed

Pickel, Kerri L; Sneyd, Danielle E

2018-01-01

We compared the influence of a weapon's presence on eyewitnesses' memory for a White versus a Black male perpetrator. Prior data indicate that unusual objects in visual scenes attract attention and that a weapon's effect depends on how unusual it seems within the context in which it appears. Therefore, given the stereotype linking Black men and weapons, we predicted a weaker weapon focus effect with the Black perpetrator. The results of Experiment 1 supported this hypothesis using White and Black witnesses. Moreover, in Experiment 2 the weapon focus effect became nonsignificant when the Black perpetrator wore a style of clothing that is strongly associated with Black men. We propose that observing an armed Black perpetrator automatically activates a stereotype linking Black men with weapons and crime, which in turn reduces the perceived unusualness of the weapon and thus its ability to attract attention.

Secure Container For Discarded Hypodermic Needles

NASA Technical Reports Server (NTRS)

Lee, Angelene M.

1992-01-01

Container designed for safe retention of discarded blood-collecting hypodermic needles and similar sharp objects used in life-science experiments aboard spacecraft. Needles inserted through self-closing lid and retained magnetically. They are inserted, sharp end first, through spring-loaded flap. Long needles and needles on syringes cannot turn around in container. Can be emptied, cleaned, and reused. Used on Earth to provide unusually secure containment of sharp objects.

A hybrid genetic algorithm for resolving closely spaced objects

NASA Technical Reports Server (NTRS)

Abbott, R. J.; Lillo, W. E.; Schulenburg, N.

1995-01-01

A hybrid genetic algorithm is described for performing the difficult optimization task of resolving closely spaced objects appearing in space based and ground based surveillance data. This application of genetic algorithms is unusual in that it uses a powerful domain-specific operation as a genetic operator. Results of applying the algorithm to real data from telescopic observations of a star field are presented.

Face-to-Face Packing of 2,3,9,10-Tetrasubstituted Pentacene Derivatives Revealed through a Solid State [4 + 4] Thermal Cycloaddition and Molecular Dynamic Simulation.

PubMed

Pal, Bikash; Lin, Bo-Chao; Dela Cerna, Mark Vincent Carreon; Hsu, Chao-Ping; Lin, Chih-Hsiu

2016-08-05

2,3,9,10-Substituted pentacene tetraesters and pentacene diester-dinitriles were synthesized. These pentacene derivatives underwent an unusual solid state [4 + 4] thermal dimerization with good efficiency and complete stereoselectivity. This observation indicates this series of pentacene derivatives adopt π-π stacking geometry with large mutual overlap in solid state. This notion was confirmed by molecualr dynamic simulation.

Experimental evaluation of a unique radiometer for use in solar simulation testing

NASA Technical Reports Server (NTRS)

Richmond, R. G.

1978-01-01

The vane radiometer is designed to operate over the range 0-1 solar constant and is capable of withstanding temperatures over the range -200 to +175 C. Two of these radiometers, for use in the Johnson Space Center's largest space simulator, have been evaluated for: (1) thermal sensitivity with no solar input, (2) linearity as a function of solar simulation input, and (3) output drift as a function of time. The minimum sensitivity was measured to be approximately 25.5 mV/solar constant. An unusual effect in the pressure range 760 to 1.0 torr is discussed.

Safety evaluation of new roads.

DOT National Transportation Integrated Search

2002-09-01

The primary objective of this research study was to evaluate the crash history of bypass routes to determine if there were unusual patterns or changes in the crash history on these routes over the first years of operation. The focus of the evaluation...

Measurement of Solid Rocket Propellant Burning Rate Using X-ray Imaging

NASA Astrophysics Data System (ADS)

Denny, Matthew D.

The burning rate of solid propellants can be difficult to measure for unusual burning surface geometries, but X-ray imaging can be used to measure burning rate. The objectives of this work were to measure the baseline burning rate of an electrically-controlled solid propellant (ESP) formulation with real-time X-ray radiography and to determine the uncertainty of the measurements. Two edge detection algorithms were written to track the burning surface in X-ray videos. The edge detection algorithms were informed by intensity profiles of simulated 2-D X-ray images. With a 95% confidence level, the burning rates measured by the Projected-Slope Intersection algorithm in the two combustion experiments conducted were 0.0839 in/s +/-2.86% at an average pressure of 407 psi +/-3.6% and 0.0882 in/s +/-3.04% at 410 psi +/-3.9%. The uncertainty percentages were based on the statistics of a Monte Carlo analysis on burning rate.

Clinical characterization of unusual cystic echinococcosis in southern part of Turkey.

PubMed

Akcam, Atlgan Tolga; Ulku, Abdullah; Koltas, Ismail Soner; Izol, Volkan; Bicer, Omer Sunkar; Kilicbagir, Emine; Sakman, Gurhan; Poyrazoglu, Hakan; Erman, Tahsin; Aridogan, Ibrahim Atilla; Parsak, Cem Kaan; Inal, Mehmet; Iskit, Serdar

2014-01-01

The incidence of primary extrahepatic cystic echinococcosis (CE) is rare. Generally, radiological and serological findings can help establish the diagnosis of hepatic and pulmonary CE, but a CE in an unusual location with atypical radiological findings may complicate the differential diagnosis. The objective of this study is to present the characteristics of cases with extrahepatic CE in respect of sites of involvement, clinical presentations, radiological findings, serological diagnostic evaluations, and outcomes of infected patients. A retrospective analysis of surgically treated CE was conducted between January 1993 and January 2014 in the General Surgery, Pediatric Surgery, Urology, Cardiovascular Surgery, Neurosurgery, and Orthopedics departments of University of Cukurova, Faculty of Medicine, Balcal Hospital. Among the 661 patients managed for CE, 134 had unusual sites of involvement. Radiological and serological examinations were used to differentiate CE from alveolar echinococcosis. Of 134 cases with unusual sites of involvement, 32 cases had liver CE (23.9%), 7 cases had lung CE (5.2%), and 2 cases had concomitant liver and lung CE (1.5%). In 93 (69.4%) cases, unusual organ involvement was isolated without any liver or lung involvement. The mean age was 45 years. Abdominal pain was the main symptom and was found in 104 patients. Thirty-one (23.1%) of 134 extrahepatic CE cases were evaluated as negative with indirect hemagglutination (IHA). However, positive results were obtained in 54 cases evaluated with Echinococcus granulosus IgG Western blot (WB), including 10 IHA-negative cases. CE with unusual localizations may cause serious problems of diagnostic confusion. The combination of clinical history, radiological findings, and serological test results (especially the WB) are valuable in diagnosing extrahepatic CE.

The Intrinsically X-Ray-weak Quasar PHL 1811. II. Optical and UV Spectra and Analysis

NASA Astrophysics Data System (ADS)

Leighly, Karen M.; Halpern, Jules P.; Jenkins, Edward B.; Casebeer, Darrin

2007-11-01

This is the second of two papers reporting observations and analysis of the unusually bright (mb=14.4), luminous (MB=-25.5), nearby (z=0.192) narrow-line quasar PHL 1811. The first paper reported that PHL 1811 is intrinsically X-ray-weak and presented a spectral energy distribution (SED). Here we present HST STIS optical and UV spectra, and ground-based optical spectra. The optical and UV line emission is very unusual. There is no evidence for forbidden or semiforbidden lines. The near-UV spectrum is dominated by very strong Fe II and Fe III, and unusual low-ionization lines such as Na I D and Ca II H and K are observed. High-ionization lines are very weak; C IV has an equivalent width of 6.6 Å, a factor of ~5 smaller than measured from quasar composite spectra. An unusual feature near 1200 Å can be deblended in terms of Lyα, N V, Si II, and C III* using the blueshifted C IV profile as a template. Photoionization modeling shows that the unusual line emission can be explained qualitatively by the unusually soft SED. Principally, a low gas temperature results in inefficient emission of collisionally excited lines, including the semiforbidden lines generally used as density diagnostics. The emission resembles that of high-density gas; in both cases this is a consequence of inefficient cooling. PHL 1811 is very unusual, but we note that quasar surveys may be biased against finding similar objects. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with proposal 9181. Based on observations obtained at Kitt Peak National Observatory, a division of the National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.

Characteristics of challenging behaviours in adults with autistic disorder, PDD-NOS, and intellectual disability.

PubMed

Matson, Johnny L; Rivet, Tessa T

2008-12-01

Challenging behaviours are frequently a problem for people with autism spectrum disorders (ASD) and intellectual disability (ID). A better understanding of which individuals display which behaviours, at what rates, and the relationship of these behaviours to comorbid psychopathology would have important implications. A group of 161 adults with ASD (autistic disorder or Pervasive Developmental Disorder--Not Otherwise Specified [PDD-NOS]) and 159 matched controls with ID only residing in two large residential facilities in Southeastern United States, were studied using the Autism Spectrum Disorders--Behavior Problems for Adults (ASD-BPA). In all four categories of challenging behaviour measured by the ASD-BPA (Aggression/Destruction, Stereotypy, Self-Injurious Behavior, and Disruptive Behavior), frequency of challenging behaviours increased with severity of autistic symptoms. The greatest group differences were found for Stereotypy (repeated/unusual vocalisations/body movements and unusual object play), Self-Injurious Behavior (harming self and mouthing/swallowing objects), Aggression/Destruction (banging on objects), and Disruptive Behavior (elopement). Challenging behaviours in people with ASD and ID are barriers to effective education, training, and social development, and often persist throughout adulthood. Thus, programs designed to remediate such behaviours should continue across the life-span of these individuals.

Impalement of an unusual foreign body on the temporomandibular joint causing severe trismus.

PubMed

Ito, Ryohei; Kubota, Kosei; Furudate, Ken; Nakagawa, Hiroshi; Kon, Takao; Tamura, Yoshihiro; Kobayashi, Wataru

2016-12-01

A penetrating injury by a foreign body is comparatively common in the oral and maxillofacial region. On the other hand, injury to the temporomandibular joint (TMJ) by a foreign object is very rare. The TMJ is an anatomically narrow space surrounded by hard bony processes. An unusual case of trauma with severe trismus caused by a foreign body that impaled the TMJ is reported. A 55-year-old man presented with a 5 × 1-cm laceration to the right cheek caused by a flying object propelled during the use of a lawn mower. The edge of the foreign body had a metallic wire, which became imbedded in the wound. His jaw opening was severely limited. Computed tomography revealed that the foreign body was 3 mm in diameter and was impaled on the articular capsule. The object was successfully removed, and the wound and interior of the TMJ were irrigated. Rehabilitation of mouth opening was started on postoperative day 3. On day 9, mouth opening had improved to 35 mm, and he was discharged. After 1 year, mouth opening was 45 mm with no sign of any TMJ disorders. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

THE SWIFT BAT SURVEY DETECTS TWO OPTICAL BROAD LINE, X-RAY HEAVILY OBSCURED ACTIVE GALAXIES: NVSS 193013+341047 AND IRAS 05218-1212

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

Hogg, J. Drew; Winter, Lisa M.; Mushotzky, Richard F.

2012-06-20

The Swift Burst Alert Telescope (BAT) is discovering interesting new objects while monitoring the sky in the 14-195 keV band. Here we present the X-ray properties and spectral energy distributions (SEDs) for two unusual active galactic nucleus sources. Both NVSS 193013+341047 and IRAS 05218-1212 are absorbed, Compton-thin, but heavily obscured (N{sub H} {approx} 10{sup 23} cm{sup -2}), X-ray sources at redshifts <0.1. The SEDs reveal these galaxies to be very red, with high extinction in the optical and UV. A similar SED is seen for the extremely red objects (EROs) detected in the higher redshift universe. This suggests that thesemore » unusual BAT-detected sources are a low-redshift (z << 1) analog to EROs, which recent evidence suggests are a class of the elusive type II quasars. Studying the multi-wavelength properties of these sources may reveal the properties of their high-redshift counterparts.« less

Kinetic simulation of edge instability in fusion plasmas

NASA Astrophysics Data System (ADS)

Fulton, Daniel Patrick

In this work, gyrokinetic simulations in edge plasmas of both tokamaks and field reversed. configurations (FRC) have been carried out using the Gyrokinetic Toroidal Code (GTC) and A New Code (ANC) has been formulated for cross-separatrix FRC simulation. In the tokamak edge, turbulent transport in the pedestal of an H-mode DIII-D plasma is. studied via simulations of electrostatic driftwaves. Annulus geometry is used and simulations focus on two radial locations corresponding to the pedestal top with mild pressure gradient and steep pressure gradient. A reactive trapped electron instability with typical ballooning mode structure is excited in the pedestal top. At the steep gradient, the electrostatic instability exhibits unusual mode structure, peaking at poloidal angles theta=+- pi/2. Simulations find this unusual mode structure is due to steep pressure gradients in the pedestal but not due to the particular DIII-D magnetic geometry. Realistic DIII-D geometry has a stabilizing effect compared to a simple circular tokamak geometry. Driftwave instability in FRC is studied for the first time using gyrokinetic simulation. GTC. is upgraded to treat realistic equilibrium calculated by an MHD equilibrium code. Electrostatic local simulations in outer closed flux surfaces find ion-scale modes are stable due to the large ion gyroradius and that electron drift-interchange modes are excited by electron temperature gradient and bad magnetic curvature. In the scrape-off layer (SOL) ion-scale modes are excited by density gradient and bad curvature. Collisions have weak effects on instabilities both in the core and SOL. Simulation results are consistent with density fluctuation measurements in the C-2 experiment using Doppler backscattering (DBS). The critical density gradients measured by the DBS qualitatively agree with the linear instability threshold calculated by GTC simulations. One outstanding critical issue in the FRC is the interplay between turbulence in the FRC. core and SOL regions. While the magnetic flux coordinates used by GTC provide a number of computational advantages, they present unique challenges at the magnetic field separatrix. To address this limitation, a new code, capable of coupled core-SOL simulations, is formulated, implemented, and successfully verified.

An Unusual Hydrophobic Core Confers Extreme Flexibility to HEAT Repeat Proteins

PubMed Central

Kappel, Christian; Zachariae, Ulrich; Dölker, Nicole; Grubmüller, Helmut

2010-01-01

Alpha-solenoid proteins are suggested to constitute highly flexible macromolecules, whose structural variability and large surface area is instrumental in many important protein-protein binding processes. By equilibrium and nonequilibrium molecular dynamics simulations, we show that importin-β, an archetypical α-solenoid, displays unprecedentedly large and fully reversible elasticity. Our stretching molecular dynamics simulations reveal full elasticity over up to twofold end-to-end extensions compared to its bound state. Despite the absence of any long-range intramolecular contacts, the protein can return to its equilibrium structure to within 3 Å backbone RMSD after the release of mechanical stress. We find that this extreme degree of flexibility is based on an unusually flexible hydrophobic core that differs substantially from that of structurally similar but more rigid globular proteins. In that respect, the core of importin-β resembles molten globules. The elastic behavior is dominated by nonpolar interactions between HEAT repeats, combined with conformational entropic effects. Our results suggest that α-solenoid structures such as importin-β may bridge the molecular gap between completely structured and intrinsically disordered proteins. PMID:20816072

Unusual Crystallization Behavior Close to the Glass Transition

NASA Astrophysics Data System (ADS)

Desgranges, Caroline; Delhommelle, Jerome

2018-03-01

Using molecular simulations, we shed light on the mechanism underlying crystal nucleation in metal alloys and unravel the interplay between crystal nucleation and glass transition, as the conditions of crystallization lie close to this transition. While decreasing the temperature of crystallization usually results in a lower free energy barrier, we find an unexpected reversal of behavior for glass-forming alloys as the temperature of crystallization approaches the glass transition. For this purpose, we simulate the crystallization process in two glass-forming Copper alloys, Ag6 Cu4 , which has a positive heat of mixing, and CuZr, characterized by a large negative heat of mixing. Our results allow us to identify this unusual behavior as directly correlated with a nonmonotonic temperature dependence for the formation energy of connected icosahedral structures, which are incompatible with crystalline order and impede the development of the crystal nucleus, leading to an unexpectedly larger free energy barrier at low temperature. This, in turn, promotes the formation of a predominantly closed-packed critical nucleus, with fewer defects, thereby suggesting a new way to control the structure of the crystal nucleus, which is of key importance in catalysis.

Thermoluminescence of Antarctic meteorites: A rapid screening technique for terrestrial age estimation, pairing studies and identification of specimens with unusual prefall histories

NASA Technical Reports Server (NTRS)

Sutton, S. R.; Walker, R. M.

1986-01-01

Thermoluminescence (TL) is a promising technique for rapid screening of the large numbers of Antarctic meteorites, permitting identification of interesting specimens that can then be studied in detail by other, more definite techniques. Specifically, TL permits determination of rough terrestrial age, identification of potential paired groups and location of specimens with unusual pre-fall histories. Meteorites with long terrestrial ages are particularly valuable for studying transport and weathering mechanisms. Pairing studies are possible because TL variations among meteorites are large compared to variations within individual objects, especially for natural TL. Available TL data for several L3 fragments, three of which were paired by other techniques, are presented as an example of the use of TL parameters in pairing studies. Additional TL measurements, specifically a blind test, are recommended to satisfactorily establish the reliability of this pairing property. The TL measurements also identify fragments with unusual pre-fall histories, such an near-Sun orbits.

Synchronous Parallel Emulation and Discrete Event Simulation System with Self-Contained Simulation Objects and Active Event Objects

NASA Technical Reports Server (NTRS)

Steinman, Jeffrey S. (Inventor)

1998-01-01

The present invention is embodied in a method of performing object-oriented simulation and a system having inter-connected processor nodes operating in parallel to simulate mutual interactions of a set of discrete simulation objects distributed among the nodes as a sequence of discrete events changing state variables of respective simulation objects so as to generate new event-defining messages addressed to respective ones of the nodes. The object-oriented simulation is performed at each one of the nodes by assigning passive self-contained simulation objects to each one of the nodes, responding to messages received at one node by generating corresponding active event objects having user-defined inherent capabilities and individual time stamps and corresponding to respective events affecting one of the passive self-contained simulation objects of the one node, restricting the respective passive self-contained simulation objects to only providing and receiving information from die respective active event objects, requesting information and changing variables within a passive self-contained simulation object by the active event object, and producing corresponding messages specifying events resulting therefrom by the active event objects.

Catastrophic Disruption Threshold and Maximum Deflection from Kinetic Impact

NASA Astrophysics Data System (ADS)

Cheng, A. F.

2017-12-01

The use of a kinetic impactor to deflect an asteroid on a collision course with Earth was described in the NASA Near-Earth Object Survey and Deflection Analysis of Alternatives (2007) as the most mature approach for asteroid deflection and mitigation. The NASA DART mission will demonstrate asteroid deflection by kinetic impact at the Potentially Hazardous Asteroid 65803 Didymos in October, 2022. The kinetic impactor approach is considered to be applicable with warning times of 10 years or more and with hazardous asteroid diameters of 400 m or less. In principle, a larger kinetic impactor bringing greater kinetic energy could cause a larger deflection, but input of excessive kinetic energy will cause catastrophic disruption of the target, leaving possibly large fragments still on collision course with Earth. Thus the catastrophic disruption threshold limits the maximum deflection from a kinetic impactor. An often-cited rule of thumb states that the maximum deflection is 0.1 times the escape velocity before the target will be disrupted. It turns out this rule of thumb does not work well. A comparison to numerical simulation results shows that a similar rule applies in the gravity limit, for large targets more than 300 m, where the maximum deflection is roughly the escape velocity at momentum enhancement factor β=2. In the gravity limit, the rule of thumb corresponds to pure momentum coupling (μ=1/3), but simulations find a slightly different scaling μ=0.43. In the smaller target size range that kinetic impactors would apply to, the catastrophic disruption limit is strength-controlled. A DART-like impactor won't disrupt any target asteroid down to significantly smaller size than the 50 m below which a hazardous object would not penetrate the atmosphere in any case unless it is unusually strong.

Engineering optical properties using plasmonic nanostructures

NASA Astrophysics Data System (ADS)

Tamma, Venkata Ananth

Plasmonic nanostructures can be engineered to take on unusual optical properties not found in natural materials. The optical responses of plasmonic materials are functions of the structural parameters and symmetry of the nanostructures, material parameters of the nanostructure and its surroundings and the incidence angle, frequency and polarization state of light. The scattering and hence the visibility of an object could be reduced by coating it with a plasmonic material. In this thesis, presented is an optical frequency scattering cancelation device composed of a silicon nanorod coated by a plasmonic gold nanostructure. The principle of operation was theoretically analyzed using Mie theory and the device design was verified by extensive numerical simulations. The device was fabricated using a combination of nanofabrication techniques such as electron beam lithography and focused ion beam milling. The optical responses of the scattering cancelation device and a control sample of bare silicon rod were directly visualized using near-field microscopy coupled with heterodyne interferometric detection. The experimental results were analyzed and found to match very well with theoretical prediction from numerical simulations thereby validating the design principles and our implementation. Plasmonic nanostructures could be engineered to exhibit unique optical properties such as Fano resonance characterized by narrow asymmetrical lineshape. We present dynamic tuning and symmetry lowering of Fano resonances in plasmonic nanostructures fabricated on flexible substrates. The tuning of Fano resonance was achieved by application of uniaxial mechanical stress. The design of the nanostructures was facilitated by extensive numerical simulations and the symmetry lowering was analyzed using group theoretical methods. The nanostructures were fabricated using electron beam lithography and optically characterized for various mechanical stress. The experimental results were in good agreement with the numerical simulations. The mechanically tunable plasmonic nanostructure could serve as a platform for dynamically tunable nanophotonic devices such as sensors and tunable filters.

Breed x sex effects on birth weight in Brahman-Simmental embryo transfer calves

USDA-ARS?s Scientific Manuscript database

Brahman cross calves exhibit unusual inheritance of birth weight: Brahman-sired crossbreds out of Bos taurus females are heavier with greater difference between sexes than calves of the reciprocal cross. The objective of this work was to compare birth weight in various crosses of Brahman, Simmenta...

Explaining Autism: Its Discursive and Neuroanatomical Characteristics.

ERIC Educational Resources Information Center

Oller, John W., Jr.; Rascon, Dana

This paper reviews the existing empirical research on autism in the context of the semiotic theories of Charles S. Peirce. His ideas of the generalized logic of relations are seen as explaining the unusual associations (or lack thereof) in autism. Concepts of "indices" or signs singling out distinct objects, and "adinity" or…

Tennis Rackets and the Parallel Axis Theorem

ERIC Educational Resources Information Center

Christie, Derek

2014-01-01

This simple experiment uses an unusual graph straightening exercise to confirm the parallel axis theorem for an irregular object. Along the way, it estimates experimental values for g and the moment of inertia of a tennis racket. We use Excel to find a 95% confidence interval for the true values.

The Peanut Plant and Light: Spermidines from Peanut Flowers and Studies of their Photoisomerization

USDA-ARS?s Scientific Manuscript database

Early history and significance of the peanut crop is discussed. Annual world production of peanuts at 30 million tons makes this crop one of the most important agricultural commodities. Unusual physiology, inflorescence, and infructescence of the peanut plant make it an attractive object for scienti...

Increasing of horizontal velocity of particles leaving a belt conveyor

NASA Astrophysics Data System (ADS)

Tavares, Abraão; Faria, Allbens

2017-06-01

We investigate the transport of granular materials by a conveyor belt via numerical simulations. We report an unusual increasing of particles horizontal velocity when they leave the belt and initiate free-fall. Using Discrete Elements Method, the mechanism underlying this phenomenon were investigated, and a study on how particle and system properties influences this effect were conducted.

TH28 (Krautter's star) and its string of Herbig-Haro objects

NASA Technical Reports Server (NTRS)

Graham, J. A.; Heyer, Mark H.

1988-01-01

A high-quality spectrogram of the unusual T Tauri-like star Th28 and its string of Herbig-Haro (HH) objects has been obtained. New velocities and line intensities for the star and the gaseous knots are reported, and data are given for a third HH object located 87 arcsec to the SE along the same collimation axis as defined by the other features. Th28 has a heliocentric velocity of +5 km/s which is close to the velocity of the CO in the area. The star's spectral type is probably in the G8-K2 range.

X-ray and optical observations of 2 new cataclysmic variables

NASA Technical Reports Server (NTRS)

Singh, K. P.; Szkody, P.; Barrett, P.; Schlegel, E.; White, N. E.; Silber, A.; Fierce, E.; Hoard, D.; Hakala, P. J.; Piirola, V.;

Surgeon-authored Virtual Laparoscopic Adrenalectomy Module is Judged Effective and Preferred over Traditional Teaching Tools

PubMed Central

Kurenov, Sergei; Cendan, Juan; Dindar, Sahel; Attwood, Kristopher; Hassett, James; Nawotniak, Ruth; Cherr, Gregory; Cance, William G.; Peters, Jörg

2018-01-01

Objective The study assesses user acceptance and effectiveness of a surgeon-authored virtual reality training module authored by surgeons using the Toolkit for Illustration Procedures in Surgery (TIPS). Methods Laparoscopic adrenalectomy was selected to test the TIPS framework on an unusual and complex procedure. No commercial simulation module exists to teach this procedure. A specialist surgeon authored the module, including force-feedback interactive simulation and designed a quiz to test knowledge of the key procedural steps. Five practicing surgeons with 15 to 24 years of experience peer-reviewed and tested the module. Fourteen residents and nine fellows trained with the module and answered the quiz, pre-use and post-use. Participants received an overview during Surgical Grand Rounds session and a 20-minute one- on-one tutorial followed by a 30 minute of instruction in addition to a force-feedback interactive simulation session. Additionally, in answering questionnaires, the trainees reflected on their learning experience and their experience with the TIPS framework. Results Correct quiz response rates on procedural steps improved significantly post-use over pre-use. In the questionnaire, 96% of the respondents stated that the TIPS module prepares them well or very well for the adrenalectomy, and 87% indicated that the module successfully teaches the steps of the procedure. All subjects indicated that they preferred the module compare to training using purely physical props, one-on-one teaching, medical atlases, and video recordings. Conclusions Improved quiz scores and endorsement by the participants of the TIPS adrenalectomy module establish the viability of surgeons authoring virtual reality training. PMID:27758896

[Münchhausen syndrome by proxy].

PubMed

Le Heuzey, M-F; Mouren, M-C

2008-01-01

Münchhausen syndrome by proxy is a factitious disorder, a disease produced or simulated by a parent, the mother in most cases. Clinical presentation is miscellaneous (factitious bleeding, epilepsy, apnea are frequent) and unusual. Physicians participate in the abuse by their therapeutic and diagnostical measures. It is very important to think about this diagnostic in any ambiguous situation in order to evaluate and protect the child.

"Water and Environmental Systems": Achieving Student-Centered Learning Objectives with an Undergraduate Journal.

ERIC Educational Resources Information Center

Charlesworth, Susanne M.; Foster, Ian D. L.

1996-01-01

Describes and evaluates an unusual and innovative assessment procedure used in an undergraduate hydrology and oceanography class. Working in teams, English students produce research articles published by an in-house, though refereed, academic journal. Professors and students agree that the process stimulates students to perform at their highest…

34 CFR 222.64 - What other requirements must a local educational agency meet in order to be eligible for...

Code of Federal Regulations, 2014 CFR

2014-07-01

... SECONDARY EDUCATION, DEPARTMENT OF EDUCATION IMPACT AID PROGRAMS Additional Assistance for Heavily Impacted... applicant's current expenditures are affected by unusual geographical factors; and (ii) As a result, those... factors on which the applicant is basing its request for compensation under this section and objective...

34 CFR 222.64 - What other requirements must a local educational agency meet in order to be eligible for...

Code of Federal Regulations, 2012 CFR

2012-07-01

... SECONDARY EDUCATION, DEPARTMENT OF EDUCATION IMPACT AID PROGRAMS Additional Assistance for Heavily Impacted... applicant's current expenditures are affected by unusual geographical factors; and (ii) As a result, those... factors on which the applicant is basing its request for compensation under this section and objective...

Hey, There's a Forest in that Classroom!

ERIC Educational Resources Information Center

Page, Scott; Coppedge, Ginny

2004-01-01

In this article, the author describes another teacher's unique approach to teaching science in one unusual second grade classroom. Immediately upon entering the classroom, the author was surrounded by an array of colors, shapes, and objects typically found in a forest. A multitude of puppets, stuffed animals, and live animals filled the classroom.…

Business as Un-Usual through Dislocatory Moments--Change for Sustainability and Scope for Subjectivity in Classroom Practice

ERIC Educational Resources Information Center

Andersson, Pernilla

2018-01-01

This paper makes a contribution to the debate that has been described as a tension between instrumental and emancipatory educational objectives in environment and sustainability education. The contribution involves a methodological approach (introd-) using the concept 'dislocatory moments', to identify and analyse moments in classroom practice…

Understanding the Effect Size of Lisdexamfetamine Dimesylate for Treating ADHD in Children and Adults

ERIC Educational Resources Information Center

Faraone, Stephen V.

2012-01-01

Objective: An earlier meta-analysis of pediatric clinical trials indicated that lisdexamfetamine dimesylate (LDX) had a greater effect size than other stimulant medications. This work tested the hypothesis that the apparent increased efficacy was artifactual. Method: The authors assessed two potential artifacts: an unusually high precision of…

Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites

PubMed Central

Dar, M. Ibrahim; Jacopin, Gwénolé; Meloni, Simone; Mattoni, Alessandro; Arora, Neha; Boziki, Ariadni; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Grätzel, Michael

2016-01-01

Emission characteristics of metal halide perovskites play a key role in the current widespread investigations into their potential uses in optoelectronics and photonics. However, a fundamental understanding of the molecular origin of the unusual blueshift of the bandgap and dual emission in perovskites is still lacking. In this direction, we investigated the extraordinary photoluminescence behavior of three representatives of this important class of photonic materials, that is, CH3NH3PbI3, CH3NH3PbBr3, and CH(NH2)2PbBr3, which emerged from our thorough studies of the effects of temperature on their bandgap and emission decay dynamics using time-integrated and time-resolved photoluminescence spectroscopy. The low-temperature (<100 K) photoluminescence of CH3NH3PbI3 and CH3NH3PbBr3 reveals two distinct emission peaks, whereas that of CH(NH2)2PbBr3 shows a single emission peak. Furthermore, irrespective of perovskite composition, the bandgap exhibits an unusual blueshift by raising the temperature from 15 to 300 K. Density functional theory and classical molecular dynamics simulations allow for assigning the additional photoluminescence peak to the presence of molecularly disordered orthorhombic domains and also rationalize that the unusual blueshift of the bandgap with increasing temperature is due to the stabilization of the valence band maximum. Our findings provide new insights into the salient emission properties of perovskite materials, which define their performance in solar cells and light-emitting devices. PMID:27819049

Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites.

PubMed

Dar, M Ibrahim; Jacopin, Gwénolé; Meloni, Simone; Mattoni, Alessandro; Arora, Neha; Boziki, Ariadni; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Grätzel, Michael

2016-10-01

Emission characteristics of metal halide perovskites play a key role in the current widespread investigations into their potential uses in optoelectronics and photonics. However, a fundamental understanding of the molecular origin of the unusual blueshift of the bandgap and dual emission in perovskites is still lacking. In this direction, we investigated the extraordinary photoluminescence behavior of three representatives of this important class of photonic materials, that is, CH 3 NH 3 PbI 3 , CH 3 NH 3 PbBr 3 , and CH(NH 2 ) 2 PbBr 3 , which emerged from our thorough studies of the effects of temperature on their bandgap and emission decay dynamics using time-integrated and time-resolved photoluminescence spectroscopy. The low-temperature (<100 K) photoluminescence of CH 3 NH 3 PbI 3 and CH 3 NH 3 PbBr 3 reveals two distinct emission peaks, whereas that of CH(NH 2 ) 2 PbBr 3 shows a single emission peak. Furthermore, irrespective of perovskite composition, the bandgap exhibits an unusual blueshift by raising the temperature from 15 to 300 K. Density functional theory and classical molecular dynamics simulations allow for assigning the additional photoluminescence peak to the presence of molecularly disordered orthorhombic domains and also rationalize that the unusual blueshift of the bandgap with increasing temperature is due to the stabilization of the valence band maximum. Our findings provide new insights into the salient emission properties of perovskite materials, which define their performance in solar cells and light-emitting devices.

Diagnostic Value of Run Chart Analysis: Using Likelihood Ratios to Compare Run Chart Rules on Simulated Data Series

PubMed Central

Anhøj, Jacob

2015-01-01

Run charts are widely used in healthcare improvement, but there is little consensus on how to interpret them. The primary aim of this study was to evaluate and compare the diagnostic properties of different sets of run chart rules. A run chart is a line graph of a quality measure over time. The main purpose of the run chart is to detect process improvement or process degradation, which will turn up as non-random patterns in the distribution of data points around the median. Non-random variation may be identified by simple statistical tests including the presence of unusually long runs of data points on one side of the median or if the graph crosses the median unusually few times. However, there is no general agreement on what defines “unusually long” or “unusually few”. Other tests of questionable value are frequently used as well. Three sets of run chart rules (Anhoej, Perla, and Carey rules) have been published in peer reviewed healthcare journals, but these sets differ significantly in their sensitivity and specificity to non-random variation. In this study I investigate the diagnostic values expressed by likelihood ratios of three sets of run chart rules for detection of shifts in process performance using random data series. The study concludes that the Anhoej rules have good diagnostic properties and are superior to the Perla and the Carey rules. PMID:25799549

Optimization and surgical design for applications in pediatric cardiology

NASA Astrophysics Data System (ADS)

Marsden, Alison; Bernstein, Adam; Taylor, Charles; Feinstein, Jeffrey

2007-11-01

The coupling of shape optimization to cardiovascular blood flow simulations has potential to improve the design of current surgeries and to eventually allow for optimization of surgical designs for individual patients. This is particularly true in pediatric cardiology, where geometries vary dramatically between patients, and unusual geometries can lead to unfavorable hemodynamic conditions. Interfacing shape optimization to three-dimensional, time-dependent fluid mechanics problems is particularly challenging because of the large computational cost and the difficulty in computing objective function gradients. In this work a derivative-free optimization algorithm is coupled to a three-dimensional Navier-Stokes solver that has been tailored for cardiovascular applications. The optimization code employs mesh adaptive direct search in conjunction with a Kriging surrogate. This framework is successfully demonstrated on several geometries representative of cardiovascular surgical applications. We will discuss issues of cost function choice for surgical applications, including energy loss and wall shear stress distribution. In particular, we will discuss the creation of new designs for the Fontan procedure, a surgery done in pediatric cardiology to treat single ventricle heart defects.

Atomistic modeling of interphases in spider silk fibers

NASA Astrophysics Data System (ADS)

Fossey, Stephen Andrew

The objective of this work is to create an atomistic model to account for the unusual physical properties of silk fibers. Silk fibers have exceptional mechanical toughness, which makes them of interest as high performance fibers. In order to explain the toughness, a model for the molecular structure based on simple geometric reasoning was formulated. The model consists of very small crystallites, on the order of 5 nm, connected by a noncrystalline interphase. The interphase is a region between the crystalline phase and the amorphous phase, which is defined by the geometry of the system. The interphase is modeled as a very thin (<5 nm) film of noncrystalline polymer constructed using a Monte Carlo, rotational isomeric states approach followed by simulated annealing in order to achieve equilibrium chain configurations and density. No additional assumptions are made about density, orientation, or packing. The mechanical properties of the interphase are calculated using the method of Theodoreau and Suter. Finally, observable properties such as wide angle X-ray scattering and methyl rotation rates are calculated and compared with experimental data available in the literature.

Interface-induced multiferroism by design in complex oxide superlattices

PubMed Central

Guo, Hangwen; Wang, Zhen; Dong, Shuai; Ghosh, Saurabh; Saghayezhian, Mohammad; Chen, Lina; Weng, Yakui; Herklotz, Andreas; Ward, Thomas Z.; Jin, Rongying; Pantelides, Sokrates T.; Zhu, Yimei; Zhang, Jiandi; Plummer, E. W.

2017-01-01

Interfaces between materials present unique opportunities for the discovery of intriguing quantum phenomena. Here, we explore the possibility that, in the case of superlattices, if one of the layers is made ultrathin, unexpected properties can be induced between the two bracketing interfaces. We pursue this objective by combining advanced growth and characterization techniques with theoretical calculations. Using prototype La2/3Sr1/3MnO3 (LSMO)/BaTiO3 (BTO) superlattices, we observe a structural evolution in the LSMO layers as a function of thickness. Atomic-resolution EM and spectroscopy reveal an unusual polar structure phase in ultrathin LSMO at a critical thickness caused by interfacing with the adjacent BTO layers, which is confirmed by first principles calculations. Most important is the fact that this polar phase is accompanied by reemergent ferromagnetism, making this system a potential candidate for ultrathin ferroelectrics with ferromagnetic ordering. Monte Carlo simulations illustrate the important role of spin–lattice coupling in LSMO. These results open up a conceptually intriguing recipe for developing functional ultrathin materials via interface-induced spin–lattice coupling. PMID:28607082

Interface-induced multiferroism by design in complex oxide superlattices

DOE PAGES

Guo, Hangwen; Wang, Zhen; Dong, Shuai; ...

2017-05-19

Interfaces between materials present unique opportunities for the discovery of intriguing quantum phenomena. Here, we explore the possibility that, in the case of superlattices, if one of the layers is made ultrathin, unexpected properties can be induced between the two bracketing interfaces. We pursue this objective by combining advanced growth and characterization techniques with theoretical calculations. Using prototype La 2/3Sr 1/3MnO 3 (LSMO)/BaTiO 3 (BTO) superlattices, we observe a structural evolution in the LSMO layers as a function of thickness. Atomic-resolution EM and spectroscopy reveal an unusual polar structure phase in ultrathin LSMO at a critical thickness caused by interfacingmore » with the adjacent BTO layers, which is confirmed by first principles calculations. Most important is the fact that this polar phase is accompanied by reemergent ferromagnetism, making this system a potential candidate for ultrathin ferroelectrics with ferromagnetic ordering. Monte Carlo simulations illustrate the important role of spin–lattice coupling in LSMO. These results open up a conceptually intriguing recipe for developing functional ultrathin materials via interface-induced spin–lattice coupling.« less

Reducing uncertainty about objective functions in adaptive management

USGS Publications Warehouse

Williams, B.K.

2012-01-01

This paper extends the uncertainty framework of adaptive management to include uncertainty about the objectives to be used in guiding decisions. Adaptive decision making typically assumes explicit and agreed-upon objectives for management, but allows for uncertainty as to the structure of the decision process that generates change through time. Yet it is not unusual for there to be uncertainty (or disagreement) about objectives, with different stakeholders expressing different views not only about resource responses to management but also about the appropriate management objectives. In this paper I extend the treatment of uncertainty in adaptive management, and describe a stochastic structure for the joint occurrence of uncertainty about objectives as well as models, and show how adaptive decision making and the assessment of post-decision monitoring data can be used to reduce uncertainties of both kinds. Different degrees of association between model and objective uncertainty lead to different patterns of learning about objectives. ?? 2011.

An unusual and spectacular case of spindle cell lipoma of the posterior neck invading the spinal cervical canal and posterior cranial fossa.

PubMed

Petit, Damien; Menei, Philippe; Fournier, Henri-Dominique

2011-11-01

The authors describe the first case of spindle cell lipoma of the posterior neck invading the upper cervical spinal canal and the posterior cranial fossa. Spindle cell lipoma is an extremely rare variant of benign lipoma. It usually occurs as a solitary subcutaneous well-circumscribed lesion in the posterior neck or shoulders of adult men. Local aggressiveness is unusual. This 61-year-old man presented with an increased left cerebellar syndrome and headaches. He also had a posterior neck tumefaction, which had been known about for a long time. Computed tomography and MR imaging studies revealed a voluminous mass extending to the upper cervical canal and posterior cranial fossa and eroding the neighboring bones. The lesion was well delimited, and contrast enhancement was intense and heterogeneous. The tumor, which had initially developed under the muscles of the posterior neck, was totally resected. Histological assessment revealed numerous fat cells with spindle cells secreting collagen. The large size of the tumor and the submuscular location, bone erosion, and compression of the CNS were unusual in this rare subtype of benign adipose tumor. Its presentation could simulate a sarcoma.

High-pressure phase transitions of nitinol NiTi to a semiconductor with an unusual topological structure

NASA Astrophysics Data System (ADS)

Liu, Guangtao; Liu, Hanyu; Feng, Xiaolei; Redfern, Simon A. T.

2018-04-01

Systematic ab initio structure simulations have been used to explore the high-pressure behavior of nitinol (NiTi) at zero temperature. Our crystal structure prediction and first-principles calculations reveal that the known B 19 phase is dynamically unstable, and an orthorhombic structure (Pbcm) and a face-centered-cubic B 32 structure (F d 3 ¯m ) become stable above ˜4 and 29 GPa, respectively. The predicted, highest-pressure, B 32 phase is composed of two interpenetrating diamond structures, with a structural topology that is quite distinct from that of the other phases of NiTi. Interestingly, the B 32 phase shows an unusual semiconducting characteristic as a result of its unique band structure and the nature of 3 d orbitals localization, whose expected synthesis pressure is accessible to current experimental techniques.

Reversible dilatancy in entangled single-wire materials.

PubMed

Rodney, David; Gadot, Benjamin; Martinez, Oriol Riu; du Roscoat, Sabine Rolland; Orgéas, Laurent

2016-01-01

Designing structures that dilate rapidly in both tension and compression would benefit devices such as smart filters, actuators or fasteners. This property however requires an unusual Poisson ratio, or Poisson function at finite strains, which has to vary with applied strain and exceed the familiar bounds: less than 0 in tension and above 1/2 in compression. Here, by combining mechanical tests and discrete element simulations, we show that a simple three-dimensional architected material, made of a self-entangled single long coiled wire, behaves in between discrete and continuum media, with a large and reversible dilatancy in both tension and compression. This unusual behaviour arises from an interplay between the elongation of the coiled wire and rearrangements due to steric effects, which, unlike in traditional discrete media, are hysteretically reversible when the architecture is made of an elastic fibre.

Structure and dynamics of propylammonium nitrate-acetonitrile mixtures: An intricate multi-scale system probed with experimental and theoretical techniques.

PubMed

Campetella, Marco; Mariani, Alessandro; Sadun, Claudia; Wu, Boning; Castner, Edward W; Gontrani, Lorenzo

2018-04-07

In this article, we report the study of structural and dynamical properties for a series of acetonitrile/propylammonium nitrate mixtures as a function of their composition. These systems display an unusual increase in intensity in their X-ray diffraction patterns in the low-q regime, and their 1 H-NMR diffusion-ordered NMR spectroscopy (DOSY) spectra display unusual diffusivities. However, the magnitude of both phenomena for mixtures of propylammonium nitrate is smaller than those observed for ethylammonium nitrate mixtures with the same cosolvent, suggesting that the cation alkyl tail plays an important role in these observations. The experimental X-ray scattering data are compared with the results of molecular dynamics simulations, including both ab initio studies used to interpret short-range interactions and classical simulations to describe longer range interactions. The higher level calculations highlight the presence of a strong hydrogen bond network within the ionic liquid, only slightly perturbed even at high acetonitrile concentration. These strong interactions lead to the symmetry breaking of the NO 3 - vibrations, with a splitting of about 88 cm -1 in the ν 3 antisymmetric stretch. The classical force field simulations use a greater number of ion pairs, but are not capable of fully describing the longest range interactions, although they do successfully account for the observed concentration trend, and the analysis of the models confirms the nano-inhomogeneity of these kinds of samples.

Structure and dynamics of propylammonium nitrate-acetonitrile mixtures: An intricate multi-scale system probed with experimental and theoretical techniques

NASA Astrophysics Data System (ADS)

Campetella, Marco; Mariani, Alessandro; Sadun, Claudia; Wu, Boning; Castner, Edward W.; Gontrani, Lorenzo

2018-04-01

In this article, we report the study of structural and dynamical properties for a series of acetonitrile/propylammonium nitrate mixtures as a function of their composition. These systems display an unusual increase in intensity in their X-ray diffraction patterns in the low-q regime, and their 1H-NMR diffusion-ordered NMR spectroscopy (DOSY) spectra display unusual diffusivities. However, the magnitude of both phenomena for mixtures of propylammonium nitrate is smaller than those observed for ethylammonium nitrate mixtures with the same cosolvent, suggesting that the cation alkyl tail plays an important role in these observations. The experimental X-ray scattering data are compared with the results of molecular dynamics simulations, including both ab initio studies used to interpret short-range interactions and classical simulations to describe longer range interactions. The higher level calculations highlight the presence of a strong hydrogen bond network within the ionic liquid, only slightly perturbed even at high acetonitrile concentration. These strong interactions lead to the symmetry breaking of the NO3 - vibrations, with a splitting of about 88 cm-1 in the ν3 antisymmetric stretch. The classical force field simulations use a greater number of ion pairs, but are not capable of fully describing the longest range interactions, although they do successfully account for the observed concentration trend, and the analysis of the models confirms the nano-inhomogeneity of these kinds of samples.

Modelling the development of defects during composite reinforcements and prepreg forming

PubMed Central

Hamila, N.; Madeo, A.

2016-01-01

Defects in composite materials are created during manufacture to a large extent. To avoid them as much as possible, it is important that process simulations model the onset and the development of these defects. It is then possible to determine the manufacturing conditions that lead to the absence or to the controlled presence of such defects. Three types of defects that may appear during textile composite reinforcement or prepreg forming are analysed and modelled in this paper. Wrinkling is one of the most common flaws that occur during textile composite reinforcement forming processes. The influence of the different rigidities of the textile reinforcement is studied. The concept of ‘locking angle’ is questioned. A second type of unusual behaviour of fibrous composite reinforcements that can be seen as a flaw during their forming process is the onset of peculiar ‘transition zones’ that are directly related to the bending stiffness of the fibres. The ‘transition zones’ are due to the bending stiffness of fibres. The standard continuum mechanics of Cauchy is not sufficient to model these defects. A second gradient approach is presented that allows one to account for such unusual behaviours and to master their onset and development during forming process simulations. Finally, the large slippages that may occur during a preform forming are discussed and simulated with meso finite-element models used for macroscopic forming. This article is part of the themed issue ‘Multiscale modelling of the structural integrity of composite materials’. PMID:27242300

Modelling the development of defects during composite reinforcements and prepreg forming.

PubMed

Boisse, P; Hamila, N; Madeo, A

2016-07-13

Defects in composite materials are created during manufacture to a large extent. To avoid them as much as possible, it is important that process simulations model the onset and the development of these defects. It is then possible to determine the manufacturing conditions that lead to the absence or to the controlled presence of such defects. Three types of defects that may appear during textile composite reinforcement or prepreg forming are analysed and modelled in this paper. Wrinkling is one of the most common flaws that occur during textile composite reinforcement forming processes. The influence of the different rigidities of the textile reinforcement is studied. The concept of 'locking angle' is questioned. A second type of unusual behaviour of fibrous composite reinforcements that can be seen as a flaw during their forming process is the onset of peculiar 'transition zones' that are directly related to the bending stiffness of the fibres. The 'transition zones' are due to the bending stiffness of fibres. The standard continuum mechanics of Cauchy is not sufficient to model these defects. A second gradient approach is presented that allows one to account for such unusual behaviours and to master their onset and development during forming process simulations. Finally, the large slippages that may occur during a preform forming are discussed and simulated with meso finite-element models used for macroscopic forming. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. © 2016 The Author(s).

Multiple hepatic lesions in a case of isolated hepatic tuberculosis simulating metastases on 18F-FDG PET/CT imaging.

PubMed

Karunanithi, Sellam; Sharma, Punit; Jain, Tarun Kumar; Vijay, Maneesh Kumar; Kumar, Rakesh

2014-01-01

Hepatic tuberculosis is an unusual form of extrapulmonary tuberculosis and constitutes less than 1% of all cases of tuberculosis. Imaging studies for hepatic tuberculosis are nonspecific and mimic primary or metastatic carcinoma. Here we present ¹⁸F-FDG PET/CT images of a 25-year-old male patient with isolated hepatic tuberculosis.

Model-Driven Study of Visual Memory

DTIC Science & Technology

2004-12-01

dimensional stimuli (synthetic human faces ) afford important insights into episodic recognition memory. The results were well accommodated by a summed...the unusual properties of the z-transformed ROCS. 15. SUBJECT TERMS Memory, visual memory, computational model, human memory, faces , identity 16...3 Accomplishments/New Findings 3 Work on Objective One: Recognition Memory for Synthetic Faces . 3 Experim ent 1

Neurophysiological Indices of Atypical Auditory Processing and Multisensory Integration Are Associated with Symptom Severity in Autism

ERIC Educational Resources Information Center

Brandwein, Alice B.; Foxe, John J.; Butler, John S.; Frey, Hans-Peter; Bates, Juliana C.; Shulman, Lisa H.; Molholm, Sophie

2015-01-01

Atypical processing and integration of sensory inputs are hypothesized to play a role in unusual sensory reactions and social-cognitive deficits in autism spectrum disorder (ASD). Reports on the relationship between objective metrics of sensory processing and clinical symptoms, however, are surprisingly sparse. Here we examined the relationship…

Emergency Victim Care. A Training Manual for Emergency Medical Technicians. Module 11--Childbirth, Pediatric Emergencies. Revised.

ERIC Educational Resources Information Center

Ohio State Dept. of Education, Columbus. Div. of Vocational Education.

This training manual for emergency medical technicians, one of 14 modules that comprise the Emergency Victim Care textbook, covers childbirth and pediatric emergencies. Objectives stated for the two chapters are for the students to be able to describe: emergency procedures for normal childbirth, unusual childbirth emergencies, emergency care for…

ELLIPSOMETRY OF ELECTROCHEMICAL SURFACE LAYERS

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

Muller, R.H.

1977-06-01

Ellipsometry is concerned with the analysis and interpretation of changes in the state of polarization caused by reflection. The technique has found increasing interest in recent years for the measurement of thin films because it is unusually sensitive, disturbs the object minimally and can be applied to surfaces contained in any optically transparent medium. Film thicknesses amenable to measurement range from fractional monoatomic coverage to microscopic thicknesses. The measurement of changes in the state of polarization of light due to reflection provides an unusually sensitive tool for observing surface layers in any optically transparent environment. A fast, self-compensating ellipsometer hasmore » been used to observe the electrochemical formation of reacted surface layers. The optical effect of mass-transport boundary layers and component imperfections have been taken into account in the interpretation of results.« less

WONKA: objective novel complex analysis for ensembles of protein-ligand structures.

PubMed

Bradley, A R; Wall, I D; von Delft, F; Green, D V S; Deane, C M; Marsden, B D

2015-10-01

WONKA is a tool for the systematic analysis of an ensemble of protein-ligand structures. It makes the identification of conserved and unusual features within such an ensemble straightforward. WONKA uses an intuitive workflow to process structural co-ordinates. Ligand and protein features are summarised and then presented within an interactive web application. WONKA's power in consolidating and summarising large amounts of data is described through the analysis of three bromodomain datasets. Furthermore, and in contrast to many current methods, WONKA relates analysis to individual ligands, from which we find unusual and erroneous binding modes. Finally the use of WONKA as an annotation tool to share observations about structures is demonstrated. WONKA is freely available to download and install locally or can be used online at http://wonka.sgc.ox.ac.uk.

A Survey of PWNe around Narrow-Pulse Gamma-ray Pulsars

NASA Astrophysics Data System (ADS)

Romani, Roger

2010-09-01

We propose here, on behalf of the Fermi LAT team, ACIS observations of the X-ray counterparts of six unusual gamma-ray pulsars discovered by the LAT. The targets, four seen only in the gamma-rays, two also radio-detected, have unusual single or narrow double pulse profiles, which require particular emission geometries for different pulsar models. By measuring the arcsecond-scale structure of the wind nebula termination shocks of these young (<100kyr) objects, CXO can pin down the viewing angle and test the pulsar physics. All have known X-ray fluxes and we can also extract spectral and distance estimates needed to interpret the GeV gamma-rays. The survey sample covers a range of ages, spindown powers and expected inclinations, making it a powerful test of pulsar emission models.

Unusual tremor syndromes: know in order to recognise.

PubMed

Ure, Robert J; Dhanju, Sanveer; Lang, Anthony E; Fasano, Alfonso

2016-11-01

Tremor is a common neurological condition in clinical practice; yet, few syndromes are widely recognised and discussed in the literature. As a result, there is an overdiagnosis of well-known causes, such as essential tremor. Many important unusual syndromes should be considered in the differential diagnosis of patients with tremor. The objective of this review is to provide broad clinical information to aid in the recognition and treatment of various unusual tremor syndromes in the adult and paediatric populations. The review comprised of a comprehensive online search using PubMed, Ovid database and Google Scholar to identify the available literature for each unusual tremor syndrome. The review includes fragile X-associated tremor/ataxia syndrome, spinocerebellar ataxia type 12, tremors caused by autosomal recessive cerebellar ataxias, myorhythmia, isolated tongue tremor, Wilson's disease, slow orthostatic tremor, peripheral trauma-induced tremor, tardive tremor and rabbit syndrome, paroxysmal tremors (hereditary chin tremor, bilateral high-frequency synchronous discharges, head tremor, limb-shaking transient ischaemic attack), bobble-head doll syndrome, spasmus nutans and shuddering attacks. Rare tremors generally present with an action tremor and a variable combination of postural and kinetic components with resting tremors less frequently seen. The phenomenology of myorhythmia is still vague and a clinical definition is proposed. The recognition of these entities should facilitate the correct diagnosis and guide the physician to a prompt intervention. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Recovery from unusual attitudes: HUD vs. back-up display in a static F/A-18 simulator.

PubMed

Huber, Samuel W

2006-04-01

Spatial disorientation (SD) remains one of the most important causes of fatal fighter aircraft accidents. The aim of this study was to give a recommendation for the use of the head-up display (HUD) or back-up attitude directional indicator (ADI) in a state of spatial disorientation based on the respective performance in an unusual attitude recovery task. Seven fighter pilots joining a conversion course to the F/A-18 participated in this study. Flight time will be presented as range (and mean in parentheses). Total military flight experience of the subjects was 835-1759 h (1412 h). Flight time on the F/A-18 was 41-123 h (70 h). The study was performed in a fixed base F/A-18D Weapons Tactics Trainer. We tested the recovery from 11 unusual attitudes and analyzed decision time (DT), total recovery time (TRT), and error rates for the HUD or the back-up ADI. We found no differences regarding either reaction times or error rates. For the HUD we found a DT (mean +/- SD) of 1.3 +/- 0.4 s, a TRT of 9.1 +/- 4.1 s, and an error rate of 29%. For the ADI the respective values were a DT of 1.4 +/- 0.4 s, a TRT of 8.3 +/- 3.8 s, and an error rate of 27%. Unusual attitude recoveries are performed equally well using the HUD or the back-up ADI. Switching from one instrument to the other during recovery should be avoided since it would probably result in a loss of time without benefit.

Speckle phase near random surfaces

NASA Astrophysics Data System (ADS)

Chen, Xiaoyi; Cheng, Chuanfu; An, Guoqiang; Han, Yujing; Rong, Zhenyu; Zhang, Li; Zhang, Meina

2018-03-01

Based on Kirchhoff approximation theory, the speckle phase near random surfaces with different roughness is numerically simulated. As expected, the properties of the speckle phase near the random surfaces are different from that in far field. In addition, as scattering distances and roughness increase, the average fluctuations of the speckle phase become larger. Unusually, the speckle phase is somewhat similar to the corresponding surface topography. We have performed experiments to verify the theoretical simulation results. Studies in this paper contribute to understanding the evolution of speckle phase near a random surface and provide a possible way to identify a random surface structure based on its speckle phase.

Atomic-Scale Visualization of Quasiparticle Interference on a Type-II Weyl Semimetal Surface.

PubMed

Zheng, Hao; Bian, Guang; Chang, Guoqing; Lu, Hong; Xu, Su-Yang; Wang, Guangqiang; Chang, Tay-Rong; Zhang, Songtian; Belopolski, Ilya; Alidoust, Nasser; Sanchez, Daniel S; Song, Fengqi; Jeng, Horng-Tay; Yao, Nan; Bansil, Arun; Jia, Shuang; Lin, Hsin; Hasan, M Zahid

2016-12-23

We combine quasiparticle interference simulation (theory) and atomic resolution scanning tunneling spectromicroscopy (experiment) to visualize the interference patterns on a type-II Weyl semimetal Mo_{x}W_{1-x}Te_{2} for the first time. Our simulation based on first-principles band topology theoretically reveals the surface electron scattering behavior. We identify the topological Fermi arc states and reveal the scattering properties of the surface states in Mo_{0.66}W_{0.34}Te_{2}. In addition, our result reveals an experimental signature of the topology via the interconnectivity of bulk and surface states, which is essential for understanding the unusual nature of this material.

A retrograde object near Jupiter's orbit

NASA Astrophysics Data System (ADS)

Connors, M.; Wiegert, P.

2018-02-01

Asteroid 2007 VW266 is among the rare objects with a heliocentric retrograde orbit, and its semimajor axis is within a Hill sphere radius of that of Jupiter. This raised the interesting possibility that it could be in co-orbital retrograde resonance with Jupiter, a second "counter-orbital" object in addition to recently discovered 2015 BZ509. We find instead that the object is in 13/14 retrograde mean motion resonance (also referred to as 13/-14). The object is shown to have entered its present orbit about 1700 years ago, and it will leave it in about 8000 years, both through close approach to Jupiter. Entry and exit states both avoid 1:1 retrograde resonance, but the retrograde nature is preserved. The temporary stable state is due to an elliptic orbit with high inclination keeping nodal passages far from the associated planet. We discuss the motion of this unusual object based on modeling and theory, and its observational prospects.

Climate Shocks and Migration: An Agent-Based Modeling Approach.

PubMed

Entwisle, Barbara; Williams, Nathalie E; Verdery, Ashton M; Rindfuss, Ronald R; Walsh, Stephen J; Malanson, George P; Mucha, Peter J; Frizzelle, Brian G; McDaniel, Philip M; Yao, Xiaozheng; Heumann, Benjamin W; Prasartkul, Pramote; Sawangdee, Yothin; Jampaklay, Aree

2016-09-01

This is a study of migration responses to climate shocks. We construct an agent-based model that incorporates dynamic linkages between demographic behaviors, such as migration, marriage, and births, and agriculture and land use, which depend on rainfall patterns. The rules and parameterization of our model are empirically derived from qualitative and quantitative analyses of a well-studied demographic field site, Nang Rong district, Northeast Thailand. With this model, we simulate patterns of migration under four weather regimes in a rice economy: 1) a reference, 'normal' scenario; 2) seven years of unusually wet weather; 3) seven years of unusually dry weather; and 4) seven years of extremely variable weather. Results show relatively small impacts on migration. Experiments with the model show that existing high migration rates and strong selection factors, which are unaffected by climate change, are likely responsible for the weak migration response.

EXPLOITATION AND OPTIMIZATION OF RESERVOIR PERFORMANCE IN HUNTON FORMATION, OKLAHOMA

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

Mohan Kelkar

2002-03-31

The West Carney Field in Lincoln County, Oklahoma is one of few newly discovered oil fields in Oklahoma. Although profitable, the field exhibits several unusual characteristics. These include decreasing water-oil ratios, decreasing gas-oil ratios, decreasing bottomhole pressures during shut-ins in some wells, and transient behavior for water production in many wells. This report explains the unusual characteristics of West Carney Field based on detailed geological and engineering analyses. We propose a geological history that explains the presence of mobile water and oil in the reservoir. The combination of matrix and fractures in the reservoir explains the reservoir's flow behavior. Wemore » confirm our hypothesis by matching observed performance with a simulated model and develop procedures for correlating core data to log data so that the analysis can be extended to other, similar fields where the core coverage may be limited.« less

Collective Traffic-like Movement of Ants on a Trail: Dynamical Phases and Phase Transitions

NASA Astrophysics Data System (ADS)

Kunwar, Ambarish; John, Alexander; Nishinari, Katsuhiro; Schadschneider, Andreas; Chowdhury, Debashish

2004-11-01

The traffic-like collective movement of ants on a trail can be described by a stochastic cellular automaton model. We have earlier investigated its unusual flow-density relation by using various mean field approximations and computer simulations. In this paper, we study the model following an alternative approach based on the analogy with the zero range process, which is one of the few known exactly solvable stochastic dynamical models. We show that our theory can quantitatively account for the unusual non-monotonic dependence of the average speed of the ants on their density for finite lattices with periodic boundary conditions. Moreover, we argue that the model exhibits a continuous phase transition at the critial density only in a limiting case. Furthermore, we investigate the phase diagram of the model by replacing the periodic boundary conditions by open boundary conditions.

Climate Shocks and Migration: An Agent-Based Modeling Approach

PubMed Central

Entwisle, Barbara; Williams, Nathalie E.; Verdery, Ashton M.; Rindfuss, Ronald R.; Walsh, Stephen J.; Malanson, George P.; Mucha, Peter J.; Frizzelle, Brian G.; McDaniel, Philip M.; Yao, Xiaozheng; Heumann, Benjamin W.; Prasartkul, Pramote; Sawangdee, Yothin; Jampaklay, Aree

2016-01-01

This is a study of migration responses to climate shocks. We construct an agent-based model that incorporates dynamic linkages between demographic behaviors, such as migration, marriage, and births, and agriculture and land use, which depend on rainfall patterns. The rules and parameterization of our model are empirically derived from qualitative and quantitative analyses of a well-studied demographic field site, Nang Rong district, Northeast Thailand. With this model, we simulate patterns of migration under four weather regimes in a rice economy: 1) a reference, ‘normal’ scenario; 2) seven years of unusually wet weather; 3) seven years of unusually dry weather; and 4) seven years of extremely variable weather. Results show relatively small impacts on migration. Experiments with the model show that existing high migration rates and strong selection factors, which are unaffected by climate change, are likely responsible for the weak migration response. PMID:27594725

Las Palmeras Molecular Dynamics: A flexible and modular molecular dynamics code

NASA Astrophysics Data System (ADS)

Davis, Sergio; Loyola, Claudia; González, Felipe; Peralta, Joaquín

2010-12-01

Las Palmeras Molecular Dynamics (LPMD) is a highly modular and extensible molecular dynamics (MD) code using interatomic potential functions. LPMD is able to perform equilibrium MD simulations of bulk crystalline solids, amorphous solids and liquids, as well as non-equilibrium MD (NEMD) simulations such as shock wave propagation, projectile impacts, cluster collisions, shearing, deformation under load, heat conduction, heterogeneous melting, among others, which involve unusual MD features like non-moving atoms and walls, unstoppable atoms with constant-velocity, and external forces like electric fields. LPMD is written in C++ as a compromise between efficiency and clarity of design, and its architecture is based on separate components or plug-ins, implemented as modules which are loaded on demand at runtime. The advantage of this architecture is the ability to completely link together the desired components involved in the simulation in different ways at runtime, using a user-friendly control file language which describes the simulation work-flow. As an added bonus, the plug-in API (Application Programming Interface) makes it possible to use the LPMD components to analyze data coming from other simulation packages, convert between input file formats, apply different transformations to saved MD atomic trajectories, and visualize dynamical processes either in real-time or as a post-processing step. Individual components, such as a new potential function, a new integrator, a new file format, new properties to calculate, new real-time visualizers, and even a new algorithm for handling neighbor lists can be easily coded, compiled and tested within LPMD by virtue of its object-oriented API, without the need to modify the rest of the code. LPMD includes already several pair potential functions such as Lennard-Jones, Morse, Buckingham, MCY and the harmonic potential, as well as embedded-atom model (EAM) functions such as the Sutton-Chen and Gupta potentials. Integrators to choose include Euler (if only for demonstration purposes), Verlet and Velocity Verlet, Leapfrog and Beeman, among others. Electrostatic forces are treated as another potential function, by default using the plug-in implementing the Ewald summation method. Program summaryProgram title: LPMD Catalogue identifier: AEHG_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHG_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License version 3 No. of lines in distributed program, including test data, etc.: 509 490 No. of bytes in distributed program, including test data, etc.: 6 814 754 Distribution format: tar.gz Programming language: C++ Computer: 32-bit and 64-bit workstation Operating system: UNIX RAM: Minimum 1024 bytes Classification: 7.7 External routines: zlib, OpenGL Nature of problem: Study of Statistical Mechanics and Thermodynamics of condensed matter systems, as well as kinetics of non-equilibrium processes in the same systems. Solution method: Equilibrium and non-equilibrium molecular dynamics method, Monte Carlo methods. Restrictions: Rigid molecules are not supported. Polarizable atoms and chemical bonds (proteins) either. Unusual features: The program is able to change the temperature of the simulation cell, the pressure, cut regions of the cell, color the atoms by properties, even during the simulation. It is also possible to fix the positions and/or velocity of groups of atoms. Visualization of atoms and some physical properties during the simulation. Additional comments: The program does not only perform molecular dynamics and Monte Carlo simulations, it is also able to filter and manipulate atomic configurations, read and write different file formats, convert between them, evaluate different structural and dynamical properties. Running time: 50 seconds on a 1000-step simulation of 4000 argon atoms, running on a single 2.67 GHz Intel processor.

Neoproterozoic 'snowball Earth' simulations with a coupled climate/ice-sheet model.

PubMed

Hyde, W T; Crowley, T J; Baum, S K; Peltier, W R

2000-05-25

Ice sheets may have reached the Equator in the late Proterozoic era (600-800 Myr ago), according to geological and palaeomagnetic studies, possibly resulting in a 'snowball Earth'. But this period was a critical time in the evolution of multicellular animals, posing the question of how early life survived under such environmental stress. Here we present computer simulations of this unusual climate stage with a coupled climate/ice-sheet model. To simulate a snowball Earth, we use only a reduction in the solar constant compared to present-day conditions and we keep atmospheric CO2 concentrations near present levels. We find rapid transitions into and out of full glaciation that are consistent with the geological evidence. When we combine these results with a general circulation model, some of the simulations result in an equatorial belt of open water that may have provided a refugium for multicellular animals.

Calibration and evaluation of a dispersant application system

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

Shum, J.S.

1987-05-01

The report presents recommended methods for calibrating and operating boat-mounted dispersant application systems. Calibration of one commercially-available system and several unusual problems encountered in calibration are described. Charts and procedures for selecting pump rates and other operating parameters in order to achieve a desired dosage are provided. The calibration was performed at the EPA's Oil and Hazardous Materials Simulated Environmental Test Tank (OHMSETT) facility in Leonardo, New Jersey.

Degenerated uterine fibroid mimicking hydrometra: fallacy in CT

PubMed Central

Tok, CH; Bux, SI; Mohamed, SI; Lim, BK

2006-01-01

Fibroids are the commonest uterine neoplasms, occurring in 20% - 30% of women of reproductive age. In women who have pelvic masses of unknown cause, unusual manifestations of fibroids such as necrosis or degeneration may simulate a carcinoma or hydrometra resulting in problems with image interpretation. We report a case of an unsuspected large degenerated uterine fibroid in a lady mistakenly diagnosed as hydrometra on computed tomography scanning. PMID:21614328

Tinea Incognito

PubMed Central

Ive, F. Adrian; Marks, Ronald

1968-01-01

Fourteen cases are described in which the local application of corticosteroid preparations to ringworm infections of the skin have resulted in unusual clinical pictures. A kerion-like lesion due to Trichophyton rubrum, intertriginous infections simulating candidiasis and due to Epidermophyton floccosum, and pictures resembling poikiloderma, papular rosacea, and indeterminate leprosy are among the changes that were seen in these patients. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6 PMID:5662546

Knowledge and understanding of dissolved solids in the Rio Grande–San Acacia, New Mexico, to Fort Quitman, Texas, and plan for future studies and monitoring

USGS Publications Warehouse

Moyer, Douglas; Anderholm, Scott K.; Hogan, James F.; Phillips, Fred M.; Hibbs, Barry J.; Witcher, James C.; Matherne, Anne Marie; Falk, Sarah E.

2013-01-01

-Focused Hydrogeology Studies at Inflow Sources: Map dissolved-solids concentrations in the Rio Grande and underlying alluvial aquifer; perform hydrogeologic characterization of subsurface areas containing unusually high concentrations of dissolved solids. -Modeling of Dissolved Solids: Develop models to simulate the transport and storage of dissolved solids in both surface-water and groundwater systems.

The Noggin Factor in Survey Research: Developing New Techniques for Assessing Nonresponse Bias.

ERIC Educational Resources Information Center

Clark, Sheldon B.

The primary objective of this paper is to encourage survey researchers not to become overly reliant on the literature for generic solutions to non-response bias problems. In addition, the paper recounts an example of how a non-traditional approach was used to maximize the usefulness of data collected under unusual constraints and with an a priori…

The Dark Side of Iapetus: New Evidence for an Exogenous Origin

NASA Technical Reports Server (NTRS)

Buratti, B. J.; Mosher, J. A.

1994-01-01

The Saturnian satellite Iapetus presents one of the most unusual appearances of any object in the Solar System: one hemisphere is about 10 times as bright as the other. The origin of the dark hemisphere - which reflects only a few percent of the solar radiation falling on it - is one of the great enigmas of planetary science.

DISCOVERY OF A POSSIBLE COOL WHITE DWARF COMPANION FROM THE AllWISE MOTION SURVEY

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

Fajardo-Acosta, Sergio B.; Kirkpatrick, J. Davy; Gelino, Christopher R.

We present optical and near-infrared spectroscopy of WISEA J061543.91-124726.8, which we rediscovered as a high motion object in the AllWISE survey. The spectra of this object are unusual; while the red optical ( λ > 7000 Å) and near-infrared spectra exhibit characteristic TiO, VO, and H{sub 2}O bands of a late-M dwarf, the blue portion of its optical spectrum shows a significant excess of emission relative to late-M-type templates. The excess emission is relatively featureless, with the exception of a prominent and very broad Na i D doublet. We find that no single, ordinary star can reproduce these spectral characteristics.more » The most likely explanation is an unresolved binary system of an M7 dwarf and a cool white dwarf. The flux of a cool white dwarf drops in the optical red and near-infrared, due to collision-induced absorption, thus allowing the flux of a late-M dwarf to show through. This scenario, however, does not explain the Na D feature, which is unlike that of any known white dwarf, but which could perhaps be explained via unusual abundance or pressure conditions.« less

Microwave Treatment for Cardiac Arrhythmias

NASA Technical Reports Server (NTRS)

Hernandez-Moya, Sonia

2009-01-01

NASA seeks to transfer the NASA developed microwave ablation technology, designed for the treatment of ventricular tachycardia (irregular heart beat), to industry. After a heart attack, many cells surrounding the resulting scar continue to live but are abnormal electrically; they may conduct impulses unusually slowly or fire when they would typically be silent. These diseased areas might disturb smooth signaling by forming a reentrant circuit in the muscle. The objective of microwave ablation is to heat and kill these diseased cells to restore appropriate electrical activity in the heart. This technology is a method and apparatus that provides for propagating microwave energy into heart tissues to produce a desired temperature profile therein at tissue depths sufficient for thermally ablating arrhythmogenic cardiac tissue while preventing excessive heating of surrounding tissues, organs, and blood. A wide bandwidth double-disk antenna is effective for this purpose over a bandwidth of about six gigahertz. A computer simulation provides initial screening capabilities for an antenna such as antenna, frequency, power level, and power application duration. The simulation also allows optimization of techniques for specific patients or conditions. In comparison with other methods that involve direct-current pulses or radio frequencies below 1 GHz, this method may prove more effective in treating ventricular tachycardia. This is because the present method provides for greater control of the location, cross-sectional area, and depth of a lesion via selection of the location and design of the antenna and the choice of microwave power and frequency.

Extreme Magnetosphere-Ionosphere Coupling at the Plasmapause: a - In-A Bright SAR Arc

NASA Astrophysics Data System (ADS)

Baumgardner, J.; Wroten, J.; Semeter, J.; Mendillo, M.; Kozyra, J.

2007-05-01

Heat conduction from the ring current - plasmapause interaction region generates high electron temperature within the ionosphere that drive stable auroral red (SAR) arc emission at 6300 A. On the night of 29 October 1991, a SAR arc was observed using an all-sky imager and meridional imaging spectrograph at Millstone Hill. At xxxx UT, the SAR arc was south of Millstone at approximate L = 2 and reached emission levels of 13,000 rayleighs (R). Over two solar cycle of imaging observations have been made at Millstone Hill, and SAR arc brightness levels (excluding this event) averaged ~ 500 R. Simultaneous observations using the incoherent scatter radar (ISR), a DMSP satellite pass, the MSIS neutral atmosphere and SAR arc modeling using the Rees and Roble formalism succeeded in simulations of the observed emission. The reason for the unusual brightness was not the extreme temperatures achieved (and therefore heat conduction input), but the fact that the end of the plasmapause field line where the elevated Te values were measured did not occur in the ionospheric trough, but equatorward of it, thereby having far more ambient electrons to heat and subsequently collide with atomic oxygen. This unusual spatial geometry probably resulted from unusual convection patterns early in a superstorm scenario.

Are Antarctic minke whales unusually abundant because of 20th century whaling?

PubMed

Ruegg, Kristen C; Anderson, Eric C; Scott Baker, C; Vant, Murdoch; Jackson, Jennifer A; Palumbi, Stephen R

2010-01-01

Severe declines in megafauna worldwide illuminate the role of top predators in ecosystem structure. In the Antarctic, the Krill Surplus Hypothesis posits that the killing of more than 2 million large whales led to competitive release for smaller krill-eating species like the Antarctic minke whale. If true, the current size of the Antarctic minke whale population may be unusually high as an indirect result of whaling. Here, we estimate the long-term population size of the Antarctic minke whale prior to whaling by sequencing 11 nuclear genetic markers from 52 modern samples purchased in Japanese meat markets. We use coalescent simulations to explore the potential influence of population substructure and find that even though our samples are drawn from a limited geographic area, our estimate reflects ocean-wide genetic diversity. Using Bayesian estimates of the mutation rate and coalescent-based analyses of genetic diversity across loci, we calculate the long-term population size of the Antarctic minke whale to be 670,000 individuals (95% confidence interval: 374,000-1,150,000). Our estimate of long-term abundance is similar to, or greater than, contemporary abundance estimates, suggesting that managing Antarctic ecosystems under the assumption that Antarctic minke whales are unusually abundant is not warranted.

Comparing cosmological hydrodynamic simulations with observations of high- redshift galaxy formation

NASA Astrophysics Data System (ADS)

Finlator, Kristian Markwart

We use cosmological hydrodynamic simulations to study the impact of outflows and radiative feedback on high-redshift galaxies. For outflows, we consider simulations that assume (i) no winds, (ii) a "constant-wind" model in which the mass-loading factor and outflow speed are constant, and (iii) "momentum-driven" winds in which both parameters vary smoothly with mass. In order to treat radiative feedback, we develop a moment-based radiative transfer technique that operates in both post-processing and coupled radiative hydrodynamic modes. We first ask how outflows impact the broadband spectral energy distributions (SEDs) of six observed reionization-epoch galaxies. Simulations reproduce five regardless of the outflow prescription, while the sixth suggests an unusually bursty star formation history. We conclude that (i) simulations broadly account for available constraints on reionization-epoch galaxies, (ii) individual SEDs do not constrain outflows, and (iii) SED comparisons efficiently isolate objects that challenge simulations. We next study how outflows impact the galaxy mass metallicity relation (MZR). Momentum-driven outflows uniquely reproduce observations at z = 2. In this scenario, galaxies obey two equilibria: (i) The rate at which a galaxy processes gas into stars and outflows tracks its inflow rate; and (ii) The gas enrichment rate owing to star formation balances the dilution rate owing to inflows. Combining these conditions indicates that the MZR is dominated by the (instantaneous) variation of outflows with mass, with more-massive galaxies driving less gas into outflows per unit stellar mass formed. Turning to radiative feedback, we use post-processing simulations to study the topology of reionization. Reionization begins in overdensities and then "leaks" directly into voids, with filaments reionizing last owing to their high density and low emissivity. This result conflicts with previous findings that voids ionize last. We argue that it owes to the uniqely-biased emissivity field produced by our star formation prescriptions, which have previously been shown to reproduce numerous post-reionization constraints. Finally, preliminary results from coupled radiative hydrodynamic simulations indicate that reionization suppresses the star formation rate density by at most 10-20% by z = 5. This is much less than previous estimates, which we attribute to our unique reionization topology although confirmation will have to await more detailed modeling.

Thermal Analysis of Unusual Local-scale Features on the Surface of Vesta

NASA Technical Reports Server (NTRS)

Tosi, F.; Capria, M. T.; DeSanctis, M. C.; Capaccioni, F.; Palomba, E.; Zambon, F.; Ammannito, E.; Blewett, D. T.; Combe, J.-Ph.; Denevi, B. W.;

Modeling the long-term evolution of space debris

DOEpatents

Nikolaev, Sergei; De Vries, Willem H.; Henderson, John R.; Horsley, Matthew A.; Jiang, Ming; Levatin, Joanne L.; Olivier, Scot S.; Pertica, Alexander J.; Phillion, Donald W.; Springer, Harry K.

2017-03-07

A space object modeling system that models the evolution of space debris is provided. The modeling system simulates interaction of space objects at simulation times throughout a simulation period. The modeling system includes a propagator that calculates the position of each object at each simulation time based on orbital parameters. The modeling system also includes a collision detector that, for each pair of objects at each simulation time, performs a collision analysis. When the distance between objects satisfies a conjunction criterion, the modeling system calculates a local minimum distance between the pair of objects based on a curve fitting to identify a time of closest approach at the simulation times and calculating the position of the objects at the identified time. When the local minimum distance satisfies a collision criterion, the modeling system models the debris created by the collision of the pair of objects.

Left hand tactile agnosia after posterior callosal lesion.

PubMed

Balsamo, Maddalena; Trojano, Luigi; Giamundo, Arcangelo; Grossi, Dario

2008-09-01

We report a patient with a hemorrhagic lesion encroaching upon the posterior third of the corpus callosum but sparing the splenium. She showed marked difficulties in recognizing objects and shapes perceived through her left hand, while she could appreciate elementary sensorial features of items tactually presented to the same hand flawlessly. This picture, corresponding to classical descriptions of unilateral associative tactile agnosia, was associated with finger agnosia of the left hand. This very unusual case report can be interpreted as an instance of disconnection syndrome, and allows a discussion of mechanisms involved in tactile object recognition.

MASTER OT J072007.30+451611.6: Cataclysmic Variable with an Extreme Hot Spot

NASA Astrophysics Data System (ADS)

Denisenko, D.

2018-05-01

MASTER team has reported an unusual object MASTER OT J072007.30+451611.6 in ATel #11620 (T. Pogrosheva et al.). The object was observed at 17.0-17.2m during 9 minutes from 22:15:26 to 22:24:30 UT on 2018-04-26, but was below the detection limit (18.8m) 45 minutes before the first positive observation and 43 minutes after the last one. As noted by S. Otero in AAVSO VSX entry, MASTER OT J072007.30+451611.6 has an X-ray counterpart XMMSL2 J072007.4+451615.

Coherent Multimodal Sensory Information Allows Switching between Gravitoinertial Contexts

PubMed Central

Barbiero, Marie; Rousseau, Célia; Papaxanthis, Charalambos; White, Olivier

2017-01-01

Whether the central nervous system is capable to switch between contexts critically depends on experimental details. Motor control studies regularly adopt robotic devices to perturb the dynamics of a certain task. Other approaches investigate motor control by altering the gravitoinertial context itself as in parabolic flights and human centrifuges. In contrast to conventional robotic experiments, where only the hand is perturbed, these gravitoinertial or immersive settings coherently plunge participants into new environments. However, radically different they are, perfect adaptation of motor responses are commonly reported. In object manipulation tasks, this translates into a good matching of the grasping force or grip force to the destabilizing load force. One possible bias in these protocols is the predictability of the forthcoming dynamics. Here we test whether the successful switching and adaptation processes observed in immersive environments are a consequence of the fact that participants can predict the perturbation schedule. We used a short arm human centrifuge to decouple the effects of space and time on the dynamics of an object manipulation task by adding an unnatural explicit position-dependent force. We created different dynamical contexts by asking 20 participants to move the object at three different paces. These contextual sessions were interleaved such that we could simulate concurrent learning. We assessed adaptation by measuring how grip force was adjusted to this unnatural load force. We found that the motor system can switch between new unusual dynamical contexts, as reported by surprisingly well-adjusted grip forces, and that this capacity is not a mere consequence of the ability to predict the time course of the upcoming dynamics. We posit that a coherent flow of multimodal sensory information born in a homogeneous milieu allows switching between dynamical contexts. PMID:28553233

Formation of Kuiper-belt binaries through multiple chaotic scattering encounters with low-mass intruders

NASA Astrophysics Data System (ADS)

Astakhov, Sergey A.; Lee, Ernestine A.; Farrelly, David

2005-06-01

The discovery that many trans-Neptunian objects exist in pairs, or binaries, is proving invaluable for shedding light on the formation, evolution and structure of the outer Solar system. Based on recent systematic searches it has been estimated that up to 10 per cent of Kuiper-belt objects might be binaries. However, all examples discovered to date are unusual, as compared with near-Earth and main-belt asteroid binaries, for their mass ratios of the order of unity and their large, eccentric orbits. In this article we propose a common dynamical origin for these compositional and orbital properties based on four-body simulations in the Hill approximation. Our calculations suggest that binaries are produced through the following chain of events. Initially, long-lived quasi-bound binaries form by two bodies getting entangled in thin layers of dynamical chaos produced by solar tides within the Hill sphere. Next, energy transfer through gravitational scattering with a low-mass intruder nudges the binary into a nearby non-chaotic, stable zone of phase space. Finally, the binary hardens (loses energy) through a series of relatively gentle gravitational scattering encounters with further intruders. This produces binary orbits that are well fitted by Kepler ellipses. Dynamically, the overall process is strongly favoured if the original quasi-bound binary contains comparable masses. We propose a simplified model of chaotic scattering to explain these results. Our findings suggest that the observed preference for roughly equal-mass ratio binaries is probably a real effect; that is, it is not primarily due to an observational bias for widely separated, comparably bright objects. Nevertheless, we predict that a sizeable population of very unequal-mass Kuiper-belt binaries is probably awaiting discovery.

Development and Experimental Application of International Affairs Indicators. Volume B. Supportive Research

DTIC Science & Technology

1974-06-01

i INDICATORS Approaches to Early Warning The Quantitative Indicators Approach: A ... 5 Summary Indicators and Early Warning...Indicators for Early ^ Wa rning 3. Quantitative Signs of Unusual or Ominous Activity 9 13 4. Simulated Cables 25 5 . TEXSCAN...Behavior) for Czechoslovakia 1 mmmmm mmm LIST OF FIGURES vi Pa£« 1. 2. 3. 4. 5 . 6. 7. 8. 9. 10. U. 12. 13. 14. 15. 16. 17. 18

Studying Transonic Gases With a Hydraulic Analog

NASA Technical Reports Server (NTRS)

Wagner, W.; Lepore, F.

1986-01-01

Water table for hydraulic-flow research yields valuable information about gas flow at transonic speeds. Used to study fuel and oxidizer flow in high-pressure rocket engines. Method applied to gas flows in such equipment as furnaces, nozzles, and chemical lasers. Especially suitable when wall contours nonuniform, discontinuous, or unusually shaped. Wall shapes changed quickly for study and evaluated on spot. Method used instead of computer simulation when computer models unavailable, inaccurate, or costly to run.

Influence of Light Conditions on Biology and Chemistry in the Peanut Plant: Flavonoids and Spermidines from Peanut (Arachis hypogaea) Flowers and Studies of the Photoisomerization of Spermidine Conjugates

USDA-ARS?s Scientific Manuscript database

Early history and significance of the peanut crop is discussed. Annual world production of peanuts at 30 million tons makes this crop one of the most important agricultural commodities. Unusual physiology, inflorescence, and infructescence of the peanut plant make it an attractive object for scienti...

"This Must Have Been a Grand Sight": George Bent and the Battle of Platte Bridge

ERIC Educational Resources Information Center

Haack, Steven C.

2010-01-01

The Battle of Platte Bridge, July 26, 1865, is a noteworthy event in the annals of the American Indian Wars. An alliance of Cheyenne, Sioux, and Arapahoe, numbering in excess of 2,000 warriors, traveled three days to a specific military objective, an undertaking unusual both in terms of its magnitude and its level of organization. The battle,…

Manufacture of Lunar Regolith Simulants

NASA Technical Reports Server (NTRS)

Rickman, D. L.; Wilson, S. A.; Stoeser, D. B.; Weinstein, M. A.; Edmunson, J. E.

2013-01-01

The manufacture of lunar regolith simulants can use many technologies unfamiliar to the aerospace industry. Many of these technologies are extensively used in the mining industry. Rock crushing, grinding, process control as a function of particle size, as well as other essential concepts are explained here. Notes are provided on special considerations necessary, given the unusual nature of the desired final product. For example, wet grinding, which is an industry norm, can alter the behavior of simulant materials. As the geologic materials used for simulants can contain minerals such as quartz and pyrite, guidance is provided regarding concepts, risks, measurement, and handling. Extractive metallurgy can be used to produce high-grade components for subsequent manufacture, reducing the compromises inherent in using just rock. Several of the components needed in simulants such as glasses, agglutinates, and breccias are simply not available or not reasonably matched by existing terrestrial resources. Therefore, techniques to produce these in useful quantities were developed and used. Included in this list is the synthesis of specific minerals. The manufacture of two simulants, NU-LHT-1M and NU-LHT-2M, is covered in detail.

Filtered gradient reconstruction algorithm for compressive spectral imaging

NASA Astrophysics Data System (ADS)

Mejia, Yuri; Arguello, Henry

2017-04-01

Compressive sensing matrices are traditionally based on random Gaussian and Bernoulli entries. Nevertheless, they are subject to physical constraints, and their structure unusually follows a dense matrix distribution, such as the case of the matrix related to compressive spectral imaging (CSI). The CSI matrix represents the integration of coded and shifted versions of the spectral bands. A spectral image can be recovered from CSI measurements by using iterative algorithms for linear inverse problems that minimize an objective function including a quadratic error term combined with a sparsity regularization term. However, current algorithms are slow because they do not exploit the structure and sparse characteristics of the CSI matrices. A gradient-based CSI reconstruction algorithm, which introduces a filtering step in each iteration of a conventional CSI reconstruction algorithm that yields improved image quality, is proposed. Motivated by the structure of the CSI matrix, Φ, this algorithm modifies the iterative solution such that it is forced to converge to a filtered version of the residual ΦTy, where y is the compressive measurement vector. We show that the filtered-based algorithm converges to better quality performance results than the unfiltered version. Simulation results highlight the relative performance gain over the existing iterative algorithms.

A Rapidly Moving Shell in the Orion Nebula

NASA Technical Reports Server (NTRS)

Walter, Donald K.; O'Dell, C. R.; Hu, Xihai; Dufour, Reginald J.

1995-01-01

A well-resolved elliptical shell in the inner Orion Nebula has been investigated by monochromatic imaging plus high- and low-resolution spectroscopy. We find that it is of low ionization and the two bright ends are moving at -39 and -49 km/s with respect to OMC-1. There is no central object, even in the infrared J bandpass although H2 emission indicates a possible association with the nearby very young pre-main-sequence star J&W 352, which is one of the youngest pre-main-sequence stars in the inner Orion Nebula. Many of the characteristics of this object (low ionization, blue shift) are like those of the Herbig-Haro objects, although the symmetric form would make it an unusual member of that class.

Bioinspired spring origami

NASA Astrophysics Data System (ADS)

Faber, Jakob A.; Arrieta, Andres F.; Studart, André R.

2018-03-01

Origami enables folding of objects into a variety of shapes in arts, engineering, and biological systems. In contrast to well-known paper-folded objects, the wing of the earwig has an exquisite natural folding system that cannot be sufficiently described by current origami models. Such an unusual biological system displays incompatible folding patterns, remains open by a bistable locking mechanism during flight, and self-folds rapidly without muscular actuation. We show that these notable functionalities arise from the protein-rich joints of the earwig wing, which work as extensional and rotational springs between facets. Inspired by this biological wing, we establish a spring origami model that broadens the folding design space of traditional origami and allows for the fabrication of precisely tunable, four-dimensional–printed objects with programmable bioinspired morphing functionalities.

NASA Langley Distributed Propulsion VTOL Tilt-Wing Aircraft Testing, Modeling, Simulation, Control, and Flight Test Development

NASA Technical Reports Server (NTRS)

Rothhaar, Paul M.; Murphy, Patrick C.; Bacon, Barton J.; Gregory, Irene M.; Grauer, Jared A.; Busan, Ronald C.; Croom, Mark A.

2014-01-01

Control of complex Vertical Take-Off and Landing (VTOL) aircraft traversing from hovering to wing born flight mode and back poses notoriously difficult modeling, simulation, control, and flight-testing challenges. This paper provides an overview of the techniques and advances required to develop the GL-10 tilt-wing, tilt-tail, long endurance, VTOL aircraft control system. The GL-10 prototype's unusual and complex configuration requires application of state-of-the-art techniques and some significant advances in wind tunnel infrastructure automation, efficient Design Of Experiments (DOE) tunnel test techniques, modeling, multi-body equations of motion, multi-body actuator models, simulation, control algorithm design, and flight test avionics, testing, and analysis. The following compendium surveys key disciplines required to develop an effective control system for this challenging vehicle in this on-going effort.

Body models in forensic ballistics: reconstruction of a gunshot injury to the chest by bullet fragmentation after shooting through a finger.

PubMed

Thali, M J; Kneubuehl, B P; Dirnhofer, R; Zollinger, U

2001-11-15

Forensic science uses substitutes to reconstruct injury patterns in order to answer questions regarding the dynamic formation of unusual injuries. Using a case study, an experimental simulation of a finger was designed, for the first time with a combination of hard wood and glycerin soap. With this model as an intermediate target simulation, it was possible not only to demonstrate the "bullet-body (finger) interaction", but also to recreate the wound pattern found in the victim. This case demonstrates that by using ballistic models and body-part substitutes, gunshot cases can be reproduced simply and economically, without coming into conflict with ethical guidelines.

Cannibalism, Kuru, and Mad Cows: Prion Disease As a "Choose-Your-Own-Experiment" Case Study to Simulate Scientific Inquiry in Large Lectures.

PubMed

Serrano, Antonio; Liebner, Jeffrey; Hines, Justin K

2016-01-01

Despite significant efforts to reform undergraduate science education, students often perform worse on assessments of perceptions of science after introductory courses, demonstrating a need for new educational interventions to reverse this trend. To address this need, we created An Inexplicable Disease, an engaging, active-learning case study that is unusual because it aims to simulate scientific inquiry by allowing students to iteratively investigate the Kuru epidemic of 1957 in a choose-your-own-experiment format in large lectures. The case emphasizes the importance of specialization and communication in science and is broadly applicable to courses of any size and sub-discipline of the life sciences.

Gas turbine system simulation: An object-oriented approach

NASA Technical Reports Server (NTRS)

Drummond, Colin K.; Follen, Gregory J.; Putt, Charles W.

1993-01-01

A prototype gas turbine engine simulation has been developed that offers a generalized framework for the simulation of engines subject to steady-state and transient operating conditions. The prototype is in preliminary form, but it successfully demonstrates the viability of an object-oriented approach for generalized simulation applications. Although object oriented programming languages are-relative to FORTRAN-somewhat austere, it is proposed that gas turbine simulations of an interdisciplinary nature will benefit significantly in terms of code reliability, maintainability, and manageability. This report elucidates specific gas turbine simulation obstacles that an object-oriented framework can overcome and describes the opportunity for interdisciplinary simulation that the approach offers.

Synchronous parallel system for emulation and discrete event simulation

NASA Technical Reports Server (NTRS)

Steinman, Jeffrey S. (Inventor)

1992-01-01

A synchronous parallel system for emulation and discrete event simulation having parallel nodes responds to received messages at each node by generating event objects having individual time stamps, stores only the changes to state variables of the simulation object attributable to the event object, and produces corresponding messages. The system refrains from transmitting the messages and changing the state variables while it determines whether the changes are superseded, and then stores the unchanged state variables in the event object for later restoral to the simulation object if called for. This determination preferably includes sensing the time stamp of each new event object and determining which new event object has the earliest time stamp as the local event horizon, determining the earliest local event horizon of the nodes as the global event horizon, and ignoring the events whose time stamps are less than the global event horizon. Host processing between the system and external terminals enables such a terminal to query, monitor, command or participate with a simulation object during the simulation process.

Synchronous Parallel System for Emulation and Discrete Event Simulation

NASA Technical Reports Server (NTRS)

Steinman, Jeffrey S. (Inventor)

2001-01-01

A synchronous parallel system for emulation and discrete event simulation having parallel nodes responds to received messages at each node by generating event objects having individual time stamps, stores only the changes to the state variables of the simulation object attributable to the event object and produces corresponding messages. The system refrains from transmitting the messages and changing the state variables while it determines whether the changes are superseded, and then stores the unchanged state variables in the event object for later restoral to the simulation object if called for. This determination preferably includes sensing the time stamp of each new event object and determining which new event object has the earliest time stamp as the local event horizon, determining the earliest local event horizon of the nodes as the global event horizon, and ignoring events whose time stamps are less than the global event horizon. Host processing between the system and external terminals enables such a terminal to query, monitor, command or participate with a simulation object during the simulation process.

Label-free, single-object sensing with a microring resonator: FDTD simulation.

PubMed

Nguyen, Dan T; Norwood, Robert A

2013-01-14

Label-free, single-object sensing with a microring resonator is investigated numerically using the finite difference time-domain (FDTD) method. A pulse with ultra-wide bandwidth that spans over several resonant modes of the ring and of the sensing object is used for simulation, enabling a single-shot simulation of the microring sensing. The FDTD simulation not only can describe the circulation of the light in a whispering-gallery-mode (WGM) microring and multiple interactions between the light and the sensing object, but also other important factors of the sensing system, such as scattering and radiation losses. The FDTD results show that the simulation can yield a resonant shift of the WGM cavity modes. Furthermore, it can also extract eigenmodes of the sensing object, and therefore information from deep inside the object. The simulation method is not only suitable for a single object (single molecule, nano-, micro-scale particle) but can be extended to the problem of multiple objects as well.

The Nature of the Remarkable Transient GRB 110328A

NASA Astrophysics Data System (ADS)

Fruchter, Andrew

2010-09-01

One orbit was approved for GO/DD 12447. The PI was given permission to use time under his related approved GRB program, 12370, for subsequent observations of this GRB. To allow the second visit to go forward quickly, it was kept on the schedule as GO/DD 12447, but the orbit was charged to GO 12370. As a result, THE SECOND VISIT OF 12447 HAS THE PROPRIETARY PERIOD ASSOCIATED WITH 12370. We apologize for the confusion caused by this change. However, it was done to allow rapid observations of an unusual astrophysical object.We propose HST observations of the extraordinary transient, GRB 110328A. This object triggered the Swift automatic burst detection twice over the course of about ninety minutes, and has continued to be a bright X-ray source for the two days since. While this behavior might typically suggest a Galactic source, the high Galactic latitude of the object, and its coincidence with a star-forming galaxy at z=0.35 instead suggests a new type of extragalactic transient. WFC3 imaging in the optical and NIR will allow us to search for a varying point source to far greater depth than could be done from the ground, given the presence of an apparent host, and the use of the F160W filter may allow us to pierce enshrouding dust, if extinction is the reason for the present lack of a detection in the optical. While we do not yet know the astrophysical source of this transient, it appears unique among the hundreds of transients so far detected by Swift. This alone should provide strong grounds for HST observations of this unusual and potentially important object.

Multimaterial magnetically assisted 3D printing of composite materials.

PubMed

Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R

2015-10-23

3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature.

V1494 Aql: Eclipsing Fast Nova with an Unusual Orbital Light Curve

NASA Astrophysics Data System (ADS)

Kato, Taichi; Ishioka, Ryoko; Uemura, Makoto; Starkey, Donn R.; Krajci, Tom

2004-03-01

We present the time-resolved photometry of V1494 Aql (Nova Aql 1999 No. 2) between 2001 November and 2003 June. The object is confirmed to be an eclipsing nova with a period of 0.1346138(2)d. The eclipses were present in all observed epochs. The orbital light curve shows a rather unusual profile, consisting of a bump-like feature at phase 0.6-0.7 and a dip-like feature at phase 0.2-0.4. These features were probably persistently present in all available observations between 2001 and 2003. A period analysis outside of the eclipses has confirmed that these variations have a period common to the orbital period, and are unlikely to be interpreted as superhumps. We suspect that the structure (probably in the accretion disk) fixed in the binary rotational frame is somehow responsible for this feature.

Multimaterial magnetically assisted 3D printing of composite materials

NASA Astrophysics Data System (ADS)

Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R.

2015-10-01

3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature.

Constraints on the Nature of CID-42: Recoil Kick or Supermassive Black Hole Pair?

NASA Technical Reports Server (NTRS)

Blecha, Laura; Civano, Francesca; Elvis, Martin; Loeb, Abraham

2012-01-01

The galaxy CXOC J100043.1+020637, also known as CID-42, is a highly unusual object. An apparent galaxy merger remnant, it displays signatures of both an inspiraling, kiloparsecscale active galactic nucleus (AGN) pair and of a recoiling AGN with a kick velocity approximately greater than 1300 km s(exp -1). Among recoiling AGN candidates, CID-42 alone has both spatial offsets (in optical and X-ray bands) and spectroscopic offsets. In order to constrain the relative likelihood of both scenarios, we develop models using hydrodynamic galaxy merger simulations coupled with radiative transfer calculations. Our gas-rich, major merger models are generally well matched to the galactic morphology and to the inferred stellar mass and star formation rate. We show that a recoiling supermassive black hole (SMBH) in CID-42 should be observable as an AGN at the time of observation. However, in order for the recoiling AGN to produce narrow-line emission, it must be observed shortly after the kick while it still inhabits a dense gaseous region, implying a large total kick velocity (vk approximately greater than 2000 km s(exp -1)). For the dual AGN scenario, an unusually large broad-line offset is required, and the best match to the observed morphology requires a galaxy that is less luminous than CID-42. Further, the lack of X-ray emission from one of the two optical nuclei is not easily attributed to an intrinsically quiescent SMBH or to a Compton-thick galactic environment. While the current data do not allow either the recoiling or the dual AGN scenario for CID-42 to be excluded, our models highlight the most relevant parameters for distinguishing these possibilities with future observations. In particular, high-quality, spatially-resolved spectra that can pinpoint the origin of the broad and narrow line features will be critical for determining the nature of this unique source.

Thermal Decomposition Mechanisms of Alkylimidazolium Ionic Liquids with CN-containing Anions

DTIC Science & Technology

2014-11-01

anion calculated at the M06/6-31+G(d,p) level of theory and using the generic ionic liquid (GIL) model to simulate the condensed phase methyl...decomposition mechanisms of alkylimidazolium ionic liquids with CN-containing anions 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...perform, display, or disclose the work. 14. ABSTRACT Due to the unusually high heats of vaporization of room-temperature ionic liquids (RTILs

Unusual infrared absorption increases in photo-degraded organic films

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

Shah, Satvik; Biswas, Rana; Koschny, Thomas

Degradation is among the most pressing problems facing organic materials, occurring through ingress of moisture and oxygen, and light exposure. We determine the nanoscale pathways underlying degradation by light-soaking organic films in an environmental chamber, and performing infrared spectroscopy, to identify atomic bonding changes. We utilize as a prototype the low band gap PTB7-PCBM blend. Films light-soaked in the presence of oxygen show unusual increased absorption at 1727 cm –1 attributable to increased C=O modes, and a broad increase at 3240 cm –1 attributable to hydroxyl (O–H) groups bonded within the organic matrix. Films exposed to oxygen in the dark,more » or light-soaked in an inert atmosphere, do not exhibit significant absorption changes, suggesting simultaneous exposure of oxygen and light that creates singlet excited oxygen is the detrimental factor. Our ab initio electronic structure simulations interpret these by oxidation at the α-C site of the alkyl chains in PTB7, with an irreversible rupture of the alkyl chain and formation of new C=O and C–O–H conformations at the α-C. Infrared spectroscopy coupled with ab initio simulation can provide a powerful tool for quantifying photo-structural atomic bonding changes. As a result, understanding nanoscale light-induced structural changes will open avenues to designing more stable organic materials for organic electronics.« less

Unusual infrared absorption increases in photo-degraded organic films

DOE PAGES

Shah, Satvik; Biswas, Rana; Koschny, Thomas; ...

2017-06-05

Degradation is among the most pressing problems facing organic materials, occurring through ingress of moisture and oxygen, and light exposure. We determine the nanoscale pathways underlying degradation by light-soaking organic films in an environmental chamber, and performing infrared spectroscopy, to identify atomic bonding changes. We utilize as a prototype the low band gap PTB7-PCBM blend. Films light-soaked in the presence of oxygen show unusual increased absorption at 1727 cm –1 attributable to increased C=O modes, and a broad increase at 3240 cm –1 attributable to hydroxyl (O–H) groups bonded within the organic matrix. Films exposed to oxygen in the dark,more » or light-soaked in an inert atmosphere, do not exhibit significant absorption changes, suggesting simultaneous exposure of oxygen and light that creates singlet excited oxygen is the detrimental factor. Our ab initio electronic structure simulations interpret these by oxidation at the α-C site of the alkyl chains in PTB7, with an irreversible rupture of the alkyl chain and formation of new C=O and C–O–H conformations at the α-C. Infrared spectroscopy coupled with ab initio simulation can provide a powerful tool for quantifying photo-structural atomic bonding changes. As a result, understanding nanoscale light-induced structural changes will open avenues to designing more stable organic materials for organic electronics.« less

Numerical Simulation of the 9-10 June 1972 Black Hills Storm Using CSU RAMS

NASA Technical Reports Server (NTRS)

Nair, U. S.; Hjelmfelt, Mark R.; Pielke, Roger A., Sr.

1997-01-01

Strong easterly flow of low-level moist air over the eastern slopes of the Black Hills on 9-10 June 1972 generated a storm system that produced a flash flood, devastating the area. Based on observations from this storm event, and also from the similar Big Thompson 1976 storm event, conceptual models have been developed to explain the unusually high precipitation efficiency. In this study, the Black Hills storm is simulated using the Colorado State University Regional Atmospheric Modeling System. Simulations with homogeneous and inhomogeneous initializations and different grid structures are presented. The conceptual models of storm structure proposed by previous studies are examined in light of the present simulations. Both homogeneous and inhomogeneous initialization results capture the intense nature of the storm, but the inhomogeneous simulation produced a precipitation pattern closer to the observed pattern. The simulations point to stationary tilted updrafts, with precipitation falling out to the rear as the preferred storm structure. Experiments with different grid structures point to the importance of removing the lateral boundaries far from the region of activity. Overall, simulation performance in capturing the observed behavior of the storm system was enhanced by use of inhomogeneous initialization.

Microgravity Foam Structure and Rheology

NASA Technical Reports Server (NTRS)

Durian, Douglas J.

1996-01-01

The objective of this research was to exploit rheological and multiple-light scattering techniques, and ultimately microgravity conditions, in order to quantify and elucidate the unusual elastic character of foams in terms of their underlying microscopic structure and dynamics. Special interest was in determining how this elastic character vanishes, i.e. how the foam melts into a simple viscous liquid, as a function of both increasing liquid content and shear strain rate.

A Definitive Work on Factors Impacting the Arming of Unmanned Vehicles

DTIC Science & Technology

2005-05-01

making software, which can then adjust the system to compensate for unusual activity. Behavioral models that better predict how applications, networks ... network structure of nodes and arcs. The arcs describe relations between nodes, and nodes represent objects, concepts, or events. It uses the arc...tackling things that occur outside the known problem domain. There are some newer, natural-based approaches. One deals with neural networks . There is no

Opsoclonus myoclonus syndrome: an unusual presentation for West Nile virus encephalitis

PubMed Central

Afzal, Aasim; Ashraf, Sahar

2014-01-01

A record number of West Nile virus (WNV) cases and fatalities seen in 2012 have brought to light the numerous manifestations of neuroinvasive disease. We report a case of opsoclonus myoclonus syndrome attributed to WNV and its clinical course after treatment with a combination of steroids and intravenous immunoglobulin. Our objective is to highlight opsoclonus myoclonus syndrome as a potential manifestation of WNV encephalitis. PMID:24688189

Management of Intolerance to Casting the Upper Extremities in Claustrophobic Patients

PubMed Central

Nagura, Issei; Kanatani, Takako; Sumi, Masatoshi; Inui, Atsuyuki; Mifune, Yutaka; Kokubu, Takeshi; Kurosaka, Masahiro

2014-01-01

Introduction. Some patients showed unusual responses to the immobilization without any objective findings with casts in upper extremities. We hypothesized their that intolerance with excessive anxiety to casts is due to claustrophobia triggered by cast immobilization. The aim of this study is to analyze the relevance of cast immobilization to the feeling of claustrophobia and discover how to handle them. Methods. There were nine patients who showed the caustrophobic symptoms with their casts. They were assesed whether they were aware of their claustrophobis themselves. Further we investigated the alternative immobilization to casts. Results. Seven out of nine cases that were aware of their claustrophobic tendencies either were given removable splints initially or had the casts converted to removable splints when they exhibited symptoms. The two patients who were unaware of their latent claustrophobic tendencies were identified when they showed similar claustrophobic symptoms to the previous patients soon after short arm cast application. We replaced the casts with removable splints. This resolved the issue in all cases. Conclusions. We should be aware of the claustrophobia if patients showed unusual responses to the immobilization without any objective findings with casts in upper extremities, where removal splint is practical alternative to cast to continue the treatment successfully. PMID:25379544

Anomalously soft non-Euclidean spring

NASA Astrophysics Data System (ADS)

Levin, Ido; Sharon, Eran

In this work we study the mechanical properties of a frustrated elastic ribbon spring - the non-Euclidean minimal spring. This spring belongs to the family of non-Euclidean plates: it has no spontaneous curvature, but its lateral intrinsic geometry is described by a non-Euclidean reference metric. The reference metric of the minimal spring is hyperbolic, and can be embedded as a minimal surface. We argue that the existence of a continuous set of such isometric minimal surfaces with different extensions leads to a complete degeneracy of the bulk elastic energy of the minimal spring under elongation. This degeneracy is removed only by boundary layer effects. As a result, the mechanical properties of the minimal spring are unusual: the spring is ultra-soft with rigidity that depends on the thickness, t , as t raise 0 . 7 ex 7 7 2 lower 0 . 7 ex 2, and does not explicitly depend on the ribbon's width. These predictions are confirmed by a numerical study of a constrained spring. This work is the first to address the unusual mechanical properties of constrained non-Euclidean elastic objects. We also present a novel experimental system that is capable of constructing such objects, along with many other non-Euclidean plates.

Natural analogue studies as supplements to biomineralization research

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

McNeil, M.B.

1995-09-01

Chemical reactions can alter the chemistry and crystal structure of solid objects over archeological or geological times, while preserving external physical shapes. The reactions resulting in these structures offer natural analogues to laboratory experiments in biomineralization and to biologically influenced alteration of nuclear waste packages, and thus, they offer the only available way of validating models that purport waste package behavior over archaeological or geological times. Potential uses of such analogues in the construction and validation of hypothetical mechanisms of microbiological corrosion and biomineralization are reviewed. Evidence from such analogues suggests that biofilms can control materials alteration in ways usuallymore » overlooked. The newly hypothesized mechanisms involve control by biofilms of the cation flow near the solid surface and offer plausible mechanisms for the formation of mixed-cation minerals under conditions that would lead to dealloying in abiotic experiments; they also account for the formation of unusual minerals [such as posnjakite, Cu{sub 4}SO{sub 4}(OH){sub 6{center_dot}}H{sub 2}O] and mineral morphologies unusual in corrosion [malachite, Cu{sub 2}CO{sub 3}(OH){sub 2}, rarely forms botryoidally under corrosion conditions and its occasional presence on archaeological objects that appear to have undergone microbiological corrosion may be related to biofilm phenomena].« less

How Unusual were Hurricane Harvey's Rains?

NASA Astrophysics Data System (ADS)

Emanuel, K.

2017-12-01

We apply an advanced technique for hurricane risk assessment to evaluate the probability of hurricane rainfall of Harvey's magnitude. The technique embeds a detailed computational hurricane model in the large-scale conditions represented by climate reanalyses and by climate models. We simulate 3700 hurricane events affecting the state of Texas, from each of three climate reanalyses spanning the period 1980-2016, and 2000 events from each of six climate models for each of two periods: the period 1981-2000 from historical simulations, and the period 2081-2100 from future simulations under Representative Concentration Pathway (RCP) 8.5. On the basis of these simulations, we estimate that hurricane rain of Harvey's magnitude in the state of Texas would have had an annual probability of 0.01 in the late twentieth century, and will have an annual probability of 0.18 by the end of this century, with remarkably small scatter among the six climate models downscaled. If the event frequency is changing linearly over time, this would yield an annual probability of 0.06 in 2017.

The impact of water on dislocation content and slip system activity in olivine constrained by HR-EBSD and visco-plastic self-consistent simulations

NASA Astrophysics Data System (ADS)

Wallis, D.; Hansen, L. N.; Tasaka, M.; Kumamoto, K. M.; Lloyd, G. E.; Parsons, A. J.; Kohlstedt, D. L.; Wilkinson, A. J.

2016-12-01

Changes in concentration of H+ ions in olivine have impacts on its rheological behaviour and therefore on tectonic processes involving mantle deformation. Deformation experiments on aggregates of wet olivine exhibit different evolution of crystal preferred orientations (CPO) and substructure from experiments on dry olivine, suggesting that elevated H+ concentrations impact activity of dislocation slip-systems. We use high angular-resolution electron backscatter diffraction (HR-EBSD) to map densities of different types of geometrically necessary dislocations (GND) in polycrystalline olivine deformed experimentally under wet and dry conditions and also in nature. HR-EBSD provides unprecedented angular resolution, resolving misorientations < 0.01°. We also employ visco-plastic self-consistent (VPSC) simulations to investigate changes in slip-system activity. HR-EBSD maps from experimental samples demonstrate that olivine deformed under hydrous conditions contains higher proportions of (001)[100] and (100)[001] edge dislocations than olivine deformed under anhydrous conditions. Furthermore, maps of wet olivine exhibit more polygonal subgrain boundaries indicative of enhanced recovery by dislocation climb. VPSC simulations with low critical resolved shear stresses for the (001)[100] and (100)[001] slip systems reproduce an unusual CPO with bimodal maxima of both [100] and [001] observed in wet olivine aggregates. Analysis of a mylonitic lherzolite xenolith from Lesotho reveals the same unusual CPO and similar proportions of dislocation types to `wet' experimental samples, supporting the applicability of these findings to natural deformation conditions. These results support suggestions that H+ impacts the flow properties of olivine by altering dislocation activity and climb, while also providing full quantification of GND content. In particular, the relative proportions of dislocation types may provide a basis for identifying olivine deformed under wet and dry conditions.

The Stability of Resonant Chains of Moons

NASA Astrophysics Data System (ADS)

Rimlinger, Thomas; Hamilton, Douglas

2018-04-01

Unlike other giant planets, Saturn has a satellite system that is dominated by a single massive body, Titan, which features an unusually large inclination and eccentricity. Its origin has yet to be satisfactorily explained; neither in situ formation nor capture from heliocentric orbit can easily produce all of its measured properties. We argue that dynamical instability and subsequent mergers within a resonant chain of satellites analogous to the Galilean moons could be responsible for Titan’s unusual features.To explore this idea, we perform simulations in which we vary a wide range of parameters, including the number of satellites, their masses, their spacings, and their tidal migration and eccentricity damping rates. In our preliminary modeling, we initialize our simulations with three moons in the 1:2:4 mean-motion resonance (currently occupied by Io, Europa, and Ganymede at Jupiter) and study how varying each parameter affects the resonant stability. We find that in some cases, the satellites do indeed escape from this three-body resonance, while in others, the bodies’ period ratios remain locked. We study the evolution of these systems and seek a deeper understanding of the competing mechanisms responsible for resonant capture and escape.Accordingly, we investigate the role that specific two-body eccentricity and inclination resonances play in determining stability conditions. For three satellites in a 1:2:4 resonance, there exist four nearby first-order eccentricity resonances along with many other weaker eccentricity and inclination resonances. In our simulations, we track entrance into and exit from these resonances to provide a more cohesive picture of how the system evolves and find that this evolution depends sensitively on the masses and damping rates. We will report further details of our findings and will discuss their implications for the stability of resonant chains of moons.

On the Influence of North Pacific Sea Surface Temperature on the Arctic Winter Climate

NASA Technical Reports Server (NTRS)

Hurwitz, Margaret M.; Newman, P. A.; Garfinkel, C. I.

2012-01-01

Differences between two ensembles of Goddard Earth Observing System Chemistry-Climate Model simulations isolate the impact of North Pacific sea surface temperatures (SSTs) on the Arctic winter climate. One ensemble of extended winter season forecasts is forced by unusually high SSTs in the North Pacific, while in the second ensemble SSTs in the North Pacific are unusually low. High Low differences are consistent with a weakened Western Pacific atmospheric teleconnection pattern, and in particular, a weakening of the Aleutian low. This relative change in tropospheric circulation inhibits planetary wave propagation into the stratosphere, in turn reducing polar stratospheric temperature in mid- and late winter. The number of winters with sudden stratospheric warmings is approximately tripled in the Low ensemble as compared with the High ensemble. Enhanced North Pacific SSTs, and thus a more stable and persistent Arctic vortex, lead to a relative decrease in lower stratospheric ozone in late winter, affecting the April clear-sky UV index at Northern Hemisphere mid-latitudes.

Remote Linkages to Anomalous Winter Atmospheric Ridging over the Northeastern Pacific

NASA Technical Reports Server (NTRS)

Swain, Daniel L.; Singh, Deepti; Horton, Daniel E.; Mankin, Justin S.; Ballard, Tristan C.; Diffenbaugh, Noah S.

2017-01-01

Severe drought in California between 2013 and 2016 has been linked to the multiyear persistence of anomalously high atmospheric pressure over the northeastern Pacific Ocean, which deflected the Pacific storm track northward and suppressed regional precipitation during California's winter 'rainy season.' Multiple hypotheses have emerged regarding why this high pressure ridge near the west coast of North America was so resilient-including unusual sea surface temperature patterns in the Pacific Ocean, reductions in Arctic sea ice, random atmospheric variability, or some combination thereof. Here we explore relationships between previously documented atmospheric conditions over the North Pacific and several potential remote oceanic and cryospheric influences using both observational data and a large ensemble of climate model simulations. Our results suggest that persistent wintertime atmospheric ridging similar to that implicated in California's 2013-2016 drought can at least partially be linked to unusual Pacific sea surface temperatures, and that Pacific Ocean conditions may offer some degree of cool-season foresight in this region despite the presence of substantial internal variability.

Remote Linkages to Anomalous Winter Atmospheric Ridging Over the Northeastern Pacific

NASA Astrophysics Data System (ADS)

Swain, Daniel L.; Singh, Deepti; Horton, Daniel E.; Mankin, Justin S.; Ballard, Tristan C.; Diffenbaugh, Noah S.

2017-11-01

Severe drought in California between 2013 and 2016 has been linked to the multiyear persistence of anomalously high atmospheric pressure over the northeastern Pacific Ocean, which deflected the Pacific storm track northward and suppressed regional precipitation during California's winter "rainy season." Multiple hypotheses have emerged regarding why this high pressure ridge near the west coast of North America was so resilient—including unusual sea surface temperature patterns in the Pacific Ocean, reductions in Arctic sea ice, random atmospheric variability, or some combination thereof. Here we explore relationships between previously documented atmospheric conditions over the North Pacific and several potential remote oceanic and cryospheric influences using both observational data and a large ensemble of climate model simulations. Our results suggest that persistent wintertime atmospheric ridging similar to that implicated in California's 2013-2016 drought can at least partially be linked to unusual Pacific sea surface temperatures and that Pacific Ocean conditions may offer some degree of cool-season foresight in this region despite the presence of substantial internal variability.

Origin of the unusually strong and selective binding of vanadium by polyamidoximes in seawater

DOE PAGES

Ivanov, Alexander S.; Leggett, Christina J.; Parker, Bernard F.; ...

2017-11-16

Amidoxime-functionalized polymeric adsorbents are the current state-of-the-art materials for collecting uranium (U) from seawater. However, marine tests show that vanadium (V) is preferentially extracted over U and many other cations. Here in this paper, we report a complementary and comprehensive investigation integrating ab initio simulations with thermochemical titrations and XAFS spectroscopy to understand the unusually strong and selective binding of V by polyamidoximes. While the open-chain amidoxime functionalities do not bind V, the cyclic imide-dioxime group of the adsorbent forms a peculiar non-oxido V 5+ complex, exhibiting the highest stability constant value ever observed for the V 5+ species. XAFSmore » analysis of adsorbents following deployment in environmental seawater confirms V binding solely by the imide-dioximes. Our fundamental findings offer not only guidance for future optimization of selectivity in amidoxime-based sorbent materials, but may also afford insight to understanding the extensive accumulation of V in some marine organisms.« less

Origin of the unusually strong and selective binding of vanadium by polyamidoximes in seawater

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

Ivanov, Alexander S.; Leggett, Christina J.; Parker, Bernard F.

Amidoxime-functionalized polymeric adsorbents are the current state-of-the-art materials for collecting uranium (U) from seawater. However, marine tests show that vanadium (V) is preferentially extracted over U and many other cations. Here in this paper, we report a complementary and comprehensive investigation integrating ab initio simulations with thermochemical titrations and XAFS spectroscopy to understand the unusually strong and selective binding of V by polyamidoximes. While the open-chain amidoxime functionalities do not bind V, the cyclic imide-dioxime group of the adsorbent forms a peculiar non-oxido V 5+ complex, exhibiting the highest stability constant value ever observed for the V 5+ species. XAFSmore » analysis of adsorbents following deployment in environmental seawater confirms V binding solely by the imide-dioximes. Our fundamental findings offer not only guidance for future optimization of selectivity in amidoxime-based sorbent materials, but may also afford insight to understanding the extensive accumulation of V in some marine organisms.« less

Unusual clinical and MRI features of a cerebellopontine angle medulloepithelioma. Case report and review of literature.

PubMed

Syal, Rajan; Reddy S, Jaypal; Kumar, Raj; Tyagi, Isha; Abrar, A A Wani; Krishnani, Narender; Mishra, Asht M; Gupta, Rakesh K

2006-01-01

We describe for the first time an unusual location and clinical presentation of medulloepithelioma, a rare embryonal tumor. A 5-year-old child presented with sudden onset of bilateral hearing loss. On imaging, the lesion appeared to be extra axial and was located in the right cerebello-pontine (CP) angle, extending into middle fossa along the trigeminal ganglion and in front of the brain stem into the opposite CP angle. It did not show any enhancement following contrast administration and had restricted diffusion on diffusion-weighted imaging, simulating an epidermoid. However, in vivo localized proton MR spectroscopy revealed a creatine peak dominated by a large choline resonance, peak of glycine with lactate/lipid and invisible N-acetylaspartate suggestive of a neoplastic lesion and not an epidermoid. Only subtotal resection could be performed and the patient had a stormy post-operative course due to extensive dissemination of the disease. Copyright 2006 S. Karger AG, Basel.

Angiolymphoid hyperplasia with eosinophilia-acquired port-wine-stain-like lesions: attempt at treatment with the argon laser.

PubMed

Pasyk, K A; Elsenety, E N; Schelbert, E B

1988-01-01

An unusual case of angiolymphoid hyperplasia with eosinophilia (ALHE) simulating port-wine stain in a 50-year-old woman is reported. The lesions of ALHE are typically papules or subcutaneous masses that range from light pink to red-brown in color. In addition to the usual histologic findings of ALHE, the biopsy in our patient showed some fibrin-like material and fibrous long-spacing collagen on ultrastructural examination. This unusual lesion necessitates biopsy because the differential diagnosis includes port-wine stain, sarcoidosis, lupus erythematosus, and non-Hodgkin lymphoma (mycosis fungoides). Many different forms of treatment have been attempted for ALHE including radiotherapy, cytotoxic chemotherapy, corticosteroids, and antibiotics. The lesions in our patient responded to argon laser therapy and surgical excision, though there has been recurrence on the border of the treated area. Because laser energy is noncumulative in the tissues and effective in removing the lesions, we recommend it as the treatment of choice for these lesions.

Implementation of an Open-Scenario, Long-Term Space Debris Simulation Approach

NASA Technical Reports Server (NTRS)

Nelson, Bron; Yang Yang, Fan; Carlino, Roberto; Dono Perez, Andres; Faber, Nicolas; Henze, Chris; Karacalioglu, Arif Goktug; O'Toole, Conor; Swenson, Jason; Stupl, Jan

2015-01-01

This paper provides a status update on the implementation of a flexible, long-term space debris simulation approach. The motivation is to build a tool that can assess the long-term impact of various options for debris-remediation, including the LightForce space debris collision avoidance concept that diverts objects using photon pressure [9]. State-of-the-art simulation approaches that assess the long-term development of the debris environment use either completely statistical approaches, or they rely on large time steps on the order of several days if they simulate the positions of single objects over time. They cannot be easily adapted to investigate the impact of specific collision avoidance schemes or de-orbit schemes, because the efficiency of a collision avoidance maneuver can depend on various input parameters, including ground station positions and orbital and physical parameters of the objects involved in close encounters (conjunctions). Furthermore, maneuvers take place on timescales much smaller than days. For example, LightForce only changes the orbit of a certain object (aiming to reduce the probability of collision), but it does not remove entire objects or groups of objects. In the same sense, it is also not straightforward to compare specific de-orbit methods in regard to potential collision risks during a de-orbit maneuver. To gain flexibility in assessing interactions with objects, we implement a simulation that includes every tracked space object in Low Earth Orbit (LEO) and propagates all objects with high precision and variable time-steps as small as one second. It allows the assessment of the (potential) impact of physical or orbital changes to any object. The final goal is to employ a Monte Carlo approach to assess the debris evolution during the simulation time-frame of 100 years and to compare a baseline scenario to debris remediation scenarios or other scenarios of interest. To populate the initial simulation, we use the entire space-track object catalog in LEO. We then use a high precision propagator to propagate all objects over the entire simulation duration. If collisions are detected, the appropriate number of debris objects are created and inserted into the simulation framework. Depending on the scenario, further objects, e.g. due to new launches, can be added. At the end of the simulation, the total number of objects above a cut-off size and the number of detected collisions provide benchmark parameters for the comparison between scenarios. The simulation approach is computationally intensive as it involves tens of thousands of objects; hence we use a highly parallel approach employing up to a thousand cores on the NASA Pleiades supercomputer for a single run. This paper describes our simulation approach, the status of its implementation, the approach to developing scenarios and examples of first test runs.

Ability of College Students to Simulate ADHD on Objective Measures of Attention

ERIC Educational Resources Information Center

Booksh, Randee Lee; Pella, Russell D.; Singh, Ashvind N.; Gouvier, William Drew

2010-01-01

Objective: The authors examined the ability of college students to simulate ADHD symptoms on objective and self-report measures and the relationship between knowledge of ADHD and ability to simulate ADHD. Method: Undergraduate students were assigned to a control or a simulated ADHD malingering condition and compared with a clinical AD/HD group.…

Performance Analysis of an Actor-Based Distributed Simulation

NASA Technical Reports Server (NTRS)

Schoeffler, James D.

1998-01-01

Object-oriented design of simulation programs appears to be very attractive because of the natural association of components in the simulated system with objects. There is great potential in distributing the simulation across several computers for the purpose of parallel computation and its consequent handling of larger problems in less elapsed time. One approach to such a design is to use "actors", that is, active objects with their own thread of control. Because these objects execute concurrently, communication is via messages. This is in contrast to an object-oriented design using passive objects where communication between objects is via method calls (direct calls when they are in the same address space and remote procedure calls when they are in different address spaces or different machines). This paper describes a performance analysis program for the evaluation of a design for distributed simulations based upon actors.

Structural relaxation in supercooled orthoterphenyl.

PubMed

Chong, S-H; Sciortino, F

2004-05-01

We report molecular-dynamics simulation results performed for a model of molecular liquid orthoterphenyl in supercooled states, which we then compare with both experimental data and mode-coupling-theory (MCT) predictions, aiming at a better understanding of structural relaxation in orthoterphenyl. We pay special attention to the wave number dependence of the collective dynamics. It is shown that the simulation results for the model share many features with experimental data for real system, and that MCT captures the simulation results at the semiquantitative level except for intermediate wave numbers connected to the overall size of the molecule. Theoretical results at the intermediate wave number region are found to be improved by taking into account the spatial correlation of the molecule's geometrical center. This supports the idea that unusual dynamical properties at the intermediate wave numbers, reported previously in simulation studies for the model and discernible in coherent neutron-scattering experimental data, are basically due to the coupling of the rotational motion to the geometrical-center dynamics. However, there still remain qualitative as well as quantitative discrepancies between theoretical prediction and corresponding simulation results at the intermediate wave numbers, which call for further theoretical investigation.

Design and control of one precise tracking simulation bed for Chinese 20/30 meter optic/infrared telescope

NASA Astrophysics Data System (ADS)

Ren, Changzhi; Li, Xiaoyan; Song, Xiaoli; Niu, Yong; Li, Aihua; Zhang, Zhenchao

2012-09-01

Direct drive technology is the key to solute future 30-m and larger telescope motion system to guarantee a very high tracking accuracy, in spite of unbalanced and sudden loads such as wind gusts and in spite of a structure that, because of its size, can not be infinitely stiff. However, this requires the design and realization of unusually large torque motor that the torque slew rate must be extremely steep too. A conventional torque motor design appears inadequate. This paper explores one redundant unit permanent magnet synchronous motor and its simulation bed for 30-m class telescope. Because its drive system is one high integrated electromechanical system, one complexly electromechanical design method is adopted to improve the efficiency, reliability and quality of the system during the design and manufacture circle. This paper discusses the design and control of the precise tracking simulation bed in detail.

Symmetry and charge order in Fe2OBO3 studied through polarized resonant x-ray diffraction

NASA Astrophysics Data System (ADS)

Bland, S. R.; Angst, M.; Adiga, S.; Scagnoli, V.; Johnson, R. D.; Herrero-Martín, J.; Hatton, P. D.

2010-09-01

Bond valence sum calculations have previously suggested that iron oxyborate exhibits charge order of the Fe ions with integer 2+/3+ valence states. Meanwhile transition metal oxides typically show much smaller, fractional charge disproportionations. Using resonant x-ray diffraction at the iron K edge, we find resonant features which are much larger than those ordinarily observed in charge ordered oxides. Simulations were subsequently performed using a cluster-based, monoelectronic code. The nanoscale domain structure prevents precise fitting; nevertheless the simulations confirm the diagonal charge order symmetry, as well as the unusually large charge disproportionation. We have demonstrated the conversion of linearly to nonlinearly polarized light and vice versa through full polarization analysis. Simulations show that this effect principally results from interference between the isotropic and anisotropic scattering terms. This mechanism is likely to account for similar observations in alternative systems.

Using task dynamics to quantify the affordances of throwing for long distance and accuracy.

PubMed

Wilson, Andrew D; Weightman, Andrew; Bingham, Geoffrey P; Zhu, Qin

2016-07-01

In 2 experiments, the current study explored how affordances structure throwing for long distance and accuracy. In Experiment 1, 10 expert throwers (from baseball, softball, and cricket) threw regulation tennis balls to hit a vertically oriented 4 ft × 4 ft target placed at each of 9 locations (3 distances × 3 heights). We measured their release parameters (angle, speed, and height) and showed that they scaled their throws in response to changes in the target's location. We then simulated the projectile motion of the ball and identified a continuous subspace of release parameters that produce hits to each target location. Each subspace describes the affordance of our target to be hit by a tennis ball moving in a projectile motion to the relevant location. The simulated affordance spaces showed how the release parameter combinations required for hits changed with changes in the target location. The experts tracked these changes in their performance and were successful in hitting the targets. We next tested unusual (horizontal) targets that generated correspondingly different affordance subspaces to determine whether the experts would track the affordance to generate successful hits. Do the experts perceive the affordance? They do. In Experiment 2, 5 cricketers threw to hit either vertically or horizontally oriented targets and successfully hit both, exhibiting release parameters located within the requisite affordance subspaces. We advocate a task dynamical approach to the study of affordances as properties of objects and events in the context of tasks as the future of research in this area. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Implementation of an open-scenario, long-term space debris simulation approach

NASA Astrophysics Data System (ADS)

Stupl, J.; Nelson, B.; Faber, N.; Perez, A.; Carlino, R.; Yang, F.; Henze, C.; Karacalioglu, A.; O'Toole, C.; Swenson, J.

This paper provides a status update on the implementation of a flexible, long-term space debris simulation approach. The motivation is to build a tool that can assess the long-term impact of various options for debris-remediation, including the LightForce space debris collision avoidance scheme. State-of-the-art simulation approaches that assess the long-term development of the debris environment use either completely statistical approaches, or they rely on large time steps in the order of several (5-15) days if they simulate the positions of single objects over time. They cannot be easily adapted to investigate the impact of specific collision avoidance schemes or de-orbit schemes, because the efficiency of a collision avoidance maneuver can depend on various input parameters, including ground station positions, space object parameters and orbital parameters of the conjunctions and take place in much smaller timeframes than 5-15 days. For example, LightForce only changes the orbit of a certain object (aiming to reduce the probability of collision), but it does not remove entire objects or groups of objects. In the same sense, it is also not straightforward to compare specific de-orbit methods in regard to potential collision risks during a de-orbit maneuver. To gain flexibility in assessing interactions with objects, we implement a simulation that includes every tracked space object in LEO, propagates all objects with high precision, and advances with variable-sized time-steps as small as one second. It allows the assessment of the (potential) impact of changes to any object. The final goal is to employ a Monte Carlo approach to assess the debris evolution during the simulation time-frame of 100 years and to compare a baseline scenario to debris remediation scenarios or other scenarios of interest. To populate the initial simulation, we use the entire space-track object catalog in LEO. We then use a high precision propagator to propagate all objects over the entire simulation duration. If collisions are detected, the appropriate number of debris objects are created and inserted into the simulation framework. Depending on the scenario, further objects, e.g. due to new launches, can be added. At the end of the simulation, the total number of objects above a cut-off size and the number of detected collisions provide benchmark parameters for the comparison between scenarios. The simulation approach is computationally intensive as it involves ten thousands of objects; hence we use a highly parallel approach employing up to a thousand cores on the NASA Pleiades supercomputer for a single run. This paper describes our simulation approach, the status of its implementation, the approach in developing scenarios and examples of first test runs.

Characteristic of a Digital Correlation Radiometer Back End with Finite Wordlength

NASA Technical Reports Server (NTRS)

Biswas, Sayak K.; Hyde, David W.; James, Mark W.; Cecil, Daniel J.

2017-01-01

The performance characteristic of a digital correlation radiometer signal processing back end (DBE) is analyzed using a simulator. The particular design studied here corresponds to the airborne Hurricane Imaging radiometer which was jointly developed by the NASA Marshall Space Flight Center, University of Michigan, University of Central Florida and NOAA. Laboratory and flight test data is found to be in accord with the simulation results. Overall design seems to be optimum for the typical input signal dynamic range. It was found that the performance of the digital kurtosis could be improved by lowering the DBE input power level. An unusual scaling between digital correlation channels observed in the instrument data is confirmed to be a DBE characteristic.

Effect of potassium depletion in normal males - An Apollo 15 simulation

NASA Technical Reports Server (NTRS)

Hyatt, K. H.; Hulley, S. B.; Vogel, J. M.; Spears, C. P.; Johnson, P. C.; Hoffler, G. W.; Rambaut, P. C.; Rummel, J. A.; Huntoon, C.

1975-01-01

In the course of Apollo 15, physiologic abnormalities, manifested by ectopic activity on the ECG and unusual alterations in exercise tolerance, occurred in the crew of the Lunar Excursion Module. These were associated with decreases in total body potassium, measured by K-42, of 10% and 15%. The possibility of inadequate potassium (K+) intake existed. A simulation study was performed prior to Apollo 16, corresponding in duration to Apollo 15. Subjects endured the same sleep aberrations and caloric expenditure as the Apollo 15 astronauts. Subjects consumed a diet containing only 15 mEq/d of K+ during the entire 12 days of absolute bedrest. Study implications and reasons for discrepancies between K+ loss measured by balance techniques and K-42 are reviewed.

Digital data detection and synchronization

NASA Technical Reports Server (NTRS)

Noack, T. L.; Morris, J. F.

1973-01-01

The primary accomplishments have been in the analysis and simulation of receivers and bit synchronizers. It has been discovered that tracking rate effects play, a rather fundamental role in both receiver and synchronizer performance, but that data relating to recorder time-base-error, for the proper characterization of this phenomenon, is in rather short supply. It is possible to obtain operationally useful tape recorder time-base-error data from high signal-to-noise ratio tapes using synchronizers with relatively wideband tracking loops. Low signal-to-noise ratio tapes examined in the same way would not be synchronizable. Additional areas of interest covered are receiver false lock, cycle slipping, and other unusual phenomena, which have been described to some extent in this and earlier reports and simulated during the study.

Intracardiac abscess with cutaneous fistula secondary to ventricular septal defect repair simulating sternal wound infection.

PubMed

Rafael, Aldo Elmer; Keshavamurthy, Suresh; Sepulveda, Edgardo; Miranda, Cyndee Cruz; Okamoto, Toshihiro; Pettersson, Gosta Bengt

2014-06-01

Cutaneous fistula as a clinical presentation of intracardiac abscess of the right side is such an unusual occurrence that it has not until now been reported in the English-language medical literature. We present a rare case of right-sided infective endocarditis caused by Achromobacter xylosoxidans in which recurrent infection presented as sternal wound discharge. The infection was found to have an intracardiac origin and was successfully managed by radical débridement on cardiopulmonary bypass.

Intracardiac Abscess with Cutaneous Fistula Secondary to Ventricular Septal Defect Repair Simulating Sternal Wound Infection

PubMed Central

Keshavamurthy, Suresh; Sepulveda, Edgardo; Miranda, Cyndee Cruz; Okamoto, Toshihiro; Pettersson, Gosta Bengt

2014-01-01

Cutaneous fistula as a clinical presentation of intracardiac abscess of the right side is such an unusual occurrence that it has not until now been reported in the English-language medical literature. We present a rare case of right-sided infective endocarditis caused by Achromobacter xylosoxidans in which recurrent infection presented as sternal wound discharge. The infection was found to have an intracardiac origin and was successfully managed by radical débridement on cardiopulmonary bypass. PMID:24955054

Are Droughts in the United States Great Plains Predictable on Seasonal and Longer Time Scales?

NASA Technical Reports Server (NTRS)

Schubert, Siegfried D.; Suarez, M.; Pegion, P.; Kistler, M.; Einaudi, Franco (Technical Monitor)

2001-01-01

The United States Great Plains has experienced numerous episodes of unusually dry conditions lasting anywhere from months to several years, In this presentation, we will examine the predictability of such episodes and the physical mechanisms controlling the variability of the summer climate of the continental United States. The analysis is based on ensembles of multi-year simulations and seasonal hindcasts generated with the NASA Seasonal to-Interannual Prediction Project (NSIPP-1) General Circulation Model.

Choosing health care online: a 7-Eleven case study.

PubMed

Fuller, Margaret; Beauregard, Cindy

2003-01-01

This article describes 7-Eleven's success in offering Web-based health care enrollment to its diverse workforce, which made the introduction of such service delivery strategy unusually challenging. Through its efforts, 7-Eleven was able to meet several important objectives, including helping employees better appreciate the value of their benefits, providing employees with increased services and convenience, and encouraging employees to make more cost-effective choices in their health care coverage.

Comanche Helmet-Mounted Display Symbology Simulation

NASA Technical Reports Server (NTRS)

Turpin, Terry S.; Dowell, Susan R.; Szoboszlay, Zoltan

2006-01-01

The Aeroflightdynamics Directorate (AMRDEC) conducted a simulation to examine the performance of the Comanche Contact Analog world-referenced symbology displayed on the Comanche HIDSS when compared with a compressed symbology design similar to that specified by the former MIL-STD 1295. Six experimental test pilots flew one modified ADS-33 maneuver (hover turn, bob-up), an unusual attitude recovery, and two terrain flight tactical tasks in the NASA Vertical Motion Simulator (VMS). Analysis of the pilot objective performance data and subjective data showed the following results. Objective test results showed that 1295 symbology yielded more rapid maneuvering in the hover turn bob-up than Contact Analog symbology. The average margin of difference in the time to complete the maneuver was approximately two seconds, which was statistically significant. There were no significant differences measured between symbology sets with respect to altitude or position performance measures for all other maneuvers. The NOE target ID task data showed improved accuracy in determining heading to target when using Contact Analog over MIL-STD-1295. Subjective test results, including handling qualities ratings (HQRs) and NASA-TLX workload ratings, showed small but consistent advantages of 1295 symbology over Contact Analog for most parameters. For the bob-up maneuver, 1295 symbology handling qualities were rated Desired for lateral position error and time to complete whereas Contact Analog was rated adequate. The average HQRs for all other maneuvers were rated the same for both symbology sets. Pilot comments and the results of an online questionnaire more strongly favored 1295 over Contact Analog. Repeated comments from all six pilots led to a focus on design issues with six Contact Analog symbols. Those symbols were the heading tape, horizon line, radar altitude six-second predictor, the position of the torque symbol, the absence of a hover position cue, and the widespread positioning of the symbology to the outer edges of the display field-of-view. Pilots rated the present design of three of the six symbols as having safety-of-flight implications. Those symbols were the heading tape, horizon line, and six-second predictor. To summarize, test results showed no objective data that would warrant restricting experimental test pilots from flying constrained tasks. Small but consistent advantages were recorded for the MILSTD-1295 symbology design when executing ADS-33 constrained tasks. No general performance differences were recorded for the operational maneuvers (NOE, contour flight modes) except for the azimuth-to-target task, which favored the Contact Analog heading tape design. There were consistent and strong pilot comments supporting the MIL-STD-1295 design over Contact Analog in both this current simulation and in Comanche Sim I. Three Contact Analog symbols warrant modification and further evaluation to mitigate safety-of-flight implications noted by participating test pilots. A plan for symbology redesign and testing was developed. However, the Comanche program was cancelled by Department of Army in February 2004.

Possible Signs of Fauna and Flora on Venus

NASA Astrophysics Data System (ADS)

Ksanfomality, Leonid V.; Selivanov, Arnold S.; Gektin, Yuryi M.

2015-08-01

Habitability of planets is a fundamental question of science. Some of exoplanets possess physical conditions close to those of Venus. The planet Venus, despite its dense and hot (735 K) oxygen-free atmosphere of CO2, having a high pressure of 9.2 MPa at the surface, can be a natural laboratory for this kind of studies. The only existing data on the planet’s surface are still the results obtained by the Soviet VENERA landers.The TV experiments of Venera-9 and 10 (October, 1975) and Venera-13 and 14 (March, 1982) delivered 41 panoramas of Venus surface (or their fragments). The experiments were of extreme technical complexity. There have not been any similar missions to Venus in the subsequent 40 and 33 years. In the absence of new landing missions to Venus, the VENERA panoramas have been re-processed by modern means. The results of these missions are studied anew. A dozen of relatively large objects, from a decimeter to half a meter in size, with an unusual morphology have been found which moved very slowly or changed slightly their shape. Certain unusual findings that have a structure similar to the Earth’ fauna and flora were found in different areas of the planet. There are more then 30 papers on the topic published in 2012-2014 (e.g., “Acta Astronautica”, 2014, V. 105, pp. 521-533). Due to the availability of up to eight duplicates of the images obtained and their low level of masking noise, the VENERA archive panoramas permit identifying and exploring some types of hypothetical life forms of Venus. Analysis of treated once again VENERA panoramic images revealed objects that might indicate the presence of about 12 hypothetical forms of Venusian flora and fauna. Among them is ‘amisada’ that stands out with its unusual lizard shape against the stone plates surrounding it.

Simulating complex intracellular processes using object-oriented computational modelling.

PubMed

Johnson, Colin G; Goldman, Jacki P; Gullick, William J

2004-11-01

The aim of this paper is to give an overview of computer modelling and simulation in cellular biology, in particular as applied to complex biochemical processes within the cell. This is illustrated by the use of the techniques of object-oriented modelling, where the computer is used to construct abstractions of objects in the domain being modelled, and these objects then interact within the computer to simulate the system and allow emergent properties to be observed. The paper also discusses the role of computer simulation in understanding complexity in biological systems, and the kinds of information which can be obtained about biology via simulation.

Globular Clusters Shine in a Galaxy Lacking Dark Matter

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2018-04-01

You may have seen recent news about NGC 1052DF2, a galaxy that was discovered to have little or no dark matter. Now, a new study explores what NGC 1052DF2 does have: an enigmatic population of unusually large and luminous globular clusters.Keck/LRIS spectra (left and right) and HST images (center) of the 11 clusters associated with NGC 1052DF2. The color images each span 1 1. [van Dokkum et al. 2018]An Unusual DwarfThe ultra-diffuse galaxy NGC 1052DF2, originally identified with the Dragonfly Telescope Array, has puzzled astronomers since the discovery that its dynamical mass determined by the motions of globular-cluster-like objects spotted within it is essentially the same as its stellar mass. This equivalence implies that the galaxy is strangely lacking dark matter; the upper limit set on its dark matter halo is 400 times smaller than what we would expect for such a dwarf galaxy.Led by Pieter van Dokkum (Yale University), the team that made this discovery has now followed up with detailed Hubble Space Telescope imaging and Keck spectroscopy. Their goal? To explore the objects that allowed them to make the dynamical-mass measurement: the oddly bright globular clusters of NGC 1052DF2.Sizes (circularized half-light radii) vs. absolute magnitudes for globular clusters in NGC1052DF2 (black) and the Milky Way (red). [Adapted from van Dokkum et al. 2018]Whats Up with the Globular Clusters?Van Dokkum and collaborators spectroscopically confirmed 11 compact objects associated with the faint galaxy. These objects are globular-cluster-like in their appearance, but the peak of their luminosity distribution is offset by a factor of four from globular clusters of other galaxies; these globular clusters are significantly brighter than is typical.Using the Hubble imaging, the authors determined that NGC 1052DF2s globular clusters are more than twice the size of the Milky Ways globular clusters in the same luminosity range. As is typical for globular clusters, they are an old ( 9.3 billion years) population and metal-poor.Rethinking Formation TheoriesThe long-standing picture of galaxies has closely connected old, metal-poor globular clusters to the galaxies dark-matter halos. Past studies have found that the ratio between the total globular-cluster mass and the overall mass of a galaxy (i.e., all dark + baryonic matter) holds remarkably constant across galaxies its typically 3 x 10-5. This has led researchers to believe that properties of the dark-matter halo may determine globular-cluster formation.The luminosity function of the compact objects in NGC 1052DF2. The red and blue curves show the luminosity functions of globular clusters in the Milky Way and in the typical ultra-diffuse galaxies of the Coma cluster, respectively. NGC 1052DF2s globular clusters peak at a significantly higher luminosity. [Adapted from van Dokkum et al. 2018]NGC 1052DF2, with a globular-cluster mass thats 3% of the mass of the galaxy ( 1000 times the expected ratio!), defies this picture. This unusual galaxy therefore demonstrates that the usual relation between globular-cluster mass and total galaxy mass probably isnt due to a fundamental connection between the dark-matter halo and globular-cluster formation. Instead, van Dokkum and collaborators suggest, globular-cluster formation may ultimately be a baryon-driven process.As with all unexpected discoveries in astronomy, we must now determine whether NGC 1052DF2 is simply a fluke, or whether it represents a new class of object we can expect to find more of. Either way, this unusual galaxy is forcing us to rethink what we know about galaxies and the star clusters they host.CitationPieter van Dokkum et al 2018 ApJL 856 L30. doi:10.3847/2041-8213/aab60b

OBJECT KINETIC MONTE CARLO SIMULATIONS OF MICROSTRUCTURE EVOLUTION

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

Nandipati, Giridhar; Setyawan, Wahyu; Heinisch, Howard L.

2013-09-30

The objective is to report the development of the flexible object kinetic Monte Carlo (OKMC) simulation code KSOME (kinetic simulation of microstructure evolution) which can be used to simulate microstructure evolution of complex systems under irradiation. In this report we briefly describe the capabilities of KSOME and present preliminary results for short term annealing of single cascades in tungsten at various primary-knock-on atom (PKA) energies and temperatures.

Simulation analysis of photometric data for attitude estimation of unresolved space objects

NASA Astrophysics Data System (ADS)

Du, Xiaoping; Gou, Ruixin; Liu, Hao; Hu, Heng; Wang, Yang

2017-10-01

The attitude information acquisition of unresolved space objects, such as micro-nano satellites and GEO objects under the way of ground-based optical observations, is a challenge to space surveillance. In this paper, a useful method is proposed to estimate the SO attitude state according to the simulation analysis of photometric data in different attitude states. The object shape model was established and the parameters of the BRDF model were determined, then the space object photometric model was established. Furthermore, the photometric data of space objects in different states are analyzed by simulation and the regular characteristics of the photometric curves are summarized. The simulation results show that the photometric characteristics are useful for attitude inversion in a unique way. Thus, a new idea is provided for space object identification in this paper.

Evidence for a near-Earth asteroid belt

NASA Technical Reports Server (NTRS)

Rabinowitz, D. L.; Gehrels, T.; Scotti, J. V.; Mcmillan, R. S.; Perry, M. L.; Wisniewski, W.; Larson, S. M.; Howell, E. S.; Mueller, B. E. A.

1993-01-01

In January 1991, the 0.9-m Spacewatch telescope made the first observation of an asteroid outside Earth's atmosphere but in the neighborhood of the Earth-moon system. Since then, more than 40 Earth-approaching asteroids have been discovered, including 13 smaller than 50 m. Using these data, one of us has shown that there is an excess of Earth-approaching asteroids with diameters less than 50 m, relative to the population inferred from the distribution of larger objects. Here we argue that these smaller objects - characterized by low eccentricities, widely ranging inclinations and unusual spectral properties - form a previously undetected asteroid belt concentrated near Earth. The recent discovery of additional small Earth-approaching asteroids supports this conclusion.

Knowledge-based simulation using object-oriented programming

NASA Technical Reports Server (NTRS)

Sidoran, Karen M.

1993-01-01

Simulations have become a powerful mechanism for understanding and modeling complex phenomena. Their results have had substantial impact on a broad range of decisions in the military, government, and industry. Because of this, new techniques are continually being explored and developed to make them even more useful, understandable, extendable, and efficient. One such area of research is the application of the knowledge-based methods of artificial intelligence (AI) to the computer simulation field. The goal of knowledge-based simulation is to facilitate building simulations of greatly increased power and comprehensibility by making use of deeper knowledge about the behavior of the simulated world. One technique for representing and manipulating knowledge that has been enhanced by the AI community is object-oriented programming. Using this technique, the entities of a discrete-event simulation can be viewed as objects in an object-oriented formulation. Knowledge can be factual (i.e., attributes of an entity) or behavioral (i.e., how the entity is to behave in certain circumstances). Rome Laboratory's Advanced Simulation Environment (RASE) was developed as a research vehicle to provide an enhanced simulation development environment for building more intelligent, interactive, flexible, and realistic simulations. This capability will support current and future battle management research and provide a test of the object-oriented paradigm for use in large scale military applications.

Experimental observation and simulation of unusual microwave response for the superconducting microstrip resonator at small dc magnetic field

NASA Astrophysics Data System (ADS)

Ong, C. K.; Rao, X. S.; Jin, B. B.

1999-11-01

An unusual microwave response of the surface impedance Zs of high-Tc thin films at an applied small dc magnetic field (Bdc) at 77 K, namely a decrease of Zs, is observed with the microstrip resonator technique. The resonant frequency is 1.107 GHz. The direction of Bdc is parallel or perpendicular to the a-b plane. Bdc ranges from 0 to 200 G. It is found that the surface resistance (Rs) at Bdc parallel to the a-b plane first decreases with Bdc and then increases above a crossover field. The Rs behaviour for Bdc perpendicular to the a-b plane is the same but with a different crossover field. The two behaviours can be collapsed to one curve by scaling the crossover fields. The changes of surface reactance Xs correlated linearly with the changes of Rs in the ranges of Bdc. The ratios rH of changes of Rs and Xs (rH = icons/Journals/Common/Delta" ALT="Delta" ALIGN="TOP"/> Rs/icons/Journals/Common/Delta" ALT="Delta" ALIGN="TOP"/> Xs) are 0.5 at Bdc less than the crossover field and 0.1 at Bdc greater than the crossover field. The measurements also show that the crossover field is independent of rf input power. A phenomenological model is also proposed to explain this unusual behaviour. By adjusting fitting parameters the computed results agree with the experimental results qualitatively.

Size Does Matter: Implied Object Size is Mentally Simulated during Language Comprehension

ERIC Educational Resources Information Center

de Koning, Björn B.; Wassenburg, Stephanie I.; Bos, Lisanne T.; Van der Schoot, Menno

2017-01-01

Embodied theories of language comprehension propose that readers construct a mental simulation of described objects that contains perceptual characteristics of their real-world referents. The present study is the first to investigate directly whether implied object size is mentally simulated during sentence comprehension and to study the potential…

An Innovative Approach for Assessing the Ergonomic Risks of Lifting Tasks Using a Video Motion Capture System

DTIC Science & Technology

2006-03-01

strained, unusually tired, weak or out of breadth (as cited in Townley , Hair, & Strong, 2005). The data used in these trials yielded tables of maximum...stress when lifting objects near the floor (Chaffin, Andersson, & Martin, 1999). Townley et al. (2005) quantified lifting hazards by using a two...Nachemson, A. (1986). Back injuries in industry: A retrospective study, I. Overview and cost analysis. SPINE, 11, 241-245. Townley , A.C., Hair

Changes in Naval Aviation Basic Instrument Flight Training: An Analysis.

DTIC Science & Technology

1985-12-01

position to the desired attitude in relation to the horizon [Refs. 4,5: pp.2,16-3]. C. BASIC INSTRUMENT FLIGHT TRAINING The objective of basic...were related to the treatment lecture: 1. Basic Air Work (BAW) 2. Partial Panel 3. Unusual Attitudes (full panel) 4. Initial Climb to Altitude (ICA) 5...of student aviators was compared. The modifi- cations consisted of a lecture concentrating on the fundamentals of attitude instrument flight. One group

Forced Changes of Combat Posture

DTIC Science & Technology

1988-09-30

a squad leader had not briefed his squad on their objectives in the attacK, an omission so unusual that it made the unbriefed soldier fearful for the...organizational theory . During contract negotiations, this proposed broad literature search A was drastically curtailed to "those works already known... motivation Ixi Morale Esprit de corps X1 x Poor unit cohesion and esprit de corps lxi Prior expectation of a ’quiet’ sector I I xI I I Number of new

Curiosity and exploratory behaviour towards possible and impossible events in children and adults.

PubMed

Subbotsky, Eugene

2010-08-01

In four experiments with 4-, 6-, and 9-year-old children and adults, the hypothesis was tested that, all other conditions being equal, a novel and unusual event elicits stronger curiosity and exploratory behaviour if its suggested explanation involves an element of the supernatural than if it does not (the impossible over possible effect - the I/P effect). Participants were shown an unusual phenomenon (a spontaneous disintegration of a physical object in an apparently empty box) framed in the context of either a magical (the impossible event) or scientific (the possible event) explanation. In the verbal trial, participants showed a clear understanding of the difference between the effect of genuine magic and the effect of a trick. In the behavioural trial, both children and adults showed the I/P effect. They were more likely to run the risk of losing their valuable objects in order to explore the impossible event than the possible event. Follow-up experiments showed that the I/P effect couldn't be explained as an artifact of the different degrees of cost of exploratory behaviour in the possible and impossible conditions or as a result of misinterpreting magic as tricks. The I/P effect emerged when the cost of exploratory behaviour was moderate and disappeared when the cost was perceived as too high or too low.

Prospecting for dinosaurs on the mining frontier: The value of information in America's Gilded Age.

PubMed

Rieppel, Lukas

2015-04-01

How much is a dinosaur worth? This essay offers an account of the way vertebrate fossils were priced in late 19th-century America to explore the process by which monetary values are established in science. Examining a long and drawn-out negotiation over the sale of an unusually rich dinosaur quarry in Wyoming, I argue that, on their own, abstract market principles did not suffice to mediate between supply and demand. Rather, people haggling over the price of dinosaur bones looked to social norms from the mineral industry for cues on how to value these rare and unusual objects, adopting a set of negotiation tactics that exploited asymmetries in the distribution of scarce information to secure the better end of the deal. On the mining frontier in America's Gilded Age, dinosaurs were thus valued in much the same way as any other scarce natural resource one could dig out of the ground, including gold, silver, and coal.

An X-ray investigation of the unusual supernova remnant CTB 80

NASA Technical Reports Server (NTRS)

Wang, Z. R.; Seward, F. D.

1984-01-01

The X-ray properties of SNR CTB 80 (G68.8 + 2.8) are discussed based on both low- and high-resolution images from the Einstein satellite. The X-ray maps show a point source coinciding with the region of maximum radio emission. Diffuse X-ray emission is evident mainly along the radio lobe extending about 8 arcmin east of the point source and aligned with the projected magnetic field lines. The observed X-ray luminosity is 3.2 x 10 to the 34th ergs/s with 1.0 x 10 to the 3th ergs/s from the point source (assuming a distance of 3 kpc). There is also faint, diffuse, X-ray emission south of the point source, where radio emission is absent. The unusual radio and X-ray morphologies are interpreted as a result of relativistic jets energized by the central object, and the possible association of CTB 80 with SN 1408 as recorded by Chinese observers is discussed.

Characterizing the structure of an unusually cold high latitude cloud

NASA Astrophysics Data System (ADS)

Veneziani, Marcella; Paladini, Roberta; Noriega-Crespo, Alberto; Carey, Sean; Tibbs, Christopher; Flagey, Nicolas; Piacentini, Francesco

2012-10-01

Recently the BOOMERanG 2003 experiment, with an angular resolution of 10', has detected an unusually cold cloud (T = 9 K) located at high Galactic latitudes and with an area of 0.25 deg^2. The low temperature of this object has been confirmed by a follow-up in the with Herschel which measured T = 15.3 in the range 100-500micron and with a resolution 20 times higher than BOOMERanG. Despite the cold temperature of the cloud, the measured extinction (Av=0.15 mag) seems to indicate a fairly low amount of shielding material which could justify the dust cooling. Surprisingly, while the dust content in the cloud is well constrained by a substantial amount of data, no - or very little information - is available for its gas counterpart. Therefore, we request 5hrs of 21-cm spectral line observations with the Parkes telescopes. The observations will allow us to accurately estimate the cloud HI column density, as well as to derive information about its kinematics.

A Unusual Lightning Death in an Indoor Setting: A Case Report.

PubMed

Ventura, Francesco; Barranco, Rosario; Bonsignore, Alessandro; De Stefano, Francesco

2017-03-01

Death due to lightning strikes is infrequent, above all indoors. Some cases may take on a medical legal interest due to the unusual and uncommon circumstances in which they occur. The authors report an extremely rare case of electrocution occurred inside a house in a rural area. A 53-year-old man was reached by an electrical discharge originating from lightning while he was doing renovation work on a cottage. In this case, the correct interpretation of the autopsy and histological aspects and the attentive analysis of the circumstantial and environmental data led to the correct diagnosis of death and to the reconstruction of the dynamics with which it occurred. It was in fact possible to reconstruct that during a violent thunderstorm, lightning, discharging from the bottom upward formed an electric arc. The victim, who was close to metal objects (sawhorses), was struck on the left foot and the current exited from the right hand passing through the heart causing immediate death.

Image formation of thick three-dimensional objects in differential-interference-contrast microscopy.

PubMed

Trattner, Sigal; Kashdan, Eugene; Feigin, Micha; Sochen, Nir

2014-05-01

The differential-interference-contrast (DIC) microscope is of widespread use in life sciences as it enables noninvasive visualization of transparent objects. The goal of this work is to model the image formation process of thick three-dimensional objects in DIC microscopy. The model is based on the principles of electromagnetic wave propagation and scattering. It simulates light propagation through the components of the DIC microscope to the image plane using a combined geometrical and physical optics approach and replicates the DIC image of the illuminated object. The model is evaluated by comparing simulated images of three-dimensional spherical objects with the recorded images of polystyrene microspheres. Our computer simulations confirm that the model captures the major DIC image characteristics of the simulated object, and it is sensitive to the defocusing effects.

An Evaluative Review of Simulated Dynamic Smart 3d Objects

NASA Astrophysics Data System (ADS)

Romeijn, H.; Sheth, F.; Pettit, C. J.

2012-07-01

Three-dimensional (3D) modelling of plants can be an asset for creating agricultural based visualisation products. The continuum of 3D plants models ranges from static to dynamic objects, also known as smart 3D objects. There is an increasing requirement for smarter simulated 3D objects that are attributed mathematically and/or from biological inputs. A systematic approach to plant simulation offers significant advantages to applications in agricultural research, particularly in simulating plant behaviour and the influences of external environmental factors. This approach of 3D plant object visualisation is primarily evident from the visualisation of plants using photographed billboarded images, to more advanced procedural models that come closer to simulating realistic virtual plants. However, few programs model physical reactions of plants to external factors and even fewer are able to grow plants based on mathematical and/or biological parameters. In this paper, we undertake an evaluation of plant-based object simulation programs currently available, with a focus upon the components and techniques involved in producing these objects. Through an analytical review process we consider the strengths and weaknesses of several program packages, the features and use of these programs and the possible opportunities in deploying these for creating smart 3D plant-based objects to support agricultural research and natural resource management. In creating smart 3D objects the model needs to be informed by both plant physiology and phenology. Expert knowledge will frame the parameters and procedures that will attribute the object and allow the simulation of dynamic virtual plants. Ultimately, biologically smart 3D virtual plants that react to changes within an environment could be an effective medium to visually represent landscapes and communicate land management scenarios and practices to planners and decision-makers.

Development of a Dynamically Configurable, Object-Oriented Framework for Distributed, Multi-modal Computational Aerospace Systems Simulation

NASA Technical Reports Server (NTRS)

Afjeh, Abdollah A.; Reed, John A.

2003-01-01

The following reports are presented on this project:A first year progress report on: Development of a Dynamically Configurable,Object-Oriented Framework for Distributed, Multi-modal Computational Aerospace Systems Simulation; A second year progress report on: Development of a Dynamically Configurable, Object-Oriented Framework for Distributed, Multi-modal Computational Aerospace Systems Simulation; An Extensible, Interchangeable and Sharable Database Model for Improving Multidisciplinary Aircraft Design; Interactive, Secure Web-enabled Aircraft Engine Simulation Using XML Databinding Integration; and Improving the Aircraft Design Process Using Web-based Modeling and Simulation.

Synchronization of autonomous objects in discrete event simulation

NASA Technical Reports Server (NTRS)

Rogers, Ralph V.

1990-01-01

Autonomous objects in event-driven discrete event simulation offer the potential to combine the freedom of unrestricted movement and positional accuracy through Euclidean space of time-driven models with the computational efficiency of event-driven simulation. The principal challenge to autonomous object implementation is object synchronization. The concept of a spatial blackboard is offered as a potential methodology for synchronization. The issues facing implementation of a spatial blackboard are outlined and discussed.

Coarse-grained theory of a realistic tetrahedral liquid model

NASA Astrophysics Data System (ADS)

Procaccia, I.; Regev, I.

2012-02-01

Tetrahedral liquids such as water and silica-melt show unusual thermodynamic behavior such as a density maximum and an increase in specific heat when cooled to low temperatures. Previous work had shown that Monte Carlo and mean-field solutions of a lattice model can exhibit these anomalous properties with or without a phase transition, depending on the values of the different terms in the Hamiltonian. Here we use a somewhat different approach, where we start from a very popular empirical model of tetrahedral liquids —the Stillinger-Weber model— and construct a coarse-grained theory which directly quantifies the local structure of the liquid as a function of volume and temperature. We compare the theory to molecular-dynamics simulations and show that the theory can rationalize the simulation results and the anomalous behavior.

Subatomic electronic feature from dynamic motion of Si dimer defects in Bi nanolines on Si(001)

NASA Astrophysics Data System (ADS)

Kirkham, C. J.; Longobardi, M.; Köster, S. A.; Renner, Ch.; Bowler, D. R.

2017-08-01

Scanning tunneling microscopy (STM) reveals unusual sharp features in otherwise defect-free Bi nanolines self-assembled on Si(001). They appear as subatomic thin lines perpendicular to the Bi nanoline at positive biases and as atomic size beads at negative biases. Density functional theory (DFT) simulations show that these features can be attributed to buckled Si dimers substituting for Bi dimers in the nanoline, where the sharp feature is the counterintuitive signature of these dimers flipping during scanning. The perfect correspondence between the STM data and the DFT simulation demonstrated in this paper highlights the detailed understanding we have of the complex Bi-Si(001) Haiku system. This discovery has applications in the patterning of Si dangling bonds for nanoscale electronics.

Simulation of Swap-Out Reliability For The Advance Photon Source Upgrade

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

Borland, M.

2017-06-01

The proposed upgrade of the Advanced Photon Source (APS) to a multibend-achromat lattice relies on the use of swap-out injection to accommodate the small dynamic acceptance, allow use of unusual insertion devices, and minimize collective effects at high single-bunch charge. This, combined with the short beam lifetime, will make injector reliability even more important than it is for top-up operation. We used historical data for the APS injector complex to obtain probability distributions for injector up-time and down-time durations. Using these distributions, we simulated several years of swap-out operation for the upgraded lattice for several operatingmodes. The results indicate thatmore » obtaining very high availability of beam in the storage ring will require improvements to injector reliability.« less

Sarcoidosis onset simulating a unique hepatic metastasis.

PubMed

Diéguez Castillo, Carmelo; Martín-Lagos Maldonado, Alicia; Ríos Pelegrina, Rosa María; Díaz Alcázar, María Del Mar; Roa Colomo, Amparo; Ruiz Escolano, Elena

2018-06-22

Sarcoidosis is a systemic granulomatous disease with an uncertain etiology, characterized by the production of non-necrotizing granulomas. The most frequent presentation is pulmonary and mediastinal, although it might affect any other organ. Hepatic alterations occur in 50 to 65% of the cases. Nevertheless, it is commonly subclinical or detected during a study of the alteration of liver enzymes. It is very unusual that disease onset occurs as an isolated hepatic tumor. A hepatic biopsy is usually required to confirm the diagnosis. A differential diagnosis must be established via any hepatic granulomatous disease, infectious or autoimmune disease as well as the exclusion of malignancy. We present a clinical case of a female diagnosed with an isolated hepatic sarcoidosis that simulated a unique hepatic metastatic lesion. The hepatic biopsy was diagnostic.

Monte Carlo simulation of dynamic phase transitions and frequency dispersions of hysteresis curves in core/shell ferrimagnetic cubic nanoparticle

NASA Astrophysics Data System (ADS)

Vatansever, Erol

2017-05-01

By means of Monte Carlo simulation method with Metropolis algorithm, we elucidate the thermal and magnetic phase transition behaviors of a ferrimagnetic core/shell nanocubic system driven by a time dependent magnetic field. The particle core is composed of ferromagnetic spins, and it is surrounded by an antiferromagnetic shell. At the interface of the core/shell particle, we use antiferromagnetic spin-spin coupling. We simulate the nanoparticle using classical Heisenberg spins. After a detailed analysis, our Monte Carlo simulation results suggest that present system exhibits unusual and interesting magnetic behaviors. For example, at the relatively lower temperature regions, an increment in the amplitude of the external field destroys the antiferromagnetism in the shell part of the nanoparticle, leading to a ground state with ferromagnetic character. Moreover, particular attention has been dedicated to the hysteresis behaviors of the system. For the first time, we show that frequency dispersions can be categorized into three groups for a fixed temperature for finite core/shell systems, as in the case of the conventional bulk systems under the influence of an oscillating magnetic field.

A dual-porosity model for simulating solute transport in oil shale

USGS Publications Warehouse

Glover, K.C.

1987-01-01

A model is described for simulating three-dimensional groundwater flow and solute transport in oil shale and associated geohydrologic units. The model treats oil shale as a dual-porosity medium by simulating flow and transport within fractures using the finite-element method. Diffusion of solute between fractures and the essentially static water of the shale matrix is simulated by including an analytical solution that acts as a source-sink term to the differential equation of solute transport. While knowledge of fracture orientation and spacing is needed to effectively use the model, it is not necessary to map the locations of individual fractures. The computer program listed in the report incorporates many of the features of previous dual-porosity models while retaining a practical approach to solving field problems. As a result the theory of solute transport is not extended in any appreciable way. The emphasis is on bringing together various aspects of solute transport theory in a manner that is particularly suited to the unusual groundwater flow and solute transport characteristics of oil shale systems. (Author 's abstract)

Patients with schizophrenia do not preserve automatic grouping when mentally re-grouping figures: shedding light on an ignored difficulty.

PubMed

Giersch, Anne; van Assche, Mitsouko; Capa, Rémi L; Marrer, Corinne; Gounot, Daniel

2012-01-01

Looking at a pair of objects is easy when automatic grouping mechanisms bind these objects together, but visual exploration can also be more flexible. It is possible to mentally "re-group" two objects that are not only separate but belong to different pairs of objects. "Re-grouping" is in conflict with automatic grouping, since it entails a separation of each item from the set it belongs to. This ability appears to be impaired in patients with schizophrenia. Here we check if this impairment is selective, which would suggest a dissociation between grouping and "re-grouping," or if it impacts on usual, automatic grouping, which would call for a better understanding of the interactions between automatic grouping and "re-grouping." Sixteen outpatients with schizophrenia and healthy controls had to identify two identical and contiguous target figures within a display of circles and squares alternating around a fixation point. Eye-tracking was used to check central fixation. The target pair could be located in the same or separate hemifields. Identical figures were grouped by a connector (grouped automatically) or not (to be re-grouped). Attention modulation of automatic grouping was tested by manipulating the proportion of connected and unconnected targets, thus prompting subjects to focalize on either connected or unconnected pairs. Both groups were sensitive to automatic grouping in most conditions, but patients were unusually slowed down for connected targets while focalizing on unconnected pairs. In addition, this unusual effect occurred only when targets were presented within the same hemifield. Patients and controls differed on this asymmetry between within- and across-hemifield presentation, suggesting that patients with schizophrenia do not re-group figures in the same way as controls do. We discuss possible implications on how "re-grouping" ties in with ongoing, automatic perception in healthy volunteers.

Patients with Schizophrenia Do Not Preserve Automatic Grouping When Mentally Re-Grouping Figures: Shedding Light on an Ignored Difficulty

PubMed Central

Giersch, Anne; van Assche, Mitsouko; Capa, Rémi L.; Marrer, Corinne; Gounot, Daniel

2012-01-01

Looking at a pair of objects is easy when automatic grouping mechanisms bind these objects together, but visual exploration can also be more flexible. It is possible to mentally “re-group” two objects that are not only separate but belong to different pairs of objects. “Re-grouping” is in conflict with automatic grouping, since it entails a separation of each item from the set it belongs to. This ability appears to be impaired in patients with schizophrenia. Here we check if this impairment is selective, which would suggest a dissociation between grouping and “re-grouping,” or if it impacts on usual, automatic grouping, which would call for a better understanding of the interactions between automatic grouping and “re-grouping.” Sixteen outpatients with schizophrenia and healthy controls had to identify two identical and contiguous target figures within a display of circles and squares alternating around a fixation point. Eye-tracking was used to check central fixation. The target pair could be located in the same or separate hemifields. Identical figures were grouped by a connector (grouped automatically) or not (to be re-grouped). Attention modulation of automatic grouping was tested by manipulating the proportion of connected and unconnected targets, thus prompting subjects to focalize on either connected or unconnected pairs. Both groups were sensitive to automatic grouping in most conditions, but patients were unusually slowed down for connected targets while focalizing on unconnected pairs. In addition, this unusual effect occurred only when targets were presented within the same hemifield. Patients and controls differed on this asymmetry between within- and across-hemifield presentation, suggesting that patients with schizophrenia do not re-group figures in the same way as controls do. We discuss possible implications on how “re-grouping” ties in with ongoing, automatic perception in healthy volunteers. PMID:22912621

Survival of largemouth bass from populations infected with largemouth bass virus and subjected to simulated tournament conditions

USGS Publications Warehouse

Schramm, H.L.; Davis, J.G.

2006-01-01

Mortality was measured for largemouth bass Micropterus salmoides in simulated tournaments conducted at 26??C to determine whether an easily accomplished live-well management protocol reduced mortality. Treatment fish, which received the live-well management protocol, were held for 8 h in live wells at 23??C with water containing more than 5 mg of dissolved oxygen/L and 0.3% salt (NaCl). Control fish, were confined for 8 h in live wells at 26??C (ambient temperature) with dissolved oxygen fluctuating from 3 to 5 mg/L and no salt, which simulated the live-well management practices used by largemouth bass tournament anglers. Mortality after live-well confinement was 0% for both treatment and control fish, and mortality during the first 24 h after the simulated tournaments was 2.5%. Mortality of fish observed for up to 5 d after the simulated tournaments was high for treatment fish (mean = 75%; SE = 16%) and control fish (mean = 85%; SE = 11%), and we conclude that the treatment conditions did not reduce postrelease mortality. We suggest that the unusually high posttournament mortality was related to largemouth bass virus infections. ?? Copyright by the American Fisheries Society 2006.

Design of object-oriented distributed simulation classes

NASA Technical Reports Server (NTRS)

Schoeffler, James D. (Principal Investigator)

1995-01-01

Distributed simulation of aircraft engines as part of a computer aided design package is being developed by NASA Lewis Research Center for the aircraft industry. The project is called NPSS, an acronym for 'Numerical Propulsion Simulation System'. NPSS is a flexible object-oriented simulation of aircraft engines requiring high computing speed. It is desirable to run the simulation on a distributed computer system with multiple processors executing portions of the simulation in parallel. The purpose of this research was to investigate object-oriented structures such that individual objects could be distributed. The set of classes used in the simulation must be designed to facilitate parallel computation. Since the portions of the simulation carried out in parallel are not independent of one another, there is the need for communication among the parallel executing processors which in turn implies need for their synchronization. Communication and synchronization can lead to decreased throughput as parallel processors wait for data or synchronization signals from other processors. As a result of this research, the following have been accomplished. The design and implementation of a set of simulation classes which result in a distributed simulation control program have been completed. The design is based upon MIT 'Actor' model of a concurrent object and uses 'connectors' to structure dynamic connections between simulation components. Connectors may be dynamically created according to the distribution of objects among machines at execution time without any programming changes. Measurements of the basic performance have been carried out with the result that communication overhead of the distributed design is swamped by the computation time of modules unless modules have very short execution times per iteration or time step. An analytical performance model based upon queuing network theory has been designed and implemented. Its application to realistic configurations has not been carried out.

Design of Object-Oriented Distributed Simulation Classes

NASA Technical Reports Server (NTRS)

Schoeffler, James D.

1995-01-01

Distributed simulation of aircraft engines as part of a computer aided design package being developed by NASA Lewis Research Center for the aircraft industry. The project is called NPSS, an acronym for "Numerical Propulsion Simulation System". NPSS is a flexible object-oriented simulation of aircraft engines requiring high computing speed. It is desirable to run the simulation on a distributed computer system with multiple processors executing portions of the simulation in parallel. The purpose of this research was to investigate object-oriented structures such that individual objects could be distributed. The set of classes used in the simulation must be designed to facilitate parallel computation. Since the portions of the simulation carried out in parallel are not independent of one another, there is the need for communication among the parallel executing processors which in turn implies need for their synchronization. Communication and synchronization can lead to decreased throughput as parallel processors wait for data or synchronization signals from other processors. As a result of this research, the following have been accomplished. The design and implementation of a set of simulation classes which result in a distributed simulation control program have been completed. The design is based upon MIT "Actor" model of a concurrent object and uses "connectors" to structure dynamic connections between simulation components. Connectors may be dynamically created according to the distribution of objects among machines at execution time without any programming changes. Measurements of the basic performance have been carried out with the result that communication overhead of the distributed design is swamped by the computation time of modules unless modules have very short execution times per iteration or time step. An analytical performance model based upon queuing network theory has been designed and implemented. Its application to realistic configurations has not been carried out.

Computer simulations of interferometric imaging with the VLT Interferometer and the AMBER instrument

NASA Astrophysics Data System (ADS)

Bloecker, Thomas; Hofmann, Karl-Heinz; Przygodda, Frank; Weigelt, Gerd

2000-07-01

We present computer simulations of interferometric imaging with the VLT interferometer and the AMBER instrument. These simulations include both the astrophysical modeling of a stellar object by radiative transfer calculations and the simulation of light propagation from the object to the detector (through atmosphere, telescopes, and the AMBER instrument), simulation of photon noise and detector read- out noise, and finally data processing of the interferograms. The results show the dependence of the visibility error bars on the following observational parameters: different seeing during the observation of object and reference star (Fried parameters r0,object equals 2.4 m, r0,ref. equals 2.5 m), different residual tip- tilt error ((delta) tt,object equals 2% of the Airy disk diameter, (delta) tt,ref. equals 0.1%), and object brightness (Kobject equals 3.5 mag and 11 mag, Kref. equals 3.5 mag). Exemplarily, we focus on stars in late stages of stellar evolution and study one of its key objects, the dusty supergiant IRC + 10420 that is rapidly evolving on human timescales. We show computer simulations of VLTI interferometry of IRC + 10420 with two ATs (wide-field mode, i.e. without fiber optics spatial filters) and discuss whether the visibility accuracy is sufficient to distinguish between different theoretical model predictions.

The VLT Interferometer and its AMBER Instrument: Simulations of Interferometric Imaging in the Wide-Field Mode

NASA Astrophysics Data System (ADS)

Blöcker, T.; Hofmann, K.-H.; Przygodda, F.; Weigelt, G.

We present computer simulations of interferometric imaging with the VLT interferometer and the AMBER instrument. These simulations include both the astrophysical modelling of a stellar object by radiative transfer calculations and the simulation of light propagation from the object to the detector (through atmosphere, telescopes, and the AMBER instrument), simulation of photon noise and detector read-out noise, and finally data processing of the interferograms. The results show the dependence of the visibility error bars on the following observational parameters: different seeing during the observation of object and reference star (Fried parameters r0,object and r0,ref. ranging between 0.9 m and 1.2 m), different residual tip-tilt error (δtt,object and δtt,ref. ranging between 0.1% and 20% of the Airy disk diameter), and object brightness (Kobject=3.5 mag to 13 mag, Kref.=3.5 mag). Exemplarily, we focus on stars in late stages of stellar evolution and study one of its key objects, the dusty supergiant IRC +10 420 that is rapidly evolving on human timescales. We show computer simulations of VLT interferometry of IRC +10 420 with two ATs (wide-field mode, i.e. without fiber optics spatial filters) and discuss whether the visibility accuracy is sufficient to distinguish between different theoretical model predictions.

The Reactivation of Motion influences Size Categorization in a Visuo-Haptic Illusion.

PubMed

Rey, Amandine E; Dabic, Stephanie; Versace, Remy; Navarro, Jordan

2016-09-01

People simulate themselves moving when they view a picture, read a sentence, or simulate a situation that involves motion. The simulation of motion has often been studied in conceptual tasks such as language comprehension. However, most of these studies investigated the direct influence of motion simulation on tasks inducing motion. This article investigates whether a mo- tion induced by the reactivation of a dynamic picture can influence a task that did not require motion processing. In a first phase, a dynamic picture and a static picture were systematically presented with a vibrotactile stimulus (high or low frequency). The second phase of the experiment used a priming paradigm in which a vibrotactile stimulus was presented alone and followed by pictures of objects. Participants had to categorize objects as large or small relative to their typical size (simulated size). Results showed that when the target object was preceded by the vibrotactile stimulus previously associated with the dynamic picture, participants perceived all the objects as larger and categorized them more quickly when the objects were typically "large" and more slowly when the objects were typically "small." In light of embodied cognition theories, this bias in participants' perception is assumed to be caused by an induced forward motion. generated by the reactivated dynamic picture, which affects simulation of the size of the objects.

Simulator sickness in a helicopter flight training school.

PubMed

Webb, Catherine M; Bass, Julie M; Johnson, David M; Kelley, Amanda M; Martin, Christopher R; Wildzunas, Robert M

2009-06-01

Simulator sickness (SS) is a common problem during flight training and can affect both instructor pilots (IP) and student pilots (SP). This study was conducted in response to complaints about a high incidence of SS associated with use of new simulators for rotary-wing aircraft. The problem was evaluated using the Simulator Sickness Questionnaire (SSQ) to collect data on 73 IP and 129 SP who used the new simulators. Based on analysis of these data, operator comments, and a search of the literature, we recommended limiting simulator flights to 2 h, removing unusual or unnatural maneuvers, turning off the sidescreens to reduce the field-of-view, avoiding use of improperly calibrated simulators until repaired, and stressing proper rest and health discipline among the pilots. The success of these measures was evaluated 1 yr later by collecting SSQ data on 25 IP and 50 SP. There was a main effect of time, in that after the recommendations were implemented, there was a significant reduction in nausea, oculomotor, and total SSQ scores from the pre-study to the post-study. There was also a main effect of experience, as IP reported significantly greater SS than SP for the same scores. Implementation of the recommendations reduced SS in the new simulators at the cost of limiting session duration and shutting down some simulator features. Although the optimal solution to the SS problem lies in addressing SS during a simulator's design stage, these recommendations can be used as interim solutions to reduce SS.

UV photodissociation of proline-containing peptide ions: insights from molecular dynamics.

PubMed

Girod, Marion; Sanader, Zeljka; Vojkovic, Marin; Antoine, Rodolphe; MacAleese, Luke; Lemoine, Jérôme; Bonacic-Koutecky, Vlasta; Dugourd, Philippe

2015-03-01

UV photodissociation of proline-containing peptide ions leads to unusual product ions. In this paper, we report laser-induced dissociation of a series of proline-containing peptides at 213 nm. We observe specific fragmentation pathways corresponding to the formation of (y-2), (a + 2) and (b + 2) fragment ions. This was not observed at 266 nm or for peptides which do not contain proline residues. In order to obtain insights into the fragmentation dynamics at 213 nm, a small peptide (RPK for arginine-proline-lysine) was studied both theoretically and experimentally. Calculations of absorption spectra and non-adiabatic molecular dynamics (MD) were made. Second and third excited singlet states, S(2) and S(3), lie close to 213 nm. Non-adiabatic MD simulation starting from S(2) and S(3) shows that these transitions are followed by C-C and C-N bond activation close to the proline residue. After this first relaxation step, consecutive rearrangements and proton transfers are required to produce unusual (y-2), (a + 2) and (b + 2) fragment ions. These fragmentation mechanisms were confirmed by H/D exchange experiments.

UV Photodissociation of Proline-containing Peptide Ions: Insights from Molecular Dynamics

NASA Astrophysics Data System (ADS)

Girod, Marion; Sanader, Zeljka; Vojkovic, Marin; Antoine, Rodolphe; MacAleese, Luke; Lemoine, Jérôme; Bonacic-Koutecky, Vlasta; Dugourd, Philippe

2015-03-01

UV photodissociation of proline-containing peptide ions leads to unusual product ions. In this paper, we report laser-induced dissociation of a series of proline-containing peptides at 213 nm. We observe specific fragmentation pathways corresponding to the formation of (y-2), (a + 2) and (b + 2) fragment ions. This was not observed at 266 nm or for peptides which do not contain proline residues. In order to obtain insights into the fragmentation dynamics at 213 nm, a small peptide (RPK for arginine-proline-lysine) was studied both theoretically and experimentally. Calculations of absorption spectra and non-adiabatic molecular dynamics (MD) were made. Second and third excited singlet states, S2 and S3, lie close to 213 nm. Non-adiabatic MD simulation starting from S2 and S3 shows that these transitions are followed by C-C and C-N bond activation close to the proline residue. After this first relaxation step, consecutive rearrangements and proton transfers are required to produce unusual (y-2), (a + 2) and (b + 2) fragment ions. These fragmentation mechanisms were confirmed by H/D exchange experiments.

Unusually large earthquakes inferred from tsunami deposits along the Kuril trench

USGS Publications Warehouse

Nanayama, F.; Satake, K.; Furukawa, R.; Shimokawa, K.; Atwater, B.F.; Shigeno, K.; Yamaki, S.

2003-01-01

The Pacific plate converges with northeastern Eurasia at a rate of 8-9 m per century along the Kamchatka, Kuril and Japan trenches. Along the southern Kuril trench, which faces the Japanese island of Hokkaido, this fast subduction has recurrently generated earthquakes with magnitudes of up to ???8 over the past two centuries. These historical events, on rupture segments 100-200 km long, have been considered characteristic of Hokkaido's plate-boundary earthquakes. But here we use deposits of prehistoric tsunamis to infer the infrequent occurrence of larger earthquakes generated from longer ruptures. Many of these tsunami deposits form sheets of sand that extend kilometres inland from the deposits of historical tsunamis. Stratigraphic series of extensive sand sheets, intercalated with dated volcanic-ash layers, show that such unusually large tsunamis occurred about every 500 years on average over the past 2,000-7,000 years, most recently ???350 years ago. Numerical simulations of these tsunamis are best explained by earthquakes that individually rupture multiple segments along the southern Kuril trench. We infer that such multi-segment earthquakes persistently recur among a larger number of single-segment events.

Optical and Raman microspectroscopy of nitrogen and hydrogen mixtures at high pressures

NASA Astrophysics Data System (ADS)

Ciezak, Jennifer; Jenkins, T.; Hemley, R.

2009-06-01

Extended phases of molecular solids formed from simple molecules have led to polymeric materials under extreme conditions with advanced optical, mechanical and energetic properties. Although the existence of extended phases has been demonstrated in N2, CO and CO2, recovery of the materials to ambient conditions has posed considerable difficulty. Recent molecular dynamics simulations have predicted that the addition of hydrogen to nitrogen may increase the stability of the cubic-gauche nitrogen polymer and thereby offer the possibility of synthesis at lower pressures and temperatures. Here we present optical and Raman microspectroscopy measurements performed on nitrogen and hydrogen mixtures to 85 GPa. To pressures of 30 GPa, large deviations in the internal molecular stretching modes of the mixtures relative to those of the pure material reveal unusual phase behavior. After an unusual phase separation near 35 GPa, a phase assemblage of consisting of a phase rich in both nitrogen and hydrogen, a phase of relatively amorphous nitrogen and a mixture of the two is observed. Near this pressure, Raman bands attributed to the N-N single bonded stretch were observed.

The Human Operator Simulator. Volume IX. HOS Study Guide.

DTIC Science & Technology

1978-09-01

Ad - 969*91 - 0 0 0 0 0 0 C L.J0 L.J0 - L.i0 LAdO - L~0 wO 0In dJO LAd0 16 1.dQ -WO I ~ PW0 U ~ ~. 46W 4~(.J .* - 4~~Ad 414 4’~ 4~J - 2 ~ ~ T - 4 6J0...only developed from a specific need, but it also grew out of what I consider to be an unusual and fortuitous series of experi- ences to which I had been

Stepwise Elastic Behavior in a Model Elastomer

NASA Astrophysics Data System (ADS)

Bhawe, Dhananjay M.; Cohen, Claude; Escobedo, Fernando A.

2004-12-01

MonteCarlo simulations of an entanglement-free cross-linked polymer network of semiflexible chains reveal a peculiar stepwise elastic response. For increasing stress, step jumps in strain are observed that do not correlate with changes in the number of aligned chains. We show that this unusual behavior stems from the ability of the system to form multiple ordered chain domains that exclude the cross-linking species. This novel elastomer shows a toughening behavior similar to that observed in biological structural materials, such as muscle proteins and abalone shell adhesive.

Reply to Comments by Tsurutani et al. on "Modeling Extreme `Carrington-Type' Space Weather Events Using Three-Dimensional Global MHD Simulations"

NASA Astrophysics Data System (ADS)

Ngwira, Chigomezyo M.; Pulkkinen, Antti; Kuznetsova, Maria M.; Glocer, Alex

2018-02-01

In this response, we address the three main comments by Tsurutani et al. (2018, http://doi.org/10.1002/2017JA024779) namely, unusually high plasma density, interplanetary magnetic field intensity, and fast storm recovery phase. The authors agree that there is room to improve the modeling by taking into account these comments and other aspects that were not fully explored during our initial work. We are already in the process of undertaking a more comprehensive modeling project.

Atomistic insight into the adsorption site selectivity of stepped Au(111) surfaces

NASA Astrophysics Data System (ADS)

Gaspari, Roberto; Pignedoli, Carlo A.; Fasel, Roman; Treier, Matthias; Passerone, Daniele

2010-07-01

Using classical and ab initio simulations, we study the interplay between the Au(111) surface reconstruction and monoatomic steps on a vicinal face. The experimentally observed discommensuration line patterns on a specific vicinal are reproduced and explained, and a complete description of the structure is given. An unusual atomic arrangement is shown to be responsible for the lower reactivity of hcp segments of step edges compared to the one of fcc segments. Our results provide an unprecedented understanding of the electronic and geometric properties of the complex Au(111) surface.

Determination of Flaw Growth Characteristics of Ti-6Al-4V Sheet in the Solution-Treated and Aged Condition

NASA Technical Reports Server (NTRS)

Hoeppner, David W.; Pettit, Donald E.; Feddersen, Charles E.; Hyler, Walter S.

1968-01-01

The specific experimental investigation undertaken was designed to answer these questions on Ti-6Al-4V in the solution treated and aged condition. The defect growth and fracture characteristics were studied in parent (unwelded) and welded sheet material. The results of the study indicate that cryogenic proof testing will screen smaller size defects than proof testing at ambient conditions. However some unusual crack growth behavior during the proof test simulation suggests that some further study be made of stress and time duration effects.

Spectroscopic characterization of HD 95086 b with the Gemini Planet Imager

DOE PAGES

De Rosa, Robert J.; Rameau, Julien; Patience, Jenny; ...

2016-06-21

Here, we present new H (1.5–1.8 μm) photometric and K 1 (1.9–2.2 μm) spectroscopic observations of the young exoplanet HD 95086 b obtained with the Gemini Planet Imager. The H-band magnitude has been significantly improved relative to previous measurements, whereas the low-resolution K 1 (more » $$\\lambda /\\delta \\lambda \\approx 66$$) spectrum is featureless within the measurement uncertainties and presents a monotonically increasing pseudo-continuum consistent with a cloudy atmosphere. By combining these new measurements with literature $$L^{\\prime} $$ photometry, we compare the spectral energy distribution (SED) of the planet to other young planetary-mass companions, field brown dwarfs, and to the predictions of grids of model atmospheres. HD 95086 b is over a magnitude redder in $${K}_{1}-L^{\\prime} $$ color than 2MASS J12073346–3932539 b and HR 8799 c and d, despite having a similar $$L^{\\prime} $$ magnitude. Considering only the near-infrared measurements, HD 95086 b is most analogous to the brown dwarfs 2MASS J2244316+204343 and 2MASS J21481633+4003594, both of which are thought to have dusty atmospheres. Morphologically, the SED of HD 95086 b is best fit by low temperature ($${T}_{{\\rm{eff}}}$$ = 800–1300 K), low surface gravity spectra from models which simulate high photospheric dust content. This range of effective temperatures is consistent with field L/T transition objects, but the spectral type of HD 95086 b is poorly constrained between early L and late T due to its unusual position the color–magnitude diagram, demonstrating the difficulty in spectral typing young, low surface gravity substellar objects. As one of the reddest such objects, HD 95086 b represents an important empirical benchmark against which our current understanding of the atmospheric properties of young extrasolar planets can be tested.« less

On the Astrid asteroid family

NASA Astrophysics Data System (ADS)

Carruba, V.

2016-09-01

Among asteroid families, the Astrid family is peculiar because of its unusual inclination distribution. Objects at a ≃ 2.764 au are quite dispersed in this orbital element, giving the family a `crab-like' appearance. Recent works showed that this feature is caused by the interaction of the family with the s - sC nodal secular resonance with Ceres, that spreads the inclination of asteroids near its separatrix. As a consequence, the currently observed distribution of the vW component of terminal ejection velocities obtained from inverting Gauss equation is quite leptokurtic, since this parameter mostly depends on the asteroids inclination. The peculiar orbital configuration of the Astrid family can be used to set constraints on key parameters describing the strength of the Yarkovsky force, such as the bulk and surface density and the thermal conductivity of surface material. By simulating various fictitious families with different values of these parameters, and by demanding that the current value of the kurtosis of the distribution in vW be reached over the estimated lifetime of the family, we obtained that the thermal conductivity of Astrid family members should be ≃0.001 W m-1 K-1, and that the surface and bulk density should be higher than 1000 kg m-3. Monte Carlo methods simulating Yarkovsky and stochastic Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) evolution of the Astrid family show its age to be T = 140 ± 30 Myr old, in good agreement with estimates from other groups. Its terminal ejection velocity parameter is in the range V_{EJ}= 5^{+17}_{-5} m s-1. Values of VEJ larger than 25 m s-1 are excluded from constraints from the current inclination distribution.

Searches for dark matter and new physics with unconventional signatures

NASA Astrophysics Data System (ADS)

Wulz, C.-E.; CMS Collaboration

2017-07-01

Selected results on searches for dark matter and unconventional signatures with the CMS detector are presented. Dark matter searches in channels with one or two jets, single photons, vector bosons, or top and bottom quarks combined with missing momentum in the final states are described. Unusual signatures such as displaced objects, disappearing or kinked tracks, delayed or stopped particles have also been explored. The analyses were performed with proton-proton data recorded at LHC centre-of-mass energies up to 13TeV.

Dark matter in the outer solar system

NASA Technical Reports Server (NTRS)

Owen, T.; Cruikshank, D.; De Bergh, C.; Geballe, T.

1994-01-01

There are now a large number of small bodies in the outer solar system that are known to be covered with dark material. Attempts to identify that material have been thwarted by the absence of discrete absorption features in the reflection spectra of these planetesimals. An absorption at 2.2 micrometers that appeared to be present in several objects has not been confirmed by new observations. Three absorptions in the spectrum of the unusually red planetesimal 5145 Pholus are well-established, but their identity remains a mystery.

Two Birds With One Stone: Application of Fundamental Cognitive Theory of Visual Perception Supporting Fratricide Prevention and Sensor Modeling Experimentation

DTIC Science & Technology

2008-12-01

tools capable of reducing fratricide and collateral damage. The theory of recognition-by-components developed by Dr. Irving Biederman presented a...trainer. The key to thermal combat identification was discovered in an unusual place: chick sexing. Biederman and Shiffrar [11] conducted object...professional sexers was .82. Biederman and Shiffrar conclude that “…after instruction the performance of the naïve subjects more closely resemble that of the

A study evaluating if targeted training for startle effect can improve pilot reactions in handling unexpected situations in a flight simulator

NASA Astrophysics Data System (ADS)

Gillen, Michael William

Recent airline accidents point to a crew's failure to make correct and timely decisions following a sudden and unusual event that startled the crew. This study sought to determine if targeted training could augment decision making during a startle event. Following a startle event cognitive function is impaired for a short duration of time (30-90 seconds). In aviation, critical decisions are often required to be made during this brief, but critical, time frame. A total of 40 volunteer crews (80 individual pilots) were solicited from a global U.S. passenger airline. Crews were briefed that they would fly a profile in the simulator but were not made aware of what the profile would entail. The study participants were asked to complete a survey on their background and flying preferences. Every other crew received training on how to handle a startle event. The training consisted of a briefing and simulator practice. Crew members (subjects) were either presented a low altitude or high altitude scenario to fly in a full-flight simulator. The maneuver scenarios were analyzed using a series of one-way ANOVAs, t-tests and regression for the main effect of training on crew performance. The data indicated that the trained crews flew the maneuver profiles significantly better than the untrained crews and significantly better than the Federal Aviation Administration (FAA) Airline Transport Pilot (ATP) standards. Each scenario's sub factors were analyzed using regression to examine for specific predictors of performance. The results indicate that in the case of the high altitude profile, problem diagnosis was a significant factor, in the low altitude profile, time management was also a significant factor. These predicators can be useful in further targeting training. The study's findings suggest that targeted training can help crews manage a startle event, leading to a potential reduction of inflight loss of control accidents. The training was broad and intended to cover an overall aircraft handling approach rather than being aircraft specific. Inclusion of this type of training by airlines has the potential to better aid crews in handling sudden and unusual events.

Raman Monte Carlo simulation for light propagation for tissue with embedded objects

NASA Astrophysics Data System (ADS)

Periyasamy, Vijitha; Jaafar, Humaira Bte; Pramanik, Manojit

2018-02-01

Monte Carlo (MC) stimulation is one of the prominent simulation technique and is rapidly becoming the model of choice to study light-tissue interaction. Monte Carlo simulation for light transport in multi-layered tissue (MCML) is adapted and modelled with different geometry by integrating embedded objects of various shapes (i.e., sphere, cylinder, cuboid and ellipsoid) into the multi-layered structure. These geometries would be useful in providing a realistic tissue structure such as modelling for lymph nodes, tumors, blood vessels, head and other simulation medium. MC simulations were performed on various geometric medium. Simulation of MCML with embedded object (MCML-EO) was improvised for propagation of the photon in the defined medium with Raman scattering. The location of Raman photon generation is recorded. Simulations were experimented on a modelled breast tissue with tumor (spherical and ellipsoidal) and blood vessels (cylindrical). Results were presented in both A-line and B-line scans for embedded objects to determine spatial location where Raman photons were generated. Studies were done for different Raman probabilities.

Experimental and numerical study of wastewater pollution in Yuhui channel, Jiashan city

NASA Astrophysics Data System (ADS)

Fu, Lei; Peng, Zhenhua; You, Aiju

2018-02-01

Due to the development of economics and society in China, the huge amount of wastewater becomes a serious problem in most of the Chinese cities. Therefore, the construction of wastewater treatment plant draws much more attentions than before. The discharge from the wastewater treatment plant is then considered as a point source in most of the important rivers and channels in China. In this study, a typical wastewater treatment plant extension project is introduced as a case study, a filed monitoring experiment is designed and executed to observe required data, then, a two-dimensional model is estabilished to simulate the water quality downsteam of the wastewater treatment plant, CODCr is considered as a typical pollutant during the simulation. The simulation results indicate that different discharge conditions will lead to different CODCr concentration downstream of the wastewater treatment plant, and an emergency plan should be prepared to minimize the risk of the pollution in the channel under unusual and accident conditions.

Molecular dynamics simulations and CD spectroscopy reveal hydration-induced unfolding of the intrinsically disordered LEA proteins COR15A and COR15B from Arabidopsis thaliana.

PubMed

Navarro-Retamal, Carlos; Bremer, Anne; Alzate-Morales, Jans; Caballero, Julio; Hincha, Dirk K; González, Wendy; Thalhammer, Anja

2016-10-07

The LEA (late embryogenesis abundant) proteins COR15A and COR15B from Arabidopsis thaliana are intrinsically disordered under fully hydrated conditions, but obtain α-helical structure during dehydration, which is reversible upon rehydration. To understand this unusual structural transition, both proteins were investigated by circular dichroism (CD) and molecular dynamics (MD) approaches. MD simulations showed unfolding of the proteins in water, in agreement with CD data obtained with both HIS-tagged and untagged recombinant proteins. Mainly intramolecular hydrogen bonds (H-bonds) formed by the protein backbone were replaced by H-bonds with water molecules. As COR15 proteins function in vivo as protectants in leaves partially dehydrated by freezing, unfolding was further assessed under crowded conditions. Glycerol reduced (40%) or prevented (100%) unfolding during MD simulations, in agreement with CD spectroscopy results. H-bonding analysis indicated that preferential exclusion of glycerol from the protein backbone increased stability of the folded state.

Herbig-Haro objects in the Chamaeleon II dark cloud

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

Graham, J.A.; Hartigan, P.

1988-04-01

A new photograph and some spectra have been obtained for the group of HH objects HH 52, 53, 54. A long, gaseous streamer extends from HH 54 and produces an appearance very similar to that of HH 12. The spectra provide some additional radial velocities and line-intensity measurements for the group. It is confirmed that HH 54D is a star with no unusual photometric or spectroscopic characteristics. Attention is drawn to the distance of 400 pc derived by FitzGerald (1974, 1976) for a globule in the Cha II cloud, and it is suggested that the whole complex of gas, dust,more » and stars may well be further away than the 140 pc generally assumed. The spatial and velocity characteristics of this group of HH objects are discussed. The data do not support the identifications proposed by Sandell et al. (1987) as sources for the observed flows. 32 references.« less

Follow-up Observations of SDSS and CRTS Candidate Cataclysmic Variables II

NASA Astrophysics Data System (ADS)

Szkody, Paula; Everett, Mark E.; Dai, Zhibin; Serna-Grey, Donald

2018-01-01

Spectra of 38 candidate or known cataclysmic variables are presented. Most are candidate dwarf novae or systems containing possible highly magnetic white dwarfs, while a few (KR Aur, LS Peg, V380 Oph, and V694 Mon) are previously known objects caught in unusual states. Individual spectra are used to confirm a dwarf nova nature or other classification while radial velocities of 15 systems provide orbital periods and velocity amplitudes that aid in determining the nature of the objects. Our results substantiate a polar nature for four objects, find an eclipsing SW Sex star below the period gap, another as a likely intermediate polar, as well as two dwarf novae with periods in the middle of the gap. Based on observations obtained with the Apache Point Observatory (APO) 3.5 m telescope, which is owned and operated by the Astrophysical Research Consortium (ARC).

Bioinspired spring origami.

PubMed

Faber, Jakob A; Arrieta, Andres F; Studart, André R

2018-03-23

Origami enables folding of objects into a variety of shapes in arts, engineering, and biological systems. In contrast to well-known paper-folded objects, the wing of the earwig has an exquisite natural folding system that cannot be sufficiently described by current origami models. Such an unusual biological system displays incompatible folding patterns, remains open by a bistable locking mechanism during flight, and self-folds rapidly without muscular actuation. We show that these notable functionalities arise from the protein-rich joints of the earwig wing, which work as extensional and rotational springs between facets. Inspired by this biological wing, we establish a spring origami model that broadens the folding design space of traditional origami and allows for the fabrication of precisely tunable, four-dimensional-printed objects with programmable bioinspired morphing functionalities. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Nova V2362 Cygni (Nova Cygni 2006): Spitzer, Swift, and Ground-Based Spectral Evolution

NASA Technical Reports Server (NTRS)

Lynch, David K.; Venturini, Catherine C.; Mazuk, S.; Woodward, Charles; Gehrz, Robert; Rayner, John; Helton, L.A.; Ness, Jan-Uwe; Starrfield, Sumner; Rudy, Richard J.;

The book availability study as an objective measure of performance in a health sciences library.

PubMed Central

Kolner, S J; Welch, E C

1985-01-01

In its search for an objective overall diagnostic evaluation, the University of Illinois Library of the Health Sciences' Program Evaluation Committee selected a book availability measure; it is easy to administer and repeat, results are reproducible, and comparable data exist for other academic and health sciences libraries. The study followed the standard methodology in the literature with minor modifications. Patrons searching for particular books were asked to record item(s) needed and the outcome of the search. Library staff members then determined the reasons for failures in obtaining desired items. The results of the study are five performance scores. The first four represent the percentage probability of a library's operating with ideal effectiveness; the last provides an overall performance score. The scores of the Library of the Health Sciences demonstrated no unusual availability problems. The study was easy to implement and provided meaningful, quantitative, and objective data. PMID:3995202

48 CFR 1332.114 - Unusual contract financing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 1332.114 Unusual contract financing. The designee authorized to approve unusual contract financing arrangements is set forth in CAM...

48 CFR 32.114 - Unusual contract financing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 32.114 Unusual contract financing. Any contract financing arrangement that deviates from this part is unusual contract financing...

48 CFR 432.114 - Unusual contract financing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Unusual contract financing... CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 432.114 Unusual contract financing. The HCA is authorized to approve unusual contract financing. The signed determination and finding...

An Unusual Complication of EVAR, Spontaneous Rectus Sheath Hematoma: A Case Report

PubMed Central

Sirivanichai, Chusak

2009-01-01

Objective: To report a successful conservative management in a case of spontaneous rectus sheath hematoma (SRSH) after Endovascular Aneurysmal Repair (EVAR) of infrarenal Abdominal Aortic Aneurysm (AAA). Case Presentation: An 84-year-old woman with a 6 cm in diameter infrarenal AAA underwent EVAR at our hospital. During the procedure, intravenous heparin was administered to keep the activated clotting time around 300 seconds. One hour after the procedure, the patient complained of pain on her right side abdomen. Physical examination revealed a tender mass in the right lower abdominal wall. Laboratory studies showed a fall in hemoglobin from 12.7 g/dl to 9.3 g/dl. Ultrasound (US) examination demonstrated an 8 × 5 cm hematoma within the right rectus muscle. Follow-up US examination revealed that the hematoma had enlarged and a computed tomography (CT) examination of the lower abdomen was performed. CT scan showed a smooth-shaped mass within the layers of the anterolateral abdominal wall leading to enlargement of the right rectus abdominis muscle without signs of active bleeding. A conservative management was considered. Result: The clinical course was uneventful with a stable hemodynamic state. The patient was discharged 12 days later and was doing well at the 2 week follow-up. Conclusion: Spontaneous rectus sheath hematoma is an unusual complication of a patient on anticoagulant therapy during EVAR. A prompt radiological investigation may prevent unnecessary surgical procedures in this unusual complication. PMID:23555371

Stellar Populations and Physical Conditions at 100 pc Resolution in a Lensed Galaxy at z 4

NASA Astrophysics Data System (ADS)

Berg, Danielle

2015-10-01

Large surveys of star-forming galaxies at high redshift (z > 1.5) have provided us with a broad understanding of how galaxies assemble and evolve, but the spatial and spectral limitations inherent in observing faint, distant objects mean that many of the physical processes regulating this dynamic evolution are poorly constrained. Much of our most detailed knowledge of the physical conditions in distant galaxies comes from careful studies of gravitationally lensed sources, few of which are at z>3.5. FOR J0332-3557 is a gravitationally lensed galaxy at z 4 for which we and other groups have obtained a total of 37.3 hours of VLT spectroscopy. The rest-frame UV spectrum is notable for its unusual combination of both strong emission lines in the rest-frame UV and strong Lya and interstellar absorption, and for the unusual spatial variation seen in the nebular emission lines, which are less extended than the underlying stellar continuum. We propose high spatial resolution imaging of FOR J0332-3557 with four broadband filters on WFC3, taking advantage of both the HST resolution and the lensing magnification to study star formation and extinction on 100 pc scales. Because the interpretation of our unusual rest-frame UV and optical spectra requires an accurate reddening estimate, combining these observations with ground-based spectroscopy will give the most complete picture to date of chemical evolution in a distant galaxy.

Core geometry in perspective

PubMed Central

Dillon, Moira R.; Spelke, Elizabeth S.

2015-01-01

Research on animals, infants, children, and adults provides evidence that distinct cognitive systems underlie navigation and object recognition. Here we examine whether and how these systems interact when children interpret 2D edge-based perspectival line drawings of scenes and objects. Such drawings serve as symbols early in development, and they preserve scene and object geometry from canonical points of view. Young children show limits when using geometry both in non-symbolic tasks and in symbolic map tasks that present 3D contexts from unusual, unfamiliar points of view. When presented with the familiar viewpoints in perspectival line drawings, however, do children engage more integrated geometric representations? In three experiments, children successfully interpreted line drawings with respect to their depicted scene or object. Nevertheless, children recruited distinct processes when navigating based on the information in these drawings, and these processes depended on the context in which the drawings were presented. These results suggest that children are flexible but limited in using geometric information to form integrated representations of scenes and objects, even when interpreting spatial symbols that are highly familiar and faithful renditions of the visual world. PMID:25441089

Exceptional Solar-System Objects

NASA Astrophysics Data System (ADS)

Zellner, Benjamin

1990-12-01

This is a target-of-opportunity proposal for HST observations to be executed if a previously unknown, truly exceptional solar-system object or phenomenon is discovered either in the normal course of HST work or by anyone, anywhere. Trails due to unknown moving objects will often appear on HST images made for other purposes. A short trail seen near the opposition point or at high ecliptic latitude could represent a major addition to our knowledge of the solar system. Thus we further propose that all short trials seen on HST images taken in favorable regions of the sky be given a quick analysis in the Observation Support System for their possible significance. If an unusual object is found we propose to: (1) Seek from the owner of data rights permission to proceed as may be appropriate; (2) Contact the Minor Planet Center for an evaluation of the significance of the discovery; and (3) For an object that appears to be of great significance where effective groundbased followup appears unlikely, request the HST schedule be replanned for followup images and physical studies using HST.

Molecular dynamics correctly models the unusual major conformation of the GAGU RNA internal loop and with NMR reveals an unusual minor conformation.

PubMed

Spasic, Aleksandar; Kennedy, Scott D; Needham, Laura; Manoharan, Muthiah; Kierzek, Ryszard; Turner, Douglas H; Mathews, David H

2018-05-01

The RNA "GAGU" duplex, (5'GAC GAGU GUCA) 2 , contains the internal loop (5'-GAGU-3') 2 , which has two conformations in solution as determined by NMR spectroscopy. The major conformation has a loop structure consisting of trans -Watson-Crick/Hoogsteen GG pairs, A residues stacked on each other, U residues bulged outside the helix, and all sugars with a C2'- endo conformation. This differs markedly from the internal loops, (5'-G AG C-3') 2 , (5'-A AG U-3') 2 , and (5'-UAGG-3') 2 , which all have cis -Watson-Crick/Watson-Crick AG "imino" pairs flanked by cis -Watson-Crick/Watson-Crick canonical pairs resulting in maximal hydrogen bonding. Here, molecular dynamics was used to test whether the Amber force field (ff99 + bsc0 + OL3) approximates molecular interactions well enough to keep stable the unexpected conformation of the GAGU major duplex structure and the NMR structures of the duplexes containing (5'-G AG C-3') 2 , (5'-A AG U-3') 2 , and (5'-U AG G-3') 2 internal loops. One-microsecond simulations were repeated four times for each of the duplexes starting in their NMR conformations. With the exception of (5'-UAGG-3') 2 , equivalent simulations were also run starting with alternative conformations. Results indicate that the Amber force field keeps the NMR conformations of the duplexes stable for at least 1 µsec. They also demonstrate an unexpected minor conformation for the (5'-GAGU-3') 2 loop that is consistent with newly measured NMR spectra of duplexes with natural and modified nucleotides. Thus, unrestrained simulations led to the determination of the previously unknown minor conformation. The stability of the native (5'-GAGU-3') 2 internal loop as compared to other loops can be explained by changes in hydrogen bonding and stacking as the flanking bases are changed. © 2018 Spasic et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Simulation of Physical Experiments in Immersive Virtual Environments

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.; Wasfy, Tamer M.

2001-01-01

An object-oriented event-driven immersive Virtual environment is described for the creation of virtual labs (VLs) for simulating physical experiments. Discussion focuses on a number of aspects of the VLs, including interface devices, software objects, and various applications. The VLs interface with output devices, including immersive stereoscopic screed(s) and stereo speakers; and a variety of input devices, including body tracking (head and hands), haptic gloves, wand, joystick, mouse, microphone, and keyboard. The VL incorporates the following types of primitive software objects: interface objects, support objects, geometric entities, and finite elements. Each object encapsulates a set of properties, methods, and events that define its behavior, appearance, and functions. A container object allows grouping of several objects. Applications of the VLs include viewing the results of the physical experiment, viewing a computer simulation of the physical experiment, simulation of the experiments procedure, computational steering, and remote control of the physical experiment. In addition, the VL can be used as a risk-free (safe) environment for training. The implementation of virtual structures testing machines, virtual wind tunnels, and a virtual acoustic testing facility is described.

OSS: OSSOS Survey Simulator

NASA Astrophysics Data System (ADS)

Petit, J.-M.; Kavelaars, J. J.; Gladman, B.; Alexandersen, M.

2018-05-01

Comparing properties of discovered trans-Neptunian Objects (TNOs) with dynamical models is impossible due to the observational biases that exist in surveys. The OSSOS Survey Simulator takes an intrinsic orbital model (from, for example, the output of a dynamical Kuiper belt emplacement simulation) and applies the survey biases, so the biased simulated objects can be directly compared with real discoveries.

Explanation of Europa's Unusual Polarization Properties: The Regolith is Sub-micron, Fine-Grained, High Porosity Material

NASA Astrophysics Data System (ADS)

Nelson, R. M.; Boryta, M. D.; Hapke, B. W.; Manatt, K. S.; Nebedum, A.; Kroner, D. O.; Shkuratov, Y.; Psarev, V.; Vanderoort, K.; Smythe, W. D.

2015-12-01

For several decades, unusual reflectance and polarization phase curves have been reported on Europa by experienced ground based astronomers (Rosenbush et al., 1997, 2015). The observed reflectance phase curve is consistent with the phase curves reported in the laboratory in fine grained particulate media (Nelson et al., 2000, 2002, Shkuratov et al., 2002). Shkuratov et al. (2002) also measured polarization properties of fine grained media showing that they relate to the coherent backscatter enhancement phenomenon and are consistent with the astronomical data. We have reconfigured a goniometric photopolarimeter (GPP) (Nelson et al., 2000, 2002) to measure in the laboratory the polarization phase curves of highly reflective particulate materials that simulate the Europa's predominately water ice regolith. We apply the Helmholtz Reciprocity Principle - we present our samples with linearly polarized light and measure the change in the intensity of the reflected component with phase angle from 0.05 to 15 degrees. This is physically equivalent to the astronomical polarization measurements. We report here the polarization phase curves for a suite of high albedo particulates of size 0.1

Dynamics of Unusual Debris Flows on Martian Sand Dunes

NASA Technical Reports Server (NTRS)

Miyamoto, Hideaki; Dohm, James M.; Baker, Victor R.; Beyer, Ross A.; Bourke, Mary

2004-01-01

Gullies that dissect sand dunes in Russell impact crater often display debris flow-like deposits in their distal reaches. The possible range of both the rheological properties and the flow rates are estimated using a numerical simulation code of a Bingham plastic flow to help explain the formation of these features. Our simulated results are best explained by a rapid debris flow. For example, a debris flow with the viscosity of 10(exp 2) Pa s and the yield strength of 10(exp 2) Pa can form the observed deposits with a flow rate of 0.5 cu m/s sustained over several minutes and total discharged water volume on the order of hundreds of cubic meters, which may be produced by melting a surface layer of interstitial ice within the dune deposits to several centimeters depth.

Water boiling inside carbon nanotubes: toward efficient drug release.

PubMed

Chaban, Vitaly V; Prezhdo, Oleg V

2011-07-26

We show using molecular dynamics simulation that spatial confinement of water inside carbon nanotubes (CNTs) substantially increases its boiling temperature and that a small temperature growth above the boiling point dramatically raises the inside pressure. Capillary theory successfully predicts the boiling point elevation down to 2 nm, below which large deviations between the theory and atomistic simulation take place. Water behaves qualitatively different inside narrow CNTs, exhibiting transition into an unusual phase, where pressure is gas-like and grows linearly with temperature, while the diffusion constant is temperature-independent. Precise control over boiling by CNT diameter, together with the rapid growth of inside pressure above the boiling point, suggests a novel drug delivery protocol. Polar drug molecules are packaged inside CNTs; the latter are delivered into living tissues and heated by laser. Solvent boiling facilitates drug release.

The curious case of cuprous chloride: Giant thermal resistance and anharmonic quasiparticle spectra driven by dispersion nesting

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Saikat; Bansal, Dipanshu; Delaire, Olivier; Perrodin, Didier; Bourret-Courchesne, Edith; Singh, David J.; Lindsay, Lucas

2017-09-01

Strongly anharmonic phonon properties of CuCl are investigated with inelastic neutron-scattering measurements and first-principles simulations. An unusual quasiparticle spectral peak emerges in the phonon density of states with increasing temperature, in both simulations and measurements, emanating from exceptionally strong coupling between conventional phonon modes. Associated with this strong anharmonicity, the lattice thermal conductivity of CuCl is extremely low and exhibits anomalous, nonmonotonic pressure dependence. We show how this behavior arises from the structure of the phonon dispersions augmenting the phase space available for anharmonic three-phonon scattering processes, and contrast this mechanism with common arguments based on negative Grüneisen parameters. These results demonstrate the importance of considering intrinsic phonon-dispersion structure toward understanding scattering processes and designing new ultralow thermal conductivity materials.

Nitriding kinetics of Si-SiC powder mixtures as simulations of reaction bonded Si3N4-SiC composites

NASA Technical Reports Server (NTRS)

Lightfoot, A.; Sheldon, B. W.; Flint, J. H.; Haggerty, J. S.

1989-01-01

The nitriding kinetics of Si and Si plus SiC powder mixtures were studied to simulate the fabrication of RBSN-SiC ceramic matrix composites. Very clean, assynthesized, and solvent-exposed powders were studied; C-rich and Si-rich SiC 0.04-0.05 micron diameter powders were mixed in varying concentrations with SiH4-derived 0.2-0.3 micron diameter Si powder. Complete nitridation is achieved with C-rich SiC powders in 140 min at 1250 C, and in the centers of Si-rich SiC powders in 15 min. The effects on the incubation periods, fast reaction periods, and slow reaction periods that characterize these nitriding processes were studied to explain unusual reverse reaction gradients and other effects of contamination.

Mechanics of wind ripple stratigraphy.

PubMed

Forrest, S B; Haff, P K

1992-03-06

Stratigraphic patterns preserved under translating surface undulations or ripples in a depositional eolian environment are computed on a grain by grain basis using physically based cellular automata models. The spontaneous appearance, growth, and motion of the simulated ripples correspond in many respects to the behavior of natural ripples. The simulations show that climbing strata can be produced by impact alone; direct action of fluid shear is unnecessary. The model provides a means for evaluating the connection between mechanical processes occurring in the paleoenvironment during deposition and the resulting stratigraphy preserved in the geologic column: vertical compression of small laminae above a planar surface indicates nascent ripple growth; supercritical laminae are associated with unusually intense deposition episodes; and a plane erosion surface separating sets of well-developed laminae is consistent with continued migration of mature ripples during a hiatus in deposition.

Simulation study of sulfonate cluster swelling in ionomers

NASA Astrophysics Data System (ADS)

Allahyarov, Elshad; Taylor, Philip L.; Löwen, Hartmut

2009-12-01

We have performed simulations to study how increasing humidity affects the structure of Nafion-like ionomers under conditions of low sulfonate concentration and low humidity. At the onset of membrane hydration, the clusters split into smaller parts. These subsequently swell, but then maintain constant the number of sulfonates per cluster. We find that the distribution of water in low-sulfonate membranes depends strongly on the sulfonate concentration. For a relatively low sulfonate concentration, nearly all the side-chain terminal groups are within cluster formations, and the average water loading per cluster matches the water content of membrane. However, for a relatively higher sulfonate concentration the water-to-sulfonate ratio becomes nonuniform. The clusters become wetter, while the intercluster bridges become drier. We note the formation of unusual shells of water-rich material that surround the sulfonate clusters.

Safety and reliability analysis in a polyvinyl chloride batch process using dynamic simulator-case study: Loss of containment incident.

PubMed

Rizal, Datu; Tani, Shinichi; Nishiyama, Kimitoshi; Suzuki, Kazuhiko

2006-10-11

In this paper, a novel methodology in batch plant safety and reliability analysis is proposed using a dynamic simulator. A batch process involving several safety objects (e.g. sensors, controller, valves, etc.) is activated during the operational stage. The performance of the safety objects is evaluated by the dynamic simulation and a fault propagation model is generated. By using the fault propagation model, an improved fault tree analysis (FTA) method using switching signal mode (SSM) is developed for estimating the probability of failures. The timely dependent failures can be considered as unavailability of safety objects that can cause the accidents in a plant. Finally, the rank of safety object is formulated as performance index (PI) and can be estimated using the importance measures. PI shows the prioritization of safety objects that should be investigated for safety improvement program in the plants. The output of this method can be used for optimal policy in safety object improvement and maintenance. The dynamic simulator was constructed using Visual Modeler (VM, the plant simulator, developed by Omega Simulation Corp., Japan). A case study is focused on the loss of containment (LOC) incident at polyvinyl chloride (PVC) batch process which is consumed the hazardous material, vinyl chloride monomer (VCM).

Deep Optical Observations of Unusual Neutron Star Calvera with the GTC

NASA Astrophysics Data System (ADS)

Shibanov, Yury; Danilenko, Andrey; Zharikov, Sergey; Shternin, Peter; Zyuzin, Dima

2016-11-01

Calvera is an unusual, isolated neutron star with a pure thermal X-ray spectrum typical of central compact objects in supernova remnants. On the other hand, its rotation period and spin-down rate are typical of ordinary rotation-powered pulsars. It was discovered and studied through X-rays, and has not yet been detected in other spectral domains. We present deep optical imaging of the Calvera field, obtained with the Gran Telescopio Canarias, in the g\\prime and I\\prime bands. Within the vicinity of ≈ 1\\prime\\prime of Calvera, we detected two point-like objects that were invisible at previous shallow observations. However, accurate astrometry showed that neither of them can be identified with the pulsar. We put new upper limits of g\\prime \\gt 27.87 and I\\prime \\gt 26.84 on its optical brightness. We also reanalyzed all available archival X-ray data on Calvera. Comparison of the Calvera thermal emission parameters and upper limits on optical and non-thermal X-ray emission with respective data on rotation-powered pulsars shows that Calvera might belong to the class of ordinary middle-aged pulsars, if we assume that its distance is in the range of 1.5-5 kpc. Based on observations made with the Gran Telescopio Canarias (GTC), installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, on the island of La Palma, program GTC1-14AMEX.

Persistence of an unusual pelagic zooplankton assemblage in a clear, mountain lake

USGS Publications Warehouse

Larson, G.L.; Hoffman, R.L.; C. David, McIntire

2002-01-01

The planktonic zooplankton assemblage in Mowich Lake, Mount Rainier National Park (MORA), was composed almost entirely of rotifers in 1966 and 1967. Adult pelagic crustacean taxa were rare. Their paucity was attributed to predation by kokanee salmon (Oncorhynchus nerka), which had been stocked in 1961. During a park-wide survey of 24 lakes in 1988, Mowich Lake was the only one that did not contain at least one planktonic crustacean species. Given the apparent persistence of the unusual pelagic zooplankton assemblage in Mowich Lake, the first objective of this study was to document the interannual variation in the taxonomic structure of the zooplankton assemblages in the lake from 1988 through 1999. A second objective was to determine if it was possible to predict the taxonomic composition of the pelagic crustacean zooplankton assemblage in Mowich Lake prior to the stocking of kokanee salmon. The Mowich Lake zooplankton assemblages in 1988-1999 were consistent with those in 1966 and 1967. Crustacean taxa were extremely rare, but they included most of the primary taxa collected from 23 MORA lakes surveyed in 1988. Nonetheless, the 1988 collections showed that the September rotifer assemblage in Mowich Lake was similar to 10 of the 24 lakes sampled. Seven of the 10 lakes were dominated by cladocerans, primarily Daphnia rosea and Holopedium gibberum. Therefore, it appeared that either one or both of these species may have numerically dominated the crustacean zooplankton assemblage in the lake prior to 1961.

Persistence of an unusual pelagic zooplankton assemblage in a clear mountain lake

USGS Publications Warehouse

Larson, Gary L.; Hoffman, Robert L.; McIntire, C.D.

2002-01-01

The planktonic zooplankton assemblage in Mowich Lake, Mount Rainier National Park (MORA), was composed almost entirely of rotifers in 1966 and 1967. Adult pelagic crustacean taxa were rare. Their paucity was attributed to predation by kokanee salmon (Oncorhynchus nerka), which had been stocked in 1961. During a park-wide survey of 24 lakes in 1988, Mowich Lake was the only one that did not contain at least one planktonic crustacean species. Given the apparent persistence of the unusual pelagic zooplankton assemblage in Mowich Lake, the first objective of this study was to document the interannual variation in the taxonomic structure of the zooplankton assemblages in the lake from 1988 through 1999. A second objective was to determine if it was possible to predict the taxonomic composition of the pelagic crustacean zooplankton assemblage in Mowich Lake prior to the stocking of kokanee salmon. The Mowich Lake zooplankton assemblages in 1988a??1999 were consistent with those in 1966 and 1967. Crustacean taxa were extremely rare, but they included most of the primary taxa collected from 23 MORA lakes surveyed in 1988. Nonetheless, the 1988 collections showed that the September rotifer assemblage in Mowich Lake was similar to 10 of the 24 lakes sampled. Seven of the 10 lakes were dominated by cladocerans, primarily Daphnia rosea and Holopedium gibberum. Therefore, it appeared that either one or both of these species may have numerically dominated the crustacean zooplankton assemblage in the lake prior to 1961.

Interoperability format translation and transformation between IFC architectural design file and simulation file formats

DOEpatents

Chao, Tian-Jy; Kim, Younghun

2015-02-03

Automatically translating a building architecture file format (Industry Foundation Class) to a simulation file, in one aspect, may extract data and metadata used by a target simulation tool from a building architecture file. Interoperability data objects may be created and the extracted data is stored in the interoperability data objects. A model translation procedure may be prepared to identify a mapping from a Model View Definition to a translation and transformation function. The extracted data may be transformed using the data stored in the interoperability data objects, an input Model View Definition template, and the translation and transformation function to convert the extracted data to correct geometric values needed for a target simulation file format used by the target simulation tool. The simulation file in the target simulation file format may be generated.

Masses, Radii, and Cloud Properties of the HR 8799 Planets

NASA Technical Reports Server (NTRS)

Marley, Mark S.; Saumon, Didier; Cushing, Michael; Ackerman, Andrew S.; Fortney, Jonathan J.; Freedman, Richard

2012-01-01

The near-infrared colors of the planets directly imaged around the A star HR 8799 are much redder than most field brown dwarfs of the same effective temperature. Previous theoretical studies of these objects have compared the photometric and limited spectral data of the planets to the predictions of various atmosphere and evolution models and concluded that the atmospheres of planets b, c, and d are unusually cloudy or have unusual cloud properties. Most studies have also found that the inferred radii of some or all of the planets disagree with expectations of standard giant planet evolution models. Here we compare the available data to the predictions of our own set of atmospheric and evolution models that have been extensively tested against field L and T dwarfs, including the reddest L dwarfs. Unlike almost all previous studies we specify mutually self-consistent choices for effective temperature, gravity, cloud properties, and planetary radius. This procedure yields plausible and self-consistent values for the masses, effective temperatures, and cloud properties of all three planets. We find that the cloud properties of the HR 8799 planets are in fact not unusual but rather follow previously recognized trends including a gravity dependence on the temperature of the L to T spectral transition, some reasons for which we discuss. We find that the inferred mass of planet b is highly sensitive to the H and K band spectrum. Solutions for planets c and particularly d are less certain but are consistent with the generally accepted constraints on the age of the primary star and orbital dynamics. We also confirm that as for L and T dwarfs and solar system giant planets, non-equilibrium chemistry driven by atmospheric mixing is also important for these objects. Given the preponderance of data suggesting that the L to T spectral type transition is gravity dependent, we present a new evolution calculation that predicts cooling tracks on the near-infrared color-magnitude diagram. Finally we argue that the range of uncertainty conventionally quoted for the bolometric luminosity of all three planets is too small.

An unusual very low-mass high-amplitude pre-main sequence periodic variable

NASA Astrophysics Data System (ADS)

Rodríguez-Ledesma, M. V.; Mundt, R.; Ibrahimov, M.; Messina, S.; Parihar, P.; Hessman, F. V.; Alves de Oliveira, C.; Herbst, W.

2012-08-01

Aims: We have investigated the nature of the variability of CHS 7797, an unusual periodic variable in the Orion Nebula Cluster. Methods: An extensive I-band photometric data set of CHS 7797 was compiled between 2004-2010 using various telescopes. Further optical data have been collected in R and z' bands. In addition, simultaneous observations of the ONC region including CHS 7797 were performed in the I,J,Ks & IRAC 3.6 and 4.5 μm bands over a time interval of ≈40 d. Results: CHS 7797 shows an unusual large-amplitude variation of ≈1.7 mag in the R,I, and z' bands with a period 17.786 ± 0.03 d (FAP = 1 × 10-15%). The amplitude of the brightness modulation decreases only slightly at longer wavelengths. The star is faint during ≈2/3 of the period and the shape of the phased light-curves for the seven different observing seasons shows minor changes and small-amplitude variations. Interestingly, there are no significant colour-flux correlations for λ ≲ 2 μm, while the object becomes redder when fainter at longer wavelengths. CHS 7797 has a spectral type of M 6 and an estimated mass between 0.04-0.1 M⊙. Conclusions: The analysis of the data suggests that the periodic variability of CHS 7797 is most probably caused by an orbital motion. Variability as a result of rotational brightness modulation by a hot spot is excluded by the lack of any colour-brightness correlation in the optical. The latter indicates that CHS 7797 is most probably occulted by circumstellar matter in which grains have grown from typical 0.1 μm to ≈1-2 μm sizes. We discuss two possible scenarios in which CHS 7797 is periodically eclipsed by structures in a disc, namely that CHS 7797 is a single object with a circumstellar disc, or that CHS 7797 is a binary system, similar to KH 15D, in which an inclined circumbinary disc is responsible of the variability. Possible reasons for the typical 0.3 mag variations in I-band at a given phase are discussed.

Statistical Evaluations of Variations in Dairy Cows’ Milk Yields as a Precursor of Earthquakes

PubMed Central

Yamauchi, Hiroyuki; Hayakawa, Masashi; Asano, Tomokazu; Ohtani, Nobuyo; Ohta, Mitsuaki

2017-01-01

Simple Summary There are many reports of abnormal changes occurring in various natural systems prior to earthquakes. Unusual animal behavior is one of these abnormalities; however, there are few objective indicators and to date, reliability has remained uncertain. We found that milk yields of dairy cows decreased prior to an earthquake in our previous case study. In this study, we examined the reliability of decreases in milk yields as a precursor for earthquakes using long-term observation data. In the results, milk yields decreased approximately three weeks before earthquakes. We have come to the conclusion that dairy cow milk yields have applicability as an objectively observable unusual animal behavior prior to earthquakes, and dairy cows respond to some physical or chemical precursors of earthquakes. Abstract Previous studies have provided quantitative data regarding unusual animal behavior prior to earthquakes; however, few studies include long-term, observational data. Our previous study revealed that the milk yields of dairy cows decreased prior to an extremely large earthquake. To clarify whether the milk yields decrease prior to earthquakes, we examined the relationship between earthquakes of various magnitudes and daily milk yields. The observation period was one year. In the results, cross-correlation analyses revealed a significant negative correlation between earthquake occurrence and milk yields approximately three weeks beforehand. Approximately a week and a half beforehand, a positive correlation was revealed, and the correlation gradually receded to zero as the day of the earthquake approached. Future studies that use data from a longer observation period are needed because this study only considered ten earthquakes and therefore does not have strong statistical power. Additionally, we compared the milk yields with the subionospheric very low frequency/low frequency (VLF/LF) propagation data indicating ionospheric perturbations. The results showed that anomalies of VLF/LF propagation data emerged prior to all of the earthquakes following decreases in milk yields; the milk yields decreased earlier than propagation anomalies. We mention how ultralow frequency magnetic fields are a stimulus that could reduce milk yields. This study suggests that dairy cow milk yields decrease prior to earthquakes, and that they might respond to stimuli emerging earlier than ionospheric perturbations. PMID:28282889

Physically Based Modeling and Simulation with Dynamic Spherical Volumetric Simplex Splines

PubMed Central

Tan, Yunhao; Hua, Jing; Qin, Hong

2009-01-01

In this paper, we present a novel computational modeling and simulation framework based on dynamic spherical volumetric simplex splines. The framework can handle the modeling and simulation of genus-zero objects with real physical properties. In this framework, we first develop an accurate and efficient algorithm to reconstruct the high-fidelity digital model of a real-world object with spherical volumetric simplex splines which can represent with accuracy geometric, material, and other properties of the object simultaneously. With the tight coupling of Lagrangian mechanics, the dynamic volumetric simplex splines representing the object can accurately simulate its physical behavior because it can unify the geometric and material properties in the simulation. The visualization can be directly computed from the object’s geometric or physical representation based on the dynamic spherical volumetric simplex splines during simulation without interpolation or resampling. We have applied the framework for biomechanic simulation of brain deformations, such as brain shifting during the surgery and brain injury under blunt impact. We have compared our simulation results with the ground truth obtained through intra-operative magnetic resonance imaging and the real biomechanic experiments. The evaluations demonstrate the excellent performance of our new technique. PMID:20161636

Object oriented studies into artificial space debris

NASA Technical Reports Server (NTRS)

Adamson, J. M.; Marshall, G.

1988-01-01

A prototype simulation is being developed under contract to the Royal Aerospace Establishment (RAE), Farnborough, England, to assist in the discrimination of artificial space objects/debris. The methodology undertaken has been to link Object Oriented programming, intelligent knowledge based system (IKBS) techniques and advanced computer technology with numeric analysis to provide a graphical, symbolic simulation. The objective is to provide an additional layer of understanding on top of conventional classification methods. Use is being made of object and rule based knowledge representation, multiple reasoning, truth maintenance and uncertainty. Software tools being used include Knowledge Engineering Environment (KEE) and SymTactics for knowledge representation. Hooks are being developed within the SymTactics framework to incorporate mathematical models describing orbital motion and fragmentation. Penetration and structural analysis can also be incorporated. SymTactics is an Object Oriented discrete event simulation tool built as a domain specific extension to the KEE environment. The tool provides facilities for building, debugging and monitoring dynamic (military) simulations.

Computer simulations of interferometric imaging with the Very Large Telescope Interferometer and its Astronomical Multibeam Recombiner instrument

NASA Astrophysics Data System (ADS)

Przygodda, Frank; Bloecker, Thomas; Hofmann, Karl-Heinz; Weigelt, Gerd

2001-05-01

We present computer simulations of interferometric imaging with the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory and the Astronomical Multibeam Recombiner (AMBER) phase-closure instrument. These simulations include both the astrophysical modeling of a stellar object by radiative-transfer calculations and the simulation of light propagation from the object to the detector (through atmosphere, telescopes, and the AMBER instrument), simulation of photon noise and detector readout noise, and finally data processing of the interferograms. The results show the dependence of the visibility error bars on the following observational parameters: different seeing during the observation of object and reference star (Fried parameters r0,object and r0,ref ranging between 0.9 and 1.2 m), different residual tip-tilt error ((delta) tt,object and (delta) tt,ref ranging between 0.1% and 20% of the Airy-disk diameter), and object brightness (Kobject equals 0.7 to 10.2 mag, Kref equals 0.7 mag). As an example, we focus on stars in late stages of stellar evolution and study one of the key objects of that kind, the dusty super-giant IRC + 10420, which is rapidly evolving on human time scales. We show computer simulations of VLT interferometer (visibility and phase-closure measurements) of IRC + 10420 with two and three auxiliary telescopes (in AMBER wide-field mode, i.e., without fiber optic spatial filters) and discuss whether the visibility accuracy is sufficient to distinguish between different theoretical model predictions.

MCNP6 simulation of radiographs generated from megaelectron volt X-rays for characterizing a computed tomography system

NASA Astrophysics Data System (ADS)

Dooraghi, Alex A.; Tringe, Joseph W.

2018-04-01

To evaluate conventional munition, we simulated an x-ray computed tomography (CT) system for generating radiographs from nominal x-ray energies of 6 or 9 megaelectron volts (MeV). CT simulations, informed by measured data, allow for optimization of both system design and acquisition techniques necessary to enhance image quality. MCNP6 radiographic simulation tools were used to model ideal detector responses (DR) that assume either (1) a detector response proportional to photon flux (N) or (2) a detector response proportional to energy flux (E). As scatter may become significant with MeV x-ray systems, simulations were performed with and without the inclusion of object scatter. Simulations were compared against measurements of a cylindrical munition component principally composed of HMX, tungsten and aluminum encased in carbon fiber. Simulations and measurements used a 6 MeV peak energy x-ray spectrum filtered with 3.175 mm of tantalum. A detector response proportional to energy which includes object scatter agrees to within 0.6 % of the measured line integral of the linear attenuation coefficient. Exclusion of scatter increases the difference between measurement and simulation to 5 %. A detector response proportional to photon flux agrees to within 20 % when object scatter is included in the simulation and 27 % when object scatter is excluded.

A BROWN DWARF CENSUS FROM THE SIMP SURVEY

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

Robert, Jasmin; Gagné, Jonathan; Artigau, Étienne

We have conducted a near-infrared (NIR) proper motion survey, the Sondage Infrarouge de Mouvement Propre, in order to discover field ultracool dwarfs (UCD) in the solar neighborhood. The survey was conducted by imaging ∼28% of the sky with the Caméra PAnoramique Proche-InfraRouge both in the southern hemisphere at the Cerro Tololo Inter-American Observatory 1.5 m telescope, and in the northern hemisphere at the Observatoire du Mont-Mégantic 1.6 m telescope and comparing the source positions from these observations with the Two Micron All-Sky Survey Point Source Catalog (2MASS PSC). Additional color criteria were used to further discriminate unwanted astrophysical sources. Wemore » present the results of an NIR spectroscopic follow-up of 169 M, L, and T dwarfs. Among the sources discovered are 2 young field brown dwarfs, 6 unusually red M and L dwarfs, 25 unusually blue M and L dwarfs, 2 candidate unresolved L+T binaries, and 24 peculiar UCDs. Additionally, we add 9 L/T transition dwarfs (L6–T4.5) to the already known objects.« less

[Several mechanisms of visual gnosis disorders in local brain lesions].

PubMed

Meerson, Ia A

1981-01-01

The object of the studies were peculiarities of recognizing visual images by patients with local cerebral lesions under conditions of incomplete sets of the image features, disjunction of the latter, distortion of their spatial arrangement, and unusual spatial orientation of the image as a whole. It was found that elimination of even one essential feature sharply hampered the recognition of the image both by healthy individuals (control), and patients with extraoccipital lesions, whereas elimination of several nonessential features only slowed down the process. In distinction from this the difficulties of the recognition of incomplete images by patients with occipital lesions were directly proportional to the number of the eliminated features irrespective of the latters' significance, i.e. these patients were unable to evaluate the hierarchy of the features. The recognition process in these patients were followed the way of scanning individual features. The reaccumulation and summation. The recognition of the fragmental, spatially distorted and unusually oriented images was found to be affected selectively in patients with parietal lobe affections. The patients with occipital lesions recognized such images practically as good as the ordinary ones.

A Brown Dwarf Census from the SIMP Survey

NASA Astrophysics Data System (ADS)

Robert, Jasmin; Gagné, Jonathan; Artigau, Étienne; Lafrenière, David; Nadeau, Daniel; Doyon, René; Malo, Lison; Albert, Loïc; Simard, Corinne; Bardalez Gagliuffi, Daniella C.; Burgasser, Adam J.

2016-10-01

We have conducted a near-infrared (NIR) proper motion survey, the Sondage Infrarouge de Mouvement Propre, in order to discover field ultracool dwarfs (UCD) in the solar neighborhood. The survey was conducted by imaging ˜28% of the sky with the Caméra PAnoramique Proche-InfraRouge both in the southern hemisphere at the Cerro Tololo Inter-American Observatory 1.5 m telescope, and in the northern hemisphere at the Observatoire du Mont-Mégantic 1.6 m telescope and comparing the source positions from these observations with the Two Micron All-Sky Survey Point Source Catalog (2MASS PSC). Additional color criteria were used to further discriminate unwanted astrophysical sources. We present the results of an NIR spectroscopic follow-up of 169 M, L, and T dwarfs. Among the sources discovered are 2 young field brown dwarfs, 6 unusually red M and L dwarfs, 25 unusually blue M and L dwarfs, 2 candidate unresolved L+T binaries, and 24 peculiar UCDs. Additionally, we add 9 L/T transition dwarfs (L6-T4.5) to the already known objects.

Anomalously Soft Non-Euclidean Springs

NASA Astrophysics Data System (ADS)

Levin, Ido; Sharon, Eran

2016-01-01

In this work we study the mechanical properties of a frustrated elastic ribbon spring—the non-Euclidean minimal spring. This spring belongs to the family of non-Euclidean plates: it has no spontaneous curvature, but its lateral intrinsic geometry is described by a non-Euclidean reference metric. The reference metric of the minimal spring is hyperbolic, and can be embedded as a minimal surface. We argue that the existence of a continuous set of such isometric minimal surfaces with different extensions leads to a complete degeneracy of the bulk elastic energy of the minimal spring under elongation. This degeneracy is removed only by boundary layer effects. As a result, the mechanical properties of the minimal spring are unusual: the spring is ultrasoft with a rigidity that depends on the thickness t as t7 /2 and does not explicitly depend on the ribbon's width. Moreover, we show that as the ribbon is widened, the rigidity may even decrease. These predictions are confirmed by a numerical study of a constrained spring. This work is the first to address the unusual mechanical properties of constrained non-Euclidean elastic objects.

Objective measures of situation awareness in a simulated medical environment

PubMed Central

Wright, M; Taekman, J; Endsley, M

2004-01-01

One major limitation in the use of human patient simulators is a lack of objective, validated measures of human performance. Objective measures are necessary if simulators are to be used to evaluate the skills and training of medical practitioners and teams or to evaluate the impact of new processes or equipment design on overall system performance. Situation awareness (SA) refers to a person's perception and understanding of their dynamic environment. This awareness and comprehension is critical in making correct decisions that ultimately lead to correct actions in medical care settings. An objective measure of SA may be more sensitive and diagnostic than traditional performance measures. This paper reviews a theory of SA and discusses the methods required for developing an objective measure of SA within the context of a simulated medical environment. Analysis and interpretation of SA data for both individual and team performance in health care are also presented. PMID:15465958

The Relationship between Clinical Presentation and Unusual Sensory Interests in Autism Spectrum Disorders: A Preliminary Investigation

ERIC Educational Resources Information Center

Zachor, Ditza A.; Ben-Itzchak, Esther

2014-01-01

Unusual responses to sensory stimuli have been described in autism spectrum disorder (ASD).The study examined the frequencies of "unusual sensory interests" and "negative sensory responses" and their relation to functioning in a large ASD population (n = 679). Having "unusual sensory interests" was reported in 70.4%…

Interoperability format translation and transformation between IFC architectural design file and simulation file formats

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

Chao, Tian-Jy; Kim, Younghun

Automatically translating a building architecture file format (Industry Foundation Class) to a simulation file, in one aspect, may extract data and metadata used by a target simulation tool from a building architecture file. Interoperability data objects may be created and the extracted data is stored in the interoperability data objects. A model translation procedure may be prepared to identify a mapping from a Model View Definition to a translation and transformation function. The extracted data may be transformed using the data stored in the interoperability data objects, an input Model View Definition template, and the translation and transformation function tomore » convert the extracted data to correct geometric values needed for a target simulation file format used by the target simulation tool. The simulation file in the target simulation file format may be generated.« less

A Little Vacation on Mars: Mars Simulation Microbial Challenge Experiments

NASA Astrophysics Data System (ADS)

Boston, P.; Todd, P.; Van De Camp, J.; Northup, D.; Spilde, M.

2008-06-01

Communities of microbial organisms isolated from a variety of extreme environments were subjected to 1 to 5 weeks of simulated Martian environmental conditions using the Mars Environment Simulation Chamber at the Techshot, Inc. facility in Greenville, Indiana. The goal of the overall experiment program was to assess survival of test Earth organisms under Mars full spectrum sunlight, low-latitude daily temperature profile and various Mars-atmosphere pressures (~50 mbar to 500 mbar, 100% CO2) and low moisture content. Organisms surviving after 5 weeks at 100 mbar included those from gypsum surface fracture communities in a Permian aged evaporite basin, desert varnish on andesite lavas around a manganese mine, and iron and manganese oxidizing organisms isolated from two caves in Mew Mexico. Phylogenetic DNA analysis revealed strains of cyanobacteria, bacterial genera (present in all surviving communities) Asticacaulis, Achromobacter, Comamonas, Pantoea, Verrucomicrobium, Bacillus, Gemmatimonas, Actinomyces, and others. At least one microcolonial fungal strain from a desert varnish community and at least one strain from Utah survived simulations. Strains related to the unusual cave bacterial group Bacteroidetes are present in survivor communities that resist isolation into pure culture implying that their consortial relationships may be critical to their survival.

Simulations of Merging Helion Bunches on the AGS Injection Porch

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

Gardner, C. J.

During the setup of helions for the FY2014 RHIC run it was discovered that the standard scheme for merging bunches on the AGS injection porch required an injection kicker pulse shorter than what was available. To overcome this difficulty, K. Zeno proposed and developed an interesting and unusual alternative which uses RF harmonic numbers 12, 4, 2 (rather than the standard 8, 4, 2) to merge 8 helion bunches into 2. In this note we carry out simulations that illustrate how the alternative scheme works and how it compares with the standard scheme. This is done in Sections 13 andmore » 14. A scheme in which 6 bunches are merged into 1 is simulated in Section 15. This may be useful if more helions per merged bunch are needed in future runs. General formulae for the simulations are given in Sections 9 through 12. For completeness, Sections 1 through 8 give a derivation of the turn-by-turn equations of longitudinal motion at constant magnetic field. The derivation is based on the work of MacLachlan. The reader may wish to skip over these Sections and start with Section 9.« less

The role of calcium and sodium in toxicity of an effluent to mysid shrimp (Mysidopsis bahia)

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

Kline, E.R.; Stekoll, M.S.

2000-01-01

The source of acute toxicity of an aged gold mill effluent to juvenile mysid shrimp (Mysidopsis bahia [Americamysis bahia]) was identified. Effluent osmolality was equivalent to that of 12 ppt seawater. At five effluent concentrations ranging from 4 to 100% (v/v), using 12 ppt seawater for dilution, the onset of responses was most rapid at 37% effluent. Simulated effluent was created by adding Na{sup +}, Ca{sup 2+}, Mg{sup 2+}, K{sup +}, Cl{sup {minus}}, and SO{sub 4}{sup 2{minus}} to distilled water at concentrations equal to those measured in the effluent. The unusual finding of a more rapid onset of responses atmore » 37% than at 100% effluent was duplicated with simulated effluent, demonstrating that responses of M. bahia to effluent were attributable to one or more of the six ions that were included in simulated effluent. Proportionally, excess Ca{sup 2+} and Na{sup +} concentrations in effluent and in simulated effluent, along with the results of the previous experiments, demonstrated that excess Ca{sup 2+} was the sole source of effluent toxicity and that Na{sup +} deficiency, relative to the proportion in seawater, reduced Ca{sup 2+} toxicity.« less

Do dichromats see colours in this way? Assessing simulation tools without colorimetric measurements.

PubMed

Lillo Jover, Julio A; Álvaro Llorente, Leticia; Moreira Villegas, Humberto; Melnikova, Anna

2016-11-01

Simulcheck evaluates Colour Simulation Tools (CSTs, they transform colours to mimic those seen by colour vision deficients). Two CSTs (Variantor and Coblis) were used to know if the standard Simulcheck version (direct measurement based, DMB) can be substituted by another (RGB values based) not requiring sophisticated measurement instruments. Ten normal trichromats performed the two psychophysical tasks included in the Simulcheck method. The Pseudoachromatic Stimuli Identification task provided the h uv (hue angle) values of the pseudoachromatic stimuli: colours seen as red or green by normal trichromats but as grey by colour deficient people. The Minimum Achromatic Contrast task was used to compute the L R (relative luminance) values of the pseudoachromatic stimuli. Simulcheck DMB version showed that Variantor was accurate to simulate protanopia but neither Variantor nor Coblis were accurate to simulate deuteranopia. Simulcheck RGB version provided accurate h uv values, so this variable can be adequately estimated when lacking a colorimeter —an expensive and unusual apparatus—. Contrary, the inaccuracy of the L R estimations provided by Simulcheck RGB version makes it advisable to compute this variable from the measurements performed with a photometer, a cheap and easy to find apparatus.

Modeling ground-based timber harvesting systems using computer simulation

Treesearch

Jingxin Wang; Chris B. LeDoux

2001-01-01

Modeling ground-based timber harvesting systems with an object-oriented methodology was investigated. Object-oriented modeling and design promote a better understanding of requirements, cleaner designs, and better maintainability of the harvesting simulation system. The model developed simulates chainsaw felling, drive-to-tree feller-buncher, swing-to-tree single-grip...

Simulations in Foreign Languages.

ERIC Educational Resources Information Center

Nebraska State Dept. of Education, Lincoln. Div. of Instructional Services.

The purpose of this publication is to define minimal competencies for foreign language classes. The term "simulation" refers to role playing. The simulations are stated in terms of practical communication performance objectives. The intent is to have the student direct his learning in the basic skills toward an immediate objective rather than a…

Phase transitions and thermodynamic properties of antiferromagnetic Ising model with next-nearest-neighbor interactions on the Kagomé lattice

NASA Astrophysics Data System (ADS)

Ramazanov, M. K.; Murtazaev, A. K.; Magomedov, M. A.; Badiev, M. K.

2018-06-01

We study phase transitions and thermodynamic properties in the two-dimensional antiferromagnetic Ising model with next-nearest-neighbor interaction on a Kagomé lattice by Monte Carlo simulations. A histogram data analysis shows that a second-order transition occurs in the model. From the analysis of obtained data, we can assume that next-nearest-neighbor ferromagnetic interactions in two-dimensional antiferromagnetic Ising model on a Kagomé lattice excite the occurrence of a second-order transition and unusual behavior of thermodynamic properties on the temperature dependence.

A high-altitude barium radial injection experiment

NASA Technical Reports Server (NTRS)

Wescott, E. M.; Stenbaek-Nielsen, H. C.; Hallinan, T. J.; Deehr, C. S.; Romick, G. J.; Olson, J. V.; Roederer, J. G.; Sydora, R.

1980-01-01

A rocket launched from Poker Flat, Alaska, carried a new type of high-explosive barium shaped charge to 571 km, where detonation injected a thin disk of barium vapor with high velocity nearly perpendicular to the magnetic field. The TV images of the injection are spectacular, revealing three major regimes of expanding plasma which showed early instabilities in the neutral gas. The most unusual effect of the injection is a peculiar rayed barium-ion structure lying in the injection plane and centered on a 5 km 'black hole' surrounding the injection point. Preliminary electrostatic computer simulations show a similar rayed development.

Exploitation and Optimization of Reservoir Performance in Hunton Formation, Oklahoma, Budget Period I, Class Revisit

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

Kelkar, Mohan

2002-04-02

This report explains the unusual characteristics of West Carney Field based on detailed geological and engineering analyses. A geological history that explains the presence of mobile water and oil in the reservoir was proposed. The combination of matrix and fractures in the reservoir explains the reservoir?s flow behavior. We confirm our hypothesis by matching observed performance with a simulated model and develop procedures for correlating core data to log data so that the analysis can be extended to other, similar fields where the core coverage may be limited.

Evaluation of a Cyber Security System for Hospital Network.

PubMed

Faysel, Mohammad A

2015-01-01

Most of the cyber security systems use simulated data in evaluating their detection capabilities. The proposed cyber security system utilizes real hospital network connections. It uses a probabilistic data mining algorithm to detect anomalous events and takes appropriate response in real-time. On an evaluation using real-world hospital network data consisting of incoming network connections collected for a 24-hour period, the proposed system detected 15 unusual connections which were undetected by a commercial intrusion prevention system for the same network connections. Evaluation of the proposed system shows a potential to secure protected patient health information on a hospital network.

Test facility for 6000 hour life test of 30 cm mercury ion thruster

NASA Technical Reports Server (NTRS)

Caldwell, J. J.

1973-01-01

The environmental and instrumentation requirements for long term testing of electrical propulsion thrusters which impose severe and unusual requirements upon the simulation facility were studied. High speed ions ejected from a mercury thruster erode material from collecting surfaces, which is then scattered and redeposited upon other surfaces, with resultant damage to the chamber and test article. By collecting the thruster plume on a frozen mercury surface damage to the thruster and chamber by back-scattered erosion products was minimized. Provisions for unattended operation, remote data acquisition, personnel safety, and instrumentation for assessing thruster performance are also discussed.

Photoletter to the editor: Atypical primary cutaneous mucormycosis of the scalp.

PubMed

García-Sepúlveda, Ricardo; Navarrete-Solís, Josefina; Villanueva-Lozano, Hiram; de J Treviño-Rangel, Rogelio; González, Gloria M; Enríquez-Rojas, Jorge; Molina-Durazo, Javier; Arenas-Guzmán, Roberto

2017-12-01

Mucormycosis of the scalp is a rare cutaneous presentation of the disease. It is also an unusual infection in children. We present the case of a 4-year-old girl with acute lymphoblastic leukemia, who presented with atypical cutaneous mucormycosis simulating an ecthyma gangrenosum lesion. Risk factors for the infection are diabetes, neoplastic diseases, immunosuppression in organ transplant recipients, and neutropenia. The cutaneos forms have been associated with trauma, burns and surgical wounds. First line treatment is amphotericin B. Posaconazole was recently approved to treat invasive mucormycosis. Surgical removal of the infected tissue is indicated.

Automated Portable Test (APT) System: overview and prospects

NASA Technical Reports Server (NTRS)

Bittner, A. C.; Smith, M. G.; Kennedy, R. S.; Staley, C. F.; Harbeson, M. M.

1985-01-01

The Automated Portable Test (APT) System is a notebook-sized, computer-based, human-performance and subjective-status assessment system. It is now being used in a wide range of environmental studies (e.g., simulator aftereffects, flight tests, drug effects, and hypoxia). Three questionnaires and 15 performance tests have been implemented, and the adaptation of 30 more tests is underway or is planned. The APT System is easily transportable, is inexpensive, and has the breadth of expansion options required for field and laboratory applications. The APT System is a powerful and expandable tool for human assessment in remote and unusual environments.

84 gigahertz observations of five Crab-like supernova remnants

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

Salter, C. J.; Reynolds, S. P.; Hogg, D. E.

1989-03-01

Flux density measurements at 3.6 mm have been made to extend the frequency coverage for three Crablike remnants and two Crablike components within remnants whose large-scale morphologies show shell-type structure. All five objects show flat, polarized, nonthermal radio spectra and associated X-ray emission characteristic of this class. The flux density is found to be lower than expected on the basis of an extrapolation of the spectrum from lower frequencies. If this is due to steepening caused by evolutionary effects, severe constraints can be put on the characteristics of the objects showing spectral steepening: all must be less than 2000 yrmore » old, and the supernovae in which they were born must all have had very unusual properties. 30 refs.« less

Surface materials on unusual planetary object Chiron

NASA Technical Reports Server (NTRS)

Hartmann, W. K.; Cruikshank, D. P.; Degewij, J.; Capps, R. W.

1981-01-01

JHK near-infrared colorimetry of the surface of the planetary object 2060 Chiron has yielded colors consistent with those of outer solar system asteroids, which have: (1) albedos of only a few percent, (2) C-, RD-, or DM-type spectra, and (3) no known H2O ice absorption features. The colors are also in keeping with theoretical colors for certain size distributions of dirty ice grains. Along with VJHK colorimetric data, results suggest that the spectrally dominant surface is probably dark, carbonaceous-like silicate dust with a possible, microscale admixture of ice grains. It is concluded that, if Chiron has the low albedo common to such materials on known interplanetary bodies, its diameter may lie in the 310-400 km range and therefore place it among the eight largest asteroids.

Neural activity associated with self, other, and object-based counterfactual thinking.

PubMed

De Brigard, Felipe; Nathan Spreng, R; Mitchell, Jason P; Schacter, Daniel L

2015-04-01

Previous research has shown that autobiographical episodic counterfactual thinking-i.e., mental simulations about alternative ways in which one's life experiences could have occurred-engages the brain's default network (DN). However, it remains unknown whether or not the DN is also engaged during impersonal counterfactual thoughts, specifically those involving other people or objects. The current study compares brain activity during counterfactual simulations involving the self, others and objects. In addition, counterfactual thoughts involving others were manipulated in terms of similarity and familiarity with the simulated characters. The results indicate greater involvement of DN during person-based (i.e., self and other) as opposed to object-based counterfactual simulations. However, the involvement of different regions of the DN during other-based counterfactual simulations was modulated by how close and/or similar the simulated character was perceived to be by the participant. Simulations involving unfamiliar characters preferentially recruited dorsomedial prefrontal cortex. Simulations involving unfamiliar similar characters, characters with whom participants identified personality traits, recruited lateral temporal gyrus. Finally, our results also revealed differential coupling of right hippocampus with lateral prefrontal and temporal cortex during counterfactual simulations involving familiar similar others, but with left transverse temporal gyrus and medial frontal and inferior temporal gyri during counterfactual simulations involving either oneself or unfamiliar dissimilar others. These results suggest that different brain mechanisms are involved in the simulation of personal and impersonal counterfactual thoughts, and that the extent to which regions associated with autobiographical memory are recruited during the simulation of counterfactuals involving others depends on the perceived similarity and familiarity with the simulated individuals. Copyright © 2015 Elsevier Inc. All rights reserved.

Neural activity associated with self, other, and object-based counterfactual thinking

PubMed Central

De Brigard, Felipe; Spreng, R. Nathan; Mitchell, Jason P.; Schacter, Daniel L.

2016-01-01

Previous research has shown that autobiographical episodic counterfactual thinking—i.e., mental simulations about alternative ways in which one’s life experiences could have occurred—engages the brain’s default network (DN). However, it remains unknown whether or not the DN is also engaged during impersonal counterfactual thoughts, specifically those involving other people or objects. The current study compares brain activity during counterfactual simulations involving the self, others and objects. In addition, counterfactual thoughts involving others were manipulated in terms of similarity and familiarity with the simulated characters. The results indicate greater involvement of DN during person-based (i.e., self and other) as opposed to object-based counterfactual simulations. However, the involvement of different regions of the DN during other-based counterfactual simulations was modulated by how close and/or similar the simulated character was perceived to be by the participant. Simulations involving unfamiliar characters preferentially recruited dorsomedial prefrontal cortex. Simulations involving unfamiliar similar characters, characters with whom participants identified personality traits, recruited lateral temporal gyrus. Finally, our results also revealed differential coupling of right hippocampus with lateral prefrontal and temporal cortex during counterfactual simulations involving familiar similar others, but with left transverse temporal gyrus and medial frontal and inferior temporal gyri during counterfactual simulations involving either oneself or unfamiliar dissimilar others. These results suggest that different brain mechanisms are involved in the simulation of personal and impersonal counterfactual thoughts, and that the extent to which regions associated with autobiographical memory are recruited during the simulation of counterfactuals involving others depends on the perceived similarity and familiarity with the simulated individuals. PMID:25579447

A web portal for hydrodynamical, cosmological simulations

NASA Astrophysics Data System (ADS)

Ragagnin, A.; Dolag, K.; Biffi, V.; Cadolle Bel, M.; Hammer, N. J.; Krukau, A.; Petkova, M.; Steinborn, D.

2017-07-01

This article describes a data centre hosting a web portal for accessing and sharing the output of large, cosmological, hydro-dynamical simulations with a broad scientific community. It also allows users to receive related scientific data products by directly processing the raw simulation data on a remote computing cluster. The data centre has a multi-layer structure: a web portal, a job control layer, a computing cluster and a HPC storage system. The outer layer enables users to choose an object from the simulations. Objects can be selected by visually inspecting 2D maps of the simulation data, by performing highly compounded and elaborated queries or graphically by plotting arbitrary combinations of properties. The user can run analysis tools on a chosen object. These services allow users to run analysis tools on the raw simulation data. The job control layer is responsible for handling and performing the analysis jobs, which are executed on a computing cluster. The innermost layer is formed by a HPC storage system which hosts the large, raw simulation data. The following services are available for the users: (I) CLUSTERINSPECT visualizes properties of member galaxies of a selected galaxy cluster; (II) SIMCUT returns the raw data of a sub-volume around a selected object from a simulation, containing all the original, hydro-dynamical quantities; (III) SMAC creates idealized 2D maps of various, physical quantities and observables of a selected object; (IV) PHOX generates virtual X-ray observations with specifications of various current and upcoming instruments.

Application of bicyclic and cage compounds

NASA Technical Reports Server (NTRS)

Clark, R. D.; Archuleta, B. S.

1976-01-01

The results of a literature survey of the field of bicyclic and cage compounds were presented, with the objective of identifying those types of compounds with unusual physical and chemical stability, and determining what practical applications have been found for these compounds. Major applications have been as polymers, polymer additives, medicinals, and pesticides. Lesser applications have included fuels, fuel additives, lubricants, lubricant additives, and perfumes. Several areas where further work might be useful were also outlined; these are primarily in the areas of polymers, polymer additives, medicinals, and synthetic lubricants.

Three-dimensional computed topography analysis of a patient with an unusual anatomy of the maxillary second and third molars.

PubMed

Zhao, Jin; Li, Yan; Yang, Zhi-Wei; Wang, Wei; Meng, Yan

2011-10-01

We present a case of a patient with rare anatomy of a maxillary second molar with three mesiobuccal root canals and a maxillary third molar with four separate roots, identified using multi-slice computed topography (CT) and three-dimensional reconstruction techniques. The described case enriched/might enrich our knowledge about possible anatomical aberrations of maxillary molars. In addition, we demonstrate the role of multi-slice CT as an objective tool for confirmatory diagnosis and successful endodontic management.

Ocular changes with oxaliplatin.

PubMed

O'Dea, Denise; Handy, Catherine M; Wexler, Ann

2006-04-01

Ocular toxicity, although uncommon, can occur with many chemotherapeutic agents. Platinum compounds have been documented to produce a variety of ocular side effects, and reports have been made of ocular toxicity with oxaliplatin. This article reports on four patients who experienced ocular symptoms while receiving oxaliplatin. The symptoms included tunnel vision and visual loss with postural changes. One patient had objective findings that included papilledema. All of the changes were reversible. Oxaliplatin will continue to be used widely, so clinicians treating patients with it must be alert for unusual toxicities such as those described in this article.

[Deployment surgery from the viewpoint of the German Red Cross].

PubMed

Grabarek, V

1997-01-01

The German military coinages "deployment medicine" and "deployment surgery" are unusual within the Red Cross Germany (DRK). For its (surgical) deployments, the DRK complies exclusively with the principles of the International Red Cross and Red Crescent Movement. The mobile surgical unit of the DRK's rapid module system is an intentionally "low-tech" medical/surgical unit that also does without any dispensable medical conveniences. For its purposes and objectives it is optimally equipped, and enables the DRK to provide prompt and flexible regionally adjusted relief that is compatible with the Red Cross worldwide.

Problems in depth perception : a method of simulating objects moving in depth.

DOT National Transportation Integrated Search

1965-12-01

Equations were developed for the simulation on a screen of the movement of an object or surface toward or away from an observer by the movement of a positive photographic transparency of the object or surface away or toward a point source. The genera...

A giant protogalactic disk linked to the cosmic web

NASA Astrophysics Data System (ADS)

Martin, D. Christopher; Matuszewski, Mateusz; Morrissey, Patrick; Neill, James D.; Moore, Anna; Cantalupo, Sebastiano; Prochaska, J. Xavier; Chang, Daphne

2015-08-01

The specifics of how galaxies form from, and are fuelled by, gas from the intergalactic medium remain uncertain. Hydrodynamic simulations suggest that `cold accretion flows'--relatively cool (temperatures of the order of 104 kelvin), unshocked gas streaming along filaments of the cosmic web into dark-matter halos--are important. These flows are thought to deposit gas and angular momentum into the circumgalactic medium, creating disk- or ring-like structures that eventually coalesce into galaxies that form at filamentary intersections. Recently, a large and luminous filament, consistent with such a cold accretion flow, was discovered near the quasi-stellar object QSO UM287 at redshift 2.279 using narrow-band imaging. Unfortunately, imaging is not sufficient to constrain the physical characteristics of the filament, to determine its kinematics, to explain how it is linked to nearby sources, or to account for its unusual brightness, more than a factor of ten above what is expected for a filament. Here we report a two-dimensional spectroscopic investigation of the emitting structure. We find that the brightest emission region is an extended rotating hydrogen disk with a velocity profile that is characteristic of gas in a dark-matter halo with a mass of 1013 solar masses. This giant protogalactic disk appears to be connected to a quiescent filament that may extend beyond the virial radius of the halo. The geometry is strongly suggestive of a cold accretion flow.

A giant protogalactic disk linked to the cosmic web.

PubMed

Martin, D Christopher; Matuszewski, Mateusz; Morrissey, Patrick; Neill, James D; Moore, Anna; Cantalupo, Sebastiano; Prochaska, J Xavier; Chang, Daphne

2015-08-13

The specifics of how galaxies form from, and are fuelled by, gas from the intergalactic medium remain uncertain. Hydrodynamic simulations suggest that 'cold accretion flows'--relatively cool (temperatures of the order of 10(4) kelvin), unshocked gas streaming along filaments of the cosmic web into dark-matter halos--are important. These flows are thought to deposit gas and angular momentum into the circumgalactic medium, creating disk- or ring-like structures that eventually coalesce into galaxies that form at filamentary intersections. Recently, a large and luminous filament, consistent with such a cold accretion flow, was discovered near the quasi-stellar object QSO UM287 at redshift 2.279 using narrow-band imaging. Unfortunately, imaging is not sufficient to constrain the physical characteristics of the filament, to determine its kinematics, to explain how it is linked to nearby sources, or to account for its unusual brightness, more than a factor of ten above what is expected for a filament. Here we report a two-dimensional spectroscopic investigation of the emitting structure. We find that the brightest emission region is an extended rotating hydrogen disk with a velocity profile that is characteristic of gas in a dark-matter halo with a mass of 10(13) solar masses. This giant protogalactic disk appears to be connected to a quiescent filament that may extend beyond the virial radius of the halo. The geometry is strongly suggestive of a cold accretion flow.

A Coordinated Initialization Process for the Distributed Space Exploration Simulation (DSES)

NASA Technical Reports Server (NTRS)

Phillips, Robert; Dexter, Dan; Hasan, David; Crues, Edwin Z.

2007-01-01

This document describes the federate initialization process that was developed at the NASA Johnson Space Center with the HIIA Transfer Vehicle Flight Controller Trainer (HTV FCT) simulations and refined in the Distributed Space Exploration Simulation (DSES). These simulations use the High Level Architecture (HLA) IEEE 1516 to provide the communication and coordination between the distributed parts of the simulation. The purpose of the paper is to describe a generic initialization sequence that can be used to create a federate that can: 1. Properly initialize all HLA objects, object instances, interactions, and time management 2. Check for the presence of all federates 3. Coordinate startup with other federates 4. Robustly initialize and share initial object instance data with other federates.

A Monte Carlo method using octree structure in photon and electron transport

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

Ogawa, K.; Maeda, S.

Most of the early Monte Carlo calculations in medical physics were used to calculate absorbed dose distributions, and detector responses and efficiencies. Recently, data acquisition in Single Photon Emission CT (SPECT) has been simulated by a Monte Carlo method to evaluate scatter photons generated in a human body and a collimator. Monte Carlo simulations in SPECT data acquisition are generally based on the transport of photons only because the photons being simulated are low energy, and therefore the bremsstrahlung productions by the electrons generated are negligible. Since the transport calculation of photons without electrons is much simpler than that withmore » electrons, it is possible to accomplish the high-speed simulation in a simple object with one medium. Here, object description is important in performing the photon and/or electron transport using a Monte Carlo method efficiently. The authors propose a new description method using an octree representation of an object. Thus even if the boundaries of each medium are represented accurately, high-speed calculation of photon transport can be accomplished because the number of voxels is much fewer than that of the voxel-based approach which represents an object by a union of the voxels of the same size. This Monte Carlo code using the octree representation of an object first establishes the simulation geometry by reading octree string, which is produced by forming an octree structure from a set of serial sections for the object before the simulation; then it transports photons in the geometry. Using the code, if the user just prepares a set of serial sections for the object in which he or she wants to simulate photon trajectories, he or she can perform the simulation automatically using the suboptimal geometry simplified by the octree representation without forming the optimal geometry by handwriting.« less

Effects of functional group mass variance on vibrational properties and thermal transport in graphene

DOE PAGES

Lindsay, L.; Kuang, Y.

2017-03-13

Intrinsic thermal resistivity critically depends on features of phonon dispersions dictated by harmonic interatomic forces and masses. We present the effects of functional group mass variance on vibrational properties and thermal conductivity (κ ) of functionalized graphene from first principles calculations. We also use graphane, a buckled graphene backbone with covalently bonded Hydrogen atoms on both sides, as the base material and vary the mass of the Hydrogen atoms to simulate the effect of mass variance from other functional groups. We find non-monotonic behavior of κ with increasing mass of the functional group and an unusual cross-over from acoustic-dominated tomore » optic-dominated thermal transport behavior. We connect this cross-over to changes in the phonon dispersion with varying mass which suppress acoustic phonon velocities, but also give unusually high velocity optic modes. Further, we show that out-of-plane acoustic vibrations contribute significantly more to thermal transport than in-plane acoustic modes despite breaking of a reflection symmetry based scattering selection rule responsible for their large contributions in graphene. Our work demonstrates the potential for manipulation and engineering of thermal transport properties in two dimensional materials toward targeted applications.« less

Effects of functional group mass variance on vibrational properties and thermal transport in graphene

NASA Astrophysics Data System (ADS)

Lindsay, L.; Kuang, Y.

2017-03-01

Intrinsic thermal resistivity critically depends on features of phonon dispersions dictated by harmonic interatomic forces and masses. Here we present the effects of functional group mass variance on vibrational properties and thermal conductivity (κ ) of functionalized graphene from first-principles calculations. We use graphane, a buckled graphene backbone with covalently bonded hydrogen atoms on both sides, as the base material and vary the mass of the hydrogen atoms to simulate the effect of mass variance from other functional groups. We find nonmonotonic behavior of κ with increasing mass of the functional group and an unusual crossover from acoustic-dominated to optic-dominated thermal transport behavior. We connect this crossover to changes in the phonon dispersion with varying mass which suppress acoustic phonon velocities, but also give unusually high velocity optic modes. Further, we show that out-of-plane acoustic vibrations contribute significantly more to thermal transport than in-plane acoustic modes despite breaking of a reflection-symmetry-based scattering selection rule responsible for their large contributions in graphene. This work demonstrates the potential for manipulation and engineering of thermal transport properties in two-dimensional materials toward targeted applications.

Effects of functional group mass variance on vibrational properties and thermal transport in graphene

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

Lindsay, L.; Kuang, Y.

Intrinsic thermal resistivity critically depends on features of phonon dispersions dictated by harmonic interatomic forces and masses. We present the effects of functional group mass variance on vibrational properties and thermal conductivity (κ ) of functionalized graphene from first principles calculations. We also use graphane, a buckled graphene backbone with covalently bonded Hydrogen atoms on both sides, as the base material and vary the mass of the Hydrogen atoms to simulate the effect of mass variance from other functional groups. We find non-monotonic behavior of κ with increasing mass of the functional group and an unusual cross-over from acoustic-dominated tomore » optic-dominated thermal transport behavior. We connect this cross-over to changes in the phonon dispersion with varying mass which suppress acoustic phonon velocities, but also give unusually high velocity optic modes. Further, we show that out-of-plane acoustic vibrations contribute significantly more to thermal transport than in-plane acoustic modes despite breaking of a reflection symmetry based scattering selection rule responsible for their large contributions in graphene. Our work demonstrates the potential for manipulation and engineering of thermal transport properties in two dimensional materials toward targeted applications.« less

Particle size effect on strength, failure, and shock behavior in polytetrafluoroethylene-Al-W granular composite materials

NASA Astrophysics Data System (ADS)

Herbold, E. B.; Nesterenko, V. F.; Benson, D. J.; Cai, J.; Vecchio, K. S.; Jiang, F.; Addiss, J. W.; Walley, S. M.; Proud, W. G.

2008-11-01

The variation of metallic particle size and sample porosity significantly alters the dynamic mechanical properties of high density granular composite materials processed using a cold isostatically pressed mixture of polytetrafluoroethylene (PTFE), aluminum (Al), and tungsten (W) powders. Quasistatic and dynamic experiments are performed with identical constituent mass fractions with variations in the size of the W particles and pressing conditions. The relatively weak polymer matrix allows the strength and fracture modes of this material to be governed by the granular type behavior of agglomerated metal particles. A higher ultimate compressive strength was observed in relatively high porosity samples with small W particles compared to those with coarse W particles in all experiments. Mesoscale granular force chains of the metallic particles explain this unusual phenomenon as observed in hydrocode simulations of a drop-weight test. Macrocracks forming below the critical failure strain for the matrix and unusual behavior due to a competition between densification and fracture in dynamic tests of porous samples were also observed. Numerical modeling of shock loading of this granular composite material demonstrated that the internal energy, specifically thermal energy, of the soft PTFE matrix can be tailored by the W particle size distribution.

Extensive unusual lesions on a large number of immersed human victims found to be from cookiecutter sharks (Isistius spp.): an examination of the Yemenia plane crash.

PubMed

Ribéreau-Gayon, Agathe; Rando, Carolyn; Schuliar, Yves; Chapenoire, Stéphane; Crema, Enrico R; Claes, Julien; Seret, Bernard; Maleret, Vincent; Morgan, Ruth M

2017-03-01

Accurate determination of the origin and timing of trauma is key in medicolegal investigations when the cause and manner of death are unknown. However, distinction between criminal and accidental perimortem trauma and postmortem modifications can be challenging when facing unidentified trauma. Postmortem examination of the immersed victims of the Yemenia airplane crash (Comoros, 2009) demonstrated the challenges in diagnosing extensive unusual circular lesions found on the corpses. The objective of this study was to identify the origin and timing of occurrence (peri- or postmortem) of the lesions.A retrospective multidisciplinary study using autopsy reports (n = 113) and postmortem digital photos (n = 3 579) was conducted. Of the 113 victims recovered from the crash, 62 (54.9 %) presented unusual lesions (n = 560) with a median number of 7 (IQR 3 ∼ 13) and a maximum of 27 per corpse. The majority of lesions were elliptic (58 %) and had an area smaller than 10 cm 2 (82.1 %). Some lesions (6.8 %) also showed clear tooth notches on their edges. These findings identified most of the lesions as consistent with postmortem bite marks from cookiecutter sharks (Isistius spp.). It suggests that cookiecutter sharks were important agents in the degradation of the corpses and thus introduced potential cognitive bias in the research of the cause and manner of death. A novel set of evidence-based identification criteria for cookiecutter bite marks on human bodies is developed to facilitate more accurate medicolegal diagnosis of cookiecutter bites.

The architecture of Newton, a general-purpose dynamics simulator

NASA Technical Reports Server (NTRS)

Cremer, James F.; Stewart, A. James

1989-01-01

The architecture for Newton, a general-purpose system for simulating the dynamics of complex physical objects, is described. The system automatically formulates and analyzes equations of motion, and performs automatic modification of this system equations when necessitated by changes in kinematic relationships between objects. Impact and temporary contact are handled, although only using simple models. User-directed influence of simulations is achieved using Newton's module, which can be used to experiment with the control of many-degree-of-freedom articulated objects.

A simulation study of detection of weapon of mass destruction based on radar

NASA Astrophysics Data System (ADS)

Sharifahmadian, E.; Choi, Y.; Latifi, S.

2013-05-01

Typical systems used for detection of Weapon of Mass Destruction (WMD) are based on sensing objects using gamma rays or neutrons. Nonetheless, depending on environmental conditions, current methods for detecting fissile materials have limited distance of effectiveness. Moreover, radiation related to gamma- rays can be easily shielded. Here, detecting concealed WMD from a distance is simulated and studied based on radar, especially WideBand (WB) technology. The WB-based method capitalizes on the fact that electromagnetic waves penetrate through different materials at different rates. While low-frequency waves can pass through objects more easily, high-frequency waves have a higher rate of absorption by objects, making the object recognition easier. Measuring the penetration depth allows one to identify the sensed material. During simulation, radar waves and propagation area including free space, and objects in the scene are modeled. In fact, each material is modeled as a layer with a certain thickness. At start of simulation, a modeled radar wave is radiated toward the layers. At the receiver side, based on the received signals from every layer, each layer can be identified. When an electromagnetic wave passes through an object, the wave's power will be subject to a certain level of attenuation depending of the object's characteristics. Simulation is performed using radar signals with different frequencies (ranges MHz-GHz) and powers to identify different layers.

Characteristics and Core Curricular Elements of Medical Simulation Fellowships in North America.

PubMed

Ahmed, Rami A; Frey, Jennifer; Gardner, Aimee K; Gordon, James A; Yudkowsky, Rachel; Tekian, Ara

2016-05-01

Background In the past few years, there has been rapid growth in the number of simulation fellowships for physicians in the United States and Canada, with the objective of producing faculty with expertise and leadership training in medical simulation. Relatively little is known about the collective content and structure of these new fellowship opportunities. Objective We sought to identify a common set of core curricular elements among existing simulation fellowships and to obtain demographic background information on participants and leadership. Methods We designed a web-based survey and circulated it to simulation fellowship directors in the United States and Canada. The questions explored aspects of the fellowship curriculum. A grounded theory approach was used to qualitatively analyze fellowship goals and objectives. Results Of the 29 program directors surveyed, 23 responded (79%). The most commonly listed goals and objectives were to increase skills in simulation curriculum development, simulation operations and training environment setup, research, educational theory, administration, and debriefing. The majority of the responding fellowship directors (17 of 22, 77%) indicated that a set of consensus national guidelines would benefit their fellowship program. Conclusions Simulation fellowships are experiencing a period of rapid growth. Development of a common set of program guidelines is a widely shared objective among fellowship directors.

Characteristics and Core Curricular Elements of Medical Simulation Fellowships in North America

PubMed Central

Ahmed, Rami A.; Frey, Jennifer; Gardner, Aimee K.; Gordon, James A.; Yudkowsky, Rachel; Tekian, Ara

2016-01-01

Background In the past few years, there has been rapid growth in the number of simulation fellowships for physicians in the United States and Canada, with the objective of producing faculty with expertise and leadership training in medical simulation. Relatively little is known about the collective content and structure of these new fellowship opportunities. Objective We sought to identify a common set of core curricular elements among existing simulation fellowships and to obtain demographic background information on participants and leadership. Methods We designed a web-based survey and circulated it to simulation fellowship directors in the United States and Canada. The questions explored aspects of the fellowship curriculum. A grounded theory approach was used to qualitatively analyze fellowship goals and objectives. Results Of the 29 program directors surveyed, 23 responded (79%). The most commonly listed goals and objectives were to increase skills in simulation curriculum development, simulation operations and training environment setup, research, educational theory, administration, and debriefing. The majority of the responding fellowship directors (17 of 22, 77%) indicated that a set of consensus national guidelines would benefit their fellowship program. Conclusions Simulation fellowships are experiencing a period of rapid growth. Development of a common set of program guidelines is a widely shared objective among fellowship directors. PMID:27168898

Growth of Staphylococcus and Salmonella on Frankfurters With and Without Sodium Nitrite

PubMed Central

Bayne, Henry G.; Michener, H. David

1975-01-01

Conventional and nitrite-free frankfurters in loosely wrapped packages were compared as to their ability to support growth of Salmonella, Staphylococcus, and their naturally occurring spoilage flora at 7 C (simulating refrigerated storage) and 20 C (simulating possible temperature abuse). At 7 C Salmonella did not grow in either type of frankfurter; Staphylococcus and the natural spoilage flora sometimes grew more rapidly in the absence of nitrite, but the difference was not significant. At 20 C growth of Salmonella, Staphylococcus, and of the spoilage flora was, at most, only slightly faster on nitrite-free frankfurters. Salmonella was not suppressed in broth culture experiments at the pH and nitrite content found in frankfurters. Although either type of frankfurter can become hazardous due to growth of Salmonella or Staphylococcus, no unusual or additional hazard resulted from the omission of nitrite from frankfurters. PMID:952

High-resolution gravity model of Venus

NASA Technical Reports Server (NTRS)

Reasenberg, R. D.; Goldberg, Z. M.

1992-01-01

The anomalous gravity field of Venus shows high correlation with surface features revealed by radar. We extract gravity models from the Doppler tracking data from the Pioneer Venus Orbiter by means of a two-step process. In the first step, we solve the nonlinear spacecraft state estimation problem using a Kalman filter-smoother. The Kalman filter has been evaluated through simulations. This evaluation and some unusual features of the filter are discussed. In the second step, we perform a geophysical inversion using a linear Bayesian estimator. To allow an unbiased comparison between gravity and topography, we use a simulation technique to smooth and distort the radar topographic data so as to yield maps having the same characteristics as our gravity maps. The maps presented cover 2/3 of the surface of Venus and display the strong topography-gravity correlation previously reported. The topography-gravity scatter plots show two distinct trends.

Carbon Nanotube Based Molecular Electronics and Motors: A View from Classical and Quantum Dynamics Simulations

NASA Technical Reports Server (NTRS)

Srivastava, Deepak; Saini, Subhash (Technical Monitor)

1998-01-01

The tubular forms of fullerenes popularly known as carbon nanotubes are experimentally produced as single-, multiwall, and rope configurations. The nanotubes and nanoropes have shown to exhibit unusual mechanical and electronic properties. The single wall nanotubes exhibit both semiconducting and metallic behavior. In short undefected lengths they are the known strongest fibers which are unbreakable even when bent in half. Grown in ropes their tensile strength is approximately 100 times greater than steel at only one sixth the weight. Employing large scale classical and quantum molecular dynamics simulations we will explore the use of carbon nanotubes and carbon nanotube junctions in 2-, 3-, and 4-point molecular electronic device components, dynamic strength characterization for compressive, bending and torsional strains, and chemical functionalization for possible use in a nanoscale molecular motor. The above is an unclassified material produced for non-competitive basic research in the nanotechnology area.

A Supramolecular Ice Growth Inhibitor.

PubMed

Drori, Ran; Li, Chao; Hu, Chunhua; Raiteri, Paolo; Rohl, Andrew L; Ward, Michael D; Kahr, Bart

2016-10-12

Safranine O, a synthetic dye, was found to inhibit growth of ice at millimolar concentrations with an activity comparable to that of highly evolved antifreeze glycoproteins. Safranine inhibits growth of ice crystals along the crystallographic a-axis, resulting in bipyramidal needles extended along the <0001> directions as well as and plane-specific thermal hysteresis (TH) activity. The interaction of safranine with ice is reversible, distinct from the previously reported behavior of antifreeze proteins. Spectroscopy and molecular dynamics indicate that safranine forms aggregates in aqueous solution at micromolar concentrations. Metadynamics simulations and aggregation theory suggested that as many as 30 safranine molecules were preorganized in stacks at the concentrations where ice growth inhibition was observed. The simulations and single-crystal X-ray structure of safranine revealed regularly spaced amino and methyl substituents in the aggregates, akin to the ice-binding site of antifreeze proteins. Collectively, these observations suggest an unusual link between supramolecular assemblies of small molecules and functional proteins.

Simulation Studies of Mechanical Properties of Novel Silica Nano-structures

NASA Astrophysics Data System (ADS)

Muralidharan, Krishna; Torras Costa, Joan; Trickey, Samuel B.

2006-03-01

Advances in nanotechnology and the importance of silica as a technological material continue to stimulate computational study of the properties of possible novel silica nanostructures. Thus we have done classical molecular dynamics (MD) and multi-scale quantum mechanical (QM/MD) simulation studies of the mechanical properties of single-wall and multi-wall silica nano-rods of varying dimensions. Such nano-rods have been predicted by Mallik et al. to be unusually strong in tensile failure. Here we compare failure mechanisms of such nano-rods under tension, compression, and bending. The concurrent multi-scale QM/MD studies use the general PUPIL system (Torras et al.). In this case, PUPIL provides automated interoperation of the MNDO Transfer Hamiltonian QM code (Taylor et al.) and a locally written MD code. Embedding of the QM-forces domain is via the scheme of Mallik et al. Work supported by NSF ITR award DMR-0325553.

Molecular driving forces behind the tetrahydrofuran–water miscibility gap

DOE PAGES

Smith, Micholas Dean; Mostofian, Barmak; Petridis, Loukas; ...

2016-01-06

The tetrahydrofuran water binary system exhibits an unusual closed-loop miscibility gap (transitions from a miscible regime to an immiscible regime back to another miscible regime as the temperature increases). Here, using all-atom molecular dynamics simulations, we probe the structural and dynamical behavior of the binary system in the temperature regime of this gap at four different mass ratios, and we compare the behavior of bulk water and tetrahydrofuran. The changes in structure and dynamics observed in the simulations indicate that the temperature region associated with the miscibility gap is distinctive. Within the miscibility-gap temperature region, the self diffusion of watermore » is significantly altered and the second virial coefficients (pair interaction strengths) show parabolic-like behavior. Altogether, the results suggest that the gap is the result of differing trends with temperature of minor structural changes, which produces interaction virials with parabolic temperature dependence near the miscibility gap.« less

Extinction phase transitions in a model of ecological and evolutionary dynamics

NASA Astrophysics Data System (ADS)

Barghathi, Hatem; Tackkett, Skye; Vojta, Thomas

2017-07-01

We study the non-equilibrium phase transition between survival and extinction of spatially extended biological populations using an agent-based model. We especially focus on the effects of global temporal fluctuations of the environmental conditions, i.e., temporal disorder. Using large-scale Monte-Carlo simulations of up to 3 × 107 organisms and 105 generations, we find the extinction transition in time-independent environments to be in the well-known directed percolation universality class. In contrast, temporal disorder leads to a highly unusual extinction transition characterized by logarithmically slow population decay and enormous fluctuations even for large populations. The simulations provide strong evidence for this transition to be of exotic infinite-noise type, as recently predicted by a renormalization group theory. The transition is accompanied by temporal Griffiths phases featuring a power-law dependence of the life time on the population size.

Software To Secure Distributed Propulsion Simulations

NASA Technical Reports Server (NTRS)

Blaser, Tammy M.

2003-01-01

Distributed-object computing systems are presented with many security threats, including network eavesdropping, message tampering, and communications middleware masquerading. NASA Glenn Research Center, and its industry partners, has taken an active role in mitigating the security threats associated with developing and operating their proprietary aerospace propulsion simulations. In particular, they are developing a collaborative Common Object Request Broker Architecture (CORBA) Security (CORBASec) test bed to secure their distributed aerospace propulsion simulations. Glenn has been working with its aerospace propulsion industry partners to deploy the Numerical Propulsion System Simulation (NPSS) object-based technology. NPSS is a program focused on reducing the cost and time in developing aerospace propulsion engines

A Hybrid Parachute Simulation Environment for the Orion Parachute Development Project

NASA Technical Reports Server (NTRS)

Moore, James W.

2011-01-01

A parachute simulation environment (PSE) has been developed that aims to take advantage of legacy parachute simulation codes and modern object-oriented programming techniques. This hybrid simulation environment provides the parachute analyst with a natural and intuitive way to construct simulation tasks while preserving the pedigree and authority of established parachute simulations. NASA currently employs four simulation tools for developing and analyzing air-drop tests performed by the CEV Parachute Assembly System (CPAS) Project. These tools were developed at different times, in different languages, and with different capabilities in mind. As a result, each tool has a distinct interface and set of inputs and outputs. However, regardless of the simulation code that is most appropriate for the type of test, engineers typically perform similar tasks for each drop test such as prediction of loads, assessment of altitude, and sequencing of disreefs or cut-aways. An object-oriented approach to simulation configuration allows the analyst to choose models of real physical test articles (parachutes, vehicles, etc.) and sequence them to achieve the desired test conditions. Once configured, these objects are translated into traditional input lists and processed by the legacy simulation codes. This approach minimizes the number of sim inputs that the engineer must track while configuring an input file. An object oriented approach to simulation output allows a common set of post-processing functions to perform routine tasks such as plotting and timeline generation with minimal sensitivity to the simulation that generated the data. Flight test data may also be translated into the common output class to simplify test reconstruction and analysis.

Unusual Sediment Transportation Processes Under Low Pressure Environments and Implications For Gullies and Recurring Slope Lineae (RSL)

NASA Astrophysics Data System (ADS)

Raack, J.; Herny, C.; Conway, S. J.; Balme, M. R.; Carpy, S.; Patel, M.

2017-12-01

Recently and presently active mass wasting features such as gullies and recurring slope lineae (RSL) are common on the surface of Mars, but their origin and triggering mechanisms are under intense debate. While several active mass wasting features have been linked to sublimation of CO2ice, dry granular flows (avalanches), or a combination of both effects, others have been more closely linked to liquid water or briny outflows (e.g. for RSL). However, liquid water on the surface of Mars is unstable under present-day low pressures and surface temperatures. Nevertheless, numerical modeling and remote sensing data have shown that maximum surface temperatures can exceed the frost point of water and that liquid water could exist on the surface of actual Mars in a transient state. But to explain the observed spatial extent of RSL and recent modification of gullies, it is estimated that relatively large amounts of liquid water are necessary. It is proving challenging to generate such quantities from the atmosphere. In this contribution we explore the potential effects of boiling water (boiling occurs at martian pressures slightly above the frost point of 273 K) on sediment transport. We will present the outcomes of a series of experiments under low surface and water temperatures (between 278 and 297 K, analogous to surface temperatures observed near RSL) and low pressures (between 8 and 11 mbar). We simulate sediment transport by boiling liquid water over a sloping bed of unconsolidated sediment. Our results reveal a suite of unusual and very reactive sediment transportation processes, which are not produced under terrestrial pressures. We will discuss the impact of these unusual sediment transport processes on estimates of water budgets for active mass wasting processes.

Simulated and Real Sheet-of-Light 3D Object Scanning Using a-Si:H Thin Film PSD Arrays.

PubMed

Contreras, Javier; Tornero, Josep; Ferreira, Isabel; Martins, Rodrigo; Gomes, Luis; Fortunato, Elvira

2015-11-30

A MATLAB/SIMULINK software simulation model (structure and component blocks) has been constructed in order to view and analyze the potential of the PSD (Position Sensitive Detector) array concept technology before it is further expanded or developed. This simulation allows changing most of its parameters, such as the number of elements in the PSD array, the direction of vision, the viewing/scanning angle, the object rotation, translation, sample/scan/simulation time, etc. In addition, results show for the first time the possibility of scanning an object in 3D when using an a-Si:H thin film 128 PSD array sensor and hardware/software system. Moreover, this sensor technology is able to perform these scans and render 3D objects at high speeds and high resolutions when using a sheet-of-light laser within a triangulation platform. As shown by the simulation, a substantial enhancement in 3D object profile image quality and realism can be achieved by increasing the number of elements of the PSD array sensor as well as by achieving an optimal position response from the sensor since clearly the definition of the 3D object profile depends on the correct and accurate position response of each detector as well as on the size of the PSD array.

Signs of Life on Venus

NASA Astrophysics Data System (ADS)

Ksanfomality, L.

2012-04-01

The search for "habitable zones" in extrasolar planetary systems is based on the premise of "normal" physical conditions in a habitable zone, i.e. pressure, temperature range, and atmospheric composition similar to those on the Earth. However, one should not exclude completely the possibility of the existence of life at relatively high temperatures, despite the fact that at the first glance it seems impossible. The planet Venus with its dense, hot (735 K), oxigenless CO2 - atmosphere and high 92 bar-pressure at the surface could be the natural laboratory for the studies of this type. Amid exoplanets, celestial bodies with the physical conditions similar to the Venusian can be met. The only existing data of actual close-in observations of Venus' surface are the results of a series of missions of the soviet VENERA landers which took place the 1970's and 80's in the atmosphere and on the surface of Venus. For 36 and 29 years since these missions, respectively, I repeatedly returned to the obtained images of the Venus' surface in order to reveal on them any unusual objects observed in the real conditions of Venus. The new analysis of the Venus' panoramas was based on the search of unusual elements in two ways. Since the efficiency of the VENERA landers maintained for a long time they produced a large number of primary television panoramas during the lander's work. Thus, one can try to detect: (a) any differences in successive images (appearance or disappearance of parts of the image or change of their shape), and understand what these changes are related to (e.g., wind), and whether they are related to hypothetical habitability of a planet. Another sign (b) of the wanted object is their morphological peculiarities which distinguishes them from the ordinary surface details. The results of VENERA-9 (1975) and VENERA -13 (1982) are of the main interest. A few relatively large objects ranging from a decimeter to half meter and with unusual morphology were observed in some images, but were absent in the other or altered their shape. What sources of energy, in principle, could be used by life in the high temperature oxigenless atmosphere? The objects found are large enough, they are not micro-organisms. It is most natural to assume that, like on Earth, Venusian fauna is heterotrophic, and the source of its life is hypothetical autotrophic flora. There is enough light for flora's photosynthesis. Since the critical temperature of water on Venus is about 320°C and the temperature at the surface is about 460°C, the metabolism of organisms on Venus (if any) should be built without water, on the basis of some other liquid medium. Based on data analyzed it has been suggested that because of the limited energy capacity of the Venusian fauna, the temporal characteristics of their physical actions can be much longer than that of the Earth.

Simulating Electrophoresis with Discrete Charge and Drag

NASA Astrophysics Data System (ADS)

Mowitz, Aaron J.; Witten, Thomas A.

A charged asymmetric rigid cluster of colloidal particles in saline solution can respond in exotic ways to an electric field: it may spin or move transversely. These distinctive motions arise from the drag force of the neutralizing countercharge surrounding the cluster. Because of this drag, calculating the motion of arbitrary asymmetric objects with nonuniform charge is impractical by conventional methods. Here we present a new method of simulating electrophoresis, in which we replace the continuous object and the surrounding countercharge with discrete point-draggers, called Stokeslets. The balance of forces imposes a linear, self-consistent relation among the drag and Coulomb forces on the Stokeslets, which allows us to easily determine the object's motion via matrix inversion. By explicitly enforcing charge+countercharge neutrality, the simulation recovers the distinctive features of electrophoretic motion to few-percent accuracy using as few as 1000 Stokeslets. In particular, for uniformly charged objects, we observe the characteristic Smoluchowski independence of mobility on object size and shape. We then discuss electrophoretic motion of asymmetric objects, where our simulation method is particularly advantageous. This work is supported by a Grant from the US-Israel Binational Science Foundation.

Toward a unified model of face and object recognition in the human visual system

PubMed Central

Wallis, Guy

2013-01-01

Our understanding of the mechanisms and neural substrates underlying visual recognition has made considerable progress over the past 30 years. During this period, accumulating evidence has led many scientists to conclude that objects and faces are recognised in fundamentally distinct ways, and in fundamentally distinct cortical areas. In the psychological literature, in particular, this dissociation has led to a palpable disconnect between theories of how we process and represent the two classes of object. This paper follows a trend in part of the recognition literature to try to reconcile what we know about these two forms of recognition by considering the effects of learning. Taking a widely accepted, self-organizing model of object recognition, this paper explains how such a system is affected by repeated exposure to specific stimulus classes. In so doing, it explains how many aspects of recognition generally regarded as unusual to faces (holistic processing, configural processing, sensitivity to inversion, the other-race effect, the prototype effect, etc.) are emergent properties of category-specific learning within such a system. Overall, the paper describes how a single model of recognition learning can and does produce the seemingly very different types of representation associated with faces and objects. PMID:23966963

Simulator study of flight characteristics of a large twin-fuselage cargo transport airplane during approach and landing

NASA Technical Reports Server (NTRS)

Grantham, W. D.; Deal, P. L.; Keyser, G. L., Jr.; Smith, P. M.

1983-01-01

A six degree-of-freedom, ground-based simulator study was conducted to evaluate the low speed flight characteristics of a twin fuselage cargo transport airplane and to compare these characteristics with those of a large, single fuselage (reference) transport configuration which was similar to the Lockheed C-5C airplane. The primary piloting task was the approach and landing. The results indicated that in order to achieve "acceptable' low speed handling qualities on the twin fuselage concept, considerable stability and control augmentation was required, and although the augmented airplane could be landed safely under adverse conditions, the roll performance of the aircraft had to be improved appreciably before the handling qualities were rated as being "satisfactory.' These ground-based simulation results indicated that a value of t sub phi = 30 (time required to bank 30 deg) less than 6 sec should result in "acceptable' roll response characteristics, and when t sub phi = 30 is less than 3.8 sec, "satisfactory' roll response should be attainable on such large and unusually configured aircraft as the subject twin fuselage cargo transport concept.

Hyperspectral imaging simulation of object under sea-sky background

NASA Astrophysics Data System (ADS)

Wang, Biao; Lin, Jia-xuan; Gao, Wei; Yue, Hui

2016-10-01

Remote sensing image simulation plays an important role in spaceborne/airborne load demonstration and algorithm development. Hyperspectral imaging is valuable in marine monitoring, search and rescue. On the demand of spectral imaging of objects under the complex sea scene, physics based simulation method of spectral image of object under sea scene is proposed. On the development of an imaging simulation model considering object, background, atmosphere conditions, sensor, it is able to examine the influence of wind speed, atmosphere conditions and other environment factors change on spectral image quality under complex sea scene. Firstly, the sea scattering model is established based on the Philips sea spectral model, the rough surface scattering theory and the water volume scattering characteristics. The measured bi directional reflectance distribution function (BRDF) data of objects is fit to the statistical model. MODTRAN software is used to obtain solar illumination on the sea, sky brightness, the atmosphere transmittance from sea to sensor and atmosphere backscattered radiance, and Monte Carlo ray tracing method is used to calculate the sea surface object composite scattering and spectral image. Finally, the object spectrum is acquired by the space transformation, radiation degradation and adding the noise. The model connects the spectrum image with the environmental parameters, the object parameters, and the sensor parameters, which provide a tool for the load demonstration and algorithm development.

Pressure-induced emergence of unusually high-frequency transverse excitations in a liquid alkali metal: Evidence of two types of collective excitations contributing to the transverse dynamics at high pressures

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

Bryk, Taras; Lviv Polytechnic National University, 12 S. Bandera Street, UA-79013 Lviv; Ruocco, G.

Unlike phonons in crystals, the collective excitations in liquids cannot be treated as propagation of harmonic displacements of atoms around stable local energy minima. The viscoelasticity of liquids, reflected in transition from the adiabatic to elastic high-frequency speed of sound and in absence of the long-wavelength transverse excitations, results in dispersions of longitudinal (L) and transverse (T) collective excitations essentially different from the typical phonon ones. Practically, nothing is known about the effect of high pressure on the dispersion of collective excitations in liquids, which causes strong changes in liquid structure. Here dispersions of L and T collective excitations inmore » liquid Li in the range of pressures up to 186 GPa were studied by ab initio simulations. Two methodologies for dispersion calculations were used: direct estimation from the peak positions of the L/T current spectral functions and simulation-based calculations of wavenumber-dependent collective eigenmodes. It is found that at ambient pressure, the longitudinal and transverse dynamics are well separated, while at high pressures, the transverse current spectral functions, density of vibrational states, and dispersions of collective excitations yield evidence of two types of propagating modes that contribute strongly to transverse dynamics. Emergence of the unusually high-frequency transverse modes gives evidence of the breakdown of a regular viscoelastic theory of transverse dynamics, which is based on coupling of a single transverse propagating mode with shear relaxation. The explanation of the observed high-frequency shift above the viscoelastic value is given by the presence of another branch of collective excitations. With the pressure increasing, coupling between the two types of collective excitations is rationalized within a proposed extended viscoelastic model of transverse dynamics.« less

Mission and Safety Critical (MASC) plans for the MASC Kernel simulation

NASA Technical Reports Server (NTRS)

1991-01-01

This report discusses a prototype for Mission and Safety Critical (MASC) kernel simulation which explains the intended approach and how the simulation will be used. Smalltalk is chosen for the simulation because of usefulness in quickly building working models of the systems and its object-oriented approach to software. A scenario is also introduced to give details about how the simulation works. The eventual system will be a fully object-oriented one implemented in Ada via Dragoon. To implement the simulation, a scenario using elements typical of those in the Space Station, was created.

Evidence for similar early but not late representation of possible and impossible objects

PubMed Central

Freud, Erez; Hadad, Bat-Sheva; Avidan, Galia; Ganel, Tzvi

2015-01-01

The perceptual processes that mediate the ability to efficiently represent object 3D structure are still not fully understood. The current study was aimed to shed light on these processes by utilizing spatially possible and impossible objects that could not be created in real 3D space. Despite being perceived as exceptionally unusual, impossible objects still possess fundamental Gestalt attributes and valid local depth cues that may support their initial successful representation. Based on this notion and on recent findings from our lab, we hypothesized that the initial representation of impossible objects would involve common mechanisms to those mediating typical object perception while the perceived differences between possible and impossible objects would emerge later along the processing hierarchy. In Experiment 1, participants preformed same/different classifications of two markers superimposed on a display containing two objects (possible or impossible). Faster reaction times were observed for displays in which the markers were superimposed on the same object (“object-based benefit”). Importantly, this benefit was similar for possible and impossible objects, suggesting that the representations of the two object categories rely on similar perceptual organization processes. Yet, responses for impossible objects were slower compared to possible objects. Experiment 2 was designed to examine the origin of this effect. Participants classified the location of two markers while exposure duration was manipulated. A similar pattern of performance was found for possible and impossible objects for the short exposure duration, with differences in accuracy between these two types of objects emerging only for longer exposure durations. Overall, these findings provide evidence that the representation of object structure relies on a multi-level process and that object impossibility selectively impairs the rendering of fine-detailed description of object structure. PMID:25762949

Cost effective simulation-based multiobjective optimization in the performance of an internal combustion engine

NASA Astrophysics Data System (ADS)

Aittokoski, Timo; Miettinen, Kaisa

2008-07-01

Solving real-life engineering problems can be difficult because they often have multiple conflicting objectives, the objective functions involved are highly nonlinear and they contain multiple local minima. Furthermore, function values are often produced via a time-consuming simulation process. These facts suggest the need for an automated optimization tool that is efficient (in terms of number of objective function evaluations) and capable of solving global and multiobjective optimization problems. In this article, the requirements on a general simulation-based optimization system are discussed and such a system is applied to optimize the performance of a two-stroke combustion engine. In the example of a simulation-based optimization problem, the dimensions and shape of the exhaust pipe of a two-stroke engine are altered, and values of three conflicting objective functions are optimized. These values are derived from power output characteristics of the engine. The optimization approach involves interactive multiobjective optimization and provides a convenient tool to balance between conflicting objectives and to find good solutions.

Unusual spacecraft materials

NASA Technical Reports Server (NTRS)

Post, Jonathan V.

1990-01-01

For particularly innovative space exploration missions, unusual requirements are levied on the structural components of the spacecraft. In many cases, the preferred solution is the utilization of unusual materials. This trend is forecast to continue. Several hypothetic examples are discussed.

A tale of two congresses: the psychological study of psychical, occult, and religious phenomena, 1900-1909.

PubMed

Taves, Ann

2014-01-01

In so far as researchers viewed psychical, occult, and religious phenomena as both objectively verifiable and resistant to extant scientific explanations, their study posed thorny issues for experimental psychologists. Controversies over the study of psychical and occult phenomena at the Fourth Congress of International Psychology (Paris, 1900) and religious phenomena at the Sixth (Geneva, 1909) raise the question of why the latter was accepted as a legitimate object of study, whereas the former was not. Comparison of the Congresses suggests that those interested in the study of religion were willing to forego the quest for objective evidence and focus on experience, whereas those most invested in psychical research were not. The shift in focus did not overcome many of the methodological difficulties. Sub-specialization formalized distinctions between psychical, religious, and pathological phenomena; obscured similarities; and undercut the nascent comparative study of unusual experiences that had emerged at the early Congresses. © 2014 Wiley Periodicals, Inc.

The near-infrared counterpart of a variable galactic plane radio source

NASA Technical Reports Server (NTRS)

Margon, Bruce; Phillips, Andrew C.; Ciardullo, Robin; Jacoby, George H.

1992-01-01

A near-infrared counterpart to the highly variable, unresolved galactic plane radio source GT 0116 + 622 is identified. This source is of particular interest, as it has been previously suggested to be the counterpart of the gamma-ray source Cas gamma-l. The present NIR and red images detect a faint, spatially extended (3 arcsec FWHM), very red object coincident with the radio position. There is complex spatial structure which may be due in part to an unrelated superposed foreground object. Observations on multiple nights show no evidence for flux variability, despite the high amplitude variability on a time-scale of days reported for the radio source. The data are consistent with an interpretation of GT 0116 + 622 as an unusually variable, obscured active galaxy at a distance of several hundred megaparsecs, although more exotic, and in particular galactic, interpretations cannot yet be ruled out. If the object is extragalactic, the previously suggested identification with the gamma-ray source would seem unlikely.

The discovery of the peculiar L dwarf ULAS J222711-004547

NASA Astrophysics Data System (ADS)

Marocco, F.; Day-Jones, A. C.; Jones, H. R. A.; Pinfield, D. J.; Burningham, B.; Zhang, Z. H.

We present the discovery of a very peculiar L dwarf from the UKIDSS Large Area Survey (LAS), ULAS J222711-004547. Its very red infrared colours (MKO J-K = 2.79) make it the reddest brown dwarf discovered so far. The object was discovered as part of a large spectroscopic campaign aimed at constraining the sub-stellar birth rate. We obtained a moderate resolution spectrum of this target using the echelle spectrograph XSHOOTER on VLT/UT2, and classified it as L7pec, confirming its very red nature. We show that applying a simple de-reddening curve to the spectrum of ULAS J222711-004547, this becomes very similar to the spectrum of a L7 spectroscopic standard. Therefore we conclude that the reddening of the spectrum is mostly due to an excess of dust in the photosphere of the object. This new discovery joins the list of unusually red L dwarfs, whose nature is not yet fully understood, and poses a new important challenge to atmospheric modeling of substellar objects.

The Loneliest Young Star (Artist Concept)

NASA Image and Video Library

2016-07-27

This artist's concept shows an unusual celestial object called CX330 was first detected as a source of X-ray light in 2009 by NASA's Chandra X-Ray Observatory while it was surveying the bulge in the central region of the Milky Way. A 2016 study in the Monthly Notices of the Royal Astronomical Society found that CX330 is the most isolated young star that has been discovered. Researchers compared NASA's Wide-field Infrared Survey Explorer (WISE) data from 2010 with NASA's Spitzer Space Telescope data from 2007 to come to this conclusion. CX330 is not near any star-forming region. As of the most recent observation, which was August 2015, this object was outbursting, meaning it was launching "jets" of material that slam into the gas and dust around it. Astronomers plan to continue studying the object, including with future telescopes that could view CX330 in other wavelengths of light. http://photojournal.jpl.nasa.gov/catalog/PIA20700

(1173) Anchises - thermophysical and dynamical studies of a dynamically unstable Jovian Trojan

NASA Astrophysics Data System (ADS)

Horner, J.; Müller, T. G.; Lykawka, P. S.

2012-07-01

We have performed detailed thermophysical and dynamical modelling of the Jovian Trojan (1173) Anchises. Our results show that this is the most unusual object. By examining observational data of Anchises taken by IRAS, Akari and WISE at wavelengths between 11.5 and 60 μm, together with the variations in its optical light curve, we find that Anchises is most likely an elongated body, with an axis ratio, a/b, of around 1.4. This results in calculated best-fitting dimensions for Anchises of 170 × 121 × 121 km (or an equivalent diameter of 136 +18/-11 km). We find that the observations of Anchises are best fitted by the object having a retrograde sense of rotation, and an unusually high thermal inertia in the range 25-100 J m-2 s-0.5 K-1 (3σ confidence level). The geometric albedo of Anchises is found to be 0.027 (+0.006/-0.007). Anchises therefore has one of the highest published thermal inertias of any object larger than 100 km in diameter, at such large heliocentric distances, as well as being one of the lowest albedo objects ever observed. More observations (visual and thermal) are needed to see whether there is a link between the very shallow phase curve, with almost no opposition effect, and the derived thermal properties for this large Trojan asteroid. Our dynamical investigation of Anchises' orbit has revealed it to be dynamically unstable on time-scales of hundreds of millions of years, similar to the unstable Neptunian Trojans 2001 QR322 and 2008 LC18. Unlike those objects, however, we find that the dynamical stability of Anchises is not a function of its initial orbital elements, the result of the exceptional precision with which its orbit is known. Our results are the first to show that a Jovian Trojan is dynamically unstable, and add further weight to the idea that the planetary Trojans likely represent a significant ongoing contribution to the dynamically unstable Centaur population, the parents of the short-period comets. The observed instability (fully half of all clones of Anchises escape the Solar system within 350 Myr) does not rule out a primordial origin for Anchises, but, when taken in concert with the result of our thermophysical analysis, suggest that it would be a fascinating target for a future study.

Self-adaptive Fault-Tolerance of HLA-Based Simulations in the Grid Environment

NASA Astrophysics Data System (ADS)

Huang, Jijie; Chai, Xudong; Zhang, Lin; Li, Bo Hu

The objects of a HLA-based simulation can access model services to update their attributes. However, the grid server may be overloaded and refuse the model service to handle objects accesses. Because these objects have been accessed this model service during last simulation loop and their medium state are stored in this server, this may terminate the simulation. A fault-tolerance mechanism must be introduced into simulations. But the traditional fault-tolerance methods cannot meet the above needs because the transmission latency between a federate and the RTI in grid environment varies from several hundred milliseconds to several seconds. By adding model service URLs to the OMT and expanding the HLA services and model services with some interfaces, this paper proposes a self-adaptive fault-tolerance mechanism of simulations according to the characteristics of federates accessing model services. Benchmark experiments indicate that the expanded HLA/RTI can make simulations self-adaptively run in the grid environment.

2MASS J13243553+6358281 Is an Early T-type Planetary-mass Object in the AB Doradus Moving Group

NASA Astrophysics Data System (ADS)

Gagné, Jonathan; Allers, Katelyn N.; Theissen, Christopher A.; Faherty, Jacqueline K.; Bardalez Gagliuffi, Daniella; Artigau, Étienne

2018-02-01

We present new radial velocity and trigonometric distance measurements indicating that the unusually red and photometrically variable T2 dwarf 2MASS J13243553+6358281 is a member of the young (∼150 Myr) AB Doradus moving group (ABDMG) based on its space velocity. We estimate its model-dependent mass in the range 11–12 M Jup at the age of the ABDMG, and its trigonometric distance of 12.7 ± 1.5 pc makes it one of the nearest known isolated planetary-mass objects. The unusually red continuum of 2MASS J13243553+6358281 in the near-infrared was previously suspected to be caused by an unresolved L + T brown dwarf binary, although it was never observed with high spatial resolution imaging. This new evidence of youth suggests that a low surface gravity may be sufficient to explain this peculiar feature. Using the new parallax we find that its absolute J-band magnitude is ∼0.4 mag fainter than equivalent-type field brown dwarfs, suggesting that the binary hypothesis is unlikely. The fundamental properties of 2MASS J13243553+6358281 follow the spectral type sequence of other known high-likelihood members of the ABDMG. The effective temperature of 2MASS J13243553+6358281 provides the first precise constraint on the L/T transition at a known young age and indicates that it happens at a temperature of ∼1150 K at ∼150 Myr, compared to ∼1250 K for field brown dwarfs.

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

Plotkin, Richard M.; Gallo, Elena; Shemmer, Ohad

Over the past 15 yr, examples of exotic radio-quiet quasars with intrinsically weak or absent broad emission line regions (BELRs) have emerged from large-scale spectroscopic sky surveys. Here, we present spectroscopy of seven such weak emission line quasars (WLQs) at moderate redshifts (z = 1.4–1.7) using the X-shooter spectrograph, which provides simultaneous optical and near-infrared spectroscopy covering the rest-frame ultraviolet (UV) through optical. These new observations effectively double the number of WLQs with spectroscopy in the optical rest-frame, and they allow us to compare the strengths of (weak) high-ionization emission lines (e.g., C iv) to low-ionization lines (e.g., Mg ii,more » Hβ, Hα) in individual objects. We detect broad Hβ and Hα emission in all objects, and these lines are generally toward the weaker end of the distribution expected for typical quasars (e.g., Hβ has rest-frame equivalent widths ranging from 15–40 Å). However, these low-ionization lines are not exceptionally weak, as is the case for high-ionization lines in WLQs. The X-shooter spectra also display relatively strong optical Fe ii emission, Hβ FWHM ≲ 4000 km s{sup −1}, and significant C iv blueshifts (≈1000–5500 km s{sup −1}) relative to the systemic redshift; two spectra also show elevated UV Fe ii emission, and an outflowing component to their (weak) Mg ii emission lines. These properties suggest that WLQs are exotic versions of “wind-dominated” quasars. Their BELRs either have unusual high-ionization components, or their BELRs are in an atypical photoionization state because of an unusually soft continuum.« less

Polarimetric survey of main-belt asteroids. V. The unusual polarimetric behavior of V-type asteroids

NASA Astrophysics Data System (ADS)

Gil-Hutton, R.; López-Sisterna, C.; Calandra, M. F.

2017-03-01

Aims: We present the results of a polarimetric survey of main-belt asteroids at Complejo Astronómico El Leoncito (CASLEO), San Juan, Argentina. The aims of this survey are to increase the database of asteroid polarimetry, to estimate diversity in polarimetric properties of asteroids that belong to different taxonomic classes, and to search for objects that exhibit anomalous polarimetric properties. Methods: The data were obtained using the CASPROF and CASPOL polarimeters at the 2.15 m telescope. The CASPROF polarimeter is a two-hole aperture polarimeter with rapid modulation and CASPOL is a polarimeter based on a CCD detector, which allows us to observe fainter objects with better signal-to-noise ratio. Results: The survey began in 1995 and data on a large sample of asteroids were obtained until 2012. A second period began in 2013 using a polarimeter with a more sensitive detector in order to study small asteroids, families, and special taxonomic groups. We obtained 55 polarimetric measurements for 28 V-type main belt asteroids, all of them polarimetrically observed for the first time. The data obtained in this survey let us find polarimetric parameters for (1459) Magnya and for a group of 11 small V-type objects with similar polarimetric behavior. These polarization curves are unusual since they show a shallow minimum and a small inversion angle in comparison with (4) Vesta, although they have a steeper slope at α0. This polarimetric behavior could be explained by differences in the regoliths of these asteroids. The observations of (2579) Spartacus, and perhaps also (3944) Halliday, indicate a inversion angle larger than 24-25°. Based on observations carried out at the Complejo Astronómico El Leoncito, operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina and the National Universities of La Plata, Córdoba, and San Juan.

Interstellar Interloper 1I/2017 U1: Observations from the NOT and WIYN Telescopes

NASA Astrophysics Data System (ADS)

Jewitt, David; Luu, Jane; Rajagopal, Jayadev; Kotulla, Ralf; Ridgway, Susan; Liu, Wilson; Augusteijn, Thomas

2017-12-01

We present observations of the interstellar interloper 1I/2017 U1 (’Oumuamua) taken during its 2017 October flyby of Earth. The optical colors B - V = 0.70 ± 0.06, V - R = 0.45 ± 0.05, overlap those of the D-type Jovian Trojan asteroids and are incompatible with the ultrared objects that are abundant in the Kuiper Belt. With a mean absolute magnitude H V = 22.95 and assuming a geometric albedo p V = 0.1, we find an average radius of 55 m. No coma is apparent; we deduce a limit to the dust mass production rate of only ˜2 × 10-4 kg s-1, ruling out the existence of exposed ice covering more than a few m2 of the surface. Volatiles in this body, if they exist, must lie beneath an involatile surface mantle ≳0.5 m thick, perhaps a product of prolonged cosmic-ray processing in the interstellar medium. The light curve range is unusually large at ˜2.0 ± 0.2 mag. Interpreted as a rotational light curve the body has axis ratio ≥ {6.3}-1.1+1.3:1 and semi-axes ˜230 m × 35 m. A ≳6:1 axis ratio is extreme relative to most small solar system asteroids and suggests that albedo variations may additionally contribute to the variability. The light curve is consistent with a two-peaked period ˜8.26 hr, but the period is non-unique as a result of aliasing in the data. Except for its unusually elongated shape, 1I/2017 U1 is a physically unremarkable, sub-kilometer, slightly red, rotating object from another planetary system. The steady-state population of similar, ˜100 m scale interstellar objects inside the orbit of Neptune is ˜104, each with a residence time of ˜10 years.

Simulating 3D deformation using connected polygons

NASA Astrophysics Data System (ADS)

Tarigan, J. T.; Jaya, I.; Hardi, S. M.; Zamzami, E. M.

2018-03-01

In modern 3D application, interaction between user and the virtual world is one of an important factor to increase the realism. This interaction can be visualized in many forms; one of them is object deformation. There are many ways to simulate object deformation in virtual 3D world; each comes with different level of realism and performance. Our objective is to present a new method to simulate object deformation by using a graph-connected polygon. In this solution, each object contains multiple level of polygons in different level of volume. The proposed solution focusses on performance rather while maintaining the acceptable level of realism. In this paper, we present the design and implementation of our solution and show that this solution is usable in performance sensitive 3D application such as games and virtual reality.

Change in Unusually Hot and Cold Temperatures in the Contiguous 48 States, 1948-2015

EPA Pesticide Factsheets

This map shows trends in unusually hot and cold temperatures at individual weather stations that have operated consistently since 1948. In this case, the term ??unusually hot?? refers to a daily maximum temperature that is hotter than the 95th percentile temperature during the 1948??2015 period. Thus, the maximum temperature on a particular day at a particular station would be considered ??unusually hot?? if it falls within the warmest 5 percent of measurements at that station during the 1948??2015 period. The map shows changes in the total number of days per year that were hotter than the 95th percentile. Red upward-pointing symbols show where these unusually hot days are becoming more common. Blue downward-pointing symbols show where unusually hot days are becoming less common. For more information: www.epa.gov/climatechange/science/indicators

Making the Invisible Visible: Enhancing Students' Conceptual Understanding by Introducing Representations of Abstract Objects in a Simulation

ERIC Educational Resources Information Center

Olympiou, Georgios; Zacharias, Zacharia; deJong, Ton

2013-01-01

This study aimed to identify if complementing representations of concrete objects with representations of abstract objects improves students' conceptual understanding as they use a simulation to experiment in the domain of "Light and Color". Moreover, we investigated whether students' prior knowledge is a factor that must be considered in deciding…

An object oriented Python interface for atomistic simulations

NASA Astrophysics Data System (ADS)

Hynninen, T.; Himanen, L.; Parkkinen, V.; Musso, T.; Corander, J.; Foster, A. S.

2016-01-01

Programmable simulation environments allow one to monitor and control calculations efficiently and automatically before, during, and after runtime. Environments directly accessible in a programming environment can be interfaced with powerful external analysis tools and extensions to enhance the functionality of the core program, and by incorporating a flexible object based structure, the environments make building and analysing computational setups intuitive. In this work, we present a classical atomistic force field with an interface written in Python language. The program is an extension for an existing object based atomistic simulation environment.

Seismic shaking scenarios in realistic 3D crustal model of Northern Italy

NASA Astrophysics Data System (ADS)

Molinari, I.; Morelli, A.; Basini, P.; Berbellini, A.

2013-12-01

Simulation of seismic wave propagation in realistic crustal structures is a fundamental tool to evaluate earthquake-generated ground shaking and assess seismic hazard. Current-generation numerical codes, and modern HPC infrastructures, allow for realistic simulations in complex 3D geologic structures. We apply such methodology to the Po Plain in Northern Italy -- a region with relatively rare earthquakes but having large property and industrial exposure, as it became clear during the two M~6 events of May 20-29, 2012. Historical seismicity is well known in this region, with maximum magnitudes estimates reaching M~7, and wave field amplitudes may be significantly amplified by the presence of the very thick sedimentary basin. Our goal is to produce estimates of expected ground shaking in Northern Italy through detailed deterministic simulations of ground motion due to expected earthquakes. We defined a three-dimensional model of the earth's crust using geo-statistical tools to merge the abundant information existing in the form of borehole data and seismic reflection profiles that had been shot in the '70s and the '80s for hydrocarbon exploration. Such information, that has been used by geologists to infer the deep structural setup, had never been merged to build a 3D model to be used for seismological simulations. We implement the model in SPECFEM3D_Cartesian and a hexahedral mesh with elements of ~2km, that allows us to simulate waves with minimum period of ~2 seconds. The model has then been optimized through comparison between simulated and recorded seismograms for the ~20 moderate-magnitude events (Mw > 4.5) that have been instrumentally recorded in the last 15 years. Realistic simulations in the frequency band of most common engineering relevance -- say, ~1 Hz -- at such a large scale would require an extremely detailed structural model, currently not available, and prohibitive computational resources. However, an interest is growing in longer period ground motion -- that impacts on the seismic response of taller structures (Cauzzi and Faccioli, 2008) -- and it is not unusual to consider the wave field up to 20s. In such period range, our Po Plain structural model has shown to be able to reproduce well basin resonance and amplification effects at stations boarding the sedimentary plain. We then simulate seismic shaking scenarios for possible sources tied to devastating historical earthquakes that are known to have occurred in the region --- such as the M~6 event that hit Modena in 1501; and the Verona, M~6.7 in 1117, quake that caused well-documented strong effects in an unusually wide area with radius of hundreds of kilometers. We explore different source geometries and rupture histories for each earthquake. We mainly focus our attention on the synthesis of the prominent surface waves that are highly amplified in deep sedimentary basin structures (e.g., Smerzini et al, 2011; Koketsu and Miyage, 2008). Such simulations hold high relevance because of the large local property exposure, due to extensive industrial and touristic infrastructure. We show that deterministic ground motion calculation can indeed provide information to be actively used to mitigate the effects of desctructive earthquakes on critical infrastructures.

48 CFR 235.070 - Indemnification against unusually hazardous risks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Indemnification against unusually hazardous risks. 235.070 Section 235.070 Federal Acquisition Regulations System DEFENSE... DEVELOPMENT CONTRACTING 235.070 Indemnification against unusually hazardous risks. ...

Pleasantness, activation, and sex differences in advertising.

PubMed

Whissell, C; McCall, L

1997-10-01

Advertisements in men's, women's, girls', and boys' magazines (n = 38,195 words) were scored objectively in terms of 15 measures of linguistic style, e.g., use of common words, use of long words, use of specific words and emotional tone (pleasantness and activation, as measured by the Dictionary of Affect). There were several sex- and age-related differences among advertisements from different sources. Advertisements from boys' magazines were extremely active, those from women's and girls' magazines were shorter and unusually pleasant. In two follow-up studies (N = 122 volunteers), objective emotional measures of advertising text proved to be related to ratings of persuasion and of success of appeal for individual advertisements. The most preferred advertisement for women was pleasant and active, that for men unpleasant and active. When men and women created advertisements, women's were shorter and more pleasant.

Lumbar Pseudomeningocele Causing Hydronephrosis

PubMed Central

Hamilton, Rita G; Brown, Steven W; Goetz, Lance L; Miner, Michael

2009-01-01

Background/Objective: Pseudomeningocele is most commonly the result of a rent in the meninges during spine surgery. Noniatrogenic causes exist but are rare. Pseudomeningoceles may heal spontaneously, but they may also slowly enlarge. They rarely present as a mass within the abdomen. The objective of this study was to present the first case report of hydronephrosis secondary to lumbar pseudomeningocele. Design: Single case report and literature review. Methods: Single case report. Results: This man had undergone extensive lumbar spine surgery for pain and spondylolisthesis. He subsequently developed a pseudomeningocele that caused hydronephrosis of the left kidney. He was treated with surgical intervention and had resolution of his hydronephrosis and his flank and groin pain. He also had improvement of his back pain. Conclusions: This report shows an unusual cause of hydronephrosis—a pseudomeningocele presenting as an abdominal mass that compressed the ureter. PMID:19264055

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

Muder, R.R.; Reddy, S.C.; Yu, V.L.

Using an objective scoring system, chest radiographs were reviewed in 23 cases of pneumonia due to the Pittsburgh pneumonia agent (PPA, Tatlockia micdadei, Legionella micdadei), including six cases of pneumonia with simultaneous isolation of PPA and L pneumophila (Legionnaires' disease). Infiltrates were typically segmental to lobar; nodular infiltrates were noted in three cases. Spread to additional lobes after presentation occurred in four of 17 PPA infections. Pneumonia caused by both PPA and L pneumophila was unusually severe, with involvement of all lobes occurring in four of six cases, compared with one of 17 cases of PPA infection (p>0.02). Radiographic severitymore » did not correlate with underlying disease, immune status, or outcome. The majority of patients receiving erythromycin demonstrated objective radiologic improvement. In a patients, population that included nonimmunosuppressed patient, nodule formation and rapid radiologic progression were not found to be characteristic of PPA pneumonia.« less

The Problems in Experimental Foundation of Causal Mechanics

NASA Astrophysics Data System (ADS)

Parkhomov, A. G.

Causal mechanics developed by N.A.Kozyrev (1958,1968) and based on the concept of active properties of time has been a subject for emotional scientific discussions for four decades running. An unusual combination of the attributes "emotional" and "scientific" refers not only to the fact that N.A.Kozyrev's theory provides insight into a number of "dark" effects and phenomena of science such as quantum nonlocality, violation of parity, asymmetry of the right-hand and l-hand in biological objects. The most important thing is that the theory infers the everyday correlation between all objects and processes in the universe — even the most widely spaced ones. What is most appealing is that the universal correlation results from a few simple postulates that are consistent with common sense. Equally important is that causal mechanics is consistent with both classic and quantum mechanics…

IMPLEMENTATION OF FIRST-PASSAGE TIME APPROACH FOR OBJECT KINETIC MONTE CARLO SIMULATIONS OF IRRADIATION

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

Nandipati, Giridhar; Setyawan, Wahyu; Heinisch, Howard L.

2014-06-30

The objective of the work is to implement a first-passage time (FPT) approach to deal with very fast 1D diffusing SIA clusters in KSOME (kinetic simulations of microstructural evolution) [1] to achieve longer time-scales during irradiation damage simulations. The goal is to develop FPT-KSOME, which has the same flexibility as KSOME.

Self-learning computers for surgical planning and prediction of postoperative alignment.

PubMed

Lafage, Renaud; Pesenti, Sébastien; Lafage, Virginie; Schwab, Frank J

2018-02-01

In past decades, the role of sagittal alignment has been widely demonstrated in the setting of spinal conditions. As several parameters can be affected, identifying the driver of the deformity is the cornerstone of a successful treatment approach. Despite the importance of restoring sagittal alignment for optimizing outcome, this task remains challenging. Self-learning computers and optimized algorithms are of great interest in spine surgery as in that they facilitate better planning and prediction of postoperative alignment. Nowadays, computer-assisted tools are part of surgeons' daily practice; however, the use of such tools remains to be time-consuming. NARRATIVE REVIEW AND RESULTS: Computer-assisted methods for the prediction of postoperative alignment consist of a three step analysis: identification of anatomical landmark, definition of alignment objectives, and simulation of surgery. Recently, complex rules for the prediction of alignment have been proposed. Even though this kind of work leads to more personalized objectives, the number of parameters involved renders it difficult for clinical use, stressing the importance of developing computer-assisted tools. The evolution of our current technology, including machine learning and other types of advanced algorithms, will provide powerful tools that could be useful in improving surgical outcomes and alignment prediction. These tools can combine different types of advanced technologies, such as image recognition and shape modeling, and using this technique, computer-assisted methods are able to predict spinal shape. The development of powerful computer-assisted methods involves the integration of several sources of information such as radiographic parameters (X-rays, MRI, CT scan, etc.), demographic information, and unusual non-osseous parameters (muscle quality, proprioception, gait analysis data). In using a larger set of data, these methods will aim to mimic what is actually done by spine surgeons, leading to real tailor-made solutions. Integrating newer technology can change the current way of planning/simulating surgery. The use of powerful computer-assisted tools that are able to integrate several parameters and learn from experience can change the traditional way of selecting treatment pathways and counseling patients. However, there is still much work to be done to reach a desired level as noted in other orthopedic fields, such as hip surgery. Many of these tools already exist in non-medical fields and their adaptation to spine surgery is of considerable interest.

Hubble and ESO's VLT provide unique 3D views of remote galaxies

NASA Astrophysics Data System (ADS)

2009-03-01

Astronomers have obtained exceptional 3D views of distant galaxies, seen when the Universe was half its current age, by combining the twin strengths of the NASA/ESA Hubble Space Telescope's acute eye, and the capacity of ESO's Very Large Telescope to probe the motions of gas in tiny objects. By looking at this unique "history book" of our Universe, at an epoch when the Sun and the Earth did not yet exist, scientists hope to solve the puzzle of how galaxies formed in the remote past. ESO PR Photo 10a/09 A 3D view of remote galaxies ESO PR Photo 10b/09 Measuring motions in 3 distant galaxies ESO PR Video 10a/09 Galaxies in collision For decades, distant galaxies that emitted their light six billion years ago were no more than small specks of light on the sky. With the launch of the Hubble Space Telescope in the early 1990s, astronomers were able to scrutinise the structure of distant galaxies in some detail for the first time. Under the superb skies of Paranal, the VLT's FLAMES/GIRAFFE spectrograph (ESO 13/02) -- which obtains simultaneous spectra from small areas of extended objects -- can now also resolve the motions of the gas in these distant galaxies (ESO 10/06). "This unique combination of Hubble and the VLT allows us to model distant galaxies almost as nicely as we can close ones," says François Hammer, who led the team. "In effect, FLAMES/GIRAFFE now allows us to measure the velocity of the gas at various locations in these objects. This means that we can see how the gas is moving, which provides us with a three-dimensional view of galaxies halfway across the Universe." The team has undertaken the Herculean task of reconstituting the history of about one hundred remote galaxies that have been observed with both Hubble and GIRAFFE on the VLT. The first results are coming in and have already provided useful insights for three galaxies. In one galaxy, GIRAFFE revealed a region full of ionised gas, that is, hot gas composed of atoms that have been stripped of one or several electrons. This is normally due to the presence of very hot, young stars. However, even after staring at the region for more than 11 days, Hubble did not detect any stars! "Clearly this unusual galaxy has some hidden secrets," says Mathieu Puech, lead author of one of the papers reporting this study. Comparisons with computer simulations suggest that the explanation lies in the collision of two very gas-rich spiral galaxies. The heat produced by the collision would ionise the gas, making it too hot for stars to form. Another galaxy that the astronomers studied showed the opposite effect. There they discovered a bluish central region enshrouded in a reddish disc, almost completely hidden by dust. "The models indicate that gas and stars could be spiralling inwards rapidly," says Hammer. This might be the first example of a disc rebuilt after a major merger (ESO 01/05). Finally, in a third galaxy, the astronomers identified a very unusual, extremely blue, elongated structure -- a bar -- composed of young, massive stars, rarely observed in nearby galaxies. Comparisons with computer simulations showed the astronomers that the properties of this object are well reproduced by a collision between two galaxies of unequal mass. "The unique combination of Hubble and FLAMES/GIRAFFE at the VLT makes it possible to model distant galaxies in great detail, and reach a consensus on the crucial role of galaxy collisions for the formation of stars in a remote past," says Puech. "It is because we can now see how the gas is moving that we can trace back the mass and the orbits of the ancestral galaxies relatively accurately. Hubble and the VLT are real ‘time machines' for probing the Universe's history", adds Sébastien Peirani, lead author of another paper reporting on this study. The astronomers are now extending their analysis to the whole sample of galaxies observed. "The next step will then be to compare this with closer galaxies, and so, piece together a picture of the evolution of galaxies over the past six to eight billion years, that is, over half the age of the Universe," concludes Hammer.

Pelvic abscess associated with a Lippes loop. An unusual case.

PubMed

Hochner-Celnikier, D; Milwidsky, A; Menashe, M; Ariel, I; Palti, Z

1983-08-01

An unusual case occurred of Lippes-Loop-associated pelvic abscess, characterized by a relatively mild clinical course and an unusual localization in the pelvis. This case emphasizes the importance of considering the association between intrauterine devices and pelvic abscess.

Object-oriented Technology for Compressor Simulation

NASA Technical Reports Server (NTRS)

Drummond, C. K.; Follen, G. J.; Cannon, M. R.

1994-01-01

An object-oriented basis for interdisciplinary compressor simulation can, in principle, overcome several barriers associated with the traditional structured (procedural) development approach. This paper presents the results of a research effort with the objective to explore the repercussions on design, analysis, and implementation of a compressor model in an object oriented (OO) language, and to examine the ability of the OO system design to accommodate computational fluid dynamics (CFD) code for compressor performance prediction. Three fundamental results are that: (1) the selection of the object oriented language is not the central issue; enhanced (interdisciplinary) analysis capability derives from a broader focus on object-oriented technology; (2) object-oriented designs will produce more effective and reusable computer programs when the technology is applied to issues involving complex system inter-relationships (more so than when addressing the complex physics of an isolated discipline); and (3) the concept of disposable prototypes is effective for exploratory research programs, but this requires organizations to have a commensurate long-term perspective. This work also suggests that interdisciplinary simulation can be effectively accomplished (over several levels of fidelity) with a mixed language treatment (i.e., FORTRAN-C++), reinforcing the notion the OO technology implementation into simulations is a 'journey' in which the syntax can, by design, continuously evolve.

Single-qubit decoherence under a separable coupling to a random matrix environment

NASA Astrophysics Data System (ADS)

Carrera, M.; Gorin, T.; Seligman, T. H.

2014-08-01

This paper describes the dynamics of a quantum two-level system (qubit) under the influence of an environment modeled by an ensemble of random matrices. In distinction to earlier work, we consider here separable couplings and focus on a regime where the decoherence time is of the same order of magnitude as the environmental Heisenberg time. We derive an analytical expression in the linear response approximation, and study its accuracy by comparison with numerical simulations. We discuss a series of unusual properties, such as purity oscillations, strong signatures of spectral correlations (in the environment Hamiltonian), memory effects, and symmetry-breaking equilibrium states.

Dark- and bright-rogue-wave solutions for media with long-wave-short-wave resonance.

PubMed

Chen, Shihua; Grelu, Philippe; Soto-Crespo, J M

2014-01-01

Exact explicit rogue-wave solutions of intricate structures are presented for the long-wave-short-wave resonance equation. These vector parametric solutions feature coupled dark- and bright-field counterparts of the Peregrine soliton. Numerical simulations show the robustness of dark and bright rogue waves in spite of the onset of modulational instability. Dark fields originate from the complex interplay between anomalous dispersion and the nonlinearity driven by the coupled long wave. This unusual mechanism, not available in scalar nonlinear wave equation models, can provide a route to the experimental realization of dark rogue waves in, for instance, negative index media or with capillary-gravity waves.

Modal testing with Asher's method using a Fourier analyzer and curve fitting

NASA Technical Reports Server (NTRS)

Gold, R. R.; Hallauer, W. L., Jr.

1979-01-01

An unusual application of the method proposed by Asher (1958) for structural dynamic and modal testing is discussed. Asher's method has the capability, using the admittance matrix and multiple-shaker sinusoidal excitation, of separating structural modes having indefinitely close natural frequencies. The present application uses Asher's method in conjunction with a modern Fourier analyzer system but eliminates the necessity of exciting the test structure simultaneously with several shakers. Evaluation of this approach with numerically simulated data demonstrated its effectiveness; the parameters of two modes having almost identical natural frequencies were accurately identified. Laboratory evaluation of this approach was inconclusive because of poor experimental input data.

Giant asymmetric self-phase modulation in superconductor thin films

NASA Astrophysics Data System (ADS)

Robson, Charles W.; Biancalana, Fabio

2018-04-01

Self-phase modulation (SPM) of light pulses is found to occur strongly, at low incident intensities, in the coupling of light with superconductors. We develop a theory from a synthesis of the time-dependent Ginzburg-Landau (TDGL) equation and basic electrodynamics which shows the strongly non-linear phase accumulated in the interaction. Unusually, the SPM of the pulse in this system is found to be highly asymmetric, producing a strongly redshifted spectrum when interacting with a superconducting thin film, and it develops in just a few nanometers of propagation. In this paper we present theoretical results and simulations in the THz regime, for both hyperbolic secant and supergaussian-shaped pulses.

EIT image regularization by a new Multi-Objective Simulated Annealing algorithm.

PubMed

Castro Martins, Thiago; Sales Guerra Tsuzuki, Marcos

2015-01-01

Multi-Objective Optimization can be used to produce regularized Electrical Impedance Tomography (EIT) images where the weight of the regularization term is not known a priori. This paper proposes a novel Multi-Objective Optimization algorithm based on Simulated Annealing tailored for EIT image reconstruction. Images are reconstructed from experimental data and compared with images from other Multi and Single Objective optimization methods. A significant performance enhancement from traditional techniques can be inferred from the results.

48 CFR 250.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Special procedures for unusually hazardous or nuclear risks. 250.104-3 Section 250.104-3 Federal Acquisition Regulations System... unusually hazardous or nuclear risks. ...

48 CFR 250.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Special procedures for unusually hazardous or nuclear risks. 250.104-3 Section 250.104-3 Federal Acquisition Regulations System... unusually hazardous or nuclear risks. ...

48 CFR 250.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Special procedures for unusually hazardous or nuclear risks. 250.104-3 Section 250.104-3 Federal Acquisition Regulations System... unusually hazardous or nuclear risks. ...

48 CFR 250.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Special procedures for unusually hazardous or nuclear risks. 250.104-3 Section 250.104-3 Federal Acquisition Regulations System... unusually hazardous or nuclear risks. ...

48 CFR 250.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Special procedures for unusually hazardous or nuclear risks. 250.104-3 Section 250.104-3 Federal Acquisition Regulations System... unusually hazardous or nuclear risks. ...

48 CFR 632.114 - Unusual contract financing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Unusual contract financing. 632.114 Section 632.114 Federal Acquisition Regulations System DEPARTMENT OF STATE GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 632.114 Unusual contract financing. The...

48 CFR 2432.114 - Unusual contract financing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Unusual contract financing... DEVELOPMENT GENERAL CONTRACTING REQUIREMENTS CONTRACT FINANCING Non-Commercial Item Purchase Financing 2432.114 Unusual contract financing. The Senior Procurement Executive is the agency head for the purpose of...

Quantifying learning in medical students during a critical care medicine elective: a comparison of three evaluation instruments.

PubMed

Rogers, P L; Jacob, H; Rashwan, A S; Pinsky, M R

2001-06-01

To compare three different evaluative instruments and determine which is able to measure different aspects of medical student learning. Student learning was evaluated by using written examinations, objective structured clinical examination, and patient simulator that used two clinical scenarios before and after a structured critical care elective, by using a crossover design. Twenty-four 4th-yr students enrolled in the critical care medicine elective. All students took a multiple-choice written examination; evaluated a live simulated critically ill patient, requested data from a nurse, and intervened as appropriate at different stations (objective structured clinical examination); and evaluated the computer-controlled patient simulator and intervened as appropriate. Students' knowledge was assessed by using a multiple-choice examination containing the same data incorporated into the other examinations. Student performance on the objective structured clinical examination was evaluated at five stations. Both objective structured clinical examination and simulator tests were videotaped for subsequent scores of responses, quality of responses, and response time. The videotapes were reviewed for specific behaviors by faculty masked to time of examination. Students were expected to perform the following: a) assess airway, breathing, and circulation; b) prepare a mannequin for intubation; c) provide appropriate ventilator settings; d) manage hypotension; and e) request, interpret, and provide appropriate intervention for pulmonary artery catheter data. Students were expected to perform identical behaviors during the simulator examination; however, the entire examination was performed on the whole-body computer-controlled mannequin. The primary outcome measure was the difference in examination scores before and after the rotation. The mean preelective scores were 77 +/- 16%, 47 +/- 15%, and 41 +/- 14% for the written examination, objective structured clinical examination, and simulator, respectively, compared with 89 +/- 11%, 76 +/- 12%, and 62 +/- 15% after the elective (p <.0001). Prerotation scores for the written examination were significantly higher than the objective structured clinical examination or the simulator; postrotation scores were highest for the written examination and lowest for the simulator. Written examinations measure acquisition of knowledge but fail to predict if students can apply knowledge to problem solving, whereas both the objective structured clinical examination and the computer-controlled patient simulator can be used as effective performance evaluation tools.

Refinement of Objective Motion Cueing Criteria Investigation Based on Three Flight Tasks

NASA Technical Reports Server (NTRS)

Zaal, Petrus M. T.; Schroeder, Jeffery A.; Chung, William W.

2017-01-01

The objective of this paper is to refine objective motion cueing criteria for commercial transport simulators based on pilots' performance in three flying tasks. Actuator hardware and software algorithms determine motion cues. Today, during a simulator qualification, engineers objectively evaluate only the hardware. Pilot inspectors subjectively assess the overall motion cueing system (i.e., hardware plus software); however, it is acknowledged that pinpointing any deficiencies that might arise to either hardware or software is challenging. ICAO 9625 has an Objective Motion Cueing Test (OMCT), which is now a required test in the FAA's part 60 regulations for new devices, evaluating the software and hardware together; however, it lacks accompanying fidelity criteria. Hosman has documented OMCT results for a statistical sample of eight simulators which is useful, but having validated criteria would be an improvement. In a previous experiment, we developed initial objective motion cueing criteria that this paper is trying to refine. Sinacori suggested simple criteria which are in reasonable agreement with much of the literature. These criteria often necessitate motion displacements greater than most training simulators can provide. While some of the previous work has used transport aircraft in their studies, the majority used fighter aircraft or helicopters. Those that used transport aircraft considered degraded flight characteristics. As a result, earlier criteria lean more towards being sufficient, rather than necessary, criteria for typical transport aircraft training applications. Considering the prevalence of 60-inch, six-legged hexapod training simulators, a relevant question is "what are the necessary criteria that can be used with the ICAO 9625 diagnostic?" This study adds to the literature as follows. First, it examines well-behaved transport aircraft characteristics, but in three challenging tasks. The tasks are equivalent to the ones used in our previous experiment, allowing us to directly compare the results and add to the previous data. Second, it uses the Vertical Motion Simulator (VMS), the world's largest vertical displacement simulator. This allows inclusion of relatively large motion conditions, much larger than a typical training simulator can provide. Six new motion configurations were used that explore the motion responses between the initial objective motion cueing boundaries found in a previous experiment and what current hexapod simulators typically provide. Finally, a sufficiently large pilot pool added statistical reliability to the results.

Skull Base Inverted Papilloma: A Comprehensive Review

PubMed Central

Wassef, Shafik N.; Batra, Pete S.; Barnett, Samuel

2012-01-01

Skull base inverted papilloma (IP) is an unusual entity for many neurosurgeons. IP is renowned for its high rate of recurrence, its ability to cause local destruction, and its association with malignancy. This paper is a comprehensive review of the reports, studies, and reviews published in the current biomedical literature from 1947 to September 2010 and synthesize this information to focus on its potential invasion to the base of the skull and possible intradural extension. The objective is to familiarize the clinician with the different aspects of this unusual disease. The role of modern diagnostic tools in medical imaging in order to assess clearly the limits of the tumors and to enhance the efficiency and the safety in the choice of a surgical approach is pointed out. The treatment guidelines for IP have undergone a complex evolution that continues today. Radical excision of the tumour is technically difficult and often incomplete. Successful management of IP requires resection of the affected mucosa which could be achieved with open surgery, endoscopic, or combined approach. Radio and chemotherapy were used for certain indications. More optimally research would be a multicenter randomized trials with large size cohorts. PMID:23346418

WISE J233237.05-505643.5: A Double-Peaked Broad-Lined AGN with Spiral-Shaped Radio Morphology

NASA Technical Reports Server (NTRS)

Tsai, Chao Wei; Jarrett, Thomas H.; Stern, Daniel; Emonts, Bjorn; Barrows, R. Scott; Assef, Roberto J.; Norris, Ray P.; Eisenhardt, Peter R. M.; Lonsdale, Carol; Blain, Andrew W.;

Testing the Martian Methane from Cometary Debris Hypothesis: The Unusually Close 24 Jan 2018 Interaction Between Comet C/2007 H2 (Skiff) and Mars

NASA Technical Reports Server (NTRS)

Fries, M.; Archer, D.; Christou, T.; Conrad, P.; Eigenbrode, J.; Kate, I. L. ten; Steele, A.

2018-01-01

In previous work we proposed a hypothesis wherein debris moving along cometary orbits interacting with Mars (e.g. meteor showers) may be responsible for transient local increases of methane observed in the martian atmosphere (henceforth 'the hypothesis' ). An examination of the literature of methane detections dating back to 1997 showed that each detection was made, at most, 16 days after an interaction between Mars and one of seven small bodies (six comets and the unusual object 5335 Damocles)[ibid]. Two observations of high-altitude, transient visible plumes on Mars also correlate with cometary interactions, one occurring on the same day as the plume observation and the second observation occurring three days afterwards, and with two of the same seven small bodies. The proposed mechanism for methane production is dissemination of carbon-rich cometary material on infall into Mars' atmosphere followed by methane production via UV photolysis, a process that has been observed in laboratory experiments. Given this set of observations it is necessary and indeed conducive to the scientific process to explore and robustly test the hypothesis.

Could a Hexagonal Sunspot Have Been Observed During the Maunder Minimum?

NASA Astrophysics Data System (ADS)

Carrasco, V. M. S.; Vaquero, J. M.; Gallego, M. C.

2018-03-01

The Maunder Minimum is the period between 1645 and 1715. Its main characteristic is abnormally low and prolonged solar activity. However, some authors have doubted the low level of solar activity during that period by questioning the accuracy and objectivity of the observers. This work presents a particular case of a sunspot observed during the Maunder Minimum with an unusual shape of its umbra and penumbra: a hexagon. This sunspot was observed by Cassini in November 1676, just at the core of the Maunder Minimum. This historical observation is compared with a twin case that occurred recently in May 2016. The conclusion reached is that Cassini's record is another example of the good quality of the observations that were made during the Maunder Minimum, showing the meticulousness of the astronomers of that epoch. This sunspot observation made by Cassini does not support the conclusions of Zolotova and Ponyavin ( Astrophys. J. 800, 42, 2015) that professional astronomers in the seventeenth century only registered round sunspots. Finally, a discussion is given of the importance of this kind of unusual sunspot record for a better assessment of the true level of solar activity in the Maunder Minimum.

Bioavailability of Bioactive Molecules from Olive Leaf Extracts and its Functional Value.

PubMed

Martín-Vertedor, Daniel; Garrido, María; Pariente, José Antonio; Espino, Javier; Delgado-Adámez, Jonathan

2016-07-01

Olive leaves are an important low-cost source of bioactive compounds. The present study aimed to examine the effect of in vitro digestibility of an olive leaf aqueous extract so as to prove the availability of its phenolic compounds as well as its antioxidant, antimicrobial, and anticancer activity after a simulated digestion process. The total phenolic content was significantly higher in the pure lyophilized extract. Phenolic compounds, however, decreased by 60% and 90% in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF), respectively. Regarding antioxidant activity, it was reduced by 10% and 50% after gastric and intestinal digestion, respectively; despite this fact, high antioxidant capacity was found in both SGF and SIF. Moreover, the olive leaf extract showed an unusual combined antimicrobial action at low concentration, which suggested their great potential as nutraceuticals, particularly as a source of phenolic compounds. Finally, olive leaf extracts produced a general dose-dependent cytotoxic effect against U937 cells. To sum up, these findings suggest that the olive leaf aqueous extract maintains its beneficial properties after a simulated digestion process, and therefore its regular consumption could be helpful in the management and the prevention of oxidative stress-related chronic disease, bacterial infection, or even cancer. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Dynamics of crystalline acetanilide: Analysis using neutron scattering and computer simulation

NASA Astrophysics Data System (ADS)

Hayward, R. L.; Middendorf, H. D.; Wanderlingh, U.; Smith, J. C.

1995-04-01

The unusual temperature dependence of several optical spectroscopic vibrational bands in crystalline acetanilide has been interpreted as providing evidence for dynamic localization. Here we examine the vibrational dynamics of crystalline acetanilide over a spectral range of ˜20-4000 cm-1 using incoherent neutron scattering experiments, phonon normal mode calculations and molecular dynamics simulations. A molecular mechanics energy function is parametrized and used to perform the normal mode analyses in the full configurational space of the crystal i.e., including the intramolecular and intermolecular degrees of freedom. One- and multiphonon incoherent inelastic neutron scattering intensities are calculated from harmonic analyses in the first Brillouin zone and compared with the experimental data presented here. Phonon dispersion relations and mean-square atomic displacements are derived from the harmonic model and compared with data derived from coherent inelastic neutron scattering and neutron and x-ray diffraction. To examine the temperature effects on the vibrations the full, anharmonic potential function is used in molecular dynamics simulations of the crystal at 80, 140, and 300 K. Several, but not all, of the spectral features calculated from the molecular dynamics simulations exhibit temperature-dependent behavior in agreement with experiment. The significance of the results for the interpretation of the optical spectroscopic results and possible improvements to the model are discussed.

Isolated Traumatic Bilateral First Rib Fracture: A Rare Entity

PubMed Central

Chatterjee, Souvik; Dey, Rajesh; Ray, Ramdip; Sinha, Santanu

2011-01-01

Since the first rib is protected very well by the overlying soft tissue and bones, its fracture is a major injury and a considerable force is required to do it. Therefore, an isolated fracture of this rib is unusual. A 28-year-old healthy female had an accident while crossing the road and a heavy object fell on her. She had severe pain behind her clavicle region and was immediately hospitalized and examined. Thorough clinical examination and different relevant investigations surprisingly disclosed isolated bilateral first rib fracture which is a very rare clinical condition. PMID:25191390

Comet or asteroid shower in the late Eocene?

PubMed

Tagle, Roald; Claeys, Philippe

2004-07-23

The passage of a comet shower approximately 35 million years ago is generally advocated to explain the coincidence during Earth's late Eocene of an unusually high flux of interplanetary dust particles and the formation of the two largest craters in the Cenozoic, Popigai and the Chesapeake Bay. However, new platinum-group element analyses indicate that Popigai was formed by the impact of an L-chondrite meteorite. Such an asteroidal projectile is difficult to reconcile with a cometary origin. Perhaps instead the higher delivery rate of extraterrestrial matter, dust, and large objects was caused by a major collision in the asteroid belt.

An unconventional depiction of viewpoint in rock art.

PubMed

Pettigrew, Jack; Scott-Virtue, Lee

2015-01-01

Rock art in Africa sometimes takes advantage of three-dimensional features of the rock wall, such as fissures or protuberances, that can be incorporated into the artistic composition (Lewis-Williams, 2002). More commonly, rock artists choose uniform walls on which two-dimensional depictions may represent three-dimensional figures or objects. In this report we present such a two-dimensional depiction in rock art that we think reveals an intention by the artist to represent an unusual three-dimensional viewpoint, namely, with the two human figures facing into the rock wall, instead of the accustomed Western viewpoint facing out!

How Simbol-X Will Reveal the Most Obscured High Energy Sources of our Galaxy

NASA Astrophysics Data System (ADS)

Chaty, S.

2009-05-01

The INTEGRAL satellite has revealed a major population of supergiant High Mass X-ray Binaries in our Galaxy, revolutionizing our understanding of binary systems and their evolution. This population, constituted of a compact object orbiting around a supergiant star, have unusual properties, either being extremely absorbed, or exhibiting very short flares. I will first describe the characteristics of these sources, that only intensive multi-wavelength observations have led us to disentangle, before showing that Simbol-X, thanks to its energy range and sensitivity, will allow us to go further in the understanding of these supergiant HMXBs.

An unusual metastasis of a papillary thyroidian carcinoma with follicular pattern.

PubMed

Coconu, M; Berdan, G; Roşculescu, I; Herlea, V

1998-01-01

The case of a 67-year-old man is presented. He was admitted for the presence of a left parietal tumour with progressive growing, without any other objective or subjective symptomatology. CT-scan detects a left parietal osteolytic area. The histopathological aspect suggested an adenocarcinomatous metastasis with papillary pattern, moderately differentiated. With the purpose of diagnosing the original tumour, immunnohistochemical techniques were performed, which led to a diagnosis of a thyroidian carcinoma. At the histological examination of the surgical extirpated thyroid, it was proved to be a papillary carcinoma (Chan, 1990, Hay, 1990), the follicular pattern.

Unusual Metastases in Renal Cell Carcinoma: A Single Institution Experience and Review of Literature

PubMed Central

Villarreal-Garza, Cynthia; Perez-Alvarez, Sandra I.; Gonzalez-Espinoza, Ivan R.; Leon-Rodriguez, Eucario

2010-01-01

Background To report location and management of atypical metastases from renal cell carcinoma (RCC) in the Instituto Nacional de Ciencias Medicas e Investigacion Salvador Zubiran (INCMNSZ) in Mexico City. Methods Between 1987 to 2009, 545 patients with RCC were retrospectively identified at the INCMNSZ. Patients with unusual metastases confirmed by histopathology were analyzed. Epidemiological, clinical, diagnosis, treatment and outcome data were reviewed. Results Sixty patients developed 98 unusual metastases secondary to RCC. The group was comprised of 35 men (58.3%), with a median age of 60 years at diagnosis. Metachronous unusual metastases with primary renal cancer were observed in 37 individuals (61.7%). Median time from primary RCC diagnosis to the first unusual metastasis was 16.5 months. Median survival from diagnosis of the first unusual metastasis to death was 5.0 months (CI 95%: 2.8-7.2 months). Patients with an initial solitary metastatic lesion in an unusual site (28.3%) had a better survival compared to patients who primarily presented with multiple metastases, 17.0 (CI 95%: 6.1-27.9) Vs 3.0 months (CI 95%: 0.9-5.1), p = 0.001. Unusual metastasis resection (21 patients) improved survival, 25.0 (CI 95%: 5.1-44.9) Vs 3.0 months (CI 95%: 0.8-5.2), p < 0.0001. No survival difference was observed between localization of unsual metastases (p = 0.72). Conclusions In patients with advanced RCC we suggest an individual diagnostic and surgical approach to achieve complete resection with disease-free margins, even in the presence of unusual metastatic sites, multifocality, or history of metastasectomy. These strategy might provide not only palliation for symptoms, but an opportunity for meaningful disease free and overall survival. PMID:29147198

A nationwide, cross-sectional survey on unusual sleep postures and sleep-disordered breathing-related symptoms in people with Down syndrome.

PubMed

Kuroda, H; Sawatari, H; Ando, S; Ohkusa, T; Rahmawati, A; Ono, J; Nishizaka, M; Hashiguchi, N; Matsuoka, F; Chishaki, A

2017-07-01

People with Down syndrome (DS) often have sleep-disordered breathing (SDB). Unusual sleep postures, such as leaning forward and sitting, are observed in people with DS. This study aimed to clarify the prevalence of unusual sleep postures and their relationships with SDB-related symptoms (SDB-RSs), such as snoring, witnessed apnoea, nocturnal awakening and excessive daytime sleepiness. A questionnaire, including demographic characteristics and the presence of unusual sleep postures, as well as SDB-RSs, was completed by 1149 parents of people with DS from Japan. Unusual sleep postures were recorded in 483 (42.0%) people with DS. These participants were significantly younger and had a history of low muscle tone more frequently than people without unusual sleep postures. In all ages, the leaning forward posture was more frequent than sitting. People with DS with unusual sleep postures suffered from SDB-RSs. Those who slept in the sitting posture had more frequent SDB-RSs than did those who slept with the leaning forward posture. Snoring, witnessed apnoea and nocturnal awakening were observed in 73.6, 27.2 and 58.2% of participants, respectively. Snoring increased with aging. Witnessed apnoea was more common in males and in those with hypothyroidism than in females and in those without hypothyroidism. Our study shows that there is a close relationship between unusual sleep postures and SDB-RSs. We recommend that all people with DS with unusual sleep postures should be checked for the presence of SDB. © 2017 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

Object-oriented approach for gas turbine engine simulation

NASA Technical Reports Server (NTRS)

Curlett, Brian P.; Felder, James L.

1995-01-01

An object-oriented gas turbine engine simulation program was developed. This program is a prototype for a more complete, commercial grade engine performance program now being proposed as part of the Numerical Propulsion System Simulator (NPSS). This report discusses architectural issues of this complex software system and the lessons learned from developing the prototype code. The prototype code is a fully functional, general purpose engine simulation program, however, only the component models necessary to model a transient compressor test rig have been written. The production system will be capable of steady state and transient modeling of almost any turbine engine configuration. Chief among the architectural considerations for this code was the framework in which the various software modules will interact. These modules include the equation solver, simulation code, data model, event handler, and user interface. Also documented in this report is the component based design of the simulation module and the inter-component communication paradigm. Object class hierarchies for some of the code modules are given.

A Coordinated Initialization Process for the Distributed Space Exploration Simulation

NASA Technical Reports Server (NTRS)

Crues, Edwin Z.; Phillips, Robert G.; Dexter, Dan; Hasan, David

2007-01-01

A viewgraph presentation on the federate initialization process for the Distributed Space Exploration Simulation (DSES) is described. The topics include: 1) Background: DSES; 2) Simulation requirements; 3) Nine Step Initialization; 4) Step 1: Create the Federation; 5) Step 2: Publish and Subscribe; 6) Step 3: Create Object Instances; 7) Step 4: Confirm All Federates Have Joined; 8) Step 5: Achieve initialize Synchronization Point; 9) Step 6: Update Object Instances With Initial Data; 10) Step 7: Wait for Object Reflections; 11) Step 8: Set Up Time Management; 12) Step 9: Achieve startup Synchronization Point; and 13) Conclusions

Using mixed reality, force feedback and tactile augmentation to improve the realism of medical simulation.

PubMed

Fisher, J Brian; Porter, Susan M

2002-01-01

This paper describes an application of a display approach which uses chromakey techniques to composite real and computer-generated images allowing a user to see his hands and medical instruments collocated with the display of virtual objects during a medical training simulation. Haptic feedback is provided through the use of a PHANTOM force feedback device in addition to tactile augmentation, which allows the user to touch virtual objects by introducing corresponding real objects in the workspace. A simplified catheter introducer insertion simulation was developed to demonstrate the capabilities of this approach.

47 CFR 32.25 - Unusual items and contingent liabilities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Unusual items and contingent liabilities. 32.25 Section 32.25 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES General Instructions § 32.25 Unusual items and...

47 CFR 32.25 - Unusual items and contingent liabilities.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 2 2013-10-01 2013-10-01 false Unusual items and contingent liabilities. 32.25 Section 32.25 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES General Instructions § 32.25 Unusual items and...

47 CFR 32.25 - Unusual items and contingent liabilities.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 2 2014-10-01 2014-10-01 false Unusual items and contingent liabilities. 32.25 Section 32.25 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES UNIFORM SYSTEM OF ACCOUNTS FOR TELECOMMUNICATIONS COMPANIES General Instructions § 32.25 Unusual items and...

Ray tracing analysis of overlapping objects in refraction contrast imaging.

PubMed

Hirano, Masatsugu; Yamasaki, Katsuhito; Okada, Hiroshi; Sakurai, Takashi; Kondoh, Takeshi; Katafuchi, Tetsuro; Sugimura, Kazuro; Kitazawa, Sohei; Kitazawa, Riko; Maeda, Sakan; Tamura, Shinichi

2005-08-01

We simulated refraction contrast imaging in overlapping objects using the ray tracing method. The easiest case, in which two columnar objects (blood vessels) with a density of 1.0 [g/cm3], run at right angles in air, was calculated. For absorption, we performed simulation using the Snell law adapted to the object's boundary. A pair of bright and dark spot results from the interference of refracted X-rays where the blood vessels crossed. This has the possibility of increasing the visibility of the image.

Acoustic Parametric Array for Identifying Standoff Targets

NASA Astrophysics Data System (ADS)

Hinders, M. K.; Rudd, K. E.

2010-02-01

An integrated simulation method for investigating nonlinear sound beams and 3D acoustic scattering from any combination of complicated objects is presented. A standard finite-difference simulation method is used to model pulsed nonlinear sound propagation from a source to a scattering target via the KZK equation. Then, a parallel 3D acoustic simulation method based on the finite integration technique is used to model the acoustic wave interaction with the target. Any combination of objects and material layers can be placed into the 3D simulation space to study the resulting interaction. Several example simulations are presented to demonstrate the simulation method and 3D visualization techniques. The combined simulation method is validated by comparing experimental and simulation data and a demonstration of how this combined simulation method assisted in the development of a nonlinear acoustic concealed weapons detector is also presented.

Linking actions and objects: Context-specific learning of novel weight priors.

PubMed

Trewartha, Kevin M; Flanagan, J Randall

2017-06-01

Distinct explicit and implicit memory processes support weight predictions used when lifting objects and making perceptual judgments about weight, respectively. The first time that an object is encountered weight is predicted on the basis of learned associations, or priors, linking size and material to weight. A fundamental question is whether the brain maintains a single, global representation of priors, or multiple representations that can be updated in a context specific way. A second key question is whether the updating of priors, or the ability to scale lifting forces when repeatedly lifting unusually weighted objects requires focused attention. To investigate these questions we compared the adaptability of weight predictions used when lifting objects and judging their weights in different groups of participants who experienced size-weight inverted objects passively (with the objects placed on the hands) or actively (where participants lift the objects) under full or divided attention. To assess weight judgments we measured the size-weight illusion after every 20 trials of experience with the inverted objects both passively and actively. The attenuation of the illusion that arises when lifting inverted object was found to be context-specific such that the attenuation was larger when the mode of interaction with the inverted objects matched the method of assessment of the illusion. Dividing attention during interaction with the inverted objects had no effect on attenuation of the illusion, but did slow the rate at which lifting forces were scaled to the weight inverted objects. These findings suggest that the brain stores multiple representations of priors that are context specific, and that focused attention is important for scaling lifting forces, but not for updating weight predictions used when judging object weight. Copyright © 2017 Elsevier B.V. All rights reserved.

Effective description of a 3D object for photon transportation in Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Suganuma, R.; Ogawa, K.

2000-06-01

Photon transport simulation by means of the Monte Carlo method is an indispensable technique for examining scatter and absorption correction methods in SPECT and PET. The authors have developed a method for object description with maximum size regions (maximum rectangular regions: MRRs) to speed up photon transport simulation, and compared the computation time with that for conventional object description methods, a voxel-based (VB) method and an octree method, in the simulations of two kinds of phantoms. The simulation results showed that the computation time with the proposed method became about 50% of that with the VD method and about 70% of that with the octree method for a high resolution MCAT phantom. Here, details of the expansion of the MRR method to three dimensions are given. Moreover, the effectiveness of the proposed method was compared with the VB and octree methods.

Clinical simulation as a boundary object in design of health IT-systems.

PubMed

Rasmussen, Stine Loft; Jensen, Sanne; Lyng, Karen Marie

2013-01-01

Healthcare organizations are very complex, holding numerous stakeholders with various approaches and goals towards the design of health IT-systems. Some of these differences may be approached by applying the concept of boundary objects in a participatory IT-design process. Traditionally clinical simulation provides the opportunity to evaluate the design and the usage of clinical IT-systems without endangering the patients and interrupting clinical work. In this paper we present how clinical simulation additionally holds the potential to function as a boundary object in the design process. The case points out that clinical simulation provides an opportunity for discussions and mutual learning among the various stakeholders involved in design of standardized electronic clinical documentation templates. The paper presents and discusses the use of clinical simulation in the translation, transfer and transformation of knowledge between various stakeholders in a large healthcare organization.

OSIRIS - an object-oriented parallel 3D PIC code for modeling laser and particle beam-plasma interaction

NASA Astrophysics Data System (ADS)

Hemker, Roy

1999-11-01

The advances in computational speed make it now possible to do full 3D PIC simulations of laser plasma and beam plasma interactions, but at the same time the increased complexity of these problems makes it necessary to apply modern approaches like object oriented programming to the development of simulation codes. We report here on our progress in developing an object oriented parallel 3D PIC code using Fortran 90. In its current state the code contains algorithms for 1D, 2D, and 3D simulations in cartesian coordinates and for 2D cylindrically-symmetric geometry. For all of these algorithms the code allows for a moving simulation window and arbitrary domain decomposition for any number of dimensions. Recent 3D simulation results on the propagation of intense laser and electron beams through plasmas will be presented.

Biopathways representation and simulation on hybrid functional petri net.

PubMed

Matsuno, Hiroshi; Tanaka, Yukiko; Aoshima, Hitoshi; Doi, Atsushi; Matsui, Mika; Miyano, Satoru

2011-01-01

The following two matters should be resolved in order for biosimulation tools to be accepted by users in biology/medicine: (1) remove issues which are irrelevant to biological importance, and (2) allow users to represent biopathways intuitively and understand/manage easily the details of representation and simulation mechanism. From these criteria, we firstly define a novel notion of Petri net called Hybrid Functional Petri Net (HFPN). Then, we introduce a software tool, Genomic Object Net, for representing and simulating biopathways, which we have developed by employing the architecture of HFPN. In order to show the usefulness of Genomic Object Net for representing and simulating biopathways, we show two HFPN representations of gene regulation mechanisms of Drosophila melanogaster (fruit fly) circadian rhythm and apoptosis induced by Fas ligand. The simulation results of these biopathways are also correlated with biological observations. The software is available to academic users from http://www.GenomicObject.Net/.

[Team training and assessment in mixed reality-based simulated operating room : Current state of research in the field of simulation in spine surgery exemplified by the ATMEOS project].

PubMed

Stefan, P; Pfandler, M; Wucherer, P; Habert, S; Fürmetz, J; Weidert, S; Euler, E; Eck, U; Lazarovici, M; Weigl, M; Navab, N

2018-04-01

Surgical simulators are being increasingly used as an attractive alternative to clinical training in addition to conventional animal models and human specimens. Typically, surgical simulation technology is designed for the purpose of teaching technical surgical skills (so-called task trainers). Simulator training in surgery is therefore in general limited to the individual training of the surgeon and disregards the participation of the rest of the surgical team. The objective of the project Assessment and Training of Medical Experts based on Objective Standards (ATMEOS) is to develop an immersive simulated operating room environment that enables the training and assessment of multidisciplinary surgical teams under various conditions. Using a mixed reality approach, a synthetic patient model, real surgical instruments and radiation-free virtual X‑ray imaging are combined into a simulation of spinal surgery. In previous research studies, the concept was evaluated in terms of realism, plausibility and immersiveness. In the current research, assessment measurements for technical and non-technical skills are developed and evaluated. The aim is to observe multidisciplinary surgical teams in the simulated operating room during minimally invasive spinal surgery and objectively assess the performance of the individual team members and the entire team. Moreover, the effectiveness of training methods and surgical techniques or success critical factors, e. g. management of crisis situations, can be captured and objectively assessed in the controlled environment.

Speckle correlation method used to measure object's in-plane velocity.

PubMed

Smíd, Petr; Horváth, Pavel; Hrabovský, Miroslav

2007-06-20

We present a measurement of an object's in-plane velocity in one direction by the use of the speckle correlation method. Numerical correlations of speckle patterns recorded periodically during motion of the object under investigation give information used to evaluate the object's in-plane velocity. The proposed optical setup uses a detection plane in the image field and enables one to detect the object's velocity within the interval (10-150) microm x s(-1). Simulation analysis shows a way of controlling the measuring range. The presented theory, simulation analysis, and setup are verified through an experiment of measurement of the velocity profile of an object.

Simulation and fitting of complex reaction network TPR: The key is the objective function

DOE PAGES

Savara, Aditya Ashi

2016-07-07

In this research, a method has been developed for finding improved fits during simulation and fitting of data from complex reaction network temperature programmed reactions (CRN-TPR). It was found that simulation and fitting of CRN-TPR presents additional challenges relative to simulation and fitting of simpler TPR systems. The method used here can enable checking the plausibility of proposed chemical mechanisms and kinetic models. The most important finding was that when choosing an objective function, use of an objective function that is based on integrated production provides more utility in finding improved fits when compared to an objective function based onmore » the rate of production. The response surface produced by using the integrated production is monotonic, suppresses effects from experimental noise, requires fewer points to capture the response behavior, and can be simulated numerically with smaller errors. For CRN-TPR, there is increased importance (relative to simple reaction network TPR) in resolving of peaks prior to fitting, as well as from weighting of experimental data points. Using an implicit ordinary differential equation solver was found to be inadequate for simulating CRN-TPR. Lastly, the method employed here was capable of attaining improved fits in simulation and fitting of CRN-TPR when starting with a postulated mechanism and physically realistic initial guesses for the kinetic parameters.« less

48 CFR 1850.403 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Special procedures for unusually hazardous or nuclear risks. 1850.403 Section 1850.403 Federal Acquisition Regulations System... Residual Powers 1850.403 Special procedures for unusually hazardous or nuclear risks. ...

48 CFR 1850.403 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Special procedures for unusually hazardous or nuclear risks. 1850.403 Section 1850.403 Federal Acquisition Regulations System... Residual Powers 1850.403 Special procedures for unusually hazardous or nuclear risks. ...

48 CFR 2832.114 - Unusual contract financing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Unusual contract financing... Contracting Requirements CONTRACT FINANCING Non-Commercial Item Purchase Financing 2832.114 Unusual contract financing. The HCA, or designee at a level not lower than the BPC, is the official authorized to approve...

Signature modelling and radiometric rendering equations in infrared scene simulation systems

NASA Astrophysics Data System (ADS)

Willers, Cornelius J.; Willers, Maria S.; Lapierre, Fabian

2011-11-01

The development and optimisation of modern infrared systems necessitates the use of simulation systems to create radiometrically realistic representations (e.g. images) of infrared scenes. Such simulation systems are used in signature prediction, the development of surveillance and missile sensors, signal/image processing algorithm development and aircraft self-protection countermeasure system development and evaluation. Even the most cursory investigation reveals a multitude of factors affecting the infrared signatures of realworld objects. Factors such as spectral emissivity, spatial/volumetric radiance distribution, specular reflection, reflected direct sunlight, reflected ambient light, atmospheric degradation and more, all affect the presentation of an object's instantaneous signature. The signature is furthermore dynamically varying as a result of internal and external influences on the object, resulting from the heat balance comprising insolation, internal heat sources, aerodynamic heating (airborne objects), conduction, convection and radiation. In order to accurately render the object's signature in a computer simulation, the rendering equations must therefore account for all the elements of the signature. In this overview paper, the signature models, rendering equations and application frameworks of three infrared simulation systems are reviewed and compared. The paper first considers the problem of infrared scene simulation in a framework for simulation validation. This approach provides concise definitions and a convenient context for considering signature models and subsequent computer implementation. The primary radiometric requirements for an infrared scene simulator are presented next. The signature models and rendering equations implemented in OSMOSIS (Belgian Royal Military Academy), DIRSIG (Rochester Institute of Technology) and OSSIM (CSIR & Denel Dynamics) are reviewed. In spite of these three simulation systems' different application focus areas, their underlying physics-based approach is similar. The commonalities and differences between the different systems are investigated, in the context of their somewhat different application areas. The application of an infrared scene simulation system towards the development of imaging missiles and missile countermeasures are briefly described. Flowing from the review of the available models and equations, recommendations are made to further enhance and improve the signature models and rendering equations in infrared scene simulators.

Three-dimensional simulation and auto-stereoscopic 3D display of the battlefield environment based on the particle system algorithm

NASA Astrophysics Data System (ADS)

Ning, Jiwei; Sang, Xinzhu; Xing, Shujun; Cui, Huilong; Yan, Binbin; Yu, Chongxiu; Dou, Wenhua; Xiao, Liquan

2016-10-01

The army's combat training is very important now, and the simulation of the real battlefield environment is of great significance. Two-dimensional information has been unable to meet the demand at present. With the development of virtual reality technology, three-dimensional (3D) simulation of the battlefield environment is possible. In the simulation of 3D battlefield environment, in addition to the terrain, combat personnel and the combat tool ,the simulation of explosions, fire, smoke and other effects is also very important, since these effects can enhance senses of realism and immersion of the 3D scene. However, these special effects are irregular objects, which make it difficult to simulate with the general geometry. Therefore, the simulation of irregular objects is always a hot and difficult research topic in computer graphics. Here, the particle system algorithm is used for simulating irregular objects. We design the simulation of the explosion, fire, smoke based on the particle system and applied it to the battlefield 3D scene. Besides, the battlefield 3D scene simulation with the glasses-free 3D display is carried out with an algorithm based on GPU 4K super-multiview 3D video real-time transformation method. At the same time, with the human-computer interaction function, we ultimately realized glasses-free 3D display of the simulated more realistic and immersed 3D battlefield environment.

Utility of a novel error-stepping method to improve gradient-based parameter identification by increasing the smoothness of the local objective surface: a case-study of pulmonary mechanics.

PubMed

Docherty, Paul D; Schranz, Christoph; Chase, J Geoffrey; Chiew, Yeong Shiong; Möller, Knut

2014-05-01

Accurate model parameter identification relies on accurate forward model simulations to guide convergence. However, some forward simulation methodologies lack the precision required to properly define the local objective surface and can cause failed parameter identification. The role of objective surface smoothness in identification of a pulmonary mechanics model was assessed using forward simulation from a novel error-stepping method and a proprietary Runge-Kutta method. The objective surfaces were compared via the identified parameter discrepancy generated in a Monte Carlo simulation and the local smoothness of the objective surfaces they generate. The error-stepping method generated significantly smoother error surfaces in each of the cases tested (p<0.0001) and more accurate model parameter estimates than the Runge-Kutta method in three of the four cases tested (p<0.0001) despite a 75% reduction in computational cost. Of note, parameter discrepancy in most cases was limited to a particular oblique plane, indicating a non-intuitive multi-parameter trade-off was occurring. The error-stepping method consistently improved or equalled the outcomes of the Runge-Kutta time-integration method for forward simulations of the pulmonary mechanics model. This study indicates that accurate parameter identification relies on accurate definition of the local objective function, and that parameter trade-off can occur on oblique planes resulting prematurely halted parameter convergence. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Design of an air traffic computer simulation system to support investigation of civil tiltrotor aircraft operations

NASA Technical Reports Server (NTRS)

Rogers, Ralph V.

1993-01-01

The TATSS Project's goal was to develop a design for computer software that would support the attainment of the following objectives for the air traffic simulation model: (1) Full freedom of movement for each aircraft object in the simulation model. Each aircraft object may follow any designated flight plan or flight path necessary as required by the experiment under consideration. (2) Object position precision up to +/- 3 meters vertically and +/- 15 meters horizontally. (3) Aircraft maneuvering in three space with the object position precision identified above. (4) Air traffic control operations and procedures. (5) Radar, communication, navaid, and landing aid performance. (6) Weather. (7) Ground obstructions and terrain. (8) Detection and recording of separation violations. (9) Measures of performance including deviations from flight plans, air space violations, air traffic control messages per aircraft, and traditional temporal based measures.

System and method for measuring residual stress

DOEpatents

Prime, Michael B.

2002-01-01

The present invention is a method and system for determining the residual stress within an elastic object. In the method, an elastic object is cut along a path having a known configuration. The cut creates a portion of the object having a new free surface. The free surface then deforms to a contour which is different from the path. Next, the contour is measured to determine how much deformation has occurred across the new free surface. Points defining the contour are collected in an empirical data set. The portion of the object is then modeled in a computer simulator. The points in the empirical data set are entered into the computer simulator. The computer simulator then calculates the residual stress along the path which caused the points within the object to move to the positions measured in the empirical data set. The calculated residual stress is then presented in a useful format to an analyst.

Yawed-Rolling Tire Mechanical Properties Testing of the Navy T-45 Aircraft Tires

NASA Technical Reports Server (NTRS)

Daugherty, Robert H.

2000-01-01

The T-45 Goshawk is a United States Navy Jet aircraft used primarily as a trainer. The aircraft design makes use of "off the shelf" hardware as much as possible and was found to have unusual directional control issues during around operations. The aircraft was involved in numerous pilot-induced-oscillation incidents as well as observed to have unusual directional control reactions to failed main gear tires, a condition that is normally handled relatively easily by conventional aircraft steering control techniques. The behavior of the aircraft's tires had previously been modeled in simulators as a result of approximations provided in 40-year-old reference publications. Since knowledge of the true tire cornering and braking behavior is essential to modeling, understanding, and fixing directional control problems, the United States Navy requested assistance from the NASA Langley Research Center's (LARC) Aircraft Landing Dynamics Facility (ALDF) to define the yawed-rolling mechanical properties of the T-45 aircraft tires. The purpose of this report is to document the results of testing the subject tires at the NASA LaRC ALDF in September 1998. Brief descriptions of the Instrumented Tire Test Vehicle (ITTV) are included to familiarize the reader with the ITTV capabilities, data acquisition system, test and measurement techniques, data accuracy, and analysis and presentation of the testing results.

Mechanical energy fluctuations in granular chains: the possibility of rogue fluctuations or waves.

PubMed

Han, Ding; Westley, Matthew; Sen, Surajit

2014-09-01

The existence of rogue or freak waves in the ocean has been known for some time. They have been reported in the context of optical lattices and the financial market. We ask whether such waves are generic to late time behavior in nonlinear systems. In that vein, we examine the dynamics of an alignment of spherical elastic beads held within fixed, rigid walls at zero precompression when they are subjected to sufficiently rich initial conditions. Here we define such waves generically as unusually large energy fluctuations that sustain for short periods of time. Our simulations suggest that such unusually large fluctuations ("hot spots") and occasional series of such fluctuations through space and time ("rogue fluctuations") are likely to exist in the late time dynamics of the granular chain system at zero dissipation. We show that while hot spots are common in late time evolution, rogue fluctuations are seen in purely nonlinear systems (i.e., no precompression) at late enough times. We next show that the number of such fluctuations grows exponentially with increasing nonlinearity whereas rogue fluctuations decrease superexponentially with increasing precompression. Dissipation-free granular alignment systems may be possible to realize as integrated circuits and hence our observations may potentially be testable in the laboratory.

From first to second and back to first intermediate host: the unusual transmission route of Curtuteria australis (Digenea: Echinostomatidae).

PubMed

McFarland, L H; Mouritsen, K N; Poulin, Robert

2003-06-01

The trematode Curtuteria australis uses the whelk Cominella glandiformis as first intermediate host and the cockle Austrovenus stutchburyi as second intermediate host before maturing in shorebirds. The whelk also happen to be an important predator of cockles on intertidal mudflats. In this study we show that whelks can act as temporary paratenic hosts for the trematode. A single whelk feeding on 1 cockle can ingest large numbers of metacercariae, which remain within the whelk for 1-3 days before passing out in feces. The viability of these metacercariae assessed as the percentage capable of successfully excysting under conditions simulating those inside a bird's digestive tract, is lower after passage through a whelk (48%) than before (59%). Still, given that shorebird definitive hosts prey on whelks as well as cockles, survival inside the whelk allows C. australis to complete its life cycle: overall, though, whelk predation is likely to be an important sink for the trematode population. To our knowledge, this is the first report of a trematode using a snail as both first intermediate host and paratenic host, offering an alternative transmission route for the parasite as a result of the unusual trophic relationships of its hosts.

An Ada Object Oriented Missile Flight Simulation

DTIC Science & Technology

1991-09-01

identify by block number) This thesis uses the Ada programming language in the design and development of an air-to-air missile flight simulation with...object oriented techniques and sound software engineering principles. The simulation is designed to be more understandable, modifiable, efficient and...Department of Computer Science ii ABSTRACT This thesis uses the Ada programming language in the design and development of an air-to-air missile flight

Step 1: Human System Integration Simulation and Flight Test Progress Report

NASA Technical Reports Server (NTRS)

2005-01-01

The Access 5 Human Systems Integration Work Package produced simulation and flight demonstration planning products for use throughout the program. These included: Test Objectives for Command, Control, Communications; Pilot Questionnaire for Command, Control, Communications; Air Traffic Controller Questionnaire for Command, Control, Communications; Test Objectives for Collision Avoidance; Pilot Questionnaire for Collision Avoidance; Plans for Unmanned Aircraft Systems Control Station Simulations Flight Requirements for the Airspace Operations Demonstration

Objective Fidelity Evaluation in Multisensory Virtual Environments: Auditory Cue Fidelity in Flight Simulation

PubMed Central

Meyer, Georg F.; Wong, Li Ting; Timson, Emma; Perfect, Philip; White, Mark D.

2012-01-01

We argue that objective fidelity evaluation of virtual environments, such as flight simulation, should be human-performance-centred and task-specific rather than measure the match between simulation and physical reality. We show how principled experimental paradigms and behavioural models to quantify human performance in simulated environments that have emerged from research in multisensory perception provide a framework for the objective evaluation of the contribution of individual cues to human performance measures of fidelity. We present three examples in a flight simulation environment as a case study: Experiment 1: Detection and categorisation of auditory and kinematic motion cues; Experiment 2: Performance evaluation in a target-tracking task; Experiment 3: Transferrable learning of auditory motion cues. We show how the contribution of individual cues to human performance can be robustly evaluated for each task and that the contribution is highly task dependent. The same auditory cues that can be discriminated and are optimally integrated in experiment 1, do not contribute to target-tracking performance in an in-flight refuelling simulation without training, experiment 2. In experiment 3, however, we demonstrate that the auditory cue leads to significant, transferrable, performance improvements with training. We conclude that objective fidelity evaluation requires a task-specific analysis of the contribution of individual cues. PMID:22957068

48 CFR 50.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... unusually hazardous or nuclear risks. 50.104-3 Section 50.104-3 Federal Acquisition Regulations System... Extraordinary Contractual Actions 50.104-3 Special procedures for unusually hazardous or nuclear risks. (a... nuclear risks should be submitted to the contracting officer and shall include the following information...

48 CFR 50.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... unusually hazardous or nuclear risks. 50.104-3 Section 50.104-3 Federal Acquisition Regulations System... Extraordinary Contractual Actions 50.104-3 Special procedures for unusually hazardous or nuclear risks. (a... nuclear risks should be submitted to the contracting officer and shall include the following information...

48 CFR 50.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... unusually hazardous or nuclear risks. 50.104-3 Section 50.104-3 Federal Acquisition Regulations System... Extraordinary Contractual Actions 50.104-3 Special procedures for unusually hazardous or nuclear risks. (a... nuclear risks should be submitted to the contracting officer and shall include the following information...

48 CFR 50.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... unusually hazardous or nuclear risks. 50.104-3 Section 50.104-3 Federal Acquisition Regulations System... Extraordinary Contractual Actions 50.104-3 Special procedures for unusually hazardous or nuclear risks. (a... nuclear risks should be submitted to the contracting officer and shall include the following information...

Response of the Pre-Oriented Goal-Directed Attention to Usual and Unusual Distractors: A Preliminary Study

PubMed Central

Baghdadi, Golnaz; Towhidkhah, Farzad; Rostami, Reza; Raza, Mohsen

2017-01-01

Introduction: In this study, we investigated the distraction power of the unusual and usual images on the attention of 20 healthy primary school children. Methods: Our study was different from previous ones in that the participants were asked to fix the initial position of their attention on a predefined location after being presented with unusual images as distractors. The goals were presented in locations, which were far from the attraction basin of distractors. We expected that the pre-orienting of the attention to the position of targets would reduce the attractive effect of unusual images compared to the usual ones. The percentage of correct responses and the reaction time were measured as behavioral indicators of attention performance. Results: Results showed that using the goal-directed attention, subjects ignored both kinds of distractors nearly the same way. Conclusion: With regard to previous reports about more attraction towards the unusual images, it is suggested that the dynamics of the visual attention system be sensitive to the initial condition. That is, changing the initial position of the attention can lead to the decrement of the unusual images effects. However, several other possibilities such as a probable delay in processing unusual features could explain this observation, too. PMID:28540000

Vision-based overlay of a virtual object into real scene for designing room interior

NASA Astrophysics Data System (ADS)

Harasaki, Shunsuke; Saito, Hideo

2001-10-01

In this paper, we introduce a geometric registration method for augmented reality (AR) and an application system, interior simulator, in which a virtual (CG) object can be overlaid into a real world space. Interior simulator is developed as an example of an AR application of the proposed method. Using interior simulator, users can visually simulate the location of virtual furniture and articles in the living room so that they can easily design the living room interior without placing real furniture and articles, by viewing from many different locations and orientations in real-time. In our system, two base images of a real world space are captured from two different views for defining a projective coordinate of object 3D space. Then each projective view of a virtual object in the base images are registered interactively. After such coordinate determination, an image sequence of a real world space is captured by hand-held camera with tracking non-metric measured feature points for overlaying a virtual object. Virtual objects can be overlaid onto the image sequence by taking each relationship between the images. With the proposed system, 3D position tracking device, such as magnetic trackers, are not required for the overlay of virtual objects. Experimental results demonstrate that 3D virtual furniture can be overlaid into an image sequence of the scene of a living room nearly at video rate (20 frames per second).

Method and system for fault accommodation of machines

NASA Technical Reports Server (NTRS)

Goebel, Kai Frank (Inventor); Subbu, Rajesh Venkat (Inventor); Rausch, Randal Thomas (Inventor); Frederick, Dean Kimball (Inventor)

2011-01-01

A method for multi-objective fault accommodation using predictive modeling is disclosed. The method includes using a simulated machine that simulates a faulted actual machine, and using a simulated controller that simulates an actual controller. A multi-objective optimization process is performed, based on specified control settings for the simulated controller and specified operational scenarios for the simulated machine controlled by the simulated controller, to generate a Pareto frontier-based solution space relating performance of the simulated machine to settings of the simulated controller, including adjustment to the operational scenarios to represent a fault condition of the simulated machine. Control settings of the actual controller are adjusted, represented by the simulated controller, for controlling the actual machine, represented by the simulated machine, in response to a fault condition of the actual machine, based on the Pareto frontier-based solution space, to maximize desirable operational conditions and minimize undesirable operational conditions while operating the actual machine in a region of the solution space defined by the Pareto frontier.

Jet-like features near the Nucleus of Chiron

NASA Technical Reports Server (NTRS)

Elliot, J. L.; Olkin, C. B.; Dunham, E. W.; Ford, C. H.; Gilmore, D. K.; Kurtz, D.; Lazzaro, D.; Rank, D. M.; Temi, P.; Bandyopadhyay, R. M.;

Time-Resolved Near-Infrared Photometry of Extreme Kuiper Belt Object Haumea

NASA Astrophysics Data System (ADS)

Lacerda, Pedro

2009-02-01

We present time-resolved near-infrared (J and H) photometry of the extreme Kuiper belt object (136108) Haumea (formerly 2003 EL61) taken to further investigate rotational variability of this object. The new data show that the near-infrared peak-to-peak photometric range is similar to the value at visible wavelengths, ΔmR = 0.30 ± 0.02 mag. Detailed analysis of the new and previous data reveals subtle visible/near-infrared color variations across the surface of Haumea. The color variations are spatially correlated with a previously identified surface region, redder in B - R and darker than the mean surface. Our photometry indicates that the J - H colors of Haumea (J - H = -0.057 ± 0.016 mag) and its brightest satellite Hi'iaka (J - H = -0.399 ± 0.034 mag) are significantly (greater than 9σ) different. The satellite Hi'iaka is unusually blue in J - H, consistent with strong 1.5 μm water-ice absorption. The phase coefficient of Haumea is found to increase monotonically with wavelength in the range 0.4 < λ < 1.3. We compare our findings with other solar system objects and discuss implications regarding the surface of Haumea.

Application of Microsoft's ActiveX and DirectX technologies to the visulization of physical system dynamics

NASA Astrophysics Data System (ADS)

Mann, Christopher; Narasimhamurthi, Natarajan

1998-08-01

This paper discusses a specific implementation of a web and complement based simulation systems. The overall simulation container is implemented within a web page viewed with Microsoft's Internet Explorer 4.0 web browser. Microsoft's ActiveX/Distributed Component Object Model object interfaces are used in conjunction with the Microsoft DirectX graphics APIs to provide visualization functionality for the simulation. The MathWorks' Matlab computer aided control system design program is used as an ActiveX automation server to provide the compute engine for the simulations.

Development of a Dynamically Configurable,Object-Oriented Framework for Distributed, Multi-modal Computational Aerospace Systems Simulation

NASA Technical Reports Server (NTRS)

Afjeh, Abdollah A.; Reed, John A.

2003-01-01

This research is aimed at developing a neiv and advanced simulation framework that will significantly improve the overall efficiency of aerospace systems design and development. This objective will be accomplished through an innovative integration of object-oriented and Web-based technologies ivith both new and proven simulation methodologies. The basic approach involves Ihree major areas of research: Aerospace system and component representation using a hierarchical object-oriented component model which enables the use of multimodels and enforces component interoperability. Collaborative software environment that streamlines the process of developing, sharing and integrating aerospace design and analysis models. . Development of a distributed infrastructure which enables Web-based exchange of models to simplify the collaborative design process, and to support computationally intensive aerospace design and analysis processes. Research for the first year dealt with the design of the basic architecture and supporting infrastructure, an initial implementation of that design, and a demonstration of its application to an example aircraft engine system simulation.

Validity evidence for the Simulated Colonoscopy Objective Performance Evaluation scoring system.

PubMed

Trinca, Kristen D; Cox, Tiffany C; Pearl, Jonathan P; Ritter, E Matthew

2014-02-01

Low-cost, objective systems to assess and train endoscopy skills are needed. The aim of this study was to evaluate the ability of Simulated Colonoscopy Objective Performance Evaluation to assess the skills required to perform endoscopy. Thirty-eight subjects were included in this study, all of whom performed 4 tasks. The scoring system measured performance by calculating precision and efficiency. Data analysis assessed the relationship between colonoscopy experience and performance on each task and the overall score. Endoscopic trainees' Simulated Colonoscopy Objective Performance Evaluation scores correlated significantly with total colonoscopy experience (r = .61, P = .003) and experience in the past 12 months (r = .63, P = .002). Significant differences were seen among practicing endoscopists, nonendoscopic surgeons, and trainees (P < .0001). When the 4 tasks were analyzed, each showed significant correlation with colonoscopy experience (scope manipulation, r = .44, P = .044; tool targeting, r = .45, P = .04; loop management, r = .47, P = .032; mucosal inspection, r = .65, P = .001) and significant differences in performance between the endoscopist groups, except for mucosal inspection (scope manipulation, P < .0001; tool targeting, P = .002; loop management, P = .0008; mucosal inspection, P = .27). Simulated Colonoscopy Objective Performance Evaluation objectively assesses the technical skills required to perform endoscopy and shows promise as a platform for proficiency-based skills training. Published by Elsevier Inc.

Improving the accuracy of the diagnosis of schizophrenia by means of virtual reality.

PubMed

Sorkin, Anna; Weinshall, Daphna; Modai, Ilan; Peled, Avi

2006-03-01

The authors' goal was to improve the diagnosis of schizophrenia by using virtual reality technology to build a complex, multimodal environment in which cognitive functions can be studied (and measured) in parallel. The authors studied sensory integration within working memory by means of computer navigation through a virtual maze. The simulated journey consisted of a series of rooms, each of which included three doors. Each door was characterized by three features (color, shape, and sound), and a single combination of features--the door-opening rule--was correct. Subjects had to learn the rule and use it. The participants were 39 schizophrenic patients and 21 healthy comparison subjects. Upon completion, each subject was assigned a performance profile, including various error scores, response time, navigation ability, and strategy. A classification procedure based on the subjects' performance profile correctly predicted 85% of the schizophrenic patients (and all of the comparison subjects). Several performance variables showed significant correlations with scores on a standard diagnostic measure (Positive and Negative Syndrome Scale), suggesting potential use of these measurements for the diagnosis of schizophrenia. On the other hand, the patients did not show unusual repetition of response despite stimulus cessation (called "perseveration" in classical studies of schizophrenia), which is a common symptom of the disease. This deficit appeared only when the subjects did not receive proper explanation of the task. The ability to study multimodal performance simultaneously by using virtual reality technology opens new possibilities for the diagnosis of schizophrenia with objective procedures.

Non-Dependent and Dependent Daily Cannabis Users Differ in Mental Health but Not Prospective Memory Ability

PubMed Central

Braidwood, Ruth; Mansell, Samantha; Waldron, Jon; Rendell, Peter G.; Kamboj, Sunjeev K.; Curran, H. Valerie

2018-01-01

Research suggests that daily cannabis users have impaired memory for past events, but it is not clear whether they are also impaired in prospective memory (PM) for future events. The present study examined PM in daily cannabis users who were either dependent (n = 18) or non-dependent (n = 18), and compared them with non-using controls (n = 18). The effect of future event simulation (FES) on PM performance was also examined. Participants were matched across groups on age, gender, and highest level of education. The virtual week (VW) was used to objectively assess PM abilities, both at baseline and following FES. Other measures used were: cannabis use variables, immediate and delayed prose recall, phonemic and category fluency, spot-the-word test (premorbid intelligence), Beck Depression Inventory, Beck Anxiety Inventory, and a measure of schizotypy (Oxford-Liverpool Inventory of Feelings and Experiences: unusual experiences subscale). No group differences were found in PM performance on the VW, and FES did not improve PM performance in any group. Dependent cannabis users scored higher on depression, anxiety, and schizotypy than both other groups with non-dependent cannabis users scoring at a similar level to controls. There were no group differences in alcohol use. Findings suggest that when carefully matched on baseline variables, and not differing in premorbid IQ or alcohol use, young, near-daily cannabis users do not differ from non-using controls in PM performance. PMID:29636705

The ROSAT Deep Survey. 2; Optical Identification, Photometry and Spectra of X-Ray Sources in the Lockman Field

NASA Technical Reports Server (NTRS)

Schmidt, M.; Hasinger, G.; Gunn, J.; Schneider, D.; Burg, R.; Giacconi, R.; Lehmann, I.; MacKenty, J.; Truemper, J.; Zamorani, G.

1998-01-01

The ROSAT Deep Survey includes a complete sample of 50 X-ray sources with fluxes in the 0.5 - 2 keV band larger than 5.5 x 10(exp -15)erg/sq cm/s in the Lockman field (Hasinger et al., Paper 1). We have obtained deep broad-band CCD images of the field and spectra of many optical objects near the positions of the X-ray sources. We define systematically the process leading to the optical identifications of the X-ray sources. For this purpose, we introduce five identification (ID) classes that characterize the process in each case. Among the 50 X-ray sources, we identify 39 AGNs, 3 groups of galaxies, 1 galaxy and 3 galactic stars. Four X-ray sources remain unidentified so far; two of these objects may have an unusually large ratio of X-ray to optical flux.

A search for cataclysmic binaries containing strongly magnetic white dwarfs

NASA Technical Reports Server (NTRS)

Bond, H. E.; Chanmugam, G.

1982-01-01

The AM Herculis type binaries which contain accreting white dwarfs with surface magnetic fields of a few times 10 to the seventh power gauss were studied. If white dwarfs in cataclysmic binaries have a range of field strengths similar to that among single white dwarfs. AM Her like systems should exist with fields as high as 3 x 10 to the eighth power gauss. It is suggested that such objects will not have the strong optical polarization of the AM Her variables; however, they exhibit high harmonic cyclotron emission, making them spectacular UV sources. We made IUE observations of seven candidate cataclysmic variables selected for optical similarity to AM Her binaries. Although all seven objects were detected in the UV, none display unusually strong UV continua. It is suggested that the distribution of magnetic field strengths among single white dwarfs may be different from that among binaries.

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

McGreer, Ian D.; Fan Xiaohui; Bian Fuyan

We report the discovery of a gravitationally lensed quasar identified serendipitously in the Sloan Digital Sky Survey (SDSS). The object, SDSS J094604.90+183541.8, was initially targeted for spectroscopy as a luminous red galaxy, but the SDSS spectrum has the features of both a z = 0.388 galaxy and a z = 4.8 quasar. We have obtained additional imaging that resolves the system into two quasar images separated by 3.''06 and a bright galaxy that is strongly blended with one of the quasar images. We confirm spectroscopically that the two quasar images represent a single-lensed source at z = 4.8 with amore » total magnification of 3.2, and we derive a model for the lensing galaxy. This is the highest redshift lensed quasar currently known. We examine the issues surrounding the selection of such an unusual object from existing data and briefly discuss implications for lensed quasar surveys.« less

Creativity and Memory: Effects of an Episodic Specificity Induction on Divergent Thinking

PubMed Central

Madore, Kevin P.; Addis, Donna Rose; Schacter, Daniel L.

2015-01-01

After receiving an episodic specificity induction - brief training in recollecting details of a recent event - people produce more episodic details when imagining future events and solving means-end problems than after receiving a control induction not focused on episodic retrieval. Here we show for the first time that an episodic specificity induction also enhances divergent creative thinking. In Experiment 1, participants exhibited a selective boost on a divergent thinking task that involves generating unusual uses of common objects after a specificity induction compared with a control induction; by contrast, performance was similar on an object association task thought to involve little divergent thinking. In Experiment 2, we replicated the specificity induction effect on divergent thinking using a different control induction, and also found that participants performed similarly on a convergent thinking task following both inductions. These experiments provide novel evidence that episodic memory is involved in divergent creative thinking. PMID:26205963

A high-redshift IRAS galaxy with huge luminosity - Hidden quasar or protogalaxy?

NASA Technical Reports Server (NTRS)

Rowan-Robinson, M.; Broadhurst, T.; Oliver, S. J.; Taylor, A. N.; Lawrence, A.; Mcmahon, R. G.; Lonsdale, C. J.; Hacking, P. B.; Conrow, T.

1991-01-01

An emission line galaxy with the enormous far-IR luminosity of 3 x 10 to the 14th solar has been found at z = 2.286. The spectrum is very unusual, showing lines of high excitation but with very weak Lyman-alpha emission. A self-absorbed synchrotron model for the IR energy distribution cannot be ruled out, but a thermal origin seems more plausible. A radio-quiet quasar embedded in a very dusty galaxy could account for the IR emission, as might a starburst embedded in 1-10 billion solar masses of dust. The latter case demands so much dust that the object would probably be a massive galaxy in the process of formation. The presence of a large amount of dust in an object of such high redshift implies the generation of heavy elements at an early cosmological epoch.

New Details about Interstellar Visitor on This Week @NASA – November 24, 2017

NASA Image and Video Library

2017-11-24

New data reveal that the interstellar asteroid that recently zipped through our solar system is rocky, cigar-shaped, and has a somewhat reddish hue. It’s the first confirmed object from another star observed in our solar system, and was discovered Oct. 19 by the University of Hawaii’s Pan-STARRS1 telescope team, funded by NASA’s Near-Earth Object Observations Program. The telescope team named it ‘Oumuamua (oh MOO-uh MOO-uh) – Hawaiian for “a messenger from afar arriving first.” The unusually-shaped asteroid, which is up to a quarter mile long and perhaps 10 times as long as it is wide, may provide new clues into how other solar systems formed. Also, Advanced Weather Satellite Launched, James Webb Space Telescope Completes Final Cryogenic Testing, Recurring Martian Streaks: Flowing Sand, Not Water? and Happy Thanksgiving, from Space!

Commentaries on “Informatics and Medicine: From Molecules to Populations”

PubMed Central

Altman, R. B.; Balling, R.; Brinkley, J. F.; Coiera, E.; Consorti, F.; Dhansay, M. A.; Geissbuhler, A.; Hersh, W.; Kwankam, S. Y.; Lorenzi, N. M.; Martin-Sanchez, F.; Mihalas, G. I.; Shahar, Y.; Takabayashi, K.; Wiederhold, G.

2009-01-01

Summary Objective To discuss interdisciplinary research and education in the context of informatics and medicine by commenting on the paper of Kuhn et al. “Informatics and Medicine: From Molecules to Populations”. Method Inviting an international group of experts in biomedical and health informatics and related disciplines to comment on this paper. Results and Conclusions The commentaries include a wide range of reasoned arguments and original position statements which, while strongly endorsing the educational needs identified by Kuhn et al., also point out fundamental challenges that are very specific to the unusual combination of scientific, technological, personal and social problems characterizing biomedical informatics. They point to the ultimate objectives of managing difficult human health problems, which are unlikely to yield to technological solutions alone. The psychological, societal, and environmental components of health and disease are emphasized by several of the commentators, setting the stage for further debate and constructive suggestions. PMID:18690363

Detailed Test Objectives (DTOs) and Detailed Supplementary Objectives (DSOs)

NASA Technical Reports Server (NTRS)

2002-01-01

The purpose of this experiment is to demonstrate the performance and operations of the GPS during orbiter ascent, entry and landing phases utilizing a modified military GPS receiver processor and the existing orbiter GPS antennas. The purpose of this experiment is to demonstrate the capability to perform a manually controlled landing in the presence of a crosswind. Changes in gastrointestinal function and physiology as a result of spaceflight affect drug absorption and the bioavailability of oral medications, which can compromise therapeutic effectiveness. This DSO will lead to the design and development of effective pharmocological countermeasures and therapeutic adjustments for spaceflight. A previous observation suggested that discordant sensory stimuli caused by an unusual motion environment disrupted spatial orientation and balance control in a returning crewmember by triggering a state change in central vestibular processing. The findings of the current investigation are expected to demonstrate the degree to which challenging motion environments may affect post-flight (re)adaptation to gravity.

Penetrating skull fracture by a wooden object: Management dilemmas and literature review

PubMed Central

Arifin, Muhammad Zafrullah; Gill, Arwinder Singh; Faried, Ahmad

2012-01-01

Most penetrating skull injuries are caused by gun shot wounds or missiles. The compound depressed skull fracture represents an acute neurosurgical emergency. Management and diagnosis of such cases have been described, but its occurence following a fall onto a piece of wood is quite unusual. A 75-year-old female fell onto a piece of wood that penetrated her skull on the left frontal region and was treated in our department. The patient had no neurological deficits during presentation. She was managed surgically and removal of the wooden object was performed to prevent early or late infection complications. Wooden foreign bodies often pose a different set of challenges as far as penetrating injuries to the brain are concerned. Radiological difficulties and increased rates of infection due to its porous nature make these types of injuries particularly interesting. Their early diagnosis and appropriate treatment can minimize the risk of complications. PMID:23293668

Negotiation of intracellular membrane barriers by TAT-modified gold nanoparticles.

PubMed

Krpetić, Zeljka; Saleemi, Samia; Prior, Ian A; Sée, Violaine; Qureshi, Rumana; Brust, Mathias

2011-06-28

This paper contributes to the debate on how nanosized objects negotiate membrane barriers inside biological cells. The uptake of peptide-modified gold nanoparticles by HeLa cells has been quantified using atomic emission spectroscopy. The TAT peptide from the HIV virus was singled out as a particularly effective promoter of cellular uptake. The evolution of the intracellular distribution of TAT-modified gold nanoparticles with time has been studied in detail by TEM and systematic image analysis. An unusual trend of particles disappearing from the cytosol and the nucleus and accumulating massively in vesicular bodies was observed. Subsequent release of the particles, both by membrane rupture and by direct transfer across the membrane boundary, was frequently found. Ultimately, near total clearing of particles from the cells occurred. This work provides support for the hypothesis that cell-penetrating peptides can enable small objects to negotiate membrane barriers also in the absence of dedicated transport mechanisms.

Electrochemically induced actuation of liquid metal marbles

NASA Astrophysics Data System (ADS)

Tang, Shi-Yang; Sivan, Vijay; Khoshmanesh, Khashayar; O'Mullane, Anthony P.; Tang, Xinke; Gol, Berrak; Eshtiaghi, Nicky; Lieder, Felix; Petersen, Phred; Mitchell, Arnan; Kalantar-Zadeh, Kourosh

2013-06-01

Controlled actuation of soft objects with functional surfaces in aqueous environments presents opportunities for liquid phase electronics, novel assembled super-structures and unusual mechanical properties. We show the extraordinary electrochemically induced actuation of liquid metal droplets coated with nanoparticles, so-called ``liquid metal marbles''. We demonstrate that nanoparticle coatings of these marbles offer an extra dimension for affecting the bipolar electrochemically induced actuation. The nanoparticles can readily migrate along the surface of liquid metals, upon the application of electric fields, altering the capacitive behaviour and surface tension in a highly asymmetric fashion. Surprising actuation behaviours are observed illustrating that nanoparticle coatings can have a strong effect on the movement of these marbles. This significant novel phenomenon, combined with unique properties of liquid metal marbles, represents an exciting platform for enabling diverse applications that cannot be achieved using rigid metal beads.Controlled actuation of soft objects with functional surfaces in aqueous environments presents opportunities for liquid phase electronics, novel assembled super-structures and unusual mechanical properties. We show the extraordinary electrochemically induced actuation of liquid metal droplets coated with nanoparticles, so-called ``liquid metal marbles''. We demonstrate that nanoparticle coatings of these marbles offer an extra dimension for affecting the bipolar electrochemically induced actuation. The nanoparticles can readily migrate along the surface of liquid metals, upon the application of electric fields, altering the capacitive behaviour and surface tension in a highly asymmetric fashion. Surprising actuation behaviours are observed illustrating that nanoparticle coatings can have a strong effect on the movement of these marbles. This significant novel phenomenon, combined with unique properties of liquid metal marbles, represents an exciting platform for enabling diverse applications that cannot be achieved using rigid metal beads. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr00185g

Adverse Reactions to Zolpidem: Case Reports and a Review of the Literature

PubMed Central

Miyaoka, Tsuyoshi; Tsuji, Seiichi; Inami, Yasushi; Nishida, Akira; Horiguchi, Jun

2010-01-01

Objective: Zolpidem, a nonbenzodiazepine hypnotic, is very effective and widely prescribed in clinical practice for the treatment of insomnia and is thought to have few adverse effects. However, zolpidem-induced adverse effects have begun to be reported in the literature, but few systemic descriptions of the adverse effects (especially for psychotic reactions) of zolpidem have been undertaken. In light of the accumulating reports of adverse reactions to zolpidem, we present 2 case reports of zolpidem-induced adverse effects and review the literature on this subject. Data Sources: Articles were selected by the authors on the basis of our experience and by a PubMed search using the terms zolpidem or side effects or adverse effects or adverse reactions. Study Selection and Data Extraction: Publications relevant to the objective of this article were obtained (1992–2010), and some adverse neuropsychiatric reactions were summarized. Data Synthesis: Zolpidem has been associated with the development of adverse neuropsychiatric reactions, such as hallucinations/sensory distortion, amnesia, sleepwalking/somnambulism, and nocturnal eating. The following 4 variables should be considered when prescribing zolpidem: (1) gender: women have been found to have a significantly higher serum zolpidem concentration than men; (2) zolpidem dose: the adverse reactions that develop are dose dependent; (3) protein binding affinity: a high proportion of zolpidem is protein bound; therefore, low serum albumin results in a higher level of free zolpidem leading to adverse psychiatric reactions; and (4) cytochrome P450 (CYP) isoenzyme inhibition: concomitant administration of zolpidem and other drugs may cause interactions that lead to increased concentrations of zolpidem. Conclusions: Zolpidem is clinically very effective in treating insomnia. However, while rare, zolpidem-induced unusual complex behavior may develop. Primary care physicians should be alert to the possible unusual complex adverse effects of zolpidem. PMID:21494350

A Search for X-Ray Evidence of a Compact Companion to the Unusual Wolf-Rayet Star HD 50896 (EZ CMa)

NASA Technical Reports Server (NTRS)

Skinner, Stephen L.; Itoh, Masayuki; Nagase, Fumiaki

1998-01-01

We analyze results of a approx.25 ksec ASCA X-ray observation of the unusual Wolf-Rayet star HD 50896 (= EZ CMa). This WN5 star shows optical and ultraviolet variability at a 3.766 day period, which has been interpreted as a possible signature of a compact companion. Our objective was to search for evidence of hard X-rays (greater than or equal to 5 keV) which could be present if the WN5 wind is accreting onto a compact object. The ASCA spectra are dominated by emission below 5 keV and show no significant emission in the harder 5-10 keV range. Weak emission lines are present, and the X-rays arise in an optically thin plasma which spans a range of temperatures from less than or equal to 0.4 keV up to at least approx. 2 keV. Excess X-ray absorption above the interstellar value is present, but the column density is no larger than N(sub H) approx. 10(exp 22)/sq cm. The absorption-corrected X-ray luminosity L(sub x)(0.5 - 10 keV) = 10(exp 32.85) erg/s gives L(sub x)/ L(sub bol) approx. 10(exp -6), a value that is typical of WN stars. No X-ray variability was detected. Our main conclusion is that the X-ray properties of HD 50896 are inconsistent with the behavior expected for wind accretion onto a neutron star or black hole companion. Alternative models based on wind shocks can explain most aspects of the X-ray behavior, and we argue that the hotter plasma near approx. 2 keV could be due to the WR wind shocking onto a normal (nondegenerate) companion.

Modeling motor vehicle crashes using Poisson-gamma models: examining the effects of low sample mean values and small sample size on the estimation of the fixed dispersion parameter.

PubMed

Lord, Dominique

2006-07-01

There has been considerable research conducted on the development of statistical models for predicting crashes on highway facilities. Despite numerous advancements made for improving the estimation tools of statistical models, the most common probabilistic structure used for modeling motor vehicle crashes remains the traditional Poisson and Poisson-gamma (or Negative Binomial) distribution; when crash data exhibit over-dispersion, the Poisson-gamma model is usually the model of choice most favored by transportation safety modelers. Crash data collected for safety studies often have the unusual attributes of being characterized by low sample mean values. Studies have shown that the goodness-of-fit of statistical models produced from such datasets can be significantly affected. This issue has been defined as the "low mean problem" (LMP). Despite recent developments on methods to circumvent the LMP and test the goodness-of-fit of models developed using such datasets, no work has so far examined how the LMP affects the fixed dispersion parameter of Poisson-gamma models used for modeling motor vehicle crashes. The dispersion parameter plays an important role in many types of safety studies and should, therefore, be reliably estimated. The primary objective of this research project was to verify whether the LMP affects the estimation of the dispersion parameter and, if it is, to determine the magnitude of the problem. The secondary objective consisted of determining the effects of an unreliably estimated dispersion parameter on common analyses performed in highway safety studies. To accomplish the objectives of the study, a series of Poisson-gamma distributions were simulated using different values describing the mean, the dispersion parameter, and the sample size. Three estimators commonly used by transportation safety modelers for estimating the dispersion parameter of Poisson-gamma models were evaluated: the method of moments, the weighted regression, and the maximum likelihood method. In an attempt to complement the outcome of the simulation study, Poisson-gamma models were fitted to crash data collected in Toronto, Ont. characterized by a low sample mean and small sample size. The study shows that a low sample mean combined with a small sample size can seriously affect the estimation of the dispersion parameter, no matter which estimator is used within the estimation process. The probability the dispersion parameter becomes unreliably estimated increases significantly as the sample mean and sample size decrease. Consequently, the results show that an unreliably estimated dispersion parameter can significantly undermine empirical Bayes (EB) estimates as well as the estimation of confidence intervals for the gamma mean and predicted response. The paper ends with recommendations about minimizing the likelihood of producing Poisson-gamma models with an unreliable dispersion parameter for modeling motor vehicle crashes.

Dynamic extension of the Simulation Problem Analysis Kernel (SPANK)

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

Sowell, E.F.; Buhl, W.F.

1988-07-15

The Simulation Problem Analysis Kernel (SPANK) is an object-oriented simulation environment for general simulation purposes. Among its unique features is use of the directed graph as the primary data structure, rather than the matrix. This allows straightforward use of graph algorithms for matching variables and equations, and reducing the problem graph for efficient numerical solution. The original prototype implementation demonstrated the principles for systems of algebraic equations, allowing simulation of steady-state, nonlinear systems (Sowell 1986). This paper describes how the same principles can be extended to include dynamic objects, allowing simulation of general dynamic systems. The theory is developed andmore » an implementation is described. An example is taken from the field of building energy system simulation. 2 refs., 9 figs.« less

Object-oriented code SUR for plasma kinetic simulation

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

Levchenko, V.D.; Sigov, Y.S.

1995-12-31

We have developed a self-consistent simulation code based on object-oriented model of plasma (OOMP) for solving the Vlasov/Poisson (V/P), Vlasov/Maxwell (V/M), Bhatnagar-Gross-Krook (BGK) as well as Fokker-Planck (FP) kinetic equations. The application of an object-oriented approach (OOA) to simulation of plasmas and plasma-like media by means of splitting methods permits to uniformly describe and solve the wide circle of plasma kinetics problems, including those being very complicated: many-dimensional, relativistic, with regard for collisions, specific boundary conditions etc. This paper gives the brief description of possibilities of the SUR code, as a concrete realization of OOMP.

FRAGMENTATION AND EVOLUTION OF MOLECULAR CLOUDS. II. THE EFFECT OF DUST HEATING

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

Urban, Andrea; Evans, Neal J.; Martel, Hugo

2010-02-20

We investigate the effect of heating by luminosity sources in a simulation of clustered star formation. Our heating method involves a simplified continuum radiative transfer method that calculates the dust temperature. The gas temperature is set by the dust temperature. We present the results of four simulations; two simulations assume an isothermal equation of state and the two other simulations include dust heating. We investigate two mass regimes, i.e., 84 M{sub sun} and 671 M{sub sun}, using these two different energetics algorithms. The mass functions for the isothermal simulations and simulations that include dust heating are drastically different. In themore » isothermal simulation, we do not form any objects with masses above 1 M{sub sun}. However, the simulation with dust heating, while missing some of the low-mass objects, forms high-mass objects ({approx}20 M{sub sun}) which have a distribution similar to the Salpeter initial mass function. The envelope density profiles around the stars formed in our simulation match observed values around isolated, low-mass star-forming cores. We find the accretion rates to be highly variable and, on average, increasing with final stellar mass. By including radiative feedback from stars in a cluster-scale simulation, we have determined that it is a very important effect which drastically affects the mass function and yields important insights into the formation of massive stars.« less

Ground water in Dale Valley, New York

USGS Publications Warehouse

Randall, Allan D.

1979-01-01

Dale Valley is a broad valley segment, enlarged by glacial erosion, at the headwaters of Little Tonawanda Creek near Warsaw , New York. A thin, shallow alluvial aquifer immediately underlies the valley floor but is little used. A deeper gravel aquifer, buried beneath many feet of lake deposits, is tapped by several industrial wells. A finite-difference digital model treated the deep aquifer as two-dimensional with recharge and discharge through a confining layer. It was calibrated by simulating (1) natural conditions, (2) an 18-day aquifer test, and (3) 91 days of well-field operation. Streamflow records and model simulations suggest that in moderately wet years such as 1974, a demand of 750 gallons per minute could be met by withdrawal from the creek and from the aquifer without excessive drawdown at production wells or existing domestic wells. With reasonable but unverified model adjustments to simulate an unusually dry year, the model predicts that a demand of 600 gallons per minute could be met from the same sources. Water high in chloride has migrated from bedrock into parts of the deep aquifer. Industrial pumpage, faults in the bedrock, and the natural flow system may be responsible. (Woodard-USGS)

Steady-state shear flows via nonequilibrium molecular dynamics and smooth-particle applied mechanics

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

Posch, H.A.; Hoover, W.G.; Kum, O.

1995-08-01

We simulate both microscopic and macroscopic shear flows in two space dimensions using nonequilibrium molecular dynamics and smooth-particle applied mechanics. The time-reversible {ital microscopic} equations of motion are isomorphic to the smooth-particle description of inviscid {ital macroscopic} continuum mechanics. The corresponding microscopic particle interactions are relatively weak and long ranged. Though conventional Green-Kubo theory suggests instability or divergence in two-dimensional flows, we successfully define and measure a finite shear viscosity coefficient by simulating stationary plane Couette flow. The special nature of the weak long-ranged smooth-particle functions corresponds to an unusual kind of microscopic transport. This microscopic analog is mainly kinetic,more » even at high density. For the soft Lucy potential which we use in the present work, nearly all the system energy is potential, but the resulting shear viscosity is nearly all kinetic. We show that the measured shear viscosities can be understood, in terms of a simple weak-scattering model, and that this understanding is useful in assessing the usefulness of continuum simulations using the smooth-particle method. We apply that method to the Rayleigh-Benard problem of thermally driven convection in a gravitational field.« less

Invasion-Flowback Processes During Hydraulic Fracturing Well Interference

NASA Astrophysics Data System (ADS)

Kenzhekhanov, Shaken; He, Kai; Xu, Liang; Lord, Paul; Lozano, Martin; Neeves, Keith; Yin, Xiaolong

2017-11-01

Drainage-imbibition cycles that simulate hydraulic fracturing fluid's invasion and flowback during well interference were investigated using NOA81 microfluidic micromodels. Well interference is quite common in unconventional oil and gas fields. It is not unusual for the fracturing fluid injected into a well to be discovered in a nearby well. Normally, the effect of such interference is considered to be negative, as fracturing fluid will be imbibed into the porous rock and block the flow path of hydrocarbons. However, field data show that some interferences are beneficial, and microfluidic experiments presented in this study show that surfactant in the fracturing fluid may be a reason for the observed positive interference. Two fluid drainage-imbibition cycles were conducted in micromodels. The first cycle simulates fracturing of the old well and the second cycle simulates fluid invasion from the new well into the old well's fracture network. The experimental data show that while most such interferences indeed can cause production loss, when the old well's fracturing fluid does not contain surfactant yet the new well's fracturing fluid does, interference can be positive, as the residual water saturation in the porous medium is effectively reduced by surfactants.

Computational chemistry

NASA Technical Reports Server (NTRS)

Arnold, J. O.

1987-01-01

With the advent of supercomputers, modern computational chemistry algorithms and codes, a powerful tool was created to help fill NASA's continuing need for information on the properties of matter in hostile or unusual environments. Computational resources provided under the National Aerodynamics Simulator (NAS) program were a cornerstone for recent advancements in this field. Properties of gases, materials, and their interactions can be determined from solutions of the governing equations. In the case of gases, for example, radiative transition probabilites per particle, bond-dissociation energies, and rates of simple chemical reactions can be determined computationally as reliably as from experiment. The data are proving to be quite valuable in providing inputs to real-gas flow simulation codes used to compute aerothermodynamic loads on NASA's aeroassist orbital transfer vehicles and a host of problems related to the National Aerospace Plane Program. Although more approximate, similar solutions can be obtained for ensembles of atoms simulating small particles of materials with and without the presence of gases. Computational chemistry has application in studying catalysis, properties of polymers, all of interest to various NASA missions, including those previously mentioned. In addition to discussing these applications of computational chemistry within NASA, the governing equations and the need for supercomputers for their solution is outlined.

Characterizing hydrophobicity at the nanoscale: a molecular dynamics simulation study.

PubMed

Bandyopadhyay, Dibyendu; Choudhury, Niharendu

2012-06-14

We use molecular dynamics (MD) simulations of water near nanoscopic surfaces to characterize hydrophobic solute-water interfaces. By using nanoscopic paraffin like plates as model solutes, MD simulations in isothermal-isobaric ensemble have been employed to identify characteristic features of such an interface. Enhanced water correlation, density fluctuations, and position dependent compressibility apart from surface specific hydrogen bond distribution and molecular orientations have been identified as characteristic features of such interfaces. Tetrahedral order parameter that quantifies the degree of tetrahedrality in the water structure and an orientational order parameter, which quantifies the orientational preferences of the second solvation shell water around a central water molecule, have also been calculated as a function of distance from the plate surface. In the vicinity of the surface these two order parameters too show considerable sensitivity to the surface hydrophobicity. The potential of mean force (PMF) between water and the surface as a function of the distance from the surface has also been analyzed in terms of direct interaction and induced contribution, which shows unusual effect of plate hydrophobicity on the solvent induced PMF. In order to investigate hydrophobic nature of these plates, we have also investigated interplate dewetting when two such plates are immersed in water.

Structure and osmotic pressure of ionic microgel dispersions

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

Hedrick, Mary M.; Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050; Chung, Jun Kyung

We investigate structural and thermodynamic properties of aqueous dispersions of ionic microgels—soft colloidal gel particles that exhibit unusual phase behavior. Starting from a coarse-grained model of microgel macroions as charged spheres that are permeable to microions, we perform simulations and theoretical calculations using two complementary implementations of Poisson-Boltzmann (PB) theory. Within a one-component model, based on a linear-screening approximation for effective electrostatic pair interactions, we perform molecular dynamics simulations to compute macroion-macroion radial distribution functions, static structure factors, and macroion contributions to the osmotic pressure. For the same model, using a variational approximation for the free energy, we compute bothmore » macroion and microion contributions to the osmotic pressure. Within a spherical cell model, which neglects macroion correlations, we solve the nonlinear PB equation to compute microion distributions and osmotic pressures. By comparing the one-component and cell model implementations of PB theory, we demonstrate that the linear-screening approximation is valid for moderately charged microgels. By further comparing cell model predictions with simulation data for osmotic pressure, we chart the cell model’s limits in predicting osmotic pressures of salty dispersions.« less

A Simplified Ab Initio Cosmic-ray Modulation Model with Simulated Time Dependence and Predictive Capability

NASA Astrophysics Data System (ADS)

Moloto, K. D.; Engelbrecht, N. E.; Burger, R. A.

2018-06-01

A simplified ab initio approach is followed to model cosmic-ray proton modulation, using a steady-state three-dimensional stochastic solver of the Parker transport equation that simulates some effects of time dependence. Standard diffusion coefficients based on Quasilinear Theory and Nonlinear Guiding Center Theory are employed. The spatial and temporal dependences of the various turbulence quantities required as inputs for the diffusion, as well as the turbulence-reduced drift coefficients, follow from parametric fits to results from a turbulence transport model as well as from spacecraft observations of these turbulence quantities. Effective values are used for the solar wind speed, magnetic field magnitude, and tilt angle in the modulation model to simulate temporal effects due to changes in the large-scale heliospheric plasma. The unusually high cosmic-ray intensities observed during the 2009 solar minimum follow naturally from the current model for most of the energies considered. This demonstrates that changes in turbulence contribute significantly to the high intensities during that solar minimum. We also discuss and illustrate how this model can be used to predict future cosmic-ray intensities, and comment on the reliability of such predictions.

Cosmic reionization on computers. II. Reionization history and its back-reaction on early galaxies

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

Gnedin, Nickolay Y.; Kaurov, Alexander A., E-mail: gnedin@fnal.gov, E-mail: kaurov@uchicago.edu

We compare the results from several sets of cosmological simulations of cosmic reionization, produced under the Cosmic Reionization On Computers project, with existing observational data on the high-redshift Lyα forest and the abundance of Lyα emitters. We find good consistency with the observational measurements and previous simulation work. By virtue of having several independent realizations for each set of numerical parameters, we are able to explore the effect of cosmic variance on observable quantities. One unexpected conclusion we are forced into is that cosmic variance is unusually large at z > 6, with both our simulations and, most likely, observationalmore » measurements still not fully converged for even such basic quantities as the average Gunn-Peterson optical depth or the volume-weighted neutral fraction. We also find that reionization has little effect on the early galaxies or on global cosmic star formation history, because galaxies whose gas content is affected by photoionization contain no molecular (i.e., star-forming) gas in the first place. In particular, measurements of the faint end of the galaxy luminosity function by the James Webb Space Telescope are unlikely to provide a useful constraint on reionization.« less

Unusual Fears in Children with Autism

ERIC Educational Resources Information Center

Mayes, Susan Dickerson; Calhoun, Susan L.; Aggarwal, Richa; Baker, Courtney; Mathapati, Santosh; Molitoris, Sarah; Mayes, Rebecca D.

2013-01-01

Unusual fears have long been recognized as common in autism, but little research exists. In our sample of 1033 children with autism, unusual fears were reported by parents of 421 (41%) of the children, representing 92 different fears. Many additional children had common childhood fears (e.g., dogs, bugs, and the dark). More than half of children…

NOAA declares string of seal deaths in New England an unusual mortality

Science.gov Websites

Alerts NOAA Organizations Working With NOAA Media & Constituents NOAA In Your State Emergency string of seal deaths in New England an unusual mortality event Public reminded to maintain safe distance the Working Group on Marine Mammal Unusual Mortality Events, a panel of international experts

48 CFR 1450.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Special procedures for unusually hazardous or nuclear risks. 1450.104-3 Section 1450.104-3 Federal Acquisition Regulations System... Extraordinary Contractual Actions 1450.104-3 Special procedures for unusually hazardous or nuclear risks. The CO...

48 CFR 1450.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Special procedures for unusually hazardous or nuclear risks. 1450.104-3 Section 1450.104-3 Federal Acquisition Regulations System... Extraordinary Contractual Actions 1450.104-3 Special procedures for unusually hazardous or nuclear risks. The CO...

48 CFR 1450.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Special procedures for unusually hazardous or nuclear risks. 1450.104-3 Section 1450.104-3 Federal Acquisition Regulations System... Extraordinary Contractual Actions 1450.104-3 Special procedures for unusually hazardous or nuclear risks. The CO...

48 CFR 1450.104-3 - Special procedures for unusually hazardous or nuclear risks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Special procedures for unusually hazardous or nuclear risks. 1450.104-3 Section 1450.104-3 Federal Acquisition Regulations System... Extraordinary Contractual Actions 1450.104-3 Special procedures for unusually hazardous or nuclear risks. The CO...